frp/client/visitor.go

331 lines
7.7 KiB
Go

// Copyright 2017 fatedier, fatedier@gmail.com
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package client
import (
"bytes"
"context"
"fmt"
"io"
"io/ioutil"
"net"
"sync"
"time"
"github.com/fatedier/frp/models/config"
"github.com/fatedier/frp/models/msg"
frpNet "github.com/fatedier/frp/utils/net"
"github.com/fatedier/frp/utils/util"
"github.com/fatedier/frp/utils/xlog"
frpIo "github.com/fatedier/golib/io"
"github.com/fatedier/golib/pool"
fmux "github.com/hashicorp/yamux"
)
// Visitor is used for forward traffics from local port tot remote service.
type Visitor interface {
Run() error
Close()
}
func NewVisitor(ctx context.Context, ctl *Control, cfg config.VisitorConf) (visitor Visitor) {
xl := xlog.FromContextSafe(ctx).Spawn().AppendPrefix(cfg.GetBaseInfo().ProxyName)
baseVisitor := BaseVisitor{
ctl: ctl,
ctx: xlog.NewContext(ctx, xl),
}
switch cfg := cfg.(type) {
case *config.StcpVisitorConf:
visitor = &StcpVisitor{
BaseVisitor: &baseVisitor,
cfg: cfg,
}
case *config.XtcpVisitorConf:
visitor = &XtcpVisitor{
BaseVisitor: &baseVisitor,
cfg: cfg,
}
}
return
}
type BaseVisitor struct {
ctl *Control
l net.Listener
closed bool
mu sync.RWMutex
ctx context.Context
}
type StcpVisitor struct {
*BaseVisitor
cfg *config.StcpVisitorConf
}
func (sv *StcpVisitor) Run() (err error) {
sv.l, err = net.Listen("tcp", fmt.Sprintf("%s:%d", sv.cfg.BindAddr, sv.cfg.BindPort))
if err != nil {
return
}
go sv.worker()
return
}
func (sv *StcpVisitor) Close() {
sv.l.Close()
}
func (sv *StcpVisitor) worker() {
xl := xlog.FromContextSafe(sv.ctx)
for {
conn, err := sv.l.Accept()
if err != nil {
xl.Warn("stcp local listener closed")
return
}
go sv.handleConn(conn)
}
}
func (sv *StcpVisitor) handleConn(userConn net.Conn) {
xl := xlog.FromContextSafe(sv.ctx)
defer userConn.Close()
xl.Debug("get a new stcp user connection")
visitorConn, err := sv.ctl.connectServer()
if err != nil {
return
}
defer visitorConn.Close()
now := time.Now().Unix()
newVisitorConnMsg := &msg.NewVisitorConn{
ProxyName: sv.cfg.ServerName,
SignKey: util.GetAuthKey(sv.cfg.Sk, now),
Timestamp: now,
UseEncryption: sv.cfg.UseEncryption,
UseCompression: sv.cfg.UseCompression,
}
err = msg.WriteMsg(visitorConn, newVisitorConnMsg)
if err != nil {
xl.Warn("send newVisitorConnMsg to server error: %v", err)
return
}
var newVisitorConnRespMsg msg.NewVisitorConnResp
visitorConn.SetReadDeadline(time.Now().Add(10 * time.Second))
err = msg.ReadMsgInto(visitorConn, &newVisitorConnRespMsg)
if err != nil {
xl.Warn("get newVisitorConnRespMsg error: %v", err)
return
}
visitorConn.SetReadDeadline(time.Time{})
if newVisitorConnRespMsg.Error != "" {
xl.Warn("start new visitor connection error: %s", newVisitorConnRespMsg.Error)
return
}
var remote io.ReadWriteCloser
remote = visitorConn
if sv.cfg.UseEncryption {
remote, err = frpIo.WithEncryption(remote, []byte(sv.cfg.Sk))
if err != nil {
xl.Error("create encryption stream error: %v", err)
return
}
}
if sv.cfg.UseCompression {
remote = frpIo.WithCompression(remote)
}
frpIo.Join(userConn, remote)
}
type XtcpVisitor struct {
*BaseVisitor
cfg *config.XtcpVisitorConf
}
func (sv *XtcpVisitor) Run() (err error) {
sv.l, err = net.Listen("tcp", fmt.Sprintf("%s:%d", sv.cfg.BindAddr, sv.cfg.BindPort))
if err != nil {
return
}
go sv.worker()
return
}
func (sv *XtcpVisitor) Close() {
sv.l.Close()
}
func (sv *XtcpVisitor) worker() {
xl := xlog.FromContextSafe(sv.ctx)
for {
conn, err := sv.l.Accept()
if err != nil {
xl.Warn("xtcp local listener closed")
return
}
go sv.handleConn(conn)
}
}
func (sv *XtcpVisitor) handleConn(userConn net.Conn) {
xl := xlog.FromContextSafe(sv.ctx)
defer userConn.Close()
xl.Debug("get a new xtcp user connection")
if sv.ctl.serverUDPPort == 0 {
xl.Error("xtcp is not supported by server")
return
}
raddr, err := net.ResolveUDPAddr("udp",
fmt.Sprintf("%s:%d", sv.ctl.clientCfg.ServerAddr, sv.ctl.serverUDPPort))
if err != nil {
xl.Error("resolve server UDP addr error")
return
}
visitorConn, err := net.DialUDP("udp", nil, raddr)
if err != nil {
xl.Warn("dial server udp addr error: %v", err)
return
}
defer visitorConn.Close()
now := time.Now().Unix()
natHoleVisitorMsg := &msg.NatHoleVisitor{
ProxyName: sv.cfg.ServerName,
SignKey: util.GetAuthKey(sv.cfg.Sk, now),
Timestamp: now,
}
err = msg.WriteMsg(visitorConn, natHoleVisitorMsg)
if err != nil {
xl.Warn("send natHoleVisitorMsg to server error: %v", err)
return
}
// Wait for client address at most 10 seconds.
