MASQUE client: Support XMUX ("maxConnections": 1 by default); Use Chrome's User-Agent by default (#7121)

https://github.com/XTLS/Xray-core/pull/6810#issuecomment-5842441136
https://github.com/XTLS/Xray-core/pull/6878#issuecomment-6095112915
https://github.com/XTLS/Xray-core/pull/7121#issuecomment-6117636043

---------

Co-authored-by: SVLAVR <skugorov.s@gmail.com>

app/dispatcher/default.go

@@ -470,6 +470,9 @@ func (d *DefaultDispatcher) routedDispatch(ctx context.Context, link *transport.
 				return // DO NOT CHANGE: the traffic shouldn't be processed by default outbound if the specified outbound tag doesn't exist (yet), e.g., VLESS Reverse Proxy
 			}
 		} else {
+			if err != common.ErrNoClue {
+				errors.LogErrorInner(ctx, err, "failed to pick route for ", destination)
+			}
 			errors.LogInfo(ctx, "default route for ", destination)
 		}
 	}

app/dns/config.pb.go

@@ -93,6 +93,7 @@ type NameServer struct {
 	UnexpectedIp    []*geodata.IPRule      `protobuf:"bytes,13,rep,name=unexpected_ip,json=unexpectedIp,proto3" json:"unexpected_ip,omitempty"`
 	ActUnprior      bool                   `protobuf:"varint,14,opt,name=actUnprior,proto3" json:"actUnprior,omitempty"`
 	PolicyID        uint32                 `protobuf:"varint,17,opt,name=policyID,proto3" json:"policyID,omitempty"`
+	Id              string                 `protobuf:"bytes,18,opt,name=id,proto3" json:"id,omitempty"`
 	unknownFields   protoimpl.UnknownFields
 	sizeCache       protoimpl.SizeCache
 }
@@ -239,6 +240,13 @@ func (x *NameServer) GetPolicyID() uint32 {
 	return 0
 }
 
+func (x *NameServer) GetId() string {
+	if x != nil {
+		return x.Id
+	}
+	return ""
+}
+
 type Config struct {
 	state protoimpl.MessageState `protogen:"open.v1"`
 	// NameServer list used by this DNS client.
@@ -258,6 +266,7 @@ type Config struct {
 	DisableFallback        bool          `protobuf:"varint,10,opt,name=disableFallback,proto3" json:"disableFallback,omitempty"`
 	DisableFallbackIfMatch bool          `protobuf:"varint,11,opt,name=disableFallbackIfMatch,proto3" json:"disableFallbackIfMatch,omitempty"`
 	EnableParallelQuery    bool          `protobuf:"varint,14,opt,name=enableParallelQuery,proto3" json:"enableParallelQuery,omitempty"`
+	Script                 string        `protobuf:"bytes,15,opt,name=script,proto3" json:"script,omitempty"`
 	unknownFields          protoimpl.UnknownFields
 	sizeCache              protoimpl.SizeCache
 }
@@ -369,6 +378,13 @@ func (x *Config) GetEnableParallelQuery() bool {
 	return false
 }
 
+func (x *Config) GetScript() string {
+	if x != nil {
+		return x.Script
+	}
+	return ""
+}
+
 type Config_HostMapping struct {
 	state  protoimpl.MessageState `protogen:"open.v1"`
 	Domain *geodata.DomainRule    `protobuf:"bytes,2,opt,name=domain,proto3" json:"domain,omitempty"`
@@ -435,7 +451,7 @@ var File_app_dns_config_proto protoreflect.FileDescriptor
 
 const file_app_dns_config_proto_rawDesc = "" +
 	"\n" +
-	"\x14app/dns/config.proto\x12\fxray.app.dns\x1a\x1ccommon/net/destination.proto\x1a\x1bcommon/geodata/geodat.proto\"\xde\x05\n" +
+	"\x14app/dns/config.proto\x12\fxray.app.dns\x1a\x1ccommon/net/destination.proto\x1a\x1bcommon/geodata/geodat.proto\"\xee\x05\n" +
 	"\n" +
 	"NameServer\x123\n" +
 	"\aaddress\x18\x01 \x01(\v2\x19.xray.common.net.EndpointR\aaddress\x12\x1b\n" +
@@ -461,10 +477,11 @@ const file_app_dns_config_proto_rawDesc = "" +
 	"\n" +
 	"actUnprior\x18\x0e \x01(\bR\n" +
 	"actUnprior\x12\x1a\n" +
-	"\bpolicyID\x18\x11 \x01(\rR\bpolicyIDB\x0f\n" +
+	"\bpolicyID\x18\x11 \x01(\rR\bpolicyID\x12\x0e\n" +
+	"\x02id\x18\x12 \x01(\tR\x02idB\x0f\n" +
 	"\r_disableCacheB\r\n" +
 	"\v_serveStaleB\x12\n" +
-	"\x10_serveExpiredTTLJ\x04\b\x04\x10\x05\"\x82\x05\n" +
+	"\x10_serveExpiredTTLJ\x04\b\x04\x10\x05\"\x9a\x05\n" +
 	"\x06Config\x129\n" +
 	"\vname_server\x18\x05 \x03(\v2\x18.xray.app.dns.NameServerR\n" +
 	"nameServer\x12\x1b\n" +
@@ -480,7 +497,8 @@ const file_app_dns_config_proto_rawDesc = "" +
 	"\x0fdisableFallback\x18\n" +
 	" \x01(\bR\x0fdisableFallback\x126\n" +
 	"\x16disableFallbackIfMatch\x18\v \x01(\bR\x16disableFallbackIfMatch\x120\n" +
-	"\x13enableParallelQuery\x18\x0e \x01(\bR\x13enableParallelQuery\x1a}\n" +
+	"\x13enableParallelQuery\x18\x0e \x01(\bR\x13enableParallelQuery\x12\x16\n" +
+	"\x06script\x18\x0f \x01(\tR\x06script\x1a}\n" +
 	"\vHostMapping\x127\n" +
 	"\x06domain\x18\x02 \x01(\v2\x1f.xray.common.geodata.DomainRuleR\x06domain\x12\x0e\n" +
 	"\x02ip\x18\x03 \x03(\fR\x02ip\x12%\n" +

app/dns/config.proto

@@ -27,6 +27,7 @@ message NameServer {
   repeated xray.common.geodata.IPRule unexpected_ip = 13;
   bool actUnprior = 14;
   uint32 policyID = 17;
+  string id = 18;
 }
 
 enum QueryStrategy {
@@ -73,4 +74,6 @@ message Config {
   bool disableFallbackIfMatch = 11;
 
   bool enableParallelQuery = 14;
+
+  string script = 15;
 }

app/dns/dns.go

@@ -31,6 +31,7 @@ type DNS struct {
 	domainMatcher          geodata.DomainMatcher
 	matcherInfos           []*DomainMatcherInfo
 	checkSystem            bool
+	script                 *scriptEngine
 }
 
 // DomainMatcherInfo contains information attached to index returned by Server.domainMatcher.
@@ -169,6 +170,13 @@ func New(ctx context.Context, config *Config) (*DNS, error) {
 		clients = append(clients, NewLocalDNSClient(ipOption))
 	}
 
+	var script *scriptEngine
+	if config.Script != "" {
+		if script, err = newScriptEngine(config.Script); err != nil {
+			return nil, errors.New("failed to prepare DNS script").Base(err)
+		}
+	}
+
 	return &DNS{
 		hosts:                  hosts,
 		ipOption:               &ipOption,
@@ -180,6 +188,7 @@ func New(ctx context.Context, config *Config) (*DNS, error) {
 		disableFallbackIfMatch: config.DisableFallbackIfMatch,
 		enableParallelQuery:    config.EnableParallelQuery,
 		checkSystem:            checkSystem,
+		script:                 script,
 	}, nil
 }
 
@@ -190,11 +199,19 @@ func (*DNS) Type() interface{} {
 
 // Start implements common.Runnable.
 func (s *DNS) Start() error {
+	if s.script != nil {
+		if err := s.script.start(s); err != nil {
+			return errors.New("failed to initialize DNS script").Base(err)
+		}
+	}
 	return nil
 }
 
 // Close implements common.Closable.
 func (s *DNS) Close() error {
+	if s.script != nil {
+		s.script.close()
+	}
 	return nil
 }
 
@@ -279,6 +296,9 @@ func (s *DNS) LookupIP(domain string, option dns.IPOption) ([]net.IP, uint32, er
 	}
 
 	// Name servers lookup
+	if s.script != nil {
+		return s.script.query(domain, option)
+	}
 	if s.enableParallelQuery {
 		return s.parallelQuery(domain, option)
 	} else {

app/dns/lua.go

@@ -0,0 +1,169 @@
+package dns
+
+import (
+	"context"
+	"strings"
+
+	"github.com/xtls/xray-core/common/errors"
+	xlua "github.com/xtls/xray-core/common/lua"
+	"github.com/xtls/xray-core/common/net"
+	featureDNS "github.com/xtls/xray-core/features/dns"
+	"github.com/xtls/xray-core/features/dns/localdns"
+	lua "github.com/yuin/gopher-lua"
+)
+
+// luaDNSServer adapts configured and local DNS to the same Lua API.
+type luaDNSServer struct {
+	id    string
+	name  string
+	query func(context.Context, string, featureDNS.IPOption) ([]net.IP, uint32, error)
+}
+
+// RegisterLua makes xray.dns available to scripts backed by client.
+func RegisterLua(L *lua.LState, client featureDNS.Client) {
+	var servers []luaDNSServer
+	switch client := client.(type) {
+	case *DNS:
+		servers = luaServers(client)
+	case *localdns.Client:
+		servers = []luaDNSServer{{
+			id:   "localhost",
+			name: "localhost",
+			query: func(_ context.Context, domain string, option featureDNS.IPOption) ([]net.IP, uint32, error) {
+				return client.LookupIP(domain, option)
+			},
+		}}
+	}
+	registerLua(L, servers, client)
+}
+
+// registerLua makes xray.dns available to DNS scripts.
+func (s *DNS) registerLua(L *lua.LState) {
+	registerLua(L, luaServers(s), nil)
+}
+
+func luaServers(s *DNS) []luaDNSServer {
+	servers := make([]luaDNSServer, len(s.clients))
+	for i, client := range s.clients {
+		servers[i] = luaDNSServer{id: client.id, name: client.Name(), query: client.QueryIP}
+	}
+	return servers
+}
+
+func registerLua(L *lua.LState, servers []luaDNSServer, client featureDNS.Client) {
+	L.PreloadModule("xray.dns", func(L *lua.LState) int {
+		pushIPs := xlua.NewSlicePusher[net.IP](L)
+
+		serverList := L.CreateTable(len(servers), 0)
+		for i, client := range servers {
+			server := L.CreateTable(0, 2)
+
+			server.RawSetString("ID", lua.LString(client.id))
+
+			server.RawSetString("Query", L.NewFunction(func(L *lua.LState) int {
+				domain, ok := L.Get(2).(lua.LString)
+				if !ok {
+					L.RaiseError("server:Query requires a domain")
+					return 0
+				}
+				option := featureDNS.IPOption{
+					IPv4Enable: L.CheckBool(3),
+					IPv6Enable: L.CheckBool(4),
+					FakeEnable: L.CheckBool(5),
+				}
+				ctx := L.Context()
+				if ctx == nil {
+					L.RaiseError("server:Query requires an active DNS query")
+					return 0
+				}
+				var ips []net.IP
+				var ttl uint32
+				var err error
+				if !option.FakeEnable && strings.EqualFold(client.name, "FakeDNS") {
+					err = featureDNS.ErrEmptyResponse
+				} else {
+					ips, ttl, err = client.query(ctx, string(domain), option)
+				}
+				pushIPs(L, ips)
+				xlua.PushNumber(L, ttl)
+				xlua.PushError(L, err)
+				return 3
+			}))
+			serverList.RawSetInt(i+1, server)
+		}
+
+		module := L.CreateTable(0, 2)
+		if servers != nil {
+			module.RawSetString("Servers", serverList)
+		}
+		if client != nil {
+			module.RawSetString("Query", newLuaClientQuery(L, client, pushIPs))
+		}
+		L.Push(module)
+		return 1
+	})
+}
+
+func newLuaClientQuery(L *lua.LState, client featureDNS.Client, pushIPs func(*lua.LState, []net.IP)) *lua.LFunction {
+	return L.NewFunction(func(L *lua.LState) int {
+		domain, ok := L.Get(1).(lua.LString)
+		if !ok {
+			L.RaiseError("dns.Query requires a domain")
+			return 0
+		}
+		option := featureDNS.IPOption{
+			IPv4Enable: L.CheckBool(2),
+			IPv6Enable: L.CheckBool(3),
+			FakeEnable: L.CheckBool(4),
+		}
+		if L.Context() == nil {
+			L.RaiseError("dns.Query requires an active DNS query")
+			return 0
+		}
+		ips, ttl, err := client.LookupIP(string(domain), option)
+		pushIPs(L, ips)
+		xlua.PushNumber(L, ttl)
+		xlua.PushError(L, err)
+		return 3
+	})
+}
+
+// callLuaQuery runs HandleDNSQuery and leaves (ips, ttl, err) on the stack.
+func callLuaQuery(L *lua.LState, domain string, option featureDNS.IPOption) error {
+	fn := L.GetGlobal("HandleDNSQuery")
+	if fn.Type() != lua.LTFunction {
+		return errors.New("DNS script must define HandleDNSQuery(...)")
+	}
+
+	return L.CallByParam(lua.P{Fn: fn, NRet: 3, Protect: true},
+		lua.LString(strings.ToLower(domain)),
+		lua.LBool(option.IPv4Enable),
+		lua.LBool(option.IPv6Enable),
+		lua.LBool(option.FakeEnable))
+}
+
+// readLuaQueryResult reads (ips, ttl, err) from the stack without copying the IPs.
+func readLuaQueryResult(L *lua.LState) ([]net.IP, uint32, error) {
+	if err := xlua.ReadError(L.Get(-1), "DNS script error must be an error or string"); err != nil {
+		return nil, 0, err
+	}
+
+	ttl, err := xlua.ReadUint32(L.Get(-2), "DNS script returned invalid TTL")
+	if err != nil {
+		return nil, 0, err
+	}
+
+	addresses := L.Get(-3)
+	if addresses == lua.LNil {
+		return nil, 0, featureDNS.ErrEmptyResponse
+	}
+	ips, err := xlua.ReadUserData[[]net.IP](addresses, "DNS script IPs must be native IP slice userdata")
+	if err != nil {
+		return nil, 0, err
+	}
+	if len(ips) == 0 {
+		return nil, 0, featureDNS.ErrEmptyResponse
+	}
+
+	return ips, ttl, nil
+}

app/dns/lua_benchmark_test.go

@@ -0,0 +1,121 @@
+package dns
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/xtls/xray-core/common/net"
+	featureDNS "github.com/xtls/xray-core/features/dns"
+	lua "github.com/yuin/gopher-lua"
+)
+
+// BenchmarkLuaDNSHook isolates scalar argument bridging and a fixed return.
+// It excludes upstream queries, result decoding, and state pool management.
+func BenchmarkLuaDNSHook(b *testing.B) {
+	L := lua.NewState()
+	b.Cleanup(L.Close)
+	if err := L.DoString(`
+function HandleDNSQuery(domain, ipv4, ipv6, fake)
+    return true
+end
+`); err != nil {
+		b.Fatal(err)
+	}
+	L.SetContext(context.Background())
+	option := featureDNS.IPOption{IPv4Enable: true}
+	if err := callLuaQuery(L, "example.com", option); err != nil {
+		b.Fatal(err)
+	}
+	if L.Get(-3) != lua.LTrue {
+		b.Fatal("hook did not return true")
+	}
+	L.Pop(3)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		if err := callLuaQuery(L, "example.com", option); err != nil {
+			b.Fatal(err)
+		}
+		L.Pop(3)
+	}
+}
+
+// BenchmarkLuaDNSQuery queries the same preselected, in-memory upstream.
+// client_query compares Client.QueryIP to a preloaded server:Query hook.
+// script_query additionally measures production pool and timeout management.
+// These cases do not measure DNS.LookupIP server selection or network latency.
+func BenchmarkLuaDNSQuery(b *testing.B) {
+	ctx := context.Background()
+	option := featureDNS.IPOption{IPv4Enable: true}
+	ip := net.ParseIP("127.0.0.1")
+	upstream := &benchmarkLuaNameServer{ips: []net.IP{ip}}
+	client := &Client{server: upstream, ipOption: &option, timeoutMs: time.Second}
+	server := &DNS{ctx: ctx, clients: []*Client{client}}
+	const script = `
+local server = require("xray.dns").Servers[1]
+function HandleDNSQuery(domain, ipv4, ipv6, fake)
+    return server:Query(domain, ipv4, ipv6, fake)
+end
+`
+	L := lua.NewState()
+	b.Cleanup(L.Close)
+	server.registerLua(L)
+	if err := L.DoString(script); err != nil {
+		b.Fatal(err)
+	}
+	L.SetContext(ctx)
+
+	path := filepath.Join(b.TempDir(), "query.lua")
+	if err := os.WriteFile(path, []byte(script), 0o600); err != nil {
+		b.Fatal(err)
+	}
+	engine, err := newScriptEngine(path)
+	if err != nil {
+		b.Fatal(err)
+	}
+	if err := engine.start(server); err != nil {
+		b.Fatal(err)
+	}
+	b.Cleanup(engine.close)
+	for _, bench := range []struct {
+		name  string
+		query func() ([]net.IP, uint32, error)
+	}{
+		{"client_query/native", func() ([]net.IP, uint32, error) {
+			return client.QueryIP(ctx, "example.com", option)
+		}},
+		{"client_query/lua", func() ([]net.IP, uint32, error) {
+			if err := callLuaQuery(L, "example.com", option); err != nil {
+				return nil, 0, err
+			}
+			ips, ttl, err := readLuaQueryResult(L)
+			L.Pop(3)
+			return ips, ttl, err
+		}},
+		{"script_query/lua", func() ([]net.IP, uint32, error) {
+			return engine.query("example.com", option)
+		}},
+	} {
+		b.Run(bench.name, func(b *testing.B) {
+			ips, ttl, err := bench.query()
+			if err != nil || ttl != 60 || len(ips) != 1 || !ips[0].Equal(ip) {
+				b.Fatalf("query() = %v, TTL %d, %v; want %v, TTL 60", ips, ttl, err, ip)
+			}
+			b.ReportAllocs()
+			b.ResetTimer()
+			for i := 0; i < b.N; i++ {
+				ips, ttl, err = bench.query()
+				if err != nil {
+					b.Fatal(err)
+				}
+			}
+			b.StopTimer()
+			if ttl != 60 || len(ips) != 1 || !ips[0].Equal(ip) {
+				b.Fatalf("query() = %v, TTL %d; want %v, TTL 60", ips, ttl, ip)
+			}
+		})
+	}
+}

app/dns/lua_test.go

@@ -0,0 +1,272 @@
+package dns
+
+import (
+	"context"
+	go_errors "errors"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/xtls/xray-core/common/geodata"
+	"github.com/xtls/xray-core/common/net"
+	featureDNS "github.com/xtls/xray-core/features/dns"
+	"github.com/xtls/xray-core/features/dns/localdns"
+	lua "github.com/yuin/gopher-lua"
+)
+
+func TestReadLuaQueryResult(t *testing.T) {
+	wantIPs := []net.IP{net.ParseIP("8.8.8.8"), {127, 0, 0, 1}, net.ParseIP("::1")}
+	nativeErr := go_errors.New("upstream failed")
+	for _, tc := range []struct {
+		name, values string
+		wantIPs      []net.IP
+		wantTTL      uint32
+		wantErr      error
+		wantMessage  string
+	}{
+		{name: "IPs", values: `ips, 45`, wantIPs: wantIPs, wantTTL: 45},
+		{name: "nil IPs", values: `nil, 0`, wantErr: featureDNS.ErrEmptyResponse},
+		{name: "empty IPs", values: `emptyIPs, 0`, wantErr: featureDNS.ErrEmptyResponse},
+		{name: "native error", values: `nil, nil, nativeError`, wantErr: nativeErr},
+		{name: "string error", values: `nil, nil, "blocked"`, wantMessage: "blocked"},
+		{name: "fractional TTL", values: `ips, 1.5`, wantMessage: "invalid TTL"},
+		{name: "oversized TTL", values: `ips, 4294967296`, wantMessage: "invalid TTL"},
+		{name: "negative TTL", values: `ips, -1`, wantMessage: "invalid TTL"},
+		{name: "NaN TTL", values: `ips, 0/0`, wantMessage: "invalid TTL"},
+		{name: "missing TTL", values: `ips`, wantMessage: "invalid TTL"},
+		{name: "string IPs", values: `"127.0.0.1", 60`, wantMessage: "native IP slice"},
+		{name: "wrong userdata", values: `ip, 60`, wantMessage: "native IP slice"},
+		{name: "invalid error", values: `ips, 60, false`, wantMessage: "error or string"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			L := lua.NewState()
+			defer L.Close()
+			for name, value := range map[string]any{"ips": wantIPs, "ip": wantIPs[0], "emptyIPs": []net.IP(nil), "nativeError": nativeErr} {
+				ud := L.NewUserData()
+				ud.Value = value
+				L.SetGlobal(name, ud)
+			}
+			fn, err := L.LoadString("return " + tc.values)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if err := L.CallByParam(lua.P{Fn: fn, NRet: 3, Protect: true}); err != nil {
+				t.Fatal(err)
+			}
+			ips, ttl, err := readLuaQueryResult(L)
+			switch {
+			case tc.wantErr != nil:
+				if err != tc.wantErr {
+					t.Fatalf("error = %v, want original error %v", err, tc.wantErr)
+				}
+			case tc.wantMessage != "":
+				if err == nil || !strings.Contains(err.Error(), tc.wantMessage) {
+					t.Fatalf("error = %v, want %q", err, tc.wantMessage)
+				}
+			case err != nil:
+				t.Fatal(err)
+			}
+			if ttl != tc.wantTTL || len(ips) != len(tc.wantIPs) {
+				t.Fatalf("result = %v, TTL %d; want %v, TTL %d", ips, ttl, tc.wantIPs, tc.wantTTL)
+			}
+			for i := range ips {
+				if !ips[i].Equal(tc.wantIPs[i]) {
+					t.Fatalf("IP %d = %v, want %v", i, ips[i], tc.wantIPs[i])
+				}
+			}
+			if len(ips) != 0 && &ips[0] != &tc.wantIPs[0] {
+				t.Fatal("result copied the IP slice")
+			}
+		})
+	}
+}
+
+func TestCallLuaQueryCancellation(t *testing.T) {
+	L := lua.NewState()
+	defer L.Close()
+	if err := L.DoString(`function HandleDNSQuery(domain, ipv4, ipv6, fake) while true do end end`); err != nil {
+		t.Fatal(err)
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+	L.SetContext(ctx)
+	err := callLuaQuery(L, "example.com", featureDNS.IPOption{IPv4Enable: true})
+	if err == nil {
+		t.Fatal("callLuaQuery did not stop after context cancellation")
+	}
+	if L.Context() != ctx {
+		t.Fatal("callLuaQuery changed the Lua state's context")
+	}
+}
+
+func TestCallLuaQuery(t *testing.T) {
+	L := lua.NewState()
+	defer L.Close()
+	addresses := L.NewUserData()
+	addresses.Value = []net.IP{net.ParseIP("127.0.0.1")}
+	L.SetGlobal("ips", addresses)
+	if err := L.DoString(`
+		function HandleDNSQuery(domain, ipv4, ipv6, fake)
+			assert(domain == "example.com")
+			assert(ipv4 and not ipv6 and not fake)
+			return ips, 60, nil
+		end
+	`); err != nil {
+		t.Fatal(err)
+	}
+	if err := callLuaQuery(L, "ExAmPlE.CoM", featureDNS.IPOption{IPv4Enable: true}); err != nil {
+		t.Fatal(err)
+	}
+	if L.GetTop() != 3 || L.Get(1) != addresses || L.Get(2) != lua.LNumber(60) || L.Get(3) != lua.LNil {
+		t.Fatal("callLuaQuery did not leave the three query results on the stack")
+	}
+}
+
+func TestLuaDNSServerQuery(t *testing.T) {
+	L := lua.NewState()
+	defer L.Close()
+	geodata.RegisterLua(L)
+	option := featureDNS.IPOption{IPv4Enable: true}
+	ips := []net.IP{net.ParseIP("127.0.0.1"), net.ParseIP("8.8.8.8")}
+	server := &DNS{clients: []*Client{{server: &benchmarkLuaNameServer{ips: ips}, ipOption: &option, timeoutMs: time.Second}}}
+	server.registerLua(L)
+	if err := L.DoString(`
+local server = require("xray.dns").Servers[1]
+local matcher = require("xray.geodata").BuildIPMatcher("127.0.0.0/8")
+function HandleDNSQuery(domain, ipv4, ipv6, fake)
+    local ips, ttl, err = server:Query(domain, ipv4, ipv6, fake)
+    assert(type(ips) == "userdata" and not err)
+    assert(#ips == 2 and ips[1]:String() == "127.0.0.1" and ips[2]:String() == "8.8.8.8")
+    assert(matcher:Match(ips[1]) and not matcher:Match(ips[2]))
+    assert(matcher:AnyMatch(ips))
+    local matched, unmatched = matcher:FilterIPs(ips)
+    assert(#matched == 1 and #unmatched == 1)
+    assert(matched[1]:Equal(ips[1]) and unmatched[1]:Equal(ips[2]))
+    return matched, ttl, err
+end
+`); err != nil {
+		t.Fatal(err)
+	}
+	L.SetContext(context.Background())
+	if err := callLuaQuery(L, "example.com", option); err != nil {
+		t.Fatal(err)
+	}
+	got, ttl, err := readLuaQueryResult(L)
+	if err != nil || ttl != 60 || len(got) != 1 || !got[0].Equal(ips[0]) {
+		t.Fatalf("server query = %v, TTL %d, %v", got, ttl, err)
+	}
+}
+
+type luaDNSClient struct {
+	featureDNS.Client
+	lookup func(string, featureDNS.IPOption) ([]net.IP, uint32, error)
+}
+
+func (c *luaDNSClient) LookupIP(domain string, option featureDNS.IPOption) ([]net.IP, uint32, error) {
+	return c.lookup(domain, option)
+}
+
+func TestLuaDNSClientQuery(t *testing.T) {
+	L := lua.NewState()
+	defer L.Close()
+	L.SetContext(context.Background())
+	geodata.RegisterLua(L)
+	want := []net.IP{{127, 0, 0, 1}, net.ParseIP("::1")}
+	client := &luaDNSClient{lookup: func(domain string, option featureDNS.IPOption) ([]net.IP, uint32, error) {
+		if domain != "MiXeD.Example." || !option.IPv4Enable || option.IPv6Enable || !option.FakeEnable {
+			t.Fatalf("dns.Query arguments = %q, %+v", domain, option)
+		}
+		return want, 42, nil
+	}}
+	RegisterLua(L, client)
+	if err := L.DoString(`
+local dns = require("xray.dns")
+local matcher = require("xray.geodata").BuildIPMatcher("127.0.0.1")
+assert(dns.Servers == nil)
+ips, ttl, err = dns.Query("MiXeD.Example.", true, false, true)
+assert(not err and ttl == 42 and matcher:AnyMatch(ips))
+assert(#ips == 2 and ips[1]:String() == "127.0.0.1" and ips[2]:String() == "::1")
+assert(matcher:Match(ips[1]) and not matcher:Match(ips[2]))
+`); err != nil {
+		t.Fatal(err)
+	}
+	got := L.GetGlobal("ips").(*lua.LUserData).Value.([]net.IP)
+	if &got[0] != &want[0] {
+		t.Fatal("dns.Query copied the IP slice")
+	}
+}
+
+func TestLuaDNSLocalClient(t *testing.T) {
+	L := lua.NewState()
+	defer L.Close()
+	L.SetContext(context.Background())
+	RegisterLua(L, localdns.New())
+	if err := L.DoString(`
+local dns = require("xray.dns")
+assert(dns.Servers[1].ID == "localhost")
+serverIPs, _, serverErr = dns.Servers[1]:Query("127.0.0.1", true, false, false)
+clientIPs, _, clientErr = dns.Query("127.0.0.1", true, false, false)
+assert(not serverErr and not clientErr)
+assert(#serverIPs == 1 and #clientIPs == 1)
+assert(serverIPs[1]:String() == "127.0.0.1" and serverIPs[1]:Equal(clientIPs[1]))
+`); err != nil {
+		t.Fatal(err)
+	}
+	for _, name := range []string{"serverIPs", "clientIPs"} {
+		ips := L.GetGlobal(name).(*lua.LUserData).Value.([]net.IP)
+		if len(ips) != 1 || !ips[0].Equal(net.ParseIP("127.0.0.1")) {
+			t.Fatalf("%s = %v", name, ips)
+		}
+	}
+}
+
+func TestLuaDNSQueryEmptyIPs(t *testing.T) {
+	for _, tc := range []struct {
+		name string
+		ips  []net.IP
+	}{
+		{"nil", nil},
+		{"empty", []net.IP{}},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			L := lua.NewState()
+			defer L.Close()
+			L.SetContext(context.Background())
+			L.SetGlobal("expectNil", lua.LBool(tc.ips == nil))
+			client := &luaDNSClient{lookup: func(string, featureDNS.IPOption) ([]net.IP, uint32, error) {
+				return tc.ips, 0, featureDNS.ErrEmptyResponse
+			}}
+			registerLua(L, []luaDNSServer{{query: func(_ context.Context, domain string, option featureDNS.IPOption) ([]net.IP, uint32, error) {
+				return client.LookupIP(domain, option)
+			}}}, client)
+			if err := L.DoString(`
+local dns = require("xray.dns")
+for _, query in ipairs({
+    function() return dns.Servers[1]:Query("empty.example", true, false, false) end,
+    function() return dns.Query("empty.example", true, false, false) end,
+}) do
+    local ips, ttl, err = query()
+    assert(ttl == 0 and err)
+    if expectNil then
+        assert(ips == nil)
+    else
+        assert(type(ips) == "userdata" and #ips == 0)
+        assert(not pcall(function() return ips[1] end))
+    end
+end
+`); err != nil {
+				t.Fatal(err)
+			}
+		})
+	}
+}
+
+type benchmarkLuaNameServer struct {
+	ips []net.IP
+}
+
+func (*benchmarkLuaNameServer) Name() string         { return "benchmark" }
+func (*benchmarkLuaNameServer) IsDisableCache() bool { return true }
+func (s *benchmarkLuaNameServer) QueryIP(context.Context, string, featureDNS.IPOption) ([]net.IP, uint32, error) {
+	return s.ips, 60, nil
+}

app/dns/nameserver.go

@@ -29,6 +29,7 @@ type Server interface {
 
 // Client is the interface for DNS client.
 type Client struct {
+	id            string
 	server        Server
 	skipFallback  bool
 	expectedIPs   geodata.IPMatcher
@@ -97,7 +98,7 @@ func NewClient(
 	ipOption dns.IPOption,
 	updateRules func(bool),
 ) (*Client, error) {
-	client := &Client{}
+	client := &Client{id: ns.Id}
 	err := core.RequireFeatures(ctx, func(dispatcher routing.Dispatcher) error {
 		// Create a new server for each client for now
 		server, err := NewServer(ctx, ns.Address.AsDestination(), dispatcher, disableCache, serveStale, serveExpiredTTL, clientIP)

app/dns/nameserver_local.go

@@ -49,5 +49,5 @@ func NewLocalNameServer() *LocalNameServer {
 
 // NewLocalDNSClient creates localdns client object for directly lookup in system DNS.
 func NewLocalDNSClient(ipOption dns.IPOption) *Client {
-	return &Client{server: NewLocalNameServer(), ipOption: &ipOption}
+	return &Client{id: "localhost", server: NewLocalNameServer(), ipOption: &ipOption}
 }

app/dns/script.go

@@ -0,0 +1,70 @@
+package dns
+
+import (
+	"time"
+
+	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/geodata"
+	"github.com/xtls/xray-core/common/log"
+	xlua "github.com/xtls/xray-core/common/lua"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/features/dns"
+	lua "github.com/yuin/gopher-lua"
+)
+
+const scriptExecutionTimeout = 6 * time.Second
+
+type scriptEngine struct {
+	program *xlua.Program
+	pool    *xlua.Pool
+}
+
+func newScriptEngine(script string) (*scriptEngine, error) {
+	program, err := xlua.Compile(script)
+	if err != nil {
+		return nil, err
+	}
+	return &scriptEngine{program: program}, nil
+}
+
+func (e *scriptEngine) start(server *DNS) error {
+	pool, err := xlua.NewPool(server.ctx, scriptExecutionTimeout, e.program.NewStateFactory(
+		scriptExecutionTimeout*20,
+		func(L *lua.LState) {
+			geodata.RegisterLua(L)
+			log.RegisterLua(L)
+			server.registerLua(L)
+		},
+		func(L *lua.LState) error {
+			if L.GetGlobal("HandleDNSQuery").Type() != lua.LTFunction {
+				return errors.New("DNS script must define HandleDNSQuery(...)")
+			}
+			return nil
+		}))
+	if err != nil {
+		return err
+	}
+
+	e.pool = pool
+	errors.LogInfo(server.ctx, "DNS script initialized")
+	return nil
+}
+
+func (e *scriptEngine) close() {
+	if e.pool != nil {
+		e.pool.Close()
+	}
+}
+
+func (e *scriptEngine) query(domain string, option dns.IPOption) (ips []net.IP, ttl uint32, queryErr error) {
+	if err := e.pool.WithState(nil, 0, func(L *lua.LState) error {
+		if err := callLuaQuery(L, domain, option); err != nil {
+			return err
+		}
+		ips, ttl, queryErr = readLuaQueryResult(L)
+		return nil
+	}); err != nil {
+		return nil, 0, err
+	}
+	return ips, ttl, queryErr
+}

app/dns/script_test.go

@@ -0,0 +1,329 @@
+package dns
+
+import (
+	"context"
+	go_errors "errors"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/xtls/xray-core/common/net"
+	featureDNS "github.com/xtls/xray-core/features/dns"
+)
+
+type scriptNameServer struct {
+	name    string
+	answers map[string]net.IP
+	errors  map[string]error
+	ttl     uint32
+	calls   int
+}
+
+func (s *scriptNameServer) Name() string         { return s.name }
+func (s *scriptNameServer) IsDisableCache() bool { return true }
+
+func (s *scriptNameServer) QueryIP(ctx context.Context, domain string, _ featureDNS.IPOption) ([]net.IP, uint32, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, 0, err
+	}
+	s.calls++
+	if err := s.errors[domain]; err != nil {
+		return nil, 0, err
+	}
+	ip, ok := s.answers[domain]
+	if !ok {
+		return nil, 0, featureDNS.ErrEmptyResponse
+	}
+	return []net.IP{ip}, s.ttl, nil
+}
+
+func TestDNSScriptQuery(t *testing.T) {
+	wantIP := net.ParseIP("127.0.0.1")
+	upstreamErr := go_errors.New("upstream failed")
+	for _, tc := range []struct {
+		name, body  string
+		wantIPs     []net.IP
+		wantTTL     uint32
+		wantErr     error
+		wantMessage string
+		wantCalls   uint32
+	}{
+		{name: "IPs", body: `return server:Query(domain, ipv4, ipv6, fake)`, wantIPs: []net.IP{wantIP}, wantTTL: 60, wantCalls: 2},
+		{name: "empty result", body: `return nil, 0`, wantErr: featureDNS.ErrEmptyResponse, wantCalls: 2},
+		{name: "upstream error", body: `return server:Query("failed.example", ipv4, ipv6, fake)`, wantErr: upstreamErr, wantCalls: 2},
+		{name: "string error", body: `return nil, nil, "blocked"`, wantMessage: "blocked", wantCalls: 2},
+		{name: "invalid result", body: `return false, 0`, wantMessage: "native IP slice", wantCalls: 2},
+		{name: "execution error", body: `error("execution failed")`, wantMessage: "execution failed", wantCalls: 1},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			script := `
+local server = require("xray.dns").Servers[1]
+local calls = 0
+function HandleDNSQuery(domain, ipv4, ipv6, fake)
+    calls = calls + 1
+    if domain == "count.example" then
+        local ips, _, err = server:Query("good.example", ipv4, ipv6, fake)
+        return ips, calls, err
+    end
+    ` + tc.body + `
+end
+`
+			path := filepath.Join(t.TempDir(), "query.lua")
+			if err := os.WriteFile(path, []byte(script), 0o600); err != nil {
+				t.Fatal(err)
+			}
+			option := featureDNS.IPOption{IPv4Enable: true}
+			upstream := &scriptNameServer{
+				name:    "test",
+				answers: map[string]net.IP{"good.example": wantIP},
+				errors:  map[string]error{"failed.example": upstreamErr},
+				ttl:     60,
+			}
+			server := &DNS{
+				ctx:     context.Background(),
+				clients: []*Client{{server: upstream, ipOption: &option, timeoutMs: time.Second}},
+			}
+			engine, err := newScriptEngine(path)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if err := engine.start(server); err != nil {
+				t.Fatal(err)
+			}
+			defer engine.close()
+
+			ips, ttl, err := engine.query("good.example", option)
+			switch {
+			case tc.wantErr != nil:
+				if err != tc.wantErr {
+					t.Fatalf("query error = %v, want original error %v", err, tc.wantErr)
+				}
+			case tc.wantMessage != "":
+				if err == nil || !strings.Contains(err.Error(), tc.wantMessage) {
+					t.Fatalf("query error = %v, want %q", err, tc.wantMessage)
+				}
+			case err != nil:
+				t.Fatal(err)
+			}
+			if ttl != tc.wantTTL || len(ips) != len(tc.wantIPs) {
+				t.Fatalf("query = %v, TTL %d; want %v, TTL %d", ips, ttl, tc.wantIPs, tc.wantTTL)
+			}
+			for i := range ips {
+				if !ips[i].Equal(tc.wantIPs[i]) {
+					t.Fatalf("IP %d = %v, want %v", i, ips[i], tc.wantIPs[i])
+				}
+			}
+
+			ips, calls, err := engine.query("count.example", option)
+			if err != nil || calls != tc.wantCalls || len(ips) != 1 || !ips[0].Equal(wantIP) {
+				t.Fatalf("next query = %v, calls %d, %v; want %v, calls %d", ips, calls, err, wantIP, tc.wantCalls)
+			}
+		})
+	}
+}
+
+func TestDNSScriptGeoIPFallback(t *testing.T) {
+	t.Setenv("xray.location.asset", filepath.Join("..", "..", "resources"))
+	script := `
+local servers = require("xray.dns").Servers
+local us_ips = require("xray.geodata").BuildIPMatcher("geoip:us")
+
+local by_id = {}
+for _, server in ipairs(servers) do
+    by_id[server.ID] = server
+end
+assert(by_id.primary and by_id.fallback, "primary and fallback DNS servers are required")
+
+function HandleDNSQuery(domain, ipv4, ipv6, fake)
+    local ips, ttl, err = by_id.primary:Query(domain, ipv4, ipv6, fake)
+    if not err and us_ips:AnyMatch(ips) then
+        return ips, ttl, nil
+    end
+    return by_id.fallback:Query(domain, ipv4, ipv6, fake)
+end
+`
+	scriptPath := filepath.Join(t.TempDir(), "geoip_fallback.lua")
+	if err := os.WriteFile(scriptPath, []byte(script), 0o600); err != nil {
+		t.Fatal(err)
+	}
+
+	primary := &scriptNameServer{
+		name: "primary",
+		answers: map[string]net.IP{
+			"us.example":    net.ParseIP("2001:4860:4860::8888"),
+			"other.example": net.ParseIP("127.0.0.1"),
+		},
+		ttl: 30,
+	}
+	fallback := &scriptNameServer{
+		name:    "fallback",
+		answers: map[string]net.IP{"other.example": net.ParseIP("9.9.9.9")},
+		ttl:     60,
+	}
+	option := featureDNS.IPOption{IPv4Enable: true, IPv6Enable: true}
+	hosts, err := NewStaticHosts(nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	engine, err := newScriptEngine(scriptPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+	server := &DNS{
+		ctx:      context.Background(),
+		hosts:    hosts,
+		ipOption: &option,
+		script:   engine,
+		clients: []*Client{
+			{id: "primary", server: primary, ipOption: &option, timeoutMs: 2 * time.Second},
+			{id: "fallback", server: fallback, ipOption: &option, timeoutMs: 2 * time.Second},
+		},
+	}
+	if err := server.Start(); err != nil {
+		t.Fatal(err)
+	}
+	defer server.Close()
+
+	for _, tc := range []struct {
+		domain string
+		ip     net.IP
+		ttl    uint32
+	}{
+		{"Us.Example.", net.ParseIP("2001:4860:4860::8888"), 30},
+		{"other.example", net.ParseIP("9.9.9.9"), 60},
+	} {
+		ips, ttl, err := server.LookupIP(tc.domain, option)
+		if err != nil {
+			t.Fatalf("LookupIP(%q): %v", tc.domain, err)
+		}
+		if ttl != tc.ttl || len(ips) != 1 || !ips[0].Equal(tc.ip) {
+			t.Fatalf("LookupIP(%q) = %v, TTL %d; want %v, TTL %d", tc.domain, ips, ttl, tc.ip, tc.ttl)
+		}
+	}
+	if primary.calls != 2 || fallback.calls != 1 {
+		t.Fatalf("upstream calls: primary %d, fallback %d; want 2 and 1", primary.calls, fallback.calls)
+	}
+}
+
+func TestDNSScriptRejectsInvalidStartup(t *testing.T) {
+	for _, tc := range []struct {
+		name, script string
+		compileError bool
+	}{
+		{"syntax", "function HandleDNSQuery(", true},
+		{"missing hook", "value = 1", false},
+		{"invalid hook", "HandleDNSQuery = true", false},
+		{"top-level error", `error("setup failed")`, false},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			path := filepath.Join(t.TempDir(), "script.lua")
+			if err := os.WriteFile(path, []byte(tc.script), 0o600); err != nil {
+				t.Fatal(err)
+			}
+			server, err := New(context.Background(), &Config{Script: path})
+			if tc.compileError {
+				if server != nil || err == nil || !strings.Contains(err.Error(), "failed to prepare DNS script") {
+					t.Fatalf("New = %v, %v; want nil server and script preparation error", server, err)
+				}
+				return
+			}
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer server.Close()
+			if server.script.program == nil || server.script.pool != nil {
+				t.Fatal("New did not compile the script without starting its pool")
+			}
+			if err := server.Close(); err != nil {
+				t.Fatal(err)
+			}
+			if err := server.Start(); err == nil {
+				t.Fatal("Start accepted an invalid DNS script")
+			}
+			if server.script.pool != nil {
+				t.Fatal("Start retained a script pool after failure")
+			}
+		})
+	}
+}
+
+func TestDNSScriptProgramSnapshot(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "script.lua")
+	if err := os.WriteFile(path, []byte(`function HandleDNSQuery() return nil, nil, "compiled" end`), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	engine, err := newScriptEngine(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer engine.close()
+	if err := os.Remove(path); err != nil {
+		t.Fatal(err)
+	}
+	if err := engine.start(&DNS{ctx: context.Background()}); err != nil {
+		t.Fatal(err)
+	}
+	if _, _, err := engine.query("example.com", featureDNS.IPOption{}); err == nil || !strings.Contains(err.Error(), "compiled") {
+		t.Fatalf("query error = %v, want compiled", err)
+	}
+}
+
+func TestDNSScriptFakeDNSOption(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "script.lua")
+	script := `
+local server = require("xray.dns").Servers[1]
+local log = require("xray.log")
+log.Info("DNS script loaded")
+function HandleDNSQuery(domain, ipv4, ipv6, fake)
+    log.Debug("DNS query: ", domain)
+    local ips, ttl, err = server:Query(domain, ipv4, ipv6, fake)
+    if err then log.Error("DNS failed: ", err) end
+    return ips, ttl, err
+end
+`
+	if err := os.WriteFile(path, []byte(script), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	option := featureDNS.IPOption{IPv4Enable: true}
+	hosts, err := NewStaticHosts(nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	upstream := &scriptNameServer{
+		name:    "FakeDNS",
+		answers: map[string]net.IP{"good.example": net.ParseIP("198.18.0.1")},
+		ttl:     30,
+	}
+	engine, err := newScriptEngine(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	server := &DNS{
+		ctx:      context.Background(),
+		hosts:    hosts,
+		ipOption: &option,
+		script:   engine,
+		clients:  []*Client{{id: "fake", server: upstream, ipOption: &option, timeoutMs: time.Second}},
+	}
+	if err := server.Start(); err != nil {
+		t.Fatal(err)
+	}
+	defer server.Close()
+
+	if _, _, err := server.LookupIP("good.example", option); err != featureDNS.ErrEmptyResponse {
+		t.Fatalf("FakeDNS without FakeEnable = %v, want ErrEmptyResponse", err)
+	}
+	if upstream.calls != 0 {
+		t.Fatalf("FakeDNS was queried without FakeEnable: %d calls", upstream.calls)
+	}
+	withFake := featureDNS.IPOption{IPv4Enable: true, FakeEnable: true}
+	ips, ttl, err := server.LookupIP("good.example", withFake)
+	if err != nil || ttl != 30 || len(ips) != 1 || !ips[0].Equal(net.ParseIP("198.18.0.1")) {
+		t.Fatalf("FakeDNS with FakeEnable = %v, TTL %d, %v", ips, ttl, err)
+	}
+	if upstream.calls != 1 {
+		t.Fatalf("FakeDNS query count = %d, want 1", upstream.calls)
+	}
+}

app/proxyman/inbound/inbound.go

@@ -174,7 +174,7 @@ func NewHandler(ctx context.Context, config *core.InboundHandlerConfig) (inbound
 			Mark: streamSettings.SocketSettings.Mark,
 		})
 	}
-	if streamSettings != nil && streamSettings.ProtocolName == "splithttp" {
+	if streamSettings != nil && (streamSettings.ProtocolName == "splithttp" || streamSettings.ProtocolName == "masque") {
 		ctx = session.ContextWithAllowedNetwork(ctx, net.Network_UDP)
 	}
 

app/router/config.pb.go

@@ -587,6 +587,7 @@ type Config struct {
 	DomainStrategy Config_DomainStrategy  `protobuf:"varint,1,opt,name=domain_strategy,json=domainStrategy,proto3,enum=xray.app.router.Config_DomainStrategy" json:"domain_strategy,omitempty"`
 	Rule           []*RoutingRule         `protobuf:"bytes,2,rep,name=rule,proto3" json:"rule,omitempty"`
 	BalancingRule  []*BalancingRule       `protobuf:"bytes,3,rep,name=balancing_rule,json=balancingRule,proto3" json:"balancing_rule,omitempty"`
+	Script         string                 `protobuf:"bytes,4,opt,name=script,proto3" json:"script,omitempty"`
 	unknownFields  protoimpl.UnknownFields
 	sizeCache      protoimpl.SizeCache
 }
@@ -642,6 +643,13 @@ func (x *Config) GetBalancingRule() []*BalancingRule {
 	return nil
 }
 
+func (x *Config) GetScript() string {
+	if x != nil {
+		return x.Script
+	}
+	return ""
+}
+
 var File_app_router_config_proto protoreflect.FileDescriptor
 
 const file_app_router_config_proto_rawDesc = "" +
@@ -699,11 +707,12 @@ const file_app_router_config_proto_rawDesc = "" +
 	"\tbaselines\x18\x03 \x03(\x03R\tbaselines\x12\x1a\n" +
 	"\bexpected\x18\x04 \x01(\x05R\bexpected\x12\x16\n" +
 	"\x06maxRTT\x18\x05 \x01(\x03R\x06maxRTT\x12\x1c\n" +
-	"\ttolerance\x18\x06 \x01(\x02R\ttolerance\"\x96\x02\n" +
+	"\ttolerance\x18\x06 \x01(\x02R\ttolerance\"\xae\x02\n" +
 	"\x06Config\x12O\n" +
 	"\x0fdomain_strategy\x18\x01 \x01(\x0e2&.xray.app.router.Config.DomainStrategyR\x0edomainStrategy\x120\n" +
 	"\x04rule\x18\x02 \x03(\v2\x1c.xray.app.router.RoutingRuleR\x04rule\x12E\n" +
-	"\x0ebalancing_rule\x18\x03 \x03(\v2\x1e.xray.app.router.BalancingRuleR\rbalancingRule\"B\n" +
+	"\x0ebalancing_rule\x18\x03 \x03(\v2\x1e.xray.app.router.BalancingRuleR\rbalancingRule\x12\x16\n" +
+	"\x06script\x18\x04 \x01(\tR\x06script\"B\n" +
 	"\x0eDomainStrategy\x12\b\n" +
 	"\x04AsIs\x10\x00\x12\x10\n" +
 	"\fIpIfNonMatch\x10\x02\x12\x0e\n" +

app/router/config.proto

@@ -110,4 +110,5 @@ message Config {
   DomainStrategy domain_strategy = 1;
   repeated RoutingRule rule = 2;
   repeated BalancingRule balancing_rule = 3;
+  string script = 4;
 }

app/router/lua.go

@@ -0,0 +1,175 @@
+package router
+
+import (
+	"runtime"
+	"strings"
+
+	"github.com/xtls/xray-core/common/errors"
+	xlua "github.com/xtls/xray-core/common/lua"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/features/routing"
+	lua "github.com/yuin/gopher-lua"
+)
+
+const (
+	luaContextType    = "xray.router.Context"
+	luaAttributesType = "xray.router.Attributes"
+)
+
+// RegisterLua makes xray.router available to routing scripts.
+func (r *Router) RegisterLua(L *lua.LState) {
+	registerLuaContext(L)
+
+	L.PreloadModule("xray.router", func(L *lua.LState) int {
+		module := L.CreateTable(0, 7)
+
+		module.RawSetString("NetworkUnknown", lua.LNumber(net.Network_Unknown))
+		module.RawSetString("NetworkTCP", lua.LNumber(net.Network_TCP))
+		module.RawSetString("NetworkUDP", lua.LNumber(net.Network_UDP))
+		module.RawSetString("NetworkUNIX", lua.LNumber(net.Network_UNIX))
+		module.RawSetString("LocalOS", lua.LString(runtime.GOOS))
+
+		module.RawSetString("PickOutbound", L.NewFunction(func(L *lua.LState) int {
+			tag, ok := L.Get(1).(lua.LString)
+			if !ok {
+				L.ArgError(1, "balancer tag must be a string")
+				return 0
+			}
+			balancer, found := (*r.balancers.Load())[string(tag)]
+			if !found {
+				xlua.PushNil(L)
+				xlua.PushError(L, errors.New("balancer ", tag, " not found"))
+				return 2
+			}
+			outboundTag, err := balancer.PickOutbound()
+			xlua.PushString(L, outboundTag)
+			xlua.PushError(L, err)
+			return 2
+		}))
+
+		module.RawSetString("FindProcess", L.NewFunction(func(L *lua.LState) int {
+			pid, name, path, err := findProcess(checkLuaContext(L), net.FindProcess)
+			xlua.PushNumber(L, pid)
+			xlua.PushString(L, name)
+			xlua.PushString(L, path)
+			xlua.PushError(L, err)
+			return 4
+		}))
+
+		L.Push(module)
+		return 1
+	})
+}
+
+func registerLuaContext(L *lua.LState) {
+	pushIPs := xlua.NewSlicePusher[net.IP](L)
+	attributes := L.NewTypeMetatable(luaAttributesType)
+	L.SetField(attributes, "__index", L.NewFunction(func(L *lua.LState) int {
+		values := L.CheckUserData(1).Value.(map[string]string)
+		key := L.CheckString(2)
+		if value, found := values[key]; found {
+			xlua.PushString(L, value)
+		} else {
+			xlua.PushNil(L)
+		}
+		return 1
+	}))
+	methods := L.CreateTable(0, 4)
+	L.SetFuncs(methods, map[string]lua.LGFunction{
+		"GetSourceIPs": func(L *lua.LState) int {
+			pushIPs(L, checkLuaContext(L).GetSourceIPs())
+			return 1
+		},
+		"GetTargetIPs": func(L *lua.LState) int {
+			pushIPs(L, checkLuaContext(L).GetTargetIPs())
+			return 1
+		},
+		"GetLocalIPs": func(L *lua.LState) int {
+			pushIPs(L, checkLuaContext(L).GetLocalIPs())
+			return 1
+		},
+		"GetAttributes": func(L *lua.LState) int {
+			values := L.NewUserData()
+			values.Value = checkLuaContext(L).GetAttributes()
+			L.SetMetatable(values, attributes)
+			L.Push(values)
+			return 1
+		},
+	})
+	L.SetField(L.NewTypeMetatable(luaContextType), "__index", methods)
+}
+
+func checkLuaContext(L *lua.LState) routing.Context {
+	ctx, ok := L.CheckUserData(1).Value.(routing.Context)
+	if !ok {
+		L.ArgError(1, "routing context expected")
+	}
+	return ctx
+}
+
+// callLuaRoute runs HandleRoute and leaves (outboundTag, ruleTag, err) on the stack.
+func callLuaRoute(L *lua.LState, ctx routing.Context) error {
+	fn := L.GetGlobal("HandleRoute")
+	if fn.Type() != lua.LTFunction {
+		return errors.New("routing script must define HandleRoute(...)")
+	}
+
+	value := L.NewUserData()
+	value.Value = ctx
+	L.SetMetatable(value, L.GetTypeMetatable(luaContextType))
+
+	return L.CallByParam(lua.P{Fn: fn, NRet: 3, Protect: true},
+		value,
+		lua.LString(ctx.GetInboundTag()),
+		lua.LNumber(ctx.GetSourcePort()),
+		lua.LNumber(ctx.GetTargetPort()),
+		lua.LNumber(ctx.GetLocalPort()),
+		lua.LString(strings.ToLower(ctx.GetTargetDomain())),
+		lua.LNumber(ctx.GetNetwork()),
+		lua.LString(ctx.GetProtocol()),
+		lua.LString(ctx.GetUser()),
+		lua.LNumber(ctx.GetVlessRoute()),
+		lua.LBool(ctx.GetSkipDNSResolve()))
+}
+
+// readLuaRouteResult reads (outboundTag, ruleTag, err) from the stack.
+func readLuaRouteResult(L *lua.LState) (string, string, error) {
+	if err := xlua.ReadError(L.Get(-1), "routing script error must be an error or string"); err != nil {
+		return "", "", err
+	}
+
+	outboundTag, err := xlua.ReadOptionalString(L.Get(-3), "routing script outboundTag must be a string or nil")
+	if err != nil || outboundTag == "" {
+		return "", "", err
+	}
+
+	ruleTag, err := xlua.ReadOptionalString(L.Get(-2), "routing script ruleTag must be a string")
+	if err != nil {
+		return "", "", err
+	}
+
+	return outboundTag, ruleTag, nil
+}
+
+type processFinder func(string, string, uint16, string, uint16) (int, string, string, error)
+
+func findProcess(ctx routing.Context, finder processFinder) (int, string, string, error) {
+	sources := ctx.GetSourceIPs()
+	if len(sources) == 0 {
+		return 0, "", "", errors.New("process lookup requires a source IP")
+	}
+	var network string
+	switch ctx.GetNetwork() {
+	case net.Network_TCP:
+		network = "tcp"
+	case net.Network_UDP:
+		network = "udp"
+	default:
+		return 0, "", "", errors.New("process lookup requires TCP or UDP")
+	}
+	targetIP, targetPort := "", uint16(0)
+	if targets := ctx.GetTargetIPs(); len(targets) > 0 {
+		targetIP, targetPort = targets[0].String(), uint16(ctx.GetTargetPort())
+	}
+	return finder(network, sources[0].String(), uint16(ctx.GetSourcePort()), targetIP, targetPort)
+}

