package trojan import ( "context" "time" "github.com/xtls/xray-core/common" "github.com/xtls/xray-core/common/buf" "github.com/xtls/xray-core/common/errors" "github.com/xtls/xray-core/common/net" "github.com/xtls/xray-core/common/protocol" "github.com/xtls/xray-core/common/retry" "github.com/xtls/xray-core/common/session" "github.com/xtls/xray-core/common/signal" "github.com/xtls/xray-core/common/task" core "github.com/xtls/xray-core/core" "github.com/xtls/xray-core/features/policy" "github.com/xtls/xray-core/transport" "github.com/xtls/xray-core/transport/internet" "github.com/xtls/xray-core/transport/internet/stat" ) // Client is a inbound handler for trojan protocol type Client struct { serverPicker protocol.ServerPicker policyManager policy.Manager } // NewClient create a new trojan 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 stat.Connection err := retry.ExponentialBackoff(5, 100).On(func() error { server = c.serverPicker.PickServer() rawConn, err := dialer.Dial(ctx, server.Destination()) 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().NetAddr()).WriteToLog(session.ExportIDToError(ctx)) defer conn.Close() iConn := conn statConn, ok := iConn.(*stat.CounterConnection) if ok { iConn = statConn.Connection } user := server.PickUser() account, ok := user.Account.(*MemoryAccount) if !ok { return newError("user account is not valid") } connWriter := &ConnWriter{ Flow: account.Flow, } var newCtx context.Context var newCancel context.CancelFunc if session.TimeoutOnlyFromContext(ctx) { newCtx, newCancel = context.WithCancel(context.Background()) } sessionPolicy := c.policyManager.ForLevel(user.Level) ctx, cancel := context.WithCancel(ctx) timer := signal.CancelAfterInactivity(ctx, func() { cancel() if newCancel != nil { newCancel() } }, sessionPolicy.Timeouts.ConnectionIdle) postRequest := func() error { defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly) bufferWriter := buf.NewBufferedWriter(buf.NewWriter(conn)) connWriter.Writer = bufferWriter connWriter.Target = destination connWriter.Account = account var bodyWriter buf.Writer if destination.Network == net.Network_UDP { bodyWriter = &PacketWriter{Writer: connWriter, Target: destination} } else { bodyWriter = connWriter } // write some request payload to buffer if err = buf.CopyOnceTimeout(link.Reader, bodyWriter, time.Millisecond*100); err != nil && err != buf.ErrNotTimeoutReader && err != buf.ErrReadTimeout { return newError("failed to write A request payload").Base(err).AtWarning() } // Flush; bufferWriter.WriteMultiBufer now is bufferWriter.writer.WriteMultiBuffer if err = bufferWriter.SetBuffered(false); err != nil { return newError("failed to flush payload").Base(err).AtWarning() } // Send header if not sent yet if _, err = connWriter.Write([]byte{}); err != nil { return err.(*errors.Error).AtWarning() } if err = buf.Copy(link.Reader, bodyWriter, buf.UpdateActivity(timer)); err != nil { return newError("failed to transfer request payload").Base(err).AtInfo() } return nil } getResponse := func() error { defer timer.SetTimeout(sessionPolicy.Timeouts.UplinkOnly) var reader buf.Reader if network == net.Network_UDP { reader = &PacketReader{ Reader: conn, } } else { reader = buf.NewReader(conn) } return buf.Copy(reader, link.Writer, buf.UpdateActivity(timer)) } if newCtx != nil { ctx = newCtx } responseDoneAndCloseWriter := task.OnSuccess(getResponse, task.Close(link.Writer)) if err := task.Run(ctx, postRequest, responseDoneAndCloseWriter); 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)) })) }