更改目录结构

server/pkg/arpdis/icmp.go

@@ -0,0 +1,101 @@
+package arpdis
+
+import (
+	"errors"
+	"net"
+	"os"
+	"time"
+
+	"golang.org/x/net/icmp"
+	"golang.org/x/net/ipv4"
+)
+
+const (
+	ProtocolICMP     = 1
+	ProtocolIPv6ICMP = 58
+)
+
+func doPing(ip string) error {
+	raddr, _ := net.ResolveIPAddr("ip4:icmp", ip)
+	conn, err := icmp.ListenPacket("ip4:icmp", "")
+	if err != nil {
+		return err
+	}
+
+	ipv4Conn := conn.IPv4PacketConn()
+	// 限制跳跃数
+	err = ipv4Conn.SetTTL(10)
+	if err != nil {
+		return err
+	}
+
+	msg := &icmp.Message{
+		Type: ipv4.ICMPTypeEcho,
+		Code: 0,
+		Body: &icmp.Echo{
+			ID:   os.Getpid() & 0xffff,
+			Seq:  1,
+			Data: timeToBytes(time.Now()),
+		},
+	}
+
+	b, err := msg.Marshal(nil)
+	if err != nil {
+		return err
+	}
+	_, err = conn.WriteTo(b, raddr)
+	if err != nil {
+		return err
+	}
+
+	_ = conn.SetReadDeadline(time.Now().Add(time.Second * 2))
+
+	for {
+		buf := make([]byte, 512)
+		n, dst, err := conn.ReadFrom(buf)
+		if err != nil {
+			return err
+		}
+		if dst.String() != ip {
+			continue
+		}
+
+		var result *icmp.Message
+		result, err = icmp.ParseMessage(ProtocolICMP, buf[:n])
+		if err != nil {
+			return err
+		}
+
+		switch result.Type {
+		case ipv4.ICMPTypeEchoReply:
+			// success
+			if rply, ok := result.Body.(*icmp.Echo); ok {
+				_ = rply
+				// log.Printf("%+v \n", rply)
+			}
+			return nil
+
+		// case ipv4.ICMPTypeTimeExceeded:
+		// case ipv4.ICMPTypeDestinationUnreachable:
+		default:
+			return errors.New("DestinationUnreachable")
+		}
+	}
+}
+
+func timeToBytes(t time.Time) []byte {
+	nsec := t.UnixNano()
+	b := make([]byte, 8)
+	for i := uint8(0); i < 8; i++ {
+		b[i] = byte((nsec >> ((7 - i) * 8)) & 0xff)
+	}
+	return b
+}
+
+func bytesToTime(b []byte) time.Time {
+	var nsec int64
+	for i := uint8(0); i < 8; i++ {
+		nsec += int64(b[i]) << ((7 - i) * 8)
+	}
+	return time.Unix(nsec/1000000000, nsec%1000000000)
+}