Fix processing domain address in packet

transport/fakeip/packet.go

@@ -17,22 +17,30 @@ type NATPacketConn struct {
 func NewNATPacketConn(conn N.PacketConn, origin M.Socksaddr, destination M.Socksaddr) *NATPacketConn {
 	return &NATPacketConn{
 		PacketConn:  conn,
-		origin:      origin,
-		destination: destination,
+		origin:      socksaddrWithoutPort(origin),
+		destination: socksaddrWithoutPort(destination),
 	}
 }
 
 func (c *NATPacketConn) ReadPacket(buffer *buf.Buffer) (destination M.Socksaddr, err error) {
 	destination, err = c.PacketConn.ReadPacket(buffer)
-	if destination == c.origin {
-		destination = c.destination
+	if socksaddrWithoutPort(destination) == c.origin {
+		destination = M.Socksaddr{
+			Addr: c.destination.Addr,
+			Fqdn: c.destination.Fqdn,
+			Port: destination.Port,
+		}
 	}
 	return
 }
 
 func (c *NATPacketConn) WritePacket(buffer *buf.Buffer, destination M.Socksaddr) error {
-	if destination == c.destination {
-		destination = c.origin
+	if socksaddrWithoutPort(destination) == c.destination {
+		destination = M.Socksaddr{
+			Addr: c.origin.Addr,
+			Fqdn: c.origin.Fqdn,
+			Port: destination.Port,
+		}
 	}
 	return c.PacketConn.WritePacket(buffer, destination)
 }
@@ -40,3 +48,8 @@ func (c *NATPacketConn) WritePacket(buffer *buf.Buffer, destination M.Socksaddr)
 func (c *NATPacketConn) Upstream() any {
 	return c.PacketConn
 }
+
+func socksaddrWithoutPort(destination M.Socksaddr) M.Socksaddr {
+	destination.Port = 0
+	return destination
+}

transport/hysteria/protocol.go

@@ -498,7 +498,12 @@ func (c *PacketConn) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
 		return
 	}
 	n = copy(p, msg.Data)
-	addr = M.ParseSocksaddrHostPort(msg.Host, msg.Port).UDPAddr()
+	destination := M.ParseSocksaddrHostPort(msg.Host, msg.Port)
+	if destination.IsFqdn() {
+		addr = destination
+	} else {
+		addr = destination.UDPAddr()
+	}
 	return
 }
 

transport/trojan/protocol.go

@@ -131,7 +131,11 @@ func (c *ClientPacketConn) ReadFrom(p []byte) (n int, addr net.Addr, err error)
 		return
 	}
 	n = buffer.Len()
-	addr = destination.UDPAddr()
+	if destination.IsFqdn() {
+		addr = destination
+	} else {
+		addr = destination.UDPAddr()
+	}
 	return
 }
 

transport/vless/client.go

@@ -198,7 +198,11 @@ func (c *PacketConn) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
 	if err != nil {
 		return
 	}
-	addr = c.destination.UDPAddr()
+	if c.destination.IsFqdn() {
+		addr = c.destination
+	} else {
+		addr = c.destination.UDPAddr()
+	}
 	return
 }
 

transport/vless/service.go

@@ -147,7 +147,11 @@ func (c *serverPacketConn) ReadFrom(p []byte) (n int, addr net.Addr, err error)
 	if err != nil {
 		return
 	}
-	addr = c.destination.UDPAddr()
+	if c.destination.IsFqdn() {
+		addr = c.destination
+	} else {
+		addr = c.destination.UDPAddr()
+	}
 	return
 }