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 from vpp_ip import VppIpAddress
  13 from vpp_papi import VppEnum
  14
  15
  16 class BFDDiagCode(NumericConstant):
  17     """ BFD Diagnostic Code """
  18     no_diagnostic = 0
  19     control_detection_time_expired = 1
  20     echo_function_failed = 2
  21     neighbor_signaled_session_down = 3
  22     forwarding_plane_reset = 4
  23     path_down = 5
  24     concatenated_path_down = 6
  25     administratively_down = 7
  26     reverse_concatenated_path_down = 8
  27
  28     desc_dict = {
  29         no_diagnostic: "No diagnostic",
  30         control_detection_time_expired: "Control Detection Time Expired",
  31         echo_function_failed: "Echo Function Failed",
  32         neighbor_signaled_session_down: "Neighbor Signaled Session Down",
  33         forwarding_plane_reset: "Forwarding Plane Reset",
  34         path_down: "Path Down",
  35         concatenated_path_down: "Concatenated Path Down",
  36         administratively_down: "Administratively Down",
  37         reverse_concatenated_path_down: "Reverse Concatenated Path Down",
  38     }
  39
  40
  41 class BFDState(NumericConstant):
  42     """ BFD State """
  43     admin_down = 0
  44     down = 1
  45     init = 2
  46     up = 3
  47
  48     desc_dict = {
  49         admin_down: "AdminDown",
  50         down: "Down",
  51         init: "Init",
  52         up: "Up",
  53     }
  54
  55
  56 class BFDAuthType(NumericConstant):
  57     """ BFD Authentication Type """
  58     no_auth = 0
  59     simple_pwd = 1
  60     keyed_md5 = 2
  61     meticulous_keyed_md5 = 3
  62     keyed_sha1 = 4
  63     meticulous_keyed_sha1 = 5
  64
  65     desc_dict = {
  66         no_auth: "No authentication",
  67         simple_pwd: "Simple Password",
  68         keyed_md5: "Keyed MD5",
  69         meticulous_keyed_md5: "Meticulous Keyed MD5",
  70         keyed_sha1: "Keyed SHA1",
  71         meticulous_keyed_sha1: "Meticulous Keyed SHA1",
  72     }
  73
  74
  75 def bfd_is_auth_used(pkt):
  76     """ is packet authenticated? """
  77     return "A" in pkt.sprintf("%BFD.flags%")
  78
  79
  80 def bfd_is_simple_pwd_used(pkt):
  81     """ is simple password authentication used? """
  82     return bfd_is_auth_used(pkt) and pkt.auth_type == BFDAuthType.simple_pwd
  83
  84
  85 def bfd_is_sha1_used(pkt):
  86     """ is sha1 authentication used? """
  87     return bfd_is_auth_used(pkt) and pkt.auth_type in \
  88         (BFDAuthType.keyed_sha1, BFDAuthType.meticulous_keyed_sha1)
  89
  90
  91 def bfd_is_md5_used(pkt):
  92     """ is md5 authentication used? """
  93     return bfd_is_auth_used(pkt) and pkt.auth_type in \
  94         (BFDAuthType.keyed_md5, BFDAuthType.meticulous_keyed_md5)
  95
  96
  97 def bfd_is_md5_or_sha1_used(pkt):
  98     """ is md5 or sha1 used? """
  99     return bfd_is_md5_used(pkt) or bfd_is_sha1_used(pkt)
 100
 101
 102 class BFD(Packet):
 103     """ BFD protocol layer for scapy """
 104
 105     udp_dport = 3784  #: BFD destination port per RFC 5881
 106     udp_dport_echo = 3785  # : BFD destination port for ECHO per RFC 5881
 107     udp_sport_min = 49152  #: BFD source port min value per RFC 5881
 108     udp_sport_max = 65535  #: BFD source port max value per RFC 5881
 109     bfd_pkt_len = 24  # : length of BFD pkt without authentication section
 110     sha1_auth_len = 28  # : length of authentication section if SHA1 used
 111
 112     name = "BFD"
 113
 114     fields_desc = [
 115         BitField("version", 1, 3),
 116         BitEnumField("diag", 0, 5, BFDDiagCode.desc_dict),
 117         BitEnumField("state", 0, 2, BFDState.desc_dict),
 118         FlagsField("flags", 0, 6, ['M', 'D', 'A', 'C', 'F', 'P']),
 119         XByteField("detect_mult", 0),
 120         BitField("length", bfd_pkt_len, 8),
 121         BitField("my_discriminator", 0, 32),
