LjhAUMEM
2026-05-29 17:44:06 +08:00
committed by GitHub
parent 66a8100737
commit 2b42699623
5 changed files with 520 additions and 525 deletions
+262 -246
View File
@@ -1,14 +1,21 @@
package xicmp
import (
"bytes"
"context"
"crypto/rand"
"encoding/binary"
goerrors "errors"
"fmt"
"io"
mathrand "math/rand"
"net"
"strings"
"net/netip"
"sync"
"time"
_ "unsafe"
"github.com/xtls/xray-core/common/crypto"
"github.com/xtls/xray-core/common"
"github.com/xtls/xray-core/common/errors"
"github.com/xtls/xray-core/transport/internet/finalmask"
"golang.org/x/net/icmp"
@@ -16,149 +23,115 @@ import (
"golang.org/x/net/ipv6"
)
const (
initPollDelay = 500 * time.Millisecond
maxPollDelay = 10 * time.Second
pollDelayMultiplier = 2.0
pollLimit = 16
windowSize = 1000
)
var pool = sync.Pool{
New: func() any {
return make([]byte, finalmask.UDPSize)
},
}
type packet struct {
p []byte
addr net.Addr
}
type seqStatus struct {
needSeqByte bool
seqByte byte
err error
}
type xicmpConnClient struct {
conn net.PacketConn
icmpConn *icmp.PacketConn
typ icmp.Type
id int
seq int
proto int
seqStatus map[int]*seqStatus
pollChan chan struct{}
readQueue chan *packet
writeQueue chan *packet
closed bool
mutex sync.Mutex
icmp4 *icmp.PacketConn
icmp6 *icmp.PacketConn
udp bool
ips []netip.Addr
clientID [8]byte
id int
seq int
readCh chan packet
closedCh chan struct{}
mu sync.Mutex
}
func NewConnClient(c *Config, raw net.PacketConn) (net.PacketConn, error) {
network := "ip4:icmp"
typ := icmp.Type(ipv4.ICMPTypeEcho)
proto := 1
if strings.Contains(c.Ip, ":") {
network = "ip6:ipv6-icmp"
typ = ipv6.ICMPTypeEchoRequest
proto = 58
var icmp4, icmp6 *icmp.PacketConn
var err4, err6 error
if c.DGRAM {
icmp4, err4 = icmp.ListenPacket("udp4", "0.0.0.0")
icmp6, err6 = icmp.ListenPacket("udp6", "::")
} else {
icmp4, err4 = icmp.ListenPacket("ip4:icmp", "0.0.0.0")
icmp6, err6 = icmp.ListenPacket("ip6:ipv6-icmp", "::")
}
if err4 != nil || err6 != nil {
return nil, errors.Combine(err4, err6)
}
icmpConn, err := icmp.ListenPacket(network, c.Ip)
if err != nil {
return nil, errors.New("xicmp listen err").Base(err)
ips := make([]netip.Addr, 0, len(c.IPs))
for _, ip := range c.IPs {
ips = append(ips, netip.MustParseAddr(ip))
}
if c.Id == 0 {
c.Id = int32(crypto.RandBetween(0, 65535))
}
var clientID [8]byte
common.Must2(rand.Read(clientID[:]))
conn := &xicmpConnClient{
conn: raw,
icmpConn: icmpConn,
typ: typ,
id: int(c.Id),
seq: 1,
proto: proto,
seqStatus: make(map[int]*seqStatus),
pollChan: make(chan struct{}, pollLimit),
readQueue: make(chan *packet, 256),
writeQueue: make(chan *packet, 256),
icmp4: icmp4,
icmp6: icmp6,
udp: c.DGRAM,
ips: ips,
clientID: clientID,
id: mathrand.Intn(65536),
seq: 1,
readCh: make(chan packet),
closedCh: make(chan struct{}),
}
go conn.recvLoop()
go conn.sendLoop()
go conn.recv4()
go conn.recv6()
return conn, nil
}
func (c *xicmpConnClient) encode(p []byte) ([]byte, error) {
c.mutex.Lock()
defer c.mutex.Unlock()
needSeqByte := false
var seqByte byte
data := p
if len(p) > 0 {
needSeqByte = true
seqByte = p[0]
}
msg := icmp.Message{
Type: c.typ,
Code: 0,
Body: &icmp.Echo{
ID: c.id,
Seq: c.seq,
Data: data,
},
}
buf, err := msg.Marshal(nil)
if err != nil {
return nil, err
}
if len(buf) > finalmask.UDPSize {
return nil, errors.New("xicmp len(buf) > finalmask.UDPSize")
}
c.seqStatus[c.seq] = &seqStatus{
needSeqByte: needSeqByte,
seqByte: seqByte,
}
delete(c.seqStatus, int(uint16(c.seq-windowSize)))
c.seq++
if c.seq == 65536 {
delete(c.seqStatus, int(uint16(c.seq-windowSize)))
c.seq = 1
}
return buf, nil
func (c *xicmpConnClient) ring(a, b uint16) uint16 {
return min(a-b, b-a)
}
func (c *xicmpConnClient) recvLoop() {
var buf [finalmask.UDPSize]byte
