1 """ BFD protocol implementation """
3 from random import randint
4 from socket import AF_INET, AF_INET6, inet_pton
5 from scapy.all import bind_layers
6 from scapy.layers.inet import UDP
7 from scapy.packet import Packet
8 from scapy.fields import BitField, BitEnumField, XByteField, FlagsField,\
9 ConditionalField, StrField
10 from vpp_object import VppObject
11 from util import NumericConstant
12 from vpp_ip import VppIpAddress
13 from vpp_papi import VppEnum
16 class BFDDiagCode(NumericConstant):
17 """ BFD Diagnostic Code """
19 control_detection_time_expired = 1
20 echo_function_failed = 2
21 neighbor_signaled_session_down = 3
22 forwarding_plane_reset = 4
24 concatenated_path_down = 6
25 administratively_down = 7
26 reverse_concatenated_path_down = 8
29 no_diagnostic: "No diagnostic",
30 control_detection_time_expired: "Control Detection Time Expired",
31 echo_function_failed: "Echo Function Failed",
32 neighbor_signaled_session_down: "Neighbor Signaled Session Down",
33 forwarding_plane_reset: "Forwarding Plane Reset",
34 path_down: "Path Down",
35 concatenated_path_down: "Concatenated Path Down",
36 administratively_down: "Administratively Down",
37 reverse_concatenated_path_down: "Reverse Concatenated Path Down",
41 class BFDState(NumericConstant):
49 admin_down: "AdminDown",
56 class BFDAuthType(NumericConstant):
57 """ BFD Authentication Type """
61 meticulous_keyed_md5 = 3
63 meticulous_keyed_sha1 = 5
66 no_auth: "No authentication",
67 simple_pwd: "Simple Password",
68 keyed_md5: "Keyed MD5",
69 meticulous_keyed_md5: "Meticulous Keyed MD5",
70 keyed_sha1: "Keyed SHA1",
71 meticulous_keyed_sha1: "Meticulous Keyed SHA1",
75 def bfd_is_auth_used(pkt):
76 """ is packet authenticated? """
77 return "A" in pkt.sprintf("%BFD.flags%")
80 def bfd_is_simple_pwd_used(pkt):
81 """ is simple password authentication used? """
82 return bfd_is_auth_used(pkt) and pkt.auth_type == BFDAuthType.simple_pwd
85 def bfd_is_sha1_used(pkt):
86 """ is sha1 authentication used? """
87 return bfd_is_auth_used(pkt) and pkt.auth_type in \
88 (BFDAuthType.keyed_sha1, BFDAuthType.meticulous_keyed_sha1)
91 def bfd_is_md5_used(pkt):
92 """ is md5 authentication used? """
93 return bfd_is_auth_used(pkt) and pkt.auth_type in \
94 (BFDAuthType.keyed_md5, BFDAuthType.meticulous_keyed_md5)
97 def bfd_is_md5_or_sha1_used(pkt):
98 """ is md5 or sha1 used? """
99 return bfd_is_md5_used(pkt) or bfd_is_sha1_used(pkt)
103 """ BFD protocol layer for scapy """
105 udp_dport = 3784 #: BFD destination port per RFC 5881
106 udp_dport_echo = 3785 # : BFD destination port for ECHO per RFC 5881
107 udp_sport_min = 49152 #: BFD source port min value per RFC 5881
108 udp_sport_max = 65535 #: BFD source port max value per RFC 5881
109 bfd_pkt_len = 24 # : length of BFD pkt without authentication section
110 sha1_auth_len = 28 # : length of authentication section if SHA1 used
115 BitField("version", 1, 3),
116 BitEnumField("diag", 0, 5, BFDDiagCode.desc_dict),
117 BitEnumField("state", 0, 2, BFDState.desc_dict),
118 FlagsField("flags", 0, 6, ['M', 'D', 'A', 'C', 'F', 'P']),
119 XByteField("detect_mult", 0),
120 BitField("length", bfd_pkt_len, 8),
121 BitField("my_discriminator", 0, 32),
122 BitField("your_discriminator", 0, 32),
123 BitField("desired_min_tx_interval", 0, 32),
124 BitField("required_min_rx_interval", 0, 32),
125 BitField("required_min_echo_rx_interval", 0, 32),
127 BitEnumField("auth_type", 0, 8, BFDAuthType.desc_dict),
129 ConditionalField(BitField("auth_len", 0, 8), bfd_is_auth_used),
130 ConditionalField(BitField("auth_key_id", 0, 8), bfd_is_auth_used),
131 ConditionalField(BitField("auth_reserved", 0, 8),
132 bfd_is_md5_or_sha1_used),
