chore: support splice for direct outbound

adapter/outbound/base.go

@@ -204,6 +204,14 @@ func (c *conn) Upstream() any {
 	return c.ExtendedConn
 }
 
+func (c *conn) WriterReplaceable() bool {
+	return true
+}
+
+func (c *conn) ReaderReplaceable() bool {
+	return true
+}
+
 func NewConn(c net.Conn, a C.ProxyAdapter) C.Conn {
 	if _, ok := c.(syscall.Conn); !ok { // exclusion system conn like *net.TCPConn
 		c = N.NewDeadlineConn(c) // most conn from outbound can't handle readDeadline correctly

common/buf/sing.go

@@ -9,12 +9,12 @@ const BufferSize = buf.BufferSize
 
 type Buffer = buf.Buffer
 
-var (
-	New          = buf.New
-	StackNew     = buf.StackNew
-	StackNewSize = buf.StackNewSize
-	With         = buf.With
-)
+var New = buf.New
+var NewSize = buf.NewSize
+var StackNew = buf.StackNew
+var StackNewSize = buf.StackNewSize
+var With = buf.With
+var As = buf.As
 
 var KeepAlive = common.KeepAlive
 

common/callback/callback.go

@@ -36,6 +36,14 @@ func (c *firstWriteCallBackConn) Upstream() any {
 	return c.Conn
 }
 
+func (c *firstWriteCallBackConn) WriterReplaceable() bool {
+	return c.written
+}
+
+func (c *firstWriteCallBackConn) ReaderReplaceable() bool {
+	return true
+}
+
 var _ N.ExtendedConn = (*firstWriteCallBackConn)(nil)
 
 func NewFirstWriteCallBackConn(c C.Conn, callback func(error)) C.Conn {

common/net/bufconn.go

@@ -69,6 +69,16 @@ func (c *BufferedConn) ReadBuffer(buffer *buf.Buffer) (err error) {
 	return c.ExtendedConn.ReadBuffer(buffer)
 }
 
+func (c *BufferedConn) ReadCached() *buf.Buffer { // call in sing/common/bufio.Copy
+	if c.r.Buffered() > 0 {
+		length := c.r.Buffered()
+		b, _ := c.r.Peek(length)
+		_, _ = c.r.Discard(length)
+		return buf.As(b)
+	}
+	return nil
+}
+
 func (c *BufferedConn) Upstream() any {
 	return c.ExtendedConn
 }

common/net/refconn.go

@@ -67,6 +67,14 @@ func (c *refConn) WriteBuffer(buffer *buf.Buffer) error {
 	return c.conn.WriteBuffer(buffer)
 }
 
+func (c *refConn) ReaderReplaceable() bool { // Relay() will handle reference
+	return true
+}
+
+func (c *refConn) WriterReplaceable() bool { // Relay() will handle reference
+	return true
+}
+
 var _ ExtendedConn = (*refConn)(nil)
 
 func NewRefConn(conn net.Conn, ref any) net.Conn {

common/net/sing.go

@@ -3,6 +3,7 @@ package net
 import (
 	"context"
 	"net"
+	"runtime"
 
 	"github.com/sagernet/sing/common"
 	"github.com/sagernet/sing/common/bufio"
@@ -33,7 +34,11 @@ func NeedHandshake(conn any) bool {
 	return false
 }
 
+type CountFunc = network.CountFunc
+
 // Relay copies between left and right bidirectionally.
 func Relay(leftConn, rightConn net.Conn) {
+	defer runtime.KeepAlive(leftConn)
+	defer runtime.KeepAlive(rightConn)
 	_ = bufio.CopyConn(context.TODO(), leftConn, rightConn)
 }

component/dialer/tfo.go

@@ -113,6 +113,14 @@ func (c *tfoConn) NeedHandshake() bool {
 	return c.Conn == nil
 }
 
+func (c *tfoConn) ReaderReplaceable() bool {
+	return c.Conn != nil
+}
+
+func (c *tfoConn) WriterReplaceable() bool {
+	return c.Conn != nil
+}
+
 func dialTFO(ctx context.Context, netDialer net.Dialer, network, address string) (net.Conn, error) {
 	ctx, cancel := context.WithCancel(ctx)
 	dialer := tfo.Dialer{Dialer: netDialer, DisableTFO: false}

