test/bfd.py

   1 """ BFD protocol implementation """
   2
   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
  13
  14 class BFDDiagCode(NumericConstant):
  15     """ BFD Diagnostic Code """
  16     no_diagnostic = 0
  17     control_detection_time_expired = 1
  18     echo_function_failed = 2
  19     neighbor_signaled_session_down = 3
  20     forwarding_plane_reset = 4
  21     path_down = 5
  22     concatenated_path_down = 6
  23     administratively_down = 7
  24     reverse_concatenated_path_down = 8
  25
  26     desc_dict = {
  27         no_diagnostic: "No diagnostic",
  28         control_detection_time_expired: "Control Detection Time Expired",
  29         echo_function_failed: "Echo Function Failed",
  30         neighbor_signaled_session_down: "Neighbor Signaled Session Down",
  31         forwarding_plane_reset: "Forwarding Plane Reset",
  32         path_down: "Path Down",
  33         concatenated_path_down: "Concatenated Path Down",
  34         administratively_down: "Administratively Down",
  35         reverse_concatenated_path_down: "Reverse Concatenated Path Down",
  36     }
  37
  38     def __init__(self, value):
  39         NumericConstant.__init__(self, value)
  40
  41
  42 class BFDState(NumericConstant):
  43     """ BFD State """
  44     admin_down = 0
  45     down = 1
  46     init = 2
  47     up = 3
  48
  49     desc_dict = {
  50         admin_down: "AdminDown",
  51         down: "Down",
  52         init: "Init",
  53         up: "Up",
  54     }
  55
  56     def __init__(self, value):
  57         NumericConstant.__init__(self, value)
  58
  59
  60 class BFDAuthType(NumericConstant):
  61     """ BFD Authentication Type """
  62     no_auth = 0
  63     simple_pwd = 1
  64     keyed_md5 = 2
  65     meticulous_keyed_md5 = 3
  66     keyed_sha1 = 4
  67     meticulous_keyed_sha1 = 5
  68
  69     desc_dict = {
  70         no_auth: "No authentication",
  71         simple_pwd: "Simple Password",
  72         keyed_md5: "Keyed MD5",
  73         meticulous_keyed_md5: "Meticulous Keyed MD5",
  74         keyed_sha1: "Keyed SHA1",
  75         meticulous_keyed_sha1: "Meticulous Keyed SHA1",
  76     }
  77
  78     def __init__(self, value):
  79         NumericConstant.__init__(self, value)
  80
  81
  82 def bfd_is_auth_used(pkt):
  83     """ is packet authenticated? """
  84     return "A" in pkt.sprintf("%BFD.flags%")
  85
  86
  87 def bfd_is_simple_pwd_used(pkt):
  88     """ is simple password authentication used? """
  89     return bfd_is_auth_used(pkt) and pkt.auth_type == BFDAuthType.simple_pwd
  90
  91
  92 def bfd_is_sha1_used(pkt):
  93     """ is sha1 authentication used? """
  94     return bfd_is_auth_used(pkt) and pkt.auth_type in \
  95         (BFDAuthType.keyed_sha1, BFDAuthType.meticulous_keyed_sha1)
  96
  97
  98 def bfd_is_md5_used(pkt):
  99     """ is md5 authentication used? """
 100     return bfd_is_auth_used(pkt) and pkt.auth_type in \
 101         (BFDAuthType.keyed_md5, BFDAuthType.meticulous_keyed_md5)
 102
 103
 104 def bfd_is_md5_or_sha1_used(pkt):
 105     """ is md5 or sha1 used? """
 106     return bfd_is_md5_used(pkt) or bfd_is_sha1_used(pkt)
 107
 108
 109 class BFD(Packet):
 110     """ BFD protocol layer for scapy """
 111
 112     udp_dport = 3784  #: BFD destination port per RFC 5881
 113     udp_dport_echo = 3785  # : BFD destination port for ECHO per RFC 5881
 114     udp_sport_min = 49152  #: BFD source port min value per RFC 5881
 115     udp_sport_max = 65535  #: BFD source port max value per RFC 5881
 116     bfd_pkt_len = 24  # : length of BFD pkt without authentication section
 117     sha1_auth_len = 28  # : length of authentication section if SHA1 used
 118
 119     name = "BFD"
 120
 121     fields_desc = [
 122         BitField("version", 1, 3),
 123         BitEnumField("diag", 0, 5, BFDDiagCode.desc_dict),
 124         BitEnumField("state", 0, 2, BFDState.desc_dict),
 125         FlagsField("flags", 0, 6, ['M', 'D', 'A', 'C', 'F', 'P']),
 126         XByteField("detect_mult", 0),
 127         BitField("length", bfd_pkt_len, 8),
 128         BitField("my_discriminator", 0, 32),
 129         BitField("your_discriminator", 0, 32),
 130         BitField("desired_min_tx_interval", 0, 32),
 131         BitField("required_min_rx_interval", 0, 32),
 132         BitField("required_min_echo_rx_interval", 0, 32),
 133         ConditionalField(
 134             BitEnumField("auth_type", 0, 8, BFDAuthType.desc_dict),
