func googleAddr(c *icmp.PacketConn, protocol int) (net.Addr, error) {
const host = "www.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")
}
}
for _, ip := range ips {
switch protocol {
case iana.ProtocolICMP:
if ip.To4() != nil {
return netaddr(ip)
}
case iana.ProtocolIPv6ICMP:
if ip.To16() != nil && ip.To4() == nil {
return netaddr(ip)
}
}
}
return nil, errors.New("no A or AAAA record")
}
func (p *Pinger) recvICMP(conn *icmp.PacketConn, recv chan<- *packet, ctx *context, wg *sync.WaitGroup) {
p.debugln("recvICMP(): Start")
for {
select {
case <-ctx.stop:
p.debugln("recvICMP(): <-ctx.stop")
wg.Done()
p.debugln("recvICMP(): wg.Done()")
return
default:
}
bytes := make([]byte, 512)
conn.SetReadDeadline(time.Now().Add(time.Millisecond * 100))
p.debugln("recvICMP(): ReadFrom Start")
_, ra, err := conn.ReadFrom(bytes)
p.debugln("recvICMP(): ReadFrom End")
if err != nil {
if neterr, ok := err.(*net.OpError); ok {
if neterr.Timeout() {
p.debugln("recvICMP(): Read Timeout")
continue
} else {
p.debugln("recvICMP(): OpError happen", err)
p.mu.Lock()
ctx.err = err
p.mu.Unlock()
p.debugln("recvICMP(): close(ctx.done)")
close(ctx.done)
p.debugln("recvICMP(): wg.Done()")
wg.Done()
return
}
}
}
p.debugln("recvICMP(): p.recv <- packet")
select {
case recv <- &packet{bytes: bytes, addr: ra}:
case <-ctx.stop:
p.debugln("recvICMP(): <-ctx.stop")
wg.Done()
p.debugln("recvICMP(): wg.Done()")
return
}
}
}
func (p *Pinger) sendICMP(conn, conn6 *icmp.PacketConn) (map[string]*net.IPAddr, error) {
p.debugln("sendICMP(): Start")
p.mu.Lock()
p.id = rand.Intn(0xffff)
p.seq = rand.Intn(0xffff)
p.mu.Unlock()
queue := make(map[string]*net.IPAddr)
wg := new(sync.WaitGroup)
for key, addr := range p.addrs {
var typ icmp.Type
var cn *icmp.PacketConn
if isIPv4(addr.IP) {
typ = ipv4.ICMPTypeEcho
cn = conn
} else if isIPv6(addr.IP) {
typ = ipv6.ICMPTypeEchoRequest
cn = conn6
} else {
continue
}
if cn == nil {
continue
}
t := timeToBytes(time.Now())
if p.Size-TimeSliceLength != 0 {
t = append(t, byteSliceOfSize(p.Size-TimeSliceLength)...)
}
p.mu.Lock()
bytes, err := (&icmp.Message{
Type: typ, Code: 0,
Body: &icmp.Echo{
ID: p.id, Seq: p.seq,
Data: t,
},
}).Marshal(nil)
p.mu.Unlock()
if err != nil {
wg.Wait()
return queue, err
}
queue[key] = addr
var dst net.Addr = addr
if p.network == "udp" {
dst = &net.UDPAddr{IP: addr.IP, Zone: addr.Zone}
}
p.debugln("sendICMP(): Invoke goroutine")
wg.Add(1)
go func(conn *icmp.PacketConn, ra net.Addr, b []byte) {
for {
if _, err := conn.WriteTo(bytes, ra); err != nil {
if neterr, ok := err.(*net.OpError); ok {
if neterr.Err == syscall.ENOBUFS {
continue
}
}
}
break
}
p.debugln("sendICMP(): WriteTo End")
wg.Done()
}(cn, dst, bytes)
}
wg.Wait()
p.debugln("sendICMP(): End")
return queue, nil
}
func (p *Pinger) run(once bool) {
p.debugln("Run(): Start")
var conn, conn6 *icmp.PacketConn
if p.hasIPv4 {
if conn = p.listen(ipv4Proto[p.network], p.source); conn == nil {
return
}
defer conn.Close()
}
if p.hasIPv6 {
if conn6 = p.listen(ipv6Proto[p.network], p.source6); conn6 == nil {
return
}
defer conn6.Close()
}
recv := make(chan *packet, 1)
recvCtx := newContext()
wg := new(sync.WaitGroup)
p.debugln("Run(): call recvICMP()")
if conn != nil {
wg.Add(1)
go p.recvICMP(conn, recv, recvCtx, wg)
}
if conn6 != nil {
wg.Add(1)
go p.recvICMP(conn6, recv, recvCtx, wg)
}
p.debugln("Run(): call sendICMP()")
queue, err := p.sendICMP(conn, conn6)
ticker := time.NewTicker(p.MaxRTT)
mainloop:
for {
select {
case <-p.ctx.stop:
p.debugln("Run(): <-p.ctx.stop")
break mainloop
case <-recvCtx.done:
p.debugln("Run(): <-recvCtx.done")
p.mu.Lock()
err = recvCtx.err
p.mu.Unlock()
break mainloop
case <-ticker.C:
p.mu.Lock()
handler := p.OnIdle
p.mu.Unlock()
if handler != nil {
handler()
}
if once || err != nil {
break mainloop
}
p.debugln("Run(): call sendICMP()")
queue, err = p.sendICMP(conn, conn6)
case r := <-recv:
p.debugln("Run(): <-recv")
p.procRecv(r, queue)
}
}
ticker.Stop()
p.debugln("Run(): close(recvCtx.stop)")
close(recvCtx.stop)
p.debugln("Run(): wait recvICMP()")
wg.Wait()
p.mu.Lock()
p.ctx.err = err
p.mu.Unlock()
p.debugln("Run(): close(p.ctx.done)")
close(p.ctx.done)
p.debugln("Run(): End")
}