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_papi import VppEnum
15 class BFDDiagCode(NumericConstant):
16 """ BFD Diagnostic Code """
18 control_detection_time_expired = 1
19 echo_function_failed = 2
20 neighbor_signaled_session_down = 3
21 forwarding_plane_reset = 4
23 concatenated_path_down = 6
24 administratively_down = 7
25 reverse_concatenated_path_down = 8
28 no_diagnostic: "No diagnostic",
29 control_detection_time_expired: "Control Detection Time Expired",
30 echo_function_failed: "Echo Function Failed",
31 neighbor_signaled_session_down: "Neighbor Signaled Session Down",
32 forwarding_plane_reset: "Forwarding Plane Reset",
33 path_down: "Path Down",
34 concatenated_path_down: "Concatenated Path Down",
35 administratively_down: "Administratively Down",
36 reverse_concatenated_path_down: "Reverse Concatenated Path Down",
40 class BFDState(NumericConstant):
48 admin_down: "AdminDown",
55 class BFDAuthType(NumericConstant):
56 """ BFD Authentication Type """
60 meticulous_keyed_md5 = 3
62 meticulous_keyed_sha1 = 5
65 no_auth: "No authentication",
66 simple_pwd: "Simple Password",
67 keyed_md5: "Keyed MD5",
68 meticulous_keyed_md5: "Meticulous Keyed MD5",
69 keyed_sha1: "Keyed SHA1",
70 meticulous_keyed_sha1: "Meticulous Keyed SHA1",
74 def bfd_is_auth_used(pkt):
75 """ is packet authenticated? """
76 return "A" in pkt.sprintf("%BFD.flags%")
79 def bfd_is_simple_pwd_used(pkt):
80 """ is simple password authentication used? """
81 return bfd_is_auth_used(pkt) and pkt.auth_type == BFDAuthType.simple_pwd
84 def bfd_is_sha1_used(pkt):
85 """ is sha1 authentication used? """
86 return bfd_is_auth_used(pkt) and pkt.auth_type in \
87 (BFDAuthType.keyed_sha1, BFDAuthType.meticulous_keyed_sha1)
90 def bfd_is_md5_used(pkt):
91 """ is md5 authentication used? """
92 return bfd_is_auth_used(pkt) and pkt.auth_type in \
93 (BFDAuthType.keyed_md5, BFDAuthType.meticulous_keyed_md5)
96 def bfd_is_md5_or_sha1_used(pkt):
97 """ is md5 or sha1 used? """
98 return bfd_is_md5_used(pkt) or bfd_is_sha1_used(pkt)
102 """ BFD protocol layer for scapy """
104 udp_dport = 3784 #: BFD destination port per RFC 5881
105 udp_dport_echo = 3785 # : BFD destination port for ECHO per RFC 5881
106 udp_sport_min = 49152 #: BFD source port min value per RFC 5881
107 udp_sport_max = 65535 #: BFD source port max value per RFC 5881
108 bfd_pkt_len = 24 # : length of BFD pkt without authentication section
109 sha1_auth_len = 28 # : length of authentication section if SHA1 used
114 BitField("version", 1, 3),
115 BitEnumField("diag", 0, 5, BFDDiagCode.desc_dict),
116 BitEnumField("state", 0, 2, BFDState.desc_dict),
117 FlagsField("flags", 0, 6, ['M', 'D', 'A', 'C', 'F', 'P']),
118 XByteField("detect_mult", 0),
119 BitField("length", bfd_pkt_len, 8),
120 BitField("my_discriminator", 0, 32),
121 BitField("your_discriminator", 0, 32),
122 BitField("desired_min_tx_interval", 0, 32),
123 BitField("required_min_rx_interval", 0, 32),
124 BitField("required_min_echo_rx_interval", 0, 32),
126 BitEnumField("auth_type", 0, 8, BFDAuthType.desc_dict),
128 ConditionalField(BitField("auth_len", 0, 8), bfd_is_auth_used),
129 ConditionalField(BitField("auth_key_id", 0, 8), bfd_is_auth_used),
130 ConditionalField(BitField("auth_reserved", 0, 8),
131 bfd_is_md5_or_sha1_used),
133 BitField("auth_seq_num", 0, 32), bfd_is_md5_or_sha1_used),
134 ConditionalField(StrField("auth_key_hash", "0" * 16), bfd_is_md5_used),
136 StrField("auth_key_hash", "0" * 20), bfd_is_sha1_used),
140 return self.sprintf("BFD(my_disc=%BFD.my_discriminator%,"
141 "your_disc=%BFD.your_discriminator%)")
144 # glue the BFD packet class to scapy parser
145 bind_layers(UDP, BFD, dport=BFD.udp_dport)
148 class BFD_vpp_echo(Packet):
149 """ BFD echo packet as used by VPP (non-rfc, as rfc doesn't define one) """
