def _do_dns_packet(self, packet, event):
dnsp = packet.find('dns')
if len(dnsp.questions) > 1:
self._drop(packet, event.ofp.buffer_id, event.port)
return
question = dnsp.questions[0]
response = None
log.debug("Question: %s" % (question.name))
if question.qtype == dns.rr.A_TYPE and question.name == self.service_name:
# Some one is asking about our service so let's
# choose one of data centers and answer him
dc_ip = self._choose_server()
response = dns.rr(question.name, question.qtype, question.qclass,
0, 4, dc_ip)
elif question.qtype == dns.rr.PTR_TYPE:
# for now we assume that only our dns is resolvable
response = dns.rr(question.name, question.qtype, question.qclass,
0, len(self.service_name), self.service_name)
else:
self._drop(packet, event.ofp.buffer_id, event.port)
return
self._send_dns_response_packet(packet, dnsp, question, response, event.port)
def _answer_A (self, q):
if not q.name.endswith('.local'):
log.info('ignoring question: %s' % q)
return None, None
name = q.name[:-len('.local')]
for node in core.Outband.t.nodes:
if (node.name.lower() == name.lower()):
# TODO multiple addresses in the response?
port = node.ports[max(node.ports)]
log.info('answering: %s %s' % (q.name, port.ip))
ttl = 120 # 2 minutes
addr = IPAddr(port.ip).toRaw() # byte-order ???
r = pkt_dns.rr(q.name, q.qtype, q.qclass, ttl, 4, addr)
return port, r
return None, None
def _answer_A (self, q):
if not q.name.endswith('.local'):
log.info('ignoring question: %s' % q)
return None, None
name = q.name[:-len('.local')]
for node in core.Outband.t.nodes:
if (node.name.lower() == name.lower()):
# TODO multiple addresses in the response?
port = node.ports[max(node.ports)]
log.info('answering: %s %s' % (q.name, port.ip))
ttl = 120 # 2 minutes
addr = IPAddr(port.ip).toRaw() # byte-order ???
r = pkt_dns.rr(q.name, q.qtype, q.qclass, ttl, 4, addr)
return port, r
return None, None
def _answer_PTR (self, q):
if not q.name.endswith('.in-addr.arpa'):
log.info('ignoring question: %s' % q)
return None, None
name = q.name[:-len('.in-addr.arpa')]
ip = name.split('.')
ip.reverse()
ip = '.'.join(ip)
node, port = core.Outband.t.ip_and_port(ip)
if not node:
return None, None
log.info('answering: %s %s' % (q.name, node.name))
ttl = 120 # 2 minutes
domain = putName('', node.name + '.local')
domain = domain.encode('ascii', 'ignore')
r = pkt_dns.rr(q.name, q.qtype, q.qclass, ttl, len(domain), domain)
return port, r
def _answer_PTR (self, q):
if not q.name.endswith('.in-addr.arpa'):
log.info('ignoring question: %s' % q)
return None, None
name = q.name[:-len('.in-addr.arpa')]
ip = name.split('.')
