dns: unify the Lua API for local and configured DNS

Expose localdns.Client in xray.dns.Servers with the ID "localhost",
so Lua scripts can use the same server API for both clients.

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.
@@ -258,8 +266,10 @@ 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"`
-	unknownFields          protoimpl.UnknownFields
-	sizeCache              protoimpl.SizeCache
+	// Absolute path to the Lua DNS query script.
+	Script        string `protobuf:"bytes,15,opt,name=script,proto3" json:"script,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *Config) Reset() {
@@ -369,6 +379,13 @@ 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 +452,7 @@ 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 +478,11 @@ 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 +498,8 @@ 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 +74,7 @@ message Config {
   bool disableFallbackIfMatch = 11;
 
   bool enableParallelQuery = 14;
+
+  // Absolute path to the Lua DNS query script.
+  string script = 15;
 }

app/dns/dns.go

@@ -31,6 +31,8 @@ type DNS struct {
 	domainMatcher          geodata.DomainMatcher
 	matcherInfos           []*DomainMatcherInfo
 	checkSystem            bool
+	script                 *scriptEngine
+	scriptPath             string
 }
 
 // DomainMatcherInfo contains information attached to index returned by Server.domainMatcher.
@@ -180,6 +182,7 @@ func New(ctx context.Context, config *Config) (*DNS, error) {
 		disableFallbackIfMatch: config.DisableFallbackIfMatch,
 		enableParallelQuery:    config.EnableParallelQuery,
 		checkSystem:            checkSystem,
+		scriptPath:             config.Script,
 	}, nil
 }
 
@@ -190,11 +193,21 @@ func (*DNS) Type() interface{} {
 
 // Start implements common.Runnable.
 func (s *DNS) Start() error {
+	if s.scriptPath != "" {
+		engine, err := newScriptEngine(s.scriptPath, s)
+		if err != nil {
+			return errors.New("failed to initialize DNS script").Base(err)
+		}
+		s.script = engine
+	}
 	return nil
 }
 
 // Close implements common.Closable.
 func (s *DNS) Close() error {
+	if s.script != nil {
+		s.script.close()
+	}
 	return nil
 }
 
@@ -257,6 +270,9 @@ 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 +1,201 @@
+package dns
+
+import (
+	"context"
+	"math"
+	"strings"
+
+	"github.com/xtls/xray-core/common/errors"
+	"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 {
+		serverList := L.NewTable()
+		for i, client := range servers {
+			server := L.NewTable()
+
+			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)
+				}
+				addresses := L.NewUserData()
+				addresses.Value = ips
+				L.Push(addresses)
+				L.Push(lua.LNumber(ttl))
+				if err != nil {
+					ud := L.NewUserData()
+					ud.Value = err
+					L.Push(ud)
+				} else {
+					L.Push(lua.LNil)
+				}
+				return 3
+			}))
+			serverList.RawSetInt(i+1, server)
+		}
+
+		module := L.NewTable()
+		if servers != nil {
+			module.RawSetString("Servers", serverList)
+		}
+		if client != nil {
+			module.RawSetString("Query", newLuaClientQuery(L, client))
+		}
+		L.Push(module)
+		return 1
+	})
+}
+
+func newLuaClientQuery(L *lua.LState, client featureDNS.Client) *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)
+		addresses := L.NewUserData()
+		addresses.Value = ips
+		L.Push(addresses)
+		L.Push(lua.LNumber(ttl))
+		if err != nil {
+			ud := L.NewUserData()
+			ud.Value = err
+			L.Push(ud)
+		} else {
+			L.Push(lua.LNil)
+		}
+		return 3
+	})
+}
+
+// CallLuaHook invokes HandleDNSQuery in the supplied state.
+// Returned slices and IP bytes may share storage with DNS caches or matcher inputs.
+func (s *DNS) CallLuaHook(L *lua.LState, ctx context.Context, domain string, option featureDNS.IPOption) ([]net.IP, uint32, error) {
+	previous, top := L.Context(), L.GetTop()
+	L.SetContext(ctx)
+	defer func() {
+		L.SetTop(top)
+		if previous == nil {
+			L.RemoveContext()
+		} else {
+			L.SetContext(previous)
+		}
+	}()
+	fn := L.GetGlobal("HandleDNSQuery")
+	if fn.Type() != lua.LTFunction {
+		return nil, 0, errors.New("DNS script must define HandleDNSQuery(domain, ipv4, ipv6, fake)")
+	}
+	if err := 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)); err != nil {
+		return nil, 0, err
+	}
+	return readLuaDNSResult(L.Get(-3), L.Get(-2), L.Get(-1))
+}
+
+func readLuaDNSResult(addresses, ttlValue, errorValue lua.LValue) ([]net.IP, uint32, error) {
+	if errorValue != lua.LNil {
+		if ud, ok := errorValue.(*lua.LUserData); ok {
+			if err, ok := ud.Value.(error); ok {
+				return nil, 0, err
+			}
+		}
+		if s, ok := errorValue.(lua.LString); ok {
+			return nil, 0, errors.New(string(s))
+		}
+		return nil, 0, errors.New("DNS script error must be an error or string")
+	}
+	ttl, ok := ttlValue.(lua.LNumber)
+	if !ok || ttl < 0 || ttl > math.MaxUint32 || math.Trunc(float64(ttl)) != float64(ttl) {
+		return nil, 0, errors.New("DNS script returned invalid TTL")
+	}
+	if addresses == lua.LNil {
+		return nil, 0, featureDNS.ErrEmptyResponse
+	}
+	ud, ok := addresses.(*lua.LUserData)
+	if !ok {
+		return nil, 0, errors.New("DNS script IPs must be native IP slice userdata")
+	}
+	ips, ok := ud.Value.([]net.IP)
+	if !ok {
+		return nil, 0, errors.New("DNS script IPs must be native IP slice userdata")
+	}
+	if len(ips) == 0 {
+		return nil, 0, featureDNS.ErrEmptyResponse
+	}
+	return ips, uint32(ttl), nil
+}

app/dns/lua_test.go

@@ -0,0 +1,296 @@
+package dns
+
+import (
+	"context"
+	go_errors "errors"
+	"math"
+	"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 TestReadLuaDNSResult(t *testing.T) {
+	L := lua.NewState()
+	defer L.Close()
+	want := []net.IP{net.ParseIP("8.8.8.8"), {127, 0, 0, 1}, net.ParseIP("::1")}
+	addresses := L.NewUserData()
+	addresses.Value = want
+	ips, ttl, err := readLuaDNSResult(addresses, lua.LNumber(45), lua.LNil)
+	if err != nil || ttl != 45 || len(ips) != len(want) {
+		t.Fatalf("readLuaDNSResult() = %v, TTL %d, %v", ips, ttl, err)
+	}
+	for i := range want {
+		if !ips[i].Equal(want[i]) {
+			t.Fatalf("IP %d = %v, want %v", i, ips[i], want[i])
+		}
+	}
+}
+
+func TestReadLuaDNSResultValidation(t *testing.T) {
+	L := lua.NewState()
+	defer L.Close()
+
+	for _, tc := range []struct {
+		name   string
+		change func(*[3]lua.LValue)
+		want   string
+	}{
+		{"fractional TTL", func(v *[3]lua.LValue) { v[1] = lua.LNumber(1.5) }, "invalid TTL"},
+		{"oversized TTL", func(v *[3]lua.LValue) { v[1] = lua.LNumber(4294967296) }, "invalid TTL"},
+		{"negative TTL", func(v *[3]lua.LValue) { v[1] = lua.LNumber(-1) }, "invalid TTL"},
+		{"NaN TTL", func(v *[3]lua.LValue) { v[1] = lua.LNumber(math.NaN()) }, "invalid TTL"},
+		{"missing TTL", func(v *[3]lua.LValue) { v[1] = lua.LNil }, "invalid TTL"},
+		{"string IPs", func(v *[3]lua.LValue) { v[0] = lua.LString("127.0.0.1") }, "native IP slice"},
+		{"wrong userdata", func(v *[3]lua.LValue) { v[0].(*lua.LUserData).Value = net.ParseIP("127.0.0.1") }, "native IP slice"},
+		{"script error", func(v *[3]lua.LValue) { v[2] = lua.LString("blocked by script") }, "blocked by script"},
+		{"invalid error", func(v *[3]lua.LValue) { v[2] = lua.LTrue }, "error or string"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			addresses := L.NewUserData()
+			addresses.Value = []net.IP{net.ParseIP("127.0.0.1")}
+			values := [3]lua.LValue{addresses, lua.LNumber(60), lua.LNil}
+			tc.change(&values)
+			_, _, err := readLuaDNSResult(values[0], values[1], values[2])
+			if err == nil || !strings.Contains(err.Error(), tc.want) {
+				t.Fatalf("readLuaDNSResult error = %v, want %q", err, tc.want)
+			}
+		})
+	}
+
+	addresses := L.NewUserData()
+	addresses.Value = []net.IP(nil)
+	for _, empty := range []lua.LValue{addresses, lua.LNil} {
+		if _, _, err := readLuaDNSResult(empty, lua.LNumber(0), lua.LNil); !go_errors.Is(err, featureDNS.ErrEmptyResponse) {
+			t.Fatalf("empty result error = %v, want ErrEmptyResponse", err)
+		}
+	}
+	wantErr := go_errors.New("upstream failed")
+	errorValue := L.NewUserData()
+	errorValue.Value = wantErr
+	if _, _, err := readLuaDNSResult(lua.LNil, lua.LNil, errorValue); err != wantErr {
+		t.Fatalf("upstream error = %v, want original error %v", err, wantErr)
+	}
+}
+
+func TestCallLuaHookCancellation(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.WithTimeout(context.Background(), 50*time.Millisecond)
+	defer cancel()
+	_, _, err := (&DNS{}).CallLuaHook(L, ctx, "example.com", featureDNS.IPOption{IPv4Enable: true})
+	if err == nil {
+		t.Fatal("CallLuaHook did not stop after context cancellation")
+	}
+	if L.Context() != nil {
+		t.Fatal("CallLuaHook left the canceled context on the Lua state")
+	}
+}
+
+func TestCallLuaHookNormalizesDomain(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)
+	}
+	s := &DNS{}
+	if _, _, err := s.CallLuaHook(L, context.Background(), "ExAmPlE.CoM", featureDNS.IPOption{IPv4Enable: true}); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestCallLuaHookRestoresState(t *testing.T) {
+	for _, tc := range []struct {
+		name    string
+		body    string
+		wantErr bool
+	}{
+		{"success", `return ips, 60`, false},
+		{"error", `error("failed")`, true},
+	} {
+		t.Run(tc.name, func(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() " + tc.body + " end"); err != nil {
+				t.Fatal(err)
+			}
+			previous, cancel := context.WithCancel(context.Background())
+			defer cancel()
+			L.SetContext(previous)
+			L.Push(lua.LTrue)
+			_, _, err := (&DNS{}).CallLuaHook(L, context.Background(), "example.com", featureDNS.IPOption{IPv4Enable: true})
+			if (err != nil) != tc.wantErr {
+				t.Fatalf("hook error = %v, want error %t", err, tc.wantErr)
+			}
+			if L.Context() != previous || L.GetTop() != 1 || L.Get(1) != lua.LTrue {
+				t.Fatal("hook did not restore the previous context and 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(matcher:AnyMatch(ips))
+    local matched = matcher:FilterIPs(ips)
+    return matched, ttl, err
+end
+`); err != nil {
+		t.Fatal(err)
+	}
+	got, ttl, err := server.CallLuaHook(L, context.Background(), "example.com", option)
+	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())
+	defer L.RemoveContext()
+	geodata.RegisterLua(L)
+	want := []net.IP{{127, 0, 0, 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))
+`); 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())
+	defer L.RemoveContext()
+	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)
+`); 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)
+		}
+	}
+}
+
+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
+}
+
+// BenchmarkLuaDNSHookCall isolates a preloaded Lua hook and its server:Query bridge.
+// The direct case measures the same DNS client without Lua.
+func BenchmarkLuaDNSHookCall(b *testing.B) {
+	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{clients: []*Client{client}}
+	L := lua.NewState()
+	defer L.Close()
+	server.RegisterLua(L)
+	if err := L.DoString(`
+local server = require("xray.dns").Servers[1]
+function HandleDNSQuery(domain, ipv4, ipv6, fake)
+    return server:Query(domain, ipv4, ipv6, fake)
+end
+`); err != nil {
+		b.Fatal(err)
+	}
+
+	ctx := context.Background()
+	for _, bench := range []struct {
+		name  string
+		query func() ([]net.IP, uint32, error)
+	}{
+		{"direct", func() ([]net.IP, uint32, error) { return client.QueryIP(ctx, "example.com", option) }},
+		{"lua_hook", func() ([]net.IP, uint32, error) { return server.CallLuaHook(L, ctx, "example.com", option) }},
+	} {
+		b.Run(bench.name, func(b *testing.B) {
+			b.ReportAllocs()
+			b.ResetTimer()
+			var ips []net.IP
+			var ttl uint32
+			var err error
+			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/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 +1,73 @@
+package dns
+
+import (
+	"context"
+	"time"
+
+	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/geodata"
+	"github.com/xtls/xray-core/common/log"
+	luamgr "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 = 10 * time.Second
+
+type scriptEngine struct {
+	dns  *DNS
+	pool *luamgr.Pool
+}
+
+func newScriptEngine(path string, server *DNS) (*scriptEngine, error) {
+	program, err := luamgr.CompileFile(path)
+	if err != nil {
+		return nil, err
+	}
+	e := &scriptEngine{dns: server}
+	e.pool, err = luamgr.NewPool(server.ctx, func(poolCtx context.Context) (*lua.LState, error) {
+		initCtx, cancel := context.WithTimeout(poolCtx, scriptExecutionTimeout)
+		defer cancel()
+		L, err := program.NewState(initCtx, func(L *lua.LState) {
+			geodata.RegisterLua(L)
+			log.RegisterLua(L)
+			server.RegisterLua(L)
+		})
+		if err != nil {
+			return nil, err
+		}
+		if L.GetGlobal("HandleDNSQuery").Type() != lua.LTFunction {
+			L.Close()
+			return nil, errors.New("DNS script must define HandleDNSQuery(domain, ipv4, ipv6, fake)")
+		}
+		return L, nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	errors.LogInfo(server.ctx, "DNS script initialized from ", path)
+	return e, nil
+}
+
+func (e *scriptEngine) close() {
+	e.pool.Close()
+}
+
+func (e *scriptEngine) query(domain string, option dns.IPOption) ([]net.IP, uint32, error) {
+	L, err := e.pool.Acquire()
+	if err != nil {
+		return nil, 0, err
+	}
+	reusable := false
+	defer func() {
+		e.pool.Release(L, reusable)
+	}()
+	queryCtx, cancel := context.WithTimeout(e.pool.Context(), scriptExecutionTimeout)
+	defer cancel()
+	ips, ttl, err := e.dns.CallLuaHook(L, queryCtx, domain, option)
+	if err == nil {
+		reusable = true
+	}
+	return ips, ttl, err
+}

app/dns/script_test.go

@@ -0,0 +1,197 @@
+package dns
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/xtls/xray-core/common/net"
+	featureDNS "github.com/xtls/xray-core/features/dns"
+)
+
+type geoIPScriptNameServer struct {
+	name    string
+	answers map[string]net.IP
+	ttl     uint32
+	calls   int
+}
+
+func (s *geoIPScriptNameServer) Name() string         { return s.name }
+func (s *geoIPScriptNameServer) IsDisableCache() bool { return true }
+
+func (s *geoIPScriptNameServer) QueryIP(ctx context.Context, domain string, _ featureDNS.IPOption) ([]net.IP, uint32, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, 0, err
+	}
+	s.calls++
+	ip, ok := s.answers[domain]
+	if !ok {
+		return nil, 0, featureDNS.ErrEmptyResponse
+	}
+	return []net.IP{ip}, s.ttl, nil
+}
+
+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 := &geoIPScriptNameServer{
+		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 := &geoIPScriptNameServer{
+		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)
+	}
+	server := &DNS{
+		ctx:        context.Background(),
+		hosts:      hosts,
+		ipOption:   &option,
+		scriptPath: scriptPath,
+		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   string
+		script string
+	}{
+		{"syntax", "function HandleDNSQuery("},
+		{"missing hook", "value = 1"},
+		{"top-level error", `error("setup failed")`},
+	} {
+		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 := &DNS{ctx: context.Background(), scriptPath: path}
+			if err := server.Start(); err == nil {
+				t.Fatal("Start accepted an invalid DNS script")
+			}
+			if server.script != nil {
+				t.Fatal("Start retained a script engine after failure")
+			}
+		})
+	}
+}
+
+func TestDNSScriptHookErrorAndFakeDNSOption(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)
+    if domain == "bad.example" then error("script failure") end
+    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 := &geoIPScriptNameServer{
+		name:    "FakeDNS",
+		answers: map[string]net.IP{"good.example": net.ParseIP("198.18.0.1")},
+		ttl:     30,
+	}
+	server := &DNS{
+		ctx:        context.Background(),
+		hosts:      hosts,
+		ipOption:   &option,
+		scriptPath: path,
+		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("bad.example", option); err == nil || !strings.Contains(err.Error(), "script failure") {
+		t.Fatalf("hook failure = %v, want script failure", err)
+	}
+	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/router/config.pb.go

@@ -587,8 +587,10 @@ 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"`
-	unknownFields  protoimpl.UnknownFields
-	sizeCache      protoimpl.SizeCache
+	// Absolute path to the Lua routing script.
+	Script        string `protobuf:"bytes,4,opt,name=script,proto3" json:"script,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *Config) Reset() {
@@ -642,6 +644,13 @@ 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 +708,12 @@ 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 +110,6 @@ message Config {
   DomainStrategy domain_strategy = 1;
   repeated RoutingRule rule = 2;
   repeated BalancingRule balancing_rule = 3;
+  // Absolute path to the Lua routing script.
+  string script = 4;
 }

app/router/lua.go

@@ -0,0 +1,206 @@
+package router
+
+import (
+	"context"
+	"runtime"
+
+	"github.com/xtls/xray-core/common/errors"
+	"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.NewTable()
+
+		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(2).(lua.LString)
+			if !ok {
+				L.ArgError(2, "balancer tag must be a string")
+				return 0
+			}
+			balancer, found := (*r.balancers.Load())[string(tag)]
+			if !found {
+				L.Push(lua.LNil)
+				pushLuaError(L, errors.New("balancer ", tag, " not found"))
+				return 2
+			}
+			outboundTag, err := balancer.PickOutbound()
+			L.Push(lua.LString(outboundTag))
+			pushLuaError(L, err)
+			return 2
+		}))
+
+		module.RawSetString("FindProcess", L.NewFunction(func(L *lua.LState) int {
+			pid, name, path, err := findProcess(checkLuaContext(L), net.FindProcess)
+			L.Push(lua.LNumber(pid))
+			L.Push(lua.LString(name))
+			L.Push(lua.LString(path))
+			pushLuaError(L, err)
+			return 4
+		}))
+
+		L.Push(module)
+		return 1
+	})
+}
+
+func registerLuaContext(L *lua.LState) {
+	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 {
+			L.Push(lua.LString(value))
+		} else {
+			L.Push(lua.LNil)
+		}
+		return 1
+	}))
+	methods := L.NewTable()
+	L.SetFuncs(methods, map[string]lua.LGFunction{
+		"GetSourceIPs": func(L *lua.LState) int {
+			return pushLuaIPs(L, checkLuaContext(L).GetSourceIPs())
+		},
+		"GetTargetIPs": func(L *lua.LState) int {
+			return pushLuaIPs(L, checkLuaContext(L).GetTargetIPs())
+		},
+		"GetLocalIPs": func(L *lua.LState) int {
+			return pushLuaIPs(L, checkLuaContext(L).GetLocalIPs())
+		},
+		"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
+}
+
+func pushLuaIPs(L *lua.LState, ips []net.IP) int {
+	addresses := L.NewUserData()
+	addresses.Value = ips
+	L.Push(addresses)
+	return 1
+}
+
+func pushLuaError(L *lua.LState, err error) {
+	if err == nil {
+		L.Push(lua.LNil)
+		return
+	}
+	value := L.NewUserData()
+	value.Value = err
+	L.Push(value)
+}
+
+// CallLuaHook invokes HandleRoute in the supplied state.
+func (r *Router) CallLuaHook(L *lua.LState, ctx context.Context, routeCtx routing.Context) (string, string, error) {
+	previous, top := L.Context(), L.GetTop()
+	L.SetContext(ctx)
+	defer func() {
+		L.SetTop(top)
+		if previous == nil {
+			L.RemoveContext()
+		} else {
+			L.SetContext(previous)
+		}
+	}()
+	fn := L.GetGlobal("HandleRoute")
+	if fn.Type() != lua.LTFunction {
+		return "", "", errors.New("routing script must define HandleRoute(...)")
+	}
+	value := L.NewUserData()
+	value.Value = routeCtx
+	L.SetMetatable(value, L.GetTypeMetatable(luaContextType))
+	if err := L.CallByParam(lua.P{Fn: fn, NRet: 3, Protect: true},
+		value, lua.LString(routeCtx.GetInboundTag()), lua.LNumber(routeCtx.GetSourcePort()),
+		lua.LNumber(routeCtx.GetTargetPort()), lua.LNumber(routeCtx.GetLocalPort()),
+		lua.LString(routeCtx.GetTargetDomain()), lua.LNumber(routeCtx.GetNetwork()),
+		lua.LString(routeCtx.GetProtocol()), lua.LString(routeCtx.GetUser()),
+		lua.LNumber(routeCtx.GetVlessRoute()), lua.LBool(routeCtx.GetSkipDNSResolve())); err != nil {
+		return "", "", err
+	}
+	return readLuaRouteResult(L.Get(-3), L.Get(-2), L.Get(-1))
+}
+
+func readLuaRouteResult(tagValue, ruleValue, errorValue lua.LValue) (string, string, error) {
+	if errorValue != lua.LNil {
+		if value, ok := errorValue.(*lua.LUserData); ok {
+			if err, ok := value.Value.(error); ok {
+				return "", "", err
+			}
+		}
+		if value, ok := errorValue.(lua.LString); ok {
+			return "", "", errors.New(string(value))
+		}
+		return "", "", errors.New("routing script error must be an error or string")
+	}
+	if tagValue == lua.LNil {
+		return "", "", nil
+	}
+	tag, ok := tagValue.(lua.LString)
+	if !ok {
+		return "", "", errors.New("routing script outboundTag must be a string or nil")
+	}
+	if tag == "" {
+		return "", "", nil
+	}
+	var ruleTag string
+	if ruleValue != lua.LNil {
+		value, ok := ruleValue.(lua.LString)
+		if !ok {
+			return "", "", errors.New("routing script ruleTag must be a string")
+		}
+		ruleTag = string(value)
+	}
+	return string(tag), 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_test.go

@@ -0,0 +1,292 @@
+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) (*Router, *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 r, L
+}
+
+func TestLuaRouteBinding(t *testing.T) {
+	r, 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(matcher:AnyMatch(sourceIPs) and matcher:AnyMatch(targetIPs) and matcher:AnyMatch(localIPs))
+    assert(attributes.key == "value" and attributes.missing == nil)
+    assert(not pcall(function() attributes.key = "changed" end))
+    return "out", "rule"
+end`)
+
+	ctx := newLuaRouteTestContext()
+	tag, rule, err := r.CallLuaHook(L, context.Background(), ctx)
+	if err != nil || tag != "out" || rule != "rule" {
+		t.Fatalf("hook = %q, %q, %v", tag, rule, err)
+	}
+	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 TestLuaRouteResult(t *testing.T) {
+	nativeErr := go_errors.New("native failure")
+	for _, tc := range []struct {
+		name, body, tag, rule, wantErr string
+		native                         bool
+	}{
+		{name: "route", body: `return "out", "rule"`, tag: "out", rule: "rule"},
+		{name: "no match", body: `return nil`},
+		{name: "empty tag", body: `return ""`},
+		{name: "invalid tag", body: `return 1`, wantErr: "outboundTag"},
+		{name: "invalid rule", body: `return "out", false`, wantErr: "ruleTag"},
+		{name: "string error", body: `return nil, nil, "script failure"`, wantErr: "script failure"},
+		{name: "native error", body: `return nil, nil, nativeError`, native: true},
+		{name: "runtime error", body: `error("runtime failure")`, wantErr: "runtime failure"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			r, L := newLuaRouterState(t, "function HandleRoute() "+tc.body+" end")
+			value := L.NewUserData()
+			value.Value = nativeErr
+			L.SetGlobal("nativeError", value)
+			previous := context.WithValue(context.Background(), struct{}{}, true)
+			L.SetContext(previous)
+			L.Push(lua.LTrue)
+
+			tag, rule, err := r.CallLuaHook(L, context.Background(), &routing_session.Context{})
+			if tag != tc.tag || rule != tc.rule {
+				t.Fatalf("result = %q, %q, %v", tag, rule, err)
+			}
+			switch {
+			case tc.native:
+				if err != nativeErr {
+					t.Fatalf("error = %v, want original error", err)
+				}
+			case tc.wantErr != "":
+				if err == nil || !strings.Contains(err.Error(), tc.wantErr) {
+					t.Fatalf("error = %v, want %q", err, tc.wantErr)
+				}
+			case err != nil:
+				t.Fatal(err)
+			}
+			if L.Context() != previous || L.GetTop() != 1 || L.Get(1) != lua.LTrue {
+				t.Fatal("hook did not restore the previous context and stack")
+			}
+		})
+	}
+}
+
+func TestLuaRouteCancellation(t *testing.T) {
+	r, L := newLuaRouterState(t, `function HandleRoute() while true do end end`)
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+	if _, _, err := r.CallLuaHook(L, ctx, &routing_session.Context{}); err == nil {
+		t.Fatal("CallLuaHook did not stop after context cancellation")
+	}
+	if L.Context() != nil || L.GetTop() != 0 {
+		t.Fatal("CallLuaHook did not restore the Lua state")
+	}
+}
+
+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)
+			}
+		})
+	}
+}
+
+// BenchmarkLuaRouteHookCall isolates a preloaded Lua hook and its routing context bridge.
+// The direct case runs an equivalent native routing rule.
+func BenchmarkLuaRouteHookCall(b *testing.B) {
+	r := new(Router)
+	if err := r.Init(context.Background(), &Config{Rule: []*RoutingRule{{
+		TargetTag:  &RoutingRule_Tag{Tag: "out"},
+		RuleTag:    "rule",
+		InboundTag: []string{"in"},
+		Networks:   []net.Network{net.Network_TCP},
+		Ip: []*geodata.IPRule{{
+			Value: &geodata.IPRule_Custom{Custom: &geodata.CIDRRule{
+				Cidr: &geodata.CIDR{Ip: []byte{127, 0, 0, 0}, Prefix: 8},
+			}},
+		}},
+	}}}, nil, nil, nil); err != nil {
+		b.Fatal(err)
+	}
+	L := lua.NewState()
+	defer L.Close()
+	r.RegisterLua(L)
+	geodata.RegisterLua(L)
+	if err := L.DoString(`
+local router = require("xray.router")
+local matcher = require("xray.geodata").BuildIPMatcher("127.0.0.0/8")
+function HandleRoute(ctx, inboundTag, sourcePort, targetPort, localPort,
+    targetDomain, network, protocol, user, vlessRoute, skipDNSResolve)
+    if inboundTag == "in" and network == router.NetworkTCP and matcher:AnyMatch(ctx:GetTargetIPs()) then
+        return "out", "rule"
+    end
+end
+`); err != nil {
+		b.Fatal(err)
+	}
+
+	ctx := context.Background()
+	routeCtx := newLuaRouteTestContext()
+	for _, benchmark := range []struct {
+		name  string
+		route func() (string, string, error)
+	}{
+		{"direct", func() (string, string, error) {
+			route, err := r.PickRoute(routeCtx)
+			if err != nil {
+				return "", "", err
+			}
+			return route.GetOutboundTag(), route.GetRuleTag(), nil
+		}},
+		{"lua_hook", func() (string, string, error) {
+			return r.CallLuaHook(L, ctx, routeCtx)
+		}},
+	} {
+		b.Run(benchmark.name, func(b *testing.B) {
+			b.ReportAllocs()
+			b.ResetTimer()
+			var tag, rule string
+			var err error
+			for i := 0; i < b.N; i++ {
+				tag, rule, err = benchmark.route()
+				if err != nil {
+					b.Fatal(err)
+				}
+			}
+			b.StopTimer()
+			if tag != "out" || rule != "rule" {
+				b.Fatalf("route() = %q, %q; want out, rule", tag, rule)
+			}
+		})
+	}
+}
+
+var _ routing.Context = (*luaRouteTestContext)(nil)

app/router/router.go

@@ -20,6 +20,8 @@ import (
 type Router struct {
 	domainStrategy Config_DomainStrategy
 	rules          atomic.Pointer[[]*Rule]
+	scriptPath     string
+	script         *scriptEngine
 	balancers      atomic.Pointer[map[string]*Balancer]
 	dns            dns.Client
 
@@ -40,6 +42,7 @@ type Route struct {
 // Init initializes the Router.
 func (r *Router) Init(ctx context.Context, config *Config, d dns.Client, ohm outbound.Manager, dispatcher routing.Dispatcher) error {
 	r.domainStrategy = config.DomainStrategy
+	r.scriptPath = config.Script
 	r.dns = d
 	r.ctx = ctx
 	r.ohm = ohm
@@ -52,6 +55,10 @@ 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 +228,13 @@ func (r *Router) pickRouteInternal(ctx routing.Context) (*Rule, routing.Context,
 
 // Start implements common.Runnable.
 func (r *Router) Start() error {
+	if r.scriptPath != "" {
+		engine, err := newScriptEngine(r.scriptPath, r)
+		if err != nil {
+			return errors.New("failed to initialize routing script").Base(err)
+		}
+		r.script = engine
+	}
 	return nil
 }
 
@@ -235,6 +249,9 @@ 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 +1,79 @@
+package router
+
+import (
+	"context"
+	"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"
+	luamgr "github.com/xtls/xray-core/common/lua"
+	"github.com/xtls/xray-core/features/routing"
+	lua "github.com/yuin/gopher-lua"
+)
+
+const scriptExecutionTimeout = 10 * time.Second
+
+type scriptEngine struct {
+	router *Router
+	pool   *luamgr.Pool
+}
+
+func newScriptEngine(path string, router *Router) (*scriptEngine, error) {
+	program, err := luamgr.CompileFile(path)
+	if err != nil {
+		return nil, err
+	}
+	e := &scriptEngine{router: router}
+	e.pool, err = luamgr.NewPool(router.ctx, func(poolCtx context.Context) (*lua.LState, error) {
+		initCtx, cancel := context.WithTimeout(poolCtx, scriptExecutionTimeout)
+		defer cancel()
+		L, err := program.NewState(initCtx, func(L *lua.LState) {
+			geodata.RegisterLua(L)
+			log.RegisterLua(L)
+			router.RegisterLua(L)
+			dns.RegisterLua(L, router.dns)
+		})
+		if err != nil {
+			return nil, err
+		}
+		if L.GetGlobal("HandleRoute").Type() != lua.LTFunction {
+			L.Close()
+			return nil, errors.New("routing script must define HandleRoute(...)")
+		}
+		return L, nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	errors.LogInfo(router.ctx, "routing script initialized from ", path)
+	return e, nil
+}
+
+func (e *scriptEngine) close() {
+	e.pool.Close()
+}
+
+func (e *scriptEngine) pickRoute(ctx routing.Context) (routing.Route, error) {
+	L, err := e.pool.Acquire()
+	if err != nil {
+		return nil, err
+	}
+	reusable := false
+	defer func() {
+		e.pool.Release(L, reusable)
+	}()
+	callCtx, cancel := context.WithTimeout(e.pool.Context(), scriptExecutionTimeout)
+	defer cancel()
+	tag, ruleTag, err := e.router.CallLuaHook(L, callCtx, ctx)
+	if err != nil {
+		return nil, err
+	}
+	reusable = true
+	if tag == "" {
+		return nil, common.ErrNoClue
+	}
+	return &Route{Context: ctx, outboundTag: tag, ruleTag: ruleTag}, nil
+}

app/router/script_test.go

@@ -0,0 +1,372 @@
+package router
+
+import (
+	"context"
+	stdnet "net"
+	"os"
+	"path/filepath"
+	"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 }{
+		{"syntax error", "function HandleRoute("},
+		{"missing hook", "value = 1"},
+		{"initialization error", `error("setup failed")`},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			r := new(Router)
+			if err := r.Init(context.Background(), &Config{Script: writeRouteScript(t, tc.script)}, nil, nil, nil); err != nil {
+				t.Fatal(err)
+			}
+			defer r.Close()
+			if err := r.Start(); err == nil {
+				t.Fatal("Start accepted an invalid routing script")
+			}
+		})
+	}
+}
+
+func TestRouterScriptRouting(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
+	}}
+	r := startLuaRouter(t, `
+function HandleRoute(ctx, inbound)
+    if inbound == "miss" then return nil end
+    return "lua-out", "lua-rule"
+end`, 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)
+	if err != nil || route.GetOutboundTag() != "lua-out" || route.GetRuleTag() != "lua-rule" || route.(*Route).Context != ctx {
+		t.Fatalf("route = %v, %v", route, err)
+	}
+	ctx.Inbound.Tag = "miss"
+	if route, err := r.PickRoute(ctx); route != nil || err != common.ErrNoClue {
+		t.Fatalf("miss = %v, %v", route, err)
+	}
+	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 TestRouterScriptStateReuse(t *testing.T) {
+	r := startLuaRouter(t, `
+local calls = 0
+function HandleRoute(ctx, inbound)
+    calls = calls + 1
+    if inbound == "miss" then return nil end
+    if inbound == "fail" then error("failed") end
+    return tostring(calls)
+end`, nil, nil)
+	ctx := newLuaRouteTestContext()
+	pick := func(want string) {
+		t.Helper()
+		route, err := r.PickRoute(ctx)
+		if err != nil || route.GetOutboundTag() != want {
+			t.Fatalf("route = %v, %v, want %q", route, err, want)
+		}
+	}
+
+	pick("1")
+	ctx.Inbound.Tag = "miss"
+	if _, err := r.PickRoute(ctx); err != common.ErrNoClue {
+		t.Fatalf("miss = %v", err)
+	}
+	ctx.Inbound.Tag = "in"
+	pick("3")
+	ctx.Inbound.Tag = "fail"
+	if _, err := r.PickRoute(ctx); err == nil {
+		t.Fatal("script error was ignored")
+	}
+	ctx.Inbound.Tag = "in"
+	pick("1")
+}
+
+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)
+	}
+	defer instance.Close()
+	if err := instance.Start(); err != nil {
+		t.Fatal(err)
+	}
+	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/buf/readv_windows.go