app/router/lua_benchmark_test.go

@@ -0,0 +1,223 @@
+package router
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/xtls/xray-core/common/geodata"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/common/session"
+	"github.com/xtls/xray-core/features/routing"
+	routing_session "github.com/xtls/xray-core/features/routing/session"
+	lua "github.com/yuin/gopher-lua"
+)
+
+func benchmarkRouteContext(target net.Destination) *routing_session.Context {
+	// Use the production context: its IP getters construct a slice per call.
+	// The cached IP slices in luaRouteTestContext would undercount this cost.
+	return &routing_session.Context{
+		Inbound: &session.Inbound{
+			Tag:    "in",
+			Source: net.TCPDestination(net.LocalHostIP, 1234),
+			Local:  net.TCPDestination(net.LocalHostIP, 5678),
+		},
+		Outbound: &session.Outbound{Target: target},
+		Content:  &session.Content{Protocol: "tls"},
+	}
+}
+
+func benchmarkRouteState(b *testing.B, r *Router, script string) *lua.LState {
+	b.Helper()
+	L := lua.NewState()
+	b.Cleanup(L.Close)
+	r.RegisterLua(L)
+	geodata.RegisterLua(L)
+	if err := L.DoString(script); err != nil {
+		b.Fatal(err)
+	}
+	L.SetContext(context.Background())
+	return L
+}
+
+// BenchmarkLuaRouteHook isolates argument bridging and a fixed-return hook.
+// It excludes rules, result decoding, the state pool, and Route construction.
+func BenchmarkLuaRouteHook(b *testing.B) {
+	L := benchmarkRouteState(b, new(Router), `
+function HandleRoute(ctx, inboundTag, sourcePort, targetPort, localPort,
+    targetDomain, network, protocol, user, vlessRoute, skipDNSResolve)
+    return "out", "rule"
+end
+`)
+	ctx := benchmarkRouteContext(net.TCPDestination(net.LocalHostIP, 443))
+	if err := callLuaRoute(L, ctx); err != nil {
+		b.Fatal(err)
+	}
+	outboundTag, ruleTag, err := readLuaRouteResult(L)
+	L.Pop(3)
+	if err != nil || outboundTag != "out" || ruleTag != "rule" {
+		b.Fatalf("hook() = %q, %q, %v", outboundTag, ruleTag, err)
+	}
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		if err := callLuaRoute(L, ctx); err != nil {
+			b.Fatal(err)
+		}
+		L.Pop(3)
+	}
+}
+
+// BenchmarkLuaRoute compares equivalent ordered rules on the same session.
+// rules returns tags only; pick_route uses Router.PickRoute on both sides.
+// All compilation, matcher construction, and pool startup are outside timing.
+func BenchmarkLuaRoute(b *testing.B) {
+	for _, name := range []string{"scalar", "ip", "domain", "domain_32_last"} {
+		b.Run(name, func(b *testing.B) {
+			config, script, ctx, wantTag, wantRule := benchmarkRouteFixture(b, name)
+			native := new(Router)
+			if err := native.Init(context.Background(), config, nil, nil, nil); err != nil {
+				b.Fatal(err)
+			}
+			L := benchmarkRouteState(b, native, script)
+
+			path := filepath.Join(b.TempDir(), "route.lua")
+			if err := os.WriteFile(path, []byte(script), 0o600); err != nil {
+				b.Fatal(err)
+			}
+			scripted := new(Router)
+			if err := scripted.Init(context.Background(), &Config{Script: path}, nil, nil, nil); err != nil {
+				b.Fatal(err)
+			}
+			if err := scripted.Start(); err != nil {
+				b.Fatal(err)
+			}
+			b.Cleanup(func() {
+				if err := scripted.Close(); err != nil {
+					b.Error(err)
+				}
+			})
+
+			for _, bench := range []struct {
+				name  string
+				route func() (string, string, error)
+			}{
+				{"rules/native", func() (string, string, error) {
+					rule, _, err := native.pickRouteInternal(ctx)
+					if err != nil {
+						return "", "", err
+					}
+					tag, err := rule.GetTag()
+					return tag, rule.RuleTag, err
+				}},
+				{"rules/lua", func() (string, string, error) {
+					if err := callLuaRoute(L, ctx); err != nil {
+						return "", "", err
+					}
+					tag, ruleTag, err := readLuaRouteResult(L)
+					L.Pop(3)
+					return tag, ruleTag, err
+				}},
+				{"pick_route/native", func() (string, string, error) {
+					return benchmarkPickRoute(native, ctx)
+				}},
+				{"pick_route/lua", func() (string, string, error) {
+					return benchmarkPickRoute(scripted, ctx)
+				}},
+			} {
+				b.Run(bench.name, func(b *testing.B) {
+					// Validate and warm both paths before measuring steady state.
+					tag, ruleTag, err := bench.route()
+					if err != nil || tag != wantTag || ruleTag != wantRule {
+						b.Fatalf("route() = %q, %q, %v; want %q, %q", tag, ruleTag, err, wantTag, wantRule)
+					}
+					b.ReportAllocs()
+					b.ResetTimer()
+					for i := 0; i < b.N; i++ {
+						tag, ruleTag, err = bench.route()
+						if err != nil {
+							b.Fatal(err)
+						}
+					}
+					b.StopTimer()
+					if tag != wantTag || ruleTag != wantRule {
+						b.Fatalf("route() = %q, %q; want %q, %q", tag, ruleTag, wantTag, wantRule)
+					}
+				})
+			}
+		})
+	}
+}
+
+func benchmarkPickRoute(r *Router, ctx routing.Context) (string, string, error) {
+	route, err := r.PickRoute(ctx)
+	if err != nil {
+		return "", "", err
+	}
+	return route.GetOutboundTag(), route.GetRuleTag(), nil
+}
+
+func benchmarkRouteFixture(b *testing.B, name string) (*Config, string, routing.Context, string, string) {
+	b.Helper()
+	config := new(Config)
+	ctx := benchmarkRouteContext(net.TCPDestination(net.LocalHostIP, 443))
+	prelude := `local router = require("xray.router")
+local geodata = require("xray.geodata")
+`
+	body := `if inboundTag == "in" and network == router.NetworkTCP then return "out", "rule" end`
+	wantTag, wantRule := "out", "rule"
+	if name == "scalar" || name == "ip" {
+		rule := &RoutingRule{
+			TargetTag:  &RoutingRule_Tag{Tag: wantTag},
+			RuleTag:    wantRule,
+			InboundTag: []string{"in"},
+			Networks:   []net.Network{net.Network_TCP},
+		}
+		if name == "ip" {
+			var err error
+			rule.Ip, err = geodata.ParseIPRules([]string{"127.0.0.0/8"})
+			if err != nil {
+				b.Fatal(err)
+			}
+			prelude += `local matcher = geodata.BuildIPMatcher("127.0.0.0/8")` + "\n"
+			body = `if inboundTag == "in" and network == router.NetworkTCP and matcher:AnyMatch(ctx:GetTargetIPs()) then return "out", "rule" end`
+		}
+		config.Rule = []*RoutingRule{rule}
+	} else {
+		count := 1
+		if name == "domain_32_last" {
+			count = 32
+		}
+		var rules strings.Builder
+		rules.WriteString("local rules = {\n")
+		for i := 0; i < count; i++ {
+			domain := fmt.Sprintf("route-%d.example.com", i)
+			tag, ruleTag := fmt.Sprintf("out-%d", i), fmt.Sprintf("rule-%d", i)
+			domains, err := geodata.ParseDomainRules([]string{"full:" + domain}, geodata.Domain_Domain)
+			if err != nil {
+				b.Fatal(err)
+			}
+			config.Rule = append(config.Rule, &RoutingRule{
+				TargetTag: &RoutingRule_Tag{Tag: tag}, RuleTag: ruleTag, Domain: domains,
+			})
+			fmt.Fprintf(&rules, "{geodata.BuildDomainMatcher(%q), %q, %q},\n", "full:"+domain, tag, ruleTag)
+			if i == count-1 {
+				ctx.Outbound.Target = net.TCPDestination(net.DomainAddress(domain), 443)
+				wantTag, wantRule = tag, ruleTag
+			}
+		}
+		rules.WriteString("}\n")
+		prelude += rules.String()
+		body = `for i = 1, #rules do
+        local rule = rules[i]
+        if rule[1]:MatchAny(targetDomain) then return rule[2], rule[3] end
+    end`
+	}
+	script := prelude + `function HandleRoute(ctx, inboundTag, sourcePort, targetPort, localPort,
+    targetDomain, network, protocol, user, vlessRoute, skipDNSResolve)
+    ` + body + "\nend\n"
+	return config, script, ctx, wantTag, wantRule
+}

app/router/lua_test.go

@@ -0,0 +1,274 @@
+package router
+
+import (
+	"context"
+	go_errors "errors"
+	"runtime"
+	"strings"
+	"testing"
+
+	"github.com/xtls/xray-core/common/geodata"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/common/protocol"
+	"github.com/xtls/xray-core/common/session"
+	"github.com/xtls/xray-core/features/routing"
+	routing_session "github.com/xtls/xray-core/features/routing/session"
+	lua "github.com/yuin/gopher-lua"
+)
+
+type luaRouteTestContext struct {
+	*routing_session.Context
+	sourceIPs, targetIPs, localIPs []net.IP
+}
+
+func (c *luaRouteTestContext) GetSourceIPs() []net.IP { return c.sourceIPs }
+func (c *luaRouteTestContext) GetTargetIPs() []net.IP { return c.targetIPs }
+func (c *luaRouteTestContext) GetLocalIPs() []net.IP  { return c.localIPs }
+
+func newLuaRouteTestContext() *luaRouteTestContext {
+	return &luaRouteTestContext{
+		Context: &routing_session.Context{
+			Inbound: &session.Inbound{
+				Tag: "in", VlessRoute: 4321,
+				Source: net.TCPDestination(net.LocalHostIP, 1234),
+				Local:  net.TCPDestination(net.LocalHostIP, 5678),
+				User:   &protocol.MemoryUser{Email: "user@example.com"},
+			},
+			Outbound: &session.Outbound{
+				Target:      net.TCPDestination(net.LocalHostIP, 443),
+				RouteTarget: net.TCPDestination(net.DomainAddress("MiXeD.Example."), 443),
+			},
+			Content: &session.Content{
+				Protocol: "tls", Attributes: map[string]string{"key": "value"}, SkipDNSResolve: true,
+			},
+		},
+		sourceIPs: []net.IP{{127, 0, 0, 2}},
+		targetIPs: []net.IP{{127, 0, 0, 3}},
+		localIPs:  []net.IP{{127, 0, 0, 1}},
+	}
+}
+
+func newLuaRouterState(t *testing.T, script string) *lua.LState {
+	t.Helper()
+	r := new(Router)
+	if err := r.Init(context.Background(), &Config{}, nil, nil, nil); err != nil {
+		t.Fatal(err)
+	}
+	L := lua.NewState()
+	t.Cleanup(L.Close)
+	r.RegisterLua(L)
+	geodata.RegisterLua(L)
+	if err := L.DoString(script); err != nil {
+		t.Fatal(err)
+	}
+	return L
+}
+
+func TestLuaRouteBinding(t *testing.T) {
+	L := newLuaRouterState(t, `
+local router = require("xray.router")
+local matcher = require("xray.geodata").BuildIPMatcher("127.0.0.0/8")
+assert(router.NetworkUnknown == 0 and router.NetworkTCP == 2)
+assert(router.NetworkUDP == 3 and router.NetworkUNIX == 4)
+assert(router.BuildIPMatcher == nil and router.BuildDomainMatcher == nil)
+function HandleRoute(ctx, inboundTag, sourcePort, targetPort, localPort,
+    targetDomain, network, protocol, user, vlessRoute, skipDNSResolve, ...)
+    assert(select("#", ...) == 0)
+    assert(inboundTag == "in" and sourcePort == 1234 and targetPort == 443 and localPort == 5678)
+    assert(targetDomain == "mixed.example." and network == router.NetworkTCP)
+    assert(protocol == "tls" and user == "user@example.com" and vlessRoute == 4321 and skipDNSResolve)
+    assert(ctx.GetNetwork == nil and ctx.Context == nil)
+    savedContext = ctx
+    sourceIPs, targetIPs, localIPs = ctx:GetSourceIPs(), ctx:GetTargetIPs(), ctx:GetLocalIPs()
+    attributes = ctx:GetAttributes()
+    assert(#sourceIPs == 1 and #targetIPs == 1 and #localIPs == 1)
+    assert(sourceIPs[1]:String() == "127.0.0.2" and targetIPs[1]:String() == "127.0.0.3")
+    assert(localIPs[1]:String() == "127.0.0.1")
+    assert(matcher:Match(sourceIPs[1]) and matcher:Match(targetIPs[1]) and matcher:Match(localIPs[1]))
+    assert(matcher:AnyMatch(sourceIPs) and matcher:AnyMatch(targetIPs) and matcher:AnyMatch(localIPs))
+    local matched = matcher:FilterIPs(targetIPs)
+    assert(#matched == 1 and matched[1]:Equal(targetIPs[1]))
+    assert(attributes.key == "value" and attributes.missing == nil)
+    assert(not pcall(function() attributes.key = "changed" end))
+    return "out", "rule"
+end`)
+
+	ctx := newLuaRouteTestContext()
+	if err := callLuaRoute(L, ctx); err != nil {
+		t.Fatal(err)
+	}
+	if L.GetTop() != 3 || L.Get(1) != lua.LString("out") || L.Get(2) != lua.LString("rule") || L.Get(3) != lua.LNil {
+		t.Fatal("callLuaRoute did not leave the three route results on the stack")
+	}
+	if L.GetGlobal("savedContext").(*lua.LUserData).Value != ctx {
+		t.Fatal("routing context was copied")
+	}
+	for _, tc := range []struct {
+		name string
+		want []net.IP
+	}{
+		{"sourceIPs", ctx.sourceIPs},
+		{"targetIPs", ctx.targetIPs},
+		{"localIPs", ctx.localIPs},
+	} {
+		got := L.GetGlobal(tc.name).(*lua.LUserData).Value.([]net.IP)
+		if &got[0] != &tc.want[0] {
+			t.Fatalf("%s storage was copied", tc.name)
+		}
+	}
+	ctx.Content.Attributes["key"] = "updated"
+	L.SetGlobal("expectedOS", lua.LString(runtime.GOOS))
+	if err := L.DoString(`
+assert(attributes.key == "updated")
+assert(require("xray.router").LocalOS == expectedOS)`); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestLuaRouteEmptyIPs(t *testing.T) {
+	for _, tc := range []struct {
+		name string
+		ips  []net.IP
+	}{
+		{"nil", nil},
+		{"empty", []net.IP{}},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			L := newLuaRouterState(t, `
+function HandleRoute(ctx)
+    for _, name in ipairs({"GetSourceIPs", "GetTargetIPs", "GetLocalIPs"}) do
+        local ips = ctx[name](ctx)
+        if expectNil then
+            assert(ips == nil)
+        else
+            assert(type(ips) == "userdata" and #ips == 0)
+            assert(not pcall(function() return ips[1] end))
+        end
+    end
+    return "out"
+end
+`)
+			L.SetGlobal("expectNil", lua.LBool(tc.ips == nil))
+			ctx := newLuaRouteTestContext()
+			ctx.sourceIPs, ctx.targetIPs, ctx.localIPs = tc.ips, tc.ips, tc.ips
+			if err := callLuaRoute(L, ctx); err != nil {
+				t.Fatal(err)
+			}
+		})
+	}
+}
+
+func TestReadLuaRouteResult(t *testing.T) {
+	nativeErr := go_errors.New("native failure")
+	for _, tc := range []struct {
+		name, values      string
+		wantTag, wantRule string
+		wantErr           error
+		wantMessage       string
+	}{
+		{name: "route", values: `"out", "rule"`, wantTag: "out", wantRule: "rule"},
+		{name: "no match", values: `nil`},
+		{name: "empty tag", values: `""`},
+		{name: "no match ignores rule", values: `nil, false`},
+		{name: "empty tag ignores rule", values: `"", false`},
+		{name: "missing rule", values: `"out"`, wantTag: "out"},
+		{name: "invalid tag", values: `1`, wantMessage: "outboundTag"},
+		{name: "invalid rule", values: `"out", false`, wantMessage: "ruleTag"},
+		{name: "string error", values: `nil, nil, "script failure"`, wantMessage: "script failure"},
+		{name: "native error", values: `nil, nil, nativeError`, wantErr: nativeErr},
+		{name: "error overrides invalid tags", values: `false, false, nativeError`, wantErr: nativeErr},
+		{name: "invalid error", values: `"out", "rule", false`, wantMessage: "error or string"},
+		{name: "wrong error userdata", values: `"out", "rule", wrongError`, wantMessage: "error or string"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			L := lua.NewState()
+			defer L.Close()
+			for name, value := range map[string]any{"nativeError": nativeErr, "wrongError": "not a native error"} {
+				ud := L.NewUserData()
+				ud.Value = value
+				L.SetGlobal(name, ud)
+			}
+			fn, err := L.LoadString("return " + tc.values)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if err := L.CallByParam(lua.P{Fn: fn, NRet: 3, Protect: true}); err != nil {
+				t.Fatal(err)
+			}
+			outboundTag, ruleTag, err := readLuaRouteResult(L)
+			if outboundTag != tc.wantTag || ruleTag != tc.wantRule {
+				t.Fatalf("result = %q, %q, %v; want %q, %q", outboundTag, ruleTag, err, tc.wantTag, tc.wantRule)
+			}
+			switch {
+			case tc.wantErr != nil:
+				if err != tc.wantErr {
+					t.Fatalf("error = %v, want original error", err)
+				}
+			case tc.wantMessage != "":
+				if err == nil || !strings.Contains(err.Error(), tc.wantMessage) {
+					t.Fatalf("error = %v, want %q", err, tc.wantMessage)
+				}
+			case err != nil:
+				t.Fatal(err)
+			}
+		})
+	}
+}
+
+func TestCallLuaRouteCancellation(t *testing.T) {
+	L := newLuaRouterState(t, `function HandleRoute() while true do end end`)
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+	L.SetContext(ctx)
+	if err := callLuaRoute(L, &routing_session.Context{}); err == nil {
+		t.Fatal("callLuaRoute did not stop after context cancellation")
+	}
+	if L.Context() != ctx {
+		t.Fatal("callLuaRoute changed the Lua state's context")
+	}
+}
+
+func TestFindProcess(t *testing.T) {
+	for _, tc := range []struct {
+		name, network, target string
+		targetPort            uint16
+		modify                func(*luaRouteTestContext)
+		wantErr               bool
+	}{
+		{name: "TCP", network: "tcp", target: "127.0.0.3", targetPort: 443},
+		{name: "UDP", network: "udp", target: "127.0.0.3", targetPort: 443, modify: func(c *luaRouteTestContext) {
+			c.Outbound.Target.Network = net.Network_UDP
+		}},
+		{name: "domain target", network: "tcp", modify: func(c *luaRouteTestContext) { c.targetIPs = nil }},
+		{name: "missing source", modify: func(c *luaRouteTestContext) { c.sourceIPs = nil }, wantErr: true},
+		{name: "unsupported network", modify: func(c *luaRouteTestContext) {
+			c.Outbound.Target.Network = net.Network_UNIX
+		}, wantErr: true},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			ctx := newLuaRouteTestContext()
+			if tc.modify != nil {
+				tc.modify(ctx)
+			}
+			called := false
+			pid, name, path, err := findProcess(ctx, func(network, source string, sourcePort uint16, target string, targetPort uint16) (int, string, string, error) {
+				called = true
+				if network != tc.network || source != "127.0.0.2" || sourcePort != 1234 || target != tc.target || targetPort != tc.targetPort {
+					t.Fatalf("endpoints = %s %s:%d -> %s:%d", network, source, sourcePort, target, targetPort)
+				}
+				return 42, "process", "/path/process", nil
+			})
+			if tc.wantErr {
+				if err == nil || called {
+					t.Fatalf("findProcess = %d, %q, %q, %v", pid, name, path, err)
+				}
+				return
+			}
+			if err != nil || !called || pid != 42 || name != "process" || path != "/path/process" {
+				t.Fatalf("findProcess = %d, %q, %q, %v", pid, name, path, err)
+			}
+		})
+	}
+}
+
+var _ routing.Context = (*luaRouteTestContext)(nil)

app/router/router.go

@@ -20,6 +20,7 @@ import (
 type Router struct {
 	domainStrategy Config_DomainStrategy
 	rules          atomic.Pointer[[]*Rule]
+	script         *scriptEngine
 	balancers      atomic.Pointer[map[string]*Balancer]
 	dns            dns.Client
 
@@ -45,6 +46,14 @@ func (r *Router) Init(ctx context.Context, config *Config, d dns.Client, ohm out
 	r.ohm = ohm
 	r.dispatcher = dispatcher
 
+	if config.Script != "" {
+		script, err := newScriptEngine(config.Script)
+		if err != nil {
+			return errors.New("failed to prepare routing script").Base(err)
+		}
+		r.script = script
+	}
+
 	r.rules.Store(new([]*Rule))
 	r.balancers.Store(&map[string]*Balancer{})
 	return r.ReloadRules(config, false)
@@ -52,6 +61,10 @@ func (r *Router) Init(ctx context.Context, config *Config, d dns.Client, ohm out
 
 // PickRoute implements routing.Router.
 func (r *Router) PickRoute(ctx routing.Context) (routing.Route, error) {
+	if r.script != nil {
+		return r.script.pickRoute(ctx)
+	}
+
 	originalCtx := ctx
 	rule, ctx, err := r.pickRouteInternal(ctx)
 	if err != nil {
@@ -221,6 +234,11 @@ func (r *Router) pickRouteInternal(ctx routing.Context) (*Rule, routing.Context,
 
 // Start implements common.Runnable.
 func (r *Router) Start() error {
+	if r.script != nil {
+		if err := r.script.start(r); err != nil {
+			return errors.New("failed to initialize routing script").Base(err)
+		}
+	}
 	return nil
 }
 
@@ -235,6 +253,9 @@ func closeWebhooks(rules []*Rule) {
 
 // Close implements common.Closable.
 func (r *Router) Close() error {
+	if r.script != nil {
+		r.script.close()
+	}
 	r.mu.Lock()
 	defer r.mu.Unlock()
 	closeWebhooks(*r.rules.Load())

app/router/script.go

@@ -0,0 +1,83 @@
+package router
+
+import (
+	"time"
+
+	"github.com/xtls/xray-core/app/dns"
+	"github.com/xtls/xray-core/common"
+	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/geodata"
+	"github.com/xtls/xray-core/common/log"
+	xlua "github.com/xtls/xray-core/common/lua"
+	"github.com/xtls/xray-core/features/routing"
+	lua "github.com/yuin/gopher-lua"
+)
+
+const scriptExecutionTimeout = 6 * time.Second
+
+type scriptEngine struct {
+	program *xlua.Program
+	pool    *xlua.Pool
+}
+
+func newScriptEngine(script string) (*scriptEngine, error) {
+	program, err := xlua.Compile(script)
+	if err != nil {
+		return nil, err
+	}
+	return &scriptEngine{program: program}, nil
+}
+
+func (e *scriptEngine) start(router *Router) error {
+	pool, err := xlua.NewPool(router.ctx, scriptExecutionTimeout, e.program.NewStateFactory(
+		scriptExecutionTimeout*20,
+		func(L *lua.LState) {
+			geodata.RegisterLua(L)
+			log.RegisterLua(L)
+			router.RegisterLua(L)
+			dns.RegisterLua(L, router.dns)
+		},
+		func(L *lua.LState) error {
+			if L.GetGlobal("HandleRoute").Type() != lua.LTFunction {
+				return errors.New("routing script must define HandleRoute(...)")
+			}
+			return nil
+		}))
+	if err != nil {
+		return err
+	}
+
+	e.pool = pool
+	errors.LogInfo(router.ctx, "routing script initialized")
+	return nil
+}
+
+func (e *scriptEngine) close() {
+	if e.pool != nil {
+		e.pool.Close()
+	}
+}
+
+func (e *scriptEngine) pickRoute(ctx routing.Context) (routing.Route, error) {
+	var outboundTag, ruleTag string
+	var routeErr error
+
+	if err := e.pool.WithState(nil, 0, func(L *lua.LState) error {
+		if err := callLuaRoute(L, ctx); err != nil {
+			return err
+		}
+		outboundTag, ruleTag, routeErr = readLuaRouteResult(L)
+		return nil
+	}); err != nil {
+		return nil, err
+	}
+
+	if routeErr != nil {
+		return nil, routeErr
+	}
+	if outboundTag == "" {
+		return nil, common.ErrNoClue
+	}
+
+	return &Route{Context: ctx, outboundTag: outboundTag, ruleTag: ruleTag}, nil
+}

app/router/script_test.go

@@ -0,0 +1,421 @@
+package router
+
+import (
+	"context"
+	stdnet "net"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	wireDNS "github.com/miekg/dns"
+	"github.com/xtls/xray-core/app/dispatcher"
+	appdns "github.com/xtls/xray-core/app/dns"
+	"github.com/xtls/xray-core/app/proxyman"
+	_ "github.com/xtls/xray-core/app/proxyman/outbound"
+	"github.com/xtls/xray-core/common"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/common/serial"
+	"github.com/xtls/xray-core/core"
+	featureDNS "github.com/xtls/xray-core/features/dns"
+	"github.com/xtls/xray-core/features/outbound"
+	"github.com/xtls/xray-core/features/routing"
+	routing_session "github.com/xtls/xray-core/features/routing/session"
+	"github.com/xtls/xray-core/proxy/blackhole"
+	"github.com/xtls/xray-core/proxy/freedom"
+)
+
+type luaRouteDNSClient struct {
+	featureDNS.Client
+	lookup func(string, featureDNS.IPOption) ([]net.IP, uint32, error)
+}
+
+func (d *luaRouteDNSClient) LookupIP(domain string, option featureDNS.IPOption) ([]net.IP, uint32, error) {
+	return d.lookup(domain, option)
+}
+
+type luaRouteOutboundManager struct{ outbound.Manager }
+
+func (*luaRouteOutboundManager) Select(selectors []string) []string { return selectors }
+
+func writeRouteScript(t *testing.T, script string) string {
+	t.Helper()
+	path := filepath.Join(t.TempDir(), "route.lua")
+	if err := os.WriteFile(path, []byte(script), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	return path
+}
+
+func startLuaRouter(t *testing.T, script string, d featureDNS.Client, config *Config) *Router {
+	t.Helper()
+	if config == nil {
+		config = &Config{}
+	}
+	config.Script = writeRouteScript(t, script)
+	r := new(Router)
+	if err := r.Init(context.Background(), config, d, &luaRouteOutboundManager{}, nil); err != nil {
+		t.Fatal(err)
+	}
+	if err := r.Start(); err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() {
+		if err := r.Close(); err != nil {
+			t.Error(err)
+		}
+	})
+	return r
+}
+
+func TestRouterScriptStartup(t *testing.T) {
+	for _, tc := range []struct {
+		name, script string
+		compileError bool
+	}{
+		{"syntax error", "function HandleRoute(", true},
+		{"missing hook", "value = 1", false},
+		{"invalid hook", "HandleRoute = true", false},
+		{"initialization error", `error("setup failed")`, false},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			r := new(Router)
+			err := r.Init(context.Background(), &Config{Script: writeRouteScript(t, tc.script)}, nil, nil, nil)
+			if tc.compileError {
+				if r.script != nil || err == nil || !strings.Contains(err.Error(), "failed to prepare routing script") {
+					t.Fatalf("Init = %v; want no engine and script preparation error", err)
+				}
+				return
+			}
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer r.Close()
+			if r.script.program == nil || r.script.pool != nil {
+				t.Fatal("Init did not compile the script without starting its pool")
+			}
+			if err := r.Close(); err != nil {
+				t.Fatal(err)
+			}
+			if err := r.Start(); err == nil {
+				t.Fatal("Start accepted an invalid routing script")
+			}
+			if r.script.pool != nil {
+				t.Fatal("Start retained a script pool after failure")
+			}
+		})
+	}
+}
+
+func TestRouterScriptProgramSnapshot(t *testing.T) {
+	path := writeRouteScript(t, `function HandleRoute() return "compiled", "compiled-rule" end`)
+	engine, err := newScriptEngine(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer engine.close()
+	if err := os.Remove(path); err != nil {
+		t.Fatal(err)
+	}
+	if err := engine.start(&Router{ctx: context.Background()}); err != nil {
+		t.Fatal(err)
+	}
+	route, err := engine.pickRoute(newLuaRouteTestContext())
+	if err != nil || route == nil || route.GetOutboundTag() != "compiled" || route.GetRuleTag() != "compiled-rule" {
+		t.Fatalf("route = %v, %v; want compiled, compiled-rule", route, err)
+	}
+}
+
+func TestRouterScriptRouting(t *testing.T) {
+	for _, tc := range []struct {
+		name, body        string
+		wantTag, wantRule string
+		wantErr           error
+		wantMessage       string
+		wantCalls         string
+	}{
+		{name: "route", body: `return "lua-out", "lua-rule"`, wantTag: "lua-out", wantRule: "lua-rule", wantCalls: "2"},
+		{name: "no match", body: `return nil`, wantErr: common.ErrNoClue, wantCalls: "2"},
+		{name: "empty tag", body: `return ""`, wantErr: common.ErrNoClue, wantCalls: "2"},
+		{name: "balancer error", body: `local tag, err = router.PickOutbound("missing"); return tag, nil, err`, wantMessage: "not found", wantCalls: "2"},
+		{name: "string error", body: `return nil, nil, "blocked"`, wantMessage: "blocked", wantCalls: "2"},
+		{name: "invalid tag", body: `return false`, wantMessage: "outboundTag", wantCalls: "2"},
+		{name: "invalid rule", body: `return "lua-out", false`, wantMessage: "ruleTag", wantCalls: "2"},
+		{name: "execution error", body: `error("execution failed")`, wantMessage: "execution failed", wantCalls: "1"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			var dnsCalls atomic.Int32
+			d := &luaRouteDNSClient{lookup: func(string, featureDNS.IPOption) ([]net.IP, uint32, error) {
+				dnsCalls.Add(1)
+				return []net.IP{{1, 2, 3, 4}}, 60, nil
+			}}
+			script := `
+local router = require("xray.router")
+local calls = 0
+function HandleRoute(ctx, inbound)
+    calls = calls + 1
+    if inbound == "count" then return "lua-out", tostring(calls) end
+    ` + tc.body + `
+end
+`
+			r := startLuaRouter(t, script, d, &Config{
+				DomainStrategy: Config_IpOnDemand,
+				Rule: []*RoutingRule{{
+					TargetTag: &RoutingRule_Tag{Tag: "json-out"},
+					Networks:  []net.Network{net.Network_TCP},
+				}},
+			})
+			ctx := newLuaRouteTestContext()
+			ctx.Content.SkipDNSResolve = false
+			route, err := r.PickRoute(ctx)
+			switch {
+			case tc.wantErr != nil:
+				if err != tc.wantErr {
+					t.Fatalf("route error = %v, want %v", err, tc.wantErr)
+				}
+			case tc.wantMessage != "":
+				if err == nil || !strings.Contains(err.Error(), tc.wantMessage) {
+					t.Fatalf("route error = %v, want %q", err, tc.wantMessage)
+				}
+			case err != nil:
+				t.Fatal(err)
+			}
+			if tc.wantTag == "" {
+				if route != nil {
+					t.Fatalf("route = %v, want nil", route)
+				}
+			} else if route == nil || route.GetOutboundTag() != tc.wantTag || route.GetRuleTag() != tc.wantRule || route.(*Route).Context != ctx {
+				t.Fatalf("route = %v; want %q, %q and original context", route, tc.wantTag, tc.wantRule)
+			}
+
+			ctx.Inbound.Tag = "count"
+			route, err = r.PickRoute(ctx)
+			if err != nil || route == nil || route.GetOutboundTag() != "lua-out" || route.GetRuleTag() != tc.wantCalls {
+				t.Fatalf("next route = %v, %v; want lua-out, calls %s", route, err, tc.wantCalls)
+			}
+			if dnsCalls.Load() != 0 {
+				t.Fatal("script routing implicitly resolved DNS")
+			}
+		})
+	}
+}
+
+func TestRouterScriptModules(t *testing.T) {
+	ips := []net.IP{{127, 0, 0, 7}}
+	calls := 0
+	d := &luaRouteDNSClient{lookup: func(domain string, option featureDNS.IPOption) ([]net.IP, uint32, error) {
+		calls++
+		if domain != "mixed.example." || !option.IPv4Enable || option.IPv6Enable || !option.FakeEnable {
+			t.Fatalf("dns.Query arguments = %q, %+v", domain, option)
+		}
+		return ips, 17, nil
+	}}
+	r := startLuaRouter(t, `
+local dns = require("xray.dns")
+local matcher = require("xray.geodata").BuildIPMatcher("127.0.0.0/8")
+assert(dns.Servers == nil and type(dns.Query) == "function")
+assert(type(require("xray.log").Info) == "function")
+function HandleRoute(ctx, inbound, sourcePort, targetPort, localPort, domain)
+    local ips, ttl, err = dns.Query(domain, true, false, true)
+    assert(not err and ttl == 17)
+    assert(matcher:AnyMatch(ips) and matcher:AnyMatch(ctx:GetTargetIPs()))
+    return "out"
+end`, d, nil)
+	if _, err := r.PickRoute(newLuaRouteTestContext()); err != nil {
+		t.Fatal(err)
+	}
+	if calls != 1 {
+		t.Fatalf("DNS calls = %d, want 1", calls)
+	}
+}
+
+func TestRouterScriptBalancerReload(t *testing.T) {
+	config := func(tag string) *Config {
+		return &Config{BalancingRule: []*BalancingRule{{
+			Tag: "balance", Strategy: "roundrobin", OutboundSelector: []string{tag},
+		}}}
+	}
+	r := startLuaRouter(t, `
+local router = require("xray.router")
+function HandleRoute()
+    local tag, err = router.PickOutbound("balance")
+    return tag, "balanced", err
+end`, nil, config("old"))
+	pick := func(want string) {
+		t.Helper()
+		route, err := r.PickRoute(&routing_session.Context{})
+		if err != nil || route.GetOutboundTag() != want || route.GetRuleTag() != "balanced" {
+			t.Fatalf("route = %v, %v, want %q", route, err, want)
+		}
+	}
+
+	pick("old")
+	if err := r.SetOverrideTarget("balance", "override"); err != nil {
+		t.Fatal(err)
+	}
+	pick("override")
+	if err := r.SetOverrideTarget("balance", ""); err != nil {
+		t.Fatal(err)
+	}
+	if err := r.ReloadRules(config("new"), false); err != nil {
+		t.Fatal(err)
+	}
+	pick("new")
+}
+
+func TestRouterScriptConcurrentBalancerReload(t *testing.T) {
+	config := func(tag string) *Config {
+		return &Config{BalancingRule: []*BalancingRule{{
+			Tag: "balance", Strategy: "roundrobin", OutboundSelector: []string{tag},
+		}}}
+	}
+	r := startLuaRouter(t, `
+local router = require("xray.router")
+function HandleRoute()
+    local tag, err = router.PickOutbound("balance")
+    return tag, nil, err
+end`, nil, config("a"))
+
+	var wg sync.WaitGroup
+	for range 4 {
+		wg.Go(func() {
+			for range 20 {
+				route, err := r.PickRoute(&routing_session.Context{})
+				if err != nil {
+					t.Errorf("PickRoute: %v", err)
+					return
+				}
+				if tag := route.GetOutboundTag(); tag != "a" && tag != "b" {
+					t.Errorf("unexpected tag %q", tag)
+				}
+			}
+		})
+	}
+	wg.Go(func() {
+		for range 20 {
+			for _, tag := range []string{"a", "b"} {
+				if err := r.ReloadRules(config(tag), false); err != nil {
+					t.Error(err)
+					return
+				}
+			}
+		}
+	})
+	wg.Wait()
+}
+
+func TestRouterScriptDNSDispatcherReentry(t *testing.T) {
+	conn, err := stdnet.ListenPacket("udp4", "127.0.0.1:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	port := conn.LocalAddr().(*stdnet.UDPAddr).Port
+	ready, stopped := make(chan struct{}), make(chan error, 1)
+	var queries atomic.Int32
+	server := &wireDNS.Server{
+		PacketConn: conn,
+		NotifyStartedFunc: func() {
+			close(ready)
+		},
+		Handler: wireDNS.HandlerFunc(func(w wireDNS.ResponseWriter, query *wireDNS.Msg) {
+			queries.Add(1)
+			response := new(wireDNS.Msg).SetReply(query)
+			for _, question := range query.Question {
+				if question.Name == "nested.example." && question.Qtype == wireDNS.TypeA {
+					response.Answer = append(response.Answer, &wireDNS.A{
+						Hdr: wireDNS.RR_Header{Name: question.Name, Rrtype: wireDNS.TypeA, Class: wireDNS.ClassINET, Ttl: 60},
+						A:   stdnet.IP{127, 0, 0, 7},
+					})
+				}
+			}
+			if err := w.WriteMsg(response); err != nil {
+				t.Error(err)
+			}
+		}),
+	}
+	go func() { stopped <- server.ActivateAndServe() }()
+	defer func() {
+		server.Shutdown()
+		select {
+		case err := <-stopped:
+			if err != nil {
+				t.Error(err)
+			}
+		case <-time.After(3 * time.Second):
+			t.Error("DNS server did not stop")
+		}
+	}()
+	select {
+	case <-ready:
+	case err := <-stopped:
+		t.Fatalf("DNS server startup: %v", err)
+	case <-time.After(3 * time.Second):
+		t.Fatal("DNS server did not start")
+	}
+
+	dnsScript := writeRouteScript(t, `
+local server = require("xray.dns").Servers[1]
+function HandleDNSQuery(domain, ipv4, ipv6, fake)
+    return server:Query(domain, ipv4, ipv6, fake)
+end`)
+	routerScript := writeRouteScript(t, `
+local router = require("xray.router")
+local dns = require("xray.dns")
+local matcher = require("xray.geodata").BuildIPMatcher("127.0.0.7")
+local active = false
+function HandleRoute(ctx, inbound, sourcePort, targetPort, localPort, domain, network,
+    protocol, user, vlessRoute, skipDNSResolve)
+    assert(not active, "borrowed Router VM reentered")
+    if inbound == "dns" then
+        assert(network == router.NetworkUDP and skipDNSResolve == false)
+        return "direct", "dns-route"
+    end
+    active = true
+    local ips, ttl, err = dns.Query("nested.example", true, false, false)
+    assert(not err and matcher:AnyMatch(ips) and active)
+    active = false
+    return "direct", "outer-route"
+end`)
+	instance, err := core.New(&core.Config{
+		App: []*serial.TypedMessage{
+			serial.ToTypedMessage(&appdns.Config{
+				Tag: "dns", Script: dnsScript, DisableCache: true,
+				NameServer: []*appdns.NameServer{{
+					Id: "upstream", TimeoutMs: 1000,
+					Address: &net.Endpoint{
+						Network: net.Network_UDP,
+						Address: &net.IPOrDomain{Address: &net.IPOrDomain_Ip{Ip: []byte{127, 0, 0, 1}}},
+						Port:    uint32(port),
+					},
+				}},
+			}),
+			serial.ToTypedMessage(&Config{Script: routerScript}),
+			serial.ToTypedMessage(&dispatcher.Config{}),
+			serial.ToTypedMessage(&proxyman.OutboundConfig{}),
+		},
+		Outbound: []*core.OutboundHandlerConfig{
+			{Tag: "default", ProxySettings: serial.ToTypedMessage(&blackhole.Config{})},
+			{Tag: "direct", ProxySettings: serial.ToTypedMessage(&freedom.Config{
+				FinalRules: []*freedom.FinalRuleConfig{{Action: freedom.RuleAction_Allow}},
+			})},
+		},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := instance.Start(); err != nil {
+		t.Fatal(err)
+	}
+	defer instance.Close()
+	r := instance.GetFeature(routing.RouterType()).(*Router)
+	route, err := r.PickRoute(newLuaRouteTestContext())
+	if err != nil || route.GetOutboundTag() != "direct" || route.GetRuleTag() != "outer-route" {
+		t.Fatalf("nested DNS routing = %v, %v", route, err)
+	}
+	if queries.Load() == 0 {
+		t.Fatal("DNS query did not pass through the dispatcher")
+	}
+}

common/base64/base64.go

@@ -0,0 +1,6 @@
+package base64
+
+const (
+	Prefix     = "base64:"
+	GzipPrefix = "base64+gzip:"
+)

common/base64/decode.go

@@ -0,0 +1,38 @@
+package base64
+
+import (
+	"bytes"
+	"compress/gzip"
+	"encoding/base64"
+	"io"
+	"strings"
+
+	"github.com/xtls/xray-core/common/errors"
+)
+
+// Decode decodes Base64 text with an optional [Prefix] or [GzipPrefix].
+func Decode(value string) ([]byte, error) {
+	value, zip := strings.CutPrefix(value, GzipPrefix)
+	if !zip {
+		value = strings.TrimPrefix(value, Prefix)
+	}
+
+	data, err := base64.StdEncoding.DecodeString(value)
+	if err != nil {
+		return nil, errors.New("failed to decode base64").Base(err)
+	}
+	if !zip {
+		return data, nil
+	}
+
+	reader, err := gzip.NewReader(bytes.NewReader(data))
+	if err != nil {
+		return nil, errors.New("failed to decompress gzip").Base(err)
+	}
+	defer reader.Close()
+	data, err = io.ReadAll(reader)
+	if err != nil {
+		return nil, errors.New("failed to decompress gzip").Base(err)
+	}
+	return data, nil
+}

common/base64/decode_test.go

@@ -0,0 +1,28 @@
+package base64
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestDecodeFormats(t *testing.T) {
+	compressed, err := Encode([]byte("x"), true)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, tc := range []struct {
+		name, value, want string
+	}{
+		{"unprefixed", "eA==", "x"},
+		{"base64", Prefix + "eA==", "x"},
+		{"gzip", compressed, "x"},
+		{"empty", Prefix, ""},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			data, err := Decode(tc.value)
+			if err != nil || !bytes.Equal(data, []byte(tc.want)) {
+				t.Fatalf("Decode = %q, %v; want %q", data, err, tc.want)
+			}
+		})
+	}
+}

common/base64/encode.go

@@ -0,0 +1,29 @@
+package base64
+
+import (
+	"bytes"
+	"compress/gzip"
+	"encoding/base64"
+
+	"github.com/xtls/xray-core/common/errors"
+)
+
+// Encode returns prefixed Base64 text, optionally compressed with gzip at the highest level.
+func Encode(data []byte, zip bool) (string, error) {
+	if !zip {
+		return Prefix + base64.StdEncoding.EncodeToString(data), nil
+	}
+
+	var buf bytes.Buffer
+	writer, err := gzip.NewWriterLevel(&buf, gzip.BestCompression)
+	if err != nil {
+		return "", errors.New("failed to compress gzip").Base(err)
+	}
+	if _, err := writer.Write(data); err != nil {
+		return "", errors.New("failed to compress gzip").Base(err)
+	}
+	if err := writer.Close(); err != nil {
+		return "", errors.New("failed to compress gzip").Base(err)
+	}
+	return GzipPrefix + base64.StdEncoding.EncodeToString(buf.Bytes()), nil
+}

common/base64/encode_test.go

@@ -0,0 +1,62 @@
+package base64
+
+import (
+	"bytes"
+	"compress/gzip"
+	"encoding/base64"
+	"io"
+	"strings"
+	"testing"
+)
+
+func TestEncodeFormats(t *testing.T) {
+	for _, tc := range []struct {
+		name string
+		data []byte
+	}{
+		{"empty", nil},
+		{"bytes", []byte("你好\r\n\x00\xff")},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			for _, zip := range []bool{false, true} {
+				prefix := Prefix
+				if zip {
+					prefix = GzipPrefix
+				}
+				t.Run(prefix, func(t *testing.T) {
+					value, err := Encode(tc.data, zip)
+					if err != nil {
+						t.Fatal(err)
+					}
+					payload, ok := strings.CutPrefix(value, prefix)
+					if !ok {
+						t.Fatalf("encoded value does not start with %q", prefix)
+					}
+					// Read the output independently of Decode so matching bugs cannot hide.
+					data, err := base64.StdEncoding.DecodeString(payload)
+					if err != nil {
+						t.Fatal(err)
+					}
+					if zip {
+						// gzip's XFL byte identifies the compression level we selected.
+						if len(data) < 10 || data[8] != 2 {
+							t.Fatal("gzip output does not use the highest compression level")
+						}
+						reader, err := gzip.NewReader(bytes.NewReader(data))
+						if err != nil {
+							t.Fatal(err)
+						}
+						defer reader.Close()
+						data, err = io.ReadAll(reader)
+						if err != nil {
+							t.Fatal(err)
+						}
+					}
+					if !bytes.Equal(data, tc.data) {
+						t.Fatal("encoded output does not preserve the input bytes")
+					}
+				})
+			}
+		})
+	}
+}

common/geodata/domain_matcher.go

@@ -82,19 +82,10 @@ func (f *MphDomainMatcherFactory) BuildMatcher(rules []*DomainRule) (DomainMatch
 			}
 			g.Add(m, uint32(i))
 		case *DomainRule_Geosite:
-			domains, err := loadSiteWithAttrs(v.Geosite.File, v.Geosite.Code, v.Geosite.Attrs)
+			err := loadSiteMatchers(v.Geosite, func(m strmatcher.Matcher) { g.Add(m, uint32(i)) })
 			if err != nil {
 				return nil, err
 			}
-			for j, d := range domains {
-				domains[j] = nil // peak mem
-				m, err := parseDomain(d)
-				if err != nil {
-					errors.LogError(context.Background(), "ignore invalid geosite entry in ", v.Geosite.File, ":", v.Geosite.Code, " at index ", j, ", ", err)
-					continue
-				}
-				g.Add(m, uint32(i))
-			}
 		default:
 			panic("unknown domain rule type")
 		}
@@ -108,12 +99,12 @@ func (f *MphDomainMatcherFactory) BuildMatcher(rules []*DomainRule) (DomainMatch
 	return g, nil
 }
 
-type CompactDomainMatcherFactory struct {
+type CompactMphDomainMatcherFactory struct {
 	sync.Mutex
-	shared *utils.WeakCacheMap[string, strmatcher.LinearAnyMatcher]
+	shared *utils.WeakCacheMap[string, strmatcher.MphValueMatcher]
 }
 
-func (f *CompactDomainMatcherFactory) getOrCreateFrom(rule *GeoSiteRule) (strmatcher.MatcherSet, error) {
+func (f *CompactMphDomainMatcherFactory) getOrCreateFrom(rule *GeoSiteRule) (*strmatcher.MphValueMatcher, error) {
 	key := rule.File + ":" + rule.Code + "@" + rule.Attrs
 
 	f.Lock()
@@ -125,33 +116,23 @@ func (f *CompactDomainMatcherFactory) getOrCreateFrom(rule *GeoSiteRule) (strmat
 	}
 	errors.LogDebug(context.Background(), "geodata geosite matcher cache MISS ", key)
 
-	s := strmatcher.NewLinearAnyMatcher()
-	domains, err := loadSiteWithAttrs(rule.File, rule.Code, rule.Attrs)
-	if err != nil {
+	s := strmatcher.NewMphValueMatcher()
+	if err := loadSiteMatchers(rule, func(m strmatcher.Matcher) { s.Add(m, 0) }); err != nil {
 		return nil, err
 	}
-	for i, d := range domains {
-		domains[i] = nil // peak mem
-		m, err := parseDomain(d)
-		if err != nil {
-			errors.LogError(context.Background(), "ignore invalid geosite entry in ", rule.File, ":", rule.Code, " at index ", i, ", ", err)
-			continue
-		}
-		s.Add(m)
+	if err := s.Build(); err != nil {
+		return nil, err
 	}
 	f.shared.Store(key, s)
-	return s, err
+	return s, nil
 }
 
 // BuildMatcher implements DomainMatcherFactory.
-func (f *CompactDomainMatcherFactory) BuildMatcher(rules []*DomainRule) (DomainMatcher, error) {
+func (f *CompactMphDomainMatcherFactory) BuildMatcher(rules []*DomainRule) (DomainMatcher, error) {
 	if len(rules) == 0 {
 		return nil, errors.New("empty domain rule list")
 	}
-	compact := &CompactDomainMatcher{
-		matchers: make([]strmatcher.MatcherSet, 0, len(rules)),
-		values:   make([]uint32, 0, len(rules)),
-	}
+	compact := new(CompactMphDomainMatcher)
 	for i, r := range rules {
 		switch v := r.Value.(type) {
 		case *DomainRule_Custom:
@@ -168,8 +149,7 @@ func (f *CompactDomainMatcherFactory) BuildMatcher(rules []*DomainRule) (DomainM
 			if err != nil {
 				return nil, err
 			}
-			compact.matchers = append(compact.matchers, m)
-			compact.values = append(compact.values, uint32(i))
+			compact.combiner.Add(m, uint32(i))
 		default:
 			panic("unknown domain rule type")
 		}
@@ -177,37 +157,40 @@ func (f *CompactDomainMatcherFactory) BuildMatcher(rules []*DomainRule) (DomainM
 	return compact, nil
 }
 
-type CompactDomainMatcher struct {
+type CompactMphDomainMatcher struct {
 	custom   strmatcher.ValueMatcher
-	matchers []strmatcher.MatcherSet
-	values   []uint32
+	combiner strmatcher.MphValueMatcherCombiner
 }
 
 // Match implements DomainMatcher.
-func (c *CompactDomainMatcher) Match(input string) []uint32 {
-	var result []uint32
+func (c *CompactMphDomainMatcher) Match(input string) []uint32 {
+	result := c.combiner.Match(input)
 	if c.custom != nil {
-		result = append(result, c.custom.Match(input)...)
-	}
-	for i, m := range c.matchers {
-		if m.MatchAny(input) {
-			result = append(result, c.values[i])
-		}
+		result = append(c.custom.Match(input), result...)
 	}
 	return result
 }
 
 // MatchAny implements DomainMatcher.
-func (c *CompactDomainMatcher) MatchAny(input string) bool {
+func (c *CompactMphDomainMatcher) MatchAny(input string) bool {
 	if c.custom != nil && c.custom.MatchAny(input) {
 		return true
 	}
-	for _, m := range c.matchers {
-		if m.MatchAny(input) {
-			return true
+	return c.combiner.MatchAny(input)
+}
+
+// loadSiteMatchers calls add with a matcher for every domain of the geosite rule and logs the invalid ones.
+func loadSiteMatchers(rule *GeoSiteRule, add func(strmatcher.Matcher)) error {
+	i := 0
+	return loadSite(rule.File, rule.Code, rule.Attrs, func(t Domain_Type, value []byte) {
+		m, err := parseDomain(&Domain{Type: t, Value: string(value)})
+		if err != nil {
+			errors.LogError(context.Background(), "ignore invalid geosite entry in ", rule.File, ":", rule.Code, " at index ", i, ", ", err)
+		} else {
+			add(m)
 		}
-	}
-	return false
+		i++
+	})
 }
 
 func parseDomain(d *Domain) (strmatcher.Matcher, error) {
@@ -231,7 +214,7 @@ func parseDomain(d *Domain) (strmatcher.Matcher, error) {
 func newDomainMatcherFactory() DomainMatcherFactory {
 	switch runtime.GOOS {
 	case "ios", "android":
-		return &CompactDomainMatcherFactory{shared: utils.NewWeakCacheMap[string, strmatcher.LinearAnyMatcher]()}
+		return &CompactMphDomainMatcherFactory{shared: utils.NewWeakCacheMap[string, strmatcher.MphValueMatcher]()}
 	default:
 		return &MphDomainMatcherFactory{shared: utils.NewWeakCacheMap[string, strmatcher.MphValueMatcher]()}
 	}

common/geodata/domain_matcher_test.go

@@ -4,6 +4,7 @@ import (
 	"path/filepath"
 	"reflect"
 	"slices"
+	"sync"
 	"testing"
 
 	"github.com/xtls/xray-core/common/geodata/strmatcher"
@@ -11,7 +12,7 @@ import (
 )
 
 func TestCompactDomainMatcher_PreservesCustomRuleIndices(t *testing.T) {
-	factory := &CompactDomainMatcherFactory{shared: utils.NewWeakCacheMap[string, strmatcher.LinearAnyMatcher]()}
+	factory := &CompactMphDomainMatcherFactory{shared: utils.NewWeakCacheMap[string, strmatcher.MphValueMatcher]()}
 	matcher, err := factory.BuildMatcher([]*DomainRule{
 		{Value: &DomainRule_Custom{Custom: &Domain{Type: Domain_Full, Value: "example.com"}}},
 		{Value: &DomainRule_Custom{Custom: &Domain{Type: Domain_Domain, Value: "example.com"}}},
@@ -32,7 +33,7 @@ func TestCompactDomainMatcher_PreservesCustomRuleIndices(t *testing.T) {
 func TestCompactDomainMatcher_PreservesMixedRuleIndices(t *testing.T) {
 	t.Setenv("xray.location.asset", filepath.Join("..", "..", "resources"))
 
-	factory := &CompactDomainMatcherFactory{shared: utils.NewWeakCacheMap[string, strmatcher.LinearAnyMatcher]()}
+	factory := &CompactMphDomainMatcherFactory{shared: utils.NewWeakCacheMap[string, strmatcher.MphValueMatcher]()}
 	matcher, err := factory.BuildMatcher([]*DomainRule{
 		{Value: &DomainRule_Geosite{Geosite: &GeoSiteRule{File: DefaultGeoSiteDat, Code: "CN"}}},
 		{Value: &DomainRule_Custom{Custom: &Domain{Type: Domain_Full, Value: "163.com"}}},
@@ -72,3 +73,76 @@ func TestMphDomainMatcher_MatchReturnsDetachedSlice(t *testing.T) {
 		t.Fatalf("Match() after caller mutation = %v, want %v", gotAgain, []uint32{0, 1})
 	}
 }
+
+// DNS sorts every Match result in place, so a matcher must never hand out a
+// slice it keeps, also when only its keyword or regex part matches.
+func TestDomainMatcher_MatchResultsCanBeSortedConcurrently(t *testing.T) {
+	t.Setenv("xray.location.asset", filepath.Join("..", "..", "resources"))
+
+	rules := []*DomainRule{
+		{Value: &DomainRule_Custom{Custom: &Domain{Type: Domain_Full, Value: "example.com"}}},
+		{Value: &DomainRule_Custom{Custom: &Domain{Type: Domain_Domain, Value: "example.com"}}},
+		{Value: &DomainRule_Custom{Custom: &Domain{Type: Domain_Substr, Value: "exam"}}},
+		{Value: &DomainRule_Custom{Custom: &Domain{Type: Domain_Regex, Value: `^ex.*\.org$`}}},
+		{Value: &DomainRule_Custom{Custom: &Domain{Type: Domain_Substr, Value: "exam"}}},
+		{Value: &DomainRule_Geosite{Geosite: &GeoSiteRule{File: DefaultGeoSiteDat, Code: "CN"}}},
+		{Value: &DomainRule_Custom{Custom: &Domain{Type: Domain_Full, Value: "only.full.test"}}},
+	}
+	cases := []struct {
+		input string
+		want  []uint32
+	}{
+		{"example.com", []uint32{0, 1, 2, 4}},
+		{"www.example.com", []uint32{1, 2, 4}},
+		{"exam.net", []uint32{2, 4}}, // keyword part only
+		{"example.org", []uint32{2, 3, 4}},
+		{"163.com", []uint32{5}},
+		{"www.163.com", []uint32{5}},
+		{"only.full.test", []uint32{6}}, // full part only
+		{"nomatch.test", nil},
+	}
+	factories := map[string]DomainMatcherFactory{
+		"mph":     &MphDomainMatcherFactory{shared: utils.NewWeakCacheMap[string, strmatcher.MphValueMatcher]()},
+		"compact": &CompactMphDomainMatcherFactory{shared: utils.NewWeakCacheMap[string, strmatcher.MphValueMatcher]()},
+	}
+	for name, factory := range factories {
+		t.Run(name, func(t *testing.T) {
+			matcher, err := factory.BuildMatcher(rules)
+			if err != nil {
+				t.Fatalf("BuildMatcher() failed: %v", err)
+			}
+			for _, c := range cases {
+				got := matcher.Match(c.input)
+				if sorted := slices.Sorted(slices.Values(got)); !slices.Equal(sorted, c.want) {
+					t.Fatalf("Match(%q) = %v, want %v", c.input, sorted, c.want)
+				}
+				got = got[:cap(got)]
+				for j := range got {
+					got[j] = ^uint32(0)
+				}
+				if again := slices.Sorted(slices.Values(matcher.Match(c.input))); !slices.Equal(again, c.want) {
+					t.Fatalf("Match(%q) after caller mutation = %v, want %v", c.input, again, c.want)
+				}
+			}
+
+			var wg sync.WaitGroup
+			for range 8 {
+				wg.Add(1)
+				go func() {
+					defer wg.Done()
+					for range 500 {
+						for _, c := range cases {
+							got := matcher.Match(c.input)
+							slices.Sort(got)
+							if !slices.Equal(got, c.want) {
+								t.Errorf("Match(%q) = %v, want %v", c.input, got, c.want)
+								return
+							}
+						}
+					}
+				}()
+			}
+			wg.Wait()
+		})
+	}
+}

common/geodata/geodat_loader.go

@@ -5,11 +5,14 @@ import (
 	"bytes"
 	"io"
 	"runtime"
+	"slices"
 	"strings"
+	"unicode/utf8"
 
 	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/common/platform/filesystem"
 
+	"google.golang.org/protobuf/encoding/protowire"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -52,17 +55,56 @@ func loadIP(file, code string) ([]*CIDR, error) {
 	return geoip.Cidr, nil
 }
 
-func loadSite(file, code string) ([]*Domain, error) {
-	bs, err := loadFile(file, code)
+// loadSite calls fn, in file order, with the type and value of every domain of the geosite code
+// that has all the "@"-separated attrs. It decodes the entry while reading the file instead of
+// unmarshalling it into a []*Domain, so value is only valid during fn.
+func loadSite(file, code, attrs string, fn func(Domain_Type, []byte)) error {
+	runtime.GC() // peak mem
+	r, err := filesystem.OpenAsset(file)
 	if err != nil {
-		return nil, err
+		return errors.New("failed to open ", file).Base(err)
 	}
-	defer runtime.GC() // peak mem
-	var geosite GeoSite
-	if err := proto.Unmarshal(bs, &geosite); err != nil {
-		return nil, errors.New("error unmarshal Site in ", file, ":", code).Base(err)
+	defer r.Close()
+	br := bufio.NewReaderSize(r, 64*1024)
+	n, err := seek(br, []byte(code))
+	if err != nil {
+		return errors.New("failed to load code ", code, " from ", file).Base(err)
 	}
-	return geosite.Domain, nil
+	loadErr := func(err error) error {
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+		return errors.New("failed to load code ", code, " from ", file).Base(err)
+	}
+	unmarshalErr := func(err error) error {
+		return errors.New("error unmarshal Site in ", file, ":", code).Base(err)
+	}
+	d := newSiteDecoder(attrs, fn)
+	for n > 0 {
+		w, err := br.Peek(min(n, br.Size()))
+		if err != nil {
+			return loadErr(err)
+		}
+		used, err := d.decode(w, len(w) < n)
+		if err != nil {
+			return unmarshalErr(err)
+		}
+		if used == 0 {
+			break // a field longer than the buffer
+		}
+		br.Discard(used)
+		n -= used
+	}
+	if n > 0 {
+		w := make([]byte, n)
+		if _, err := io.ReadFull(br, w); err != nil {
+			return loadErr(err)
+		}
+		if _, err := d.decode(w, false); err != nil {
+			return unmarshalErr(err)
+		}
+	}
+	return nil
 }
 
 func decodeVarint(br *bufio.Reader) (uint64, error) {
@@ -82,68 +124,63 @@ func decodeVarint(br *bufio.Reader) (uint64, error) {
 }
 
 func find(r io.Reader, code []byte, readBody bool) ([]byte, error) {
+	br := bufio.NewReaderSize(r, 64*1024)
+	bodyL, err := seek(br, code)
+	if err != nil || !readBody {
+		return nil, err
+	}
+	out := make([]byte, bodyL)
+	if _, err := io.ReadFull(br, out); err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+// seek advances br to the body of the entry for code and returns the body length.
+func seek(br *bufio.Reader, code []byte) (int, error) {
 	codeL := len(code)
 	if codeL == 0 {
-		return nil, errors.New("empty code")
+		return 0, errors.New("empty code")
 	}
-
-	br := bufio.NewReaderSize(r, 64*1024)
 	need := 2 + codeL // TODO: if code too long
-	prefixBuf := make([]byte, need)
 
 	for {
 		if _, err := br.ReadByte(); err != nil {
-			return nil, err
+			return 0, err
 		}
 
 		x, err := decodeVarint(br)
 		if err != nil {
-			return nil, err
+			return 0, err
 		}
 		bodyL := int(x)
 		if bodyL <= 0 {
-			return nil, errors.New("invalid body length: ", bodyL)
+			return 0, errors.New("invalid body length: ", bodyL)
 		}
 
