Add tests for TUN system stack (TCP/UDP)

Co-authored-by: RPRX <63339210+RPRX@users.noreply.github.com>

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)

go.mod

@@ -24,11 +24,11 @@ require (
 	github.com/vishvananda/netlink v1.3.1
 	github.com/xtls/reality v0.0.0-20260908062103-8cdf7bf9c7f0
 	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
@@ -57,7 +57,7 @@ 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

go.sum

@@ -111,8 +111,8 @@ 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 +121,12 @@ 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 v0.0.0-20190215142949-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 +134,14 @@ 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=

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 +36,8 @@ 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 "xdrive":
+		return "xdrive", nil
 	default:
 		return "", errors.New("Config: unknown transport protocol: ", p)
 	}
@@ -59,6 +61,7 @@ type StreamConfig struct {
 	WSSettings          *WebSocketConfig   `json:"wsSettings"`
 	HTTPUPGRADESettings *HttpUpgradeConfig `json:"httpupgradeSettings"`
 	HysteriaSettings    *HysteriaConfig    `json:"hysteriaSettings"`
+	XDRIVESettings      *XDriveConfig      `json:"xdriveSettings"`
 	SocketSettings      *SocketConfig      `json:"sockopt"`
 }
 
@@ -192,6 +195,16 @@ func (c *StreamConfig) Build() (*internet.StreamConfig, error) {
 			Settings:     serial.ToTypedMessage(hs),
 		})
 	}
+	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

@@ -23,6 +23,7 @@ import (
 	"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"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -794,3 +795,50 @@ 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/tun.go

@@ -20,6 +20,7 @@ type TunConfig struct {
 	UserLevel              uint32   `json:"userLevel"`
 	AutoSystemRoutingTable []string `json:"autoSystemRoutingTable"`
 	AutoOutboundsInterface *string  `json:"autoOutboundsInterface"`
+	Stack                  string   `json:"stack"`
 }
 
 func (v *TunConfig) Build() (proto.Message, error) {
@@ -31,6 +32,7 @@ func (v *TunConfig) Build() (proto.Message, error) {
 		DNS:                    v.DNS,
 		UserLevel:              v.UserLevel,
 		AutoSystemRoutingTable: v.AutoSystemRoutingTable,
+		Stack:                  v.Stack,
 	}
 	if v.AutoOutboundsInterface != nil {
 		config.AutoOutboundsInterface = *v.AutoOutboundsInterface
@@ -52,6 +54,11 @@ func (v *TunConfig) Build() (proto.Message, error) {
 	if config.MTU == 0 {
 		config.MTU = 1500
 	}
+	switch config.Stack {
+	case "", "gvisor", "system":
+	default:
+		return nil, fmt.Errorf("unknown tun stack: %s (must be \"gvisor\" or \"system\")", config.Stack)
+	}
 	return config, nil
 }
 

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

main/distro/all/all.go

@@ -60,6 +60,7 @@ import (
 	_ "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/tun/config.pb.go

@@ -32,6 +32,7 @@ type Config struct {
 	AutoSystemRoutingTable []string               `protobuf:"bytes,6,rep,name=auto_system_routing_table,json=autoSystemRoutingTable,proto3" json:"auto_system_routing_table,omitempty"`
 	AutoOutboundsInterface string                 `protobuf:"bytes,7,opt,name=auto_outbounds_interface,json=autoOutboundsInterface,proto3" json:"auto_outbounds_interface,omitempty"`
 	Desc                   string                 `protobuf:"bytes,8,opt,name=desc,proto3" json:"desc,omitempty"`
+	Stack                  string                 `protobuf:"bytes,9,opt,name=stack,proto3" json:"stack,omitempty"`
 	unknownFields          protoimpl.UnknownFields
 	sizeCache              protoimpl.SizeCache
 }
@@ -122,11 +123,18 @@ func (x *Config) GetDesc() string {
 	return ""
 }
 
+func (x *Config) GetStack() string {
+	if x != nil {
+		return x.Stack
+	}
+	return ""
+}
+
 var File_proxy_tun_config_proto protoreflect.FileDescriptor
 
 const file_proxy_tun_config_proto_rawDesc = "" +
 	"\n" +
-	"\x16proxy/tun/config.proto\x12\x0exray.proxy.tun\"\x82\x02\n" +
+	"\x16proxy/tun/config.proto\x12\x0exray.proxy.tun\"\x98\x02\n" +
 	"\x06Config\x12\x12\n" +
 	"\x04name\x18\x01 \x01(\tR\x04name\x12\x10\n" +
 	"\x03MTU\x18\x02 \x01(\rR\x03MTU\x12\x18\n" +
@@ -136,7 +144,8 @@ const file_proxy_tun_config_proto_rawDesc = "" +
 	"user_level\x18\x05 \x01(\rR\tuserLevel\x129\n" +
 	"\x19auto_system_routing_table\x18\x06 \x03(\tR\x16autoSystemRoutingTable\x128\n" +
 	"\x18auto_outbounds_interface\x18\a \x01(\tR\x16autoOutboundsInterface\x12\x12\n" +
-	"\x04desc\x18\b \x01(\tR\x04descBL\n" +
+	"\x04desc\x18\b \x01(\tR\x04desc\x12\x14\n" +
+	"\x05stack\x18\t \x01(\tR\x05stackBL\n" +
 	"\x12com.xray.proxy.tunP\x01Z#github.com/xtls/xray-core/proxy/tun\xaa\x02\x0eXray.Proxy.Tunb\x06proto3"
 
 var (

proxy/tun/config.proto

@@ -15,4 +15,5 @@ message Config {
   repeated string auto_system_routing_table = 6;
   string auto_outbounds_interface = 7;
   string desc = 8;
+  string stack = 9;
 }

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)
@@ -124,7 +143,9 @@ func (t *Handler) Start() error {
 
 	tunStackOptions := StackOptions{
 		Tun:         tunInterface,
+		MTU:         t.config.MTU,
 		IdleTimeout: t.policyManager.ForLevel(t.config.UserLevel).Timeouts.ConnectionIdle,
+		Backend:     t.config.Stack,
 	}
 	tunStack, err := NewStack(t.ctx, tunStackOptions, t)
 	if err != nil {
@@ -171,7 +192,8 @@ 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 +225,18 @@ 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/tun/stack.go

@@ -1,7 +1,10 @@
 package tun
 
 import (
+	"context"
 	"time"
+
+	"github.com/xtls/xray-core/common/errors"
 )
 
 // Stack interface implement ip protocol stack, bridging raw network packets and data streams
@@ -13,5 +16,39 @@ type Stack interface {
 // StackOptions for the stack implementation
 type StackOptions struct {
 	Tun         Tun
+	MTU         uint32
 	IdleTimeout time.Duration
+	// Backend selects the concrete Stack implementation, see NewStack.
+	Backend string
+}
+
+const (
+	// StackGVisor selects the full-featured gVisor based stack (default).
+	StackGVisor = "gvisor"
+	// StackSystem selects the lightweight, Xray-native stack, see newSystemStack.
+	StackSystem = "system"
+)
+
+// NewStack builds the ip stack selected by options.Backend.
+//
+// gVisor (the default/"gvisor" backend) is a general purpose stack, built
+// with the semantics needed for a real, lossy public network in mind:
+// congestion control, SACK/RACK loss recovery, retransmission timers, etc.
+// TUN traffic instead travels over a local, kernel-to-userspace channel that
+// neither reorders nor drops packets in normal operation, so none of that
+// complexity is actually required to shuffle bytes between it and the
+// dispatcher. The "system" backend trades gVisor's generality for a much
+// smaller, more direct code path tailored to that trusted, in-order channel:
+// no congestion control, no SACK/RACK, minimal buffering, and a plain RTO
+// timer as a safety net for the rare real loss, rather than a full
+// re-implementation of one. See stack_system.go for details.
+func NewStack(ctx context.Context, options StackOptions, handler *Handler) (Stack, error) {
+	switch options.Backend {
+	case "", StackGVisor:
+		return newGVisorStack(ctx, options, handler)
+	case StackSystem:
+		return newSystemStack(ctx, options, handler)
+	default:
+		return nil, errors.New("unknown tun stack: ", options.Backend)
+	}
 }

proxy/tun/stack_gvisor.go

@@ -42,8 +42,8 @@ type stackGVisor struct {
 	endpoint    stack.LinkEndpoint
 }
 
-// NewStack builds new ip stack (using gVisor)
-func NewStack(ctx context.Context, options StackOptions, handler *Handler) (Stack, error) {
+// newGVisorStack builds new ip stack (using gVisor)
+func newGVisorStack(ctx context.Context, options StackOptions, handler *Handler) (Stack, error) {
 	gStack := &stackGVisor{
 		ctx:         ctx,
 		tun:         options.Tun,

proxy/tun/stack_system.go

@@ -0,0 +1,370 @@
+package tun
+
+import (
+	"context"
+	"crypto/rand"
+	"encoding/binary"
+	"errors"
+	"sync"
+	"time"
+
+	xerrors "github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/net"
+	tunicmp "github.com/xtls/xray-core/proxy/tun/icmp"
+	"gvisor.dev/gvisor/pkg/buffer"
+	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/checksum"
+	"gvisor.dev/gvisor/pkg/tcpip/header"
+	"gvisor.dev/gvisor/pkg/tcpip/seqnum"
+	"gvisor.dev/gvisor/pkg/tcpip/stack"
+)
+
+// stackSystem is the lightweight, Xray-native ip stack, see NewStack.
+//
+// It reads and parses IPv4/IPv6 packets directly off the tun device (through
+// the GVisorDevice interface, already implemented for every supported
+// platform), without involving gVisor's stack.Stack, NIC or routing
+// machinery. UDP and ICMP echo reuse the exact same handlers as the gVisor
+// backend (udpConnectionHandler, tun/icmp) since those were already
+// implemented in terms of raw bytes. TCP is handled by a small dedicated
+// state machine, see stack_system_tcp.go.
+type stackSystem struct {
+	ctx         context.Context
+	device      GVisorDevice
+	mtu         uint32
+	idleTimeout time.Duration
+	// handler is stored as the narrower ConnectionHandler interface (which
+	// *Handler satisfies) rather than *Handler itself, so the stack can be
+	// exercised in tests with a lightweight fake, the same way stack_system_test.go does.
+	handler ConnectionHandler
+
+	udp *udpConnectionHandler
+
+	tcpMu sync.Mutex
+	tcp   map[tcpKey]*tcpConn
+
+	cancel context.CancelFunc
+}
+
+const systemStackDefaultMTU = 1500
+
+// newSystemStack builds the lightweight "system" ip stack, see NewStack.
+func newSystemStack(ctx context.Context, options StackOptions, handler *Handler) (Stack, error) {
+	device, ok := options.Tun.(GVisorDevice)
+	if !ok {
+		return nil, xerrors.New("tun stack \"system\" is not supported by this tun device")
+	}
+	mtu := options.MTU
+	if mtu == 0 {
+		mtu = systemStackDefaultMTU
+	}
+	return &stackSystem{
+		ctx:         ctx,
+		device:      device,
+		mtu:         mtu,
+		idleTimeout: options.IdleTimeout,
+		handler:     handler,
+		tcp:         make(map[tcpKey]*tcpConn),
+	}, nil
+}
+
+// Start is called by Handler to bring the stack to life
+func (s *stackSystem) Start() error {
+	ctx, cancel := context.WithCancel(s.ctx)
+	s.cancel = cancel
+	s.udp = newUdpConnectionHandler(s.handler.HandleConnection, s.writeRawUDPPacket)
+
+	go s.dispatchLoop(ctx)
+	go s.idleReapLoop(ctx)
+	return nil
+}
+
+// Close is called by Handler to shut down the stack
+func (s *stackSystem) Close() error {
+	if s.cancel != nil {
+		s.cancel()
+	}
+
+	s.tcpMu.Lock()
+	conns := make([]*tcpConn, 0, len(s.tcp))
+	for _, c := range s.tcp {
+		conns = append(conns, c)
+	}
+	s.tcp = make(map[tcpKey]*tcpConn)
+	s.tcpMu.Unlock()
+
+	for _, c := range conns {
+		c.abort(errStackClosed)
+	}
+
+	return nil
+}
+
+// dispatchLoop reads and demultiplexes packets off the tun device, until ctx
+// is cancelled or the device fails permanently. It mirrors LinkEndpoint's own
+// dispatchLoop (stack_gvisor_endpoint.go), reusing the exact same GVisorDevice
+// contract, but hands packets to this file's own IPv4/IPv6 parsing instead of
+// gVisor's NIC/stack.Stack.
+func (s *stackSystem) dispatchLoop(ctx context.Context) {
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		default:
+		}
+
+		version, packet, err := s.device.ReadPacket()
+		if err != nil {
+			if errors.Is(err, ErrQueueEmpty) {
+				s.device.Wait()
+				continue
+			}
+			return
+		}
+
+		s.handlePacket(version, packet)
+		packet.DecRef()
+	}
+}
+
+func (s *stackSystem) handlePacket(version byte, packet *stack.PacketBuffer) {
+	data := concatSlices(packet.AsSlices())
+	if len(data) == 0 {
+		return
+	}
+
+	switch version {
+	case 4:
+		s.handleIPv4(data)
+	case 6:
+		s.handleIPv6(data)
+	}
+}
+
+func concatSlices(slices [][]byte) []byte {
+	if len(slices) == 1 {
+		return slices[0]
+	}
+	total := 0
+	for _, sl := range slices {
+		total += len(sl)
+	}
+	if total == 0 {
+		return nil
+	}
+	data := make([]byte, 0, total)
+	for _, sl := range slices {
+		data = append(data, sl...)
+	}
+	return data
+}
+
+func (s *stackSystem) handleIPv4(data []byte) {
+	hdr := header.IPv4(data)
+	if !hdr.IsValid(len(data)) {
+		return
+	}
+	// fragmentation is not supported: the tun MTU is expected to keep locally
+	// generated packets from ever needing it, same as the gVisor backend's
+	// default configuration
+	if hdr.More() || hdr.FragmentOffset() != 0 {
+		return
+	}
+
+	s.handleTransport(header.IPv4ProtocolNumber, hdr.TransportProtocol(), hdr.SourceAddress(), hdr.DestinationAddress(), hdr.Payload())
+}
+
+func (s *stackSystem) handleIPv6(data []byte) {
+	hdr := header.IPv6(data)
+	if !hdr.IsValid(len(data)) {
+		return
+	}
+
+	// only directly-encapsulated transport headers are handled, IPv6
+	// extension headers (rare for ordinary locally generated traffic) are not
+	// walked, same limitation as the fragmentation one above
+	s.handleTransport(header.IPv6ProtocolNumber, hdr.TransportProtocol(), hdr.SourceAddress(), hdr.DestinationAddress(), hdr.Payload())
+}
+
+func (s *stackSystem) handleTransport(netProto tcpip.NetworkProtocolNumber, transProto tcpip.TransportProtocolNumber, srcIP, dstIP tcpip.Address, payload []byte) {
+	switch transProto {
+	case header.TCPProtocolNumber:
+		s.handleTCP(netProto, srcIP, dstIP, payload)
+	case header.UDPProtocolNumber:
+		s.handleUDP(netProto, srcIP, dstIP, payload)
+	case header.ICMPv4ProtocolNumber:
+		if netProto == header.IPv4ProtocolNumber {
+			s.handleICMP(netProto, srcIP, dstIP, payload)
+		}
+	case header.ICMPv6ProtocolNumber:
+		if netProto == header.IPv6ProtocolNumber {
+			s.handleICMP(netProto, srcIP, dstIP, payload)
+		}
+	}
+}
+
+func (s *stackSystem) handleUDP(netProto tcpip.NetworkProtocolNumber, srcIP, dstIP tcpip.Address, payload []byte) {
+	if len(payload) < header.UDPMinimumSize {
+		return
+	}
+	udpHdr := header.UDP(payload)
+	length := udpHdr.Length()
+	if int(length) < header.UDPMinimumSize || int(length) > len(payload) {
+		return
+	}
+
+	// source/destination of the packet we process as incoming are, in other terms,
+	// src is the side behind tun, dst is the side behind the dispatcher
+	src := net.UDPDestination(net.IPAddress(srcIP.AsSlice()), net.Port(udpHdr.SourcePort()))
+	dst := net.UDPDestination(net.IPAddress(dstIP.AsSlice()), net.Port(udpHdr.DestinationPort()))
+	s.udp.HandlePacket(src, dst, payload[header.UDPMinimumSize:length])
+}
+
+func (s *stackSystem) handleICMP(netProto tcpip.NetworkProtocolNumber, srcIP, dstIP tcpip.Address, message []byte) {
+	ident, sequence, ok := tunicmp.ParseEchoRequest(netProto, message)
+	if !ok {
+		return
+	}
+
+	reply, err := tunicmp.BuildLocalEchoReply(netProto, message, dstIP, srcIP)
+	if err != nil {
+		xerrors.LogInfoInner(s.ctx, err, "[tun] failed to build local icmp echo reply")
+		return
+	}
+
+	xerrors.LogDebug(s.ctx, "[tun][icmp] ", tunicmp.ProtocolLabel(netProto), " local echo reply ", dstIP, " -> ", srcIP, " id=", ident, " seq=", sequence)
+
+	transProto := header.ICMPv4ProtocolNumber
+	if netProto == header.IPv6ProtocolNumber {
+		transProto = header.ICMPv6ProtocolNumber
+	}
+	if err := s.writeTransportSegment(netProto, tcpip.TransportProtocolNumber(transProto), dstIP, srcIP, reply); err != nil {
+		xerrors.LogInfoInner(s.ctx, err, "[tun] failed to write local icmp echo reply")
+	}
+}
+
+func (s *stackSystem) writeRawUDPPacket(payload []byte, src net.Destination, dst net.Destination) error {
+	udpLen := header.UDPMinimumSize + len(payload)
+	srcIP := tcpip.AddrFromSlice(src.Address.IP())
+	dstIP := tcpip.AddrFromSlice(dst.Address.IP())
+
+	netProto := header.IPv4ProtocolNumber
+	if !dst.Address.Family().IsIPv4() {
+		netProto = header.IPv6ProtocolNumber
+	}
+
+	segment := make([]byte, udpLen)
+	udpHdr := header.UDP(segment)
+	udpHdr.Encode(&header.UDPFields{
+		SrcPort: uint16(src.Port),
+		DstPort: uint16(dst.Port),
+		Length:  uint16(udpLen),
+	})
+	copy(segment[header.UDPMinimumSize:], payload)
+
+	xsum := header.PseudoHeaderChecksum(header.UDPProtocolNumber, srcIP, dstIP, uint16(udpLen))
+	udpHdr.SetChecksum(^udpHdr.CalculateChecksum(checksum.Checksum(payload, xsum)))
+
+	return s.writeTransportSegment(netProto, header.UDPProtocolNumber, srcIP, dstIP, segment)
+}
+
+// writeTransportSegment wraps a fully built, already checksummed transport
+// layer segment (UDP, ICMP or TCP) with an IP header and writes it to the tun
+// device.
+func (s *stackSystem) writeTransportSegment(netProto tcpip.NetworkProtocolNumber, transProto tcpip.TransportProtocolNumber, srcIP, dstIP tcpip.Address, segment []byte) error {
+	ipHdrSize := header.IPv4MinimumSize
+	if netProto == header.IPv6ProtocolNumber {
+		ipHdrSize = header.IPv6MinimumSize
+	}
+
+	pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
+		ReserveHeaderBytes: ipHdrSize,
+		Payload:            buffer.MakeWithData(segment),
+	})
+	defer pkt.DecRef()
+
+	if netProto == header.IPv4ProtocolNumber {
+		ipHdr := header.IPv4(pkt.NetworkHeader().Push(header.IPv4MinimumSize))
+		ipHdr.Encode(&header.IPv4Fields{
+			TotalLength: uint16(header.IPv4MinimumSize + len(segment)),
+			TTL:         64,
+			Protocol:    uint8(transProto),
+			SrcAddr:     srcIP,
+			DstAddr:     dstIP,
+		})
+		ipHdr.SetChecksum(^ipHdr.CalculateChecksum())
+	} else {
+		ipHdr := header.IPv6(pkt.NetworkHeader().Push(header.IPv6MinimumSize))
+		ipHdr.Encode(&header.IPv6Fields{
+			PayloadLength:     uint16(len(segment)),
+			TransportProtocol: transProto,
+			HopLimit:          64,
+			SrcAddr:           srcIP,
+			DstAddr:           dstIP,
+		})
+	}
+
+	if err := s.device.WritePacket(pkt); err != nil {
+		return xerrors.New("failed to write raw packet: ", err.String())
+	}
+	return nil
+}
+
+// idleReapLoop periodically aborts tcp connections that have seen no traffic
+// for longer than idleTimeout, finally putting that option to use (it was
+// tracked but never read anywhere before the "system" backend existed).
+func (s *stackSystem) idleReapLoop(ctx context.Context) {
+	if s.idleTimeout <= 0 {
+		return
+	}
+	interval := s.idleTimeout / 4
+	if interval < time.Second {
+		interval = time.Second
+	}
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			s.reapIdleConnections()
+		}
+	}
+}
+
+func (s *stackSystem) reapIdleConnections() {
+	deadline := time.Now().Add(-s.idleTimeout)
+
+	s.tcpMu.Lock()
+	var idle []*tcpConn
+	for _, c := range s.tcp {
+		if c.lastActiveTime().Before(deadline) {
+			idle = append(idle, c)
+		}
+	}
+	s.tcpMu.Unlock()
+
+	for _, c := range idle {
+		c.abort(errConnIdleTimeout)
+	}
+}
+
+func (s *stackSystem) removeTCPConn(key tcpKey, c *tcpConn) {
+	s.tcpMu.Lock()
+	if existing, ok := s.tcp[key]; ok && existing == c {
+		delete(s.tcp, key)
+	}
+	s.tcpMu.Unlock()
+}
+
+// randomSequenceNumber returns a random initial sequence number for a new
+// connection. It doesn't need to be cryptographically unpredictable (the tun
+// channel is local and trusted), just varied enough to avoid confusion with
+// prior incarnations of the same 4-tuple.
+func randomSequenceNumber() seqnum.Value {
+	var b [4]byte
+	_, _ = rand.Read(b[:])
+	return seqnum.Value(binary.BigEndian.Uint32(b[:]))
+}