@@ -5,7 +5,8 @@ import (
 )
 
 type windowsReader struct {
-	bufs []syscall.WSABuf
+	bufs  []syscall.WSABuf
+	ready bool
 }
 
 func (r *windowsReader) Init(bs []*Buffer) {
@@ -15,6 +16,7 @@ func (r *windowsReader) Init(bs []*Buffer) {
 	for _, b := range bs {
 		r.bufs = append(r.bufs, syscall.WSABuf{Len: uint32(Size), Buf: &b.v[0]})
 	}
+	r.ready = false
 }
 
 func (r *windowsReader) Clear() {
@@ -25,6 +27,14 @@ func (r *windowsReader) Clear() {
 }
 
 func (r *windowsReader) Read(fd uintptr) int32 {
+	// On the first invocation, we return -1 to indicate "not ready"
+	// to make rawConn.Read wait for readability using the runtime's own mechanism
+	// because syscall.WSARecv() is a blocking call when used with nil OVERLAPPED
+	if !r.ready {
+		r.ready = true
+		return -1
+	}
+
 	var nBytes uint32
 	var flags uint32
 	err := syscall.WSARecv(syscall.Handle(fd), &r.bufs[0], uint32(len(r.bufs)), &nBytes, &flags, nil, nil)

common/geodata/lua.go

@@ -0,0 +1,58 @@
+package geodata
+
+import (
+	lua "github.com/yuin/gopher-lua"
+	luar "layeh.com/gopher-luar"
+)
+
+// 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.NewTable()
+
+		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
+			}
+			L.Push(luar.New(L, matcher))
+			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
+			}
+			L.Push(luar.New(L, matcher))
+			return 1
+		}))
+		L.Push(module)
+		return 1
+	})
+}
+
+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 +1,66 @@
+package geodata
+
+import (
+	"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")
+			}
+		})
+	}
+}

common/log/lua.go

@@ -0,0 +1,50 @@
+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.NewTable()
+		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 {
+				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 != "" {
+						content.WriteString(filepath.Base(strings.TrimPrefix(caller.Source, "@")))
+						content.WriteString(": ")
+					}
+				}
+				for i := 1; i <= L.GetTop(); i++ {
+					value := L.Get(i)
+					// Use Error() for Go errors in userdata.
+					if ud, ok := value.(*lua.LUserData); ok {
+						if err, ok := ud.Value.(error); ok {
+							content.WriteString(err.Error())
+							continue
+						}
+					}
+					content.WriteString(L.ToStringMeta(value).String())
+				}
+				Record(&GeneralMessage{
+					Severity: severity,
+					Content:  content.String(),
+				})
+				return 0
+			}))
+		}
+		L.Push(module)
+		return 1
+	})
+}

common/log/lua_test.go

@@ -0,0 +1,92 @@
+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) {
+	logHandler.RLock()
+	previous := logHandler.Handler
+	logHandler.RUnlock()
+	t.Cleanup(func() { RegisterHandler(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)
+		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)
+	}
+
+	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: hook"},
+		{Severity_Info, "[Info] <string>: anonymous"},
+	}
+	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)
+		}
+	}
+}

common/lua/pool.go

@@ -0,0 +1,138 @@
+package lua
+
+import (
+	"context"
+	"errors"
+	"sync"
+
+	glua "github.com/yuin/gopher-lua"
+)
+
+const maxIdleStates = 16
+
+// LStateFactory must initialize a state fully and observe ctx while doing so.
+// The pool owns any non-nil state it returns, even when it also returns an error.
+type LStateFactory func(ctx context.Context) (*glua.LState, error)
+
+// Pool lends each state to one caller at a time. It grows on contention and
+// keeps up to maxIdleStates idle states until Close. Callers decide whether a
+// state is reusable.
+type Pool struct {
+	ctx    context.Context
+	cancel context.CancelFunc
+
+	factory LStateFactory
+	idle    []*glua.LState
+
+	mu     sync.Mutex
+	active sync.WaitGroup
+	closed bool
+}
+
+// NewPool initializes one state before returning, so top-level errors surface at startup.
+func NewPool(ctx context.Context, factory LStateFactory) (*Pool, error) {
+	poolCtx, cancel := context.WithCancel(ctx)
+
+	// Create one state now to catch factory errors at startup.
+	state, err := factory(poolCtx)
+	if err != nil {
+		cancel()
+		if state != nil {
+			state.Close()
+		}
+		return nil, err
+	}
+	if state == nil {
+		cancel()
+		return nil, errors.New("Lua state factory returned nil")
+	}
+	if err := poolCtx.Err(); err != nil {
+		state.Close()
+		cancel()
+		return nil, err
+	}
+
+	return &Pool{ctx: poolCtx, cancel: cancel, factory: factory, idle: []*glua.LState{state}}, nil
+}
+
+// Context is cancelled by Close. Query contexts should derive from it.
+func (p *Pool) Context() context.Context {
+	return p.ctx
+}
+
+// Acquire returns an initialized exclusive state, growing the pool if necessary.
+func (p *Pool) Acquire() (*glua.LState, error) {
+	p.mu.Lock()
+	if p.closed || p.ctx.Err() != nil {
+		p.mu.Unlock()
+		return nil, p.ctx.Err()
+	}
+
+	p.active.Add(1)
+
+	n := len(p.idle)
+	if n != 0 {
+		state := p.idle[n-1]
+		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(p.ctx)
+	if err == nil && state == nil {
+		err = errors.New("Lua state factory returned nil")
+	}
+	if err != nil {
+		if state != nil {
+			state.Close()
+		}
+		p.active.Done()
+		return nil, err
+	}
+	if err := p.ctx.Err(); err != nil {
+		state.Close()
+		p.active.Done()
+		return nil, err
+	}
+
+	return state, nil
+}
+
+// Release returns a healthy state to the pool and closes a failed or cancelled one.
+func (p *Pool) Release(state *glua.LState, reusable bool) {
+	if reusable {
+		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 active work, 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 +1,197 @@
+package lua
+
+import (
+	"context"
+	"errors"
+	"testing"
+	"time"
+
+	glua "github.com/yuin/gopher-lua"
+)
+
+func TestPoolFactoryFailureClosesReturnedState(t *testing.T) {
+	failure := errors.New("factory failed")
+	state := glua.NewState()
+	_, err := NewPool(context.Background(), func(context.Context) (*glua.LState, error) {
+		return state, failure
+	})
+	if !errors.Is(err, failure) || !state.IsClosed() {
+		t.Fatalf("NewPool error = %v, state closed = %t", err, state.IsClosed())
+	}
+
+	var failedState *glua.LState
+	calls := 0
+	pool, err := NewPool(context.Background(), func(context.Context) (*glua.LState, error) {
+		calls++
+		if calls == 1 {
+			return glua.NewState(), nil
+		}
+		failedState = glua.NewState()
+		return failedState, failure
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer pool.Close()
+	borrowed, err := pool.Acquire()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer pool.Release(borrowed, true)
+	_, err = pool.Acquire()
+	if !errors.Is(err, failure) || !failedState.IsClosed() {
+		t.Fatalf("Acquire error = %v, state closed = %t", err, failedState.IsClosed())
+	}
+}
+
+func TestPoolReusesStatesAndLimitsIdle(t *testing.T) {
+	created := 0
+	pool, err := NewPool(context.Background(), func(context.Context) (*glua.LState, error) {
+		created++
+		return glua.NewState(), nil
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer pool.Close()
+
+	states := make([]*glua.LState, maxIdleStates+3)
+	for i := range states {
+		states[i], err = pool.Acquire()
+		if err != nil {
+			t.Fatal(err)
+		}
+	}
+	for _, state := range states {
+		pool.Release(state, true)
+	}
+	for i, state := range states {
+		if got, want := state.IsClosed(), i >= maxIdleStates; got != want {
+			t.Fatalf("state %d closed = %t, want %t", i, got, want)
+		}
+	}
+	borrowed, err := pool.Acquire()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if created != len(states) {
+		t.Fatalf("Acquire created %d states, want %d", created, len(states))
+	}
+	pool.Release(borrowed, true)
+}
+
+func TestPoolCloseCancelsAndWaitsForBorrowedState(t *testing.T) {
+	pool, err := NewPool(context.Background(), func(context.Context) (*glua.LState, error) {
+		return glua.NewState(), nil
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	state, err := pool.Acquire()
+	if err != nil {
+		t.Fatal(err)
+	}
+	done := make(chan struct{})
+	go func() {
+		pool.Close()
+		close(done)
+	}()
+	select {
+	case <-pool.Context().Done():
+	case <-time.After(time.Second):
+		pool.Release(state, false)
+		t.Fatal("Close did not cancel the pool context")
+	}
+	select {
+	case <-done:
+		pool.Release(state, false)
+		t.Fatal("Close returned while a state was borrowed")
+	default:
+	}
+	pool.Release(state, true)
+	select {
+	case <-done:
+	case <-time.After(time.Second):
+		t.Fatal("Close did not finish after Release")
+	}
+	if !state.IsClosed() {
+		t.Fatal("borrowed state was not closed")
+	}
+	if _, err := pool.Acquire(); !errors.Is(err, context.Canceled) {
+		t.Fatalf("Acquire after Close = %v, want context.Canceled", err)
+	}
+	pool.Close()
+}
+
+func TestPoolCloseCancelsStateCreation(t *testing.T) {
+	started := make(chan struct{})
+	first := true
+	pool, err := NewPool(context.Background(), func(ctx context.Context) (*glua.LState, error) {
+		if first {
+			first = false
+			return glua.NewState(), nil
+		}
+		close(started)
+		<-ctx.Done()
+		return nil, ctx.Err()
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	borrowed, err := pool.Acquire()
+	if err != nil {
+		t.Fatal(err)
+	}
+	acquireDone := make(chan error, 1)
+	go func() {
+		_, err := pool.Acquire()
+		acquireDone <- err
+	}()
+	<-started
+	closeDone := make(chan struct{})
+	go func() {
+		pool.Close()
+		close(closeDone)
+	}()
+	select {
+	case err := <-acquireDone:
+		if !errors.Is(err, context.Canceled) {
+			t.Fatalf("Acquire during Close = %v, want context.Canceled", err)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("state creation did not stop after Close")
+	}
+	select {
+	case <-closeDone:
+		pool.Release(borrowed, false)
+		t.Fatal("Close returned while the initial state was borrowed")
+	default:
+	}
+	pool.Release(borrowed, true)
+	select {
+	case <-closeDone:
+	case <-time.After(time.Second):
+		t.Fatal("Close did not finish after Release")
+	}
+}
+
+func BenchmarkPoolAcquireRelease(b *testing.B) {
+	pool, err := NewPool(context.Background(), func(context.Context) (*glua.LState, error) {
+		return glua.NewState(), nil
+	})
+	if err != nil {
+		b.Fatal(err)
+	}
+	defer pool.Close()
+
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		state, err := pool.Acquire()
+		if err != nil {
+			b.Fatal(err)
+		}
+		pool.Release(state, true)
+	}
+	b.StopTimer()
+}

common/lua/program.go

@@ -0,0 +1,56 @@
+// Package lua provides shared GopherLua programs and state management for Xray scripts.
+package lua
+
+import (
+	"bufio"
+	"context"
+	"os"
+
+	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
+}
+
+// CompileFile reads and compiles a Lua file once.
+func CompileFile(path string) (*Program, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	chunk, err := parse.Parse(bufio.NewReader(f), path)
+	if err != nil {
+		return nil, err
+	}
+	proto, err := glua.Compile(chunk, path)
+	if err != nil {
+		return nil, err
+	}
+	return &Program{proto: proto}, nil
+}
+
+// NewState creates a VM, makes modules available, and executes the file top level.
+// Module loaders run only when Lua calls require. Each state gets its own globals.
+// The caller owns the returned state.
+func (p *Program) NewState(ctx context.Context, register func(*glua.LState)) (*glua.LState, error) {
+	L := glua.NewState()
+	if register != nil {
+		register(L)
+	}
+	L.SetContext(ctx)
+	L.Push(L.NewFunctionFromProto(p.proto))
+	err := L.PCall(0, 0, nil)
+	L.RemoveContext()
+	if err == nil {
+		err = ctx.Err()
+	}
+	if err != nil {
+		L.Close()
+		return nil, err
+	}
+	return L, nil
+}

common/lua/program_test.go

@@ -0,0 +1,55 @@
+package lua
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+
+	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 := CompileFile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	first, err := program.NewState(context.Background(), nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer first.Close()
+	first.SetGlobal("value", glua.LNumber(42))
+	second, err := program.NewState(context.Background(), 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 := CompileFile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+	state, err := program.NewState(ctx, 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)
+	}
+}

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)
+		}
+	}
+}

go.mod

@@ -23,19 +23,21 @@ 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 v0.55.0
+	golang.org/x/crypto v0.57.0
 	golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842
-	golang.org/x/net v0.58.0
-	golang.org/x/sync v0.22.0
-	golang.org/x/sys v0.47.0
+	golang.org/x/net v0.59.0
+	golang.org/x/sync v0.23.0
+	golang.org/x/sys v0.48.0
 	golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2
 	golang.zx2c4.com/wireguard v0.0.0-20250521234502-f333402bd9cb
-	golang.zx2c4.com/wireguard/windows v1.0.1
-	google.golang.org/grpc v1.83.2
+	golang.zx2c4.com/wireguard/windows v1.1.1
+	google.golang.org/grpc v1.84.0
 	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
 )
@@ -57,9 +59,9 @@ require (
 	github.com/vishvananda/netns v0.0.5 // indirect
 	github.com/wlynxg/anet v0.0.5 // indirect
 	go.yaml.in/yaml/v3 v3.0.5 // indirect
-	golang.org/x/text v0.41.0 // indirect
+	golang.org/x/text v0.42.0 // indirect
 	golang.org/x/time v0.14.0 // indirect
 	golang.org/x/tools v0.49.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20260526163538-3dc84a4a5aaa // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20260706201446-f0a921348800 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 )

go.sum

@@ -2,16 +2,13 @@ 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/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
-github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+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=
 github.com/ghodss/yaml v1.0.1-0.20220118164431-d8423dcdf344/go.mod h1:GIjDIg/heH5DOkXY3YJ/wNhfHsQHoXGjl8G8amsYQ1I=
-github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
-github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
-github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
-github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
 github.com/go-quicktest/qt v1.102.0 h1:HSQxCeh5YZH3EL3W39ixjtyaEhcWSXQHtHnMBzSs474=
 github.com/go-quicktest/qt v1.102.0/go.mod h1:p4lGIVX+8Wa6ZPNDvqcxq36XpUDLh42FLetFU7odllI=
 github.com/golang/mock v1.7.0-rc.1 h1:YojYx61/OLFsiv6Rw1Z96LpldJIy31o+UHmwAUMJ6/U=
@@ -91,18 +88,9 @@ 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=
-go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ64=
-go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
-go.opentelemetry.io/otel v1.44.0 h1:JjwHmHpA4iZ3wBxluu2fbbE7j4kqlE8jXyAyPXH7HqU=
-go.opentelemetry.io/otel v1.44.0/go.mod h1:BMgjTHL9WPRlRjL2oZCBTL4whCGtXch2H4BhOPIAyYc=
-go.opentelemetry.io/otel/metric v1.44.0 h1:1w0gILTcHdr3YI+ixLyjemwrVnsMURbTZFrSYCdDdmc=
-go.opentelemetry.io/otel/metric v1.44.0/go.mod h1:8O7hanEPBNgEMmybD3s2VBKcgWOCsA6tzHBPODAiquo=
-go.opentelemetry.io/otel/sdk v1.44.0 h1:nHYwb9lK+fJPU/dnT6s7W7Z8itMWyqrnVfbheVYrZ58=
-go.opentelemetry.io/otel/sdk v1.44.0/go.mod h1:Osuydd3Se74nqjAKxid74N5eC+jfEqfTegHRnq58oK0=
-go.opentelemetry.io/otel/sdk/metric v1.44.0 h1:3LlKgI+VjbVsjNRFZJZAJ30WjXC5VkNRks6si09iEfI=
-go.opentelemetry.io/otel/sdk/metric v1.44.0/go.mod h1:5B5pMARnXxKhltooO4xUuCBorl65a4EpnTalObqOigA=
-go.opentelemetry.io/otel/trace v1.44.0 h1:jxF5CsGYCe74MCRx2X4g7WsY/VBKRqqpNvXlX/6gtIk=
-go.opentelemetry.io/otel/trace v1.44.0/go.mod h1:oLl1jrMQAVo6v3GAggN+1VH9VIz9iUSvW53sW1Q8PIE=
+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=
@@ -111,8 +99,8 @@ go4.org/netipx v0.0.0-20231129151722-fdeea329fbba h1:0b9z3AuHCjxk0x/opv64kcgZLBs
 go4.org/netipx v0.0.0-20231129151722-fdeea329fbba/go.mod h1:PLyyIXexvUFg3Owu6p/WfdlivPbZJsZdgWZlrGope/Y=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
-golang.org/x/crypto v0.55.0 h1:+KWHjbgOaAQ66dh/YlkZKHlz9ZUlq61AFirAR9ntP8M=
-golang.org/x/crypto v0.55.0/go.mod h1:uq0V9dE/fzQuJtbnL+2EhWOE63vo164FY8xqEnV9xis=
+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/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=
@@ -121,12 +109,13 @@ 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 v0.58.0 h1:ynWG7rqYi4ccpTEuPZ2QGWHktVEM9DMCj9yzDE0Q7To=
-golang.org/x/net v0.58.0/go.mod h1:YwCddHnFlT7eLQqVprV19OnhLGtc5xOKgE0RyqgfWAU=
+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/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 v0.22.0 h1:SZjpbeLmrCk4xhRSZFNZW5gFUeCeFgjekvI/+gfScek=
-golang.org/x/sync v0.22.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
+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=
@@ -134,14 +123,14 @@ golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20211019181941-9d821ace8654/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.2.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.10.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.47.0 h1:o7XGOvZQCADBQQ4Y7VNq2dRWQR7JmOUW8Kxx4ZsNgWs=
-golang.org/x/sys v0.47.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+golang.org/x/sys v0.48.0 h1:bbX/i/6MgT9BVLM9RT1thmxL04yeTAhbEz4SyadbXoo=
+golang.org/x/sys v0.48.0/go.mod h1:hNLxWAXmnKAxqDtdwIYC4bM9oQPEecfsnNMuSxOs3og=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
-golang.org/x/text v0.41.0 h1:vz/seA0lnX87Othu2f/0L24RcgrXD9/YFTSuGjj3rH8=
-golang.org/x/text v0.41.0/go.mod h1:jvf1O8ajNzZqhSrQBPbutR/EB83Cc0CFrezNQIwbb5M=
+golang.org/x/text v0.42.0 h1:JbOZXgfeCPU9gacVtYliJqOhD+zhrEqK4LfdpmlUZqI=
+golang.org/x/text v0.42.0/go.mod h1:ojzP1Z+2QtioaF8DTtO8K5q7JWVVYwZKenzujK0Zd0E=
 golang.org/x/time v0.14.0 h1:MRx4UaLrDotUKUdCIqzPC48t1Y9hANFKIRpNx+Te8PI=
 golang.org/x/time v0.14.0/go.mod h1:eL/Oa2bBBK0TkX57Fyni+NgnyQQN4LitPmob2Hjnqw4=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
@@ -157,14 +146,14 @@ golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2 h1:B82qJJgjvYKsXS9jeu
 golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2/go.mod h1:deeaetjYA+DHMHg+sMSMI58GrEteJUUzzw7en6TJQcI=
 golang.zx2c4.com/wireguard v0.0.0-20250521234502-f333402bd9cb h1:whnFRlWMcXI9d+ZbWg+4sHnLp52d5yiIPUxMBSt4X9A=
 golang.zx2c4.com/wireguard v0.0.0-20250521234502-f333402bd9cb/go.mod h1:rpwXGsirqLqN2L0JDJQlwOboGHmptD5ZD6T2VmcqhTw=
-golang.zx2c4.com/wireguard/windows v1.0.1 h1:eOxiDVbywPC+ZQqvdCK7x+ZwWXKbYv50TtH8ysFIbw8=
-golang.zx2c4.com/wireguard/windows v1.0.1/go.mod h1:+fbT3FFdX4zzYDLwJh5+HPEcNN/3HyNdzhNSVsQM+zs=
+golang.zx2c4.com/wireguard/windows v1.1.1 h1:8/H97U1v1PNDNcBsMZgU3KFuND9MQdTsU2NOwmCXArE=
+golang.zx2c4.com/wireguard/windows v1.1.1/go.mod h1:+fbT3FFdX4zzYDLwJh5+HPEcNN/3HyNdzhNSVsQM+zs=
 gonum.org/v1/gonum v0.17.0 h1:VbpOemQlsSMrYmn7T2OUvQ4dqxQXU+ouZFQsZOx50z4=
 gonum.org/v1/gonum v0.17.0/go.mod h1:El3tOrEuMpv2UdMrbNlKEh9vd86bmQ6vqIcDwxEOc1E=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20260526163538-3dc84a4a5aaa h1:mZHHdPZl0dbGHCflZgAq/Q468DWVFcU2whhB2KAo8fk=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20260526163538-3dc84a4a5aaa/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
-google.golang.org/grpc v1.83.2 h1:EManeRomTObA0BU7I8vXgg/78uE5MJ9M8B39EX2WscU=
-google.golang.org/grpc v1.83.2/go.mod h1:YPI1hK3kDked6iHvgX3tR0y+nX/qpMFKhPgFsokw1S8=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20260706201446-f0a921348800 h1:qEHAMpSaUhtD0p3NbEEI83HwNGFxEwaSJ1G9PLnCBZE=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20260706201446-f0a921348800/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
+google.golang.org/grpc v1.84.0 h1:soMyaPJ8pAak5PIQ0DGBUir0XRo2fRoMqhNWMLlLxO0=
+google.golang.org/grpc v1.84.0/go.mod h1:ljCht0DrxQrXBDRTZp52Qxh3Ffk8CdYm2sj4O2QN2C0=
 google.golang.org/protobuf v1.36.12 h1:pJOKDDOyeXErUroCihFAd5LQuwXBSpVnKGrj5o/fwxc=
 google.golang.org/protobuf v1.36.12/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
@@ -177,6 +166,8 @@ 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

@@ -14,9 +14,11 @@ import (
 	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/common/geodata"
 	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/common/platform"
 )
 
 type NameServerConfig struct {
+	ID              string     `json:"id"`
 	Address         *Address   `json:"address"`
 	ClientIP        *Address   `json:"clientIp"`
 	Port            uint16     `json:"port"`
@@ -43,6 +45,7 @@ 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 +63,7 @@ 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 +138,7 @@ 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 +164,7 @@ 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"`
@@ -278,6 +284,14 @@ func (c *DNSConfig) Build() (*dns.Config, error) {
 		QueryStrategy:          resolveQueryStrategy(c.QueryStrategy),
 	}
 
+	if c.Script != "" {
+		path, err := platform.ResolveLuaFile(c.Script)
+		if err != nil {
+			return nil, errors.New("failed to resolve DNS script: ", c.Script).Base(err)
+		}
+		config.Script = path
+	}
+
 	if c.ClientIP != nil {
 		if !c.ClientIP.Family().IsIP() {
 			return nil, errors.New("not an IP address:", c.ClientIP.String())

infra/conf/dns_test.go

@@ -2,6 +2,8 @@ package conf_test
 
 import (
 	"encoding/json"
+	"os"
+	"path/filepath"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
@@ -122,3 +124,51 @@ func TestDNSConfigParsing(t *testing.T) {
 		}
 	}
 }
+
+func TestDNSScriptConfig(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("xray.location.confdir", dir)
+	path := filepath.Join(dir, "lookup.lua")
+	if err := os.WriteFile(path, []byte("function HandleDNSQuery(domain, ipv4, ipv6, fake) end"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+
+	for _, tc := range []struct {
+		name      string
+		script    string
+		wantError bool
+	}{
+		{"relative", "lookup.lua", false},
+		{"absolute", path, false},
+		{"missing", "missing.lua", true},
+		{"directory", dir, true},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			built, err := (&DNSConfig{Script: tc.script}).Build()
+			if tc.wantError {
+				if err == nil {
+					t.Fatal("Build accepted an invalid script path")
+				}
+				return
+			}
+			if err != nil {
+				t.Fatal(err)
+			}
+			if built.Script != path {
+				t.Fatalf("script path = %q, want %q", built.Script, path)
+			}
+		})
+	}
+
+	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)
+	}
+}

infra/conf/masque.go

@@ -0,0 +1,37 @@
+package conf
+
+import (
+	"net/netip"
+
+	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/protocol"
+	"github.com/xtls/xray-core/proxy/masque"
+	"google.golang.org/protobuf/proto"
+)
+
+type MasqueClientConfig struct {
+	Address   *Address `json:"address"`
+	Port      uint16   `json:"port"`
+	RemoteDNS []string `json:"remoteDNS"`
+}
+
+func (c *MasqueClientConfig) Build() (proto.Message, error) {
+	if c.Address == nil {
+		return nil, errors.New(`MASQUE: "address" is not set`)
+	}
+	if c.Port == 0 {
+		return nil, errors.New(`MASQUE: "port" is not set`)
+	}
+	for _, s := range c.RemoteDNS {
+		if _, err := netip.ParseAddr(s); err != nil {
+			return nil, errors.New(`MASQUE: invalid "remoteDNS" `, s).Base(err)
+		}
+	}
+	return &masque.ClientConfig{
+		Server: &protocol.ServerEndpoint{
+			Address: c.Address.Build(),
+			Port:    uint32(c.Port),
+		},
+		RemoteDns: c.RemoteDNS,
+	}, nil
+}

infra/conf/masque_test.go

@@ -0,0 +1,85 @@
+package conf_test
+
+import (
+	"encoding/json"
+	"testing"
+
+	. "github.com/xtls/xray-core/infra/conf"
+	"github.com/xtls/xray-core/transport/internet/masque"
+)
+
+func TestMasqueConfig(t *testing.T) {
+	creator := func() Buildable {
+		return new(MasqueConfig)
+	}
+
+	runMultiTestCase(t, []TestCase{
+		{
+			Input:  `{}`,
+			Parser: loadJSON(creator),
+			Output: &masque.Config{Path: "/.well-known/masque/ip/*/*/"},
+		},
+		{
+			Input: `{
+				"host": "example.com:8443",
+				"path": "/.well-known/masque/ip/{target}/{ipproto}/",
+				"headers": {"Authorization": "Basic dTpw"}
+			}`,
+			Parser: loadJSON(creator),
+			Output: &masque.Config{
+				Host:    "example.com:8443",
+				Path:    "/.well-known/masque/ip/*/*/",
+				Headers: map[string]string{"Authorization": "Basic dTpw"},
+			},
+		},
+		{
+			Input:  `{"path": "/masque/ip{?target,ipproto}"}`,
+			Parser: loadJSON(creator),
+			Output: &masque.Config{Path: "/masque/ip?target=*&ipproto=*"},
+		},
+	})
+
+	for _, input := range []string{
+		`{"path": "/masque/{target}/{ipproto}/{dns}"}`,
+		`{"path": "masque"}`,
+		`{"host": "example.com/path"}`,
+		`{"headers": {"host": "example.com"}}`,
+		`{"headers": {"Capsule-Protocol": "?0"}}`,
+		`{"headers": {"X Token": "a"}}`,
+		`{"headers": {"X-Token": "a\r\nb"}}`,
+	} {
+		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)
+		if err := json.Unmarshal([]byte(s), c); err != nil {
+			return err
+		}
+		_, err := c.Build()
+		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"}, "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 {
+			t.Errorf("expected an error for %s", input)
+		}
+	}
+}

infra/conf/router.go

@@ -7,6 +7,7 @@ import (
 	"github.com/xtls/xray-core/app/router"
 	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/common/geodata"
+	"github.com/xtls/xray-core/common/platform"
 	"github.com/xtls/xray-core/common/serial"
 
 	"google.golang.org/protobuf/proto"
@@ -72,6 +73,7 @@ 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 +94,15 @@ func (c *RouterConfig) getDomainStrategy() router.Config_DomainStrategy {
 
 func (c *RouterConfig) Build() (*router.Config, error) {
 	config := new(router.Config)
+
+	if c.Script != "" {
+		path, err := platform.ResolveLuaFile(c.Script)
+		if err != nil {
+			return nil, errors.New("failed to resolve routing script").Base(err)
+		}
+		config.Script = path
+	}
+
 	config.DomainStrategy = c.getDomainStrategy()
 
 	var rawRuleList []json.RawMessage

infra/conf/router_test.go

@@ -2,6 +2,8 @@ package conf_test
 
 import (
 	"encoding/json"
+	"os"
+	"path/filepath"
 	"testing"
 	"time"
 	_ "unsafe"
@@ -236,3 +238,39 @@ func TestRouterConfig(t *testing.T) {
 		},
 	})
 }
+
+func TestRouterScriptConfig(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("xray.location.confdir", dir)
+	path := filepath.Join(dir, "route.lua")
+	if err := os.WriteFile(path, []byte("function HandleRoute() end"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+
+	for _, tc := range []struct {
+		name      string
+		script    string
+		wantError bool
+	}{
+		{"relative", "route.lua", false},
+		{"absolute", path, false},
+		{"missing", "missing.lua", true},
+		{"directory", dir, true},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			built, err := (&RouterConfig{Script: tc.script}).Build()
+			if tc.wantError {
+				if err == nil {
+					t.Fatal("Build accepted invalid script path")
+				}
+				return
+			}
+			if err != nil {
+				t.Fatal(err)
+			}
+			if built.Script != path {
+				t.Fatalf("script path = %q, want %q", built.Script, path)
+			}
+		})
+	}
+}

infra/conf/transport_finalmask.go

@@ -14,7 +14,6 @@ import (
 	googleuuid "github.com/google/uuid"
 	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/common/net"
-	"github.com/xtls/xray-core/transport/internet"
 	"github.com/xtls/xray-core/transport/internet/finalmask/fragment"
 	"github.com/xtls/xray-core/transport/internet/finalmask/header/custom"
 	"github.com/xtls/xray-core/transport/internet/finalmask/mkcp/aes128gcm"
@@ -909,22 +908,13 @@ func (c *Realm) Build() (proto.Message, error) {
 }
 
 type UDPHop struct {
-	Sockopt     *SocketConfig `json:"sockopt"`
-	Mode        string        `json:"mode"`
-	Interval    Int32Range    `json:"interval"`
-	RemotePorts PortList      `json:"remotePorts"`
-	RemoteIPs   []string      `json:"remoteIPs"`
+	Mode        string     `json:"mode"`
+	Interval    Int32Range `json:"interval"`
+	RemoteIPs   []string   `json:"remoteIPs"`
+	RemotePorts PortList   `json:"remotePorts"`
 }
 
 func (c *UDPHop) Build() (proto.Message, error) {
-	var sockopt *internet.SocketConfig
-	if c.Sockopt != nil {
-		var err error
-		sockopt, err = c.Sockopt.Build()
-		if err != nil {
-			return nil, err
-		}
-	}
 	var local, remote, remoteOnce bool
 	for _, mode := range strings.Split(c.Mode, ",") {
 		switch strings.ToLower(mode) {
@@ -953,14 +943,13 @@ func (c *UDPHop) Build() (proto.Message, error) {
 		return nil, errors.New("invalid ip ", ip)
 	}
 	return &udphop.Config{
-		Sockopt:     sockopt,
 		Local:       local,
 		Remote:      remote,
 		RemoteOnce:  remoteOnce,
 		IntervalMin: int64(c.Interval.From),
 		IntervalMax: int64(c.Interval.To),
-		RemotePorts: c.RemotePorts.Build().Ports(),
 		RemoteIPs:   remoteIPs,
+		RemotePorts: c.RemotePorts.Build().Ports(),
 	}, nil
 }
 

infra/conf/transport_internet.go

@@ -36,6 +36,10 @@ func (p TransportProtocol) Build() (string, error) {
 		return "", errors.PrintRemovedFeatureError("QUIC transport (without web service, etc.)", "XHTTP stream-one H3")
 	case "hysteria":
 		return "hysteria", nil
+	case "masque":
+		return "masque", nil
+	case "xdrive":
+		return "xdrive", nil
 	default:
 		return "", errors.New("Config: unknown transport protocol: ", p)
 	}
@@ -59,6 +63,8 @@ type StreamConfig struct {
 	WSSettings          *WebSocketConfig   `json:"wsSettings"`
 	HTTPUPGRADESettings *HttpUpgradeConfig `json:"httpupgradeSettings"`
 	HysteriaSettings    *HysteriaConfig    `json:"hysteriaSettings"`
+	MASQUESettings      *MasqueConfig      `json:"masqueSettings"`
+	XDRIVESettings      *XDriveConfig      `json:"xdriveSettings"`
 	SocketSettings      *SocketConfig      `json:"sockopt"`
 }
 
@@ -192,6 +198,26 @@ func (c *StreamConfig) Build() (*internet.StreamConfig, error) {
 			Settings:     serial.ToTypedMessage(hs),
 		})
 	}
+	if c.MASQUESettings != nil {
+		ms, err := c.MASQUESettings.Build()
+		if err != nil {
+			return nil, errors.New("Failed to build MASQUE config.").Base(err)
+		}
+		config.TransportSettings = append(config.TransportSettings, &internet.TransportConfig{
+			ProtocolName: "masque",
+			Settings:     serial.ToTypedMessage(ms),
+		})
+	}
+	if c.XDRIVESettings != nil {
+		xs, err := c.XDRIVESettings.Build()
+		if err != nil {
+			return nil, errors.New("Failed to build XDRIVE config.").Base(err)
+		}
+		config.TransportSettings = append(config.TransportSettings, &internet.TransportConfig{
+			ProtocolName: "xdrive",
+			Settings:     serial.ToTypedMessage(xs),
+		})
+	}
 	if c.SocketSettings != nil {
 		ss, err := c.SocketSettings.Build()
 		if err != nil {

infra/conf/transport_method.go

@@ -20,9 +20,12 @@ import (
 	"github.com/xtls/xray-core/transport/internet/httpupgrade"
 	"github.com/xtls/xray-core/transport/internet/hysteria"
 	"github.com/xtls/xray-core/transport/internet/kcp"
+	"github.com/xtls/xray-core/transport/internet/masque"
 	"github.com/xtls/xray-core/transport/internet/splithttp"
 	"github.com/xtls/xray-core/transport/internet/tcp"
 	"github.com/xtls/xray-core/transport/internet/websocket"
+	"github.com/xtls/xray-core/transport/internet/xdrive"
+	"golang.org/x/net/http/httpguts"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -785,6 +788,46 @@ func (c *HysteriaConfig) Build() (proto.Message, error) {
 	return config, nil
 }
 
+type MasqueConfig struct {
+	Host    string            `json:"host"`
+	Path    string            `json:"path"`
+	Headers map[string]string `json:"headers"`
+}
+
+func (c *MasqueConfig) Build() (proto.Message, error) {
+	path := c.Path
+	if path == "" {
+		path = masque.DefaultPath
+	}
+	path = strings.NewReplacer(
+		"{target}", "*", "{ipproto}", "*",
+		"{?target,ipproto}", "?target=*&ipproto=*", "{?ipproto,target}", "?ipproto=*&target=*",
+		"{&target,ipproto}", "&target=*&ipproto=*", "{&ipproto,target}", "&ipproto=*&target=*",
+	).Replace(path)
+	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)
+		}
+	}
+	for k, v := range c.Headers {
+		if !httpguts.ValidHeaderFieldName(k) || !httpguts.ValidHeaderFieldValue(v) {
+			return nil, errors.New(`invalid header in "headers": `, strconv.Quote(k))
+		}
+		switch strings.ToLower(k) {
+		case "host", "capsule-protocol":
+			return nil, errors.New(`"headers" can't contain "`, k, `"`)
+		}
+	}
+	return &masque.Config{
+		Host:    c.Host,
+		Path:    path,
+		Headers: c.Headers,
+	}, nil
+}
+
 func readFileOrString(f string, s []string) ([]byte, error) {
 	if len(f) > 0 {
 		return filesystem.ReadCert(f)
@@ -794,3 +837,50 @@ func readFileOrString(f string, s []string) ([]byte, error) {
 	}
 	return nil, errors.New("both file and bytes are empty.")
 }
+
+type XDriveConfig struct {
+	RemoteFolder      string          `json:"remoteFolder"`
+	Service           string          `json:"service"`
+	Secrets           []string        `json:"secrets"`
+	SegmentBytes      uint32          `json:"segmentBytes"`
+	FlushIntervalMs   uint32          `json:"flushIntervalMs"`
+	PollIntervalMs    uint32          `json:"pollIntervalMs"`
+	MaxPollIntervalMs uint32          `json:"maxPollIntervalMs"`
+	SessionTTLSeconds uint32          `json:"sessionTtlSeconds"`
+	Concurrency       uint32          `json:"concurrency"`
+	EagerWindowMs     uint32          `json:"eagerWindowMs"`
+	HoleTimeoutMs     uint32          `json:"holeTimeoutMs"`
+	Template          json.RawMessage `json:"template"`
+}
+
+// Build implements Buildable.
+func (c *XDriveConfig) Build() (proto.Message, error) {
+	switch c.Service {
+	case "local":
+	case "Google Drive":
+		if len(c.Secrets) != 3 {
+			return nil, errors.New("Google Drive needs 3 secrets in order of ClientID, ClientSecret, RefreshToken")
+		}
+	case "template":
+		if len(c.Template) == 0 {
+			return nil, errors.New(`service "template" needs a "template" object`)
+		}
+	default:
+		return nil, errors.New("unsupported service")
+	}
+	config := &xdrive.Config{
+		RemoteFolder:      c.RemoteFolder,
+		Service:           c.Service,
+		Secrets:           c.Secrets,
+		SegmentBytes:      c.SegmentBytes,
+		FlushIntervalMs:   c.FlushIntervalMs,
+		PollIntervalMs:    c.PollIntervalMs,
+		MaxPollIntervalMs: c.MaxPollIntervalMs,
+		SessionTtlSeconds: c.SessionTTLSeconds,
+		Concurrency:       c.Concurrency,
+		EagerWindowMs:     c.EagerWindowMs,
+		HoleTimeoutMs:     c.HoleTimeoutMs,
+		Template:          string(c.Template),
+	}
+	return config, nil
+}

infra/conf/transport_test.go

@@ -291,3 +291,76 @@ func TestHeaderCustomUDPBuildRejectsExprWithoutArgs(t *testing.T) {
 		t.Fatalf("expected transform arg rejection, got %v", err)
 	}
 }
+
+func TestXDriveStreamConfig(t *testing.T) {
+	config := new(StreamConfig)
+	if err := json.Unmarshal([]byte(`{
+		"method": "xdrive",
+		"xdriveSettings": {
+			"remoteFolder": "/tmp/xdrive",
+			"service": "local"
+		}
+	}`), config); err != nil {
+		t.Fatalf("Unmarshal: %v", err)
+	}
+
+	built, err := config.Build()
+	if err != nil {
+		t.Fatalf("Build: %v", err)
+	}
+	if built.ProtocolName != "xdrive" {
+		t.Fatalf("ProtocolName is %q, want %q", built.ProtocolName, "xdrive")
+	}
+	if len(built.TransportSettings) != 1 || built.TransportSettings[0].ProtocolName != "xdrive" {
+		t.Fatalf("TransportSettings is %v, want a single xdrive entry", built.TransportSettings)
+	}
+}
+
+func TestXDriveRejectsUnknownService(t *testing.T) {
+	config := new(XDriveConfig)
+	if err := json.Unmarshal([]byte(`{"remoteFolder": "/tmp/xdrive", "service": "Dropbox"}`), config); err != nil {
+		t.Fatalf("Unmarshal: %v", err)
+	}
+	if _, err := config.Build(); err == nil {
+		t.Fatal("Build accepted an unsupported service")
+	}
+}
+
+func TestXDriveTemplateStreamConfig(t *testing.T) {
+	config := new(StreamConfig)
+	if err := json.Unmarshal([]byte(`{
+		"method": "xdrive",
+		"xdriveSettings": {
+			"remoteFolder": "folder",
+			"service": "template",
+			"secrets": ["user", "pass"],
+			"template": {
+				"flatten": true,
+				"auth": {"type": "basic", "username": "{secret0}", "password": "{secret1}"},
+				"put": {"method": "PUT", "url": "https://dav.example/{folder}/{name}"},
+				"get": {"method": "GET", "url": "https://dav.example/{folder}/{name}"},
+				"delete": {"method": "DELETE", "url": "https://dav.example/{folder}/{name}"},
+				"list": {"method": "PROPFIND", "url": "https://dav.example/{folder}/", "namesRegex": "<d:href>/folder/([^<]+)</d:href>"}
+			}
+		}
+	}`), config); err != nil {
+		t.Fatalf("Unmarshal: %v", err)
+	}
+	built, err := config.Build()
+	if err != nil {
+		t.Fatalf("Build: %v", err)
+	}
+	if built.ProtocolName != "xdrive" {
+		t.Fatalf("ProtocolName is %q, want xdrive", built.ProtocolName)
+	}
+}
+
+func TestXDriveTemplateNeedsTemplate(t *testing.T) {
+	config := new(XDriveConfig)
+	if err := json.Unmarshal([]byte(`{"remoteFolder": "f", "service": "template"}`), config); err != nil {
+		t.Fatalf("Unmarshal: %v", err)
+	}
+	if _, err := config.Build(); err == nil {
+		t.Fatal("Build accepted a template service without a template")
+	}
+}

infra/conf/wireguard.go

@@ -59,14 +59,13 @@ func (c *WireGuardPeerConfig) Build() (*wireguard.PeerConfig, error) {
 type WireGuardConfig struct {
 	IsClient bool `json:""`
 
-	NoKernelTun    bool                   `json:"noKernelTun"`
-	SecretKey      string                 `json:"secretKey"`
-	Address        []string               `json:"address"`
-	Peers          []*WireGuardPeerConfig `json:"peers"`
-	MTU            int32                  `json:"mtu"`
-	Reserved       []byte                 `json:"reserved"`
-	DomainStrategy string                 `json:"domainStrategy"`
-	DNS            []string               `json:"remoteDNS"`
+	NoKernelTun bool                   `json:"noKernelTun"`
+	SecretKey   string                 `json:"secretKey"`
+	Address     []string               `json:"address"`
+	Peers       []*WireGuardPeerConfig `json:"peers"`
+	MTU         int32                  `json:"mtu"`
+	Reserved    []byte                 `json:"reserved"`
+	DNS         []string               `json:"remoteDNS"`
 }
 
 func (c *WireGuardConfig) Build() (proto.Message, error) {
@@ -125,21 +124,6 @@ func (c *WireGuardConfig) Build() (proto.Message, error) {
 	}
 	config.Reserved = c.Reserved
 