 135             bfd_is_auth_used),
 136         ConditionalField(BitField("auth_len", 0, 8), bfd_is_auth_used),
 137         ConditionalField(BitField("auth_key_id", 0, 8), bfd_is_auth_used),
 138         ConditionalField(BitField("auth_reserved", 0, 8),
 139                          bfd_is_md5_or_sha1_used),
 140         ConditionalField(
 141             BitField("auth_seq_num", 0, 32), bfd_is_md5_or_sha1_used),
 142         ConditionalField(StrField("auth_key_hash", "0" * 16), bfd_is_md5_used),
 143         ConditionalField(
 144             StrField("auth_key_hash", "0" * 20), bfd_is_sha1_used),
 145     ]
 146
 147     def mysummary(self):
 148         return self.sprintf("BFD(my_disc=%BFD.my_discriminator%,"
 149                             "your_disc=%BFD.your_discriminator%)")
 150
 151 # glue the BFD packet class to scapy parser
 152 bind_layers(UDP, BFD, dport=BFD.udp_dport)
 153
 154
 155 class BFD_vpp_echo(Packet):
 156     """ BFD echo packet as used by VPP (non-rfc, as rfc doesn't define one) """
 157
 158     udp_dport = 3785  #: BFD echo destination port per RFC 5881
 159     name = "BFD_VPP_ECHO"
 160
 161     fields_desc = [
 162         BitField("discriminator", 0, 32),
 163         BitField("expire_time_clocks", 0, 64),
 164         BitField("checksum", 0, 64)
 165     ]
 166
 167     def mysummary(self):
 168         return self.sprintf(
 169             "BFD_VPP_ECHO(disc=%BFD_VPP_ECHO.discriminator%,"
 170             "expire_time_clocks=%BFD_VPP_ECHO.expire_time_clocks%)")
 171
 172 # glue the BFD echo packet class to scapy parser
 173 bind_layers(UDP, BFD_vpp_echo, dport=BFD_vpp_echo.udp_dport)
 174
 175
 176 class VppBFDAuthKey(VppObject):
 177     """ Represents BFD authentication key in VPP """
 178
 179     def __init__(self, test, conf_key_id, auth_type, key):
 180         self._test = test
 181         self._key = key
 182         self._auth_type = auth_type
 183         test.assertIn(auth_type, BFDAuthType.desc_dict)
 184         self._conf_key_id = conf_key_id
 185
 186     @property
 187     def test(self):
 188         """ Test which created this key """
 189         return self._test
 190
 191     @property
 192     def auth_type(self):
 193         """ Authentication type for this key """
 194         return self._auth_type
 195
 196     @property
 197     def key(self):
 198         """ key data """
 199         return self._key
 200
 201     @key.setter
 202     def key(self, value):
 203         self._key = value
 204
 205     @property
 206     def conf_key_id(self):
 207         """ configuration key ID """
 208         return self._conf_key_id
 209
 210     def add_vpp_config(self):
 211         self.test.vapi.bfd_auth_set_key(
 212             self._conf_key_id, self._auth_type, self._key)
 213         self._test.registry.register(self, self.test.logger)
 214
 215     def get_bfd_auth_keys_dump_entry(self):
 216         """ get the entry in the auth keys dump corresponding to this key """
 217         result = self.test.vapi.bfd_auth_keys_dump()
 218         for k in result:
 219             if k.conf_key_id == self._conf_key_id:
 220                 return k
 221         return None
 222
 223     def query_vpp_config(self):
 224         return self.get_bfd_auth_keys_dump_entry() is not None
 225
 226     def remove_vpp_config(self):
 227         self.test.vapi.bfd_auth_del_key(self._conf_key_id)
 228
 229     def object_id(self):
 230         return "bfd-auth-key-%s" % self._conf_key_id
 231
 232     def __str__(self):
 233         return self.object_id()
 234
 235
 236 class VppBFDUDPSession(VppObject):
 237     """ Represents BFD UDP session in VPP """
 238
 239     def __init__(self, test, interface, peer_addr, local_addr=None, af=AF_INET,
 240                  desired_min_tx=300000, required_min_rx=300000, detect_mult=3,
 241                  sha1_key=None, bfd_key_id=None):
 242         self._test = test
 243         self._interface = interface
 244         self._af = af
 245         self._local_addr = local_addr
 246         if local_addr is not None:
 247             self._local_addr_n = inet_pton(af, local_addr)
 248         else:
 249             self._local_addr_n = None
 250         self._peer_addr = peer_addr
 251         self._peer_addr_n = inet_pton(af, peer_addr)
 252         self._desired_min_tx = desired_min_tx
 253         self._required_min_rx = required_min_rx
 254         self._detect_mult = detect_mult
 255         self._sha1_key = sha1_key