134 BitField("auth_seq_num", 0, 32), bfd_is_md5_or_sha1_used),
135 ConditionalField(StrField("auth_key_hash", "0" * 16), bfd_is_md5_used),
137 StrField("auth_key_hash", "0" * 20), bfd_is_sha1_used),
141 return self.sprintf("BFD(my_disc=%BFD.my_discriminator%,"
142 "your_disc=%BFD.your_discriminator%)")
145 # glue the BFD packet class to scapy parser
146 bind_layers(UDP, BFD, dport=BFD.udp_dport)
149 class BFD_vpp_echo(Packet):
150 """ BFD echo packet as used by VPP (non-rfc, as rfc doesn't define one) """
152 udp_dport = 3785 #: BFD echo destination port per RFC 5881
153 name = "BFD_VPP_ECHO"
156 BitField("discriminator", 0, 32),
157 BitField("expire_time_clocks", 0, 64),
158 BitField("checksum", 0, 64)
163 "BFD_VPP_ECHO(disc=%BFD_VPP_ECHO.discriminator%,"
164 "expire_time_clocks=%BFD_VPP_ECHO.expire_time_clocks%)")
167 # glue the BFD echo packet class to scapy parser
168 bind_layers(UDP, BFD_vpp_echo, dport=BFD_vpp_echo.udp_dport)
171 class VppBFDAuthKey(VppObject):
172 """ Represents BFD authentication key in VPP """
174 def __init__(self, test, conf_key_id, auth_type, key):
177 self._auth_type = auth_type
178 test.assertIn(auth_type, BFDAuthType.desc_dict)
179 self._conf_key_id = conf_key_id
183 """ Test which created this key """
188 """ Authentication type for this key """
189 return self._auth_type
197 def key(self, value):
201 def conf_key_id(self):
202 """ configuration key ID """
203 return self._conf_key_id
205 def add_vpp_config(self):
206 self.test.vapi.bfd_auth_set_key(
207 conf_key_id=self._conf_key_id, auth_type=self._auth_type,
208 key=self._key, key_len=len(self._key))
209 self._test.registry.register(self, self.test.logger)
211 def get_bfd_auth_keys_dump_entry(self):
212 """ get the entry in the auth keys dump corresponding to this key """
213 result = self.test.vapi.bfd_auth_keys_dump()
215 if k.conf_key_id == self._conf_key_id:
219 def query_vpp_config(self):
220 return self.get_bfd_auth_keys_dump_entry() is not None
222 def remove_vpp_config(self):
223 self.test.vapi.bfd_auth_del_key(conf_key_id=self._conf_key_id)
226 return "bfd-auth-key-%s" % self._conf_key_id
229 class VppBFDUDPSession(VppObject):
230 """ Represents BFD UDP session in VPP """
232 def __init__(self, test, interface, peer_addr, local_addr=None, af=AF_INET,
233 desired_min_tx=300000, required_min_rx=300000, detect_mult=3,
234 sha1_key=None, bfd_key_id=None, is_tunnel=False):
236 self._interface = interface
239 self._local_addr = VppIpAddress(local_addr)
241 self._local_addr = None
242 self._peer_addr = VppIpAddress(peer_addr)
243 self._desired_min_tx = desired_min_tx
244 self._required_min_rx = required_min_rx
245 self._detect_mult = detect_mult
246 self._sha1_key = sha1_key
247 if bfd_key_id is not None:
248 self._bfd_key_id = bfd_key_id
250 self._bfd_key_id = randint(0, 255)
251 self._is_tunnel = is_tunnel
255 """ Test which created this session """
260 """ Interface on which this session lives """
261 return self._interface
265 """ Address family - AF_INET or AF_INET6 """
269 def local_addr(self):
270 """ BFD session local address (VPP address) """
271 if self._local_addr is None:
272 if self.af == AF_INET:
273 return self._interface.local_ip4
274 elif self.af == AF_INET6:
275 return self._interface.local_ip6
277 raise Exception("Unexpected af '%s'" % self.af)
278 return self._local_addr.address
282 """ BFD session peer address """
283 return self._peer_addr.address
285 def get_bfd_udp_session_dump_entry(self):
286 """ get the namedtuple entry from bfd udp session dump """
287 result = self.test.vapi.bfd_udp_session_dump()
289 self.test.logger.debug("session entry: %s" % str(s))
290 if s.sw_if_index == self.interface.sw_if_index:
291 if self.af == AF_INET \