proxy/tun/stack_system_tcp.go

@@ -0,0 +1,725 @@
+package tun
+
+import (
+	"io"
+	"sync"
+	"time"
+
+	xerrors "github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/net"
+	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/checksum"
+	"gvisor.dev/gvisor/pkg/tcpip/header"
+	"gvisor.dev/gvisor/pkg/tcpip/seqnum"
+)
+
+// This file implements a small, dedicated TCP state machine for the "system"
+// tun stack, see stack_system.go. It intentionally does not implement window
+// scaling, SACK, timestamps, congestion control, fast retransmit or
+// out-of-order reassembly: the tun channel only ever carries packets produced
+// by the local OS network stack and handed to us directly, so it neither
+// reorders nor drops them the way the public internet does; a single RTO
+// timer (also used for zero-window probing) is enough to make the connection
+// robust against the rare occasions a segment does not make it through.
+const (
+	minRTO         = 300 * time.Millisecond
+	maxRTO         = 30 * time.Second
+	maxRTORetries  = 12
+	lingerDuration = 5 * time.Second
+
+	// maxSendBuffer/maxRecvBuffer match the gVisor backend's own default
+	// buffer sizes (tcp.DefaultSendBufferSize/DefaultReceiveBufferSize), so
+	// switching between backends does not change buffering expectations.
+	maxSendBuffer = 1 << 20
+	maxRecvBuffer = 1 << 20
+)
+
+var (
+	errStackClosed     = xerrors.New("tun stack closed")
+	errConnReset       = xerrors.New("connection reset by peer")
+	errConnClosed      = xerrors.New("use of closed network connection")
+	errConnIdleTimeout = xerrors.New("connection idle timeout")
+	errConnTimedOut    = xerrors.New("connection timed out")
+)
+
+type tcpState uint8
+
+const (
+	stateSynRcvd tcpState = iota
+	stateEstablished
+	stateCloseWait // peer's FIN was received; we may still send until we close too
+	stateClosing   // our FIN was sent (from Established or CloseWait)
+	stateTimeWait  // both FINs exchanged and acked; short linger before removal
+	stateClosed    // terminal, removed from the connection table
+)
+
+// tcpKey identifies a tcp connection the same way it appears on the wire
+// flowing from the app behind the tun device towards its destination.
+type tcpKey struct {
+	netProto tcpip.NetworkProtocolNumber
+	srcAddr  tcpip.Address
+	srcPort  uint16
+	dstAddr  tcpip.Address
+	dstPort  uint16
+}
+
+// tcpConn is a minimal TCP endpoint implementing net.Conn. It deliberately
+// exposes only plain Read/Write (never ReadMultiBuffer/WriteMultiBuffer) so
+// that stat.CounterConnection in handler.go keeps accounting traffic
+// correctly, matching the udpConn precedent in udp_fullcone.go.
+type tcpConn struct {
+	stack *stackSystem
+	key   tcpKey
+	src   net.Destination
+	dst   net.Destination
+
+	ourMSS int
+
+	mu   sync.Mutex
+	cond *sync.Cond
+
+	state tcpState
+
+	// send side. sendQueue[0] always holds the byte at sequence sndUna: acked
+	// bytes are trimmed off the front, so no separate "acked" bookkeeping is
+	// needed. sendQueue[:unsentOffset] has been transmitted at least once;
+	// sendQueue[unsentOffset:] never has.
+	iss          seqnum.Value
+	sndUna       seqnum.Value
+	sndNxt       seqnum.Value
+	sndMSS       int
+	peerWindow   uint32
+	sendQueue    []byte
+	unsentOffset int
+	closeCalled  bool
+	finSent      bool
+	finAcked     bool
+	finSeq       seqnum.Value
+
+	// receive side.
+	irs          seqnum.Value
+	rcvNxt       seqnum.Value
+	recvQueue    [][]byte
+	recvOffset   int
+	recvBuffered int
+	recvClosed   bool
+
+	err error
+
+	lastActive time.Time
+
+	rtoTimer    *time.Timer
+	rtoBackoff  int
+	lingerTimer *time.Timer
+}
+
+var _ net.Conn = (*tcpConn)(nil)
+
+// outgoingMSS returns the MSS we can use without ever needing IP
+// fragmentation (unsupported), given the tun device's MTU.
+func outgoingMSS(mtu uint32, netProto tcpip.NetworkProtocolNumber) int {
+	ipHdrSize := header.IPv4MinimumSize
+	if netProto == header.IPv6ProtocolNumber {
+		ipHdrSize = header.IPv6MinimumSize
+	}
+	mss := int(mtu) - ipHdrSize - header.TCPMinimumSize
+	const minMSS = 88
+	if mss < minMSS {
+		mss = minMSS
+	}
+	return mss
+}
+
+// handleTCP is the tcp entry point from stackSystem.handleTransport.
+func (s *stackSystem) handleTCP(netProto tcpip.NetworkProtocolNumber, srcIP, dstIP tcpip.Address, payload []byte) {
+	if len(payload) < header.TCPMinimumSize {
+		return
+	}
+	tcpHdr := header.TCP(payload)
+	if _, _, ok := header.TCPValid(tcpHdr, nil, 0, tcpip.Address{}, tcpip.Address{}, true); !ok {
+		return
+	}
+
+	key := tcpKey{
+		netProto: netProto,
+		srcAddr:  srcIP,
+		srcPort:  tcpHdr.SourcePort(),
+		dstAddr:  dstIP,
+		dstPort:  tcpHdr.DestinationPort(),
+	}
+
+	s.tcpMu.Lock()
+	conn, ok := s.tcp[key]
+	s.tcpMu.Unlock()
+
+	if ok {
+		conn.handleSegment(tcpHdr)
+		return
+	}
+
+	flags := tcpHdr.Flags()
+	if flags&header.TCPFlagRst != 0 {
+		return // never generate a reset in response to a reset
+	}
+	if flags&header.TCPFlagSyn != 0 && flags&header.TCPFlagAck == 0 {
+		s.newTCPConn(key, tcpHdr)
+		return
+	}
+
+	// any other segment referencing an unknown connection: let the peer know
+	// promptly it no longer/never existed, same as a real kernel would
+	s.sendRawTCPReset(key, tcpHdr)
+}
+
+func (s *stackSystem) newTCPConn(key tcpKey, tcpHdr header.TCP) {
+	synOpts := header.ParseSynOptions(tcpHdr.Options(), false)
+
+	c := &tcpConn{
+		stack: s,
+		key:   key,
+		src:   net.TCPDestination(net.IPAddress(key.srcAddr.AsSlice()), net.Port(key.srcPort)),
+		dst:   net.TCPDestination(net.IPAddress(key.dstAddr.AsSlice()), net.Port(key.dstPort)),
+		state: stateSynRcvd,
+	}
+	c.cond = sync.NewCond(&c.mu)
+
+	c.iss = randomSequenceNumber()
+	c.sndUna = c.iss
+	c.sndNxt = c.iss.Add(1)
+
+	c.irs = seqnum.Value(tcpHdr.SequenceNumber())
+	c.rcvNxt = c.irs.Add(1)
+
+	c.ourMSS = outgoingMSS(s.mtu, key.netProto)
+	c.sndMSS = int(synOpts.MSS)
+	if c.sndMSS <= 0 || c.sndMSS > c.ourMSS {
+		c.sndMSS = c.ourMSS
+	}
+	c.lastActive = time.Now()
+
+	s.tcpMu.Lock()
+	s.tcp[key] = c
+	s.tcpMu.Unlock()
+
+	c.mu.Lock()
+	c.sendSynAckLocked()
+	c.mu.Unlock()
+}
+
+// sendRawTCPReset replies to a segment that does not match any known
+// connection, following the rules of RFC 9293 §3.10.7.1.
+func (s *stackSystem) sendRawTCPReset(key tcpKey, tcpHdr header.TCP) {
+	flags := tcpHdr.Flags()
+	segLen := seqnum.Size(len(tcpHdr.Payload()))
+	if flags&header.TCPFlagSyn != 0 {
+		segLen++
+	}
+	if flags&header.TCPFlagFin != 0 {
+		segLen++
+	}
+
+	var seq, ack seqnum.Value
+	var ackFlag header.TCPFlags
+	if flags&header.TCPFlagAck != 0 {
+		seq = seqnum.Value(tcpHdr.AckNumber())
+	} else {
+		ack = seqnum.Value(tcpHdr.SequenceNumber()).Add(segLen)
+		ackFlag = header.TCPFlagAck
+	}
+
+	segment := make([]byte, header.TCPMinimumSize)
+	rst := header.TCP(segment)
+	rst.Encode(&header.TCPFields{
+		SrcPort:    key.dstPort,
+		DstPort:    key.srcPort,
+		SeqNum:     uint32(seq),
+		AckNum:     uint32(ack),
+		DataOffset: header.TCPMinimumSize,
+		Flags:      header.TCPFlagRst | ackFlag,
+		WindowSize: 0,
+	})
+	xsum := header.PseudoHeaderChecksum(header.TCPProtocolNumber, key.dstAddr, key.srcAddr, uint16(len(segment)))
+	rst.SetChecksum(^rst.CalculateChecksum(xsum))
+
+	if err := s.writeTransportSegment(key.netProto, header.TCPProtocolNumber, key.dstAddr, key.srcAddr, segment); err != nil {
+		xerrors.LogInfoInner(s.ctx, err, "[tun] failed to write tcp reset")
+	}
+}
+
+func (c *tcpConn) lastActiveTime() time.Time {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return c.lastActive
+}
+
+// abort is the externally callable (unlocked) equivalent of abortLocked,
+// used by the idle reaper and by Close's callers indirectly through it.
+func (c *tcpConn) abort(err error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.abortLocked(err)
+}
+
+func (c *tcpConn) abortLocked(err error) {
+	if c.state == stateClosed {
+		return
+	}
+	c.state = stateClosed
+	c.stopRTOLocked()
+	c.stopLingerLocked()
+	c.err = err
+	c.cond.Broadcast()
+	// deliberately does not send an RST: if the peer sends anything else for
+	// this connection later, it will miss the (now removed) table entry and
+	// get a fresh, correctly-addressed reset from sendRawTCPReset above.
+	c.stack.removeTCPConn(c.key, c)
+}
+
+// handleSegment processes one already-demultiplexed incoming segment.
+func (c *tcpConn) handleSegment(tcpHdr header.TCP) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if c.state == stateClosed {
+		return
+	}
+	c.lastActive = time.Now()
+
+	flags := tcpHdr.Flags()
+
+	if flags&header.TCPFlagRst != 0 {
+		c.abortLocked(errConnReset)
+		return
+	}
+
+	if c.state == stateSynRcvd {
+		c.handleSynRcvdSegmentLocked(tcpHdr)
+		return
+	}
+
+	if flags&header.TCPFlagSyn != 0 {
+		// unexpected SYN on an already-established connection is not
+		// modeled; treat it like the peer abandoned and reset it
+		c.abortLocked(errConnReset)
+		return
+	}
+
+	if flags&header.TCPFlagAck != 0 {
+		c.handleAckLocked(seqnum.Value(tcpHdr.AckNumber()), tcpHdr.WindowSize())
+	}
+
+	c.acceptInOrderLocked(seqnum.Value(tcpHdr.SequenceNumber()), tcpHdr.Payload(), flags&header.TCPFlagFin != 0)
+}
+
+func (c *tcpConn) handleSynRcvdSegmentLocked(tcpHdr header.TCP) {
+	flags := tcpHdr.Flags()
+
+	if flags&header.TCPFlagSyn != 0 {
+		// peer's retransmission of the original SYN, our SYN-ACK likely
+		// hasn't reached them yet: resend it and rely entirely on their own
+		// retransmission timer rather than running one on our side too
+		c.sendSynAckLocked()
+		return
+	}
+	if flags&header.TCPFlagAck == 0 {
+		return
+	}
+	if seqnum.Value(tcpHdr.AckNumber()) != c.sndNxt {
+		// does not acknowledge our SYN correctly; a well-behaved peer will
+		// simply retry, so it is safe to just ignore this segment
+		return
+	}
+
+	c.state = stateEstablished
+	go c.stack.handler.HandleConnection(c, c.dst)
+
+	c.handleAckLocked(seqnum.Value(tcpHdr.AckNumber()), tcpHdr.WindowSize())
+	c.acceptInOrderLocked(seqnum.Value(tcpHdr.SequenceNumber()), tcpHdr.Payload(), flags&header.TCPFlagFin != 0)
+}
+
+// acceptInOrderLocked handles the data/FIN portion of a segment once it is
+// known to be neither a SYN nor a RST. Only strictly in-order segments are
+// accepted; anything else is dropped (relying on the peer's retransmission)
+// since the tun channel is expected to already deliver packets in order.
+func (c *tcpConn) acceptInOrderLocked(seq seqnum.Value, payload []byte, fin bool) {
+	if seq != c.rcvNxt {
+		c.sendAckLocked()
+		return
+	}
+
+	accept := payload
+	if room := c.recvWindowLocked(); uint32(len(accept)) > room {
+		accept = accept[:room]
+	}
+	if len(accept) > 0 {
+		c.enqueueRecvLocked(accept)
+		c.rcvNxt = c.rcvNxt.Add(seqnum.Size(len(accept)))
+	}
+
+	finAccepted := false
+	if fin && len(accept) == len(payload) {
+		c.onFinLocked()
+		c.rcvNxt = c.rcvNxt.Add(1)
+		finAccepted = true
+	}
+
+	if len(accept) > 0 || finAccepted || len(accept) < len(payload) {
+		c.sendAckLocked()
+	}
+}
+
+func (c *tcpConn) onFinLocked() {
+	if c.recvClosed {
+		return
+	}
+	c.recvClosed = true
+	c.cond.Broadcast()
+	if c.state == stateEstablished {
+		c.state = stateCloseWait
+	}
+	c.maybeFinishCloseLocked()
+}
+
+func (c *tcpConn) handleAckLocked(ackNum seqnum.Value, windowSize uint16) {
+	if ackNum.LessThan(c.sndUna) {
+		// old/duplicate ack: no fast-retransmit heuristics implemented
+		c.peerWindow = uint32(windowSize)
+		c.trySendLocked()
+		return
+	}
+	if c.sndNxt.LessThan(ackNum) {
+		// acknowledges more than we ever sent: lenient clamp instead of
+		// rejecting the segment outright
+		ackNum = c.sndNxt
+	}
+
+	if advanced := c.sndUna.Size(ackNum); advanced > 0 {
+		c.sndUna = ackNum
+		n := int(advanced)
+		if n > len(c.sendQueue) {
+			n = len(c.sendQueue)
+		}
+		c.sendQueue = c.sendQueue[n:]
+		c.unsentOffset -= n
+		if c.unsentOffset < 0 {
+			c.unsentOffset = 0
+		}
+		c.rtoBackoff = 0
+		if c.finSent && c.sndUna == c.sndNxt {
+			c.finAcked = true
+		}
+		c.cond.Broadcast()
+	}
+
+	c.peerWindow = uint32(windowSize)
+	c.trySendLocked()
+	c.maybeFinishCloseLocked()
+}
+
+func (c *tcpConn) maybeFinishCloseLocked() {
+	if c.state == stateClosing && c.finAcked && c.recvClosed {
+		c.state = stateTimeWait
+		c.startLingerLocked()
+	}
+}
+
+func (c *tcpConn) recvWindowLocked() uint32 {
+	room := maxRecvBuffer - c.recvBuffered
+	if room < 0 {
+		room = 0
+	}
+	if room > 0xffff {
+		room = 0xffff
+	}
+	return uint32(room)
+}
+
+func (c *tcpConn) enqueueRecvLocked(payload []byte) {
+	data := make([]byte, len(payload))
+	copy(data, payload)
+	c.recvQueue = append(c.recvQueue, data)
+	c.recvBuffered += len(data)
+	c.cond.Broadcast()
+}
+
+// sendOneChunkLocked transmits up to maxLen bytes of never-yet-sent data (if
+// any remains), advancing sndNxt/unsentOffset. It returns the number of
+// bytes sent, 0 if none remained.
+func (c *tcpConn) sendOneChunkLocked(maxLen int) int {
+	remaining := len(c.sendQueue) - c.unsentOffset
+	if remaining <= 0 {
+		return 0
+	}
+	if maxLen > remaining {
+		maxLen = remaining
+	}
+	if maxLen > c.sndMSS {
+		maxLen = c.sndMSS
+	}
+	if maxLen <= 0 {
+		return 0
+	}
+	data := c.sendQueue[c.unsentOffset : c.unsentOffset+maxLen]
+	c.sendDataSegmentLocked(c.sndNxt, data, false)
+	c.sndNxt = c.sndNxt.Add(seqnum.Size(maxLen))
+	c.unsentOffset += maxLen
+	return maxLen
+}
+
+func (c *tcpConn) trySendLocked() {
+	switch c.state {
+	case stateSynRcvd, stateTimeWait, stateClosed:
+		return
+	}
+
+	for {
+		inFlight := int(c.sndUna.Size(c.sndNxt))
+		windowLeft := int(c.peerWindow) - inFlight
+		if windowLeft <= 0 {
+			break
+		}
+		if c.sendOneChunkLocked(windowLeft) == 0 {
+			break
+		}
+	}
+
+	if c.closeCalled && !c.finSent && c.unsentOffset == len(c.sendQueue) {
+		c.finSeq = c.sndNxt
+		c.sendDataSegmentLocked(c.finSeq, nil, true)
+		c.sndNxt = c.sndNxt.Add(1)
+		c.finSent = true
+	}
+
+	c.refreshRTOLocked()
+}
+
+func (c *tcpConn) outstandingLocked() bool {
+	if c.unsentOffset > 0 {
+		return true // already-transmitted data pending ack
+	}
+	if len(c.sendQueue) > c.unsentOffset && c.peerWindow == 0 {
+		return true // blocked purely by a zero window; need to probe
+	}
+	if c.finSent && !c.finAcked {
+		return true // FIN transmitted but not yet acked
+	}
+	return false
+}
+
+func (c *tcpConn) refreshRTOLocked() {
+	if c.outstandingLocked() {
+		c.scheduleRTOLocked()
+	} else {
+		c.stopRTOLocked()
+	}
+}
+
+func (c *tcpConn) rtoDurationLocked() time.Duration {
+	d := minRTO * time.Duration(uint64(1)<<uint(c.rtoBackoff))
+	if d > maxRTO || d <= 0 {
+		d = maxRTO
+	}
+	return d
+}
+
+func (c *tcpConn) scheduleRTOLocked() {
+	d := c.rtoDurationLocked()
+	if c.rtoTimer == nil {
+		c.rtoTimer = time.AfterFunc(d, c.onRTOTimerFired)
+	} else {
+		c.rtoTimer.Reset(d)
+	}
+}
+
+func (c *tcpConn) stopRTOLocked() {
+	if c.rtoTimer != nil {
+		c.rtoTimer.Stop()
+	}
+}
+
+func (c *tcpConn) onRTOTimerFired() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.onRTOFireLocked()
+}
+
+func (c *tcpConn) onRTOFireLocked() {
+	if c.state == stateClosed || !c.outstandingLocked() {
+		return
+	}
+	if c.rtoBackoff >= maxRTORetries {
+		c.abortLocked(errConnTimedOut)
+		return
+	}
+	c.rtoBackoff++
+
+	switch {
+	case c.unsentOffset > 0:
+		c.sendDataSegmentLocked(c.sndUna, c.sendQueue[:c.unsentOffset], false)
+	case len(c.sendQueue) > c.unsentOffset:
+		// nothing in flight, but blocked by a zero peer window: probe with
+		// exactly one new byte, per RFC 9293 §3.8.6.1
+		c.sendOneChunkLocked(1)
+	case c.finSent && !c.finAcked:
+		c.sendDataSegmentLocked(c.finSeq, nil, true)
+	}
+
+	c.refreshRTOLocked()
+}
+
+func (c *tcpConn) startLingerLocked() {
+	c.stopRTOLocked()
+	c.lingerTimer = time.AfterFunc(lingerDuration, func() {
+		c.mu.Lock()
+		defer c.mu.Unlock()
+		c.abortLocked(errConnClosed)
+	})
+}
+
+func (c *tcpConn) stopLingerLocked() {
+	if c.lingerTimer != nil {
+		c.lingerTimer.Stop()
+	}
+}
+
+// transmitLocked builds, checksums and writes a single tcp segment.
+func (c *tcpConn) transmitLocked(seq, ack seqnum.Value, flags header.TCPFlags, payload []byte, options []byte) {
+	headerLen := header.TCPMinimumSize + len(options)
+	segment := make([]byte, headerLen+len(payload))
+	tcpHdr := header.TCP(segment)
+	tcpHdr.Encode(&header.TCPFields{
+		SrcPort:    c.key.dstPort,
+		DstPort:    c.key.srcPort,
+		SeqNum:     uint32(seq),
+		AckNum:     uint32(ack),
+		DataOffset: uint8(headerLen),
+		Flags:      flags,
+		WindowSize: uint16(c.recvWindowLocked()),
+	})
+	copy(tcpHdr.Options(), options)
+	copy(segment[headerLen:], payload)
+
+	xsum := header.PseudoHeaderChecksum(header.TCPProtocolNumber, c.key.dstAddr, c.key.srcAddr, uint16(len(segment)))
+	xsum = checksum.Checksum(payload, xsum)
+	tcpHdr.SetChecksum(^tcpHdr.CalculateChecksum(xsum))
+
+	if err := c.stack.writeTransportSegment(c.key.netProto, header.TCPProtocolNumber, c.key.dstAddr, c.key.srcAddr, segment); err != nil {
+		xerrors.LogInfoInner(c.stack.ctx, err, "[tun] failed to write tcp segment")
+	}
+}
+
+func (c *tcpConn) sendSynAckLocked() {
+	var optBuf [header.TCPOptionMSSLength]byte
+	n := header.EncodeMSSOption(uint32(c.ourMSS), optBuf[:])
+	c.transmitLocked(c.iss, c.rcvNxt, header.TCPFlagSyn|header.TCPFlagAck, nil, optBuf[:n])
+}
+
+func (c *tcpConn) sendAckLocked() {
+	c.transmitLocked(c.sndNxt, c.rcvNxt, header.TCPFlagAck, nil, nil)
+}
+
+func (c *tcpConn) sendDataSegmentLocked(seq seqnum.Value, payload []byte, fin bool) {
+	flags := header.TCPFlagAck
+	if fin {
+		flags |= header.TCPFlagFin
+	}
+	c.transmitLocked(seq, c.rcvNxt, flags, payload, nil)
+}
+
+// Read implements net.Conn.
+func (c *tcpConn) Read(p []byte) (int, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	for len(c.recvQueue) == 0 && c.err == nil && !c.recvClosed {
+		c.cond.Wait()
+	}
+	if c.err != nil {
+		return 0, c.err
+	}
+	if len(c.recvQueue) == 0 {
+		return 0, io.EOF
+	}
+
+	before := c.recvWindowLocked()
+
+	chunk := c.recvQueue[0]
+	n := copy(p, chunk[c.recvOffset:])
+	c.recvOffset += n
+	c.recvBuffered -= n
+	if c.recvOffset == len(chunk) {
+		c.recvQueue = c.recvQueue[1:]
+		c.recvOffset = 0
+	}
+
+	// let the peer know promptly if reading just freed up a previously
+	// exhausted window, instead of waiting for it to probe us for an update
+	if after := c.recvWindowLocked(); before == 0 && after > 0 {
+		c.sendAckLocked()
+	}
+
+	return n, nil
+}
+
+// Write implements net.Conn.
+func (c *tcpConn) Write(p []byte) (int, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if c.closeCalled {
+		return 0, errConnClosed
+	}
+
+	total := 0
+	for total < len(p) {
+		if c.err != nil {
+			return total, c.err
+		}
+		if c.closeCalled {
+			return total, errConnClosed
+		}
+		room := maxSendBuffer - len(c.sendQueue)
+		if room <= 0 {
+			c.cond.Wait()
+			continue
+		}
+		n := len(p) - total
+		if n > room {
+			n = room
+		}
+		c.sendQueue = append(c.sendQueue, p[total:total+n]...)
+		total += n
+	}
+
+	c.trySendLocked()
+	return total, nil
+}
+
+// Close implements net.Conn.
+func (c *tcpConn) Close() error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if c.closeCalled {
+		return nil
+	}
+	c.closeCalled = true
+	c.cond.Broadcast()
+
+	switch c.state {
+	case stateEstablished, stateCloseWait:
+		c.state = stateClosing
+	default:
+		return nil
+	}
+
+	c.trySendLocked()
+	return nil
+}
+
+func (c *tcpConn) LocalAddr() net.Addr  { return c.dst.RawNetAddr() }
+func (c *tcpConn) RemoteAddr() net.Addr { return c.src.RawNetAddr() }
+
+func (c *tcpConn) SetDeadline(t time.Time) error      { return nil }
+func (c *tcpConn) SetReadDeadline(t time.Time) error  { return nil }
+func (c *tcpConn) SetWriteDeadline(t time.Time) error { return nil }

proxy/tun/stack_system_test.go

@@ -0,0 +1,448 @@
+package tun
+
+import (
+	"context"
+	"io"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/xtls/xray-core/common/net"
+	"gvisor.dev/gvisor/pkg/buffer"
+	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/checksum"
+	"gvisor.dev/gvisor/pkg/tcpip/header"
+	"gvisor.dev/gvisor/pkg/tcpip/stack"
+)
+
+// fakeGVisorDevice is an in-memory GVisorDevice used to script conversations
+// with the "system" stack without any real tun device or privileges.
+type fakeGVisorDevice struct {
+	inbound  chan []byte
+	outbound chan []byte
+	notify   chan struct{}
+}
+
+func newFakeGVisorDevice() *fakeGVisorDevice {
+	return &fakeGVisorDevice{
+		inbound:  make(chan []byte, 256),
+		outbound: make(chan []byte, 256),
+		notify:   make(chan struct{}, 1),
+	}
+}
+
+func (d *fakeGVisorDevice) push(data []byte) {
+	d.inbound <- data
+	select {
+	case d.notify <- struct{}{}:
+	default:
+	}
+}
+
+func (d *fakeGVisorDevice) ReadPacket() (byte, *stack.PacketBuffer, error) {
+	select {
+	case data := <-d.inbound:
+		version := data[0] >> 4
+		pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{Payload: buffer.MakeWithData(data)})
+		return version, pkt, nil
+	default:
+		return 0, nil, ErrQueueEmpty
+	}
+}
+
+func (d *fakeGVisorDevice) WritePacket(packet *stack.PacketBuffer) tcpip.Error {
+	var data []byte
+	for _, s := range packet.AsSlices() {
+		data = append(data, s...)
+	}
+	d.outbound <- data
+	return nil
+}
+
+func (d *fakeGVisorDevice) Wait() {
+	select {
+	case <-d.notify:
+	case <-time.After(20 * time.Millisecond):
+	}
+}
+
+func (d *fakeGVisorDevice) recv(t *testing.T, timeout time.Duration) []byte {
+	t.Helper()
+	select {
+	case data := <-d.outbound:
+		return data
+	case <-time.After(timeout):
+		t.Fatal("timed out waiting for outbound packet")
+		return nil
+	}
+}
+
+var _ GVisorDevice = (*fakeGVisorDevice)(nil)
+
+// echoHandler is a ConnectionHandler that echoes back everything it reads on
+// each connection, and records connections/destinations it has seen.
+type echoHandler struct {
+	mu    sync.Mutex
+	conns []net.Conn
+	dests []net.Destination
+	done  chan struct{}
+}
+
+func newEchoHandler() *echoHandler {
+	return &echoHandler{done: make(chan struct{}, 8)}
+}
+
+func (h *echoHandler) HandleConnection(conn net.Conn, dest net.Destination) {
+	h.mu.Lock()
+	h.conns = append(h.conns, conn)
+	h.dests = append(h.dests, dest)
+	h.mu.Unlock()
+
+	_, _ = io.Copy(conn, conn)
+	_ = conn.Close()
+	h.done <- struct{}{}
+}
+
+func newTestStackSystem(device GVisorDevice, handler ConnectionHandler, idleTimeout time.Duration) (*stackSystem, context.CancelFunc) {
+	ctx, cancel := context.WithCancel(context.Background())
+	s := &stackSystem{
+		ctx:         ctx,
+		device:      device,
+		mtu:         1500,
+		idleTimeout: idleTimeout,
+		handler:     handler,
+		tcp:         make(map[tcpKey]*tcpConn),
+	}
+	return s, cancel
+}
+
+func testIP(s string) tcpip.Address {
+	return tcpip.AddrFrom4Slice(net.ParseIP(s).To4())
+}
+
+const (
+	testPeerIP   = "10.0.0.2"
+	testTargetIP = "10.0.0.1"
+	testPeerPort = uint16(51234)
+	testDstPort  = uint16(8080)
+)
+
+// buildIPv4TCP builds a raw IPv4+TCP segment, computing valid checksums.
+func buildIPv4TCP(src, dst tcpip.Address, srcPort, dstPort uint16, seq, ack uint32, flags header.TCPFlags, window uint16, payload []byte, options []byte) []byte {
+	headerLen := header.TCPMinimumSize + len(options)
+	totalLen := header.IPv4MinimumSize + headerLen + len(payload)
+	data := make([]byte, totalLen)
+
+	ipHdr := header.IPv4(data)
+	ipHdr.Encode(&header.IPv4Fields{
+		TotalLength: uint16(totalLen),
+		TTL:         64,
+		Protocol:    uint8(header.TCPProtocolNumber),
+		SrcAddr:     src,
+		DstAddr:     dst,
+	})
+	ipHdr.SetChecksum(^ipHdr.CalculateChecksum())
+
+	tcpHdr := header.TCP(data[header.IPv4MinimumSize:])
+	tcpHdr.Encode(&header.TCPFields{
+		SrcPort:    srcPort,
+		DstPort:    dstPort,
+		SeqNum:     seq,
+		AckNum:     ack,
+		DataOffset: uint8(headerLen),
+		Flags:      flags,
+		WindowSize: window,
+	})
+	copy(tcpHdr.Options(), options)
+	copy(data[header.IPv4MinimumSize+headerLen:], payload)
+
+	xsum := header.PseudoHeaderChecksum(header.TCPProtocolNumber, src, dst, uint16(headerLen+len(payload)))
+	xsum = checksum.Checksum(payload, xsum)
+	tcpHdr.SetChecksum(^tcpHdr.CalculateChecksum(xsum))
+
+	return data
+}
+
+func parseIPv4TCP(t *testing.T, data []byte) header.TCP {
+	t.Helper()
+	ipHdr := header.IPv4(data)
+	if !ipHdr.IsValid(len(data)) {
+		t.Fatalf("invalid ipv4 packet")
+	}
+	return header.TCP(ipHdr.Payload())
+}
+
+func TestSystemStackTCPHandshakeEchoClose(t *testing.T) {
+	device := newFakeGVisorDevice()
+	handler := newEchoHandler()
+	s, cancel := newTestStackSystem(device, handler, time.Minute)
+	defer cancel()
+	if err := s.Start(); err != nil {
+		t.Fatalf("Start: %v", err)
+	}
+	defer s.Close()
+
+	src := testIP(testPeerIP)
+	dst := testIP(testTargetIP)
+
+	iss := uint32(1000)
+	device.push(buildIPv4TCP(src, dst, testPeerPort, testDstPort, iss, 0, header.TCPFlagSyn, 65535, nil, nil))
+
+	synAck := parseIPv4TCP(t, device.recv(t, time.Second))
+	if synAck.Flags() != header.TCPFlagSyn|header.TCPFlagAck {
+		t.Fatalf("expected SYN-ACK, got flags %v", synAck.Flags())
+	}
+	if synAck.AckNumber() != iss+1 {
+		t.Fatalf("unexpected ack number %d, want %d", synAck.AckNumber(), iss+1)
+	}
+	serverISS := synAck.SequenceNumber()
+
+	// final handshake ACK
+	device.push(buildIPv4TCP(src, dst, testPeerPort, testDstPort, iss+1, serverISS+1, header.TCPFlagAck, 65535, nil, nil))
+
+	// send data
+	payload := []byte("hello world")
+	device.push(buildIPv4TCP(src, dst, testPeerPort, testDstPort, iss+1, serverISS+1, header.TCPFlagAck|header.TCPFlagPsh, 65535, payload, nil))
+
+	// drain outbound packets until the full echo has been observed, acking
+	// any data segments as they arrive so the connection can make progress
+	var echoed []byte
+	deadline := time.After(2 * time.Second)
+	for len(echoed) < len(payload) {
+		select {
+		case raw := <-device.outbound:
+			tcpHdr := parseIPv4TCP(t, raw)
+			if len(tcpHdr.Payload()) > 0 {
+				echoed = append(echoed, tcpHdr.Payload()...)
+				device.push(buildIPv4TCP(src, dst, testPeerPort, testDstPort,
+					iss+1+uint32(len(payload)), tcpHdr.SequenceNumber()+uint32(len(tcpHdr.Payload())),
+					header.TCPFlagAck, 65535, nil, nil))
+			}
+		case <-deadline:
+			t.Fatalf("timed out waiting for echo, got %q so far", echoed)
+		}
+	}
+	if string(echoed) != string(payload) {
+		t.Fatalf("echo mismatch: got %q want %q", echoed, payload)
+	}
+
+	h := handler
+	h.mu.Lock()
+	if len(h.dests) != 1 || h.dests[0].NetAddr() != "10.0.0.1:8080" {
+		t.Fatalf("unexpected destination recorded: %+v", h.dests)
+	}
+	h.mu.Unlock()
+
+	// peer sends FIN
+	finSeq := iss + 1 + uint32(len(payload))
+	device.push(buildIPv4TCP(src, dst, testPeerPort, testDstPort, finSeq, serverISS+1+uint32(len(payload)), header.TCPFlagFin|header.TCPFlagAck, 65535, nil, nil))
+
+	select {
+	case <-handler.done:
+	case <-time.After(2 * time.Second):
+		t.Fatal("echo handler never finished after peer FIN")
+	}
+
+	var sawAckOfFin, sawOurFin bool
+	var ourFinSeq uint32
+	deadline = time.After(2 * time.Second)
+	for !sawAckOfFin || !sawOurFin {
+		select {
+		case raw := <-device.outbound:
+			tcpHdr := parseIPv4TCP(t, raw)
+			if tcpHdr.Flags()&header.TCPFlagFin != 0 {
+				sawOurFin = true
+				ourFinSeq = tcpHdr.SequenceNumber()
+			}
+			if tcpHdr.AckNumber() == finSeq+1 {
+				sawAckOfFin = true
+			}
+		case <-deadline:
+			t.Fatalf("timed out waiting for our fin/ack (sawAckOfFin=%v sawOurFin=%v)", sawAckOfFin, sawOurFin)
+		}
+	}
+
+	// ack our FIN, completing a graceful close
+	device.push(buildIPv4TCP(src, dst, testPeerPort, testDstPort, finSeq+1, ourFinSeq+1, header.TCPFlagAck, 65535, nil, nil))
+
+	deadline = time.After(2 * time.Second)
+	for {
+		s.tcpMu.Lock()
+		var conn *tcpConn
+		for _, c := range s.tcp {
+			conn = c
+		}
+		s.tcpMu.Unlock()
+		if conn == nil {
+			t.Fatal("connection unexpectedly removed before linger")
+		}
+		conn.mu.Lock()
+		state := conn.state
+		conn.mu.Unlock()
+		if state == stateTimeWait {
+			break
+		}
+		select {
+		case <-deadline:
+			t.Fatalf("connection did not reach TimeWait, state=%d", state)
+		case <-time.After(10 * time.Millisecond):
+		}
+	}
+}
+
+func TestSystemStackTCPUnknownConnectionReset(t *testing.T) {
+	device := newFakeGVisorDevice()
+	handler := newEchoHandler()
+	s, cancel := newTestStackSystem(device, handler, time.Minute)
+	defer cancel()
+	if err := s.Start(); err != nil {
+		t.Fatalf("Start: %v", err)
+	}
+	defer s.Close()
+
+	src := testIP(testPeerIP)
+	dst := testIP(testTargetIP)
+
+	// an ACK referencing a connection the stack has never seen
+	device.push(buildIPv4TCP(src, dst, testPeerPort, testDstPort, 5000, 0, header.TCPFlagAck, 65535, nil, nil))
+
+	rst := parseIPv4TCP(t, device.recv(t, time.Second))
+	if rst.Flags()&header.TCPFlagRst == 0 {
+		t.Fatalf("expected RST, got flags %v", rst.Flags())
+	}
+	if rst.SequenceNumber() != 5000 {
+		t.Fatalf("expected reset seq to echo the ack number 5000, got %d", rst.SequenceNumber())
+	}
+}
+
+func TestSystemStackTCPRetransmit(t *testing.T) {
+	device := newFakeGVisorDevice()
+	handler := newEchoHandler()
+	s, cancel := newTestStackSystem(device, handler, time.Minute)
+	defer cancel()
+	if err := s.Start(); err != nil {
+		t.Fatalf("Start: %v", err)
+	}
+	defer s.Close()
+
+	src := testIP(testPeerIP)
+	dst := testIP(testTargetIP)
+
+	iss := uint32(2000)
+	device.push(buildIPv4TCP(src, dst, testPeerPort, testDstPort, iss, 0, header.TCPFlagSyn, 65535, nil, nil))
+	synAck := parseIPv4TCP(t, device.recv(t, time.Second))
+	serverISS := synAck.SequenceNumber()
+	device.push(buildIPv4TCP(src, dst, testPeerPort, testDstPort, iss+1, serverISS+1, header.TCPFlagAck, 65535, nil, nil))
+
+	payload := []byte("hi")
+	device.push(buildIPv4TCP(src, dst, testPeerPort, testDstPort, iss+1, serverISS+1, header.TCPFlagAck|header.TCPFlagPsh, 65535, payload, nil))
+
+	// consume the data-ack and the first echoed data segment, but do NOT ack
+	// the echoed data, forcing a retransmit
+	var first []byte
+	deadline := time.After(2 * time.Second)
+	for len(first) == 0 {
+		select {
+		case raw := <-device.outbound:
+			tcpHdr := parseIPv4TCP(t, raw)
+			if len(tcpHdr.Payload()) > 0 {
+				first = append([]byte(nil), tcpHdr.Payload()...)
+			}
+		case <-deadline:
+			t.Fatal("timed out waiting for first echoed segment")
+		}
+	}
+
+	// now wait for a retransmission of the same bytes, without acking
+	deadline = time.After(2 * time.Second)
+	for {
+		select {
+		case raw := <-device.outbound:
+			tcpHdr := parseIPv4TCP(t, raw)
+			if string(tcpHdr.Payload()) == string(first) {
+				return // retransmit observed, test passes
+			}
+		case <-deadline:
+			t.Fatal("timed out waiting for retransmission of unacked data")
+		}
+	}
+}
+
+func TestSystemStackIdleReap(t *testing.T) {
+	device := newFakeGVisorDevice()
+	handler := newEchoHandler()
+	s, cancel := newTestStackSystem(device, handler, time.Millisecond)
+	defer cancel()
+	if err := s.Start(); err != nil {
+		t.Fatalf("Start: %v", err)
+	}
+	defer s.Close()
+
+	src := testIP(testPeerIP)
+	dst := testIP(testTargetIP)
+
+	device.push(buildIPv4TCP(src, dst, testPeerPort, testDstPort, 1, 0, header.TCPFlagSyn, 65535, nil, nil))
+	device.recv(t, time.Second) // SYN-ACK
+
+	deadline := time.After(2 * time.Second)
+	for {
+		s.tcpMu.Lock()
+		n := len(s.tcp)
+		s.tcpMu.Unlock()
+		if n == 0 {
+			return
+		}
+		select {
+		case <-deadline:
+			t.Fatal("idle connection was not reaped")
+		case <-time.After(10 * time.Millisecond):
+		}
+	}
+}
+
+func TestSystemStackUDPEcho(t *testing.T) {
+	device := newFakeGVisorDevice()
+	handler := newEchoHandler()
+	s, cancel := newTestStackSystem(device, handler, time.Minute)
+	defer cancel()
+	if err := s.Start(); err != nil {
+		t.Fatalf("Start: %v", err)
+	}
+	defer s.Close()
+
+	src := testIP(testPeerIP)
+	dst := testIP(testTargetIP)
+
+	payload := []byte("ping")
+	udpLen := header.UDPMinimumSize + len(payload)
+	totalLen := header.IPv4MinimumSize + udpLen
+	data := make([]byte, totalLen)
+	ipHdr := header.IPv4(data)
+	ipHdr.Encode(&header.IPv4Fields{
+		TotalLength: uint16(totalLen),
+		TTL:         64,
+		Protocol:    uint8(header.UDPProtocolNumber),
+		SrcAddr:     src,
+		DstAddr:     dst,
+	})
+	ipHdr.SetChecksum(^ipHdr.CalculateChecksum())
+	udpHdr := header.UDP(data[header.IPv4MinimumSize:])
+	udpHdr.Encode(&header.UDPFields{SrcPort: testPeerPort, DstPort: testDstPort, Length: uint16(udpLen)})
+	copy(data[header.IPv4MinimumSize+header.UDPMinimumSize:], payload)
+	xsum := header.PseudoHeaderChecksum(header.UDPProtocolNumber, src, dst, uint16(udpLen))
+	udpHdr.SetChecksum(^udpHdr.CalculateChecksum(checksum.Checksum(payload, xsum)))
+
+	device.push(data)
+
+	select {
+	case <-handler.done:
+	case <-time.After(time.Second):
+		t.Fatal("udp handler never invoked/finished")
+	}
+
+	handler.mu.Lock()
+	defer handler.mu.Unlock()
+	if len(handler.dests) != 1 || handler.dests[0].Network != net.Network_UDP {
+		t.Fatalf("unexpected udp destination recorded: %+v", handler.dests)
+	}
+}

proxy/tun/tun_android.go

@@ -7,9 +7,12 @@ import (
 	"net"
 	"strconv"
 