 256         if bfd_key_id is not None:
 257             self._bfd_key_id = bfd_key_id
 258         else:
 259             self._bfd_key_id = randint(0, 255)
 260
 261     @property
 262     def test(self):
 263         """ Test which created this session """
 264         return self._test
 265
 266     @property
 267     def interface(self):
 268         """ Interface on which this session lives """
 269         return self._interface
 270
 271     @property
 272     def af(self):
 273         """ Address family - AF_INET or AF_INET6 """
 274         return self._af
 275
 276     @property
 277     def local_addr(self):
 278         """ BFD session local address (VPP address) """
 279         if self._local_addr is None:
 280             if self.af == AF_INET:
 281                 return self._interface.local_ip4
 282             elif self.af == AF_INET6:
 283                 return self._interface.local_ip6
 284             else:
 285                 raise Exception("Unexpected af '%s'" % self.af)
 286         return self._local_addr
 287
 288     @property
 289     def local_addr_n(self):
 290         """ BFD session local address (VPP address) - raw, suitable for API """
 291         if self._local_addr is None:
 292             if self.af == AF_INET:
 293                 return self._interface.local_ip4n
 294             elif self.af == AF_INET6:
 295                 return self._interface.local_ip6n
 296             else:
 297                 raise Exception("Unexpected af '%s'" % self.af)
 298         return self._local_addr_n
 299
 300     @property
 301     def peer_addr(self):
 302         """ BFD session peer address """
 303         return self._peer_addr
 304
 305     @property
 306     def peer_addr_n(self):
 307         """ BFD session peer address - raw, suitable for API """
 308         return self._peer_addr_n
 309
 310     def get_bfd_udp_session_dump_entry(self):
 311         """ get the namedtuple entry from bfd udp session dump """
 312         result = self.test.vapi.bfd_udp_session_dump()
 313         for s in result:
 314             self.test.logger.debug("session entry: %s" % str(s))
 315             if s.sw_if_index == self.interface.sw_if_index:
 316                 if self.af == AF_INET \
 317                         and s.is_ipv6 == 0 \
 318                         and self.interface.local_ip4n == s.local_addr[:4] \
 319                         and self.interface.remote_ip4n == s.peer_addr[:4]:
 320                     return s
 321                 if self.af == AF_INET6 \
 322                         and s.is_ipv6 == 1 \
 323                         and self.interface.local_ip6n == s.local_addr \
 324                         and self.interface.remote_ip6n == s.peer_addr:
 325                     return s
 326         return None
 327
 328     @property
 329     def state(self):
 330         """ BFD session state """
 331         session = self.get_bfd_udp_session_dump_entry()
 332         if session is None:
 333             raise Exception("Could not find BFD session in VPP response")
 334         return session.state
 335
 336     @property
 337     def desired_min_tx(self):
 338         """ desired minimum tx interval """
 339         return self._desired_min_tx
 340
 341     @property
 342     def required_min_rx(self):
 343         """ required minimum rx interval """
 344         return self._required_min_rx
 345
 346     @property
 347     def detect_mult(self):
 348         """ detect multiplier """
 349         return self._detect_mult
 350
 351     @property
 352     def sha1_key(self):
 353         """ sha1 key """
 354         return self._sha1_key
 355
 356     @property
 357     def bfd_key_id(self):
 358         """ bfd key id in use """
 359         return self._bfd_key_id
 360
 361     def activate_auth(self, key, bfd_key_id=None, delayed=False):
 362         """ activate authentication for this session """
 363         self._bfd_key_id = bfd_key_id if bfd_key_id else randint(0, 255)
 364         self._sha1_key = key
 365         is_ipv6 = 1 if AF_INET6 == self.af else 0
 366         conf_key_id = self._sha1_key.conf_key_id
 367         is_delayed = 1 if delayed else 0
 368         self.test.vapi.bfd_udp_auth_activate(self._interface.sw_if_index,
 369                                              self.local_addr_n,
 370                                              self.peer_addr_n,
 371                                              is_ipv6=is_ipv6,