func (c *xicmpConnClient) closed() bool {
select {
case <-c.closedCh:
return true
default:
return false
}
}
func (c *xicmpConnClient) recv4() {
var b [finalmask.UDPSize]byte
for {
if c.closed {
break
if c.closed() {
return
}
n, addr, err := c.icmpConn.ReadFrom(buf[:])
n, addr, err := c.icmp4.ReadFrom(b[:])
if err != nil {
var netErr net.Error
if goerrors.As(err, &netErr) && netErr.Timeout() {
select {
case c.readCh <- packet{
err: err,
}:
case <-c.closedCh:
return
}
}
continue
}
msg, err := icmp.ParseMessage(1, b[:n])
if err != nil {
continue
}
msg, err := icmp.ParseMessage(c.proto, buf[:n])
if err != nil {
continue
}
if msg.Type != ipv4.ICMPTypeEchoReply && msg.Type != ipv6.ICMPTypeEchoReply {
if msg.Type != ipv4.ICMPTypeEchoReply {
continue
}
@@ -167,180 +140,223 @@ func (c *xicmpConnClient) recvLoop() {
continue
}
c.mutex.Lock()
seqStatus, ok := c.seqStatus[echo.Seq]
c.mutex.Unlock()
// errors.LogDebug(context.Background(), "id ", echo.ID, " seq ", echo.Seq, " addr ", addr)
if !c.udp && echo.ID != c.id {
continue
}
if c.ring(uint16(echo.Seq), uint16(c.seq)) > 1000 {
continue
}
if len(echo.Data) > 8 && bytes.Equal(echo.Data[:8], c.clientID[:]) {
continue
}
p := pool.Get().([]byte)[:len(echo.Data)]
copy(p, echo.Data)
if !c.udp {
addr = &net.UDPAddr{IP: addr.(*net.IPAddr).IP}
}
select {
case c.readCh <- packet{
p: p,
addr: addr,
}:
case <-c.closedCh:
pool.Put(p)
return
}
}
}
func (c *xicmpConnClient) recv6() {
var b [finalmask.UDPSize]byte
for {
if c.closed() {
break
}
n, addr, err := c.icmp6.ReadFrom(b[:])
if err != nil {
var netErr net.Error
if goerrors.As(err, &netErr) && netErr.Timeout() {
select {
case c.readCh <- packet{
err: err,
}:
case <-c.closedCh:
return
}
}
continue
}
msg, err := icmp.ParseMessage(58, b[:n])
if err != nil {
continue
}
if msg.Type != ipv6.ICMPTypeEchoReply {
continue
}
echo, ok := msg.Body.(*icmp.Echo)
if !ok {
continue
}
if seqStatus.needSeqByte {
if len(echo.Data) <= 1 {
continue
}
if echo.Data[0] == seqStatus.seqByte {
continue
}
echo.Data = echo.Data[1:]
// errors.LogDebug(context.Background(), "id ", echo.ID, " seq ", echo.Seq, " addr ", addr)
if !c.udp && echo.ID != c.id {
continue
}
if len(echo.Data) > 0 {
c.mutex.Lock()
delete(c.seqStatus, echo.Seq)
c.mutex.Unlock()
buf := make([]byte, len(echo.Data))
copy(buf, echo.Data)
select {
case c.readQueue <- &packet{
p: buf,
addr: &net.UDPAddr{IP: addr.(*net.IPAddr).IP},
}:
default:
errors.LogDebug(context.Background(), addr, " ", echo.Seq, " ", echo.ID, " mask read err queue full")
}
select {
case c.pollChan <- struct{}{}:
default:
}
if c.ring(uint16(echo.Seq), uint16(c.seq)) > 1000 {
continue
}
}
errors.LogDebug(context.Background(), "xicmp closed")
if len(echo.Data) > 8 && bytes.Equal(echo.Data[:8], c.clientID[:]) {
continue
}
close(c.pollChan)
close(c.readQueue)
p := pool.Get().([]byte)[:len(echo.Data)]
copy(p, echo.Data)
c.mutex.Lock()
defer c.mutex.Unlock()
c.closed = true
close(c.writeQueue)
}
func (c *xicmpConnClient) sendLoop() {
var addr net.Addr
pollDelay := initPollDelay
pollTimer := time.NewTimer(pollDelay)
for {
var p *packet
pollTimerExpired := false
if !c.udp {
addr = &net.UDPAddr{IP: addr.(*net.IPAddr).IP}
}
select {
case p = <-c.writeQueue:
default:
select {
case p = <-c.writeQueue:
case <-c.pollChan:
case <-pollTimer.C:
pollTimerExpired = true
}
}
if p != nil {
addr = p.addr
select {
case <-c.pollChan:
default:
}
} else if addr != nil {
encoded, _ := c.encode(nil)
p = &packet{
p: encoded,
addr: addr,
}
}
if pollTimerExpired {
pollDelay = time.Duration(float64(pollDelay) * pollDelayMultiplier)
if pollDelay > maxPollDelay {
pollDelay = maxPollDelay
}
} else {
if !pollTimer.Stop() {