+	"github.com/xtls/xray-core/common/buf"
 	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/common/platform"
 	"golang.org/x/sys/unix"
+	"gvisor.dev/gvisor/pkg/buffer"
+	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/tcpip/link/fdbased"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
 )
@@ -22,6 +25,22 @@ type AndroidTun struct {
 // DefaultTun implements Tun
 var _ Tun = (*AndroidTun)(nil)
 
+// AndroidTun implements GVisorDevice, used by the "system" (lite) ip stack
+var _ GVisorDevice = (*AndroidTun)(nil)
+
+// fdReadWriter adapts a raw, already non-blocking file descriptor to io.Reader/io.Writer,
+// so it can be used with buf.Buffer.ReadFrom, without the ownership/finalizer overhead of
+// wrapping it in an *os.File (the fd is owned and closed elsewhere).
+type fdReadWriter int
+
+func (f fdReadWriter) Read(p []byte) (int, error) {
+	return unix.Read(int(f), p)
+}
+
+func (f fdReadWriter) Write(p []byte) (int, error) {
+	return unix.Write(int(f), p)
+}
+
 // NewTun builds new tun interface handler
 func NewTun(options *Config) (Tun, error) {
 	fd, err := strconv.Atoi(platform.NewEnvFlag(platform.TunFdKey).GetValue(func() string { return "0" }))
@@ -78,6 +97,72 @@ func (t *AndroidTun) newEndpoint() (stack.LinkEndpoint, error) {
 	})
 }
 
+// ReadPacket implements GVisorDevice method to read one packet from the tun device, used by
+// the "system" (lite) ip stack. The gVisor backed stack instead talks to the fd directly through
+// fdbased.New above, for lower overhead batched IO, bypassing GVisorDevice entirely.
+// It is expected that the method will not block, rather return ErrQueueEmpty when there is nothing on the line,
+// which will make the stack call Wait which should implement desired push-back
+func (t *AndroidTun) ReadPacket() (byte, *stack.PacketBuffer, error) {
+	// request memory to write from reusable buffer pool
+	b := buf.NewWithSize(int32(t.options.MTU))
+
+	// read the bytes from the interface file descriptor, which is already non-blocking
+	n, err := b.ReadFrom(fdReadWriter(t.tunFd))
+	if err == unix.EAGAIN || err == unix.EWOULDBLOCK || err == unix.EINTR {
+		b.Release()
+		return 0, nil, ErrQueueEmpty
+	}
+	if err != nil {
+		b.Release()
+		return 0, nil, err
+	}
+
+	// discard empty packets
+	if n == 0 {
+		b.Release()
+		return 0, nil, ErrQueueEmpty
+	}
+
+	// network protocol version from the first nibble of the raw packet
+	version := b.Byte(0) >> 4
+	packetBuffer := buffer.MakeWithData(b.Bytes())
+	return version, stack.NewPacketBuffer(stack.PacketBufferOptions{
+		Payload:           packetBuffer,
+		IsForwardedPacket: true,
+		OnRelease: func() {
+			b.Release()
+		},
+	}), nil
+}
+
+// WritePacket implements GVisorDevice method to write one packet to the tun device
+func (t *AndroidTun) WritePacket(packet *stack.PacketBuffer) tcpip.Error {
+	// request memory to write from reusable buffer pool
+	b := buf.NewWithSize(int32(t.options.MTU))
+	defer b.Release()
+
+	// copy the bytes of slices that compose the packet into the allocated buffer, no
+	// extra header is needed here, unlike Darwin/FreeBSD's utun devices
+	for _, packetElement := range packet.AsSlices() {
+		_, _ = b.Write(packetElement)
+	}
+
+	if _, err := fdReadWriter(t.tunFd).Write(b.Bytes()); err != nil {
+		if err == unix.EAGAIN || err == unix.EWOULDBLOCK {
+			return &tcpip.ErrWouldBlock{}
+		}
+		return &tcpip.ErrAborted{}
+	}
+	return nil
+}
+
+// Wait blocks until the tun fd is likely readable again, rather than spinning the CPU.
+// A bounded timeout keeps this responsive to a Close() racing a call already parked here.
+func (t *AndroidTun) Wait() {
+	fds := []unix.PollFd{{Fd: int32(t.tunFd), Events: unix.POLLIN}}
+	_, _ = unix.Poll(fds, 1000)
+}
+
 func setinterface(network, address string, fd uintptr, iface *net.Interface) error {
 	return unix.BindToDevice(int(fd), iface.Name)
 }

proxy/tun/tun_linux.go

@@ -10,9 +10,12 @@ import (
 	"sync"
 
 	"github.com/vishvananda/netlink"
+	"github.com/xtls/xray-core/common/buf"
 	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/common/platform"
 	"golang.org/x/sys/unix"
+	"gvisor.dev/gvisor/pkg/buffer"
+	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/tcpip/link/fdbased"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
 )
@@ -35,6 +38,22 @@ type LinuxTun struct {
 // LinuxTun implements Tun
 var _ Tun = (*LinuxTun)(nil)
 
+// LinuxTun implements GVisorDevice, used by the "system" (lite) ip stack
+var _ GVisorDevice = (*LinuxTun)(nil)
+
+// fdReadWriter adapts a raw, already non-blocking file descriptor to io.Reader/io.Writer,
+// so it can be used with buf.Buffer.ReadFrom, without the ownership/finalizer overhead of
+// wrapping it in an *os.File (the fd is owned and closed elsewhere, see LinuxTun.Close).
+type fdReadWriter int
+
+func (f fdReadWriter) Read(p []byte) (int, error) {
+	return unix.Read(int(f), p)
+}
+
+func (f fdReadWriter) Write(p []byte) (int, error) {
+	return unix.Write(int(f), p)
+}
+
 // NewTun builds new tun interface handler (linux specific)
 func NewTun(options *Config) (Tun, error) {
 	tunFd, tunLink, fdProvided, err := openFromEnv(options.Name)
@@ -228,6 +247,72 @@ func (t *LinuxTun) newEndpoint() (stack.LinkEndpoint, error) {
 	})
 }
 
+// ReadPacket implements GVisorDevice method to read one packet from the tun device, used by
+// the "system" (lite) ip stack. The gVisor backed stack instead talks to the fd directly through
+// fdbased.New above, for lower overhead batched IO, bypassing GVisorDevice entirely.
+// It is expected that the method will not block, rather return ErrQueueEmpty when there is nothing on the line,
+// which will make the stack call Wait which should implement desired push-back
+func (t *LinuxTun) ReadPacket() (byte, *stack.PacketBuffer, error) {
+	// request memory to write from reusable buffer pool
+	b := buf.NewWithSize(int32(t.options.MTU))
+
+	// read the bytes from the interface file descriptor, which is already non-blocking
+	n, err := b.ReadFrom(fdReadWriter(t.tunFd))
+	if err == unix.EAGAIN || err == unix.EWOULDBLOCK || err == unix.EINTR {
+		b.Release()
+		return 0, nil, ErrQueueEmpty
+	}
+	if err != nil {
+		b.Release()
+		return 0, nil, err
+	}
+
+	// discard empty packets
+	if n == 0 {
+		b.Release()
+		return 0, nil, ErrQueueEmpty
+	}
+
+	// network protocol version from the first nibble of the raw packet
+	version := b.Byte(0) >> 4
+	packetBuffer := buffer.MakeWithData(b.Bytes())
+	return version, stack.NewPacketBuffer(stack.PacketBufferOptions{
+		Payload:           packetBuffer,
+		IsForwardedPacket: true,
+		OnRelease: func() {
+			b.Release()
+		},
+	}), nil
+}
+
+// WritePacket implements GVisorDevice method to write one packet to the tun device
+func (t *LinuxTun) WritePacket(packet *stack.PacketBuffer) tcpip.Error {
+	// request memory to write from reusable buffer pool
+	b := buf.NewWithSize(int32(t.options.MTU))
+	defer b.Release()
+
+	// copy the bytes of slices that compose the packet into the allocated buffer, no
+	// Linux specific header is needed here, unlike Darwin/FreeBSD's utun devices
+	for _, packetElement := range packet.AsSlices() {
+		_, _ = b.Write(packetElement)
+	}
+
+	if _, err := fdReadWriter(t.tunFd).Write(b.Bytes()); err != nil {
+		if err == unix.EAGAIN || err == unix.EWOULDBLOCK {
+			return &tcpip.ErrWouldBlock{}
+		}
+		return &tcpip.ErrAborted{}
+	}
+	return nil
+}
+
+// Wait blocks until the tun fd is likely readable again, rather than spinning the CPU.
+// A bounded timeout keeps this responsive to a Close() racing a call already parked here.
+func (t *LinuxTun) Wait() {
+	fds := []unix.PollFd{{Fd: int32(t.tunFd), Events: unix.POLLIN}}
+	_, _ = unix.Poll(fds, 1000)
+}
+
 func setinterface(network, address string, fd uintptr, iface *net.Interface) error {
 	return unix.BindToDevice(int(fd), iface.Name)
 }

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),
+			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{
@@ -371,87 +336,48 @@ 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 {
 	net.PacketConn
-	resolveFunc func(host string) (net.IP, error)
-	dest        *net.UDPAddr
+	dest *net.UDPAddr
 }
 
 func (c *udpConnClient) ReadMultiBuffer() (buf.MultiBuffer, error) {
@@ -478,15 +404,8 @@ func (c *udpConnClient) WriteMultiBuffer(mb buf.MultiBuffer) error {
 		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 +442,59 @@ 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
+	c.m = make(map[string]entry)
+	go c.gc()
+}
+
+func (c *cache) gc() {
+	ticker := time.NewTicker(time.Minute)
+	for {
+		now := <-ticker.C
+		c.mu.Lock()
+		for key, entry := range c.m {
+			if now.After(entry.deadline) {
+				delete(c.m, key)
+			}
+		}
+		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,
 	}
@@ -124,8 +128,10 @@ 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
 	}
 
@@ -166,7 +172,10 @@ func (tun *netTun) WriteNotify() {
 	view := pkt.ToView()
 	pkt.DecRef()
 
-	tun.incomingPacket <- view
+	select {
+	case tun.incomingPacket <- view:
+	case <-tun.closed:
+	}
 }
 
 func (tun *netTun) Close() error {
@@ -179,8 +188,9 @@ 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 +229,7 @@ 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 +257,12 @@ 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 +581,12 @@ 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 +595,11 @@ 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 +700,137 @@ 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/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/memory_settings.go

@@ -1,7 +1,12 @@
 package internet
 
 import (
+	"context"
+	"reflect"
+
+	"github.com/xtls/xray-core/common"
 	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/common/net/cnc"
 	"github.com/xtls/xray-core/transport/internet/finalmask"
 )
 
@@ -12,8 +17,7 @@ type MemoryStreamConfig struct {
 	ProtocolSettings interface{}
 	SecurityType     string
 	SecuritySettings interface{}
-	TcpmaskManager   *finalmask.TcpmaskManager
-	UdpmaskManager   *finalmask.UdpmaskManager
+	FinalMask        *finalmask.FinalMask
 	QuicParams       *QuicParams
 	SocketSettings   *SocketConfig
 	DownloadSettings *MemoryStreamConfig
@@ -51,33 +55,53 @@ func ToMemoryStreamConfig(s *StreamConfig) (*MemoryStreamConfig, error) {
 		mss.SecuritySettings = ess
 	}
 
-	if s != nil && len(s.Tcpmasks) > 0 {
-		var masks []finalmask.Tcpmask
-		for _, msg := range s.Tcpmasks {
-			instance, err := msg.GetInstance()
-			if err != nil {
-				return nil, err
-			}
-			masks = append(masks, instance.(finalmask.Tcpmask))
+	var tcpMasks []finalmask.TCPMask
+	var udpMasks []finalmask.UDPMask
+
+	if s != nil {
+		for i := range s.Tcpmasks {
+			instance := common.Must2(s.Tcpmasks[i].GetInstance())
+			tcpMasks = append(tcpMasks, instance.(finalmask.TCPMask))
+		}
+		for i := range s.Udpmasks {
+			instance := common.Must2(s.Udpmasks[i].GetInstance())
+			udpMasks = append(udpMasks, instance.(finalmask.UDPMask))
 		}
-		mss.TcpmaskManager = finalmask.NewTcpmaskManager(masks)
 	}
 
+	dialTCP := func(ctx context.Context, dest net.Destination) (net.Conn, error) {
+		return DialSystem(ctx, dest, mss.SocketSettings)
+	}
+	listen := func(ctx context.Context, addr net.Addr) (net.Listener, error) {
+		return ListenSystem(ctx, addr, mss.SocketSettings)
+	}
+	dialUDP := func(ctx context.Context, dest net.Destination) (net.PacketConn, net.Addr, error) {
+		conn, err := DialSystem(ctx, dest, mss.SocketSettings)
+		if err != nil {
+			return nil, nil, err
+		}
+		var newConn net.PacketConn
+		var udpAddr net.Addr
+		switch c := conn.(type) {
+		case *PacketConnWrapper:
+			newConn = c.PacketConn
+			udpAddr = conn.RemoteAddr()
+		case *cnc.Connection:
+			newConn = &FakePacketConn{Conn: c}
+			udpAddr = &net.UDPAddr{IP: []byte{0, 0, 0, 0}, Port: 0}
+		default:
+			panic(reflect.TypeOf(c))
+		}
+		return newConn, udpAddr, nil
+	}
+	listenPacket := func(ctx context.Context, addr net.Addr) (net.PacketConn, error) {
+		return ListenSystemPacket(ctx, addr, mss.SocketSettings)
+	}
+	mss.FinalMask = finalmask.NewFinalMask(tcpMasks, udpMasks, dialTCP, listen, dialUDP, listenPacket)
+
 	if s != nil && s.QuicParams != nil {
 		mss.QuicParams = s.QuicParams
 	}
 
-	if s != nil && len(s.Udpmasks) > 0 {
-		var masks []finalmask.Udpmask
-		for _, msg := range s.Udpmasks {
-			instance, err := msg.GetInstance()
-			if err != nil {
-				return nil, err
-			}
-			masks = append(masks, instance.(finalmask.Udpmask))
-		}
-		mss.UdpmaskManager = finalmask.NewUdpmaskManager(masks)
-	}
-
 	return mss, nil
 }

transport/internet/splithttp/dialer.go

@@ -8,7 +8,7 @@ import (
 	"net/http"
 	"net/http/httptrace"
 	"net/url"
-	reflect "reflect"
+	"reflect"
 	"runtime"
 	"strconv"
 	"sync"
@@ -25,6 +25,7 @@ import (
 	"github.com/xtls/xray-core/common/signal/done"
 	"github.com/xtls/xray-core/transport/internet"
 	"github.com/xtls/xray-core/transport/internet/browser_dialer"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
 	"github.com/xtls/xray-core/transport/internet/hysteria/congestion"
 	"github.com/xtls/xray-core/transport/internet/hysteria/congestion/bbr"
 	"github.com/xtls/xray-core/transport/internet/reality"
@@ -116,20 +117,17 @@ func createHTTPClient(dest net.Destination, streamSettings *internet.MemoryStrea
 	transportConfig := streamSettings.ProtocolSettings.(*Config)
 
 	dialContext := func(ctxInner context.Context) (net.Conn, error) {
-		conn, err := internet.DialSystem(ctxInner, dest, streamSettings.SocketSettings)
+		var conn net.Conn
+		var err error
+		if streamSettings.FinalMask != nil {
+			conn, err = streamSettings.FinalMask.DialTCP(ctxInner, dest)
+		} else {
+			conn, err = internet.DialSystem(ctxInner, dest, streamSettings.SocketSettings)
+		}
 		if err != nil {
 			return nil, err
 		}
 
-		if streamSettings.TcpmaskManager != nil {
-			newConn, err := streamSettings.TcpmaskManager.WrapConnClient(conn)
-			if err != nil {
-				conn.Close()
-				return nil, errors.New("mask err").Base(err)
-			}
-			conn = newConn
-		}
-
 		if realityConfig != nil {
 			return reality.UClient(conn, realityConfig, ctxInner, dest)
 		}
@@ -196,30 +194,29 @@ func createHTTPClient(dest net.Destination, streamSettings *internet.MemoryStrea
 			TLSClientConfig: gotlsConfig,
 			Dial: func(ctx context.Context, addr string, tlsCfg *gotls.Config, cfg *quic.Config) (*quic.Conn, error) {
 				var pktConn net.PacketConn
-				var udpAddr *net.UDPAddr
-
-				raw, err := internet.DialSystem(ctx, dest, streamSettings.SocketSettings)
-				if err != nil {
-					return nil, 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 streamSettings.UdpmaskManager != nil {
-					newConn, err := streamSettings.UdpmaskManager.WrapPacketConnClient(pktConn)
+				var udpAddr net.Addr
+				if streamSettings.FinalMask != nil {
+					conn, err := 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
+					udpAddr = conn.RemoteAddr()
+				} else {
+					conn, err := internet.DialSystem(ctx, dest, 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
+						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}

transport/internet/splithttp/hub.go

@@ -463,31 +463,17 @@ func ListenXH(ctx context.Context, address net.Address, port net.Port, streamSet
 	l.isH3 = len(tlsConfig.NextProtos) == 1 && tlsConfig.NextProtos[0] == "h3"
 
 	var err error
-	if port == net.Port(0) { // unix
-		l.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 XHTTP on ", address).Base(err)
+	if l.isH3 {
+		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)
 		}
-		errors.LogInfo(ctx, "listening UNIX domain socket for XHTTP on ", address)
-	} else if l.isH3 { // quic
-		Conn, err := internet.ListenSystemPacket(context.Background(), &net.UDPAddr{
-			IP:   address.IP(),
-			Port: int(port),
-		}, streamSettings.SocketSettings)
 		if err != nil {
 			return nil, errors.New("failed to listen UDP for XHTTP/3 on ", address, ":", port).Base(err)
 		}
-		if streamSettings.UdpmaskManager != nil {
-			newConn, err := streamSettings.UdpmaskManager.WrapPacketConnServer(Conn)
-			if err != nil {
-				Conn.Close()
-				return nil, errors.New("mask err").Base(err)
-			}
-			Conn = newConn
-		}
 
 		quicParams := streamSettings.QuicParams
 		if quicParams == nil {
@@ -512,7 +498,7 @@ func ListenXH(ctx context.Context, address net.Address, port net.Port, streamSet
 			common.Must2(rand.Read((*k)[:]))
 		}
 
-		tr := &quic.Transport{Conn: Conn, DisableGSO: quicParams.DisableGSO, StatelessResetKey: k}
+		tr := &quic.Transport{Conn: pktConn, DisableGSO: quicParams.DisableGSO, StatelessResetKey: k}
 
 		l.h3listener, err = tr.ListenEarly(tlsConfig, quicConfig)
 		if err != nil {
@@ -534,21 +520,24 @@ func ListenXH(ctx context.Context, address net.Address, port net.Port, streamSet
 				errors.LogErrorInner(ctx, err, "failed to serve HTTP/3 for XHTTP/3")
 			}
 			_ = tr.Close()
-			_ = Conn.Close()
+			_ = pktConn.Close()
 		}()
-	} else { // tcp
-		l.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 XHTTP on ", address, ":", port).Base(err)
+	} else {
+		var addr net.Addr
+		if port == net.Port(0) { // unix
+			addr = &net.UnixAddr{Name: address.Domain(), Net: "unix"}
+		} else { // tcp
+			addr = &net.TCPAddr{IP: address.IP(), Port: int(port)}
 		}
-		errors.LogInfo(ctx, "listening TCP for XHTTP on ", address, ":", port)
-	}
-
-	if !l.isH3 && streamSettings.TcpmaskManager != nil {
-		l.listener, _ = streamSettings.TcpmaskManager.WrapListener(l.listener)
+		if streamSettings.FinalMask != nil {
+			l.listener, err = streamSettings.FinalMask.Listen(ctx, addr)
+		} else {
+			l.listener, err = internet.ListenSystem(ctx, addr, streamSettings.SocketSettings)
+		}
+		if err != nil {
+			return nil, errors.New("failed to listen ", addr.Network(), " for XHTTP on ", address, ":", port).Base(err)
+		}
+		errors.LogInfo(ctx, "listening ", addr.Network(), " for XHTTP on ", address, ":", port)
 	}
 
 	// tcp/unix (h1/h2)

transport/internet/system_dialer.go

@@ -235,5 +235,5 @@ func (c *FakePacketConn) WriteTo(p []byte, _ net.Addr) (n int, err error) {
 }
 
 func (c *FakePacketConn) LocalAddr() net.Addr {
-	return &net.UDPAddr{IP: c.Conn.LocalAddr().(*net.TCPAddr).IP, Port: c.Conn.LocalAddr().(*net.TCPAddr).Port}
+	return &net.UDPAddr{IP: []byte{0, 0, 0, 0}}
 }

transport/internet/tcp/dialer.go

@@ -19,18 +19,15 @@ import (
 // Dial dials a new TCP connection to the given destination.
 func Dial(ctx context.Context, dest net.Destination, streamSettings *internet.MemoryStreamConfig) (stat.Connection, error) {
 	errors.LogInfo(ctx, "dialing TCP to ", dest)
-	conn, err := internet.DialSystem(ctx, dest, streamSettings.SocketSettings)
-	if err != nil {
-		return nil, err
+	var conn net.Conn
+	var err error
+	if streamSettings.FinalMask != nil {
+		conn, err = streamSettings.FinalMask.DialTCP(ctx, dest)
+	} else {
+		conn, err = internet.DialSystem(ctx, dest, streamSettings.SocketSettings)
 	}
-
-	if streamSettings.TcpmaskManager != nil {
-		newConn, err := streamSettings.TcpmaskManager.WrapConnClient(conn)
-		if err != nil {
-			conn.Close()
-			return nil, errors.New("mask err").Base(err)
-		}
-		conn = newConn
+	if err != nil {
+		return nil, errors.New("failed to dial to dest").Base(err)
 	}
 
 	if config := tls.ConfigFromStreamSettings(streamSettings); config != nil {

transport/internet/tcp/hub.go

@@ -41,29 +41,21 @@ func ListenTCP(ctx context.Context, address net.Address, port net.Port, streamSe
 	}
 	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 on ", address).Base(err)
-		}
-		errors.LogInfo(ctx, "listening Unix Domain Socket on ", address)
+		addr = &net.UnixAddr{Name: address.Domain(), Net: "unix"}
+	} else { // tcp
+		addr = &net.TCPAddr{IP: address.IP(), Port: int(port)}
+	}
+	if streamSettings.FinalMask != nil {
+		listener, err = streamSettings.FinalMask.Listen(ctx, addr)
 	} else {
-		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 on ", address, ":", port).Base(err)
-		}
-		errors.LogInfo(ctx, "listening TCP on ", address, ":", port)
+		listener, err = internet.ListenSystem(ctx, addr, streamSettings.SocketSettings)
 	}
-
-	if streamSettings.TcpmaskManager != nil {
-		listener, _ = streamSettings.TcpmaskManager.WrapListener(listener)
+	if err != nil {
+		return nil, errors.New("failed to listen ", addr.Network(), " on ", address, ":", port).Base(err)
 	}
+	errors.LogInfo(ctx, "listening ", addr.Network(), " on ", address, ":", port)
 
 	if streamSettings.SocketSettings != nil && streamSettings.SocketSettings.AcceptProxyProtocol {
 		errors.LogWarning(ctx, "accepting PROXY protocol")

transport/internet/udp/dialer.go

@@ -2,12 +2,9 @@ package udp
 
 import (
 	"context"
-	"reflect"
 
 	"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/common/net/cnc"
 	"github.com/xtls/xray-core/transport/internet"
 	"github.com/xtls/xray-core/transport/internet/stat"
 )
@@ -15,40 +12,14 @@ import (
 func init() {
 	common.Must(internet.RegisterTransportDialer(protocolName,
 		func(ctx context.Context, dest net.Destination, streamSettings *internet.MemoryStreamConfig) (stat.Connection, error) {
-			var sockopt *internet.SocketConfig
-			if streamSettings != nil {
-				sockopt = streamSettings.SocketSettings
-			}
-			conn, err := internet.DialSystem(ctx, dest, sockopt)
-			if err != nil {
-				return nil, err
-			}
-
-			if streamSettings != nil && 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,
+			if streamSettings != nil && streamSettings.FinalMask != nil {
+				return streamSettings.FinalMask.DialUDP(ctx, dest)
+			} else {
+				var sockopt *internet.SocketConfig
+				if streamSettings != nil && streamSettings.SocketSettings != nil {
+					sockopt = streamSettings.SocketSettings
 				}
+				return internet.DialSystem(ctx, dest, sockopt)
 			}
-
-			return conn, nil
 		}))
 }

transport/internet/udp/hub.go

@@ -58,24 +58,15 @@ func ListenUDP(ctx context.Context, address net.Address, port net.Port, streamSe
 	}
 
 	var err error
-	hub.conn, err = internet.ListenSystemPacket(ctx, &net.UDPAddr{
-		IP:   address.IP(),
-		Port: int(port),
-	}, sockopt)
+	if streamSettings.FinalMask != nil {
+		hub.conn, err = streamSettings.FinalMask.ListenPacket(ctx, &net.UDPAddr{IP: address.IP(), Port: int(port)})
+	} else {
+		hub.conn, err = internet.ListenSystemPacket(ctx, &net.UDPAddr{IP: address.IP(), Port: int(port)}, streamSettings.SocketSettings)
+	}
 	if err != nil {
 		return nil, err
 	}
 