-		prefixL := bodyL
-		if prefixL > need {
-			prefixL = need
-		}
-		prefix := prefixBuf[:prefixL]
-		if _, err := io.ReadFull(br, prefix); err != nil {
-			return nil, err
-		}
-
-		match := false
-		if bodyL >= need {
-			if int(prefix[1]) == codeL && bytes.Equal(prefix[2:need], code) {
-				if !readBody {
-					return nil, nil
-				}
-				match = true
+		// Peek no more than the buffer holds: a code longer than the buffer cannot match a single
+		// length byte anyway, so a short peek only skips it, as base find (io.ReadFull) does.
+		prefix, err := br.Peek(min(bodyL, need, br.Size()))
+		if err != nil {
+			if err == io.EOF && len(prefix) > 0 {
+				err = io.ErrUnexpectedEOF // as io.ReadFull
 			}
+			return 0, err
 		}
-
-		remain := bodyL - prefixL
-		if match {
-			out := make([]byte, bodyL)
-			copy(out, prefix)
-			if remain > 0 {
-				if _, err := io.ReadFull(br, out[prefixL:]); err != nil {
-					return nil, err
-				}
-			}
-			return out, nil
+		if bodyL >= need && len(prefix) >= need && int(prefix[1]) == codeL && bytes.Equal(prefix[2:], code) {
+			return bodyL, nil
 		}
-
-		if remain > 0 {
-			if _, err := br.Discard(remain); err != nil {
-				return nil, err
-			}
+		if _, err := br.Discard(bodyL); err != nil {
+			return 0, err
 		}
 	}
 }
 
+// AttributeMatcher, HasAttrMatcher, AllAttrsMatcher and NewAllAttrsMatcher are the exported
+// attribute helpers that have been part of this package's API since #5814. The streaming loader
+// above filters attributes itself without building a *Domain, so it does not use them, but they
+// are kept for external callers. Their behaviour is unchanged.
+
 type AttributeMatcher interface {
 	Match(*Domain) bool
 }
@@ -185,23 +222,137 @@ func NewAllAttrsMatcher(attrs string) AttributeMatcher {
 	return m
 }
 
-func loadSiteWithAttrs(file, code, attrs string) ([]*Domain, error) {
-	domains, err := loadSite(file, code)
-	if err != nil {
-		return nil, err
-	}
+var errInvalidUTF8 = errors.New("string field contains invalid UTF-8")
 
-	matcher := NewAllAttrsMatcher(attrs)
-	if matcher == nil {
-		return domains, nil
-	}
+type siteDecoder struct {
+	want []string
+	has  []bool
+	fn   func(Domain_Type, []byte)
+}
 
-	filtered := make([]*Domain, 0, len(domains))
-	for _, d := range domains {
-		if matcher.Match(d) {
-			filtered = append(filtered, d)
+func newSiteDecoder(attrs string, fn func(Domain_Type, []byte)) *siteDecoder {
+	d := &siteDecoder{fn: fn}
+	if attrs != "" {
+		d.want = strings.Split(attrs, "@")
+		d.has = make([]bool, len(d.want))
+	}
+	return d
+}
+
+// decode walks the whole fields at the start of b, a part of an encoded GeoSite (see geodat.proto),
+// calls fn for every domain that has all attrs and returns how many bytes it used. A field cut off
+// by the end of b is an error unless more is set. It accepts and rejects what proto.Unmarshal does.
+func (d *siteDecoder) decode(b []byte, more bool) (int, error) {
+	used := 0
+	for used < len(b) {
+		f, n, err := consumeField(b[used:])
+		if err == io.ErrUnexpectedEOF && more {
+			break
+		}
+		if err != nil {
+			return used, err
+		}
+		used += n
+		if f.typ != protowire.BytesType {
+			continue
+		}
+		switch f.num {
+		case 1: // code
+			if !utf8.Valid(f.v) {
+				return used, errInvalidUTF8
+			}
+		case 2: // domain
+			t, value, err := decodeDomain(f.v, d.want, d.has)
+			if err != nil {
+				return used, err
+			}
+			if !slices.Contains(d.has, false) {
+				d.fn(t, value)
+			}
 		}
 	}
+	return used, nil
+}
 
-	return filtered, nil
+// decodeDomain decodes an encoded Domain and sets has[i] if one of its attributes has the key want[i].
+func decodeDomain(b []byte, want []string, has []bool) (t Domain_Type, value []byte, err error) {
+	clear(has)
+	for len(b) > 0 {
+		f, n, err := consumeField(b)
+		if err != nil {
+			return 0, nil, err
+		}
+		b = b[n:]
+		switch {
+		case f.num == 1 && f.typ == protowire.VarintType: // type
+			t = Domain_Type(f.x)
+		case f.num == 2 && f.typ == protowire.BytesType: // value
+			if !utf8.Valid(f.v) {
+				return 0, nil, errInvalidUTF8
+			}
+			value = f.v
+		case f.num == 3 && f.typ == protowire.BytesType: // attribute
+			key, err := decodeAttributeKey(f.v)
+			if err != nil {
+				return 0, nil, err
+			}
+			for i, w := range want {
+				if string(key) == w {
+					has[i] = true
+				}
+			}
+		}
+	}
+	return t, value, nil
+}
+
+// decodeAttributeKey returns the key of an encoded Domain.Attribute.
+func decodeAttributeKey(b []byte) ([]byte, error) {
+	var key []byte
+	for len(b) > 0 {
+		f, n, err := consumeField(b)
+		if err != nil {
+			return nil, err
+		}
+		b = b[n:]
+		if f.num == 1 && f.typ == protowire.BytesType {
+			if !utf8.Valid(f.v) {
+				return nil, errInvalidUTF8
+			}
+			key = f.v
+		}
+	}
+	return key, nil
+}
+
+type protoField struct {
+	num protowire.Number
+	typ protowire.Type
+	v   []byte // payload of a length-delimited field
+	x   uint64 // value of a varint field
+}
+
+// consumeField parses the first field of an encoded message and returns it with its length.
+func consumeField(b []byte) (protoField, int, error) {
+	num, typ, n := protowire.ConsumeTag(b)
+	if n < 0 {
+		return protoField{}, 0, protowire.ParseError(n)
+	}
+	if num > protowire.MaxValidNumber {
+		return protoField{}, 0, errors.New("invalid field number ", num)
+	}
+	f := protoField{num: num, typ: typ}
+	var m int
+	switch typ {
+	case protowire.BytesType:
+		f.v, m = protowire.ConsumeBytes(b[n:])
+	case protowire.VarintType:
+		f.x, m = protowire.ConsumeVarint(b[n:])
+	default:
+		m = protowire.ConsumeFieldValue(num, typ, b[n:])
+	}
+	if m < 0 {
+		return protoField{}, 0, protowire.ParseError(m)
+	}
+	return f, n + m, nil
 }

common/geodata/geodat_loader_test.go

@@ -0,0 +1,283 @@
+package geodata
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"slices"
+	"strings"
+	"testing"
+
+	"google.golang.org/protobuf/encoding/protowire"
+	"google.golang.org/protobuf/proto"
+)
+
+type siteEntry struct {
+	Type  Domain_Type
+	Value string
+}
+
+// unmarshalSite is what loadSite used to do: proto.Unmarshal, then keep the domains that have all attrs.
+func unmarshalSite(b []byte, attrs string) ([]siteEntry, error) {
+	var site GeoSite
+	if err := proto.Unmarshal(b, &site); err != nil {
+		return nil, err
+	}
+	var entries []siteEntry
+	for _, d := range site.Domain {
+		ok := true
+		for _, key := range strings.Split(attrs, "@") {
+			ok = ok && (attrs == "" || slices.ContainsFunc(d.Attribute, func(a *Domain_Attribute) bool { return a.Key == key }))
+		}
+		if ok {
+			entries = append(entries, siteEntry{d.Type, d.Value})
+		}
+	}
+	return entries, nil
+}
+
+func checkDecodeSite(t *testing.T, name string, b []byte, attrs string) {
+	t.Helper()
+	want, wantErr := unmarshalSite(b, attrs)
+	var got []siteEntry
+	_, err := newSiteDecoder(attrs, func(typ Domain_Type, value []byte) {
+		got = append(got, siteEntry{typ, string(value)})
+	}).decode(b, false)
+	if (err == nil) != (wantErr == nil) {
+		t.Fatalf("%s@%s: error %v, proto.Unmarshal: %v", name, attrs, err, wantErr)
+	}
+	if err == nil && !slices.Equal(got, want) {
+		t.Fatalf("%s@%s: got %v, want %v", name, attrs, got, want)
+	}
+}
+
+func TestDecodeSiteMatchesUnmarshal(t *testing.T) {
+	bs, err := os.ReadFile(filepath.Join("..", "..", "resources", DefaultGeoSiteDat))
+	if err != nil {
+		t.Fatal(err)
+	}
+	for len(bs) > 0 {
+		num, typ, n := protowire.ConsumeTag(bs)
+		if n < 0 || num != 1 || typ != protowire.BytesType {
+			t.Fatal("unexpected GeoSiteList field")
+		}
+		entry, m := protowire.ConsumeBytes(bs[n:])
+		if m < 0 {
+			t.Fatal(protowire.ParseError(m))
+		}
+		bs = bs[n+m:]
+
+		var site GeoSite
+		if err := proto.Unmarshal(entry, &site); err != nil {
+			t.Fatal(err)
+		}
+		queries := []string{"", "none"}
+		for _, d := range site.Domain {
+			for _, a := range d.Attribute {
+				if !slices.Contains(queries, a.Key) {
+					queries = append(queries, a.Key, a.Key+"@none")
+				}
+			}
+		}
+		for _, attrs := range queries {
+			checkDecodeSite(t, site.Code, entry, attrs)
+		}
+	}
+}
+
+func TestDecodeSiteUnusualEncodings(t *testing.T) {
+	field := func(num protowire.Number, v []byte) []byte {
+		return protowire.AppendBytes(protowire.AppendTag(nil, num, protowire.BytesType), v)
+	}
+	typ := func(v Domain_Type) []byte {
+		return protowire.AppendVarint(protowire.AppendTag(nil, 1, protowire.VarintType), uint64(v))
+	}
+	value := func(s string) []byte { return field(2, []byte(s)) }
+	attr := func(keys ...string) []byte {
+		var b []byte
+		for _, k := range keys {
+			b = append(b, field(1, []byte(k))...)
+		}
+		return field(3, b)
+	}
+	domain := func(fields ...[]byte) []byte { return field(2, slices.Concat(fields...)) }
+	unknown := protowire.AppendFixed32(protowire.AppendTag(nil, 9, protowire.Fixed32Type), 1)
+
+	for name, b := range map[string][]byte{
+		"unknown field":   domain(typ(Domain_Full), unknown, value("example.com")),
+		"repeated value":  domain(value("a.com"), typ(Domain_Full), value("b.com")),
+		"repeated type":   domain(typ(Domain_Full), value("a.com"), typ(Domain_Regex)),
+		"repeated key":    domain(value("a.com"), attr("cn", "ads")),
+		"type as bytes":   domain(field(1, []byte("x")), value("a.com")),
+		"no value":        domain(typ(Domain_Domain), attr("cn")),
+		"truncated":       domain(typ(Domain_Full), value("example.com"))[:10],
+		"invalid utf8":    domain(value("example.\xff")),
+		"invalid key":     domain(value("a.com"), attr("\xff")),
+		"bad field":       protowire.AppendVarint(protowire.AppendTag(nil, protowire.MaxValidNumber+1, protowire.VarintType), 1),
+		"stray end group": protowire.AppendTag(nil, 5, protowire.EndGroupType),
+	} {
+		for _, attrs := range []string{"", "cn", "ads", "cn@ads"} {
+			checkDecodeSite(t, name, b, attrs)
+		}
+	}
+}
+
+// TestLoadSiteReadsInPieces covers what real lists never do: an entry far longer than the read
+// buffer, with a field longer than the buffer in the middle, and a file cut short.
+func TestLoadSiteReadsInPieces(t *testing.T) {
+	site := &GeoSite{Code: "BIG"}
+	for i := range 5000 {
+		d := &Domain{Type: Domain_Domain, Value: strings.Repeat("x", i%40) + ".example.com"}
+		if i%3 == 0 {
+			d.Attribute = []*Domain_Attribute{{Key: "cn"}}
+		}
+		if i == 2500 {
+			d = &Domain{Type: Domain_Regex, Value: strings.Repeat("a", 100_000)}
+		}
+		site.Domain = append(site.Domain, d)
+	}
+	list := &GeoSiteList{Entry: []*GeoSite{{Code: "SMALL", Domain: []*Domain{{Type: Domain_Full, Value: "a.com"}}}, site}}
+	bs, err := proto.Marshal(list)
+	if err != nil {
+		t.Fatal(err)
+	}
+	entry, err := proto.Marshal(site)
+	if err != nil {
+		t.Fatal(err)
+	}
+	dir := t.TempDir()
+	t.Setenv("xray.location.asset", dir)
+	write := func(b []byte) {
+		if err := os.WriteFile(filepath.Join(dir, "big.dat"), b, 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	for _, attrs := range []string{"", "cn"} {
+		want, _ := unmarshalSite(entry, attrs)
+		var got []siteEntry
+		write(bs)
+		err := loadSite("big.dat", "BIG", attrs, func(typ Domain_Type, value []byte) {
+			got = append(got, siteEntry{typ, string(value)})
+		})
+		if err != nil || !slices.Equal(got, want) {
+			t.Fatalf("attrs %q: %d entries, want %d, error %v", attrs, len(got), len(want), err)
+		}
+		for _, cut := range []int{30_000, len(bs) - 150_000, len(bs) - 1} {
+			write(bs[:cut])
+			if err := loadSite("big.dat", "BIG", attrs, func(Domain_Type, []byte) {}); err == nil {
+				t.Fatalf("file cut at %d of %d: no error", cut, len(bs))
+			}
+		}
+	}
+}
+
+// oneEntryGeoSiteFile wraps an encoded GeoSite as a one-entry GeoSiteList, the file loadSite reads.
+func oneEntryGeoSiteFile(entry []byte) []byte {
+	return protowire.AppendBytes(protowire.AppendTag(nil, 1, protowire.BytesType), entry)
+}
+
+// TestLoadSiteWindowedMatchesSingleShot checks that the windowed reader in loadSite (its Peek/Discard
+// loop, the more-break when a field is cut by a window edge, the used==0 fallback for a field longer
+// than the buffer, and the tail path) reaches exactly the same result as decoding the whole entry at
+// once, for a category several 64 KiB windows long, valid and then mutated near a window edge and
+// early in the file: same error-or-not, and the same emitted (type, value) sequence when both accept.
+func TestLoadSiteWindowedMatchesSingleShot(t *testing.T) {
+	const window = 64 * 1024
+	site := &GeoSite{Code: "BIG"}
+	for i := range 12000 { // ~250 KiB, four windows
+		d := &Domain{Type: Domain_Domain, Value: fmt.Sprintf("host%d.%s.example.com", i, strings.Repeat("y", i%30))}
+		if i%3 == 0 {
+			d.Attribute = []*Domain_Attribute{{Key: "cn"}}
+		}
+		site.Domain = append(site.Domain, d)
+	}
+	// a field longer than the buffer, straddling the third window, to force the used==0 fallback
+	site.Domain = slices.Insert(site.Domain, 8000, &Domain{Type: Domain_Regex, Value: strings.Repeat("a", 90_000)})
+	entry, err := proto.Marshal(site)
+	if err != nil {
+		t.Fatal(err)
+	}
+	dir := t.TempDir()
+	t.Setenv("xray.location.asset", dir)
+
+	// mutations of the encoded entry: unchanged, a byte flipped at several offsets (early windows and
+	// either side of a window edge), and truncations at the same places.
+	type mut struct {
+		name string
+		make func([]byte) []byte
+	}
+	muts := []mut{{"valid", func(b []byte) []byte { return b }}}
+	for _, off := range []int{3, 40, 4000, window - 1, window, window + 1, 2*window - 2, 2 * window} {
+		if off < len(entry) {
+			off := off
+			muts = append(muts, mut{fmt.Sprintf("flip@%d", off), func(b []byte) []byte {
+				c := slices.Clone(b)
+				c[off] ^= 0xff
+				return c
+			}})
+			muts = append(muts, mut{fmt.Sprintf("cut@%d", off), func(b []byte) []byte { return slices.Clone(b[:off]) }})
+		}
+	}
+
+	for _, attrs := range []string{"", "cn"} {
+		for _, m := range muts {
+			e := m.make(entry)
+			// single-shot reference: decode the whole entry in one call
+			var want []siteEntry
+			_, wantErr := newSiteDecoder(attrs, func(typ Domain_Type, value []byte) {
+				want = append(want, siteEntry{typ, string(value)})
+			}).decode(e, false)
+			// windowed: loadSite reads the file 64 KiB at a time
+			if err := os.WriteFile(filepath.Join(dir, "w.dat"), oneEntryGeoSiteFile(e), 0o644); err != nil {
+				t.Fatal(err)
+			}
+			var got []siteEntry
+			gotErr := loadSite("w.dat", "BIG", attrs, func(typ Domain_Type, value []byte) {
+				got = append(got, siteEntry{typ, string(value)})
+			})
+			if (gotErr == nil) != (wantErr == nil) {
+				t.Fatalf("%s attrs=%q: windowed err %v, single-shot err %v", m.name, attrs, gotErr, wantErr)
+			}
+			if gotErr == nil && !slices.Equal(got, want) {
+				t.Fatalf("%s attrs=%q: windowed got %d entries, single-shot %d", m.name, attrs, len(got), len(want))
+			}
+		}
+	}
+}
+
+// TestLoadSiteLongCode covers a geosite entry whose code is longer than the 64 KiB read buffer. seek
+// must skip it (find compares a single length byte, so it never matches such a code) and still find a
+// later entry, and looking the long code up must fail cleanly, like a missing code, not panic.
+func TestLoadSiteLongCode(t *testing.T) {
+	longCode := strings.Repeat("Z", 70000)
+	list := &GeoSiteList{Entry: []*GeoSite{
+		{Code: "FIRST", Domain: []*Domain{{Type: Domain_Full, Value: "first.com"}}},
+		{Code: longCode, Domain: []*Domain{{Type: Domain_Full, Value: "huge.com"}}},
+		{Code: "AFTER", Domain: []*Domain{{Type: Domain_Domain, Value: "after.com"}}},
+	}}
+	bs, err := proto.Marshal(list)
+	if err != nil {
+		t.Fatal(err)
+	}
+	dir := t.TempDir()
+	t.Setenv("xray.location.asset", dir)
+	if err := os.WriteFile(filepath.Join(dir, "lc.dat"), bs, 0o644); err != nil {
+		t.Fatal(err)
+	}
+	collect := func(code string) ([]siteEntry, error) {
+		var got []siteEntry
+		err := loadSite("lc.dat", code, "", func(typ Domain_Type, value []byte) {
+			got = append(got, siteEntry{typ, string(value)})
+		})
+		return got, err
+	}
+	if got, err := collect("FIRST"); err != nil || !slices.Equal(got, []siteEntry{{Domain_Full, "first.com"}}) {
+		t.Fatalf("FIRST: %v %v", got, err)
+	}
+	if got, err := collect("AFTER"); err != nil || !slices.Equal(got, []siteEntry{{Domain_Domain, "after.com"}}) {
+		t.Fatalf("AFTER (past the oversized entry): %v %v", got, err)
+	}
+	if _, err := collect(longCode); err == nil {
+		t.Fatal("oversized code: expected a not-found error, got nil")
+	}
+}

common/geodata/lua.go

@@ -0,0 +1,163 @@
+package geodata
+
+import (
+	xlua "github.com/xtls/xray-core/common/lua"
+	"github.com/xtls/xray-core/common/net"
+	lua "github.com/yuin/gopher-lua"
+)
+
+// RegisterLua makes xray.geodata available to require in an LState.
+func RegisterLua(L *lua.LState) {
+	L.PreloadModule("xray.geodata", func(L *lua.LState) int {
+		module := L.CreateTable(0, 2)
+
+		module.RawSetString("BuildDomainMatcher", L.NewFunction(func(L *lua.LState) int {
+			parsed, err := ParseDomainRules(luaRules(L), Domain_Domain)
+			if err != nil {
+				L.RaiseError("%v", err)
+				return 0
+			}
+			matcher, err := DomainReg.BuildDomainMatcher(parsed)
+			if err != nil {
+				L.RaiseError("%v", err)
+				return 0
+			}
+			xlua.PushWithDirectMethods(L, matcher, map[string]xlua.DirectMethod{
+				"Match":    newLuaDomainMatch(xlua.NewSlicePusher[uint32](L)),
+				"MatchAny": luaDomainMatchAny,
+			})
+			return 1
+		}))
+
+		module.RawSetString("BuildIPMatcher", L.NewFunction(func(L *lua.LState) int {
+			parsed, err := ParseIPRules(luaRules(L))
+			if err != nil {
+				L.RaiseError("%v", err)
+				return 0
+			}
+			matcher, err := IPReg.BuildIPMatcher(parsed)
+			if err != nil {
+				L.RaiseError("%v", err)
+				return 0
+			}
+			xlua.PushWithDirectMethods(L, matcher, map[string]xlua.DirectMethod{
+				"Match":     luaIPMatch,
+				"AnyMatch":  luaIPAnyMatch,
+				"Matches":   luaIPMatches,
+				"FilterIPs": newLuaIPFilterIPs(xlua.NewSlicePusher[net.IP](L)),
+			})
+			return 1
+		}))
+
+		L.Push(module)
+		return 1
+	})
+}
+
+// Read native Go values by type assertion; slices keep their original storage.
+func readLuaIPMatcherArgs[T any](L *lua.LState) (IPMatcher, T, bool) {
+	var input T
+	if L.GetTop() != 2 {
+		return nil, input, false
+	}
+	value, ok := L.Get(1).(*lua.LUserData)
+	if !ok {
+		return nil, input, false
+	}
+	matcher, ok := value.Value.(IPMatcher)
+	if !ok {
+		return nil, input, false
+	}
+	if L.Get(2) == lua.LNil {
+		return matcher, input, true
+	}
+	value, ok = L.Get(2).(*lua.LUserData)
+	if !ok {
+		return nil, input, false
+	}
+	input, ok = value.Value.(T)
+	return matcher, input, ok
+}
+
+func luaIPMatch(L *lua.LState) (int, bool) {
+	matcher, ip, ok := readLuaIPMatcherArgs[net.IP](L)
+	if !ok {
+		return 0, false
+	}
+	L.Push(lua.LBool(matcher.Match(ip)))
+	return 1, true
+}
+
+func luaIPAnyMatch(L *lua.LState) (int, bool) {
+	matcher, ips, ok := readLuaIPMatcherArgs[[]net.IP](L)
+	if !ok {
+		return 0, false
+	}
+	L.Push(lua.LBool(matcher.AnyMatch(ips)))
+	return 1, true
+}
+
+func luaIPMatches(L *lua.LState) (int, bool) {
+	matcher, ips, ok := readLuaIPMatcherArgs[[]net.IP](L)
+	if !ok {
+		return 0, false
+	}
+	L.Push(lua.LBool(matcher.Matches(ips)))
+	return 1, true
+}
+
+func newLuaIPFilterIPs(pushIPs func(*lua.LState, []net.IP)) xlua.DirectMethod {
+	return func(L *lua.LState) (int, bool) {
+		matcher, ips, ok := readLuaIPMatcherArgs[[]net.IP](L)
+		if !ok {
+			return 0, false
+		}
+		matched, unmatched := matcher.FilterIPs(ips)
+		pushIPs(L, matched)
+		pushIPs(L, unmatched)
+		return 2, true
+	}
+}
+
+func newLuaDomainMatch(pushMatches func(*lua.LState, []uint32)) xlua.DirectMethod {
+	return func(L *lua.LState) (int, bool) {
+		if L.GetTop() == 2 {
+			if value, ok := L.Get(1).(*lua.LUserData); ok {
+				matcher, validMatcher := value.Value.(DomainMatcher)
+				domain, validDomain := L.Get(2).(lua.LString)
+				if validMatcher && validDomain {
+					pushMatches(L, matcher.Match(string(domain)))
+					return 1, true
+				}
+			}
+		}
+		return 0, false
+	}
+}
+
+func luaDomainMatchAny(L *lua.LState) (int, bool) {
+	if L.GetTop() == 2 {
+		if value, ok := L.Get(1).(*lua.LUserData); ok {
+			matcher, validMatcher := value.Value.(DomainMatcher)
+			domain, validDomain := L.Get(2).(lua.LString)
+			if validMatcher && validDomain {
+				L.Push(lua.LBool(matcher.MatchAny(string(domain))))
+				return 1, true
+			}
+		}
+	}
+	return 0, false
+}
+
+func luaRules(L *lua.LState) []string {
+	rules := make([]string, L.GetTop())
+	for i := range rules {
+		value, ok := L.Get(i + 1).(lua.LString)
+		if !ok {
+			L.RaiseError("geodata rules must be strings")
+			return nil
+		}
+		rules[i] = string(value)
+	}
+	return rules
+}

common/geodata/lua_test.go

@@ -0,0 +1,172 @@
+package geodata
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/xtls/xray-core/common/net"
+	lua "github.com/yuin/gopher-lua"
+)
+
+func TestLuaIPMatcher(t *testing.T) {
+	L := lua.NewState()
+	defer L.Close()
+	RegisterLua(L)
+	ip := L.NewUserData()
+	ip.Value = net.ParseIP("127.0.0.1")
+	L.SetGlobal("ip", ip)
+	ips := L.NewUserData()
+	ips.Value = []net.IP{ip.Value.(net.IP), net.ParseIP("8.8.8.8")}
+	L.SetGlobal("ips", ips)
+	if err := L.DoString(`
+		local matcher = require("xray.geodata").BuildIPMatcher("127.0.0.0/8", "::1")
+		assert(matcher:Match(ip))
+		assert(matcher:AnyMatch(ips))
+		assert(not matcher:Matches(ips))
+		local matched, unmatched = matcher:FilterIPs(ips)
+		assert(type(matched) == "userdata" and type(unmatched) == "userdata")
+		assert(#matched == 1 and #unmatched == 1)
+	`); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestLuaDomainMatcher(t *testing.T) {
+	L := lua.NewState()
+	defer L.Close()
+	RegisterLua(L)
+	if err := L.DoString(`
+		local matcher = require("xray.geodata").BuildDomainMatcher("example.com", "full:other.com")
+		assert(matcher:MatchAny("example.com"))
+		assert(matcher:MatchAny("www.example.com"))
+		assert(matcher:MatchAny("other.com"))
+		assert(not matcher:MatchAny("www.other.com"))
+		assert(#(matcher:Match("www.example.com")) == 1)
+	`); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestLuaMatchersRejectInvalidRules(t *testing.T) {
+	for _, tc := range []struct {
+		name   string
+		script string
+	}{
+		{"IP rule", `require("xray.geodata").BuildIPMatcher("not-an-ip")`},
+		{"non-string domain rule", `require("xray.geodata").BuildDomainMatcher("example.com", true)`},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			L := lua.NewState()
+			defer L.Close()
+			RegisterLua(L)
+			if err := L.DoString(tc.script); err == nil {
+				t.Fatal("invalid geodata rule was accepted")
+			}
+		})
+	}
+}
+
+func TestLuaMatcherArgumentsAndAliases(t *testing.T) {
+	L := lua.NewState()
+	defer L.Close()
+	RegisterLua(L)
+	ip := L.NewUserData()
+	ip.Value = net.ParseIP("127.0.0.1")
+	L.SetGlobal("ip", ip)
+	if err := L.DoString(`
+local geodata = require("xray.geodata")
+local matcher = geodata.BuildIPMatcher("127.0.0.0/8")
+assert(matcher.Match == matcher.match and matcher.AnyMatch == matcher.anyMatch)
+assert(matcher.Matches == matcher.matches and matcher.FilterIPs == matcher.filterIPs)
+assert(matcher:match(ip))
+assert(matcher:anyMatch({ip}) and matcher:matches({ip}))
+assert(not matcher:AnyMatch(nil))
+assert(matcher:Matches(nil) == matcher:Matches({}))
+local matched, unmatched = matcher:FilterIPs({ip})
+assert(#matched == 1 and matched[1]:Equal(ip))
+assert(matcher:AnyMatch(matched) and matcher:Matches(matched))
+local filtered, excluded = matcher:filterIPs(matched)
+assert(#filtered == 1 and #excluded == 0 and filtered[1]:Equal(ip))
+local emptyMatched, emptyUnmatched = matcher:FilterIPs(nil)
+assert(#emptyMatched == 0 and #emptyUnmatched == 0)
+matcher:SetReverse(true)
+assert(not matcher:Match(ip) and not matcher:AnyMatch(matched))
+matcher:ToggleReverse()
+assert(matcher:Match(ip) and matcher:AnyMatch(matched))
+assert(matcher.missing == nil)
+
+local domain = geodata.BuildDomainMatcher("full:example.com")
+assert(domain.Match == domain.match and domain.MatchAny == domain.matchAny)
+assert(domain:matchAny("example.com"))
+assert(#domain:Match("example.com") == 1)
+assert(domain:match("example.com")[1] == 0)
+assert(not pcall(function() matcher:AnyMatch() end))
+assert(not pcall(function() matcher:AnyMatch(matched, true) end))
+assert(not pcall(function() matcher.AnyMatch(ip, matched) end))
+assert(not pcall(function() matcher:Match(true) end))
+assert(not pcall(function() domain:MatchAny(123) end))
+assert(not pcall(function() domain:MatchAny("example.com", true) end))
+assert(not pcall(function() matcher:FilterIPs(true) end))
+assert(not pcall(function() matcher:FilterIPs(matched, true) end))
+assert(not pcall(function() domain:Match(123) end))
+assert(not pcall(function() domain:Match("example.com", true) end))
+`); err != nil {
+		t.Fatal(err)
+	}
+}
+
+// BenchmarkLuaMatcherCall measures repeated calls with prebuilt matchers and inputs.
+func BenchmarkLuaMatcherCall(b *testing.B) {
+	L := lua.NewState()
+	defer L.Close()
+	RegisterLua(L)
+	ip := net.ParseIP("127.0.0.1")
+	for name, value := range map[string]any{"ip": ip, "ips": []net.IP{ip}} {
+		ud := L.NewUserData()
+		ud.Value = value
+		L.SetGlobal(name, ud)
+	}
+	if err := L.DoString(`
+local geodata = require("xray.geodata")
+ipMatcher = geodata.BuildIPMatcher("127.0.0.0/8")
+domainMatcher = geodata.BuildDomainMatcher("full:example.com")
+`); err != nil {
+		b.Fatal(err)
+	}
+	for _, benchmark := range []struct {
+		name, expression string
+	}{
+		{"ip_match", "ipMatcher:Match(ip)"},
+		{"ip_match_lower", "ipMatcher:match(ip)"},
+		{"ip_any_match", "ipMatcher:AnyMatch(ips)"},
+		{"ip_any_match_lower", "ipMatcher:anyMatch(ips)"},
+		{"ip_matches", "ipMatcher:Matches(ips)"},
+		{"ip_matches_lower", "ipMatcher:matches(ips)"},
+		{"domain_match_any", `domainMatcher:MatchAny("example.com")`},
+		{"domain_match_any_lower", `domainMatcher:matchAny("example.com")`},
+		{"ip_filter", "select(1, ipMatcher:FilterIPs(ips)) ~= nil"},
+		{"ip_filter_lower", "select(1, ipMatcher:filterIPs(ips)) ~= nil"},
+		{"domain_match", `#domainMatcher:Match("example.com") == 1`},
+		{"domain_match_lower", `#domainMatcher:match("example.com") == 1`},
+		{"ip_lua_table", "ipMatcher:AnyMatch({ip})"},
+		{"ip_lua_table_lower", "ipMatcher:anyMatch({ip})"},
+	} {
+		b.Run(benchmark.name, func(b *testing.B) {
+			if err := L.DoString(fmt.Sprintf("function benchmarkMatch() return %s end", benchmark.expression)); err != nil {
+				b.Fatal(err)
+			}
+			fn := L.GetGlobal("benchmarkMatch")
+			b.ReportAllocs()
+			b.ResetTimer()
+			for i := 0; i < b.N; i++ {
+				if err := L.CallByParam(lua.P{Fn: fn, NRet: 1, Protect: true}); err != nil {
+					b.Fatal(err)
+				}
+				if L.Get(-1) != lua.LTrue {
+					b.Fatal("matcher returned false")
+				}
+				L.Pop(1)
+			}
+		})
+	}
+}

common/geodata/strmatcher/indexmatcher_mph.go

@@ -52,7 +52,9 @@ func (g *MphIndexMatcher) Add(matcher Matcher) uint32 {
 func (g *MphIndexMatcher) Build() error {
 	if g.mph != nil {
 		runtime.GC() // peak mem
-		g.mph.Build()
+		if err := g.mph.Build(); err != nil {
+			return err
+		}
 	}
 	runtime.GC() // peak mem
 	if g.ac != nil {
@@ -64,23 +66,17 @@ func (g *MphIndexMatcher) Build() error {
 
 // Match implements IndexMatcher.Match.
 func (g *MphIndexMatcher) Match(input string) []uint32 {
-	result := make([][]uint32, 0, 5)
+	var result []uint32
 	if g.mph != nil {
-		if matches := g.mph.Match(input); len(matches) > 0 {
-			result = append(result, matches)
-		}
+		result = g.mph.Match(input) // a new slice, returned without another copy
 	}
 	if g.ac != nil {
-		if matches := g.ac.Match(input); len(matches) > 0 {
-			result = append(result, matches)
-		}
+		result = append(result, g.ac.Match(input)...)
 	}
 	if g.regex != nil {
-		if matches := g.regex.Match(input); len(matches) > 0 {
-			result = append(result, matches)
-		}
+		result = append(result, g.regex.Match(input)...)
 	}
-	return CompositeMatches(result)
+	return result
 }
 
 // MatchAny implements IndexMatcher.MatchAny.

common/geodata/strmatcher/indexmatcher_mph_test.go

@@ -78,6 +78,10 @@ func TestMphIndexMatcher(t *testing.T) {
 			Input:  "example.com",
 			Output: []uint32{10, 4},
 		},
+		{
+			Input:  "apis.org",
+			Output: []uint32{2, 6},
+		},
 	}
 	matcherGroup := NewMphIndexMatcher()
 	for _, rule := range rules {
@@ -87,8 +91,13 @@ func TestMphIndexMatcher(t *testing.T) {
 	}
 	matcherGroup.Build()
 	for _, test := range cases {
-		if m := matcherGroup.Match(test.Input); !reflect.DeepEqual(m, test.Output) {
+		m := matcherGroup.Match(test.Input)
+		if !reflect.DeepEqual(m, test.Output) {
 			t.Error("unexpected output: ", m, " for test case ", test)
 		}
+		clear(m) // the caller owns the result, so this must not change the next one
+		if m := matcherGroup.Match(test.Input); !reflect.DeepEqual(m, test.Output) {
+			t.Error("unexpected output after clearing the previous one: ", m, " for test case ", test)
+		}
 	}
 }

common/geodata/strmatcher/matchergroup_mph.go

@@ -1,231 +1,440 @@
 package strmatcher
 
 import (
+	"bytes"
+	"cmp"
+	"encoding/binary"
 	"errors"
 	"math"
-	"math/bits"
-	"runtime"
-	"sort"
+	"slices"
 	"strings"
 	"unsafe"
 )
 
-// PrimeRK is the prime base used in Rabin-Karp algorithm.
-const PrimeRK = 16777619
-
-// RollingHash calculates the rolling murmurHash of given string based on a provided suffix hash.
-func RollingHash(hash uint32, input string) uint32 {
-	for i := len(input) - 1; i >= 0; i-- {
-		hash = hash*PrimeRK + uint32(input[i])
-	}
-	return hash
-}
-
-// MemHash is the hash function used by go map, it utilizes available hardware instructions(behaves
-// as aeshash if aes instruction is available).
-// With different seed, each MemHash<seed> performs as distinct hash functions.
-func MemHash(seed uint32, input string) uint32 {
-	return uint32(strhash(unsafe.Pointer(&input), uintptr(seed))) // nosemgrep
-}
-
+// Flags of a level1 slot, stored above the record offset.
 const (
-	mphMatchTypeCount = 2 // Full and Domain
+	mphDomain  = 1 << 31 // matches the pattern and its subdomains
+	mphFull    = 1 << 30 // matches the pattern only
+	mphParent  = 1 << 29 // matches subdomains only, from a pattern with a leading dot
+	mphOffMask = mphParent - 1
 )
 
-type mphRuleInfo struct {
-	rollingHash uint32
-	matchers    [mphMatchTypeCount][]uint32
+// Kinds of an added pattern, indexes of mphKinds.
+const (
+	mphKindFull = iota
+	mphKindParent
+	mphKindDomain
+)
+
+// mphKinds are the slot flags in the order Match reports their values.
+var mphKinds = [...]uint32{mphFull, mphParent, mphDomain}
+
+// mphMultipliers are odd multipliers for the suffix hash. Build moves to the next one if two patterns collide.
+var mphMultipliers = [...]uint64{0x9e3779b97f4a7c15, 0xc2b2ae3d27d4eb4f, 0x165667b19e3779f9, 0x27d4eb2f165667c5}
+
+var (
+	errMphCollision = errors.New("strmatcher: suffix hash collision in MphMatcherGroup")
+	errMphBuilt     = errors.New("strmatcher: MphMatcherGroup is already built")
+)
+
+type mphEntry struct {
+	off   uint32 // pattern start in buf
+	value uint32
+	n     uint32 // pattern length
+	kind  uint8
 }
 
-// MphMatcherGroup is an implementation of MatcherGroup.
-// It implements Rabin-Karp algorithm and minimal perfect hash table for Full and Domain matcher.
+// MphMatcherGroup is an implementation of MatcherGroup for Full and Domain matchers.
+// Each distinct pattern is stored once as a record in arena: its length (255 means a uvarint length follows),
+// its bytes and, if the group holds more than one distinct value, its values. A minimal perfect hash table
+// built with hash, displace and compress (http://cmph.sourceforge.net/papers/esa09.pdf) maps a pattern to its
+// record. Patterns are hashed from the right, so one pass over the input hashes all its parent domains.
 type MphMatcherGroup struct {
-	patterns    string   // All rule patterns concatenated
-	patternOffs []uint32 // RuleIdx -> patterns[patternOffs[i]:patternOffs[i+1]], index 0 reserved for failed lookup
-	values      []uint32 // All registered matcher values concatenated
-	valueOffs   []uint32 // RuleIdx -> values[valueOffs[i]:valueOffs[i+1]] (Full Matcher takes precedence)
-	level0      []uint32 // RollingHash & Mask -> seed for Memhash
-	level0Mask  uint32   // Mask restricting RollingHash to 0 ~ len(level0)
-	level1      []uint32 // Memhash<seed> & Mask -> stored index for rules
-	level1Mask  uint32   // Mask for restricting Memhash<seed> to 0 ~ len(level1)
-	rules       []string // RuleIdx -> pattern string, only used for building
-	ruleInfos   *map[string]mphRuleInfo
+	arena  string
+	level0 []uint16 // bucket -> seed
+	level1 []uint32 // slot -> flags | record offset
+	fp     []uint8  // slot -> low byte of its pattern's hash, rejects most misses without reading arena
+	n0, n1 uint32
+	mul    uint64 // multiplier of the suffix hash
+	single uint32 // the only value if !multi
+	multi  bool
+
+	buf     []byte // build only, patterns in Add order
+	entries []mphEntry
 }
 
 func NewMphMatcherGroup() *MphMatcherGroup {
-	return &MphMatcherGroup{
-		rules:      []string{""},
-		level0:     nil,
-		level0Mask: 0,
-		level1:     nil,
-		level1Mask: 0,
-		ruleInfos:  &map[string]mphRuleInfo{}, // Only used for building, destroyed after build complete
-	}
+	return new(MphMatcherGroup)
 }
 
 // AddFullMatcher implements MatcherGroupForFull.
 func (g *MphMatcherGroup) AddFullMatcher(matcher FullMatcher, value uint32) {
-	pattern := strings.ToLower(matcher.Pattern())
-	g.addPattern(0, "", pattern, matcher.Type(), value)
+	g.add(matcher.Pattern(), mphKindFull, value)
 }
 
 // AddDomainMatcher implements MatcherGroupForDomain.
 func (g *MphMatcherGroup) AddDomainMatcher(matcher DomainMatcher, value uint32) {
-	pattern := strings.ToLower(matcher.Pattern())
-	hash := g.addPattern(0, "", pattern, matcher.Type(), value) // For full domain match
-	g.addPattern(hash, pattern, ".", matcher.Type(), value)     // For partial domain match
+	g.add(matcher.Pattern(), mphKindDomain, value)
 }
 
-func (g *MphMatcherGroup) addPattern(suffixHash uint32, suffixPattern string, pattern string, matcherType Type, value uint32) uint32 {
-	fullPattern := pattern + suffixPattern
-	info, found := (*g.ruleInfos)[fullPattern]
-	if !found {
-		info = mphRuleInfo{rollingHash: RollingHash(suffixHash, pattern)}
-		g.rules = append(g.rules, fullPattern)
+func (g *MphMatcherGroup) add(pattern string, kind uint8, value uint32) {
+	if g.arena != "" {
+		panic(errMphBuilt)
+	}
+	pattern = strings.ToLower(pattern)
+	off := uint32(len(g.buf))
+	g.buf = append(g.buf, pattern...)
+	g.entries = append(g.entries, mphEntry{off: off, value: value, n: uint32(len(pattern)), kind: kind})
+	if len(pattern) > 0 && pattern[0] == '.' {
+		// ".x" has always matched "*.x" as well, so it also gets a parent-only record for "x"
+		g.entries = append(g.entries, mphEntry{off: off + 1, value: value, n: uint32(len(pattern) - 1), kind: mphKindParent})
 	}
-	info.matchers[matcherType] = append(info.matchers[matcherType], value)
-	(*g.ruleInfos)[fullPattern] = info
-	return info.rollingHash
 }
 
-// Build builds a minimal perfect hash table for insert rules.
-// Algorithm used: Hash, displace, and compress. See http://cmph.sourceforge.net/papers/esa09.pdf
+func (g *MphMatcherGroup) key(i uint32) []byte {
+	e := &g.entries[i]
+	return g.buf[e.off : e.off+e.n]
+}
+
+// Build builds the hash table. It must be called once, after the last Add.
 func (g *MphMatcherGroup) Build() error {
-	ruleCount := len(*g.ruleInfos)
-	g.level0 = make([]uint32, nextPow2(ruleCount/4))
-	g.level0Mask = uint32(len(g.level0) - 1)
-	g.level1 = make([]uint32, nextPow2(ruleCount))
-	g.level1Mask = uint32(len(g.level1) - 1)
-
-	// Flatten patterns and values so the built group has no per-rule objects
-	valueCount := 0
-	for _, ruleInfo := range *g.ruleInfos {
-		valueCount += len(ruleInfo.matchers[Full]) + len(ruleInfo.matchers[Domain])
+	if g.arena != "" {
+		return errMphBuilt
 	}
-	g.patterns = strings.Join(g.rules, "")
-	if uint64(len(g.patterns)) > math.MaxUint32 || uint64(valueCount) > math.MaxUint32 {
+	if uint64(len(g.buf)) > math.MaxUint32 {
 		return errors.New("too many rules for MphMatcherGroup")
 	}
-	g.patternOffs = make([]uint32, len(g.rules)+1)
-	g.values = make([]uint32, 0, valueCount)
-	g.valueOffs = make([]uint32, len(g.rules)+1)
-
-	// Create buckets based on all rule's rolling hash
-	buckets := make([][]uint32, len(g.level0))
-	for ruleIdx := 1; ruleIdx < len(g.rules); ruleIdx++ { // Traverse rules starting from index 1 (0 reserved for failed lookup)
-		ruleInfo := (*g.ruleInfos)[g.rules[ruleIdx]]
-		bucketIdx := ruleInfo.rollingHash & g.level0Mask
-		buckets[bucketIdx] = append(buckets[bucketIdx], uint32(ruleIdx))
-		g.patternOffs[ruleIdx+1] = g.patternOffs[ruleIdx] + uint32(len(g.rules[ruleIdx]))
-		g.values = append(append(g.values, ruleInfo.matchers[Full]...), ruleInfo.matchers[Domain]...)
-		g.valueOffs[ruleIdx+1] = uint32(len(g.values))
+	recs := g.writeRecords()
+	if len(g.arena) > mphOffMask {
+		return errors.New("too many rules for MphMatcherGroup")
 	}
-	g.rules = nil
-	g.ruleInfos = nil // Set ruleInfos nil to release memory
-	runtime.GC()      // peak mem
-
-	// Sort buckets in descending order with respect to each bucket's size
-	bucketIdxs := make([]int, len(buckets))
-	for bucketIdx := range buckets {
-		bucketIdxs[bucketIdx] = bucketIdx
+	hashes := make([]uint64, len(recs))
+	for _, mul := range mphMultipliers {
+		for i, rec := range recs {
+			hashes[i] = mphMix(mphHash(mul, g.recKey(rec)))
+		}
+		g.mul = mul
+		if err := g.place(recs, hashes); err != errMphCollision {
+			return err
+		}
 	}
-	sort.Slice(bucketIdxs, func(i, j int) bool { return len(buckets[bucketIdxs[i]]) > len(buckets[bucketIdxs[j]]) })
+	return errMphCollision
+}
 
-	// Exercise Hash, Displace, and Compress algorithm to construct minimal perfect hash table
-	occupied := make([]bool, len(g.level1)) // Whether a second-level hash has been already used
-	hashedBucket := make([]uint32, 0, 4)    // Second-level hashes for each rule in a specific bucket
-	for _, bucketIdx := range bucketIdxs {
-		bucket := buckets[bucketIdx]
-		hashedBucket = hashedBucket[:0]
-		seed := uint32(0)
-		for len(hashedBucket) != len(bucket) {
-			for _, ruleIdx := range bucket {
-				memHash := MemHash(seed, g.pattern(ruleIdx)) & g.level1Mask
-				if occupied[memHash] { // Collision occurred with this seed
-					for _, hash := range hashedBucket { // Revert all values in this hashed bucket
-						occupied[hash] = false
-						g.level1[hash] = 0
-					}
-					hashedBucket = hashedBucket[:0]
-					seed++ // Try next seed
-					break
-				}
-				occupied[memHash] = true
-				g.level1[memHash] = ruleIdx // The final value in the hash table
-				hashedBucket = append(hashedBucket, memHash)
+// writeRecords writes one record per distinct pattern to arena and returns flags | offset of each.
+func (g *MphMatcherGroup) writeRecords() []uint32 {
+	g.multi = false
+	if len(g.entries) > 0 {
+		g.single = g.entries[0].value
+		for _, e := range g.entries {
+			if e.value != g.single {
+				g.multi = true
+				break
 			}
 		}
-		g.level0[bucketIdx] = seed // Displacement value for this bucket
+	}
+	// Equal patterns become neighbours in Add order, so their values keep their priority
+	order := make([]uint32, len(g.entries))
+	for i := range order {
+		order[i] = uint32(i)
+	}
+	slices.SortFunc(order, func(a, b uint32) int {
+		return cmp.Or(bytes.Compare(g.key(a), g.key(b)), cmp.Compare(a, b))
+	})
+
+	size := len(g.buf) + len(g.entries) + 2
+	if g.multi {
+		size += 3 * len(g.entries)
+	}
+	arena := make([]byte, 0, size)
+	recs := make([]uint32, 0, len(order))
+	var vals [len(mphKinds)][]uint32
+	for i := 0; i < len(order); {
+		k := g.key(order[i])
+		for t := range vals {
+			vals[t] = vals[t][:0]
+		}
+		for ; i < len(order) && bytes.Equal(g.key(order[i]), k); i++ {
+			e := &g.entries[order[i]]
+			if !slices.Contains(vals[e.kind], e.value) {
+				vals[e.kind] = append(vals[e.kind], e.value)
+			}
+		}
+		rec := uint32(len(arena))
+		if len(k) < 255 {
+			arena = append(arena, byte(len(k)))
+		} else {
+			arena = binary.AppendUvarint(append(arena, 255), uint64(len(k)))
+		}
+		arena = append(arena, k...)
+		for t, v := range vals {
+			if len(v) == 0 {
+				continue
+			}
+			rec |= mphKinds[t]
+			if g.multi {
+				arena = binary.AppendUvarint(arena, uint64(len(v)))
+				for _, x := range v {
+					arena = binary.AppendUvarint(arena, uint64(x))
+				}
+			}
+		}
+		recs = append(recs, rec)
+	}
+	// Lookups may point one byte past a pattern, and an empty group needs a record at offset 0 for empty slots
+	arena = append(arena, 0)
+	if len(recs) == 0 {
+		arena = append(arena, 0)
+	}
+	g.buf, g.entries = nil, nil
+	if cap(arena)-len(arena) > len(arena)/32 {
+		arena = slices.Clone(arena)
+	}
+	g.arena = unsafe.String(unsafe.SliceData(arena), len(arena)) // arena is not written after this
+	return recs
+}
+
+// place fills level0, level1 and fp: records are bucketed by hash, and each bucket, largest first, gets
+// the first seed that puts all its records in free slots.
+func (g *MphMatcherGroup) place(recs []uint32, hashes []uint64) error {
+	r := len(recs)
+	n0, n1 := max(1, r/3), max(1, r+r/99)
+	g.n0, g.n1 = uint32(n0), uint32(n1)
+	g.level0 = make([]uint16, n0)
+	g.level1 = make([]uint32, n1)
+	g.fp = make([]uint8, n1)
+
+	start := make([]uint32, n0+1)
+	for _, h := range hashes {
+		start[g.bucket(h)+1]++
+	}
+	for b := range n0 {
+		start[b+1] += start[b]
+	}
+	members := make([]uint32, r)
+	fill := slices.Clone(start[:n0])
+	for i, h := range hashes {
+		b := g.bucket(h)
+		members[fill[b]] = uint32(i)
+		fill[b]++
+	}
+	fill = nil
+	buckets := make([]uint32, n0)
+	for b := range buckets {
+		buckets[b] = uint32(b)
+	}
+	slices.SortStableFunc(buckets, func(a, b uint32) int {
+		return cmp.Compare(start[b+1]-start[b], start[a+1]-start[a])
+	})
+
+	occupied := make([]uint64, (n1+63)/64)
+	var slots []uint32
+next:
+	for _, b := range buckets {
+		m := members[start[b]:start[b+1]]
+		if len(m) == 0 {
+			break
+		}
+		for i := range m {
+			for j := range i {
+				if hashes[m[i]] == hashes[m[j]] {
+					return errMphCollision // no seed can separate them
+				}
+			}
+		}
+	search:
+		for seed := range math.MaxUint16 + 1 {
+			slots = slots[:0]
+			for _, ri := range m {
+				s := g.slot(hashes[ri], uint16(seed))
+				if occupied[s/64]&(1<<(s%64)) != 0 || slices.Contains(slots, s) {
+					continue search
+				}
+				slots = append(slots, s)
+			}
+			for k, ri := range m {
+				s := slots[k]
+				occupied[s/64] |= 1 << (s % 64)
+				g.level1[s] = recs[ri]
+				g.fp[s] = uint8(hashes[ri])
+			}
+			g.level0[b] = uint16(seed)
+			continue next
+		}
+		return errors.New("strmatcher: no seed found for a bucket in MphMatcherGroup")
 	}
 	return nil
 }
 
-func (g *MphMatcherGroup) pattern(ruleIdx uint32) string {
-	return g.patterns[g.patternOffs[ruleIdx]:g.patternOffs[ruleIdx+1]]
+// mphHash is the suffix hash of s, taken from the right: the hash of s[i:] is the state after reading s[i].
+func mphHash(mul uint64, s string) uint64 {
+	h := uint64(0)
+	for i := len(s) - 1; i >= 0; i-- {
+		h = h*mul + uint64(s[i])
+	}
+	return h
 }
 
-// valuesOf caps the capacity, so appending to a Match result can't overwrite the next rule's values.
-func (g *MphMatcherGroup) valuesOf(ruleIdx uint32) []uint32 {
-	start, end := g.valueOffs[ruleIdx], g.valueOffs[ruleIdx+1]
-	return g.values[start:end:end]
+// mphMix spreads the weak low bits of a suffix hash.
+func mphMix(h uint64) uint64 {
+	h ^= h >> 32
+	h *= 0xd6e8feb86659fd93
+	return h ^ h>>32
 }
 
-// Lookup searches for input in minimal perfect hash table and returns its index. 0 indicates not found.
-func (g *MphMatcherGroup) Lookup(rollingHash uint32, input string) uint32 {
-	i0 := rollingHash & g.level0Mask
-	seed := g.level0[i0]
-	i1 := MemHash(seed, input) & g.level1Mask
-	n := g.level1[i1]
-	// Build only puts valid rule indices in level1, so n+1 < len(patternOffs) and the span is inside patterns.
-	// Skip the bounds checks, they made this hot path measurably slower than indexing a []string
-	offs := (*[2]uint32)(unsafe.Add(unsafe.Pointer(unsafe.SliceData(g.patternOffs)), uintptr(n)*4))
-	if start := offs[0]; int(offs[1]-start) == len(input) && unsafe.String((*byte)(unsafe.Add(unsafe.Pointer(unsafe.StringData(g.patterns)), start)), len(input)) == input {
-		return n
+func (g *MphMatcherGroup) bucket(f uint64) uint32 {
+	return uint32(((f >> 32) * uint64(g.n0)) >> 32)
+}
+
+func (g *MphMatcherGroup) slot(f uint64, seed uint16) uint32 {
+	x := ((f ^ uint64(seed)*0x9e3779b97f4a7c15) * 0xc4ceb9fe1a85ec53) >> 32
+	return uint32((x * uint64(g.n1)) >> 32)
+}
+
+func (g *MphMatcherGroup) uvarint(p uint32) (x, next uint32) {
+	for shift := 0; ; shift += 7 {
+		c := g.arena[p]
+		p++
+		x |= uint32(c&0x7f) << shift
+		if c < 0x80 {
+			return x, p
+		}
+	}
+}
+
+// recSpan returns where the pattern of the record at off starts and how long it is.
+func (g *MphMatcherGroup) recSpan(off uint32) (p, n uint32) {
+	n, p = uint32(g.arena[off]), off+1
+	if n == 255 {
+		n, p = g.uvarint(p)
+	}
+	return p, n
+}
+
+func (g *MphMatcherGroup) recKey(rec uint32) string {
+	p, n := g.recSpan(rec & mphOffMask)
+	return g.arena[p : p+n]
+}
+
+// lookup returns the level1 entry of s, or 0 if s is not a pattern. h is the suffix hash of s.
+func (g *MphMatcherGroup) lookup(h uint64, s string) uint32 {
+	f := mphMix(h)
+	// bucket < n0 == len(level0) and slot < n1 == len(level1) == len(fp), skip the bounds checks
+	seed := *(*uint16)(unsafe.Add(unsafe.Pointer(unsafe.SliceData(g.level0)), uintptr(g.bucket(f))*2))
+	slot := uintptr(g.slot(f, seed))
+	if *(*uint8)(unsafe.Add(unsafe.Pointer(unsafe.SliceData(g.fp)), slot)) != uint8(f) {
+		return 0
+	}
+	e := *(*uint32)(unsafe.Add(unsafe.Pointer(unsafe.SliceData(g.level1)), slot*4))
+	if len(s) < 255 {
+		// A record whose length byte is len(s) has len(s) pattern bytes after it
+		p := unsafe.Add(unsafe.Pointer(unsafe.StringData(g.arena)), e&mphOffMask)
+		if int(*(*byte)(p)) == len(s) && unsafe.String((*byte)(unsafe.Add(p, 1)), len(s)) == s {
+			return e
+		}
+		return 0
+	}
+	if g.recKey(e) == s {
+		return e
 	}
 	return 0
 }
 
-// Match implements MatcherGroup.Match.
-func (g *MphMatcherGroup) Match(input string) []uint32 {
-	matches := make([][]uint32, 0, 5)
-	hash := uint32(0)
-	for i := len(input) - 1; i >= 0; i-- {
-		hash = hash*PrimeRK + uint32(input[i])
-		if input[i] == '.' {
-			if mphIdx := g.Lookup(hash, input[i:]); mphIdx != 0 {
-				matches = append(matches, g.valuesOf(mphIdx))
+// appendValues appends the values of record e for the flags in want, in mphKinds order.
+func (g *MphMatcherGroup) appendValues(dst []uint32, e, want uint32) []uint32 {
+	if !g.multi {
+		for _, flag := range mphKinds {
+			if e&want&flag != 0 {
+				dst = append(dst, g.single)
+			}
+		}
+		return dst
+	}
+	if e&want == 0 {
+		return dst
+	}
+	p, n := g.recSpan(e & mphOffMask)
+	p += n
+	for _, flag := range mphKinds {
+		if e&flag == 0 {
+			continue
+		}
+		var count, v uint32
+		for count, p = g.uvarint(p); count > 0; count-- {
+			v, p = g.uvarint(p)
+			if want&flag != 0 {
+				dst = append(dst, v)
 			}
 		}
 	}
-	if mphIdx := g.Lookup(hash, input); mphIdx != 0 {
-		matches = append(matches, g.valuesOf(mphIdx))
+	return dst
+}
+
+// Match implements MatcherGroup.Match. Values of an exact match come first (Full, then Domain), then those of
+// the parent domains, nearest first.
+func (g *MphMatcherGroup) Match(input string) []uint32 {
+	var stack [8]uint32
+	parents := stack[:0] // TLD side first
+	h, mul := uint64(0), g.mul
+	for i := len(input) - 1; i >= 0; i-- {
+		if input[i] == '.' {
+			if e := g.lookup(h, input[i+1:]); e&(mphDomain|mphParent) != 0 {
+				parents = append(parents, e)
+			}
+		}
+		h = h*mul + uint64(input[i])
 	}
-	return CompositeMatchesReverse(matches)
+	exact := g.lookup(h, input)
+	if exact&(mphFull|mphDomain) == 0 && len(parents) == 0 {
+		return nil
+	}
+	result := g.appendValues(make([]uint32, 0, len(parents)+1), exact, mphFull|mphDomain)
+	for k := len(parents) - 1; k >= 0; k-- {
+		result = g.appendValues(result, parents[k], mphParent|mphDomain)
+	}
+	return result
 }
 
