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