<-pollTimer.C
}
pollDelay = initPollDelay
}
pollTimer.Reset(pollDelay)
if c.closed {
case c.readCh <- packet{
p: p,
addr: addr,
}:
case <-c.closedCh:
pool.Put(p)
return
}
if p != nil {
_, err := c.icmpConn.WriteTo(p.p, p.addr)
if err != nil {
errors.LogDebug(context.Background(), p.addr, " xicmp writeto err ", err)
}
}
}
}
func (c *xicmpConnClient) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
packet, ok := <-c.readQueue
if !ok {
return 0, nil, net.ErrClosed
select {
case packet := <-c.readCh:
if packet.p != nil {
n = copy(p, packet.p)
pool.Put(packet.p)
}
return n, packet.addr, packet.err
case <-c.closedCh:
return 0, nil, io.EOF
}
if len(p) < len(packet.p) {
errors.LogDebug(context.Background(), packet.addr, " mask read err short buffer ", len(p), " ", len(packet.p))
return 0, packet.addr, nil
}
copy(p, packet.p)
return len(packet.p), packet.addr, nil
}
func (c *xicmpConnClient) WriteTo(p []byte, addr net.Addr) (n int, err error) {
encoded, err := c.encode(p)
if len(p)+16 > finalmask.UDPSize {
errors.LogError(context.Background(), "drop packet to ", addr, " with size ", len(p))
return 0, nil
}
c.mu.Lock()
seq := c.seq
c.seq += 1
c.seq %= 65536
c.mu.Unlock()
ip := addr.(*net.UDPAddr).IP
if len(c.ips) > 0 {
ip = c.ips[mathrand.Intn(len(c.ips))].AsSlice()
}
if c.udp {
addr = &net.UDPAddr{IP: ip}
} else {
addr = &net.IPAddr{IP: ip}
}
b := pool.Get().([]byte)[:finalmask.UDPSize]
defer pool.Put(b)
copy(b[8:], c.clientID[:])
copy(b[16:], p)
if ip.To4() != nil {
b = marshal(b, ipv4.ICMPTypeEcho, c.id, seq, 8+len(p))
_, err = c.icmp4.WriteTo(b, addr)
} else {
b = marshal(b, ipv6.ICMPTypeEchoRequest, c.id, seq, 8+len(p))
_, err = c.icmp6.WriteTo(b, addr)
}
if err != nil {
errors.LogDebug(context.Background(), addr, " xicmp wireformat err ", err)
return 0, nil
errors.LogErrorInner(context.Background(), err, "xicmp write")
return 0, err
}
c.mutex.Lock()
defer c.mutex.Unlock()
if c.closed {
return 0, io.ErrClosedPipe
}
select {
case c.writeQueue <- &packet{
p: encoded,
addr: &net.IPAddr{IP: addr.(*net.UDPAddr).IP},
}:
return len(p), nil
default:
errors.LogDebug(context.Background(), addr, " mask write err queue full")
return 0, nil
}
return len(p), nil
}
func (c *xicmpConnClient) Close() error {
c.closed = true
_ = c.icmpConn.Close()
return c.conn.Close()
c.mu.Lock()
defer c.mu.Unlock()
if c.closed() {
return nil
}
close(c.closedCh)
_ = c.icmp4.Close()
_ = c.icmp6.Close()
_ = c.conn.Close()
return nil
}
func (c *xicmpConnClient) LocalAddr() net.Addr {
return &net.UDPAddr{
IP: c.icmpConn.LocalAddr().(*net.IPAddr).IP,
Port: c.id,
}
return c.conn.LocalAddr()
}
func (c *xicmpConnClient) SetDeadline(t time.Time) error {
return c.icmpConn.SetDeadline(t)
_ = c.icmp4.SetDeadline(t)
_ = c.icmp6.SetDeadline(t)
return nil
}
func (c *xicmpConnClient) SetReadDeadline(t time.Time) error {
return c.icmpConn.SetReadDeadline(t)
_ = c.icmp4.SetReadDeadline(t)
_ = c.icmp6.SetReadDeadline(t)
return nil
}
func (c *xicmpConnClient) SetWriteDeadline(t time.Time) error {
return c.icmpConn.SetWriteDeadline(t)
_ = c.icmp4.SetWriteDeadline(t)
_ = c.icmp6.SetWriteDeadline(t)
return nil
}
//go:linkname checksum golang.org/x/net/icmp.checksum
func checksum(b []byte) uint16
func marshal(b []byte, typ icmp.Type, id, seq int, dataLen int) []byte {
is4 := false
switch typ := typ.(type) {
case ipv4.ICMPType:
is4 = true
b[0] = byte(typ)
case ipv6.ICMPType:
b[0] = byte(typ)
default:
panic(fmt.Sprintf("%T %v", typ, typ))
}
clear(b[1:4])
binary.BigEndian.PutUint16(b[4:], uint16(id))
binary.BigEndian.PutUint16(b[6:], uint16(seq))
if is4 {
s := checksum(b[:8+dataLen])
b[2] ^= byte(s)
b[3] ^= byte(s >> 8)
}
return b[:8+dataLen]
}