 // MatchAny implements MatcherGroup.MatchAny.
 func (g *MphMatcherGroup) MatchAny(input string) bool {
-	hash := uint32(0)
+	h, mul := uint64(0), g.mul
+	for i := len(input) - 1; i >= 0; i-- {
+		if input[i] == '.' && g.lookup(h, input[i+1:])&(mphDomain|mphParent) != 0 {
+			return true
+		}
+		h = h*mul + uint64(input[i])
+	}
+	return g.lookup(h, input)&(mphFull|mphDomain) != 0
+}
+
+// mphSuffix is the suffix hash of input[off:], a parent domain of the input.
+type mphSuffix struct {
+	h   uint64
+	off int
+}
+
+// mphSuffixes appends the suffix hashes of the parent domains of input to dst, TLD side first, and returns them
+// with the hash of input itself: what MatchAny computes, computed once for several groups.
+func mphSuffixes(dst []mphSuffix, mul uint64, input string) ([]mphSuffix, uint64) {
+	h := uint64(0)
 	for i := len(input) - 1; i >= 0; i-- {
-		hash = hash*PrimeRK + uint32(input[i])
 		if input[i] == '.' {
-			if g.Lookup(hash, input[i:]) != 0 {
-				return true
-			}
+			dst = append(dst, mphSuffix{h, i + 1})
+		}
+		h = h*mul + uint64(input[i])
+	}
+	return dst, h
+}
+
+// matchAnyHashed is MatchAny with parents and h from mphSuffixes(_, mul, input).
+func (g *MphMatcherGroup) matchAnyHashed(input string, parents []mphSuffix, h, mul uint64) bool {
+	if g.mul != mul {
+		return g.MatchAny(input) // built with a later multiplier after a collision
+	}
+	for _, p := range parents {
+		if g.lookup(p.h, input[p.off:])&(mphDomain|mphParent) != 0 {
+			return true
 		}
 	}
-	return g.Lookup(hash, input) != 0
+	return g.lookup(h, input)&(mphFull|mphDomain) != 0
 }
-
-func nextPow2(v int) int {
-	if v <= 1 {
-		return 1
-	}
-	const MaxUInt = ^uint(0)
-	n := (MaxUInt >> bits.LeadingZeros(uint(v))) + 1
-	return int(n)
-}
-
-//go:noescape
-//go:linkname strhash runtime.strhash
-func strhash(p unsafe.Pointer, h uintptr) uintptr

common/geodata/strmatcher/matchergroup_mph_internal_test.go

@@ -0,0 +1,108 @@
+package strmatcher
+
+import (
+	"slices"
+	"testing"
+)
+
+func TestMphMatcherGroupHashCollision(t *testing.T) {
+	saved := mphMultipliers
+	defer func() { mphMultipliers = saved }()
+
+	mphMultipliers[0] = 1 // anagrams collide
+	g := NewMphMatcherGroup()
+	g.AddFullMatcher(FullMatcher("ab.com"), 1)
+	g.AddDomainMatcher(DomainMatcher("ba.com"), 2)
+	g.AddDomainMatcher(DomainMatcher("com"), 3)
+	if err := g.Build(); err != nil {
+		t.Fatal(err)
+	}
+	if g.mul != saved[1] {
+		t.Errorf("multiplier %#x, want the second one %#x", g.mul, saved[1])
+	}
+	for input, want := range map[string][]uint32{"ab.com": {1, 3}, "x.ba.com": {2, 3}, "x.ab.com": {3}, "ba.com": {2, 3}} {
+		if m := g.Match(input); !slices.Equal(m, want) {
+			t.Errorf("Match(%q) = %v, want %v", input, m, want)
+		}
+	}
+
+	// Thue-Morse strings of 2048 bytes and their complements collide for every odd multiplier
+	mphMultipliers = saved
+	a, b := make([]byte, 2048), make([]byte, 2048)
+	for i := range a {
+		a[i], b[i] = "ab"[bitsOnes(i)%2], "ba"[bitsOnes(i)%2]
+	}
+	g = NewMphMatcherGroup()
+	g.AddFullMatcher(FullMatcher(a), 1)
+	g.AddFullMatcher(FullMatcher(b), 1)
+	if err := g.Build(); err != errMphCollision {
+		t.Errorf("Build() = %v, want %v", err, errMphCollision)
+	}
+}
+
+func bitsOnes(i int) int {
+	n := 0
+	for ; i > 0; i &= i - 1 {
+		n++
+	}
+	return n
+}
+
+func TestMphValueMatcherCombiner(t *testing.T) {
+	build := func(matchers ...Matcher) *MphValueMatcher {
+		m := NewMphValueMatcher()
+		for _, x := range matchers {
+			m.Add(x, 0)
+		}
+		if err := m.Build(); err != nil {
+			t.Fatal(err)
+		}
+		return m
+	}
+	regex, err := Regex.New(`^a\d+\.net$`)
+	if err != nil {
+		t.Fatal(err)
+	}
+	saved := mphMultipliers
+	t.Cleanup(func() { mphMultipliers = saved })
+	mphMultipliers[0] = 1 // anagrams collide, so this one falls back to its own hash pass
+	collided := build(FullMatcher("ab.com"), DomainMatcher("ba.com"))
+	mphMultipliers = saved
+	if collided.mph.mul == mphMultipliers[0] {
+		t.Fatal("collided matcher uses the first multiplier")
+	}
+	matchers := []*MphValueMatcher{
+		build(DomainMatcher("example.com"), FullMatcher("full.org"), DomainMatcher(".dot.io")),
+		collided,
+		build(regex, SubstrMatcher("keyword")),
+		build(),
+		build(DomainMatcher("com"), DomainMatcher("a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s")),
+	}
+	var s MphValueMatcherCombiner
+	for i, m := range matchers {
+		s.Add(m, uint32(10+i))
+	}
+	inputs := []string{
+		"", ".", "..", "com", "example.com", "www.example.com", "xexample.com", "example.com.", "full.org", "x.full.org",
+		"dot.io", "x.dot.io", ".dot.io", "ab.com", "x.ab.com", "ba.com", "x.ba.com", "a12.net", "a12.net.x", "my-keyword.org",
+		"a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s", "0.a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s", "b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s",
+		"x.y.z.1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16.17.ab.com", "x.y.z.1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16.17.org",
+	}
+	for _, input := range inputs {
+		var want []uint32
+		for i, m := range matchers {
+			if m.MatchAny(input) {
+				want = append(want, uint32(10+i))
+			}
+		}
+		if got := s.Match(input); !slices.Equal(got, want) {
+			t.Errorf("Match(%q) = %v, want %v", input, got, want)
+		}
+		if got := s.MatchAny(input); got != (len(want) > 0) {
+			t.Errorf("MatchAny(%q) = %v", input, got)
+		}
+	}
+	if n := testing.AllocsPerRun(100, func() { s.MatchAny("www.a.b.c.example.org") }); n != 0 {
+		t.Errorf("MatchAny allocates %v times", n)
+	}
+}

common/geodata/strmatcher/matchergroup_mph_test.go

@@ -4,6 +4,7 @@ import (
 	"math/rand"
 	"reflect"
 	"slices"
+	"strings"
 	"testing"
 
 	"github.com/xtls/xray-core/common"
@@ -304,7 +305,7 @@ func TestMphMatcherGroupRandom(t *testing.T) {
 				domain["."+p] = append(domain["."+p], value)
 			}
 		}
-		g.Build()
+		common.Must(g.Build())
 		for _, input := range inputs {
 			keys := []string{input} // Whole input first, then "." suffixes from longest to shortest
 			for i := range len(input) {
@@ -316,7 +317,10 @@ func TestMphMatcherGroupRandom(t *testing.T) {
 			for _, k := range keys {
 				want = append(append(want, full[k]...), domain[k]...)
 			}
-			if m := g.Match(input); !slices.Equal(m, want) {
+			// Compared as sets: Match reports a value once per matching pattern, and orders them differently
+			// from want for patterns and inputs with a leading dot
+			m := g.Match(input)
+			if !slices.Equal(sortedSet(m), sortedSet(want)) {
 				t.Fatalf("seed %d: Match(%q) = %v, want %v", seed, input, m, want)
 			}
 			if m := g.MatchAny(input); m != (len(want) > 0) {
@@ -338,3 +342,79 @@ func TestMphMatcherGroupAppend(t *testing.T) {
 		t.Error("expect [2], but ", m)
 	}
 }
+
+func sortedSet(v []uint32) []uint32 {
+	v = slices.Clone(v)
+	slices.Sort(v)
+	return slices.Compact(v)
+}
+
+func TestMphMatcherGroupLongPattern(t *testing.T) {
+	long := strings.Repeat("a", 300) + ".com"
+	for _, values := range [][4]uint32{{1, 2, 3, 4}, {7, 7, 7, 7}} {
+		g := NewMphMatcherGroup()
+		g.AddDomainMatcher(DomainMatcher(long), values[0])
+		g.AddFullMatcher(FullMatcher("x."+long), values[1])
+		g.AddFullMatcher(FullMatcher(long[:255]), values[2]) // the shortest pattern stored with a long length
+		g.AddFullMatcher(FullMatcher(long[:254]), values[3])
+		common.Must(g.Build())
+		cases := []struct {
+			input string
+			want  []uint32
+		}{
+			{long, []uint32{values[0]}},
+			{"www." + long, []uint32{values[0]}},
+			{"x." + long, []uint32{values[1], values[0]}},
+			{long[1:], nil},
+			{"a" + long, nil},
+			{long[:255], []uint32{values[2]}},
+			{long[:254], []uint32{values[3]}},
+			{long[:256], nil},
+			{long[:253], nil},
+		}
+		for _, c := range cases {
+			if m := g.Match(c.input); !slices.Equal(m, c.want) {
+				t.Errorf("Match(%d bytes) = %v, want %v", len(c.input), m, c.want)
+			}
+			if m := g.MatchAny(c.input); m != (c.want != nil) {
+				t.Errorf("MatchAny(%d bytes) = %v", len(c.input), m)
+			}
+		}
+	}
+
+	// A pattern longer than 65535 bytes builds and matches: a record's length is a uvarint,
+	// so the only cap was the build-time length field, now widened to uint32.
+	huge := strings.Repeat("a", 70000)
+	g := NewMphMatcherGroup()
+	g.AddFullMatcher(FullMatcher(strings.Repeat("a", 65535)), 1)
+	g.AddDomainMatcher(DomainMatcher(huge+".com"), 2)
+	g.AddFullMatcher(FullMatcher("a.com"), 3)
+	common.Must(g.Build())
+	if !g.MatchAny(strings.Repeat("a", 65535)) || g.MatchAny(strings.Repeat("a", 65534)) {
+		t.Error("wrong answer for a 65535-byte pattern")
+	}
+	if m := g.Match(huge + ".com"); !slices.Equal(m, []uint32{2}) {
+		t.Errorf("Match(%d-byte input) = %v, want [2]", len(huge)+4, m)
+	}
+	if m := g.Match("x." + huge + ".com"); !slices.Equal(m, []uint32{2}) {
+		t.Errorf("Match(subdomain of a %d-byte pattern) = %v, want [2]", len(huge)+4, m)
+	}
+	if g.MatchAny(huge) { // the 70000-byte label on its own is not a rule
+		t.Error("unexpected match for the bare 70000-byte label")
+	}
+}
+
+func TestMphMatcherGroupBuildOnce(t *testing.T) {
+	g := NewMphMatcherGroup()
+	g.AddFullMatcher(FullMatcher("a.com"), 1)
+	common.Must(g.Build())
+	if err := g.Build(); err == nil || !g.MatchAny("a.com") {
+		t.Errorf("second Build() = %v, MatchAny(a.com) = %v", err, g.MatchAny("a.com"))
+	}
+	defer func() {
+		if recover() == nil {
+			t.Error("Add after Build did not panic")
+		}
+	}()
+	g.AddDomainMatcher(DomainMatcher("b.com"), 2)
+}

common/geodata/strmatcher/matchers.go

@@ -2,10 +2,12 @@ package strmatcher
 
 import (
 	"errors"
+	"math/bits"
 	"regexp"
 	"regexp/syntax"
 	"slices"
 	"strings"
+	"unicode"
 	"unicode/utf8"
 
 	"golang.org/x/net/idna"
@@ -75,7 +77,9 @@ func (m SubstrMatcher) Match(s string) bool {
 // RegexMatcher is an implementation of Matcher.
 type RegexMatcher struct {
 	pattern  *regexp.Regexp
-	literals []string // every match contains all of them, longest first
+	literals []string  // every match contains all of them, longest first
+	tail     []byteSet // tail[i] holds the bytes a matching input can have i bytes before its end
+	rest     *byteSet  // the bytes it can have further before, nil if any
 }
 
 func newRegexMatcher(pattern string) (Matcher, error) {
@@ -87,10 +91,239 @@ func newRegexMatcher(pattern string) (Matcher, error) {
 	if re, err := syntax.Parse(pattern, syntax.Perl); err == nil { // same flags as regexp.Compile
 		m.literals = requiredLiterals(re, nil)
 		slices.SortStableFunc(m.literals, func(a, b string) int { return len(b) - len(a) })
+		m.tail, m.rest = tailGuard(re)
 	}
 	return m, nil
 }
 
+// byteSet is a set of bytes. The bytes >= 0x80 share one bit with 0x7f.
+type byteSet [4]uint32
+
+func (s *byteSet) add(c byte)      { c = min(c, 0x7f); s[c>>5] |= 1 << (c & 31) }
+func (s *byteSet) has(c byte) bool { c = min(c, 0x7f); return s[c>>5]&(1<<(c&31)) != 0 }
+func (s *byteSet) or(t *byteSet) {
+	for i := range s {
+		s[i] |= t[i]
+	}
+}
+
+var allBytes = byteSet{^uint32(0), ^uint32(0), ^uint32(0), ^uint32(0)}
+
+// tailLen is how many positions before the end of the input tailGuard tells apart.
+const tailLen = 8
+
+// tailBudget caps how many repetition steps tailGuard walks. Only nested repeats can make the
+// walk explode, so only they are charged: a flat pattern, however long, is walked once and keeps
+// its guard.
+const tailBudget = 100000
+
+// tailWalk is a set of positions in the input, counted in bytes before its end.
+type tailWalk struct {
+	at   uint32 // bit i: exactly i bytes before the end, for i < tailLen
+	far  bool   // tailLen or more bytes before the end
+	free bool   // not tied to the end of the input yet
+}
+
+func (w tailWalk) union(v tailWalk) tailWalk {
+	return tailWalk{w.at | v.at, w.far || v.far, w.free || v.free}
+}
+
+type tailBuilder struct {
+	tail [tailLen]byteSet
+	rest byteSet
+	void bool
+	work int
+}
+
+// tailGuard walks re backwards from the end of the input and collects the bytes an input
+// matching re can have at each position before its end. It returns nil, nil when a branch
+// of re does not end with $ or when nested repeats push the walk past tailBudget.
+func tailGuard(re *syntax.Regexp) ([]byteSet, *byteSet) {
+	var b tailBuilder
+	w := b.walk(re, tailWalk{free: true})
+	b.stop(w)
+	if b.void {
+		return nil, nil
+	}
+	if w.at != 0 { // a match can start here, so any bytes can come before
+		for i := bits.TrailingZeros32(w.at); i < tailLen; i++ {
+			b.tail[i] = allBytes
+		}
+	}
+	if w.at != 0 || w.far {
+		b.rest = allBytes
+	}
+	n := tailLen
+	for n > 0 && b.tail[n-1] == b.rest {
+		n--
+	}
+	var tail []byteSet
+	if n > 0 {
+		tail = slices.Clone(b.tail[:n])
+	}
+	if b.rest != allBytes {
+		rest := b.rest
+		return tail, &rest
+	}
+	return tail, nil
+}
+
+// stop ends the paths of w. One that never met $ lets its match be followed by anything.
+func (b *tailBuilder) stop(w tailWalk) {
+	if w.free {
+		b.void = true
+	}
+}
+
+func (b *tailBuilder) walk(re *syntax.Regexp, w tailWalk) tailWalk {
+	if w == (tailWalk{}) || b.void {
+		return w
+	}
+	switch re.Op {
+	case syntax.OpNoMatch:
+		return tailWalk{}
+	case syntax.OpLiteral:
+		for i := len(re.Rune) - 1; i >= 0; i-- {
+			var set byteSet
+			set.add(byte(min(re.Rune[i], utf8.RuneSelf)))
+			if re.Flags&syntax.FoldCase != 0 {
+				for f := unicode.SimpleFold(re.Rune[i]); f != re.Rune[i]; f = unicode.SimpleFold(f) {
+					set.add(byte(min(f, utf8.RuneSelf)))
+				}
+			}
+			w = b.step(w, &set)
+		}
+		return w
+	case syntax.OpCharClass:
+		var set byteSet
+		for i := 0; i+1 < len(re.Rune); i += 2 {
+			for r := min(re.Rune[i], utf8.RuneSelf); r <= min(re.Rune[i+1], utf8.RuneSelf); r++ {
+				set.add(byte(r))
+			}
+		}
+		return b.step(w, &set)
+	case syntax.OpAnyChar, syntax.OpAnyCharNotNL: // a domain has no \n to reject
+		return b.step(w, &allBytes)
+	case syntax.OpBeginText: // nothing comes before
+		b.stop(w)
+		return tailWalk{}
+	case syntax.OpEndText:
+		out := tailWalk{at: w.at & 1}
+		if w.free {
+			out.at = 1
+		}
+		return out
+	case syntax.OpCapture:
+		return b.walk(re.Sub[0], w)
+	case syntax.OpConcat:
+		for i := len(re.Sub) - 1; i >= 0; i-- {
+			w = b.walk(re.Sub[i], w)
+		}
+		return w
+	case syntax.OpAlternate:
+		var out tailWalk
+		for _, sub := range re.Sub {
+			out = out.union(b.walk(sub, w))
+		}
+		return out
+	case syntax.OpQuest:
+		return b.repeat(re.Sub[0], w, 1)
+	case syntax.OpStar:
+		return b.repeat(re.Sub[0], w, -1)
+	case syntax.OpPlus:
+		return b.repeat(re.Sub[0], b.walk(re.Sub[0], w), -1)
+	case syntax.OpRepeat:
+		for i := 0; i < re.Min; i++ {
+			if b.charge() {
+				return w
+			}
+			w = b.walk(re.Sub[0], w)
+		}
+		if re.Max < 0 {
+			return b.repeat(re.Sub[0], w, -1)
+		}
+		return b.repeat(re.Sub[0], w, re.Max-re.Min)
+	}
+	return w // empty match, line and word boundaries: no constraint
+}
+
+// charge counts one repetition step and reports whether the walk has run out of budget. Only
+// repeats re-walk their body, so charging them alone bounds the blow-up of nested repeats while
+// leaving a single linear pass, of any length, free.
+func (b *tailBuilder) charge() bool {
+	b.work++
+	if b.work > tailBudget {
+		b.void = true
+	}
+	return b.void
+}
+
+// repeat walks back over up to n more repetitions of re, any number if n < 0.
+func (b *tailBuilder) repeat(re *syntax.Regexp, w tailWalk, n int) tailWalk {
+	for ; n != 0; n-- {
+		if b.charge() {
+			return w
+		}
+		next := w.union(b.walk(re, w))
+		if next == w {
+			break
+		}
+		w = next
+	}
+	return w
+}
+
+// step walks back over one character whose last byte is in set. A character that can be
+// non-ASCII can take up to 4 bytes, all >= 0x80; regexp matches an invalid byte as U+FFFD.
+func (b *tailBuilder) step(w tailWalk, set *byteSet) tailWalk {
+	out := tailWalk{far: w.far, free: w.free}
+	if w.far {
+		b.rest.or(set)
+	}
+	width := 1
+	if set.has(0x80) {
+		width = utf8.UTFMax
+	}
+	for i := 0; i < tailLen; i++ {
+		if w.at&(1<<i) == 0 {
+			continue
+		}
+		b.tail[i].or(set)
+		for n := 1; n <= width; n++ {
+			if j := i + n; j < tailLen {
+				out.at |= 1 << j
+				if n < width {
+					b.tail[j].add(0x80)
+				}
+			} else {
+				out.far = true
+				if n < width {
+					b.rest.add(0x80)
+				}
+			}
+		}
+	}
+	return out
+}
+
+// mayMatch reports whether s passes the tail guard.
+func (m *RegexMatcher) mayMatch(s string) bool {
+	n := len(s)
+	if m.rest == nil {
+		n = min(n, len(m.tail))
+	}
+	for i := 0; i < n; i++ {
+		set := m.rest
+		if i < len(m.tail) {
+			set = &m.tail[i]
+		}
+		if !set.has(s[len(s)-1-i]) {
+			return false
+		}
+	}
+	return true
+}
+
 // requiredLiterals appends to dst the case-sensitive strings that every match of re contains.
 func requiredLiterals(re *syntax.Regexp, dst []string) []string {
 	switch re.Op {
@@ -126,6 +359,9 @@ func (m *RegexMatcher) String() string {
 }
 
 func (m *RegexMatcher) Match(s string) bool {
+	if !m.mayMatch(s) {
+		return false
+	}
 	for _, l := range m.literals {
 		if !strings.Contains(s, l) {
 			return false

common/geodata/strmatcher/matchers_regex_test.go

@@ -1,9 +1,16 @@
 package strmatcher
 
 import (
+	"hash/fnv"
+	"math/rand/v2"
 	"regexp"
+	"regexp/syntax"
 	"slices"
+	"strconv"
+	"strings"
 	"testing"
+	"unicode"
+	"unicode/utf8"
 )
 
 var regexLiteralCases = []struct {
@@ -37,6 +44,147 @@ func TestRegexRequiredLiterals(t *testing.T) {
 	}
 }
 
+var regexTailCases = []struct {
+	pattern string
+	guard   bool
+	match   []string // inputs the pattern matches
+	reject  []string // inputs the tail guard alone rejects
+}{
+	{`^[a-z]([a-z0-9-]{0,61}[a-z0-9])?$`, true, []string{"a", "localhost", "x-1"}, []string{"www.example.com", "localhost.", "LOCALHOST", "a b"}},
+	{`(^|\.)[a-z][1-9][0-9][a-z]\.com$`, true, []string{"a12b.com", "x.q10z.com"}, []string{"google.com", "a12b.co", "a12b.com.", "ab12.com"}},
+	{`^hses[1-7]?\.akamaized\.net$`, true, []string{"hses.akamaized.net", "hses3.akamaized.net"}, []string{"xhses.akamaized.net", "www.hses.akamaized.net"}},
+	{`(?i)k\.net$`, true, []string{"k.net", "K.NET", "\u212a.net"}, []string{"x.net", "k.nex"}},
+	{`[^.]+\.cn$`, true, []string{"a.cn", "\xff.cn", "\u4e2d.cn"}, []string{"a.cnn", "a.c"}},
+	{`\x{FFFD}$`, true, []string{"\xff", "a\xc3", "\uFFFD"}, []string{"a", "\xff."}},
+	{`^.\.cn$`, true, []string{"a.cn", "\u4E2D.cn", "\xff.cn"}, []string{"ab.cn"}},
+	{`^$`, true, []string{""}, []string{"a"}},
+	{`(^|\.)youyuapi\..+$`, false, []string{"youyuapi.com"}, nil},
+	{`abc`, false, []string{"abc", "xabcx"}, nil},
+	{`^ab`, false, []string{"ab", "abc"}, nil},
+	{`a$|b`, false, []string{"a", "bx"}, nil},
+	{`(?m)a$`, false, []string{"a", "a\nb"}, nil},
+	{strings.Repeat(`(?:abcdefgh(?:a`, 20) + strings.Repeat(`)*)*`, 20) + `\.com$`, false, []string{".com", "abcdefgha.com"}, nil}, // over tailBudget
+}
+
+func TestRegexTailGuard(t *testing.T) {
+	for _, test := range regexTailCases {
+		m, err := newRegexMatcher(test.pattern)
+		if err != nil {
+			t.Fatal(err)
+		}
+		rm := m.(*RegexMatcher)
+		if guard := rm.tail != nil || rm.rest != nil; guard != test.guard {
+			t.Errorf("%s: guard %v, want %v", test.pattern, guard, test.guard)
+		}
+		for _, s := range test.match {
+			if !rm.pattern.MatchString(s) || !rm.Match(s) {
+				t.Errorf("%s: %q does not match", test.pattern, s)
+			}
+		}
+		for _, s := range test.reject {
+			if rm.pattern.MatchString(s) || rm.mayMatch(s) {
+				t.Errorf("%s: %q passes the guard", test.pattern, s)
+			}
+		}
+	}
+}
+
+// TestRegexTailGuardFlatAlternation checks that a long but non-recursive pattern keeps its
+// guard. Only nested repeats are charged against tailBudget, so a flat alternation of many
+// names, however large, is walked once and guarded; its guard is checked against regexp.
+func TestRegexTailGuardFlatAlternation(t *testing.T) {
+	var sb strings.Builder
+	sb.WriteString("(?:")
+	for i := 0; i < 20000; i++ {
+		if i > 0 {
+			sb.WriteByte('|')
+		}
+		sb.WriteString("name")
+		sb.WriteString(strconv.Itoa(i))
+	}
+	sb.WriteString(`)\.example\.com$`)
+	m, err := newRegexMatcher(sb.String())
+	if err != nil {
+		t.Fatal(err)
+	}
+	rm := m.(*RegexMatcher)
+	if rm.tail == nil && rm.rest == nil {
+		t.Fatal("flat alternation of 20000 names lost its guard")
+	}
+	for _, s := range []string{"name0.example.com", "name19999.example.com", "x.name12345.example.com"} {
+		if !rm.pattern.MatchString(s) || !rm.Match(s) {
+			t.Errorf("%q should match", s)
+		}
+	}
+	for _, s := range []string{"name0.example.org", "name0.example.com.", "name0.example.con", "google.com"} {
+		if rm.pattern.MatchString(s) {
+			t.Fatalf("test bug: %q matches the pattern", s)
+		}
+		if rm.mayMatch(s) {
+			t.Errorf("%q should be rejected by the guard", s)
+		}
+	}
+}
+
+// sampleMatch appends a string that re matches, assertions aside, unless it runs out of
+// budget, which it spends one per call so that nested repeats stay cheap.
+func sampleMatch(sb *strings.Builder, re *syntax.Regexp, rnd *rand.Rand, budget *int) {
+	if *budget <= 0 {
+		return
+	}
+	*budget--
+	switch re.Op {
+	case syntax.OpLiteral:
+		for _, r := range re.Rune {
+			if re.Flags&syntax.FoldCase != 0 {
+				for n := rnd.IntN(4); n > 0; n-- {
+					r = unicode.SimpleFold(r)
+				}
+			}
+			sampleRune(sb, r, rnd)
+		}
+	case syntax.OpCharClass:
+		if len(re.Rune) > 0 {
+			i := rnd.IntN(len(re.Rune)/2) * 2
+			sampleRune(sb, re.Rune[i]+rnd.Int32N(min(re.Rune[i+1]-re.Rune[i]+1, 300)), rnd)
+		}
+	case syntax.OpAnyChar, syntax.OpAnyCharNotNL:
+		sampleRune(sb, []rune{'a', '.', '\n', 0xe9, 0x212a, utf8.RuneError}[rnd.IntN(6)], rnd)
+	case syntax.OpCapture:
+		sampleMatch(sb, re.Sub[0], rnd, budget)
+	case syntax.OpConcat:
+		for _, sub := range re.Sub {
+			sampleMatch(sb, sub, rnd, budget)
+		}
+	case syntax.OpAlternate:
+		sampleMatch(sb, re.Sub[rnd.IntN(len(re.Sub))], rnd, budget)
+	case syntax.OpQuest, syntax.OpStar, syntax.OpPlus, syntax.OpRepeat:
+		lo, hi := 0, 3
+		switch re.Op {
+		case syntax.OpQuest:
+			hi = 1
+		case syntax.OpPlus:
+			lo = 1
+		case syntax.OpRepeat:
+			lo, hi = re.Min, re.Min+3
+			if re.Max >= 0 {
+				hi = min(hi, re.Max)
+			}
+		}
+		for n := lo + rnd.IntN(hi-lo+1); n > 0; n-- {
+			sampleMatch(sb, re.Sub[0], rnd, budget)
+		}
+	}
+}
+
+func sampleRune(sb *strings.Builder, r rune, rnd *rand.Rand) {
+	if r == utf8.RuneError && rnd.IntN(2) == 0 {
+		sb.WriteByte(0x80 | byte(rnd.IntN(0x80))) // regexp matches an invalid byte as U+FFFD
+		return
+	}
+	sb.WriteRune(r)
+}
+
 func FuzzRegexMatcher(f *testing.F) {
 	inputs := []string{
 		"", "x", "yy", "abd", "ccc", "ABC", "abCDef", "abcdef", "abababcc", "a.b", "a\xffb", "a\uFFFDb",
@@ -47,14 +195,39 @@ func FuzzRegexMatcher(f *testing.F) {
 			f.Add(test.pattern, s)
 		}
 	}
+	for _, test := range regexTailCases {
+		for _, s := range append(test.match, test.reject...) {
+			f.Add(test.pattern, s)
+		}
+	}
 	f.Fuzz(func(t *testing.T, pattern, s string) {
 		re, err := regexp.Compile(pattern)
 		if err != nil {
 			return
 		}
 		m, _ := newRegexMatcher(pattern)
-		if got, want := m.Match(s), re.MatchString(s); got != want {
-			t.Errorf("pattern %q, input %q: got %v, want %v", pattern, s, got, want)
+		check := func(s string) {
+			if got, want := m.Match(s), re.MatchString(s); got != want {
+				t.Errorf("pattern %q, input %q: got %v, want %v", pattern, s, got, want)
+			}
+		}
+		check(s)
+		// random inputs seldom match, so also try strings built from the pattern
+		parsed, _ := syntax.Parse(pattern, syntax.Perl)
+		h := fnv.New64a()
+		h.Write([]byte(s))
+		rnd := rand.New(rand.NewPCG(h.Sum64(), 1))
+		for range 8 {
+			var sb strings.Builder
+			budget := 256
+			sampleMatch(&sb, parsed, rnd, &budget)
+			sample := sb.String()
+			check(sample)
+			check(s + sample)
+			if len(sample) > 0 && len(s) > 0 {
+				i := rnd.IntN(len(sample))
+				check(sample[:i] + s[:1] + sample[i+1:])
+			}
 		}
 	})
 }

common/geodata/strmatcher/valuematcher_mph.go

@@ -46,7 +46,9 @@ func (g *MphValueMatcher) Add(matcher Matcher, value uint32) {
 func (g *MphValueMatcher) Build() error {
 	if g.mph != nil {
 		runtime.GC() // peak mem
-		g.mph.Build()
+		if err := g.mph.Build(); err != nil {
+			return err
+		}
 	}
 	runtime.GC() // peak mem
 	if g.ac != nil {
@@ -58,23 +60,17 @@ func (g *MphValueMatcher) Build() error {
 
 // Match implements ValueMatcher.Match.
 func (g *MphValueMatcher) Match(input string) []uint32 {
-	result := make([][]uint32, 0, 5)
+	var result []uint32
 	if g.mph != nil {
-		if matches := g.mph.Match(input); len(matches) > 0 {
-			result = append(result, matches)
-		}
+		result = g.mph.Match(input) // a new slice, returned without another copy
 	}
 	if g.ac != nil {
-		if matches := g.ac.Match(input); len(matches) > 0 {
-			result = append(result, matches)
-		}
+		result = append(result, g.ac.Match(input)...)
 	}
 	if g.regex != nil {
-		if matches := g.regex.Match(input); len(matches) > 0 {
-			result = append(result, matches)
-		}
+		result = append(result, g.regex.Match(input)...)
 	}
-	return CompositeMatches(result)
+	return result
 }
 
 // MatchAny implements ValueMatcher.MatchAny.
@@ -87,3 +83,62 @@ func (g *MphValueMatcher) MatchAny(input string) bool {
 	}
 	return g.regex != nil && g.regex.MatchAny(input)
 }
+
+func (g *MphValueMatcher) matchAnyHashed(input string, parents []mphSuffix, h, mul uint64) bool {
+	if g.mph != nil && g.mph.matchAnyHashed(input, parents, h, mul) {
+		return true
+	}
+	if g.ac != nil && g.ac.MatchAny(input) {
+		return true
+	}
+	return g.regex != nil && g.regex.MatchAny(input)
+}
+
+// MphValueMatcherCombiner combines several built MphValueMatchers, each bound to one value, and matches an input
+// against them as their MatchAny would, hashing the input once for all of them.
+type MphValueMatcherCombiner struct {
+	matchers []*MphValueMatcher
+	values   []uint32
+}
+
+// Add adds a built matcher that stands for value.
+func (s *MphValueMatcherCombiner) Add(m *MphValueMatcher, value uint32) {
+	s.matchers = append(s.matchers, m)
+	s.values = append(s.values, value)
+}
+
+// Match returns the values of the matchers that match input, in Add order.
+func (s *MphValueMatcherCombiner) Match(input string) []uint32 {
+	if len(s.matchers) == 0 {
+		return nil
+	}
+	var stack [16]mphSuffix
+	mul := mphMultipliers[0]
+	parents, h := mphSuffixes(stack[:0], mul, input)
+	var result []uint32
+	for i, m := range s.matchers {
+		if m.matchAnyHashed(input, parents, h, mul) {
+			result = append(result, s.values[i])
+		}
+	}
+	return result
+}
+
+// MatchAny returns true as soon as one matcher matches input.
+func (s *MphValueMatcherCombiner) MatchAny(input string) bool {
+	switch len(s.matchers) {
+	case 0:
+		return false
+	case 1:
+		return s.matchers[0].MatchAny(input) // nothing to share, and it stops at the first matching suffix
+	}
+	var stack [16]mphSuffix
+	mul := mphMultipliers[0]
+	parents, h := mphSuffixes(stack[:0], mul, input)
+	for _, m := range s.matchers {
+		if m.matchAnyHashed(input, parents, h, mul) {
+			return true
+		}
+	}
+	return false
+}

common/log/lua.go

@@ -0,0 +1,61 @@
+package log
+
+import (
+	"path/filepath"
+	"strings"
+
+	lua "github.com/yuin/gopher-lua"
+)
+
+// RegisterLua makes xray.log available to require in an LState.
+func RegisterLua(L *lua.LState) {
+	L.PreloadModule("xray.log", func(L *lua.LState) int {
+		module := L.CreateTable(0, 4)
+		var source, prefix string // cache
+		for name, severity := range map[string]Severity{
+			"Debug":   Severity_Debug,
+			"Info":    Severity_Info,
+			"Warning": Severity_Warning,
+			"Error":   Severity_Error,
+		} {
+			module.RawSetString(name, L.NewFunction(func(L *lua.LState) int {
+				if GetSeverity() < severity {
+					return 0
+				}
+				var content strings.Builder
+				// Prefix with the calling script's filename.
+				if caller, ok := L.GetStack(1); ok {
+					if _, err := L.GetInfo("S", caller, lua.LNil); err == nil && caller.Source != "" {
+						if caller.Source != source {
+							source = caller.Source
+							prefix = filepath.Base(strings.TrimPrefix(source, "@")) + ": "
+						}
+						content.WriteString(prefix)
+					}
+				}
+				for i := 1; i <= L.GetTop(); i++ {
+					content.WriteString(luaLogString(L, L.Get(i)))
+				}
+				Record(&GeneralMessage{
+					Severity: severity,
+					Content:  content.String(),
+				})
+				return 0
+			}))
+		}
+		L.Push(module)
+		return 1
+	})
+}
+
+func luaLogString(L *lua.LState, value lua.LValue) string {
+	if ud, ok := value.(*lua.LUserData); ok {
+		if err, ok := ud.Value.(error); ok {
+			return err.Error()
+		}
+	}
+	if _, ok := L.GetMetaField(value, "__tostring").(*lua.LFunction); ok {
+		return L.ToStringMeta(value).String()
+	}
+	return value.String()
+}

common/log/lua_test.go

@@ -0,0 +1,213 @@
+package log
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+
+	lua "github.com/yuin/gopher-lua"
+)
+
+type luaLogHandler struct {
+	messages []Message
+}
+
+func (h *luaLogHandler) Handle(msg Message) {
+	h.messages = append(h.messages, msg)
+}
+
+func TestLuaLog(t *testing.T) {
+	previous := logHandler.Load()
+	t.Cleanup(func() { logHandler.Store(previous) })
+	handler := &luaLogHandler{}
+	RegisterHandler(handler)
+
+	L := lua.NewState()
+	defer L.Close()
+	RegisterLua(L)
+	nativeError := L.NewUserData()
+	nativeError.Value = fmt.Errorf("lookup failed: %w", errors.New("upstream timeout"))
+	L.SetGlobal("nativeError", nativeError)
+	path := filepath.Join(t.TempDir(), "logging.lua")
+	if err := os.WriteFile(path, []byte(`
+		local log = require("xray.log")
+		assert(log == require("xray.log"))
+		log.Debug("query: ", "example.com")
+		log.Info("count=", 42, ", enabled=", true, ", value=", nil)
+		log.Warning(setmetatable({}, {
+			__tostring = function() return "fallback" end
+		}))
+		assert(select("#", log.Error("failed")) == 0)
+		log.Error("DNS failed: ", nativeError)
+		log.Warning(nativeError)
+		local ok, err = pcall(function() error("Lua failure", 0) end)
+		assert(not ok)
+		log.Error(err)
+		local calls = 0
+		local custom = setmetatable({}, {
+			__tostring = function() calls = calls + 1; return "custom" end
+		})
+		log.Info(custom, custom)
+		assert(calls == 2)
+		log.Info("a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l")
+		log.Info()
+		function logHook()
+			log.Info("hook")
+		end
+	`), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	if err := L.DoFile(path); err != nil {
+		t.Fatal(err)
+	}
+	if err := L.DoString(`
+		logHook()
+		require("xray.log").Info("anonymous")
+	`); err != nil {
+		t.Fatal(err)
+	}
+	other := filepath.Join(t.TempDir(), "other.lua")
+	if err := os.WriteFile(other, []byte(`
+		local log = require("xray.log")
+		log.Info("other")
+		logHook()
+		log.Info("other again")
+	`), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	if err := L.DoFile(other); err != nil {
+		t.Fatal(err)
+	}
+
+	want := []struct {
+		severity Severity
+		message  string
+	}{
+		{Severity_Debug, "[Debug] logging.lua: query: example.com"},
+		{Severity_Info, "[Info] logging.lua: count=42, enabled=true, value=nil"},
+		{Severity_Warning, "[Warning] logging.lua: fallback"},
+		{Severity_Error, "[Error] logging.lua: failed"},
+		{Severity_Error, "[Error] logging.lua: DNS failed: lookup failed: upstream timeout"},
+		{Severity_Warning, "[Warning] logging.lua: lookup failed: upstream timeout"},
+		{Severity_Error, "[Error] logging.lua: Lua failure"},
+		{Severity_Info, "[Info] logging.lua: customcustom"},
+		{Severity_Info, "[Info] logging.lua: abcdefghijkl"},
+		{Severity_Info, "[Info] logging.lua: "},
+		{Severity_Info, "[Info] logging.lua: hook"},
+		{Severity_Info, "[Info] <string>: anonymous"},
+		{Severity_Info, "[Info] other.lua: other"},
+		{Severity_Info, "[Info] logging.lua: hook"},
+		{Severity_Info, "[Info] other.lua: other again"},
+	}
+	if len(handler.messages) != len(want) {
+		t.Fatalf("logged %d messages, want %d", len(handler.messages), len(want))
+	}
+	for i, expected := range want {
+		msg, ok := handler.messages[i].(*GeneralMessage)
+		if !ok {
+			t.Fatalf("message %d has type %T, want *GeneralMessage", i, handler.messages[i])
+		}
+		if msg.Severity != expected.severity || msg.String() != expected.message {
+			t.Errorf("message %d = %q with severity %v, want %q with severity %v", i, msg.String(), msg.Severity, expected.message, expected.severity)
+		}
+	}
+}
+
+type luaSeverityLogHandler struct {
+	luaLogHandler
+	level Severity
+}
+
+func (h *luaSeverityLogHandler) Severity() Severity { return h.level }
+
+func TestLuaLogSeverity(t *testing.T) {
+	previous := logHandler.Load()
+	t.Cleanup(func() { logHandler.Store(previous) })
+	L := lua.NewState()
+	defer L.Close()
+	RegisterLua(L)
+	for _, level := range []Severity{Severity_Unknown, Severity_Error, Severity_Warning, Severity_Info, Severity_Debug, Severity_Warning} {
+		t.Run(level.String(), func(t *testing.T) {
+			handler := &luaSeverityLogHandler{level: level}
+			RegisterHandler(handler)
+			want := []Severity{}
+			for _, severity := range []Severity{Severity_Error, Severity_Warning, Severity_Info, Severity_Debug} {
+				if severity <= level {
+					want = append(want, severity)
+				}
+			}
+			if err := L.DoString(fmt.Sprintf(`
+				local log = require("xray.log")
+				local calls = 0
+				local value = setmetatable({}, {
+					__tostring = function() calls = calls + 1; return "message" end
+				})
+				for _, write in ipairs({log.Error, log.Warning, log.Info, log.Debug}) do
+					assert(select("#", write(value)) == 0)
+				end
+				assert(calls == %d)
+			`, len(want))); err != nil {
+				t.Fatal(err)
+			}
+			if len(handler.messages) != len(want) {
+				t.Fatalf("logged %d messages, want %d", len(handler.messages), len(want))
+			}
+			for i, severity := range want {
+				msg := handler.messages[i].(*GeneralMessage)
+				if msg.Severity != severity || msg.Content != "<string>: message" {
+					t.Errorf("message %d = %v, want severity %v and content %q", i, msg, severity, "<string>: message")
+				}
+			}
+		})
+	}
+}
+
+type luaDiscardLogHandler struct{ level Severity }
+
+func (luaDiscardLogHandler) Handle(Message)       {}
+func (h luaDiscardLogHandler) Severity() Severity { return h.level }
+
+func BenchmarkLuaLog(b *testing.B) {
+	benchmarkLuaLog(b, Severity_Debug)
+}
+
+func BenchmarkLuaLogFiltered(b *testing.B) {
+	benchmarkLuaLog(b, Severity_Warning)
+}
+
+func benchmarkLuaLog(b *testing.B, level Severity) {
+	previous := logHandler.Load()
+	b.Cleanup(func() { logHandler.Store(previous) })
+	RegisterHandler(luaDiscardLogHandler{level: level})
+	L := lua.NewState()
+	defer L.Close()
+	RegisterLua(L)
+	if err := L.DoString(`custom = setmetatable({}, {__tostring = function() return "custom" end})`); err != nil {
+		b.Fatal(err)
+	}
+	for _, benchmark := range []struct {
+		name, arguments string
+	}{
+		{"strings", `"query: ", "example.com"`},
+		{"mixed", `"count=", 42, ", enabled=", true, ", value=", nil`},
+		{"many_arguments", `"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l"`},
+		{"tostring", "custom"},
+	} {
+		b.Run(benchmark.name, func(b *testing.B) {
+			if err := L.DoString(fmt.Sprintf(`local log = require("xray.log")
+function benchmarkLog() log.Info(%s) end`, benchmark.arguments)); err != nil {
+				b.Fatal(err)
+			}
+			fn := L.GetGlobal("benchmarkLog")
+			b.ReportAllocs()
+			b.ResetTimer()
+			for i := 0; i < b.N; i++ {
+				if err := L.CallByParam(lua.P{Fn: fn, NRet: 0, Protect: true}); err != nil {
+					b.Fatal(err)
+				}
+			}
+		})
+	}
+}

common/lua/lua.go

@@ -0,0 +1,3 @@
+// Package lua provides shared GopherLua programs, state management, and value
+// conversion and validation helpers for Xray scripts.
+package lua

common/lua/luar.go

@@ -0,0 +1,65 @@
+package lua
+
+import (
+	glua "github.com/yuin/gopher-lua"
+	luar "layeh.com/gopher-luar"
+)
+
+// NewSlicePusher captures luar's slice metatable during state initialization.
+// The returned function wraps slices without reflection or metatable lookup,
+// and pushes nil for nil slices. Use it with this state or its coroutines.
+func NewSlicePusher[T any](L *glua.LState) func(*glua.LState, []T) {
+	metatable := luar.New(L, []T{}).(*glua.LUserData).Metatable
+	return func(L *glua.LState, values []T) {
+		if values == nil {
+			L.Push(glua.LNil)
+			return
+		}
+		userdata := L.NewUserData()
+		userdata.Value = values
+		userdata.Metatable = metatable
+		L.Push(userdata)
+	}
+}
+
+// DirectMethod handles a Lua call without luar's reflected method invocation.
+// It returns the result count and whether it handled the arguments. On false,
+// it must leave the stack unchanged for the original luar wrapper.
+type DirectMethod func(L *glua.LState) (nresults int, handled bool)
+
+// PushWithDirectMethods pushes a luar userdata with typed Go method bindings.
+// Handled calls bypass luar's argument conversion and reflect.Call; method lookup
+// uses the methods table directly instead of luar's reflected __index handler.
+// value must expose methods only. Bindings and their closures are installed once
+// per Go type per LState, outside the method-call hot path.
+func PushWithDirectMethods(L *glua.LState, value any, directMethods map[string]DirectMethod) {
+	userdata := luar.New(L, value).(*glua.LUserData)
+	metatable := userdata.Metatable.(*glua.LTable)
+	methods := metatable.RawGetString("methods").(*glua.LTable)
+	if metatable.RawGetString("__index") != methods {
+		for name, direct := range directMethods {
+			original := methods.RawGetString(name)
+			fn := L.NewFunction(func(L *glua.LState) int {
+				if nresults, handled := direct(L); handled {
+					return nresults
+				}
+				return callLuarMethod(L, original)
+			})
+			// Keep luar's method aliases on the same direct binding.
+			for key, method := methods.Next(glua.LNil); key != glua.LNil; key, method = methods.Next(key) {
+				if method == original {
+					methods.RawSet(key, fn)
+				}
+			}
+		}
+		metatable.RawSetString("__index", methods)
+	}
+	L.Push(userdata)
+}
+
+func callLuarMethod(L *glua.LState, method glua.LValue) int {
+	nargs := L.GetTop()
+	L.Insert(method, 1)
+	L.Call(nargs, glua.MultRet)
+	return L.GetTop()
+}

common/lua/luar_test.go

@@ -0,0 +1,84 @@
+package lua
+
+import (
+	"net"
+	"testing"
+
+	glua "github.com/yuin/gopher-lua"
+	luar "layeh.com/gopher-luar"
+)
+
+func TestSlicePusher(t *testing.T) {
+	L := glua.NewState()
+	defer L.Close()
+	push := NewSlicePusher[int](L)
+	values := []int{3, 5}
+	L.SetGlobal("getValues", L.NewFunction(func(L *glua.LState) int {
+		push(L, values)
+		return 1
+	}))
+	if err := L.DoString(`
+local values = getValues()
+assert(#values == 2 and values[1] == 3 and values[2] == 5)
+values[2] = 7
+local co = coroutine.create(function()
+    local values = getValues()
+    assert(#values == 2 and values[1] == 3 and values[2] == 7)
+    return true
+end)
+local ok, result = coroutine.resume(co)
+assert(ok and result == true)
+`); err != nil {
+		t.Fatal(err)
+	}
+	if values[1] != 7 {
+		t.Fatal("slice storage was copied")
+	}
+	push(L, nil)
+	if L.Get(-1) != glua.LNil {
+		t.Fatal("nil slice must push Lua nil")
+	}
+	L.Pop(1)
+	push(L, []int{})
+	L.SetGlobal("empty", L.Get(-1))
+	L.Pop(1)
+	if err := L.DoString(`assert(type(empty) == "userdata" and #empty == 0)`); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestSlicePusherMetatablePerState(t *testing.T) {
+	first := glua.NewState()
+	defer first.Close()
+	second := glua.NewState()
+	defer second.Close()
+	NewSlicePusher[int](first)(first, []int{1})
+	NewSlicePusher[int](second)(second, []int{1})
+	if first.Get(-1).(*glua.LUserData).Metatable == second.Get(-1).(*glua.LUserData).Metatable {
+		t.Fatal("independent states share a slice metatable")
+	}
+}
+
+func BenchmarkSlicePusher(b *testing.B) {
+	L := glua.NewState()
+	defer L.Close()
+	ips := []net.IP{net.ParseIP("127.0.0.1")}
+	pushIPs := NewSlicePusher[net.IP](L)
+	for _, benchmark := range []struct {
+		name string
+		push func(*glua.LState, []net.IP)
+	}{
+		{"bare", func(L *glua.LState, ips []net.IP) { PushUserData(L, ips) }},
+		{"luar", func(L *glua.LState, ips []net.IP) { L.Push(luar.New(L, ips)) }},
+		{"cached", pushIPs},
+	} {
+		b.Run(benchmark.name, func(b *testing.B) {
+			b.ReportAllocs()
+			b.ResetTimer()
+			for i := 0; i < b.N; i++ {
+				benchmark.push(L, ips)
+				L.Pop(1)
+			}
+		})
+	}
+}

common/lua/pool.go

@@ -0,0 +1,151 @@
+package lua
+
+import (
+	"context"
+	"errors"
+	"sync"
+	"time"
+
+	glua "github.com/yuin/gopher-lua"
+)
+
+const maxIdleStates = 16
+
+// Pool lends each state to one caller at a time. It grows on contention and
+// keeps up to maxIdleStates idle states until Close. Acquire/Release callers
+// decide reusability; WithState uses its callback's error.
+type Pool struct {
+	ctx     context.Context
+	cancel  context.CancelFunc
+	timeout time.Duration
+
+	factory LStateFactory
+	idle    []*glua.LState
+	top     int
+
+	mu     sync.Mutex
+	active sync.WaitGroup
+	closed bool
+}
+
+// NewPool tests the factory by creating one state during initialization.
+func NewPool(ctx context.Context, timeout time.Duration, factory LStateFactory) (*Pool, error) {
+	if timeout <= 0 {
+		return nil, errors.New("Lua pool timeout must be positive")
+	}
+
+	poolCtx, cancel := context.WithCancel(ctx)
+
+	state, err := factory(poolCtx)
+	if err != nil {
+		cancel()
+		return nil, err
+	}
+
+	return &Pool{ctx: poolCtx, cancel: cancel, timeout: timeout, factory: factory, idle: []*glua.LState{state}, top: state.GetTop()}, nil
+}
+
+// Acquire returns an initialized exclusive state, growing the pool if necessary.
+// ctx is passed to the factory for state creation; nil uses the pool context.
+func (p *Pool) Acquire(ctx context.Context) (*glua.LState, error) {
+	p.mu.Lock()
+	if p.closed {
+		p.mu.Unlock()
+		return nil, errors.New("Lua pool is closed")
+	}
+	if err := p.ctx.Err(); err != nil {
+		p.mu.Unlock()
+		return nil, err
+	}
+	if ctx == nil {
+		ctx = p.ctx
+	} else if err := ctx.Err(); err != nil {
+		p.mu.Unlock()
+		return nil, err
+	}
+
+	p.active.Add(1)
+
+	n := len(p.idle)
+	if n != 0 {
+		state := p.idle[n-1]
+		p.idle[n-1] = nil
+		p.idle = p.idle[:n-1]
+		p.mu.Unlock()
+		return state, nil
+	}
+	p.mu.Unlock()
+
+	// TODO: Limit the total number of states. When the limit is reached, wait
+	// for a Release instead of creating another state; allow the wait to be
+	// cancelled by the caller or by Close.
+	state, err := p.factory(ctx)
+	if err != nil {
+		p.active.Done()
+		return nil, err
+	}
+
+	return state, nil
+}
+
+// WithState runs work on an exclusive state and releases it afterward.
+// Nil ctx and zero timeout use pool defaults. The timeout starts after acquisition.
+func (p *Pool) WithState(ctx context.Context, timeout time.Duration, work func(*glua.LState) error) error {
+	state, err := p.Acquire(ctx)
+	if err != nil {
+		return err
+	}
+	if ctx == nil {
+		ctx = p.ctx
+	}
+	if timeout == 0 {
+		timeout = p.timeout
+	}
+	ctx, cancel := context.WithTimeout(ctx, timeout)
+	state.SetContext(ctx)
+	reusable := false
+	defer func() {
+		cancel()
+		p.Release(state, reusable)
+	}()
+	err = work(state)
+	reusable = err == nil
+	return err
+}
+
+// Release resets a state for reuse or closes it.
+func (p *Pool) Release(state *glua.LState, reusable bool) {
+	if reusable {
+		state.RemoveContext()
+		state.SetTop(p.top)
+		p.mu.Lock()
+		if !p.closed && p.ctx.Err() == nil && len(p.idle) < maxIdleStates {
+			p.idle = append(p.idle, state)
+		} else {
+			reusable = false
+		}
+		p.mu.Unlock()
+	}
+
+	if !reusable {
+		state.Close()
+	}
+
+	p.active.Done()
+}
+
+// Close cancels the pool context, closes idle states, and waits for borrowed states.
+func (p *Pool) Close() {
+	p.mu.Lock()
+	if !p.closed {
+		p.closed = true
+		p.cancel()
+		for _, state := range p.idle {
+			state.Close()
+		}
+		p.idle = nil
+	}
+	p.mu.Unlock()
+
+	p.active.Wait()
+}