ip.reverse()
ip = '.'.join(ip)
node, port = core.Outband.t.ip_and_port(ip)
if not node:
return None, None
log.info('answering: %s %s' % (q.name, node.name))
ttl = 120 # 2 minutes
domain = putName('', node.name + '.local')
domain = domain.encode('ascii', 'ignore')
r = pkt_dns.rr(q.name, q.qtype, q.qclass, ttl, len(domain), domain)
return port, r
def _handle_PacketIn(self, event):
dpid = event.connection.dpid
inport = event.port
packet = copy.deepcopy(event.parsed)
if not packet.parsed:
log.warning("%i %i ignoring unparsed packet", dpid, inport)
return
if dpid not in self.arpTable:
# New switch -- create an empty table
self.arpTable[dpid] = {}
for fake in self.fakeways:
self.arpTable[dpid][IPAddr(fake)] = Entry(
of.OFPP_NONE, dpid_to_mac(dpid))
# store the mac, ip info of the DNS SERVER into arpTable
self.arpTable[dpid][IPAddr(IP_OF_DNS_SERVER)] = Entry(
6633, EthAddr(MAC_OF_DNS_SERVER))
if packet.type == ethernet.LLDP_TYPE:
# Ignore LLDP packets
return
p = packet.find('dns')
if p is not None and p.parsed:
# Get dstName of the DNS Query
dstname = ''
for question in p.questions:
dstname = question.name
log.debug("DNS Query msg from %s: asking ip address for %s",
packet.next.srcip, dstname)
# Learn or update port/MAC info
if packet.next.srcip in self.arpTable[dpid]:
if self.arpTable[dpid][packet.next.srcip] != (inport,
packet.src):
log.info("%i %i RE-learned %s", dpid, inport,
packet.next.srcip)
else:
log.debug("%i %i learned %s", dpid, inport,
str(packet.next.srcip))
self.arpTable[dpid][packet.next.srcip] = Entry(inport, packet.src)
# generate random virtual ip for internal node
n = random.randint(128, 254)
vip = "10.0.0." + str(n)
#add the srcip and virtual destination ip pair into srcip_dstip_map
self.srcip_dstvip_map[str(packet.next.srcip)] = vip
# forming answer
answer = dns.rr(dstname, 1, 1, 5, len(vip), IPAddr(vip))
# write dns reply msg
d = dns()
d.questions = p.questions
d.answers.append(answer)
d.authorities = []
d.additional = []
d.id = p.id
d.qr = True # dns reply
d.opcode = 0 # standard
d.aa = False
d.tc = False
d.rd = False
d.ra = False
d.z = False
d.ad = False
d.cd = False
d.rcode = 0
e = ethernet(type=ethernet.IP_TYPE,
src=MAC_OF_DNS_SERVER,
dst=str(packet.src))
ip = ipv4(srcip=IPAddr(IP_OF_DNS_SERVER))
ip.dstip = packet.next.srcip
ip.protocol = ip.UDP_PROTOCOL
u = udp()
u.srcport = dns.SERVER_PORT
# get srcport from the packet and set it to the udp's dstport
m = packet.find("udp")
m.parsed
u.dstport = m.srcport
u.payload = d
ip.payload = u
e.payload = ip
msg = of.ofp_packet_out()
msg.data = e.pack()
msg.actions.append(of.ofp_action_nw_addr.set_dst(
packet.next.srcip))
msg.actions.append(of.ofp_action_dl_addr.set_dst(packet.src))
msg.actions.append(of.ofp_action_output(port=of.OFPP_IN_PORT))
msg.in_port = inport
event.connection.send(msg)
log.debug(
" DNS reply msg has been sent to %s: %s's ip address is %s" %
(str(packet.next.srcip), dstname, vip))
elif isinstance(packet.next, ipv4):
log.debug("IPv4 msg: %i %i IP %s => %s", dpid, inport,
packet.next.srcip, packet.next.dstip)
# Send any waiting packets...
self._send_lost_buffers(dpid, packet.next.srcip, packet.src,
inport)
print "Have sent lost buffers"
# Learn or update port/MAC info
if packet.next.srcip in self.arpTable[dpid]:
if self.arpTable[dpid][packet.next.srcip] != (inport,
packet.src):
log.info("%i %i RE-learned %s", dpid, inport,
packet.next.srcip)
else:
log.debug("%i %i learned %s", dpid, inport,
str(packet.next.srcip))
self.arpTable[dpid][packet.next.srcip] = Entry(inport, packet.src)
srcaddr = packet.next.srcip
dstaddr = packet.next.dstip
if (dstaddr in self.vipList):
self.srcip_dstvip_map[srcaddr] = dstaddr
dstaddr = IPAddr(REAL_IP_OF_INTERNAL_HOST)
if dstaddr in self.arpTable[dpid]:
# We have info about what port to send it out on...
prt = self.arpTable[dpid][dstaddr].port
mac = self.arpTable[dpid][dstaddr].mac
# Try to forward
icmpmsg = packet.find("icmp")
icmpmsg.parsed
# icmp echo reply from internal host
if icmpmsg.type == 0 and srcaddr == IPAddr(
REAL_IP_OF_INTERNAL_HOST):
log.info("ICMP echo reply msg from %s to %s", srcaddr,
packet.next.dstip)
if prt == inport:
log.warning(
"%i %i not sending packet for %s back out of the "
+ "input port" % (dpid, inport, str(dstaddr)))
else:
log.debug(
"%i %i installing flow for %s => %s out port %i" %
(dpid, inport, packet.next.srcip, dstaddr, prt))
# add flow entry
msg = of.ofp_flow_mod(command=of.OFPFC_ADD)
msg.match.dl_type = 0x0800 #ipv4
msg.match.nw_src = REAL_IP_OF_INTERNAL_HOST
msg.match.nw_dst = dstaddr
# change the srcip to virtual ip
msg.actions.append(
of.ofp_action_nw_addr.set_src(
IPAddr(self.srcip_dstvip_map[dstaddr])))
msg.actions.append(of.ofp_action_dl_addr.set_dst(mac))
msg.actions.append(of.ofp_action_output(port=prt))
event.connection.send(msg)
log.info(
"ICMP echo reply flow entry for internal node to %s has been installed",
packet.next.dstip)
# icmp echo reply for internal host
elif icmpmsg.type == 8 and dstaddr == IPAddr(
REAL_IP_OF_INTERNAL_HOST):
log.info("ICMP echo request msg from %s to %s",
packet.next.srcip, packet.next.dstip)
if prt == inport:
log.warning(
"%i %i not sending packet for %s back out of the "
+ "input port" % (dpid, inport, str(dstaddr)))
else:
log.debug(
"%i %i installing flow for %s => %s out port %i" %
(dpid, inport, packet.next.srcip, dstaddr, prt))
msg = of.ofp_flow_mod(command=of.OFPFC_ADD)
msg.match.dl_type = 0x0800 #ipv4 msg
msg.match.in_port = inport
msg.match.nw_dst = "10.0.0.128/255.255.255.128"
msg.actions.append(of.ofp_action_nw_addr.set_dst(dstaddr))
msg.actions.append(of.ofp_action_output(port=prt))
msg.actions.append(of.ofp_action_dl_addr.set_dst(mac))
event.connection.send(msg)
log.info(
"ICMP echo request flow entry for %s to internal host has been instaled",
packet.next.srcip)
else:
log.warning("Uninvolved icmp msg type")
return
elif self.arp_for_unknowns:
# We don't know this destination.
# First, we track this buffer so that we can try to resend it later
# if we learn the destination, second we ARP for the destination,
# which should ultimately result in it responding and us learning
# where it is
# Add to tracked buffers
if (dpid, dstaddr) not in self.lost_buffers:
self.lost_buffers[(dpid, dstaddr)] = []
bucket = self.lost_buffers[(dpid, dstaddr)]
entry = (time.time() + MAX_BUFFER_TIME, event.ofp.buffer_id,
inport)
bucket.append(entry)
while len(bucket) > MAX_BUFFERED_PER_IP:
del bucket[0]
# Expire things from our outstanding ARP list...
self.outstanding_arps = {
k: v
for k, v in self.outstanding_arps.iteritems()
if v > time.time()
}
# Check if we've already ARPed recently
if (dpid, dstaddr) in self.outstanding_arps:
# Oop, we've already done this one recently.
return
# And ARP...
self.outstanding_arps[(dpid, dstaddr)] = time.time() + 4
r = arp()
r.hwtype = r.HW_TYPE_ETHERNET
r.prototype = r.PROTO_TYPE_IP
r.hwlen = 6
r.protolen = r.protolen
r.opcode = r.REQUEST
r.hwdst = ETHER_BROADCAST
if dstaddr in self.vipList:
r.protodst = IPAddr(REAL_IP_OF_INTERNAL_HOST)
else:
r.protodst = dstaddr
r.hwsrc = packet.src
r.protosrc = packet.next.srcip
e = ethernet(type=ethernet.ARP_TYPE,
src=packet.src,
dst=ETHER_BROADCAST)
e.set_payload(r)
log.debug("%i %i ARPing for %s on behalf of %s for Ipv4" %
(dpid, inport, str(r.protodst), str(r.protosrc)))
msg = of.ofp_packet_out()
msg.data = e.pack()
msg.actions.append(of.ofp_action_output(port=of.OFPP_FLOOD))
msg.in_port = inport
event.connection.send(msg)
elif isinstance(packet.next, arp):
a = packet.next
if a.protosrc in self.arpTable[dpid]:
if self.arpTable[dpid][a.protosrc] != (inport, packet.src):
log.info("%i %i RE-learned %s", dpid, inport,
str(a.protosrc))
else:
log.debug("%i %i learned %s", dpid, inport, str(a.protosrc))
self.arpTable[dpid][a.protosrc] = Entry(inport, packet.src)
if a.protodst in self.vipList:
self.srcip_dstvip_map[a.protosrc] = str(a.protodst)
a.protodst = REAL_IP_OF_INTERNAL_HOST
log.info("%i %i ARP %s %s => %s", dpid, inport, {
arp.REQUEST: "request",
arp.REPLY: "reply"
}.get(a.opcode, 'op:%i' % (a.opcode, )), str(a.protosrc),
str(a.protodst))
if a.prototype == arp.PROTO_TYPE_IP:
if a.hwtype == arp.HW_TYPE_ETHERNET:
if a.protosrc != 0:
# Learn or update port/MAC info
if a.protosrc in self.arpTable[dpid]:
if self.arpTable[dpid][a.protosrc] != (inport,
packet.src):
log.info("%i %i RE-learned %s", dpid, inport,
str(a.protosrc))
else:
log.debug("%i %i learned %s", dpid, inport,
str(a.protosrc))
self.arpTable[dpid][a.protosrc] = Entry(
inport, packet.src)
# Send any waiting packets...
self._send_lost_buffers(dpid, a.protosrc, packet.src,
inport)
if a.opcode == arp.REPLY:
r = arp()
r.hwtype = a.hwtype
r.prototype = a.prototype
r.hwlen = a.hwlen
r.protolen = a.protolen
r.opcode = arp.REPLY
r.hwsrc = a.hwsrc
if a.protosrc == IPAddr(REAL_IP_OF_INTERNAL_HOST):
if a.protodst in self.srcip_dstvip_map:
r.protosrc = IPAddr(
self.srcip_dstvip_map[a.protodst])
else:
r.protosrc = a.protosrc
r.protodst = a.protodst
r.hwdst = self.arpTable[dpid][a.protodst].mac
e = ethernet(type=packet.type,
src=dpid_to_mac(dpid),
dst=a.hwdst)
e.set_payload(r)
log.debug("%i %i answering ARP for %s to %s" %
(dpid, inport, str(
r.protosrc), str(r.protodst)))
msg = of.ofp_packet_out()
msg.data = e.pack()
msg.actions.append(
of.ofp_action_output(
port=self.arpTable[dpid][a.protodst].port))
msg.in_port = inport
event.connection.send(msg)
return
if a.opcode == arp.REQUEST:
# Maybe we can answer
if a.protodst in self.vipList:
self.srcip_dstvip_map[a.protosrc] = str(
a.protodst)
a.protodst = IPAddr(REAL_IP_OF_INTERNAL_HOST)
if a.protodst in self.arpTable[dpid]:
# We have an answer...
if not self.arpTable[dpid][
a.protodst].isExpired():
# .. and it's relatively current, so we'll reply ourselves
r = arp()
r.hwtype = a.hwtype
r.prototype = a.prototype
r.hwlen = a.hwlen
r.protolen = a.protolen
r.opcode = arp.REPLY
r.hwdst = a.hwsrc
r.hwsrc = self.arpTable[dpid][
a.protodst].mac
r.protodst = a.protosrc
if a.protodst == IPAddr(
REAL_IP_OF_INTERNAL_HOST):
r.protosrc = IPAddr(
self.srcip_dstvip_map[a.protosrc])
else:
r.protosrc = a.protodst
e = ethernet(type=packet.type,
src=dpid_to_mac(dpid),
dst=a.hwsrc)
e.set_payload(r)
log.debug("%i %i answering ARP for %s" %
(dpid, inport, str(r.protosrc)))
msg = of.ofp_packet_out()
msg.data = e.pack()
msg.actions.append(
of.ofp_action_output(
port=of.OFPP_IN_PORT))
msg.in_port = inport
event.connection.send(msg)
return
# Didn't know how to answer or otherwise handle this ARP, so just flood it
log.debug("%i %i flooding ARP %s %s => %s" %
(dpid, inport, {
arp.REQUEST: "request",
arp.REPLY: "reply"
}.get(a.opcode, 'op:%i' % (a.opcode, )),
str(a.protosrc), str(a.protodst)))
r1 = arp()
r1.hwtype = a.HW_TYPE_ETHERNET
r1.prototype = a.PROTO_TYPE_IP
r1.hwlen = 6
r1.protolen = a.protolen
r1.opcode = arp.REQUEST
r1.hwdst = ETHER_BROADCAST
r1.protodst = IPAddr(a.protodst)
r1.hwsrc = a.hwsrc
r1.protosrc = a.protosrc
e1 = ethernet(type=ethernet.ARP_TYPE,
src=a.hwsrc,
dst=ETHER_BROADCAST)
e1.set_payload(r1)
log.debug("%i %i ARPing for %s on behalf of %s" %
(dpid, inport, str(
r1.protodst), str(r1.protosrc)))
msg1 = of.ofp_packet_out()
msg1.data = e1.pack()
msg1.actions.append(
of.ofp_action_output(port=of.OFPP_FLOOD))
msg1.in_port = inport
event.connection.send(msg1)
def _handle_PacketIn (self, event):
dpid = event.connection.dpid
inport = event.port
packet = copy.deepcopy(event.parsed)
if not packet.parsed:
log.warning("%i %i ignoring unparsed packet", dpid, inport)
return
if dpid not in self.arpTable:
# New switch -- create an empty table
self.arpTable[dpid] = {}
for fake in self.fakeways:
self.arpTable[dpid][IPAddr(fake)] = Entry(of.OFPP_NONE,
dpid_to_mac(dpid))
# store the mac, ip info of the DNS SERVER into arpTable
self.arpTable[dpid][IPAddr(IP_OF_DNS_SERVER)]=Entry(6633, EthAddr(MAC_OF_DNS_SERVER))
if packet.type == ethernet.LLDP_TYPE:
# Ignore LLDP packets
return
p = packet.find('dns')
if p is not None and p.parsed:
# Get dstName of the DNS Query
dstname = '';
for question in p.questions:
dstname = question.name
log.debug("DNS Query msg from %s: asking ip address for %s", packet.next.srcip, dstname)
# Learn or update port/MAC info
if packet.next.srcip in self.arpTable[dpid]:
if self.arpTable[dpid][packet.next.srcip] != (inport, packet.src):
log.info("%i %i RE-learned %s", dpid, inport, packet.next.srcip)
else:
log.debug("%i %i learned %s", dpid, inport, str(packet.next.srcip))
self.arpTable[dpid][packet.next.srcip] = Entry(inport, packet.src)
# generate random virtual ip for internal node
n = random.randint(128, 254)
vip = "10.0.0." + str(n)
#add the srcip and virtual destination ip pair into srcip_dstip_map
self.srcip_dstvip_map[str(packet.next.srcip)] = vip
# forming answer
answer = dns.rr(dstname, 1, 1, 5, len(vip), IPAddr(vip))
# write dns reply msg
d = dns()
d.questions = p.questions
d.answers.append(answer)
d.authorities = []
d.additional =[]
d.id = p.id
d.qr = True # dns reply
d.opcode = 0 # standard
d.aa = False
d.tc = False
d.rd = False
d.ra = False
d.z = False
d.ad = False
d.cd = False
d.rcode = 0
e = ethernet(type=ethernet.IP_TYPE, src=MAC_OF_DNS_SERVER, dst=str(packet.src))
ip = ipv4(srcip = IPAddr(IP_OF_DNS_SERVER))
