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_papi import VppEnum
  13
  14
  15 class BFDDiagCode(NumericConstant):
  16     """ BFD Diagnostic Code """
  17     no_diagnostic = 0
  18     control_detection_time_expired = 1
  19     echo_function_failed = 2
  20     neighbor_signaled_session_down = 3
  21     forwarding_plane_reset = 4
  22     path_down = 5
  23     concatenated_path_down = 6
  24     administratively_down = 7
  25     reverse_concatenated_path_down = 8
  26
  27     desc_dict = {
  28         no_diagnostic: "No diagnostic",
  29         control_detection_time_expired: "Control Detection Time Expired",
  30         echo_function_failed: "Echo Function Failed",
  31         neighbor_signaled_session_down: "Neighbor Signaled Session Down",
  32         forwarding_plane_reset: "Forwarding Plane Reset",
  33         path_down: "Path Down",
  34         concatenated_path_down: "Concatenated Path Down",
  35         administratively_down: "Administratively Down",
  36         reverse_concatenated_path_down: "Reverse Concatenated Path Down",
  37     }
  38
  39
  40 class BFDState(NumericConstant):
  41     """ BFD State """
  42     admin_down = 0
  43     down = 1
  44     init = 2
  45     up = 3
  46
  47     desc_dict = {
  48         admin_down: "AdminDown",
  49         down: "Down",
  50         init: "Init",
  51         up: "Up",
  52     }
  53
  54
  55 class BFDAuthType(NumericConstant):
  56     """ BFD Authentication Type """
  57     no_auth = 0
  58     simple_pwd = 1
  59     keyed_md5 = 2
  60     meticulous_keyed_md5 = 3
  61     keyed_sha1 = 4
  62     meticulous_keyed_sha1 = 5
  63
  64     desc_dict = {
  65         no_auth: "No authentication",
  66         simple_pwd: "Simple Password",
  67         keyed_md5: "Keyed MD5",
  68         meticulous_keyed_md5: "Meticulous Keyed MD5",
  69         keyed_sha1: "Keyed SHA1",
  70         meticulous_keyed_sha1: "Meticulous Keyed SHA1",
  71     }
  72
  73
  74 def bfd_is_auth_used(pkt):
  75     """ is packet authenticated? """
  76     return "A" in pkt.sprintf("%BFD.flags%")
  77
  78
  79 def bfd_is_simple_pwd_used(pkt):
  80     """ is simple password authentication used? """
  81     return bfd_is_auth_used(pkt) and pkt.auth_type == BFDAuthType.simple_pwd
  82
  83
  84 def bfd_is_sha1_used(pkt):
  85     """ is sha1 authentication used? """
  86     return bfd_is_auth_used(pkt) and pkt.auth_type in \
  87         (BFDAuthType.keyed_sha1, BFDAuthType.meticulous_keyed_sha1)
  88
  89
  90 def bfd_is_md5_used(pkt):
  91     """ is md5 authentication used? """
  92     return bfd_is_auth_used(pkt) and pkt.auth_type in \
  93         (BFDAuthType.keyed_md5, BFDAuthType.meticulous_keyed_md5)
  94
  95
  96 def bfd_is_md5_or_sha1_used(pkt):
  97     """ is md5 or sha1 used? """
  98     return bfd_is_md5_used(pkt) or bfd_is_sha1_used(pkt)
  99
 100
 101 class BFD(Packet):
 102     """ BFD protocol layer for scapy """
 103
 104     udp_dport = 3784  #: BFD destination port per RFC 5881
 105     udp_dport_echo = 3785  # : BFD destination port for ECHO per RFC 5881
 106     udp_sport_min = 49152  #: BFD source port min value per RFC 5881
 107     udp_sport_max = 65535  #: BFD source port max value per RFC 5881
 108     bfd_pkt_len = 24  # : length of BFD pkt without authentication section
 109     sha1_auth_len = 28  # : length of authentication section if SHA1 used
 110
 111     name = "BFD"
 112
 113     fields_desc = [
 114         BitField("version", 1, 3),
 115         BitEnumField("diag", 0, 5, BFDDiagCode.desc_dict),
 116         BitEnumField("state", 0, 2, BFDState.desc_dict),
 117         FlagsField("flags", 0, 6, ['M', 'D', 'A', 'C', 'F', 'P']),
 118         XByteField("detect_mult", 0),
 119         BitField("length", bfd_pkt_len, 8),
 120         BitField("my_discriminator", 0, 32),
 121         BitField("your_discriminator", 0, 32),
 122         BitField("desired_min_tx_interval", 0, 32),
 123         BitField("required_min_rx_interval", 0, 32),
 124         BitField("required_min_echo_rx_interval", 0, 32),
 125         ConditionalField(
 126             BitEnumField("auth_type", 0, 8, BFDAuthType.desc_dict),
 127             bfd_is_auth_used),
 128         ConditionalField(BitField("auth_len", 0, 8), bfd_is_auth_used),
 129         ConditionalField(BitField("auth_key_id", 0, 8), bfd_is_auth_used),
 130         ConditionalField(BitField("auth_reserved", 0, 8),
 131                          bfd_is_md5_or_sha1_used),
 132         ConditionalField(
 133             BitField("auth_seq_num", 0, 32), bfd_is_md5_or_sha1_used),
 134         ConditionalField(StrField("auth_key_hash", "0" * 16), bfd_is_md5_used),
 135         ConditionalField(
 136             StrField("auth_key_hash", "0" * 20), bfd_is_sha1_used),
 137     ]
 138
 139     def mysummary(self):
 140         return self.sprintf("BFD(my_disc=%BFD.my_discriminator%,"
