Xray-core/proxy/trojan/client.go
2021-10-20 00:57:14 +08:00

227 lines
6.5 KiB
Go

package trojan
import (
"context"
"syscall"
"time"
"github.com/xtls/xray-core/transport/internet/stat"
"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/platform"
"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/features/stats"
"github.com/xtls/xray-core/transport"
"github.com/xtls/xray-core/transport/internet"
"github.com/xtls/xray-core/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 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()).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 rawConn syscall.RawConn
var sctx context.Context
allowUDP443 := false
switch connWriter.Flow {
case XRO + "-udp443", XRD + "-udp443", XRS + "-udp443":
allowUDP443 = true
connWriter.Flow = connWriter.Flow[:16]
fallthrough
case XRO, XRD, XRS:
if destination.Address.Family().IsDomain() && destination.Address.Domain() == muxCoolAddress {
return newError(connWriter.Flow + " doesn't support Mux").AtWarning()
}
if destination.Network == net.Network_UDP {
if !allowUDP443 && destination.Port == 443 {
return newError(connWriter.Flow + " stopped UDP/443").AtInfo()
}
connWriter.Flow = ""
} else { // enable XTLS only if making TCP request
if xtlsConn, ok := iConn.(*xtls.Conn); ok {
xtlsConn.RPRX = true
xtlsConn.SHOW = xtls_show
xtlsConn.MARK = "XTLS"
if connWriter.Flow == XRS {
sctx = ctx
connWriter.Flow = XRD
}
if connWriter.Flow == XRD {
xtlsConn.DirectMode = true
if sc, ok := xtlsConn.Connection.(syscall.Conn); ok {
rawConn, _ = sc.SyscallConn()
}
}
} else {
return newError(`failed to use ` + connWriter.Flow + `, maybe "security" is not "xtls"`).AtWarning()
}
}
default:
if _, ok := iConn.(*xtls.Conn); ok {
panic(`To avoid misunderstanding, you must fill in Trojan "flow" when using XTLS.`)
}
}
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)
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)
}
if rawConn != nil {
var counter stats.Counter
if statConn != nil {
counter = statConn.ReadCounter
}
return ReadV(reader, link.Writer, timer, iConn.(*xtls.Conn), rawConn, counter, sctx)
}
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))
}))
const defaultFlagValue = "NOT_DEFINED_AT_ALL"
xtlsShow := platform.NewEnvFlag("xray.trojan.xtls.show").GetValue(func() string { return defaultFlagValue })
if xtlsShow == "true" {
xtls_show = true
}
}