var natHoleRespMsg msg.NatHoleResp
visitorConn.SetReadDeadline(time.Now().Add(10 * time.Second))
buf := pool.GetBuf(1024)
n, err := visitorConn.Read(buf)
if err != nil {
xl.Warn("get natHoleRespMsg error: %v", err)
return
}
err = msg.ReadMsgInto(bytes.NewReader(buf[:n]), &natHoleRespMsg)
if err != nil {
xl.Warn("get natHoleRespMsg error: %v", err)
return
}
visitorConn.SetReadDeadline(time.Time{})
pool.PutBuf(buf)
if natHoleRespMsg.Error != "" {
xl.Error("natHoleRespMsg get error info: %s", natHoleRespMsg.Error)
return
}
xl.Trace("get natHoleRespMsg, sid [%s], client address [%s], visitor address [%s]", natHoleRespMsg.Sid, natHoleRespMsg.ClientAddr, natHoleRespMsg.VisitorAddr)
// Close visitorConn, so we can use it's local address.
visitorConn.Close()
// send sid message to client
laddr, _ := net.ResolveUDPAddr("udp", visitorConn.LocalAddr().String())
daddr, err := net.ResolveUDPAddr("udp", natHoleRespMsg.ClientAddr)
if err != nil {
xl.Error("resolve client udp address error: %v", err)
return
}
lConn, err := net.DialUDP("udp", laddr, daddr)
if err != nil {
xl.Error("dial client udp address error: %v", err)
return
}
defer lConn.Close()
lConn.Write([]byte(natHoleRespMsg.Sid))
// read ack sid from client
sidBuf := pool.GetBuf(1024)
lConn.SetReadDeadline(time.Now().Add(8 * time.Second))
n, err = lConn.Read(sidBuf)
if err != nil {
xl.Warn("get sid from client error: %v", err)
return
}
lConn.SetReadDeadline(time.Time{})
if string(sidBuf[:n]) != natHoleRespMsg.Sid {
xl.Warn("incorrect sid from client")
return
}
pool.PutBuf(sidBuf)
xl.Info("nat hole connection make success, sid [%s]", natHoleRespMsg.Sid)
// wrap kcp connection
var remote io.ReadWriteCloser
remote, err = frpNet.NewKcpConnFromUdp(lConn, true, natHoleRespMsg.ClientAddr)
if err != nil {
xl.Error("create kcp connection from udp connection error: %v", err)
return
}
fmuxCfg := fmux.DefaultConfig()
fmuxCfg.KeepAliveInterval = 5 * time.Second
fmuxCfg.LogOutput = ioutil.Discard
sess, err := fmux.Client(remote, fmuxCfg)
if err != nil {
xl.Error("create yamux session error: %v", err)
return
}
defer sess.Close()
muxConn, err := sess.Open()
if err != nil {
xl.Error("open yamux stream error: %v", err)
return
}
var muxConnRWCloser io.ReadWriteCloser = muxConn
if sv.cfg.UseEncryption {
muxConnRWCloser, err = frpIo.WithEncryption(muxConnRWCloser, []byte(sv.cfg.Sk))
if err != nil {
xl.Error("create encryption stream error: %v", err)
return
}
}
if sv.cfg.UseCompression {
muxConnRWCloser = frpIo.WithCompression(muxConnRWCloser)
}
frpIo.Join(userConn, muxConnRWCloser)
xl.Debug("join connections closed")
}