 141                             "your_disc=%BFD.your_discriminator%)")
 142
 143
 144 # glue the BFD packet class to scapy parser
 145 bind_layers(UDP, BFD, dport=BFD.udp_dport)
 146
 147
 148 class BFD_vpp_echo(Packet):
 149     """ BFD echo packet as used by VPP (non-rfc, as rfc doesn't define one) """
 150
 151     udp_dport = 3785  #: BFD echo destination port per RFC 5881
 152     name = "BFD_VPP_ECHO"
 153
 154     fields_desc = [
 155         BitField("discriminator", 0, 32),
 156         BitField("expire_time_clocks", 0, 64),
 157         BitField("checksum", 0, 64)
 158     ]
 159
 160     def mysummary(self):
 161         return self.sprintf(
 162             "BFD_VPP_ECHO(disc=%BFD_VPP_ECHO.discriminator%,"
 163             "expire_time_clocks=%BFD_VPP_ECHO.expire_time_clocks%)")
 164
 165
 166 # glue the BFD echo packet class to scapy parser
 167 bind_layers(UDP, BFD_vpp_echo, dport=BFD_vpp_echo.udp_dport)
 168
 169
 170 class VppBFDAuthKey(VppObject):
 171     """ Represents BFD authentication key in VPP """
 172
 173     def __init__(self, test, conf_key_id, auth_type, key):
 174         self._test = test
 175         self._key = key
 176         self._auth_type = auth_type
 177         test.assertIn(auth_type, BFDAuthType.desc_dict)
 178         self._conf_key_id = conf_key_id
 179
 180     @property
 181     def test(self):
 182         """ Test which created this key """
 183         return self._test
 184
 185     @property
 186     def auth_type(self):
 187         """ Authentication type for this key """
 188         return self._auth_type
 189
 190     @property
 191     def key(self):
 192         """ key data """
 193         return self._key
 194
 195     @key.setter
 196     def key(self, value):
 197         self._key = value
 198
 199     @property
 200     def conf_key_id(self):
 201         """ configuration key ID """
 202         return self._conf_key_id
 203
 204     def add_vpp_config(self):
 205         self.test.vapi.bfd_auth_set_key(
 206             conf_key_id=self._conf_key_id, auth_type=self._auth_type,
 207             key=self._key, key_len=len(self._key))
 208         self._test.registry.register(self, self.test.logger)
 209
 210     def get_bfd_auth_keys_dump_entry(self):
 211         """ get the entry in the auth keys dump corresponding to this key """
 212         result = self.test.vapi.bfd_auth_keys_dump()
 213         for k in result:
 214             if k.conf_key_id == self._conf_key_id:
 215                 return k
 216         return None
 217
 218     def query_vpp_config(self):
 219         return self.get_bfd_auth_keys_dump_entry() is not None
 220
 221     def remove_vpp_config(self):
 222         self.test.vapi.bfd_auth_del_key(conf_key_id=self._conf_key_id)
 223
 224     def object_id(self):
 225         return "bfd-auth-key-%s" % self._conf_key_id
 226
 227
 228 class VppBFDUDPSession(VppObject):
 229     """ Represents BFD UDP session in VPP """
 230
 231     def __init__(self, test, interface, peer_addr, local_addr=None, af=AF_INET,
 232                  desired_min_tx=300000, required_min_rx=300000, detect_mult=3,
 233                  sha1_key=None, bfd_key_id=None, is_tunnel=False):
 234         self._test = test
 235         self._interface = interface
 236         self._af = af
 237         if local_addr:
 238             self._local_addr = local_addr
 239         else:
 240             self._local_addr = None
 241         self._peer_addr = 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 peer_addr(self):
 281         """ BFD session peer address """
 282         return self._peer_addr
 283
 284     def get_bfd_udp_session_dump_entry(self):
 285         """ get the namedtuple entry from bfd udp session dump """
 286         result = self.test.vapi.bfd_udp_session_dump()
 287         for s in result:
 288             self.test.logger.debug("session entry: %s" % str(s))
 289             if s.sw_if_index == self.interface.sw_if_index:
 290                 if self.af == AF_INET \
 291                         and self.interface.local_ip4 == str(s.local_addr) \
 292                         and self.interface.remote_ip4 == str(s.peer_addr):
 293                     return s
 294                 if self.af == AF_INET6 \
 295                         and self.interface.local_ip6 == str(s.local_addr) \
 296                         and self.interface.remote_ip6 == str(s.peer_addr):
 297                     return s
 298         return None
 299
 300     @property
 301     def state(self):
 302         """ BFD session state """
 303         session = self.get_bfd_udp_session_dump_entry()
 304         if session is None:
 305             raise Exception("Could not find BFD session in VPP response")
 306         return session.state
 307
 308     @property
 309     def desired_min_tx(self):
 310         """ desired minimum tx interval """
 311         return self._desired_min_tx