-	switch strings.ToLower(c.DomainStrategy) {
-	case "forceip", "":
-		config.DomainStrategy = wireguard.DeviceConfig_FORCE_IP
-	case "forceipv4":
-		config.DomainStrategy = wireguard.DeviceConfig_FORCE_IP4
-	case "forceipv6":
-		config.DomainStrategy = wireguard.DeviceConfig_FORCE_IP6
-	case "forceipv4v6":
-		config.DomainStrategy = wireguard.DeviceConfig_FORCE_IP46
-	case "forceipv6v4":
-		config.DomainStrategy = wireguard.DeviceConfig_FORCE_IP64
-	default:
-		return nil, errors.New("unsupported domain strategy: ", c.DomainStrategy)
-	}
-
 	config.IsClient = c.IsClient
 	config.NoKernelTun = c.NoKernelTun
 	config.DNS = c.DNS

infra/conf/xray.go

@@ -16,6 +16,7 @@ import (
 	"github.com/xtls/xray-core/common/serial"
 	core "github.com/xtls/xray-core/core"
 	"github.com/xtls/xray-core/proxy/freedom"
+	"github.com/xtls/xray-core/proxy/masque"
 	"github.com/xtls/xray-core/transport/internet"
 )
 
@@ -48,6 +49,7 @@ var (
 		"vmess":       func() interface{} { return new(VMessOutboundConfig) },
 		"trojan":      func() interface{} { return new(TrojanClientConfig) },
 		"hysteria":    func() interface{} { return new(HysteriaClientConfig) },
+		"masque":      func() interface{} { return new(MasqueClientConfig) },
 		"dns":         func() interface{} { return new(DNSOutboundConfig) },
 		"wireguard":   func() interface{} { return &WireGuardConfig{IsClient: true} },
 	}, "protocol", "settings")
@@ -338,6 +340,14 @@ 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" {
+		return nil, errors.New("the masque transport can only be used by the masque outbound")
+	}
+
 	if fc, ok := ts.(*freedom.Config); ok {
 		if senderSettings.StreamSettings != nil &&
 			senderSettings.StreamSettings.SocketSettings != nil &&

main/distro/all/all.go

@@ -41,6 +41,7 @@ import (
 	_ "github.com/xtls/xray-core/proxy/freedom"
 	_ "github.com/xtls/xray-core/proxy/http"
 	_ "github.com/xtls/xray-core/proxy/loopback"
+	_ "github.com/xtls/xray-core/proxy/masque"
 	_ "github.com/xtls/xray-core/proxy/shadowsocks"
 	_ "github.com/xtls/xray-core/proxy/socks"
 	_ "github.com/xtls/xray-core/proxy/trojan"
@@ -54,12 +55,14 @@ import (
 	_ "github.com/xtls/xray-core/transport/internet/grpc"
 	_ "github.com/xtls/xray-core/transport/internet/httpupgrade"
 	_ "github.com/xtls/xray-core/transport/internet/kcp"
+	_ "github.com/xtls/xray-core/transport/internet/masque"
 	_ "github.com/xtls/xray-core/transport/internet/reality"
 	_ "github.com/xtls/xray-core/transport/internet/splithttp"
 	_ "github.com/xtls/xray-core/transport/internet/tcp"
 	_ "github.com/xtls/xray-core/transport/internet/tls"
 	_ "github.com/xtls/xray-core/transport/internet/udp"
 	_ "github.com/xtls/xray-core/transport/internet/websocket"
+	_ "github.com/xtls/xray-core/transport/internet/xdrive"
 
 	// Transport headers
 	_ "github.com/xtls/xray-core/transport/internet/headers/http"

proxy/hysteria/client.go

@@ -236,14 +236,14 @@ type UDPReader struct {
 
 func (r *UDPReader) ReadFrom(p []byte) (n int, addr *net.Destination, err error) {
 	for {
-		var buf [hysteria.MaxDatagramFrameSize]byte
+		var packet [1500]byte
 
-		n, err := r.reader.Read(buf[:])
+		n, err := r.reader.Read(packet[:])
 		if err != nil {
 			return 0, nil, err
 		}
 
-		msg, err := ParseUDPMessage(buf[:n])
+		msg, err := ParseUDPMessage(packet[:n])
 		if err != nil {
 			continue
 		}

proxy/masque/client.go

@@ -0,0 +1,328 @@
+package masque
+
+import (
+	"context"
+	go_errors "errors"
+	"io"
+	"net/netip"
+	"slices"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"golang.zx2c4.com/wireguard/tun"
+
+	"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/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/core"
+	"github.com/xtls/xray-core/features/policy"
+	"github.com/xtls/xray-core/proxy/wireguard"
+	"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/stat"
+	"github.com/xtls/xray-core/transport/internet/tls"
+)
+
+const (
+	establishTimeout = 10 * time.Second
+	retryInterval    = time.Second
+)
+
+type Client struct {
+	server        *protocol.ServerSpec
+	policyManager policy.Manager
+	remoteDNS     []netip.Addr
+
+	ctx    context.Context
+	cancel context.CancelFunc
+
+	tunnel atomic.Pointer[tunnel]
+
+	mu        sync.Mutex
+	lastErr   error
+	lastErrAt time.Time
+}
+
+func NewClient(ctx context.Context, config *ClientConfig) (*Client, error) {
+	v := core.MustFromContext(ctx)
+	p := v.GetFeature(policy.ManagerType()).(policy.Manager)
+
+	streamSettings := session.StreamSettingsFromContext(ctx).(*internet.MemoryStreamConfig)
+	if _, ok := streamSettings.ProtocolSettings.(*masque.Config); !ok {
+		return nil, errors.New("not masque transport")
+	}
+	if tls.ConfigFromStreamSettings(streamSettings) == nil {
+		return nil, errors.New(`MASQUE requires "security": "tls"`)
+	}
+	if config.Server == nil {
+		return nil, errors.New(`no target server found`)
+	}
+	server, err := protocol.NewServerSpecFromPB(config.Server)
+	if err != nil {
+		return nil, errors.New("failed to get server spec").Base(err)
+	}
+
+	dns := config.RemoteDns
+	if len(dns) == 0 {
+		dns = []string{"1.1.1.1", "1.0.0.1", "2606:4700:4700::1111", "2606:4700:4700::1001"}
+	}
+	remoteDNS := make([]netip.Addr, 0, len(dns))
+	for _, s := range dns {
+		addr, err := netip.ParseAddr(s)
+		if err != nil {
+			return nil, errors.New("invalid remote DNS server ", s).Base(err)
+		}
+		remoteDNS = append(remoteDNS, addr)
+	}
+
+	c := &Client{
+		server:        server,
+		policyManager: p,
+		remoteDNS:     remoteDNS,
+	}
+	c.ctx, c.cancel = context.WithCancel(context.Background())
+	return c, nil
+}
+
+func (c *Client) Process(ctx context.Context, link *transport.Link, dialer internet.Dialer) error {
+	outbounds := session.OutboundsFromContext(ctx)
+	ob := outbounds[len(outbounds)-1]
+	if !ob.Target.IsValid() {
+		return errors.New("target not specified")
+	}
+	ob.Name = "masque"
+	ob.CanSpliceCopy = 3
+
+	t, err := c.getTunnel(ctx, dialer)
+	if err != nil {
+		return errors.New("failed to establish CONNECT-IP tunnel").Base(err)
+	}
+
+	var newCtx context.Context
+	var newCancel context.CancelFunc
+	if session.TimeoutOnlyFromContext(ctx) {
+		newCtx, newCancel = context.WithCancel(context.Background())
+	}
+
+	sessionPolicy := c.policyManager.ForLevel(0)
+	ctx, cancel := context.WithCancel(ctx)
+	timer := signal.CancelAfterInactivity(ctx, func() {
+		cancel()
+		if newCancel != nil {
+			newCancel()
+		}
+	}, sessionPolicy.Timeouts.ConnectionIdle)
+
+	if newCtx != nil {
+		ctx = newCtx
+	}
+
+	var reader buf.Reader
+	var writer buf.Writer
+
+	switch ob.Target.Network {
+	case net.Network_TCP:
+		var conn net.Conn
+		var err error
+		if sessionPolicy.Timeouts.Handshake != 0 {
+			timeoutCtx, timeoutCancel := context.WithTimeout(ctx, sessionPolicy.Timeouts.Handshake)
+			conn, err = t.tnet.DialContext(timeoutCtx, "tcp", ob.Target.NetAddr())
+			timeoutCancel()
+		} else {
+			conn, err = t.tnet.Dial("tcp", ob.Target.NetAddr())
+		}
+		if err != nil {
+			return errors.New("failed to create TCP connection").Base(err)
+		}
+		defer conn.Close()
+		reader = buf.NewReader(conn)
+		writer = buf.NewWriter(conn)
+	case net.Network_UDP:
+		conn, err := t.tnet.Dial("udp", ob.Target.NetAddr())
+		if err != nil {
+			return errors.New("failed to create UDP connection").Base(err)
+		}
+		defer conn.Close()
+		uc := &wireguard.UDPConnClient{
+			PacketConn: conn.(*internet.PacketConnWrapper).PacketConn,
+			Dest:       conn.RemoteAddr().(*net.UDPAddr),
+		}
+		reader = uc
+		writer = uc
+	default:
+		panic(ob.Target.Network)
+	}
+
+	requestFunc := func() error {
+		defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly)
+		return buf.Copy(link.Reader, writer, buf.UpdateActivity(timer))
+	}
+
+	responseFunc := func() error {
+		defer timer.SetTimeout(sessionPolicy.Timeouts.UplinkOnly)
+		return buf.Copy(reader, link.Writer, buf.UpdateActivity(timer))
+	}
+
+	responseDonePost := task.OnSuccess(responseFunc, task.Close(link.Writer))
+	if err := task.Run(ctx, requestFunc, responseDonePost); err != nil {
+		common.Interrupt(link.Reader)
+		common.Interrupt(link.Writer)
+		return errors.New("connection ends").Base(err)
+	}
+
+	return nil
+}
+
+func (c *Client) getTunnel(ctx context.Context, dialer internet.Dialer) (*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
+		}
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	if c.lastErr != nil && time.Since(c.lastErrAt) < retryInterval {
+		return nil, c.lastErr
+	}
+
+	t, err := c.establish(ctx, dialer)
+	if err != nil {
+		c.lastErr, c.lastErrAt = err, time.Now()
+		return nil, 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")
+	}
+	return t, nil
+}
+
+func (c *Client) establish(ctx context.Context, dialer internet.Dialer) (*tunnel, error) {
+	ctx, cancel := context.WithTimeout(context.WithoutCancel(ctx), establishTimeout)
+	defer cancel()
+	defer context.AfterFunc(c.ctx, cancel)()
+	conn, err := dialer.Dial(ctx, c.server.Destination)
+	if err != nil {
+		return nil, err
+	}
+	mconn, ok := stat.TryUnwrapStatsConn(conn).(*masque.Conn)
+	if !ok {
+		conn.Close()
+		return nil, errors.New("not a CONNECT-IP connection")
+	}
+	t, err := newTunnel(conn, mconn.LocalAddrs(), c.remoteDNS)
+	if err != nil {
+		conn.Close()
+		return nil, err
+	}
+	errors.LogInfo(ctx, "MASQUE: tunnel established from ", mconn.LocalAddrs())
+	return t, nil
+}
+
+func (c *Client) Close() error {
+	c.cancel()
+	if t := c.tunnel.Swap(nil); t != nil {
+		t.close()
+	}
+	return nil
+}
+
+type tunnel struct {
+	conn      stat.Connection
+	dev       tun.Device
+	tnet      *wireguard.Net
+	done      chan struct{}
+	closeOnce sync.Once
+}
+
+func newTunnel(conn stat.Connection, local []netip.Addr, remoteDNS []netip.Addr) (*tunnel, error) {
+	var dns []netip.Addr
+	for _, addr := range remoteDNS {
+		if slices.ContainsFunc(local, func(l netip.Addr) bool { return l.Is4() == addr.Is4() }) {
+			dns = append(dns, addr)
+		}
+	}
+	if len(dns) == 0 {
+		errors.LogWarning(context.Background(), "MASQUE: no remote DNS server is reachable from the assigned addresses ", local, ", domain names will fail to resolve")
+		dns = remoteDNS
+	}
+
+	dev, tnet, _, err := wireguard.CreateNetTUN(local, dns, masque.MinPacketSize, true)
+	if err != nil {
+		return nil, err
+	}
+	t := &tunnel{
+		conn: conn,
+		dev:  dev,
+		tnet: tnet,
+		done: make(chan struct{}),
+	}
+	go t.readFromTunnel()
+	go t.writeToTunnel()
+	return t, nil
+}
+
+func (t *tunnel) readFromTunnel() {
+	defer t.close()
+	b := make([]byte, buf.Size)
+	for {
+		n, err := t.conn.Read(b)
+		if err != nil {
+			if go_errors.Is(err, io.ErrShortBuffer) {
+				continue
+			}
+			errors.LogInfoInner(context.Background(), err, "MASQUE: tunnel closed")
+			return
+		}
+		t.dev.Write([][]byte{b[:n]}, 0)
+	}
+}
+
+func (t *tunnel) writeToTunnel() {
+	bufs := [][]byte{make([]byte, masque.MinPacketSize)}
+	sizes := []int{0}
+	for {
+		if _, err := t.dev.Read(bufs, sizes, 0); err != nil {
+			return
+		}
+		if _, err := t.conn.Write(bufs[0][:sizes[0]]); err != nil {
+			var ptb *masque.PacketTooBigError
+			if go_errors.As(err, &ptb) {
+				go t.dev.Write([][]byte{ptb.ICMP}, 0)
+			}
+		}
+	}
+}
+
+func (t *tunnel) close() {
+	t.closeOnce.Do(func() {
+		close(t.done)
+		t.conn.Close()
+		t.dev.Close()
+	})
+}
+
+func init() {
+	common.Must(common.RegisterConfig((*ClientConfig)(nil), func(ctx context.Context, config interface{}) (interface{}, error) {
+		return NewClient(ctx, config.(*ClientConfig))
+	}))
+}

proxy/masque/config.pb.go

@@ -0,0 +1,136 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// versions:
+// 	protoc-gen-go v1.36.11
+// 	protoc        v6.33.5
+// source: proxy/masque/config.proto
+
+package masque
+
+import (
+	protocol "github.com/xtls/xray-core/common/protocol"
+	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
+	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
+	reflect "reflect"
+	sync "sync"
+	unsafe "unsafe"
+)
+
+const (
+	// Verify that this generated code is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
+	// Verify that runtime/protoimpl is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
+)
+
+type ClientConfig struct {
+	state         protoimpl.MessageState   `protogen:"open.v1"`
+	Server        *protocol.ServerEndpoint `protobuf:"bytes,1,opt,name=server,proto3" json:"server,omitempty"`
+	RemoteDns     []string                 `protobuf:"bytes,2,rep,name=remote_dns,json=remoteDns,proto3" json:"remote_dns,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *ClientConfig) Reset() {
+	*x = ClientConfig{}
+	mi := &file_proxy_masque_config_proto_msgTypes[0]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *ClientConfig) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*ClientConfig) ProtoMessage() {}
+
+func (x *ClientConfig) ProtoReflect() protoreflect.Message {
+	mi := &file_proxy_masque_config_proto_msgTypes[0]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use ClientConfig.ProtoReflect.Descriptor instead.
+func (*ClientConfig) Descriptor() ([]byte, []int) {
+	return file_proxy_masque_config_proto_rawDescGZIP(), []int{0}
+}
+
+func (x *ClientConfig) GetServer() *protocol.ServerEndpoint {
+	if x != nil {
+		return x.Server
+	}
+	return nil
+}
+
+func (x *ClientConfig) GetRemoteDns() []string {
+	if x != nil {
+		return x.RemoteDns
+	}
+	return nil
+}
+
+var File_proxy_masque_config_proto protoreflect.FileDescriptor
+
+const file_proxy_masque_config_proto_rawDesc = "" +
+	"\n" +
+	"\x19proxy/masque/config.proto\x12\x11xray.proxy.masque\x1a!common/protocol/server_spec.proto\"k\n" +
+	"\fClientConfig\x12<\n" +
+	"\x06server\x18\x01 \x01(\v2$.xray.common.protocol.ServerEndpointR\x06server\x12\x1d\n" +
+	"\n" +
+	"remote_dns\x18\x02 \x03(\tR\tremoteDnsBU\n" +
+	"\x15com.xray.proxy.masqueP\x01Z&github.com/xtls/xray-core/proxy/masque\xaa\x02\x11Xray.Proxy.Masqueb\x06proto3"
+
+var (
+	file_proxy_masque_config_proto_rawDescOnce sync.Once
+	file_proxy_masque_config_proto_rawDescData []byte
+)
+
+func file_proxy_masque_config_proto_rawDescGZIP() []byte {
+	file_proxy_masque_config_proto_rawDescOnce.Do(func() {
+		file_proxy_masque_config_proto_rawDescData = protoimpl.X.CompressGZIP(unsafe.Slice(unsafe.StringData(file_proxy_masque_config_proto_rawDesc), len(file_proxy_masque_config_proto_rawDesc)))
+	})
+	return file_proxy_masque_config_proto_rawDescData
+}
+
+var file_proxy_masque_config_proto_msgTypes = make([]protoimpl.MessageInfo, 1)
+var file_proxy_masque_config_proto_goTypes = []any{
+	(*ClientConfig)(nil),            // 0: xray.proxy.masque.ClientConfig
+	(*protocol.ServerEndpoint)(nil), // 1: xray.common.protocol.ServerEndpoint
+}
+var file_proxy_masque_config_proto_depIdxs = []int32{
+	1, // 0: xray.proxy.masque.ClientConfig.server:type_name -> xray.common.protocol.ServerEndpoint
+	1, // [1:1] is the sub-list for method output_type
+	1, // [1:1] is the sub-list for method input_type
+	1, // [1:1] is the sub-list for extension type_name
+	1, // [1:1] is the sub-list for extension extendee
+	0, // [0:1] is the sub-list for field type_name
+}
+
+func init() { file_proxy_masque_config_proto_init() }
+func file_proxy_masque_config_proto_init() {
+	if File_proxy_masque_config_proto != nil {
+		return
+	}
+	type x struct{}
+	out := protoimpl.TypeBuilder{
+		File: protoimpl.DescBuilder{
+			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
+			RawDescriptor: unsafe.Slice(unsafe.StringData(file_proxy_masque_config_proto_rawDesc), len(file_proxy_masque_config_proto_rawDesc)),
+			NumEnums:      0,
+			NumMessages:   1,
+			NumExtensions: 0,
+			NumServices:   0,
+		},
+		GoTypes:           file_proxy_masque_config_proto_goTypes,
+		DependencyIndexes: file_proxy_masque_config_proto_depIdxs,
+		MessageInfos:      file_proxy_masque_config_proto_msgTypes,
+	}.Build()
+	File_proxy_masque_config_proto = out.File
+	file_proxy_masque_config_proto_goTypes = nil
+	file_proxy_masque_config_proto_depIdxs = nil
+}

proxy/masque/config.proto

@@ -0,0 +1,14 @@
+syntax = "proto3";
+
+package xray.proxy.masque;
+option csharp_namespace = "Xray.Proxy.Masque";
+option go_package = "github.com/xtls/xray-core/proxy/masque";
+option java_package = "com.xray.proxy.masque";
+option java_multiple_files = true;
+
+import "common/protocol/server_spec.proto";
+
+message ClientConfig {
+  xray.common.protocol.ServerEndpoint server = 1;
+  repeated string remote_dns = 2;
+}

proxy/tun/handler.go

@@ -37,6 +37,25 @@ type Handler struct {
 	downlinkCounter stats.Counter
 }
 
+type tunUDPStatsWriter struct {
+	writer  buf.Writer
+	counter stats.Counter
+}
+
+func (w *tunUDPStatsWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
+	for len(mb) > 0 {
+		remaining, packet := buf.SplitFirst(mb)
+		packetSize := packet.Len()
+		if err := w.writer.WriteMultiBuffer(buf.MultiBuffer{packet}); err != nil {
+			buf.ReleaseMulti(remaining)
+			return err
+		}
+		w.counter.Add(int64(packetSize))
+		mb = remaining
+	}
+	return nil
+}
+
 // ConnectionHandler interface with the only method that stack is going to push new connections to
 type ConnectionHandler interface {
 	HandleConnection(conn net.Conn, destination net.Destination)
@@ -104,7 +123,7 @@ func (t *Handler) Start() error {
 			iface := updater.Get()
 			if iface == nil {
 				errors.LogInfo(context.Background(), "[tun] falied to set interface > iface == nil")
-				return nil
+				return errors.New("iface not found")
 			}
 			return c.Control(func(fd uintptr) {
 				addrPort, _ := netip.ParseAddrPort(address)
@@ -171,7 +190,8 @@ func (t *Handler) HandleConnection(conn net.Conn, destination net.Destination) {
 		return
 	}
 	source := net.DestinationFromAddr(remote)
-	if t.uplinkCounter != nil || t.downlinkCounter != nil {
+	isUDP := destination.Network == net.Network_UDP
+	if !isUDP && (t.uplinkCounter != nil || t.downlinkCounter != nil) {
 		conn = &stat.CounterConnection{
 			Connection:   conn,
 			ReadCounter:  t.uplinkCounter,
@@ -203,9 +223,18 @@ func (t *Handler) HandleConnection(conn net.Conn, destination net.Destination) {
 	})
 	errors.LogInfo(ctx, "processing from ", source, " to ", destination)
 
+	reader := &buf.TimeoutWrapperReader{Reader: buf.NewReader(conn)}
+	writer := buf.NewWriter(conn)
+	if isUDP {
+		reader.Counter = t.uplinkCounter
+		if t.downlinkCounter != nil {
+			writer = &tunUDPStatsWriter{writer: writer, counter: t.downlinkCounter}
+		}
+	}
+
 	link := &transport.Link{
-		Reader: &buf.TimeoutWrapperReader{Reader: buf.NewReader(conn)},
-		Writer: buf.NewWriter(conn),
+		Reader: reader,
+		Writer: writer,
 	}
 	if err := t.dispatcher.DispatchLink(ctx, destination, link); err != nil {
 		errors.LogError(ctx, errors.New("connection closed").Base(err))

proxy/wireguard/client.go

@@ -3,7 +3,6 @@ package wireguard
 import (
 	"context"
 	"fmt"
-	gonet "net"
 	"net/netip"
 	"reflect"
 	"strings"
@@ -28,14 +27,10 @@ import (
 	"github.com/xtls/xray-core/features/stats"
 	"github.com/xtls/xray-core/transport"
 	"github.com/xtls/xray-core/transport/internet"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
 	"golang.zx2c4.com/wireguard/device"
 )
 
-type entry struct {
-	got  []net.IP
-	time time.Time
-}
-
 type Handler struct {
 	conf          *DeviceConfig
 	policyManager policy.Manager
@@ -49,11 +44,6 @@ type Handler struct {
 	tnet *Net
 	dev  *device.Device
 	mu   sync.Mutex
-
-	// TODO: cache cleanup loop
-	local   bool
-	cache   map[string]entry
-	cacheMu sync.Mutex
 }
 
 func NewClient(ctx context.Context, conf *DeviceConfig) (*Handler, error) {
@@ -109,15 +99,10 @@ func NewClient(ctx context.Context, conf *DeviceConfig) (*Handler, error) {
 		return nil, err
 	}
 
-	local := false
 	dns := conf.DNS
 	if len(dns) == 0 {
 		dns = []string{"1.1.1.1", "1.0.0.1", "2606:4700:4700::1111", "2606:4700:4700::1001"}
 	}
-	if len(dns) == 1 && dns[0] == "local" {
-		local = true
-		dns = nil
-	}
 	dnses := make([]netip.Addr, 0, len(dns))
 	for _, dns := range dns {
 		dnses = append(dnses, netip.MustParseAddr(dns))
@@ -151,9 +136,6 @@ func NewClient(ctx context.Context, conf *DeviceConfig) (*Handler, error) {
 
 		tun:  tun,
 		tnet: tnet,
-
-		local: local,
-		cache: make(map[string]entry),
 	}, nil
 }
 
@@ -172,22 +154,6 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 		return err
 	}
 
-	var addr netip.Addr
-	if ob.Target.Address.Family().IsDomain() {
-		ip, err := h.resolveRemote(ob.Target.Address.String())
-		if err != nil {
-			return errors.New("failed to resolve domain").Base(err)
-		}
-		addr, _ = netip.AddrFromSlice(ip)
-	} else {
-		addr, _ = netip.AddrFromSlice(ob.Target.Address.IP())
-	}
-
-	addrPort := netip.AddrPortFrom(addr, ob.Target.Port.Value())
-	if !addrPort.IsValid() {
-		return errors.New("invalid target ", ob.Target)
-	}
-
 	var newCtx context.Context
 	var newCancel context.CancelFunc
 	if session.TimeoutOnlyFromContext(ctx) {
@@ -216,10 +182,10 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 		var err error
 		if sessionPolicy.Timeouts.Handshake != 0 {
 			timeoutCtx, timeoutCancel := context.WithTimeout(ctx, sessionPolicy.Timeouts.Handshake)
-			conn, err = h.tnet.DialContextTCPAddrPort(timeoutCtx, addrPort)
+			conn, err = h.tnet.DialContext(timeoutCtx, "tcp", ob.Target.NetAddr())
 			timeoutCancel()
 		} else {
-			conn, err = h.tnet.DialContextTCPAddrPort(ctx, addrPort)
+			conn, err = h.tnet.Dial("tcp", ob.Target.NetAddr())
 		}
 		if err != nil {
 			return errors.New("failed to create TCP connection").Base(err)
@@ -228,15 +194,14 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 		reader = buf.NewReader(conn)
 		writer = buf.NewWriter(conn)
 	case net.Network_UDP:
-		conn, err := h.tnet.DialUDPAddrPort(netip.AddrPort{}, addrPort)
+		conn, err := h.tnet.Dial("udp", ob.Target.NetAddr())
 		if err != nil {
 			return errors.New("failed to create UDP connection").Base(err)
 		}
 		defer conn.Close()
-		c := &udpConnClient{
-			PacketConn:  conn.(*internet.PacketConnWrapper).PacketConn,
-			resolveFunc: h.resolveRemote,
-			dest:        gonet.UDPAddrFromAddrPort(addrPort),
+		c := &UDPConnClient{
+			PacketConn: conn.(*internet.PacketConnWrapper).PacketConn,
+			Dest:       conn.RemoteAddr().(*net.UDPAddr),
 		}
 		reader = c
 		writer = c
@@ -293,26 +258,26 @@ func (h *Handler) init(ctx context.Context) error {
 		if err != nil {
 			return nil, err
 		}
-		conn, err := internet.DialSystem(ctx, dest, h.streamSettings.SocketSettings)
-		if err != nil {
-			return nil, err
-		}
 		var pktConn net.PacketConn
-		switch c := conn.(type) {
-		case *internet.PacketConnWrapper:
-			pktConn = c.PacketConn
-		case *cnc.Connection:
-			pktConn = &internet.FakePacketConn{Conn: c}
-		default:
-			panic(reflect.TypeOf(c))
-		}
-		if h.streamSettings.UdpmaskManager != nil {
-			newConn, err := h.streamSettings.UdpmaskManager.WrapPacketConnClient(pktConn)
+		if h.streamSettings.FinalMask != nil {
+			conn, err := h.streamSettings.FinalMask.DialUDP(ctx, dest)
 			if err != nil {
-				pktConn.Close()
-				return nil, errors.New("mask err").Base(err)
+				return nil, errors.New("failed to dial to dest").Base(err)
+			}
+			pktConn = conn.(*finalmask.PacketConnWrapper).PacketConn
+		} else {
+			conn, err := internet.DialSystem(ctx, dest, h.streamSettings.SocketSettings)
+			if err != nil {
+				return nil, errors.New("failed to dial to dest").Base(err)
+			}
+			switch c := conn.(type) {
+			case *internet.PacketConnWrapper:
+				pktConn = c.PacketConn
+			case *cnc.Connection:
+				pktConn = &internet.FakePacketConn{Conn: c}
+			default:
+				panic(reflect.TypeOf(c))
 			}
-			pktConn = newConn
 		}
 		if h.uplinkCounter != nil || h.downlinkCounter != nil {
 			pktConn = &PacketCounterConnection{
@@ -371,90 +336,54 @@ func (h *Handler) init(ctx context.Context) error {
 }
 
 func (h *Handler) resolveLocal(host string) (net.IP, error) {
-	return h.resolveDomain(host, h.conf.DomainStrategy, func(host string) ([]net.IP, uint32, error) {
-		return h.dns.LookupIP(host, dns.IPOption{IPv4Enable: true, IPv6Enable: true})
-	})
-}
-
-func (h *Handler) resolveRemote(host string) (net.IP, error) {
-	return h.resolveDomain(host, h.conf.DomainStrategy, func(host string) ([]net.IP, uint32, error) {
-		if h.local {
-			return h.dns.LookupIP(host, dns.IPOption{IPv4Enable: true, IPv6Enable: true})
-		}
-		return h.tnet.LookupHost(host)
-	})
-}
-
-func (h *Handler) resolveDomain(host string, strategy DeviceConfig_DomainStrategy, lookupIP func(host string) ([]net.IP, uint32, error)) (net.IP, error) {
 	if ip := net.ParseIP(host); ip != nil {
 		return ip, nil
 	}
-	h.cacheMu.Lock()
-	if entry, ok := h.cache[host]; ok {
-		if time.Now().Before(entry.time) {
-			h.cacheMu.Unlock()
-			return entry.got[dice.Roll(len(entry.got))], nil
-		}
-		delete(h.cache, host)
-	}
-	h.cacheMu.Unlock()
-	ips, ttl, err := lookupIP(host)
+	ips, _, err := h.dns.LookupIP(host, dns.IPOption{IPv4Enable: true, IPv6Enable: true})
 	if err != nil {
 		return nil, err
 	}
-	if len(ips) == 0 {
-		return nil, dns.ErrEmptyResponse
-	}
-	var got4, got6 []net.IP
-	for _, ip := range ips {
-		if ip.To4() != nil {
-			got4 = append(got4, ip)
-		} else {
-			got6 = append(got6, ip)
+	got := ips
+	if h.streamSettings.SocketSettings != nil {
+		var got4, got6 []net.IP
+		for _, ip := range ips {
+			if ip.To4() != nil {
+				got4 = append(got4, ip)
+			} else {
+				got6 = append(got6, ip)
+			}
 		}
-	}
-	var got []net.IP
-	switch strategy {
-	case DeviceConfig_FORCE_IP:
-		got = ips
-		return ips[dice.Roll(len(ips))], nil
-	case DeviceConfig_FORCE_IP4:
-		got = got4
-	case DeviceConfig_FORCE_IP6:
-		got = got6
-	case DeviceConfig_FORCE_IP46:
-		got = got4
-		if len(got) == 0 {
-			got = got6
-		}
-	case DeviceConfig_FORCE_IP64:
-		got = got6
-		if len(got) == 0 {
+		switch h.streamSettings.SocketSettings.DomainStrategy {
+		case internet.DomainStrategy_AS_IS, internet.DomainStrategy_USE_IP, internet.DomainStrategy_FORCE_IP:
+			got = ips
+		case internet.DomainStrategy_USE_IP4, internet.DomainStrategy_FORCE_IP4:
 			got = got4
+		case internet.DomainStrategy_USE_IP6, internet.DomainStrategy_FORCE_IP6:
+			got = got6
+		case internet.DomainStrategy_USE_IP46, internet.DomainStrategy_FORCE_IP46:
+			got = got4
+			if len(got) == 0 {
+				got = got6
+			}
+		case internet.DomainStrategy_USE_IP64, internet.DomainStrategy_FORCE_IP64:
+			got = got6
+			if len(got) == 0 {
+				got = got4
+			}
+		}
+		if len(got) == 0 {
+			return nil, dns.ErrEmptyResponse
 		}
-	default:
-		panic(strategy)
 	}
-	if len(got) == 0 {
-		return nil, dns.ErrEmptyResponse
-	}
-	entry := entry{
-		got:  got,
-		time: time.Now().Add(time.Duration(ttl) * time.Second),
-	}
-	h.cacheMu.Lock()
-	h.cache[host] = entry
-	h.cacheMu.Unlock()
 	return got[dice.Roll(len(got))], nil
 }
 
-type udpConnClient struct {
+type UDPConnClient struct {
 	net.PacketConn
-	resolveFunc func(host string) (net.IP, error)
-	dest        *net.UDPAddr
+	Dest *net.UDPAddr
 }
 
-func (c *udpConnClient) ReadMultiBuffer() (buf.MultiBuffer, error) {
+func (c *UDPConnClient) ReadMultiBuffer() (buf.MultiBuffer, error) {
 	b := buf.New()
 	b.Resize(0, buf.Size)
 	n, addr, err := c.PacketConn.ReadFrom(b.Bytes())
@@ -473,20 +402,13 @@ func (c *udpConnClient) ReadMultiBuffer() (buf.MultiBuffer, error) {
 	return buf.MultiBuffer{b}, nil
 }
 
-func (c *udpConnClient) WriteMultiBuffer(mb buf.MultiBuffer) error {
+func (c *UDPConnClient) WriteMultiBuffer(mb buf.MultiBuffer) error {
 	for i, b := range mb {
-		dst := c.dest
+		dst := c.Dest
 		if b.UDP != nil {
 			if b.UDP.Address.Family().IsDomain() {
-				ip, err := c.resolveFunc(b.UDP.Address.String())
-				if err != nil {
-					errors.LogErrorInner(context.Background(), err, "drop packet to ", b.UDP, " with size ", len(b.Bytes()))
-					b.Release()
-					continue
-				}
-				dst = &net.UDPAddr{
-					IP:   ip,
-					Port: int(b.UDP.Port),
+				if b.UDP.Port != net.Port(dst.Port) {
+					dst = &net.UDPAddr{IP: dst.IP, Port: int(b.UDP.Port)}
 				}
 			} else {
 				dst = b.UDP.RawNetAddr().(*net.UDPAddr)
@@ -523,3 +445,66 @@ func (c *PacketCounterConnection) WriteTo(p []byte, addr net.Addr) (n int, err e
 	}
 	return
 }
+
+type entry struct {
+	saddr    []string
+	deadline time.Time
+}
+
+type cache struct {
+	running bool
+	m       map[string]entry
+	mu      sync.Mutex
+}
+
+func (c *cache) run() {
+	if c.running {
+		return
+	}
+	c.running = true
+	if c.m == nil {
+		c.m = make(map[string]entry)
+	}
+	go c.gc()
+}
+
+func (c *cache) gc() {
+	ticker := time.NewTicker(time.Minute)
+	defer ticker.Stop()
+	for now := range ticker.C {
+		c.mu.Lock()
+		for key, entry := range c.m {
+			if now.After(entry.deadline) {
+				delete(c.m, key)
+			}
+		}
+		if len(c.m) == 0 {
+			c.running = false
+			c.mu.Unlock()
+			return
+		}
+		c.mu.Unlock()
+	}
+}
+
+func (c *cache) LookupHost(host string) []string {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.run()
+	if entry, ok := c.m[host]; ok {
+		if time.Now().Before(entry.deadline) {
+			return entry.saddr
+		}
+		delete(c.m, host)
+	}
+	return nil
+}
+
+func (c *cache) Cache(host string, saddr []string, ttl uint32) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.m[host] = entry{
+		saddr:    saddr,
+		deadline: time.Now().Add(time.Second * time.Duration(ttl)),
+	}
+}

proxy/wireguard/config.pb.go

@@ -22,61 +22,6 @@ const (
 	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
 )
 
