fix: let quic-go works on outbound's packetConn

adapter/outbound/base.go

@@ -210,6 +210,8 @@ func NewConn(c net.Conn, a C.ProxyAdapter) C.Conn {
 type packetConn struct {
 	net.PacketConn
 	chain                   C.Chain
+	adapterName             string
+	connID                  string
 	actualRemoteDestination string
 }
 
@@ -227,8 +229,14 @@ func (c *packetConn) AppendToChains(a C.ProxyAdapter) {
 	c.chain = append(c.chain, a.Name())
 }
 
+func (c *packetConn) LocalAddr() net.Addr {
+	lAddr := c.PacketConn.LocalAddr()
+	return N.NewCustomAddr(c.adapterName, c.connID, lAddr) // make quic-go's connMultiplexer happy
+}
+
 func newPacketConn(pc net.PacketConn, a C.ProxyAdapter) C.PacketConn {
-	return &packetConn{pc, []string{a.Name()}, parseRemoteDestination(a.Addr())}
+	id, _ := utils.UnsafeUUIDGenerator.NewV4()
+	return &packetConn{pc, []string{a.Name()}, a.Name(), id.String(), parseRemoteDestination(a.Addr())}
 }
 
 func parseRemoteDestination(addr string) string {