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_sport_min = 49152  #: BFD source port min value per RFC 5881
 114     udp_sport_max = 65535  #: BFD source port max value per RFC 5881
 115     bfd_pkt_len = 24  # : length of BFD pkt without authentication section
 116     sha1_auth_len = 28  # : length of authentication section if SHA1 used
 117
 118     name = "BFD"
 119
 120     fields_desc = [
 121         BitField("version", 1, 3),
 122         BitEnumField("diag", 0, 5, BFDDiagCode.desc_dict),
 123         BitEnumField("state", 0, 2, BFDState.desc_dict),
 124         FlagsField("flags", 0, 6, ['M', 'D', 'A', 'C', 'F', 'P']),
 125         XByteField("detect_mult", 0),
 126         BitField("length", bfd_pkt_len, 8),
 127         BitField("my_discriminator", 0, 32),
 128         BitField("your_discriminator", 0, 32),
 129         BitField("desired_min_tx_interval", 0, 32),
 130         BitField("required_min_rx_interval", 0, 32),
 131         BitField("required_min_echo_rx_interval", 0, 32),
 132         ConditionalField(
 133             BitEnumField("auth_type", 0, 8, BFDAuthType.desc_dict),
 134             bfd_is_auth_used),
 135         ConditionalField(BitField("auth_len", 0, 8), bfd_is_auth_used),
 136         ConditionalField(BitField("auth_key_id", 0, 8), bfd_is_auth_used),
 137         ConditionalField(BitField("auth_reserved", 0, 8),
 138                          bfd_is_md5_or_sha1_used),
 139         ConditionalField(
 140             BitField("auth_seq_num", 0, 32), bfd_is_md5_or_sha1_used),
 141         ConditionalField(StrField("auth_key_hash", "0" * 16), bfd_is_md5_used),
 142         ConditionalField(
 143             StrField("auth_key_hash", "0" * 20), bfd_is_sha1_used),
 144     ]
 145
 146     def mysummary(self):
 147         return self.sprintf("BFD(my_disc=%BFD.my_discriminator%,"
 148                             "your_disc=%BFD.your_discriminator%)")
 149
 150 # glue the BFD packet class to scapy parser
 151 bind_layers(UDP, BFD, dport=BFD.udp_dport)
 152
 153
 154 class VppBFDAuthKey(VppObject):
 155     """ Represents BFD authentication key in VPP """
 156
 157     def __init__(self, test, conf_key_id, auth_type, key):
 158         self._test = test
 159         self._key = key
 160         self._auth_type = auth_type
 161         test.assertIn(auth_type, BFDAuthType.desc_dict)
 162         self._conf_key_id = conf_key_id
 163
 164     @property
 165     def test(self):
 166         """ Test which created this key """
 167         return self._test
 168
 169     @property
 170     def auth_type(self):
 171         """ Authentication type for this key """
 172         return self._auth_type
 173
 174     @property
 175     def key(self):
 176         """ key data """
 177         return self._key
 178
 179     @property
 180     def conf_key_id(self):
 181         """ configuration key ID """
 182         return self._conf_key_id
 183
 184     def add_vpp_config(self):
 185         self.test.vapi.bfd_auth_set_key(
 186             self._conf_key_id, self._auth_type, self._key)
 187         self._test.registry.register(self, self.test.logger)
 188
 189     def get_bfd_auth_keys_dump_entry(self):
 190         """ get the entry in the auth keys dump corresponding to this key """
 191         result = self.test.vapi.bfd_auth_keys_dump()
 192         for k in result:
 193             if k.conf_key_id == self._conf_key_id:
 194                 return k
 195         return None
 196
 197     def query_vpp_config(self):
 198         return self.get_bfd_auth_keys_dump_entry() is not None
 199
 200     def remove_vpp_config(self):
 201         self.test.vapi.bfd_auth_del_key(self._conf_key_id)
 202
 203     def object_id(self):
 204         return "bfd-auth-key-%s" % self._conf_key_id
 205
 206     def __str__(self):
 207         return self.object_id()
 208
 209
 210 class VppBFDUDPSession(VppObject):
 211     """ Represents BFD UDP session in VPP """
 212
 213     def __init__(self, test, interface, peer_addr, local_addr=None, af=AF_INET,
 214                  desired_min_tx=100000, required_min_rx=100000, detect_mult=3,
 215                  sha1_key=None, bfd_key_id=None):
 216         self._test = test
 217         self._interface = interface
 218         self._af = af
 219         self._local_addr = local_addr
 220         if local_addr is not None:
 221             self._local_addr_n = inet_pton(af, local_addr)
 222         else:
 223             self._local_addr_n = None
 224         self._peer_addr = peer_addr
 225         self._peer_addr_n = inet_pton(af, peer_addr)
 226         self._desired_min_tx = desired_min_tx
 227         self._required_min_rx = required_min_rx
 228         self._detect_mult = detect_mult
 229         self._sha1_key = sha1_key
 230         self._bfd_key_id = bfd_key_id if bfd_key_id else randint(0, 255)
 231
 232     @property
 233     def test(self):
 234         """ Test which created this session """
 235         return self._test
 236
 237     @property
 238     def interface(self):
 239         """ Interface on which this session lives """
 240         return self._interface
 241
 242     @property
 243     def af(self):
 244         """ Address family - AF_INET or AF_INET6 """
 245         return self._af
 246
 247     @property
 248     def local_addr(self):
 249         """ BFD session local address (VPP address) """
 250         if self._local_addr is None:
 251             if self.af == AF_INET:
 252                 return self._interface.local_ip4
 253             elif self.af == AF_INET6:
 254                 return self._interface.local_ip6
 255             else:
 256                 raise Exception("Unexpected af '%s'" % self.af)
 257         return self._local_addr
 258
 259     @property
 260     def local_addr_n(self):
 261         """ BFD session local address (VPP address) - raw, suitable for API """
 262         if self._local_addr is None:
 263             if self.af == AF_INET:
 264                 return self._interface.local_ip4n
 265             elif self.af == AF_INET6:
 266                 return self._interface.local_ip6n
 267             else:
 268                 raise Exception("Unexpected af '%s'" % self.af)
 269         return self._local_addr_n
 270
 271     @property
 272     def peer_addr(self):
 273         """ BFD session peer address """
 274         return self._peer_addr
 275
 276     @property
 277     def peer_addr_n(self):
 278         """ BFD session peer address - raw, suitable for API """
 279         return self._peer_addr_n
 280
 281     def get_bfd_udp_session_dump_entry(self):
 282         """ get the namedtuple entry from bfd udp session dump """
 283         result = self.test.vapi.bfd_udp_session_dump()
 284         for s in result:
 285             self.test.logger.debug("session entry: %s" % str(s))
 286             if s.sw_if_index == self.interface.sw_if_index:
 287                 if self.af == AF_INET \
 288                         and s.is_ipv6 == 0 \
 289                         and self.interface.local_ip4n == s.local_addr[:4] \
 290                         and self.interface.remote_ip4n == s.peer_addr[:4]:
 291                     return s
 292                 if self.af == AF_INET6 \
 293                         and s.is_ipv6 == 1 \
 294                         and self.interface.local_ip6n == s.local_addr \
 295                         and self.interface.remote_ip6n == s.peer_addr:
 296                     return s
 297         return None
 298
 299     @property
 300     def state(self):
 301         """ BFD session state """
 302         session = self.get_bfd_udp_session_dump_entry()
 303         if session is None:
 304             raise Exception("Could not find BFD session in VPP response")
 305         return session.state
 306
 307     @property
 308     def desired_min_tx(self):
 309         """ desired minimum tx interval """
 310         return self._desired_min_tx
 311
 312     @property
 313     def required_min_rx(self):
 314         """ required minimum rx interval """
 315         return self._required_min_rx
 316
 317     @property
 318     def detect_mult(self):
 319         """ detect multiplier """
 320         return self._detect_mult
 321
 322     @property
 323     def sha1_key(self):
 324         """ sha1 key """
 325         return self._sha1_key
 326
 327     @property
 328     def bfd_key_id(self):
 329         """ bfd key id in use """
 330         return self._bfd_key_id
 331
 332     def activate_auth(self, key, bfd_key_id=None, delayed=False):
 333         """ activate authentication for this session """
 334         self._bfd_key_id = bfd_key_id if bfd_key_id else randint(0, 255)
 335         self._sha1_key = key