-type DeviceConfig_DomainStrategy int32
-
-const (
-	DeviceConfig_FORCE_IP   DeviceConfig_DomainStrategy = 0
-	DeviceConfig_FORCE_IP4  DeviceConfig_DomainStrategy = 1
-	DeviceConfig_FORCE_IP6  DeviceConfig_DomainStrategy = 2
-	DeviceConfig_FORCE_IP46 DeviceConfig_DomainStrategy = 3
-	DeviceConfig_FORCE_IP64 DeviceConfig_DomainStrategy = 4
-)
-
-// Enum value maps for DeviceConfig_DomainStrategy.
-var (
-	DeviceConfig_DomainStrategy_name = map[int32]string{
-		0: "FORCE_IP",
-		1: "FORCE_IP4",
-		2: "FORCE_IP6",
-		3: "FORCE_IP46",
-		4: "FORCE_IP64",
-	}
-	DeviceConfig_DomainStrategy_value = map[string]int32{
-		"FORCE_IP":   0,
-		"FORCE_IP4":  1,
-		"FORCE_IP6":  2,
-		"FORCE_IP46": 3,
-		"FORCE_IP64": 4,
-	}
-)
-
-func (x DeviceConfig_DomainStrategy) Enum() *DeviceConfig_DomainStrategy {
-	p := new(DeviceConfig_DomainStrategy)
-	*p = x
-	return p
-}
-
-func (x DeviceConfig_DomainStrategy) String() string {
-	return protoimpl.X.EnumStringOf(x.Descriptor(), protoreflect.EnumNumber(x))
-}
-
-func (DeviceConfig_DomainStrategy) Descriptor() protoreflect.EnumDescriptor {
-	return file_proxy_wireguard_config_proto_enumTypes[0].Descriptor()
-}
-
-func (DeviceConfig_DomainStrategy) Type() protoreflect.EnumType {
-	return &file_proxy_wireguard_config_proto_enumTypes[0]
-}
-
-func (x DeviceConfig_DomainStrategy) Number() protoreflect.EnumNumber {
-	return protoreflect.EnumNumber(x)
-}
-
-// Deprecated: Use DeviceConfig_DomainStrategy.Descriptor instead.
-func (DeviceConfig_DomainStrategy) EnumDescriptor() ([]byte, []int) {
-	return file_proxy_wireguard_config_proto_rawDescGZIP(), []int{1, 0}
-}
-
 type PeerConfig struct {
 	state         protoimpl.MessageState `protogen:"open.v1"`
 	PublicKey     string                 `protobuf:"bytes,1,opt,name=public_key,json=publicKey,proto3" json:"public_key,omitempty"`
@@ -154,19 +99,18 @@ func (x *PeerConfig) GetAllowedIps() []string {
 }
 
 type DeviceConfig struct {
-	state          protoimpl.MessageState      `protogen:"open.v1"`
-	SecretKey      string                      `protobuf:"bytes,1,opt,name=secret_key,json=secretKey,proto3" json:"secret_key,omitempty"`
-	Endpoint       []string                    `protobuf:"bytes,2,rep,name=endpoint,proto3" json:"endpoint,omitempty"`
-	Peers          []*PeerConfig               `protobuf:"bytes,3,rep,name=peers,proto3" json:"peers,omitempty"`
-	Users          []*protocol.User            `protobuf:"bytes,5,rep,name=users,proto3" json:"users,omitempty"`
-	Mtu            int32                       `protobuf:"varint,4,opt,name=mtu,proto3" json:"mtu,omitempty"`
-	Reserved       []byte                      `protobuf:"bytes,6,opt,name=reserved,proto3" json:"reserved,omitempty"`
-	DomainStrategy DeviceConfig_DomainStrategy `protobuf:"varint,7,opt,name=domain_strategy,json=domainStrategy,proto3,enum=xray.proxy.wireguard.DeviceConfig_DomainStrategy" json:"domain_strategy,omitempty"`
-	IsClient       bool                        `protobuf:"varint,8,opt,name=is_client,json=isClient,proto3" json:"is_client,omitempty"`
-	NoKernelTun    bool                        `protobuf:"varint,9,opt,name=no_kernel_tun,json=noKernelTun,proto3" json:"no_kernel_tun,omitempty"`
-	DNS            []string                    `protobuf:"bytes,10,rep,name=DNS,proto3" json:"DNS,omitempty"`
-	unknownFields  protoimpl.UnknownFields
-	sizeCache      protoimpl.SizeCache
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	SecretKey     string                 `protobuf:"bytes,1,opt,name=secret_key,json=secretKey,proto3" json:"secret_key,omitempty"`
+	Endpoint      []string               `protobuf:"bytes,2,rep,name=endpoint,proto3" json:"endpoint,omitempty"`
+	Peers         []*PeerConfig          `protobuf:"bytes,3,rep,name=peers,proto3" json:"peers,omitempty"`
+	Users         []*protocol.User       `protobuf:"bytes,5,rep,name=users,proto3" json:"users,omitempty"`
+	Mtu           int32                  `protobuf:"varint,4,opt,name=mtu,proto3" json:"mtu,omitempty"`
+	Reserved      []byte                 `protobuf:"bytes,6,opt,name=reserved,proto3" json:"reserved,omitempty"`
+	IsClient      bool                   `protobuf:"varint,8,opt,name=is_client,json=isClient,proto3" json:"is_client,omitempty"`
+	NoKernelTun   bool                   `protobuf:"varint,9,opt,name=no_kernel_tun,json=noKernelTun,proto3" json:"no_kernel_tun,omitempty"`
+	DNS           []string               `protobuf:"bytes,10,rep,name=DNS,proto3" json:"DNS,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
 }
 
 func (x *DeviceConfig) Reset() {
@@ -241,13 +185,6 @@ func (x *DeviceConfig) GetReserved() []byte {
 	return nil
 }
 
-func (x *DeviceConfig) GetDomainStrategy() DeviceConfig_DomainStrategy {
-	if x != nil {
-		return x.DomainStrategy
-	}
-	return DeviceConfig_FORCE_IP
-}
-
 func (x *DeviceConfig) GetIsClient() bool {
 	if x != nil {
 		return x.IsClient
@@ -283,7 +220,7 @@ const file_proxy_wireguard_config_proto_rawDesc = "" +
 	"\n" +
 	"keep_alive\x18\x04 \x01(\tR\tkeepAlive\x12\x1f\n" +
 	"\vallowed_ips\x18\x05 \x03(\tR\n" +
-	"allowedIps\"\xee\x03\n" +
+	"allowedIps\"\xb4\x02\n" +
 	"\fDeviceConfig\x12\x1d\n" +
 	"\n" +
 	"secret_key\x18\x01 \x01(\tR\tsecretKey\x12\x1a\n" +
@@ -291,20 +228,11 @@ const file_proxy_wireguard_config_proto_rawDesc = "" +
 	"\x05peers\x18\x03 \x03(\v2 .xray.proxy.wireguard.PeerConfigR\x05peers\x120\n" +
 	"\x05users\x18\x05 \x03(\v2\x1a.xray.common.protocol.UserR\x05users\x12\x10\n" +
 	"\x03mtu\x18\x04 \x01(\x05R\x03mtu\x12\x1a\n" +
-	"\breserved\x18\x06 \x01(\fR\breserved\x12Z\n" +
-	"\x0fdomain_strategy\x18\a \x01(\x0e21.xray.proxy.wireguard.DeviceConfig.DomainStrategyR\x0edomainStrategy\x12\x1b\n" +
+	"\breserved\x18\x06 \x01(\fR\breserved\x12\x1b\n" +
 	"\tis_client\x18\b \x01(\bR\bisClient\x12\"\n" +
 	"\rno_kernel_tun\x18\t \x01(\bR\vnoKernelTun\x12\x10\n" +
 	"\x03DNS\x18\n" +
-	" \x03(\tR\x03DNS\"\\\n" +
-	"\x0eDomainStrategy\x12\f\n" +
-	"\bFORCE_IP\x10\x00\x12\r\n" +
-	"\tFORCE_IP4\x10\x01\x12\r\n" +
-	"\tFORCE_IP6\x10\x02\x12\x0e\n" +
-	"\n" +
-	"FORCE_IP46\x10\x03\x12\x0e\n" +
-	"\n" +
-	"FORCE_IP64\x10\x04B^\n" +
+	" \x03(\tR\x03DNSB^\n" +
 	"\x18com.xray.proxy.wireguardP\x01Z)github.com/xtls/xray-core/proxy/wireguard\xaa\x02\x14Xray.Proxy.WireGuardb\x06proto3"
 
 var (
@@ -319,23 +247,20 @@ func file_proxy_wireguard_config_proto_rawDescGZIP() []byte {
 	return file_proxy_wireguard_config_proto_rawDescData
 }
 
-var file_proxy_wireguard_config_proto_enumTypes = make([]protoimpl.EnumInfo, 1)
 var file_proxy_wireguard_config_proto_msgTypes = make([]protoimpl.MessageInfo, 2)
 var file_proxy_wireguard_config_proto_goTypes = []any{
-	(DeviceConfig_DomainStrategy)(0), // 0: xray.proxy.wireguard.DeviceConfig.DomainStrategy
-	(*PeerConfig)(nil),               // 1: xray.proxy.wireguard.PeerConfig
-	(*DeviceConfig)(nil),             // 2: xray.proxy.wireguard.DeviceConfig
-	(*protocol.User)(nil),            // 3: xray.common.protocol.User
+	(*PeerConfig)(nil),    // 0: xray.proxy.wireguard.PeerConfig
+	(*DeviceConfig)(nil),  // 1: xray.proxy.wireguard.DeviceConfig
+	(*protocol.User)(nil), // 2: xray.common.protocol.User
 }
 var file_proxy_wireguard_config_proto_depIdxs = []int32{
-	1, // 0: xray.proxy.wireguard.DeviceConfig.peers:type_name -> xray.proxy.wireguard.PeerConfig
-	3, // 1: xray.proxy.wireguard.DeviceConfig.users:type_name -> xray.common.protocol.User
-	0, // 2: xray.proxy.wireguard.DeviceConfig.domain_strategy:type_name -> xray.proxy.wireguard.DeviceConfig.DomainStrategy
-	3, // [3:3] is the sub-list for method output_type
-	3, // [3:3] is the sub-list for method input_type
-	3, // [3:3] is the sub-list for extension type_name
-	3, // [3:3] is the sub-list for extension extendee
-	0, // [0:3] is the sub-list for field type_name
+	0, // 0: xray.proxy.wireguard.DeviceConfig.peers:type_name -> xray.proxy.wireguard.PeerConfig
+	2, // 1: xray.proxy.wireguard.DeviceConfig.users:type_name -> xray.common.protocol.User
+	2, // [2:2] is the sub-list for method output_type
+	2, // [2:2] is the sub-list for method input_type
+	2, // [2:2] is the sub-list for extension type_name
+	2, // [2:2] is the sub-list for extension extendee
+	0, // [0:2] is the sub-list for field type_name
 }
 
 func init() { file_proxy_wireguard_config_proto_init() }
@@ -348,14 +273,13 @@ func file_proxy_wireguard_config_proto_init() {
 		File: protoimpl.DescBuilder{
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: unsafe.Slice(unsafe.StringData(file_proxy_wireguard_config_proto_rawDesc), len(file_proxy_wireguard_config_proto_rawDesc)),
-			NumEnums:      1,
+			NumEnums:      0,
 			NumMessages:   2,
 			NumExtensions: 0,
 			NumServices:   0,
 		},
 		GoTypes:           file_proxy_wireguard_config_proto_goTypes,
 		DependencyIndexes: file_proxy_wireguard_config_proto_depIdxs,
-		EnumInfos:         file_proxy_wireguard_config_proto_enumTypes,
 		MessageInfos:      file_proxy_wireguard_config_proto_msgTypes,
 	}.Build()
 	File_proxy_wireguard_config_proto = out.File

proxy/wireguard/config.proto

@@ -17,13 +17,6 @@ message PeerConfig {
 }
 
 message DeviceConfig {
-  enum DomainStrategy {
-    FORCE_IP = 0;
-    FORCE_IP4 = 1;
-    FORCE_IP6 = 2;
-    FORCE_IP46 = 3;
-    FORCE_IP64 = 4;
-  }
   string secret_key = 1;
   repeated string endpoint = 2;
   repeated PeerConfig peers = 3;
@@ -31,7 +24,6 @@ message DeviceConfig {
   int32 mtu = 4;
 
   bytes reserved = 6;
-  DomainStrategy domain_strategy = 7;
   bool is_client = 8;
   bool no_kernel_tun = 9;
   repeated string DNS = 10;

proxy/wireguard/netstack.go

@@ -15,6 +15,8 @@ import (
 	"net"
 	"net/netip"
 	"os"
+	"regexp"
+	"strconv"
 	"strings"
 	"syscall"
 	"time"
@@ -42,6 +44,7 @@ type netTun struct {
 	events         chan tun.Event
 	notifyHandle   *channel.NotificationHandle
 	incomingPacket chan *buffer.View
+	closed         chan struct{}
 	mtu            int
 	dnsServers     []netip.Addr
 	hasV4, hasV6   bool
@@ -58,6 +61,7 @@ func CreateNetTUN(localAddresses, dnsServers []netip.Addr, mtu int, handleLocal
 		stack:          stack.New(opts),
 		events:         make(chan tun.Event, 10),
 		incomingPacket: make(chan *buffer.View),
+		closed:         make(chan struct{}),
 		dnsServers:     dnsServers,
 		mtu:            mtu,
 	}
@@ -124,12 +128,15 @@ func (tun *netTun) Events() <-chan tun.Event {
 }
 
 func (tun *netTun) Read(buf [][]byte, sizes []int, offset int) (int, error) {
-	view, ok := <-tun.incomingPacket
-	if !ok {
+	var view *buffer.View
+	select {
+	case view = <-tun.incomingPacket:
+	case <-tun.closed:
 		return 0, os.ErrClosed
 	}
 
 	n, err := view.Read(buf[0][offset:])
+	view.Release()
 	if err != nil {
 		return 0, err
 	}
@@ -166,7 +173,11 @@ func (tun *netTun) WriteNotify() {
 	view := pkt.ToView()
 	pkt.DecRef()
 
-	tun.incomingPacket <- view
+	select {
+	case tun.incomingPacket <- view:
+	case <-tun.closed:
+		view.Release()
+	}
 }
 
 func (tun *netTun) Close() error {
@@ -179,8 +190,9 @@ func (tun *netTun) Close() error {
 		close(tun.events)
 	}
 
-	if tun.incomingPacket != nil {
-		close(tun.incomingPacket)
+	// we don't close incomingPacket, because WriteNotify may be mid-send on it (DNS lookup) and would panic.
+	if tun.closed != nil {
+		close(tun.closed)
 	}
 
 	return nil
@@ -219,6 +231,7 @@ type Net struct {
 	DialUDPAddrPort        func(laddr, raddr netip.AddrPort) (net.Conn, error)
 	dnsServers             []netip.Addr
 	hasV4, hasV6           bool
+	cache                  cache
 }
 
 func convertToFullAddr(endpoint netip.AddrPort) (tcpip.FullAddress, tcpip.NetworkProtocolNumber) {
@@ -246,9 +259,12 @@ var (
 	errServerTemporarilyMisbehaving = errors.New("server misbehaving")
 	errCanceled                     = errors.New("operation was canceled")
 	errTimeout                      = errors.New("i/o timeout")
+	errNumericPort                  = errors.New("port must be numeric")
+	errNoSuitableAddress            = errors.New("no suitable address found")
+	errMissingAddress               = errors.New("missing address")
 )
 
-func (net *Net) LookupHost(host string) (addrs []net.IP, ttl uint32, err error) {
+func (net *Net) LookupHost(host string) (addrs []string, err error) {
 	return net.LookupContextHost(context.Background(), host)
 }
 
@@ -567,9 +583,12 @@ func (tnet *Net) tryOneName(ctx context.Context, name string, qtype dnsmessage.T
 	return dnsmessage.Parser{}, "", lastErr
 }
 
-func (tnet *Net) LookupContextHost(ctx context.Context, host string) ([]net.IP, uint32, error) {
+func (tnet *Net) LookupContextHost(ctx context.Context, host string) ([]string, error) {
+	if saddr := tnet.cache.LookupHost(host); saddr != nil {
+		return saddr, nil
+	}
 	if host == "" || (!tnet.hasV6 && !tnet.hasV4) {
-		return nil, 0, &net.DNSError{Err: errNoSuchHost.Error(), Name: host, IsNotFound: true}
+		return nil, &net.DNSError{Err: errNoSuchHost.Error(), Name: host, IsNotFound: true}
 	}
 	zlen := len(host)
 	if strings.IndexByte(host, ':') != -1 {
@@ -578,11 +597,11 @@ func (tnet *Net) LookupContextHost(ctx context.Context, host string) ([]net.IP,
 		}
 	}
 	if ip, err := netip.ParseAddr(host[:zlen]); err == nil {
-		return []net.IP{ip.AsSlice()}, 0, nil
+		return []string{ip.String()}, nil
 	}
 
 	if !isDomainName(host) {
-		return nil, 0, &net.DNSError{Err: errNoSuchHost.Error(), Name: host, IsNotFound: true}
+		return nil, &net.DNSError{Err: errNoSuchHost.Error(), Name: host, IsNotFound: true}
 	}
 	type result struct {
 		p      dnsmessage.Parser
@@ -683,11 +702,137 @@ func (tnet *Net) LookupContextHost(ctx context.Context, host string) ([]net.IP,
 	}
 
 	if len(addrs) == 0 && lastErr != nil {
-		return nil, 0, lastErr
+		return nil, lastErr
 	}
-	ips := make([]net.IP, 0, len(addrs))
+	saddrs := make([]string, 0, len(addrs))
 	for _, ip := range addrs {
-		ips = append(ips, ip.AsSlice())
+		saddrs = append(saddrs, ip.String())
 	}
-	return ips, ttl, nil
+	tnet.cache.Cache(host, saddrs, ttl)
+	return saddrs, nil
+}
+
+func partialDeadline(now, deadline time.Time, addrsRemaining int) (time.Time, error) {
+	if deadline.IsZero() {
+		return deadline, nil
+	}
+	timeRemaining := deadline.Sub(now)
+	if timeRemaining <= 0 {
+		return time.Time{}, errTimeout
+	}
+	timeout := timeRemaining / time.Duration(addrsRemaining)
+	const saneMinimum = 2 * time.Second
+	if timeout < saneMinimum {
+		if timeRemaining < saneMinimum {
+			timeout = timeRemaining
+		} else {
+			timeout = saneMinimum
+		}
+	}
+	return now.Add(timeout), nil
+}
+
+var protoSplitter = regexp.MustCompile(`^(tcp|udp|ping)(4|6)?$`)
+
+func (tnet *Net) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
+	if ctx == nil {
+		panic("nil context")
+	}
+	var acceptV4, acceptV6 bool
+	matches := protoSplitter.FindStringSubmatch(network)
+	if matches == nil {
+		return nil, &net.OpError{Op: "dial", Err: net.UnknownNetworkError(network)}
+	} else if len(matches[2]) == 0 {
+		acceptV4 = true
+		acceptV6 = true
+	} else {
+		acceptV4 = matches[2][0] == '4'
+		acceptV6 = !acceptV4
+	}
+	var host string
+	var port int
+	if matches[1] == "ping" {
+		host = address
+	} else {
+		var sport string
+		var err error
+		host, sport, err = net.SplitHostPort(address)
+		if err != nil {
+			return nil, &net.OpError{Op: "dial", Err: err}
+		}
+		port, err = strconv.Atoi(sport)
+		if err != nil || port < 0 || port > 65535 {
+			return nil, &net.OpError{Op: "dial", Err: errNumericPort}
+		}
+	}
+	allAddr, err := tnet.LookupContextHost(ctx, host)
+	if err != nil {
+		return nil, &net.OpError{Op: "dial", Err: err}
+	}
+	var addrs []netip.AddrPort
+	for _, addr := range allAddr {
+		ip, err := netip.ParseAddr(addr)
+		if err == nil && ((ip.Is4() && acceptV4) || (ip.Is6() && acceptV6)) {
+			addrs = append(addrs, netip.AddrPortFrom(ip, uint16(port)))
+		}
+	}
+	if len(addrs) == 0 && len(allAddr) != 0 {
+		return nil, &net.OpError{Op: "dial", Err: errNoSuitableAddress}
+	}
+
+	var firstErr error
+	for i, addr := range addrs {
+		select {
+		case <-ctx.Done():
+			err := ctx.Err()
+			if err == context.Canceled {
+				err = errCanceled
+			} else if err == context.DeadlineExceeded {
+				err = errTimeout
+			}
+			return nil, &net.OpError{Op: "dial", Err: err}
+		default:
+		}
+
+		dialCtx := ctx
+		if deadline, hasDeadline := ctx.Deadline(); hasDeadline {
+			partialDeadline, err := partialDeadline(time.Now(), deadline, len(addrs)-i)
+			if err != nil {
+				if firstErr == nil {
+					firstErr = &net.OpError{Op: "dial", Err: err}
+				}
+				break
+			}
+			if partialDeadline.Before(deadline) {
+				var cancel context.CancelFunc
+				dialCtx, cancel = context.WithDeadline(ctx, partialDeadline)
+				defer cancel()
+			}
+		}
+
+		var c net.Conn
+		switch matches[1] {
+		case "tcp":
+			c, err = tnet.DialContextTCPAddrPort(dialCtx, addr)
+		case "udp":
+			c, err = tnet.DialUDPAddrPort(netip.AddrPort{}, addr)
+		case "ping":
+			err = errors.New("not support")
+			// c, err = tnet.DialPingAddr(netip.Addr{}, addr.Addr())
+		}
+		if err == nil {
+			return c, nil
+		}
+		if firstErr == nil {
+			firstErr = err
+		}
+	}
+	if firstErr == nil {
+		firstErr = &net.OpError{Op: "dial", Err: errMissingAddress}
+	}
+	return nil, firstErr
+}
+
+func (tnet *Net) Dial(network, address string) (net.Conn, error) {
+	return tnet.DialContext(context.Background(), network, address)
 }

proxy/wireguard/server.go

@@ -258,18 +258,16 @@ func (s *Server) Start() error {
 		return errors.New("address is domain")
 	}
 	listenFunc := func() (net.PacketConn, error) {
-		pktConn, err := internet.ListenSystemPacket(context.Background(), &net.UDPAddr{IP: s.src.Address.IP(), Port: int(s.src.Port)}, s.streamSettings.SocketSettings)
+		var pktConn net.PacketConn
+		var err error
+		if s.streamSettings.FinalMask != nil {
+			pktConn, err = s.streamSettings.FinalMask.ListenPacket(context.Background(), &net.UDPAddr{IP: s.src.Address.IP(), Port: int(s.src.Port)})
+		} else {
+			pktConn, err = internet.ListenSystemPacket(context.Background(), &net.UDPAddr{IP: s.src.Address.IP(), Port: int(s.src.Port)}, s.streamSettings.SocketSettings)
+		}
 		if err != nil {
 			return nil, err
 		}
-		if s.streamSettings.UdpmaskManager != nil {
-			newConn, err := s.streamSettings.UdpmaskManager.WrapPacketConnServer(pktConn)
-			if err != nil {
-				pktConn.Close()
-				return nil, errors.New("mask err").Base(err)
-			}
-			pktConn = newConn
-		}
 		if s.uplinkCounter != nil || s.downlinkCounter != nil {
 			pktConn = &PacketCounterConnection{
 				PacketConn:   pktConn,

testing/scenarios/masque_test.go

@@ -0,0 +1,275 @@
+package scenarios
+
+import (
+	"context"
+	gotls "crypto/tls"
+	"crypto/x509"
+	go_errors "errors"
+	"io"
+	"net/http"
+	"net/netip"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/apernet/quic-go"
+	"github.com/apernet/quic-go/http3"
+	"golang.org/x/sync/errgroup"
+	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
+	"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
+	"gvisor.dev/gvisor/pkg/tcpip/network/ipv6"
+
+	"github.com/xtls/xray-core/app/log"
+	"github.com/xtls/xray-core/app/proxyman"
+	"github.com/xtls/xray-core/common"
+	clog "github.com/xtls/xray-core/common/log"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/common/protocol"
+	"github.com/xtls/xray-core/common/protocol/tls/cert"
+	"github.com/xtls/xray-core/common/serial"
+	core "github.com/xtls/xray-core/core"
+	"github.com/xtls/xray-core/proxy/dokodemo"
+	"github.com/xtls/xray-core/proxy/masque"
+	"github.com/xtls/xray-core/proxy/wireguard"
+	"github.com/xtls/xray-core/testing/servers/tcp"
+	"github.com/xtls/xray-core/testing/servers/udp"
+	"github.com/xtls/xray-core/transport/internet"
+	transmasque "github.com/xtls/xray-core/transport/internet/masque"
+	"github.com/xtls/xray-core/transport/internet/masque/connectip"
+	"github.com/xtls/xray-core/transport/internet/tls"
+)
+
+var (
+	masqueServerV4 = netip.MustParseAddr("10.13.0.1")
+	masqueServerV6 = netip.MustParseAddr("fd13::1")
+	masqueClientV4 = netip.MustParsePrefix("10.13.0.2/32")
+	masqueClientV6 = netip.MustParsePrefix("fd13::2/128")
+)
+
+const (
+	masqueEchoPort      = 7
+	masqueAuthorization = "Basic dTpw"
+)
+
+func startMasqueServer(t *testing.T) (net.Port, [32]byte) {
+	dev, _, gstack, err := wireguard.CreateNetTUN([]netip.Addr{masqueServerV4, masqueServerV6}, nil, transmasque.MinPacketSize, false)
+	common.Must(err)
+	t.Cleanup(func() { dev.Close() })
+
+	for _, addr := range []netip.Addr{masqueServerV4, masqueServerV6} {
+		proto := ipv4.ProtocolNumber
+		if addr.Is6() {
+			proto = ipv6.ProtocolNumber
+		}
+		local := tcpip.FullAddress{NIC: 1, Addr: tcpip.AddrFromSlice(addr.AsSlice()), Port: masqueEchoPort}
+		l, err := gonet.ListenTCP(gstack, local, proto)
+		common.Must(err)
+		go func() {
+			for {
+				c, err := l.Accept()
+				if err != nil {
+					return
+				}
+				go func() {
+					defer c.Close()
+					b := make([]byte, 2048)
+					for {
+						n, err := c.Read(b)
+						if err != nil {
+							return
+						}
+						if _, err := c.Write(xor(b[:n])); err != nil {
+							return
+						}
+					}
+				}()
+			}
+		}()
+		u, err := gonet.DialUDP(gstack, &local, nil, proto)
+		common.Must(err)
+		go func() {
+			b := make([]byte, 2048)
+			for {
+				n, addr, err := u.ReadFrom(b)
+				if err != nil {
+					return
+				}
+				u.WriteTo(xor(b[:n]), addr)
+			}
+		}()
+	}
+
+	var current atomic.Pointer[connectip.Conn]
+	go func() {
+		bufs := [][]byte{make([]byte, transmasque.MinPacketSize)}
+		sizes := []int{0}
+		for {
+			if _, err := dev.Read(bufs, sizes, 0); err != nil {
+				return
+			}
+			if conn := current.Load(); conn != nil {
+				if icmp, _ := conn.WritePacket(bufs[0][:sizes[0]]); len(icmp) > 0 {
+					go dev.Write([][]byte{icmp}, 0)
+				}
+			}
+		}
+	}()
+
+	handler := func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != transmasque.DefaultPath {
+			w.WriteHeader(http.StatusNotFound)
+			return
+		}
+		if r.Header.Get("Authorization") != masqueAuthorization {
+			w.WriteHeader(http.StatusUnauthorized)
+			return
+		}
+		req, err := connectip.ParseProxyRequest(r)
+		if err != nil {
+			var perr *connectip.ProxyRequestParseError
+			if go_errors.As(err, &perr) {
+				w.WriteHeader(perr.HTTPStatus)
+			}
+			return
+		}
+		conn, err := (&connectip.Proxy{}).Proxy(w, req)
+		if err != nil {
+			return
+		}
+		defer conn.Close()
+		common.Must(conn.AssignAddresses([]netip.Prefix{masqueClientV4, masqueClientV6}))
+		common.Must(conn.AdvertiseRoute([]connectip.IPRoute{
+			{StartIP: netip.IPv4Unspecified(), EndIP: netip.AddrFrom4([4]byte{255, 255, 255, 255})},
+			{StartIP: netip.IPv6Unspecified(), EndIP: netip.AddrFrom16([16]byte{0: 0xff, 1: 0xff, 2: 0xff, 3: 0xff, 4: 0xff, 5: 0xff, 6: 0xff, 7: 0xff, 8: 0xff, 9: 0xff, 10: 0xff, 11: 0xff, 12: 0xff, 13: 0xff, 14: 0xff, 15: 0xff})},
+		}))
+		go func() {
+			for {
+				ar, err := conn.ReceiveAddressRequest(context.Background())
+				if err != nil {
+					return
+				}
+				assigned := make([]netip.Prefix, len(ar.Prefixes))
+				for i, p := range ar.Prefixes {
+					if p.Addr().Is4() {
+						assigned[i] = masqueClientV4
+					} else {
+						assigned[i] = masqueClientV6
+					}
+				}
+				ar.Respond(assigned, nil)
+			}
+		}()
+		current.Store(conn)
+		b := make([]byte, 2048)
+		for {
+			n, err := conn.ReadPacket(b)
+			if err != nil {
+				if go_errors.Is(err, io.ErrShortBuffer) {
+					continue
+				}
+				return
+			}
+			dev.Write([][]byte{b[:n]}, 0)
+		}
+	}
+
+	certificate, certHash := cert.MustGenerate(nil, cert.CommonName("localhost"))
+	key := common.Must2(x509.ParsePKCS8PrivateKey(certificate.PrivateKey))
+	tlsConfig := &gotls.Config{
+		Certificates: []gotls.Certificate{{Certificate: [][]byte{certificate.Certificate}, PrivateKey: key}},
+		NextProtos:   []string{http3.NextProtoH3},
+	}
+	pktConn := common.Must2(net.ListenUDP("udp", &net.UDPAddr{IP: net.LocalHostIP.IP()}))
+	tr := &quic.Transport{Conn: pktConn}
+	ln := common.Must2(tr.ListenEarly(tlsConfig, &quic.Config{EnableDatagrams: true, InitialPacketSize: 1350}))
+	server := &http3.Server{Handler: http.HandlerFunc(handler), EnableDatagrams: true}
+	go server.ServeListener(ln)
+	t.Cleanup(func() {
+		server.Close()
+		ln.Close()
+		tr.Close()
+		pktConn.Close()
+	})
+
+	return net.Port(pktConn.LocalAddr().(*net.UDPAddr).Port), certHash
+}
+
+func TestMasque(t *testing.T) {
+	serverPort, certHash := startMasqueServer(t)
+
+	tcpPort := tcp.PickPort()
+	tcp6Port := tcp.PickPort()
+	udpPort := udp.PickPort()
+	dokodemoTo := func(port net.Port, addr netip.Addr, network net.Network) *core.InboundHandlerConfig {
+		return &core.InboundHandlerConfig{
+			ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
+				PortList: &net.PortList{Range: []*net.PortRange{net.SinglePortRange(port)}},
+				Listen:   net.NewIPOrDomain(net.LocalHostIP),
+			}),
+			ProxySettings: serial.ToTypedMessage(&dokodemo.Config{
+				RewriteAddress:  net.NewIPOrDomain(net.IPAddress(addr.AsSlice())),
+				RewritePort:     masqueEchoPort,
+				AllowedNetworks: []net.Network{network},
+			}),
+		}
+	}
+	clientConfig := &core.Config{
+		App: []*serial.TypedMessage{
+			serial.ToTypedMessage(&log.Config{
+				ErrorLogLevel: clog.Severity_Debug,
+				ErrorLogType:  log.LogType_Console,
+			}),
+		},
+		Inbound: []*core.InboundHandlerConfig{
+			dokodemoTo(tcpPort, masqueServerV4, net.Network_TCP),
+			dokodemoTo(tcp6Port, masqueServerV6, net.Network_TCP),
+			dokodemoTo(udpPort, masqueServerV4, net.Network_UDP),
+		},
+		Outbound: []*core.OutboundHandlerConfig{
+			{
+				ProxySettings: serial.ToTypedMessage(&masque.ClientConfig{
+					Server: &protocol.ServerEndpoint{
+						Address: net.NewIPOrDomain(net.LocalHostIP),
+						Port:    uint32(serverPort),
+					},
+				}),
+				SenderSettings: serial.ToTypedMessage(&proxyman.SenderConfig{
+					StreamSettings: &internet.StreamConfig{
+						ProtocolName: "masque",
+						TransportSettings: []*internet.TransportConfig{
+							{
+								ProtocolName: "masque",
+								Settings: serial.ToTypedMessage(&transmasque.Config{
+									Path:    transmasque.DefaultPath,
+									Headers: map[string]string{"Authorization": masqueAuthorization},
+								}),
+							},
+						},
+						SecurityType: serial.GetMessageType(&tls.Config{}),
+						SecuritySettings: []*serial.TypedMessage{
+							serial.ToTypedMessage(&tls.Config{
+								ServerName:           "localhost",
+								PinnedPeerCertSha256: [][]byte{certHash[:]},
+							}),
+						},
+					},
+				}),
+			},
+		},
+	}
+
+	servers, err := InitializeServerConfigs(clientConfig)
+	common.Must(err)
+	defer CloseAllServers(servers)
+
+	var errg errgroup.Group
+	for range 3 {
+		errg.Go(testTCPConn(tcpPort, 1024*1024, time.Second*20))
+	}
+	errg.Go(testTCPConn(tcp6Port, 1024*1024, time.Second*20))
+	errg.Go(testUDPConn(udpPort, 1024, time.Second*5))
+	if err := errg.Wait(); err != nil {
+		t.Error(err)
+	}
+}

testing/scenarios/wireguard_test.go

@@ -65,6 +65,7 @@ func TestWireguard(t *testing.T) {
 				ProxySettings: serial.ToTypedMessage(&freedom.Config{
 					FinalRules: []*freedom.FinalRuleConfig{{Action: freedom.RuleAction_Allow}},
 				}),
+				SenderSettings: serial.ToTypedMessage(&proxyman.SenderConfig{}),
 			},
 		},
 	}
@@ -104,6 +105,7 @@ func TestWireguard(t *testing.T) {
 						AllowedIps: []string{"0.0.0.0/0", "::0/0"},
 					}},
 				}),
+				SenderSettings: serial.ToTypedMessage(&proxyman.SenderConfig{}),
 			},
 		},
 	}

transport/internet/finalmask/finalmask.go

@@ -2,103 +2,291 @@ package finalmask
 
 import (
 	"context"
-	"net"
+	"fmt"
 	"slices"
 
 	"github.com/xtls/xray-core/common/buf"
 	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/net"
 )
 
-type Udpmask interface {
-	WrapPacketConnClient(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error)
-	WrapPacketConnServer(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error)
+type Dialer struct {
+	DialTCP func(net.Destination) (net.Conn, error)
+	DialUDP func(net.Destination) (net.Conn, error)
 }
 
-type UdpmaskManager struct {
-	udpmasks []Udpmask
+type ListenConfig struct {
+	Listen       func(net.Addr) (net.Listener, error)
+	ListenPacket func(net.Addr) (net.PacketConn, error)
 }
 
-func NewUdpmaskManager(udpmasks []Udpmask) *UdpmaskManager {
-	slices.Reverse(udpmasks)
-	return &UdpmaskManager{udpmasks: udpmasks}
+type TCPMask interface {
+	WrapConnClient(net.Conn, *net.Destination, *Dialer) (net.Conn, error)
+	WrapConnServer(net.Conn) (net.Conn, error)
+	// Listen(net.Listener) (net.Listener, error)
 }
 
-func (m *UdpmaskManager) WrapPacketConnClient(raw net.PacketConn) (net.PacketConn, error) {
-	var sizes []int
-	var conns []net.PacketConn
-	for i, mask := range m.udpmasks {
-		if _, ok := mask.(headerConn); ok {
-			conn, err := mask.WrapPacketConnClient(nil, i, len(m.udpmasks)-1)
-			if err != nil {
-				return nil, err
-			}
-			sizes = append(sizes, conn.(headerSize).Size())
-			conns = append(conns, conn)
-		} else {
-			if len(conns) > 0 {
-				raw = &headerManagerConn{sizes: sizes, conns: conns, PacketConn: raw}
-				sizes = nil
-				conns = nil
-			}
-			var err error
-			raw, err = mask.WrapPacketConnClient(raw, i, len(m.udpmasks)-1)
-			if err != nil {
-				return nil, err
+type UDPMask interface {
+	WrapPacketConnClient(net.PacketConn, *net.Destination, *Dialer) (net.PacketConn, error)
+	WrapPacketConnServer(net.PacketConn, net.Addr, *ListenConfig) (net.PacketConn, error)
+}
+
+type FinalMask struct {
+	tcpMasks     []TCPMask
+	udpMasks     []UDPMask
+	dialTCP      func(context.Context, net.Destination) (net.Conn, error)
+	listen       func(context.Context, net.Addr) (net.Listener, error)
+	dialUDP      func(context.Context, net.Destination) (net.PacketConn, net.Addr, error)
+	listenPacket func(context.Context, net.Addr) (net.PacketConn, error)
+}
+
+func NewFinalMask(tcpMasks []TCPMask, udpMasks []UDPMask, dialTCP func(context.Context, net.Destination) (net.Conn, error), listen func(context.Context, net.Addr) (net.Listener, error), dialUDP func(context.Context, net.Destination) (net.PacketConn, net.Addr, error), listenPacket func(context.Context, net.Addr) (net.PacketConn, error)) *FinalMask {
+	slices.Reverse(tcpMasks)
+	slices.Reverse(udpMasks)
+	return &FinalMask{
+		tcpMasks:     tcpMasks,
+		udpMasks:     udpMasks,
+		dialTCP:      dialTCP,
+		dialUDP:      dialUDP,
+		listen:       listen,
+		listenPacket: listenPacket,
+	}
+}
+
+func (fm *FinalMask) DialTCP(ctx context.Context, dest net.Destination) (net.Conn, error) {
+	if len(fm.tcpMasks) == 0 {
+		return fm.dialTCP(ctx, dest)
+	}
+	for i := range fm.tcpMasks {
+		if i > 0 {
+			if _, ok := fm.tcpMasks[i].(interface{ HandleDial() }); ok {
+				return nil, fmt.Errorf("incorrect index: %d %T", i, fm.tcpMasks[i])
 			}
 		}
 	}
-
-	if len(conns) > 0 {
-		raw = &headerManagerConn{sizes: sizes, conns: conns, PacketConn: raw}
-		sizes = nil
-		conns = nil
+	var conn net.Conn
+	var err error
+	if _, ok := fm.tcpMasks[0].(interface{ HandleDial() }); !ok {
+		conn, err = fm.dialTCP(ctx, dest)
+		if err != nil {
+			return nil, err
+		}
 	}
-	return raw, nil
+	dialer := &Dialer{
+		DialTCP: func(dest net.Destination) (net.Conn, error) {
+			return fm.dialTCP(ctx, dest)
+		},
+		DialUDP: func(dest net.Destination) (net.Conn, error) {
+			conn, addr, err := fm.dialUDP(ctx, dest)
+			if err != nil {
+				return nil, err
+			}
+			return &PacketConnWrapper{PacketConn: conn, udpAddr: addr}, err
+		},
+	}
+	for i := range fm.tcpMasks {
+		var newConn net.Conn
+		newConn, err = fm.tcpMasks[i].WrapConnClient(conn, &dest, dialer)
+		if err != nil {
+			_ = conn.Close()
+			return nil, err
+		}
+		conn = newConn
+	}
+	return conn, nil
 }
 
