func (o *OgoInstance) linkDiscoveryLoop(dpid net.HardwareAddr) {
for {
select {
case <-o.shutdown:
return
// Every two seconds send a link discovery packet.
case <-time.After(time.Second * 2):
e := eth.New()
e.Ethertype = 0xa0f1
e.HWSrc = dpid[2:]
linkDsc := NewLinkDiscovery()
linkDsc.SrcDPID = dpid
e.Data = linkDsc
pkt := ofp10.NewPacketOut()
pkt.Data = e
pkt.AddAction(ofp10.NewActionOutput(ofp10.P_ALL))
if sw, ok := Switch(dpid); ok {
sw.Send(pkt)
}
}
}
}
func (this *L3Forwarder) PacketIn(dpid net.HardwareAddr, pkt *ofp10.PacketIn) {
ethFrame := pkt.Data
ip := &ipv4.IPv4{}
// Ignore link discovery packet types.
if ethFrame.Ethertype == 0xa0f1 || ethFrame.Ethertype == 0x88cc {
return
}
if _, found := this.arpTable.Dpid(dpid); !found {
for _, fake := range this.fakeways {
this.arpTable.Add(dpid, net.ParseIP(fake), host{dpidToMac(dpid), ofp10.P_NONE})
}
}
if ethFrame.Ethertype == eth.IPv4_MSG {
ip = ethFrame.Data.(*ipv4.IPv4)
this.arpTable.Add(dpid, ip.NWSrc, host{ethFrame.HWSrc, pkt.InPort})
log.Println(dpid, pkt.InPort, "IP", ip.NWSrc, "->", ip.NWDst)
sendLostBuffers(dpid, ip.NWSrc, ethFrame.HWSrc, pkt.InPort)
dstaddr := ip.NWDst
if host, found := this.arpTable.Host(dpid, dstaddr); found {
if host.port == pkt.InPort {
log.Println(dpid, pkt.InPort, "not sending packet for", dstaddr.String(), "back out of the input port")
} else {
log.Println(dpid, pkt.InPort, "installing flow for", ip.NWSrc, "=>", ip.NWDst, "out port", host.port)
}
msg := ofp10.NewFlowMod()
msg.Match.InPort = pkt.InPort
msg.Match.DLDst = ethFrame.HWDst
msg.Match.DLSrc = ethFrame.HWSrc
msg.Match.Wildcards = ofp10.FW_ALL ^ ofp10.FW_DL_SRC ^ ofp10.FW_DL_DST
msg.Command = ofp10.FC_ADD
msg.AddAction(ofp10.NewActionDLDst(host.mac))
msg.AddAction(ofp10.NewActionOutput(host.port))
msg.IdleTimeout = 30
msg.HardTimeout = 20
msg.BufferId = pkt.BufferId
if sw, ok := ogo.Switch(dpid); ok {
sw.Send(msg)
}
} else {
if _, found := lostBuffers[pair{dpid.String(), ip.NWDst.String()}]; !found {
lostBuffers[pair{dpid.String(), ip.NWDst.String()}] = make([]buffer, 0)
}
lostBuffers[pair{dpid.String(), ip.NWDst.String()}] = append(lostBuffers[pair{dpid.String(), ip.NWDst.String()}], buffer{pkt.BufferId, pkt.InPort})
arpReq, err := arp.New(arp.Type_Request)
if err != nil {
panic(err)
}
arpReq.HWDst, _ = net.ParseMAC("ff:ff:ff:ff:ff:ff")
arpReq.IPDst = ip.NWDst
arpReq.HWSrc = ethFrame.HWSrc
arpReq.IPSrc = ip.NWSrc
e := eth.New()
e.Ethertype = eth.ARP_MSG
e.HWSrc = ethFrame.HWSrc
e.HWDst, _ = net.ParseMAC("ff:ff:ff:ff:ff:ff")
e.Data = arpReq
log.Println(dpid, pkt.InPort, "ARPing for", arpReq.IPDst, "on behalf of", arpReq.IPSrc)
msg := ofp10.NewPacketOut()
msg.InPort = pkt.InPort
msg.Data = e
msg.AddAction(ofp10.NewActionOutput(ofp10.P_FLOOD))
if sw, ok := ogo.Switch(dpid); ok {
sw.Send(msg)
}
}
} else if ethFrame.Ethertype == eth.ARP_MSG {
a := ethFrame.Data.(*arp.ARP)
log.Println(dpid, pkt.InPort, "ARP", a.Operation, a.IPSrc, "->", a.IPDst)
if _, found := this.arpTable.Host(dpid, a.IPSrc); found {
log.Println("RE-learned:", dpid, pkt.InPort, a.IPSrc)
} else {
log.Println("learned:", dpid, pkt.InPort, a.IPSrc)
}
this.arpTable.Add(dpid, a.IPSrc, host{ethFrame.HWSrc, pkt.InPort})
sendLostBuffers(dpid, a.IPSrc, ethFrame.HWSrc, pkt.InPort)
if a.Operation == arp.Type_Request {
if host, found := this.arpTable.Host(dpid, a.IPDst); found {
arpReply, err := arp.New(arp.Type_Reply)
if err != nil {
panic(err)
}
arpReply.HWType = a.HWType
arpReply.ProtoType = a.ProtoType
arpReply.HWLength = a.HWLength
arpReply.ProtoLength = a.ProtoLength
arpReply.HWDst = a.HWSrc
arpReply.IPDst = a.IPSrc
arpReply.IPSrc = a.IPDst
arpReply.HWSrc = host.mac
e := eth.New()
e.Ethertype = ethFrame.Ethertype
e.HWSrc = dpidToMac(dpid)
e.HWDst = a.HWSrc
e.Data = arpReply
log.Println(dpid, pkt.InPort, "answering ARP for", arpReply.IPSrc)
msg := ofp10.NewPacketOut()
msg.InPort = pkt.InPort
msg.Data = e
msg.AddAction(ofp10.NewActionOutput(ofp10.P_IN_PORT))
if sw, ok := ogo.Switch(dpid); ok {
sw.Send(msg)
}
return
}
}
log.Println(dpid, pkt.InPort, "Flooding ARP", a.IPSrc, "->", a.IPDst)
msg := ofp10.NewPacketOut()
msg.InPort = pkt.InPort
msg.Data = ðFrame
msg.AddAction(ofp10.NewActionOutput(ofp10.P_FLOOD))
if sw, ok := ogo.Switch(dpid); ok {
sw.Send(msg)
}
}
}