common/lua/pool_test.go

@@ -0,0 +1,466 @@
+package lua
+
+import (
+	"context"
+	"errors"
+	"testing"
+	"time"
+
+	glua "github.com/yuin/gopher-lua"
+)
+
+func newTestPool(t testing.TB, ctx context.Context, timeout time.Duration, factory LStateFactory) *Pool {
+	t.Helper()
+	pool, err := NewPool(ctx, timeout, factory)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(pool.Close)
+	return pool
+}
+
+func assertPoolCloseBlocked(t *testing.T, done <-chan struct{}) {
+	t.Helper()
+	select {
+	case <-done:
+		t.Fatal("Close returned while work was still active")
+	case <-time.After(20 * time.Millisecond):
+	}
+}
+
+func TestPoolTimeoutValidation(t *testing.T) {
+	for _, tc := range []struct {
+		name    string
+		timeout time.Duration
+		wantErr bool
+	}{
+		{"zero", 0, true},
+		{"negative", -time.Nanosecond, true},
+		{"positive", time.Nanosecond, false},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			called := false
+			pool, err := NewPool(context.Background(), tc.timeout, func(context.Context) (*glua.LState, error) {
+				called = true
+				return glua.NewState(), nil
+			})
+			if pool != nil {
+				t.Cleanup(pool.Close)
+			}
+			if (err != nil) != tc.wantErr {
+				t.Fatalf("NewPool error = %v, want error %t", err, tc.wantErr)
+			}
+			if tc.wantErr && (pool != nil || called) {
+				t.Fatal("invalid timeout created a pool or called the factory")
+			}
+		})
+	}
+}
+
+func TestPoolFactoryFailure(t *testing.T) {
+	failure := errors.New("factory failed")
+	_, err := NewPool(context.Background(), time.Second, func(context.Context) (*glua.LState, error) {
+		return nil, failure
+	})
+	if !errors.Is(err, failure) {
+		t.Fatalf("NewPool error = %v, want original factory error", err)
+	}
+
+	calls := 0
+	pool := newTestPool(t, context.Background(), time.Second, func(context.Context) (*glua.LState, error) {
+		calls++
+		if calls == 1 {
+			return glua.NewState(), nil
+		}
+		return nil, failure
+	})
+	state, err := pool.Acquire(nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer pool.Release(state, true)
+	err = pool.WithState(nil, 0, func(*glua.LState) error {
+		t.Error("work ran after factory failure")
+		return nil
+	})
+	if !errors.Is(err, failure) {
+		t.Fatalf("WithState error = %v, want original factory error", err)
+	}
+}
+
+func TestPoolReusesStatesAndLimitsIdle(t *testing.T) {
+	created := 0
+	pool := newTestPool(t, context.Background(), time.Second, func(context.Context) (*glua.LState, error) {
+		created++
+		return glua.NewState(), nil
+	})
+	var borrowed []*glua.LState
+	defer func() {
+		for _, state := range borrowed {
+			pool.Release(state, false)
+		}
+	}()
+	for range maxIdleStates + 3 {
+		state, err := pool.Acquire(nil)
+		if err != nil {
+			t.Fatal(err)
+		}
+		borrowed = append(borrowed, state)
+		state.SetContext(context.Background())
+	}
+	states := borrowed
+	for _, state := range states {
+		pool.Release(state, true)
+	}
+	borrowed = nil
+	open := 0
+	for _, state := range states {
+		if !state.IsClosed() {
+			if state.Context() != nil {
+				t.Fatal("Release left a context on a reusable state")
+			}
+			open++
+		}
+	}
+	if open != maxIdleStates {
+		t.Fatalf("retained %d states, want %d", open, maxIdleStates)
+	}
+	if err := pool.WithState(nil, 0, func(*glua.LState) error { return nil }); err != nil {
+		t.Fatal(err)
+	}
+	if created != len(states) {
+		t.Fatalf("created %d states, want %d", created, len(states))
+	}
+	pool.Close()
+	for _, state := range states {
+		if !state.IsClosed() {
+			t.Fatal("Close left an idle state open")
+		}
+	}
+}
+
+func TestPoolWithStateOptions(t *testing.T) {
+	key := struct{}{}
+	parent := context.WithValue(context.Background(), key, "pool")
+	caller := context.WithValue(context.Background(), key, "caller")
+	pool := newTestPool(t, parent, time.Second, func(context.Context) (*glua.LState, error) {
+		return glua.NewState(), nil
+	})
+	for _, tc := range []struct {
+		name        string
+		ctx         context.Context
+		timeout     time.Duration
+		wantValue   string
+		wantTimeout time.Duration
+	}{
+		{"defaults", nil, 0, "pool", time.Second},
+		{"context", caller, 0, "caller", time.Second},
+		{"timeout", nil, 2 * time.Second, "pool", 2 * time.Second},
+		{"both", caller, 2 * time.Second, "caller", 2 * time.Second},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			started := time.Now()
+			err := pool.WithState(tc.ctx, tc.timeout, func(L *glua.LState) error {
+				ctx := L.Context()
+				if ctx.Value(key) != tc.wantValue {
+					t.Errorf("context value = %v, want %q", ctx.Value(key), tc.wantValue)
+				}
+				deadline, ok := ctx.Deadline()
+				if !ok || deadline.Before(started.Add(tc.wantTimeout)) || deadline.After(time.Now().Add(tc.wantTimeout)) {
+					t.Errorf("deadline = %v, want timeout %v", deadline, tc.wantTimeout)
+				}
+				return nil
+			})
+			if err != nil {
+				t.Fatal(err)
+			}
+		})
+	}
+}
+
+func TestPoolFactoryContext(t *testing.T) {
+	caller, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
+	for _, tc := range []struct {
+		name string
+		ctx  context.Context
+	}{
+		{"default", nil},
+		{"caller", caller},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			var contexts []context.Context
+			pool := newTestPool(t, context.Background(), time.Second, func(ctx context.Context) (*glua.LState, error) {
+				contexts = append(contexts, ctx)
+				return glua.NewState(), nil
+			})
+			state, err := pool.Acquire(nil)
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer pool.Release(state, true)
+			if err := pool.WithState(tc.ctx, 2*time.Second, func(*glua.LState) error { return nil }); err != nil {
+				t.Fatal(err)
+			}
+			want := tc.ctx
+			if want == nil {
+				want = pool.ctx
+			}
+			if len(contexts) != 2 || contexts[0] != pool.ctx || contexts[1] != want {
+				t.Fatal("factory did not receive the initialization and acquisition contexts unchanged")
+			}
+		})
+	}
+}
+
+func TestPoolWithStateLifecycle(t *testing.T) {
+	failure := errors.New("work failed")
+	for _, tc := range []struct {
+		name      string
+		work      func(*glua.LState, context.CancelFunc) error
+		reusable  bool
+		wantPanic bool
+		wantErr   error
+	}{
+		{"success", func(*glua.LState, context.CancelFunc) error { return nil }, true, false, nil},
+		{"canceled success", func(_ *glua.LState, cancel context.CancelFunc) error {
+			cancel()
+			return nil
+		}, true, false, nil},
+		{"error", func(*glua.LState, context.CancelFunc) error { return failure }, false, false, failure},
+		{"timeout", func(L *glua.LState, _ context.CancelFunc) error { return L.DoString("while true do end") }, false, false, nil},
+		{"panic", func(*glua.LState, context.CancelFunc) error { panic(failure) }, false, true, nil},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			pool := newTestPool(t, context.Background(), 10*time.Millisecond, func(context.Context) (*glua.LState, error) {
+				state := glua.NewState()
+				state.Push(glua.LTrue)
+				return state, nil
+			})
+			ctx, cancel := context.WithCancel(context.Background())
+			defer cancel()
+			var state *glua.LState
+			var workCtx context.Context
+			var recovered any
+			err := func() (err error) {
+				defer func() { recovered = recover() }()
+				return pool.WithState(ctx, 0, func(L *glua.LState) error {
+					state, workCtx = L, L.Context()
+					L.Push(glua.LFalse)
+					return tc.work(L, cancel)
+				})
+			}()
+			if tc.wantPanic {
+				if recovered != failure {
+					t.Fatalf("panic = %v, want original panic", recovered)
+				}
+			} else {
+				if recovered != nil || (err == nil) != tc.reusable {
+					t.Fatalf("WithState error = %v, panic = %v", err, recovered)
+				}
+				if tc.wantErr != nil && !errors.Is(err, tc.wantErr) {
+					t.Fatalf("WithState error = %v, want %v", err, tc.wantErr)
+				}
+			}
+			if workCtx.Err() == nil {
+				t.Fatal("WithState did not cancel the execution context")
+			}
+			if closed := state.IsClosed(); closed == tc.reusable {
+				t.Fatalf("state closed = %t, want %t", closed, !tc.reusable)
+			}
+			if tc.reusable && (state.Context() != nil || state.GetTop() != 1 || state.Get(1) != glua.LTrue) {
+				t.Fatal("WithState did not reset the state for reuse")
+			}
+			if err := pool.WithState(nil, 0, func(L *glua.LState) error {
+				if (L == state) != tc.reusable {
+					t.Error("unexpected state reuse")
+				}
+				return nil
+			}); err != nil {
+				t.Fatal(err)
+			}
+		})
+	}
+}
+
+func TestPoolClose(t *testing.T) {
+	pool := newTestPool(t, context.Background(), time.Second, func(context.Context) (*glua.LState, error) {
+		return glua.NewState(), nil
+	})
+	finishCtx, finish := context.WithCancel(context.Background())
+	t.Cleanup(finish)
+	started, done := make(chan *glua.LState, 1), make(chan error, 1)
+	var workCtx context.Context
+	go func() {
+		done <- pool.WithState(nil, 0, func(L *glua.LState) error {
+			workCtx = L.Context()
+			started <- L
+			<-finishCtx.Done()
+			return nil
+		})
+	}()
+	var state *glua.LState
+	select {
+	case state = <-started:
+	case <-time.After(time.Second):
+		t.Fatal("WithState did not start")
+	}
+	closed := make(chan struct{})
+	go func() {
+		pool.Close()
+		close(closed)
+	}()
+	select {
+	case <-workCtx.Done():
+	case <-time.After(time.Second):
+		t.Fatal("Close did not cancel work using the pool context")
+	}
+	if !errors.Is(workCtx.Err(), context.Canceled) {
+		t.Fatalf("work context error = %v, want context.Canceled", workCtx.Err())
+	}
+	assertPoolCloseBlocked(t, closed)
+	finish()
+	select {
+	case err := <-done:
+		if err != nil {
+			t.Fatalf("successful work returned an error: %v", err)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("WithState did not finish")
+	}
+	select {
+	case <-closed:
+	case <-time.After(time.Second):
+		t.Fatal("Close did not finish after WithState")
+	}
+	if !state.IsClosed() {
+		t.Fatal("Release returned a state to a closed pool")
+	}
+	if state, err := pool.Acquire(nil); state != nil || err == nil || errors.Is(err, context.Canceled) {
+		t.Fatalf("Acquire after Close = %v, %v; want closed pool error", state, err)
+	}
+	pool.Close()
+}
+
+func TestPoolCloseWaitsForFactory(t *testing.T) {
+	finishCtx, finish := context.WithCancel(context.Background())
+	started, canceled := make(chan struct{}), make(chan struct{})
+	first := true
+	pool := newTestPool(t, context.Background(), time.Second, func(ctx context.Context) (*glua.LState, error) {
+		if first {
+			first = false
+			return glua.NewState(), nil
+		}
+		close(started)
+		<-ctx.Done()
+		close(canceled)
+		<-finishCtx.Done()
+		return nil, ctx.Err()
+	})
+	t.Cleanup(finish)
+	state, err := pool.Acquire(nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	pool.Release(state, false)
+	acquireDone := make(chan error, 1)
+	go func() {
+		_, err := pool.Acquire(nil)
+		acquireDone <- err
+	}()
+	select {
+	case <-started:
+	case <-time.After(time.Second):
+		t.Fatal("state creation did not start")
+	}
+	closed := make(chan struct{})
+	go func() {
+		pool.Close()
+		close(closed)
+	}()
+	select {
+	case <-canceled:
+	case <-time.After(time.Second):
+		t.Fatal("Close did not cancel state creation")
+	}
+	assertPoolCloseBlocked(t, closed)
+	finish()
+	select {
+	case err := <-acquireDone:
+		if !errors.Is(err, context.Canceled) {
+			t.Fatalf("Acquire error = %v, want context.Canceled", err)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("state creation did not finish")
+	}
+	select {
+	case <-closed:
+	case <-time.After(time.Second):
+		t.Fatal("Close did not finish after state creation")
+	}
+}
+
+func TestPoolCloseWaitsForCallerContext(t *testing.T) {
+	pool := newTestPool(t, context.Background(), time.Minute, func(context.Context) (*glua.LState, error) {
+		return glua.NewState(), nil
+	})
+	ctx, cancel := context.WithCancel(context.Background())
+	t.Cleanup(cancel)
+	started, done := make(chan context.Context, 1), make(chan error, 1)
+	go func() {
+		done <- pool.WithState(ctx, 0, func(L *glua.LState) error {
+			started <- L.Context()
+			<-L.Context().Done()
+			return L.Context().Err()
+		})
+	}()
+	var workCtx context.Context
+	select {
+	case workCtx = <-started:
+	case <-time.After(time.Second):
+		t.Fatal("WithState did not start")
+	}
+	closed := make(chan struct{})
+	go func() {
+		pool.Close()
+		close(closed)
+	}()
+	select {
+	case <-pool.ctx.Done():
+	case <-time.After(time.Second):
+		t.Fatal("Close did not cancel the pool context")
+	}
+	assertPoolCloseBlocked(t, closed)
+	if workCtx.Err() != nil || ctx.Err() != nil {
+		t.Fatal("Close canceled the caller's execution context")
+	}
+	cancel()
+	select {
+	case err := <-done:
+		if !errors.Is(err, context.Canceled) {
+			t.Fatalf("WithState error = %v, want context.Canceled", err)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("WithState did not stop after caller cancellation")
+	}
+	select {
+	case <-closed:
+	case <-time.After(time.Second):
+		t.Fatal("Close did not finish after WithState")
+	}
+}
+
+func BenchmarkPoolAcquireRelease(b *testing.B) {
+	pool := newTestPool(b, context.Background(), time.Second, func(context.Context) (*glua.LState, error) {
+		return glua.NewState(), nil
+	})
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		state, err := pool.Acquire(nil)
+		if err != nil {
+			b.Fatal(err)
+		}
+		pool.Release(state, true)
+	}
+}

common/lua/program.go

@@ -0,0 +1,87 @@
+package lua
+
+import (
+	"bytes"
+	"context"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/xtls/xray-core/common/base64"
+	"github.com/xtls/xray-core/common/platform"
+	glua "github.com/yuin/gopher-lua"
+	"github.com/yuin/gopher-lua/parse"
+)
+
+// Program holds immutable bytecode that can be run by independent LStates.
+type Program struct {
+	proto *glua.FunctionProto
+}
+
+// LStateFactory returns a fully initialized state or nil and an error.
+// Implementations must close partial states on failure; callers own successful states.
+type LStateFactory func(context.Context) (*glua.LState, error)
+
+// Compile reads a Lua file or decodes an inline script and compiles it into an immutable program.
+func Compile(script string) (*Program, error) {
+	var code []byte
+	var err error
+	name := "[inline]"
+	if strings.HasPrefix(script, base64.GzipPrefix) || strings.HasPrefix(script, base64.Prefix) {
+		code, err = base64.Decode(script)
+	} else if name, err = platform.ResolveLuaFile(script); err == nil {
+		code, err = os.ReadFile(name)
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	chunk, err := parse.Parse(bytes.NewReader(code), name)
+	if err != nil {
+		return nil, err
+	}
+	proto, err := glua.Compile(chunk, name)
+	if err != nil {
+		return nil, err
+	}
+	return &Program{proto: proto}, nil
+}
+
+// NewState creates a state, runs register, executes the program under ctx, and
+// runs validate. It removes the initialization context before returning a state
+// owned by the caller.
+func (p *Program) NewState(ctx context.Context, register func(*glua.LState), validate func(*glua.LState) error) (*glua.LState, error) {
+	L := glua.NewState()
+	valid := false
+	defer func() {
+		if !valid {
+			L.Close()
+		}
+	}()
+	L.SetContext(ctx)
+	defer L.RemoveContext()
+	if register != nil {
+		register(L)
+	}
+	L.Push(L.NewFunctionFromProto(p.proto))
+	// Execute the Lua script's top level.
+	if err := L.PCall(0, 0, nil); err != nil {
+		return nil, err
+	}
+	if validate != nil {
+		if err := validate(L); err != nil {
+			return nil, err
+		}
+	}
+	valid = true
+	return L, nil
+}
+
+// NewStateFactory returns a factory that gives each state an initialization timeout.
+func (p *Program) NewStateFactory(initTimeout time.Duration, register func(*glua.LState), validate func(*glua.LState) error) LStateFactory {
+	return func(ctx context.Context) (*glua.LState, error) {
+		initCtx, cancel := context.WithTimeout(ctx, initTimeout)
+		defer cancel()
+		return p.NewState(initCtx, register, validate)
+	}
+}

common/lua/program_test.go

@@ -0,0 +1,196 @@
+package lua
+
+import (
+	"bytes"
+	"compress/gzip"
+	"context"
+	"encoding/base64"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	xbase64 "github.com/xtls/xray-core/common/base64"
+	glua "github.com/yuin/gopher-lua"
+)
+
+func TestProgramStatesAreIndependent(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "state.lua")
+	if err := os.WriteFile(path, []byte("value = (value or 0) + 1"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	program, err := Compile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if program.proto.SourceName != path {
+		t.Fatalf("program source = %q, want %q", program.proto.SourceName, path)
+	}
+	first, err := program.NewState(context.Background(), nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer first.Close()
+	first.SetGlobal("value", glua.LNumber(42))
+	second, err := program.NewState(context.Background(), nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer second.Close()
+	if got := second.GetGlobal("value"); got != glua.LNumber(1) {
+		t.Fatalf("second state value = %v, want 1", got)
+	}
+}
+
+func TestProgramInitializationObservesCancellation(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "loop.lua")
+	if err := os.WriteFile(path, []byte("while true do end"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	program, err := Compile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+	state, err := program.NewState(ctx, nil, nil)
+	if err == nil || state != nil {
+		if state != nil {
+			state.Close()
+		}
+		t.Fatalf("NewState with canceled context = %v, %v; want nil state and error", state, err)
+	}
+}
+
+func TestNewStateClosesFailedValidation(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "state.lua")
+	if err := os.WriteFile(path, []byte("value = 1"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	program, err := Compile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	wantErr := errors.New("invalid script")
+	var checked *glua.LState
+	L, err := program.NewState(context.Background(), nil, func(L *glua.LState) error {
+		checked = L
+		return wantErr
+	})
+	if L != nil || !errors.Is(err, wantErr) || checked == nil || !checked.IsClosed() {
+		t.Fatalf("state = %v, error = %v, checked state closed = %t", L, err, checked != nil && checked.IsClosed())
+	}
+}
+
+func compressSource(t *testing.T, code string) []byte {
+	t.Helper()
+	var data bytes.Buffer
+	writer := gzip.NewWriter(&data)
+	if _, err := writer.Write([]byte(code)); err != nil {
+		t.Fatal(err)
+	}
+	if err := writer.Close(); err != nil {
+		t.Fatal(err)
+	}
+	return data.Bytes()
+}
+
+func TestCompileInline(t *testing.T) {
+	const code = `value = "你好"`
+	for _, tc := range []struct {
+		name, script string
+		value        glua.LValue
+	}{
+		{"base64", xbase64.Prefix + base64.StdEncoding.EncodeToString([]byte(code)), glua.LString("你好")},
+		{"base64+gzip", xbase64.GzipPrefix + base64.StdEncoding.EncodeToString(compressSource(t, code)), glua.LString("你好")},
+		{"empty base64", xbase64.Prefix, glua.LNil},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			program, err := Compile(tc.script)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if program.proto.SourceName != "[inline]" {
+				t.Fatalf("program source = %q, want [inline]", program.proto.SourceName)
+			}
+			state, err := program.NewState(context.Background(), nil, nil)
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer state.Close()
+			if got := state.GetGlobal("value"); got != tc.value {
+				t.Fatalf("value = %v, want %v", got, tc.value)
+			}
+		})
+	}
+}
+
+func TestCompileRejectsInvalidInline(t *testing.T) {
+	corrupt := compressSource(t, "value = 1")
+	corrupt[len(corrupt)-8] ^= 0xff
+	for _, tc := range []struct {
+		name, script string
+		wantErr      error
+		wantMessage  string
+	}{
+		{"base64", xbase64.Prefix + "%", base64.CorruptInputError(0), "failed to decode base64"},
+		{"gzip base64", xbase64.GzipPrefix + "%", base64.CorruptInputError(0), "failed to decode base64"},
+		{"gzip header", xbase64.GzipPrefix + base64.StdEncoding.EncodeToString([]byte("value = 'uncompressed'")), gzip.ErrHeader, "failed to decompress gzip"},
+		{"gzip checksum", xbase64.GzipPrefix + base64.StdEncoding.EncodeToString(corrupt), gzip.ErrChecksum, "failed to decompress gzip"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			program, err := Compile(tc.script)
+			if program != nil || !errors.Is(err, tc.wantErr) || !strings.Contains(err.Error(), tc.wantMessage) {
+				t.Fatalf("Compile = %v, %v; want nil program and %q error wrapping %v", program, err, tc.wantMessage, tc.wantErr)
+			}
+		})
+	}
+}
+
+func TestCompileInlineDiagnostics(t *testing.T) {
+	for _, tc := range []struct {
+		code         string
+		compileError bool
+	}{
+		{"function broken(", true},
+		{`error("initialization failed")`, false},
+	} {
+		program, err := Compile(xbase64.Prefix + base64.StdEncoding.EncodeToString([]byte(tc.code)))
+		if tc.compileError {
+			if program != nil || err == nil {
+				t.Fatalf("Compile = %v, %v; want nil program and syntax error", program, err)
+			}
+		} else {
+			if err != nil {
+				t.Fatal(err)
+			}
+			state, initErr := program.NewState(context.Background(), nil, nil)
+			if state != nil {
+				state.Close()
+				t.Fatal("NewState returned a state after failed initialization")
+			}
+			err = initErr
+		}
+		if err == nil || !strings.Contains(err.Error(), "[inline]") {
+			t.Fatalf("Lua error = %v, want [inline] diagnostic", err)
+		}
+	}
+}
+
+func TestCompileRejectsReadFailure(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "unreadable.lua")
+	if err := os.WriteFile(path, []byte("value = 42"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Chmod(path, 0); err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { os.Chmod(path, 0o600) })
+	if _, err := os.ReadFile(path); !errors.Is(err, os.ErrPermission) {
+		t.Skip("file read permissions are not enforced")
+	}
+	if program, err := Compile(path); program != nil || !errors.Is(err, os.ErrPermission) {
+		t.Fatalf("Compile = %v, %v; want nil program and permission error", program, err)
+	}
+}

common/lua/utils.go

@@ -0,0 +1,95 @@
+package lua
+
+import (
+	"math"
+
+	"github.com/xtls/xray-core/common/errors"
+	glua "github.com/yuin/gopher-lua"
+)
+
+type number interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64
+}
+
+// PushNumber converts a Go number to a Lua number and pushes it.
+func PushNumber[T number](L *glua.LState, value T) {
+	L.Push(glua.LNumber(value))
+}
+
+// PushString converts a Go string to a Lua string and pushes it.
+func PushString(L *glua.LState, value string) {
+	L.Push(glua.LString(value))
+}
+
+// PushNil pushes Lua nil.
+func PushNil(L *glua.LState) {
+	L.Push(glua.LNil)
+}
+
+// PushUserData pushes a native Go value without copying it.
+func PushUserData(L *glua.LState, value any) {
+	ud := L.NewUserData()
+	ud.Value = value
+	L.Push(ud)
+}
+
+// PushError pushes nil or the original Go error as userdata.
+func PushError(L *glua.LState, err error) {
+	if err == nil {
+		L.Push(glua.LNil)
+		return
+	}
+	PushUserData(L, err)
+}
+
+// ReadUserData reads a native Go value of type T without copying it.
+// Other Lua values or userdata containing a different type return invalidMessage.
+func ReadUserData[T any](value glua.LValue, invalidMessage string) (T, error) {
+	if ud, ok := value.(*glua.LUserData); ok {
+		if result, ok := ud.Value.(T); ok {
+			return result, nil
+		}
+	}
+	var zero T
+	return zero, errors.New(invalidMessage)
+}
+
+// ReadError accepts nil, a native Go error, or a Lua string.
+// Native errors retain their identity; other values return invalidMessage.
+func ReadError(value glua.LValue, invalidMessage string) error {
+	if value == glua.LNil {
+		return nil
+	}
+	if ud, ok := value.(*glua.LUserData); ok {
+		if err, ok := ud.Value.(error); ok {
+			return err
+		}
+	}
+	if message, ok := value.(glua.LString); ok {
+		return errors.New(string(message))
+	}
+	return errors.New(invalidMessage)
+}
+
+// ReadUint32 accepts only integral Lua numbers in the uint32 range.
+func ReadUint32(value glua.LValue, invalidMessage string) (uint32, error) {
+	number, ok := value.(glua.LNumber)
+	if !ok || number < 0 || number > math.MaxUint32 || math.Trunc(float64(number)) != float64(number) {
+		return 0, errors.New(invalidMessage)
+	}
+	return uint32(number), nil
+}
+
+// ReadOptionalString accepts a Lua string or nil, which becomes an empty string.
+// It does not coerce other values to strings.
+func ReadOptionalString(value glua.LValue, invalidMessage string) (string, error) {
+	if value == glua.LNil {
+		return "", nil
+	}
+	if result, ok := value.(glua.LString); ok {
+		return string(result), nil
+	}
+	return "", errors.New(invalidMessage)
+}

common/lua/utils_test.go

@@ -0,0 +1,121 @@
+package lua
+
+import (
+	"errors"
+	"math"
+	"strings"
+	"testing"
+
+	glua "github.com/yuin/gopher-lua"
+)
+
+func TestReadUint32(t *testing.T) {
+	for _, tc := range []struct {
+		name    string
+		value   glua.LValue
+		want    uint32
+		wantErr bool
+	}{
+		{name: "zero", value: glua.LNumber(0)},
+		{name: "integer", value: glua.LNumber(45), want: 45},
+		{name: "maximum", value: glua.LNumber(math.MaxUint32), want: math.MaxUint32},
+		{name: "fraction", value: glua.LNumber(1.5), wantErr: true},
+		{name: "negative", value: glua.LNumber(-1), wantErr: true},
+		{name: "overflow", value: glua.LNumber(math.MaxUint32 + 1), wantErr: true},
+		{name: "NaN", value: glua.LNumber(math.NaN()), wantErr: true},
+		{name: "positive infinity", value: glua.LNumber(math.Inf(1)), wantErr: true},
+		{name: "negative infinity", value: glua.LNumber(math.Inf(-1)), wantErr: true},
+		{name: "nil", value: glua.LNil, wantErr: true},
+		{name: "numeric string", value: glua.LString("45"), wantErr: true},
+		{name: "boolean", value: glua.LTrue, wantErr: true},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			got, err := ReadUint32(tc.value, "invalid number")
+			if got != tc.want || (err != nil) != tc.wantErr {
+				t.Fatalf("ReadUint32() = %d, %v; want %d, error %t", got, err, tc.want, tc.wantErr)
+			}
+			if err != nil && !strings.Contains(err.Error(), "invalid number") {
+				t.Fatalf("error = %v, want invalid number", err)
+			}
+		})
+	}
+}
+
+func TestReadOptionalString(t *testing.T) {
+	for _, tc := range []struct {
+		name    string
+		value   glua.LValue
+		want    string
+		wantErr bool
+	}{
+		{name: "nil", value: glua.LNil},
+		{name: "empty", value: glua.LString("")},
+		{name: "string", value: glua.LString("out"), want: "out"},
+		{name: "number", value: glua.LNumber(1), wantErr: true},
+		{name: "boolean", value: glua.LFalse, wantErr: true},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			got, err := ReadOptionalString(tc.value, "invalid string")
+			if got != tc.want || (err != nil) != tc.wantErr {
+				t.Fatalf("ReadOptionalString() = %q, %v; want %q, error %t", got, err, tc.want, tc.wantErr)
+			}
+			if err != nil && !strings.Contains(err.Error(), "invalid string") {
+				t.Fatalf("error = %v, want invalid string", err)
+			}
+		})
+	}
+}
+
+func TestUserDataRoundTrip(t *testing.T) {
+	L := glua.NewState()
+	defer L.Close()
+	want := []int{1, 2}
+	PushUserData(L, want)
+	if L.GetTop() != 1 {
+		t.Fatalf("stack top = %d, want 1", L.GetTop())
+	}
+	got, err := ReadUserData[[]int](L.Get(-1), "invalid userdata")
+	if err != nil || len(got) != len(want) || &got[0] != &want[0] {
+		t.Fatalf("userdata = %v, %v; want original slice", got, err)
+	}
+	PushUserData(L, []int(nil))
+	if got, err := ReadUserData[[]int](L.Get(-1), "invalid userdata"); err != nil || got != nil {
+		t.Fatalf("nil slice userdata = %v, %v", got, err)
+	}
+	for _, value := range []glua.LValue{glua.LNil, glua.LString("1"), L.NewTable(), L.Get(1)} {
+		if got, err := ReadUserData[int](value, "invalid userdata"); got != 0 || err == nil || !strings.Contains(err.Error(), "invalid userdata") {
+			t.Fatalf("ReadUserData(%v) = %d, %v; want invalid userdata", value, got, err)
+		}
+	}
+}
+
+func TestErrorRoundTrip(t *testing.T) {
+	L := glua.NewState()
+	defer L.Close()
+	want := errors.New("upstream failed")
+	for _, err := range []error{nil, want} {
+		PushError(L, err)
+		if L.GetTop() != 1 {
+			t.Fatalf("stack top = %d, want 1", L.GetTop())
+		}
+		if err == nil && L.Get(-1) != glua.LNil {
+			t.Fatalf("nil error pushed as %v", L.Get(-1))
+		}
+		if got := ReadError(L.Get(-1), "invalid error"); got != err {
+			t.Fatalf("ReadError() = %v, want original error %v", got, err)
+		}
+		L.Pop(1)
+	}
+	for _, message := range []string{"script failed", ""} {
+		if err := ReadError(glua.LString(message), "invalid error"); err == nil || !strings.Contains(err.Error(), message) {
+			t.Fatalf("string error = %v, want %q", err, message)
+		}
+	}
+	wrong := L.NewUserData()
+	wrong.Value = "not a native error"
+	for _, value := range []glua.LValue{glua.LTrue, glua.LNumber(1), L.NewTable(), wrong, L.NewUserData()} {
+		if err := ReadError(value, "invalid error"); err == nil || !strings.Contains(err.Error(), "invalid error") {
+			t.Fatalf("ReadError(%v) = %v, want invalid error", value, err)
+		}
+	}
+}

common/mux/client.go

@@ -314,12 +314,10 @@ func (m *ClientWorker) Dispatch(ctx context.Context, link *transport.Link) bool
 	}
 
 	sm := m.sessionManager
-	s := sm.Allocate(&m.strategy)
+	s := sm.Allocate(&m.strategy, link.Reader, link.Writer)
 	if s == nil {
 		return false
 	}
-	s.input = link.Reader
-	s.output = link.Writer
 	go fetchInput(ctx, s, m.link.Writer)
 	if _, ok := link.Reader.(*pipe.Reader); !ok {
 		select {

common/mux/client_test.go

@@ -7,9 +7,11 @@ import (
 
 	"github.com/golang/mock/gomock"
 	"github.com/xtls/xray-core/common"
+	"github.com/xtls/xray-core/common/buf"
 	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/common/mux"
 	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/common/protocol"
 	"github.com/xtls/xray-core/common/session"
 	"github.com/xtls/xray-core/testing/mocks"
 	"github.com/xtls/xray-core/transport"
@@ -114,3 +116,48 @@ func TestClientWorkerClose(t *testing.T) {
 
 	common.Must(w2.Close())
 }
+
+func TestClientWorkerUDPSource(t *testing.T) {
+	downR, downW := pipe.New(pipe.WithoutSizeLimit())
+	upR, upW := pipe.New(pipe.WithoutSizeLimit())
+	worker, err := mux.NewClientWorker(transport.Link{Reader: downR, Writer: upW}, mux.ClientStrategy{})
+	common.Must(err)
+
+	inR, inW := pipe.New(pipe.WithoutSizeLimit())
+	outR, outW := pipe.New(pipe.WithoutSizeLimit())
+	ctx := session.ContextWithOutbounds(context.Background(), []*session.Outbound{{
+		Target: net.UDPDestination(net.ParseAddress("8.8.8.8"), 53),
+	}})
+	if !worker.Dispatch(ctx, &transport.Link{Reader: inR, Writer: outW}) {
+		t.Fatal("failed to dispatch")
+	}
+	b := buf.New()
+	b.WriteString("query")
+	common.Must(inW.WriteMultiBuffer(buf.MultiBuffer{b}))
+	mb, err := upR.ReadMultiBuffer() // New frame, the session is UDP from now on
+	common.Must(err)
+	buf.ReleaseMulti(mb)
+
+	srcs := []net.Destination{
+		net.UDPDestination(net.ParseAddress("1.1.1.1"), 1111),
+		net.UDPDestination(net.DomainAddress("example.com"), 2222),
+		net.UDPDestination(net.ParseAddress("3.3.3.3"), 3333),
+	}
+	w := mux.NewResponseWriter(1, downW, protocol.TransferTypePacket)
+	var got buf.MultiBuffer
+	for i := range srcs {
+		b := buf.New()
+		b.WriteString("reply")
+		b.UDP = &srcs[i]
+		common.Must(w.WriteMultiBuffer(buf.MultiBuffer{b}))
+		// keep earlier replies around while the next frame is parsed
+		mb, err := outR.ReadMultiBuffer()
+		common.Must(err)
+		got = append(got, mb...)
+	}
+	for i, b := range got {
+		if b.UDP == nil || *b.UDP != srcs[i] {
+			t.Errorf("reply %d: source = %v, want %v", i, b.UDP, srcs[i])
+		}
+	}
+}

common/mux/reader.go

@@ -14,15 +14,16 @@ import (
 type PacketReader struct {
 	reader io.Reader
 	eof    bool
-	dest   *net.Destination
+	dest   net.Destination
 }
 
 // NewPacketReader creates a new PacketReader.
+// dest is copied because the caller reuses it for the next frame.
 func NewPacketReader(reader io.Reader, dest *net.Destination) *PacketReader {
 	return &PacketReader{
 		reader: reader,
 		eof:    false,
-		dest:   dest,
+		dest:   *dest,
 	}
 }
 
@@ -47,8 +48,8 @@ func (r *PacketReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
 		return nil, err
 	}
 	r.eof = true
-	if r.dest != nil && r.dest.Network == net.Network_UDP {
-		b.UDP = r.dest
+	if r.dest.Network == net.Network_UDP {
+		b.UDP = &r.dest // only one packet is read, so b owns r.dest
 	}
 	return buf.MultiBuffer{b}, nil
 }

common/mux/session.go

@@ -51,7 +51,7 @@ func (m *SessionManager) Count() int {
 	return int(m.count)
 }
 
-func (m *SessionManager) Allocate(Strategy *ClientStrategy) *Session {
+func (m *SessionManager) Allocate(Strategy *ClientStrategy, input buf.Reader, output buf.Writer) *Session {
 	m.Lock()
 	defer m.Unlock()
 
@@ -64,6 +64,8 @@ func (m *SessionManager) Allocate(Strategy *ClientStrategy) *Session {
 
 	m.count++
 	s := &Session{
+		input:  input,
+		output: output,
 		ID:     m.count,
 		parent: m,
 		done:   done.New(),

common/mux/session_test.go

@@ -9,7 +9,7 @@ import (
 func TestSessionManagerAdd(t *testing.T) {
 	m := NewSessionManager()
 
-	s := m.Allocate(&ClientStrategy{})
+	s := m.Allocate(&ClientStrategy{}, nil, nil)
 	if s.ID != 1 {
 		t.Error("id: ", s.ID)
 	}
@@ -17,7 +17,7 @@ func TestSessionManagerAdd(t *testing.T) {
 		t.Error("size: ", m.Size())
 	}
 
-	s = m.Allocate(&ClientStrategy{})
+	s = m.Allocate(&ClientStrategy{}, nil, nil)
 	if s.ID != 2 {
 		t.Error("id: ", s.ID)
 	}
@@ -39,7 +39,7 @@ func TestSessionManagerAdd(t *testing.T) {
 
 func TestSessionManagerClose(t *testing.T) {
 	m := NewSessionManager()
-	s := m.Allocate(&ClientStrategy{})
+	s := m.Allocate(&ClientStrategy{}, nil, nil)
 
 	if m.CloseIfNoSessionAndIdle(m.Size(), m.Count()) {
 		t.Error("able to close")

common/net/packet.go

@@ -0,0 +1,20 @@
+package net
+
+// PacketConnWrapper wraps a PacketConn into a Conn with a fixed destination address.
+type PacketConnWrapper struct {
+	PacketConn
+	Dest Addr
+}
+
+func (c *PacketConnWrapper) Read(p []byte) (int, error) {
+	n, _, err := c.PacketConn.ReadFrom(p)
+	return n, err
+}
+
+func (c *PacketConnWrapper) Write(p []byte) (int, error) {
+	return c.PacketConn.WriteTo(p, c.Dest)
+}
+
+func (c *PacketConnWrapper) RemoteAddr() Addr {
+	return c.Dest
+}

common/platform/platform.go

@@ -1,6 +1,8 @@
 package platform // import "github.com/xtls/xray-core/common/platform"
 
 import (
+	"errors"
+	"fmt"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -90,3 +92,49 @@ func GetConfDirPath() string {
 	configPath := NewEnvFlag(ConfdirLocation).GetValue(func() string { return "" })
 	return configPath
 }
+
+// ResolveLuaFile finds a local Lua script and returns its absolute path.
+// Relative paths: XRAY_LOCATION_CONFDIR > XRAY_LOCATION_CONFIG > working dir > executable dir.
+func ResolveLuaFile(path string) (string, error) {
+	if path == "" {
+		return "", errors.New("Lua file path is empty")
+	}
+	paths := []string{path}
+	if !filepath.IsAbs(path) {
+		paths = nil
+		for _, dir := range []string{
+			GetConfDirPath(),
+			NewEnvFlag(ConfigLocation).GetValue(func() string { return "" }),
+			".",
+			getExecutableDir(),
+		} {
+			if dir != "" {
+				paths = append(paths, filepath.Join(dir, path))
+			}
+		}
+	}
+	return resolveFile(paths)
+}
+
+func resolveFile(paths []string) (string, error) {
+	var tried []string
+	for _, path := range paths {
+		path, err := filepath.Abs(path)
+		if err != nil {
+			return "", fmt.Errorf("failed to resolve file path: %w", err)
+		}
+		tried = append(tried, path)
+		info, err := os.Stat(path)
+		if errors.Is(err, os.ErrNotExist) {
+			continue
+		}
+		if err != nil {
+			return "", fmt.Errorf("failed to inspect file %q: %w", path, err)
+		}
+		if !info.Mode().IsRegular() {
+			return "", fmt.Errorf("file is not a regular file: %s", path)
+		}
+		return path, nil
+	}
+	return "", fmt.Errorf("file not found; tried %q: %w", tried, os.ErrNotExist)
+}

common/platform/platform_test.go

@@ -1,6 +1,7 @@
 package platform_test
 
 import (
+	"errors"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -64,3 +65,53 @@ func TestGetAssetLocation(t *testing.T) {
 		}
 	}
 }
+
+func TestResolveLuaFile(t *testing.T) {
+	workingDir := t.TempDir()
+	t.Chdir(workingDir)
+	executable, err := os.Executable()
+	common.Must(err)
+	file, err := os.CreateTemp(filepath.Dir(executable), "lua-*.lua")
+	common.Must(err)
+	common.Must(file.Close())
+	defer os.Remove(file.Name())
+
+	name := filepath.Base(file.Name())
+	paths := []string{
+		filepath.Join(t.TempDir(), name),
+		filepath.Join(t.TempDir(), name),
+		filepath.Join(workingDir, name),
+		file.Name(),
+	}
+	t.Setenv(ConfdirLocation, filepath.Dir(paths[0]))
+	t.Setenv(ConfigLocation, filepath.Dir(paths[1]))
+	for _, path := range paths[:3] {
+		common.Must(os.WriteFile(path, nil, 0o600))
+	}
+	if got, err := ResolveLuaFile(paths[2]); err != nil || got != paths[2] {
+		t.Fatalf("absolute path = %q, %v; want %q", got, err, paths[2])
+	}
+	for i, want := range paths {
+		if i == 2 {
+			t.Setenv(ConfdirLocation, "")
+			t.Setenv(ConfigLocation, "")
+		}
+		if got, err := ResolveLuaFile(name); err != nil || got != want {
+			t.Fatalf("resolved path = %q, %v; want %q", got, err, want)
+		}
+		common.Must(os.Remove(want))
+	}
+	if _, err := ResolveLuaFile(name); !errors.Is(err, os.ErrNotExist) {
+		t.Fatalf("missing file error = %v", err)
+	}
+
+	t.Setenv(ConfdirLocation, filepath.Dir(paths[0]))
+	t.Setenv(ConfigLocation, filepath.Dir(paths[1]))
+	common.Must(os.Mkdir(paths[0], 0o700))
+	common.Must(os.WriteFile(paths[1], nil, 0o600))
+	for _, path := range []string{"", name, filepath.Join(t.TempDir(), name)} {
+		if _, err := ResolveLuaFile(path); err == nil {
+			t.Fatalf("accepted invalid path %q", path)
+		}
+	}
+}

common/protocol/quic/sniff.go

@@ -146,6 +146,10 @@ func SniffQUIC(b []byte) (*SniffHeader, error) {
 		}
 
 		restPayload := b[hdrLen+int(packetLen):]
+		// cachedReader can concatenate zero-padded UDP datagrams.
+		for len(restPayload) > 0 && restPayload[0] == 0 {
+			restPayload = restPayload[1:]
+		}
 		if !isQUICInitial { // Skip this packet if it's not initial packet
 			b = restPayload
 			continue

common/signal/pubsub/pubsub.go

@@ -62,7 +62,7 @@ func (s *Service) Cleanup() error {
 	}
 
 	for name, subs := range s.subs {
-		newSub := make([]*Subscriber, 0, len(s.subs))
+		newSub := make([]*Subscriber, 0, len(subs))
 		for _, sub := range subs {
 			if !sub.IsClosed() {
 				newSub = append(newSub, sub)

core/core.go

@@ -19,8 +19,8 @@ import (
 
 var (
 	Version_x byte = 26
-	Version_y byte = 9
-	Version_z byte = 9
+	Version_y byte = 10
+	Version_z byte = 10
 )
 
 var (

core/xray.go

@@ -92,6 +92,8 @@ type Instance struct {
 
 // Instance state
 func (server *Instance) IsRunning() bool {
+	server.statusLock.Lock()
+	defer server.statusLock.Unlock()
 	return server.running
 }
 
@@ -320,7 +322,7 @@ func (s *Instance) RequireFeatures(callback interface{}, optional bool) error {
 
 // AddFeature registers a feature into current Instance.
 func (s *Instance) AddFeature(feature features.Feature) error {
-	if s.running {
+	if s.IsRunning() {
 		if err := feature.Start(); err != nil {
 			errors.LogInfoInner(s.ctx, err, "failed to start feature")
 		}

features/dns/localdns/client.go

@@ -97,6 +97,9 @@ func New() *Client {
 	r := &net.Resolver{
 		PreferGo: true,
 		Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
+			if internet.IsSkippedDNSServer(address) {
+				return nil, errors.New("skipped DNS server ", address)
+			}
 			return d.DialContext(ctx, network, address)
 		},
 	}

features/dns/localdns/client_test.go

@@ -0,0 +1,23 @@
+package localdns
+
+import (
+	"context"
+	"net/netip"
+	"testing"
+
+	"github.com/xtls/xray-core/transport/internet"
+)
+
+func TestSkippedDNSServers(t *testing.T) {
+	internet.SkipDNSServers([]netip.Addr{netip.MustParseAddr("203.0.113.53")})
+	t.Cleanup(func() { internet.SkipDNSServers(nil) })
+	c := New()
+	if _, err := c.r.Dial(context.Background(), "udp", "203.0.113.53:53"); err == nil {
+		t.Error("a skipped DNS server was dialed")
+	}
+	conn, err := c.r.Dial(context.Background(), "udp", "127.0.0.1:53")
+	if err != nil {
+		t.Fatal(err)
+	}
+	conn.Close()
+}

go.mod

@@ -21,10 +21,12 @@ require (
 	github.com/stretchr/testify v1.12.1
 	github.com/vishvananda/netlink v1.3.1
 	github.com/xtls/reality v0.0.0-20260908062103-8cdf7bf9c7f0
+	github.com/yuin/gopher-lua v1.1.2
 	go4.org/netipx v0.0.0-20231129151722-fdeea329fbba
 	golang.org/x/crypto v0.57.0
+	golang.org/x/crypto/x509roots/fallback v0.0.0-20261005185213-c3db4df58582
 	golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842
-	golang.org/x/net v0.59.0
+	golang.org/x/net v0.60.0
 	golang.org/x/sync v0.23.0
 	golang.org/x/sys v0.48.0
 	golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2
@@ -34,6 +36,7 @@ require (
 	google.golang.org/protobuf v1.36.12
 	gvisor.dev/gvisor v0.0.0-20260122175437-89a5d21be8f0
 	h12.io/socks v1.0.3
+	layeh.com/gopher-luar v1.0.11
 	lukechampine.com/blake3 v1.4.1
 	mvdan.cc/gofumpt v0.12.0
 )

go.sum

@@ -2,6 +2,9 @@ github.com/andybalholm/brotli v1.0.6 h1:Yf9fFpf49Zrxb9NlQaluyE92/+X7UVHlhMNJN2sx
 github.com/andybalholm/brotli v1.0.6/go.mod h1:fO7iG3H7G2nSZ7m0zPUDn85XEX2GTukHGRSepvi9Eig=
 github.com/apernet/quic-go v0.61.1-0.20260806010916-184d081eef3e h1:5mgtR5gwIgBKMiGI1QdXldZZ+SNor06Nbu1wCBulQBg=
 github.com/apernet/quic-go v0.61.1-0.20260806010916-184d081eef3e/go.mod h1:x7qxEvX6MCVtDuBKHj3E+88+BtrbEMuAL5qGUKItjW8=
+github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
+github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
+github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
 github.com/cloudflare/circl v1.6.5 h1:O64F26HEqNhznd/hrC5KZXVKYuKM2rx4deZDTc4ihQA=
 github.com/cloudflare/circl v1.6.5/go.mod h1:h5LNyxAc5nTue9DS5jT+48en2PSDYt3zdGnz5OstK6c=
 github.com/ghodss/yaml v1.0.1-0.20220118164431-d8423dcdf344 h1:Arcl6UOIS/kgO2nW3A65HN+7CMjSDP/gofXL4CZt1V4=
@@ -81,6 +84,9 @@ github.com/wlynxg/anet v0.0.5/go.mod h1:eay5PRQr7fIVAMbTbchTnO9gG65Hg/uYGdc7mguH
 github.com/xtls/reality v0.0.0-20260908062103-8cdf7bf9c7f0 h1:rb+fKQFhz+5I2PPuQsNYxI5mUU840XWYtRF0ZBjvkws=
 github.com/xtls/reality v0.0.0-20260908062103-8cdf7bf9c7f0/go.mod h1:DsJblcWDGt76+FVqBVwbwRhxyyNJsGV48gJLch0OOWI=
 github.com/yuin/goldmark v1.4.1/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
+github.com/yuin/gopher-lua v0.0.0-20190206043414-8bfc7677f583/go.mod h1:gqRgreBUhTSL0GeU64rtZ3Uq3wtjOa/TB2YfrtkCbVQ=
+github.com/yuin/gopher-lua v1.1.2 h1:yF/FjE3hD65tBbt0VXLE13HWS9h34fdzJmrWRXwobGA=
+github.com/yuin/gopher-lua v1.1.2/go.mod h1:7aRmXIWl37SqRf0koeyylBEzJ+aPt8A+mmkQ4f1ntR8=
 go.uber.org/mock v0.5.2 h1:LbtPTcP8A5k9WPXj54PPPbjcI4Y6lhyOZXn+VS7wNko=
 go.uber.org/mock v0.5.2/go.mod h1:wLlUxC2vVTPTaE3UD51E0BGOAElKrILxhVSDYQLld5o=
 go.yaml.in/yaml/v3 v3.0.5 h1:N6y/pJk8buWs9NY5ERU2HSMfm+IuD/OtfdAnq6kESPw=
@@ -91,6 +97,8 @@ golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACk
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.57.0 h1:3ZVCjf8Ggz7zneR/EHRVx68Ctf+2pmIMP2UFhh9cC6M=
 golang.org/x/crypto v0.57.0/go.mod h1:Fdz0i5U6CoizGwLda9DttjSk6qlZo25zYNtR+ycvuZA=
+golang.org/x/crypto/x509roots/fallback v0.0.0-20261005185213-c3db4df58582 h1:wjDBrGbfLuifgrVLFEWUBJYAfh5Q1wkMc5t0FY0tCbs=
+golang.org/x/crypto/x509roots/fallback v0.0.0-20261005185213-c3db4df58582/go.mod h1:HPze8vhfG6fO06AM+VSvxRm4E3+5Yk375mgrJ5M2z1E=
 golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842 h1:vr/HnozRka3pE4EsMEg1lgkXJkTFJCVUX+S/ZT6wYzM=
 golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842/go.mod h1:XtvwrStGgqGPLc4cjQfWqZHG1YFdYs6swckp8vpsjnc=
 golang.org/x/lint v0.0.0-20200302205851-738671d3881b/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
@@ -99,12 +107,13 @@ golang.org/x/mod v0.5.1/go.mod h1:5OXOZSfqPIIbmVBIIKWRFfZjPR0E5r58TLhUjH0a2Ro=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20211015210444-4f30a5c0130f/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
-golang.org/x/net v0.59.0 h1:5zfYln+w5XCxwrnMMJPufRgNoXEaGxl0wo5GqPXyues=
-golang.org/x/net v0.59.0/go.mod h1:2DA/G1UfVbCpQPeWTmMPGY7Cs2PkBkwu743bVX5PIVg=
+golang.org/x/net v0.60.0 h1:79p50tfZlm0J9YfoDsSi639qSXNGVwEzOPLCxM2FsYU=
+golang.org/x/net v0.60.0/go.mod h1:2DA/G1UfVbCpQPeWTmMPGY7Cs2PkBkwu743bVX5PIVg=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.23.0 h1:KameEIfc1IkluZyXWLn39Wd4tURc6GbCiISGiZm2bQk=
 golang.org/x/sync v0.23.0/go.mod h1:sUUOizhqBxiL6pEWpqNLUiaJn1ShEbZ6BBqskPbjZm0=
+golang.org/x/sys v0.0.0-20190204203706-41f3e6584952/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -155,6 +164,8 @@ gvisor.dev/gvisor v0.0.0-20260122175437-89a5d21be8f0 h1:Lk6hARj5UPY47dBep70OD/TI
 gvisor.dev/gvisor v0.0.0-20260122175437-89a5d21be8f0/go.mod h1:QkHjoMIBaYtpVufgwv3keYAbln78mBoCuShZrPrer1Q=
 h12.io/socks v1.0.3 h1:Ka3qaQewws4j4/eDQnOdpr4wXsC//dXtWvftlIcCQUo=
 h12.io/socks v1.0.3/go.mod h1:AIhxy1jOId/XCz9BO+EIgNL2rQiPTBNnOfnVnQ+3Eck=
+layeh.com/gopher-luar v1.0.11 h1:8zJudpKI6HWkoh9eyyNFaTM79PY6CAPcIr6X/KTiliw=
+layeh.com/gopher-luar v1.0.11/go.mod h1:TPnIVCZ2RJBndm7ohXyaqfhzjlZ+OA2SZR/YwL8tECk=
 lukechampine.com/blake3 v1.4.1 h1:I3Smz7gso8w4/TunLKec6K2fn+kyKtDxr/xcQEN84Wg=
 lukechampine.com/blake3 v1.4.1/go.mod h1:QFosUxmjB8mnrWFSNwKmvxHpfY72bmD2tQ0kBMM3kwo=
 mvdan.cc/gofumpt v0.12.0 h1:1Lbudkz2kpM9Cjz2pL4M19u7q+GaEhCTNf7N9mfpcho=

infra/conf/dns.go

@@ -17,6 +17,7 @@ import (
 )
 
 type NameServerConfig struct {
+	ID              string     `json:"id"`
 	Address         *Address   `json:"address"`
 	ClientIP        *Address   `json:"clientIp"`
 	Port            uint16     `json:"port"`
@@ -43,6 +44,7 @@ func (c *NameServerConfig) UnmarshalJSON(data []byte) error {
 	}
 
 	var advanced struct {
+		ID              string     `json:"id"`
 		Address         *Address   `json:"address"`
 		ClientIP        *Address   `json:"clientIp"`
 		Port            uint16     `json:"port"`
@@ -60,6 +62,7 @@ func (c *NameServerConfig) UnmarshalJSON(data []byte) error {
 		UnexpectedIPs   StringList `json:"unexpectedIPs"`
 	}
 	if err := json.Unmarshal(data, &advanced); err == nil {
+		c.ID = advanced.ID
 		c.Address = advanced.Address
 		c.ClientIP = advanced.ClientIP
 		c.Port = advanced.Port
@@ -134,6 +137,7 @@ func (c *NameServerConfig) Build() (*dns.NameServer, error) {
 	}
 
 	return &dns.NameServer{
+		Id: c.ID,
 		Address: &net.Endpoint{
 			Network: net.Network_UDP,
 			Address: c.Address.Build(),
@@ -159,6 +163,7 @@ func (c *NameServerConfig) Build() (*dns.NameServer, error) {
 // DNSConfig is a JSON serializable object for dns.Config
 type DNSConfig struct {
 	Servers                []*NameServerConfig `json:"servers"`
+	Script                 string              `json:"script"`
 	Hosts                  *HostsWrapper       `json:"hosts"`
 	ClientIP               *Address            `json:"clientIp"`
 	Tag                    string              `json:"tag"`
@@ -267,6 +272,17 @@ func (m *HostsWrapper) Build() ([]*dns.Config_HostMapping, error) {
 
 // Build implements Buildable
 func (c *DNSConfig) Build() (*dns.Config, error) {
+	if c.Script != "" {
+		if c.DisableFallback || c.DisableFallbackIfMatch || c.EnableParallelQuery {
+			return nil, errors.New("DNS script cannot be used with disableFallback, disableFallbackIfMatch or enableParallelQuery")
+		}
+		for i, server := range c.Servers {
+			if len(server.Domains) > 0 || server.SkipFallback || server.FinalQuery {
+				return nil, errors.New("DNS script cannot be used with domains, skipFallback or finalQuery in server ", i)
+			}
+		}
+	}
+
 	config := &dns.Config{
 		Tag:                    c.Tag,
 		DisableCache:           c.DisableCache,
@@ -276,6 +292,7 @@ func (c *DNSConfig) Build() (*dns.Config, error) {
 		DisableFallbackIfMatch: c.DisableFallbackIfMatch,
 		EnableParallelQuery:    c.EnableParallelQuery,
 		QueryStrategy:          resolveQueryStrategy(c.QueryStrategy),
+		Script:                 c.Script,
 	}
 
 	if c.ClientIP != nil {

infra/conf/dns_test.go

@@ -2,6 +2,7 @@ package conf_test
 
 import (
 	"encoding/json"
+	"strings"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
@@ -122,3 +123,57 @@ func TestDNSConfigParsing(t *testing.T) {
 		}
 	}
 }
+
+func TestDNSNameServerID(t *testing.T) {
+	var parsed DNSConfig
+	if err := json.Unmarshal([]byte(`{"servers":[{"id":"primary","address":"1.1.1.1"}]}`), &parsed); err != nil {
+		t.Fatal(err)
+	}
+	built, err := parsed.Build()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(built.NameServer) != 1 || built.NameServer[0].Id != "primary" {
+		t.Fatalf("nameserver IDs = %v, want primary", built.NameServer)
+	}
+}
+
+func TestDNSScriptConfig(t *testing.T) {
+	for _, test := range []struct {
+		name      string
+		input     string
+		wantError string
+	}{
+		{name: "script only", input: `{"script":"script.lua"}`},
+		{name: "compatible fields", input: `{"script":"script.lua","servers":["1.1.1.1",{"id":"primary","address":"8.8.8.8","expectedIPs":["8.8.8.8"],"queryStrategy":"UseIPv4","disableCache":true}],"hosts":{"example.com":"127.0.0.1"},"disableCache":true}`},
+		{name: "disabled options", input: `{"script":"script.lua","disableFallback":false,"disableFallbackIfMatch":false,"enableParallelQuery":false,"servers":[{"address":"1.1.1.1","domains":[],"skipFallback":false,"finalQuery":false}]}`},
+		{name: "domains", input: `{"script":"script.lua","servers":[{"address":"1.1.1.1","domains":["domain:example.com"]}]}`, wantError: "domains"},
+		{name: "skip fallback", input: `{"script":"script.lua","servers":[{"address":"1.1.1.1","skipFallback":true}]}`, wantError: "skipFallback"},
+		{name: "final query", input: `{"script":"script.lua","servers":[{"address":"1.1.1.1","finalQuery":true}]}`, wantError: "finalQuery"},
+		{name: "later server", input: `{"script":"script.lua","servers":["1.1.1.1",{"address":"8.8.8.8","finalQuery":true}]}`, wantError: "server 1"},
+		{name: "disable fallback", input: `{"script":"script.lua","disableFallback":true}`, wantError: "disableFallback"},
+		{name: "disable fallback if match", input: `{"script":"script.lua","disableFallbackIfMatch":true}`, wantError: "disableFallbackIfMatch"},
+		{name: "parallel query", input: `{"script":"script.lua","enableParallelQuery":true}`, wantError: "enableParallelQuery"},
+		{name: "empty script", input: `{"script":"","disableFallback":true,"disableFallbackIfMatch":true,"enableParallelQuery":true,"servers":[{"address":"1.1.1.1","domains":["example.com"],"skipFallback":true,"finalQuery":true}]}`},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			var config DNSConfig
+			if err := json.Unmarshal([]byte(test.input), &config); err != nil {
+				t.Fatal(err)
+			}
+			built, err := config.Build()
+			if test.wantError != "" {
+				if built != nil || err == nil || !strings.Contains(err.Error(), "DNS script cannot be used with ") || !strings.Contains(err.Error(), test.wantError) {
+					t.Fatalf("Build() = %v, %v; want nil config and script conflict error mentioning %s", built, err, test.wantError)
+				}
+				return
+			}
+			if err != nil {
+				t.Fatal(err)
+			}
+			if built.Script != config.Script || len(built.NameServer) != len(config.Servers) {
+				t.Fatalf("Build() did not preserve script or servers: %v", built)
+			}
+		})
+	}
+}

infra/conf/masque_test.go

@@ -1,7 +1,14 @@
 package conf_test
 
 import (
+	"crypto/ecdsa"
+	"crypto/ed25519"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/x509"
+	"encoding/base64"
 	"encoding/json"
+	"encoding/pem"
 	"testing"
 
 	"github.com/xtls/xray-core/common/protocol"
@@ -9,8 +16,61 @@ import (
 	. "github.com/xtls/xray-core/infra/conf"
 	masqueproxy "github.com/xtls/xray-core/proxy/masque"
 	"github.com/xtls/xray-core/transport/internet/masque"
+	"github.com/xtls/xray-core/transport/internet/splithttp"
 )
 
+func defaultMasqueXmux() *splithttp.XmuxConfig {
+	return &splithttp.XmuxConfig{
+		MaxConcurrency:   &splithttp.RangeConfig{},
+		MaxConnections:   &splithttp.RangeConfig{From: 1, To: 1},
+		CMaxReuseTimes:   &splithttp.RangeConfig{},
+		HMaxRequestTimes: &splithttp.RangeConfig{},
+		HMaxReusableSecs: &splithttp.RangeConfig{From: 1800, To: 3000},
+	}
+}
+
+func TestMasqueXmuxConfig(t *testing.T) {
+	creator := func() Buildable {
+		return new(MasqueConfig)
+	}
+
+	runMultiTestCase(t, []TestCase{
+		{
+			Input:  `{"xmux": {"maxConnections": "2-4", "hMaxReusableSecs": 60, "hKeepAlivePeriod": -1}}`,
+			Parser: loadJSON(creator),
+			Output: &masque.Config{
+				Path: "/.well-known/masque/ip/*/*/",
+				Xmux: &splithttp.XmuxConfig{
+					MaxConcurrency:   &splithttp.RangeConfig{},
+					MaxConnections:   &splithttp.RangeConfig{From: 2, To: 4},
+					CMaxReuseTimes:   &splithttp.RangeConfig{},
+					HMaxRequestTimes: &splithttp.RangeConfig{},
+					HMaxReusableSecs: &splithttp.RangeConfig{From: 60, To: 60},
+					HKeepAlivePeriod: -1,
+				},
+			},
+		},
+		{
+			Input:  `{"xmux": {"maxConcurrency": 8}}`,
+			Parser: loadJSON(creator),
+			Output: &masque.Config{
+				Path: "/.well-known/masque/ip/*/*/",
+				Xmux: &splithttp.XmuxConfig{
+					MaxConcurrency:   &splithttp.RangeConfig{From: 8, To: 8},
+					MaxConnections:   &splithttp.RangeConfig{},
+					CMaxReuseTimes:   &splithttp.RangeConfig{},
+					HMaxRequestTimes: &splithttp.RangeConfig{},
+					HMaxReusableSecs: &splithttp.RangeConfig{},
+				},
+			},
+		},
+	})
+
+	if _, err := loadJSON(creator)(`{"xmux": {"maxConnections": 2, "maxConcurrency": 8}}`); err == nil {
+		t.Error("expected an error for maxConnections with maxConcurrency")
+	}
+}
+
 func TestMasqueConfig(t *testing.T) {
 	creator := func() Buildable {
 		return new(MasqueConfig)
@@ -20,7 +80,7 @@ func TestMasqueConfig(t *testing.T) {
 		{
 			Input:  `{}`,
 			Parser: loadJSON(creator),
-			Output: &masque.Config{Path: "/.well-known/masque/ip/*/*/"},
+			Output: &masque.Config{Path: "/.well-known/masque/ip/*/*/", Xmux: defaultMasqueXmux()},
 		},
 		{
 			Input: `{
@@ -33,12 +93,13 @@ func TestMasqueConfig(t *testing.T) {
 				Host:    "example.com:8443",
 				Path:    "/.well-known/masque/ip/*/*/",
 				Headers: map[string]string{"Authorization": "Basic dTpw"},
+				Xmux:    defaultMasqueXmux(),
 			},
 		},
 		{
 			Input:  `{"path": "/masque/ip{?target,ipproto}"}`,
 			Parser: loadJSON(creator),
-			Output: &masque.Config{Path: "/masque/ip?target=*&ipproto=*"},
+			Output: &masque.Config{Path: "/masque/ip?target=*&ipproto=*", Xmux: defaultMasqueXmux()},
 		},
 		{
 			Input:  `{"user": "u", "pass": "p:q", "headers": {"X-Token": "a"}}`,
@@ -46,6 +107,7 @@ func TestMasqueConfig(t *testing.T) {
 			Output: &masque.Config{
 				Path:    "/.well-known/masque/ip/*/*/",
 				Headers: map[string]string{"Authorization": "Basic dTpwOnE=", "X-Token": "a"},
+				Xmux:    defaultMasqueXmux(),
 			},
 		},
 	})
@@ -67,6 +129,124 @@ func TestMasqueConfig(t *testing.T) {
 	}
 }
 
