package socks import ( "v2ray.com/core/common/alloc" "v2ray.com/core/common/log" v2net "v2ray.com/core/common/net" "v2ray.com/core/proxy" "v2ray.com/core/proxy/socks/protocol" "v2ray.com/core/transport/internet/udp" ) func (this *Server) listenUDP() error { this.udpServer = udp.NewUDPServer(this.packetDispatcher) udpHub, err := udp.ListenUDP(this.meta.Address, this.meta.Port, udp.ListenOption{Callback: this.handleUDPPayload}) if err != nil { log.Error("Socks: Failed to listen on udp ", this.meta.Address, ":", this.meta.Port) return err } this.udpMutex.Lock() this.udpAddress = v2net.UDPDestination(this.config.GetNetAddress(), this.meta.Port) this.udpHub = udpHub this.udpMutex.Unlock() return nil } func (this *Server) handleUDPPayload(payload *alloc.Buffer, session *proxy.SessionInfo) { source := session.Source log.Info("Socks: Client UDP connection from ", source) request, err := protocol.ReadUDPRequest(payload.Value) payload.Release() if err != nil { log.Error("Socks: Failed to parse UDP request: ", err) return } if request.Data.Len() == 0 { request.Data.Release() return } if request.Fragment != 0 { log.Warning("Socks: Dropping fragmented UDP packets.") // TODO handle fragments request.Data.Release() return } log.Info("Socks: Send packet to ", request.Destination(), " with ", request.Data.Len(), " bytes") log.Access(source, request.Destination, log.AccessAccepted, "") this.udpServer.Dispatch(&proxy.SessionInfo{Source: source, Destination: request.Destination(), Inbound: this.meta}, request.Data, func(destination v2net.Destination, payload *alloc.Buffer) { response := &protocol.Socks5UDPRequest{ Fragment: 0, Address: request.Destination().Address, Port: request.Destination().Port, Data: payload, } log.Info("Socks: Writing back UDP response with ", payload.Len(), " bytes to ", destination) udpMessage := alloc.NewLocalBuffer(2048).Clear() response.Write(udpMessage) this.udpMutex.RLock() if !this.accepting { this.udpMutex.RUnlock() return } nBytes, err := this.udpHub.WriteTo(udpMessage.Value, destination) this.udpMutex.RUnlock() udpMessage.Release() response.Data.Release() if err != nil { log.Error("Socks: failed to write UDP message (", nBytes, " bytes) to ", destination, ": ", err) } }) }