-func (m *UdpmaskManager) WrapPacketConnServer(raw net.PacketConn) (net.PacketConn, error) {
-	var sizes []int
-	var conns []net.PacketConn
-	for i, mask := range m.udpmasks {
-		if _, ok := mask.(headerConn); ok {
-			conn, err := mask.WrapPacketConnServer(nil, i, len(m.udpmasks)-1)
-			if err != nil {
-				return nil, err
+func (fm *FinalMask) Listen(ctx context.Context, addr net.Addr) (net.Listener, error) {
+	if len(fm.tcpMasks) == 0 {
+		return fm.listen(ctx, addr)
+	}
+	off := 0
+	listener, err := fm.listen(ctx, addr)
+	if err != nil {
+		return nil, err
+	}
+	for i := range fm.tcpMasks {
+		if _, ok := fm.tcpMasks[i].(interface {
+			Listen(net.Listener) (net.Listener, error)
+		}); ok {
+			if i-off == 0 {
+				l, err := fm.tcpMasks[i].(interface {
+					Listen(net.Listener) (net.Listener, error)
+				}).Listen(listener)
+				if err != nil {
+					listener.Close()
+					return nil, err
+				}
+				listener = l
+			} else {
+				l, err := fm.tcpMasks[i].(interface {
+					Listen(net.Listener) (net.Listener, error)
+				}).Listen(&TCPListener{Listener: listener, tcpMasks: fm.tcpMasks[off:i]})
+				if err != nil {
+					listener.Close()
+					return nil, err
+				}
+				listener = l
 			}
-			sizes = append(sizes, conn.(headerSize).Size())
-			conns = append(conns, conn)
-		} else {
-			if len(conns) > 0 {
-				raw = &headerManagerConn{sizes: sizes, conns: conns, PacketConn: raw}
-				sizes = nil
-				conns = nil
-			}
-			var err error
-			raw, err = mask.WrapPacketConnServer(raw, i, len(m.udpmasks)-1)
-			if err != nil {
-				return nil, err
+			off = i + 1
+		}
+	}
+	if off < len(fm.tcpMasks) {
+		return &TCPListener{Listener: listener, tcpMasks: fm.tcpMasks[off:]}, nil
+	}
+	return listener, nil
+}
+
+func (fm *FinalMask) DialUDP(ctx context.Context, dest net.Destination) (net.Conn, error) {
+	if len(fm.udpMasks) == 0 {
+		conn, addr, err := fm.dialUDP(ctx, dest)
+		if err != nil {
+			return nil, err
+		}
+		return &PacketConnWrapper{PacketConn: conn, udpAddr: addr}, nil
+	}
+	for i := range fm.udpMasks {
+		if i > 0 {
+			if _, ok := fm.udpMasks[i].(interface{ HandleDial() }); ok {
+				return nil, fmt.Errorf("incorrect index: %d %T", i, fm.udpMasks[i])
 			}
 		}
 	}
-
+	var conn net.PacketConn
+	var addr net.Addr
+	var err error
+	if _, ok := fm.udpMasks[0].(interface{ HandleDial() }); !ok {
+		conn, addr, err = fm.dialUDP(ctx, dest)
+		if err != nil {
+			return nil, err
+		}
+	}
+	dialer := &Dialer{
+		DialTCP: func(dest net.Destination) (net.Conn, error) {
+			return fm.dialTCP(ctx, dest)
+		},
+		DialUDP: func(dest net.Destination) (net.Conn, error) {
+			conn, addr, err := fm.dialUDP(ctx, dest)
+			if err != nil {
+				return nil, err
+			}
+			return &PacketConnWrapper{PacketConn: conn, udpAddr: addr}, err
+		},
+	}
+	var sizes []int
+	var conns []net.PacketConn
+	for i := range fm.udpMasks {
+		var newConn net.PacketConn
+		if _, ok := fm.udpMasks[i].(interface{ HeaderConn() }); ok {
+			newConn, err = fm.udpMasks[i].WrapPacketConnClient(nil, nil, nil)
+			if err != nil {
+				_ = conn.Close()
+				return nil, err
+			}
+			sizes = append(sizes, newConn.(interface{ Size() int }).Size())
+			conns = append(conns, newConn)
+		} else {
+			if len(conns) > 0 {
+				conn = &headerManagerConn{PacketConn: conn, sizes: sizes, conns: conns}
+				sizes = nil
+				conns = nil
+			}
+			newConn, err = fm.udpMasks[i].WrapPacketConnClient(conn, &dest, dialer)
+			if err != nil {
+				_ = conn.Close()
+				return nil, err
+			}
+			conn = newConn
+		}
+	}
 	if len(conns) > 0 {
-		raw = &headerManagerConn{sizes: sizes, conns: conns, PacketConn: raw}
+		conn = &headerManagerConn{PacketConn: conn, sizes: sizes, conns: conns}
 		sizes = nil
 		conns = nil
 	}
-	return raw, nil
+	if addr == nil {
+		addr = &net.UDPAddr{IP: []byte{0, 0, 0, 0}}
+	}
+	return &PacketConnWrapper{PacketConn: conn, udpAddr: addr}, nil
+}
+
+func (fm *FinalMask) ListenPacket(ctx context.Context, addr net.Addr) (net.PacketConn, error) {
+	if len(fm.udpMasks) == 0 {
+		return fm.listenPacket(ctx, addr)
+	}
+	for i := range fm.udpMasks {
+		if i > 0 {
+			if _, ok := fm.udpMasks[i].(interface{ HandleListen() }); ok {
+				return nil, fmt.Errorf("incorrect index: %d %T", i, fm.udpMasks[i])
+			}
+		}
+	}
+	var conn net.PacketConn
+	var err error
+	if _, ok := fm.udpMasks[0].(interface{ HandleListen() }); !ok {
+		conn, err = fm.listenPacket(ctx, addr)
+		if err != nil {
+			return nil, err
+		}
+	}
+	lc := &ListenConfig{
+		Listen:       func(addr net.Addr) (net.Listener, error) { return fm.listen(ctx, addr) },
+		ListenPacket: func(addr net.Addr) (net.PacketConn, error) { return fm.listenPacket(ctx, addr) },
+	}
+	var sizes []int
+	var conns []net.PacketConn
+	for i := range fm.udpMasks {
+		var newConn net.PacketConn
+		if _, ok := fm.udpMasks[i].(interface{ HeaderConn() }); ok {
+			newConn, err = fm.udpMasks[i].WrapPacketConnServer(nil, nil, nil)
+			if err != nil {
+				_ = conn.Close()
+				return nil, err
+			}
+			sizes = append(sizes, newConn.(interface{ Size() int }).Size())
+			conns = append(conns, newConn)
+		} else {
+			if len(conns) > 0 {
+				conn = &headerManagerConn{PacketConn: conn, sizes: sizes, conns: conns}
+				sizes = nil
+				conns = nil
+			}
+			newConn, err = fm.udpMasks[i].WrapPacketConnServer(conn, addr, lc)
+			if err != nil {
+				_ = conn.Close()
+				return nil, err
+			}
+			conn = newConn
+		}
+	}
+	if len(conns) > 0 {
+		conn = &headerManagerConn{PacketConn: conn, sizes: sizes, conns: conns}
+		sizes = nil
+		conns = nil
+	}
+	return conn, nil
 }
 
 const (
 	UDPSize = 4096
 )
 
-type headerConn interface {
-	HeaderConn()
+type PacketConnWrapper struct {
+	net.PacketConn
+	udpAddr net.Addr
 }
 
-type headerSize interface {
-	Size() int
+func (c *PacketConnWrapper) RemoteAddr() net.Addr {
+	return c.udpAddr
+}
+
+func (c *PacketConnWrapper) Read(b []byte) (n int, err error) {
+	n, _, err = c.PacketConn.ReadFrom(b)
+	return
+}
+
+func (c *PacketConnWrapper) Write(b []byte) (n int, err error) {
+	return c.PacketConn.WriteTo(b, c.udpAddr)
 }
 
 type headerManagerConn struct {
@@ -191,72 +379,27 @@ func (c *headerManagerConn) WriteTo(p []byte, addr net.Addr) (n int, err error)
 	return len(p), nil
 }
 
-type Tcpmask interface {
-	WrapConnClient(net.Conn) (net.Conn, error)
-	WrapConnServer(net.Conn) (net.Conn, error)
-}
-
-type TcpmaskManager struct {
-	tcpmasks []Tcpmask
-}
-
-func NewTcpmaskManager(tcpmasks []Tcpmask) *TcpmaskManager {
-	slices.Reverse(tcpmasks)
-	return &TcpmaskManager{tcpmasks: tcpmasks}
-}
-
-func (m *TcpmaskManager) WrapConnClient(raw net.Conn) (net.Conn, error) {
-	var err error
-	for _, mask := range m.tcpmasks {
-		raw, err = mask.WrapConnClient(raw)
-		if err != nil {
-			return nil, err
-		}
-	}
-	return raw, nil
-}
-
-func (m *TcpmaskManager) WrapConnServer(raw net.Conn) (net.Conn, error) {
-	var err error
-	for _, mask := range m.tcpmasks {
-		raw, err = mask.WrapConnServer(raw)
-		if err != nil {
-			return nil, err
-		}
-	}
-	return raw, nil
-}
-
-func (m *TcpmaskManager) WrapListener(l net.Listener) (net.Listener, error) {
-	return NewTcpListener(m, l)
-}
-
-type tcpListener struct {
-	m *TcpmaskManager
+type TCPListener struct {
 	net.Listener
+	tcpMasks []TCPMask
 }
 
-func NewTcpListener(m *TcpmaskManager, l net.Listener) (net.Listener, error) {
-	return &tcpListener{
-		m:        m,
-		Listener: l,
-	}, nil
-}
-
-func (l *tcpListener) Accept() (net.Conn, error) {
+func (l *TCPListener) Accept() (net.Conn, error) {
 	conn, err := l.Listener.Accept()
 	if err != nil {
 		return conn, err
 	}
 
-	newConn, err := l.m.WrapConnServer(conn)
-	if err != nil {
-		errors.LogDebugInner(context.Background(), err, "mask err")
-		_ = conn.Close()
-		return nil, err
+	for i := range l.tcpMasks {
+		var newConn net.Conn
+		newConn, err = l.tcpMasks[i].WrapConnServer(conn)
+		if err != nil {
+			_ = conn.Close()
+			return nil, err
+		}
+		conn = newConn
 	}
-
-	return newConn, nil
+	return conn, nil
 }
 
 type TcpMaskConn interface {

transport/internet/finalmask/fragment/config.go

@@ -1,11 +1,14 @@
 package fragment
 
-import "net"
+import (
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
+)
 
-func (c *Config) WrapConnClient(raw net.Conn) (net.Conn, error) {
-	return NewConnClient(c, raw, false)
+func (c *Config) WrapConnClient(conn net.Conn, dest *net.Destination, dialer *finalmask.Dialer) (net.Conn, error) {
+	return NewConnClient(c, conn, false)
 }
 
-func (c *Config) WrapConnServer(raw net.Conn) (net.Conn, error) {
-	return NewConnServer(c, raw, true)
+func (c *Config) WrapConnServer(conn net.Conn) (net.Conn, error) {
+	return NewConnServer(c, conn, true)
 }

transport/internet/finalmask/header/custom/config.go

@@ -1,29 +1,30 @@
 package custom
 
 import (
-	"net"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
 )
 
-func (c *TCPConfig) WrapConnClient(raw net.Conn) (net.Conn, error) {
-	return NewConnClientTCP(c, raw)
+func (c *TCPConfig) WrapConnClient(conn net.Conn, dest *net.Destination, dialer *finalmask.Dialer) (net.Conn, error) {
+	return NewConnClientTCP(c, conn)
 }
 
-func (c *TCPConfig) WrapConnServer(raw net.Conn) (net.Conn, error) {
-	return NewConnServerTCP(c, raw)
+func (c *TCPConfig) WrapConnServer(conn net.Conn) (net.Conn, error) {
+	return NewConnServerTCP(c, conn)
 }
 
-func (c *UDPConfig) WrapPacketConnClient(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	return NewConnClientUDP(c, raw)
+func (c *UDPConfig) WrapPacketConnClient(conn net.PacketConn, dest *net.Destination, dialer *finalmask.Dialer) (net.PacketConn, error) {
+	return NewConnClientUDP(c, conn)
 }
 
-func (c *UDPConfig) WrapPacketConnServer(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	return NewConnServerUDP(c, raw)
+func (c *UDPConfig) WrapPacketConnServer(conn net.PacketConn, addr net.Addr, lc *finalmask.ListenConfig) (net.PacketConn, error) {
+	return NewConnServerUDP(c, conn)
 }
 
-func (c *UDPStandaloneConfig) WrapPacketConnClient(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	return NewConnClientUDPStandalone(c, raw)
+func (c *UDPStandaloneConfig) WrapPacketConnClient(conn net.PacketConn, dest *net.Destination, dialer *finalmask.Dialer) (net.PacketConn, error) {
+	return NewConnClientUDPStandalone(c, conn)
 }
 
-func (c *UDPStandaloneConfig) WrapPacketConnServer(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	return NewConnServerUDPStandalone(c, raw)
+func (c *UDPStandaloneConfig) WrapPacketConnServer(conn net.PacketConn, addr net.Addr, lc *finalmask.ListenConfig) (net.PacketConn, error) {
+	return NewConnServerUDPStandalone(c, conn)
 }

transport/internet/finalmask/header/custom/metadata_test.go

@@ -9,8 +9,6 @@ import (
 	"strings"
 	"testing"
 	"time"
-
-	"github.com/xtls/xray-core/transport/internet/finalmask"
 )
 
 func TestMetadataEvaluatorRejectsUnknownName(t *testing.T) {
@@ -156,7 +154,7 @@ func TestMetadataUDPStandaloneWriteUsesRemotePort(t *testing.T) {
 	}
 	defer serverRaw.Close()
 
-	client, err := finalmask.NewUdpmaskManager([]finalmask.Udpmask{cfg}).WrapPacketConnClient(clientRaw)
+	client, err := cfg.WrapPacketConnClient(clientRaw, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -301,7 +299,7 @@ func TestMetadataTCPHandshakeUsesEndpointPorts(t *testing.T) {
 	}
 	defer serverRaw.Close()
 
-	client, err := clientCfg.WrapConnClient(clientRaw)
+	client, err := clientCfg.WrapConnClient(clientRaw, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}

transport/internet/finalmask/header/custom/state_test.go

@@ -5,8 +5,6 @@ import (
 	"net"
 	"testing"
 	"time"
-
-	"github.com/xtls/xray-core/transport/internet/finalmask"
 )
 
 func mustSendRecvUDP(t *testing.T, from net.PacketConn, to net.PacketConn, msg []byte) {
@@ -48,7 +46,6 @@ func TestStateUDPResponseReusesPriorCapturedValues(t *testing.T) {
 			},
 		},
 	}
-	maskManager := finalmask.NewUdpmaskManager([]finalmask.Udpmask{cfg})
 
 	clientRaw, err := net.ListenPacket("udp", "127.0.0.1:0")
 	if err != nil {
@@ -62,11 +59,11 @@ func TestStateUDPResponseReusesPriorCapturedValues(t *testing.T) {
 	}
 	defer serverRaw.Close()
 
-	client, err := maskManager.WrapPacketConnClient(clientRaw)
+	client, err := cfg.WrapPacketConnClient(clientRaw, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
-	server, err := maskManager.WrapPacketConnServer(serverRaw)
+	server, err := cfg.WrapPacketConnServer(serverRaw, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}

transport/internet/finalmask/header/custom/tcp_runtime_test.go

@@ -37,7 +37,7 @@ func TestDSLTCPHandshakeReusesCapturedValue(t *testing.T) {
 	defer clientRaw.Close()
 	defer serverRaw.Close()
 
-	client, err := cfg.WrapConnClient(clientRaw)
+	client, err := cfg.WrapConnClient(clientRaw, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -117,7 +117,7 @@ func TestDSLTCPClientRejectsMismatchedResponseSequence(t *testing.T) {
 	defer clientRaw.Close()
 	defer serverRaw.Close()
 
-	client, err := clientCfg.WrapConnClient(clientRaw)
+	client, err := clientCfg.WrapConnClient(clientRaw, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}

transport/internet/finalmask/mkcp/aes128gcm/config.go

@@ -1,15 +1,16 @@
 package aes128gcm
 
 import (
-	"net"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
 )
 
 func (c *Config) HeaderConn() {}
 
-func (c *Config) WrapPacketConnClient(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	return NewConnClient(c, raw)
+func (c *Config) WrapPacketConnClient(conn net.PacketConn, dest *net.Destination, dialer *finalmask.Dialer) (net.PacketConn, error) {
+	return NewConnClient(c, conn)
 }
 
-func (c *Config) WrapPacketConnServer(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	return NewConnServer(c, raw)
+func (c *Config) WrapPacketConnServer(conn net.PacketConn, addr net.Addr, lc *finalmask.ListenConfig) (net.PacketConn, error) {
+	return NewConnServer(c, conn)
 }

transport/internet/finalmask/mkcp/header/config.go

@@ -1,15 +1,16 @@
 package header
 
 import (
-	"net"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
 )
 
 func (c *Config) HeaderConn() {}
 
-func (c *Config) WrapPacketConnClient(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	return NewConnClient(c, raw)
+func (c *Config) WrapPacketConnClient(conn net.PacketConn, dest *net.Destination, dialer *finalmask.Dialer) (net.PacketConn, error) {
+	return NewConnClient(c, conn)
 }
 
-func (c *Config) WrapPacketConnServer(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	return NewConnServer(c, raw)
+func (c *Config) WrapPacketConnServer(conn net.PacketConn, addr net.Addr, lc *finalmask.ListenConfig) (net.PacketConn, error) {
+	return NewConnServer(c, conn)
 }

transport/internet/finalmask/mkcp/original/config.go

@@ -1,15 +1,16 @@
 package original
 
 import (
-	"net"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
 )
 
 func (c *Config) HeaderConn() {}
 
-func (c *Config) WrapPacketConnClient(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	return NewConnClient(c, raw)
+func (c *Config) WrapPacketConnClient(conn net.PacketConn, dest *net.Destination, dialer *finalmask.Dialer) (net.PacketConn, error) {
+	return NewConnClient(c, conn)
 }
 
-func (c *Config) WrapPacketConnServer(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	return NewConnServer(c, raw)
+func (c *Config) WrapPacketConnServer(conn net.PacketConn, addr net.Addr, lc *finalmask.ListenConfig) (net.PacketConn, error) {
+	return NewConnServer(c, conn)
 }

transport/internet/finalmask/noise/config.go

@@ -1,11 +1,14 @@
 package noise
 
-import "net"
+import (
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
+)
 
-func (c *Config) WrapPacketConnClient(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	return NewConnClient(c, raw)
+func (c *Config) WrapPacketConnClient(conn net.PacketConn, dest *net.Destination, dialer *finalmask.Dialer) (net.PacketConn, error) {
+	return NewConnClient(c, conn)
 }
 
-func (c *Config) WrapPacketConnServer(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	return NewConnServer(c, raw)
+func (c *Config) WrapPacketConnServer(conn net.PacketConn, addr net.Addr, lc *finalmask.ListenConfig) (net.PacketConn, error) {
+	return NewConnServer(c, conn)
 }

transport/internet/finalmask/realm/config.go

@@ -1,23 +1,14 @@
 package realm
 
 import (
-	"net"
-
-	"github.com/xtls/xray-core/common/errors"
-	"github.com/xtls/xray-core/transport/internet"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
 )
 
-func (c *Config) WrapPacketConnClient(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	_, ok1 := raw.(*internet.FakePacketConn)
-	if level != 0 || ok1 {
-		return nil, errors.New("realm requires being at the outermost level")
-	}
-	return NewConnClient(c, raw)
+func (c *Config) WrapPacketConnClient(conn net.PacketConn, dest *net.Destination, dialer *finalmask.Dialer) (net.PacketConn, error) {
+	return NewConnClient(c, conn)
 }
 
-func (c *Config) WrapPacketConnServer(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	if level != 0 {
-		return nil, errors.New("realm requires being at the outermost level")
-	}
-	return NewConnServer(c, raw)
+func (c *Config) WrapPacketConnServer(conn net.PacketConn, addr net.Addr, lc *finalmask.ListenConfig) (net.PacketConn, error) {
+	return NewConnServer(c, conn)
 }

transport/internet/finalmask/salamander/config.go

@@ -1,23 +1,24 @@
 package salamander
 
 import (
-	"net"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
 )
 
 func (c *Config) HeaderConn() {}
 
-func (c *Config) WrapPacketConnClient(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	return NewSalamanderConnClient(c, raw)
+func (c *Config) WrapPacketConnClient(conn net.PacketConn, dest *net.Destination, dialer *finalmask.Dialer) (net.PacketConn, error) {
+	return NewSalamanderConnClient(c, conn)
 }
 
-func (c *Config) WrapPacketConnServer(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	return NewSalamanderConnServer(c, raw)
+func (c *Config) WrapPacketConnServer(conn net.PacketConn, addr net.Addr, lc *finalmask.ListenConfig) (net.PacketConn, error) {
+	return NewSalamanderConnServer(c, conn)
 }
 
-func (c *GeckoConfig) WrapPacketConnClient(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	return NewGeckoConnClient(c, raw)
+func (c *GeckoConfig) WrapPacketConnClient(conn net.PacketConn, dest *net.Destination, dialer *finalmask.Dialer) (net.PacketConn, error) {
+	return NewGeckoConnClient(c, conn)
 }
 
-func (c *GeckoConfig) WrapPacketConnServer(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	return NewGeckoConnServer(c, raw)
+func (c *GeckoConfig) WrapPacketConnServer(conn net.PacketConn, addr net.Addr, lc *finalmask.ListenConfig) (net.PacketConn, error) {
+	return NewGeckoConnServer(c, conn)
 }

transport/internet/finalmask/sudoku/config.go

@@ -1,19 +1,18 @@
 package sudoku
 
 import (
-	"net"
-
-	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
 )
 
 // Sudoku in finalmask mode is a pure appearance transform with no standalone handshake.
 // TCP always keeps classic sudoku on uplink and uses packed downlink optimization on server writes.
-func (c *Config) WrapConnClient(raw net.Conn) (net.Conn, error) {
-	return newPackedDirectionalConn(raw, c, true)
+func (c *Config) WrapConnClient(conn net.Conn, dest *net.Destination, dialer *finalmask.Dialer) (net.Conn, error) {
+	return newPackedDirectionalConn(conn, c, true)
 }
 
-func (c *Config) WrapConnServer(raw net.Conn) (net.Conn, error) {
-	return newPackedDirectionalConn(raw, c, false)
+func (c *Config) WrapConnServer(conn net.Conn) (net.Conn, error) {
+	return newPackedDirectionalConn(conn, c, false)
 }
 
 func newPackedDirectionalConn(raw net.Conn, config *Config, readPacked bool) (net.Conn, error) {
@@ -36,16 +35,10 @@ func newPackedDirectionalConn(raw net.Conn, config *Config, readPacked bool) (ne
 	return newWrappedConn(raw, reader, writer), nil
 }
 
-func (c *Config) WrapPacketConnClient(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	if level != levelCount {
-		return nil, errors.New("sudoku udp mask must be the innermost mask in chain")
-	}
-	return NewUDPConn(raw, c)
+func (c *Config) WrapPacketConnClient(conn net.PacketConn, dest *net.Destination, dialer *finalmask.Dialer) (net.PacketConn, error) {
+	return NewUDPConn(conn, c)
 }
 
-func (c *Config) WrapPacketConnServer(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	if level != levelCount {
-		return nil, errors.New("sudoku udp mask must be the innermost mask in chain")
-	}
-	return NewUDPConn(raw, c)
+func (c *Config) WrapPacketConnServer(conn net.PacketConn, addr net.Addr, lc *finalmask.ListenConfig) (net.PacketConn, error) {
+	return NewUDPConn(conn, c)
 }

transport/internet/finalmask/tcp_test.go

@@ -2,12 +2,14 @@ package finalmask_test
 
 import (
 	"bytes"
+	"context"
 	"io"
-	"net"
+	gonet "net"
 	"strings"
 	"testing"
 	"time"
 
+	"github.com/xtls/xray-core/common/net"
 	"github.com/xtls/xray-core/transport/internet/finalmask"
 	"github.com/xtls/xray-core/transport/internet/finalmask/header/custom"
 )
@@ -20,11 +22,14 @@ func mustSendRecvTcp(
 ) {
 	t.Helper()
 
+	waitCh := make(chan error)
+
 	go func() {
 		_, err := from.Write(msg)
 		if err != nil {
-			t.Error(err)
+			t.Fatal(err)
 		}
+		close(waitCh)
 	}()
 
 	buf := make([]byte, 1024)
@@ -40,18 +45,23 @@ func mustSendRecvTcp(
 	if !bytes.Equal(buf[:n], msg) {
 		t.Fatalf("unexpected data %q", buf[:n])
 	}
+
+	<-waitCh
 }
 
 type layerMaskTcp struct {
 	name string
-	mask finalmask.Tcpmask
+	mask finalmask.TCPMask
 }
 
 type failingWrapMask struct{}
 
-func (failingWrapMask) TCP()                                            {}
-func (f failingWrapMask) WrapConnClient(raw net.Conn) (net.Conn, error) { return raw, nil }
-func (f failingWrapMask) WrapConnServer(raw net.Conn) (net.Conn, error) {
+func (failingWrapMask) TCP() {}
+func (f failingWrapMask) WrapConnClient(conn net.Conn, dest *net.Destination, dialer *finalmask.Dialer) (net.Conn, error) {
+	return conn, nil
+}
+
+func (f failingWrapMask) WrapConnServer(conn net.Conn) (net.Conn, error) {
 	return nil, io.ErrClosedPipe
 }
 
@@ -92,32 +102,31 @@ func TestConnReadWrite(t *testing.T) {
 		t.Run(c.name, func(t *testing.T) {
 			mask := c.mask
 
-			maskManager := finalmask.NewTcpmaskManager([]finalmask.Tcpmask{mask})
+			dialTCP := func(ctx context.Context, dest net.Destination) (net.Conn, error) {
+				return net.Dial("tcp", dest.NetAddr())
+			}
+			listen := func(ctx context.Context, addr net.Addr) (net.Listener, error) {
+				return net.Listen("tcp", addr.String())
+			}
+			finalMask := finalmask.NewFinalMask([]finalmask.TCPMask{mask}, nil, dialTCP, listen, nil, nil)
 
-			ln, err := net.Listen("tcp", "127.0.0.1:0")
+			listener, err := finalMask.Listen(context.Background(), &net.TCPAddr{IP: net.LocalHostIP.IP()})
 			if err != nil {
 				t.Fatal(err)
 			}
+			t.Cleanup(func() { listener.Close() })
 
-			client, err := net.Dial("tcp", ln.Addr().String())
+			client, err := finalMask.DialTCP(context.Background(), net.TCPDestination(net.IPAddress(listener.Addr().(*net.TCPAddr).IP), net.Port(listener.Addr().(*net.TCPAddr).Port)))
 			if err != nil {
 				t.Fatal(err)
 			}
+			t.Cleanup(func() { client.Close() })
 
-			client, err = maskManager.WrapConnClient(client)
-			if err != nil {
-				t.Fatal(err)
-			}
-
-			server, err := ln.Accept()
-			if err != nil {
-				t.Fatal(err)
-			}
-
-			server, err = maskManager.WrapConnServer(server)
+			server, err := listener.Accept()
 			if err != nil {
 				t.Fatal(err)
 			}
+			t.Cleanup(func() { server.Close() })
 
 			_ = client.SetDeadline(time.Now().Add(time.Second))
 			_ = server.SetDeadline(time.Now().Add(time.Second))
@@ -150,34 +159,32 @@ func TestTCPcustomStaticHandshakeRoundTrip(t *testing.T) {
 			},
 		},
 	}
-	maskManager := finalmask.NewTcpmaskManager([]finalmask.Tcpmask{cfg})
 
-	ln, err := net.Listen("tcp", "127.0.0.1:0")
-	if err != nil {
-		t.Fatal(err)
+	dialTCP := func(ctx context.Context, dest net.Destination) (net.Conn, error) {
+		return net.Dial("tcp", dest.NetAddr())
 	}
-	defer ln.Close()
+	listen := func(ctx context.Context, addr net.Addr) (net.Listener, error) {
+		return net.Listen("tcp", addr.String())
+	}
+	finalMask := finalmask.NewFinalMask([]finalmask.TCPMask{cfg}, nil, dialTCP, listen, nil, nil)
 
-	clientRaw, err := net.Dial("tcp", ln.Addr().String())
+	listener, err := finalMask.Listen(context.Background(), &net.TCPAddr{IP: net.LocalHostIP.IP()})
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer clientRaw.Close()
+	defer listener.Close()
 
-	serverRaw, err := ln.Accept()
+	client, err := finalMask.DialTCP(context.Background(), net.TCPDestination(net.IPAddress(listener.Addr().(*net.TCPAddr).IP), net.Port(listener.Addr().(*net.TCPAddr).Port)))
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer serverRaw.Close()
+	defer client.Close()
 
-	client, err := maskManager.WrapConnClient(clientRaw)
-	if err != nil {
-		t.Fatal(err)
-	}
-	server, err := maskManager.WrapConnServer(serverRaw)
+	server, err := listener.Accept()
 	if err != nil {
 		t.Fatal(err)
 	}
+	defer server.Close()
 
 	_ = client.SetDeadline(time.Now().Add(time.Second))
 	_ = server.SetDeadline(time.Now().Add(time.Second))
@@ -220,11 +227,11 @@ func TestTCPcustomClientRejectsMismatchedServerSequence(t *testing.T) {
 		},
 	}
 
-	clientRaw, serverRaw := net.Pipe()
+	clientRaw, serverRaw := gonet.Pipe()
 	defer clientRaw.Close()
 	defer serverRaw.Close()
 
-	client, err := clientCfg.WrapConnClient(clientRaw)
+	client, err := clientCfg.WrapConnClient(clientRaw, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -257,42 +264,37 @@ func TestTCPcustomClientRejectsMismatchedServerSequence(t *testing.T) {
 }
 
 func TestTCPWrapListenerRejectsImmediateWrapErrors(t *testing.T) {
-	clientManager := finalmask.NewTcpmaskManager([]finalmask.Tcpmask{failingWrapMask{}})
-	serverManager := finalmask.NewTcpmaskManager([]finalmask.Tcpmask{failingWrapMask{}})
+	dialTCP := func(ctx context.Context, dest net.Destination) (net.Conn, error) {
+		return net.Dial("tcp", dest.NetAddr())
+	}
+	listen := func(ctx context.Context, addr net.Addr) (net.Listener, error) {
+		return net.Listen("tcp", addr.String())
+	}
+	finalMask := finalmask.NewFinalMask([]finalmask.TCPMask{failingWrapMask{}}, nil, dialTCP, listen, nil, nil)
 
-	rawLn, err := net.Listen("tcp", "127.0.0.1:0")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer rawLn.Close()
-
-	ln, err := serverManager.WrapListener(rawLn)
+	listener, err := finalMask.Listen(context.Background(), &net.TCPAddr{IP: net.LocalHostIP.IP()})
 	if err != nil {
 		t.Fatal(err)
 	}
+	defer listener.Close()
 
 	accepted := make(chan struct {
 		conn net.Conn
 		err  error
 	}, 1)
 	go func() {
-		conn, err := ln.Accept()
+		conn, err := listener.Accept()
 		accepted <- struct {
 			conn net.Conn
 			err  error
 		}{conn: conn, err: err}
 	}()
 
-	clientRaw, err := net.Dial("tcp", rawLn.Addr().String())
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer clientRaw.Close()
-
-	client, err := clientManager.WrapConnClient(clientRaw)
+	client, err := finalMask.DialTCP(context.Background(), net.TCPDestination(net.IPAddress(listener.Addr().(*net.TCPAddr).IP), net.Port(listener.Addr().(*net.TCPAddr).Port)))
 	if err != nil {
 		t.Fatal(err)
 	}
+	defer client.Close()
 
 	_ = client.SetDeadline(time.Now().Add(time.Second))
 

transport/internet/finalmask/udp_test.go

@@ -2,13 +2,15 @@ package finalmask_test
 
 import (
 	"bytes"
+	"context"
 	"encoding/binary"
 	"io"
-	"net"
+	gonet "net"
 	"sync/atomic"
 	"testing"
 	"time"
 
+	"github.com/xtls/xray-core/common/net"
 	"github.com/xtls/xray-core/proxy"
 	"github.com/xtls/xray-core/transport/internet/finalmask"
 	"github.com/xtls/xray-core/transport/internet/finalmask/header/custom"
@@ -51,7 +53,7 @@ func mustSendRecv(
 
 type layerMask struct {
 	name   string
-	mask   finalmask.Udpmask
+	mask   finalmask.UDPMask
 	layers int
 }
 
@@ -213,25 +215,23 @@ func newStandaloneStunLikeUDPServerConfig() *custom.UDPStandaloneConfig {
 func newUDPClientServerPair(t *testing.T, cfg *custom.UDPStandaloneConfig) (net.PacketConn, net.PacketConn, net.PacketConn, net.PacketConn) {
 	t.Helper()
 
-	clientRaw, err := net.ListenPacket("udp", "127.0.0.1:0")
+	clientRaw, err := gonet.ListenPacket("udp", "127.0.0.1:0")
 	if err != nil {
 		t.Fatal(err)
 	}
 	t.Cleanup(func() { _ = clientRaw.Close() })
 
-	serverRaw, err := net.ListenPacket("udp", "127.0.0.1:0")
+	serverRaw, err := gonet.ListenPacket("udp", "127.0.0.1:0")
 	if err != nil {
 		t.Fatal(err)
 	}
 	t.Cleanup(func() { _ = serverRaw.Close() })
 
-	maskManager := finalmask.NewUdpmaskManager([]finalmask.Udpmask{cfg})
-
-	client, err := maskManager.WrapPacketConnClient(clientRaw)
+	client, err := cfg.WrapPacketConnClient(clientRaw, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
-	server, err := maskManager.WrapPacketConnServer(serverRaw)
+	server, err := cfg.WrapPacketConnServer(serverRaw, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -348,31 +348,39 @@ func TestPacketConnReadWrite(t *testing.T) {
 			if layers <= 0 {
 				layers = 1
 			}
-			masks := make([]finalmask.Udpmask, 0, layers)
+			masks := make([]finalmask.UDPMask, 0, layers)
 			for i := 0; i < layers; i++ {
 				masks = append(masks, mask)
 			}
-			maskManager := finalmask.NewUdpmaskManager(masks)
 
-			client, err := net.ListenPacket("udp", "127.0.0.1:0")
+			dialUDP := func(ctx context.Context, dest net.Destination) (net.PacketConn, net.Addr, error) {
+				udpAddr, err := net.ResolveUDPAddr("udp", dest.NetAddr())
+				if err != nil {
+					return nil, nil, err
+				}
+				conn, err := gonet.ListenPacket("udp", "127.0.0.1:0")
+				if err != nil {
+					return nil, nil, err
+				}
+				return conn, udpAddr, nil
+			}
+			listenPacket := func(ctx context.Context, addr net.Addr) (net.PacketConn, error) {
+				return gonet.ListenPacket(addr.Network(), addr.String())
+			}
+			finalMask := finalmask.NewFinalMask(nil, masks, nil, nil, dialUDP, listenPacket)
+
+			server, err := finalMask.ListenPacket(context.Background(), &net.UDPAddr{IP: net.LocalHostIP.IP()})
 			if err != nil {
 				t.Fatal(err)
 			}
+			t.Cleanup(func() { server.Close() })
 
-			client, err = maskManager.WrapPacketConnClient(client)
-			if err != nil {
-				t.Fatal(err)
-			}
-
-			server, err := net.ListenPacket("udp", "127.0.0.1:0")
-			if err != nil {
-				t.Fatal(err)
-			}
-
-			server, err = maskManager.WrapPacketConnServer(server)
+			clientConn, err := finalMask.DialUDP(context.Background(), net.UDPDestination(net.IPAddress(server.LocalAddr().(*net.UDPAddr).IP), net.Port(server.LocalAddr().(*net.UDPAddr).Port)))
 			if err != nil {
 				t.Fatal(err)
 			}
+			t.Cleanup(func() { clientConn.Close() })
+			client := clientConn.(*finalmask.PacketConnWrapper).PacketConn
 
 			_ = client.SetDeadline(time.Now().Add(time.Second))
 			_ = server.SetDeadline(time.Now().Add(time.Second))
@@ -397,21 +405,20 @@ func TestUDPcustomStaticHeaderWireShape(t *testing.T) {
 			{Rand: 1, RandMin: 0x30, RandMax: 0x40},
 		},
 	}
-	maskManager := finalmask.NewUdpmaskManager([]finalmask.Udpmask{cfg})
 
-	clientRaw, err := net.ListenPacket("udp", "127.0.0.1:0")
+	clientRaw, err := gonet.ListenPacket("udp", "127.0.0.1:0")
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer clientRaw.Close()
 
-	serverRaw, err := net.ListenPacket("udp", "127.0.0.1:0")
+	serverRaw, err := gonet.ListenPacket("udp", "127.0.0.1:0")
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer serverRaw.Close()
 
-	client, err := maskManager.WrapPacketConnClient(clientRaw)
+	client, err := cfg.WrapPacketConnClient(clientRaw, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -642,11 +649,11 @@ func TestSudokuBDD(t *testing.T) {
 			Ascii:    "prefer_ascii",
 		}
 
-		clientRaw, serverRaw := net.Pipe()
+		clientRaw, serverRaw := gonet.Pipe()
 		defer clientRaw.Close()
 		defer serverRaw.Close()
 
-		clientConn, err := cfg.WrapConnClient(clientRaw)
+		clientConn, err := cfg.WrapConnClient(clientRaw, nil, nil)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -683,11 +690,11 @@ func TestSudokuBDD(t *testing.T) {
 			PaddingMax: 0,
 		}
 
-		clientRaw, serverRaw := net.Pipe()
+		clientRaw, serverRaw := gonet.Pipe()
 		defer clientRaw.Close()
 		defer serverRaw.Close()
 
-		clientConn, err := cfg.WrapConnClient(clientRaw)
+		clientConn, err := cfg.WrapConnClient(clientRaw, nil, nil)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -738,10 +745,10 @@ func TestSudokuBDD(t *testing.T) {
 		countWireBytes := func(wrapServer func(net.Conn, *sudoku.Config) (net.Conn, error), cfg *sudoku.Config) int64 {
 			t.Helper()
 
-			clientRaw, serverRaw := net.Pipe()
+			clientRaw, serverRaw := gonet.Pipe()
 			watchedServerRaw := &countingConn{Conn: serverRaw}
 
-			clientConn, err := cfg.WrapConnClient(clientRaw)
+			clientConn, err := cfg.WrapConnClient(clientRaw, nil, nil)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -793,11 +800,11 @@ func TestSudokuBDD(t *testing.T) {
 			CustomTables: []string{"xpxvvpvv", "vxpvxvvp"},
 		}
 
-		clientRaw, serverRaw := net.Pipe()
+		clientRaw, serverRaw := gonet.Pipe()
 		defer clientRaw.Close()
 		defer serverRaw.Close()
 
-		clientConn, err := cfg.WrapConnClient(clientRaw)
+		clientConn, err := cfg.WrapConnClient(clientRaw, nil, nil)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -835,11 +842,11 @@ func TestSudokuBDD(t *testing.T) {
 			PaddingMax:   0,
 		}
 
-		clientRaw, serverRaw := net.Pipe()
+		clientRaw, serverRaw := gonet.Pipe()
 		defer clientRaw.Close()
 		defer serverRaw.Close()
 
-		clientConn, err := cfg.WrapConnClient(clientRaw)
+		clientConn, err := cfg.WrapConnClient(clientRaw, nil, nil)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -868,19 +875,6 @@ func TestSudokuBDD(t *testing.T) {
 		}
 	})
 
