feat: Integrate UoT support in inbound and outbound handling

protocol/mysql/outbound.go

@@ -14,11 +14,11 @@ import (
 	"github.com/sagernet/sing-box/log"
 	"github.com/sagernet/sing-box/option"
 	"github.com/sagernet/sing/common"
-	"github.com/sagernet/sing/common/bufio"
 	E "github.com/sagernet/sing/common/exceptions"
 	"github.com/sagernet/sing/common/logger"
 	M "github.com/sagernet/sing/common/metadata"
 	N "github.com/sagernet/sing/common/network"
+	"github.com/sagernet/sing/common/uot"
 	"github.com/sagernet/smux"
 
 	"github.com/go-mysql-org/go-mysql/client"
@@ -51,6 +51,13 @@ type muxSession struct {
 	conn    net.Conn
 }
 
+func closeMuxSession(entry *muxSession) {
+	if entry == nil {
+		return
+	}
+	_ = common.Close(entry.session, entry.conn)
+}
+
 func NewOutbound(ctx context.Context, router adapter.Router, logger log.ContextLogger, tag string, options option.MySQLOutboundOptions) (adapter.Outbound, error) {
 	outboundDialer, err := dialer.New(ctx, options.DialerOptions, options.ServerIsDomain())
 	if err != nil {
@@ -153,7 +160,7 @@ func (h *Outbound) getSession(index int) (*smux.Session, error) {
 		return entry.session, nil
 	}
 	if entry != nil {
-		entry.conn.Close()
+		closeMuxSession(entry)
 		h.sessions[index] = nil
 	}
 
@@ -171,7 +178,7 @@ func (h *Outbound) getSession(index int) (*smux.Session, error) {
 			h.sessions[index] = nil
 		}
 		h.sessionAccess.Unlock()
-		conn.Close()
+		_ = common.Close(session, conn)
 	}(index, entry.session, entry.conn)
 
 	return entry.session, nil
@@ -183,7 +190,7 @@ func (h *Outbound) invalidateSession(index int, session *smux.Session) {
 
 	if current := h.sessions[index]; current != nil && current.session == session {
 		h.sessions[index] = nil
-		current.conn.Close()
+		closeMuxSession(current)
 	}
 }
 
@@ -234,24 +241,30 @@ func (h *Outbound) DialContext(ctx context.Context, network string, destination
 		h.logger.InfoContext(ctx, "outbound connection to ", destination)
 		return h.openStream(ctx, commandTCP, destination)
 	case N.NetworkUDP:
-		h.logger.InfoContext(ctx, "outbound packet connection to ", destination)
-		conn, err := h.openStream(ctx, commandUDP, destination)
+		h.logger.InfoContext(ctx, "outbound UoT packet connection to ", destination)
+		conn, err := h.openStream(ctx, commandUDP, uot.RequestDestination(uot.Version))
 		if err != nil {
 			return nil, err
 		}
-		return bufio.NewBindPacketConn(&packetConn{conn}, destination), nil
+		return uot.NewLazyConn(conn, uot.Request{
+			IsConnect:   true,
+			Destination: destination,
+		}), nil
 	default:
 		return nil, E.New("unsupported network: ", network)
 	}
 }
 
 func (h *Outbound) ListenPacket(ctx context.Context, destination M.Socksaddr) (net.PacketConn, error) {
-	h.logger.InfoContext(ctx, "outbound packet connection to ", destination)
-	conn, err := h.openStream(ctx, commandUDP, destination)
+	h.logger.InfoContext(ctx, "outbound UoT packet connection to ", destination)
+	conn, err := h.openStream(ctx, commandUDP, uot.RequestDestination(uot.Version))
 	if err != nil {
 		return nil, err
 	}
-	return &packetConn{conn}, nil
+	return uot.NewLazyConn(conn, uot.Request{
+		IsConnect:   false,
+		Destination: destination,
+	}), nil
 }
 
 func (h *Outbound) InterfaceUpdated() {
@@ -280,17 +293,3 @@ func (h *Outbound) Close() error {
 	}
 	return err
 }
-
-// packetConn wraps a net.Conn as a net.PacketConn for UDP-over-TCP
-type packetConn struct {
-	net.Conn
-}
-
-func (c *packetConn) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
-	n, err = c.Conn.Read(p)
-	return
-}
-
-func (c *packetConn) WriteTo(p []byte, addr net.Addr) (n int, err error) {
-	return c.Conn.Write(p)
-}