fix transparent proxy

listener/ftcp/metadata.go

@@ -8,7 +8,7 @@ import (
 
 const (
 	defaultTTL            = 60 * time.Second
-	defaultReadBufferSize = 1024
+	defaultReadBufferSize = 1500
 	defaultReadQueueSize  = 128
 	defaultBacklog        = 128
 )

listener/redirect/tcp/listener.go

@@ -0,0 +1,66 @@
+package tcp
+
+import (
+	"context"
+	"net"
+
+	"github.com/go-gost/core/listener"
+	"github.com/go-gost/core/logger"
+	md "github.com/go-gost/core/metadata"
+	metrics "github.com/go-gost/core/metrics/wrapper"
+	"github.com/go-gost/core/registry"
+)
+
+func init() {
+	registry.ListenerRegistry().Register("red", NewListener)
+	registry.ListenerRegistry().Register("redir", NewListener)
+	registry.ListenerRegistry().Register("redirect", NewListener)
+}
+
+type redirectListener struct {
+	ln      net.Listener
+	logger  logger.Logger
+	md      metadata
+	options listener.Options
+}
+
+func NewListener(opts ...listener.Option) listener.Listener {
+	options := listener.Options{}
+	for _, opt := range opts {
+		opt(&options)
+	}
+	return &redirectListener{
+		logger:  options.Logger,
+		options: options,
+	}
+}
+
+func (l *redirectListener) Init(md md.Metadata) (err error) {
+	if err = l.parseMetadata(md); err != nil {
+		return
+	}
+
+	lc := net.ListenConfig{}
+	if l.md.tproxy {
+		lc.Control = l.control
+	}
+	ln, err := lc.Listen(context.Background(), "tcp", l.options.Addr)
+	if err != nil {
+		return err
+	}
+
+	l.ln = metrics.WrapListener(l.options.Service, ln)
+	return
+}
+
+func (l *redirectListener) Accept() (conn net.Conn, err error) {
+	return l.ln.Accept()
+}
+
+func (l *redirectListener) Addr() net.Addr {
+	return l.ln.Addr()
+}
+
+func (l *redirectListener) Close() error {
+	return l.ln.Close()
+}

listener/redirect/tcp/listener_linux.go

@@ -0,0 +1,15 @@
+package tcp
+
+import (
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+func (l *redirectListener) control(network, address string, c syscall.RawConn) error {
+	return c.Control(func(fd uintptr) {
+		if err := unix.SetsockoptInt(int(fd), unix.SOL_IP, unix.IP_TRANSPARENT, 1); err != nil {
+			l.logger.Errorf("set sockopt: %v", err)
+		}
+	})
+}

listener/redirect/tcp/listener_other.go

@@ -0,0 +1,12 @@
+//go:build !linux
+
+package tcp
+
+import (
+	"errors"
+	"syscall"
+)
+
+func (l *redirectListener) control(network, address string, c syscall.RawConn) error {
+	return errors.New("TProxy is not available on non-linux platform")
+}

listener/redirect/tcp/metadata.go

@@ -0,0 +1,17 @@
+package tcp
+
+import (
+	mdata "github.com/go-gost/core/metadata"
+)
+
+type metadata struct {
+	tproxy bool
+}
+
+func (l *redirectListener) parseMetadata(md mdata.Metadata) (err error) {
+	const (
+		tproxy = "tproxy"
+	)
+	l.md.tproxy = mdata.GetBool(md, tproxy)
+	return
+}

listener/redirect/udp/metadata.go

@@ -8,7 +8,7 @@ import (
 
 const (
 	defaultTTL            = 60 * time.Second
-	defaultReadBufferSize = 1024
+	defaultReadBufferSize = 1500
 )
 
 type metadata struct {