frp/pkg/nathole/controller.go

383 lines
11 KiB
Go
Raw Normal View History

// Copyright 2023 The frp Authors
//
// 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 nathole
import (
"context"
"crypto/md5"
"encoding/hex"
"fmt"
"net"
"strconv"
"sync"
"time"
"github.com/fatedier/golib/errors"
"github.com/samber/lo"
"golang.org/x/sync/errgroup"
"github.com/fatedier/frp/pkg/msg"
"github.com/fatedier/frp/pkg/transport"
"github.com/fatedier/frp/pkg/util/log"
"github.com/fatedier/frp/pkg/util/util"
)
// NatHoleTimeout seconds.
var NatHoleTimeout int64 = 10
func NewTransactionID() string {
id, _ := util.RandID()
return fmt.Sprintf("%d%s", time.Now().Unix(), id)
}
type ClientCfg struct {
name string
sk string
sidCh chan string
}
type Session struct {
sid string
analysisKey string
recommandMode int
recommandIndex int
visitorMsg *msg.NatHoleVisitor
visitorTransporter transport.MessageTransporter
vResp *msg.NatHoleResp
vNatFeature *NatFeature
vBehavior RecommandBehavior
clientMsg *msg.NatHoleClient
clientTransporter transport.MessageTransporter
cResp *msg.NatHoleResp
cNatFeature *NatFeature
cBehavior RecommandBehavior
notifyCh chan struct{}
}
func (s *Session) genAnalysisKey() {
hash := md5.New()
vIPs := lo.Uniq(parseIPs(s.visitorMsg.MappedAddrs))
if len(vIPs) > 0 {
hash.Write([]byte(vIPs[0]))
}
hash.Write([]byte(s.vNatFeature.NatType))
hash.Write([]byte(s.vNatFeature.Behavior))
hash.Write([]byte(strconv.FormatBool(s.vNatFeature.RegularPortsChange)))
cIPs := lo.Uniq(parseIPs(s.clientMsg.MappedAddrs))
if len(cIPs) > 0 {
hash.Write([]byte(cIPs[0]))
}
hash.Write([]byte(s.cNatFeature.NatType))
hash.Write([]byte(s.cNatFeature.Behavior))
hash.Write([]byte(strconv.FormatBool(s.cNatFeature.RegularPortsChange)))
s.analysisKey = hex.EncodeToString(hash.Sum(nil))
}
type Controller struct {
clientCfgs map[string]*ClientCfg
sessions map[string]*Session
analyzer *Analyzer
mu sync.RWMutex
}
func NewController(analysisDataReserveDuration time.Duration) (*Controller, error) {
return &Controller{
clientCfgs: make(map[string]*ClientCfg),
sessions: make(map[string]*Session),
analyzer: NewAnalyzer(analysisDataReserveDuration),
}, nil
}
func (c *Controller) CleanWorker(ctx context.Context) {
ticker := time.NewTicker(time.Hour)
defer ticker.Stop()
for {
select {
case <-ticker.C:
start := time.Now()
count, total := c.analyzer.Clean()
log.Trace("clean %d/%d nathole analysis data, cost %v", count, total, time.Since(start))
case <-ctx.Done():
return
}
}
}
func (c *Controller) ListenClient(name string, sk string) chan string {
cfg := &ClientCfg{
name: name,
sk: sk,
sidCh: make(chan string),
}
c.mu.Lock()
defer c.mu.Unlock()
c.clientCfgs[name] = cfg
return cfg.sidCh
}
func (c *Controller) CloseClient(name string) {
c.mu.Lock()
defer c.mu.Unlock()
delete(c.clientCfgs, name)
}
func (c *Controller) GenSid() string {
t := time.Now().Unix()
id, _ := util.RandID()
return fmt.Sprintf("%d%s", t, id)
}
func (c *Controller) HandleVisitor(m *msg.NatHoleVisitor, transporter transport.MessageTransporter) {
if m.PreCheck {
_, ok := c.clientCfgs[m.ProxyName]
if !ok {
_ = transporter.Send(c.GenNatHoleResponse(m.TransactionID, nil, fmt.Sprintf("xtcp server for [%s] doesn't exist", m.ProxyName)))
} else {
_ = transporter.Send(c.GenNatHoleResponse(m.TransactionID, nil, ""))
}
return
}
sid := c.GenSid()
session := &Session{
