func ExamplePacketConn_nonPrivilegedPing() {
switch runtime.GOOS {
case "darwin":
case "linux":
log.Println("you may need to adjust the net.ipv4.ping_group_range kernel state")
default:
log.Println("not supported on", runtime.GOOS)
return
}
c, err := icmp.ListenPacket("udp6", "fe80::1%en0")
if err != nil {
log.Fatal(err)
}
defer c.Close()
wm := icmp.Message{
Type: ipv6.ICMPTypeEchoRequest, Code: 0,
Body: &icmp.Echo{
ID: os.Getpid() & 0xffff, Seq: 1,
Data: []byte("HELLO-R-U-THERE"),
},
}
wb, err := wm.Marshal(nil)
if err != nil {
log.Fatal(err)
}
if _, err := c.WriteTo(wb, &net.UDPAddr{IP: net.ParseIP("ff02::1"), Zone: "en0"}); err != nil {
log.Fatal(err)
}
rb := make([]byte, 1500)
n, peer, err := c.ReadFrom(rb)
if err != nil {
log.Fatal(err)
}
rm, err := icmp.ParseMessage(58, rb[:n])
if err != nil {
log.Fatal(err)
}
switch rm.Type {
case ipv6.ICMPTypeEchoReply:
log.Printf("got reflection from %v", peer)
default:
log.Printf("got %+v; want echo reply", rm)
}
}
func ExamplePacketConn_nonPrivilegedPing() {
c, err := icmp.ListenPacket("udp6", "fe80::1%en0")
if err != nil {
log.Fatal(err)
}
defer c.Close()
wm := icmp.Message{
Type: ipv6.ICMPTypeEchoRequest, Code: 0,
Body: &icmp.Echo{
ID: os.Getpid() & 0xffff, Seq: 1,
Data: []byte("HELLO-R-U-THERE"),
},
}
wb, err := wm.Marshal(nil)
if err != nil {
log.Fatal(err)
}
if _, err := c.WriteTo(wb, &net.UDPAddr{IP: net.ParseIP("ff02::1"), Zone: "en0"}); err != nil {
log.Fatal(err)
}
rb := make([]byte, 1500)
n, peer, err := c.ReadFrom(rb)
if err != nil {
log.Fatal(err)
}
rm, err := icmp.ParseMessage(iana.ProtocolIPv6ICMP, rb[:n])
if err != nil {
log.Fatal(err)
}
switch rm.Type {
case ipv6.ICMPTypeEchoReply:
log.Printf("got reflection from %v", peer)
default:
log.Printf("got %+v; want echo reply", rm)
}
}
func TestPingGoogle(t *testing.T) {
if testing.Short() {
t.Skip("to avoid external network")
}
switch runtime.GOOS {
case "darwin":
case "linux":
t.Log("you may need to adjust the net.ipv4.ping_group_range kernel state")
default:
t.Skipf("not supported on %s", runtime.GOOS)
}
m, ok := nettest.SupportsRawIPSocket()
for i, tt := range pingGoogleTests {
if tt.network[:2] == "ip" && !ok {
t.Log(m)
continue
}
c, err := icmp.ListenPacket(tt.network, tt.address)
if err != nil {
t.Error(err)
continue
}
defer c.Close()
dst, err := googleAddr(c, tt.protocol)
if err != nil {
t.Error(err)
continue
}
wm := icmp.Message{
Type: tt.mtype, Code: 0,
Body: &icmp.Echo{
ID: os.Getpid() & 0xffff, Seq: 1 << uint(i),
Data: []byte("HELLO-R-U-THERE"),
},
}
wb, err := wm.Marshal(nil)
if err != nil {
t.Error(err)
continue
}
if n, err := c.WriteTo(wb, dst); err != nil {
t.Error(err, dst)
continue
} else if n != len(wb) {
t.Errorf("got %v; want %v", n, len(wb))
continue
}
rb := make([]byte, 1500)
n, peer, err := c.ReadFrom(rb)
if err != nil {
t.Error(err)
continue
}
rm, err := icmp.ParseMessage(tt.protocol, rb[:n])
if err != nil {
t.Error(err)
continue
}
switch rm.Type {
case ipv4.ICMPTypeEchoReply, ipv6.ICMPTypeEchoReply:
t.Logf("got reflection from %v", peer)
default:
t.Errorf("got %+v; want echo reply", rm)
}
}
}
func ExamplePacketConn_tracingIPPacketRoute() {
// Tracing an IP packet route to www.google.com.
