package trojan import ( "context" core "github.com/v2fly/v2ray-core/v5" "github.com/v2fly/v2ray-core/v5/common" "github.com/v2fly/v2ray-core/v5/common/buf" "github.com/v2fly/v2ray-core/v5/common/net" "github.com/v2fly/v2ray-core/v5/common/net/packetaddr" "github.com/v2fly/v2ray-core/v5/common/protocol" "github.com/v2fly/v2ray-core/v5/common/retry" "github.com/v2fly/v2ray-core/v5/common/session" "github.com/v2fly/v2ray-core/v5/common/signal" "github.com/v2fly/v2ray-core/v5/common/task" "github.com/v2fly/v2ray-core/v5/features/policy" "github.com/v2fly/v2ray-core/v5/proxy" "github.com/v2fly/v2ray-core/v5/transport" "github.com/v2fly/v2ray-core/v5/transport/internet" "github.com/v2fly/v2ray-core/v5/transport/internet/udp" ) // Client is an 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 internet.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() user := server.PickUser() account, ok := user.Account.(*MemoryAccount) if !ok { return newError("user account is not valid") } sessionPolicy := c.policyManager.ForLevel(user.Level) ctx, cancel := context.WithCancel(ctx) timer := signal.CancelAfterInactivity(ctx, cancel, sessionPolicy.Timeouts.ConnectionIdle) if packetConn, err := packetaddr.ToPacketAddrConn(link, destination); err == nil { postRequest := func() error { defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly) var buffer [2048]byte n, addr, err := packetConn.ReadFrom(buffer[:]) if err != nil { return newError("failed to read a packet").Base(err) } dest := net.DestinationFromAddr(addr) bufferWriter := buf.NewBufferedWriter(buf.NewWriter(conn)) connWriter := &ConnWriter{Writer: bufferWriter, Target: dest, Account: account} packetWriter := &PacketWriter{Writer: connWriter, Target: dest} // write some request payload to buffer if _, err := packetWriter.WriteTo(buffer[:n], addr); err != nil { return newError("failed to write a request payload").Base(err) } // Flush; bufferWriter.WriteMultiBuffer now is bufferWriter.writer.WriteMultiBuffer if err = bufferWriter.SetBuffered(false); err != nil { return newError("failed to flush payload").Base(err).AtWarning() } return udp.CopyPacketConn(packetWriter, packetConn, udp.UpdateActivity(timer)) } getResponse := func() error { defer timer.SetTimeout(sessionPolicy.Timeouts.UplinkOnly) packetReader := &PacketReader{Reader: conn} packetConnectionReader := &PacketConnectionReader{reader: packetReader} return udp.CopyPacketConn(packetConn, packetConnectionReader, udp.UpdateActivity(timer)) } 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 } postRequest := func() error { defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly) var bodyWriter buf.Writer bufferWriter := buf.NewBufferedWriter(buf.NewWriter(conn)) connWriter := &ConnWriter{Writer: bufferWriter, Target: destination, Account: account} if destination.Network == net.Network_UDP { bodyWriter = &PacketWriter{Writer: connWriter, Target: destination} } else { bodyWriter = connWriter } // write some request payload to buffer err = buf.CopyOnceTimeout(link.Reader, bodyWriter, proxy.FirstPayloadTimeout) switch err { case buf.ErrNotTimeoutReader, buf.ErrReadTimeout: if err := connWriter.WriteHeader(); err != nil { return newError("failed to write request header").Base(err).AtWarning() } case nil: default: return newError("failed to write a request payload").Base(err).AtWarning() } // Flush; bufferWriter.WriteMultiBuffer now is bufferWriter.writer.WriteMultiBuffer if err = bufferWriter.SetBuffered(false); err != nil { return newError("failed to flush payload").Base(err).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)) } 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)) })) }