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mirror of https://github.com/v2fly/v2ray-core.git synced 2024-11-02 09:17:55 -04:00
v2fly/proxy/trojan/server.go
2022-04-07 00:06:46 +08:00

432 lines
13 KiB
Go

package trojan
import (
"context"
"io"
"strconv"
"time"
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/errors"
"github.com/v2fly/v2ray-core/v5/common/log"
"github.com/v2fly/v2ray-core/v5/common/net"
"github.com/v2fly/v2ray-core/v5/common/protocol"
udp_proto "github.com/v2fly/v2ray-core/v5/common/protocol/udp"
"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/features/routing"
"github.com/v2fly/v2ray-core/v5/transport/internet"
"github.com/v2fly/v2ray-core/v5/transport/internet/tls"
"github.com/v2fly/v2ray-core/v5/transport/internet/udp"
)
func init() {
common.Must(common.RegisterConfig((*ServerConfig)(nil), func(ctx context.Context, config interface{}) (interface{}, error) {
return NewServer(ctx, config.(*ServerConfig))
}))
}
// Server is an inbound connection handler that handles messages in trojan protocol.
type Server struct {
policyManager policy.Manager
validator *Validator
fallbacks map[string]map[string]*Fallback // or nil
}
// NewServer creates a new trojan inbound handler.
func NewServer(ctx context.Context, config *ServerConfig) (*Server, error) {
validator := new(Validator)
for _, user := range config.Users {
u, err := user.ToMemoryUser()
if err != nil {
return nil, newError("failed to get trojan user").Base(err).AtError()
}
if err := validator.Add(u); err != nil {
return nil, newError("failed to add user").Base(err).AtError()
}
}
v := core.MustFromContext(ctx)
server := &Server{
policyManager: v.GetFeature(policy.ManagerType()).(policy.Manager),
validator: validator,
}
if config.Fallbacks != nil {
server.fallbacks = make(map[string]map[string]*Fallback)
for _, fb := range config.Fallbacks {
if server.fallbacks[fb.Alpn] == nil {
server.fallbacks[fb.Alpn] = make(map[string]*Fallback)
}
server.fallbacks[fb.Alpn][fb.Path] = fb
}
if server.fallbacks[""] != nil {
for alpn, pfb := range server.fallbacks {
if alpn != "" { // && alpn != "h2" {
for path, fb := range server.fallbacks[""] {
if pfb[path] == nil {
pfb[path] = fb
}
}
}
}
}
}
return server, nil
}
// AddUser implements proxy.UserManager.AddUser().
func (s *Server) AddUser(ctx context.Context, u *protocol.MemoryUser) error {
return s.validator.Add(u)
}
// RemoveUser implements proxy.UserManager.RemoveUser().
func (s *Server) RemoveUser(ctx context.Context, e string) error {
return s.validator.Del(e)
}
// Network implements proxy.Inbound.Network().
func (s *Server) Network() []net.Network {
return []net.Network{net.Network_TCP, net.Network_UNIX}
}
// Process implements proxy.Inbound.Process().
func (s *Server) Process(ctx context.Context, network net.Network, conn internet.Connection, dispatcher routing.Dispatcher) error {
sid := session.ExportIDToError(ctx)
iConn := conn
if statConn, ok := iConn.(*internet.StatCouterConnection); ok {
iConn = statConn.Connection
}
sessionPolicy := s.policyManager.ForLevel(0)
if err := conn.SetReadDeadline(time.Now().Add(sessionPolicy.Timeouts.Handshake)); err != nil {
return newError("unable to set read deadline").Base(err).AtWarning()
}
first := buf.New()
defer first.Release()
firstLen, err := first.ReadFrom(conn)
if err != nil {
return newError("failed to read first request").Base(err)
}
newError("firstLen = ", firstLen).AtInfo().WriteToLog(sid)
bufferedReader := &buf.BufferedReader{
Reader: buf.NewReader(conn),
Buffer: buf.MultiBuffer{first},
}
var user *protocol.MemoryUser
apfb := s.fallbacks
isfb := apfb != nil
shouldFallback := false
if firstLen < 58 || first.Byte(56) != '\r' {
// invalid protocol
err = newError("not trojan protocol")
log.Record(&log.AccessMessage{
From: conn.RemoteAddr(),
To: "",
Status: log.AccessRejected,
Reason: err,
})
shouldFallback = true
} else {
user = s.validator.Get(hexString(first.BytesTo(56)))
if user == nil {
// invalid user, let's fallback
err = newError("not a valid user")
log.Record(&log.AccessMessage{
From: conn.RemoteAddr(),
To: "",
Status: log.AccessRejected,
Reason: err,
})