 122         BitField("your_discriminator", 0, 32),
 123         BitField("desired_min_tx_interval", 0, 32),
 124         BitField("required_min_rx_interval", 0, 32),
 125         BitField("required_min_echo_rx_interval", 0, 32),
 126         ConditionalField(
 127             BitEnumField("auth_type", 0, 8, BFDAuthType.desc_dict),
 128             bfd_is_auth_used),
 129         ConditionalField(BitField("auth_len", 0, 8), bfd_is_auth_used),
 130         ConditionalField(BitField("auth_key_id", 0, 8), bfd_is_auth_used),
 131         ConditionalField(BitField("auth_reserved", 0, 8),
 132                          bfd_is_md5_or_sha1_used),
 133         ConditionalField(
 134             BitField("auth_seq_num", 0, 32), bfd_is_md5_or_sha1_used),
 135         ConditionalField(StrField("auth_key_hash", "0" * 16), bfd_is_md5_used),
 136         ConditionalField(
 137             StrField("auth_key_hash", "0" * 20), bfd_is_sha1_used),
 138     ]
 139
 140     def mysummary(self):
 141         return self.sprintf("BFD(my_disc=%BFD.my_discriminator%,"
 142                             "your_disc=%BFD.your_discriminator%)")
 143
 144
 145 # glue the BFD packet class to scapy parser
 146 bind_layers(UDP, BFD, dport=BFD.udp_dport)
 147
 148
 149 class BFD_vpp_echo(Packet):
 150     """ BFD echo packet as used by VPP (non-rfc, as rfc doesn't define one) """
 151
 152     udp_dport = 3785  #: BFD echo destination port per RFC 5881
 153     name = "BFD_VPP_ECHO"
 154
 155     fields_desc = [
 156         BitField("discriminator", 0, 32),
 157         BitField("expire_time_clocks", 0, 64),
 158         BitField("checksum", 0, 64)
 159     ]
 160
 161     def mysummary(self):
 162         return self.sprintf(
 163             "BFD_VPP_ECHO(disc=%BFD_VPP_ECHO.discriminator%,"
 164             "expire_time_clocks=%BFD_VPP_ECHO.expire_time_clocks%)")
 165
 166
 167 # glue the BFD echo packet class to scapy parser
 168 bind_layers(UDP, BFD_vpp_echo, dport=BFD_vpp_echo.udp_dport)
 169
 170
 171 class VppBFDAuthKey(VppObject):
 172     """ Represents BFD authentication key in VPP """
 173
 174     def __init__(self, test, conf_key_id, auth_type, key):
 175         self._test = test
 176         self._key = key
 177         self._auth_type = auth_type
 178         test.assertIn(auth_type, BFDAuthType.desc_dict)
 179         self._conf_key_id = conf_key_id
 180
 181     @property
 182     def test(self):
 183         """ Test which created this key """
 184         return self._test
 185
 186     @property
 187     def auth_type(self):
 188         """ Authentication type for this key """
 189         return self._auth_type
 190
 191     @property
 192     def key(self):
 193         """ key data """
 194         return self._key
 195
 196     @key.setter
 197     def key(self, value):
 198         self._key = value
 199
 200     @property
 201     def conf_key_id(self):
 202         """ configuration key ID """
 203         return self._conf_key_id
 204
 205     def add_vpp_config(self):
 206         self.test.vapi.bfd_auth_set_key(
 207             conf_key_id=self._conf_key_id, auth_type=self._auth_type,
 208             key=self._key, key_len=len(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(conf_key_id=self._conf_key_id)
 224
 225     def object_id(self):
 226         return "bfd-auth-key-%s" % self._conf_key_id
 227
 228
 229 class VppBFDUDPSession(VppObject):
 230     """ Represents BFD UDP session in VPP """
 231
 232     def __init__(self, test, interface, peer_addr, local_addr=None, af=AF_INET,
 233                  desired_min_tx=300000, required_min_rx=300000, detect_mult=3,
 234                  sha1_key=None, bfd_key_id=None, is_tunnel=False):
 235         self._test = test
 236         self._interface = interface
 237         self._af = af
 238         if local_addr:
 239             self._local_addr = VppIpAddress(local_addr)
 240         else:
 241             self._local_addr = None
 242         self._peer_addr = VppIpAddress(peer_addr)
 243         self._desired_min_tx = desired_min_tx
 244         self._required_min_rx = required_min_rx
 245         self._detect_mult = detect_mult
 246         self._sha1_key = sha1_key
 247         if bfd_key_id is not None:
 248             self._bfd_key_id = bfd_key_id
 249         else:
 250             self._bfd_key_id = randint(0, 255)
 251         self._is_tunnel = is_tunnel
 252
 253     @property
 254     def test(self):
 255         """ Test which created this session """
 256         return self._test
 257
 258     @property
 259     def interface(self):
 260         """ Interface on which this session lives """
 261         return self._interface
 262
 263     @property
 264     def af(self):
 265         """ Address family - AF_INET or AF_INET6 """
 266         return self._af
 267
 268     @property
 269     def local_addr(self):
 270         """ BFD session local address (VPP address) """
 271         if self._local_addr is None:
 272             if self.af == AF_INET:
 273                 return self._interface.local_ip4
 274             elif self.af == AF_INET6:
 275                 return self._interface.local_ip6
 276             else:
 277                 raise Exception("Unexpected af '%s'" % self.af)
 278         return self._local_addr.address
 279
 280     @property
 281     def peer_addr(self):
 282         """ BFD session peer address """
 283         return self._peer_addr.address
 284
 285     def get_bfd_udp_session_dump_entry(self):
 286         """ get the namedtuple entry from bfd udp session dump """
 287         result = self.test.vapi.bfd_udp_session_dump()
 288         for s in result:
 289             self.test.logger.debug("session entry: %s" % str(s))
 290             if s.sw_if_index == self.interface.sw_if_index:
 291                 if self.af == AF_INET \
 292                         and self.interface.local_ip4 == str(s.local_addr) \
 293                         and self.interface.remote_ip4 == str(s.peer_addr):
 294                     return s
 295                 if self.af == AF_INET6 \
 296                         and self.interface.local_ip6 == str(s.local_addr) \
 297                         and self.interface.remote_ip6 == str(s.peer_addr):
 298                     return s
 299         return None
 300
 301     @property
 302     def state(self):
 303         """ BFD session state """
 304         session = self.get_bfd_udp_session_dump_entry()
 305         if session is None:
 306             raise Exception("Could not find BFD session in VPP response")
 307         return session.state
 308
 309     @property
 310     def desired_min_tx(self):
 311         """ desired minimum tx interval """
 312         return self._desired_min_tx
 313
 314     @property
 315     def required_min_rx(self):
 316         """ required minimum rx interval """
 317         return self._required_min_rx
 318
 319     @property
 320     def detect_mult(self):
 321         """ detect multiplier """
 322         return self._detect_mult
 323
 324     @property
 325     def sha1_key(self):
 326         """ sha1 key """
 327         return self._sha1_key
 328
 329     @property
 330     def bfd_key_id(self):
 331         """ bfd key id in use """
 332         return self._bfd_key_id
 333
 334     @property
 335     def is_tunnel(self):
 336         return self._is_tunnel
 337
 338     def activate_auth(self, key, bfd_key_id=None, delayed=False):
 339         """ activate authentication for this session """
 340         self._bfd_key_id = bfd_key_id if bfd_key_id else randint(0, 255)
 341         self._sha1_key = key
 342         conf_key_id = self._sha1_key.conf_key_id
 343         is_delayed = 1 if delayed else 0