-	raw := hub.conn
-
-	if streamSettings.UdpmaskManager != nil {
-		hub.conn, err = streamSettings.UdpmaskManager.WrapPacketConnServer(raw)
-		if err != nil {
-			raw.Close()
-			return nil, errors.New("mask err").Base(err)
-		}
-	}
-
 	errors.LogInfo(ctx, "listening UDP on ", address, ":", port)
 	hub.udpConn, _ = hub.conn.(*net.UDPConn)
 	hub.cache = make(chan *udp.Packet, hub.capacity)

transport/internet/websocket/dialer.go

@@ -48,20 +48,16 @@ func dialWebSocket(ctx context.Context, dest net.Destination, streamSettings *in
 
 	dialer := &websocket.Dialer{
 		NetDial: func(network, addr string) (net.Conn, error) {
-			conn, err := internet.DialSystem(ctx, dest, streamSettings.SocketSettings)
+			var conn net.Conn
+			var err error
+			if streamSettings.FinalMask != nil {
+				conn, err = streamSettings.FinalMask.DialTCP(ctx, dest)
+			} else {
+				conn, err = internet.DialSystem(ctx, dest, streamSettings.SocketSettings)
+			}
 			if err != nil {
-				return nil, err
+				return nil, errors.New("failed to dial to dest").Base(err)
 			}
-
-			if streamSettings.TcpmaskManager != nil {
-				newConn, err := streamSettings.TcpmaskManager.WrapConnClient(conn)
-				if err != nil {
-					conn.Close()
-					return nil, errors.New("mask err").Base(err)
-				}
-				conn = newConn
-			}
-
 			return conn, err
 		},
 		ReadBufferSize:   4 * 1024,
@@ -79,19 +75,15 @@ func dialWebSocket(ctx context.Context, dest net.Destination, streamSettings *in
 		if fingerprint := tls.GetFingerprint(tConfig.Fingerprint); fingerprint != nil {
 			dialer.NetDialTLSContext = func(_ context.Context, _, addr string) (net.Conn, error) {
 				// Like the NetDial in the dialer
-				pconn, err := internet.DialSystem(ctx, dest, streamSettings.SocketSettings)
-				if err != nil {
-					errors.LogErrorInner(ctx, err, "failed to dial to "+addr)
-					return nil, err
+				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 streamSettings.TcpmaskManager != nil {
-					newConn, err := streamSettings.TcpmaskManager.WrapConnClient(pconn)
-					if err != nil {
-						pconn.Close()
-						return nil, errors.New("mask err").Base(err)
-					}
-					pconn = newConn
+				if err != nil {
+					return nil, errors.New("failed to dial to dest").Base(err)
 				}
 
 				// TLS and apply the handshake

transport/internet/websocket/hub.go

@@ -97,29 +97,21 @@ func ListenWS(ctx context.Context, address net.Address, port net.Port, streamSet
 	}
 	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 WS) on ", address).Base(err)
-		}
-		errors.LogInfo(ctx, "listening unix domain socket(for WS) 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 WS) on ", address, ":", port).Base(err)
-		}
-		errors.LogInfo(ctx, "listening TCP(for WS) 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 WS) on ", address, ":", port).Base(err)
+	}
+	errors.LogInfo(ctx, "listening ", addr.Network(), "(for WS) on ", address, ":", port)
 
 	if streamSettings.SocketSettings != nil && streamSettings.SocketSettings.AcceptProxyProtocol {
 		errors.LogWarning(ctx, "accepting PROXY protocol")

transport/internet/xdrive/client.go

@@ -0,0 +1,153 @@
+package xdrive
+
+import (
+	"context"
+	gotls "crypto/tls"
+	"net/http"
+	"time"
+
+	"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/reality"
+	"github.com/xtls/xray-core/transport/internet/tls"
+	"golang.org/x/net/http2"
+)
+
+type serviceTransport struct {
+	plain  http.RoundTripper
+	secure http.RoundTripper
+}
+
+func (t *serviceTransport) RoundTrip(r *http.Request) (*http.Response, error) {
+	if r.URL.Scheme == "https" {
+		return t.secure.RoundTrip(r)
+	}
+	return t.plain.RoundTrip(r)
+}
+
+func newServiceClient(streamSettings *internet.MemoryStreamConfig, timeout time.Duration, maxConns int) *http.Client {
+	var (
+		tlsConfig     *tls.Config
+		realityConfig *reality.Config
+		sockopt       *internet.SocketConfig
+		fronting      *net.Destination
+	)
+	if streamSettings != nil {
+		tlsConfig = tls.ConfigFromStreamSettings(streamSettings)
+		realityConfig = reality.ConfigFromStreamSettings(streamSettings)
+		sockopt = streamSettings.SocketSettings
+		fronting = streamSettings.Destination
+	}
+	overHTTP2 := allowsHTTP2(tlsConfig, realityConfig)
+
+	dial := func(ctx context.Context, addr string) (net.Conn, net.Destination, error) {
+		host, err := net.ParseDestination("tcp:" + addr)
+		if err != nil {
+			return nil, host, errors.New("bad address: ", addr).Base(err)
+		}
+
+		target := host
+		if fronting != nil {
+			target.Address = fronting.Address
+			if fronting.Port != 0 {
+				target.Port = fronting.Port
+			}
+		}
+
+		var conn net.Conn
+		if streamSettings.FinalMask != nil {
+			conn, err = streamSettings.FinalMask.DialTCP(ctx, target)
+		} else {
+			conn, err = internet.DialSystem(ctx, target, sockopt)
+		}
+		if err != nil {
+			return nil, host, errors.New("failed to dial to dest").Base(err)
+		}
+		return conn, host, nil
+	}
+
+	dialPlain := func(ctx context.Context, network, addr string) (net.Conn, error) {
+		conn, _, err := dial(ctx, addr)
+		return conn, err
+	}
+
+	dialTLS := func(ctx context.Context, addr string) (net.Conn, error) {
+		conn, host, err := dial(ctx, addr)
+		if err != nil {
+			return nil, err
+		}
+
+		if realityConfig != nil {
+			return reality.UClient(conn, realityConfig, ctx, host)
+		}
+
+		gotlsConfig := &gotls.Config{ServerName: host.Address.String()}
+		if tlsConfig != nil {
+			gotlsConfig = tlsConfig.GetTLSConfig(tls.WithDestination(host))
+		}
+		if len(gotlsConfig.NextProtos) != 1 {
+			if overHTTP2 {
+				gotlsConfig.NextProtos = []string{"h2"}
+			} else {
+				gotlsConfig.NextProtos = []string{"http/1.1"}
+			}
+		}
+
+		if tlsConfig != nil {
+			if fingerprint := tls.GetFingerprint(tlsConfig.Fingerprint); fingerprint != nil {
+				uconn := tls.UClient(conn, gotlsConfig, fingerprint)
+				if err := uconn.(*tls.UConn).HandshakeContext(ctx); err != nil {
+					conn.Close()
+					return nil, err
+				}
+				return uconn, nil
+			}
+		}
+		return tls.Client(conn, gotlsConfig), nil
+	}
+
+	var secure http.RoundTripper
+	if overHTTP2 {
+		secure = &http2.Transport{
+			DialTLSContext: func(ctx context.Context, network, addr string, cfg *gotls.Config) (net.Conn, error) {
+				return dialTLS(ctx, addr)
+			},
+			IdleConnTimeout: net.ConnIdleTimeout,
+		}
+	} else {
+		secure = &http.Transport{
+			DialTLSContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
+				return dialTLS(ctx, addr)
+			},
+			IdleConnTimeout:     net.ConnIdleTimeout,
+			MaxIdleConns:        maxConns,
+			MaxIdleConnsPerHost: maxConns,
+			MaxConnsPerHost:     maxConns,
+		}
+	}
+
+	return &http.Client{
+		Transport: &serviceTransport{
+			plain: &http.Transport{
+				DialContext:         dialPlain,
+				IdleConnTimeout:     net.ConnIdleTimeout,
+				MaxIdleConns:        maxConns,
+				MaxIdleConnsPerHost: maxConns,
+				MaxConnsPerHost:     maxConns,
+			},
+			secure: secure,
+		},
+		Timeout: timeout,
+	}
+}
+
+func allowsHTTP2(tlsConfig *tls.Config, realityConfig *reality.Config) bool {
+	if realityConfig != nil {
+		return true
+	}
+	if tlsConfig == nil {
+		return false
+	}
+	return len(tlsConfig.NextProtocol) == 1 && tlsConfig.NextProtocol[0] == "h2"
+}

transport/internet/xdrive/client_test.go

@@ -0,0 +1,101 @@
+package xdrive
+
+import (
+	"context"
+	gotls "crypto/tls"
+	"net"
+	"net/http"
+	"sync"
+	"testing"
+	"time"
+
+	xnet "github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet"
+	"github.com/xtls/xray-core/transport/internet/tls"
+)
+
+func recordingTLSListener(t *testing.T, sni *string, mu *sync.Mutex) net.Listener {
+	t.Helper()
+
+	ln, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("listen: %v", err)
+	}
+	go func() {
+		for {
+			conn, err := ln.Accept()
+			if err != nil {
+				return
+			}
+			cfg := &gotls.Config{
+				GetConfigForClient: func(hello *gotls.ClientHelloInfo) (*gotls.Config, error) {
+					mu.Lock()
+					*sni = hello.ServerName
+					mu.Unlock()
+					return nil, nil
+				},
+			}
+			tconn := gotls.Server(conn, cfg)
+			tconn.HandshakeContext(context.Background())
+			tconn.Close()
+		}
+	}()
+	t.Cleanup(func() { ln.Close() })
+	return ln
+}
+
+func sniForSettings(t *testing.T, serverName string) string {
+	t.Helper()
+
+	var (
+		sni string
+		mu  sync.Mutex
+	)
+	ln := recordingTLSListener(t, &sni, &mu)
+	addr := ln.Addr().(*net.TCPAddr)
+
+	settings := &internet.MemoryStreamConfig{
+		ProtocolName: protocolName,
+		Destination: &xnet.Destination{
+			Address: xnet.ParseAddress(addr.IP.String()),
+			Port:    xnet.Port(addr.Port),
+			Network: xnet.Network_TCP,
+		},
+		SecuritySettings: &tls.Config{ServerName: serverName},
+	}
+
+	prev := driveFilesURL
+	driveFilesURL = "https://www.googleapis.com/drive/v3/files"
+	defer func() { driveFilesURL = prev }()
+
+	client := newServiceClient(settings, 5*time.Second, 8)
+	req, err := http.NewRequest(http.MethodGet, driveFilesURL, nil)
+	if err != nil {
+		t.Fatalf("request: %v", err)
+	}
+	client.Do(req)
+
+	deadline := time.Now().Add(3 * time.Second)
+	for time.Now().Before(deadline) {
+		mu.Lock()
+		got := sni
+		mu.Unlock()
+		if got != "" {
+			return got
+		}
+		time.Sleep(5 * time.Millisecond)
+	}
+	return ""
+}
+
+func TestServiceSNIDefaultsToHost(t *testing.T) {
+	if got := sniForSettings(t, ""); got != "www.googleapis.com" {
+		t.Fatalf("SNI defaulted to %q, want the host www.googleapis.com, not address", got)
+	}
+}
+
+func TestServiceSNIOverride(t *testing.T) {
+	if got := sniForSettings(t, "www.google.com"); got != "www.google.com" {
+		t.Fatalf("explicit serverName gave SNI %q, want www.google.com", got)
+	}
+}

transport/internet/xdrive/config.pb.go

@@ -0,0 +1,222 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// versions:
+// 	protoc-gen-go v1.36.11
+// 	protoc        v6.33.5
+// source: transport/internet/xdrive/config.proto
+
+package xdrive
+
+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"`
+	RemoteFolder      string                 `protobuf:"bytes,1,opt,name=remote_folder,json=remoteFolder,proto3" json:"remote_folder,omitempty"`
+	Service           string                 `protobuf:"bytes,2,opt,name=service,proto3" json:"service,omitempty"`
+	Secrets           []string               `protobuf:"bytes,3,rep,name=secrets,proto3" json:"secrets,omitempty"`
+	SegmentBytes      uint32                 `protobuf:"varint,4,opt,name=segment_bytes,json=segmentBytes,proto3" json:"segment_bytes,omitempty"`
+	FlushIntervalMs   uint32                 `protobuf:"varint,5,opt,name=flush_interval_ms,json=flushIntervalMs,proto3" json:"flush_interval_ms,omitempty"`
+	PollIntervalMs    uint32                 `protobuf:"varint,6,opt,name=poll_interval_ms,json=pollIntervalMs,proto3" json:"poll_interval_ms,omitempty"`
+	MaxPollIntervalMs uint32                 `protobuf:"varint,7,opt,name=max_poll_interval_ms,json=maxPollIntervalMs,proto3" json:"max_poll_interval_ms,omitempty"`
+	SessionTtlSeconds uint32                 `protobuf:"varint,8,opt,name=session_ttl_seconds,json=sessionTtlSeconds,proto3" json:"session_ttl_seconds,omitempty"`
+	Concurrency       uint32                 `protobuf:"varint,9,opt,name=concurrency,proto3" json:"concurrency,omitempty"`
+	EagerWindowMs     uint32                 `protobuf:"varint,10,opt,name=eager_window_ms,json=eagerWindowMs,proto3" json:"eager_window_ms,omitempty"`
+	HoleTimeoutMs     uint32                 `protobuf:"varint,11,opt,name=hole_timeout_ms,json=holeTimeoutMs,proto3" json:"hole_timeout_ms,omitempty"`
+	Template          string                 `protobuf:"bytes,12,opt,name=template,proto3" json:"template,omitempty"`
+	unknownFields     protoimpl.UnknownFields
+	sizeCache         protoimpl.SizeCache
+}
+
+func (x *Config) Reset() {
+	*x = Config{}
+	mi := &file_transport_internet_xdrive_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_xdrive_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_xdrive_config_proto_rawDescGZIP(), []int{0}
+}
+
+func (x *Config) GetRemoteFolder() string {
+	if x != nil {
+		return x.RemoteFolder
+	}
+	return ""
+}
+
+func (x *Config) GetService() string {
+	if x != nil {
+		return x.Service
+	}
+	return ""
+}
+
+func (x *Config) GetSecrets() []string {
+	if x != nil {
+		return x.Secrets
+	}
+	return nil
+}
+
+func (x *Config) GetSegmentBytes() uint32 {
+	if x != nil {
+		return x.SegmentBytes
+	}
+	return 0
+}
+
+func (x *Config) GetFlushIntervalMs() uint32 {
+	if x != nil {
+		return x.FlushIntervalMs
+	}
+	return 0
+}
+
+func (x *Config) GetPollIntervalMs() uint32 {
+	if x != nil {
+		return x.PollIntervalMs
+	}
+	return 0
+}
+
+func (x *Config) GetMaxPollIntervalMs() uint32 {
+	if x != nil {
+		return x.MaxPollIntervalMs
+	}
+	return 0
+}
+
+func (x *Config) GetSessionTtlSeconds() uint32 {
+	if x != nil {
+		return x.SessionTtlSeconds
+	}
+	return 0
+}
+
+func (x *Config) GetConcurrency() uint32 {
+	if x != nil {
+		return x.Concurrency
+	}
+	return 0
+}
+
+func (x *Config) GetEagerWindowMs() uint32 {
+	if x != nil {
+		return x.EagerWindowMs
+	}
+	return 0
+}
+
+func (x *Config) GetHoleTimeoutMs() uint32 {
+	if x != nil {
+		return x.HoleTimeoutMs
+	}
+	return 0
+}
+
+func (x *Config) GetTemplate() string {
+	if x != nil {
+		return x.Template
+	}
+	return ""
+}
+
+var File_transport_internet_xdrive_config_proto protoreflect.FileDescriptor
+
+const file_transport_internet_xdrive_config_proto_rawDesc = "" +
+	"\n" +
+	"&transport/internet/xdrive/config.proto\x12\x1exray.transport.internet.xdrive\"\xcb\x03\n" +
+	"\x06Config\x12#\n" +
+	"\rremote_folder\x18\x01 \x01(\tR\fremoteFolder\x12\x18\n" +
+	"\aservice\x18\x02 \x01(\tR\aservice\x12\x18\n" +
+	"\asecrets\x18\x03 \x03(\tR\asecrets\x12#\n" +
+	"\rsegment_bytes\x18\x04 \x01(\rR\fsegmentBytes\x12*\n" +
+	"\x11flush_interval_ms\x18\x05 \x01(\rR\x0fflushIntervalMs\x12(\n" +
+	"\x10poll_interval_ms\x18\x06 \x01(\rR\x0epollIntervalMs\x12/\n" +
+	"\x14max_poll_interval_ms\x18\a \x01(\rR\x11maxPollIntervalMs\x12.\n" +
+	"\x13session_ttl_seconds\x18\b \x01(\rR\x11sessionTtlSeconds\x12 \n" +
+	"\vconcurrency\x18\t \x01(\rR\vconcurrency\x12&\n" +
+	"\x0feager_window_ms\x18\n" +
+	" \x01(\rR\reagerWindowMs\x12&\n" +
+	"\x0fhole_timeout_ms\x18\v \x01(\rR\rholeTimeoutMs\x12\x1a\n" +
+	"\btemplate\x18\f \x01(\tR\btemplateB5Z3github.com/xtls/xray-core/transport/internet/xdriveb\x06proto3"
+
+var (
+	file_transport_internet_xdrive_config_proto_rawDescOnce sync.Once
+	file_transport_internet_xdrive_config_proto_rawDescData []byte
+)
+
+func file_transport_internet_xdrive_config_proto_rawDescGZIP() []byte {
+	file_transport_internet_xdrive_config_proto_rawDescOnce.Do(func() {
+		file_transport_internet_xdrive_config_proto_rawDescData = protoimpl.X.CompressGZIP(unsafe.Slice(unsafe.StringData(file_transport_internet_xdrive_config_proto_rawDesc), len(file_transport_internet_xdrive_config_proto_rawDesc)))
+	})
+	return file_transport_internet_xdrive_config_proto_rawDescData
+}
+
+var file_transport_internet_xdrive_config_proto_msgTypes = make([]protoimpl.MessageInfo, 1)
+var file_transport_internet_xdrive_config_proto_goTypes = []any{
+	(*Config)(nil), // 0: xray.transport.internet.xdrive.Config
+}
+var file_transport_internet_xdrive_config_proto_depIdxs = []int32{
+	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_xdrive_config_proto_init() }
+func file_transport_internet_xdrive_config_proto_init() {
+	if File_transport_internet_xdrive_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_xdrive_config_proto_rawDesc), len(file_transport_internet_xdrive_config_proto_rawDesc)),
+			NumEnums:      0,
+			NumMessages:   1,
+			NumExtensions: 0,
+			NumServices:   0,
+		},
+		GoTypes:           file_transport_internet_xdrive_config_proto_goTypes,
+		DependencyIndexes: file_transport_internet_xdrive_config_proto_depIdxs,
+		MessageInfos:      file_transport_internet_xdrive_config_proto_msgTypes,
+	}.Build()
+	File_transport_internet_xdrive_config_proto = out.File
+	file_transport_internet_xdrive_config_proto_goTypes = nil
+	file_transport_internet_xdrive_config_proto_depIdxs = nil
+}

transport/internet/xdrive/config.proto

@@ -0,0 +1,19 @@
+syntax = "proto3";
+
+package xray.transport.internet.xdrive;
+option go_package = "github.com/xtls/xray-core/transport/internet/xdrive";
+
+message Config {
+  string remote_folder = 1;
+  string service = 2;
+  repeated string secrets = 3;
+  uint32 segment_bytes = 4;
+  uint32 flush_interval_ms = 5;
+  uint32 poll_interval_ms = 6;
+  uint32 max_poll_interval_ms = 7;
+  uint32 session_ttl_seconds = 8;
+  uint32 concurrency = 9;
+  uint32 eager_window_ms = 10;
+  uint32 hole_timeout_ms = 11;
+  string template = 12;
+}

transport/internet/xdrive/conn.go

@@ -0,0 +1,139 @@
+package xdrive
+
+import (
+	"context"
+	"os"
+	"sync"
+	"time"
+
+	"github.com/xtls/xray-core/common/net"
+)
+
+var placeholderAddr = &net.TCPAddr{IP: net.IP{127, 0, 0, 1}, Port: 0}
+
+type Conn struct {
+	cancel  context.CancelFunc
+	writer  *walWriter
+	reader  *walReader
+	onClose func()
+
+	readBuf []byte
+
+	deadlineMu    sync.Mutex
+	readDeadline  time.Time
+	writeDeadline time.Time
+
+	closeOnce sync.Once
+	closeErr  error
+}
+
+func newConn(ctx context.Context, storage Storage, writePrefix, readPrefix string, p params, onClose func()) *Conn {
+	ctx, cancel := context.WithCancel(ctx)
+	return &Conn{
+		cancel:  cancel,
+		writer:  newWALWriter(ctx, storage, writePrefix, p),
+		reader:  newWALReader(ctx, storage, readPrefix, p),
+		onClose: onClose,
+	}
+}
+
+func (c *Conn) Read(b []byte) (int, error) {
+	if len(c.readBuf) == 0 {
+		data, err := c.receive()
+		if err != nil {
+			return 0, err
+		}
+		c.readBuf = data
+	}
+	n := copy(b, c.readBuf)
+	c.readBuf = c.readBuf[n:]
+	return n, nil
+}
+
+func (c *Conn) receive() ([]byte, error) {
+	deadline := c.getDeadline(true)
+	if deadline.IsZero() {
+		data, ok := <-c.reader.ch
+		if !ok {
+			return nil, c.reader.Err()
+		}
+		return data, nil
+	}
+
+	if !time.Now().Before(deadline) {
+		return nil, os.ErrDeadlineExceeded
+	}
+	timer := time.NewTimer(time.Until(deadline))
+	defer timer.Stop()
+
+	select {
+	case data, ok := <-c.reader.ch:
+		if !ok {
+			return nil, c.reader.Err()
+		}
+		return data, nil
+	case <-timer.C:
+		return nil, os.ErrDeadlineExceeded
+	}
+}
+
+func (c *Conn) Write(b []byte) (int, error) {
+	if deadline := c.getDeadline(false); !deadline.IsZero() && !time.Now().Before(deadline) {
+		return 0, os.ErrDeadlineExceeded
+	}
+	n, err := c.writer.Write(b)
+	if err == nil {
+		c.reader.Wake()
+	}
+	return n, err
+}
+
+func (c *Conn) Close() error {
+	c.closeOnce.Do(func() {
+		c.closeErr = c.writer.Close()
+		c.cancel()
+		if c.onClose != nil {
+			c.onClose()
+		}
+	})
+	return c.closeErr
+}
+
+func (c *Conn) LocalAddr() net.Addr {
+	return placeholderAddr
+}
+
+func (c *Conn) RemoteAddr() net.Addr {
+	return placeholderAddr
+}
+
+func (c *Conn) getDeadline(read bool) time.Time {
+	c.deadlineMu.Lock()
+	defer c.deadlineMu.Unlock()
+	if read {
+		return c.readDeadline
+	}
+	return c.writeDeadline
+}
+
+func (c *Conn) SetDeadline(t time.Time) error {
+	c.deadlineMu.Lock()
+	defer c.deadlineMu.Unlock()
+	c.readDeadline = t
+	c.writeDeadline = t
+	return nil
+}
+
+func (c *Conn) SetReadDeadline(t time.Time) error {
+	c.deadlineMu.Lock()
+	defer c.deadlineMu.Unlock()
+	c.readDeadline = t
+	return nil
+}
+
+func (c *Conn) SetWriteDeadline(t time.Time) error {
+	c.deadlineMu.Lock()
+	defer c.deadlineMu.Unlock()
+	c.writeDeadline = t
+	return nil
+}