go.mod

@@ -28,7 +28,7 @@ require (
 	github.com/openacid/low v0.1.21
 	github.com/oschwald/geoip2-golang v1.8.0
 	github.com/sagernet/netlink v0.0.0-20220905062125-8043b4a9aa97
-	github.com/sagernet/sing v0.2.5-0.20230423085534-0902e6216207
+	github.com/sagernet/sing v0.2.5-0.20230425145913-0c037cb0e2c8
 	github.com/sagernet/sing-mux v0.0.0-20230424015424-9b0d527c3bb0
 	github.com/sagernet/sing-shadowtls v0.1.2-0.20230417103049-4f682e05f19b
 	github.com/sagernet/sing-vmess v0.1.5-0.20230417103030-8c3070ae3fb3

go.sum

@@ -145,8 +145,8 @@ github.com/sagernet/netlink v0.0.0-20220905062125-8043b4a9aa97 h1:iL5gZI3uFp0X6E
 github.com/sagernet/netlink v0.0.0-20220905062125-8043b4a9aa97/go.mod h1:xLnfdiJbSp8rNqYEdIW/6eDO4mVoogml14Bh2hSiFpM=
 github.com/sagernet/sing v0.0.0-20220817130738-ce854cda8522/go.mod h1:QVsS5L/ZA2Q5UhQwLrn0Trw+msNd/NPGEhBKR/ioWiY=
 github.com/sagernet/sing v0.1.8/go.mod h1:jt1w2u7lJQFFSGLiRrRIs5YWmx4kAPfWuOejuDW9qMk=
-github.com/sagernet/sing v0.2.5-0.20230423085534-0902e6216207 h1:+dDVjW20IT+e8maKryaDeRY2+RFmTFdrQeIzqE2WOss=
-github.com/sagernet/sing v0.2.5-0.20230423085534-0902e6216207/go.mod h1:Ta8nHnDLAwqySzKhGoKk4ZIB+vJ3GTKj7UPrWYvM+4w=
+github.com/sagernet/sing v0.2.5-0.20230425145913-0c037cb0e2c8 h1:bf0WjE6g+bRhNCSe5u0xTeZLK/NboSy1/tI4eqPjvU0=
+github.com/sagernet/sing v0.2.5-0.20230425145913-0c037cb0e2c8/go.mod h1:Ta8nHnDLAwqySzKhGoKk4ZIB+vJ3GTKj7UPrWYvM+4w=
 github.com/sagernet/sing-mux v0.0.0-20230424015424-9b0d527c3bb0 h1:87jyxzTjq01VgEiUVSMNRKjCfsSfp/QwyUVT37eXY50=
 github.com/sagernet/sing-mux v0.0.0-20230424015424-9b0d527c3bb0/go.mod h1:pF+RnLvCAOhECrvauy6LYOpBakJ/vuaF1Wm4lPsWryI=
 github.com/sagernet/sing-shadowtls v0.1.2-0.20230417103049-4f682e05f19b h1:ouW/6IDCrxkBe19YSbdCd7buHix7b+UZ6BM4Zz74XF4=

tunnel/statistic/tracker.go

@@ -1,11 +1,13 @@
 package statistic
 
 import (
+	"io"
 	"net"
 	"time"
 
 	"github.com/Dreamacro/clash/common/atomic"
 	"github.com/Dreamacro/clash/common/buf"
+	N "github.com/Dreamacro/clash/common/net"
 	"github.com/Dreamacro/clash/common/utils"
 	C "github.com/Dreamacro/clash/constant"
 
@@ -61,6 +63,15 @@ func (tt *tcpTracker) ReadBuffer(buffer *buf.Buffer) (err error) {
 	return
 }
 
+func (tt *tcpTracker) UnwrapReader() (io.Reader, []N.CountFunc) {
+	return tt.Conn, []N.CountFunc{func(download int64) {
+		if tt.pushToManager {
+			tt.manager.PushDownloaded(download)
+		}
+		tt.DownloadTotal.Add(download)
+	}}
+}
+
 func (tt *tcpTracker) Write(b []byte) (int, error) {
 	n, err := tt.Conn.Write(b)
 	upload := int64(n)
@@ -81,6 +92,15 @@ func (tt *tcpTracker) WriteBuffer(buffer *buf.Buffer) (err error) {
 	return
 }
 
+func (tt *tcpTracker) UnwrapWriter() (io.Writer, []N.CountFunc) {
+	return tt.Conn, []N.CountFunc{func(upload int64) {
+		if tt.pushToManager {
+			tt.manager.PushUploaded(upload)
+		}
+		tt.UploadTotal.Add(upload)
+	}}
+}
+
 func (tt *tcpTracker) Close() error {
 	tt.manager.Leave(tt)
 	return tt.Conn.Close()