// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package icmp_test
import (
"errors"
"flag"
"fmt"
"net"
"os"
"runtime"
"sync"
"testing"
"time"
"golang.org/x/net/icmp"
"golang.org/x/net/internal/iana"
"golang.org/x/net/ipv4"
"golang.org/x/net/ipv6"
"golang.org/x/net/nettest"
)
var testDiag = flag.Bool("diag", false, "whether to test ICMP message exchange with external network")
type diagTest struct {
network, address string
protocol int
m icmp.Message
}
func TestDiag(t *testing.T) {
if !*testDiag {
t.Skip("avoid external network")
}
t.Run("Ping/NonPrivileged", func(t *testing.T) {
if m, ok := supportsNonPrivilegedICMP(); !ok {
t.Skip(m)
}
for i, dt := range []diagTest{
{
"udp4", "0.0.0.0", iana.ProtocolICMP,
icmp.Message{
Type: ipv4.ICMPTypeEcho, Code: 0,
Body: &icmp.Echo{
ID: os.Getpid() & 0xffff,
Data: []byte("HELLO-R-U-THERE"),
},
},
},
{
"udp6", "::", iana.ProtocolIPv6ICMP,
icmp.Message{
Type: ipv6.ICMPTypeEchoRequest, Code: 0,
Body: &icmp.Echo{
ID: os.Getpid() & 0xffff,
Data: []byte("HELLO-R-U-THERE"),
},
},
},
} {
if err := doDiag(dt, i); err != nil {
t.Error(err)
}
}
})
t.Run("Ping/Privileged", func(t *testing.T) {
if !nettest.SupportsRawSocket() {
t.Skipf("not supported on %s/%s", runtime.GOOS, runtime.GOARCH)
}
for i, dt := range []diagTest{
{
"ip4:icmp", "0.0.0.0", iana.ProtocolICMP,
icmp.Message{
Type: ipv4.ICMPTypeEcho, Code: 0,
Body: &icmp.Echo{
ID: os.Getpid() & 0xffff,
Data: []byte("HELLO-R-U-THERE"),
},
},
},
{
"ip6:ipv6-icmp", "::", iana.ProtocolIPv6ICMP,
icmp.Message{
Type: ipv6.ICMPTypeEchoRequest, Code: 0,
Body: &icmp.Echo{
ID: os.Getpid() & 0xffff,
Data: []byte("HELLO-R-U-THERE"),
},
},
},
} {
if err := doDiag(dt, i); err != nil {
t.Error(err)
}
}
})
t.Run("Probe/Privileged", func(t *testing.T) {
if !nettest.SupportsRawSocket() {
t.Skipf("not supported on %s/%s", runtime.GOOS, runtime.GOARCH)
}
for i, dt := range []diagTest{
{
"ip4:icmp", "0.0.0.0", iana.ProtocolICMP,
icmp.Message{
Type: ipv4.ICMPTypeExtendedEchoRequest, Code: 0,
Body: &icmp.ExtendedEchoRequest{
ID: os.Getpid() & 0xffff,
Local: true,
Extensions: []icmp.Extension{
&icmp.InterfaceIdent{
Class: 3, Type: 1,
Name: "doesnotexist",
},
},
},
},
},
{
"ip6:ipv6-icmp", "::", iana.ProtocolIPv6ICMP,
icmp.Message{
Type: ipv6.ICMPTypeExtendedEchoRequest, Code: 0,
Body: &icmp.ExtendedEchoRequest{
ID: os.Getpid() & 0xffff,
Local: true,
Extensions: []icmp.Extension{
&icmp.InterfaceIdent{
Class: 3, Type: 1,
Name: "doesnotexist",
},
},
},
},
},
} {
if err := doDiag(dt, i); err != nil {
t.Error(err)
}
}
})
}
func doDiag(dt diagTest, seq int) error {
c, err := icmp.ListenPacket(dt.network, dt.address)
if err != nil {
return err
}
defer c.Close()
dst, err := googleAddr(c, dt.protocol)
if err != nil {
return err
}
if dt.network != "udp6" && dt.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)
f.Accept(ipv6.ICMPTypeExtendedEchoReply)
if err := c.IPv6PacketConn().SetICMPFilter(&f); err != nil {
return err
}
}
switch m := dt.m.Body.(type) {
case *icmp.Echo:
m.Seq = 1 << uint(seq)
case *icmp.ExtendedEchoRequest:
m.Seq = 1 << uint(seq)
}
wb, err := dt.m.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(dt.protocol, rb[:n])
if err != nil {
return err
}
switch {
case dt.m.Type == ipv4.ICMPTypeEcho && rm.Type == ipv4.ICMPTypeEchoReply:
fallthrough
case dt.m.Type == ipv6.ICMPTypeEchoRequest && rm.Type == ipv6.ICMPTypeEchoReply:
fallthrough
case dt.m.Type == ipv4.ICMPTypeExtendedEchoRequest && rm.Type == ipv4.ICMPTypeExtendedEchoReply:
fallthrough
case dt.m.Type == ipv6.ICMPTypeExtendedEchoRequest && rm.Type == ipv6.ICMPTypeExtendedEchoReply:
return nil
default:
return fmt.Errorf("got %+v from %v; want echo reply or extended echo reply", rm, peer)
}
}
func googleAddr(c *icmp.PacketConn, protocol int) (net.Addr, error) {
host := "ipv4.google.com"
if protocol == iana.ProtocolIPv6ICMP {
host = "ipv6.google.com"
}
ips, err := net.LookupIP(host)
if err != nil {
return nil, err
}
netaddr := func(ip net.IP) (net.Addr, error) {
switch c.LocalAddr().(type) {
case *net.UDPAddr:
return &net.UDPAddr{IP: ip}, nil
case *net.IPAddr:
return &net.IPAddr{IP: ip}, nil
default:
return nil, errors.New("neither UDPAddr nor IPAddr")
}
}
if len(ips) > 0 {
return netaddr(ips[0])
}
return nil, errors.New("no A or AAAA record")
}
func TestConcurrentNonPrivilegedListenPacket(t *testing.T) {
if testing.Short() {
t.Skip("avoid external network")
}
if m, ok := supportsNonPrivilegedICMP(); !ok {
t.Skip(m)
}
network, address := "udp4", "127.0.0.1"
if !nettest.SupportsIPv4() {
network, address = "udp6", "::1"
}
const N = 1000
var wg sync.WaitGroup
wg.Add(N)
for i := 0; i < N; i++ {
go func() {
defer wg.Done()
c, err := icmp.ListenPacket(network, address)
if err != nil {
t.Error(err)
return
}
c.Close()
}()
}
wg.Wait()
}
var (
nonPrivOnce sync.Once
nonPrivMsg string
nonPrivICMP bool
)
func supportsNonPrivilegedICMP() (string, bool) {
nonPrivOnce.Do(func() {
switch runtime.GOOS {
case "darwin":
nonPrivICMP = true
case "linux":
for _, t := range []struct{ network, address string }{
{"udp4", "127.0.0.1"},
{"udp6", "::1"},
} {
c, err := icmp.ListenPacket(t.network, t.address)
if err != nil {
nonPrivMsg = "you may need to adjust the net.ipv4.ping_group_range kernel state"
return
}
c.Close()
}
nonPrivICMP = true
default:
nonPrivMsg = "not supported on " + runtime.GOOS
}
})
return nonPrivMsg, nonPrivICMP
}