-	t.Run("GivenSudokuUDPMask_WhenNotInnermost_ThenWrapFails", func(t *testing.T) {
-		cfg := &sudoku.Config{Password: "sudoku-udp"}
-		raw, err := net.ListenPacket("udp", "127.0.0.1:0")
-		if err != nil {
-			t.Fatal(err)
-		}
-		defer raw.Close()
-
-		if _, err := cfg.WrapPacketConnClient(raw, 0, 1); err == nil {
-			t.Fatal("expected innermost check failure")
-		}
-	})
-
 	t.Run("GivenSudokuMultiTableUDPMask_WhenClientSendsMultipleDatagrams_ThenPayloadMatches", func(t *testing.T) {
 		cfg := &sudoku.Config{
 			Password:     "sudoku-udp-multi",
@@ -889,25 +883,24 @@ func TestSudokuBDD(t *testing.T) {
 			PaddingMin:   0,
 			PaddingMax:   0,
 		}
-		maskManager := finalmask.NewUdpmaskManager([]finalmask.Udpmask{cfg})
 
-		clientRaw, err := net.ListenPacket("udp", "127.0.0.1:0")
+		clientRaw, err := gonet.ListenPacket("udp", "127.0.0.1:0")
 		if err != nil {
 			t.Fatal(err)
 		}
 		defer clientRaw.Close()
 
-		serverRaw, err := net.ListenPacket("udp", "127.0.0.1:0")
+		serverRaw, err := gonet.ListenPacket("udp", "127.0.0.1:0")
 		if err != nil {
 			t.Fatal(err)
 		}
 		defer serverRaw.Close()
 
-		client, err := maskManager.WrapPacketConnClient(clientRaw)
+		client, err := cfg.WrapPacketConnClient(clientRaw, nil, nil)
 		if err != nil {
 			t.Fatal(err)
 		}
-		server, err := maskManager.WrapPacketConnServer(serverRaw)
+		server, err := cfg.WrapPacketConnServer(serverRaw, nil, nil)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -961,7 +954,7 @@ func TestSudokuBDD(t *testing.T) {
 		}
 		defer serverRaw.Close()
 
-		clientConn, err := cfg.WrapConnClient(clientRaw)
+		clientConn, err := cfg.WrapConnClient(clientRaw, nil, nil)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -1008,11 +1001,11 @@ func TestSudokuBDD(t *testing.T) {
 			Ascii:    "prefer_entropy",
 		}
 
-		clientRaw, serverRaw := net.Pipe()
+		clientRaw, serverRaw := gonet.Pipe()
 		defer clientRaw.Close()
 		defer serverRaw.Close()
 
-		clientConn, err := cfg.WrapConnClient(clientRaw)
+		clientConn, err := cfg.WrapConnClient(clientRaw, nil, nil)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -1032,11 +1025,11 @@ func TestSudokuBDD(t *testing.T) {
 			Ascii:    "prefer_entropy",
 		}
 
-		clientRaw, serverRaw := net.Pipe()
+		clientRaw, serverRaw := gonet.Pipe()
 		defer clientRaw.Close()
 		defer serverRaw.Close()
 
-		clientConn, err := cfg.WrapConnClient(clientRaw)
+		clientConn, err := cfg.WrapConnClient(clientRaw, nil, nil)
 		if err != nil {
 			t.Fatal(err)
 		}

transport/internet/finalmask/udphop/config.go

@@ -1,20 +1,17 @@
 package udphop
 
 import (
-	"net"
-
 	"github.com/xtls/xray-core/common/errors"
-	"github.com/xtls/xray-core/transport/internet"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
 )
 
-func (c *Config) WrapPacketConnClient(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	_, ok1 := raw.(*internet.FakePacketConn)
-	if level != 0 || ok1 {
-		return nil, errors.New("udphop requires being at the outermost level")
-	}
-	return NewUDPHopConn(c, raw)
+func (c *Config) HandleDial() {}
+
+func (c *Config) WrapPacketConnClient(conn net.PacketConn, dest *net.Destination, dialer *finalmask.Dialer) (net.PacketConn, error) {
+	return NewUDPHopConn(c, dest, dialer)
 }
 
-func (c *Config) WrapPacketConnServer(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
+func (c *Config) WrapPacketConnServer(conn net.PacketConn, addr net.Addr, lc *finalmask.ListenConfig) (net.PacketConn, error) {
 	return nil, errors.New("udphop: client only")
 }

transport/internet/finalmask/udphop/config.pb.go

@@ -7,7 +7,6 @@
 package udphop
 
 import (
-	internet "github.com/xtls/xray-core/transport/internet"
 	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
 	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
 	reflect "reflect"
@@ -24,14 +23,13 @@ const (
 
 type Config struct {
 	state         protoimpl.MessageState `protogen:"open.v1"`
-	Sockopt       *internet.SocketConfig `protobuf:"bytes,1,opt,name=sockopt,proto3" json:"sockopt,omitempty"`
 	Local         bool                   `protobuf:"varint,2,opt,name=local,proto3" json:"local,omitempty"`
 	Remote        bool                   `protobuf:"varint,3,opt,name=remote,proto3" json:"remote,omitempty"`
 	RemoteOnce    bool                   `protobuf:"varint,4,opt,name=remote_once,json=remoteOnce,proto3" json:"remote_once,omitempty"`
 	IntervalMin   int64                  `protobuf:"varint,5,opt,name=interval_min,json=intervalMin,proto3" json:"interval_min,omitempty"`
 	IntervalMax   int64                  `protobuf:"varint,6,opt,name=interval_max,json=intervalMax,proto3" json:"interval_max,omitempty"`
-	RemotePorts   []uint32               `protobuf:"varint,7,rep,packed,name=remote_ports,json=remotePorts,proto3" json:"remote_ports,omitempty"`
-	RemoteIPs     []string               `protobuf:"bytes,8,rep,name=remoteIPs,proto3" json:"remoteIPs,omitempty"`
+	RemoteIPs     []string               `protobuf:"bytes,7,rep,name=remoteIPs,proto3" json:"remoteIPs,omitempty"`
+	RemotePorts   []uint32               `protobuf:"varint,8,rep,packed,name=remote_ports,json=remotePorts,proto3" json:"remote_ports,omitempty"`
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
 }
@@ -66,13 +64,6 @@ func (*Config) Descriptor() ([]byte, []int) {
 	return file_transport_internet_finalmask_udphop_config_proto_rawDescGZIP(), []int{0}
 }
 
-func (x *Config) GetSockopt() *internet.SocketConfig {
-	if x != nil {
-		return x.Sockopt
-	}
-	return nil
-}
-
 func (x *Config) GetLocal() bool {
 	if x != nil {
 		return x.Local
@@ -108,16 +99,16 @@ func (x *Config) GetIntervalMax() int64 {
 	return 0
 }
 
-func (x *Config) GetRemotePorts() []uint32 {
+func (x *Config) GetRemoteIPs() []string {
 	if x != nil {
-		return x.RemotePorts
+		return x.RemoteIPs
 	}
 	return nil
 }
 
-func (x *Config) GetRemoteIPs() []string {
+func (x *Config) GetRemotePorts() []uint32 {
 	if x != nil {
-		return x.RemoteIPs
+		return x.RemotePorts
 	}
 	return nil
 }
@@ -126,17 +117,16 @@ var File_transport_internet_finalmask_udphop_config_proto protoreflect.FileDescr
 
 const file_transport_internet_finalmask_udphop_config_proto_rawDesc = "" +
 	"\n" +
-	"0transport/internet/finalmask/udphop/config.proto\x12(xray.transport.internet.finalmask.udphop\x1a\x1ftransport/internet/config.proto\"\x9f\x02\n" +
-	"\x06Config\x12?\n" +
-	"\asockopt\x18\x01 \x01(\v2%.xray.transport.internet.SocketConfigR\asockopt\x12\x14\n" +
+	"0transport/internet/finalmask/udphop/config.proto\x12(xray.transport.internet.finalmask.udphop\"\xe4\x01\n" +
+	"\x06Config\x12\x14\n" +
 	"\x05local\x18\x02 \x01(\bR\x05local\x12\x16\n" +
 	"\x06remote\x18\x03 \x01(\bR\x06remote\x12\x1f\n" +
 	"\vremote_once\x18\x04 \x01(\bR\n" +
 	"remoteOnce\x12!\n" +
 	"\finterval_min\x18\x05 \x01(\x03R\vintervalMin\x12!\n" +
-	"\finterval_max\x18\x06 \x01(\x03R\vintervalMax\x12!\n" +
-	"\fremote_ports\x18\a \x03(\rR\vremotePorts\x12\x1c\n" +
-	"\tremoteIPs\x18\b \x03(\tR\tremoteIPsB\x9a\x01\n" +
+	"\finterval_max\x18\x06 \x01(\x03R\vintervalMax\x12\x1c\n" +
+	"\tremoteIPs\x18\a \x03(\tR\tremoteIPs\x12!\n" +
+	"\fremote_ports\x18\b \x03(\rR\vremotePortsJ\x04\b\x01\x10\x02B\x9a\x01\n" +
 	",com.xray.transport.internet.finalmask.udphopP\x01Z=github.com/xtls/xray-core/transport/internet/finalmask/udphop\xaa\x02(Xray.Transport.Internet.Finalmask.Udphopb\x06proto3"
 
 var (
@@ -153,16 +143,14 @@ func file_transport_internet_finalmask_udphop_config_proto_rawDescGZIP() []byte
 
 var file_transport_internet_finalmask_udphop_config_proto_msgTypes = make([]protoimpl.MessageInfo, 1)
 var file_transport_internet_finalmask_udphop_config_proto_goTypes = []any{
-	(*Config)(nil),                // 0: xray.transport.internet.finalmask.udphop.Config
-	(*internet.SocketConfig)(nil), // 1: xray.transport.internet.SocketConfig
+	(*Config)(nil), // 0: xray.transport.internet.finalmask.udphop.Config
 }
 var file_transport_internet_finalmask_udphop_config_proto_depIdxs = []int32{
-	1, // 0: xray.transport.internet.finalmask.udphop.Config.sockopt:type_name -> xray.transport.internet.SocketConfig
-	1, // [1:1] is the sub-list for method output_type
-	1, // [1:1] is the sub-list for method input_type
-	1, // [1:1] is the sub-list for extension type_name
-	1, // [1:1] is the sub-list for extension extendee
-	0, // [0:1] is the sub-list for field type_name
+	0, // [0:0] is the sub-list for method output_type
+	0, // [0:0] is the sub-list for method input_type
+	0, // [0:0] is the sub-list for extension type_name
+	0, // [0:0] is the sub-list for extension extendee
+	0, // [0:0] is the sub-list for field type_name
 }
 
 func init() { file_transport_internet_finalmask_udphop_config_proto_init() }

transport/internet/finalmask/udphop/config.proto

@@ -6,16 +6,14 @@ option go_package = "github.com/xtls/xray-core/transport/internet/finalmask/udph
 option java_package = "com.xray.transport.internet.finalmask.udphop";
 option java_multiple_files = true;
 
-import "transport/internet/config.proto";
-
 message Config {
-  xray.transport.internet.SocketConfig sockopt = 1;
+  reserved 1;
   bool local = 2;
   bool remote = 3;
   bool remote_once = 4;
   int64 interval_min = 5;
   int64 interval_max = 6;
-  repeated uint32 remote_ports = 7;
-  repeated string remoteIPs = 8;
+  repeated string remoteIPs = 7;
+  repeated uint32 remote_ports = 8;
 }
 

transport/internet/finalmask/udphop/conn.go

@@ -6,9 +6,7 @@ import (
 	goerrors "errors"
 	"io"
 	mrand "math/rand"
-	gonet "net"
 	"net/netip"
-	"reflect"
 	"sync"
 	"time"
 
@@ -16,8 +14,6 @@ import (
 	"github.com/xtls/xray-core/common/crypto"
 	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/common/net"
-	"github.com/xtls/xray-core/common/net/cnc"
-	"github.com/xtls/xray-core/transport/internet"
 	"github.com/xtls/xray-core/transport/internet/finalmask"
 )
 
@@ -34,16 +30,14 @@ type packet struct {
 }
 
 type udpHopConn struct {
-	conn       net.PacketConn
-	sockopt    *internet.SocketConfig
-	local      bool
-	remote     bool
-	remoteOnce bool
+	dialer *finalmask.Dialer
+	local  bool
+	remote bool
 
 	intervalMin int64
 	intervalMax int64
-	remotePorts []uint32
 	remoteIPs   []netip.Prefix
+	remotePorts []uint32
 
 	deadline      time.Time
 	readDeadline  time.Time
@@ -55,10 +49,10 @@ type udpHopConn struct {
 	readCh  chan packet
 	closeCh chan struct{}
 	wg      sync.WaitGroup
-	mu      sync.Mutex
+	mu      sync.RWMutex
 }
 
-func NewUDPHopConn(c *Config, raw net.PacketConn) (net.PacketConn, error) {
+func NewUDPHopConn(c *Config, dest *net.Destination, dialer *finalmask.Dialer) (net.PacketConn, error) {
 	if c.IntervalMin < 5 || c.IntervalMax < 5 {
 		return nil, errors.New("invalid interval")
 	}
@@ -66,22 +60,40 @@ func NewUDPHopConn(c *Config, raw net.PacketConn) (net.PacketConn, error) {
 	for _, ip := range c.RemoteIPs {
 		remoteIPs = append(remoteIPs, netip.MustParsePrefix(ip))
 	}
-	conn := &udpHopConn{
-		conn:       raw,
-		sockopt:    c.Sockopt,
-		local:      c.Local,
-		remote:     c.Remote,
-		remoteOnce: c.RemoteOnce,
+	remotePorts := c.RemotePorts
+	if c.Remote || c.RemoteOnce {
+		if len(remoteIPs) > 0 {
+			dest.Address = net.IPAddress(randPrefix(remoteIPs[mrand.Intn(len(remoteIPs))]))
+		}
+		if len(remotePorts) > 0 {
+			dest.Port = net.Port(remotePorts[mrand.Intn(len(remotePorts))])
+		}
+	}
+	conn, err := dialer.DialUDP(*dest)
+	if err != nil {
+		return nil, err
+	}
+	cur := conn.(*finalmask.PacketConnWrapper).PacketConn
+	addr := conn.RemoteAddr().(*net.UDPAddr)
+	client := &udpHopConn{
+		dialer: dialer,
+		local:  c.Local,
+		remote: c.Remote,
 
 		intervalMin: c.IntervalMin,
 		intervalMax: c.IntervalMax,
-		remotePorts: c.RemotePorts,
 		remoteIPs:   remoteIPs,
+		remotePorts: remotePorts,
 
+		cur:     cur,
+		addr:    addr,
 		readCh:  make(chan packet),
 		closeCh: make(chan struct{}),
 	}
-	return conn, nil
+	go client.run()
+	client.wg.Add(1)
+	go client.recv(client.cur)
+	return client, nil
 }
 
 func (c *udpHopConn) closed() bool {
@@ -93,61 +105,67 @@ func (c *udpHopConn) closed() bool {
 	}
 }
 
-func (c *udpHopConn) hop(addr *net.UDPAddr) {
+func (c *udpHopConn) run() {
+	ticker := time.NewTicker(time.Second * time.Duration(crypto.RandBetween(c.intervalMin, c.intervalMax+1)))
+	defer ticker.Stop()
+	for {
+		select {
+		case <-c.closeCh:
+			return
+		case <-ticker.C:
+			ticker.Reset(time.Second * time.Duration(crypto.RandBetween(c.intervalMin, c.intervalMax+1)))
+			c.hop()
+		}
+	}
+}
+
+func (c *udpHopConn) hop() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
 	if c.closed() {
 		return
 	}
-	newAddr := &net.UDPAddr{IP: addr.IP, Port: addr.Port}
-	newConn := c.conn
-	if c.remote || c.remoteOnce && c.addr == nil {
-		if len(c.remotePorts) > 0 {
-			newAddr.Port = int(c.remotePorts[mrand.Intn(len(c.remotePorts))])
-		}
+	oldIP := c.addr.IP
+	oldPort := c.addr.Port
+	if c.remote {
 		if len(c.remoteIPs) > 0 {
-			newAddr.IP = randPrefix(c.remoteIPs[mrand.Intn(len(c.remoteIPs))])
+			c.addr.IP = randPrefix(c.remoteIPs[mrand.Intn(len(c.remoteIPs))])
+		}
+		if len(c.remotePorts) > 0 {
+			c.addr.Port = int(c.remotePorts[mrand.Intn(len(c.remotePorts))])
 		}
 	}
 	if c.local {
-		raw, err := internet.DialSystem(context.Background(), net.UDPDestination(net.IPAddress(newAddr.IP), net.Port(newAddr.Port)), c.sockopt)
+		conn, err := c.dialer.DialUDP(net.UDPDestination(net.IPAddress(c.addr.IP), net.Port(c.addr.Port)))
 		if err != nil {
+			c.addr.IP = oldIP
+			c.addr.Port = oldPort
 			errors.LogErrorInner(context.Background(), err, "hop err")
 			return
 		}
-		switch c := raw.(type) {
-		case *internet.PacketConnWrapper:
-			newConn = c.PacketConn
-		case *cnc.Connection:
-			newConn = &internet.FakePacketConn{Conn: c}
-		default:
-			panic(reflect.TypeOf(c))
-		}
-		newConn.SetDeadline(c.deadline)
-		newConn.SetReadDeadline(c.readDeadline)
-		newConn.SetWriteDeadline(c.writeDeadline)
+		conn.SetDeadline(c.deadline)
+		conn.SetReadDeadline(c.readDeadline)
+		conn.SetWriteDeadline(c.writeDeadline)
 		if c.pre != nil {
 			_ = c.pre.Close()
 		}
 		c.pre = c.cur
+		c.cur = conn.(*finalmask.PacketConnWrapper).PacketConn
 		c.wg.Add(1)
-		go c.recv(newConn)
+		go c.recv(c.cur)
 	}
-	c.addr = newAddr
-	c.cur = newConn
 }
 
 func (c *udpHopConn) recv(conn net.PacketConn) {
 	defer c.wg.Done()
 
 	for {
-		if c.closed() {
-			return
-		}
 		p := pool.Get().([]byte)
 		n, addr, err := conn.ReadFrom(p)
 		if err != nil {
 			pool.Put(p[:cap(p)])
-			if goerrors.Is(err, io.EOF) || goerrors.Is(err, io.ErrClosedPipe) || goerrors.Is(err, gonet.ErrClosed) {
-				break
+			if c.closed() {
+				return
 			}
 			var netErr net.Error
 			if goerrors.As(err, &netErr) && netErr.Timeout() {
@@ -156,9 +174,10 @@ func (c *udpHopConn) recv(conn net.PacketConn) {
 				case <-c.closeCh:
 					return
 				}
+				continue
 			}
 			errors.LogErrorInner(context.Background(), err, "recv err")
-			continue
+			return
 		}
 		select {
 		case c.readCh <- packet{p: p[:n], addr: addr}:
@@ -169,22 +188,6 @@ func (c *udpHopConn) recv(conn net.PacketConn) {
 	}
 }
 
-func (c *udpHopConn) hopLoop() {
-	ticker := time.NewTicker(time.Second * time.Duration(crypto.RandBetween(c.intervalMin, c.intervalMax+1)))
-	defer ticker.Stop()
-	for {
-		select {
-		case <-ticker.C:
-			ticker.Reset(time.Second * time.Duration(crypto.RandBetween(c.intervalMin, c.intervalMax+1)))
-			c.mu.Lock()
-			c.hop(c.addr)
-			c.mu.Unlock()
-		case <-c.closeCh:
-			return
-		}
-	}
-}
-
 func (c *udpHopConn) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
 	packet, ok := <-c.readCh
 	if ok {
@@ -194,21 +197,12 @@ func (c *udpHopConn) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
 		}
 		return n, packet.addr, packet.err
 	}
-	return 0, nil, io.EOF
+	return 0, nil, io.ErrClosedPipe
 }
 
 func (c *udpHopConn) WriteTo(p []byte, addr net.Addr) (n int, err error) {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-
-	if c.cur == nil {
-		c.hop(addr.(*net.UDPAddr))
-		if c.cur == nil {
-			return 0, nil
-		}
-		go c.hopLoop()
-	}
-
+	c.mu.RLock()
+	defer c.mu.RUnlock()
 	_, err = c.cur.WriteTo(p, c.addr)
 	if err != nil {
 		errors.LogErrorInner(context.Background(), err, "send err")
@@ -227,15 +221,12 @@ func (c *udpHopConn) Close() error {
 	if c.pre != nil {
 		_ = c.pre.Close()
 	}
-	if c.cur != nil {
-		_ = c.cur.Close()
-	}
-	_ = c.conn.Close()
+	_ = c.cur.Close()
 	c.wg.Wait()
 	select {
-	case p := <-c.readCh:
-		if p.p != nil {
-			pool.Put(p.p[:cap(p.p)])
+	case packet := <-c.readCh:
+		if packet.p != nil {
+			pool.Put(packet.p[:cap(packet.p)])
 		}
 	default:
 	}
@@ -244,7 +235,9 @@ func (c *udpHopConn) Close() error {
 }
 
 func (c *udpHopConn) LocalAddr() net.Addr {
-	return c.conn.LocalAddr()
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	return c.cur.LocalAddr()
 }
 
 func (c *udpHopConn) SetDeadline(t time.Time) error {
@@ -254,10 +247,7 @@ func (c *udpHopConn) SetDeadline(t time.Time) error {
 	if c.pre != nil {
 		_ = c.pre.SetDeadline(t)
 	}
-	if c.cur != nil {
-		_ = c.cur.SetDeadline(t)
-	}
-	return nil
+	return c.cur.SetDeadline(t)
 }
 
 func (c *udpHopConn) SetReadDeadline(t time.Time) error {
@@ -267,10 +257,7 @@ func (c *udpHopConn) SetReadDeadline(t time.Time) error {
 	if c.pre != nil {
 		_ = c.pre.SetReadDeadline(t)
 	}
-	if c.cur != nil {
-		_ = c.cur.SetReadDeadline(t)
-	}
-	return nil
+	return c.cur.SetReadDeadline(t)
 }
 
 func (c *udpHopConn) SetWriteDeadline(t time.Time) error {
@@ -280,10 +267,7 @@ func (c *udpHopConn) SetWriteDeadline(t time.Time) error {
 	if c.pre != nil {
 		_ = c.pre.SetWriteDeadline(t)
 	}
-	if c.cur != nil {
-		_ = c.cur.SetWriteDeadline(t)
-	}
-	return nil
+	return c.cur.SetWriteDeadline(t)
 }
 
 func randPrefix(p netip.Prefix) []byte {

transport/internet/finalmask/xdns/config.go

@@ -1,21 +1,14 @@
 package xdns
 
 import (
-	"net"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
 )
 
-func (c *Config) WrapPacketConnClient(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	// _, ok1 := raw.(*internet.FakePacketConn)
-	// _, ok2 := raw.(*udphop.UdpHopPacketConn)
-	// if level != 0 || ok1 || ok2 {
-	// 	return nil, errors.New("xdns requires being at the outermost level")
-	// }
-	return NewConnClient(c, raw)
+func (c *Config) WrapPacketConnClient(conn net.PacketConn, dest *net.Destination, dialer *finalmask.Dialer) (net.PacketConn, error) {
+	return NewConnClient(c, conn)
 }
 
-func (c *Config) WrapPacketConnServer(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	// if level != 0 {
-	// 	return nil, errors.New("xdns requires being at the outermost level")
-	// }
-	return NewConnServer(c, raw)
+func (c *Config) WrapPacketConnServer(conn net.PacketConn, addr net.Addr, lc *finalmask.ListenConfig) (net.PacketConn, error) {
+	return NewConnServer(c, conn)
 }

transport/internet/finalmask/xicmp/client.go

@@ -8,8 +8,7 @@ import (
 	goerrors "errors"
 	"fmt"
 	"io"
-	mathrand "math/rand"
-	"net"
+	mrand "math/rand"
 	"net/netip"
 	"sync"
 	"time"
@@ -17,6 +16,7 @@ import (
 
 	"github.com/xtls/xray-core/common"
 	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/net"
 	"github.com/xtls/xray-core/transport/internet/finalmask"
 	"golang.org/x/net/icmp"
 	"golang.org/x/net/ipv4"
@@ -36,11 +36,11 @@ type packet struct {
 }
 
 type xicmpConnClient struct {
-	conn     net.PacketConn
 	icmp4    *icmp.PacketConn
 	icmp6    *icmp.PacketConn
 	udp      bool
 	ips      []netip.Addr
+	ip       net.IP
 	clientID [8]byte
 	id       int
 	seq      int
@@ -50,7 +50,7 @@ type xicmpConnClient struct {
 	mu       sync.Mutex
 }
 
-func NewConnClient(c *Config, raw net.PacketConn) (net.PacketConn, error) {
+func NewConnClient(c *Config, dest *net.Destination) (net.PacketConn, error) {
 	var icmp4, icmp6 *icmp.PacketConn
 	var err4, err6 error
 	if c.DGRAM {
@@ -69,17 +69,24 @@ func NewConnClient(c *Config, raw net.PacketConn) (net.PacketConn, error) {
 		ips = append(ips, netip.MustParseAddr(ip))
 	}
 
+	var ip net.IP
+	if len(ips) > 0 {
+		ip = ips[mrand.Intn(len(ips))].AsSlice()
+	} else {
+		ip = dest.Address.IP()
+	}
+
 	var clientID [8]byte
 	common.Must2(rand.Read(clientID[:]))
 
 	conn := &xicmpConnClient{
-		conn:     raw,
 		icmp4:    icmp4,
 		icmp6:    icmp6,
 		udp:      c.DGRAM,
 		ips:      ips,
+		ip:       ip,
 		clientID: clientID,
-		id:       mathrand.Intn(65536),
+		id:       mrand.Intn(65536),
 		seq:      1,
 		readCh:   make(chan packet),
 		closeCh:  make(chan struct{}),
@@ -92,10 +99,6 @@ func NewConnClient(c *Config, raw net.PacketConn) (net.PacketConn, error) {
 	return conn, nil
 }
 
-func (c *xicmpConnClient) ring(a, b uint16) uint16 {
-	return min(a-b, b-a)
-}
-
 func (c *xicmpConnClient) closed() bool {
 	select {
 	case <-c.closeCh:
@@ -110,12 +113,11 @@ func (c *xicmpConnClient) recv4() {
 
 	var b [finalmask.UDPSize]byte
 	for {
-		if c.closed() {
-			return
-		}
-
 		n, addr, err := c.icmp4.ReadFrom(b[:])
 		if err != nil {
+			if c.closed() {
+				return
+			}
 			var netErr net.Error
 			if goerrors.As(err, &netErr) && netErr.Timeout() {
 				select {
@@ -125,9 +127,10 @@ func (c *xicmpConnClient) recv4() {
 				case <-c.closeCh:
 					return
 				}
+				continue
 			}
-			errors.LogErrorInner(context.Background(), err, "recv4 err")
-			continue
+			errors.LogErrorInner(context.Background(), err, "recv err 4")
+			return
 		}
 
 		msg, err := icmp.ParseMessage(1, b[:n])
@@ -150,10 +153,6 @@ func (c *xicmpConnClient) recv4() {
 			continue
 		}
 
-		if c.ring(uint16(echo.Seq), uint16(c.seq)) > 1000 {
-			continue
-		}
-
 		if len(echo.Data) > 8 && bytes.Equal(echo.Data[:8], c.clientID[:]) {
 			continue
 		}
@@ -182,12 +181,11 @@ func (c *xicmpConnClient) recv6() {
 
 	var b [finalmask.UDPSize]byte
 	for {
-		if c.closed() {
-			return
-		}
-
 		n, addr, err := c.icmp6.ReadFrom(b[:])
 		if err != nil {
+			if c.closed() {
+				return
+			}
 			var netErr net.Error
 			if goerrors.As(err, &netErr) && netErr.Timeout() {
 				select {
@@ -197,9 +195,10 @@ func (c *xicmpConnClient) recv6() {
 				case <-c.closeCh:
 					return
 				}
+				continue
 			}
-			errors.LogErrorInner(context.Background(), err, "recv6 err")
-			continue
+			errors.LogErrorInner(context.Background(), err, "recv err 6")
+			return
 		}
 
 		msg, err := icmp.ParseMessage(58, b[:n])
@@ -222,10 +221,6 @@ func (c *xicmpConnClient) recv6() {
 			continue
 		}
 
-		if c.ring(uint16(echo.Seq), uint16(c.seq)) > 1000 {
-			continue
-		}
-
 		if len(echo.Data) > 8 && bytes.Equal(echo.Data[:8], c.clientID[:]) {
 			continue
 		}
@@ -273,9 +268,9 @@ func (c *xicmpConnClient) WriteTo(p []byte, addr net.Addr) (n int, err error) {
 	c.seq %= 65536
 	c.mu.Unlock()
 
-	ip := addr.(*net.UDPAddr).IP
+	ip := c.ip
 	if len(c.ips) > 0 {
-		ip = c.ips[mathrand.Intn(len(c.ips))].AsSlice()
+		ip = c.ips[mrand.Intn(len(c.ips))].AsSlice()
 	}
 
 	if c.udp {
@@ -314,7 +309,6 @@ func (c *xicmpConnClient) Close() error {
 	close(c.closeCh)
 	_ = c.icmp4.Close()
 	_ = c.icmp6.Close()
-	_ = c.conn.Close()
 	c.wg.Wait()
 	select {
 	case p := <-c.readCh:
@@ -328,7 +322,7 @@ func (c *xicmpConnClient) Close() error {
 }
 
 func (c *xicmpConnClient) LocalAddr() net.Addr {
-	return c.conn.LocalAddr()
+	return &net.UDPAddr{IP: []byte{0, 0, 0, 0}}
 }
 
 func (c *xicmpConnClient) SetDeadline(t time.Time) error {

transport/internet/finalmask/xicmp/config.go

@@ -1,23 +1,23 @@
 package xicmp
 
 import (
-	"net"
+	"errors"
 
-	"github.com/xtls/xray-core/common/errors"
-	"github.com/xtls/xray-core/transport/internet"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
 )
 
-func (c *Config) WrapPacketConnClient(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	_, ok1 := raw.(*internet.FakePacketConn)
-	if level != 0 || ok1 {
-		return nil, errors.New("xicmp requires being at the outermost level")
+func (c *Config) HandleDial() {}
+
+func (c *Config) HandleListen() {}
+
+func (c *Config) WrapPacketConnClient(conn net.PacketConn, dest *net.Destination, dialer *finalmask.Dialer) (net.PacketConn, error) {
+	if dest.Address.Family().IsDomain() && len(c.IPs) == 0 {
+		return nil, errors.New("empty ip addresses")
 	}
-	return NewConnClient(c, raw)
+	return NewConnClient(c, dest)
 }
 
-func (c *Config) WrapPacketConnServer(raw net.PacketConn, level int, levelCount int) (net.PacketConn, error) {
-	if level != 0 {
-		return nil, errors.New("xicmp requires being at the outermost level")
-	}
-	return NewConnServer(c, raw)
+func (c *Config) WrapPacketConnServer(conn net.PacketConn, addr net.Addr, lc *finalmask.ListenConfig) (net.PacketConn, error) {
+	return NewConnServer(c)
 }

transport/internet/finalmask/xicmp/server.go

@@ -37,7 +37,6 @@ type record struct {
 }
 
 type xicmpConnServer struct {
-	conn    net.PacketConn
 	icmp4   *icmp.PacketConn
 	icmp6   *icmp.PacketConn
 	ips     map[netip.Addr]struct{}
@@ -48,7 +47,7 @@ type xicmpConnServer struct {
 	mu      sync.Mutex
 }
 
-func NewConnServer(c *Config, raw net.PacketConn) (net.PacketConn, error) {
+func NewConnServer(c *Config) (net.PacketConn, error) {
 	icmp4, err := icmp.ListenPacket("ip4:icmp", "0.0.0.0")
 	if err != nil {
 		return nil, err
@@ -64,7 +63,6 @@ func NewConnServer(c *Config, raw net.PacketConn) (net.PacketConn, error) {
 	}
 
 	conn := &xicmpConnServer{
-		conn:    raw,
 		icmp4:   icmp4,
 		icmp6:   icmp6,
 		ips:     ips,
@@ -115,12 +113,11 @@ func (c *xicmpConnServer) recv4() {
 
 	var b [finalmask.UDPSize]byte
 	for {
-		if c.closed() {
-			return
-		}
-
 		n, addr, err := c.icmp4.ReadFrom(b[:])
 		if err != nil {
+			if c.closed() {
+				return
+			}
 			var netErr net.Error
 			if goerrors.As(err, &netErr) && netErr.Timeout() {
 				select {
@@ -130,9 +127,10 @@ func (c *xicmpConnServer) recv4() {
 				case <-c.closeCh:
 					return
 				}
+				continue
 			}
-			errors.LogErrorInner(context.Background(), err, "recv4 err")
-			continue
+			errors.LogErrorInner(context.Background(), err, "recv err 4")
+			return
 		}
 
 		msg, err := icmp.ParseMessage(1, b[:n])
@@ -195,12 +193,11 @@ func (c *xicmpConnServer) recv6() {
 
 	var b [finalmask.UDPSize]byte
 	for {
-		if c.closed() {
-			return
-		}
-
 		n, addr, err := c.icmp6.ReadFrom(b[:])
 		if err != nil {
+			if c.closed() {
+				return
+			}
 			var netErr net.Error
 			if goerrors.As(err, &netErr) && netErr.Timeout() {
 				select {
@@ -210,9 +207,10 @@ func (c *xicmpConnServer) recv6() {
 				case <-c.closeCh:
 					return
 				}
+				continue
 			}
-			errors.LogErrorInner(context.Background(), err, "recv6 err")
-			continue
+			errors.LogErrorInner(context.Background(), err, "recv err 6")
+			return
 		}
 
 		msg, err := icmp.ParseMessage(58, b[:n])
@@ -330,7 +328,6 @@ func (c *xicmpConnServer) Close() error {
 	close(c.closeCh)
 	_ = c.icmp4.Close()
 	_ = c.icmp6.Close()
-	_ = c.conn.Close()
 	c.wg.Wait()
 	select {
 	case p := <-c.readCh:
@@ -344,7 +341,7 @@ func (c *xicmpConnServer) Close() error {
 }
 
 func (c *xicmpConnServer) LocalAddr() net.Addr {
-	return c.conn.LocalAddr()
+	return &net.UDPAddr{IP: []byte{0, 0, 0, 0}}
 }
 
 func (c *xicmpConnServer) SetDeadline(t time.Time) error {

transport/internet/finalmask/xicmp/server_oob.go

@@ -39,7 +39,6 @@ type record struct {
 }
 
 type xicmpConnServer struct {
-	conn    net.PacketConn
 	icmp4   *icmp.PacketConn
 	icmp6   *icmp.PacketConn
 	ipv4PC  *ipv4.PacketConn
@@ -52,7 +51,7 @@ type xicmpConnServer struct {
 	mu      sync.Mutex
 }
 
-func NewConnServer(c *Config, raw net.PacketConn) (net.PacketConn, error) {
+func NewConnServer(c *Config) (net.PacketConn, error) {
 	icmp4, err := icmp.ListenPacket("ip4:icmp", "0.0.0.0")
 	if err != nil {
 		return nil, err
@@ -68,7 +67,6 @@ func NewConnServer(c *Config, raw net.PacketConn) (net.PacketConn, error) {
 	}
 
 	conn := &xicmpConnServer{
-		conn:    raw,
 		icmp4:   icmp4,
 		icmp6:   icmp6,
 		ipv4PC:  icmp4.IPv4PacketConn(),
@@ -124,12 +122,11 @@ func (c *xicmpConnServer) recv4() {
 
 	var b [finalmask.UDPSize]byte
 	for {
-		if c.closed() {
-			return
-		}
-
 		n, cm, addr, err := c.ipv4PC.ReadFrom(b[:])
 		if err != nil {
+			if c.closed() {
+				return
+			}
 			var netErr net.Error
 			if goerrors.As(err, &netErr) && netErr.Timeout() {
 				select {
@@ -139,9 +136,10 @@ func (c *xicmpConnServer) recv4() {
 				case <-c.closeCh:
 					return
 				}
+				continue
 			}
-			errors.LogErrorInner(context.Background(), err, "recv4 err")
-			continue
+			errors.LogErrorInner(context.Background(), err, "recv err 4")
+			return
 		}
 
 		msg, err := icmp.ParseMessage(1, b[:n])
@@ -205,12 +203,11 @@ func (c *xicmpConnServer) recv6() {
 
 	var b [finalmask.UDPSize]byte
 	for {
-		if c.closed() {
-			return
-		}
-
 		n, cm, addr, err := c.ipv6PC.ReadFrom(b[:])
 		if err != nil {
+			if c.closed() {
+				return
+			}
 			var netErr net.Error
 			if goerrors.As(err, &netErr) && netErr.Timeout() {
 				select {
@@ -220,9 +217,10 @@ func (c *xicmpConnServer) recv6() {
 				case <-c.closeCh:
 					return
 				}
+				continue
 			}
-			errors.LogErrorInner(context.Background(), err, "recv6 err")
-			continue
+			errors.LogErrorInner(context.Background(), err, "recv err 6")
+			return
 		}
 
 		msg, err := icmp.ParseMessage(58, b[:n])
@@ -341,7 +339,6 @@ func (c *xicmpConnServer) Close() error {
 	close(c.closeCh)
 	_ = c.icmp4.Close()
 	_ = c.icmp6.Close()
-	_ = c.conn.Close()
 	c.wg.Wait()
 	select {
 	case p := <-c.readCh:
@@ -355,7 +352,7 @@ func (c *xicmpConnServer) Close() error {
 }
 
 func (c *xicmpConnServer) LocalAddr() net.Addr {
-	return c.conn.LocalAddr()
+	return &net.UDPAddr{IP: []byte{0, 0, 0, 0}}
 }
 
 func (c *xicmpConnServer) SetDeadline(t time.Time) error {

transport/internet/finalmask/xmc/config.go

@@ -2,10 +2,12 @@ package xmc
 
 import (
 	"fmt"
-	"net"
+
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
 )
 
-func (c *Config) WrapConnClient(conn net.Conn) (net.Conn, error) {
+func (c *Config) WrapConnClient(conn net.Conn, dest *net.Destination, dialer *finalmask.Dialer) (net.Conn, error) {
 	profiles, err := profilesFromConfig(c.Profiles)
 	if err != nil {
 		return nil, fmt.Errorf("minecraft finalmask: %w", err)

transport/internet/grpc/dial.go

@@ -83,7 +83,6 @@ func getGrpcClient(ctx context.Context, dest net.Destination, streamSettings *in
 	}
 	tlsConfig := tls.ConfigFromStreamSettings(streamSettings)
 	realityConfig := reality.ConfigFromStreamSettings(streamSettings)
-	sockopt := streamSettings.SocketSettings
 	grpcSettings := streamSettings.ProtocolSettings.(*Config)
 
 	if client, found := globalDialerMap[dialerConf{dest, streamSettings}]; found && client.GetState() != connectivity.Shutdown {
@@ -124,17 +123,13 @@ func getGrpcClient(ctx context.Context, dest net.Destination, streamSettings *in
 			gctx = session.ContextWithOutbounds(gctx, session.OutboundsFromContext(ctx))
 			gctx = session.ContextWithTimeoutOnly(gctx, true)
 