ip.dstip = packet.next.srcip
ip.protocol = ip.UDP_PROTOCOL
u = udp()
u.srcport = dns.SERVER_PORT
# get srcport from the packet and set it to the udp's dstport
m = packet.find("udp")
m.parsed
u.dstport = m.srcport
u.payload = d
ip.payload = u
e.payload = ip
msg = of.ofp_packet_out()
msg.data = e.pack()
msg.actions.append(of.ofp_action_nw_addr.set_dst(packet.next.srcip))
msg.actions.append(of.ofp_action_dl_addr.set_dst(packet.src))
msg.actions.append(of.ofp_action_output(port = of.OFPP_IN_PORT))
msg.in_port = inport
event.connection.send(msg)
log.debug(" DNS reply msg has been sent to %s: %s's ip address is %s" % (str(packet.next.srcip), dstname, vip))
elif isinstance(packet.next, ipv4):
log.debug("IPv4 msg: %i %i IP %s => %s", dpid,inport,
packet.next.srcip,packet.next.dstip)
# Send any waiting packets...
self._send_lost_buffers(dpid, packet.next.srcip, packet.src, inport)
print "Have sent lost buffers"
# Learn or update port/MAC info
if packet.next.srcip in self.arpTable[dpid]:
if self.arpTable[dpid][packet.next.srcip] != (inport, packet.src):
log.info("%i %i RE-learned %s", dpid,inport,packet.next.srcip)
else:
log.debug("%i %i learned %s", dpid,inport,str(packet.next.srcip))
self.arpTable[dpid][packet.next.srcip] = Entry(inport, packet.src)
srcaddr = packet.next.srcip
dstaddr = packet.next.dstip
if(dstaddr in self.vipList):
self.srcip_dstvip_map[srcaddr] = dstaddr
dstaddr = IPAddr(REAL_IP_OF_INTERNAL_HOST)
if dstaddr in self.arpTable[dpid]:
# We have info about what port to send it out on...
prt = self.arpTable[dpid][dstaddr].port
mac = self.arpTable[dpid][dstaddr].mac
# Try to forward
icmpmsg = packet.find("icmp")
icmpmsg.parsed
# icmp echo reply from internal host
if icmpmsg.type == 0 and srcaddr == IPAddr(REAL_IP_OF_INTERNAL_HOST):
log.info("ICMP echo reply msg from %s to %s", srcaddr, packet.next.dstip)
if prt == inport:
log.warning("%i %i not sending packet for %s back out of the " +
"input port" % (dpid, inport, str(dstaddr)))
else:
log.debug("%i %i installing flow for %s => %s out port %i"
% (dpid, inport, packet.next.srcip, dstaddr, prt))
# add flow entry
msg = of.ofp_flow_mod(command = of.OFPFC_ADD)
msg.match.dl_type = 0x0800 #ipv4
msg.match.nw_src = REAL_IP_OF_INTERNAL_HOST
msg.match.nw_dst = dstaddr
# change the srcip to virtual ip
msg.actions.append(of.ofp_action_nw_addr.set_src(IPAddr(self.srcip_dstvip_map[dstaddr])))
msg.actions.append(of.ofp_action_dl_addr.set_dst(mac))
msg.actions.append(of.ofp_action_output(port = prt))
event.connection.send(msg)
log.info("ICMP echo reply flow entry for internal node to %s has been installed", packet.next.dstip)
# icmp echo reply for internal host
elif icmpmsg.type == 8 and dstaddr == IPAddr(REAL_IP_OF_INTERNAL_HOST):
log.info("ICMP echo request msg from %s to %s", packet.next.srcip, packet.next.dstip)
if prt == inport:
log.warning("%i %i not sending packet for %s back out of the " +
"input port" % (dpid, inport, str(dstaddr)))
else:
log.debug("%i %i installing flow for %s => %s out port %i"
% (dpid, inport, packet.next.srcip, dstaddr, prt))
msg = of.ofp_flow_mod(command = of.OFPFC_ADD)
msg.match.dl_type = 0x0800 #ipv4 msg
msg.match.in_port = inport
msg.match.nw_dst = "10.0.0.128/255.255.255.128"
msg.actions.append(of.ofp_action_nw_addr.set_dst(dstaddr))
msg.actions.append(of.ofp_action_output(port = prt))
msg.actions.append(of.ofp_action_dl_addr.set_dst(mac))
event.connection.send(msg)
log.info("ICMP echo request flow entry for %s to internal host has been instaled", packet.next.srcip)
else:
log.warning("Uninvolved icmp msg type")
return
elif self.arp_for_unknowns:
# We don't know this destination.
# First, we track this buffer so that we can try to resend it later
# if we learn the destination, second we ARP for the destination,
# which should ultimately result in it responding and us learning
# where it is
# Add to tracked buffers
if (dpid,dstaddr) not in self.lost_buffers:
self.lost_buffers[(dpid,dstaddr)] = []
bucket = self.lost_buffers[(dpid,dstaddr)]
entry = (time.time() + MAX_BUFFER_TIME,event.ofp.buffer_id,inport)
bucket.append(entry)
while len(bucket) > MAX_BUFFERED_PER_IP: del bucket[0]
# Expire things from our outstanding ARP list...
self.outstanding_arps = {k:v for k,v in
self.outstanding_arps.iteritems() if v > time.time()}
# Check if we've already ARPed recently
if (dpid,dstaddr) in self.outstanding_arps:
# Oop, we've already done this one recently.
return
# And ARP...
self.outstanding_arps[(dpid,dstaddr)] = time.time() + 4
r = arp()
r.hwtype = r.HW_TYPE_ETHERNET
r.prototype = r.PROTO_TYPE_IP
r.hwlen = 6
r.protolen = r.protolen
r.opcode = r.REQUEST
r.hwdst = ETHER_BROADCAST
if dstaddr in self.vipList:
r.protodst = IPAddr(REAL_IP_OF_INTERNAL_HOST)
else:
r.protodst = dstaddr
r.hwsrc = packet.src
r.protosrc = packet.next.srcip
e = ethernet(type=ethernet.ARP_TYPE, src=packet.src,
dst=ETHER_BROADCAST)
e.set_payload(r)
log.debug("%i %i ARPing for %s on behalf of %s for Ipv4" % (dpid, inport, str(r.protodst), str(r.protosrc)))
msg = of.ofp_packet_out()
msg.data = e.pack()
msg.actions.append(of.ofp_action_output(port = of.OFPP_FLOOD))
msg.in_port = inport
event.connection.send(msg)
elif isinstance(packet.next, arp):
a = packet.next
if a.protosrc in self.arpTable[dpid]:
if self.arpTable[dpid][a.protosrc] != (inport, packet.src):
log.info("%i %i RE-learned %s", dpid,inport,str(a.protosrc))
else:
log.debug("%i %i learned %s", dpid,inport,str(a.protosrc))
self.arpTable[dpid][a.protosrc] = Entry(inport, packet.src)
if a.protodst in self.vipList:
self.srcip_dstvip_map[a.protosrc] = str(a.protodst)
a.protodst = REAL_IP_OF_INTERNAL_HOST
log.info("%i %i ARP %s %s => %s", dpid, inport,
{arp.REQUEST:"request",arp.REPLY:"reply"}.get(a.opcode,
'op:%i' % (a.opcode,)), str(a.protosrc), str(a.protodst))
if a.prototype == arp.PROTO_TYPE_IP:
if a.hwtype == arp.HW_TYPE_ETHERNET:
if a.protosrc != 0:
# Learn or update port/MAC info
if a.protosrc in self.arpTable[dpid]:
if self.arpTable[dpid][a.protosrc] != (inport, packet.src):
log.info("%i %i RE-learned %s", dpid,inport,str(a.protosrc))
else:
log.debug("%i %i learned %s", dpid,inport,str(a.protosrc))
self.arpTable[dpid][a.protosrc] = Entry(inport, packet.src)
