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