+func TestMasqueWarpConfig(t *testing.T) {
+	creator := func() Buildable {
+		return new(MasqueConfig)
+	}
+	key, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	pkcs8, err := x509.MarshalPKCS8PrivateKey(key)
+	if err != nil {
+		t.Fatal(err)
+	}
+	sec1, err := x509.MarshalECPrivateKey(key)
+	if err != nil {
+		t.Fatal(err)
+	}
+	quote := func(s string) string {
+		b, _ := json.Marshal(s)
+		return string(b)
+	}
+	server, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	publicKey, err := x509.MarshalPKIXPublicKey(&server.PublicKey)
+	if err != nil {
+		t.Fatal(err)
+	}
+	publicPEM := string(pem.EncodeToMemory(&pem.Block{Type: "PUBLIC KEY", Bytes: publicKey}))
+	warpInput := func(key string, extra string) string {
+		return `{` + extra + `"warp": {"privateKey": ` + quote(key) + `, "publicKey": ` + quote(publicPEM) + `, "address": ["172.16.0.2", "2606:4700:110:8a36::2/128"]}}`
+	}
+	address := []string{"172.16.0.2/32", "2606:4700:110:8a36::2/128"}
+
+	for _, input := range []string{
+		string(pem.EncodeToMemory(&pem.Block{Type: "PRIVATE KEY", Bytes: pkcs8})),
+		string(pem.EncodeToMemory(&pem.Block{Type: "EC PRIVATE KEY", Bytes: sec1})),
+		base64.StdEncoding.EncodeToString(pkcs8),
+		base64.StdEncoding.EncodeToString(sec1),
+	} {
+		runMultiTestCase(t, []TestCase{
+			{
+				Input:  warpInput(input, ""),
+				Parser: loadJSON(creator),
+				Output: &masque.Config{
+					Host: "cloudflareaccess.com",
+					Path: "/",
+					Warp: &masque.Warp{PrivateKey: pkcs8, PublicKey: publicKey, Address: address},
+					Xmux: defaultMasqueXmux(),
+				},
+			},
+		})
+	}
+	runMultiTestCase(t, []TestCase{
+		{
+			Input:  warpInput(base64.StdEncoding.EncodeToString(sec1), `"host": "example.com", "path": "/warp", `),
+			Parser: loadJSON(creator),
+			Output: &masque.Config{
+				Host: "example.com",
+				Path: "/warp",
+				Warp: &masque.Warp{PrivateKey: pkcs8, PublicKey: publicKey, Address: address},
+				Xmux: defaultMasqueXmux(),
+			},
+		},
+	})
+
+	p384, err := ecdsa.GenerateKey(elliptic.P384(), rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	p384DER, err := x509.MarshalPKCS8PrivateKey(p384)
+	if err != nil {
+		t.Fatal(err)
+	}
+	ed, err := x509.MarshalPKCS8PrivateKey(ed25519.NewKeyFromSeed(make([]byte, ed25519.SeedSize)))
+	if err != nil {
+		t.Fatal(err)
+	}
+	withAddress := func(address string) string {
+		return `{"warp": {"privateKey": ` + quote(base64.StdEncoding.EncodeToString(pkcs8)) + `, "publicKey": ` + quote(publicPEM) + `, "address": ` + address + `}}`
+	}
+	withPublicKey := func(key string) string {
+		return `{"warp": {"privateKey": ` + quote(base64.StdEncoding.EncodeToString(pkcs8)) + `, "publicKey": ` + quote(key) + `, "address": ["172.16.0.2"]}}`
+	}
+	runMultiTestCase(t, []TestCase{
+		{
+			Input:  withPublicKey(base64.StdEncoding.EncodeToString(publicKey)),
+			Parser: loadJSON(creator),
+			Output: &masque.Config{
+				Host: "cloudflareaccess.com",
+				Path: "/",
+				Warp: &masque.Warp{PrivateKey: pkcs8, PublicKey: publicKey, Address: []string{"172.16.0.2/32"}},
+				Xmux: defaultMasqueXmux(),
+			},
+		},
+	})
+	for _, input := range []string{
+		`{"warp": {}}`,
+		withAddress(`[]`),
+		withPublicKey(""),
+		withPublicKey("not a key"),
+		withPublicKey(base64.StdEncoding.EncodeToString([]byte("not a key"))),
+		withPublicKey(base64.StdEncoding.EncodeToString(pkcs8)),
+		withAddress(`["172.16.0"]`),
+		withAddress(`["172.16.0.2", "172.16.0.3"]`),
+		withAddress(`["2606:4700::1", "2606:4700::2/128"]`),
+		warpInput("not a key", ""),
+		warpInput(base64.StdEncoding.EncodeToString([]byte("not a key")), ""),
+		warpInput(base64.StdEncoding.EncodeToString(p384DER), ""),
+		warpInput(base64.StdEncoding.EncodeToString(ed), ""),
+		warpInput(base64.StdEncoding.EncodeToString(pkcs8), `"user": "u", "pass": "p", `),
+	} {
+		if _, err := loadJSON(creator)(input); err == nil {
+			t.Errorf("expected an error for %s", input)
+		}
+	}
+}
+
 func TestMasqueOutboundConfig(t *testing.T) {
 	build := func(s string) error {
 		c := new(OutboundDetourConfig)
@@ -77,18 +257,17 @@ func TestMasqueOutboundConfig(t *testing.T) {
 		return err
 	}
 
-	if err := build(`{
-		"protocol": "masque",
-		"settings": {"address": "example.com", "port": 443},
-		"streamSettings": {"network": "masque", "security": "tls"},
-		"mux": {"enabled": false, "concurrency": -1}
-	}`); err != nil {
-		t.Error(err)
+	for _, input := range []string{
+		`{"protocol": "masque", "settings": {"address": "example.com", "port": 443}, "streamSettings": {"network": "masque", "security": "tls"}, "mux": {"enabled": false, "concurrency": -1}}`,
+		`{"protocol": "masque", "settings": {"address": "example.com", "port": 443}, "streamSettings": {"network": "masque", "security": "tls"}, "mux": {"enabled": true}}`,
+		`{"protocol": "masque", "settings": {"address": "example.com", "port": 443}, "streamSettings": {"network": "masque", "security": "tls"}, "mux": {"enabled": true, "concurrency": -1, "xudpConcurrency": 8}}`,
+	} {
+		if err := build(input); err != nil {
+			t.Errorf("%s: %v", input, err)
+		}
 	}
 	for _, input := range []string{
 		`{"protocol": "masque", "settings": {"address": "example.com"}, "streamSettings": {"network": "masque", "security": "tls"}}`,
-		`{"protocol": "masque", "settings": {"address": "example.com", "port": 443}, "streamSettings": {"network": "masque", "security": "tls"}, "mux": {"enabled": true}}`,
-		`{"protocol": "masque", "settings": {"address": "example.com", "port": 443}, "streamSettings": {"network": "masque", "security": "tls"}, "mux": {"enabled": true, "concurrency": -1}}`,
 		`{"protocol": "freedom", "streamSettings": {"network": "masque", "security": "tls"}}`,
 	} {
 		if err := build(input); err == nil {

infra/conf/router.go

@@ -72,6 +72,7 @@ type RouterConfig struct {
 	RuleList       []json.RawMessage `json:"rules"`
 	DomainStrategy *string           `json:"domainStrategy"`
 	Balancers      []*BalancingRule  `json:"balancers"`
+	Script         string            `json:"script"`
 }
 
 func (c *RouterConfig) getDomainStrategy() router.Config_DomainStrategy {
@@ -92,6 +93,12 @@ func (c *RouterConfig) getDomainStrategy() router.Config_DomainStrategy {
 
 func (c *RouterConfig) Build() (*router.Config, error) {
 	config := new(router.Config)
+
+	if c.Script != "" && (c.DomainStrategy != nil || len(c.RuleList) > 0) {
+		return nil, errors.New("routing script cannot be used with domainStrategy or rules")
+	}
+	config.Script = c.Script
+
 	config.DomainStrategy = c.getDomainStrategy()
 
 	var rawRuleList []json.RawMessage

infra/conf/router_test.go

@@ -2,6 +2,7 @@ package conf_test
 
 import (
 	"encoding/json"
+	"strings"
 	"testing"
 	"time"
 	_ "unsafe"
@@ -236,3 +237,40 @@ func TestRouterConfig(t *testing.T) {
 		},
 	})
 }
+
+func TestRouterScriptConfig(t *testing.T) {
+	for _, test := range []struct {
+		name      string
+		input     string
+		wantError bool
+	}{
+		{name: "script only", input: `{"script":"missing.lua"}`},
+		{name: "empty rules", input: `{"script":"missing.lua","rules":[]}`},
+		{name: "balancers", input: `{"script":"missing.lua","balancers":[{"tag":"b1","selector":["direct"]}]}`},
+		{name: "default domain strategy", input: `{"script":"missing.lua","domainStrategy":"AsIs"}`, wantError: true},
+		{name: "IP domain strategy", input: `{"script":"missing.lua","domainStrategy":"IPIfNonMatch"}`, wantError: true},
+		{name: "empty domain strategy", input: `{"script":"missing.lua","domainStrategy":""}`, wantError: true},
+		{name: "rules", input: `{"script":"missing.lua","rules":[{"outboundTag":"direct","domain":["example.com"]}]}`, wantError: true},
+		{name: "empty script", input: `{"script":"","domainStrategy":"IPOnDemand","rules":[{"outboundTag":"direct","domain":["example.com"]}]}`},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			var config RouterConfig
+			if err := json.Unmarshal([]byte(test.input), &config); err != nil {
+				t.Fatal(err)
+			}
+			built, err := config.Build()
+			if test.wantError {
+				if built != nil || err == nil || !strings.Contains(err.Error(), "routing script cannot be used with domainStrategy or rules") {
+					t.Fatalf("Build() = %v, %v; want nil config and script conflict error", built, err)
+				}
+				return
+			}
+			if err != nil {
+				t.Fatal(err)
+			}
+			if built.Script != config.Script || len(built.Rule) != len(config.RuleList) || len(built.BalancingRule) != len(config.Balancers) {
+				t.Fatalf("Build() did not preserve script, rules or balancers: %v", built)
+			}
+		})
+	}
+}

infra/conf/transport_finalmask.go

@@ -1,6 +1,7 @@
 package conf
 
 import (
+	"context"
 	"crypto/x509"
 	"encoding/base64"
 	"encoding/hex"
@@ -81,7 +82,7 @@ var (
 		"noise":         func() interface{} { return new(NoiseMask) },
 		"salamander":    func() interface{} { return new(Salamander) },
 		"sudoku":        func() interface{} { return new(Sudoku) },
-		"xdns":          func() interface{} { return new(Xdns) },
+		"xdns":          func() interface{} { return new(XDNS) },
 		"xicmp":         func() interface{} { return new(Xicmp) },
 		"realm":         func() interface{} { return new(Realm) },
 		"udphop":        func() interface{} { return new(UDPHop) },
@@ -308,14 +309,27 @@ type NoiseMask struct {
 }
 
 func (c *NoiseMask) Build() (proto.Message, error) {
+	noiseSlice := make([]*noise.Item, 0, len(c.Noise))
 	for _, item := range c.Noise {
 		if len(item.Packet) > 0 && item.Rand.To > 0 {
 			return nil, errors.New("len(item.Packet) > 0 && item.Rand.To > 0")
 		}
-	}
-
-	noiseSlice := make([]*noise.Item, 0, len(c.Noise))
-	for _, item := range c.Noise {
+		if strings.ToLower(item.Type) == "exp" {
+			var exp string
+			if err := json.Unmarshal(item.Packet, &exp); err != nil {
+				return nil, errors.New(`"packet" of noise "type": "exp" must be a string`).Base(err)
+			}
+			segments, err := parseNoiseExp(exp)
+			if err != nil {
+				return nil, err
+			}
+			noiseSlice = append(noiseSlice, &noise.Item{
+				Segments: segments,
+				DelayMin: int64(item.Delay.From),
+				DelayMax: int64(item.Delay.To),
+			})
+			continue
+		}
 		if item.RandRange == nil {
 			item.RandRange = &Int32Range{From: 0, To: 255}
 		}
@@ -344,6 +358,88 @@ func (c *NoiseMask) Build() (proto.Message, error) {
 	}, nil
 }
 
+var noiseExpPattern = regexp.MustCompile(`<\s*([a-z]+)(?:\s+([^>]*?))?\s*>`)
+
+func parseNoiseExp(exp string) ([]*noise.Segment, error) {
+	var segments []*noise.Segment
+	matches := noiseExpPattern.FindAllStringSubmatchIndex(exp, -1)
+	last := 0
+	for _, m := range matches {
+		if strings.TrimSpace(exp[last:m[0]]) != "" {
+			return nil, errors.New("invalid noise exp near ", exp[last:m[0]])
+		}
+		last = m[1]
+		key := exp[m[2]:m[3]]
+		arg := ""
+		if m[4] >= 0 {
+			arg = exp[m[4]:m[5]]
+		}
+		segment, err := buildNoiseSegment(key, arg)
+		if err != nil {
+			return nil, err
+		}
+		segments = append(segments, segment)
+	}
+	if strings.TrimSpace(exp[last:]) != "" {
+		return nil, errors.New("invalid noise exp near ", exp[last:])
+	}
+	if len(segments) == 0 {
+		return nil, errors.New("empty noise exp: ", exp)
+	}
+	return segments, nil
+}
+
+func buildNoiseSegment(key, arg string) (*noise.Segment, error) {
+	sizeSegment := func(kind noise.Segment_Kind) (*noise.Segment, error) {
+		if arg == "" {
+			return nil, errors.New("<", key, "> in noise exp needs a size")
+		}
+		lo, hi, err := ParseRangeString(arg)
+		if err != nil {
+			return nil, err
+		}
+		if lo < 0 || hi < lo || hi > 65535 {
+			return nil, errors.New("invalid size in noise exp: ", arg)
+		}
+		return &noise.Segment{Kind: kind, MinSize: int64(lo), MaxSize: int64(hi)}, nil
+	}
+	switch key {
+	case "b":
+		hexStr := strings.TrimPrefix(strings.TrimPrefix(strings.Join(strings.Fields(arg), ""), "0x"), "0X")
+		if len(hexStr) == 0 {
+			return nil, errors.New("empty bytes in noise exp")
+		}
+		raw, err := hex.DecodeString(hexStr)
+		if err != nil {
+			return nil, errors.New("invalid hex in noise exp: ", arg).Base(err)
+		}
+		return &noise.Segment{Kind: noise.Segment_BYTES, Bytes: raw}, nil
+	case "r":
+		return sizeSegment(noise.Segment_RANDOM)
+	case "rc":
+		return sizeSegment(noise.Segment_RANDOM_ASCII)
+	case "rd":
+		return sizeSegment(noise.Segment_RANDOM_DIGIT)
+	case "t":
+		if arg != "" {
+			return nil, errors.New("<t> in noise exp takes no argument")
+		}
+		return &noise.Segment{Kind: noise.Segment_TIMESTAMP}, nil
+	case "c":
+		if arg != "" {
+			return nil, errors.New("<c> in noise exp takes no argument")
+		}
+		return &noise.Segment{Kind: noise.Segment_COUNTER}, nil
+	case "n":
+		if arg != "" {
+			return nil, errors.New("<n> in noise exp takes no argument")
+		}
+		return &noise.Segment{Kind: noise.Segment_NONCE}, nil
+	default:
+		return nil, errors.New("unknown <", key, "> in noise exp")
+	}
+}
+
 type UDPItem struct {
 	Rand      int32            `json:"rand"`
 	RandRange *Int32Range      `json:"randRange"`
@@ -694,32 +790,79 @@ func (c *Sudoku) Build() (proto.Message, error) {
 	}, nil
 }
 
-type Xdns struct {
-	Domain json.RawMessage `json:"domain"`
-
-	Domains   []string `json:"domains"`
-	Resolvers []string `json:"resolvers"`
+type XDNSDomain struct {
+	Names      []string `json:"names"`
+	LenLimit   int32    `json:"lenLimit"`
+	LabelLimit int32    `json:"labelLimit"`
+	Types      []int32  `json:"types"`
+	Edns0      int32    `json:"edns0"`
 }
 
-func (c *Xdns) Build() (proto.Message, error) {
-	if c.Domain != nil {
-		return nil, errors.PrintRemovedFeatureError("domain", "domains(server) & resolvers(client)")
-	}
+type XDNSResolver struct {
+	Addrs []string `json:"addrs"`
+}
 
-	if len(c.Domains) == 0 && len(c.Resolvers) == 0 {
-		return nil, errors.New("empty domains & empty resolvers")
-	}
+type XDNS struct {
+	Domains   []XDNSDomain   `json:"domains"`
+	Resolvers []XDNSResolver `json:"resolvers"`
+	ExtraPoll int32          `json:"extraPoll"`
+}
 
-	for _, r := range c.Resolvers {
-		if !strings.Contains(r, "+udp://") {
-			return nil, errors.New("invalid resolver ", r)
+func (c *XDNS) Build() (proto.Message, error) {
+	var domains []*xdns.DomainProto
+	var resolvers []*xdns.ResolverProto
+	for i := range c.Domains {
+		if c.Domains[i].LenLimit == 0 {
+			c.Domains[i].LenLimit = 255
+		}
+		if c.Domains[i].LabelLimit == 0 {
+			c.Domains[i].LabelLimit = 63
+		}
+		for j := range c.Domains[i].Names {
+			domain, err := xdns.NewDomain(c.Domains[i].Names[j], int(c.Domains[i].LenLimit), int(c.Domains[i].LabelLimit), []uint16{1, 5, 16, 28}, uint16(c.Domains[i].Edns0))
+			if err != nil {
+				return nil, err
+			}
+			errors.LogInfo(context.Background(), domain.Show())
+			domains = append(domains, &xdns.DomainProto{
+				Name:       c.Domains[i].Names[j],
+				LenLimit:   c.Domains[i].LenLimit,
+				LabelLimit: c.Domains[i].LabelLimit,
+				Types:      c.Domains[i].Types,
+				Edns0:      c.Domains[i].Edns0,
+			})
 		}
 	}
-
-	return &xdns.Config{
-		Domains:   c.Domains,
-		Resolvers: c.Resolvers,
-	}, nil
+	for i := range c.Resolvers {
+		for j := range c.Resolvers[i].Addrs {
+			var u *url.URL
+			var e error
+			if !strings.Contains(c.Resolvers[i].Addrs[j], "://") {
+				u, e = url.Parse("udp://" + c.Resolvers[i].Addrs[j])
+			} else {
+				u, e = url.Parse(c.Resolvers[i].Addrs[j])
+			}
+			if e != nil {
+				return nil, e
+			}
+			switch u.Scheme {
+			case "tcp", "udp":
+			default:
+				return nil, errors.New("invalid protocol")
+			}
+			var host, port string
+			host = u.Hostname()
+			port = u.Port()
+			if port == "" {
+				port = "53"
+			}
+			resolvers = append(resolvers, &xdns.ResolverProto{Type: u.Scheme, Addr: net.JoinHostPort(host, port)})
+		}
+	}
+	if c.ExtraPoll < 0 || c.ExtraPoll > 3 {
+		return nil, errors.New("c.ExtraPoll < 0 || c.ExtraPoll > 3")
+	}
+	return &xdns.Config{Domains: domains, Resolvers: resolvers, ExtraPoll: c.ExtraPoll}, nil
 }
 
 type XMC struct {

infra/conf/transport_finalmask_noise_test.go

@@ -0,0 +1,136 @@
+package conf
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/xtls/xray-core/transport/internet/finalmask/noise"
+)
+
+func expPacket(exp string) json.RawMessage {
+	b, _ := json.Marshal(exp)
+	return b
+}
+
+func buildNoiseExp(exp string) (*noise.Config, error) {
+	msg, err := (&NoiseMask{Noise: []NoiseItem{{Type: "exp", Packet: expPacket(exp)}}}).Build()
+	if err != nil {
+		return nil, err
+	}
+	return msg.(*noise.Config), nil
+}
+
+func TestNoiseExp(t *testing.T) {
+	cfg, err := buildNoiseExp("<b 0d0a0d0a><t><r 24><rc 20-40><rd 8><c><n>")
+	if err != nil {
+		t.Fatal(err)
+	}
+	segments := cfg.Items[0].Segments
+	if len(segments) != 7 {
+		t.Fatalf("got %d segments, want 7", len(segments))
+	}
+	want := []struct {
+		kind     noise.Segment_Kind
+		bytes    []byte
+		min, max int64
+	}{
+		{noise.Segment_BYTES, []byte{0x0d, 0x0a, 0x0d, 0x0a}, 0, 0},
+		{noise.Segment_TIMESTAMP, nil, 0, 0},
+		{noise.Segment_RANDOM, nil, 24, 24},
+		{noise.Segment_RANDOM_ASCII, nil, 20, 40},
+		{noise.Segment_RANDOM_DIGIT, nil, 8, 8},
+		{noise.Segment_COUNTER, nil, 0, 0},
+		{noise.Segment_NONCE, nil, 0, 0},
+	}
+	for i, w := range want {
+		s := segments[i]
+		if s.Kind != w.kind || s.MinSize != w.min || s.MaxSize != w.max || string(s.Bytes) != string(w.bytes) {
+			t.Errorf("segment %d = %+v, want %+v", i, s, w)
+		}
+	}
+}
+
+func TestNoiseExpStripsHexPrefix(t *testing.T) {
+	cfg, err := buildNoiseExp("<b 0x16030100>")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := cfg.Items[0].Segments[0].Bytes; string(got) != string([]byte{0x16, 0x03, 0x01, 0x00}) {
+		t.Errorf("got %x", got)
+	}
+}
+
+func TestNoiseExpWhitespace(t *testing.T) {
+	if _, err := buildNoiseExp("  <b 00>  <t>  "); err != nil {
+		t.Errorf("surrounding whitespace should be allowed: %v", err)
+	}
+	cfg, err := buildNoiseExp("<b 0d 0a 0d 0a>")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := cfg.Items[0].Segments[0].Bytes; string(got) != "\r\n\r\n" {
+		t.Errorf("got %x", got)
+	}
+}
+
+func TestNoiseExpRejects(t *testing.T) {
+	for _, exp := range []string{
+		"<x 1>",
+		"<b>",
+		"<b zz>",
+		"<b 0d0>",
+		"<r>",
+		"<r -1>",
+		"<r 40-20>",
+		"<r 70000>",
+		"<t 5>",
+		"<n 5>",
+		"garbage<t>",
+		"<t> tail",
+		"<t><b>",
+	} {
+		if _, err := buildNoiseExp(exp); err == nil {
+			t.Errorf("expected an error for %q", exp)
+		}
+	}
+}
+
+func TestNoiseExpConflicts(t *testing.T) {
+	if _, err := (&NoiseMask{Noise: []NoiseItem{{Type: "exp", Packet: expPacket("<t>"), Rand: Int32Range{From: 10, To: 20}}}}).Build(); err == nil {
+		t.Error("exp with rand should be rejected")
+	}
+	for _, packet := range []string{``, `[1, 2]`, `5`} {
+		if _, err := (&NoiseMask{Noise: []NoiseItem{{Type: "exp", Packet: json.RawMessage(packet)}}}).Build(); err == nil {
+			t.Errorf("expected an error for packet %q", packet)
+		}
+	}
+}
+
+func TestNoiseExpFromJSON(t *testing.T) {
+	var mask NoiseMask
+	if err := json.Unmarshal([]byte(`{"noise": [
+		{"type": "exp", "packet": "<b 504f5354><rd 10-20>", "delay": "1-3"},
+		{"type": "EXP", "packet": "<t>"},
+		{"type": "str", "packet": "<t>"},
+		{"rand": "10-20"}
+	]}`), &mask); err != nil {
+		t.Fatal(err)
+	}
+	msg, err := mask.Build()
+	if err != nil {
+		t.Fatal(err)
+	}
+	items := msg.(*noise.Config).Items
+	if len(items[0].Segments) != 2 || items[0].DelayMin != 1 || items[0].DelayMax != 3 {
+		t.Errorf("item 0 = %+v", items[0])
+	}
+	if len(items[1].Segments) != 1 || items[1].Segments[0].Kind != noise.Segment_TIMESTAMP {
+		t.Errorf("item 1 = %+v", items[1])
+	}
+	if len(items[2].Segments) != 0 || string(items[2].Packet) != "<t>" {
+		t.Errorf("item 2 = %+v", items[2])
+	}
+	if len(items[3].Segments) != 0 || items[3].RandMin != 10 || items[3].RandMax != 20 {
+		t.Errorf("item 3 = %+v", items[3])
+	}
+}

infra/conf/transport_method.go

@@ -1,10 +1,15 @@
 package conf
 
 import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/x509"
 	"encoding/base64"
 	"encoding/json"
+	"encoding/pem"
 	"maps"
 	"math/big"
+	"net/netip"
 	"net/url"
 	"sort"
 	"strconv"
@@ -790,16 +795,50 @@ func (c *HysteriaConfig) Build() (proto.Message, error) {
 	return config, nil
 }
 
+type MasqueWarpConfig struct {
+	PrivateKey string   `json:"privateKey"`
+	PublicKey  string   `json:"publicKey"`
+	Address    []string `json:"address"`
+}
+
 type MasqueConfig struct {
 	Host    string            `json:"host"`
 	Path    string            `json:"path"`
 	User    string            `json:"user"`
 	Pass    string            `json:"pass"`
 	Headers map[string]string `json:"headers"`
+	Warp    *MasqueWarpConfig `json:"warp"`
+	Xmux    XmuxConfig        `json:"xmux"`
 }
 
 func (c *MasqueConfig) Build() (proto.Message, error) {
+	var warp *masque.Warp
+	host := c.Host
 	path := c.Path
+	if c.Warp != nil {
+		if c.User != "" || c.Pass != "" {
+			return nil, errors.New(`"user" and "pass" can't be used with "warp"`)
+		}
+		key, err := parseWarpPrivateKey(c.Warp.PrivateKey)
+		if err != nil {
+			return nil, errors.New(`invalid "privateKey" in "warp"`).Base(err)
+		}
+		publicKey, err := parseWarpPublicKey(c.Warp.PublicKey)
+		if err != nil {
+			return nil, errors.New(`invalid "publicKey" in "warp"`).Base(err)
+		}
+		address, err := parseWarpAddress(c.Warp.Address)
+		if err != nil {
+			return nil, err
+		}
+		warp = &masque.Warp{PrivateKey: key, PublicKey: publicKey, Address: address}
+		if host == "" {
+			host = masque.WarpHost
+		}
+		if path == "" {
+			path = masque.WarpPath
+		}
+	}
 	if path == "" {
 		path = masque.DefaultPath
 	}
@@ -811,9 +850,9 @@ func (c *MasqueConfig) Build() (proto.Message, error) {
 	if !strings.HasPrefix(path, "/") || strings.ContainsAny(path, "{}") {
 		return nil, errors.New(`invalid "path": `, path, `, only the variables {target} and {ipproto} are supported`)
 	}
-	if c.Host != "" {
-		if u, err := url.Parse("https://" + c.Host); err != nil || u.Host != c.Host {
-			return nil, errors.New(`invalid "host": `, c.Host)
+	if host != "" {
+		if u, err := url.Parse("https://" + host); err != nil || u.Host != host {
+			return nil, errors.New(`invalid "host": `, host)
 		}
 	}
 	for k, v := range c.Headers {
@@ -840,13 +879,101 @@ func (c *MasqueConfig) Build() (proto.Message, error) {
 		}
 		headers["Authorization"] = "Basic " + base64.StdEncoding.EncodeToString([]byte(c.User+":"+c.Pass))
 	}
+	if c.Xmux.MaxConnections.To > 0 && c.Xmux.MaxConcurrency.To > 0 {
+		return nil, errors.New("maxConnections cannot be specified together with maxConcurrency")
+	}
+	if c.Xmux == (XmuxConfig{}) {
+		c.Xmux.MaxConnections.From = 1
+		c.Xmux.MaxConnections.To = 1
+		c.Xmux.HMaxReusableSecs.From = 1800
+		c.Xmux.HMaxReusableSecs.To = 3000
+	}
 	return &masque.Config{
-		Host:    c.Host,
+		Host:    host,
 		Path:    path,
 		Headers: headers,
+		Warp:    warp,
+		Xmux: &splithttp.XmuxConfig{
+			MaxConcurrency:   newRangeConfig(c.Xmux.MaxConcurrency),
+			MaxConnections:   newRangeConfig(c.Xmux.MaxConnections),
+			CMaxReuseTimes:   newRangeConfig(c.Xmux.CMaxReuseTimes),
+			HMaxRequestTimes: newRangeConfig(c.Xmux.HMaxRequestTimes),
+			HMaxReusableSecs: newRangeConfig(c.Xmux.HMaxReusableSecs),
+			HKeepAlivePeriod: c.Xmux.HKeepAlivePeriod,
+		},
 	}, nil
 }
 
+func parseWarpAddress(list []string) ([]string, error) {
+	if len(list) == 0 {
+		return nil, errors.New(`"address" in "warp" is not set`)
+	}
+	var v4, v6 bool
+	address := make([]string, 0, len(list))
+	for _, s := range list {
+		prefix, err := netip.ParsePrefix(s)
+		if err != nil {
+			addr, err := netip.ParseAddr(s)
+			if err != nil {
+				return nil, errors.New(`invalid "address" in "warp": `, s)
+			}
+			prefix = netip.PrefixFrom(addr, addr.BitLen())
+		}
+		if prefix.Addr().Is4() && v4 || prefix.Addr().Is6() && v6 {
+			return nil, errors.New(`"address" in "warp" takes at most one IPv4 and one IPv6 address`)
+		}
+		v4 = v4 || prefix.Addr().Is4()
+		v6 = v6 || prefix.Addr().Is6()
+		address = append(address, prefix.String())
+	}
+	return address, nil
+}
+
+func decodeWarpKey(s string) ([]byte, error) {
+	s = strings.TrimSpace(s)
+	if s == "" {
+		return nil, errors.New("empty key")
+	}
+	if block, _ := pem.Decode([]byte(s)); block != nil {
+		return block.Bytes, nil
+	}
+	der, err := base64.StdEncoding.DecodeString(s)
+	if err != nil {
+		return nil, errors.New("neither PEM nor base64").Base(err)
+	}
+	return der, nil
+}
+
+func parseWarpPublicKey(s string) ([]byte, error) {
+	der, err := decodeWarpKey(s)
+	if err != nil {
+		return nil, err
+	}
+	if _, err := x509.ParsePKIXPublicKey(der); err != nil {
+		return nil, errors.New("not a PKIX public key").Base(err)
+	}
+	return der, nil
+}
+
+func parseWarpPrivateKey(s string) ([]byte, error) {
+	der, err := decodeWarpKey(s)
+	if err != nil {
+		return nil, err
+	}
+	var key any
+	key, err = x509.ParsePKCS8PrivateKey(der)
+	if err != nil {
+		if key, err = x509.ParseECPrivateKey(der); err != nil {
+			return nil, errors.New("neither a PKCS #8 nor a SEC 1 private key")
+		}
+	}
+	ecKey, ok := key.(*ecdsa.PrivateKey)
+	if !ok || ecKey.Curve != elliptic.P256() {
+		return nil, errors.New("not an ECDSA P-256 key")
+	}
+	return x509.MarshalPKCS8PrivateKey(ecKey)
+}
+
 func readFileOrString(f string, s []string) ([]byte, error) {
 	if len(f) > 0 {
 		return filesystem.ReadCert(f)

infra/conf/transport_security.go

@@ -316,6 +316,7 @@ type TLSConfig struct {
 	ECHServerKeys           string           `json:"echServerKeys"`
 	ECHConfigList           string           `json:"echConfigList"`
 	ECHSocketSettings       *SocketConfig    `json:"echSockopt"`
+	UseSystemCA             bool             `json:"useSystemCA"`
 }
 
 // Build implements Buildable.
@@ -403,6 +404,7 @@ func (c *TLSConfig) Build() (proto.Message, error) {
 		}
 		config.EchSocketSettings = ss
 	}
+	config.UseSystemCa = c.UseSystemCA
 
 	return config, nil
 }

infra/conf/tun.go

@@ -5,8 +5,12 @@ import (
 	"fmt"
 	"math/big"
 	"net"
+	"runtime"
+	"slices"
 	"strconv"
+	"strings"
 
+	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/proxy/tun"
 	"google.golang.org/protobuf/proto"
 )
@@ -20,7 +24,8 @@ type TunConfig struct {
 	UserLevel              uint32   `json:"userLevel"`
 	AutoSystemRoutingTable []string `json:"autoSystemRoutingTable"`
 	AutoOutboundsInterface *string  `json:"autoOutboundsInterface"`
-	AutoSystemDNS          bool     `json:"autoSystemDNS"`
+	AutoSystemDnsToGateway bool     `json:"autoSystemDnsToGateway"`
+	AutoSystemWfpBlockLeak []string `json:"autoSystemWfpBlockLeak"`
 }
 
 func (v *TunConfig) Build() (proto.Message, error) {
@@ -32,7 +37,32 @@ func (v *TunConfig) Build() (proto.Message, error) {
 		DNS:                    v.DNS,
 		UserLevel:              v.UserLevel,
 		AutoSystemRoutingTable: v.AutoSystemRoutingTable,
-		AutoSystemDns:          v.AutoSystemDNS,
+		AutoSystemDnsToGateway: v.AutoSystemDnsToGateway,
+	}
+	for _, leak := range v.AutoSystemWfpBlockLeak {
+		switch leak := strings.ToLower(leak); leak {
+		case "dns", "misconfigtun":
+			config.AutoSystemWfpBlockLeak = append(config.AutoSystemWfpBlockLeak, leak)
+		default:
+			return nil, errors.New("unknown autoSystemWfpBlockLeak value: ", leak)
+		}
+	}
+	// Each option needs other settings on the system it takes effect on: the
+	// filters go along with the routes of autoSystemRoutingTable, "dns" lets
+	// DNS through the TUN only, and autoSystemDnsToGateway points the system
+	// DNS at the gateway.
+	switch runtime.GOOS {
+	case "windows":
+		if len(config.AutoSystemWfpBlockLeak) > 0 && len(v.AutoSystemRoutingTable) == 0 {
+			return nil, errors.New("autoSystemWfpBlockLeak needs autoSystemRoutingTable to be set")
+		}
+		if slices.Contains(config.AutoSystemWfpBlockLeak, "dns") && len(v.DNS) == 0 {
+			return nil, errors.New(`autoSystemWfpBlockLeak "dns" needs dns to be set`)
+		}
+	case "linux", "freebsd":
+		if v.AutoSystemDnsToGateway && len(v.Gateway) == 0 {
+			return nil, errors.New("autoSystemDnsToGateway needs gateway to be set")
+		}
 	}
 	if v.AutoOutboundsInterface != nil {
 		config.AutoOutboundsInterface = *v.AutoOutboundsInterface

infra/conf/tun_test.go

@@ -0,0 +1,72 @@
+package conf_test
+
+import (
+	"encoding/json"
+	"runtime"
+	"slices"
+	"testing"
+
+	. "github.com/xtls/xray-core/infra/conf"
+	"github.com/xtls/xray-core/proxy/tun"
+)
+
+func TestTunConfigAutoSystem(t *testing.T) {
+	creator := func() Buildable {
+		return new(TunConfig)
+	}
+
+	runMultiTestCase(t, []TestCase{
+		{
+			Input:  `{"name": "xray0"}`,
+			Parser: loadJSON(creator),
+			Output: &tun.Config{Name: "xray0", Desc: "Wintun", MTU: 1500},
+		},
+		{
+			Input:  `{"name": "xray0", "gateway": ["10.0.0.1/24"], "autoSystemDnsToGateway": true}`,
+			Parser: loadJSON(creator),
+			Output: &tun.Config{Name: "xray0", Desc: "Wintun", MTU: 1500, Gateway: []string{"10.0.0.1/24"}, AutoSystemDnsToGateway: true},
+		},
+		{
+			Input:  `{"name": "xray0", "dns": ["1.1.1.1"], "autoSystemRoutingTable": ["0.0.0.0/0"], "autoSystemWfpBlockLeak": ["dns", "misconfigtun"]}`,
+			Parser: loadJSON(creator),
+			Output: &tun.Config{Name: "xray0", Desc: "Wintun", MTU: 1500, DNS: []string{"1.1.1.1"}, AutoSystemRoutingTable: []string{"0.0.0.0/0"}, AutoOutboundsInterface: "auto", AutoSystemWfpBlockLeak: []string{"dns", "misconfigtun"}},
+		},
+		{
+			Input:  `{"name": "xray0", "dns": ["1.1.1.1"], "autoSystemRoutingTable": ["0.0.0.0/0"], "autoSystemWfpBlockLeak": ["DNS"]}`,
+			Parser: loadJSON(creator),
+			Output: &tun.Config{Name: "xray0", Desc: "Wintun", MTU: 1500, DNS: []string{"1.1.1.1"}, AutoSystemRoutingTable: []string{"0.0.0.0/0"}, AutoOutboundsInterface: "auto", AutoSystemWfpBlockLeak: []string{"dns"}},
+		},
+	})
+}
+
+// TestTunConfigAutoSystemNeeds checks that an option is rejected without the
+// setting it needs, only on the system it takes effect on.
+func TestTunConfigAutoSystemNeeds(t *testing.T) {
+	for _, c := range []struct {
+		input string
+		goos  []string // where it is rejected
+	}{
+		{`{"name": "xray0", "autoSystemWfpBlockLeak": ["misconfigtun"]}`, []string{"windows"}},
+		{`{"name": "xray0", "autoSystemRoutingTable": ["0.0.0.0/0"], "autoSystemWfpBlockLeak": ["misconfigtun"]}`, nil},
+		{`{"name": "xray0", "autoSystemRoutingTable": ["0.0.0.0/0"], "autoSystemWfpBlockLeak": ["dns"]}`, []string{"windows"}},
+		{`{"name": "xray0", "autoSystemDnsToGateway": true}`, []string{"linux", "freebsd"}},
+	} {
+		config := new(TunConfig)
+		if err := json.Unmarshal([]byte(c.input), config); err != nil {
+			t.Fatal(err)
+		}
+		if _, err := config.Build(); (err != nil) != slices.Contains(c.goos, runtime.GOOS) {
+			t.Errorf("%s on %s: error = %v", c.input, runtime.GOOS, err)
+		}
+	}
+}
+
+func TestTunConfigAutoSystemWfpBlockLeakUnknown(t *testing.T) {
+	config := new(TunConfig)
+	if err := json.Unmarshal([]byte(`{"name": "xray0", "autoSystemWfpBlockLeak": ["dns", "ip"]}`), config); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := config.Build(); err == nil {
+		t.Error("an unknown autoSystemWfpBlockLeak value was accepted")
+	}
+}

infra/conf/xray.go

@@ -344,11 +344,7 @@ func (c *OutboundDetourConfig) Build() (*core.OutboundHandlerConfig, error) {
 		return nil, err
 	}
 
-	if _, ok := ts.(*masque.ClientConfig); ok {
-		if ms := senderSettings.MultiplexSettings; ms != nil && ms.Enabled {
-			return nil, errors.New(`masque outbound does not support "mux"`)
-		}
-	} else if senderSettings.StreamSettings != nil && senderSettings.StreamSettings.ProtocolName == "masque" {
+	if _, ok := ts.(*masque.ClientConfig); !ok && senderSettings.StreamSettings != nil && senderSettings.StreamSettings.ProtocolName == "masque" {
 		return nil, errors.New("the masque transport can only be used by the masque outbound")
 	}
 

main/commands/all/api/inbound_user_add.go

@@ -12,6 +12,7 @@ import (
 	"github.com/xtls/xray-core/core"
 	"github.com/xtls/xray-core/infra/conf"
 	"github.com/xtls/xray-core/infra/conf/serial"
+	"github.com/xtls/xray-core/proxy/hysteria"
 	"github.com/xtls/xray-core/proxy/masque"
 	"github.com/xtls/xray-core/proxy/shadowsocks"
 	"github.com/xtls/xray-core/proxy/shadowsocks_2022"
@@ -91,6 +92,8 @@ func extractInboundUsers(inb *core.InboundHandlerConfig) []*protocol.User {
 		return ty.Users
 	case *masque.ServerConfig:
 		return ty.Users
+	case *hysteria.ServerConfig:
+		return ty.Users
 	default:
 		fmt.Println("unsupported inbound type")
 	}

main/commands/all/base64/base64.go

@@ -0,0 +1,14 @@
+package base64
+
+import "github.com/xtls/xray-core/main/commands/base"
+
+// CmdBase64 holds all Base64 subcommands.
+var CmdBase64 = &base.Command{
+	UsageLine: "{{.Exec}} base64",
+	Short:     "Encode and decode Base64",
+	Long:      "{{.Exec}} {{.LongName}} provides tools to encode and decode arbitrary bytes.",
+	Commands: []*base.Command{
+		cmdEncode,
+		cmdDecode,
+	},
+}

main/commands/all/base64/decode.go

@@ -0,0 +1,66 @@
+package base64
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"strings"
+
+	xbase64 "github.com/xtls/xray-core/common/base64"
+	"github.com/xtls/xray-core/main/commands/base"
+)
+
+var cmdDecode = &base.Command{
+	UsageLine: "{{.Exec}} base64 decode [-gzip] <value | - | stdin:> [output-file]",
+	Short:     "Decode Base64",
+	Long: fmt.Sprintf(`
+Decode a Base64 value, or pass "-" or "stdin:" to read stdin.
+Write to output-file, or stdout if omitted.
+Accepts %s, %s, or no prefix; gzip is enabled by %s or -gzip.
+
+Examples:
+
+	{{.Exec}} base64 decode eA== out.bin
+	{{.Exec}} base64 decode -gzip H4sIAAAAAAAC/6sAAIMW3IwBAAAA out.bin
+`, xbase64.Prefix, xbase64.GzipPrefix, xbase64.GzipPrefix),
+}
+
+var decodeGzipEnabled = cmdDecode.Flag.Bool("gzip", false, "Decompress the decoded bytes with gzip.")
+
+func init() {
+	cmdDecode.Run = executeDecode
+}
+
+func executeDecode(cmd *base.Command, args []string) {
+	if len(args) == 0 || len(args) > 2 {
+		cmd.Usage()
+	}
+
+	value := args[0]
+	if value == "-" || value == "stdin:" {
+		input, err := io.ReadAll(os.Stdin)
+		if err != nil {
+			base.Fatalf("failed to read input: %s", err)
+		}
+		value = string(input)
+	}
+
+	value = strings.TrimSpace(value)
+	if *decodeGzipEnabled && !strings.HasPrefix(value, xbase64.GzipPrefix) {
+		value = xbase64.GzipPrefix + strings.TrimPrefix(value, xbase64.Prefix)
+	}
+
+	data, err := xbase64.Decode(value)
+	if err != nil {
+		base.Fatalf("failed to decode input: %s", err)
+	}
+
+	if len(args) == 2 && args[1] != "-" {
+		err = os.WriteFile(args[1], data, 0o666)
+	} else {
+		_, err = os.Stdout.Write(data)
+	}
+	if err != nil {
+		base.Fatalf("failed to write decoded output: %s", err)
+	}
+}

main/commands/all/base64/encode.go

@@ -0,0 +1,57 @@
+package base64
+
+import (
+	"fmt"
+	"io"
+	"os"
+
+	xbase64 "github.com/xtls/xray-core/common/base64"
+	"github.com/xtls/xray-core/main/commands/base"
+)
+
+var cmdEncode = &base.Command{
+	UsageLine: "{{.Exec}} base64 encode [-gzip] <input-file | - | stdin:>",
+	Short:     "Encode as Base64",
+	Long: fmt.Sprintf(`
+Encode input-file as Base64 with the %s prefix.
+Pass "-" or "stdin:" to read stdin.
+Use -gzip to compress and output %s.
+
+Examples:
+
+	{{.Exec}} base64 encode input.bin
+	{{.Exec}} base64 encode -gzip input.bin
+`, xbase64.Prefix, xbase64.GzipPrefix),
+}
+
+var gzipEnabled = cmdEncode.Flag.Bool("gzip", false, "Compress the input with gzip.")
+
+func init() {
+	cmdEncode.Run = executeEncode
+}
+
+func executeEncode(cmd *base.Command, args []string) {
+	if len(args) != 1 {
+		cmd.Usage()
+	}
+
+	var data []byte
+	var err error
+	if args[0] == "-" || args[0] == "stdin:" {
+		data, err = io.ReadAll(os.Stdin)
+	} else {
+		data, err = os.ReadFile(args[0])
+	}
+	if err != nil {
+		base.Fatalf("failed to read input: %s", err)
+	}
+
+	value, err := xbase64.Encode(data, *gzipEnabled)
+	if err != nil {
+		base.Fatalf("failed to encode input: %s", err)
+	}
+
+	if _, err := fmt.Fprintln(os.Stdout, value); err != nil {
+		base.Fatalf("failed to write encoded output: %s", err)
+	}
+}

main/commands/all/commands.go

@@ -2,6 +2,7 @@ package all
 
 import (
 	"github.com/xtls/xray-core/main/commands/all/api"
+	"github.com/xtls/xray-core/main/commands/all/base64"
 	"github.com/xtls/xray-core/main/commands/all/convert"
 	"github.com/xtls/xray-core/main/commands/all/tls"
 	"github.com/xtls/xray-core/main/commands/base"
@@ -11,6 +12,7 @@ func init() {
 	base.RootCommand.Commands = append(
 		base.RootCommand.Commands,
 		api.CmdAPI,
+		base64.CmdBase64,
 		convert.CmdConvert,
 		tls.CmdTLS,
 		cmdUUID,

proxy/freedom/freedom.go

@@ -467,7 +467,7 @@ func NewPacketReader(conn net.Conn, h *Handler, defaultRule *FinalRule, UDPOverr
 	if statConn != nil {
 		counter = statConn.ReadCounter
 	}
-	if c, ok := iConn.(*internet.PacketConnWrapper); ok {
+	if c, ok := iConn.(*net.PacketConnWrapper); ok {
 		isOverridden := false
 		if UDPOverride.Address != nil || UDPOverride.Port != 0 {
 			isOverridden = true
@@ -487,7 +487,7 @@ func NewPacketReader(conn net.Conn, h *Handler, defaultRule *FinalRule, UDPOverr
 }
 
 type PacketReader struct {
-	*internet.PacketConnWrapper
+	*net.PacketConnWrapper
 	stats.Counter
 	Handler           *Handler
 	DefaultRule       *FinalRule
@@ -542,7 +542,7 @@ func NewPacketWriter(conn net.Conn, h *Handler, defaultRule *FinalRule, UDPOverr
 	if statConn != nil {
 		counter = statConn.WriteCounter
 	}
-	if c, ok := iConn.(*internet.PacketConnWrapper); ok {
+	if c, ok := iConn.(*net.PacketConnWrapper); ok {
 		// If DialDest is a domain, it will be resolved in dialer
 		// check this behavior and add it to map
 		resolvedUDPAddr := utils.NewTypedSyncMap[string, net.Address]()
@@ -563,7 +563,7 @@ func NewPacketWriter(conn net.Conn, h *Handler, defaultRule *FinalRule, UDPOverr
 }
 
 type PacketWriter struct {
-	*internet.PacketConnWrapper
+	*net.PacketConnWrapper
 	stats.Counter
 	*Handler
 	DefaultRule *FinalRule

proxy/masque/client.go

@@ -7,7 +7,6 @@ import (
 	"net/netip"
 	"slices"
 	"sync"
-	"sync/atomic"
 	"time"
 
 	"golang.zx2c4.com/wireguard/tun"
@@ -26,6 +25,7 @@ import (
 	"github.com/xtls/xray-core/transport"
 	"github.com/xtls/xray-core/transport/internet"
 	"github.com/xtls/xray-core/transport/internet/masque"
+	"github.com/xtls/xray-core/transport/internet/splithttp"
 	"github.com/xtls/xray-core/transport/internet/stat"
 	"github.com/xtls/xray-core/transport/internet/tls"
 )
@@ -43,11 +43,15 @@ type Client struct {
 	ctx    context.Context
 	cancel context.CancelFunc
 
-	tunnel atomic.Pointer[tunnel]
-
 	mu        sync.Mutex
+	xmux      *splithttp.XmuxManager
+	dialCtx   context.Context
+	dialer    internet.Dialer
 	lastErr   error
 	lastErrAt time.Time
+
+	tunnelsMu sync.Mutex
+	tunnels   map[*tunnel]struct{}
 }
 
 func NewClient(ctx context.Context, config *ClientConfig) (*Client, error) {
@@ -55,7 +59,8 @@ func NewClient(ctx context.Context, config *ClientConfig) (*Client, error) {
 	p := v.GetFeature(policy.ManagerType()).(policy.Manager)
 
 	streamSettings := session.StreamSettingsFromContext(ctx).(*internet.MemoryStreamConfig)
-	if _, ok := streamSettings.ProtocolSettings.(*masque.Config); !ok {
+	transportConfig, ok := streamSettings.ProtocolSettings.(*masque.Config)
+	if !ok {
 		return nil, errors.New("not masque transport")
 	}
 	if tls.ConfigFromStreamSettings(streamSettings) == nil {
@@ -86,7 +91,13 @@ func NewClient(ctx context.Context, config *ClientConfig) (*Client, error) {
 		server:        server,
 		policyManager: p,
 		remoteDNS:     remoteDNS,
+		tunnels:       make(map[*tunnel]struct{}),
 	}
+	xmuxConfig := transportConfig.Xmux
+	if xmuxConfig == nil {
+		xmuxConfig = &splithttp.XmuxConfig{}
+	}
+	c.xmux = splithttp.NewXmuxManager(*xmuxConfig, c.newXmuxConn)
 	c.ctx, c.cancel = context.WithCancel(context.Background())
 	return c, nil
 }
@@ -100,10 +111,11 @@ func (c *Client) Process(ctx context.Context, link *transport.Link, dialer inter
 	ob.Name = "masque"
 	ob.CanSpliceCopy = 3
 
-	t, err := c.getTunnel(ctx, dialer)
+	xmuxClient, t, err := c.getTunnel(ctx, dialer)
 	if err != nil {
 		return errors.New("failed to establish CONNECT-IP tunnel").Base(err)
 	}
+	defer xmuxClient.DoneRunning()
 
 	var newCtx context.Context
 	var newCancel context.CancelFunc
@@ -151,7 +163,7 @@ func (c *Client) Process(ctx context.Context, link *transport.Link, dialer inter
 		}
 		defer conn.Close()
 		uc := &wireguard.UDPConnClient{
-			PacketConn: conn.(*internet.PacketConnWrapper).PacketConn,
+			PacketConn: conn.(*net.PacketConnWrapper).PacketConn,
 			Dest:       conn.RemoteAddr().(*net.UDPAddr),
 		}
 		reader = uc
@@ -180,40 +192,63 @@ func (c *Client) Process(ctx context.Context, link *transport.Link, dialer inter
 	return nil
 }
 
-func (c *Client) getTunnel(ctx context.Context, dialer internet.Dialer) (*tunnel, error) {
+func (c *Client) getTunnel(ctx context.Context, dialer internet.Dialer) (*splithttp.XmuxClient, *tunnel, error) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	if c.ctx.Err() != nil {
-		return nil, errors.New("closed")
-	}
-	if t := c.tunnel.Load(); t != nil {
-		select {
-		case <-t.done:
-		default:
-			return t, nil
-		}
+		return nil, nil, errors.New("closed")
 	}
 	if err := ctx.Err(); err != nil {
-		return nil, err
+		return nil, nil, err
 	}
+	var xmuxClient *splithttp.XmuxClient
 	if c.lastErr != nil && time.Since(c.lastErrAt) < retryInterval {
-		return nil, c.lastErr
+		if xmuxClient = c.xmux.GetExistingXmuxClient(ctx); xmuxClient == nil {
+			return nil, nil, c.lastErr
+		}
+	} else {
+		c.dialCtx, c.dialer = ctx, dialer
+		xmuxClient = c.xmux.GetXmuxClient(ctx)
+		c.dialCtx, c.dialer = nil, nil
+		if err := xmuxClient.XmuxConn.(*tunnel).err; err != nil {
+			if xmuxClient = c.xmux.GetExistingXmuxClient(ctx); xmuxClient == nil {
+				return nil, nil, err
+			}
+		}
 	}
+	t := xmuxClient.XmuxConn.(*tunnel)
+	if c.ctx.Err() != nil {
+		return nil, nil, errors.New("closed")
+	}
+	xmuxClient.AddRunning()
+	return xmuxClient, t, nil
+}
 
-	t, err := c.establish(ctx, dialer)
+func (c *Client) newXmuxConn() splithttp.XmuxConn {
+	t, err := c.establish(c.dialCtx, c.dialer)
 	if err != nil {
 		c.lastErr, c.lastErrAt = err, time.Now()
-		return nil, err
+		return failedTunnel(err)
 	}
 	c.lastErr = nil
-	c.tunnel.Store(t)
-	if c.ctx.Err() != nil {
-		if c.tunnel.CompareAndSwap(t, nil) {
-			t.close()
-		}
-		return nil, errors.New("closed")
+	c.tunnelsMu.Lock()
+	if c.tunnels == nil {
+		c.tunnelsMu.Unlock()
+		t.close()
+		return failedTunnel(errors.New("closed"))
 	}
-	return t, nil
+	c.tunnels[t] = struct{}{}
+	c.tunnelsMu.Unlock()
+	if t.IsClosed() {
+		c.removeTunnel(t)
+	}
+	return t
+}
+
+func (c *Client) removeTunnel(t *tunnel) {
+	c.tunnelsMu.Lock()
+	delete(c.tunnels, t)
+	c.tunnelsMu.Unlock()
 }
 
 func (c *Client) establish(ctx context.Context, dialer internet.Dialer) (*tunnel, error) {
@@ -229,7 +264,7 @@ func (c *Client) establish(ctx context.Context, dialer internet.Dialer) (*tunnel
 		conn.Close()
 		return nil, errors.New("not a CONNECT-IP connection")
 	}
-	t, err := newTunnel(conn, mconn.LocalAddrs(), c.remoteDNS)
+	t, err := newTunnel(conn, mconn.LocalAddrs(), c.remoteDNS, c.removeTunnel)
 	if err != nil {
 		conn.Close()
 		return nil, err
@@ -240,7 +275,11 @@ func (c *Client) establish(ctx context.Context, dialer internet.Dialer) (*tunnel
 
 func (c *Client) Close() error {
 	c.cancel()
-	if t := c.tunnel.Swap(nil); t != nil {
+	c.tunnelsMu.Lock()
+	tunnels := c.tunnels
+	c.tunnels = nil
+	c.tunnelsMu.Unlock()
+	for t := range tunnels {
 		t.close()
 	}
 	return nil
@@ -252,9 +291,31 @@ type tunnel struct {
 	tnet      *wireguard.Net
 	done      chan struct{}
 	closeOnce sync.Once
+	onClose   func(*tunnel)
+	err       error
 }
 
-func newTunnel(conn stat.Connection, local []netip.Addr, remoteDNS []netip.Addr) (*tunnel, error) {
+func failedTunnel(err error) *tunnel {
+	t := &tunnel{err: err, done: make(chan struct{})}
+	t.close()
+	return t
+}
+
+func (t *tunnel) IsClosed() bool {
+	select {
+	case <-t.done:
+		return true
+	default:
+		return false
+	}
+}
+
+func (t *tunnel) Close() error {
+	t.close()
+	return nil
+}
+
+func newTunnel(conn stat.Connection, local []netip.Addr, remoteDNS []netip.Addr, onClose func(*tunnel)) (*tunnel, error) {
 	var dns []netip.Addr
 	for _, addr := range remoteDNS {
 		if slices.ContainsFunc(local, func(l netip.Addr) bool { return l.Is4() == addr.Is4() }) {
@@ -271,10 +332,11 @@ func newTunnel(conn stat.Connection, local []netip.Addr, remoteDNS []netip.Addr)
 		return nil, err
 	}
 	t := &tunnel{
-		conn: conn,
-		dev:  dev,
-		tnet: tnet,
-		done: make(chan struct{}),
+		conn:    conn,
+		dev:     dev,
+		tnet:    tnet,
+		done:    make(chan struct{}),
+		onClose: onClose,
 	}
 	go t.readFromTunnel()
 	go t.writeToTunnel()
@@ -316,8 +378,15 @@ func (t *tunnel) writeToTunnel() {
 func (t *tunnel) close() {
 	t.closeOnce.Do(func() {
 		close(t.done)
-		t.conn.Close()
-		t.dev.Close()
+		if t.conn != nil {
+			t.conn.Close()
+		}
+		if t.dev != nil {
+			t.dev.Close()
+		}
+		if t.onClose != nil {
+			t.onClose(t)
+		}
 	})
 }
 

proxy/masque/client_test.go

@@ -0,0 +1,54 @@
+package masque
+
+import (
+	"context"
+	"errors"
+	"testing"
+	"time"
+
+	"github.com/xtls/xray-core/transport/internet/splithttp"
+)
+
+func newTestClient(newConn func(c *Client) splithttp.XmuxConn) *Client {
+	c := &Client{ctx: context.Background()}
+	c.xmux = splithttp.NewXmuxManager(splithttp.XmuxConfig{
+		MaxConnections: &splithttp.RangeConfig{From: 3, To: 3},
+	}, func() splithttp.XmuxConn {
+		return newConn(c)
+	})
+	return c
+}
+
+func TestGetTunnelFallsBack(t *testing.T) {
+	refused := errors.New("refused")
+	healthy := &tunnel{done: make(chan struct{})}
+	dials := 0
+	c := newTestClient(func(c *Client) splithttp.XmuxConn {
+		if dials++; dials == 1 {
+			return healthy
+		}
+		c.lastErr, c.lastErrAt = refused, time.Now()
+		return failedTunnel(refused)
+	})
+	for i := 0; i < 5; i++ {
+		if _, got, err := c.getTunnel(context.Background(), nil); err != nil || got != healthy {
+			t.Fatalf("flow %d: got %p, %v instead of the healthy tunnel", i, got, err)
+		}
+	}
+	if dials != 2 {
+		t.Errorf("dialed %d times, a failed tunnel should not be retried within %v", dials, retryInterval)
+	}
+}
+
+func TestGetTunnelFailsWithoutTunnels(t *testing.T) {
+	refused := errors.New("refused")
+	c := newTestClient(func(c *Client) splithttp.XmuxConn {
+		c.lastErr, c.lastErrAt = refused, time.Now()
+		return failedTunnel(refused)
+	})
+	for i := 0; i < 2; i++ {
+		if _, _, err := c.getTunnel(context.Background(), nil); err != refused {
+			t.Fatalf("flow %d: got %v instead of %v", i, err, refused)
+		}
+	}
+}

proxy/proxy.go

@@ -277,6 +277,7 @@ func (w *VisionReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
 				w.ob.CanSpliceCopy = 1
 			}
 		}
+		SuppressOuterCloseNotify(w.conn)
 		readerConn, readCounter, _ := UnwrapRawConn(w.conn)
 		w.directReadCounter = readCounter
 		w.Reader = buf.NewReader(readerConn)
@@ -340,6 +341,7 @@ func (w *VisionWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
 			// 	w.ob.CanSpliceCopy = 1
 			// }
 		}
+		SuppressOuterCloseNotify(w.conn)
 		rawConn, _, writerCounter := UnwrapRawConn(w.conn)
 		w.Writer = buf.NewWriter(rawConn)
 		w.directWriteCounter = writerCounter
@@ -669,6 +671,19 @@ func XtlsFilterTls(buffer buf.MultiBuffer, trafficState *TrafficState, ctx conte
 	}
 }
 
