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