package shadowsocks import ( "context" "v2ray.com/core" "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/session" "v2ray.com/core/common/signal" "v2ray.com/core/common/task" "v2ray.com/core/features/policy" "v2ray.com/core/transport" "v2ray.com/core/transport/internet" ) // Client is a inbound handler for Shadowsocks protocol type Client struct { serverPicker protocol.ServerPicker policyManager policy.Manager } // NewClient create a new Shadowsocks client. 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 parse server spec").Base(err) } serverList.AddServer(s) } if serverList.Size() == 0 { return nil, newError("0 server") } v := core.MustFromContext(ctx) client := &Client{ serverPicker: protocol.NewRoundRobinServerPicker(serverList), policyManager: v.GetFeature(policy.ManagerType()).(policy.Manager), } return client, nil } // Process implements OutboundHandler.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 := outbound.Target network := destination.Network var server *protocol.ServerSpec var conn internet.Connection err := retry.ExponentialBackoff(5, 100).On(func() error { server = c.serverPicker.PickServer() dest := server.Destination() dest.Network = network 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").AtWarning().Base(err) } newError("tunneling request to ", destination, " via ", server.Destination()).WriteToLog(session.ExportIDToError(ctx)) defer conn.Close() request := &protocol.RequestHeader{ Version: Version, Address: destination.Address, Port: destination.Port, } if destination.Network == net.Network_TCP { request.Command = protocol.RequestCommandTCP } else { request.Command = protocol.RequestCommandUDP } user := server.PickUser() account, ok := user.Account.(*MemoryAccount) if !ok { return newError("user account is not valid") } request.User = user if account.OneTimeAuth == Account_Auto || account.OneTimeAuth == Account_Enabled { request.Option |= RequestOptionOneTimeAuth } sessionPolicy := c.policyManager.ForLevel(user.Level) ctx, cancel := context.WithCancel(ctx) timer := signal.CancelAfterInactivity(ctx, cancel, sessionPolicy.Timeouts.ConnectionIdle) if request.Command == protocol.RequestCommandTCP { bufferedWriter := buf.NewBufferedWriter(buf.NewWriter(conn)) bodyWriter, err := WriteTCPRequest(request, bufferedWriter) if err != nil { return newError("failed to write request").Base(err) } if err := bufferedWriter.SetBuffered(false); err != nil { return err } requestDone := func() error { defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly) return buf.Copy(link.Reader, bodyWriter, buf.UpdateActivity(timer)) } responseDone := func() error { defer timer.SetTimeout(sessionPolicy.Timeouts.UplinkOnly) responseReader, err := ReadTCPResponse(user, conn) if err != nil { return err } return buf.Copy(responseReader, link.Writer, buf.UpdateActivity(timer)) } var responseDoneAndCloseWriter = task.Single(responseDone, task.OnSuccess(task.Close(link.Writer))) if err := task.Run(task.WithContext(ctx), task.Parallel(requestDone, responseDoneAndCloseWriter))(); err != nil { return newError("connection ends").Base(err) } return nil } if request.Command == protocol.RequestCommandUDP { writer := &buf.SequentialWriter{Writer: &UDPWriter{ Writer: conn, Request: request, }} requestDone := func() error { defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly) if err := buf.Copy(link.Reader, writer, buf.UpdateActivity(timer)); err != nil { return newError("failed to transport all UDP request").Base(err) } return nil } responseDone := func() error { defer timer.SetTimeout(sessionPolicy.Timeouts.UplinkOnly) reader := &UDPReader{ Reader: conn, User: user, } if err := buf.Copy(reader, link.Writer, buf.UpdateActivity(timer)); err != nil { return newError("failed to transport all UDP response").Base(err) } return nil } var responseDoneAndCloseWriter = task.Single(responseDone, task.OnSuccess(task.Close(link.Writer))) if err := task.Run(task.WithContext(ctx), task.Parallel(requestDone, responseDoneAndCloseWriter))(); err != nil { return newError("connection ends").Base(err) } return nil } return nil } func init() { common.Must(common.RegisterConfig((*ClientConfig)(nil), func(ctx context.Context, config interface{}) (interface{}, error) { return NewClient(ctx, config.(*ClientConfig)) })) }