def handle_dns(self, dpid, inport, ofp_reason, total_frame_len, buffer_id,
packet):
dnsh = packet.find('dns')
if not dnsh:
log.err('received invalid DNS packet', system='dnsspy')
return CONTINUE
log.msg(str(dnsh), system='dnsspy')
for answer in dnsh.answers:
if answer.qtype == dns.dns.rr.A_TYPE:
val = self.ip_records[answer.rddata]
if answer.name not in val:
val.insert(0, answer.name)
log.msg("add dns entry: %s %s" %
(answer.rddata, answer.name),
system='dnsspy')
for addition in dnsh.additional:
# WHAT IS THIS?! XXX
# for char in addition.name:
# # some debugging magic in case we have a bad parse in DNS
# if not curses.ascii.isascii(char):
# for byte in dnsh.get_layer():
# print '%x' % byte,
# print ''
# continue
if addition.qtype == dns.dns.rr.A_TYPE:
val = self.ip_records[addition.rddata]
if addition.name not in val:
val.insert(0, addition.name)
log.msg("additional dns entry: %s %s" %
(addition.rddata, addition.name),
system='dnsspy')
return CONTINUE
def handle_dns(self, dpid, inport, ofp_reason, total_frame_len, buffer_id, packet):
eaddr = util.convert_to_eaddr(packet.src)
dnsh = packet.find('dns')
if not self.permit_ether_addr(eaddr):
print "Dropping DNS Packet - MAC Address not allowed"
return STOP
if not dnsh:
print "Invalid DNS packet:", dnsh, packet
return CONTINUE
print "DNS Packet:", dnsh
for question in dnsh.questions:
if eaddr in Homework.st['dnsList'] and question.name in Homework.st['dnsList'][eaddr]:
print "DNS Resquest blocked for", question.name
return STOP
flow = util.extract_flow(packet)
Homework.install_datapath_flow(
dpid, flow, 3, 10,
[[openflow.OFPAT_OUTPUT, [-1, openflow.OFPP_NORMAL]]],
buffer_id, openflow.OFP_DEFAULT_PRIORITY, inport, packet.arr
)
return CONTINUE
def handle_dns(self, dpid, inport, ofp_reason, total_frame_len, buffer_id, packet):
dnsh = packet.find('dns')
if not dnsh:
log.err('received invalid DNS packet',system='dnsspy')
return CONTINUE
log.msg(str(dnsh),system='dnsspy')
for answer in dnsh.answers:
if answer.qtype == dns.dns.rr.A_TYPE:
val = self.ip_records[answer.rddata]
if answer.name not in val:
val.insert(0, answer.name)
log.msg("add dns entry: %s %s" % (answer.rddata, answer.name), system='dnsspy')
for addition in dnsh.additional:
# WHAT IS THIS?! XXX
# for char in addition.name:
# # some debugging magic in case we have a bad parse in DNS
# if not curses.ascii.isascii(char):
# for byte in dnsh.get_layer():
# print '%x' % byte,
# print ''
# continue
if addition.qtype == dns.dns.rr.A_TYPE:
val = self.ip_records[addition.rddata]
if addition.name not in val:
val.insert(0, addition.name)
log.msg("additional dns entry: %s %s" % (addition.rddata, addition.name), system='dnsspy')
return CONTINUE
def handle_dns_response(self, dpid, inport, ofp_reason, total_frame_len, buffer_id, packet):
eaddr = util.convert_to_eaddr(packet.dst)
dnsh = packet.find('dns')
if not self.permit_ether_addr(eaddr):
print "Dropping DNS Response Packet - MAC Address not allowed"
return STOP
if not dnsh:
print "\n\n +++ +++ Invalid DNS Response packet: ", dnsh
print packet
print dir(packet)
print packet.__dict__
print "\n\n"
return CONTINUE
print "DNS Response packet:", dnsh
print "*******", dir(dnsh)
print "*******", dnsh.__dict__
for answer in dnsh.answers:
if answer.qtype in dns.rrtype_to_str:
domain = answer.name + ":" + dns.rrtype_to_str[answer.qtype]
else:
domain = answer.name + ":" + str(answer.qtype)
if domain not in Homework.st['domains']:
Homework.st['domains'][domain] = set([str(answer.rddata)])
else:
Homework.st['domains'][domain].add(str(answer.rddata))
flow = util.extract_flow(packet)
Homework.install_datapath_flow(
dpid, flow, 3, 10,
[[openflow.OFPAT_OUTPUT, [-1, openflow.OFPP_NORMAL]]],
buffer_id, openflow.OFP_DEFAULT_PRIORITY, inport, dnsh.arr
)
return CONTINUE