shouldFallback = true
}
}
if isfb && shouldFallback {
return s.fallback(ctx, sid, err, sessionPolicy, conn, iConn, apfb, first, firstLen, bufferedReader)
} else if shouldFallback {
return newError("invalid protocol or invalid user")
}
clientReader := &ConnReader{Reader: bufferedReader}
if err := clientReader.ParseHeader(); err != nil {
log.Record(&log.AccessMessage{
From: conn.RemoteAddr(),
To: "",
Status: log.AccessRejected,
Reason: err,
})
return newError("failed to create request from: ", conn.RemoteAddr()).Base(err)
}
destination := clientReader.Target
if err := conn.SetReadDeadline(time.Time{}); err != nil {
return newError("unable to set read deadline").Base(err).AtWarning()
}
inbound := session.InboundFromContext(ctx)
if inbound == nil {
panic("no inbound metadata")
}
inbound.User = user
sessionPolicy = s.policyManager.ForLevel(user.Level)
if destination.Network == net.Network_UDP { // handle udp request
return s.handleUDPPayload(ctx, &PacketReader{Reader: clientReader}, &PacketWriter{Writer: conn}, dispatcher)
}
ctx = log.ContextWithAccessMessage(ctx, &log.AccessMessage{
From: conn.RemoteAddr(),
To: destination,
Status: log.AccessAccepted,
Reason: "",
Email: user.Email,
})
newError("received request for ", destination).WriteToLog(sid)
return s.handleConnection(ctx, sessionPolicy, destination, clientReader, buf.NewWriter(conn), dispatcher)
}
func (s *Server) handleUDPPayload(ctx context.Context, clientReader *PacketReader, clientWriter *PacketWriter, dispatcher routing.Dispatcher) error {
udpServer := udp.NewSplitDispatcher(dispatcher, func(ctx context.Context, packet *udp_proto.Packet) {
if err := clientWriter.WriteMultiBufferWithMetadata(buf.MultiBuffer{packet.Payload}, packet.Source); err != nil {
newError("failed to write response").Base(err).AtWarning().WriteToLog(session.ExportIDToError(ctx))
}
})
inbound := session.InboundFromContext(ctx)
user := inbound.User
for {
select {
case <-ctx.Done():
return nil
default:
p, err := clientReader.ReadMultiBufferWithMetadata()
if err != nil {
if errors.Cause(err) != io.EOF {
return newError("unexpected EOF").Base(err)
}
return nil
}
ctx = log.ContextWithAccessMessage(ctx, &log.AccessMessage{
From: inbound.Source,
To: p.Target,
Status: log.AccessAccepted,
Reason: "",
Email: user.Email,
})
newError("tunnelling request to ", p.Target).WriteToLog(session.ExportIDToError(ctx))
for _, b := range p.Buffer {
udpServer.Dispatch(ctx, p.Target, b)
}
}
}
}
func (s *Server) handleConnection(ctx context.Context, sessionPolicy policy.Session,
destination net.Destination,
clientReader buf.Reader,
clientWriter buf.Writer, dispatcher routing.Dispatcher,
) error {
ctx, cancel := context.WithCancel(ctx)
timer := signal.CancelAfterInactivity(ctx, cancel, sessionPolicy.Timeouts.ConnectionIdle)
ctx = policy.ContextWithBufferPolicy(ctx, sessionPolicy.Buffer)
link, err := dispatcher.Dispatch(ctx, destination)
if err != nil {
return newError("failed to dispatch request to ", destination).Base(err)
}
requestDone := func() error {
defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly)
if err := buf.Copy(clientReader, link.Writer, buf.UpdateActivity(timer)); err != nil {
return newError("failed to transfer request").Base(err)
}
return nil
}
responseDone := func() error {
defer timer.SetTimeout(sessionPolicy.Timeouts.UplinkOnly)
if err := buf.Copy(link.Reader, clientWriter, buf.UpdateActivity(timer)); err != nil {
return newError("failed to write response").Base(err)
}
return nil
}
requestDonePost := task.OnSuccess(requestDone, task.Close(link.Writer))
if err := task.Run(ctx, requestDonePost, responseDone); err != nil {
common.Must(common.Interrupt(link.Reader))
common.Must(common.Interrupt(link.Writer))
return newError("connection ends").Base(err)
}
return nil
}
func (s *Server) fallback(ctx context.Context, sid errors.ExportOption, err error, sessionPolicy policy.Session, connection internet.Connection, iConn internet.Connection, apfb map[string]map[string]*Fallback, first *buf.Buffer, firstLen int64, reader buf.Reader) error {
if err := connection.SetReadDeadline(time.Time{}); err != nil {
