package socks import ( "net" "github.com/v2ray/v2ray-core/common/alloc" "github.com/v2ray/v2ray-core/common/log" v2net "github.com/v2ray/v2ray-core/common/net" "github.com/v2ray/v2ray-core/proxy/socks/protocol" ) const ( bufferSize = 2 * 1024 ) var udpAddress v2net.Address func (server *SocksServer) ListenUDP(port uint16) error { addr := &net.UDPAddr{ IP: net.IP{0, 0, 0, 0}, Port: int(port), Zone: "", } conn, err := net.ListenUDP("udp", addr) if err != nil { log.Error("Socks failed to listen UDP on port %d: %v", port, err) return err } // TODO: make this configurable udpAddress = v2net.IPAddress([]byte{127, 0, 0, 1}, port) go server.AcceptPackets(conn) return nil } func (server *SocksServer) getUDPAddr() v2net.Address { return udpAddress } func (server *SocksServer) AcceptPackets(conn *net.UDPConn) error { for { buffer := alloc.NewBuffer() nBytes, addr, err := conn.ReadFromUDP(buffer.Value) if err != nil { log.Error("Socks failed to read UDP packets: %v", err) buffer.Release() continue } log.Info("Client UDP connection from %v", addr) request, err := protocol.ReadUDPRequest(buffer.Value[:nBytes]) buffer.Release() if err != nil { log.Error("Socks failed to parse UDP request: %v", err) request.Data.Release() continue } if request.Fragment != 0 { log.Warning("Dropping fragmented UDP packets.") // TODO handle fragments request.Data.Release() continue } udpPacket := v2net.NewPacket(request.Destination(), request.Data, false) log.Info("Send packet to %s with %d bytes", udpPacket.Destination().String(), request.Data.Len()) go server.handlePacket(conn, udpPacket, addr, request.Address) } } func (server *SocksServer) handlePacket(conn *net.UDPConn, packet v2net.Packet, clientAddr *net.UDPAddr, targetAddr v2net.Address) { ray := server.vPoint.DispatchToOutbound(packet) close(ray.InboundInput()) if data, ok := <-ray.InboundOutput(); ok { response := &protocol.Socks5UDPRequest{ Fragment: 0, Address: targetAddr, Data: data, } log.Info("Writing back UDP response with %d bytes from %s to %s", data.Len(), targetAddr.String(), clientAddr.String()) udpMessage := alloc.NewSmallBuffer().Clear() response.Write(udpMessage) nBytes, err := conn.WriteToUDP(udpMessage.Value, clientAddr) udpMessage.Release() response.Data.Release() if err != nil { log.Error("Socks failed to write UDP message (%d bytes) to %s: %v", nBytes, clientAddr.String(), err) } } }