 372                                              bfd_key_id=self._bfd_key_id,
 373                                              conf_key_id=conf_key_id,
 374                                              is_delayed=is_delayed)
 375
 376     def deactivate_auth(self, delayed=False):
 377         """ deactivate authentication """
 378         self._bfd_key_id = None
 379         self._sha1_key = None
 380         is_delayed = 1 if delayed else 0
 381         is_ipv6 = 1 if AF_INET6 == self.af else 0
 382         self.test.vapi.bfd_udp_auth_deactivate(self._interface.sw_if_index,
 383                                                self.local_addr_n,
 384                                                self.peer_addr_n,
 385                                                is_ipv6=is_ipv6,
 386                                                is_delayed=is_delayed)
 387
 388     def modify_parameters(self,
 389                           detect_mult=None,
 390                           desired_min_tx=None,
 391                           required_min_rx=None):
 392         """ modify session parameters """
 393         if detect_mult:
 394             self._detect_mult = detect_mult
 395         if desired_min_tx:
 396             self._desired_min_tx = desired_min_tx
 397         if required_min_rx:
 398             self._required_min_rx = required_min_rx
 399         is_ipv6 = 1 if AF_INET6 == self.af else 0
 400         self.test.vapi.bfd_udp_mod(self._interface.sw_if_index,
 401                                    self.desired_min_tx,
 402                                    self.required_min_rx,
 403                                    self.detect_mult,
 404                                    self.local_addr_n,
 405                                    self.peer_addr_n,
 406                                    is_ipv6=is_ipv6)
 407
 408     def add_vpp_config(self):
 409         is_ipv6 = 1 if AF_INET6 == self.af else 0
 410         bfd_key_id = self._bfd_key_id if self._sha1_key else None
 411         conf_key_id = self._sha1_key.conf_key_id if self._sha1_key else None
 412         self.test.vapi.bfd_udp_add(self._interface.sw_if_index,
 413                                    self.desired_min_tx,
 414                                    self.required_min_rx,
 415                                    self.detect_mult,
 416                                    self.local_addr_n,
 417                                    self.peer_addr_n,
 418                                    is_ipv6=is_ipv6,
 419                                    bfd_key_id=bfd_key_id,
 420                                    conf_key_id=conf_key_id)
 421         self._test.registry.register(self, self.test.logger)
 422
 423     def query_vpp_config(self):
 424         session = self.get_bfd_udp_session_dump_entry()
 425         return session is not None
 426
 427     def remove_vpp_config(self):
 428         is_ipv6 = 1 if AF_INET6 == self._af else 0
 429         self.test.vapi.bfd_udp_del(self._interface.sw_if_index,
 430                                    self.local_addr_n,
 431                                    self.peer_addr_n,
 432                                    is_ipv6=is_ipv6)
 433
 434     def object_id(self):
 435         return "bfd-udp-%s-%s-%s-%s" % (self._interface.sw_if_index,
 436                                         self.local_addr,
 437                                         self.peer_addr,
 438                                         self.af)
 439
 440     def __str__(self):
 441         return self.object_id()
 442
 443     def admin_up(self):
 444         """ set bfd session admin-up """
 445         is_ipv6 = 1 if AF_INET6 == self._af else 0
 446         self.test.vapi.bfd_udp_session_set_flags(1,
 447                                                  self._interface.sw_if_index,
 448                                                  self.local_addr_n,
 449                                                  self.peer_addr_n,
 450                                                  is_ipv6=is_ipv6)
 451
 452     def admin_down(self):
 453         """ set bfd session admin-down """
 454         is_ipv6 = 1 if AF_INET6 == self._af else 0
 455         self.test.vapi.bfd_udp_session_set_flags(0,
 456                                                  self._interface.sw_if_index,
 457                                                  self.local_addr_n,
 458                                                  self.peer_addr_n,
 459                                                  is_ipv6=is_ipv6)