Finalmask: Add XICMP (relies on mKCP/QUIC or WireGuard)

infra/conf/transport_internet.go

@@ -26,6 +26,7 @@ import (
 	"github.com/xtls/xray-core/transport/internet/finalmask/mkcp/original"
 	"github.com/xtls/xray-core/transport/internet/finalmask/salamander"
 	"github.com/xtls/xray-core/transport/internet/finalmask/xdns"
+	"github.com/xtls/xray-core/transport/internet/finalmask/xicmp"
 	"github.com/xtls/xray-core/transport/internet/httpupgrade"
 	"github.com/xtls/xray-core/transport/internet/hysteria"
 	"github.com/xtls/xray-core/transport/internet/kcp"
@@ -1239,6 +1240,7 @@ var (
 		"mkcp-aes128gcm":   func() interface{} { return new(Aes128Gcm) },
 		"salamander":       func() interface{} { return new(Salamander) },
 		"xdns":             func() interface{} { return new(Xdns) },
+		"xicmp":            func() interface{} { return new(Xicmp) },
 	}, "type", "settings")
 )
 
@@ -1327,6 +1329,24 @@ func (c *Xdns) Build() (proto.Message, error) {
 	}, nil
 }
 
+type Xicmp struct {
+	ListenIp string `json:"listenIp"`
+	Id       uint16 `json:"id"`
+}
+
+func (c *Xicmp) Build() (proto.Message, error) {
+	config := &xicmp.Config{
+		Ip: c.ListenIp,
+		Id: int32(c.Id),
+	}
+
+	if config.Ip == "" {
+		config.Ip = "0.0.0.0"
+	}
+
+	return config, nil
+}
+
 type Mask struct {
 	Type     string           `json:"type"`
 	Settings *json.RawMessage `json:"settings"`

transport/internet/finalmask/xdns/client.go

@@ -209,7 +209,7 @@ func (c *xdnsConnClient) WriteTo(p []byte, addr net.Addr) (n int, err error) {
 
 	encoded, err := encode(p, c.clientID, c.domain)
 	if err != nil {
-		errors.LogDebug(context.Background(), "xdns encode err", err)
+		errors.LogDebug(context.Background(), "xdns encode err ", err)
 		return 0, errors.New("xdns encode").Base(err)
 	}
 