transport/internet/xdrive/drive.go

@@ -0,0 +1,575 @@
+package xdrive
+
+import (
+	"bytes"
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/xtls/xray-core/common/dice"
+	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/transport/internet"
+)
+
+const (
+	flatSeparator = "~"
+
+	driveBoundary    = "xdrive-boundary"
+	drivePageSize    = 1000
+	driveMaxAttempts = 8
+	driveMaxInflight = 32
+	driveInlineLimit = 12000
+	driveTimeout     = 60 * time.Second
+)
+
+var (
+	driveMaxBackoff     = 8 * time.Second
+	driveTokenURL       = "https://oauth2.googleapis.com/token"
+	driveFilesURL       = "https://www.googleapis.com/drive/v3/files"
+	driveUploadURL      = "https://www.googleapis.com/upload/drive/v3/files?uploadType=multipart&fields=id,name"
+	driveInitialBackoff = 200 * time.Millisecond
+)
+
+type driveStorage struct {
+	folder       string
+	clientID     string
+	clientSecret string
+	refreshToken string
+	client       *http.Client
+	tokenURL     string
+	filesURL     string
+	uploadURL    string
+	backoff      time.Duration
+
+	tokenMu     sync.Mutex
+	token       string
+	tokenExpiry time.Time
+
+	inflight chan struct{}
+
+	idMu sync.Mutex
+	ids  map[string]string
+}
+
+func newDriveStorage(streamSettings *internet.MemoryStreamConfig, config *Config) (*driveStorage, error) {
+	if config.RemoteFolder == "" {
+		return nil, errors.New(`empty "remoteFolder", it must be a Google Drive folder id`)
+	}
+	if len(config.Secrets) != 3 {
+		return nil, errors.New("Google Drive needs 3 secrets in order of ClientID, ClientSecret, RefreshToken")
+	}
+	for i, secret := range config.Secrets {
+		if secret == "" {
+			return nil, errors.New("Google Drive secret ", i, " is empty")
+		}
+	}
+
+	return &driveStorage{
+		folder:       config.RemoteFolder,
+		clientID:     config.Secrets[0],
+		clientSecret: config.Secrets[1],
+		refreshToken: config.Secrets[2],
+		client:       newServiceClient(streamSettings, driveTimeout, driveMaxInflight),
+		tokenURL:     driveTokenURL,
+		filesURL:     driveFilesURL,
+		uploadURL:    driveUploadURL,
+		backoff:      driveInitialBackoff,
+		inflight:     make(chan struct{}, driveMaxInflight),
+		ids:          make(map[string]string),
+	}, nil
+}
+
+func flatten(name string) string {
+	return strings.ReplaceAll(name, "/", flatSeparator)
+}
+
+func quoteDriveValue(value string) string {
+	return strings.NewReplacer(`\`, `\\`, `'`, `\'`).Replace(value)
+}
+
+func (s *driveStorage) accessToken(ctx context.Context) (string, error) {
+	s.tokenMu.Lock()
+	defer s.tokenMu.Unlock()
+
+	if s.token != "" && time.Now().Before(s.tokenExpiry) {
+		return s.token, nil
+	}
+
+	form := url.Values{
+		"client_id":     {s.clientID},
+		"client_secret": {s.clientSecret},
+		"refresh_token": {s.refreshToken},
+		"grant_type":    {"refresh_token"},
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, s.tokenURL, strings.NewReader(form.Encode()))
+	if err != nil {
+		return "", errors.New("failed to build the token request").Base(err)
+	}
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+	resp, err := s.client.Do(req)
+	if err != nil {
+		return "", errors.New("failed to refresh the access token").Base(err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	if err != nil {
+		return "", errors.New("failed to read the token response").Base(err)
+	}
+	if resp.StatusCode != http.StatusOK {
+		return "", errors.New("the token endpoint answered ", resp.StatusCode, ": ", string(body))
+	}
+
+	var parsed struct {
+		AccessToken string `json:"access_token"`
+		ExpiresIn   int64  `json:"expires_in"`
+	}
+	if err := json.Unmarshal(body, &parsed); err != nil {
+		return "", errors.New("failed to parse the token response").Base(err)
+	}
+	if parsed.AccessToken == "" {
+		return "", errors.New("the token endpoint returned no access token")
+	}
+
+	lifetime := parsed.ExpiresIn
+	if lifetime > 60 {
+		lifetime -= 60
+	}
+	s.token = parsed.AccessToken
+	s.tokenExpiry = time.Now().Add(time.Duration(lifetime) * time.Second)
+	return s.token, nil
+}
+
+func jitter(backoff time.Duration) time.Duration {
+	half := backoff / 2
+	if half <= 0 {
+		return backoff
+	}
+	return half + time.Duration(dice.Roll(int(half)))
+}
+
+func rateLimited(payload []byte) bool {
+	var parsed struct {
+		Error struct {
+			Status string `json:"status"`
+			Errors []struct {
+				Reason string `json:"reason"`
+			} `json:"errors"`
+		} `json:"error"`
+	}
+	if json.Unmarshal(payload, &parsed) != nil {
+		return false
+	}
+	for _, item := range parsed.Error.Errors {
+		switch item.Reason {
+		case "rateLimitExceeded", "userRateLimitExceeded", "sharingRateLimitExceeded":
+			return true
+		}
+	}
+	return parsed.Error.Status == "RESOURCE_EXHAUSTED"
+}
+
+func retryableStatus(status int) bool {
+	switch status {
+	case http.StatusTooManyRequests, http.StatusInternalServerError,
+		http.StatusBadGateway, http.StatusServiceUnavailable, http.StatusGatewayTimeout:
+		return true
+	}
+	return false
+}
+
+func (s *driveStorage) do(ctx context.Context, method, target, contentType string, body []byte) (int, []byte, error) {
+	backoff := s.backoff
+	var lastErr error
+
+	for attempt := 0; attempt < driveMaxAttempts; attempt++ {
+		if attempt > 0 {
+			select {
+			case <-ctx.Done():
+				return 0, nil, ctx.Err()
+			case <-time.After(jitter(backoff)):
+			}
+			backoff *= 2
+			if backoff > driveMaxBackoff {
+				backoff = driveMaxBackoff
+			}
+		}
+
+		token, err := s.accessToken(ctx)
+		if err != nil {
+			lastErr = err
+			continue
+		}
+
+		select {
+		case s.inflight <- struct{}{}:
+		case <-ctx.Done():
+			return 0, nil, ctx.Err()
+		}
+
+		var reader io.Reader
+		if body != nil {
+			reader = bytes.NewReader(body)
+		}
+		req, err := http.NewRequestWithContext(ctx, method, target, reader)
+		if err != nil {
+			return 0, nil, errors.New("failed to build a Drive request").Base(err)
+		}
+		req.Header.Set("Authorization", "Bearer "+token)
+		if contentType != "" {
+			req.Header.Set("Content-Type", contentType)
+		}
+
+		resp, err := s.client.Do(req)
+		<-s.inflight
+		if err != nil {
+			if ctx.Err() != nil {
+				return 0, nil, ctx.Err()
+			}
+			lastErr = errors.New("Drive request failed").Base(err)
+			errors.LogWarningInner(ctx, err, "retrying a failed Drive request, attempt ",
+				attempt+1, " of ", driveMaxAttempts)
+			continue
+		}
+		payload, err := io.ReadAll(resp.Body)
+		resp.Body.Close()
+		if err != nil {
+			if ctx.Err() != nil {
+				return 0, nil, ctx.Err()
+			}
+			lastErr = errors.New("failed to read the Drive response").Base(err)
+			continue
+		}
+
+		if resp.StatusCode == http.StatusUnauthorized {
+			s.invalidateToken()
+			lastErr = errors.New("Drive rejected the access token")
+			continue
+		}
+		if resp.StatusCode == http.StatusForbidden && rateLimited(payload) {
+			lastErr = errors.New("Drive is rate limiting: ", string(payload))
+			errors.LogWarning(ctx, "rate limited by Drive, attempt ",
+				attempt+1, " of ", driveMaxAttempts)
+			continue
+		}
+		if retryableStatus(resp.StatusCode) {
+			lastErr = errors.New("Drive answered ", resp.StatusCode, ": ", string(payload))
+			errors.LogWarning(ctx, "retrying after Drive answered ", resp.StatusCode,
+				", attempt ", attempt+1, " of ", driveMaxAttempts)
+			continue
+		}
+		return resp.StatusCode, payload, nil
+	}
+
+	return 0, nil, lastErr
+}
+
+func (s *driveStorage) invalidateToken() {
+	s.tokenMu.Lock()
+	s.token = ""
+	s.tokenMu.Unlock()
+}
+
+func (s *driveStorage) rememberID(name, id string) {
+	s.idMu.Lock()
+	s.ids[name] = id
+	s.idMu.Unlock()
+}
+
+func (s *driveStorage) forgetID(name string) {
+	s.idMu.Lock()
+	delete(s.ids, name)
+	s.idMu.Unlock()
+}
+
+func (s *driveStorage) cachedID(name string) (string, bool) {
+	s.idMu.Lock()
+	defer s.idMu.Unlock()
+	id, ok := s.ids[name]
+	return id, ok
+}
+
+type driveFile struct {
+	id          string
+	description string
+}
+
+func (s *driveStorage) query(ctx context.Context, condition string) (map[string]driveFile, error) {
+	found := make(map[string]driveFile)
+	pageToken := ""
+
+	for {
+		params := url.Values{
+			"q":                         {"'" + quoteDriveValue(s.folder) + "' in parents and trashed = false and " + condition},
+			"fields":                    {"nextPageToken,files(id,name,description)"},
+			"pageSize":                  {fmt.Sprint(drivePageSize)},
+			"supportsAllDrives":         {"true"},
+			"includeItemsFromAllDrives": {"true"},
+		}
+		if pageToken != "" {
+			params.Set("pageToken", pageToken)
+		}
+
+		status, payload, err := s.do(ctx, http.MethodGet, s.filesURL+"?"+params.Encode(), "", nil)
+		if err != nil {
+			return nil, err
+		}
+		if status != http.StatusOK {
+			return nil, errors.New("Drive listing answered ", status, ": ", string(payload))
+		}
+
+		var parsed struct {
+			NextPageToken string `json:"nextPageToken"`
+			Files         []struct {
+				ID          string `json:"id"`
+				Name        string `json:"name"`
+				Description string `json:"description"`
+			} `json:"files"`
+		}
+		if err := json.Unmarshal(payload, &parsed); err != nil {
+			return nil, errors.New("failed to parse the Drive listing").Base(err)
+		}
+
+		for _, file := range parsed.Files {
+			found[file.Name] = driveFile{id: file.ID, description: file.Description}
+			s.rememberID(file.Name, file.ID)
+		}
+
+		pageToken = parsed.NextPageToken
+		if pageToken == "" {
+			return found, nil
+		}
+	}
+}
+
+func (s *driveStorage) resolveID(ctx context.Context, flat string) (string, error) {
+	if id, ok := s.cachedID(flat); ok {
+		return id, nil
+	}
+	found, err := s.query(ctx, "name = '"+quoteDriveValue(flat)+"'")
+	if err != nil {
+		return "", err
+	}
+	if file, ok := found[flat]; ok {
+		return file.id, nil
+	}
+	return "", errNotFound
+}
+
+func (s *driveStorage) Put(ctx context.Context, name string, data []byte) error {
+	if len(data) <= driveInlineLimit {
+		return s.putInline(ctx, name, data)
+	}
+	return s.putMedia(ctx, name, data)
+}
+
+func (s *driveStorage) putInline(ctx context.Context, name string, data []byte) error {
+	flat := flatten(name)
+
+	body, err := json.Marshal(map[string]interface{}{
+		"name":        flat,
+		"parents":     []string{s.folder},
+		"description": base64.StdEncoding.EncodeToString(data),
+	})
+	if err != nil {
+		return errors.New("failed to build the inline metadata").Base(err)
+	}
+
+	status, payload, err := s.do(ctx, http.MethodPost, s.filesURL+"?fields=id",
+		"application/json; charset=UTF-8", body)
+	if err != nil {
+		return err
+	}
+	if status != http.StatusOK {
+		return errors.New("Drive rejected the inline upload of ", name,
+			" with ", status, ": ", string(payload))
+	}
+
+	var parsed struct {
+		ID string `json:"id"`
+	}
+	if err := json.Unmarshal(payload, &parsed); err != nil {
+		return errors.New("failed to parse the Drive upload response").Base(err)
+	}
+	if parsed.ID != "" {
+		s.rememberID(flat, parsed.ID)
+	}
+	return nil
+}
+
+func (s *driveStorage) putMedia(ctx context.Context, name string, data []byte) error {
+	flat := flatten(name)
+
+	metadata, err := json.Marshal(map[string]interface{}{
+		"name":    flat,
+		"parents": []string{s.folder},
+	})
+	if err != nil {
+		return errors.New("failed to build the upload metadata").Base(err)
+	}
+
+	var body bytes.Buffer
+	fmt.Fprintf(&body, "--%s\r\nContent-Type: application/json; charset=UTF-8\r\n\r\n", driveBoundary)
+	body.Write(metadata)
+	fmt.Fprintf(&body, "\r\n--%s\r\nContent-Type: application/octet-stream\r\n\r\n", driveBoundary)
+	body.Write(data)
+	fmt.Fprintf(&body, "\r\n--%s--\r\n", driveBoundary)
+
+	status, payload, err := s.do(ctx, http.MethodPost, s.uploadURL,
+		"multipart/related; boundary="+driveBoundary, body.Bytes())
+	if err != nil {
+		return err
+	}
+	if status != http.StatusOK {
+		return errors.New("Drive upload of ", name, " answered ", status, ": ", string(payload))
+	}
+
+	var parsed struct {
+		ID string `json:"id"`
+	}
+	if err := json.Unmarshal(payload, &parsed); err != nil {
+		return errors.New("failed to parse the Drive upload response").Base(err)
+	}
+	if parsed.ID != "" {
+		s.rememberID(flat, parsed.ID)
+	}
+	return nil
+}
+
+func (s *driveStorage) Get(ctx context.Context, name string) ([]byte, error) {
+	flat := flatten(name)
+	id, err := s.resolveID(ctx, flat)
+	if err != nil {
+		return nil, err
+	}
+
+	status, payload, err := s.do(ctx, http.MethodGet,
+		s.filesURL+"/"+url.PathEscape(id)+"?alt=media&supportsAllDrives=true", "", nil)
+	if err != nil {
+		return nil, err
+	}
+	switch status {
+	case http.StatusOK:
+		if len(payload) > 0 {
+			return payload, nil
+		}
+		return s.getInline(ctx, id)
+	case http.StatusNotFound:
+		s.forgetID(flat)
+		return nil, errNotFound
+	default:
+		return nil, errors.New("Drive download of ", name, " answered ", status, ": ", string(payload))
+	}
+}
+
+func (s *driveStorage) getInline(ctx context.Context, id string) ([]byte, error) {
+	status, payload, err := s.do(ctx, http.MethodGet,
+		s.filesURL+"/"+url.PathEscape(id)+"?fields=description&supportsAllDrives=true", "", nil)
+	if err != nil {
+		return nil, err
+	}
+	if status != http.StatusOK {
+		return nil, errors.New("Drive answered ", status, " for inline data: ", string(payload))
+	}
+
+	var parsed struct {
+		Description string `json:"description"`
+	}
+	if err := json.Unmarshal(payload, &parsed); err != nil {
+		return nil, errors.New("failed to parse the inline data").Base(err)
+	}
+	if parsed.Description == "" {
+		return nil, nil
+	}
+	data, err := base64.StdEncoding.DecodeString(parsed.Description)
+	if err != nil {
+		return nil, errors.New("the inline data is not valid base64").Base(err)
+	}
+	return data, nil
+}
+
+func (s *driveStorage) deleteID(ctx context.Context, flat, id string) error {
+	status, payload, err := s.do(ctx, http.MethodDelete,
+		s.filesURL+"/"+url.PathEscape(id)+"?supportsAllDrives=true", "", nil)
+	if err != nil {
+		return err
+	}
+	s.forgetID(flat)
+	switch status {
+	case http.StatusOK, http.StatusNoContent, http.StatusNotFound:
+		return nil
+	default:
+		return errors.New("Drive deletion of ", flat, " answered ", status, ": ", string(payload))
+	}
+}
+
+func (s *driveStorage) Delete(ctx context.Context, name string) error {
+	flat := flatten(name)
+
+	if id, err := s.resolveID(ctx, flat); err == nil {
+		if err := s.deleteID(ctx, flat, id); err != nil {
+			return err
+		}
+	} else if err != errNotFound {
+		return err
+	}
+
+	children, err := s.query(ctx, "name contains '"+quoteDriveValue(flat+flatSeparator)+"'")
+	if err != nil {
+		return err
+	}
+	for childName, file := range children {
+		if err := s.deleteID(ctx, childName, file.id); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (s *driveStorage) List(ctx context.Context, prefix string) ([]Entry, error) {
+	flat := flatten(prefix) + flatSeparator
+
+	found, err := s.query(ctx, "name contains '"+quoteDriveValue(flat)+"'")
+	if err != nil {
+		return nil, err
+	}
+
+	seen := make(map[string]bool, len(found))
+	entries := make([]Entry, 0, len(found))
+	for name, file := range found {
+		rest := strings.TrimPrefix(name, flat)
+		if rest == "" {
+			continue
+		}
+		direct := true
+		if cut := strings.Index(rest, flatSeparator); cut >= 0 {
+			rest = rest[:cut]
+			direct = false
+		}
+		if seen[rest] {
+			continue
+		}
+		seen[rest] = true
+
+		entry := Entry{Name: rest}
+		if direct && file.description != "" {
+			if data, err := base64.StdEncoding.DecodeString(file.description); err == nil {
+				entry.Inline = data
+			}
+		}
+		entries = append(entries, entry)
+	}
+	return entries, nil
+}
+
+func (s *driveStorage) Close() error {
+	return nil
+}

transport/internet/xdrive/drive_live_test.go

@@ -0,0 +1,345 @@
+package xdrive
+
+import (
+	"bytes"
+	"context"
+	"crypto/rand"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/xtls/xray-core/transport/internet"
+)
+
+const liveSecretsEnv = "XRAY_XDRIVE_DRIVE_SECRETS"
+
+func liveDriveConfig(t *testing.T) *Config {
+	t.Helper()
+
+	path := os.Getenv(liveSecretsEnv)
+	if path == "" {
+		t.Skipf("set %s to run this test", liveSecretsEnv)
+	}
+
+	payload, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("reading %s: %v", path, err)
+	}
+	var secrets struct {
+		Folder       string `json:"folder"`
+		ClientID     string `json:"client_id"`
+		ClientSecret string `json:"client_secret"`
+		RefreshToken string `json:"refresh_token"`
+	}
+	if err := json.Unmarshal(payload, &secrets); err != nil {
+		t.Fatalf("parsing %s: %v", path, err)
+	}
+
+	config := &Config{
+		RemoteFolder:      secrets.Folder,
+		Service:           "Google Drive",
+		Secrets:           []string{secrets.ClientID, secrets.ClientSecret, secrets.RefreshToken},
+		SegmentBytes:      256 * 1024,
+		FlushIntervalMs:   100,
+		PollIntervalMs:    500,
+		MaxPollIntervalMs: 2000,
+		SessionTtlSeconds: 120,
+	}
+	if raw := os.Getenv("XRAY_XDRIVE_LIVE_SEGMENT"); raw != "" {
+		config.SegmentBytes = uint32(envInt(t, "XRAY_XDRIVE_LIVE_SEGMENT"))
+	}
+	if raw := os.Getenv("XRAY_XDRIVE_LIVE_CONCURRENCY"); raw != "" {
+		config.Concurrency = uint32(envInt(t, "XRAY_XDRIVE_LIVE_CONCURRENCY"))
+	}
+
+	storage, err := newDriveStorage(nil, config)
+	if err != nil {
+		t.Fatalf("newDriveStorage: %v", err)
+	}
+	defer storage.Close()
+	for _, dir := range []string{sessionsDir, streamsDir} {
+		if err := storage.Delete(context.Background(), dir); err != nil {
+			t.Fatalf("clearing %s: %v", dir, err)
+		}
+	}
+
+	return config
+}
+
+func envInt(t *testing.T, name string) int {
+	t.Helper()
+
+	parsed, err := strconv.Atoi(os.Getenv(name))
+	if err != nil {
+		t.Fatalf("%s: %v", name, err)
+	}
+	return parsed
+}
+
+func TestLiveDriveStorage(t *testing.T) {
+	config := liveDriveConfig(t)
+	storage, err := newDriveStorage(nil, config)
+	if err != nil {
+		t.Fatalf("newDriveStorage: %v", err)
+	}
+	defer storage.Close()
+
+	ctx := context.Background()
+	name := "streams/livetest/c2s/000000000.seg"
+	payload := []byte("xdrive over a real remote storage service")
+	defer storage.Delete(ctx, "streams/livetest")
+
+	start := time.Now()
+	if err := storage.Put(ctx, name, payload); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+	t.Logf("Put took %v", time.Since(start))
+
+	start = time.Now()
+	names, err := storage.List(ctx, "streams/livetest/c2s")
+	if err != nil {
+		t.Fatalf("List: %v", err)
+	}
+	t.Logf("List took %v", time.Since(start))
+	if len(names) != 1 || names[0].Name != "000000000.seg" {
+		t.Fatalf("List returned %v, want one segment", names)
+	}
+
+	start = time.Now()
+	got, err := storage.Get(ctx, name)
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	t.Logf("Get took %v", time.Since(start))
+	if !bytes.Equal(got, payload) {
+		t.Fatalf("Get returned %q, want %q", got, payload)
+	}
+
+	if _, err := storage.Get(ctx, "streams/livetest/c2s/000000009.seg"); err != errNotFound {
+		t.Fatalf("Get returned %v, want errNotFound", err)
+	}
+
+	if err := storage.Delete(ctx, "streams/livetest"); err != nil {
+		t.Fatalf("Delete: %v", err)
+	}
+	names, err = storage.List(ctx, "streams/livetest/c2s")
+	if err != nil {
+		t.Fatalf("List after delete: %v", err)
+	}
+	if len(names) != 0 {
+		t.Fatalf("List after delete returned %v", names)
+	}
+}
+
+func TestLiveDriveTransport(t *testing.T) {
+	config := liveDriveConfig(t)
+	streamSettings := &internet.MemoryStreamConfig{
+		ProtocolName:     protocolName,
+		ProtocolSettings: config,
+	}
+
+	client, server, cleanup := pairWith(t, streamSettings)
+	defer cleanup()
+
+	start := time.Now()
+	if _, err := client.Write([]byte("ping")); err != nil {
+		t.Fatalf("client write: %v", err)
+	}
+	expectRead(t, server, "ping")
+	t.Logf("client to server round took %v", time.Since(start))
+
+	start = time.Now()
+	if _, err := server.Write([]byte("pong")); err != nil {
+		t.Fatalf("server write: %v", err)
+	}
+	expectRead(t, client, "pong")
+	t.Logf("server to client round took %v", time.Since(start))
+
+	size := 400000
+	if raw := os.Getenv("XRAY_XDRIVE_LIVE_BYTES"); raw != "" {
+		parsed, err := strconv.Atoi(raw)
+		if err != nil {
+			t.Fatalf("XRAY_XDRIVE_LIVE_BYTES: %v", err)
+		}
+		size = parsed
+	}
+	payload := make([]byte, size)
+	if _, err := rand.Read(payload); err != nil {
+		t.Fatalf("rand: %v", err)
+	}
+
+	start = time.Now()
+	go func() {
+		client.Write(payload)
+	}()
+	if err := server.SetReadDeadline(time.Now().Add(5 * time.Minute)); err != nil {
+		t.Fatalf("SetReadDeadline: %v", err)
+	}
+	got := make([]byte, len(payload))
+	if _, err := io.ReadFull(server, got); err != nil {
+		t.Fatalf("ReadFull: %v", err)
+	}
+	elapsed := time.Since(start)
+	if !bytes.Equal(got, payload) {
+		t.Fatal("payload mismatch")
+	}
+	t.Logf("%d bytes took %v (%.1f KiB/s)", len(payload), elapsed,
+		float64(len(payload))/1024/elapsed.Seconds())
+}
+
+func TestLiveDriveParallelPut(t *testing.T) {
+	config := liveDriveConfig(t)
+	storage, err := newDriveStorage(nil, config)
+	if err != nil {
+		t.Fatalf("newDriveStorage: %v", err)
+	}
+	defer storage.Close()
+
+	ctx := context.Background()
+	defer storage.Delete(ctx, "streams/benchtest")
+
+	chunk := make([]byte, 256*1024)
+	if _, err := rand.Read(chunk); err != nil {
+		t.Fatalf("rand: %v", err)
+	}
+
+	if err := storage.Put(ctx, "streams/benchtest/warmup", chunk); err != nil {
+		t.Fatalf("warmup: %v", err)
+	}
+
+	start := time.Now()
+	for i := 0; i < 4; i++ {
+		if err := storage.Put(ctx, fmt.Sprintf("streams/benchtest/seq%d", i), chunk); err != nil {
+			t.Fatalf("sequential put: %v", err)
+		}
+	}
+	sequential := time.Since(start)
+	t.Logf("4 sequential puts of 256 KiB: %v (%.1f KiB/s)",
+		sequential, float64(4*len(chunk))/1024/sequential.Seconds())
+
+	start = time.Now()
+	var wg sync.WaitGroup
+	failures := make([]error, 8)
+	for i := 0; i < 8; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			failures[i] = storage.Put(ctx, fmt.Sprintf("streams/benchtest/par%d", i), chunk)
+		}(i)
+	}
+	wg.Wait()
+	parallel := time.Since(start)
+	for _, err := range failures {
+		if err != nil {
+			t.Fatalf("parallel put: %v", err)
+		}
+	}
+	t.Logf("8 parallel puts of 256 KiB: %v (%.1f KiB/s)",
+		parallel, float64(8*len(chunk))/1024/parallel.Seconds())
+
+	start = time.Now()
+	names, err := storage.List(ctx, "streams/benchtest")
+	if err != nil {
+		t.Fatalf("List: %v", err)
+	}
+	t.Logf("List of %d objects took %v", len(names), time.Since(start))
+
+	start = time.Now()
+	wg = sync.WaitGroup{}
+	for i := 0; i < 8; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			storage.Get(ctx, fmt.Sprintf("streams/benchtest/par%d", i))
+		}(i)
+	}
+	wg.Wait()
+	download := time.Since(start)
+	t.Logf("8 parallel gets of 256 KiB: %v (%.1f KiB/s)",
+		download, float64(8*len(chunk))/1024/download.Seconds())
+}
+
+func TestLiveDriveSegmentSweep(t *testing.T) {
+	config := liveDriveConfig(t)
+	storage, err := newDriveStorage(nil, config)
+	if err != nil {
+		t.Fatalf("newDriveStorage: %v", err)
+	}
+	defer storage.Close()
+
+	ctx := context.Background()
+	defer storage.Delete(ctx, "streams/sweeptest")
+
+	const total = 1024 * 1024
+	for _, size := range []int{64 * 1024, 128 * 1024, 256 * 1024, 512 * 1024} {
+		chunk := make([]byte, size)
+		if _, err := rand.Read(chunk); err != nil {
+			t.Fatalf("rand: %v", err)
+		}
+		count := total / size
+
+		start := time.Now()
+		var wg sync.WaitGroup
+		for i := 0; i < count; i++ {
+			wg.Add(1)
+			go func(i int) {
+				defer wg.Done()
+				storage.Put(ctx, fmt.Sprintf("streams/sweeptest/s%d-%d", size, i), chunk)
+			}(i)
+		}
+		wg.Wait()
+		elapsed := time.Since(start)
+
+		t.Logf("%4d KiB x %2d = 1 MiB in %8v -> %6.1f KiB/s",
+			size/1024, count, elapsed.Round(time.Millisecond),
+			float64(total)/1024/elapsed.Seconds())
+	}
+}
+
+func TestLiveDriveListLag(t *testing.T) {
+	config := liveDriveConfig(t)
+	storage, err := newDriveStorage(nil, config)
+	if err != nil {
+		t.Fatalf("newDriveStorage: %v", err)
+	}
+	defer storage.Close()
+
+	ctx := context.Background()
+	defer storage.Delete(ctx, "streams/lagtest")
+
+	const rounds = 6
+	var worst time.Duration
+
+	for i := 0; i < rounds; i++ {
+		name := fmt.Sprintf("streams/lagtest/round%d/000000000.seg", i)
+		if err := storage.Put(ctx, name, []byte("probe")); err != nil {
+			t.Fatalf("Put: %v", err)
+		}
+
+		start := time.Now()
+		var lag time.Duration
+		for {
+			names, err := storage.List(ctx, fmt.Sprintf("streams/lagtest/round%d", i))
+			if err != nil {
+				t.Fatalf("List: %v", err)
+			}
+			if len(names) == 1 {
+				lag = time.Since(start)
+				break
+			}
+			if time.Since(start) > 30*time.Second {
+				t.Fatalf("round %d: the object never showed up in a listing", i)
+			}
+		}
+		if lag > worst {
+			worst = lag
+		}
+		t.Logf("round %d: the object became listable after %v", i, lag.Round(time.Millisecond))
+	}
+	t.Logf("worst listing lag: %v", worst.Round(time.Millisecond))
+}