-			c, err := internet.DialSystem(gctx, net.TCPDestination(address, port), sockopt)
+			var c net.Conn
+			if streamSettings.FinalMask != nil {
+				c, err = streamSettings.FinalMask.DialTCP(gctx, net.TCPDestination(address, port))
+			} else {
+				c, err = internet.DialSystem(ctx, dest, streamSettings.SocketSettings)
+			}
 			if err == nil {
-				if streamSettings.TcpmaskManager != nil {
-					newConn, err := streamSettings.TcpmaskManager.WrapConnClient(c)
-					if err != nil {
-						c.Close()
-						return nil, errors.New("mask err").Base(err)
-					}
-					c = newConn
-				}
-
 				if tlsConfig != nil {
 					config := tlsConfig.GetTLSConfig(tls.WithDestination(dest))
 					if fingerprint := tls.GetFingerprint(tlsConfig.Fingerprint); fingerprint != nil {

transport/internet/grpc/hub.go

@@ -104,28 +104,20 @@ func Listen(ctx context.Context, address net.Address, port net.Port, settings *i
 	go func() {
 		var streamListener net.Listener
 		var err error
+		var addr net.Addr
 		if port == net.Port(0) { // unix
-			streamListener, err = internet.ListenSystem(ctx, &net.UnixAddr{
-				Name: address.Domain(),
-				Net:  "unix",
-			}, settings.SocketSettings)
-			if err != nil {
-				errors.LogErrorInner(ctx, err, "failed to listen on ", address)
-				return
-			}
+			addr = &net.UnixAddr{Name: address.Domain(), Net: "unix"}
 		} else { // tcp
-			streamListener, err = internet.ListenSystem(ctx, &net.TCPAddr{
-				IP:   address.IP(),
-				Port: int(port),
-			}, settings.SocketSettings)
-			if err != nil {
-				errors.LogErrorInner(ctx, err, "failed to listen on ", address, ":", port)
-				return
-			}
+			addr = &net.TCPAddr{IP: address.IP(), Port: int(port)}
 		}
-
-		if settings.TcpmaskManager != nil {
-			streamListener, _ = settings.TcpmaskManager.WrapListener(streamListener)
+		if settings.FinalMask != nil {
+			streamListener, err = settings.FinalMask.Listen(ctx, addr)
+		} else {
+			streamListener, err = internet.ListenSystem(ctx, addr, settings.SocketSettings)
+		}
+		if err != nil {
+			errors.LogErrorInner(ctx, err, "failed to listen on ", address, ":", port)
+			return
 		}
 
 		errors.LogDebug(ctx, "gRPC listen for service name `"+grpcSettings.getServiceName()+"` tun `"+grpcSettings.getTunStreamName()+"` multi tun `"+grpcSettings.getTunMultiStreamName()+"`")

transport/internet/httpupgrade/dialer.go

@@ -46,21 +46,18 @@ func (c *ConnRF) Read(b []byte) (int, error) {
 func dialhttpUpgrade(ctx context.Context, dest net.Destination, streamSettings *internet.MemoryStreamConfig) (net.Conn, error) {
 	transportConfiguration := streamSettings.ProtocolSettings.(*Config)
 
-	pconn, err := internet.DialSystem(ctx, dest, streamSettings.SocketSettings)
+	var pconn net.Conn
+	var err error
+	if streamSettings.FinalMask != nil {
+		pconn, err = streamSettings.FinalMask.DialTCP(ctx, dest)
+	} else {
+		pconn, err = internet.DialSystem(ctx, dest, streamSettings.SocketSettings)
+	}
 	if err != nil {
 		errors.LogErrorInner(ctx, err, "failed to dial to ", dest)
 		return nil, err
 	}
 
-	if streamSettings.TcpmaskManager != nil {
-		newConn, err := streamSettings.TcpmaskManager.WrapConnClient(pconn)
-		if err != nil {
-			pconn.Close()
-			return nil, errors.New("mask err").Base(err)
-		}
-		pconn = newConn
-	}
-
 	var conn net.Conn
 	var requestURL url.URL
 	tConfig := tls.ConfigFromStreamSettings(streamSettings)

transport/internet/httpupgrade/hub.go

@@ -124,29 +124,21 @@ func ListenHTTPUpgrade(ctx context.Context, address net.Address, port net.Port,
 	}
 	var listener net.Listener
 	var err error
+	var addr net.Addr
 	if port == net.Port(0) { // unix
-		listener, err = internet.ListenSystem(ctx, &net.UnixAddr{
-			Name: address.Domain(),
-			Net:  "unix",
-		}, streamSettings.SocketSettings)
-		if err != nil {
-			return nil, errors.New("failed to listen unix domain socket(for HttpUpgrade) on ", address).Base(err)
-		}
-		errors.LogInfo(ctx, "listening unix domain socket(for HttpUpgrade) on ", address)
+		addr = &net.UnixAddr{Name: address.Domain(), Net: "unix"}
 	} else { // tcp
-		listener, err = internet.ListenSystem(ctx, &net.TCPAddr{
-			IP:   address.IP(),
-			Port: int(port),
-		}, streamSettings.SocketSettings)
-		if err != nil {
-			return nil, errors.New("failed to listen TCP(for HttpUpgrade) on ", address, ":", port).Base(err)
-		}
-		errors.LogInfo(ctx, "listening TCP(for HttpUpgrade) on ", address, ":", port)
+		addr = &net.TCPAddr{IP: address.IP(), Port: int(port)}
 	}
-
-	if streamSettings.TcpmaskManager != nil {
-		listener, _ = streamSettings.TcpmaskManager.WrapListener(listener)
+	if streamSettings.FinalMask != nil {
+		listener, err = streamSettings.FinalMask.Listen(ctx, addr)
+	} else {
+		listener, err = internet.ListenSystem(ctx, addr, streamSettings.SocketSettings)
 	}
+	if err != nil {
+		return nil, errors.New("failed to listen ", addr.Network(), "(for HttpUpgrade) on ", address, ":", port).Base(err)
+	}
+	errors.LogInfo(ctx, "listening ", addr.Network(), "(for HttpUpgrade) on ", address, ":", port)
 
 	if streamSettings.SocketSettings != nil && streamSettings.SocketSettings.AcceptProxyProtocol {
 		errors.LogWarning(ctx, "accepting PROXY protocol")

transport/internet/hysteria/dialer.go

@@ -2,7 +2,7 @@ package hysteria
 
 import (
 	"context"
-	go_tls "crypto/tls"
+	gotls "crypto/tls"
 	"net/http"
 	"net/url"
 	"reflect"
@@ -28,12 +28,12 @@ import (
 type client struct {
 	sync.Mutex
 
-	dest           net.Destination
-	config         *Config
-	tlsConfig      *go_tls.Config
-	socketConfig   *internet.SocketConfig
-	udpmaskManager *finalmask.UdpmaskManager
-	quicParams     *internet.QuicParams
+	dest         net.Destination
+	config       *Config
+	tlsConfig    *gotls.Config
+	socketConfig *internet.SocketConfig
+	finalMask    *finalmask.FinalMask
+	quicParams   *internet.QuicParams
 
 	conn    *quic.Conn
 	tr      *quic.Transport
@@ -113,30 +113,29 @@ func (c *client) dial(ctx context.Context) error {
 	// }
 
 	var pktConn net.PacketConn
-	var udpAddr *net.UDPAddr
-
-	raw, err := internet.DialSystem(ctx, c.dest, c.socketConfig)
-	if err != nil {
-		return errors.New("failed to dial to dest").Base(err)
-	}
-	switch c := raw.(type) {
-	case *internet.PacketConnWrapper:
-		pktConn = c.PacketConn
-		udpAddr = raw.RemoteAddr().(*net.UDPAddr)
-	case *cnc.Connection:
-		pktConn = &internet.FakePacketConn{Conn: c}
-		udpAddr = &net.UDPAddr{IP: c.RemoteAddr().(*net.TCPAddr).IP, Port: c.RemoteAddr().(*net.TCPAddr).Port}
-	default:
-		panic(reflect.TypeOf(c))
-	}
-
-	if c.udpmaskManager != nil {
-		newConn, err := c.udpmaskManager.WrapPacketConnClient(pktConn)
+	var udpAddr net.Addr
+	if c.finalMask != nil {
+		conn, err := c.finalMask.DialUDP(ctx, c.dest)
 		if err != nil {
-			pktConn.Close()
-			return errors.New("mask err").Base(err)
+			return errors.New("failed to dial to dest").Base(err)
+		}
+		pktConn = conn.(*finalmask.PacketConnWrapper).PacketConn
+		udpAddr = conn.RemoteAddr()
+	} else {
+		conn, err := internet.DialSystem(ctx, c.dest, c.socketConfig)
+		if err != nil {
+			return errors.New("failed to dial to dest").Base(err)
+		}
+		switch c := conn.(type) {
+		case *internet.PacketConnWrapper:
+			pktConn = c.PacketConn
+			udpAddr = c.RemoteAddr()
+		case *cnc.Connection:
+			pktConn = &internet.FakePacketConn{Conn: c}
+			udpAddr = &net.UDPAddr{IP: []byte{0, 0, 0, 0}}
+		default:
+			panic(reflect.TypeOf(c))
 		}
-		pktConn = newConn
 	}
 
 	tr := &quic.Transport{Conn: pktConn, DisableGSO: quicParams.DisableGSO}
@@ -150,7 +149,7 @@ func (c *client) dial(ctx context.Context) error {
 	rt := &http3.Transport{
 		TLSClientConfig: c.tlsConfig,
 		QUICConfig:      quicConfig,
-		Dial: func(ctx context.Context, _ string, tlsCfg *go_tls.Config, cfg *quic.Config) (*quic.Conn, error) {
+		Dial: func(ctx context.Context, _ string, tlsCfg *gotls.Config, cfg *quic.Config) (*quic.Conn, error) {
 			qc, err := tr.DialEarly(ctx, udpAddr, tlsCfg, cfg)
 			if err != nil {
 				return nil, err
@@ -316,12 +315,12 @@ func Dial(ctx context.Context, dest net.Destination, streamSettings *internet.Me
 		c = manager.m[dialerConf{dest, streamSettings}]
 		if c == nil {
 			c = &client{
-				dest:           dest,
-				config:         streamSettings.ProtocolSettings.(*Config),
-				tlsConfig:      tlsConfig.GetTLSConfig(tls.WithDestination(dest)),
-				socketConfig:   streamSettings.SocketSettings,
-				udpmaskManager: streamSettings.UdpmaskManager,
-				quicParams:     streamSettings.QuicParams,
+				dest:         dest,
+				config:       streamSettings.ProtocolSettings.(*Config),
+				tlsConfig:    tlsConfig.GetTLSConfig(tls.WithDestination(dest)),
+				socketConfig: streamSettings.SocketSettings,
+				finalMask:    streamSettings.FinalMask,
+				quicParams:   streamSettings.QuicParams,
 			}
 			manager.m[dialerConf{dest, streamSettings}] = c
 		}

transport/internet/hysteria/hub.go

@@ -316,20 +316,17 @@ func Listen(ctx context.Context, address net.Address, port net.Port, streamSetti
 		quicConfig.MaxIncomingStreams = 1024
 	}
 
-	pktConn, err := internet.ListenSystemPacket(context.Background(), &net.UDPAddr{IP: address.IP(), Port: int(port)}, streamSettings.SocketSettings)
+	var pktConn net.PacketConn
+	var err error
+	if streamSettings.FinalMask != nil {
+		pktConn, err = streamSettings.FinalMask.ListenPacket(context.Background(), &net.UDPAddr{IP: address.IP(), Port: int(port)})
+	} else {
+		pktConn, err = internet.ListenSystemPacket(context.Background(), &net.UDPAddr{IP: address.IP(), Port: int(port)}, streamSettings.SocketSettings)
+	}
 	if err != nil {
 		return nil, err
 	}
 
-	if streamSettings.UdpmaskManager != nil {
-		newConn, err := streamSettings.UdpmaskManager.WrapPacketConnServer(pktConn)
-		if err != nil {
-			pktConn.Close()
-			return nil, errors.New("mask err").Base(err)
-		}
-		pktConn = newConn
-	}
-
 	var k *quic.StatelessResetKey
 	if !quicParams.DisableStatelessReset {
 		k = &quic.StatelessResetKey{}

transport/internet/hysteria/hysteria_test.go

@@ -0,0 +1,165 @@
+package hysteria
+
+import (
+	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"errors"
+	"net"
+	"runtime"
+	"testing"
+	"time"
+
+	"github.com/apernet/quic-go"
+	"github.com/xtls/xray-core/common"
+	"github.com/xtls/xray-core/common/protocol/tls/cert"
+)
+
+func TestDatagram(t *testing.T) {
+	run := func() (addr net.Addr, recv chan int64, cancel func()) {
+		cert, _ := cert.MustGenerate(nil)
+		Certificate := [][]byte{cert.Certificate}
+		PrivateKey := common.Must2(x509.ParsePKCS8PrivateKey(cert.PrivateKey))
+
+		tlsConf := &tls.Config{
+			Certificates: []tls.Certificate{
+				{
+					Certificate: Certificate,
+					PrivateKey:  PrivateKey,
+				},
+			},
+			NextProtos: []string{"h3"},
+		}
+
+		quicConf := &quic.Config{
+			InitialStreamReceiveWindow:     8388608,
+			MaxStreamReceiveWindow:         8388608,
+			InitialConnectionReceiveWindow: 8388608 * 5 / 2,
+			MaxConnectionReceiveWindow:     8388608 * 5 / 2,
+			MaxIdleTimeout:                 30 * time.Second,
+			MaxIncomingStreams:             1024,
+			DisablePathMTUDiscovery:        runtime.GOOS != "linux" && runtime.GOOS != "windows" && runtime.GOOS != "darwin",
+			EnableDatagrams:                true,
+			MaxDatagramFrameSize:           MaxDatagramFrameSize,
+			AssumePeerMaxDatagramFrameSize: MaxDatagramFrameSize,
+			DisablePathManager:             true,
+		}
+
+		pktConn := common.Must2(net.ListenPacket("udp", "127.0.0.1:0"))
+		tr := &quic.Transport{Conn: pktConn}
+		l := common.Must2(tr.Listen(tlsConf, quicConf))
+
+		recv = make(chan int64)
+		ctx, cancel := context.WithCancel(context.Background())
+
+		go func() {
+			defer pktConn.Close()
+			defer tr.Close()
+			defer l.Close()
+			defer close(recv)
+
+			var buf [1500]byte
+			for {
+				conn, err := l.Accept(ctx)
+				if err != nil {
+					if !errors.Is(err, context.Canceled) {
+						t.Error(err)
+					}
+					break
+				}
+				err = conn.SendDatagram(buf[:])
+				var qErr *quic.DatagramTooLargeError
+				if !errors.As(err, &qErr) {
+					t.Error(err)
+				}
+				recv <- qErr.MaxDatagramPayloadSize
+				defer conn.CloseWithError(0, "")
+			}
+		}()
+
+		return l.Addr(), recv, cancel
+	}
+
+	addr, recv, cancel := run()
+
+	t.Run("With ChromeParrot", func(t *testing.T) {
+		tlsConf := &tls.Config{
+			InsecureSkipVerify: true,
+		}
+
+		quicConf := &quic.Config{
+			InitialStreamReceiveWindow:     8388608,
+			MaxStreamReceiveWindow:         8388608,
+			InitialConnectionReceiveWindow: 8388608 * 5 / 2,
+			MaxConnectionReceiveWindow:     8388608 * 5 / 2,
+			MaxIdleTimeout:                 30 * time.Second,
+			KeepAlivePeriod:                10 * time.Second,
+			DisablePathMTUDiscovery:        runtime.GOOS != "linux" && runtime.GOOS != "windows" && runtime.GOOS != "darwin",
+			ChromeParrot:                   true,
+			EnableDatagrams:                true,
+			MaxDatagramFrameSize:           MaxDatagramFrameSize,
+			OmitMaxDatagramFrameSize:       true,
+			DisablePathManager:             true,
+		}
+
+		pktConn := common.Must2(net.ListenPacket("udp", "127.0.0.1:0"))
+		tr := &quic.Transport{Conn: pktConn, ConnectionIDGenerator: quic.ZeroLengthConnectionIDGenerator{}}
+		conn := common.Must2(tr.DialEarly(context.Background(), addr, tlsConf, quicConf))
+
+		defer pktConn.Close()
+		defer tr.Close()
+		defer conn.CloseWithError(0, "")
+
+		var buf [1500]byte
+		err := conn.SendDatagram(buf[:])
+		var qErr *quic.DatagramTooLargeError
+		if !errors.As(err, &qErr) || qErr.MaxDatagramPayloadSize != 1197 {
+			t.Error(err)
+		}
+		if server := <-recv; server != 1243 {
+			t.Error(server)
+		}
+	})
+
+	t.Run("Without ChromeParrot", func(t *testing.T) {
+		tlsConf := &tls.Config{
+			InsecureSkipVerify: true,
+			NextProtos:         []string{"h3"},
+		}
+
+		quicConf := &quic.Config{
+			InitialStreamReceiveWindow:     8388608,
+			MaxStreamReceiveWindow:         8388608,
+			InitialConnectionReceiveWindow: 8388608 * 5 / 2,
+			MaxConnectionReceiveWindow:     8388608 * 5 / 2,
+			MaxIdleTimeout:                 30 * time.Second,
+			KeepAlivePeriod:                10 * time.Second,
+			DisablePathMTUDiscovery:        runtime.GOOS != "linux" && runtime.GOOS != "windows" && runtime.GOOS != "darwin",
+			ChromeParrot:                   false,
+			EnableDatagrams:                true,
+			MaxDatagramFrameSize:           MaxDatagramFrameSize,
+			OmitMaxDatagramFrameSize:       true,
+			DisablePathManager:             true,
+		}
+
+		pktConn := common.Must2(net.ListenPacket("udp", "127.0.0.1:0"))
+		tr := &quic.Transport{Conn: pktConn}
+		conn := common.Must2(tr.DialEarly(context.Background(), addr, tlsConf, quicConf))
+
+		defer pktConn.Close()
+		defer tr.Close()
+		defer conn.CloseWithError(0, "")
+
+		var buf [1500]byte
+		err := conn.SendDatagram(buf[:])
+		var qErr *quic.DatagramTooLargeError
+		if !errors.As(err, &qErr) || qErr.MaxDatagramPayloadSize != 1197 {
+			t.Error(err)
+		}
+		if server := <-recv; server != 1197 {
+			t.Error(server)
+		}
+	})
+
+	cancel()
+}

transport/internet/kcp/dialer.go

@@ -3,7 +3,6 @@ package kcp
 import (
 	"context"
 	"io"
-	reflect "reflect"
 	"sync/atomic"
 
 	"github.com/xtls/xray-core/common"
@@ -11,7 +10,6 @@ import (
 	"github.com/xtls/xray-core/common/dice"
 	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/common/net"
-	"github.com/xtls/xray-core/common/net/cnc"
 	"github.com/xtls/xray-core/transport/internet"
 	"github.com/xtls/xray-core/transport/internet/stat"
 	"github.com/xtls/xray-core/transport/internet/tls"
@@ -51,36 +49,17 @@ func DialKCP(ctx context.Context, dest net.Destination, streamSettings *internet
 	dest.Network = net.Network_UDP
 	errors.LogInfo(ctx, "dialing mKCP to ", dest)
 
-	conn, err := internet.DialSystem(ctx, dest, streamSettings.SocketSettings)
+	var conn net.Conn
+	var err error
+	if streamSettings.FinalMask != nil {
+		conn, err = streamSettings.FinalMask.DialUDP(ctx, dest)
+	} else {
+		conn, err = internet.DialSystem(ctx, dest, streamSettings.SocketSettings)
+	}
 	if err != nil {
 		return nil, errors.New("failed to dial to dest: ", err).AtWarning().Base(err)
 	}
 
-	if streamSettings.UdpmaskManager != nil {
-		var pktConn net.PacketConn
-		var udpAddr *net.UDPAddr
-		switch c := conn.(type) {
-		case *internet.PacketConnWrapper:
-			pktConn = c.PacketConn
-			udpAddr = c.RemoteAddr().(*net.UDPAddr)
-		case *cnc.Connection:
-			pktConn = &internet.FakePacketConn{Conn: c}
-			udpAddr = &net.UDPAddr{IP: c.RemoteAddr().(*net.TCPAddr).IP, Port: c.RemoteAddr().(*net.TCPAddr).Port}
-		default:
-			panic(reflect.TypeOf(c))
-		}
-		newConn, err := streamSettings.UdpmaskManager.WrapPacketConnClient(pktConn)
-		if err != nil {
-			pktConn.Close()
-			return nil, errors.New("mask err").Base(err)
-		}
-		pktConn = newConn
-		conn = &internet.PacketConnWrapper{
-			PacketConn: pktConn,
-			Dest:       udpAddr,
-		}
-	}
-
 	kcpSettings := streamSettings.ProtocolSettings.(*Config)
 
 	reader := &KCPPacketReader{}

transport/internet/masque/config.go

@@ -0,0 +1,18 @@
+package masque
+
+import (
+	"github.com/xtls/xray-core/common"
+	"github.com/xtls/xray-core/transport/internet"
+)
+
+const protocolName = "masque"
+
+const DefaultPath = "/.well-known/masque/ip/*/*/"
+
+func init() {
+	common.Must(internet.RegisterProtocolConfigCreator(protocolName, func() interface{} {
+		return &Config{
+			Path: DefaultPath,
+		}
+	}))
+}

transport/internet/masque/config.pb.go

@@ -0,0 +1,146 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// versions:
+// 	protoc-gen-go v1.36.11
+// 	protoc        v6.33.5
+// source: transport/internet/masque/config.proto
+
+package masque
+
+import (
+	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
+	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
+	reflect "reflect"
+	sync "sync"
+	unsafe "unsafe"
+)
+
+const (
+	// Verify that this generated code is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
+	// Verify that runtime/protoimpl is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
+)
+
+type Config struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	Host          string                 `protobuf:"bytes,1,opt,name=host,proto3" json:"host,omitempty"`
+	Path          string                 `protobuf:"bytes,2,opt,name=path,proto3" json:"path,omitempty"`
+	Headers       map[string]string      `protobuf:"bytes,3,rep,name=headers,proto3" json:"headers,omitempty" protobuf_key:"bytes,1,opt,name=key" protobuf_val:"bytes,2,opt,name=value"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *Config) Reset() {
+	*x = Config{}
+	mi := &file_transport_internet_masque_config_proto_msgTypes[0]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *Config) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*Config) ProtoMessage() {}
+
+func (x *Config) ProtoReflect() protoreflect.Message {
+	mi := &file_transport_internet_masque_config_proto_msgTypes[0]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use Config.ProtoReflect.Descriptor instead.
+func (*Config) Descriptor() ([]byte, []int) {
+	return file_transport_internet_masque_config_proto_rawDescGZIP(), []int{0}
+}
+
+func (x *Config) GetHost() string {
+	if x != nil {
+		return x.Host
+	}
+	return ""
+}
+
+func (x *Config) GetPath() string {
+	if x != nil {
+		return x.Path
+	}
+	return ""
+}
+
+func (x *Config) GetHeaders() map[string]string {
+	if x != nil {
+		return x.Headers
+	}
+	return nil
+}
+
+var File_transport_internet_masque_config_proto protoreflect.FileDescriptor
+
+const file_transport_internet_masque_config_proto_rawDesc = "" +
+	"\n" +
+	"&transport/internet/masque/config.proto\x12\x1exray.transport.internet.masque\"\xbb\x01\n" +
+	"\x06Config\x12\x12\n" +
+	"\x04host\x18\x01 \x01(\tR\x04host\x12\x12\n" +
+	"\x04path\x18\x02 \x01(\tR\x04path\x12M\n" +
+	"\aheaders\x18\x03 \x03(\v23.xray.transport.internet.masque.Config.HeadersEntryR\aheaders\x1a:\n" +
+	"\fHeadersEntry\x12\x10\n" +
+	"\x03key\x18\x01 \x01(\tR\x03key\x12\x14\n" +
+	"\x05value\x18\x02 \x01(\tR\x05value:\x028\x01B|\n" +
+	"\"com.xray.transport.internet.masqueP\x01Z3github.com/xtls/xray-core/transport/internet/masque\xaa\x02\x1eXray.Transport.Internet.Masqueb\x06proto3"
+
+var (
+	file_transport_internet_masque_config_proto_rawDescOnce sync.Once
+	file_transport_internet_masque_config_proto_rawDescData []byte
+)
+
+func file_transport_internet_masque_config_proto_rawDescGZIP() []byte {
+	file_transport_internet_masque_config_proto_rawDescOnce.Do(func() {
+		file_transport_internet_masque_config_proto_rawDescData = protoimpl.X.CompressGZIP(unsafe.Slice(unsafe.StringData(file_transport_internet_masque_config_proto_rawDesc), len(file_transport_internet_masque_config_proto_rawDesc)))
+	})
+	return file_transport_internet_masque_config_proto_rawDescData
+}
+
+var file_transport_internet_masque_config_proto_msgTypes = make([]protoimpl.MessageInfo, 2)
+var file_transport_internet_masque_config_proto_goTypes = []any{
+	(*Config)(nil), // 0: xray.transport.internet.masque.Config
+	nil,            // 1: xray.transport.internet.masque.Config.HeadersEntry
+}
+var file_transport_internet_masque_config_proto_depIdxs = []int32{
+	1, // 0: xray.transport.internet.masque.Config.headers:type_name -> xray.transport.internet.masque.Config.HeadersEntry
+	1, // [1:1] is the sub-list for method output_type
+	1, // [1:1] is the sub-list for method input_type
+	1, // [1:1] is the sub-list for extension type_name
+	1, // [1:1] is the sub-list for extension extendee
+	0, // [0:1] is the sub-list for field type_name
+}
+
+func init() { file_transport_internet_masque_config_proto_init() }
+func file_transport_internet_masque_config_proto_init() {
+	if File_transport_internet_masque_config_proto != nil {
+		return
+	}
+	type x struct{}
+	out := protoimpl.TypeBuilder{
+		File: protoimpl.DescBuilder{
+			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
+			RawDescriptor: unsafe.Slice(unsafe.StringData(file_transport_internet_masque_config_proto_rawDesc), len(file_transport_internet_masque_config_proto_rawDesc)),
+			NumEnums:      0,
+			NumMessages:   2,
+			NumExtensions: 0,
+			NumServices:   0,
+		},
+		GoTypes:           file_transport_internet_masque_config_proto_goTypes,
+		DependencyIndexes: file_transport_internet_masque_config_proto_depIdxs,
+		MessageInfos:      file_transport_internet_masque_config_proto_msgTypes,
+	}.Build()
+	File_transport_internet_masque_config_proto = out.File
+	file_transport_internet_masque_config_proto_goTypes = nil
+	file_transport_internet_masque_config_proto_depIdxs = nil
+}

transport/internet/masque/config.proto

@@ -0,0 +1,13 @@
+syntax = "proto3";
+
+package xray.transport.internet.masque;
+option csharp_namespace = "Xray.Transport.Internet.Masque";
+option go_package = "github.com/xtls/xray-core/transport/internet/masque";
+option java_package = "com.xray.transport.internet.masque";
+option java_multiple_files = true;
+
+message Config {
+  string host = 1;
+  string path = 2;
+  map<string, string> headers = 3;
+}

transport/internet/masque/conn.go

@@ -0,0 +1,115 @@
+package masque
+
+import (
+	"context"
+	go_errors "errors"
+	"net/netip"
+	"slices"
+	"sync"
+	"time"
+
+	"github.com/apernet/quic-go"
+	"github.com/apernet/quic-go/http3"
+	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet/masque/connectip"
+)
+
+type PacketTooBigError struct {
+	ICMP []byte
+}
+
+func (e *PacketTooBigError) Error() string {
+	return "packet too big for the tunnel"
+}
+
+type Conn struct {
+	ipConn    *connectip.Conn
+	quicConn  *quic.Conn
+	local     []netip.Addr
+	closeOnce sync.Once
+}
+
+func (c *Conn) LocalAddrs() []netip.Addr {
+	return c.local
+}
+
+func (c *Conn) Read(b []byte) (int, error) {
+	return c.ipConn.ReadPacket(b)
+}
+
+func (c *Conn) Write(b []byte) (int, error) {
+	icmp, err := c.ipConn.WritePacket(b)
+	if err != nil {
+		if go_errors.Is(err, connectip.ErrMTUTooSmall) {
+			errors.LogWarning(context.Background(), "MASQUE: closing the tunnel as it cannot carry ", MinPacketSize, "-byte packets")
+		} else {
+			errors.LogInfoInner(context.Background(), err, "MASQUE: closing the tunnel as sending failed")
+		}
+		c.Close()
+		return 0, err
+	}
+	if len(icmp) > 0 {
+		return 0, &PacketTooBigError{ICMP: icmp}
+	}
+	return len(b), nil
+}
+
+func (c *Conn) Close() error {
+	c.closeOnce.Do(func() {
+		c.ipConn.Close()
+		c.quicConn.CloseWithError(quic.ApplicationErrorCode(http3.ErrCodeNoError), "")
+	})
+	return nil
+}
+
+func (c *Conn) LocalAddr() net.Addr {
+	return c.quicConn.LocalAddr()
+}
+
+func (c *Conn) RemoteAddr() net.Addr {
+	return c.quicConn.RemoteAddr()
+}
+
+func (c *Conn) SetDeadline(time.Time) error {
+	return nil
+}
+
+func (c *Conn) SetReadDeadline(time.Time) error {
+	return nil
+}
+
+func (c *Conn) SetWriteDeadline(time.Time) error {
+	return nil
+}
+
+func (c *Conn) serveAddressAssignments() {
+	for {
+		assigned, err := c.ipConn.ReceiveAddressAssignment(context.Background())
+		if err != nil {
+			return
+		}
+		for _, addr := range c.local {
+			if !slices.ContainsFunc(assigned, func(a connectip.AssignedAddress) bool { return !a.Rejected() && a.IPPrefix.Contains(addr) }) {
+				errors.LogInfo(context.Background(), "MASQUE: closing the tunnel as the proxy withdrew ", addr)
+				c.Close()
+				return
+			}
+		}
+		if len(localAddrs(assigned)) > len(c.local) {
+			errors.LogInfo(context.Background(), "MASQUE: the proxy assigned another IP family, which is used once the tunnel is set up again")
+		}
+	}
+}
+
+func (c *Conn) serveAddressRequests() {
+	for {
+		req, err := c.ipConn.ReceiveAddressRequest(context.Background())
+		if err != nil {
+			return
+		}
+		if err := req.Respond(make([]netip.Prefix, len(req.Prefixes)), nil); err != nil {
+			return
+		}
+	}
+}

transport/internet/masque/connectip/LICENSE

@@ -0,0 +1,7 @@
+Copyright 2024 Marten Seemann
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

transport/internet/masque/connectip/address.go

@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright 2024 Marten Seemann
+ * Adapted from github.com/quic-go/connect-ip-go (commit a0c35fa).
+ */
+
+package connectip
+
+import (
+	"errors"
+	"fmt"
+	"net/netip"
+	"slices"
+	"sync/atomic"
+)
+
+var (
+	rejectedIPv4Prefix = netip.PrefixFrom(netip.IPv4Unspecified(), 32)
+	rejectedIPv6Prefix = netip.PrefixFrom(netip.IPv6Unspecified(), 128)
+)
+
+type AddressRequestID uint64
+
+type AddressRequest struct {
+	Prefixes []netip.Prefix
+
+	conn      *Conn
+	requested *addressRequestCapsule
+	responded *atomic.Bool
+}
+
+func newAddressRequest(conn *Conn, requested *addressRequestCapsule) *AddressRequest {
+	return &AddressRequest{
+		Prefixes:  slices.Clone(requested.Prefixes),
+		conn:      conn,
+		requested: requested,
+		responded: &atomic.Bool{},
+	}
+}
+
+func (r *AddressRequest) Respond(assignments, additional []netip.Prefix) error {
+	if r.conn == nil {
+		return errors.New("connect-ip: invalid address request")
+	}
+	if len(assignments) != len(r.requested.RequestIDs) {
+		return fmt.Errorf(
+			"connect-ip: expected %d address assignments, got %d",
+			len(r.requested.RequestIDs),
+			len(assignments),
+		)
+	}
+	capsule := &addressAssignCapsule{
+		AssignedAddresses: make([]AssignedAddress, 0, len(assignments)+len(additional)),
+	}
+	var zeroPrefix netip.Prefix
+	for i, p := range assignments {
+		if p == zeroPrefix {
+			if r.requested.Prefixes[i].Addr().Is4() {
+				p = rejectedIPv4Prefix
+			} else {
+				p = rejectedIPv6Prefix
+			}
+		} else if !p.IsValid() || p != p.Masked() {
+			return fmt.Errorf("connect-ip: invalid assigned prefix %d: %s", i, p)
+		}
+		capsule.AssignedAddresses = append(
+			capsule.AssignedAddresses,
+			AssignedAddress{RequestID: r.requested.RequestIDs[i], IPPrefix: p},
+		)
+	}
+	for i, p := range additional {
+		if !p.IsValid() || p != p.Masked() {
+			return fmt.Errorf("connect-ip: invalid additional prefix %d: %s", i, p)
+		}
+		capsule.AssignedAddresses = append(capsule.AssignedAddresses, AssignedAddress{IPPrefix: p})
+	}
+	if !r.responded.CompareAndSwap(false, true) {
+		return errors.New("connect-ip: address request already answered")
+	}
+	restrictPeer := slices.ContainsFunc(capsule.AssignedAddresses, func(a AssignedAddress) bool { return !a.Rejected() })
+	if err := r.conn.sendAddressAssignment(capsule, restrictPeer); err != nil {
+		r.responded.Store(false)
+		return err
+	}
+	return nil
+}

transport/internet/masque/connectip/address_test.go

@@ -0,0 +1,85 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright 2024 Marten Seemann
+ * Adapted from github.com/quic-go/connect-ip-go (commit a0c35fa).
+ */
+
+package connectip
+
+import (
+	"context"
+	"net/netip"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestAddressRequests(t *testing.T) {
+	client, server := setupConns(t)
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+	prefixes := []netip.Prefix{
+		netip.MustParsePrefix("0.0.0.0/32"),
+		netip.MustParsePrefix("0.0.0.0/32"),
+		netip.MustParsePrefix("::/64"),
+	}
+	ids, err := client.RequestAddresses(prefixes)
+	require.NoError(t, err)
+	require.Equal(t, []AddressRequestID{1, 2, 3}, ids)
+	req, err := server.ReceiveAddressRequest(ctx)
+	require.NoError(t, err)
+	require.Equal(t, prefixes, req.Prefixes)
+
+	assignments := []netip.Prefix{netip.MustParsePrefix("192.0.2.1/32"), {}, {}}
+	additional := []netip.Prefix{netip.MustParsePrefix("2001:db8::/64")}
+	require.NoError(t, req.Respond(assignments, additional))
+	received, err := client.ReceiveAddressAssignment(ctx)
+	require.NoError(t, err)
+	require.Len(t, received, 4)
+	require.Equal(t, AssignedAddress{RequestID: ids[0], IPPrefix: assignments[0]}, received[0])
+	require.Equal(t, ids[1], received[1].RequestID)
+	require.True(t, received[1].Rejected())
+	require.Equal(t, ids[2], received[2].RequestID)
+	require.True(t, received[2].Rejected())
+	require.Equal(t, AssignedAddress{IPPrefix: additional[0]}, received[3])
+
+	ids, err = client.RequestAddresses(prefixes[:1])
+	require.NoError(t, err)
+	require.Equal(t, []AddressRequestID{4}, ids)
+}
+
+func TestAddressRequestValidation(t *testing.T) {
+	conn := newProxiedConn(&mockStream{})
+	defer conn.Close()
+
+	for _, prefixes := range [][]netip.Prefix{
+		nil,
+		{{}},
+		{netip.MustParsePrefix("192.0.2.1/24")},
+		{netip.MustParsePrefix("2001:db8::1/64")},
+	} {
+		ids, err := conn.RequestAddresses(prefixes)
+		require.Error(t, err)
+		require.Nil(t, ids)
+	}
+}
+
+func TestAddressResponseValidation(t *testing.T) {
+	conn := newProxiedConn(&mockStream{})
+	defer conn.Close()
+
+	prefixes := []netip.Prefix{netip.MustParsePrefix("192.0.2.1/32")}
+	req := newAddressRequest(conn, &addressRequestCapsule{RequestIDs: []AddressRequestID{1}, Prefixes: prefixes})
+	require.ErrorContains(t, (&AddressRequest{}).Respond(nil, nil), "invalid address request")
+	require.ErrorContains(t, req.Respond(nil, nil), "expected 1 address assignments")
+	require.ErrorContains(t, req.Respond(prefixes, []netip.Prefix{{}}), "invalid additional prefix")
+	require.ErrorContains(t,
+		req.Respond([]netip.Prefix{netip.MustParsePrefix("192.0.2.1/24")}, nil),
+		"invalid assigned prefix",
+	)
+
+	copied := *req
+	require.NoError(t, req.Respond(prefixes, nil))
+	require.ErrorContains(t, copied.Respond(prefixes, nil), "already answered")
+}

