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     @property
 202     def conf_key_id(self):
 203         """ configuration key ID """
 204         return self._conf_key_id
 205
 206     def add_vpp_config(self):
 207         self.test.vapi.bfd_auth_set_key(
 208             self._conf_key_id, self._auth_type, self._key)
 209         self._test.registry.register(self, self.test.logger)
 210
 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()
 214         for k in result:
 215             if k.conf_key_id == self._conf_key_id:
 216                 return k
 217         return None
 218
 219     def query_vpp_config(self):
 220         return self.get_bfd_auth_keys_dump_entry() is not None
 221
 222     def remove_vpp_config(self):
 223         self.test.vapi.bfd_auth_del_key(self._conf_key_id)
 224
 225     def object_id(self):
 226         return "bfd-auth-key-%s" % self._conf_key_id
 227
 228     def __str__(self):
 229         return self.object_id()
 230
 231
 232 class VppBFDUDPSession(VppObject):
 233     """ Represents BFD UDP session in VPP """
 234
 235     def __init__(self, test, interface, peer_addr, local_addr=None, af=AF_INET,
 236                  desired_min_tx=100000, required_min_rx=100000, detect_mult=3,
 237                  sha1_key=None, bfd_key_id=None):
 238         self._test = test
 239         self._interface = interface
 240         self._af = af
 241         self._local_addr = local_addr
 242         if local_addr is not None:
 243             self._local_addr_n = inet_pton(af, local_addr)
 244         else:
 245             self._local_addr_n = None
 246         self._peer_addr = peer_addr
 247         self._peer_addr_n = inet_pton(af, peer_addr)
 248         self._desired_min_tx = desired_min_tx
 249         self._required_min_rx = required_min_rx
 250         self._detect_mult = detect_mult
 251         self._sha1_key = sha1_key
 252         self._bfd_key_id = bfd_key_id if bfd_key_id else randint(0, 255)
 253
 254     @property
 255     def test(self):
 256         """ Test which created this session """
 257         return self._test
 258
 259     @property
 260     def interface(self):
 261         """ Interface on which this session lives """
 262         return self._interface
 263
 264     @property
 265     def af(self):
 266         """ Address family - AF_INET or AF_INET6 """
 267         return self._af
 268
 269     @property
 270     def local_addr(self):
 271         """ BFD session local address (VPP address) """
 272         if self._local_addr is None:
 273             if self.af == AF_INET:
 274                 return self._interface.local_ip4
 275             elif self.af == AF_INET6:
 276                 return self._interface.local_ip6
 277             else:
 278                 raise Exception("Unexpected af '%s'" % self.af)
 279         return self._local_addr
 280
 281     @property
 282     def local_addr_n(self):
 283         """ BFD session local address (VPP address) - raw, suitable for API """
 284         if self._local_addr is None:
 285             if self.af == AF_INET:
 286                 return self._interface.local_ip4n
 287             elif self.af == AF_INET6:
 288                 return self._interface.local_ip6n
 289             else:
 290                 raise Exception("Unexpected af '%s'" % self.af)
 291         return self._local_addr_n
 292
 293     @property
 294     def peer_addr(self):
 295         """ BFD session peer address """
 296         return self._peer_addr
 297
 298     @property
 299     def peer_addr_n(self):
 300         """ BFD session peer address - raw, suitable for API """
 301         return self._peer_addr_n
 302
 303     def get_bfd_udp_session_dump_entry(self):
 304         """ get the namedtuple entry from bfd udp session dump """
 305         result = self.test.vapi.bfd_udp_session_dump()
 306         for s in result:
 307             self.test.logger.debug("session entry: %s" % str(s))
 308             if s.sw_if_index == self.interface.sw_if_index:
 309                 if self.af == AF_INET \
 310                         and s.is_ipv6 == 0 \
 311                         and self.interface.local_ip4n == s.local_addr[:4] \
 312                         and self.interface.remote_ip4n == s.peer_addr[:4]:
 313                     return s
 314                 if self.af == AF_INET6 \
 315                         and s.is_ipv6 == 1 \
 316                         and self.interface.local_ip6n == s.local_addr \
 317                         and self.interface.remote_ip6n == s.peer_addr:
 318                     return s
 319         return None
 320
 321     @property
 322     def state(self):
 323         """ BFD session state """
 324         session = self.get_bfd_udp_session_dump_entry()
 325         if session is None:
 326             raise Exception("Could not find BFD session in VPP response")
 327         return session.state
 328
 329     @property
 330     def desired_min_tx(self):
 331         """ desired minimum tx interval """
 332         return self._desired_min_tx
 333
 334     @property
 335     def required_min_rx(self):
 336         """ required minimum rx interval """
 337         return self._required_min_rx
 338
 339     @property
 340     def detect_mult(self):
 341         """ detect multiplier """
 342         return self._detect_mult
 343
 344     @property
 345     def sha1_key(self):