 312
 313     @property
 314     def required_min_rx(self):
 315         """ required minimum rx interval """
 316         return self._required_min_rx
 317
 318     @property
 319     def detect_mult(self):
 320         """ detect multiplier """
 321         return self._detect_mult
 322
 323     @property
 324     def sha1_key(self):
 325         """ sha1 key """
 326         return self._sha1_key
 327
 328     @property
 329     def bfd_key_id(self):
 330         """ bfd key id in use """
 331         return self._bfd_key_id
 332
 333     @property
 334     def is_tunnel(self):
 335         return self._is_tunnel
 336
 337     def activate_auth(self, key, bfd_key_id=None, delayed=False):
 338         """ activate authentication for this session """
 339         self._bfd_key_id = bfd_key_id if bfd_key_id else randint(0, 255)
 340         self._sha1_key = key
 341         conf_key_id = self._sha1_key.conf_key_id
 342         is_delayed = 1 if delayed else 0
 343         self.test.vapi.bfd_udp_auth_activate(
 344             sw_if_index=self._interface.sw_if_index,
 345             local_addr=self.local_addr,
 346             peer_addr=self.peer_addr,
 347             bfd_key_id=self._bfd_key_id,
 348             conf_key_id=conf_key_id,
 349             is_delayed=is_delayed)
 350
 351     def deactivate_auth(self, delayed=False):
 352         """ deactivate authentication """
 353         self._bfd_key_id = None
 354         self._sha1_key = None
 355         is_delayed = 1 if delayed else 0
 356         self.test.vapi.bfd_udp_auth_deactivate(
 357             sw_if_index=self._interface.sw_if_index,
 358             local_addr=self.local_addr,
 359             peer_addr=self.peer_addr,
 360             is_delayed=is_delayed)
 361
 362     def modify_parameters(self,
 363                           detect_mult=None,
 364                           desired_min_tx=None,
 365                           required_min_rx=None):
 366         """ modify session parameters """
 367         if detect_mult:
 368             self._detect_mult = detect_mult
 369         if desired_min_tx:
 370             self._desired_min_tx = desired_min_tx
 371         if required_min_rx:
 372             self._required_min_rx = required_min_rx
 373         self.test.vapi.bfd_udp_mod(sw_if_index=self._interface.sw_if_index,
 374                                    desired_min_tx=self.desired_min_tx,
 375                                    required_min_rx=self.required_min_rx,
 376                                    detect_mult=self.detect_mult,
 377                                    local_addr=self.local_addr,
 378                                    peer_addr=self.peer_addr)
 379
 380     def add_vpp_config(self):
 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         is_authenticated = True if self._sha1_key else False
 384         self.test.vapi.bfd_udp_add(sw_if_index=self._interface.sw_if_index,
 385                                    desired_min_tx=self.desired_min_tx,
 386                                    required_min_rx=self.required_min_rx,
 387                                    detect_mult=self.detect_mult,
 388                                    local_addr=self.local_addr,
 389                                    peer_addr=self.peer_addr,
 390                                    bfd_key_id=bfd_key_id,
 391                                    conf_key_id=conf_key_id,
 392                                    is_authenticated=is_authenticated)
 393         self._test.registry.register(self, self.test.logger)
 394
 395     def query_vpp_config(self):
 396         session = self.get_bfd_udp_session_dump_entry()
 397         return session is not None
 398
 399     def remove_vpp_config(self):
 400         self.test.vapi.bfd_udp_del(self._interface.sw_if_index,
 401                                    local_addr=self.local_addr,
 402                                    peer_addr=self.peer_addr)
 403
 404     def object_id(self):
 405         return "bfd-udp-%s-%s-%s-%s" % (self._interface.sw_if_index,
 406                                         self.local_addr,
 407                                         self.peer_addr,
 408                                         self.af)
 409
 410     def admin_up(self):
 411         """ set bfd session admin-up """
 412         self.test.vapi.bfd_udp_session_set_flags(
 413             flags=VppEnum.vl_api_if_status_flags_t.IF_STATUS_API_FLAG_ADMIN_UP,
 414             sw_if_index=self._interface.sw_if_index,
 415             local_addr=self.local_addr,
 416             peer_addr=self.peer_addr)
 417
 418     def admin_down(self):
 419         """ set bfd session admin-down """
 420         self.test.vapi.bfd_udp_session_set_flags(
 421             flags=0, sw_if_index=self._interface.sw_if_index,
 422             local_addr=self.local_addr,
 423             peer_addr=self.peer_addr)