sid: sid,
visitorMsg: m,
visitorTransporter: transporter,
notifyCh: make(chan struct{}, 1),
}
var (
clientCfg *ClientCfg
ok bool
)
err := func() error {
c.mu.Lock()
defer c.mu.Unlock()
clientCfg, ok = c.clientCfgs[m.ProxyName]
if !ok {
return fmt.Errorf("xtcp server for [%s] doesn't exist", m.ProxyName)
}
2023-05-29 00:27:27 +08:00
if !util.ConstantTimeEqString(m.SignKey, util.GetAuthKey(clientCfg.sk, m.Timestamp)) {
return fmt.Errorf("xtcp connection of [%s] auth failed", m.ProxyName)
}
c.sessions[sid] = session
return nil
}()
if err != nil {
log.Warn("handle visitorMsg error: %v", err)
_ = transporter.Send(c.GenNatHoleResponse(m.TransactionID, nil, err.Error()))
return
}
log.Trace("handle visitor message, sid [%s]", sid)
defer func() {
c.mu.Lock()
defer c.mu.Unlock()
delete(c.sessions, sid)
}()
if err := errors.PanicToError(func() {
clientCfg.sidCh <- sid
}); err != nil {
return
}
// wait for NatHoleClient message
select {
case <-session.notifyCh:
case <-time.After(time.Duration(NatHoleTimeout) * time.Second):
log.Debug("wait for NatHoleClient message timeout, sid [%s]", sid)
return
}
// Make hole-punching decisions based on the NAT information of the client and visitor.
vResp, cResp, err := c.analysis(session)
if err != nil {
log.Debug("sid [%s] analysis error: %v", err)
vResp = c.GenNatHoleResponse(session.visitorMsg.TransactionID, nil, err.Error())
cResp = c.GenNatHoleResponse(session.clientMsg.TransactionID, nil, err.Error())
}
session.cResp = cResp
session.vResp = vResp
// send response to visitor and client
var g errgroup.Group
g.Go(func() error {
// if it's sender, wait for a while to make sure the client has send the detect messages
if vResp.DetectBehavior.Role == "sender" {
time.Sleep(1 * time.Second)
}
_ = session.visitorTransporter.Send(vResp)
return nil
})
g.Go(func() error {
// if it's sender, wait for a while to make sure the client has send the detect messages
if cResp.DetectBehavior.Role == "sender" {
time.Sleep(1 * time.Second)
}
_ = session.clientTransporter.Send(cResp)
return nil
})
_ = g.Wait()
time.Sleep(time.Duration(cResp.DetectBehavior.ReadTimeoutMs+30000) * time.Millisecond)
}
func (c *Controller) HandleClient(m *msg.NatHoleClient, transporter transport.MessageTransporter) {
c.mu.RLock()
session, ok := c.sessions[m.Sid]
c.mu.RUnlock()
if !ok {
return
}
log.Trace("handle client message, sid [%s]", session.sid)
session.clientMsg = m
session.clientTransporter = transporter
select {
case session.notifyCh <- struct{}{}:
default:
}
}
func (c *Controller) HandleReport(m *msg.NatHoleReport) {
c.mu.RLock()
session, ok := c.sessions[m.Sid]
c.mu.RUnlock()
if !ok {
log.Trace("sid [%s] report make hole success: %v, but session not found", m.Sid, m.Success)
return
}
if m.Success {
c.analyzer.ReportSuccess(session.analysisKey, session.recommandMode, session.recommandIndex)
}
log.Info("sid [%s] report make hole success: %v, mode %v, index %v",
m.Sid, m.Success, session.recommandMode, session.recommandIndex)
}
func (c *Controller) GenNatHoleResponse(transactionID string, session *Session, errInfo string) *msg.NatHoleResp {
var sid string
if session != nil {
sid = session.sid
}
return &msg.NatHoleResp{
TransactionID: transactionID,
Sid: sid,
Error: errInfo,
}
}
// analysis analyzes the NAT type and behavior of the visitor and client, then makes hole-punching decisions.
