v1.0.0

proxy/trojan/client.go

@@ -0,0 +1,212 @@
+// +build !confonly
+
+package trojan
+
+import (
+	"context"
+	"syscall"
+	"time"
+
+	"github.com/xtls/xray-core/v1/common"
+	"github.com/xtls/xray-core/v1/common/buf"
+	"github.com/xtls/xray-core/v1/common/net"
+	"github.com/xtls/xray-core/v1/common/platform"
+	"github.com/xtls/xray-core/v1/common/protocol"
+	"github.com/xtls/xray-core/v1/common/retry"
+	"github.com/xtls/xray-core/v1/common/session"
+	"github.com/xtls/xray-core/v1/common/signal"
+	"github.com/xtls/xray-core/v1/common/task"
+	core "github.com/xtls/xray-core/v1/core"
+	"github.com/xtls/xray-core/v1/features/policy"
+	"github.com/xtls/xray-core/v1/features/stats"
+	"github.com/xtls/xray-core/v1/transport"
+	"github.com/xtls/xray-core/v1/transport/internet"
+	"github.com/xtls/xray-core/v1/transport/internet/xtls"
+)
+
+// 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 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()).WriteToLog(session.ExportIDToError(ctx))
+
+	defer conn.Close()
+
+	user := server.PickUser()
+	account, ok := user.Account.(*MemoryAccount)
+	if !ok {
+		return newError("user account is not valid")
+	}
+
+	iConn := conn
+	statConn, ok := iConn.(*internet.StatCouterConnection)
+	if ok {
+		iConn = statConn.Connection
+	}
+
+	var rawConn syscall.RawConn
+
+	connWriter := &ConnWriter{}
+	allowUDP443 := false
+	switch account.Flow {
+	case XRO + "-udp443", XRD + "-udp443":
+		allowUDP443 = true
+		account.Flow = account.Flow[:16]
+		fallthrough
+	case XRO, XRD:
+		if destination.Address.Family().IsDomain() && destination.Address.Domain() == muxCoolAddress {
+			return newError(account.Flow + " doesn't support Mux").AtWarning()
+		}
+		if destination.Network == net.Network_UDP {
+			if !allowUDP443 && destination.Port == 443 {
+				return newError(account.Flow + " stopped UDP/443").AtInfo()
+			}
+		} else { // enable XTLS only if making TCP request
+			if xtlsConn, ok := iConn.(*xtls.Conn); ok {
+				xtlsConn.RPRX = true
+				xtlsConn.SHOW = trojanXTLSShow
+				connWriter.Flow = account.Flow
+				if account.Flow == XRD {
+					xtlsConn.DirectMode = true
+				}
+				if sc, ok := xtlsConn.Connection.(syscall.Conn); ok {
+					rawConn, _ = sc.SyscallConn()
+				}
+			} else {
+				return newError(`failed to use ` + account.Flow + `, maybe "security" is not "xtls"`).AtWarning()
+			}
+		}
+	case "":
+		if _, ok := iConn.(*xtls.Conn); ok {
+			panic(`To avoid misunderstanding, you must fill in Trojan "flow" when using XTLS.`)
+		}
+	default:
+		return newError("unsupported flow " + account.Flow).AtWarning()
+	}
+
+	sessionPolicy := c.policyManager.ForLevel(user.Level)
+	ctx, cancel := context.WithCancel(ctx)
+	timer := signal.CancelAfterInactivity(ctx, cancel, sessionPolicy.Timeouts.ConnectionIdle)
+
+	postRequest := func() error {
+		defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly)
+
+		var bodyWriter buf.Writer
+		bufferWriter := buf.NewBufferedWriter(buf.NewWriter(conn))
+		connWriter.Writer = bufferWriter
+		connWriter.Target = destination
+		connWriter.Account = account
+
+		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()
+		}
+
+		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)
+		}
+		if rawConn != nil {
+			var counter stats.Counter
+			if statConn != nil {
+				counter = statConn.ReadCounter
+			}
+			return ReadV(reader, link.Writer, timer, iConn.(*xtls.Conn), rawConn, counter)
+		}
+		return buf.Copy(reader, link.Writer, buf.UpdateActivity(timer))
+	}
+
+	var 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))
+	}))
+
+	const defaultFlagValue = "NOT_DEFINED_AT_ALL"
+
+	xtlsShow := platform.NewEnvFlag("xray.trojan.xtls.show").GetValue(func() string { return defaultFlagValue })
+	if xtlsShow == "true" {
+		trojanXTLSShow = true
+	}
+}