Files
NTrace-core/trace/tcp_ipv6.go
tsosunchia 6937b54cdf fix typo
2024-05-13 21:13:23 +08:00

302 lines
6.3 KiB
Go
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

package trace
import (
"encoding/binary"
"math"
"math/rand"
"net"
"sync"
"time"
"github.com/google/gopacket"
"github.com/google/gopacket/layers"
"github.com/nxtrace/NTrace-core/util"
"golang.org/x/net/context"
"golang.org/x/net/icmp"
"golang.org/x/net/ipv6"
"golang.org/x/sync/semaphore"
)
type TCPTracerv6 struct {
Config
wg sync.WaitGroup
res Result
ctx context.Context
inflightRequest map[int]chan Hop
inflightRequestLock sync.Mutex
SrcIP net.IP
icmp net.PacketConn
tcp net.PacketConn
final int
finalLock sync.Mutex
sem *semaphore.Weighted
fetchLock sync.Mutex
}
func (t *TCPTracerv6) Execute() (*Result, error) {
if len(t.res.Hops) > 0 {
return &t.res, ErrTracerouteExecuted
}
t.SrcIP, _ = util.LocalIPPortv6(t.DestIP)
// log.Println(util.LocalIPPortv6(t.DestIP))
var err error
t.tcp, err = net.ListenPacket("ip6:tcp", t.SrcIP.String())
if err != nil {
return nil, err
}
t.icmp, err = icmp.ListenPacket("ip6:58", "::")
if err != nil {
return &t.res, err
}
defer t.icmp.Close()
var cancel context.CancelFunc
t.ctx, cancel = context.WithCancel(context.Background())
defer cancel()
t.inflightRequest = make(map[int]chan Hop)
t.final = -1
go t.listenICMP()
go t.listenTCP()
t.sem = semaphore.NewWeighted(int64(t.ParallelRequests))
for ttl := t.BeginHop; ttl <= t.MaxHops; ttl++ {
// 如果到达最终跳,则退出
if t.final != -1 && ttl > t.final {
break
}
for i := 0; i < t.NumMeasurements; i++ {
t.wg.Add(1)
go t.send(ttl)
<-time.After(time.Millisecond * time.Duration(t.Config.PacketInterval))
}
if t.RealtimePrinter != nil {
// 对于实时模式应该按照TTL进行并发请求
t.wg.Wait()
t.RealtimePrinter(&t.res, ttl-1)
}
<-time.After(time.Millisecond * time.Duration(t.Config.TTLInterval))
}
go func() {
if t.AsyncPrinter != nil {
for {
t.AsyncPrinter(&t.res)
time.Sleep(200 * time.Millisecond)
}
}
}()
if t.RealtimePrinter == nil {
t.wg.Wait()
}
t.res.reduce(t.final)
return &t.res, nil
}
func (t *TCPTracerv6) listenICMP() {
lc := NewPacketListener(t.icmp, t.ctx)
go lc.Start()
for {
select {
case <-t.ctx.Done():
return
case msg := <-lc.Messages:
// log.Println(msg)
if msg.N == nil {
continue
}
rm, err := icmp.ParseMessage(58, msg.Msg[:*msg.N])
if err != nil {
// log.Println(err)
continue
}
switch rm.Type {
case ipv6.ICMPTypeTimeExceeded:
t.handleICMPMessage(msg)
case ipv6.ICMPTypeDestinationUnreachable:
t.handleICMPMessage(msg)
default:
//log.Println("received icmp message of unknown type", rm.Type)
}
}
}
}
// @title listenTCP
// @description 监听TCP的响应数据包
func (t *TCPTracerv6) listenTCP() {
lc := NewPacketListener(t.tcp, t.ctx)
go lc.Start()
for {
select {
case <-t.ctx.Done():
return
case msg := <-lc.Messages:
// log.Println(msg)
// return
if msg.N == nil {
continue
}
if msg.Peer.String() != t.DestIP.String() {
continue
}
// 解包