newError("unable to set back read deadline").Base(err).AtWarning().WriteToLog(sid)
}
newError("fallback starts").Base(err).AtInfo().WriteToLog(sid)
alpn := ""
if len(apfb) > 1 || apfb[""] == nil {
if tlsConn, ok := iConn.(*tls.Conn); ok {
alpn = tlsConn.ConnectionState().NegotiatedProtocol
newError("realAlpn = " + alpn).AtInfo().WriteToLog(sid)
}
if apfb[alpn] == nil {
alpn = ""
}
}
pfb := apfb[alpn]
if pfb == nil {
return newError(`failed to find the default "alpn" config`).AtWarning()
}
path := ""
if len(pfb) > 1 || pfb[""] == nil {
if firstLen >= 18 && first.Byte(4) != '*' { // not h2c
firstBytes := first.Bytes()
for i := 4; i <= 8; i++ { // 5 -> 9
if firstBytes[i] == '/' && firstBytes[i-1] == ' ' {
search := len(firstBytes)
if search > 64 {
search = 64 // up to about 60
}
for j := i + 1; j < search; j++ {
k := firstBytes[j]
if k == '\r' || k == '\n' { // avoid logging \r or \n
break
}
if k == ' ' {
path = string(firstBytes[i:j])
newError("realPath = " + path).AtInfo().WriteToLog(sid)
if pfb[path] == nil {
path = ""
}
break
}
}
break
}
}
}
}
fb := pfb[path]
if fb == nil {
return newError(`failed to find the default "path" config`).AtWarning()
}
ctx, cancel := context.WithCancel(ctx)
timer := signal.CancelAfterInactivity(ctx, cancel, sessionPolicy.Timeouts.ConnectionIdle)
ctx = policy.ContextWithBufferPolicy(ctx, sessionPolicy.Buffer)
var conn net.Conn
if err := retry.ExponentialBackoff(5, 100).On(func() error {
var dialer net.Dialer
conn, err = dialer.DialContext(ctx, fb.Type, fb.Dest)
if err != nil {
return err
}
return nil
}); err != nil {
return newError("failed to dial to " + fb.Dest).Base(err).AtWarning()
}
defer conn.Close()
serverReader := buf.NewReader(conn)
serverWriter := buf.NewWriter(conn)
postRequest := func() error {
defer timer.SetTimeout(sessionPolicy.Timeouts.DownlinkOnly)
if fb.Xver != 0 {
remoteAddr, remotePort, err := net.SplitHostPort(connection.RemoteAddr().String())
if err != nil {
return err
}
localAddr, localPort, err := net.SplitHostPort(connection.LocalAddr().String())
if err != nil {
return err
}
ipv4 := true
for i := 0; i < len(remoteAddr); i++ {
if remoteAddr[i] == ':' {
ipv4 = false
break
}
}
pro := buf.New()
defer pro.Release()
switch fb.Xver {
case 1:
if ipv4 {
common.Must2(pro.Write([]byte("PROXY TCP4 " + remoteAddr + " " + localAddr + " " + remotePort + " " + localPort + "\r\n")))
} else {
common.Must2(pro.Write([]byte("PROXY TCP6 " + remoteAddr + " " + localAddr + " " + remotePort + " " + localPort + "\r\n")))
}
case 2:
common.Must2(pro.Write([]byte("\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A\x21"))) // signature + v2 + PROXY
if ipv4 {
common.Must2(pro.Write([]byte("\x11\x00\x0C"))) // AF_INET + STREAM + 12 bytes
common.Must2(pro.Write(net.ParseIP(remoteAddr).To4()))
common.Must2(pro.Write(net.ParseIP(localAddr).To4()))
} else {
common.Must2(pro.Write([]byte("\x21\x00\x24"))) // AF_INET6 + STREAM + 36 bytes
common.Must2(pro.Write(net.ParseIP(remoteAddr).To16()))
common.Must2(pro.Write(net.ParseIP(localAddr).To16()))
}
p1, _ := strconv.ParseUint(remotePort, 10, 16)
p2, _ := strconv.ParseUint(localPort, 10, 16)
common.Must2(pro.Write([]byte{byte(p1 >> 8), byte(p1), byte(p2 >> 8), byte(p2)}))
}
if err := serverWriter.WriteMultiBuffer(buf.MultiBuffer{pro}); err != nil {
return newError("failed to set PROXY protocol v", fb.Xver).Base(err).AtWarning()
}
}
if err := buf.Copy(reader, serverWriter, buf.UpdateActivity(timer)); err != nil {
return newError("failed to fallback request payload").Base(err).AtInfo()
}
return nil
}
writer := buf.NewWriter(connection)
getResponse := func() error {
defer timer.SetTimeout(sessionPolicy.Timeouts.UplinkOnly)
if err := buf.Copy(serverReader, writer, buf.UpdateActivity(timer)); err != nil {
return newError("failed to deliver response payload").Base(err).AtInfo()
}
return nil
}
if err := task.Run(ctx, task.OnSuccess(postRequest, task.Close(serverWriter)), task.OnSuccess(getResponse, task.Close(writer))); err != nil {
common.Must(common.Interrupt(serverReader))
common.Must(common.Interrupt(serverWriter))
return newError("fallback ends").Base(err).AtInfo()
}
return nil
}