# Send any waiting packets...
self._send_lost_buffers(dpid, a.protosrc, packet.src, inport)
if a.opcode == arp.REPLY:
r = arp()
r.hwtype = a.hwtype
r.prototype = a.prototype
r.hwlen = a.hwlen
r.protolen = a.protolen
r.opcode = arp.REPLY
r.hwsrc = a.hwsrc
if a.protosrc == IPAddr(REAL_IP_OF_INTERNAL_HOST):
if a.protodst in self.srcip_dstvip_map:
r.protosrc = IPAddr(self.srcip_dstvip_map[a.protodst])
else:
r.protosrc = a.protosrc
r.protodst = a.protodst
r.hwdst = self.arpTable[dpid][a.protodst].mac
e = ethernet(type=packet.type, src=dpid_to_mac(dpid), dst=a.hwdst)
e.set_payload(r)
log.debug("%i %i answering ARP for %s to %s" % (dpid, inport,
str(r.protosrc), str(r.protodst)))
msg = of.ofp_packet_out()
msg.data = e.pack()
msg.actions.append(of.ofp_action_output(port = self.arpTable[dpid][a.protodst].port))
msg.in_port = inport
event.connection.send(msg)
return
if a.opcode == arp.REQUEST:
# Maybe we can answer
if a.protodst in self.vipList:
self.srcip_dstvip_map[a.protosrc] = str(a.protodst)
a.protodst = IPAddr(REAL_IP_OF_INTERNAL_HOST)
if a.protodst in self.arpTable[dpid]:
# We have an answer...
if not self.arpTable[dpid][a.protodst].isExpired():
# .. and it's relatively current, so we'll reply ourselves
r = arp()
r.hwtype = a.hwtype
r.prototype = a.prototype
r.hwlen = a.hwlen
r.protolen = a.protolen
r.opcode = arp.REPLY
r.hwdst = a.hwsrc
r.hwsrc = self.arpTable[dpid][a.protodst].mac
r.protodst = a.protosrc
if a.protodst == IPAddr(REAL_IP_OF_INTERNAL_HOST):
r.protosrc = IPAddr(self.srcip_dstvip_map[a.protosrc])
else:
r.protosrc = a.protodst
e = ethernet(type=packet.type, src=dpid_to_mac(dpid), dst=a.hwsrc)
e.set_payload(r)
log.debug("%i %i answering ARP for %s" % (dpid, inport,
str(r.protosrc)))
msg = of.ofp_packet_out()
msg.data = e.pack()
msg.actions.append(of.ofp_action_output(port =
of.OFPP_IN_PORT))
msg.in_port = inport
event.connection.send(msg)
return
# Didn't know how to answer or otherwise handle this ARP, so just flood it
log.debug("%i %i flooding ARP %s %s => %s" % (dpid, inport,
{arp.REQUEST:"request",arp.REPLY:"reply"}.get(a.opcode,
'op:%i' % (a.opcode,)), str(a.protosrc), str(a.protodst)))
r1 = arp()
r1.hwtype = a.HW_TYPE_ETHERNET
r1.prototype = a.PROTO_TYPE_IP
r1.hwlen = 6
r1.protolen = a.protolen
r1.opcode = arp.REQUEST
r1.hwdst = ETHER_BROADCAST
r1.protodst = IPAddr(a.protodst)
r1.hwsrc = a.hwsrc
r1.protosrc = a.protosrc
e1 = ethernet(type=ethernet.ARP_TYPE, src=a.hwsrc, dst=ETHER_BROADCAST)
e1.set_payload(r1)
log.debug("%i %i ARPing for %s on behalf of %s" % (dpid, inport, str(r1.protodst), str(r1.protosrc)))
msg1 = of.ofp_packet_out()
msg1.data = e1.pack()
msg1.actions.append(of.ofp_action_output(port = of.OFPP_FLOOD))
msg1.in_port = inport
event.connection.send(msg1)