def _learn_arp_entry(self, ev):
"""
Learn action to process PacketIn DHCP packets, dhcp ack packets will
be used to learn the ARP entry for the UE to install rules in the arp
table. The DHCP packets will then be sent thorugh the pipeline.
"""
msg = ev.msg
if self._dhcp_learn_scratch != msg.table_id:
# Intended for other application
return
try:
encoded_imsi = _get_encoded_imsi_from_packetin(msg)
# Decode the imsi to properly save in directoryd
imsi = decode_imsi(encoded_imsi)
except MagmaOFError as e:
# No packet direction, but intended for this table
self.logger.error("Error obtaining IMSI from pkt-in: %s", e)
return
pkt = packet.Packet(msg.data)
dhcp_header = pkt.get_protocols(dhcp.dhcp)[0]
# DHCP yiaddr is the client(UE) ip addr
# chaddr is the client mac address
self.add_arp_response_flow(imsi, dhcp_header.yiaddr, dhcp_header.chaddr)
def _assert_conversion(self, imsi):
"""
To test the validity of the conversion, we can encode the imsi and
decode to see if the two values match
"""
test_val = decode_imsi(encode_imsi(imsi))
self.assertEqual(imsi, test_val)
def check_imsi_metadata(self, flow, ue_req):
""" Checks that IMSI set in the flow metadata matches the one sent """
sent_imsi = 'IMSI' + ''.join([str(i) for i in ue_req.imsi])
imsi_action = next((a for a in flow["instructions"][0]["actions"]
if a["field"] == "metadata"), None)
self.assertIsNotNone(imsi_action)
imsi64 = imsi_action["value"]
# Convert between compacted uint IMSI and string
received_imsi = decode_imsi(imsi64)
self.assertEqual(sent_imsi, received_imsi,
"IMSI set in metadata field does not match sent IMSI")
def _get_sid(flow):
if IMSI_REG not in flow.match:
return None
return decode_imsi(flow.match[IMSI_REG])
def _get_sid(flow):
return decode_imsi(flow.match[IMSI_REG])
def get_sid(match):
encoded_imsi = match.get(IMSI_REG)
if encoded_imsi is None or encoded_imsi == 0:
raise ValueError('IMSI could not be parsed from match')
return decode_imsi(encoded_imsi)