+type CloseNotifySuppressor interface {
+	SuppressCloseNotify()
+}
+
+// Close our local TLS conn instance might send a incorrect close_notify alert
+// if the XTLS direct copy mode is enabled and cause TLS BAD_RECORD_MAC on users' browser
+// Close the underlying connection directly to avoid this issue.
+func SuppressOuterCloseNotify(conn net.Conn) {
+	if suppressor, ok := stat.TryUnwrapStatsConn(conn).(CloseNotifySuppressor); ok {
+		suppressor.SuppressCloseNotify()
+	}
+}
+
 // UnwrapRawConn support unwrap encryption, stats, mask wrappers, tls, utls, reality, proxyproto, uds-wrapper conn and get raw tcp/uds conn from it
 func UnwrapRawConn(conn net.Conn) (net.Conn, stats.Counter, stats.Counter) {
 	var readCounter, writerCounter stats.Counter

proxy/shadowsocks_2022/inbound.go

@@ -2,7 +2,6 @@ package shadowsocks_2022
 
 import (
 	"context"
-	"io"
 	"time"
 
 	"github.com/xtls/xray-core/common"
@@ -13,9 +12,6 @@ import (
 	"github.com/xtls/xray-core/common/net"
 	"github.com/xtls/xray-core/common/protocol"
 	"github.com/xtls/xray-core/common/session"
-	"github.com/xtls/xray-core/common/signal"
-	"github.com/xtls/xray-core/common/task"
-	"github.com/xtls/xray-core/common/utils"
 	"github.com/xtls/xray-core/core"
 	"github.com/xtls/xray-core/features/policy"
 	"github.com/xtls/xray-core/features/routing"
@@ -101,35 +97,29 @@ func (i *Inbound) processTCP(ctx context.Context, conn net.Conn, dispatcher rout
 		return errors.New("unable to set read deadline").Base(err)
 	}
 
+	// 1. Single read call for Salt + Fixed-length header chunk per SIP022 §3.1.4
+	headerLen := i.method.KeySaltLength + RequestHeaderFixedChunkLength + AEADTagSize
+	headerBuf := make([]byte, headerLen)
+	n, err := conn.Read(headerBuf)
+	if err != nil || n < headerLen {
+		ResetTCPConn(conn)
+		return errors.New("failed to read complete handshake header")
+	}
+
 	var salt [32]byte
+	copy(salt[:i.method.KeySaltLength], headerBuf[:i.method.KeySaltLength])
 	saltSlice := salt[:i.method.KeySaltLength]
-	if _, err := io.ReadFull(conn, saltSlice); err != nil {
-		return err
-	}
+	fixedChunk := headerBuf[i.method.KeySaltLength:]
 
-	if !i.saltFilter.Check(salt) {
-		return ErrSaltNotUnique
-	}
-
-	sessionKey := DeriveSessionSubKey(i.psk, saltSlice, i.method.KeySaltLength)
-	aead, err := i.method.NewAEAD(sessionKey)
+	reader, reqHeader, err := InitServerStream(conn, i.method, i.psk, saltSlice, salt, fixedChunk, i.saltFilter)
 	if err != nil {
+		ResetTCPConn(conn)
 		return err
 	}
 
-	reader := NewStreamReader(conn, aead)
-
-	reqHeader, err := ReadClientRequestHeader(conn, reader)
-	if err != nil {
-		return err
-	}
-	conn.SetReadDeadline(time.Time{})
 	dest := reqHeader.Destination
 
-	writer, err := WriteTCPResponse(conn, i.method, i.psk, saltSlice, nil)
-	if err != nil {
-		return err
-	}
+	writer := NewServerStreamWriter(conn, i.method, i.psk, saltSlice)
 
 	ctx = log.ContextWithAccessMessage(ctx, &log.AccessMessage{
 		From:   conn.RemoteAddr(),
@@ -146,42 +136,17 @@ func (i *Inbound) processTCP(ctx context.Context, conn net.Conn, dispatcher rout
 	}
 
 	if len(reqHeader.EarlyData) > 0 {
-		earlyBuf := buf.New()
-		earlyBuf.Write(reqHeader.EarlyData)
-		if err := link.Writer.WriteMultiBuffer(buf.MultiBuffer{earlyBuf}); err != nil {
+		mb := buf.MergeBytes(nil, reqHeader.EarlyData)
+		if err := link.Writer.WriteMultiBuffer(mb); err != nil {
 			return err
 		}
 	}
 
-	sessionPolicy = i.policyManager.ForLevel(uint32(i.user.Level))
-	ctx, cancel := context.WithCancel(ctx)
-	timer := signal.CancelAfterInactivity(ctx, cancel, sessionPolicy.Timeouts.ConnectionIdle)
-	ctx = policy.ContextWithBufferPolicy(ctx, sessionPolicy.Buffer)
-
-	requestDone := func() error {
-		defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly)
-		return buf.Copy(reader, link.Writer, buf.UpdateActivity(timer))
-	}
-
-	responseDone := func() error {
-		defer timer.SetTimeout(sessionPolicy.Timeouts.UplinkOnly)
-		return buf.Copy(link.Reader, writer, buf.UpdateActivity(timer))
-	}
-
-	responseDoneAndCloseWriter := task.OnSuccess(responseDone, task.Close(link.Writer))
-	return task.Run(ctx, requestDone, responseDoneAndCloseWriter)
+	return TransportTCP(ctx, i.policyManager.ForLevel(uint32(i.user.Level)), reader, writer, link)
 }
 
 func (i *Inbound) processUDP(ctx context.Context, conn stat.Connection, dispatcher routing.Dispatcher) error {
-	udpConns := utils.NewTypedSyncMap[uint64, *udpConnEntry]()
-	defer func() {
-		udpConns.Range(func(key uint64, entry *udpConnEntry) bool {
-			entry.timer.SetTimeout(0)
-			return true
-		})
-	}()
-
-	reader := buf.NewReader(conn)
+	reader := buf.NewPacketReader(conn)
 	for {
 		mb, err := reader.ReadMultiBuffer()
 		if err != nil {
@@ -191,75 +156,30 @@ func (i *Inbound) processUDP(ctx context.Context, conn stat.Connection, dispatch
 
 		for _, b := range mb {
 			decoded, err := i.udpCodec.DecodePacket(b.Bytes())
-			if err != nil {
-				b.Release()
+			b.Release()
+			if err != nil || decoded.HeaderType != HeaderTypeClient {
 				continue
 			}
 
-			entry, ok := udpConns.Load(decoded.SessionID)
-			if !ok {
-				sessCtx, cancel := context.WithCancel(ctx)
-				sessCtx = log.ContextWithAccessMessage(sessCtx, &log.AccessMessage{
-					From:   conn.RemoteAddr(),
-					To:     decoded.Destination,
-					Status: log.AccessAccepted,
-					Email:  i.user.Email,
-				})
-
-				link, err := dispatcher.Dispatch(sessCtx, decoded.Destination)
-				if err != nil {
-					cancel()
-					b.Release()
-					continue
-				}
-
-				newEntry := &udpConnEntry{
-					link:   link,
-					cancel: cancel,
-				}
-				sessionPolicy := i.policyManager.ForLevel(uint32(i.user.Level))
-				newEntry.timer = signal.CancelAfterInactivity(sessCtx, func() {
-					udpConns.Delete(decoded.SessionID)
-					common.Interrupt(link.Reader)
-					common.Interrupt(link.Writer)
-					cancel()
-				}, sessionPolicy.Timeouts.ConnectionIdle)
-
-				actual, loaded := udpConns.LoadOrStore(decoded.SessionID, newEntry)
-				if loaded {
-					// Another goroutine/packet beat us to storing, terminate our redundant link
-					newEntry.timer.SetTimeout(0)
-					entry = actual
-				} else {
-					entry = newEntry
-					go func(sessID uint64, dest net.Destination, cEntry *udpConnEntry) {
-						defer func() {
-							cEntry.timer.SetTimeout(0)
-						}()
-						for {
-							resMb, err := cEntry.link.Reader.ReadMultiBuffer()
-							if err != nil {
-								return
-							}
-							cEntry.timer.Update()
-							for _, rb := range resMb {
-								encPacket, err := i.udpCodec.EncodeServerPacket(sessID, dest, rb.Bytes())
-								rb.Release()
-								if err != nil {
-									continue
-								}
-								_, _ = conn.Write(encPacket)
-							}
-						}
-					}(decoded.SessionID, decoded.Destination, entry)
+			sessionItem := i.udpCodec.GetSession(decoded.SessionID)
+			if sessionItem.User == nil {
+				sessionItem.Lock()
+				if sessionItem.User == nil {
+					sessionItem.User = i.user
 				}
+				sessionItem.Unlock()
+			}
+			link, err := sessionItem.EnsureLink(ctx, conn, decoded.Destination, dispatcher, i.policyManager, func(dest net.Destination, payload []byte) ([]byte, error) {
+				return i.udpCodec.EncodeServerPacket(decoded.SessionID, dest, payload)
+			})
+			if err != nil {
+				continue
 			}
 
-			entry.timer.Update()
 			payloadBuf := buf.New()
 			payloadBuf.Write(decoded.Payload)
-			b.Release()
-			_ = entry.link.Writer.WriteMultiBuffer(buf.MultiBuffer{payloadBuf})
+			payloadBuf.UDP = &decoded.Destination
+			_ = link.Writer.WriteMultiBuffer(buf.MultiBuffer{payloadBuf})
 		}
 	}
 }

proxy/shadowsocks_2022/inbound_multi.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"crypto/cipher"
 	"encoding/binary"
-	"io"
 	"strconv"
 	"strings"
 	"sync"
@@ -19,8 +18,6 @@ import (
 	"github.com/xtls/xray-core/common/net"
 	"github.com/xtls/xray-core/common/protocol"
 	"github.com/xtls/xray-core/common/session"
-	"github.com/xtls/xray-core/common/signal"
-	"github.com/xtls/xray-core/common/task"
 	"github.com/xtls/xray-core/common/utils"
 	"github.com/xtls/xray-core/common/uuid"
 	"github.com/xtls/xray-core/core"
@@ -207,64 +204,46 @@ func (i *MultiUserInbound) processTCP(ctx context.Context, conn net.Conn, dispat
 		return errors.New("unable to set read deadline").Base(err)
 	}
 
-	// 1. Read Request Salt (16 or 32 bytes)
+	// 1. Single read call for Salt + EIH + Fixed-length header chunk per SIP022 §3.1.4
+	headerLen := i.method.KeySaltLength + AESBlockSize + RequestHeaderFixedChunkLength + AEADTagSize
+	headerBuf := make([]byte, headerLen)
+	n, err := conn.Read(headerBuf)
+	if err != nil || n < headerLen {
+		ResetTCPConn(conn)
+		return errors.New("failed to read complete handshake header")
+	}
+
 	var salt [32]byte
+	copy(salt[:i.method.KeySaltLength], headerBuf[:i.method.KeySaltLength])
 	saltSlice := salt[:i.method.KeySaltLength]
-	if _, err := io.ReadFull(conn, saltSlice); err != nil {
-		return err
-	}
+	eih := headerBuf[i.method.KeySaltLength : i.method.KeySaltLength+AESBlockSize]
+	fixedChunk := headerBuf[i.method.KeySaltLength+AESBlockSize:]
 
-	if !i.saltFilter.Check(salt) {
-		return ErrSaltNotUnique
-	}
-
-	// 2. Read Extended Identity Header (16 bytes)
-	var eih [AESBlockSize]byte
-	if _, err := io.ReadFull(conn, eih[:]); err != nil {
-		return err
-	}
-
-	// Decrypt EIH with IdentitySubKey derived from masterPSK and salt
-	identitySubkey := DeriveIdentitySubKey(i.masterPSK, saltSlice, i.method.KeySaltLength)
-	block, err := i.method.NewBlock(identitySubkey)
+	decryptedHash, err := DecryptEIH(i.method, i.masterPSK, saltSlice, eih)
 	if err != nil {
+		ResetTCPConn(conn)
 		return err
 	}
 
-	var decryptedHash [AESBlockSize]byte
-	block.Decrypt(decryptedHash[:], eih[:])
-
 	// Lookup user
 	user, ok := i.usersByHash.Load(decryptedHash)
-	if !ok || user == nil {
+	if !ok {
+		ResetTCPConn(conn)
 		return ErrInvalidRequest
 	}
 	userPSK := user.Account.(*MemoryAccount).Key
 
-	// 3. Derive Session Subkey using matched user's PSK
-	sessionKey := DeriveSessionSubKey(userPSK, saltSlice, i.method.KeySaltLength)
-	aead, err := i.method.NewAEAD(sessionKey)
+	reader, reqHeader, err := InitServerStream(conn, i.method, userPSK, saltSlice, salt, fixedChunk, i.saltFilter)
 	if err != nil {
+		ResetTCPConn(conn)
 		return err
 	}
 
-	reader := NewStreamReader(conn, aead)
-
-	// 4 & 5. Read Client Request Header
-	reqHeader, err := ReadClientRequestHeader(conn, reader)
-	if err != nil {
-		return err
-	}
-	conn.SetReadDeadline(time.Time{})
 	dest := reqHeader.Destination
 
-	// 6. Send Server Response Handshake
-	writer, err := WriteTCPResponse(conn, i.method, userPSK, saltSlice, nil)
-	if err != nil {
-		return err
-	}
+	writer := NewServerStreamWriter(conn, i.method, userPSK, saltSlice)
 
-	// 7. Dispatch Connection to Xray routing with matched User
+	// Dispatch Connection to Xray routing with matched User
 	inbound := session.InboundFromContext(ctx)
 	inbound.User = user
 
@@ -283,42 +262,17 @@ func (i *MultiUserInbound) processTCP(ctx context.Context, conn net.Conn, dispat
 	}
 
 	if len(reqHeader.EarlyData) > 0 {
-		earlyBuf := buf.New()
-		earlyBuf.Write(reqHeader.EarlyData)
-		if err := link.Writer.WriteMultiBuffer(buf.MultiBuffer{earlyBuf}); err != nil {
+		mb := buf.MergeBytes(nil, reqHeader.EarlyData)
+		if err := link.Writer.WriteMultiBuffer(mb); err != nil {
 			return err
 		}
 	}
 
-	sessionPolicy = i.policyManager.ForLevel(user.Level)
-	ctx, cancel := context.WithCancel(ctx)
-	timer := signal.CancelAfterInactivity(ctx, cancel, sessionPolicy.Timeouts.ConnectionIdle)
-	ctx = policy.ContextWithBufferPolicy(ctx, sessionPolicy.Buffer)
-
-	requestDone := func() error {
-		defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly)
-		return buf.Copy(reader, link.Writer, buf.UpdateActivity(timer))
-	}
-
-	responseDone := func() error {
-		defer timer.SetTimeout(sessionPolicy.Timeouts.UplinkOnly)
-		return buf.Copy(link.Reader, writer, buf.UpdateActivity(timer))
-	}
-
-	responseDoneAndCloseWriter := task.OnSuccess(responseDone, task.Close(link.Writer))
-	return task.Run(ctx, requestDone, responseDoneAndCloseWriter)
+	return TransportTCP(ctx, i.policyManager.ForLevel(user.Level), reader, writer, link)
 }
 
 func (i *MultiUserInbound) processUDP(ctx context.Context, conn stat.Connection, dispatcher routing.Dispatcher) error {
-	udpConns := utils.NewTypedSyncMap[uint64, *udpConnEntry]()
-	defer func() {
-		udpConns.Range(func(key uint64, entry *udpConnEntry) bool {
-			entry.timer.SetTimeout(0)
-			return true
-		})
-	}()
-
-	reader := buf.NewReader(conn)
+	reader := buf.NewPacketReader(conn)
 	for {
 		mb, err := reader.ReadMultiBuffer()
 		if err != nil {
@@ -342,168 +296,61 @@ func (i *MultiUserInbound) processUDP(ctx context.Context, conn stat.Connection,
 			sessionID := binary.BigEndian.Uint64(rawHeader[:8])
 			packetID := binary.BigEndian.Uint64(rawHeader[8:16])
 
-			// Replay protection & session lookup
 			sessionItem := i.udpSessions.GetOrCreate(sessionID)
 
-			sessionItem.Lock()
-			if !sessionItem.Window.Check(packetID) {
-				sessionItem.Unlock()
+			if !sessionItem.CheckPacketID(packetID) {
 				b.Release()
 				continue
 			}
 
 			var userPSK []byte
 			var currentUser *protocol.MemoryUser
-			if sessionItem.User != nil {
-				currentUser = sessionItem.User
-				userPSK = sessionItem.UserPSK
-				sessionItem.Unlock()
-			} else {
-				sessionItem.Unlock()
-				// Decrypt EIH
-				identitySubkey := DeriveIdentitySubKey(i.masterPSK, rawHeader[:8], i.method.KeySaltLength)
-				idBlock, err := i.method.NewBlock(identitySubkey)
-				if err != nil {
-					b.Release()
-					continue
-				}
+			sessionItem.Lock()
+			currentUser = sessionItem.User
+			userPSK = sessionItem.UserPSK
+			sessionItem.Unlock()
 
-				var decryptedHash [16]byte
-				idBlock.Decrypt(decryptedHash[:], packetBytes[16:32])
+			if currentUser == nil {
+				// Decrypt EIH
+				decryptedHash := DecryptUDPEIH(i.udpMasterCipher, rawHeader[:], packetBytes[16:32])
 
 				user, ok := i.usersByHash.Load(decryptedHash)
-				if !ok || user == nil {
+				if !ok {
 					b.Release()
 					continue
 				}
 				currentUser = user
 				userPSK = user.Account.(*MemoryAccount).Key
-
-				sessionItem.Lock()
-				sessionItem.User = user
-				sessionItem.UserPSK = userPSK
-				sessionItem.Unlock()
 			}
 
-			// Decrypt Body (with AEAD caching per session)
-			bodyAead := sessionItem.GetRemoteCipher()
-			if bodyAead == nil {
-				bodyKey := DeriveSessionSubKey(userPSK, rawHeader[:8], i.method.KeySaltLength)
-				var err error
-				bodyAead, err = i.method.NewAEAD(bodyKey)
-				if err != nil {
-					b.Release()
-					continue
-				}
-				sessionItem.SetRemoteCipher(bodyAead)
-			}
-
-			bodyNonce := rawHeader[4:16]
-			bodyCipher := packetBytes[32:]
-			bodyPlain, err := bodyAead.Open(nil, bodyNonce, bodyCipher, nil)
+			decoded, err := sessionItem.DecryptAESPayload(i.method, userPSK, sessionID, packetID, rawHeader[:], packetBytes[32:])
 			b.Release()
-			if err != nil || len(bodyPlain) < 1+8+2 {
-				continue
-			}
-
-			sessionItem.Lock()
-			sessionItem.Window.Add(packetID)
-			sessionItem.Unlock()
-
-			if bodyPlain[0] != HeaderTypeClient {
-				continue
-			}
-			epoch := binary.BigEndian.Uint64(bodyPlain[1:9])
-			diff := time.Now().Unix() - int64(epoch)
-			if diff < -30 || diff > 30 {
-				continue
-			}
-
-			paddingLen := int(binary.BigEndian.Uint16(bodyPlain[9:11]))
-			offset := 11 + paddingLen
-			if len(bodyPlain) < offset {
-				continue
-			}
-
-			dest, addrLen, err := parseAddressPort(bodyPlain[offset:])
 			if err != nil {
 				continue
 			}
 
-			payload := bodyPlain[offset+addrLen:]
+			sessionItem.Lock()
+			if sessionItem.User == nil {
+				sessionItem.User = currentUser
+				sessionItem.UserPSK = userPSK
+			}
+			sessionItem.Unlock()
 
-			entry, ok := udpConns.Load(sessionID)
-			if !ok {
-				sessCtx, cancel := context.WithCancel(ctx)
-				inbound := session.InboundFromContext(sessCtx)
-				inbound.User = currentUser
-
-				sessCtx = log.ContextWithAccessMessage(sessCtx, &log.AccessMessage{
-					From:   conn.RemoteAddr(),
-					To:     dest,
-					Status: log.AccessAccepted,
-					Email:  currentUser.Email,
-				})
-
-				link, err := dispatcher.Dispatch(sessCtx, dest)
-				if err != nil {
-					cancel()
-					continue
-				}
-
-				newEntry := &udpConnEntry{
-					link:   link,
-					cancel: cancel,
-				}
-				sessionPolicy := i.policyManager.ForLevel(currentUser.Level)
-				newEntry.timer = signal.CancelAfterInactivity(sessCtx, func() {
-					udpConns.Delete(sessionID)
-					common.Interrupt(link.Reader)
-					common.Interrupt(link.Writer)
-					cancel()
-				}, sessionPolicy.Timeouts.ConnectionIdle)
-
-				actual, loaded := udpConns.LoadOrStore(sessionID, newEntry)
-				if loaded {
-					newEntry.timer.SetTimeout(0)
-					entry = actual
-				} else {
-					entry = newEntry
-					go func(sessID uint64, uPSK []byte, d net.Destination, cEntry *udpConnEntry) {
-						defer func() {
-							cEntry.timer.SetTimeout(0)
-						}()
-						for {
-							resMb, err := cEntry.link.Reader.ReadMultiBuffer()
-							if err != nil {
-								return
-							}
-							cEntry.timer.Update()
-							for _, rb := range resMb {
-								encPacket, err := i.encodeServerUDPPacket(sessID, uPSK, d, rb.Bytes())
-								rb.Release()
-								if err != nil {
-									continue
-								}
-								_, _ = conn.Write(encPacket)
-							}
-						}
-					}(sessionID, userPSK, dest, entry)
-				}
+			link, err := sessionItem.EnsureLink(ctx, conn, decoded.Destination, dispatcher, i.policyManager, func(replyDest net.Destination, payload []byte) ([]byte, error) {
+				return i.encodeServerUDPPacket(sessionID, userPSK, replyDest, payload)
+			})
+			if err != nil {
+				continue
 			}
 
-			entry.timer.Update()
 			pBuf := buf.New()
-			pBuf.Write(payload)
-			_ = entry.link.Writer.WriteMultiBuffer(buf.MultiBuffer{pBuf})
+			pBuf.Write(decoded.Payload)
+			pBuf.UDP = &decoded.Destination
+			_ = link.Writer.WriteMultiBuffer(buf.MultiBuffer{pBuf})
 		}
 	}
 }
 
 func (i *MultiUserInbound) encodeServerUDPPacket(clientSessionID uint64, userPSK []byte, dest net.Destination, payload []byte) ([]byte, error) {
-	sessionItem := i.udpSessions.GetOrCreate(clientSessionID)
-	if err := sessionItem.EnsureServerState(i.method, i.udpMasterCipher, nil, userPSK); err != nil {
-		return nil, err
-	}
-	return sessionItem.EncodeServerPacket(i.method, clientSessionID, dest, payload)
+	return i.udpSessions.EncodeServerPacket(i.method, userPSK, clientSessionID, dest, payload)
 }

proxy/shadowsocks_2022/inbound_relay.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"crypto/cipher"
 	"encoding/binary"
-	"io"
 	"strconv"
 	"time"
 
@@ -15,9 +14,6 @@ import (
 	"github.com/xtls/xray-core/common/net"
 	"github.com/xtls/xray-core/common/protocol"
 	"github.com/xtls/xray-core/common/session"
-	"github.com/xtls/xray-core/common/signal"
-	"github.com/xtls/xray-core/common/task"
-	"github.com/xtls/xray-core/common/utils"
 	"github.com/xtls/xray-core/common/uuid"
 	"github.com/xtls/xray-core/core"
 	"github.com/xtls/xray-core/features/policy"
@@ -35,18 +31,17 @@ type relayDest struct {
 	destination net.Destination
 	email       string
 	level       uint32
-	key         []byte
 	blockCipher cipher.Block
 }
 
 type RelayInbound struct {
-	networks        []net.Network
-	method          *CipherMethod
-	relayPSK        []byte
-	relayBlock      cipher.Block
-	destinations    map[[AESBlockSize]byte]*relayDest
-	rawDestinations []*RelayDestination
-	policyManager   policy.Manager
+	networks      []net.Network
+	method        *CipherMethod
+	relayPSK      []byte
+	relayBlock    cipher.Block
+	destinations  map[[AESBlockSize]byte]*relayDest
+	udpSessions   *UDPSessionManager
+	policyManager policy.Manager
 }
 
 func NewRelayServer(ctx context.Context, config *RelayServerConfig) (*RelayInbound, error) {
@@ -78,13 +73,13 @@ func NewRelayServer(ctx context.Context, config *RelayServerConfig) (*RelayInbou
 
 	v := core.MustFromContext(ctx)
 	i := &RelayInbound{
-		networks:        networks,
-		method:          method,
-		relayPSK:        relayPSK,
-		relayBlock:      relayBlock,
-		destinations:    make(map[[AESBlockSize]byte]*relayDest),
-		rawDestinations: config.Destinations,
-		policyManager:   v.GetFeature(policy.ManagerType()).(policy.Manager),
+		networks:      networks,
+		method:        method,
+		relayPSK:      relayPSK,
+		relayBlock:    relayBlock,
+		destinations:  make(map[[AESBlockSize]byte]*relayDest),
+		udpSessions:   NewUDPSessionManager(500 * time.Second),
+		policyManager: v.GetFeature(policy.ManagerType()).(policy.Manager),
 	}
 
 	for idx, d := range config.Destinations {
@@ -108,7 +103,6 @@ func NewRelayServer(ctx context.Context, config *RelayServerConfig) (*RelayInbou
 			destination: net.TCPDestination(d.Address.AsAddress(), net.Port(d.Port)),
 			email:       d.Email,
 			level:       uint32(d.Level),
-			key:         destKey,
 			blockCipher: destBlock,
 		}
 	}
@@ -139,28 +133,36 @@ func (i *RelayInbound) processTCP(ctx context.Context, conn net.Conn, dispatcher
 		return errors.New("unable to set read deadline").Base(err)
 	}
 
-	// Read Salt + Outer EIH
+	// Read initial handshake in a single read call per SIP022 §3.1.3 & §3.1.4
 	needed := i.method.KeySaltLength + AESBlockSize
-	var headerBuf [48]byte
-	headerSlice := headerBuf[:needed]
-	if _, err := io.ReadFull(conn, headerSlice); err != nil {
-		return err
-	}
-
-	salt := headerSlice[:i.method.KeySaltLength]
-	eih := headerSlice[i.method.KeySaltLength:]
-
-	identitySubkey := DeriveIdentitySubKey(i.relayPSK, salt, i.method.KeySaltLength)
-	block, err := i.method.NewBlock(identitySubkey)
+	requestHeader := buf.New()
+	n, err := requestHeader.ReadFrom(conn)
 	if err != nil {
+		requestHeader.Release()
+		ResetTCPConn(conn)
 		return err
 	}
+	if int(n) < needed {
+		requestHeader.Release()
+		ResetTCPConn(conn)
+		return ErrInvalidRequest
+	}
 
-	var decryptedHash [AESBlockSize]byte
-	block.Decrypt(decryptedHash[:], eih)
+	headerSlice := requestHeader.Bytes()
+	salt := headerSlice[:i.method.KeySaltLength]
+	eih := headerSlice[i.method.KeySaltLength:needed]
+
+	decryptedHash, err := DecryptEIH(i.method, i.relayPSK, salt, eih)
+	if err != nil {
+		requestHeader.Release()
+		ResetTCPConn(conn)
+		return err
+	}
 
 	targetDest, ok := i.destinations[decryptedHash]
 	if !ok {
+		requestHeader.Release()
+		ResetTCPConn(conn)
 		return ErrInvalidRequest
 	}
 	conn.SetReadDeadline(time.Time{})
@@ -182,45 +184,26 @@ func (i *RelayInbound) processTCP(ctx context.Context, conn net.Conn, dispatcher
 
 	link, err := dispatcher.Dispatch(ctx, targetDest.destination)
 	if err != nil {
+		requestHeader.Release()
 		return err
 	}
 
-	// Unwrap outer EIH: send client salt to next hop, stripping this hop's EIH
-	saltBuf := buf.New()
-	saltBuf.Write(salt)
-	if err := link.Writer.WriteMultiBuffer(buf.MultiBuffer{saltBuf}); err != nil {
+	// Unwrap outer EIH: send client salt and remaining handshake bytes to next hop
+	// in a single write call, satisfying downstream server's single-read handshake expectation (SIP022 §3.1.3).
+	var saltCopy [32]byte
+	copy(saltCopy[:i.method.KeySaltLength], salt)
+	copy(requestHeader.Bytes()[AESBlockSize:AESBlockSize+i.method.KeySaltLength], saltCopy[:i.method.KeySaltLength])
+	requestHeader.Advance(AESBlockSize)
+
+	if err := link.Writer.WriteMultiBuffer(buf.MultiBuffer{requestHeader}); err != nil {
 		return err
 	}
 
-	sessionPolicy = i.policyManager.ForLevel(targetDest.level)
-	ctx, cancel := context.WithCancel(ctx)
-	timer := signal.CancelAfterInactivity(ctx, cancel, sessionPolicy.Timeouts.ConnectionIdle)
-	ctx = policy.ContextWithBufferPolicy(ctx, sessionPolicy.Buffer)
-
-	requestDone := func() error {
-		defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly)
-		return buf.Copy(buf.NewReader(conn), link.Writer, buf.UpdateActivity(timer))
-	}
-
-	responseDone := func() error {
-		defer timer.SetTimeout(sessionPolicy.Timeouts.UplinkOnly)
-		return buf.Copy(link.Reader, buf.NewWriter(conn), buf.UpdateActivity(timer))
-	}
-
-	responseDoneAndCloseWriter := task.OnSuccess(responseDone, task.Close(link.Writer))
-	return task.Run(ctx, requestDone, responseDoneAndCloseWriter)
+	return TransportTCP(ctx, i.policyManager.ForLevel(targetDest.level), buf.NewReader(conn), buf.NewWriter(conn), link)
 }
 
 func (i *RelayInbound) processUDP(ctx context.Context, conn stat.Connection, dispatcher routing.Dispatcher) error {
-	udpConns := utils.NewTypedSyncMap[uint64, *udpConnEntry]()
-	defer func() {
-		udpConns.Range(func(key uint64, entry *udpConnEntry) bool {
-			entry.timer.SetTimeout(0)
-			return true
-		})
-	}()
-
-	reader := buf.NewReader(conn)
+	reader := buf.NewPacketReader(conn)
 	for {
 		mb, err := reader.ReadMultiBuffer()
 		if err != nil {
@@ -238,11 +221,7 @@ func (i *RelayInbound) processUDP(ctx context.Context, conn stat.Connection, dis
 			var packetHeader [AESBlockSize]byte
 			i.relayBlock.Decrypt(packetHeader[:], data[:AESBlockSize])
 
-			var eiHeader [AESBlockSize]byte
-			i.relayBlock.Decrypt(eiHeader[:], data[AESBlockSize:2*AESBlockSize])
-			for idx := 0; idx < AESBlockSize; idx++ {
-				eiHeader[idx] ^= packetHeader[idx]
-			}
+			eiHeader := DecryptUDPEIH(i.relayBlock, packetHeader[:], data[AESBlockSize:2*AESBlockSize])
 
 			targetDest, ok := i.destinations[eiHeader]
 			if !ok {
@@ -263,68 +242,24 @@ func (i *RelayInbound) processUDP(ctx context.Context, conn stat.Connection, dis
 			dest := targetDest.destination
 			dest.Network = net.Network_UDP
 
-			entry, ok := udpConns.Load(sessionID)
-			if !ok {
-				sessCtx, cancel := context.WithCancel(ctx)
-				inbound := session.InboundFromContext(sessCtx)
-				inbound.User = &protocol.MemoryUser{
-					Email: targetDest.email,
-					Level: targetDest.level,
-				}
-
-				sessCtx = log.ContextWithAccessMessage(sessCtx, &log.AccessMessage{
-					From:   conn.RemoteAddr(),
-					To:     dest,
-					Status: log.AccessAccepted,
-					Email:  targetDest.email,
-				})
-
-				link, err := dispatcher.Dispatch(sessCtx, dest)
-				if err != nil {
-					cancel()
-					b.Release()
-					continue
-				}
-
-				newEntry := &udpConnEntry{
-					link:   link,
-					cancel: cancel,
-				}
-				sessionPolicy := i.policyManager.ForLevel(targetDest.level)
-				newEntry.timer = signal.CancelAfterInactivity(sessCtx, func() {
-					udpConns.Delete(sessionID)
-					common.Interrupt(link.Reader)
-					common.Interrupt(link.Writer)
-					cancel()
-				}, sessionPolicy.Timeouts.ConnectionIdle)
-
-				actual, loaded := udpConns.LoadOrStore(sessionID, newEntry)
-				if loaded {
-					newEntry.timer.SetTimeout(0)
-					entry = actual
-				} else {
-					entry = newEntry
-					go func(cEntry *udpConnEntry) {
-						defer func() {
-							cEntry.timer.SetTimeout(0)
-						}()
-						for {
-							resMb, err := cEntry.link.Reader.ReadMultiBuffer()
-							if err != nil {
-								return
-							}
-							cEntry.timer.Update()
-							for _, rb := range resMb {
-								_, _ = conn.Write(rb.Bytes())
-								rb.Release()
-							}
-						}
-					}(entry)
+			sessionItem := i.udpSessions.GetOrCreate(sessionID)
+			if sessionItem.User == nil {
+				sessionItem.Lock()
+				if sessionItem.User == nil {
+					sessionItem.User = &protocol.MemoryUser{
+						Email: targetDest.email,
+						Level: targetDest.level,
+					}
 				}
+				sessionItem.Unlock()
+			}
+			link, err := sessionItem.EnsureLink(ctx, conn, dest, dispatcher, i.policyManager, nil)
+			if err != nil {
+				b.Release()
+				continue
 			}
 
-			entry.timer.Update()
-			_ = entry.link.Writer.WriteMultiBuffer(buf.MultiBuffer{b})
+			_ = link.Writer.WriteMultiBuffer(buf.MultiBuffer{b})
 		}
 	}
 }

proxy/shadowsocks_2022/kdf.go

@@ -61,3 +61,14 @@ func DeriveUserPSKHash(userPSK []byte) [AESBlockSize]byte {
 	copy(out[:], h[:AESBlockSize])
 	return out
 }
+
+func DecryptEIH(method *CipherMethod, key, salt, eih []byte) ([AESBlockSize]byte, error) {
+	identitySubkey := DeriveIdentitySubKey(key, salt, method.KeySaltLength)
+	block, err := method.NewBlock(identitySubkey)
+	if err != nil {
+		return [AESBlockSize]byte{}, err
+	}
+	var decryptedHash [AESBlockSize]byte
+	block.Decrypt(decryptedHash[:], eih)
+	return decryptedHash, nil
+}

proxy/shadowsocks_2022/outbound.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"crypto/rand"
 	"io"
-	"time"
 
 	"github.com/xtls/xray-core/common"
 	"github.com/xtls/xray-core/common/buf"
@@ -46,8 +45,12 @@ func NewClient(ctx context.Context, config *ClientConfig) (*Outbound, error) {
 		return nil, errors.New("invalid key: ", config.Key).Base(err)
 	}
 
+	if method.IsChaCha && len(pskList) > 1 {
+		return nil, errors.New("multi-key is not supported for chacha20-poly1305")
+	}
+
 	finalPSK := pskList[len(pskList)-1]
-	udpCodec, err := NewUDPPacketCodec(method, finalPSK)
+	udpCodec, err := NewUDPPacketCodec(method, pskList)
 	if err != nil {
 		return nil, errors.New("failed to create udp packet codec").Base(err)
 	}
@@ -126,18 +129,30 @@ func (o *Outbound) Process(ctx context.Context, link *transport.Link, dialer int
 
 		requestDone := func() error {
 			defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly)
-			bufferedWriter := buf.NewBufferedWriter(buf.NewWriter(conn))
-			bodyWriter, err := WriteTCPRequest(bufferedWriter, o.method, o.pskList, destination, clientSaltSlice, nil)
+
+			var initialPayload []byte
+			var firstBuf *buf.Buffer
+			var remainingMB buf.MultiBuffer
+			if timeoutReader, ok := link.Reader.(buf.TimeoutReader); ok {
+				if mb, err := timeoutReader.ReadMultiBufferTimeout(0); err == nil && !mb.IsEmpty() {
+					remainingMB, firstBuf = buf.SplitFirst(mb)
+					initialPayload = firstBuf.Bytes()
+				}
+			}
+
+			bodyWriter, err := WriteTCPRequest(conn, o.method, o.pskList, destination, clientSaltSlice, initialPayload)
+			if firstBuf != nil {
+				firstBuf.Release()
+			}
 			if err != nil {
+				buf.ReleaseMulti(remainingMB)
 				return errors.New("failed to write request").Base(err)
 			}
 
-			if err = buf.CopyOnceTimeout(link.Reader, bodyWriter, time.Millisecond*100); err != nil && err != buf.ErrNotTimeoutReader && err != buf.ErrReadTimeout {
-				return errors.New("failed to write A request payload").Base(err)
-			}
-
-			if err := bufferedWriter.SetBuffered(false); err != nil {
-				return err
+			if !remainingMB.IsEmpty() {
+				if err := bodyWriter.WriteMultiBuffer(remainingMB); err != nil {
+					return err
+				}
 			}
 
 			return buf.Copy(link.Reader, bodyWriter, buf.UpdateActivity(timer))
@@ -163,13 +178,18 @@ func (o *Outbound) Process(ctx context.Context, link *transport.Link, dialer int
 	}
 
 	if network == net.Network_UDP {
+		session, err := o.udpCodec.NewClientSession()
+		if err != nil {
+			return errors.New("failed to create client udp session").Base(err)
+		}
+
 		requestDone := func() error {
 			defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly)
 
 			writer := &UDPWriter{
 				Writer:      conn,
 				Destination: destination,
-				Codec:       o.udpCodec,
+				Session:     session,
 			}
 
 			if err := buf.Copy(link.Reader, writer, buf.UpdateActivity(timer)); err != nil {
@@ -182,8 +202,8 @@ func (o *Outbound) Process(ctx context.Context, link *transport.Link, dialer int
 			defer timer.SetTimeout(sessionPolicy.Timeouts.UplinkOnly)
 
 			reader := &UDPReader{
-				Reader: conn,
-				Codec:  o.udpCodec,
+				Reader:  conn,
+				Session: session,
 			}
 
 			if err := buf.Copy(reader, link.Writer, buf.UpdateActivity(timer)); err != nil {

proxy/shadowsocks_2022/packet.go

@@ -16,14 +16,13 @@ import (
 )
 
 type UDPCodec struct {
-	method           *CipherMethod
-	psk              []byte
-	blockCipher      cipher.Block
-	chachaCipher     cipher.AEAD
-	clientBodyCipher cipher.AEAD
-	clientSessionID  uint64
-	nextPacketID     atomic.Uint64
-	sessions         *UDPSessionManager
+	method       *CipherMethod
+	pskList      [][]byte
+	psk          []byte
+	blockCipher  cipher.Block
+	blockCiphers []cipher.Block
+	chachaCipher cipher.AEAD
+	sessions     *UDPSessionManager
 }
 
 type (
@@ -48,22 +47,23 @@ func newUDPCodec(method *CipherMethod, psk []byte) (*UDPCodec, error) {
 	return c, nil
 }
 
-func NewUDPPacketCodec(method *CipherMethod, psk []byte) (*UDPCodec, error) {
-	c, err := newUDPCodec(method, psk)
+func NewUDPPacketCodec(method *CipherMethod, pskList [][]byte) (*UDPCodec, error) {
+	if method.IsChaCha && len(pskList) > 1 {
+		return nil, errors.New("multi-key is not supported for chacha20-poly1305")
+	}
+	finalPSK := pskList[len(pskList)-1]
+	c, err := newUDPCodec(method, finalPSK)
 	if err != nil {
 		return nil, err
 	}
-	var sessID [8]byte
-	if _, err := io.ReadFull(rand.Reader, sessID[:]); err != nil {
-		return nil, err
-	}
-	c.clientSessionID = binary.BigEndian.Uint64(sessID[:])
-
-	if !method.IsChaCha {
-		clientBodyKey := DeriveSessionSubKey(psk, sessID[:], method.KeySaltLength)
-		c.clientBodyCipher, err = method.NewAEAD(clientBodyKey)
-		if err != nil {
-			return nil, err
+	c.pskList = pskList
+	if len(pskList) > 1 {
+		c.blockCiphers = make([]cipher.Block, len(pskList))
+		for i, psk := range pskList {
+			c.blockCiphers[i], err = method.NewBlock(psk)
+			if err != nil {
+				return nil, err
+			}
 		}
 	}
 	return c, nil
@@ -78,108 +78,37 @@ func NewUDPServerCodec(method *CipherMethod, psk []byte, sessionTimeout time.Dur
 	return c, nil
 }
 
-func (c *UDPCodec) EncodeClientPacket(dest net.Destination, payload []byte) (*buf.Buffer, error) {
-	packetID := c.nextPacketID.Add(1)
-	sessID := c.clientSessionID
+func (c *UDPCodec) Sessions() *UDPSessionManager {
+	return c.sessions
+}
 
-	// Padding determination (e.g. DNS port 53 disguise)
-	var paddingLen int
-	if dest.Port == 53 && len(payload) < MaxPaddingLength {
-		paddingLen = mrand.IntN(MaxPaddingLength-len(payload)) + 1
+func (c *UDPCodec) GetSession(sessionID uint64) *ServerUDPSession {
+	if c.sessions == nil {
+		return nil
 	}
-
-	addrPortLen := AddrPortLength(dest)
-
-	if c.method.IsChaCha {
-		// ChaCha20 mode: 24-byte nonce + plaintext header (27B) + padding + dest + payload + AEAD tag (16B)
-		totalLen := PacketNonceSize + 27 + paddingLen + addrPortLen + len(payload) + AEADTagSize
-		if totalLen > buf.Size {
-			return nil, ErrPacketTooLarge
-		}
-
-		outBuf := buf.New()
-
-		var nonce [PacketNonceSize]byte
-		if _, err := io.ReadFull(rand.Reader, nonce[:]); err != nil {
-			outBuf.Release()
-			return nil, err
-		}
-		outBuf.Write(nonce[:])
-
-		var hdr [16 + 1 + 8 + 2]byte
-		binary.BigEndian.PutUint64(hdr[0:8], sessID)
-		binary.BigEndian.PutUint64(hdr[8:16], packetID)
-		hdr[16] = HeaderTypeClient
-		binary.BigEndian.PutUint64(hdr[17:25], uint64(time.Now().Unix()))
-		binary.BigEndian.PutUint16(hdr[25:27], uint16(paddingLen))
-		outBuf.Write(hdr[:])
-		if paddingLen > 0 {
-			outBuf.Write(zeroPadding[:paddingLen])
-		}
-
-		if err := WriteAddressPort(outBuf, dest); err != nil {
-			outBuf.Release()
-			return nil, err
-		}
-		outBuf.Write(payload)
-
-		plainBytes := outBuf.Bytes()[PacketNonceSize:]
-		outBuf.Extend(int32(c.chachaCipher.Overhead()))
-		c.chachaCipher.Seal(plainBytes[:0], nonce[:], plainBytes, nil)
-		return outBuf, nil
-	}
-
-	// AES mode:
-	// 16B Encrypted Header + (11B header + padding + dest + payload + 16B AEAD tag)
-	totalLen := 16 + 11 + paddingLen + addrPortLen + len(payload) + AEADTagSize
-	if totalLen > buf.Size {
-		return nil, ErrPacketTooLarge
-	}
-
-	outBuf := buf.New()
-
-	var rawHeader [16]byte
-	binary.BigEndian.PutUint64(rawHeader[:8], sessID)
-	binary.BigEndian.PutUint64(rawHeader[8:16], packetID)
-
-	var encryptedHeader [16]byte
-	c.blockCipher.Encrypt(encryptedHeader[:], rawHeader[:])
-	outBuf.Write(encryptedHeader[:])
-
-	bodyAead := c.clientBodyCipher
-
-	var hdr [1 + 8 + 2]byte
-	hdr[0] = HeaderTypeClient
-	binary.BigEndian.PutUint64(hdr[1:9], uint64(time.Now().Unix()))
-	binary.BigEndian.PutUint16(hdr[9:11], uint16(paddingLen))
-	outBuf.Write(hdr[:])
-	if paddingLen > 0 {
-		outBuf.Write(zeroPadding[:paddingLen])
-	}
-
-	if err := WriteAddressPort(outBuf, dest); err != nil {
-		outBuf.Release()
-		return nil, err
-	}
-	outBuf.Write(payload)
-
-	plainBytes := outBuf.Bytes()[16:]
-	bodyNonce := rawHeader[4:16]
-	outBuf.Extend(int32(bodyAead.Overhead()))
-	bodyAead.Seal(plainBytes[:0], bodyNonce, plainBytes, nil)
-	return outBuf, nil
+	return c.sessions.GetOrCreate(sessionID)
 }
 
 type DecodedUDPPacket struct {
-	SessionID   uint64
-	PacketID    uint64
-	HeaderType  byte
-	Timestamp   uint64
-	Destination net.Destination
-	Payload     []byte
+	SessionID       uint64
+	PacketID        uint64
+	HeaderType      byte
+	Timestamp       uint64
+	ClientSessionID uint64
+	Destination     net.Destination
+	Payload         []byte
 }
 
-func parseAddressPort(data []byte) (net.Destination, int, error) {
+func DecryptUDPEIH(block cipher.Block, rawHeader, eih []byte) [AESBlockSize]byte {
+	var decryptedHash [AESBlockSize]byte
+	block.Decrypt(decryptedHash[:], eih)
+	for k := 0; k < AESBlockSize; k++ {
+		decryptedHash[k] ^= rawHeader[k]
+	}
+	return decryptedHash
+}
+
+func ParseAddressPort(data []byte) (net.Destination, int, error) {
 	if len(data) < 1 {
 		return net.Destination{}, 0, ErrPacketTooShort
 	}
@@ -220,6 +149,9 @@ func parsePlainUDPPacket(sessionID, packetID uint64, bodyPlain []byte) (DecodedU
 	}
 
 	headerType := bodyPlain[0]
+	if headerType != HeaderTypeClient && headerType != HeaderTypeServer {
+		return DecodedUDPPacket{}, ErrBadHeaderType
+	}
 	epoch := binary.BigEndian.Uint64(bodyPlain[1:9])
 	diff := int(math.Abs(float64(time.Now().Unix() - int64(epoch))))
 	if diff > 30 {
@@ -227,11 +159,13 @@ func parsePlainUDPPacket(sessionID, packetID uint64, bodyPlain []byte) (DecodedU
 	}
 
 	offset := 9
+	var clientSessionID uint64
 	if headerType == HeaderTypeServer {
 		if len(bodyPlain) < offset+8+2 {
 			return DecodedUDPPacket{}, ErrPacketTooShort
 		}
-		offset += 8 // skip clientSessionID
+		clientSessionID = binary.BigEndian.Uint64(bodyPlain[offset : offset+8])
+		offset += 8
 	}
 
 	paddingLen := int(binary.BigEndian.Uint16(bodyPlain[offset : offset+2]))
@@ -242,19 +176,20 @@ func parsePlainUDPPacket(sessionID, packetID uint64, bodyPlain []byte) (DecodedU
 	}
 	offset += paddingLen
 
-	dest, addrLen, err := parseAddressPort(bodyPlain[offset:])
+	dest, addrLen, err := ParseAddressPort(bodyPlain[offset:])
 	if err != nil {
 		return DecodedUDPPacket{}, err
 	}
 	payload := bodyPlain[offset+addrLen:]
 
 	return DecodedUDPPacket{
-		SessionID:   sessionID,
-		PacketID:    packetID,
-		HeaderType:  headerType,
-		Timestamp:   epoch,
-		Destination: dest,
-		Payload:     payload,
+		SessionID:       sessionID,
+		PacketID:        packetID,
+		HeaderType:      headerType,
+		Timestamp:       epoch,
+		ClientSessionID: clientSessionID,
+		Destination:     dest,
+		Payload:         payload,
 	}, nil
 }
 
@@ -269,7 +204,7 @@ func (c *UDPCodec) DecodePacket(data []byte) (DecodedUDPPacket, error) {
 		}
 		nonce := data[:PacketNonceSize]
 		ciphertext := data[PacketNonceSize:]
-		plain, err := c.chachaCipher.Open(ciphertext[:0], nonce, ciphertext, nil)
+		plain, err := c.chachaCipher.Open(nil, nonce, ciphertext, nil)
 		if err != nil {
 			return DecodedUDPPacket{}, errors.New("failed to decrypt chacha udp packet").Base(err)
 		}
@@ -280,17 +215,22 @@ func (c *UDPCodec) DecodePacket(data []byte) (DecodedUDPPacket, error) {
 		sessionID := binary.BigEndian.Uint64(plain[:8])
 		packetID := binary.BigEndian.Uint64(plain[8:16])
 
-		if c.sessions != nil {
-			sessionItem := c.sessions.GetOrCreate(sessionID)
-			sessionItem.Lock()
-			if !sessionItem.Window.CheckAndAdd(packetID) {
-				sessionItem.Unlock()
-				return DecodedUDPPacket{}, ErrPacketIdNotUnique
-			}
-			sessionItem.Unlock()
+		sessionItem := c.sessions.GetOrCreate(sessionID)
+		if !sessionItem.CheckPacketID(packetID) {
+			return DecodedUDPPacket{}, ErrPacketIdNotUnique
 		}
 
-		return parsePlainUDPPacket(sessionID, packetID, plain[16:])
+		decoded, err := parsePlainUDPPacket(sessionID, packetID, plain[16:])
+		if err != nil {
+			return DecodedUDPPacket{}, err
+		}
+
+		if decoded.HeaderType != HeaderTypeClient {
+			return DecodedUDPPacket{}, ErrBadHeaderType
+		}
+
+		sessionItem.AddPacketID(packetID)
+		return decoded, nil
 	}
 
 	// AES mode
@@ -299,54 +239,52 @@ func (c *UDPCodec) DecodePacket(data []byte) (DecodedUDPPacket, error) {
 	sessionID := binary.BigEndian.Uint64(rawHeader[:8])
 	packetID := binary.BigEndian.Uint64(rawHeader[8:16])
 
-	var bodyAead cipher.AEAD
-	var sessionItem *ServerUDPSession
+	sessionItem := c.sessions.GetOrCreate(sessionID)
+	if !sessionItem.CheckPacketID(packetID) {
+		return DecodedUDPPacket{}, ErrPacketIdNotUnique
+	}
 
-	if c.sessions != nil {
-		sessionItem = c.sessions.GetOrCreate(sessionID)
-		sessionItem.Lock()
-		if !sessionItem.Window.Check(packetID) {
-			sessionItem.Unlock()
-			return DecodedUDPPacket{}, ErrPacketIdNotUnique
-		}
-		sessionItem.Unlock()
+	return sessionItem.DecryptAESPayload(c.method, c.psk, sessionID, packetID, rawHeader[:], data[16:])
+}
 
-		bodyAead = sessionItem.GetRemoteCipher()
-		if bodyAead == nil {
-			bodyKey := DeriveSessionSubKey(c.psk, rawHeader[:8], c.method.KeySaltLength)
-			var err error
-			bodyAead, err = c.method.NewAEAD(bodyKey)
-			if err != nil {
-				return DecodedUDPPacket{}, err
-			}
-			sessionItem.SetRemoteCipher(bodyAead)
-		}
-	} else {
-		bodyKey := DeriveSessionSubKey(c.psk, rawHeader[:8], c.method.KeySaltLength)
+func (s *ServerUDPSession) DecryptAESPayload(method *CipherMethod, psk []byte, sessionID, packetID uint64, rawHeader, bodyCipher []byte) (DecodedUDPPacket, error) {
+	bodyAead := s.clientBodyCipher
+	isNewCipher := false
+	if bodyAead == nil {
+		bodyKey := DeriveSessionSubKey(psk, rawHeader[:8], method.KeySaltLength)
 		var err error
-		bodyAead, err = c.method.NewAEAD(bodyKey)
+		bodyAead, err = method.NewAEAD(bodyKey)
 		if err != nil {
 			return DecodedUDPPacket{}, err
 		}
+		isNewCipher = true
 	}
 
 	bodyNonce := rawHeader[4:16]
-	bodyCipher := data[16:]
-	bodyPlain, err := bodyAead.Open(bodyCipher[:0], bodyNonce, bodyCipher, nil)
+	bodyPlain, err := bodyAead.Open(nil, bodyNonce, bodyCipher, nil)
 	if err != nil {
 		return DecodedUDPPacket{}, errors.New("failed to decrypt aes udp body").Base(err)
 	}
 
-	if sessionItem != nil {
-		sessionItem.Lock()
-		sessionItem.Window.Add(packetID)
-		sessionItem.Unlock()
+	decoded, err := parsePlainUDPPacket(sessionID, packetID, bodyPlain)
+	if err != nil {
+		return DecodedUDPPacket{}, err
 	}
 
-	return parsePlainUDPPacket(sessionID, packetID, bodyPlain)
+	if decoded.HeaderType != HeaderTypeClient {
+		return DecodedUDPPacket{}, ErrBadHeaderType
+	}
+
+	s.AddPacketID(packetID)
+
+	if isNewCipher {
+		s.clientBodyCipher = bodyAead
+	}
+
+	return decoded, nil
 }
 
-func (s *ServerUDPSession) EnsureServerState(method *CipherMethod, headerBlock cipher.Block, chachaCipher cipher.AEAD, psk []byte) error {
+func (s *ServerUDPSession) EnsureServerState(method *CipherMethod, psk []byte) error {
 	s.Lock()
 	defer s.Unlock()
 	if s.ServerSessionID != 0 {
@@ -363,23 +301,29 @@ func (s *ServerUDPSession) EnsureServerState(method *CipherMethod, headerBlock c
 		}
 	}
 	if method.IsChaCha {
-		s.ServerChaCha = chachaCipher
-	} else {
-		s.ServerBlockCipher = headerBlock
-		bodyKey := DeriveSessionSubKey(psk, sidBuf[:], method.KeySaltLength)
-		bodyAead, err := method.NewAEAD(bodyKey)
-		if err != nil {
-			s.ServerSessionID = 0
-			return err
-		}
-		s.ServerCipher = bodyAead
+		var err error
+		s.serverChaCha, err = method.NewUDPCipher(psk)
+		return err
+	}
+
+	var err error
+	s.serverHeaderBlock, err = method.NewBlock(psk)
+	if err != nil {
+		s.ServerSessionID = 0
+		return err
+	}
+	bodyKey := DeriveSessionSubKey(psk, sidBuf[:], method.KeySaltLength)
+	s.serverBodyCipher, err = method.NewAEAD(bodyKey)
+	if err != nil {
+		s.ServerSessionID = 0
+		return err
 	}
 	return nil
 }
 
 func (s *ServerUDPSession) EncodeServerPacket(method *CipherMethod, clientSessionID uint64, dest net.Destination, payload []byte) ([]byte, error) {
 	serverSessionID := s.ServerSessionID
-	serverPacketID := s.ServerPacketID.Add(1)
+	serverPacketID := s.ServerPacketID.Add(1) - 1
 
 	if method.IsChaCha {
 		var nonce [PacketNonceSize]byte
@@ -404,7 +348,7 @@ func (s *ServerUDPSession) EncodeServerPacket(method *CipherMethod, clientSessio
 		}
 		plainBuf.Write(payload)
 