 346         """ sha1 key """
 347         return self._sha1_key
 348
 349     @property
 350     def bfd_key_id(self):
 351         """ bfd key id in use """
 352         return self._bfd_key_id
 353
 354     def activate_auth(self, key, bfd_key_id=None, delayed=False):
 355         """ activate authentication for this session """
 356         self._bfd_key_id = bfd_key_id if bfd_key_id else randint(0, 255)
 357         self._sha1_key = key
 358         is_ipv6 = 1 if AF_INET6 == self.af else 0
 359         conf_key_id = self._sha1_key.conf_key_id
 360         is_delayed = 1 if delayed else 0
 361         self.test.vapi.bfd_udp_auth_activate(self._interface.sw_if_index,
 362                                              self.local_addr_n,
 363                                              self.peer_addr_n,
 364                                              is_ipv6=is_ipv6,
 365                                              bfd_key_id=self._bfd_key_id,
 366                                              conf_key_id=conf_key_id,
 367                                              is_delayed=is_delayed)
 368
 369     def deactivate_auth(self, delayed=False):
 370         """ deactivate authentication """
 371         self._bfd_key_id = None
 372         self._sha1_key = None
 373         is_delayed = 1 if delayed else 0
 374         is_ipv6 = 1 if AF_INET6 == self.af else 0
 375         self.test.vapi.bfd_udp_auth_deactivate(self._interface.sw_if_index,
 376                                                self.local_addr_n,
 377                                                self.peer_addr_n,
 378                                                is_ipv6=is_ipv6,
 379                                                is_delayed=is_delayed)
 380
 381     def modify_parameters(self,
 382                           detect_mult=None,
 383                           desired_min_tx=None,
 384                           required_min_rx=None):
 385         """ modify session parameters """
 386         if detect_mult:
 387             self._detect_mult = detect_mult
 388         if desired_min_tx:
 389             self._desired_min_tx = desired_min_tx
 390         if required_min_rx:
 391             self._required_min_rx = required_min_rx
 392         is_ipv6 = 1 if AF_INET6 == self.af else 0
 393         self.test.vapi.bfd_udp_mod(self._interface.sw_if_index,
 394                                    self.desired_min_tx,
 395                                    self.required_min_rx,
 396                                    self.detect_mult,
 397                                    self.local_addr_n,
 398                                    self.peer_addr_n,
 399                                    is_ipv6=is_ipv6)
 400
 401     def add_vpp_config(self):
 402         is_ipv6 = 1 if AF_INET6 == self.af else 0
 403         bfd_key_id = self._bfd_key_id if self._sha1_key else None
 404         conf_key_id = self._sha1_key.conf_key_id if self._sha1_key else None
 405         self.test.vapi.bfd_udp_add(self._interface.sw_if_index,
 406                                    self.desired_min_tx,
 407                                    self.required_min_rx,
 408                                    self.detect_mult,
 409                                    self.local_addr_n,
 410                                    self.peer_addr_n,
 411                                    is_ipv6=is_ipv6,
 412                                    bfd_key_id=bfd_key_id,
 413                                    conf_key_id=conf_key_id)
 414         self._test.registry.register(self, self.test.logger)
 415
 416     def query_vpp_config(self):
 417         session = self.get_bfd_udp_session_dump_entry()
 418         return session is not None
 419
 420     def remove_vpp_config(self):
 421         is_ipv6 = 1 if AF_INET6 == self._af else 0
 422         self.test.vapi.bfd_udp_del(self._interface.sw_if_index,
 423                                    self.local_addr_n,
 424                                    self.peer_addr_n,
 425                                    is_ipv6=is_ipv6)
 426
 427     def object_id(self):
 428         return "bfd-udp-%s-%s-%s-%s" % (self._interface.sw_if_index,
 429                                         self.local_addr,
 430                                         self.peer_addr,
 431                                         self.af)
 432
 433     def __str__(self):
 434         return self.object_id()
 435
 436     def admin_up(self):
 437         """ set bfd session admin-up """
 438         is_ipv6 = 1 if AF_INET6 == self._af else 0
 439         self.test.vapi.bfd_udp_session_set_flags(1,
 440                                                  self._interface.sw_if_index,
 441                                                  self.local_addr_n,
 442                                                  self.peer_addr_n,
 443                                                  is_ipv6=is_ipv6)
 444
 445     def admin_down(self):
 446         """ set bfd session admin-down """
 447         is_ipv6 = 1 if AF_INET6 == self._af else 0
 448         self.test.vapi.bfd_udp_session_set_flags(0,
 449                                                  self._interface.sw_if_index,
 450                                                  self.local_addr_n,
 451                                                  self.peer_addr_n,
 452                                                  is_ipv6=is_ipv6)