Developing lightweight computation at the DSG edge

Commit 3745d7b5 authored by Clint Armstrong's avatar Clint Armstrong Committed by Cameron Sparr
Browse files

expose ttl on returned ping

parent ef3ab45e
......@@ -65,8 +65,8 @@ func main() {
}()
pinger.OnRecv = func(pkt *ping.Packet) {
fmt.Printf("%d bytes from %s: icmp_seq=%d time=%v\n",
pkt.Nbytes, pkt.IPAddr, pkt.Seq, pkt.Rtt)
fmt.Printf("%d bytes from %s: icmp_seq=%d time=%v ttl=%v\n",
pkt.Nbytes, pkt.IPAddr, pkt.Seq, pkt.Rtt, pkt.Ttl)
}
pinger.OnFinish = func(stats *ping.Statistics) {
fmt.Printf("\n--- %s ping statistics ---\n", stats.Addr)
......
......@@ -154,6 +154,7 @@ type Pinger struct {
type packet struct {
bytes []byte
nbytes int
ttl int
}
// Packet represents a received and processed ICMP echo packet.
......@@ -172,6 +173,9 @@ type Packet struct {
// Seq is the ICMP sequence number.
Seq int
// TTL is the TTL on the packet
Ttl int
}
// Statistics represent the stats of a currently running or finished
......@@ -276,10 +280,12 @@ func (p *Pinger) run() {
if conn = p.listen(ipv4Proto[p.network], p.source); conn == nil {
return
}
conn.IPv4PacketConn().SetControlMessage(ipv4.FlagTTL, true)
} else {
if conn = p.listen(ipv6Proto[p.network], p.source); conn == nil {
return
}
conn.IPv6PacketConn().SetControlMessage(ipv6.FlagHopLimit, true)
}
defer conn.Close()
defer p.finish()
......@@ -397,7 +403,21 @@ func (p *Pinger) recvICMP(
default:
bytes := make([]byte, 512)
conn.SetReadDeadline(time.Now().Add(time.Millisecond * 100))
n, _, err := conn.ReadFrom(bytes)
var n, ttl int
var err error
if p.ipv4 {
var cm *ipv4.ControlMessage
n, cm, _, err = conn.IPv4PacketConn().ReadFrom(bytes)
if cm != nil {
ttl = cm.TTL
}
} else {
var cm *ipv6.ControlMessage
n, cm, _, err = conn.IPv6PacketConn().ReadFrom(bytes)
if cm != nil {
ttl = cm.HopLimit
}
}
if err != nil {
if neterr, ok := err.(*net.OpError); ok {
if neterr.Timeout() {
......@@ -410,7 +430,7 @@ func (p *Pinger) recvICMP(
}
}
recv <- &packet{bytes: bytes, nbytes: n}
recv <- &packet{bytes: bytes, nbytes: n, ttl: ttl}
}
}
}
......@@ -465,6 +485,7 @@ func (p *Pinger) processPacket(recv *packet) error {
Nbytes: recv.nbytes,
IPAddr: p.ipaddr,
Addr: p.addr,
Ttl: recv.ttl,
}
switch pkt := m.Body.(type) {
......
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