 344         self.test.vapi.bfd_udp_auth_activate(
 345             sw_if_index=self._interface.sw_if_index,
 346             local_addr=self.local_addr.encode(),
 347             peer_addr=self.peer_addr.encode(),
 348             bfd_key_id=self._bfd_key_id,
 349             conf_key_id=conf_key_id,
 350             is_delayed=is_delayed)
 351
 352     def deactivate_auth(self, delayed=False):
 353         """ deactivate authentication """
 354         self._bfd_key_id = None
 355         self._sha1_key = None
 356         is_delayed = 1 if delayed else 0
 357         self.test.vapi.bfd_udp_auth_deactivate(
 358             sw_if_index=self._interface.sw_if_index,
 359             local_addr=self.local_addr.encode(),
 360             peer_addr=self.peer_addr.encode(),
 361             is_delayed=is_delayed)
 362
 363     def modify_parameters(self,
 364                           detect_mult=None,
 365                           desired_min_tx=None,
 366                           required_min_rx=None):
 367         """ modify session parameters """
 368         if detect_mult:
 369             self._detect_mult = detect_mult
 370         if desired_min_tx:
 371             self._desired_min_tx = desired_min_tx
 372         if required_min_rx:
 373             self._required_min_rx = required_min_rx
 374         self.test.vapi.bfd_udp_mod(sw_if_index=self._interface.sw_if_index,
 375                                    desired_min_tx=self.desired_min_tx,
 376                                    required_min_rx=self.required_min_rx,
 377                                    detect_mult=self.detect_mult,
 378                                    local_addr=self.local_addr.encode(),
 379                                    peer_addr=self.peer_addr.encode())
 380
 381     def add_vpp_config(self):
 382         bfd_key_id = self._bfd_key_id if self._sha1_key else None
 383         conf_key_id = self._sha1_key.conf_key_id if self._sha1_key else None
 384         is_authenticated = True if self._sha1_key else False
 385         self.test.vapi.bfd_udp_add(sw_if_index=self._interface.sw_if_index,
 386                                    desired_min_tx=self.desired_min_tx,
 387                                    required_min_rx=self.required_min_rx,
 388                                    detect_mult=self.detect_mult,
 389                                    local_addr=self.local_addr.encode(),
 390                                    peer_addr=self.peer_addr.encode(),
 391                                    bfd_key_id=bfd_key_id,
 392                                    conf_key_id=conf_key_id,
 393                                    is_authenticated=is_authenticated)
 394         self._test.registry.register(self, self.test.logger)
 395
 396     def query_vpp_config(self):
 397         session = self.get_bfd_udp_session_dump_entry()
 398         return session is not None
 399
 400     def remove_vpp_config(self):
 401         self.test.vapi.bfd_udp_del(self._interface.sw_if_index,
 402                                    local_addr=self.local_addr.encode(),
 403                                    peer_addr=self.peer_addr.encode())
 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 admin_up(self):
 412         """ set bfd session admin-up """
 413         self.test.vapi.bfd_udp_session_set_flags(
 414             flags=VppEnum.vl_api_if_status_flags_t.IF_STATUS_API_FLAG_ADMIN_UP,
 415             sw_if_index=self._interface.sw_if_index,
 416             local_addr=self.local_addr.encode(),
 417             peer_addr=self.peer_addr.encode())
 418
 419     def admin_down(self):
 420         """ set bfd session admin-down """
 421         self.test.vapi.bfd_udp_session_set_flags(
 422             flags=0, sw_if_index=self._interface.sw_if_index,
 423             local_addr=self.local_addr.encode(),
 424             peer_addr=self.peer_addr.encode())