151 udp_dport = 3785 #: BFD echo destination port per RFC 5881
152 name = "BFD_VPP_ECHO"
155 BitField("discriminator", 0, 32),
156 BitField("expire_time_clocks", 0, 64),
157 BitField("checksum", 0, 64)
162 "BFD_VPP_ECHO(disc=%BFD_VPP_ECHO.discriminator%,"
163 "expire_time_clocks=%BFD_VPP_ECHO.expire_time_clocks%)")
166 # glue the BFD echo packet class to scapy parser
167 bind_layers(UDP, BFD_vpp_echo, dport=BFD_vpp_echo.udp_dport)
170 class VppBFDAuthKey(VppObject):
171 """ Represents BFD authentication key in VPP """
173 def __init__(self, test, conf_key_id, auth_type, key):
176 self._auth_type = auth_type
177 test.assertIn(auth_type, BFDAuthType.desc_dict)
178 self._conf_key_id = conf_key_id
182 """ Test which created this key """
187 """ Authentication type for this key """
188 return self._auth_type
196 def key(self, value):
200 def conf_key_id(self):
201 """ configuration key ID """
202 return self._conf_key_id
204 def add_vpp_config(self):
205 self.test.vapi.bfd_auth_set_key(
206 conf_key_id=self._conf_key_id, auth_type=self._auth_type,
207 key=self._key, key_len=len(self._key))
208 self._test.registry.register(self, self.test.logger)
210 def get_bfd_auth_keys_dump_entry(self):
211 """ get the entry in the auth keys dump corresponding to this key """
212 result = self.test.vapi.bfd_auth_keys_dump()
214 if k.conf_key_id == self._conf_key_id:
218 def query_vpp_config(self):
219 return self.get_bfd_auth_keys_dump_entry() is not None
221 def remove_vpp_config(self):
222 self.test.vapi.bfd_auth_del_key(conf_key_id=self._conf_key_id)
225 return "bfd-auth-key-%s" % self._conf_key_id
228 class VppBFDUDPSession(VppObject):
229 """ Represents BFD UDP session in VPP """
231 def __init__(self, test, interface, peer_addr, local_addr=None, af=AF_INET,
232 desired_min_tx=300000, required_min_rx=300000, detect_mult=3,
233 sha1_key=None, bfd_key_id=None, is_tunnel=False):
235 self._interface = interface
238 self._local_addr = local_addr
240 self._local_addr = None
241 self._peer_addr = peer_addr
242 self._desired_min_tx = desired_min_tx
243 self._required_min_rx = required_min_rx
244 self._detect_mult = detect_mult
245 self._sha1_key = sha1_key
246 if bfd_key_id is not None:
247 self._bfd_key_id = bfd_key_id
249 self._bfd_key_id = randint(0, 255)
250 self._is_tunnel = is_tunnel
254 """ Test which created this session """
259 """ Interface on which this session lives """
260 return self._interface
264 """ Address family - AF_INET or AF_INET6 """
268 def local_addr(self):
269 """ BFD session local address (VPP address) """
270 if self._local_addr is None:
271 if self.af == AF_INET:
272 return self._interface.local_ip4
273 elif self.af == AF_INET6:
274 return self._interface.local_ip6
276 raise Exception("Unexpected af '%s'" % self.af)
277 return self._local_addr
281 """ BFD session peer address """
282 return self._peer_addr
284 def get_bfd_udp_session_dump_entry(self):
285 """ get the namedtuple entry from bfd udp session dump """
286 result = self.test.vapi.bfd_udp_session_dump()
288 self.test.logger.debug("session entry: %s" % str(s))
289 if s.sw_if_index == self.interface.sw_if_index:
290 if self.af == AF_INET \
291 and self.interface.local_ip4 == str(s.local_addr) \
292 and self.interface.remote_ip4 == str(s.peer_addr):
294 if self.af == AF_INET6 \
295 and self.interface.local_ip6 == str(s.local_addr) \
296 and self.interface.remote_ip6 == str(s.peer_addr):
302 """ BFD session state """
303 session = self.get_bfd_udp_session_dump_entry()
305 raise Exception("Could not find BFD session in VPP response")
309 def desired_min_tx(self):
310 """ desired minimum tx interval """
311 return self._desired_min_tx
314 def required_min_rx(self):
315 """ required minimum rx interval """
316 return self._required_min_rx