packet := gopacket.NewPacket(msg.Msg[:*msg.N], layers.LayerTypeTCP, gopacket.Default)
// 从包中获取TCP layer信息
if tcpLayer := packet.Layer(layers.LayerTypeTCP); tcpLayer != nil {
tcp, _ := tcpLayer.(*layers.TCP)
// 取得目标主机的Sequence Number
if ch, ok := t.inflightRequest[int(tcp.Ack-1)]; ok {
// 最后一跳
ch <- Hop{
Success: true,
Address: msg.Peer,
}
}
}
}
}
}
func (t *TCPTracerv6) handleICMPMessage(msg ReceivedMessage) {
var sequenceNumber = binary.BigEndian.Uint32(msg.Msg[52:56])
t.inflightRequestLock.Lock()
defer t.inflightRequestLock.Unlock()
ch, ok := t.inflightRequest[int(sequenceNumber)]
if !ok {
return
}
// log.Println("发送数据", sequenceNumber)
ch <- Hop{
Success: true,
Address: msg.Peer,
}
// log.Println("发送成功")
}
func (t *TCPTracerv6) send(ttl int) error {
err := t.sem.Acquire(context.Background(), 1)
if err != nil {
return err
}
defer t.sem.Release(1)
defer t.wg.Done()
if t.final != -1 && ttl > t.final {
return nil
}
// 随机种子
r := rand.New(rand.NewSource(time.Now().UnixNano()))
_, srcPort := util.LocalIPPortv6(t.DestIP)
ipHeader := &layers.IPv6{
SrcIP: t.SrcIP,
DstIP: t.DestIP,
NextHeader: layers.IPProtocolTCP,
HopLimit: uint8(ttl),
}
// 使用Uint16兼容32位系统防止在rand的时候因使用int32而溢出
sequenceNumber := uint32(r.Intn(math.MaxUint16))
tcpHeader := &layers.TCP{
SrcPort: layers.TCPPort(srcPort),
DstPort: layers.TCPPort(t.DestPort),
Seq: sequenceNumber,
SYN: true,
Window: 14600,
}
_ = tcpHeader.SetNetworkLayerForChecksum(ipHeader)
buf := gopacket.NewSerializeBuffer()
opts := gopacket.SerializeOptions{
ComputeChecksums: true,
FixLengths: true,
}
desiredPayloadSize := t.Config.PktSize
payload := make([]byte, desiredPayloadSize)
copy(buf.Bytes(), payload)
if err := gopacket.SerializeLayers(buf, opts, tcpHeader); err != nil {
return err
}
err = ipv6.NewPacketConn(t.tcp).SetHopLimit(ttl)
if err != nil {
return err
}
if err != nil {
return err
}
start := time.Now()
if _, err := t.tcp.WriteTo(buf.Bytes(), &net.IPAddr{IP: t.DestIP}); err != nil {
return err
}
// log.Println(ttl, sequenceNumber)
t.inflightRequestLock.Lock()
hopCh := make(chan Hop)
t.inflightRequest[int(sequenceNumber)] = hopCh
t.inflightRequestLock.Unlock()
select {
case <-t.ctx.Done():
return nil
case h := <-hopCh:
rtt := time.Since(start)
if t.final != -1 && ttl > t.final {
return nil
}
if addr, ok := h.Address.(*net.IPAddr); ok && addr.IP.Equal(t.DestIP) {
t.finalLock.Lock()
if t.final == -1 || ttl < t.final {
t.final = ttl
}
t.finalLock.Unlock()
} else if addr, ok := h.Address.(*net.TCPAddr); ok && addr.IP.Equal(t.DestIP) {
t.finalLock.Lock()
if t.final == -1 || ttl < t.final {
t.final = ttl
}
t.finalLock.Unlock()
}
h.TTL = ttl
h.RTT = rtt
t.fetchLock.Lock()
defer t.fetchLock.Unlock()
h.fetchIPData(t.Config)
t.res.add(h)
case <-time.After(t.Timeout):
if t.final != -1 && ttl > t.final {
return nil
}
t.res.add(Hop{
Success: false,
Address: nil,
TTL: ttl,
RTT: 0,
Error: ErrHopLimitTimeout,
})
}
return nil
}