transport/internet/xdrive/drive_test.go

@@ -0,0 +1,690 @@
+package xdrive
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"mime"
+	"mime/multipart"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet"
+)
+
+type fakeFile struct {
+	id          string
+	name        string
+	data        []byte
+	description string
+}
+
+type fakeDrive struct {
+	server *httptest.Server
+
+	mu         sync.Mutex
+	files      map[string]*fakeFile
+	nextID     int
+	failOnce   map[string]bool
+	failStatus map[string]int
+	failBody   map[string]string
+	tokens     int
+	hosts      map[string]bool
+}
+
+func newFakeDrive(t *testing.T) *fakeDrive {
+	t.Helper()
+
+	drive := &fakeDrive{
+		files:      make(map[string]*fakeFile),
+		failOnce:   make(map[string]bool),
+		failStatus: make(map[string]int),
+		failBody:   make(map[string]string),
+		hosts:      make(map[string]bool),
+	}
+	mux := http.NewServeMux()
+	mux.Handle("/", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		http.NotFound(w, r)
+	}))
+	record := func(next http.HandlerFunc) http.HandlerFunc {
+		return func(w http.ResponseWriter, r *http.Request) {
+			drive.mu.Lock()
+			drive.hosts[r.Host] = true
+			drive.mu.Unlock()
+			next(w, r)
+		}
+	}
+	mux.HandleFunc("/token", record(drive.handleToken))
+	mux.HandleFunc("/upload", record(drive.handleUpload))
+	mux.HandleFunc("/files", record(drive.handleFiles))
+	mux.HandleFunc("/files/", record(drive.handleFile))
+	drive.server = httptest.NewServer(mux)
+
+	resetSharedStorage()
+
+	previous := []string{driveTokenURL, driveFilesURL, driveUploadURL}
+	previousBackoff := driveInitialBackoff
+	driveTokenURL = drive.server.URL + "/token"
+	driveFilesURL = drive.server.URL + "/files"
+	driveUploadURL = drive.server.URL + "/upload"
+	driveInitialBackoff = 5 * time.Millisecond
+
+	t.Cleanup(func() {
+		driveTokenURL, driveFilesURL, driveUploadURL = previous[0], previous[1], previous[2]
+		driveInitialBackoff = previousBackoff
+		drive.server.Close()
+		resetSharedStorage()
+	})
+	return drive
+}
+
+func (d *fakeDrive) handleToken(w http.ResponseWriter, r *http.Request) {
+	d.mu.Lock()
+	d.tokens++
+	d.mu.Unlock()
+	json.NewEncoder(w).Encode(map[string]interface{}{
+		"access_token": "fake-token",
+		"expires_in":   3600,
+	})
+}
+
+func (d *fakeDrive) handleUpload(w http.ResponseWriter, r *http.Request) {
+	if d.shouldFail("upload") {
+		if status, body := d.failure("upload"); status != 0 {
+			w.WriteHeader(status)
+			w.Write([]byte(body))
+			return
+		}
+		w.WriteHeader(http.StatusTooManyRequests)
+		return
+	}
+
+	_, params, err := mime.ParseMediaType(r.Header.Get("Content-Type"))
+	if err != nil {
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+	reader := multipart.NewReader(r.Body, params["boundary"])
+
+	metaPart, err := reader.NextPart()
+	if err != nil {
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+	var metadata struct {
+		Name string `json:"name"`
+	}
+	if err := json.NewDecoder(metaPart).Decode(&metadata); err != nil {
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+
+	var data []byte
+	if dataPart, err := reader.NextPart(); err == nil {
+		data, _ = io.ReadAll(dataPart)
+	}
+
+	d.mu.Lock()
+	d.nextID++
+	id := fmt.Sprintf("id-%d", d.nextID)
+	d.files[id] = &fakeFile{id: id, name: metadata.Name, data: data}
+	d.mu.Unlock()
+
+	json.NewEncoder(w).Encode(map[string]string{"id": id, "name": metadata.Name})
+}
+
+func (d *fakeDrive) handleFiles(w http.ResponseWriter, r *http.Request) {
+	if r.Method == http.MethodPost {
+		d.handleCreate(w, r)
+		return
+	}
+	d.handleList(w, r)
+}
+
+func (d *fakeDrive) handleCreate(w http.ResponseWriter, r *http.Request) {
+	if d.shouldFail("upload") {
+		if status, body := d.failure("upload"); status != 0 {
+			w.WriteHeader(status)
+			w.Write([]byte(body))
+			return
+		}
+		w.WriteHeader(http.StatusTooManyRequests)
+		return
+	}
+
+	var meta struct {
+		Name        string `json:"name"`
+		Description string `json:"description"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&meta); err != nil {
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+
+	d.mu.Lock()
+	d.nextID++
+	id := fmt.Sprintf("id-%d", d.nextID)
+	d.files[id] = &fakeFile{id: id, name: meta.Name, description: meta.Description}
+	d.mu.Unlock()
+
+	json.NewEncoder(w).Encode(map[string]string{"id": id, "name": meta.Name})
+}
+
+func (d *fakeDrive) handleList(w http.ResponseWriter, r *http.Request) {
+	if d.shouldFail("list") {
+		w.WriteHeader(http.StatusServiceUnavailable)
+		return
+	}
+
+	query := r.URL.Query().Get("q")
+	exact, prefix := parseFakeQuery(query)
+
+	type entry struct {
+		ID          string `json:"id"`
+		Name        string `json:"name"`
+		Description string `json:"description,omitempty"`
+	}
+	result := struct {
+		Files []entry `json:"files"`
+	}{}
+
+	d.mu.Lock()
+	for _, file := range d.files {
+		match := false
+		switch {
+		case exact != "":
+			match = file.name == exact
+		case prefix != "":
+			match = strings.HasPrefix(file.name, prefix)
+		}
+		if match {
+			result.Files = append(result.Files, entry{
+				ID: file.id, Name: file.name, Description: file.description,
+			})
+		}
+	}
+	d.mu.Unlock()
+
+	json.NewEncoder(w).Encode(result)
+}
+
+func (d *fakeDrive) handleFile(w http.ResponseWriter, r *http.Request) {
+	id := strings.TrimPrefix(r.URL.Path, "/files/")
+
+	d.mu.Lock()
+	file, ok := d.files[id]
+	if ok && r.Method == http.MethodDelete {
+		delete(d.files, id)
+	}
+	d.mu.Unlock()
+
+	if !ok {
+		w.WriteHeader(http.StatusNotFound)
+		return
+	}
+	if r.Method == http.MethodDelete {
+		w.WriteHeader(http.StatusNoContent)
+		return
+	}
+	if strings.Contains(r.URL.RawQuery, "fields=description") {
+		json.NewEncoder(w).Encode(map[string]string{"description": file.description})
+		return
+	}
+	w.Write(file.data)
+}
+
+func (d *fakeDrive) shouldFail(kind string) bool {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	if d.failOnce[kind] {
+		d.failOnce[kind] = false
+		return true
+	}
+	return false
+}
+
+func (d *fakeDrive) failOnceWith(kind string, status int, body string) {
+	d.mu.Lock()
+	d.failOnce[kind] = true
+	d.failStatus[kind] = status
+	d.failBody[kind] = body
+	d.mu.Unlock()
+}
+
+func (d *fakeDrive) failure(kind string) (int, string) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	if status, ok := d.failStatus[kind]; ok {
+		return status, d.failBody[kind]
+	}
+	return 0, ""
+}
+
+func (d *fakeDrive) failNext(kind string) {
+	d.mu.Lock()
+	d.failOnce[kind] = true
+	d.mu.Unlock()
+}
+
+func (d *fakeDrive) seenHosts() []string {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	out := make([]string, 0, len(d.hosts))
+	for h := range d.hosts {
+		out = append(out, h)
+	}
+	return out
+}
+
+func (d *fakeDrive) count() int {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	return len(d.files)
+}
+
+func parseFakeQuery(query string) (exact, prefix string) {
+	if value, ok := cutQuoted(query, "name = '"); ok {
+		return value, ""
+	}
+	if value, ok := cutQuoted(query, "name contains '"); ok {
+		return "", value
+	}
+	return "", ""
+}
+
+func cutQuoted(query, marker string) (string, bool) {
+	start := strings.Index(query, marker)
+	if start < 0 {
+		return "", false
+	}
+	rest := query[start+len(marker):]
+	end := strings.Index(rest, "'")
+	if end < 0 {
+		return "", false
+	}
+	return rest[:end], true
+}
+
+func driveSettings() *internet.MemoryStreamConfig {
+	return &internet.MemoryStreamConfig{
+		ProtocolName: protocolName,
+		ProtocolSettings: &Config{
+			RemoteFolder:      "folder-id",
+			Service:           "Google Drive",
+			Secrets:           []string{"client", "secret", "refresh"},
+			FlushIntervalMs:   5,
+			PollIntervalMs:    5,
+			MaxPollIntervalMs: 20,
+			SessionTtlSeconds: 1,
+		},
+	}
+}
+
+func newDriveBackend(t *testing.T) *driveStorage {
+	t.Helper()
+
+	storage, err := newDriveStorage(driveSettings(), driveSettings().ProtocolSettings.(*Config))
+	if err != nil {
+		t.Fatalf("newDriveStorage: %v", err)
+	}
+	return storage
+}
+
+func TestDriveSecrets(t *testing.T) {
+	if _, err := newDriveStorage(nil, &Config{RemoteFolder: "f", Secrets: []string{"a", "b"}}); err == nil {
+		t.Fatal("accepted two secrets")
+	}
+	if _, err := newDriveStorage(nil, &Config{Secrets: []string{"a", "b", "c"}}); err == nil {
+		t.Fatal("accepted an empty remoteFolder")
+	}
+	if _, err := newDriveStorage(nil, &Config{RemoteFolder: "f", Secrets: []string{"a", "", "c"}}); err == nil {
+		t.Fatal("accepted an empty secret")
+	}
+}
+
+func TestDriveRoundTrip(t *testing.T) {
+	drive := newFakeDrive(t)
+	storage := newDriveBackend(t)
+	ctx := context.Background()
+
+	if err := storage.Put(ctx, "streams/abc/c2s/000000000.seg", []byte("hello")); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+
+	data, err := storage.Get(ctx, "streams/abc/c2s/000000000.seg")
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	if string(data) != "hello" {
+		t.Fatalf("Get returned %q, want %q", data, "hello")
+	}
+
+	names, err := storage.List(ctx, "streams/abc/c2s")
+	if err != nil {
+		t.Fatalf("List: %v", err)
+	}
+	if len(names) != 1 || names[0].Name != "000000000.seg" {
+		t.Fatalf("List returned %v, want 1 segment", names)
+	}
+
+	if _, err := storage.Get(ctx, "streams/abc/c2s/000000009.seg"); err != errNotFound {
+		t.Fatalf("Get returned %v, want errNotFound", err)
+	}
+
+	if err := storage.Delete(ctx, "streams/abc/c2s/000000000.seg"); err != nil {
+		t.Fatalf("Delete: %v", err)
+	}
+	if drive.count() != 0 {
+		t.Fatalf("fake drive still holds %d files", drive.count())
+	}
+}
+
+func TestDriveListChildren(t *testing.T) {
+	newFakeDrive(t)
+	storage := newDriveBackend(t)
+	ctx := context.Background()
+
+	for _, name := range []string{
+		"streams/one/c2s/000000000.seg",
+		"streams/one/s2c/000000000.seg",
+		"streams/two/c2s/000000000.seg",
+	} {
+		if err := storage.Put(ctx, name, []byte("x")); err != nil {
+			t.Fatalf("Put %s: %v", name, err)
+		}
+	}
+
+	names, err := storage.List(ctx, "streams")
+	if err != nil {
+		t.Fatalf("List: %v", err)
+	}
+	if len(names) != 2 {
+		t.Fatalf("List returned %v, want 2 sessions", names)
+	}
+}
+
+func TestDriveDeleteSession(t *testing.T) {
+	drive := newFakeDrive(t)
+	storage := newDriveBackend(t)
+	ctx := context.Background()
+
+	for _, name := range []string{
+		"streams/one/c2s/000000000.seg",
+		"streams/one/c2s/000000001.end",
+		"streams/one/s2c/000000000.seg",
+		"streams/two/c2s/000000000.seg",
+	} {
+		if err := storage.Put(ctx, name, []byte("x")); err != nil {
+			t.Fatalf("Put %s: %v", name, err)
+		}
+	}
+
+	if err := storage.Delete(ctx, "streams/one"); err != nil {
+		t.Fatalf("Delete: %v", err)
+	}
+	if drive.count() != 1 {
+		t.Fatalf("fake drive holds %d files, want 1", drive.count())
+	}
+}
+
+func TestDriveRetry(t *testing.T) {
+	drive := newFakeDrive(t)
+	storage := newDriveBackend(t)
+	ctx := context.Background()
+
+	drive.failNext("upload")
+	if err := storage.Put(ctx, "sessions/abc", nil); err != nil {
+		t.Fatalf("Put did not survive a 429: %v", err)
+	}
+
+	drive.failNext("list")
+	if _, err := storage.List(ctx, "sessions"); err != nil {
+		t.Fatalf("List did not survive a 503: %v", err)
+	}
+}
+
+func TestDriveTokenCache(t *testing.T) {
+	drive := newFakeDrive(t)
+	storage := newDriveBackend(t)
+	ctx := context.Background()
+
+	for i := 0; i < 5; i++ {
+		if err := storage.Put(ctx, fmt.Sprintf("sessions/s%d", i), nil); err != nil {
+			t.Fatalf("Put: %v", err)
+		}
+	}
+	if drive.tokens != 1 {
+		t.Fatalf("token endpoint hit %d times, want 1", drive.tokens)
+	}
+}
+
+func TestDriveTransport(t *testing.T) {
+	newFakeDrive(t)
+
+	client, server, cleanup := pairWith(t, driveSettings())
+	defer cleanup()
+
+	if _, err := client.Write([]byte("ping")); err != nil {
+		t.Fatalf("client write: %v", err)
+	}
+	expectRead(t, server, "ping")
+
+	if _, err := server.Write([]byte("pong")); err != nil {
+		t.Fatalf("server write: %v", err)
+	}
+	expectRead(t, client, "pong")
+}
+
+func TestDriveLargeTransfer(t *testing.T) {
+	newFakeDrive(t)
+
+	client, server, cleanup := pairWith(t, driveSettings())
+	defer cleanup()
+
+	payload := make([]byte, 300000)
+	for i := range payload {
+		payload[i] = byte(i % 251)
+	}
+
+	go func() {
+		client.Write(payload)
+	}()
+
+	if err := server.SetReadDeadline(time.Now().Add(60 * time.Second)); err != nil {
+		t.Fatalf("SetReadDeadline: %v", err)
+	}
+	got := make([]byte, len(payload))
+	if _, err := io.ReadFull(server, got); err != nil {
+		t.Fatalf("ReadFull: %v", err)
+	}
+	for i := range got {
+		if got[i] != payload[i] {
+			t.Fatalf("payload mismatch at byte %d", i)
+		}
+	}
+}
+
+func TestRateLimited(t *testing.T) {
+	limited := []string{
+		`{"error":{"code":403,"errors":[{"reason":"userRateLimitExceeded"}]}}`,
+		`{"error":{"code":403,"errors":[{"reason":"rateLimitExceeded"}]}}`,
+		`{"error":{"code":403,"errors":[{"reason":"sharingRateLimitExceeded"}]}}`,
+		`{"error":{"status":"RESOURCE_EXHAUSTED"}}`,
+	}
+	for _, payload := range limited {
+		if !rateLimited([]byte(payload)) {
+			t.Fatalf("rateLimited missed %s", payload)
+		}
+	}
+
+	permanent := []string{
+		`{"error":{"code":403,"errors":[{"reason":"insufficientFilePermissions"}]}}`,
+		`{"error":{"code":403,"errors":[{"reason":"storageQuotaExceeded"}]}}`,
+		`not json at all`,
+	}
+	for _, payload := range permanent {
+		if rateLimited([]byte(payload)) {
+			t.Fatalf("rateLimited treated %s as temporary", payload)
+		}
+	}
+}
+
+func TestDriveRetryRateLimit(t *testing.T) {
+	drive := newFakeDrive(t)
+	storage := newDriveBackend(t)
+
+	drive.failOnceWith("upload", http.StatusForbidden,
+		`{"error":{"code":403,"errors":[{"reason":"userRateLimitExceeded"}]}}`)
+
+	if err := storage.Put(context.Background(), "sessions/abc", nil); err != nil {
+		t.Fatalf("Put did not survive a 403: %v", err)
+	}
+}
+
+func TestDriveSharedClient(t *testing.T) {
+	newFakeDrive(t)
+
+	first, err := newStorage(driveSettings())
+	if err != nil {
+		t.Fatalf("newStorage: %v", err)
+	}
+	second, err := newStorage(driveSettings())
+	if err != nil {
+		t.Fatalf("newStorage: %v", err)
+	}
+	if first != second {
+		t.Fatal("same settings did not share one storage")
+	}
+}
+
+func TestDriveInlineListing(t *testing.T) {
+	drive := newFakeDrive(t)
+	storage := newDriveBackend(t)
+	ctx := context.Background()
+
+	payload := []byte("small enough to ride along with the listing")
+	if err := storage.Put(ctx, "streams/abc/c2s/000000000.seg", payload); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+
+	entries, err := storage.List(ctx, "streams/abc/c2s")
+	if err != nil {
+		t.Fatalf("List: %v", err)
+	}
+	if len(entries) != 1 {
+		t.Fatalf("List returned %v, want 1 entry", entries)
+	}
+	if string(entries[0].Inline) != string(payload) {
+		t.Fatalf("listing carried %q, want %q", entries[0].Inline, payload)
+	}
+
+	d := drive
+	d.mu.Lock()
+	var stored *fakeFile
+	for _, f := range d.files {
+		stored = f
+	}
+	d.mu.Unlock()
+	if len(stored.data) != 0 {
+		t.Fatal("small payload was uploaded as content")
+	}
+}
+
+func TestDriveLargeContent(t *testing.T) {
+	drive := newFakeDrive(t)
+	storage := newDriveBackend(t)
+	ctx := context.Background()
+
+	payload := make([]byte, driveInlineLimit+1)
+	for i := range payload {
+		payload[i] = byte(i)
+	}
+	if err := storage.Put(ctx, "streams/abc/c2s/000000000.seg", payload); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+
+	entries, err := storage.List(ctx, "streams/abc/c2s")
+	if err != nil {
+		t.Fatalf("List: %v", err)
+	}
+	if len(entries) != 1 || entries[0].Inline != nil {
+		t.Fatalf("large payload was inlined, got %v", entries)
+	}
+
+	got, err := storage.Get(ctx, "streams/abc/c2s/000000000.seg")
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	if len(got) != len(payload) {
+		t.Fatalf("Get returned %d bytes, want %d", len(got), len(payload))
+	}
+	_ = drive
+}
+
+func TestDriveInlineGet(t *testing.T) {
+	newFakeDrive(t)
+	storage := newDriveBackend(t)
+	ctx := context.Background()
+
+	payload := []byte("only in the description")
+	if err := storage.Put(ctx, "sessions/abc", payload); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+
+	got, err := storage.Get(ctx, "sessions/abc")
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	if string(got) != string(payload) {
+		t.Fatalf("Get returned %q, want %q", got, payload)
+	}
+}
+
+func TestDriveFronting(t *testing.T) {
+	drive := newFakeDrive(t)
+
+	fake, err := url.Parse(drive.server.URL)
+	if err != nil {
+		t.Fatalf("parse: %v", err)
+	}
+	port, err := net.PortFromString(fake.Port())
+	if err != nil {
+		t.Fatalf("port: %v", err)
+	}
+
+	driveTokenURL = "http://www.googleapis.com/token"
+	driveFilesURL = "http://www.googleapis.com/files"
+	driveUploadURL = "http://www.googleapis.com/upload"
+
+	settings := driveSettings()
+	settings.Destination = &net.Destination{
+		Address: net.ParseAddress(fake.Hostname()),
+		Port:    port,
+		Network: net.Network_TCP,
+	}
+
+	storage, err := newDriveStorage(settings, settings.ProtocolSettings.(*Config))
+	if err != nil {
+		t.Fatalf("newDriveStorage: %v", err)
+	}
+
+	if err := storage.Put(context.Background(), "sessions/fronted", []byte("x")); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+	if drive.count() != 1 {
+		t.Fatalf("fake drive holds %d files, want 1", drive.count())
+	}
+
+	for _, host := range drive.seenHosts() {
+		if host != "www.googleapis.com" {
+			t.Fatalf("inner host was %q, want www.googleapis.com regardless of address", host)
+		}
+	}
+}

transport/internet/xdrive/jsonpath.go

@@ -0,0 +1,39 @@
+package xdrive
+
+import (
+	"encoding/json"
+	"strings"
+)
+
+func jsonWalk(payload []byte, path string) interface{} {
+	var root interface{}
+	if json.Unmarshal(payload, &root) != nil {
+		return nil
+	}
+	node := root
+	for _, key := range strings.Split(path, ".") {
+		obj, ok := node.(map[string]interface{})
+		if !ok {
+			return nil
+		}
+		node, ok = obj[key]
+		if !ok {
+			return nil
+		}
+	}
+	return node
+}
+
+func jsonString(payload []byte, path string) string {
+	if s, ok := jsonWalk(payload, path).(string); ok {
+		return s
+	}
+	return ""
+}
+
+func jsonNumber(payload []byte, path string) int64 {
+	if f, ok := jsonWalk(payload, path).(float64); ok {
+		return int64(f)
+	}
+	return 0
+}

transport/internet/xdrive/local.go

@@ -0,0 +1,120 @@
+package xdrive
+
+import (
+	"context"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+
+	"github.com/xtls/xray-core/common/errors"
+)
+
+const tempPrefix = ".xdrive-tmp-"
+
+type localStorage struct {
+	root string
+}
+
+func newLocalStorage(root string) (*localStorage, error) {
+	if root == "" {
+		return nil, errors.New(`empty "remoteFolder"`)
+	}
+	if err := os.MkdirAll(root, 0o700); err != nil {
+		return nil, errors.New("failed to create remote folder").Base(err)
+	}
+	return &localStorage{root: root}, nil
+}
+
+func (s *localStorage) resolve(name string) (string, error) {
+	clean := path.Clean("/" + name)
+	if clean == "/" {
+		return "", errors.New("invalid object name: ", name)
+	}
+	if strings.HasPrefix(path.Base(clean), tempPrefix) {
+		return "", errors.New("reserved object name: ", name)
+	}
+	return filepath.Join(s.root, filepath.FromSlash(clean[1:])), nil
+}
+
+func (s *localStorage) Put(ctx context.Context, name string, data []byte) error {
+	full, err := s.resolve(name)
+	if err != nil {
+		return err
+	}
+	dir := filepath.Dir(full)
+	if err := os.MkdirAll(dir, 0o700); err != nil {
+		return errors.New("failed to create folder ", dir).Base(err)
+	}
+
+	tmp, err := os.CreateTemp(dir, tempPrefix+"*")
+	if err != nil {
+		return errors.New("failed to create temp file in ", dir).Base(err)
+	}
+	tmpName := tmp.Name()
+	defer os.Remove(tmpName)
+
+	if _, err := tmp.Write(data); err != nil {
+		tmp.Close()
+		return errors.New("failed to write ", name).Base(err)
+	}
+	if err := tmp.Close(); err != nil {
+		return errors.New("failed to close ", name).Base(err)
+	}
+	if err := os.Rename(tmpName, full); err != nil {
+		return errors.New("failed to commit ", name).Base(err)
+	}
+	return nil
+}
+
+func (s *localStorage) Get(ctx context.Context, name string) ([]byte, error) {
+	full, err := s.resolve(name)
+	if err != nil {
+		return nil, err
+	}
+	data, err := os.ReadFile(full)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, errNotFound
+		}
+		return nil, errors.New("failed to read ", name).Base(err)
+	}
+	return data, nil
+}
+
+func (s *localStorage) Delete(ctx context.Context, name string) error {
+	full, err := s.resolve(name)
+	if err != nil {
+		return err
+	}
+	if err := os.RemoveAll(full); err != nil {
+		return errors.New("failed to delete ", name).Base(err)
+	}
+	return nil
+}
+
+func (s *localStorage) List(ctx context.Context, prefix string) ([]Entry, error) {
+	full, err := s.resolve(prefix)
+	if err != nil {
+		return nil, err
+	}
+	entries, err := os.ReadDir(full)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, nil
+		}
+		return nil, errors.New("failed to list ", prefix).Base(err)
+	}
+	found := make([]Entry, 0, len(entries))
+	for _, entry := range entries {
+		if strings.HasPrefix(entry.Name(), tempPrefix) {
+			continue
+		}
+		found = append(found, Entry{Name: entry.Name()})
+	}
+	return found, nil
+}
+
+func (s *localStorage) Close() error {
+	return nil
+}

transport/internet/xdrive/params.go

@@ -0,0 +1,69 @@
+package xdrive
+
+import "time"
+
+const (
+	defaultSegmentBytes    = 512 * 1024
+	defaultFlushInterval   = 20 * time.Millisecond
+	defaultMinPollInterval = 50 * time.Millisecond
+	defaultMaxPollInterval = 500 * time.Millisecond
+	defaultEagerWindow     = 2 * time.Second
+	defaultHoleTimeout     = 30 * time.Second
+	defaultSessionTTL      = 5 * time.Minute
+	defaultConcurrency     = 8
+
+	maxSegmentBytes = 16 * 1024 * 1024
+	maxConcurrency  = 64
+)
+
+type params struct {
+	segmentBytes    int
+	flushInterval   time.Duration
+	minPollInterval time.Duration
+	maxPollInterval time.Duration
+	eagerWindow     time.Duration
+	holeTimeout     time.Duration
+	sessionTTL      time.Duration
+	concurrency     int
+}
+
+func millis(value uint32, fallback time.Duration) time.Duration {
+	if value == 0 {
+		return fallback
+	}
+	return time.Duration(value) * time.Millisecond
+}
+
+func seconds(value uint32, fallback time.Duration) time.Duration {
+	if value == 0 {
+		return fallback
+	}
+	return time.Duration(value) * time.Second
+}
+
+func capped(value uint32, fallback, limit int) int {
+	if value == 0 {
+		return fallback
+	}
+	if int(value) > limit {
+		return limit
+	}
+	return int(value)
+}
+
+func paramsFromConfig(c *Config) params {
+	p := params{
+		segmentBytes:    capped(c.SegmentBytes, defaultSegmentBytes, maxSegmentBytes),
+		flushInterval:   millis(c.FlushIntervalMs, defaultFlushInterval),
+		minPollInterval: millis(c.PollIntervalMs, defaultMinPollInterval),
+		maxPollInterval: millis(c.MaxPollIntervalMs, defaultMaxPollInterval),
+		eagerWindow:     millis(c.EagerWindowMs, defaultEagerWindow),
+		holeTimeout:     millis(c.HoleTimeoutMs, defaultHoleTimeout),
+		sessionTTL:      seconds(c.SessionTtlSeconds, defaultSessionTTL),
+		concurrency:     capped(c.Concurrency, defaultConcurrency, maxConcurrency),
+	}
+	if p.maxPollInterval < p.minPollInterval {
+		p.maxPollInterval = p.minPollInterval
+	}
+	return p
+}

transport/internet/xdrive/storage.go

@@ -0,0 +1,90 @@
+package xdrive
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"strings"
+	"sync"
+
+	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/transport/internet"
+)
+
+var errNotFound = errors.New("object not found")
+
+type Entry struct {
+	Name   string
+	Inline []byte
+}
+
+type Storage interface {
+	Put(ctx context.Context, name string, data []byte) error
+	Get(ctx context.Context, name string) ([]byte, error)
+	Delete(ctx context.Context, name string) error
+	List(ctx context.Context, prefix string) ([]Entry, error)
+	Close() error
+}
+
+func newStorage(streamSettings *internet.MemoryStreamConfig) (Storage, error) {
+	config, err := streamConfig(streamSettings)
+	if err != nil {
+		return nil, err
+	}
+
+	switch config.Service {
+	case "local":
+		return newLocalStorage(config.RemoteFolder)
+	case "Google Drive":
+		return sharedStorage(streamSettings, config, func() (Storage, error) {
+			return newDriveStorage(streamSettings, config)
+		})
+	case "template":
+		return sharedStorage(streamSettings, config, func() (Storage, error) {
+			return newTemplateStorage(streamSettings, config)
+		})
+	default:
+		return nil, errors.New("unsupported service: ", config.Service)
+	}
+}
+
+var (
+	sharedMu sync.Mutex
+	shared   = make(map[string]Storage)
+)
+
+func shareKey(streamSettings *internet.MemoryStreamConfig, config *Config) string {
+	parts := []string{config.Service, config.RemoteFolder}
+	parts = append(parts, config.Secrets...)
+	if streamSettings != nil {
+		parts = append(parts, streamSettings.SecurityType)
+		if streamSettings.Destination != nil {
+			parts = append(parts, streamSettings.Destination.NetAddr())
+		}
+	}
+	sum := sha256.Sum256([]byte(strings.Join(parts, "\x00")))
+	return hex.EncodeToString(sum[:])
+}
+
+func resetSharedStorage() {
+	sharedMu.Lock()
+	shared = make(map[string]Storage)
+	sharedMu.Unlock()
+}
+
+func sharedStorage(streamSettings *internet.MemoryStreamConfig, config *Config, build func() (Storage, error)) (Storage, error) {
+	key := shareKey(streamSettings, config)
+
+	sharedMu.Lock()
+	defer sharedMu.Unlock()
+
+	if storage, ok := shared[key]; ok {
+		return storage, nil
+	}
+	storage, err := build()
+	if err != nil {
+		return nil, err
+	}
+	shared[key] = storage
+	return storage, nil
+}

transport/internet/xdrive/template.go

@@ -0,0 +1,445 @@
+package xdrive
+
+import (
+	"bytes"
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"io"
+	"net/http"
+	"regexp"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/transport/internet"
+)
+
+type authTemplate struct {
+	Type       string            `json:"type"`
+	Header     map[string]string `json:"header"`
+	Username   string            `json:"username"`
+	Password   string            `json:"password"`
+	TokenURL   string            `json:"tokenUrl"`
+	Form       map[string]string `json:"form"`
+	TokenPath  string            `json:"tokenPath"`
+	ExpiryPath string            `json:"expiryPath"`
+}
+
+type opTemplate struct {
+	Method     string            `json:"method"`
+	URL        string            `json:"url"`
+	Headers    map[string]string `json:"headers"`
+	Body       string            `json:"body"`
+	NamesRegex string            `json:"namesRegex"`
+}
+
+type retryTemplate struct {
+	Status     []int  `json:"status"`
+	RateReason string `json:"rateReason"`
+}
+
+type storageTemplate struct {
+	Flatten     bool          `json:"flatten"`
+	Concurrency int           `json:"concurrency"`
+	Auth        authTemplate  `json:"auth"`
+	Put         opTemplate    `json:"put"`
+	Get         opTemplate    `json:"get"`
+	Delete      opTemplate    `json:"delete"`
+	List        opTemplate    `json:"list"`
+	Retry       retryTemplate `json:"retry"`
+
+	names *regexp.Regexp
+}
+
+type templateStorage struct {
+	tmpl    *storageTemplate
+	client  *http.Client
+	folder  string
+	secrets []string
+
+	inflight chan struct{}
+
+	tokenMu     sync.Mutex
+	token       string
+	tokenExpiry time.Time
+}
+
+func newTemplateStorage(streamSettings *internet.MemoryStreamConfig, config *Config) (*templateStorage, error) {
+	tmpl := &storageTemplate{}
+	if err := json.Unmarshal([]byte(config.Template), tmpl); err != nil {
+		return nil, errors.New("invalid template").Base(err)
+	}
+	if tmpl.Put.URL == "" || tmpl.Get.URL == "" || tmpl.List.URL == "" || tmpl.Delete.URL == "" {
+		return nil, errors.New("template needs put, get, list and delete operations")
+	}
+	if tmpl.List.NamesRegex == "" {
+		return nil, errors.New("template list needs a namesRegex")
+	}
+	re, err := regexp.Compile(tmpl.List.NamesRegex)
+	if err != nil {
+		return nil, errors.New("bad namesRegex").Base(err)
+	}
+	if re.NumSubexp() < 1 {
+		return nil, errors.New("namesRegex needs one capture group")
+	}
+	tmpl.names = re
+
+	conc := tmpl.Concurrency
+	if conc <= 0 {
+		conc = driveMaxInflight
+	}
+	if conc > maxTemplateConcurrency {
+		conc = maxTemplateConcurrency
+	}
+
+	return &templateStorage{
+		tmpl:     tmpl,
+		client:   newServiceClient(streamSettings, driveTimeout, conc),
+		folder:   config.RemoteFolder,
+		secrets:  config.Secrets,
+		inflight: make(chan struct{}, conc),
+	}, nil
+}
+
+const maxTemplateConcurrency = 256
+
+func (s *templateStorage) baseVars() map[string]string {
+	vars := map[string]string{"folder": s.folder}
+	for i, secret := range s.secrets {
+		vars["secret"+itoa(i)] = secret
+	}
+	return vars
+}
+
+func subst(tmpl string, vars map[string]string) string {
+	if tmpl == "" || !strings.ContainsRune(tmpl, '{') {
+		return tmpl
+	}
+	out := tmpl
+	for k, v := range vars {
+		out = strings.ReplaceAll(out, "{"+k+"}", v)
+	}
+	return out
+}
+
+func itoa(i int) string {
+	if i == 0 {
+		return "0"
+	}
+	var b [20]byte
+	pos := len(b)
+	for i > 0 {
+		pos--
+		b[pos] = byte('0' + i%10)
+		i /= 10
+	}
+	return string(b[pos:])
+}
+
+func (s *templateStorage) storedName(name string) string {
+	if s.tmpl.Flatten {
+		return flatten(name)
+	}
+	return name
+}
+
+func (s *templateStorage) retryable(status int, payload []byte) bool {
+	for _, code := range s.tmpl.Retry.Status {
+		if status == code {
+			return true
+		}
+	}
+	if status == http.StatusForbidden && s.tmpl.Retry.RateReason != "" {
+		if reason := jsonString(payload, s.tmpl.Retry.RateReason); reason != "" {
+			return true
+		}
+	}
+	return false
+}
+
+func (s *templateStorage) authHeaders(ctx context.Context, vars map[string]string) (map[string]string, error) {
+	switch s.tmpl.Auth.Type {
+	case "", "none":
+		return nil, nil
+	case "static", "oauth2":
+		if s.tmpl.Auth.Type == "oauth2" {
+			token, err := s.accessToken(ctx)
+			if err != nil {
+				return nil, err
+			}
+			vars["token"] = token
+		}
+		headers := make(map[string]string, len(s.tmpl.Auth.Header))
+		for k, v := range s.tmpl.Auth.Header {
+			headers[k] = subst(v, vars)
+		}
+		return headers, nil
+	case "basic":
+		user := subst(s.tmpl.Auth.Username, vars)
+		pass := subst(s.tmpl.Auth.Password, vars)
+		enc := base64.StdEncoding.EncodeToString([]byte(user + ":" + pass))
+		return map[string]string{"Authorization": "Basic " + enc}, nil
+	default:
+		return nil, errors.New("unsupported auth type: ", s.tmpl.Auth.Type)
+	}
+}
+
+func (s *templateStorage) accessToken(ctx context.Context) (string, error) {
+	s.tokenMu.Lock()
+	defer s.tokenMu.Unlock()
+
+	if s.token != "" && time.Now().Before(s.tokenExpiry) {
+		return s.token, nil
+	}
+
+	form := make(map[string]string, len(s.tmpl.Auth.Form))
+	vars := s.baseVars()
+	values := strings.Builder{}
+	first := true
+	for k, v := range s.tmpl.Auth.Form {
+		form[k] = subst(v, vars)
+		if !first {
+			values.WriteByte('&')
+		}
+		first = false
+		values.WriteString(k)
+		values.WriteByte('=')
+		values.WriteString(form[k])
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, s.tmpl.Auth.TokenURL,
+		strings.NewReader(values.String()))
+	if err != nil {
+		return "", errors.New("failed to build the token request").Base(err)
+	}
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+	resp, err := s.client.Do(req)
+	if err != nil {
+		return "", errors.New("failed to fetch the token").Base(err)
+	}
+	defer resp.Body.Close()
+	payload, err := io.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	if err != nil {
+		return "", errors.New("failed to read the token response").Base(err)
+	}
+	if resp.StatusCode != http.StatusOK {
+		return "", errors.New("the token endpoint answered ", resp.StatusCode, ": ", string(payload))
+	}
+
+	path := s.tmpl.Auth.TokenPath
+	if path == "" {
+		path = "access_token"
+	}
+	token := jsonString(payload, path)
+	if token == "" {
+		return "", errors.New("the token response has no token at ", path)
+	}
+
+	lifetime := int64(3600)
+	if s.tmpl.Auth.ExpiryPath != "" {
+		if n := jsonNumber(payload, s.tmpl.Auth.ExpiryPath); n > 0 {
+			lifetime = n
+		}
+	}
+	if lifetime > 60 {
+		lifetime -= 60
+	}
+	s.token = token
+	s.tokenExpiry = time.Now().Add(time.Duration(lifetime) * time.Second)
+	return s.token, nil
+}
+
+func (s *templateStorage) invalidateToken() {
+	s.tokenMu.Lock()
+	s.token = ""
+	s.tokenMu.Unlock()
+}
+
+func (s *templateStorage) do(ctx context.Context, op *opTemplate, vars map[string]string, body []byte) (int, []byte, error) {
+	backoff := driveInitialBackoff
+	var lastErr error
+
+	for attempt := 0; attempt < driveMaxAttempts; attempt++ {
+		if attempt > 0 {
+			select {
+			case <-ctx.Done():
+				return 0, nil, ctx.Err()
+			case <-time.After(jitter(backoff)):
+			}
+			backoff *= 2
+			if backoff > driveMaxBackoff {
+				backoff = driveMaxBackoff
+			}
+		}
+
+		authHeaders, err := s.authHeaders(ctx, vars)
+		if err != nil {
+			lastErr = err
+			continue
+		}
+
+		method := op.Method
+		if method == "" {
+			method = http.MethodGet
+		}
+
+		var reader io.Reader
+		if body != nil {
+			reader = bytes.NewReader(body)
+		}
+		req, err := http.NewRequestWithContext(ctx, method, subst(op.URL, vars), reader)
+		if err != nil {
+			return 0, nil, errors.New("failed to build request").Base(err)
+		}
+		for k, v := range authHeaders {
+			req.Header.Set(k, v)
+		}
+		for k, v := range op.Headers {
+			req.Header.Set(k, subst(v, vars))
+		}
+
+		select {
+		case s.inflight <- struct{}{}:
+		case <-ctx.Done():
+			return 0, nil, ctx.Err()
+		}
+		resp, err := s.client.Do(req)
+		<-s.inflight
+		if err != nil {
+			if ctx.Err() != nil {
+				return 0, nil, ctx.Err()
+			}
+			lastErr = errors.New("request failed").Base(err)
+			continue
+		}
+		payload, err := io.ReadAll(resp.Body)
+		resp.Body.Close()
+		if err != nil {
+			if ctx.Err() != nil {
+				return 0, nil, ctx.Err()
+			}
+			lastErr = errors.New("failed to read response").Base(err)
+			continue
+		}
+
+		if resp.StatusCode == http.StatusUnauthorized && s.tmpl.Auth.Type == "oauth2" {
+			s.invalidateToken()
+			lastErr = errors.New("the service rejected the token")
+			continue
+		}
+		if s.retryable(resp.StatusCode, payload) {
+			lastErr = errors.New("the service answered ", resp.StatusCode)
+			continue
+		}
+		return resp.StatusCode, payload, nil
+	}
+	return 0, nil, lastErr
+}
+
+func (s *templateStorage) Put(ctx context.Context, name string, data []byte) error {
+	vars := s.baseVars()
+	vars["name"] = s.storedName(name)
+
+	body := data
+	if s.tmpl.Put.Body != "" {
+		vars["data"] = base64.StdEncoding.EncodeToString(data)
+		body = []byte(subst(s.tmpl.Put.Body, vars))
+	}
+
+	status, payload, err := s.do(ctx, &s.tmpl.Put, vars, body)
+	if err != nil {
+		return err
+	}
+	if status < 200 || status >= 300 {
+		return errors.New("put of ", name, " answered ", status, ": ", string(payload))
+	}
+	return nil
+}
+
+func (s *templateStorage) Get(ctx context.Context, name string) ([]byte, error) {
+	vars := s.baseVars()
+	vars["name"] = s.storedName(name)
+
+	status, payload, err := s.do(ctx, &s.tmpl.Get, vars, nil)
+	if err != nil {
+		return nil, err
+	}
+	switch {
+	case status >= 200 && status < 300:
+		return payload, nil
+	case status == http.StatusNotFound:
+		return nil, errNotFound
+	default:
+		return nil, errors.New("get of ", name, " answered ", status, ": ", string(payload))
+	}
+}
+
+func (s *templateStorage) Delete(ctx context.Context, name string) error {
+	vars := s.baseVars()
+	vars["name"] = s.storedName(name)
+
+	status, payload, err := s.do(ctx, &s.tmpl.Delete, vars, nil)
+	if err != nil {
+		return err
+	}
+	if status == http.StatusNotFound || (status >= 200 && status < 300) {
+		return nil
+	}
+	return errors.New("delete of ", name, " answered ", status, ": ", string(payload))
+}
+
+func (s *templateStorage) List(ctx context.Context, prefix string) ([]Entry, error) {
+	vars := s.baseVars()
+	flat := s.storedName(prefix)
+	vars["prefix"] = flat
+
+	status, payload, err := s.do(ctx, &s.tmpl.List, vars, nil)
+	if err != nil {
+		return nil, err
+	}
+	if status == http.StatusNotFound {
+		return nil, nil
+	}
+	if status < 200 || status >= 300 {
+		return nil, errors.New("list of ", prefix, " answered ", status, ": ", string(payload))
+	}
+
+	matches := s.tmpl.names.FindAllStringSubmatch(string(payload), -1)
+	if !s.tmpl.Flatten {
+		entries := make([]Entry, 0, len(matches))
+		for _, m := range matches {
+			entries = append(entries, Entry{Name: m[1]})
+		}
+		return entries, nil
+	}
+
+	want := flat + flatSeparator
+	seen := make(map[string]bool, len(matches))
+	entries := make([]Entry, 0, len(matches))
+	for _, m := range matches {
+		name := m[1]
+		if !strings.HasPrefix(name, want) {
+			continue
+		}
+		rest := strings.TrimPrefix(name, want)
+		if rest == "" {
+			continue
+		}
+		if cut := strings.Index(rest, flatSeparator); cut >= 0 {
+			rest = rest[:cut]
+		}
+		if seen[rest] {
+			continue
+		}
+		seen[rest] = true
+		entries = append(entries, Entry{Name: rest})
+	}
+	return entries, nil
+}
+
+func (s *templateStorage) Close() error {
+	return nil
+}