319 def detect_mult(self):
320 """ detect multiplier """
321 return self._detect_mult
326 return self._sha1_key
329 def bfd_key_id(self):
330 """ bfd key id in use """
331 return self._bfd_key_id
335 return self._is_tunnel
337 def activate_auth(self, key, bfd_key_id=None, delayed=False):
338 """ activate authentication for this session """
339 self._bfd_key_id = bfd_key_id if bfd_key_id else randint(0, 255)
341 conf_key_id = self._sha1_key.conf_key_id
342 is_delayed = 1 if delayed else 0
343 self.test.vapi.bfd_udp_auth_activate(
344 sw_if_index=self._interface.sw_if_index,
345 local_addr=self.local_addr,
346 peer_addr=self.peer_addr,
347 bfd_key_id=self._bfd_key_id,
348 conf_key_id=conf_key_id,
349 is_delayed=is_delayed)
351 def deactivate_auth(self, delayed=False):
352 """ deactivate authentication """
353 self._bfd_key_id = None
354 self._sha1_key = None
355 is_delayed = 1 if delayed else 0
356 self.test.vapi.bfd_udp_auth_deactivate(
357 sw_if_index=self._interface.sw_if_index,
358 local_addr=self.local_addr,
359 peer_addr=self.peer_addr,
360 is_delayed=is_delayed)
362 def modify_parameters(self,
365 required_min_rx=None):
366 """ modify session parameters """
368 self._detect_mult = detect_mult
370 self._desired_min_tx = desired_min_tx
372 self._required_min_rx = required_min_rx
373 self.test.vapi.bfd_udp_mod(sw_if_index=self._interface.sw_if_index,
374 desired_min_tx=self.desired_min_tx,
375 required_min_rx=self.required_min_rx,
376 detect_mult=self.detect_mult,
377 local_addr=self.local_addr,
378 peer_addr=self.peer_addr)
380 def add_vpp_config(self):
381 bfd_key_id = self._bfd_key_id if self._sha1_key else None
382 conf_key_id = self._sha1_key.conf_key_id if self._sha1_key else None
383 is_authenticated = True if self._sha1_key else False
384 self.test.vapi.bfd_udp_add(sw_if_index=self._interface.sw_if_index,
385 desired_min_tx=self.desired_min_tx,
386 required_min_rx=self.required_min_rx,
387 detect_mult=self.detect_mult,
388 local_addr=self.local_addr,
389 peer_addr=self.peer_addr,
390 bfd_key_id=bfd_key_id,
391 conf_key_id=conf_key_id,
392 is_authenticated=is_authenticated)
393 self._test.registry.register(self, self.test.logger)
395 def upd_vpp_config(self,
398 required_min_rx=None):
400 self._desired_min_tx = desired_min_tx
402 self._required_min_rx = required_min_rx
404 self._detect_mult = detect_mult
405 bfd_key_id = self._bfd_key_id if self._sha1_key else None
406 conf_key_id = self._sha1_key.conf_key_id if self._sha1_key else None
407 is_authenticated = True if self._sha1_key else False
408 self.test.vapi.bfd_udp_upd(sw_if_index=self._interface.sw_if_index,
409 desired_min_tx=self.desired_min_tx,
410 required_min_rx=self.required_min_rx,
411 detect_mult=self.detect_mult,
412 local_addr=self.local_addr,
413 peer_addr=self.peer_addr,
414 bfd_key_id=bfd_key_id,
415 conf_key_id=conf_key_id,
416 is_authenticated=is_authenticated)
417 self._test.registry.register(self, self.test.logger)
419 def query_vpp_config(self):
420 session = self.get_bfd_udp_session_dump_entry()
421 return session is not None
423 def remove_vpp_config(self):
424 self.test.vapi.bfd_udp_del(self._interface.sw_if_index,
425 local_addr=self.local_addr,
426 peer_addr=self.peer_addr)
429 return "bfd-udp-%s-%s-%s-%s" % (self._interface.sw_if_index,
435 """ set bfd session admin-up """
436 self.test.vapi.bfd_udp_session_set_flags(
437 flags=VppEnum.vl_api_if_status_flags_t.IF_STATUS_API_FLAG_ADMIN_UP,
438 sw_if_index=self._interface.sw_if_index,
439 local_addr=self.local_addr,
440 peer_addr=self.peer_addr)
442 def admin_down(self):
443 """ set bfd session admin-down """
444 self.test.vapi.bfd_udp_session_set_flags(
445 flags=0, sw_if_index=self._interface.sw_if_index,
446 local_addr=self.local_addr,
447 peer_addr=self.peer_addr)