package socks import ( "context" "runtime" "time" "v2ray.com/core/common" "v2ray.com/core/common/buf" "v2ray.com/core/common/net" "v2ray.com/core/common/protocol" "v2ray.com/core/common/retry" "v2ray.com/core/common/signal" "v2ray.com/core/proxy" "v2ray.com/core/transport/internet" "v2ray.com/core/transport/ray" ) // Client is a Socks5 client. type Client struct { serverPicker protocol.ServerPicker } // NewClient create a new Socks5 client based on the given config. func NewClient(ctx context.Context, config *ClientConfig) (*Client, error) { serverList := protocol.NewServerList() for _, rec := range config.Server { serverList.AddServer(protocol.NewServerSpecFromPB(*rec)) } if serverList.Size() == 0 { return nil, newError("0 target server") } return &Client{ serverPicker: protocol.NewRoundRobinServerPicker(serverList), }, nil } // Process implements proxy.Outbound.Process. func (c *Client) Process(ctx context.Context, ray ray.OutboundRay, dialer proxy.Dialer) error { destination, ok := proxy.TargetFromContext(ctx) if !ok { return newError("target not specified.") } var server *protocol.ServerSpec var conn internet.Connection err := retry.ExponentialBackoff(5, 100).On(func() error { server = c.serverPicker.PickServer() dest := server.Destination() rawConn, err := dialer.Dial(ctx, dest) if err != nil { return err } conn = rawConn return nil }) if err != nil { return newError("failed to find an available destination").Base(err) } defer conn.Close() request := &protocol.RequestHeader{ Version: socks5Version, Command: protocol.RequestCommandTCP, Address: destination.Address, Port: destination.Port, } if destination.Network == net.Network_UDP { request.Command = protocol.RequestCommandUDP } user := server.PickUser() if user != nil { request.User = user } udpRequest, err := ClientHandshake(request, conn, conn) if err != nil { return newError("failed to establish connection to server").AtWarning().Base(err) } ctx, timer := signal.CancelAfterInactivity(ctx, time.Minute*5) var requestFunc func() error var responseFunc func() error if request.Command == protocol.RequestCommandTCP { requestFunc = func() error { return buf.Copy(ray.OutboundInput(), buf.NewWriter(conn), buf.UpdateActivity(timer)) } responseFunc = func() error { defer ray.OutboundOutput().Close() return buf.Copy(buf.NewReader(conn), ray.OutboundOutput(), buf.UpdateActivity(timer)) } } else if request.Command == protocol.RequestCommandUDP { udpConn, err := dialer.Dial(ctx, udpRequest.Destination()) if err != nil { return newError("failed to create UDP connection").Base(err) } defer udpConn.Close() requestFunc = func() error { return buf.Copy(ray.OutboundInput(), buf.NewSequentialWriter(NewUDPWriter(request, udpConn)), buf.UpdateActivity(timer)) } responseFunc = func() error { defer ray.OutboundOutput().Close() reader := &UDPReader{reader: udpConn} return buf.Copy(reader, ray.OutboundOutput(), buf.UpdateActivity(timer)) } } requestDone := signal.ExecuteAsync(requestFunc) responseDone := signal.ExecuteAsync(responseFunc) if err := signal.ErrorOrFinish2(ctx, requestDone, responseDone); err != nil { return newError("connection ends").Base(err) } runtime.KeepAlive(timer) return nil } func init() { common.Must(common.RegisterConfig((*ClientConfig)(nil), func(ctx context.Context, config interface{}) (interface{}, error) { return NewClient(ctx, config.(*ClientConfig)) })) }