transport/internet/xdrive/template_test.go

@@ -0,0 +1,308 @@
+package xdrive
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/xtls/xray-core/transport/internet"
+)
+
+type fakeStore struct {
+	server *httptest.Server
+
+	mu       sync.Mutex
+	objects  map[string][]byte
+	needAuth string
+	sawAuth  string
+	tokens   int
+}
+
+func newFakeStore(t *testing.T) *fakeStore {
+	t.Helper()
+
+	store := &fakeStore{objects: make(map[string][]byte)}
+	store.server = httptest.NewServer(http.HandlerFunc(store.handle))
+	t.Cleanup(store.server.Close)
+	return store
+}
+
+func (s *fakeStore) handle(w http.ResponseWriter, r *http.Request) {
+	if r.URL.Path == "/token" {
+		s.mu.Lock()
+		s.tokens++
+		s.mu.Unlock()
+		json.NewEncoder(w).Encode(map[string]interface{}{
+			"access_token": "tok-fake", "expires_in": 3600,
+		})
+		return
+	}
+
+	if auth := r.Header.Get("Authorization"); auth != "" {
+		s.mu.Lock()
+		s.sawAuth = auth
+		s.mu.Unlock()
+	}
+	if s.needAuth != "" && r.Header.Get("Authorization") != s.needAuth {
+		w.WriteHeader(http.StatusUnauthorized)
+		return
+	}
+
+	key := strings.TrimPrefix(r.URL.Path, "/folder/")
+
+	switch r.Method {
+	case "PROPFIND":
+		s.mu.Lock()
+		var b strings.Builder
+		for name := range s.objects {
+			fmt.Fprintf(&b, "<d:href>/folder/%s</d:href>\n", name)
+		}
+		s.mu.Unlock()
+		w.Write([]byte(b.String()))
+	case http.MethodPut:
+		body, _ := io.ReadAll(r.Body)
+		s.mu.Lock()
+		s.objects[key] = body
+		s.mu.Unlock()
+		w.WriteHeader(http.StatusCreated)
+	case http.MethodGet:
+		s.mu.Lock()
+		data, ok := s.objects[key]
+		s.mu.Unlock()
+		if !ok {
+			w.WriteHeader(http.StatusNotFound)
+			return
+		}
+		w.Write(data)
+	case http.MethodDelete:
+		s.mu.Lock()
+		delete(s.objects, key)
+		s.mu.Unlock()
+		w.WriteHeader(http.StatusNoContent)
+	default:
+		w.WriteHeader(http.StatusMethodNotAllowed)
+	}
+}
+
+func (s *fakeStore) count() int {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return len(s.objects)
+}
+
+func (s *fakeStore) seenAuth() string {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.sawAuth
+}
+
+func templateSettings(store *fakeStore, auth map[string]interface{}, secrets []string) *internet.MemoryStreamConfig {
+	base := store.server.URL
+	tmpl := map[string]interface{}{
+		"flatten": true,
+		"auth":    auth,
+		"put":     map[string]interface{}{"method": "PUT", "url": base + "/folder/{name}"},
+		"get":     map[string]interface{}{"method": "GET", "url": base + "/folder/{name}"},
+		"delete":  map[string]interface{}{"method": "DELETE", "url": base + "/folder/{name}"},
+		"list": map[string]interface{}{
+			"method":     "PROPFIND",
+			"url":        base + "/folder/",
+			"namesRegex": `<d:href>/folder/([^<]+)</d:href>`,
+		},
+		"retry": map[string]interface{}{"status": []int{429, 500, 502, 503}},
+	}
+	raw, _ := json.Marshal(tmpl)
+	return &internet.MemoryStreamConfig{
+		ProtocolName: protocolName,
+		ProtocolSettings: &Config{
+			RemoteFolder:      "folder",
+			Service:           "template",
+			Secrets:           secrets,
+			Template:          string(raw),
+			FlushIntervalMs:   5,
+			PollIntervalMs:    5,
+			MaxPollIntervalMs: 20,
+			SessionTtlSeconds: 5,
+		},
+	}
+}
+
+func newTemplateBackend(t *testing.T, store *fakeStore, auth map[string]interface{}, secrets []string) *templateStorage {
+	t.Helper()
+	settings := templateSettings(store, auth, secrets)
+	storage, err := newTemplateStorage(settings, settings.ProtocolSettings.(*Config))
+	if err != nil {
+		t.Fatalf("newTemplateStorage: %v", err)
+	}
+	return storage
+}
+
+func TestTemplateRoundTrip(t *testing.T) {
+	store := newFakeStore(t)
+	storage := newTemplateBackend(t, store, map[string]interface{}{"type": "none"}, nil)
+	ctx := context.Background()
+
+	if err := storage.Put(ctx, "streams/abc/c2s/000000000.seg", []byte("hello")); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+	data, err := storage.Get(ctx, "streams/abc/c2s/000000000.seg")
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	if string(data) != "hello" {
+		t.Fatalf("Get returned %q, want hello", data)
+	}
+
+	entries, err := storage.List(ctx, "streams/abc/c2s")
+	if err != nil {
+		t.Fatalf("List: %v", err)
+	}
+	if len(entries) != 1 || entries[0].Name != "000000000.seg" {
+		t.Fatalf("List returned %v, want one segment", entries)
+	}
+
+	if _, err := storage.Get(ctx, "streams/abc/c2s/000000009.seg"); err != errNotFound {
+		t.Fatalf("Get of a missing object returned %v, want errNotFound", err)
+	}
+
+	if err := storage.Delete(ctx, "streams/abc/c2s/000000000.seg"); err != nil {
+		t.Fatalf("Delete: %v", err)
+	}
+	if store.count() != 0 {
+		t.Fatalf("store still holds %d objects", store.count())
+	}
+}
+
+func TestTemplateListReturnsDirectChildren(t *testing.T) {
+	store := newFakeStore(t)
+	storage := newTemplateBackend(t, store, map[string]interface{}{"type": "none"}, nil)
+	ctx := context.Background()
+
+	for _, name := range []string{
+		"streams/one/c2s/000000000.seg",
+		"streams/one/s2c/000000000.seg",
+		"streams/two/c2s/000000000.seg",
+	} {
+		if err := storage.Put(ctx, name, []byte("x")); err != nil {
+			t.Fatalf("Put %s: %v", name, err)
+		}
+	}
+
+	entries, err := storage.List(ctx, "streams")
+	if err != nil {
+		t.Fatalf("List: %v", err)
+	}
+	if len(entries) != 2 {
+		t.Fatalf("List returned %v, want the two session ids", entries)
+	}
+}
+
+func TestTemplateBasicAuth(t *testing.T) {
+	store := newFakeStore(t)
+	store.needAuth = "Basic dXNlcjpwYXNz"
+	auth := map[string]interface{}{"type": "basic", "username": "{secret0}", "password": "{secret1}"}
+	storage := newTemplateBackend(t, store, auth, []string{"user", "pass"})
+
+	if err := storage.Put(context.Background(), "sessions/a", []byte("x")); err != nil {
+		t.Fatalf("Put with basic auth: %v", err)
+	}
+	if store.seenAuth() != "Basic dXNlcjpwYXNz" {
+		t.Fatalf("server saw auth %q", store.seenAuth())
+	}
+}
+
+func TestTemplateOAuth(t *testing.T) {
+	store := newFakeStore(t)
+	store.needAuth = "Bearer tok-fake"
+	auth := map[string]interface{}{
+		"type":     "oauth2",
+		"tokenUrl": store.server.URL + "/token",
+		"form":     map[string]interface{}{"grant_type": "refresh_token", "refresh_token": "{secret0}"},
+		"header":   map[string]interface{}{"Authorization": "Bearer {token}"},
+	}
+	storage := newTemplateBackend(t, store, auth, []string{"refresh"})
+	ctx := context.Background()
+
+	for i := 0; i < 4; i++ {
+		if err := storage.Put(ctx, fmt.Sprintf("sessions/s%d", i), nil); err != nil {
+			t.Fatalf("Put: %v", err)
+		}
+	}
+	if store.tokens != 1 {
+		t.Fatalf("token endpoint was hit %d times, want 1", store.tokens)
+	}
+}
+
+func TestTemplateTransport(t *testing.T) {
+	store := newFakeStore(t)
+	settings := templateSettings(store, map[string]interface{}{"type": "none"}, nil)
+
+	client, server, cleanup := pairWith(t, settings)
+	defer cleanup()
+
+	if _, err := client.Write([]byte("ping")); err != nil {
+		t.Fatalf("client write: %v", err)
+	}
+	expectRead(t, server, "ping")
+
+	if _, err := server.Write([]byte("pong")); err != nil {
+		t.Fatalf("server write: %v", err)
+	}
+	expectRead(t, client, "pong")
+
+	payload := make([]byte, 300000)
+	for i := range payload {
+		payload[i] = byte(i % 251)
+	}
+	go func() { client.Write(payload) }()
+
+	if err := server.SetReadDeadline(time.Now().Add(30 * time.Second)); err != nil {
+		t.Fatalf("SetReadDeadline: %v", err)
+	}
+	got := make([]byte, len(payload))
+	if _, err := io.ReadFull(server, got); err != nil {
+		t.Fatalf("ReadFull: %v", err)
+	}
+	for i := range got {
+		if got[i] != payload[i] {
+			t.Fatalf("payload mismatch at byte %d", i)
+		}
+	}
+}
+
+func TestTemplateConcurrency(t *testing.T) {
+	store := newFakeStore(t)
+	settings := templateSettings(store, map[string]interface{}{"type": "none"}, nil)
+
+	var tmpl map[string]interface{}
+	cfg := settings.ProtocolSettings.(*Config)
+	if err := json.Unmarshal([]byte(cfg.Template), &tmpl); err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+	tmpl["concurrency"] = 4
+	raw, _ := json.Marshal(tmpl)
+	cfg.Template = string(raw)
+
+	storage, err := newTemplateStorage(settings, cfg)
+	if err != nil {
+		t.Fatalf("newTemplateStorage: %v", err)
+	}
+	if cap(storage.inflight) != 4 {
+		t.Fatalf("inflight cap is %d, want 4 from the template", cap(storage.inflight))
+	}
+}
+
+func TestTemplateConcurrencyDefault(t *testing.T) {
+	store := newFakeStore(t)
+	storage := newTemplateBackend(t, store, map[string]interface{}{"type": "none"}, nil)
+	if cap(storage.inflight) != driveMaxInflight {
+		t.Fatalf("default inflight cap is %d, want %d", cap(storage.inflight), driveMaxInflight)
+	}
+}

transport/internet/xdrive/wal.go

@@ -0,0 +1,445 @@
+package xdrive
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/xtls/xray-core/common/errors"
+)
+
+const (
+	maxCoalescedTicks = 8
+
+	segSuffix = ".seg"
+	endSuffix = ".end"
+	errSuffix = ".err"
+)
+
+func objectName(prefix string, seq int64, suffix string) string {
+	return fmt.Sprintf("%s/%09d%s", prefix, seq, suffix)
+}
+
+func parseEntry(name string) (int64, bool) {
+	dot := strings.LastIndexByte(name, '.')
+	if dot < 0 {
+		return 0, false
+	}
+	switch name[dot:] {
+	case segSuffix, endSuffix, errSuffix:
+	default:
+		return 0, false
+	}
+	seq, err := strconv.ParseInt(name[:dot], 10, 64)
+	if err != nil || seq < 0 {
+		return 0, false
+	}
+	return seq, true
+}
+
+type walWriter struct {
+	ctx     context.Context
+	storage Storage
+	prefix  string
+	params
+	sem chan struct{}
+	wg  sync.WaitGroup
+
+	mu       sync.Mutex
+	buf      []byte
+	seq      int64
+	lastSize int
+	held     int
+	closed   bool
+	err      error
+}
+
+func newWALWriter(ctx context.Context, storage Storage, prefix string, p params) *walWriter {
+	w := &walWriter{
+		ctx:     ctx,
+		storage: storage,
+		prefix:  prefix,
+		params:  p,
+		sem:     make(chan struct{}, p.concurrency),
+	}
+	go w.flushLoop()
+	return w
+}
+
+func (w *walWriter) Write(p []byte) (int, error) {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	if w.err != nil {
+		return 0, w.err
+	}
+	if w.closed {
+		return 0, io.ErrClosedPipe
+	}
+
+	w.buf = append(w.buf, p...)
+	for len(w.buf) >= w.segmentBytes {
+		if err := w.flushLocked(); err != nil {
+			return 0, err
+		}
+	}
+	return len(p), nil
+}
+
+func (w *walWriter) flushLoop() {
+	ticker := time.NewTicker(w.flushInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-w.ctx.Done():
+			return
+		case <-ticker.C:
+			w.mu.Lock()
+			if !w.closed && w.err == nil && len(w.buf) > 0 && w.readyToFlush() {
+				w.flushLocked()
+			}
+			done := w.closed || w.err != nil
+			w.mu.Unlock()
+			if done {
+				return
+			}
+		}
+	}
+}
+
+func (w *walWriter) readyToFlush() bool {
+	grew := len(w.buf) > w.lastSize
+	w.lastSize = len(w.buf)
+
+	if grew && w.held < maxCoalescedTicks {
+		w.held++
+		return false
+	}
+	w.held = 0
+	return true
+}
+
+func (w *walWriter) flushLocked() error {
+	if len(w.buf) == 0 {
+		return nil
+	}
+	if w.err != nil {
+		return w.err
+	}
+
+	n := len(w.buf)
+	if n > w.segmentBytes {
+		n = w.segmentBytes
+	}
+
+	chunk := make([]byte, n)
+	copy(chunk, w.buf[:n])
+	seq := w.seq
+	w.seq++
+
+	if n == len(w.buf) {
+		w.buf = w.buf[:0]
+	} else {
+		w.buf = append(w.buf[:0], w.buf[n:]...)
+	}
+	w.lastSize = len(w.buf)
+	w.held = 0
+
+	w.wg.Add(1)
+	go w.upload(seq, chunk)
+	return nil
+}
+
+func (w *walWriter) upload(seq int64, chunk []byte) {
+	defer w.wg.Done()
+
+	select {
+	case w.sem <- struct{}{}:
+	case <-w.ctx.Done():
+		return
+	}
+	defer func() { <-w.sem }()
+
+	if err := w.storage.Put(w.ctx, objectName(w.prefix, seq, segSuffix), chunk); err != nil {
+		w.mu.Lock()
+		if w.err == nil {
+			w.err = errors.New("failed to store segment").Base(err)
+		}
+		w.mu.Unlock()
+		w.storage.Put(w.ctx, objectName(w.prefix, seq, errSuffix), nil)
+	}
+}
+
+func (w *walWriter) Close() error {
+	w.mu.Lock()
+	if w.closed {
+		w.mu.Unlock()
+		return nil
+	}
+	w.closed = true
+	for len(w.buf) > 0 && w.err == nil {
+		w.flushLocked()
+	}
+	w.mu.Unlock()
+
+	w.wg.Wait()
+
+	w.mu.Lock()
+	err, seq := w.err, w.seq
+	w.mu.Unlock()
+
+	if err != nil {
+		return err
+	}
+	return w.storage.Put(w.ctx, objectName(w.prefix, seq, endSuffix), nil)
+}
+
+type walReader struct {
+	ctx     context.Context
+	storage Storage
+	prefix  string
+	params
+	seq int64
+
+	ch        chan []byte
+	discards  chan string
+	wake      chan struct{}
+	holeSince time.Time
+
+	errMu sync.Mutex
+	err   error
+}
+
+func newWALReader(ctx context.Context, storage Storage, prefix string, p params) *walReader {
+	r := &walReader{
+		ctx:      ctx,
+		storage:  storage,
+		prefix:   prefix,
+		params:   p,
+		ch:       make(chan []byte, p.concurrency),
+		discards: make(chan string, 4*p.concurrency),
+		wake:     make(chan struct{}, 1),
+	}
+	go r.run()
+	go r.discardLoop()
+	return r
+}
+
+func (r *walReader) Wake() {
+	select {
+	case r.wake <- struct{}{}:
+	default:
+	}
+}
+
+func (r *walReader) run() {
+	defer close(r.ch)
+
+	delay := r.minPollInterval
+	active := time.Now()
+	for {
+		polled := time.Now()
+		advanced, eof, err := r.poll()
+		if err != nil {
+			r.setErr(err)
+			return
+		}
+		if eof {
+			return
+		}
+
+		switch {
+		case advanced:
+			active = time.Now()
+			delay = r.minPollInterval
+		case time.Since(active) < r.eagerWindow:
+			delay = r.minPollInterval
+		default:
+			delay *= 2
+			if delay > r.maxPollInterval {
+				delay = r.maxPollInterval
+			}
+		}
+
+		timer := time.NewTimer(delay)
+		select {
+		case <-r.ctx.Done():
+			timer.Stop()
+			return
+		case <-timer.C:
+		case <-r.wake:
+			timer.Stop()
+			active = time.Now()
+			delay = r.minPollInterval
+			if rest := r.minPollInterval - time.Since(polled); rest > 0 {
+				select {
+				case <-r.ctx.Done():
+					return
+				case <-time.After(rest):
+				}
+			}
+		}
+	}
+}
+
+func (r *walReader) poll() (advanced, eof bool, err error) {
+	listed, err := r.storage.List(r.ctx, r.prefix)
+	if err != nil {
+		return false, false, err
+	}
+	if len(listed) == 0 {
+		return false, false, nil
+	}
+
+	pending := make(map[int64]Entry, len(listed))
+	ahead := false
+	for _, entry := range listed {
+		seq, ok := parseEntry(entry.Name)
+		if !ok {
+			continue
+		}
+		pending[seq] = entry
+		if seq > r.seq {
+			ahead = true
+		}
+	}
+
+	if _, ok := pending[r.seq]; !ok && ahead {
+		if r.holeSince.IsZero() {
+			r.holeSince = time.Now()
+		} else if time.Since(r.holeSince) >= r.holeTimeout {
+			return false, false, errors.New("segment ", r.seq,
+				" never arrived while later ones did, the peer lost it")
+		}
+	} else {
+		r.holeSince = time.Time{}
+	}
+
+	for {
+		if entry, ok := pending[r.seq]; ok && strings.HasSuffix(entry.Name, errSuffix) {
+			r.discard(r.prefix + "/" + entry.Name)
+			return advanced, false, errors.New("the peer could not store segment ", r.seq)
+		}
+
+		batch, done := r.nextBatch(pending)
+		if done {
+			return advanced, true, nil
+		}
+		if len(batch) == 0 {
+			return advanced, false, nil
+		}
+
+		chunks, err := r.fetch(batch)
+		if err != nil {
+			if err == errNotFound {
+				return advanced, false, nil
+			}
+			return advanced, false, err
+		}
+
+		for i, chunk := range chunks {
+			select {
+			case r.ch <- chunk:
+			case <-r.ctx.Done():
+				return advanced, true, nil
+			}
+			r.seq++
+			advanced = true
+			r.discard(r.prefix + "/" + batch[i].Name)
+		}
+	}
+}
+
+func (r *walReader) nextBatch(pending map[int64]Entry) (batch []Entry, done bool) {
+	for i := 0; i < r.concurrency; i++ {
+		entry, ok := pending[r.seq+int64(i)]
+		if !ok {
+			break
+		}
+		if !strings.HasSuffix(entry.Name, segSuffix) {
+			if i == 0 && strings.HasSuffix(entry.Name, endSuffix) {
+				r.discard(r.prefix + "/" + entry.Name)
+				return nil, true
+			}
+			break
+		}
+		batch = append(batch, entry)
+	}
+	return batch, false
+}
+
+func (r *walReader) fetch(batch []Entry) ([][]byte, error) {
+	chunks := make([][]byte, len(batch))
+	failures := make([]error, len(batch))
+
+	var wg sync.WaitGroup
+	for i, entry := range batch {
+		if entry.Inline != nil {
+			chunks[i] = entry.Inline
+			continue
+		}
+		wg.Add(1)
+		go func(i int, name string) {
+			defer wg.Done()
+			chunks[i], failures[i] = r.storage.Get(r.ctx, r.prefix+"/"+name)
+		}(i, entry.Name)
+	}
+	wg.Wait()
+
+	for i := range batch {
+		if failures[i] != nil {
+			return nil, failures[i]
+		}
+	}
+	return chunks, nil
+}
+
+func (r *walReader) discard(name string) {
+	select {
+	case r.discards <- name:
+	default:
+	}
+}
+
+func (r *walReader) discardLoop() {
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	sem := make(chan struct{}, r.concurrency)
+	for {
+		select {
+		case <-r.ctx.Done():
+			return
+		case name := <-r.discards:
+			sem <- struct{}{}
+			wg.Add(1)
+			go func(name string) {
+				defer wg.Done()
+				defer func() { <-sem }()
+				r.storage.Delete(r.ctx, name)
+			}(name)
+		}
+	}
+}
+
+func (r *walReader) setErr(err error) {
+	r.errMu.Lock()
+	defer r.errMu.Unlock()
+	if r.err == nil {
+		r.err = err
+	}
+}
+
+func (r *walReader) Err() error {
+	r.errMu.Lock()
+	defer r.errMu.Unlock()
+	if r.err != nil {
+		return r.err
+	}
+	return io.EOF
+}