 336         is_ipv6 = 1 if AF_INET6 == self.af else 0
 337         conf_key_id = self._sha1_key.conf_key_id
 338         is_delayed = 1 if delayed else 0
 339         self.test.vapi.bfd_udp_auth_activate(self._interface.sw_if_index,
 340                                              self.local_addr_n,
 341                                              self.peer_addr_n,
 342                                              is_ipv6=is_ipv6,
 343                                              bfd_key_id=self._bfd_key_id,
 344                                              conf_key_id=conf_key_id,
 345                                              is_delayed=is_delayed)
 346
 347     def deactivate_auth(self, delayed=False):
 348         """ deactivate authentication """
 349         self._bfd_key_id = None
 350         self._sha1_key = None
 351         is_delayed = 1 if delayed else 0
 352         is_ipv6 = 1 if AF_INET6 == self.af else 0
 353         self.test.vapi.bfd_udp_auth_deactivate(self._interface.sw_if_index,
 354                                                self.local_addr_n,
 355                                                self.peer_addr_n,
 356                                                is_ipv6=is_ipv6,
 357                                                is_delayed=is_delayed)
 358
 359     def modify_parameters(self,
 360                           detect_mult=None,
 361                           desired_min_tx=None,
 362                           required_min_rx=None):
 363         """ modify session parameters """
 364         if detect_mult:
 365             self._detect_mult = detect_mult
 366         if desired_min_tx:
 367             self._desired_min_tx = desired_min_tx
 368         if required_min_rx:
 369             self._required_min_rx = required_min_rx
 370         is_ipv6 = 1 if AF_INET6 == self.af else 0
 371         self.test.vapi.bfd_udp_mod(self._interface.sw_if_index,
 372                                    self.desired_min_tx,
 373                                    self.required_min_rx,
 374                                    self.detect_mult,
 375                                    self.local_addr_n,
 376                                    self.peer_addr_n,
 377                                    is_ipv6=is_ipv6)
 378
 379     def add_vpp_config(self):
 380         is_ipv6 = 1 if AF_INET6 == self.af else 0
 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         self.test.vapi.bfd_udp_add(self._interface.sw_if_index,
 384                                    self.desired_min_tx,
 385                                    self.required_min_rx,
 386                                    self.detect_mult,
 387                                    self.local_addr_n,
 388                                    self.peer_addr_n,
 389                                    is_ipv6=is_ipv6,
 390                                    bfd_key_id=bfd_key_id,
 391                                    conf_key_id=conf_key_id)
 392         self._test.registry.register(self, self.test.logger)
 393
 394     def query_vpp_config(self):
 395         session = self.get_bfd_udp_session_dump_entry()
 396         return session is not None
 397
 398     def remove_vpp_config(self):
 399         is_ipv6 = 1 if AF_INET6 == self._af else 0
 400         self.test.vapi.bfd_udp_del(self._interface.sw_if_index,
 401                                    self.local_addr_n,
 402                                    self.peer_addr_n,
 403                                    is_ipv6=is_ipv6)
 404
 405     def object_id(self):
 406         return "bfd-udp-%s-%s-%s-%s" % (self._interface.sw_if_index,
 407                                         self.local_addr,
 408                                         self.peer_addr,
 409                                         self.af)
 410
 411     def __str__(self):
 412         return self.object_id()
 413
 414     def admin_up(self):
 415         """ set bfd session admin-up """
 416         is_ipv6 = 1 if AF_INET6 == self._af else 0
 417         self.test.vapi.bfd_udp_session_set_flags(1,
 418                                                  self._interface.sw_if_index,
 419                                                  self.local_addr_n,
 420                                                  self.peer_addr_n,
 421                                                  is_ipv6=is_ipv6)