transport/internet/finalmask/xicmp/client.go

@@ -0,0 +1,348 @@
+package xicmp
+
+import (
+	"context"
+	"io"
+	"net"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/xtls/xray-core/common/crypto"
+	"github.com/xtls/xray-core/common/errors"
+	"golang.org/x/net/icmp"
+	"golang.org/x/net/ipv4"
+	"golang.org/x/net/ipv6"
+)
+
+const (
+	initPollDelay       = 500 * time.Millisecond
+	maxPollDelay        = 10 * time.Second
+	pollDelayMultiplier = 2.0
+	pollLimit           = 16
+)
+
+type packet struct {
+	p    []byte
+	addr net.Addr
+}
+
+type seqStatus struct {
+	needSeqByte bool
+	seqByte     byte
+	received    bool
+}
+
+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
+}
+
+func NewConnClient(c *Config, raw net.PacketConn, end bool) (net.PacketConn, error) {
+	if !end {
+		return nil, errors.New("xicmp requires being at the outermost level")
+	}
+
+	network := "ip4:icmp"
+	typ := icmp.Type(ipv4.ICMPTypeEcho)
+	proto := 1
+	if strings.Contains(c.Ip, ":") {
+		network = "ip6:ipv6-icmp"
+		typ = ipv6.ICMPTypeEchoRequest
+		proto = 58
+	}
+
+	icmpConn, err := icmp.ListenPacket(network, c.Ip)
+	if err != nil {
+		return nil, errors.New("xicmp listen err").Base(err)
+	}
+
+	if c.Id == 0 {
+		c.Id = int32(crypto.RandBetween(0, 65535))
+	}
+
+	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, 128),
+		writeQueue: make(chan *packet, 128),
+	}
+
+	go conn.recvLoop()
+	go conn.sendLoop()
+
+	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) > 8192 {
+		return nil, errors.New("xicmp len(buf) > 8192")
+	}
+
+	c.seqStatus[c.seq] = &seqStatus{
+		needSeqByte: needSeqByte,
+		seqByte:     seqByte,
+		received:    false,
+	}
+
+	c.seq++
+
+	if c.seq == 65536 {
+		c.seq = 1
+	}
+
+	return buf, nil
+}
+
+func (c *xicmpConnClient) recvLoop() {
+	for {
+		if c.closed {
+			break
+		}
+
+		var buf [8192]byte
+
+		n, addr, err := c.icmpConn.ReadFrom(buf[:])
+		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 {
+			continue
+		}
+
+		echo, ok := msg.Body.(*icmp.Echo)
+		if !ok {
+			continue
+		}
+
+		seqStatus, ok := c.seqStatus[echo.Seq]
+
+		if !ok {
+			continue
+		}
+
+		if seqStatus.received {
+			continue
+		}
+
+		if seqStatus.needSeqByte {
+			if len(echo.Data) <= 1 {
+				continue
+			}
+			if echo.Data[0] == seqStatus.seqByte {
+				continue
+			}
+			echo.Data = echo.Data[1:]
+		}
+
+		if len(echo.Data) > 0 {
+			seqStatus.received = true
+
+			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:
+			}
+
+			select {
+			case c.pollChan <- struct{}{}:
+			default:
+			}
+		}
+	}
+
+	close(c.pollChan)
+	close(c.readQueue)
+}
+
+func (c *xicmpConnClient) sendLoop() {
+	var addr net.Addr
+
+	pollDelay := initPollDelay
+	pollTimer := time.NewTimer(pollDelay)
+	for {
+		var p *packet
+		pollTimerExpired := false
+
+		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 {
+			return
+		}
+
+		if p != nil {
+			_, err := c.icmpConn.WriteTo(p.p, p.addr)
+			if err != nil {
+				errors.LogDebug(context.Background(), "xicmp writeto err ", err)
+			}
+		}
+	}
+}
+
+func (c *xicmpConnClient) Size() int32 {
+	return 0
+}
+
+func (c *xicmpConnClient) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
+	packet, ok := <-c.readQueue
+	if !ok {
+		return 0, nil, io.EOF
+	}
+	n = copy(p, packet.p)
+	if n != len(packet.p) {
+		return 0, nil, io.ErrShortBuffer
+	}
+	return n, packet.addr, nil
+}
+
+func (c *xicmpConnClient) WriteTo(p []byte, addr net.Addr) (n int, err error) {
+	encoded, err := c.encode(p)
+	if err != nil {
+		return 0, errors.New("xicmp encode").Base(err)
+	}
+
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+
+	if c.closed {
+		return 0, errors.New("xicmp closed")
+	}
+
+	select {
+	case c.writeQueue <- &packet{
+		p:    encoded,
+		addr: &net.IPAddr{IP: addr.(*net.UDPAddr).IP},
+	}:
+		return len(p), nil
+	default:
+		return 0, errors.New("xicmp queue full")
+	}
+}
+
+func (c *xicmpConnClient) Close() error {
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+
+	if c.closed {
+		return nil
+	}
+
+	c.closed = true
+	close(c.writeQueue)
+
+	_ = c.icmpConn.Close()
+	return c.conn.Close()
+}
+
+func (c *xicmpConnClient) LocalAddr() net.Addr {
+	return &net.UDPAddr{
+		IP:   c.icmpConn.LocalAddr().(*net.IPAddr).IP,
+		Port: c.id,
+	}
+}
+
+func (c *xicmpConnClient) SetDeadline(t time.Time) error {
+	return c.icmpConn.SetDeadline(t)
+}
+
+func (c *xicmpConnClient) SetReadDeadline(t time.Time) error {
+	return c.icmpConn.SetReadDeadline(t)
+}
+
+func (c *xicmpConnClient) SetWriteDeadline(t time.Time) error {
+	return c.icmpConn.SetWriteDeadline(t)
+}