Init commit

common/tunnel/copy.go

@@ -0,0 +1,37 @@
+package tunnel
+
+import (
+	"context"
+	"net"
+	"runtime"
+	"time"
+
+	"github.com/sagernet/sing/common"
+	"github.com/sagernet/sing/common/buf"
+	"github.com/sagernet/sing/common/bufio"
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+func CopyEarlyConn(ctx context.Context, conn net.Conn, serverConn net.Conn) error {
+	_payload := buf.StackNew()
+	payload := common.Dup(_payload)
+	err := conn.SetReadDeadline(time.Now().Add(100 * time.Millisecond))
+	if err != nil {
+		return err
+	}
+	_, err = payload.ReadFrom(conn)
+	if err != nil && !E.IsTimeout(err) {
+		return E.Cause(err, "read payload")
+	}
+	err = conn.SetReadDeadline(time.Time{})
+	if err != nil {
+		payload.Release()
+		return err
+	}
+	_, err = serverConn.Write(payload.Bytes())
+	if err != nil {
+		return E.Cause(err, "client handshake")
+	}
+	runtime.KeepAlive(_payload)
+	return bufio.CopyConn(ctx, conn, serverConn)
+}