package socks import ( "context" "time" core "github.com/v2fly/v2ray-core/v4" "github.com/v2fly/v2ray-core/v4/common" "github.com/v2fly/v2ray-core/v4/common/buf" "github.com/v2fly/v2ray-core/v4/common/net" "github.com/v2fly/v2ray-core/v4/common/protocol" "github.com/v2fly/v2ray-core/v4/common/retry" "github.com/v2fly/v2ray-core/v4/common/session" "github.com/v2fly/v2ray-core/v4/common/signal" "github.com/v2fly/v2ray-core/v4/common/task" "github.com/v2fly/v2ray-core/v4/features/policy" "github.com/v2fly/v2ray-core/v4/transport" "github.com/v2fly/v2ray-core/v4/transport/internet" ) // Client is a Socks5 client. type Client struct { serverPicker protocol.ServerPicker policyManager policy.Manager } // 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 { s, err := protocol.NewServerSpecFromPB(rec) if err != nil { return nil, newError("failed to get server spec").Base(err) } serverList.AddServer(s) } if serverList.Size() == 0 { return nil, newError("0 target server") } v := core.MustFromContext(ctx) return &Client{ serverPicker: protocol.NewRoundRobinServerPicker(serverList), policyManager: v.GetFeature(policy.ManagerType()).(policy.Manager), }, nil } // Process implements proxy.Outbound.Process. func (c *Client) Process(ctx context.Context, link *transport.Link, dialer internet.Dialer) error { outbound := session.OutboundFromContext(ctx) if outbound == nil || !outbound.Target.IsValid() { return newError("target not specified.") } // Destination of the inner request. destination := outbound.Target // Outbound server. var server *protocol.ServerSpec // Outbound server's destination. var dest net.Destination // Connection to the outbound server. var conn internet.Connection if 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 }); err != nil { return newError("failed to find an available destination").Base(err) } defer func() { if err := conn.Close(); err != nil { newError("failed to closed connection").Base(err).WriteToLog(session.ExportIDToError(ctx)) } }() p := c.policyManager.ForLevel(0) 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 p = c.policyManager.ForLevel(user.Level) } if err := conn.SetDeadline(time.Now().Add(p.Timeouts.Handshake)); err != nil { newError("failed to set deadline for handshake").Base(err).WriteToLog(session.ExportIDToError(ctx)) } udpRequest, err := ClientHandshake(request, conn, conn) if err != nil { return newError("failed to establish connection to server").AtWarning().Base(err) } if udpRequest != nil { if udpRequest.Address == net.AnyIP || udpRequest.Address == net.AnyIPv6 { udpRequest.Address = dest.Address } } if err := conn.SetDeadline(time.Time{}); err != nil { newError("failed to clear deadline after handshake").Base(err).WriteToLog(session.ExportIDToError(ctx)) } ctx, cancel := context.WithCancel(ctx) timer := signal.CancelAfterInactivity(ctx, cancel, p.Timeouts.ConnectionIdle) var requestFunc func() error var responseFunc func() error if request.Command == protocol.RequestCommandTCP { requestFunc = func() error { defer timer.SetTimeout(p.Timeouts.DownlinkOnly) return buf.Copy(link.Reader, buf.NewWriter(conn), buf.UpdateActivity(timer)) } responseFunc = func() error { defer timer.SetTimeout(p.Timeouts.UplinkOnly) return buf.Copy(buf.NewReader(conn), link.Writer, 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 { defer timer.SetTimeout(p.Timeouts.DownlinkOnly) return buf.Copy(link.Reader, &buf.SequentialWriter{Writer: NewUDPWriter(request, udpConn)}, buf.UpdateActivity(timer)) } responseFunc = func() error { defer timer.SetTimeout(p.Timeouts.UplinkOnly) reader := &UDPReader{reader: udpConn} return buf.Copy(reader, link.Writer, buf.UpdateActivity(timer)) } } responseDonePost := task.OnSuccess(responseFunc, task.Close(link.Writer)) if err := task.Run(ctx, requestFunc, responseDonePost); err != nil { return newError("connection ends").Base(err) } return nil } func init() { common.Must(common.RegisterConfig((*ClientConfig)(nil), func(ctx context.Context, config interface{}) (interface{}, error) { return NewClient(ctx, config.(*ClientConfig)) })) }