292 and self.interface.local_ip4 == str(s.local_addr) \
293 and self.interface.remote_ip4 == str(s.peer_addr):
295 if self.af == AF_INET6 \
296 and self.interface.local_ip6 == str(s.local_addr) \
297 and self.interface.remote_ip6 == str(s.peer_addr):
303 """ BFD session state """
304 session = self.get_bfd_udp_session_dump_entry()
306 raise Exception("Could not find BFD session in VPP response")
310 def desired_min_tx(self):
311 """ desired minimum tx interval """
312 return self._desired_min_tx
315 def required_min_rx(self):
316 """ required minimum rx interval """
317 return self._required_min_rx
320 def detect_mult(self):
321 """ detect multiplier """
322 return self._detect_mult
327 return self._sha1_key
330 def bfd_key_id(self):
331 """ bfd key id in use """
332 return self._bfd_key_id
336 return self._is_tunnel
338 def activate_auth(self, key, bfd_key_id=None, delayed=False):
339 """ activate authentication for this session """
340 self._bfd_key_id = bfd_key_id if bfd_key_id else randint(0, 255)
342 conf_key_id = self._sha1_key.conf_key_id
343 is_delayed = 1 if delayed else 0
344 self.test.vapi.bfd_udp_auth_activate(
345 sw_if_index=self._interface.sw_if_index,
346 local_addr=self.local_addr.encode(),
347 peer_addr=self.peer_addr.encode(),
348 bfd_key_id=self._bfd_key_id,
349 conf_key_id=conf_key_id,
350 is_delayed=is_delayed)
352 def deactivate_auth(self, delayed=False):
353 """ deactivate authentication """
354 self._bfd_key_id = None
355 self._sha1_key = None
356 is_delayed = 1 if delayed else 0
357 self.test.vapi.bfd_udp_auth_deactivate(
358 sw_if_index=self._interface.sw_if_index,
359 local_addr=self.local_addr.encode(),
360 peer_addr=self.peer_addr.encode(),
361 is_delayed=is_delayed)
363 def modify_parameters(self,
366 required_min_rx=None):
367 """ modify session parameters """
369 self._detect_mult = detect_mult
371 self._desired_min_tx = desired_min_tx
373 self._required_min_rx = required_min_rx
374 self.test.vapi.bfd_udp_mod(sw_if_index=self._interface.sw_if_index,
375 desired_min_tx=self.desired_min_tx,
376 required_min_rx=self.required_min_rx,
377 detect_mult=self.detect_mult,
378 local_addr=self.local_addr.encode(),
379 peer_addr=self.peer_addr.encode())
381 def add_vpp_config(self):
382 bfd_key_id = self._bfd_key_id if self._sha1_key else None
383 conf_key_id = self._sha1_key.conf_key_id if self._sha1_key else None
384 is_authenticated = True if self._sha1_key else False
385 self.test.vapi.bfd_udp_add(sw_if_index=self._interface.sw_if_index,
386 desired_min_tx=self.desired_min_tx,
387 required_min_rx=self.required_min_rx,
388 detect_mult=self.detect_mult,
389 local_addr=self.local_addr.encode(),
390 peer_addr=self.peer_addr.encode(),
391 bfd_key_id=bfd_key_id,
392 conf_key_id=conf_key_id,
393 is_authenticated=is_authenticated)
394 self._test.registry.register(self, self.test.logger)
396 def query_vpp_config(self):
397 session = self.get_bfd_udp_session_dump_entry()
398 return session is not None
400 def remove_vpp_config(self):
401 self.test.vapi.bfd_udp_del(self._interface.sw_if_index,
402 local_addr=self.local_addr.encode(),
403 peer_addr=self.peer_addr.encode())
406 return "bfd-udp-%s-%s-%s-%s" % (self._interface.sw_if_index,
412 """ set bfd session admin-up """
413 self.test.vapi.bfd_udp_session_set_flags(
414 flags=VppEnum.vl_api_if_status_flags_t.IF_STATUS_API_FLAG_ADMIN_UP,
415 sw_if_index=self._interface.sw_if_index,
416 local_addr=self.local_addr.encode(),
417 peer_addr=self.peer_addr.encode())
419 def admin_down(self):
420 """ set bfd session admin-down """
421 self.test.vapi.bfd_udp_session_set_flags(
422 flags=0, sw_if_index=self._interface.sw_if_index,
423 local_addr=self.local_addr.encode(),
424 peer_addr=self.peer_addr.encode())