const host = "www.google.com"
ips, err := net.LookupIP(host)
if err != nil {
log.Fatal(err)
}
var dst net.IPAddr
for _, ip := range ips {
if ip.To4() != nil {
dst.IP = ip
fmt.Printf("using %v for tracing an IP packet route to %s\n", dst.IP, host)
break
}
}
if dst.IP == nil {
log.Fatal("no A record found")
}
c, err := net.ListenPacket(fmt.Sprintf("ip4:%d", iana.ProtocolICMP), "0.0.0.0") // ICMP for IPv4
if err != nil {
log.Fatal(err)
}
defer c.Close()
p := ipv4.NewPacketConn(c)
if err := p.SetControlMessage(ipv4.FlagTTL|ipv4.FlagSrc|ipv4.FlagDst|ipv4.FlagInterface, true); err != nil {
log.Fatal(err)
}
wm := icmp.Message{
Type: ipv4.ICMPTypeEcho, Code: 0,
Body: &icmp.Echo{
ID: os.Getpid() & 0xffff,
Data: []byte("HELLO-R-U-THERE"),
},
}
rb := make([]byte, 1500)
for i := 1; i <= 64; i++ { // up to 64 hops
wm.Body.(*icmp.Echo).Seq = i
wb, err := wm.Marshal(nil)
if err != nil {
log.Fatal(err)
}
if err := p.SetTTL(i); err != nil {
log.Fatal(err)
}
// In the real world usually there are several
// multiple traffic-engineered paths for each hop.
// You may need to probe a few times to each hop.
begin := time.Now()
if _, err := p.WriteTo(wb, nil, &dst); err != nil {
log.Fatal(err)
}
if err := p.SetReadDeadline(time.Now().Add(3 * time.Second)); err != nil {
log.Fatal(err)
}
n, cm, peer, err := p.ReadFrom(rb)
if err != nil {
if err, ok := err.(net.Error); ok && err.Timeout() {
fmt.Printf("%v\t*\n", i)
continue
}
log.Fatal(err)
}
rm, err := icmp.ParseMessage(iana.ProtocolICMP, rb[:n])
if err != nil {
log.Fatal(err)
}
rtt := time.Since(begin)
// In the real world you need to determine whether the
// received message is yours using ControlMessage.Src,
// ControlMessage.Dst, icmp.Echo.ID and icmp.Echo.Seq.
switch rm.Type {
case ipv4.ICMPTypeTimeExceeded:
names, _ := net.LookupAddr(peer.String())
fmt.Printf("%d\t%v %+v %v\n\t%+v\n", i, peer, names, rtt, cm)
case ipv4.ICMPTypeEchoReply:
names, _ := net.LookupAddr(peer.String())
fmt.Printf("%d\t%v %+v %v\n\t%+v\n", i, peer, names, rtt, cm)
return
default:
log.Printf("unknown ICMP message: %+v\n", rm)
}
}
}
func doPing(tt pingTest, seq int) error {
c, err := icmp.ListenPacket(tt.network, tt.address)
if err != nil {
return err
}
defer c.Close()
dst, err := googleAddr(c, tt.protocol)
if err != nil {
return err
}
if tt.network != "udp6" && tt.protocol == iana.ProtocolIPv6ICMP {
var f ipv6.ICMPFilter
f.SetAll(true)
f.Accept(ipv6.ICMPTypeDestinationUnreachable)
f.Accept(ipv6.ICMPTypePacketTooBig)
f.Accept(ipv6.ICMPTypeTimeExceeded)
f.Accept(ipv6.ICMPTypeParameterProblem)
f.Accept(ipv6.ICMPTypeEchoReply)
if err := c.IPv6PacketConn().SetICMPFilter(&f); err != nil {
return err
}
}
wm := icmp.Message{
Type: tt.mtype, Code: 0,
Body: &icmp.Echo{
ID: os.Getpid() & 0xffff, Seq: 1 << uint(seq),
Data: []byte("HELLO-R-U-THERE"),
},
}
wb, err := wm.Marshal(nil)
if err != nil {
return err
}
if n, err := c.WriteTo(wb, dst); err != nil {
return err
} else if n != len(wb) {
return fmt.Errorf("got %v; want %v", n, len(wb))
}
rb := make([]byte, 1500)
if err := c.SetReadDeadline(time.Now().Add(3 * time.Second)); err != nil {
return err
}
n, peer, err := c.ReadFrom(rb)
if err != nil {
return err
}
rm, err := icmp.ParseMessage(tt.protocol, rb[:n])
if err != nil {
return err
}
switch rm.Type {
case ipv4.ICMPTypeEchoReply, ipv6.ICMPTypeEchoReply:
return nil
default:
return fmt.Errorf("got %+v from %v; want echo reply", rm, peer)
}
}