Enable splice for freedom outbound (downlink only)

- Add outbound name
- Add outbound conn in ctx
- Refactor splice: it can be turn on from all inbounds and outbounds
- Refactor splice: Add splice copy to vless inbound
- Fix http error test
- Add freedom splice toggle via env var
- Populate outbound obj in context
- Use CanSpliceCopy to mark a connection
- Turn off splice by default

proxy/vless/outbound/outbound.go

@@ -7,7 +7,6 @@ import (
 	"context"
 	gotls "crypto/tls"
 	"reflect"
-	"syscall"
 	"time"
 	"unsafe"
 
@@ -23,7 +22,6 @@ import (
 	"github.com/xtls/xray-core/common/xudp"
 	"github.com/xtls/xray-core/core"
 	"github.com/xtls/xray-core/features/policy"
-	"github.com/xtls/xray-core/features/stats"
 	"github.com/xtls/xray-core/proxy/vless"
 	"github.com/xtls/xray-core/proxy/vless/encoding"
 	"github.com/xtls/xray-core/transport"
@@ -71,9 +69,15 @@ func New(ctx context.Context, config *Config) (*Handler, error) {
 
 // Process implements proxy.Outbound.Process().
 func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer internet.Dialer) error {
+	outbound := session.OutboundFromContext(ctx)
+	if outbound == nil || !outbound.Target.IsValid() {
+		return newError("target not specified").AtError()
+	}
+	outbound.Name = "vless"
+	inbound := session.InboundFromContext(ctx)
+
 	var rec *protocol.ServerSpec
 	var conn stat.Connection
-
 	if err := retry.ExponentialBackoff(5, 200).On(func() error {
 		rec = h.serverPicker.PickServer()
 		var err error
@@ -88,16 +92,9 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 	defer conn.Close()
 
 	iConn := conn
-	statConn, ok := iConn.(*stat.CounterConnection)
-	if ok {
+	if statConn, ok := iConn.(*stat.CounterConnection); ok {
 		iConn = statConn.Connection
 	}
-
-	outbound := session.OutboundFromContext(ctx)
-	if outbound == nil || !outbound.Target.IsValid() {
-		return newError("target not specified").AtError()
-	}
-
 	target := outbound.Target
 	newError("tunneling request to ", target, " via ", rec.Destination().NetAddr()).AtInfo().WriteToLog(session.ExportIDToError(ctx))
 
@@ -123,8 +120,6 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 		Flow: account.Flow,
 	}
 
-	var netConn net.Conn
-	var rawConn syscall.RawConn
 	var input *bytes.Reader
 	var rawInput *bytes.Buffer
 	allowUDP443 := false
@@ -134,6 +129,9 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 		requestAddons.Flow = requestAddons.Flow[:16]
 		fallthrough
 	case vless.XRV:
+		if inbound != nil {
+			inbound.SetCanSpliceCopy(2)
+		}
 		switch request.Command {
 		case protocol.RequestCommandUDP:
 			if !allowUDP443 && request.Port == 443 {
@@ -146,28 +144,26 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 			var t reflect.Type
 			var p uintptr
 			if tlsConn, ok := iConn.(*tls.Conn); ok {
-				netConn = tlsConn.NetConn()
 				t = reflect.TypeOf(tlsConn.Conn).Elem()
 				p = uintptr(unsafe.Pointer(tlsConn.Conn))
 			} else if utlsConn, ok := iConn.(*tls.UConn); ok {
-				netConn = utlsConn.NetConn()
 				t = reflect.TypeOf(utlsConn.Conn).Elem()
 				p = uintptr(unsafe.Pointer(utlsConn.Conn))
 			} else if realityConn, ok := iConn.(*reality.UConn); ok {
-				netConn = realityConn.NetConn()
 				t = reflect.TypeOf(realityConn.Conn).Elem()
 				p = uintptr(unsafe.Pointer(realityConn.Conn))
 			} else {
 				return newError("XTLS only supports TLS and REALITY directly for now.").AtWarning()
 			}
-			if sc, ok := netConn.(syscall.Conn); ok {
-				rawConn, _ = sc.SyscallConn()
-			}
 			i, _ := t.FieldByName("input")
 			r, _ := t.FieldByName("rawInput")
 			input = (*bytes.Reader)(unsafe.Pointer(p + i.Offset))
 			rawInput = (*bytes.Buffer)(unsafe.Pointer(p + r.Offset))
 		}
+	default:
+		if inbound != nil {
+			inbound.SetCanSpliceCopy(3)
+		}
 	}
 
 	var newCtx context.Context
@@ -257,11 +253,8 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 					return newError(`failed to use `+requestAddons.Flow+`, found outer tls version `, utlsConn.ConnectionState().Version).AtWarning()
 				}
 			}
-			var counter stats.Counter
-			if statConn != nil {
-				counter = statConn.WriteCounter
-			}
-			err = encoding.XtlsWrite(clientReader, serverWriter, timer, netConn, counter, ctx, &numberOfPacketToFilter,
+			ctx1 := session.ContextWithOutbound(ctx, nil) // TODO enable splice
+			err = encoding.XtlsWrite(clientReader, serverWriter, timer, conn, ctx1, &numberOfPacketToFilter,
 				&enableXtls, &isTLS12orAbove, &isTLS, &cipher, &remainingServerHello)
 		} else {
 			// from clientReader.ReadMultiBuffer to serverWriter.WriteMultiBufer
@@ -293,11 +286,7 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 		}
 
 		if requestAddons.Flow == vless.XRV {
-			var counter stats.Counter
-			if statConn != nil {
-				counter = statConn.ReadCounter
-			}
-			err = encoding.XtlsRead(serverReader, clientWriter, timer, netConn, rawConn, input, rawInput, counter, ctx, account.ID.Bytes(),
+			err = encoding.XtlsRead(serverReader, clientWriter, timer, conn, input, rawInput, ctx, account.ID.Bytes(),
 				&numberOfPacketToFilter, &enableXtls, &isTLS12orAbove, &isTLS, &cipher, &remainingServerHello)
 		} else {
 			// from serverReader.ReadMultiBuffer to clientWriter.WriteMultiBufer