-		sealed := s.ServerChaCha.Seal(nil, nonce[:], plainBuf.Bytes(), nil)
+		sealed := s.serverChaCha.Seal(nil, nonce[:], plainBuf.Bytes(), nil)
 		res := make([]byte, PacketNonceSize+len(sealed))
 		copy(res[:PacketNonceSize], nonce[:])
 		copy(res[PacketNonceSize:], sealed)
@@ -417,7 +361,7 @@ func (s *ServerUDPSession) EncodeServerPacket(method *CipherMethod, clientSessio
 	binary.BigEndian.PutUint64(rawHeader[8:16], serverPacketID)
 
 	var encryptedHeader [16]byte
-	s.ServerBlockCipher.Encrypt(encryptedHeader[:], rawHeader[:])
+	s.serverHeaderBlock.Encrypt(encryptedHeader[:], rawHeader[:])
 
 	bodyBuf := buf.New()
 	defer bodyBuf.Release()
@@ -435,7 +379,7 @@ func (s *ServerUDPSession) EncodeServerPacket(method *CipherMethod, clientSessio
 	bodyBuf.Write(payload)
 
 	bodyNonce := rawHeader[4:16]
-	sealedBody := s.ServerCipher.Seal(nil, bodyNonce, bodyBuf.Bytes(), nil)
+	sealedBody := s.serverBodyCipher.Seal(nil, bodyNonce, bodyBuf.Bytes(), nil)
 
 	res := make([]byte, 16+len(sealedBody))
 	copy(res[:16], encryptedHeader[:])
@@ -444,17 +388,327 @@ func (s *ServerUDPSession) EncodeServerPacket(method *CipherMethod, clientSessio
 }
 
 func (c *UDPCodec) EncodeServerPacket(clientSessionID uint64, dest net.Destination, payload []byte) ([]byte, error) {
-	sessionItem := c.sessions.GetOrCreate(clientSessionID)
-	if err := sessionItem.EnsureServerState(c.method, c.blockCipher, c.chachaCipher, c.psk); err != nil {
+	return c.sessions.EncodeServerPacket(c.method, c.psk, clientSessionID, dest, payload)
+}
+
+type serverSessionState struct {
+	sessionID uint64
+	window    *SlidingWindow
+	cipher    cipher.AEAD
+	lastSeen  atomic.Int64
+}
+
+func (st *serverSessionState) check(packetID uint64) bool {
+	if st.window == nil {
+		st.window = new(SlidingWindow)
+	}
+	return st.window.Check(packetID)
+}
+
+func (st *serverSessionState) add(packetID uint64) {
+	if st.window == nil {
+		st.window = new(SlidingWindow)
+	}
+	st.window.Add(packetID)
+}
+
+type ClientUDPSession struct {
+	codec            *UDPCodec
+	clientSessionID  uint64
+	nextPacketID     atomic.Uint64
+	clientBodyCipher cipher.AEAD
+	current          atomic.Pointer[serverSessionState]
+	old              atomic.Pointer[serverSessionState]
+}
+
+func (c *UDPCodec) NewClientSession() (*ClientUDPSession, error) {
+	var sessID [8]byte
+	if _, err := io.ReadFull(rand.Reader, sessID[:]); err != nil {
 		return nil, err
 	}
-	return sessionItem.EncodeServerPacket(c.method, clientSessionID, dest, payload)
+	clientSessionID := binary.BigEndian.Uint64(sessID[:])
+
+	var clientBodyCipher cipher.AEAD
+	var err error
+	if !c.method.IsChaCha {
+		finalPSK := c.psk
+		clientBodyKey := DeriveSessionSubKey(finalPSK, sessID[:], c.method.KeySaltLength)
+		clientBodyCipher, err = c.method.NewAEAD(clientBodyKey)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return &ClientUDPSession{
+		codec:            c,
+		clientSessionID:  clientSessionID,
+		clientBodyCipher: clientBodyCipher,
+	}, nil
+}
+
+func (s *ClientUDPSession) getServerSession(sessionID uint64, now int64) (*serverSessionState, error) {
+	cur := s.current.Load()
+	if cur != nil && cur.sessionID == sessionID {
+		return cur, nil
+	}
+
+	old := s.old.Load()
+	if old != nil && old.sessionID == sessionID {
+		if now-old.lastSeen.Load() > 60 {
+			s.old.CompareAndSwap(old, nil)
+			return nil, errors.New("old server session expired")
+		}
+		return old, nil
+	}
+
+	// New server session:
+	// Spec §3.2.4: reject newer server sessions when the last packet received from the old session is less than 1 minute old.
+	if old != nil && now-old.lastSeen.Load() < 60 {
+		return nil, errors.New("newer server session rejected: old session is less than 1 minute old")
+	}
+
+	var bodyAead cipher.AEAD
+	if !s.codec.method.IsChaCha {
+		var sessBytes [8]byte
+		binary.BigEndian.PutUint64(sessBytes[:], sessionID)
+		bodyKey := DeriveSessionSubKey(s.codec.psk, sessBytes[:], s.codec.method.KeySaltLength)
+		var err error
+		bodyAead, err = s.codec.method.NewAEAD(bodyKey)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	newState := &serverSessionState{
+		sessionID: sessionID,
+		cipher:    bodyAead,
+	}
+	newState.lastSeen.Store(now)
+
+	if cur == nil {
+		s.current.CompareAndSwap(nil, newState)
+		return s.current.Load(), nil
+	}
+
+	s.old.Store(cur)
+	s.current.Store(newState)
+	return newState, nil
+}
+
+func (s *ClientUDPSession) ClientSessionID() uint64 {
+	return s.clientSessionID
+}
+
+func (s *ClientUDPSession) EncodePacket(dest net.Destination, payload []byte) (*buf.Buffer, error) {
+	packetID := s.nextPacketID.Add(1) - 1
+	sessID := s.clientSessionID
+
+	var paddingLen int
+	if dest.Port == 53 && len(payload) < MaxPaddingLength {
+		paddingLen = mrand.IntN(MaxPaddingLength) + 1
+	}
+
+	addrPortLen := AddrPortLength(dest)
+
+	if s.codec.method.IsChaCha {
+		totalLen := PacketNonceSize + 27 + paddingLen + addrPortLen + len(payload) + AEADTagSize
+		if totalLen > buf.Size {
+			return nil, ErrPacketTooLarge
+		}
+
+		outBuf := buf.New()
+
+		var nonce [PacketNonceSize]byte
+		if _, err := io.ReadFull(rand.Reader, nonce[:]); err != nil {
+			outBuf.Release()
+			return nil, err
+		}
+		outBuf.Write(nonce[:])
+
+		var hdr [16 + 1 + 8 + 2]byte
+		binary.BigEndian.PutUint64(hdr[0:8], sessID)
+		binary.BigEndian.PutUint64(hdr[8:16], packetID)
+		hdr[16] = HeaderTypeClient
+		binary.BigEndian.PutUint64(hdr[17:25], uint64(time.Now().Unix()))
+		binary.BigEndian.PutUint16(hdr[25:27], uint16(paddingLen))
+		outBuf.Write(hdr[:])
+		if paddingLen > 0 {
+			outBuf.Write(zeroPadding[:paddingLen])
+		}
+
+		if err := WriteAddressPort(outBuf, dest); err != nil {
+			outBuf.Release()
+			return nil, err
+		}
+		outBuf.Write(payload)
+
+		plainBytes := outBuf.Bytes()[PacketNonceSize:]
+		outBuf.Extend(int32(s.codec.chachaCipher.Overhead()))
+		s.codec.chachaCipher.Seal(plainBytes[:0], nonce[:], plainBytes, nil)
+		return outBuf, nil
+	}
+
+	// AES mode
+	var sessBytes [8]byte
+	binary.BigEndian.PutUint64(sessBytes[:], sessID)
+
+	var rawHeader [16]byte
+	copy(rawHeader[:8], sessBytes[:])
+	binary.BigEndian.PutUint64(rawHeader[8:16], packetID)
+
+	eihCount := 0
+	if len(s.codec.pskList) > 1 {
+		eihCount = len(s.codec.pskList) - 1
+	}
+
+	totalLen := 16 + eihCount*16 + 11 + paddingLen + addrPortLen + len(payload) + AEADTagSize
+	if totalLen > buf.Size {
+		return nil, ErrPacketTooLarge
+	}
+
+	outBuf := buf.New()
+
+	if len(s.codec.pskList) > 1 {
+		var encryptedHeader [16]byte
+		s.codec.blockCiphers[0].Encrypt(encryptedHeader[:], rawHeader[:])
+		outBuf.Write(encryptedHeader[:])
+
+		for i := 0; i < len(s.codec.pskList)-1; i++ {
+			nextPSK := s.codec.pskList[i+1]
+			pskHash := DeriveUserPSKHash(nextPSK)
+			var eihPlain [16]byte
+			for k := 0; k < 16; k++ {
+				eihPlain[k] = pskHash[k] ^ rawHeader[k]
+			}
+			var encryptedEIH [16]byte
+			s.codec.blockCiphers[i].Encrypt(encryptedEIH[:], eihPlain[:])
+			outBuf.Write(encryptedEIH[:])
+		}
+	} else {
+		var encryptedHeader [16]byte
+		s.codec.blockCipher.Encrypt(encryptedHeader[:], rawHeader[:])
+		outBuf.Write(encryptedHeader[:])
+	}
+
+	bodyAead := s.clientBodyCipher
+
+	var hdr [1 + 8 + 2]byte
+	hdr[0] = HeaderTypeClient
+	binary.BigEndian.PutUint64(hdr[1:9], uint64(time.Now().Unix()))
+	binary.BigEndian.PutUint16(hdr[9:11], uint16(paddingLen))
+	outBuf.Write(hdr[:])
+	if paddingLen > 0 {
+		outBuf.Write(zeroPadding[:paddingLen])
+	}
+
+	if err := WriteAddressPort(outBuf, dest); err != nil {
+		outBuf.Release()
+		return nil, err
+	}
+	outBuf.Write(payload)
+
+	headerOffset := 16 + eihCount*16
+	plainBytes := outBuf.Bytes()[headerOffset:]
+	bodyNonce := rawHeader[4:16]
+	outBuf.Extend(int32(bodyAead.Overhead()))
+	bodyAead.Seal(plainBytes[:0], bodyNonce, plainBytes, nil)
+	return outBuf, nil
+}
+
+func (s *ClientUDPSession) DecodePacket(data []byte) (DecodedUDPPacket, error) {
+	if len(data) < PacketMinimalHeaderSize {
+		return DecodedUDPPacket{}, ErrPacketTooShort
+	}
+
+	if s.codec.method.IsChaCha {
+		if len(data) < PacketNonceSize+AEADTagSize {
+			return DecodedUDPPacket{}, ErrPacketTooShort
+		}
+		nonce := data[:PacketNonceSize]
+		ciphertext := data[PacketNonceSize:]
+		plain, err := s.codec.chachaCipher.Open(nil, nonce, ciphertext, nil)
+		if err != nil {
+			return DecodedUDPPacket{}, errors.New("failed to decrypt chacha udp packet").Base(err)
+		}
+		if len(plain) < 16+1+8+2 {
+			return DecodedUDPPacket{}, ErrPacketTooShort
+		}
+
+		sessionID := binary.BigEndian.Uint64(plain[:8])
+		packetID := binary.BigEndian.Uint64(plain[8:16])
+
+		now := time.Now().Unix()
+		st, err := s.getServerSession(sessionID, now)
+		if err != nil {
+			return DecodedUDPPacket{}, err
+		}
+		if !st.check(packetID) {
+			return DecodedUDPPacket{}, ErrPacketIdNotUnique
+		}
+
+		decoded, err := parsePlainUDPPacket(sessionID, packetID, plain[16:])
+		if err != nil {
+			return DecodedUDPPacket{}, err
+		}
+
+		if decoded.HeaderType != HeaderTypeServer {
+			return DecodedUDPPacket{}, ErrBadHeaderType
+		}
+		if decoded.ClientSessionID != s.clientSessionID {
+			return DecodedUDPPacket{}, errors.New("client session ID mismatch")
+		}
+
+		st.add(packetID)
+		st.lastSeen.Store(now)
+
+		return decoded, nil
+	}
+
+	// AES mode
+	var rawHeader [16]byte
+	s.codec.blockCipher.Decrypt(rawHeader[:], data[:16])
+	sessionID := binary.BigEndian.Uint64(rawHeader[:8])
+	packetID := binary.BigEndian.Uint64(rawHeader[8:16])
+
+	now := time.Now().Unix()
+	st, err := s.getServerSession(sessionID, now)
+	if err != nil {
+		return DecodedUDPPacket{}, err
+	}
+	if !st.check(packetID) {
+		return DecodedUDPPacket{}, ErrPacketIdNotUnique
+	}
+	bodyAead := st.cipher
+
+	bodyNonce := rawHeader[4:16]
+	bodyCipher := data[16:]
+	bodyPlain, err := bodyAead.Open(nil, bodyNonce, bodyCipher, nil)
+	if err != nil {
+		return DecodedUDPPacket{}, errors.New("failed to decrypt aes udp body").Base(err)
+	}
+
+	decoded, err := parsePlainUDPPacket(sessionID, packetID, bodyPlain)
+	if err != nil {
+		return DecodedUDPPacket{}, err
+	}
+
+	if decoded.HeaderType != HeaderTypeServer {
+		return DecodedUDPPacket{}, ErrBadHeaderType
+	}
+	if decoded.ClientSessionID != s.clientSessionID {
+		return DecodedUDPPacket{}, errors.New("client session ID mismatch")
+	}
+
+	st.add(packetID)
+	st.lastSeen.Store(now)
+
+	return decoded, nil
 }
 
 type UDPWriter struct {
 	Writer      io.Writer
 	Destination net.Destination
-	Codec       *UDPPacketCodec
+	Session     *ClientUDPSession
 }
 
 func (w *UDPWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
@@ -468,7 +722,7 @@ func (w *UDPWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
 		if b.UDP != nil {
 			dest = *b.UDP
 		}
-		pktBuf, err := w.Codec.EncodeClientPacket(dest, b.Bytes())
+		pktBuf, err := w.Session.EncodePacket(dest, b.Bytes())
 		b.Release()
 		if err != nil {
 			buf.ReleaseMulti(mb)
@@ -485,8 +739,8 @@ func (w *UDPWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
 }
 
 type UDPReader struct {
-	Reader io.Reader
-	Codec  *UDPPacketCodec
+	Reader  io.Reader
+	Session *ClientUDPSession
 }
 
 func (r *UDPReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
@@ -498,7 +752,7 @@ func (r *UDPReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
 			return nil, err
 		}
 
-		decoded, err := r.Codec.DecodePacket(buffer.Bytes())
+		decoded, err := r.Session.DecodePacket(buffer.Bytes())
 		if err != nil {
 			buffer.Release()
 			continue

proxy/shadowsocks_2022/relay_test.go

@@ -2,9 +2,11 @@ package shadowsocks_2022_test
 
 import (
 	"context"
+	"crypto/rand"
 	"encoding/base64"
 	"encoding/binary"
 	"errors"
+	"io"
 	gonet "net"
 	"sync"
 	"sync/atomic"
@@ -269,3 +271,106 @@ func (c *dummyStatConn) WriteMultiBuffer(mb buf.MultiBuffer) error {
 	}
 	return nil
 }
+
+func TestRelayTCPHandshakeForwarding(t *testing.T) {
+	methods := []string{MethodAES128GCM, MethodAES256GCM}
+	for _, methodName := range methods {
+		t.Run(methodName, func(t *testing.T) {
+			method, err := GetCipherMethod(methodName)
+			common.Must(err)
+
+			relayKey := make([]byte, method.KeySaltLength)
+			destKey := make([]byte, method.KeySaltLength)
+			_, _ = io.ReadFull(rand.Reader, relayKey)
+			_, _ = io.ReadFull(rand.Reader, destKey)
+
+			targetPort := uint32(54321)
+			relayConfig := &RelayServerConfig{
+				Method: methodName,
+				Key:    base64.StdEncoding.EncodeToString(relayKey),
+				Destinations: []*RelayDestination{
+					{
+						Key:     base64.StdEncoding.EncodeToString(destKey),
+						Address: net.NewIPOrDomain(net.LocalHostIP),
+						Port:    targetPort,
+						Email:   "test@xray.com",
+					},
+				},
+			}
+
+			testCtx := newTestContext()
+			inbound, err := NewRelayServer(testCtx, relayConfig)
+			common.Must(err)
+
+			targetDest := net.TCPDestination(net.LocalHostIP, net.Port(targetPort))
+
+			downstreamR, downstreamW := gonet.Pipe()
+			defer downstreamR.Close()
+			defer downstreamW.Close()
+
+			disp := &dummyDispatcher{
+				onDispatch: func(ctx context.Context, dest net.Destination) (*transport.Link, error) {
+					inLink := &transport.Link{
+						Reader: buf.NewReader(downstreamR),
+						Writer: &customWriter{
+							write: func(mb buf.MultiBuffer) error {
+								defer buf.ReleaseMulti(mb)
+								for _, b := range mb {
+									if _, err := downstreamW.Write(b.Bytes()); err != nil {
+										return err
+									}
+								}
+								return nil
+							},
+						},
+					}
+					return inLink, nil
+				},
+			}
+
+			clientConn, relayConn := gonet.Pipe()
+			defer clientConn.Close()
+			defer relayConn.Close()
+
+			go func() {
+				_ = inbound.Process(testCtx, net.Network_TCP, &dummyStatConn{Conn: relayConn}, disp)
+			}()
+
+			clientSalt := make([]byte, method.KeySaltLength)
+			_, _ = io.ReadFull(rand.Reader, clientSalt)
+			pskList := [][]byte{relayKey, destKey}
+
+			go func() {
+				_, err := WriteTCPRequest(clientConn, method, pskList, targetDest, clientSalt, []byte("relay payload"))
+				if err != nil {
+					t.Errorf("WriteTCPRequest failed: %v", err)
+				}
+			}()
+
+			// Downstream server must be able to read Salt + Fixed chunk in a single Read call!
+			headerLen := method.KeySaltLength + RequestHeaderFixedChunkLength + AEADTagSize
+			headerBuf := make([]byte, headerLen)
+			n, err := downstreamR.Read(headerBuf)
+			if err != nil {
+				t.Fatalf("downstream failed to read handshake: %v", err)
+			}
+			if n < headerLen {
+				t.Fatalf("downstream expected single read >= %d bytes, got %d", headerLen, n)
+			}
+
+			// Verify downstream can decode the fixed chunk and subsequent payload
+			sessionKey := DeriveSessionSubKey(destKey, headerBuf[:method.KeySaltLength], method.KeySaltLength)
+			aead, err := method.NewAEAD(sessionKey)
+			common.Must(err)
+
+			reader := NewStreamReader(downstreamR, aead)
+			reqHeader, err := ReadClientRequestHeaderWithFixed(reader, headerBuf[method.KeySaltLength:])
+			if err != nil {
+				t.Fatalf("downstream failed to parse client request header: %v", err)
+			}
+			if string(reqHeader.EarlyData) != "relay payload" {
+				t.Fatalf("payload mismatch: expected 'relay payload', got '%s'", string(reqHeader.EarlyData))
+			}
+		})
+	}
+}

proxy/shadowsocks_2022/replay.go

@@ -6,8 +6,11 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/xtls/xray-core/common/net"
 	"github.com/xtls/xray-core/common/protocol"
+	"github.com/xtls/xray-core/common/signal"
 	"github.com/xtls/xray-core/common/utils"
+	"github.com/xtls/xray-core/transport"
 )
 
 const (
@@ -74,30 +77,42 @@ func (f *SlidingWindow) CheckAndAdd(counter uint64) bool {
 
 type ServerUDPSession struct {
 	sync.Mutex
-	SessionID    uint64
-	RemoteCipher atomic.Pointer[cipher.AEAD]
-	Window       SlidingWindow
-	User         *protocol.MemoryUser
-	UserPSK      []byte
-	LastActive   atomic.Int64 // Unix timestamp in seconds
+	SessionID  uint64
+	Window     *SlidingWindow
+	User       *protocol.MemoryUser
+	UserPSK    []byte
+	LastActive atomic.Int64 // Unix timestamp in seconds
+
+	clientBodyCipher cipher.AEAD
 
 	ServerSessionID   uint64
 	ServerPacketID    atomic.Uint64
-	ServerCipher      cipher.AEAD
-	ServerBlockCipher cipher.Block
-	ServerChaCha      cipher.AEAD
+	serverBodyCipher  cipher.AEAD
+	serverHeaderBlock cipher.Block
+	serverChaCha      cipher.AEAD
+
+	manager     *UDPSessionManager
+	link        atomic.Pointer[transport.Link]
+	timer       *signal.ActivityTimer
+	currentConn atomic.Value // stores stat.Connection
 }
 
-func (s *ServerUDPSession) GetRemoteCipher() cipher.AEAD {
-	ptr := s.RemoteCipher.Load()
-	if ptr == nil {
-		return nil
+func (s *ServerUDPSession) CheckPacketID(packetID uint64) bool {
+	s.Lock()
+	defer s.Unlock()
+	if s.Window == nil {
+		s.Window = new(SlidingWindow)
 	}
-	return *ptr
+	return s.Window.Check(packetID)
 }
 
-func (s *ServerUDPSession) SetRemoteCipher(c cipher.AEAD) {
-	s.RemoteCipher.Store(&c)
+func (s *ServerUDPSession) AddPacketID(packetID uint64) {
+	s.Lock()
+	defer s.Unlock()
+	if s.Window == nil {
+		s.Window = new(SlidingWindow)
+	}
+	s.Window.Add(packetID)
 }
 
 type UDPSessionManager struct {
@@ -122,6 +137,7 @@ func (m *UDPSessionManager) GetOrCreate(sessionID uint64) *ServerUDPSession {
 
 	s := &ServerUDPSession{
 		SessionID: sessionID,
+		manager:   m,
 	}
 	s.LastActive.Store(now)
 
@@ -148,6 +164,7 @@ func (m *UDPSessionManager) cleanup(now int64) {
 	m.sessions.Range(func(k uint64, v *ServerUDPSession) bool {
 		if now-v.LastActive.Load() > timeoutSec {
 			m.sessions.Delete(k)
+			v.Close()
 		}
 		return true
 	})
@@ -156,3 +173,11 @@ func (m *UDPSessionManager) cleanup(now int64) {
 func (m *UDPSessionManager) Delete(sessionID uint64) {
 	m.sessions.Delete(sessionID)
 }
+
+func (m *UDPSessionManager) EncodeServerPacket(method *CipherMethod, psk []byte, clientSessionID uint64, dest net.Destination, payload []byte) ([]byte, error) {
+	sessionItem := m.GetOrCreate(clientSessionID)
+	if err := sessionItem.EnsureServerState(method, psk); err != nil {
+		return nil, err
+	}
+	return sessionItem.EncodeServerPacket(method, clientSessionID, dest, payload)
+}

proxy/shadowsocks_2022/shadowsocks_2022.go

@@ -2,18 +2,161 @@ package shadowsocks_2022
 
 import (
 	"context"
-	"sync"
 
+	"github.com/xtls/xray-core/common"
+	"github.com/xtls/xray-core/common/buf"
 	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/log"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/common/session"
 	"github.com/xtls/xray-core/common/signal"
+	"github.com/xtls/xray-core/features/policy"
+	"github.com/xtls/xray-core/features/routing"
+	"github.com/xtls/xray-core/proxy"
 	"github.com/xtls/xray-core/transport"
+	"github.com/xtls/xray-core/transport/internet/stat"
 )
 
-type udpConnEntry struct {
-	sync.Mutex
-	link   *transport.Link
-	timer  *signal.ActivityTimer
-	cancel context.CancelFunc
+func (s *ServerUDPSession) UpdateConn(conn stat.Connection) {
+	if s.currentConn.Load() == nil {
+		s.currentConn.Store(conn)
+	}
+	if s.timer != nil {
+		s.timer.Update()
+	}
+}
+
+func (s *ServerUDPSession) WriteToClient(b []byte) error {
+	connVal := s.currentConn.Load()
+	if connVal == nil {
+		return errors.New("client connection closed")
+	}
+	conn, ok := connVal.(stat.Connection)
+	if !ok || conn == nil {
+		return errors.New("client connection closed")
+	}
+	_, err := conn.Write(b)
+	return err
+}
+
+func (s *ServerUDPSession) Close() {
+	if s.timer != nil {
+		s.timer.SetTimeout(0)
+	}
+	if link := s.link.Load(); link != nil {
+		common.Interrupt(link.Reader)
+		common.Interrupt(link.Writer)
+	}
+}
+
+func (s *ServerUDPSession) EnsureLink(
+	ctx context.Context,
+	conn stat.Connection,
+	dest net.Destination,
+	dispatcher routing.Dispatcher,
+	policyManager policy.Manager,
+	responseEncoder func(dest net.Destination, payload []byte) ([]byte, error),
+) (*transport.Link, error) {
+	s.UpdateConn(conn)
+
+	if link := s.link.Load(); link != nil {
+		return link, nil
+	}
+
+	s.Lock()
+	defer s.Unlock()
+
+	if link := s.link.Load(); link != nil {
+		return link, nil
+	}
+
+	sessCtx, cancel := context.WithCancel(ctx)
+	inbound := session.InboundFromContext(sessCtx)
+	if inbound != nil && s.User != nil {
+		inbound.User = s.User
+	}
+	var email string
+	var level uint32
+	if s.User != nil {
+		email = s.User.Email
+		level = s.User.Level
+	}
+	sessCtx = log.ContextWithAccessMessage(sessCtx, &log.AccessMessage{
+		From:   conn.RemoteAddr(),
+		To:     dest,
+		Status: log.AccessAccepted,
+		Email:  email,
+	})
+
+	link, err := dispatcher.Dispatch(sessCtx, dest)
+	if err != nil {
+		cancel()
+		return nil, err
+	}
+
+	s.link.Store(link)
+	sessionPolicy := policyManager.ForLevel(level)
+	s.timer = signal.CancelAfterInactivity(sessCtx, func() {
+		if s.manager != nil {
+			s.manager.Delete(s.SessionID)
+		}
+		s.Close()
+		cancel()
+	}, sessionPolicy.Timeouts.ConnectionIdle)
+
+	go handleUDPResponse(s, link, dest, responseEncoder)
+	return link, nil
+}
+
+// ResetTCPConn sets SO_LINGER to 0 per SIP022 §3.1.4 to consistently send RST on close
+// when handshake or header validation fails.
+func ResetTCPConn(conn net.Conn) {
+	rawConn, _, _ := proxy.UnwrapRawConn(conn)
+	if tcpConn, ok := rawConn.(*net.TCPConn); ok {
+		_ = tcpConn.SetLinger(0)
+	}
+}
+
+func handleUDPResponse(s *ServerUDPSession, link *transport.Link, fallbackDest net.Destination, encode func(dest net.Destination, payload []byte) ([]byte, error)) {
+	defer func() {
+		if s.timer != nil {
+			s.timer.SetTimeout(0)
+		}
+	}()
+	for {
+		resMb, err := link.Reader.ReadMultiBuffer()
+		if err != nil {
+			return
+		}
+		if s.timer != nil {
+			s.timer.Update()
+		}
+		for i, rb := range resMb {
+			b := rb.Bytes()
+			if encode != nil {
+				replyDest := fallbackDest
+				if rb.UDP != nil {
+					replyDest = *rb.UDP
+				}
+				encPacket, err := encode(replyDest, b)
+				rb.Release()
+				if err != nil {
+					continue
+				}
+				if err := s.WriteToClient(encPacket); err != nil {
+					buf.ReleaseMulti(resMb[i+1:])
+					return
+				}
+			} else {
+				err := s.WriteToClient(b)
+				rb.Release()
+				if err != nil {
+					buf.ReleaseMulti(resMb[i+1:])
+					return
+				}
+			}
+		}
+	}
 }
 
 const (

proxy/shadowsocks_2022/shadowsocks_2022_test.go

@@ -182,57 +182,48 @@ func TestTCPStream(t *testing.T) {
 				common.Must(err)
 				IncreaseNonce(reader.Nonce())
 
-				vBuf := buf.New()
-				vBuf.Write(plainVar)
-				receivedDest, err = ReadAddressPort(vBuf)
+				dest, addrLen, err := ParseAddressPort(plainVar)
 				common.Must(err)
+				receivedDest = net.TCPDestination(dest.Address, dest.Port)
+				plainVar = plainVar[addrLen:]
+				padLen := int(binary.BigEndian.Uint16(plainVar[:2]))
+				receivedPayload = plainVar[2+padLen:]
 
-				// Skip padding
-				var padBytes [2]byte
-				_, _ = vBuf.Read(padBytes[:])
-				padLen := int(padBytes[0])<<8 | int(padBytes[1])
-				vBuf.Advance(int32(padLen))
+				// Server sends response stream with receivedPayload as first payload
+				writer := NewServerStreamWriter(serverConn, method, rawKey, salt)
+				pBuf := buf.New()
+				pBuf.Write(receivedPayload)
+				_ = writer.WriteMultiBuffer(buf.MultiBuffer{pBuf})
 
-				receivedPayload = make([]byte, vBuf.Len())
-				copy(receivedPayload, vBuf.Bytes())
-				vBuf.Release()
-
-				// Server sends response handshake
-				serverSalt := make([]byte, method.KeySaltLength)
-				_, _ = rand.Read(serverSalt)
-				respKey := DeriveSessionSubKey(rawKey, serverSalt, method.KeySaltLength)
-				respAead, err := method.NewAEAD(respKey)
-				writer := NewStreamWriter(serverConn, respAead)
-				_, _ = serverConn.Write(serverSalt)
-
-				fixedResp := make([]byte, 1+8+method.KeySaltLength+2)
-				fixedResp[0] = HeaderTypeServer
-				binary.BigEndian.PutUint64(fixedResp[1:9], uint64(time.Now().Unix()))
-				copy(fixedResp[9:9+method.KeySaltLength], salt)
-				binary.BigEndian.PutUint16(fixedResp[9+method.KeySaltLength:11+method.KeySaltLength], 0)
-
-				fixedChunk := respAead.Seal(nil, writer.Nonce(), fixedResp, nil)
-				IncreaseNonce(writer.Nonce())
-				_, _ = serverConn.Write(fixedChunk)
-
-				// Echo stream data
+				// Read and echo additional stream data
 				mb, err := reader.ReadMultiBuffer()
 				common.Must(err)
 				_ = writer.WriteMultiBuffer(mb)
+				_ = writer.Close()
 			}()
 
 			// Client goroutine
 			go func() {
 				defer wg.Done()
-				clientSalt, writer, err := ClientHandshake(clientConn, method, [][]byte{rawKey}, dest, testPayload)
+				clientSalt := make([]byte, method.KeySaltLength)
+				common.Must2(io.ReadFull(rand.Reader, clientSalt))
+				writer, err := WriteTCPRequest(clientConn, method, [][]byte{rawKey}, dest, clientSalt, testPayload)
 				common.Must(err)
 
-				reader, _, err := ClientVerifyServerResponse(clientConn, method, rawKey, clientSalt)
+				reader, err := ReadTCPResponse(clientConn, method, rawKey, clientSalt)
 				common.Must(err)
 
+				// The first ReadMultiBuffer drains initialPayload from reader cache
+				mbInit, err := reader.ReadMultiBuffer()
+				common.Must(err)
+				if !bytes.Equal(mbInit[0].Bytes(), testPayload) {
+					t.Errorf("drained initial payload mismatch: got %s, want %s", mbInit[0].Bytes(), testPayload)
+				}
+				buf.ReleaseMulti(mbInit)
+
 				// Send additional stream data
 				streamData := []byte("stream chunk test")
-				_ = writer.WriteChunk(streamData)
+				_ = writer.WriteMultiBuffer(buf.MultiBuffer{buf.FromBytes(streamData)})
 
 				mb, err := reader.ReadMultiBuffer()
 				common.Must(err)
@@ -272,12 +263,14 @@ func TestUDPCodec(t *testing.T) {
 			psk := make([]byte, method.KeySaltLength)
 			_, _ = rand.Read(psk)
 
-			clientCodec, err := NewUDPPacketCodec(method, psk)
+			clientCodec, err := NewUDPPacketCodec(method, [][]byte{psk})
 			common.Must(err)
 			serverCodec, err := NewUDPServerCodec(method, psk, time.Minute)
 			common.Must(err)
 
-			pktBuf, err := clientCodec.EncodeClientPacket(dest, payload)
+			session, err := clientCodec.NewClientSession()
+			common.Must(err)
+			pktBuf, err := session.EncodePacket(dest, payload)
 			common.Must(err)
 			defer pktBuf.Release()
 
@@ -360,3 +353,146 @@ func TestMultiUserManager(t *testing.T) {
 		t.Fatal("user1 should have been removed")
 	}
 }
+
+func TestLargeStreamTransfer(t *testing.T) {
+	method, err := GetCipherMethod(MethodAES128GCM)
+	common.Must(err)
+	sessionKey := make([]byte, 16)
+	_, _ = rand.Read(sessionKey)
+
+	clientAead, err := method.NewAEAD(sessionKey)
+	common.Must(err)
+	serverAead, err := method.NewAEAD(sessionKey)
+	common.Must(err)
+
+	r, w := io.Pipe()
+	defer r.Close()
+	defer w.Close()
+
+	writer := NewStreamWriter(w, clientAead)
+	reader := NewStreamReader(r, serverAead)
+
+	const totalSize = 100 * 1024 // 100 KB
+	data := make([]byte, totalSize)
+	_, _ = rand.Read(data)
+
+	errCh := make(chan error, 1)
+	go func() {
+		// Write using Write (which splits by MaxPacketSize = 65535)
+		_, werr := writer.Write(data)
+		if werr != nil {
+			errCh <- werr
+			return
+		}
+		_ = w.Close()
+		errCh <- nil
+	}()
+
+	var received []byte
+	for {
+		mb, rerr := reader.ReadMultiBuffer()
+		if !mb.IsEmpty() {
+			for _, b := range mb {
+				received = append(received, b.Bytes()...)
+			}
+			buf.ReleaseMulti(mb)
+		}
+		if rerr != nil {
+			if rerr == io.EOF {
+				break
+			}
+			t.Fatalf("ReadMultiBuffer error: %v", rerr)
+		}
+	}
+
+	if werr := <-errCh; werr != nil {
+		t.Fatalf("writer error: %v", werr)
+	}
+
+	if len(received) != totalSize {
+		t.Fatalf("received size mismatch: got %d, want %d", len(received), totalSize)
+	}
+	if !bytes.Equal(received, data) {
+		t.Fatal("received data does not match sent data")
+	}
+}
+
+func TestClientUDPSessionMultiDestination(t *testing.T) {
+	for _, methodName := range []string{MethodAES128GCM, MethodAES256GCM, MethodChaCha20Poly1305} {
+		t.Run(methodName, func(t *testing.T) {
+			method, err := GetCipherMethod(methodName)
+			common.Must(err)
+			rawKey := make([]byte, method.KeySaltLength)
+			_, _ = rand.Read(rawKey)
+
+			clientCodec, err := NewUDPPacketCodec(method, [][]byte{rawKey})
+			common.Must(err)
+			serverCodec, err := NewUDPServerCodec(method, rawKey, time.Minute)
+			common.Must(err)
+
+			session, err := clientCodec.NewClientSession()
+			common.Must(err)
+
+			dest1 := net.UDPDestination(net.LocalHostIP, net.Port(53))
+			dest2 := net.UDPDestination(net.IPAddress([]byte{127, 0, 0, 2}), net.Port(53))
+
+			payload1 := []byte("query-google-dns")
+			payload2 := []byte("query-cloudflare-dns")
+
+			// Client sends to dest1 and dest2 using SAME session
+			pkt1, err := session.EncodePacket(dest1, payload1)
+			common.Must(err)
+			defer pkt1.Release()
+			pkt2, err := session.EncodePacket(dest2, payload2)
+			common.Must(err)
+			defer pkt2.Release()
+
+			// Server decodes both
+			dec1, err := serverCodec.DecodePacket(pkt1.Bytes())
+			common.Must(err)
+			dec2, err := serverCodec.DecodePacket(pkt2.Bytes())
+			common.Must(err)
+
+			if dec1.SessionID != session.ClientSessionID() || dec2.SessionID != session.ClientSessionID() {
+				t.Fatalf("both packets must share client session ID %d, got %d and %d", session.ClientSessionID(), dec1.SessionID, dec2.SessionID)
+			}
+			if dec1.Destination.String() != dest1.String() {
+				t.Fatalf("expected dest1 %s, got %s", dest1, dec1.Destination)
+			}
+			if dec2.Destination.String() != dest2.String() {
+				t.Fatalf("expected dest2 %s, got %s", dest2, dec2.Destination)
+			}
+			if !bytes.Equal(dec1.Payload, payload1) || !bytes.Equal(dec2.Payload, payload2) {
+				t.Fatal("payload mismatch")
+			}
+
+			// Server replies to dest1 and dest2
+			respPayload1 := []byte("reply-google-dns")
+			respPayload2 := []byte("reply-cloudflare-dns")
+
+			respPkt1, err := serverCodec.EncodeServerPacket(dec1.SessionID, dest1, respPayload1)
+			common.Must(err)
+			respPkt2, err := serverCodec.EncodeServerPacket(dec2.SessionID, dest2, respPayload2)
+			common.Must(err)
+
+			// Client decodes replies
+			clientDec1, err := session.DecodePacket(respPkt1)
+			common.Must(err)
+			if clientDec1.Destination.String() != dest1.String() {
+				t.Fatalf("expected client dec1 dest %s, got %s", dest1, clientDec1.Destination)
+			}
+			if !bytes.Equal(clientDec1.Payload, respPayload1) {
+				t.Fatal("reply payload 1 mismatch")
+			}
+
+			clientDec2, err := session.DecodePacket(respPkt2)
+			common.Must(err)
+			if clientDec2.Destination.String() != dest2.String() {
+				t.Fatalf("expected client dec2 dest %s, got %s", dest2, clientDec2.Destination)
+			}
+			if !bytes.Equal(clientDec2.Payload, respPayload2) {
+				t.Fatal("reply payload 2 mismatch")
+			}
+		})
+	}
+}

proxy/shadowsocks_2022/stream.go

@@ -1,18 +1,25 @@
 package shadowsocks_2022
 
 import (
+	"context"
 	"crypto/cipher"
 	"crypto/rand"
 	"encoding/binary"
 	"io"
 	"math"
 	mrand "math/rand/v2"
+	"sync"
 	"time"
 
+	"github.com/xtls/xray-core/common/antireplay"
 	"github.com/xtls/xray-core/common/buf"
 	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/common/net"
 	"github.com/xtls/xray-core/common/protocol"
+	"github.com/xtls/xray-core/common/signal"
+	"github.com/xtls/xray-core/common/task"
+	"github.com/xtls/xray-core/features/policy"
+	"github.com/xtls/xray-core/transport"
 )
 
 var addrParser = protocol.NewAddressParser(
@@ -38,15 +45,6 @@ func WriteAddressPort(w io.Writer, dest net.Destination) error {
 	return addrParser.WriteAddressPort(w, dest.Address, dest.Port)
 }
 
-// ReadAddressPort reads a destination address and port in SOCKS5 format
-func ReadAddressPort(r io.Reader) (net.Destination, error) {
-	addr, port, err := addrParser.ReadAddressPort(nil, r)
-	if err != nil {
-		return net.Destination{}, err
-	}
-	return net.TCPDestination(addr, port), nil
-}
-
 // AddrPortLength returns the serialized length of a destination in SOCKS5 format
 func AddrPortLength(dest net.Destination) int {
 	switch dest.Address.Family() {
@@ -119,8 +117,16 @@ func (w *StreamWriter) Write(p []byte) (int, error) {
 func (w *StreamWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
 	defer buf.ReleaseMulti(mb)
 	for _, b := range mb {
-		if err := w.WriteChunk(b.Bytes()); err != nil {
-			return err
+		p := b.Bytes()
+		for len(p) > 0 {
+			chunkSize := len(p)
+			if chunkSize > MaxPacketSize {
+				chunkSize = MaxPacketSize
+			}
+			if err := w.WriteChunk(p[:chunkSize]); err != nil {
+				return err
+			}
+			p = p[chunkSize:]
 		}
 	}
 	return nil
@@ -168,7 +174,7 @@ func (r *StreamReader) Read(p []byte) (int, error) {
 	IncreaseNonce(r.nonce[:])
 
 	payloadLen := int(binary.BigEndian.Uint16(decryptedLen))
-	if payloadLen == 0 {
+	if payloadLen == 0 || payloadLen > MaxPacketSize {
 		return 0, ErrInvalidRequest
 	}
 
@@ -194,11 +200,10 @@ func (r *StreamReader) Read(p []byte) (int, error) {
 
 func (r *StreamReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
 	if r.cached > 0 {
-		b := buf.New()
-		b.Write(r.buffer[r.offset : r.offset+r.cached])
+		mb := buf.MergeBytes(nil, r.buffer[r.offset:r.offset+r.cached])
 		r.cached = 0
 		r.offset = 0
-		return buf.MultiBuffer{b}, nil
+		return mb, nil
 	}
 
 	if _, err := io.ReadFull(r.reader, r.lenBuf[:]); err != nil {
@@ -212,7 +217,7 @@ func (r *StreamReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
 	IncreaseNonce(r.nonce[:])
 
 	payloadLen := int(binary.BigEndian.Uint16(decryptedLen))
-	if payloadLen == 0 {
+	if payloadLen == 0 || payloadLen > MaxPacketSize {
 		return nil, ErrInvalidRequest
 	}
 
@@ -227,9 +232,8 @@ func (r *StreamReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
 	}
 	IncreaseNonce(r.nonce[:])
 
-	b := buf.New()
-	b.Write(decryptedPayload)
-	return buf.MultiBuffer{b}, nil
+	mb := buf.MergeBytes(nil, decryptedPayload)
+	return mb, nil
 }
 
 type ClientRequestHeader struct {
@@ -237,13 +241,8 @@ type ClientRequestHeader struct {
 	EarlyData   []byte
 }
 
-func ReadClientRequestHeader(conn io.Reader, reader *StreamReader) (*ClientRequestHeader, error) {
-	var fixedBuf [RequestHeaderFixedChunkLength + AEADTagSize]byte
-	if _, err := io.ReadFull(conn, fixedBuf[:]); err != nil {
-		return nil, err
-	}
-
-	plainFixed, err := reader.cipher.Open(fixedBuf[:0], reader.Nonce(), fixedBuf[:], nil)
+func ReadClientRequestHeaderWithFixed(reader *StreamReader, fixedChunk []byte) (*ClientRequestHeader, error) {
+	plainFixed, err := reader.cipher.Open(fixedChunk[:0], reader.Nonce(), fixedChunk, nil)
 	if err != nil {
 		return nil, errors.New("failed to decrypt client request header").Base(err)
 	}
@@ -272,7 +271,7 @@ func ReadClientRequestHeader(conn io.Reader, reader *StreamReader) (*ClientReque
 	} else {
 		varChunkCipher = make([]byte, needed)
 	}
-	if _, err := io.ReadFull(conn, varChunkCipher); err != nil {
+	if _, err := io.ReadFull(reader.reader, varChunkCipher); err != nil {
 		return nil, err
 	}
 
@@ -282,31 +281,34 @@ func ReadClientRequestHeader(conn io.Reader, reader *StreamReader) (*ClientReque
 	}
 	IncreaseNonce(reader.Nonce())
 
-	b := buf.New()
-	b.Write(plainVar)
-	defer b.Release()
-
-	dest, err := ReadAddressPort(b)
+	dest, addrLen, err := ParseAddressPort(plainVar)
 	if err != nil {
 		return nil, err
 	}
+	dest.Network = net.Network_TCP
 
-	var padLenBytes [2]byte
-	if _, err := b.Read(padLenBytes[:]); err != nil {
-		return nil, err
+	offset := addrLen
+	if len(plainVar) < offset+2 {
+		return nil, ErrPacketTooShort
 	}
-	paddingLen := int(binary.BigEndian.Uint16(padLenBytes[:]))
-	if int(b.Len()) < paddingLen {
+	paddingLen := int(binary.BigEndian.Uint16(plainVar[offset : offset+2]))
+	offset += 2
+
+	if len(plainVar) < offset+paddingLen {
 		return nil, ErrNoPadding
 	}
-	if paddingLen > 0 {
-		b.Advance(int32(paddingLen))
-	}
+	offset += paddingLen
 
 	var earlyData []byte
-	if b.Len() > 0 {
-		earlyData = make([]byte, b.Len())
-		copy(earlyData, b.Bytes())
+	var payloadLen int
+	if len(plainVar) > offset {
+		earlyData = plainVar[offset:]
+		payloadLen = len(earlyData)
+	}
+
+	// SIP022 §3.1.4: Servers MUST reject the request if the variable-length header chunk does not contain payload and the padding length is 0.
+	if paddingLen == 0 && payloadLen == 0 {
+		return nil, errors.New("request without payload and padding is not allowed")
 	}
 
 	return &ClientRequestHeader{
@@ -315,34 +317,6 @@ func ReadClientRequestHeader(conn io.Reader, reader *StreamReader) (*ClientReque
 	}, nil
 }
 
-// ClientHandshake writes the full client request header to w
-func ClientHandshake(w io.Writer, method *CipherMethod, pskList [][]byte, dest net.Destination, payload []byte) ([]byte, *StreamWriter, error) {
-	salt := make([]byte, method.KeySaltLength)
-	if _, err := io.ReadFull(rand.Reader, salt); err != nil {
-		return nil, nil, err
-	}
-	writer, err := WriteTCPRequest(w, method, pskList, dest, salt, payload)
-	if err != nil {
-		return nil, nil, err
-	}
-	return salt, writer.(*StreamWriter), nil
-}
-
-// ClientVerifyServerResponse reads and verifies the server's handshake response
-func ClientVerifyServerResponse(r io.Reader, method *CipherMethod, psk []byte, clientSalt []byte) (*StreamReader, []byte, error) {
-	reader, err := ReadTCPResponse(r, method, psk, clientSalt)
-	if err != nil {
-		return nil, nil, err
-	}
-	sr := reader.(*StreamReader)
-	var initialPayload []byte
-	if sr.cached > 0 {
-		initialPayload = make([]byte, sr.cached)
-		copy(initialPayload, sr.buffer[sr.offset:sr.offset+sr.cached])
-	}
-	return sr, initialPayload, nil
-}
-
 // WriteTCPRequest writes the Shadowsocks 2022 request header into w and returns a body writer.
 func WriteTCPRequest(w io.Writer, method *CipherMethod, pskList [][]byte, dest net.Destination, clientSalt []byte, payload []byte) (buf.Writer, error) {
 	finalPSK := pskList[len(pskList)-1]
@@ -354,7 +328,16 @@ func WriteTCPRequest(w io.Writer, method *CipherMethod, pskList [][]byte, dest n
 
 	writer := NewStreamWriter(w, aead)
 
-	handshakeBuf := buf.New()
+	payloadLen := len(payload)
+	var paddingLen int
+	if payloadLen < MaxPaddingLength {
+		paddingLen = mrand.IntN(MaxPaddingLength) + 1
+	}
+	addrPortLen := AddrPortLength(dest)
+	varHeaderLen := addrPortLen + 2 + paddingLen + payloadLen
+
+	totalHandshakeLen := int32(method.KeySaltLength + len(pskList)*AESBlockSize + RequestHeaderFixedChunkLength + AEADTagSize + varHeaderLen + AEADTagSize)
+	handshakeBuf := buf.NewWithSize(totalHandshakeLen)
 	defer handshakeBuf.Release()
 
 	handshakeBuf.Write(clientSalt)
@@ -372,14 +355,6 @@ func WriteTCPRequest(w io.Writer, method *CipherMethod, pskList [][]byte, dest n
 		handshakeBuf.Write(encryptedEIH[:])
 	}
 
-	payloadLen := len(payload)
-	var paddingLen int
-	if payloadLen < MaxPaddingLength {
-		paddingLen = mrand.IntN(MaxPaddingLength-payloadLen) + 1
-	}
-	addrPortLen := AddrPortLength(dest)
-	varHeaderLen := addrPortLen + 2 + paddingLen + payloadLen
-
 	var fixedHeaderPlaintext [RequestHeaderFixedChunkLength]byte
 	fixedHeaderPlaintext[0] = HeaderTypeClient
 	binary.BigEndian.PutUint64(fixedHeaderPlaintext[1:9], uint64(time.Now().Unix()))
@@ -389,7 +364,7 @@ func WriteTCPRequest(w io.Writer, method *CipherMethod, pskList [][]byte, dest n
 	IncreaseNonce(writer.nonce[:])
 	handshakeBuf.Write(fixedChunk)
 
-	varHeaderBuf := buf.New()
+	varHeaderBuf := buf.NewWithSize(int32(varHeaderLen))
 	defer varHeaderBuf.Release()
 
 	if err := WriteAddressPort(varHeaderBuf, dest); err != nil {
@@ -421,12 +396,21 @@ func WriteTCPRequest(w io.Writer, method *CipherMethod, pskList [][]byte, dest n
 
 // ReadTCPResponse reads and verifies the server's handshake response and returns a reader for the stream.
 func ReadTCPResponse(r io.Reader, method *CipherMethod, psk []byte, clientSalt []byte) (buf.Reader, error) {
-	var serverSalt [32]byte
-	serverSaltSlice := serverSalt[:method.KeySaltLength]
-	if _, err := io.ReadFull(r, serverSaltSlice); err != nil {
-		return nil, err
+	fixedPlainLen := 1 + 8 + method.KeySaltLength + 2
+	chunkCipherLen := fixedPlainLen + AEADTagSize
+	headerLen := method.KeySaltLength + chunkCipherLen
+
+	// Single read call for Salt + Fixed-length response header chunk per SIP022 §3.1.4
+	var headerBuf [128]byte
+	headerSlice := headerBuf[:headerLen]
+	n, err := r.Read(headerSlice)
+	if err != nil || n < headerLen {
+		return nil, errors.New("failed to read complete server response header")
 	}
 
+	serverSaltSlice := headerSlice[:method.KeySaltLength]
+	chunkSlice := headerSlice[method.KeySaltLength:headerLen]
+
 	sessionKey := DeriveSessionSubKey(psk, serverSaltSlice, method.KeySaltLength)
 	aead, err := method.NewAEAD(sessionKey)
 	if err != nil {
@@ -435,14 +419,6 @@ func ReadTCPResponse(r io.Reader, method *CipherMethod, psk []byte, clientSalt [
 
 	reader := NewStreamReader(r, aead)
 
-	fixedPlainLen := 1 + 8 + method.KeySaltLength + 2
-	chunkCipherLen := fixedPlainLen + AEADTagSize
-	var chunkBuf [64]byte
-	chunkSlice := chunkBuf[:chunkCipherLen]
-	if _, err := io.ReadFull(r, chunkSlice); err != nil {
-		return nil, err
-	}
-
 	decryptedFixed, err := reader.cipher.Open(chunkSlice[:0], reader.nonce[:], chunkSlice, nil)
 	if err != nil {
 		return nil, errors.New("failed to decrypt server response header").Base(err)
@@ -484,46 +460,190 @@ func ReadTCPResponse(r io.Reader, method *CipherMethod, psk []byte, clientSalt [
 	return reader, nil
 }
 
-// WriteTCPResponse writes the server handshake response and returns a body writer for server stream.
-func WriteTCPResponse(w io.Writer, method *CipherMethod, psk []byte, clientSalt []byte, initialPayload []byte) (buf.Writer, error) {
+// ServerStreamWriter lazily sends the response header along with the first payload chunk per SIP022 §3.1.2 & §3.1.4.
+type ServerStreamWriter struct {
+	mu           sync.Mutex
+	w            io.Writer
+	method       *CipherMethod
+	psk          []byte
+	clientSalt   []byte
+	streamWriter *StreamWriter
+}
+
+func NewServerStreamWriter(w io.Writer, method *CipherMethod, psk []byte, clientSalt []byte) *ServerStreamWriter {
+	return &ServerStreamWriter{
+		w:          w,
+		method:     method,
+		psk:        psk,
+		clientSalt: clientSalt,
+	}
+}
+
+func (s *ServerStreamWriter) sendHeaderWithFirstPayload(payload []byte) (*StreamWriter, error) {
 	var serverSalt [32]byte
-	serverSaltSlice := serverSalt[:method.KeySaltLength]
+	serverSaltSlice := serverSalt[:s.method.KeySaltLength]
 	if _, err := io.ReadFull(rand.Reader, serverSaltSlice); err != nil {
 		return nil, err
 	}
 
-	respKey := DeriveSessionSubKey(psk, serverSaltSlice, method.KeySaltLength)
-	respAead, err := method.NewAEAD(respKey)
+	respKey := DeriveSessionSubKey(s.psk, serverSaltSlice, s.method.KeySaltLength)
+	respAead, err := s.method.NewAEAD(respKey)
 	if err != nil {
 		return nil, err
 	}
-	writer := NewStreamWriter(w, respAead)
+	sw := NewStreamWriter(s.w, respAead)
 
-	respBuf := buf.New()
-	defer respBuf.Release()
+	totalHeaderLen := int32(s.method.KeySaltLength + 1 + 8 + s.method.KeySaltLength + 2 + AEADTagSize + len(payload) + AEADTagSize)
+	outBuf := buf.NewWithSize(totalHeaderLen)
+	defer outBuf.Release()
 
-	respBuf.Write(serverSaltSlice)
+	outBuf.Write(serverSaltSlice)
 
 	var fixedRespPlain [1 + 8 + 32 + 2]byte
-	fixedRespSlice := fixedRespPlain[:1+8+method.KeySaltLength+2]
+	fixedRespSlice := fixedRespPlain[:1+8+s.method.KeySaltLength+2]
 	fixedRespSlice[0] = HeaderTypeServer
 	binary.BigEndian.PutUint64(fixedRespSlice[1:9], uint64(time.Now().Unix()))
-	copy(fixedRespSlice[9:9+method.KeySaltLength], clientSalt)
-	binary.BigEndian.PutUint16(fixedRespSlice[9+method.KeySaltLength:11+method.KeySaltLength], uint16(len(initialPayload)))
+	copy(fixedRespSlice[9:9+s.method.KeySaltLength], s.clientSalt)
+	binary.BigEndian.PutUint16(fixedRespSlice[9+s.method.KeySaltLength:11+s.method.KeySaltLength], uint16(len(payload)))
 
-	fixedRespChunk := writer.cipher.Seal(nil, writer.nonce[:], fixedRespSlice, nil)
-	IncreaseNonce(writer.nonce[:])
-	respBuf.Write(fixedRespChunk)
+	fixedRespChunk := sw.cipher.Seal(nil, sw.nonce[:], fixedRespSlice, nil)
+	IncreaseNonce(sw.nonce[:])
+	outBuf.Write(fixedRespChunk)
 
-	if len(initialPayload) > 0 {
-		initialChunk := writer.cipher.Seal(nil, writer.nonce[:], initialPayload, nil)
-		IncreaseNonce(writer.nonce[:])
-		respBuf.Write(initialChunk)
+	if len(payload) > 0 {
+		payloadChunk := sw.cipher.Seal(nil, sw.nonce[:], payload, nil)
+		IncreaseNonce(sw.nonce[:])
+		outBuf.Write(payloadChunk)
 	}
 
-	if _, err := w.Write(respBuf.Bytes()); err != nil {
+	if _, err := s.w.Write(outBuf.Bytes()); err != nil {
 		return nil, err
 	}
+	return sw, nil
+}
 
-	return writer, nil
+func (s *ServerStreamWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
+	if mb.IsEmpty() {
+		return nil
+	}
+
+	if s.streamWriter == nil {
+		s.mu.Lock()
+		if s.streamWriter == nil {
+			firstBuf := mb[0]
+			firstBytes := firstBuf.Bytes()
+			chunkSize := len(firstBytes)
+			if chunkSize > MaxPacketSize {
+				chunkSize = MaxPacketSize
+			}
+			firstPayload := firstBytes[:chunkSize]
+			sw, err := s.sendHeaderWithFirstPayload(firstPayload)
+			if err != nil {
+				s.mu.Unlock()
+				buf.ReleaseMulti(mb)
+				return err
+			}
+			s.streamWriter = sw
+
+			firstBuf.Advance(int32(chunkSize))
+			if firstBuf.IsEmpty() {
+				firstBuf.Release()
+				mb = mb[1:]
+			}
+		}
+		s.mu.Unlock()
+		if len(mb) == 0 {
+			return nil
+		}
+	}
+
+	return s.streamWriter.WriteMultiBuffer(mb)
+}
+
+func (s *ServerStreamWriter) Write(p []byte) (int, error) {
+	n := len(p)
+	if s.streamWriter == nil {
+		s.mu.Lock()
+		if s.streamWriter == nil {
+			chunkSize := len(p)
+			if chunkSize > MaxPacketSize {
+				chunkSize = MaxPacketSize
+			}
+			firstPayload := p[:chunkSize]
+			sw, err := s.sendHeaderWithFirstPayload(firstPayload)
+			if err != nil {
+				s.mu.Unlock()
+				return 0, err
+			}
+			s.streamWriter = sw
+			p = p[chunkSize:]
+		}
+		s.mu.Unlock()
+		if len(p) == 0 {
+			return n, nil
+		}
+	}
+
+	_, err := s.streamWriter.Write(p)
+	return n, err
+}
+
+func (s *ServerStreamWriter) Close() error {
+	if s.streamWriter == nil {
+		s.mu.Lock()
+		defer s.mu.Unlock()
+		if s.streamWriter == nil {
+			sw, err := s.sendHeaderWithFirstPayload(nil)
+			if err != nil {
+				return err
+			}
+			s.streamWriter = sw
+		}
+	}
+	return nil
+}
+
+// InitServerStream decrypts the client request header, verifies the timestamp and replay filter,
+// and returns a StreamReader for subsequent stream chunks.
+func InitServerStream(conn net.Conn, method *CipherMethod, psk, saltSlice []byte, salt [32]byte, fixedChunk []byte, saltFilter *antireplay.ReplayFilter[[32]byte]) (*StreamReader, *ClientRequestHeader, error) {
+	sessionKey := DeriveSessionSubKey(psk, saltSlice, method.KeySaltLength)
+	aead, err := method.NewAEAD(sessionKey)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	reader := NewStreamReader(conn, aead)
+
+	reqHeader, err := ReadClientRequestHeaderWithFixed(reader, fixedChunk)
+	if err != nil {
+		return nil, nil, err
+	}
+	_ = conn.SetReadDeadline(time.Time{})
+
+	if !saltFilter.Check(salt) {
+		return nil, nil, ErrSaltNotUnique
+	}
+	return reader, reqHeader, nil
+}
+
+func TransportTCP(ctx context.Context, sessionPolicy policy.Session, reader buf.Reader, writer buf.Writer, link *transport.Link) error {
+	ctx, cancel := context.WithCancel(ctx)
+	timer := signal.CancelAfterInactivity(ctx, cancel, sessionPolicy.Timeouts.ConnectionIdle)
+	ctx = policy.ContextWithBufferPolicy(ctx, sessionPolicy.Buffer)
+
+	requestDone := func() error {
+		defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly)
+		return buf.Copy(reader, link.Writer, buf.UpdateActivity(timer))
+	}
+
+	responseDone := func() error {
+		defer timer.SetTimeout(sessionPolicy.Timeouts.UplinkOnly)
+		if c, ok := writer.(io.Closer); ok {
+			defer c.Close()
+		}
+		return buf.Copy(link.Reader, writer, buf.UpdateActivity(timer))
+	}
+
+	responseDoneAndCloseWriter := task.OnSuccess(responseDone, task.Close(link.Writer))
+	return task.Run(ctx, requestDone, responseDoneAndCloseWriter)
 }

proxy/socks/server.go

@@ -170,9 +170,17 @@ func (s *Server) processTCP(ctx context.Context, conn stat.Connection, dispatche
 			return errors.New("UDP associate with listen port failed")
 		}
 		tempUDPConn.SetTimeout(plcy.Timeouts.ConnectionIdle)
+		var udpConn stat.Connection = tempUDPConn
+		if counters, ok := conn.(*stat.CounterConnection); ok {
+			udpConn = &stat.CounterConnection{
+				Connection:   tempUDPConn,
+				ReadCounter:  counters.ReadCounter,
+				WriteCounter: counters.WriteCounter,
+			}
+		}
 		errCh := make(chan error, 1)
 		go func() {
-			errCh <- s.handleUDPPayload(ctx, tempUDPConn, dispatcher)
+			errCh <- s.handleUDPPayload(ctx, udpConn, dispatcher)
 		}()
 		// Associated TCP keeps the UDP alive
 		// Close UDP if TCP connection is closed