transport/internet/masque/connectip/capsule.go

@@ -0,0 +1,308 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright 2024 Marten Seemann
+ * Adapted from github.com/quic-go/connect-ip-go (commit a0c35fa).
+ */
+
+package connectip
+
+import (
+	"cmp"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"net/netip"
+
+	"github.com/apernet/quic-go/http3"
+	"github.com/apernet/quic-go/quicvarint"
+)
+
+const (
+	capsuleTypeDatagram           http3.CapsuleType = 0
+	capsuleTypeAddressAssign      http3.CapsuleType = 1
+	capsuleTypeAddressRequest     http3.CapsuleType = 2
+	capsuleTypeRouteAdvertisement http3.CapsuleType = 3
+)
+
+const (
+	maxAddressesPerCapsule = 8192
+	maxRoutesPerCapsule    = 8192
+)
+
+type addressAssignCapsule struct {
+	AssignedAddresses []AssignedAddress
+}
+
+type AssignedAddress struct {
+	RequestID AddressRequestID
+	IPPrefix  netip.Prefix
+}
+
+func (a AssignedAddress) Rejected() bool {
+	return a.IPPrefix == rejectedIPv4Prefix || a.IPPrefix == rejectedIPv6Prefix
+}
+
+func (a AssignedAddress) len() int {
+	return quicvarint.Len(uint64(a.RequestID)) + 1 + a.IPPrefix.Addr().BitLen()/8 + 1
+}
+
+type addressRequestCapsule struct {
+	RequestIDs []AddressRequestID
+	Prefixes   []netip.Prefix
+}
+
+func parseAddressAssignCapsule(r http3.CapsuleReader) (*addressAssignCapsule, error) {
+	var assignedAddresses []AssignedAddress
+	for r.Remaining() > 0 {
+		if len(assignedAddresses) >= maxAddressesPerCapsule {
+			return nil, fmt.Errorf("%w: ADDRESS_ASSIGN capsule contains too many addresses (maximum %d)", errCapsuleLimit, maxAddressesPerCapsule)
+		}
+		requestID, prefix, err := parseAddress(r)
+		if err != nil {
+			return nil, err
+		}
+		assignedAddresses = append(assignedAddresses, AssignedAddress{RequestID: AddressRequestID(requestID), IPPrefix: prefix})
+	}
+	return &addressAssignCapsule{AssignedAddresses: assignedAddresses}, nil
+}
+
+func (c *addressAssignCapsule) append(b []byte) []byte {
+	totalLen := 0
+	for _, addr := range c.AssignedAddresses {
+		totalLen += addr.len()
+	}
+
+	b = quicvarint.Append(b, uint64(capsuleTypeAddressAssign))
+	b = quicvarint.Append(b, uint64(totalLen))
+
+	for _, addr := range c.AssignedAddresses {
+		b = quicvarint.Append(b, uint64(addr.RequestID))
+		if addr.IPPrefix.Addr().Is4() {
+			b = append(b, 4)
+		} else {
+			b = append(b, 6)
+		}
+		b = append(b, addr.IPPrefix.Addr().AsSlice()...)
+		b = append(b, byte(addr.IPPrefix.Bits()))
+	}
+	return b
+}
+
+func parseAddressRequestCapsule(r http3.CapsuleReader) (*addressRequestCapsule, error) {
+	if r.Remaining() == 0 {
+		return nil, errors.New("ADDRESS_REQUEST capsule contains no addresses")
+	}
+	capsule := &addressRequestCapsule{}
+	for r.Remaining() > 0 {
+		if len(capsule.Prefixes) >= maxAddressesPerCapsule {
+			return nil, fmt.Errorf("%w: ADDRESS_REQUEST capsule contains too many addresses (maximum %d)", errCapsuleLimit, maxAddressesPerCapsule)
+		}
+		requestID, prefix, err := parseAddress(r)
+		if err != nil {
+			return nil, err
+		}
+		if requestID == 0 {
+			return nil, errors.New("ADDRESS_REQUEST capsule contains a zero request ID")
+		}
+		capsule.RequestIDs = append(capsule.RequestIDs, AddressRequestID(requestID))
+		capsule.Prefixes = append(capsule.Prefixes, prefix)
+	}
+	return capsule, nil
+}
+
+func (c *addressRequestCapsule) append(b []byte) []byte {
+	var totalLen int
+	for i, p := range c.Prefixes {
+		totalLen += quicvarint.Len(uint64(c.RequestIDs[i])) + 1 + p.Addr().BitLen()/8 + 1
+	}
+
+	b = quicvarint.Append(b, uint64(capsuleTypeAddressRequest))
+	b = quicvarint.Append(b, uint64(totalLen))
+
+	for i, p := range c.Prefixes {
+		b = quicvarint.Append(b, uint64(c.RequestIDs[i]))
+		if p.Addr().Is4() {
+			b = append(b, 4)
+		} else {
+			b = append(b, 6)
+		}
+		b = append(b, p.Addr().AsSlice()...)
+		b = append(b, byte(p.Bits()))
+	}
+	return b
+}
+
+func parseAddress(r io.Reader) (requestID uint64, prefix netip.Prefix, _ error) {
+	vr := quicvarint.NewReader(r)
+	requestID, err := quicvarint.Read(vr)
+	if err != nil {
+		return 0, netip.Prefix{}, err
+	}
+	ipVersion, err := vr.ReadByte()
+	if err != nil {
+		return 0, netip.Prefix{}, err
+	}
+	var ip netip.Addr
+	switch ipVersion {
+	case 4:
+		var ipv4 [4]byte
+		if _, err := io.ReadFull(r, ipv4[:]); err != nil {
+			return 0, netip.Prefix{}, err
+		}
+		ip = netip.AddrFrom4(ipv4)
+	case 6:
+		var ipv6 [16]byte
+		if _, err := io.ReadFull(r, ipv6[:]); err != nil {
+			return 0, netip.Prefix{}, err
+		}
+		ip = netip.AddrFrom16(ipv6)
+	default:
+		return 0, netip.Prefix{}, fmt.Errorf("invalid IP version: %d", ipVersion)
+	}
+	prefixLen, err := vr.ReadByte()
+	if err != nil {
+		return 0, netip.Prefix{}, err
+	}
+	if int(prefixLen) > ip.BitLen() {
+		return 0, netip.Prefix{}, fmt.Errorf("prefix length %d exceeds IP address length (%d)", prefixLen, ip.BitLen())
+	}
+	prefix = netip.PrefixFrom(ip, int(prefixLen))
+	if prefix != prefix.Masked() {
+		return 0, netip.Prefix{}, errors.New("lower bits not covered by prefix length are not all zero")
+	}
+	return requestID, prefix, nil
+}
+
+type routeAdvertisementCapsule struct {
+	IPAddressRanges []IPRoute
+}
+
+type IPRoute struct {
+	StartIP    netip.Addr
+	EndIP      netip.Addr
+	IPProtocol uint8
+}
+
+func (r IPRoute) len() int { return 1 + r.StartIP.BitLen()/8 + r.EndIP.BitLen()/8 + 1 }
+
+func (r IPRoute) Prefixes() []netip.Prefix { return rangeToPrefixes(r.StartIP, r.EndIP) }
+
+func parseRouteAdvertisementCapsule(r http3.CapsuleReader) (*routeAdvertisementCapsule, error) {
+	var ranges []IPRoute
+	for r.Remaining() > 0 {
+		if len(ranges) >= maxRoutesPerCapsule {
+			return nil, fmt.Errorf("%w: ROUTE_ADVERTISEMENT capsule contains too many routes (maximum %d)", errCapsuleLimit, maxRoutesPerCapsule)
+		}
+		ipRange, err := parseIPAddressRange(r)
+		if err != nil {
+			return nil, err
+		}
+		if len(ranges) > 0 {
+			if err := checkRouteOrder(ranges[len(ranges)-1], ipRange); err != nil {
+				return nil, err
+			}
+		}
+		ranges = append(ranges, ipRange)
+	}
+	return &routeAdvertisementCapsule{IPAddressRanges: ranges}, nil
+}
+
+func (r IPRoute) validate() error {
+	if !r.StartIP.IsValid() || !r.EndIP.IsValid() || r.StartIP.Zone() != "" || r.EndIP.Zone() != "" {
+		return fmt.Errorf("invalid IP address range %s-%s", r.StartIP, r.EndIP)
+	}
+	if r.StartIP.Is4() != r.EndIP.Is4() {
+		return fmt.Errorf("IP address range %s-%s mixes IP versions", r.StartIP, r.EndIP)
+	}
+	if r.StartIP.Compare(r.EndIP) > 0 {
+		return fmt.Errorf("start IP %s is greater than end IP %s", r.StartIP, r.EndIP)
+	}
+	return nil
+}
+
+func checkRouteOrder(a, b IPRoute) error {
+	switch cmp.Or(
+		cmp.Compare(a.StartIP.BitLen(), b.StartIP.BitLen()),
+		cmp.Compare(a.IPProtocol, b.IPProtocol),
+	) {
+	case 1:
+		return fmt.Errorf("routes are not ordered by IP version and IP protocol: %s-%s (protocol %d) precedes %s-%s (protocol %d)",
+			a.StartIP, a.EndIP, a.IPProtocol, b.StartIP, b.EndIP, b.IPProtocol)
+	case 0:
+		if a.EndIP.Compare(b.StartIP) >= 0 {
+			return fmt.Errorf("IP address ranges %s-%s and %s-%s (protocol %d) overlap or are not in ascending order",
+				a.StartIP, a.EndIP, b.StartIP, b.EndIP, b.IPProtocol)
+		}
+	}
+	return nil
+}
+
+func (c *routeAdvertisementCapsule) append(b []byte) []byte {
+	var totalLen int
+	for _, ipRange := range c.IPAddressRanges {
+		totalLen += ipRange.len()
+	}
+
+	b = quicvarint.Append(b, uint64(capsuleTypeRouteAdvertisement))
+	b = quicvarint.Append(b, uint64(totalLen))
+
+	for _, ipRange := range c.IPAddressRanges {
+		if ipRange.StartIP.Is4() {
+			b = append(b, 4)
+		} else {
+			b = append(b, 6)
+		}
+		b = append(b, ipRange.StartIP.AsSlice()...)
+		b = append(b, ipRange.EndIP.AsSlice()...)
+		b = append(b, ipRange.IPProtocol)
+	}
+	return b
+}
+
+func parseIPAddressRange(r io.Reader) (IPRoute, error) {
+	var ipVersion uint8
+	if err := binary.Read(r, binary.LittleEndian, &ipVersion); err != nil {
+		return IPRoute{}, err
+	}
+
+	var startIP, endIP netip.Addr
+	switch ipVersion {
+	case 4:
+		var start, end [4]byte
+		if _, err := io.ReadFull(r, start[:]); err != nil {
+			return IPRoute{}, err
+		}
+		if _, err := io.ReadFull(r, end[:]); err != nil {
+			return IPRoute{}, err
+		}
+		startIP = netip.AddrFrom4(start)
+		endIP = netip.AddrFrom4(end)
+	case 6:
+		var start, end [16]byte
+		if _, err := io.ReadFull(r, start[:]); err != nil {
+			return IPRoute{}, err
+		}
+		if _, err := io.ReadFull(r, end[:]); err != nil {
+			return IPRoute{}, err
+		}
+		startIP = netip.AddrFrom16(start)
+		endIP = netip.AddrFrom16(end)
+	default:
+		return IPRoute{}, fmt.Errorf("invalid IP version: %d", ipVersion)
+	}
+
+	if startIP.Compare(endIP) > 0 {
+		return IPRoute{}, errors.New("start IP is greater than end IP")
+	}
+
+	var ipProtocol uint8
+	if err := binary.Read(r, binary.LittleEndian, &ipProtocol); err != nil {
+		return IPRoute{}, err
+	}
+	return IPRoute{
+		StartIP:    startIP,
+		EndIP:      endIP,
+		IPProtocol: ipProtocol,
+	}, nil
+}

transport/internet/masque/connectip/capsule_test.go

@@ -0,0 +1,449 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright 2024 Marten Seemann
+ * Adapted from github.com/quic-go/connect-ip-go (commit a0c35fa).
+ */
+
+package connectip
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"net"
+	"net/netip"
+	"testing"
+	"time"
+
+	"github.com/apernet/quic-go/http3"
+	"github.com/apernet/quic-go/quicvarint"
+	"github.com/stretchr/testify/require"
+)
+
+func newCapsuleReader(t *testing.T, typ http3.CapsuleType, payload []byte) http3.CapsuleReader {
+	t.Helper()
+
+	data := quicvarint.Append(nil, uint64(typ))
+	data = quicvarint.Append(data, uint64(len(payload)))
+	data = append(data, payload...)
+	parsedType, cr, err := http3.NewCapsuleParser(bytes.NewReader(data)).Next()
+	require.NoError(t, err)
+	require.Equal(t, typ, parsedType)
+	return cr
+}
+
+func testIncompleteCapsule(t *testing.T, data []byte, parse func(http3.CapsuleReader) error) {
+	t.Helper()
+
+	r := bytes.NewReader(data)
+	_, cr, err := http3.NewCapsuleParser(r).Next()
+	require.NoError(t, err)
+	require.NoError(t, parse(cr))
+	require.Zero(t, r.Len())
+	for i := range data {
+		_, cr, err := http3.NewCapsuleParser(bytes.NewReader(data[:i])).Next()
+		if err != nil {
+			if i == 0 {
+				require.ErrorIs(t, err, io.EOF)
+			} else {
+				require.ErrorIs(t, err, io.ErrUnexpectedEOF)
+			}
+			continue
+		}
+		require.ErrorIs(t, parse(cr), io.ErrUnexpectedEOF)
+	}
+}
+
+func testCapsuleEntryLimit[T any](t *testing.T, typ http3.CapsuleType, limit int, entry func(i int) []byte, parse func(http3.CapsuleReader) (*T, error)) {
+	t.Helper()
+	var payload []byte
+	for i := range limit {
+		payload = append(payload, entry(i)...)
+	}
+	r := newCapsuleReader(t, typ, payload)
+	_, err := parse(r)
+	require.NoError(t, err)
+	require.Zero(t, r.Remaining())
+
+	data := quicvarint.Append(nil, uint64(typ))
+	data = quicvarint.Append(data, uint64(len(payload)+1))
+	_, r, err = http3.NewCapsuleParser(bytes.NewReader(append(data, payload...))).Next()
+	require.NoError(t, err)
+	_, err = parse(r)
+	require.ErrorContains(t, err, "too many")
+	require.Equal(t, int64(1), r.Remaining())
+}
+
+func TestParseAddressAssignCapsule(t *testing.T) {
+	addr1 := quicvarint.Append(nil, 1337)
+	addr1 = append(addr1, 4)
+	addr1 = append(addr1, netip.AddrFrom4([4]byte{1, 2, 3, 0}).AsSlice()...)
+	addr1 = append(addr1, 24)
+	addr2 := quicvarint.Append(nil, 1338)
+	addr2 = append(addr2, 6)
+	addr2 = append(addr2, netip.MustParseAddr("2001:db8::1").AsSlice()...)
+	addr2 = append(addr2, 128)
+
+	data := quicvarint.Append(nil, uint64(capsuleTypeAddressAssign))
+	data = quicvarint.Append(data, uint64(len(addr1)+len(addr2)))
+	data = append(data, addr1...)
+	data = append(data, addr2...)
+
+	r := bytes.NewReader(data)
+	typ, cr, err := http3.NewCapsuleParser(r).Next()
+	require.NoError(t, err)
+	require.Equal(t, capsuleTypeAddressAssign, typ)
+	capsule, err := parseAddressAssignCapsule(cr)
+	require.NoError(t, err)
+	require.Equal(t,
+		[]AssignedAddress{
+			{RequestID: 1337, IPPrefix: netip.MustParsePrefix("1.2.3.0/24")},
+			{RequestID: 1338, IPPrefix: netip.MustParsePrefix("2001:db8::1/128")},
+		},
+		capsule.AssignedAddresses,
+	)
+	require.Zero(t, r.Len())
+}
+
+func TestParseAddressAssignCapsuleLimit(t *testing.T) {
+	entry := []byte{1, 4, 192, 0, 2, 1, 32}
+	testCapsuleEntryLimit(t, capsuleTypeAddressAssign, maxAddressesPerCapsule, func(int) []byte { return entry }, parseAddressAssignCapsule)
+}
+
+func TestAssignedAddressRejected(t *testing.T) {
+	for _, prefix := range []string{"0.0.0.0/32", "::/128"} {
+		require.True(t, (AssignedAddress{RequestID: 1, IPPrefix: netip.MustParsePrefix(prefix)}).Rejected())
+	}
+	for _, prefix := range []string{"0.0.0.0/0", "0.0.0.0/31", "::/0", "::/127", "192.0.2.1/32", "2001:db8::1/128"} {
+		require.False(t, (AssignedAddress{RequestID: 1, IPPrefix: netip.MustParsePrefix(prefix)}).Rejected())
+	}
+	require.False(t, (AssignedAddress{}).Rejected())
+}
+
+func TestWriteAddressAssignCapsule(t *testing.T) {
+	c := &addressAssignCapsule{
+		AssignedAddresses: []AssignedAddress{
+			{RequestID: 1337, IPPrefix: netip.MustParsePrefix("1.2.3.0/24")},
+			{RequestID: 1338, IPPrefix: netip.MustParsePrefix("2001:db8::1/128")},
+		},
+	}
+	data := c.append(nil)
+	r := bytes.NewReader(data)
+	typ, cr, err := http3.NewCapsuleParser(r).Next()
+	require.NoError(t, err)
+	require.Equal(t, capsuleTypeAddressAssign, typ)
+	parsed, err := parseAddressAssignCapsule(cr)
+	require.NoError(t, err)
+	require.Equal(t, c, parsed)
+	require.Zero(t, r.Len())
+}
+
+func TestParseAddressAssignCapsuleInvalid(t *testing.T) {
+	testParseAddressCapsuleInvalid(t, capsuleTypeAddressAssign, func(r http3.CapsuleReader) error {
+		_, err := parseAddressAssignCapsule(r)
+		return err
+	})
+}
+
+func testParseAddressCapsuleInvalid(t *testing.T, typ http3.CapsuleType, f func(r http3.CapsuleReader) error) {
+	t.Run("invalid IP version", func(t *testing.T) {
+		addr1 := quicvarint.Append(nil, 1337)
+		addr1 = append(addr1, 5)
+		addr1 = append(addr1, netip.AddrFrom4([4]byte{1, 2, 3, 4}).AsSlice()...)
+		addr1 = append(addr1, 32)
+		require.ErrorContains(t, f(newCapsuleReader(t, typ, addr1)), "invalid IP version: 5")
+	})
+
+	t.Run("invalid prefix length", func(t *testing.T) {
+		addr1 := quicvarint.Append(nil, 1337)
+		addr1 = append(addr1, 4)
+		addr1 = append(addr1, netip.AddrFrom4([4]byte{1, 2, 3, 4}).AsSlice()...)
+		addr1 = append(addr1, 33)
+		require.ErrorContains(t, f(newCapsuleReader(t, typ, addr1)), "prefix length 33 exceeds IP address length (32)")
+	})
+
+	t.Run("lower bits not covered by prefix length are not all zero", func(t *testing.T) {
+		addr1 := quicvarint.Append(nil, 1337)
+		addr1 = append(addr1, 4)
+		addr1 = append(addr1, netip.AddrFrom4([4]byte{1, 2, 3, 4}).AsSlice()...)
+		addr1 = append(addr1, 28)
+		require.ErrorContains(t, f(newCapsuleReader(t, typ, addr1)), "lower bits not covered by prefix length are not all zero")
+	})
+
+	t.Run("incomplete capsule", func(t *testing.T) {
+		var data []byte
+		switch typ {
+		case capsuleTypeAddressAssign:
+			data = (&addressAssignCapsule{
+				AssignedAddresses: []AssignedAddress{
+					{RequestID: 1337, IPPrefix: netip.MustParsePrefix("1.2.3.4/32")},
+					{RequestID: 1338, IPPrefix: netip.MustParsePrefix("2001:db8::1/128")},
+				},
+			}).append(nil)
+		case capsuleTypeAddressRequest:
+			data = (&addressRequestCapsule{
+				RequestIDs: []AddressRequestID{1337, 1338},
+				Prefixes:   []netip.Prefix{netip.MustParsePrefix("1.2.3.4/32"), netip.MustParsePrefix("2001:db8::1/128")},
+			}).append(nil)
+		default:
+			t.Fatalf("unexpected capsule type: %d", typ)
+		}
+
+		testIncompleteCapsule(t, data, f)
+	})
+}
+
+func TestParseAddressRequestCapsule(t *testing.T) {
+	addr1 := quicvarint.Append(nil, 1337)
+	addr1 = append(addr1, 4)
+	addr1 = append(addr1, netip.AddrFrom4([4]byte{1, 2, 3, 0}).AsSlice()...)
+	addr1 = append(addr1, 24)
+	addr2 := quicvarint.Append(nil, 1338)
+	addr2 = append(addr2, 6)
+	addr2 = append(addr2, netip.MustParseAddr("2001:db8::1").AsSlice()...)
+	addr2 = append(addr2, 128)
+	data := quicvarint.Append(nil, uint64(capsuleTypeAddressRequest))
+	data = quicvarint.Append(data, uint64(len(addr1)+len(addr2)))
+	data = append(data, addr1...)
+	data = append(data, addr2...)
+
+	r := bytes.NewReader(data)
+	typ, cr, err := http3.NewCapsuleParser(r).Next()
+	require.NoError(t, err)
+	require.Equal(t, capsuleTypeAddressRequest, typ)
+	capsule, err := parseAddressRequestCapsule(cr)
+	require.NoError(t, err)
+	require.Equal(t, []AddressRequestID{1337, 1338}, capsule.RequestIDs)
+	require.Equal(t, []netip.Prefix{netip.MustParsePrefix("1.2.3.0/24"), netip.MustParsePrefix("2001:db8::1/128")}, capsule.Prefixes)
+	require.Zero(t, r.Len())
+}
+
+func TestParseAddressRequestCapsuleLimit(t *testing.T) {
+	entry := []byte{1, 4, 192, 0, 2, 1, 32}
+	testCapsuleEntryLimit(t, capsuleTypeAddressRequest, maxAddressesPerCapsule, func(int) []byte { return entry }, parseAddressRequestCapsule)
+}
+
+func TestWriteAddressRequestCapsule(t *testing.T) {
+	c := &addressRequestCapsule{
+		RequestIDs: []AddressRequestID{1337, 1338},
+		Prefixes:   []netip.Prefix{netip.MustParsePrefix("1.2.3.0/24"), netip.MustParsePrefix("2001:db8::1/128")},
+	}
+	data := c.append(nil)
+	r := bytes.NewReader(data)
+	typ, cr, err := http3.NewCapsuleParser(r).Next()
+	require.NoError(t, err)
+	require.Equal(t, capsuleTypeAddressRequest, typ)
+	parsed, err := parseAddressRequestCapsule(cr)
+	require.NoError(t, err)
+	require.Equal(t, c, parsed)
+	require.Zero(t, r.Len())
+}
+
+func TestParseAddressRequestCapsuleInvalid(t *testing.T) {
+	t.Run("empty", func(t *testing.T) {
+		_, err := parseAddressRequestCapsule(newCapsuleReader(t, capsuleTypeAddressRequest, nil))
+		require.ErrorContains(t, err, "contains no addresses")
+	})
+	t.Run("zero request ID", func(t *testing.T) {
+		_, err := parseAddressRequestCapsule(newCapsuleReader(t, capsuleTypeAddressRequest, []byte{0, 4, 192, 0, 2, 1, 32}))
+		require.ErrorContains(t, err, "zero request ID")
+	})
+	testParseAddressCapsuleInvalid(t, capsuleTypeAddressRequest, func(r http3.CapsuleReader) error {
+		_, err := parseAddressRequestCapsule(r)
+		return err
+	})
+}
+
+func TestParseRouteAdvertisementCapsule(t *testing.T) {
+	iprange1 := []byte{4}
+	iprange1 = append(iprange1, netip.AddrFrom4([4]byte{1, 1, 1, 1}).AsSlice()...)
+	iprange1 = append(iprange1, netip.AddrFrom4([4]byte{1, 2, 3, 4}).AsSlice()...)
+	iprange1 = append(iprange1, 13)
+	iprange2 := []byte{6}
+	iprange2 = append(iprange2, netip.MustParseAddr("2001:db8::1").AsSlice()...)
+	iprange2 = append(iprange2, netip.MustParseAddr("2001:db8::100").AsSlice()...)
+	iprange2 = append(iprange2, 37)
+
+	data := quicvarint.Append(nil, uint64(capsuleTypeRouteAdvertisement))
+	data = quicvarint.Append(data, uint64(len(iprange1)+len(iprange2)))
+	data = append(data, iprange1...)
+	data = append(data, iprange2...)
+
+	r := bytes.NewReader(data)
+	typ, cr, err := http3.NewCapsuleParser(r).Next()
+	require.NoError(t, err)
+	require.Equal(t, capsuleTypeRouteAdvertisement, typ)
+	capsule, err := parseRouteAdvertisementCapsule(cr)
+	require.NoError(t, err)
+	require.Equal(t,
+		[]IPRoute{
+			{StartIP: netip.MustParseAddr("1.1.1.1"), EndIP: netip.MustParseAddr("1.2.3.4"), IPProtocol: 13},
+			{StartIP: netip.MustParseAddr("2001:db8::1"), EndIP: netip.MustParseAddr("2001:db8::100"), IPProtocol: 37},
+		},
+		capsule.IPAddressRanges,
+	)
+	require.Equal(t,
+		rangeToPrefixes(netip.MustParseAddr("1.1.1.1"), netip.MustParseAddr("1.2.3.4")),
+		capsule.IPAddressRanges[0].Prefixes(),
+	)
+	require.Equal(t,
+		rangeToPrefixes(netip.MustParseAddr("2001:db8::1"), netip.MustParseAddr("2001:db8::100")),
+		capsule.IPAddressRanges[1].Prefixes(),
+	)
+	require.Zero(t, r.Len())
+}
+
+func TestParseRouteAdvertisementCapsuleLimit(t *testing.T) {
+	entry := func(i int) []byte { return []byte{4, 10, 0, byte(i >> 8), byte(i), 10, 0, byte(i >> 8), byte(i), 0} }
+	testCapsuleEntryLimit(t, capsuleTypeRouteAdvertisement, maxRoutesPerCapsule, entry, parseRouteAdvertisementCapsule)
+}
+
+func TestWriteRouteAdvertisementCapsule(t *testing.T) {
+	c := &routeAdvertisementCapsule{
+		IPAddressRanges: []IPRoute{
+			{StartIP: netip.MustParseAddr("1.1.1.1"), EndIP: netip.MustParseAddr("1.2.3.4"), IPProtocol: 13},
+			{StartIP: netip.MustParseAddr("2001:db8::1"), EndIP: netip.MustParseAddr("2001:db8::100"), IPProtocol: 37},
+		},
+	}
+	data := c.append(nil)
+	r := bytes.NewReader(data)
+	typ, cr, err := http3.NewCapsuleParser(r).Next()
+	require.NoError(t, err)
+	require.Equal(t, capsuleTypeRouteAdvertisement, typ)
+	parsed, err := parseRouteAdvertisementCapsule(cr)
+	require.NoError(t, err)
+	require.Equal(t, c, parsed)
+	require.Zero(t, r.Len())
+}
+
+func TestParseRouteAdvertisementCapsuleInvalid(t *testing.T) {
+	t.Run("invalid IP version", func(t *testing.T) {
+		iprange1 := []byte{5}
+		iprange1 = append(iprange1, netip.AddrFrom4([4]byte{1, 1, 1, 1}).AsSlice()...)
+		iprange1 = append(iprange1, netip.AddrFrom4([4]byte{1, 1, 1, 2}).AsSlice()...)
+		iprange1 = append(iprange1, 13)
+		_, err := parseRouteAdvertisementCapsule(newCapsuleReader(t, capsuleTypeRouteAdvertisement, iprange1))
+		require.ErrorContains(t, err, "invalid IP version: 5")
+	})
+
+	t.Run("start IP is greater than end IP", func(t *testing.T) {
+		iprange1 := []byte{4}
+		iprange1 = append(iprange1, netip.AddrFrom4([4]byte{1, 2, 3, 4}).AsSlice()...)
+		iprange1 = append(iprange1, netip.AddrFrom4([4]byte{1, 1, 1, 1}).AsSlice()...)
+		iprange1 = append(iprange1, 13)
+		_, err := parseRouteAdvertisementCapsule(newCapsuleReader(t, capsuleTypeRouteAdvertisement, iprange1))
+		require.ErrorContains(t, err, "start IP is greater than end IP")
+	})
+
+	t.Run("incomplete capsule", func(t *testing.T) {
+		data := (&routeAdvertisementCapsule{
+			IPAddressRanges: []IPRoute{
+				{StartIP: netip.MustParseAddr("1.1.1.1"), EndIP: netip.MustParseAddr("2.2.2.2"), IPProtocol: 13},
+				{StartIP: netip.MustParseAddr("2001:db8::1"), EndIP: netip.MustParseAddr("2001:db8::100"), IPProtocol: 37},
+			},
+		}).append(nil)
+
+		testIncompleteCapsule(t, data, func(r http3.CapsuleReader) error {
+			_, err := parseRouteAdvertisementCapsule(r)
+			return err
+		})
+	})
+}
+
+var (
+	route4a  = IPRoute{StartIP: netip.MustParseAddr("10.0.0.0"), EndIP: netip.MustParseAddr("10.0.0.9")}
+	route4b  = IPRoute{StartIP: netip.MustParseAddr("10.0.0.10"), EndIP: netip.MustParseAddr("10.0.0.20")}
+	route4ab = IPRoute{StartIP: netip.MustParseAddr("10.0.0.9"), EndIP: netip.MustParseAddr("10.0.0.20")}
+	route6   = IPRoute{StartIP: netip.MustParseAddr("2001:db8::"), EndIP: netip.MustParseAddr("2001:db8::ffff")}
+)
+
+func withProtocol(r IPRoute, proto uint8) IPRoute {
+	r.IPProtocol = proto
+	return r
+}
+
+var routeOrderTests = []struct {
+	name   string
+	routes []IPRoute
+	err    string
+}{
+	{name: "empty"},
+	{name: "adjacent ranges", routes: []IPRoute{route4a, route4b}},
+	{name: "IPv4 before IPv6 with a lower IP protocol", routes: []IPRoute{withProtocol(route4a, 17), route6}},
+	{name: "same range for different IP protocols", routes: []IPRoute{withProtocol(route4a, 6), withProtocol(route4a, 17)}},
+	{name: "IP protocol order before address order", routes: []IPRoute{withProtocol(route4b, 6), withProtocol(route4a, 17)}},
+	{name: "IPv6 before IPv4", routes: []IPRoute{route6, route4a}, err: "not ordered by IP version and IP protocol"},
+	{name: "descending IP protocols", routes: []IPRoute{withProtocol(route4a, 17), withProtocol(route4b, 6)}, err: "not ordered by IP version and IP protocol"},
+	{name: "descending ranges", routes: []IPRoute{route4b, route4a}, err: "overlap or are not in ascending order"},
+	{name: "overlapping ranges", routes: []IPRoute{route4a, route4ab}, err: "overlap or are not in ascending order"},
+	{name: "duplicate range", routes: []IPRoute{route6, route6}, err: "overlap or are not in ascending order"},
+}
+
+func TestParseRouteAdvertisementCapsuleOrder(t *testing.T) {
+	for _, tc := range routeOrderTests {
+		t.Run(tc.name, func(t *testing.T) {
+			data := (&routeAdvertisementCapsule{IPAddressRanges: tc.routes}).append(nil)
+			_, cr, err := http3.NewCapsuleParser(bytes.NewReader(data)).Next()
+			require.NoError(t, err)
+			capsule, err := parseRouteAdvertisementCapsule(cr)
+			if tc.err != "" {
+				require.ErrorContains(t, err, tc.err)
+				return
+			}
+			require.NoError(t, err)
+			require.Equal(t, tc.routes, capsule.IPAddressRanges)
+		})
+	}
+}
+
+func TestAdvertiseRouteValidation(t *testing.T) {
+	tests := []struct {
+		name   string
+		routes []IPRoute
+		err    string
+	}{
+		{name: "invalid start IP", routes: []IPRoute{{EndIP: route4a.EndIP}}, err: "invalid IP address range"},
+		{name: "invalid end IP", routes: []IPRoute{{StartIP: route4a.StartIP}}, err: "invalid IP address range"},
+		{
+			name:   "IPv6 zone",
+			routes: []IPRoute{{StartIP: netip.MustParseAddr("fe80::1%eth0"), EndIP: netip.MustParseAddr("fe80::2%eth0")}},
+			err:    "invalid IP address range",
+		},
+		{name: "mixed IP versions", routes: []IPRoute{{StartIP: route4a.StartIP, EndIP: route6.EndIP}}, err: "mixes IP versions"},
+		{
+			name:   "IPv4 and IPv4-mapped IPv6",
+			routes: []IPRoute{{StartIP: netip.MustParseAddr("10.0.0.1"), EndIP: netip.MustParseAddr("::ffff:10.0.0.2")}},
+			err:    "mixes IP versions",
+		},
+		{name: "start after end", routes: []IPRoute{route4a, {StartIP: route4b.EndIP, EndIP: route4b.StartIP}}, err: "invalid route 1: start IP 10.0.0.20 is greater than end IP 10.0.0.10"},
+	}
+	tests = append(tests, routeOrderTests...)
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			conn := newProxiedConn(&mockStream{})
+			t.Cleanup(func() { conn.Close() })
+			err := conn.AdvertiseRoute(tc.routes)
+			if tc.err != "" {
+				require.ErrorContains(t, err, tc.err)
+				conn.mu.Lock()
+				defer conn.mu.Unlock()
+				require.Empty(t, conn.queuedWrites)
+				require.Nil(t, conn.localRoutes)
+				return
+			}
+			require.NoError(t, err)
+		})
+	}
+}
+
+func TestReceiveMisorderedRouteAdvertisement(t *testing.T) {
+	toRead := make(chan []byte, 1)
+	conn := newProxiedConn(&mockStream{toRead: toRead})
+	t.Cleanup(func() { conn.Close() })
+
+	toRead <- (&routeAdvertisementCapsule{IPAddressRanges: []IPRoute{route6, route4a}}).append(nil)
+	ctx, cancel := context.WithTimeout(t.Context(), time.Second)
+	defer cancel()
+	_, err := conn.Routes(ctx)
+	require.ErrorIs(t, err, net.ErrClosed)
+}

transport/internet/masque/connectip/cert_test.go

@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright 2024 Marten Seemann
+ * Adapted from github.com/quic-go/connect-ip-go (commit a0c35fa).
+ */
+
+package connectip
+
+import (
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/tls"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"log"
+	"math/big"
+	"time"
+
+	"github.com/apernet/quic-go/http3"
+)
+
+var (
+	tlsConf  *tls.Config
+	certPool *x509.CertPool
+)
+
+func generateCA() (*x509.Certificate, *rsa.PrivateKey, error) {
+	certTempl := &x509.Certificate{
+		SerialNumber:          big.NewInt(2019),
+		Subject:               pkix.Name{},
+		NotBefore:             time.Now(),
+		NotAfter:              time.Now().Add(24 * time.Hour),
+		IsCA:                  true,
+		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth, x509.ExtKeyUsageServerAuth},
+		KeyUsage:              x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
+		BasicConstraintsValid: true,
+	}
+	caPrivateKey, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		return nil, nil, err
+	}
+	caBytes, err := x509.CreateCertificate(rand.Reader, certTempl, certTempl, &caPrivateKey.PublicKey, caPrivateKey)
+	if err != nil {
+		return nil, nil, err
+	}
+	ca, err := x509.ParseCertificate(caBytes)
+	if err != nil {
+		return nil, nil, err
+	}
+	return ca, caPrivateKey, nil
+}
+
+func generateLeafCert(ca *x509.Certificate, caPrivateKey *rsa.PrivateKey) (*x509.Certificate, *rsa.PrivateKey, error) {
+	certTempl := &x509.Certificate{
+		SerialNumber: big.NewInt(1),
+		DNSNames:     []string{"localhost", "127.0.0.1"},
+		NotBefore:    time.Now(),
+		NotAfter:     time.Now().Add(24 * time.Hour),
+		ExtKeyUsage:  []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth, x509.ExtKeyUsageServerAuth},
+		KeyUsage:     x509.KeyUsageDigitalSignature,
+	}
+	privKey, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		return nil, nil, err
+	}
+	certBytes, err := x509.CreateCertificate(rand.Reader, certTempl, ca, &privKey.PublicKey, caPrivateKey)
+	if err != nil {
+		return nil, nil, err
+	}
+	cert, err := x509.ParseCertificate(certBytes)
+	if err != nil {
+		return nil, nil, err
+	}
+	return cert, privKey, nil
+}
+
+func init() {
+	ca, caPrivateKey, err := generateCA()
+	if err != nil {
+		log.Fatal("failed to generate CA certificate:", err)
+	}
+	leafCert, leafPrivateKey, err := generateLeafCert(ca, caPrivateKey)
+	if err != nil {
+		log.Fatal("failed to generate leaf certificate:", err)
+	}
+	certPool = x509.NewCertPool()
+	certPool.AddCert(ca)
+	tlsConf = &tls.Config{
+		Certificates: []tls.Certificate{{
+			Certificate: [][]byte{leafCert.Raw},
+			PrivateKey:  leafPrivateKey,
+		}},
+		NextProtos: []string{http3.NextProtoH3},
+	}
+}

transport/internet/masque/connectip/checksum.go

@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright 2024 Marten Seemann
+ * Adapted from github.com/quic-go/connect-ip-go (commit a0c35fa).
+ */
+
+package connectip
+
+import "encoding/binary"
+
+func calculateIPv4Checksum(header []byte) uint16 {
+	var sum uint32
+	for i := 0; i < len(header); i += 2 {
+		if i == 10 {
+			continue
+		}
+		sum += uint32(binary.BigEndian.Uint16(header[i : i+2]))
+	}
+	for (sum >> 16) > 0 {
+		sum = (sum & 0xffff) + (sum >> 16)
+	}
+	return ^uint16(sum)
+}

transport/internet/masque/connectip/checksum_test.go

@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright 2024 Marten Seemann
+ * Adapted from github.com/quic-go/connect-ip-go (commit a0c35fa).
+ */
+
+package connectip
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestIPv4ChecksumTestVector(t *testing.T) {
+	data := []byte{0x45, 0x00, 0x00, 0x73, 0x00, 0x00, 0x40, 0x00, 0x40, 0x11, 0xb8, 0x61, 0xc0, 0xa8, 0x00, 0x01, 0xc0, 0xa8, 0x00, 0xc7}
+	checksum := calculateIPv4Checksum(data)
+	require.Equal(t, uint16(0xb861), checksum)
+}
+
+func TestIPv4ChecksumWithOptions(t *testing.T) {
+	data := []byte{0x46, 0x00, 0x00, 0x77, 0x00, 0x00, 0x40, 0x00, 0x40, 0x11, 0x00, 0x00, 0xc0, 0xa8, 0x00, 0x01, 0xc0, 0xa8, 0x00, 0xc7, 0x94, 0x04, 0x00, 0x00}
+	checksum := calculateIPv4Checksum(data)
+	data[10], data[11] = byte(checksum>>8), byte(checksum)
+	require.True(t, ipv4ChecksumValid(data))
+	require.NotEqual(t, checksum, calculateIPv4Checksum(data[:20]), "the options must be covered")
+}