// return the response to the visitor and client.
func (c *Controller) analysis(session *Session) (*msg.NatHoleResp, *msg.NatHoleResp, error) {
cm := session.clientMsg
vm := session.visitorMsg
cNatFeature, err := ClassifyNATFeature(cm.MappedAddrs, parseIPs(cm.AssistedAddrs))
if err != nil {
return nil, nil, fmt.Errorf("classify client nat feature error: %v", err)
}
vNatFeature, err := ClassifyNATFeature(vm.MappedAddrs, parseIPs(vm.AssistedAddrs))
if err != nil {
return nil, nil, fmt.Errorf("classify visitor nat feature error: %v", err)
}
session.cNatFeature = cNatFeature
session.vNatFeature = vNatFeature
session.genAnalysisKey()
mode, index, cBehavior, vBehavior := c.analyzer.GetRecommandBehaviors(session.analysisKey, cNatFeature, vNatFeature)
session.recommandMode = mode
session.recommandIndex = index
session.cBehavior = cBehavior
session.vBehavior = vBehavior
timeoutMs := lo.Max([]int{cBehavior.SendDelayMs, vBehavior.SendDelayMs}) + 5000
if cBehavior.ListenRandomPorts > 0 || vBehavior.ListenRandomPorts > 0 {
timeoutMs += 30000
}
protocol := vm.Protocol
vResp := &msg.NatHoleResp{
TransactionID: vm.TransactionID,
Sid: session.sid,
Protocol: protocol,
CandidateAddrs: lo.Uniq(cm.MappedAddrs),
AssistedAddrs: lo.Uniq(cm.AssistedAddrs),
DetectBehavior: msg.NatHoleDetectBehavior{
Mode: mode,
Role: vBehavior.Role,
TTL: vBehavior.TTL,
SendDelayMs: vBehavior.SendDelayMs,
ReadTimeoutMs: timeoutMs - vBehavior.SendDelayMs,
SendRandomPorts: vBehavior.PortsRandomNumber,
ListenRandomPorts: vBehavior.ListenRandomPorts,
CandidatePorts: getRangePorts(cm.MappedAddrs, cNatFeature.PortsDifference, vBehavior.PortsRangeNumber),
},
}
cResp := &msg.NatHoleResp{
TransactionID: cm.TransactionID,
Sid: session.sid,
Protocol: protocol,
CandidateAddrs: lo.Uniq(vm.MappedAddrs),
AssistedAddrs: lo.Uniq(vm.AssistedAddrs),
DetectBehavior: msg.NatHoleDetectBehavior{
Mode: mode,
Role: cBehavior.Role,
TTL: cBehavior.TTL,
SendDelayMs: cBehavior.SendDelayMs,
ReadTimeoutMs: timeoutMs - cBehavior.SendDelayMs,
SendRandomPorts: cBehavior.PortsRandomNumber,
ListenRandomPorts: cBehavior.ListenRandomPorts,
CandidatePorts: getRangePorts(vm.MappedAddrs, vNatFeature.PortsDifference, cBehavior.PortsRangeNumber),
},
}
log.Debug("sid [%s] visitor nat: %+v, candidateAddrs: %v; client nat: %+v, candidateAddrs: %v, protocol: %s",
session.sid, *vNatFeature, vm.MappedAddrs, *cNatFeature, cm.MappedAddrs, protocol)
log.Debug("sid [%s] visitor detect behavior: %+v", session.sid, vResp.DetectBehavior)
log.Debug("sid [%s] client detect behavior: %+v", session.sid, cResp.DetectBehavior)
return vResp, cResp, nil
}
func getRangePorts(addrs []string, difference, maxNumber int) []msg.PortsRange {
if maxNumber <= 0 {
return nil
}
addr, err := lo.Last(addrs)
if err != nil {
return nil
}
var ports []msg.PortsRange
_, portStr, err := net.SplitHostPort(addr)
if err != nil {
return nil
}
port, err := strconv.Atoi(portStr)
if err != nil {
return nil
}
ports = append(ports, msg.PortsRange{
From: lo.Max([]int{port - difference - 5, port - maxNumber, 1}),
To: lo.Min([]int{port + difference + 5, port + maxNumber, 65535}),
})
return ports
}