transport/internet/xdrive/xdrive.go

@@ -0,0 +1,308 @@
+package xdrive
+
+import (
+	"context"
+	"crypto/rand"
+	"encoding/hex"
+	"fmt"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"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"
+	"github.com/xtls/xray-core/transport/internet/stat"
+)
+
+const (
+	protocolName = "xdrive"
+	sessionsDir  = "sessions"
+	streamsDir   = "streams"
+	uplinkDir    = "c2s"
+	downlinkDir  = "s2c"
+)
+
+func init() {
+	common.Must(internet.RegisterProtocolConfigCreator(protocolName, func() interface{} {
+		return new(Config)
+	}))
+	common.Must(internet.RegisterTransportDialer(protocolName, Dial))
+	common.Must(internet.RegisterTransportListener(protocolName, Serve))
+}
+
+func newSessionID() (string, error) {
+	buf := make([]byte, 16)
+	if _, err := rand.Read(buf); err != nil {
+		return "", errors.New("failed to generate session id").Base(err)
+	}
+	return hex.EncodeToString(buf), nil
+}
+
+func announceName(session string, at time.Time) string {
+	return fmt.Sprintf("%s/%d-%s", sessionsDir, at.UnixNano(), session)
+}
+
+func parseAnnounce(entry string) (string, time.Time, bool) {
+	dash := strings.IndexByte(entry, '-')
+	if dash <= 0 || dash == len(entry)-1 {
+		return "", time.Time{}, false
+	}
+	nanos, err := strconv.ParseInt(entry[:dash], 10, 64)
+	if err != nil {
+		return "", time.Time{}, false
+	}
+	return entry[dash+1:], time.Unix(0, nanos), true
+}
+
+func sessionPrefix(session string) string {
+	return streamsDir + "/" + session
+}
+
+func uplinkPrefix(session string) string {
+	return sessionPrefix(session) + "/" + uplinkDir
+}
+
+func downlinkPrefix(session string) string {
+	return sessionPrefix(session) + "/" + downlinkDir
+}
+
+func streamConfig(streamSettings *internet.MemoryStreamConfig) (*Config, error) {
+	config, ok := streamSettings.ProtocolSettings.(*Config)
+	if !ok || config == nil {
+		return nil, errors.New("invalid protocol settings")
+	}
+	return config, nil
+}
+
+func Dial(ctx context.Context, dest net.Destination, streamSettings *internet.MemoryStreamConfig) (stat.Connection, error) {
+	config, err := streamConfig(streamSettings)
+	if err != nil {
+		return nil, err
+	}
+
+	storage, err := newStorage(streamSettings)
+	if err != nil {
+		return nil, err
+	}
+
+	session, err := newSessionID()
+	if err != nil {
+		storage.Close()
+		return nil, err
+	}
+
+	if err := storage.Put(ctx, announceName(session, time.Now()), nil); err != nil {
+		storage.Close()
+		return nil, errors.New("failed to announce session ", session).Base(err)
+	}
+
+	errors.LogInfo(ctx, "opened session ", session)
+
+	return newConn(context.Background(), storage,
+		uplinkPrefix(session), downlinkPrefix(session), paramsFromConfig(config), func() {
+			storage.Close()
+		}), nil
+}
+
+type Listener struct {
+	ctx     context.Context
+	cancel  context.CancelFunc
+	storage Storage
+	addConn internet.ConnHandler
+	params
+
+	mu        sync.Mutex
+	active    map[string]bool
+	handled   map[string]time.Time
+	idleSince map[string]time.Time
+}
+
+func Serve(ctx context.Context, address net.Address, port net.Port, streamSettings *internet.MemoryStreamConfig, addConn internet.ConnHandler) (internet.Listener, error) {
+	config, err := streamConfig(streamSettings)
+	if err != nil {
+		return nil, err
+	}
+
+	storage, err := newStorage(streamSettings)
+	if err != nil {
+		return nil, err
+	}
+
+	listenerCtx, cancel := context.WithCancel(context.Background())
+	listener := &Listener{
+		ctx:       listenerCtx,
+		cancel:    cancel,
+		storage:   storage,
+		addConn:   addConn,
+		params:    paramsFromConfig(config),
+		active:    make(map[string]bool),
+		handled:   make(map[string]time.Time),
+		idleSince: make(map[string]time.Time),
+	}
+
+	go listener.acceptLoop(ctx)
+	go listener.collectLoop(ctx)
+
+	return listener, nil
+}
+
+func (l *Listener) acceptLoop(logCtx context.Context) {
+	delay := l.minPollInterval
+	active := time.Now()
+	for {
+		accepted, err := l.acceptPending(logCtx)
+		if err != nil {
+			errors.LogWarningInner(logCtx, err, "failed to list sessions")
+		}
+
+		switch {
+		case accepted:
+			active = time.Now()
+			delay = l.minPollInterval
+		case time.Since(active) < l.eagerWindow:
+			delay = l.minPollInterval
+		default:
+			delay *= 2
+			if delay > l.maxPollInterval {
+				delay = l.maxPollInterval
+			}
+		}
+
+		select {
+		case <-l.ctx.Done():
+			return
+		case <-time.After(delay):
+		}
+	}
+}
+
+func (l *Listener) acceptPending(logCtx context.Context) (bool, error) {
+	sessions, err := l.storage.List(l.ctx, sessionsDir)
+	if err != nil {
+		return false, err
+	}
+
+	accepted := false
+	for _, listed := range sessions {
+		entry := listed.Name
+		full := sessionsDir + "/" + entry
+
+		session, at, ok := parseAnnounce(entry)
+		if !ok {
+			go l.drop(full)
+			continue
+		}
+		if time.Since(at) > l.sessionTTL {
+			errors.LogInfo(logCtx, "dropping the stale announcement of session ", session)
+			go l.drop(full)
+			go l.drop(sessionPrefix(session))
+			continue
+		}
+		if !l.claim(session) {
+			continue
+		}
+		go l.drop(full)
+		errors.LogInfo(logCtx, "accepted session ", session)
+		accepted = true
+		l.addConn(l.newSessionConn(session))
+	}
+	return accepted, nil
+}
+
+func (l *Listener) drop(name string) {
+	l.storage.Delete(l.ctx, name)
+}
+
+func (l *Listener) claim(session string) bool {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	if l.active[session] || !l.handled[session].IsZero() {
+		return false
+	}
+	l.active[session] = true
+	l.handled[session] = time.Now()
+	return true
+}
+
+func (l *Listener) newSessionConn(session string) *Conn {
+	return newConn(l.ctx, l.storage,
+		downlinkPrefix(session), uplinkPrefix(session), l.params, func() {
+			l.mu.Lock()
+			delete(l.active, session)
+			l.mu.Unlock()
+		})
+}
+
+func (l *Listener) collectLoop(logCtx context.Context) {
+	interval := l.sessionTTL / 2
+	for {
+		select {
+		case <-l.ctx.Done():
+			return
+		case <-time.After(interval):
+		}
+		if err := l.collect(); err != nil {
+			errors.LogWarningInner(logCtx, err, "failed to collect abandoned sessions")
+		}
+	}
+}
+
+func (l *Listener) collect() error {
+	sessions, err := l.storage.List(l.ctx, streamsDir)
+	if err != nil {
+		return err
+	}
+
+	now := time.Now()
+	var expired []string
+
+	l.mu.Lock()
+	present := make(map[string]bool, len(sessions))
+	for _, listed := range sessions {
+		session := listed.Name
+		present[session] = true
+		if l.active[session] {
+			delete(l.idleSince, session)
+			continue
+		}
+		since, seen := l.idleSince[session]
+		if !seen {
+			l.idleSince[session] = now
+			continue
+		}
+		if now.Sub(since) >= l.sessionTTL {
+			expired = append(expired, session)
+			delete(l.idleSince, session)
+		}
+	}
+	for session := range l.idleSince {
+		if !present[session] {
+			delete(l.idleSince, session)
+		}
+	}
+	for session, at := range l.handled {
+		if !l.active[session] && now.Sub(at) >= l.sessionTTL {
+			delete(l.handled, session)
+		}
+	}
+	l.mu.Unlock()
+
+	for _, session := range expired {
+		if err := l.storage.Delete(l.ctx, sessionPrefix(session)); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (l *Listener) Addr() net.Addr {
+	return placeholderAddr
+}
+
+func (l *Listener) Close() error {
+	l.cancel()
+	return l.storage.Close()
+}

transport/internet/xdrive/xdrive_test.go

@@ -0,0 +1,583 @@
+package xdrive
+
+import (
+	"bytes"
+	"context"
+	"crypto/rand"
+	"io"
+	"os"
+	"strings"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet"
+	"github.com/xtls/xray-core/transport/internet/stat"
+)
+
+const testPatience = 30 * time.Second
+
+func settings(folder string) *internet.MemoryStreamConfig {
+	return &internet.MemoryStreamConfig{
+		ProtocolName: protocolName,
+		ProtocolSettings: &Config{
+			RemoteFolder:      folder,
+			Service:           "local",
+			FlushIntervalMs:   5,
+			PollIntervalMs:    5,
+			MaxPollIntervalMs: 20,
+			SessionTtlSeconds: 5,
+		},
+	}
+}
+
+func pair(t *testing.T) (client, server stat.Connection, cleanup func()) {
+	t.Helper()
+	return pairWith(t, settings(t.TempDir()))
+}
+
+func pairWith(t *testing.T, streamSettings *internet.MemoryStreamConfig) (client, server stat.Connection, cleanup func()) {
+	t.Helper()
+
+	accepted := make(chan stat.Connection, 1)
+
+	listener, err := Serve(context.Background(), net.LocalHostIP, net.Port(0), streamSettings, func(conn stat.Connection) {
+		accepted <- conn
+	})
+	if err != nil {
+		t.Fatalf("Serve: %v", err)
+	}
+
+	client, err = Dial(context.Background(), net.Destination{}, streamSettings)
+	if err != nil {
+		listener.Close()
+		t.Fatalf("Dial: %v", err)
+	}
+
+	select {
+	case server = <-accepted:
+	case <-time.After(testPatience):
+		client.Close()
+		listener.Close()
+		t.Fatal("listener did not accept the session")
+	}
+
+	return client, server, func() {
+		client.Close()
+		server.Close()
+		listener.Close()
+	}
+}
+
+func expectRead(t *testing.T, conn stat.Connection, want string) {
+	t.Helper()
+
+	if err := conn.SetReadDeadline(time.Now().Add(testPatience)); err != nil {
+		t.Fatalf("SetReadDeadline: %v", err)
+	}
+	buf := make([]byte, len(want))
+	if _, err := io.ReadFull(conn, buf); err != nil {
+		t.Fatalf("ReadFull: %v", err)
+	}
+	if string(buf) != want {
+		t.Fatalf("read %q, want %q", buf, want)
+	}
+}
+
+func TestRoundTrip(t *testing.T) {
+	client, server, cleanup := pair(t)
+	defer cleanup()
+
+	if _, err := client.Write([]byte("ping")); err != nil {
+		t.Fatalf("client write: %v", err)
+	}
+	expectRead(t, server, "ping")
+
+	if _, err := server.Write([]byte("pong")); err != nil {
+		t.Fatalf("server write: %v", err)
+	}
+	expectRead(t, client, "pong")
+}
+
+func TestInterleaved(t *testing.T) {
+	client, server, cleanup := pair(t)
+	defer cleanup()
+
+	for i := 0; i < 20; i++ {
+		if _, err := client.Write([]byte("up")); err != nil {
+			t.Fatalf("client write %d: %v", i, err)
+		}
+		expectRead(t, server, "up")
+
+		if _, err := server.Write([]byte("down")); err != nil {
+			t.Fatalf("server write %d: %v", i, err)
+		}
+		expectRead(t, client, "down")
+	}
+}
+
+func TestMultiSegmentTransfer(t *testing.T) {
+	client, server, cleanup := pair(t)
+	defer cleanup()
+
+	payload := make([]byte, 3*defaultSegmentBytes+1234)
+	if _, err := rand.Read(payload); err != nil {
+		t.Fatalf("rand: %v", err)
+	}
+
+	go func() {
+		client.Write(payload)
+	}()
+
+	if err := server.SetReadDeadline(time.Now().Add(30 * time.Second)); err != nil {
+		t.Fatalf("SetReadDeadline: %v", err)
+	}
+	got := make([]byte, len(payload))
+	if _, err := io.ReadFull(server, got); err != nil {
+		t.Fatalf("ReadFull: %v", err)
+	}
+	if !bytes.Equal(got, payload) {
+		t.Fatal("payload mismatch")
+	}
+}
+
+func TestCloseEOF(t *testing.T) {
+	client, server, cleanup := pair(t)
+	defer cleanup()
+
+	if _, err := client.Write([]byte("bye")); err != nil {
+		t.Fatalf("client write: %v", err)
+	}
+	if err := client.Close(); err != nil {
+		t.Fatalf("client close: %v", err)
+	}
+
+	if err := server.SetReadDeadline(time.Now().Add(5 * time.Second)); err != nil {
+		t.Fatalf("SetReadDeadline: %v", err)
+	}
+	got, err := io.ReadAll(server)
+	if err != nil {
+		t.Fatalf("ReadAll: %v", err)
+	}
+	if string(got) != "bye" {
+		t.Fatalf("read %q, want %q", got, "bye")
+	}
+}
+
+func TestReadDeadline(t *testing.T) {
+	client, _, cleanup := pair(t)
+	defer cleanup()
+
+	if err := client.SetReadDeadline(time.Now().Add(100 * time.Millisecond)); err != nil {
+		t.Fatalf("SetReadDeadline: %v", err)
+	}
+	buf := make([]byte, 4)
+	if _, err := client.Read(buf); !os.IsTimeout(err) {
+		t.Fatalf("Read returned %v, want a timeout", err)
+	}
+}
+
+func TestLocalNameEscape(t *testing.T) {
+	root := t.TempDir()
+	storage, err := newLocalStorage(root)
+	if err != nil {
+		t.Fatalf("newLocalStorage: %v", err)
+	}
+
+	if err := storage.Put(context.Background(), "../escaped", []byte("x")); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+	if _, err := os.Stat(root + "/escaped"); err != nil {
+		t.Fatalf("name was not clamped inside the root: %v", err)
+	}
+}
+
+func TestLocalMissingObject(t *testing.T) {
+	storage, err := newLocalStorage(t.TempDir())
+	if err != nil {
+		t.Fatalf("newLocalStorage: %v", err)
+	}
+
+	if _, err := storage.Get(context.Background(), "nothing/here"); err != errNotFound {
+		t.Fatalf("Get returned %v, want errNotFound", err)
+	}
+	names, err := storage.List(context.Background(), "nothing")
+	if err != nil {
+		t.Fatalf("List: %v", err)
+	}
+	if len(names) != 0 {
+		t.Fatalf("List returned %v, want none", names)
+	}
+}
+
+func TestResumeAfterIdle(t *testing.T) {
+	client, server, cleanup := pair(t)
+	defer cleanup()
+
+	if _, err := client.Write([]byte("first")); err != nil {
+		t.Fatalf("client write: %v", err)
+	}
+	expectRead(t, server, "first")
+
+	time.Sleep(200 * time.Millisecond)
+
+	if _, err := client.Write([]byte("second")); err != nil {
+		t.Fatalf("client write: %v", err)
+	}
+	expectRead(t, server, "second")
+}
+
+func TestParseEntry(t *testing.T) {
+	cases := []struct {
+		name string
+		seq  int64
+		ok   bool
+	}{
+		{"000000000.seg", 0, true},
+		{"000000042.seg", 42, true},
+		{"000000007.end", 7, true},
+		{"000000001.tmp", 0, false},
+		{"notanumber.seg", 0, false},
+		{"000000001", 0, false},
+	}
+	for _, c := range cases {
+		seq, ok := parseEntry(c.name)
+		if ok != c.ok || (ok && seq != c.seq) {
+			t.Fatalf("parseEntry(%q) = %d, %v; want %d, %v", c.name, seq, ok, c.seq, c.ok)
+		}
+	}
+}
+
+func TestParamDefaults(t *testing.T) {
+	p := paramsFromConfig(&Config{})
+	if p.segmentBytes != defaultSegmentBytes || p.flushInterval != defaultFlushInterval {
+		t.Fatalf("defaults not applied: %+v", p)
+	}
+
+	p = paramsFromConfig(&Config{SegmentBytes: 1 << 30, PollIntervalMs: 400, MaxPollIntervalMs: 100})
+	if p.segmentBytes != maxSegmentBytes {
+		t.Fatalf("segmentBytes is %d, want %d", p.segmentBytes, maxSegmentBytes)
+	}
+	if p.maxPollInterval < p.minPollInterval {
+		t.Fatalf("maxPollInterval %v below minPollInterval %v", p.maxPollInterval, p.minPollInterval)
+	}
+}
+
+func waitFor(t *testing.T, what string, done func() bool) {
+	t.Helper()
+
+	deadline := time.Now().Add(5 * time.Second)
+	for time.Now().Before(deadline) {
+		if done() {
+			return
+		}
+		time.Sleep(5 * time.Millisecond)
+	}
+	t.Fatalf("timed out waiting for %s", what)
+}
+
+func newTestListener(t *testing.T, folder string) *Listener {
+	t.Helper()
+
+	storage, err := newLocalStorage(folder)
+	if err != nil {
+		t.Fatalf("newLocalStorage: %v", err)
+	}
+	return &Listener{
+		ctx:       context.Background(),
+		storage:   storage,
+		params:    paramsFromConfig(&Config{SessionTtlSeconds: 1}),
+		active:    make(map[string]bool),
+		handled:   make(map[string]time.Time),
+		idleSince: make(map[string]time.Time),
+	}
+}
+
+func TestCollectAbandoned(t *testing.T) {
+	folder := t.TempDir()
+	listener := newTestListener(t, folder)
+
+	if err := listener.storage.Put(context.Background(), uplinkPrefix("dead")+"/000000000.seg", []byte("x")); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+
+	if err := listener.collect(); err != nil {
+		t.Fatalf("collect: %v", err)
+	}
+	names, _ := listener.storage.List(context.Background(), streamsDir)
+	if len(names) != 1 {
+		t.Fatalf("first pass removed the session, got %v", names)
+	}
+
+	listener.idleSince["dead"] = time.Now().Add(-2 * time.Second)
+	if err := listener.collect(); err != nil {
+		t.Fatalf("collect: %v", err)
+	}
+	names, _ = listener.storage.List(context.Background(), streamsDir)
+	if len(names) != 0 {
+		t.Fatalf("abandoned session still there, got %v", names)
+	}
+}
+
+func TestCollectKeepsActive(t *testing.T) {
+	folder := t.TempDir()
+	listener := newTestListener(t, folder)
+	listener.active["live"] = true
+
+	if err := listener.storage.Put(context.Background(), uplinkPrefix("live")+"/000000000.seg", []byte("x")); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+
+	listener.idleSince["live"] = time.Now().Add(-2 * time.Second)
+	if err := listener.collect(); err != nil {
+		t.Fatalf("collect: %v", err)
+	}
+	names, _ := listener.storage.List(context.Background(), streamsDir)
+	if len(names) != 1 {
+		t.Fatalf("collected an active session, got %v", names)
+	}
+}
+
+func TestParseAnnounce(t *testing.T) {
+	session, at, ok := parseAnnounce("1757000000123456789-abc123")
+	if !ok || session != "abc123" || at.UnixNano() != 1757000000123456789 {
+		t.Fatalf("parseAnnounce returned %q, %v, %v", session, at.UnixNano(), ok)
+	}
+	for _, bad := range []string{"abc123", "-abc123", "1757000000-", "notanumber-abc"} {
+		if _, _, ok := parseAnnounce(bad); ok {
+			t.Fatalf("parseAnnounce accepted %q", bad)
+		}
+	}
+}
+
+func TestStaleAnnounce(t *testing.T) {
+	folder := t.TempDir()
+	listener := newTestListener(t, folder)
+
+	ctx := context.Background()
+	stale := announceName("ghost", time.Now().Add(-time.Hour))
+	if err := listener.storage.Put(ctx, stale, nil); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+	if err := listener.storage.Put(ctx, uplinkPrefix("ghost")+"/000000000.seg", []byte("x")); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+
+	accepted, err := listener.acceptPending(ctx)
+	if err != nil {
+		t.Fatalf("acceptPending: %v", err)
+	}
+	if accepted {
+		t.Fatal("accepted a stale announcement")
+	}
+
+	waitFor(t, "the stale announcement to be removed", func() bool {
+		names, _ := listener.storage.List(ctx, sessionsDir)
+		return len(names) == 0
+	})
+	waitFor(t, "the stale session data to be removed", func() bool {
+		names, _ := listener.storage.List(ctx, streamsDir)
+		return len(names) == 0
+	})
+}
+
+func TestFreshAnnounce(t *testing.T) {
+	folder := t.TempDir()
+	listener := newTestListener(t, folder)
+	listener.addConn = func(conn stat.Connection) { conn.Close() }
+
+	ctx := context.Background()
+	if err := listener.storage.Put(ctx, announceName("fresh", time.Now()), nil); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+
+	accepted, err := listener.acceptPending(ctx)
+	if err != nil {
+		t.Fatalf("acceptPending: %v", err)
+	}
+	if !accepted {
+		t.Fatal("did not accept a fresh announcement")
+	}
+}
+
+func TestAnnouncePrecision(t *testing.T) {
+	at := time.Unix(1757000000, int64(900*time.Millisecond))
+	entry := strings.TrimPrefix(announceName("abc123", at), sessionsDir+"/")
+
+	session, parsed, ok := parseAnnounce(entry)
+	if !ok || session != "abc123" {
+		t.Fatalf("parseAnnounce(%q) returned %q, %v", entry, session, ok)
+	}
+	if !parsed.Equal(at) {
+		t.Fatalf("timestamp came back as %v, want %v", parsed, at)
+	}
+}
+
+func TestRecentAnnounceTTL(t *testing.T) {
+	folder := t.TempDir()
+	listener := newTestListener(t, folder)
+	listener.addConn = func(conn stat.Connection) { conn.Close() }
+
+	ctx := context.Background()
+	recent := time.Now().Add(-900 * time.Millisecond)
+	if err := listener.storage.Put(ctx, announceName("recent", recent), nil); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+
+	accepted, err := listener.acceptPending(ctx)
+	if err != nil {
+		t.Fatalf("acceptPending: %v", err)
+	}
+	if !accepted {
+		t.Fatal("dropped an announcement younger than the TTL")
+	}
+}
+
+func TestMissingSegment(t *testing.T) {
+	storage, err := newLocalStorage(t.TempDir())
+	if err != nil {
+		t.Fatalf("newLocalStorage: %v", err)
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	p := paramsFromConfig(&Config{PollIntervalMs: 5, MaxPollIntervalMs: 20, HoleTimeoutMs: 200})
+	if err := storage.Put(ctx, objectName("hole", 1, segSuffix), []byte("second")); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+
+	reader := newWALReader(ctx, storage, "hole", p)
+	select {
+	case _, ok := <-reader.ch:
+		if ok {
+			t.Fatal("delivered data past a missing segment")
+		}
+	case <-time.After(5 * time.Second):
+		t.Fatal("reader did not give up on a missing segment")
+	}
+
+	err = reader.Err()
+	if err == nil || err == io.EOF {
+		t.Fatalf("Err returned %v, want a failure", err)
+	}
+}
+
+func TestIdleStreamWaits(t *testing.T) {
+	storage, err := newLocalStorage(t.TempDir())
+	if err != nil {
+		t.Fatalf("newLocalStorage: %v", err)
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	p := paramsFromConfig(&Config{PollIntervalMs: 5, MaxPollIntervalMs: 20, HoleTimeoutMs: 100})
+	reader := newWALReader(ctx, storage, "idle", p)
+
+	time.Sleep(400 * time.Millisecond)
+	if err := storage.Put(ctx, objectName("idle", 0, segSuffix), []byte("late")); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+
+	select {
+	case data, ok := <-reader.ch:
+		if !ok {
+			t.Fatalf("the reader gave up on an idle stream: %v", reader.Err())
+		}
+		if string(data) != "late" {
+			t.Fatalf("read %q, want %q", data, "late")
+		}
+	case <-time.After(5 * time.Second):
+		t.Fatal("reader missed a late segment")
+	}
+}
+
+func TestFailureMarker(t *testing.T) {
+	storage, err := newLocalStorage(t.TempDir())
+	if err != nil {
+		t.Fatalf("newLocalStorage: %v", err)
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	p := paramsFromConfig(&Config{PollIntervalMs: 5, MaxPollIntervalMs: 20})
+	if err := storage.Put(ctx, objectName("broken", 0, segSuffix), []byte("first")); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+	if err := storage.Put(ctx, objectName("broken", 1, errSuffix), nil); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+
+	reader := newWALReader(ctx, storage, "broken", p)
+
+	select {
+	case data, ok := <-reader.ch:
+		if !ok || string(data) != "first" {
+			t.Fatalf("want the segment before the marker, got %q %v", data, ok)
+		}
+	case <-time.After(5 * time.Second):
+		t.Fatal("reader did not deliver the first segment")
+	}
+
+	select {
+	case _, ok := <-reader.ch:
+		if ok {
+			t.Fatal("delivered data past the failure marker")
+		}
+	case <-time.After(5 * time.Second):
+		t.Fatal("reader did not stop on the failure marker")
+	}
+
+	if err := reader.Err(); err == nil || err == io.EOF {
+		t.Fatalf("Err returned %v, want a failure", err)
+	}
+}
+
+type inlineOnlyStorage struct {
+	Storage
+	gets int64
+}
+
+func (s *inlineOnlyStorage) List(ctx context.Context, prefix string) ([]Entry, error) {
+	return []Entry{{Name: "000000000" + segSuffix, Inline: []byte("carried by the listing")}}, nil
+}
+
+func (s *inlineOnlyStorage) Get(ctx context.Context, name string) ([]byte, error) {
+	atomic.AddInt64(&s.gets, 1)
+	return nil, errNotFound
+}
+
+func (s *inlineOnlyStorage) Delete(ctx context.Context, name string) error {
+	return nil
+}
+
+func TestInlinePayload(t *testing.T) {
+	base, err := newLocalStorage(t.TempDir())
+	if err != nil {
+		t.Fatalf("newLocalStorage: %v", err)
+	}
+	storage := &inlineOnlyStorage{Storage: base}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	reader := newWALReader(ctx, storage, "inline", paramsFromConfig(&Config{PollIntervalMs: 5}))
+	select {
+	case data, ok := <-reader.ch:
+		if !ok {
+			t.Fatalf("reader stopped: %v", reader.Err())
+		}
+		if string(data) != "carried by the listing" {
+			t.Fatalf("read %q, want the inline payload", data)
+		}
+	case <-time.After(5 * time.Second):
+		t.Fatal("reader did not deliver the inline payload")
+	}
+
+	if got := atomic.LoadInt64(&storage.gets); got != 0 {
+		t.Fatalf("called Get %d times for an inline payload", got)
+	}
+}

transport/internet/xdrive/yandex_live_test.go

@@ -0,0 +1,171 @@
+package xdrive
+
+import (
+	"bytes"
+	"context"
+	"crypto/rand"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/xtls/xray-core/transport/internet"
+)
+
+const yandexBase = "https://webdav.yandex.ru"
+
+func envUint(name string, def uint32) uint32 {
+	if v := os.Getenv(name); v != "" {
+		var n uint32
+		fmt.Sscanf(v, "%d", &n)
+		if n > 0 {
+			return n
+		}
+	}
+	return def
+}
+
+func liveYandexSettings(t *testing.T) (*internet.MemoryStreamConfig, string, func()) {
+	t.Helper()
+
+	user := os.Getenv("XDRIVE_YANDEX_USER")
+	pass := os.Getenv("XDRIVE_YANDEX_PASS")
+	if user == "" || pass == "" {
+		t.Skip("set XDRIVE_YANDEX_USER and XDRIVE_YANDEX_PASS to run this test")
+	}
+
+	folder := fmt.Sprintf("xdrive-live-%d", time.Now().UnixNano())
+	dav := func(method, path string) int {
+		req, _ := http.NewRequest(method, yandexBase+path, nil)
+		req.SetBasicAuth(user, pass)
+		resp, err := http.DefaultClient.Do(req)
+		if err != nil {
+			t.Fatalf("%s %s: %v", method, path, err)
+		}
+		resp.Body.Close()
+		return resp.StatusCode
+	}
+	if code := dav("MKCOL", "/"+folder); code != 201 && code != 405 {
+		t.Fatalf("MKCOL answered %d", code)
+	}
+
+	tmpl := map[string]interface{}{
+		"flatten": true,
+		"auth":    map[string]interface{}{"type": "basic", "username": "{secret0}", "password": "{secret1}"},
+		"put":     map[string]interface{}{"method": "PUT", "url": yandexBase + "/{folder}/{name}"},
+		"get":     map[string]interface{}{"method": "GET", "url": yandexBase + "/{folder}/{name}"},
+		"delete":  map[string]interface{}{"method": "DELETE", "url": yandexBase + "/{folder}/{name}"},
+		"list": map[string]interface{}{
+			"method": "PROPFIND", "url": yandexBase + "/{folder}/",
+			"headers": map[string]interface{}{"Depth": "1"}, "namesRegex": `<d:href>[^<]*/([^/<]+)</d:href>`,
+		},
+		"retry": map[string]interface{}{"status": []int{429, 500, 502, 503}},
+	}
+	raw, _ := json.Marshal(tmpl)
+	settings := &internet.MemoryStreamConfig{
+		ProtocolName: protocolName,
+		ProtocolSettings: &Config{
+			RemoteFolder:      folder,
+			Service:           "template",
+			Secrets:           []string{user, pass},
+			Template:          string(raw),
+			SegmentBytes:      262144,
+			FlushIntervalMs:   100,
+			PollIntervalMs:    300,
+			MaxPollIntervalMs: 1500,
+			SessionTtlSeconds: 120,
+			Concurrency:       envUint("XDRIVE_LIVE_CONCURRENCY", 8),
+		},
+	}
+	cleanup := func() { dav("DELETE", "/"+folder) }
+	return settings, folder, cleanup
+}
+
+func TestLiveYandexStorage(t *testing.T) {
+	settings, _, cleanup := liveYandexSettings(t)
+	defer cleanup()
+
+	storage, err := newTemplateStorage(settings, settings.ProtocolSettings.(*Config))
+	if err != nil {
+		t.Fatalf("newTemplateStorage: %v", err)
+	}
+	ctx := context.Background()
+
+	name := "streams/live/c2s/000000000.seg"
+	payload := []byte("xdrive over real yandex webdav")
+
+	start := time.Now()
+	if err := storage.Put(ctx, name, payload); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+	t.Logf("Put took %v", time.Since(start))
+
+	start = time.Now()
+	names, err := storage.List(ctx, "streams/live/c2s")
+	if err != nil {
+		t.Fatalf("List: %v", err)
+	}
+	t.Logf("List took %v", time.Since(start))
+	if len(names) != 1 || names[0].Name != "000000000.seg" {
+		t.Fatalf("List returned %v, want one segment", names)
+	}
+
+	start = time.Now()
+	got, err := storage.Get(ctx, name)
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	t.Logf("Get took %v", time.Since(start))
+	if !bytes.Equal(got, payload) {
+		t.Fatalf("Get returned %q", got)
+	}
+
+	if _, err := storage.Get(ctx, "streams/live/c2s/000000009.seg"); err != errNotFound {
+		t.Fatalf("Get of a missing object returned %v, want errNotFound", err)
+	}
+
+	if err := storage.Delete(ctx, name); err != nil {
+		t.Fatalf("Delete: %v", err)
+	}
+}
+
+func TestLiveYandexTransport(t *testing.T) {
+	settings, _, cleanup := liveYandexSettings(t)
+	defer cleanup()
+
+	client, server, done := pairWith(t, settings)
+	defer done()
+
+	start := time.Now()
+	if _, err := client.Write([]byte("ping")); err != nil {
+		t.Fatalf("client write: %v", err)
+	}
+	expectRead(t, server, "ping")
+	t.Logf("client to server round took %v", time.Since(start))
+
+	size := 1000000
+	if raw := os.Getenv("XDRIVE_LIVE_BYTES"); raw != "" {
+		fmt.Sscanf(raw, "%d", &size)
+	}
+	payload := make([]byte, size)
+	rand.Read(payload)
+
+	start = time.Now()
+	go func() { client.Write(payload) }()
+	if err := server.SetReadDeadline(time.Now().Add(5 * time.Minute)); err != nil {
+		t.Fatalf("SetReadDeadline: %v", err)
+	}
+	got := make([]byte, len(payload))
+	if _, err := io.ReadFull(server, got); err != nil {
+		t.Fatalf("ReadFull: %v", err)
+	}
+	elapsed := time.Since(start)
+	if !bytes.Equal(got, payload) {
+		t.Fatal("payload mismatch")
+	}
+	t.Logf("%d bytes in %v -> %.1f KiB/s", len(payload), elapsed,
+		float64(len(payload))/1024/elapsed.Seconds())
+}