| """ BFD protocol implementation """ |
| |
| from random import randint |
| from socket import AF_INET, AF_INET6, inet_pton |
| from scapy.all import bind_layers |
| from scapy.layers.inet import UDP |
| from scapy.packet import Packet |
| from scapy.fields import ( |
| BitField, |
| BitEnumField, |
| XByteField, |
| FlagsField, |
| ConditionalField, |
| StrField, |
| ) |
| from vpp_object import VppObject |
| from util import NumericConstant |
| from vpp_papi import VppEnum |
| |
| BFD_UDP_SH_PORT = 3784 |
| BFD_UDP_MH_PORT = 4784 |
| |
| |
| class BFDDiagCode(NumericConstant): |
| """BFD Diagnostic Code""" |
| |
| no_diagnostic = 0 |
| control_detection_time_expired = 1 |
| echo_function_failed = 2 |
| neighbor_signaled_session_down = 3 |
| forwarding_plane_reset = 4 |
| path_down = 5 |
| concatenated_path_down = 6 |
| administratively_down = 7 |
| reverse_concatenated_path_down = 8 |
| |
| desc_dict = { |
| no_diagnostic: "No diagnostic", |
| control_detection_time_expired: "Control Detection Time Expired", |
| echo_function_failed: "Echo Function Failed", |
| neighbor_signaled_session_down: "Neighbor Signaled Session Down", |
| forwarding_plane_reset: "Forwarding Plane Reset", |
| path_down: "Path Down", |
| concatenated_path_down: "Concatenated Path Down", |
| administratively_down: "Administratively Down", |
| reverse_concatenated_path_down: "Reverse Concatenated Path Down", |
| } |
| |
| |
| class BFDState(NumericConstant): |
| """BFD State""" |
| |
| admin_down = 0 |
| down = 1 |
| init = 2 |
| up = 3 |
| |
| desc_dict = { |
| admin_down: "AdminDown", |
| down: "Down", |
| init: "Init", |
| up: "Up", |
| } |
| |
| |
| class BFDAuthType(NumericConstant): |
| """BFD Authentication Type""" |
| |
| no_auth = 0 |
| simple_pwd = 1 |
| keyed_md5 = 2 |
| meticulous_keyed_md5 = 3 |
| keyed_sha1 = 4 |
| meticulous_keyed_sha1 = 5 |
| |
| desc_dict = { |
| no_auth: "No authentication", |
| simple_pwd: "Simple Password", |
| keyed_md5: "Keyed MD5", |
| meticulous_keyed_md5: "Meticulous Keyed MD5", |
| keyed_sha1: "Keyed SHA1", |
| meticulous_keyed_sha1: "Meticulous Keyed SHA1", |
| } |
| |
| |
| def bfd_is_auth_used(pkt): |
| """is packet authenticated?""" |
| return "A" in pkt.sprintf("%BFD.flags%") |
| |
| |
| def bfd_is_simple_pwd_used(pkt): |
| """is simple password authentication used?""" |
| return bfd_is_auth_used(pkt) and pkt.auth_type == BFDAuthType.simple_pwd |
| |
| |
| def bfd_is_sha1_used(pkt): |
| """is sha1 authentication used?""" |
| return bfd_is_auth_used(pkt) and pkt.auth_type in ( |
| BFDAuthType.keyed_sha1, |
| BFDAuthType.meticulous_keyed_sha1, |
| ) |
| |
| |
| def bfd_is_md5_used(pkt): |
| """is md5 authentication used?""" |
| return bfd_is_auth_used(pkt) and pkt.auth_type in ( |
| BFDAuthType.keyed_md5, |
| BFDAuthType.meticulous_keyed_md5, |
| ) |
| |
| |
| def bfd_is_md5_or_sha1_used(pkt): |
| """is md5 or sha1 used?""" |
| return bfd_is_md5_used(pkt) or bfd_is_sha1_used(pkt) |
| |
| |
| class BFD(Packet): |
| """BFD protocol layer for scapy""" |
| |
| udp_dport = 3784 #: BFD destination port per RFC 5881 |
| udp_dport_echo = 3785 # : BFD destination port for ECHO per RFC 5881 |
| udp_sport_min = 49152 #: BFD source port min value per RFC 5881 |
| udp_sport_max = 65535 #: BFD source port max value per RFC 5881 |
| bfd_pkt_len = 24 # : length of BFD pkt without authentication section |
| sha1_auth_len = 28 # : length of authentication section if SHA1 used |
| |
| name = "BFD" |
| |
| fields_desc = [ |
| BitField("version", 1, 3), |
| BitEnumField("diag", 0, 5, BFDDiagCode.desc_dict), |
| BitEnumField("state", 0, 2, BFDState.desc_dict), |
| FlagsField("flags", 0, 6, ["M", "D", "A", "C", "F", "P"]), |
| XByteField("detect_mult", 0), |
| BitField("length", bfd_pkt_len, 8), |
| BitField("my_discriminator", 0, 32), |
| BitField("your_discriminator", 0, 32), |
| BitField("desired_min_tx_interval", 0, 32), |
| BitField("required_min_rx_interval", 0, 32), |
| BitField("required_min_echo_rx_interval", 0, 32), |
| ConditionalField( |
| BitEnumField("auth_type", 0, 8, BFDAuthType.desc_dict), bfd_is_auth_used |
| ), |
| ConditionalField(BitField("auth_len", 0, 8), bfd_is_auth_used), |
| ConditionalField(BitField("auth_key_id", 0, 8), bfd_is_auth_used), |
| ConditionalField(BitField("auth_reserved", 0, 8), bfd_is_md5_or_sha1_used), |
| ConditionalField(BitField("auth_seq_num", 0, 32), bfd_is_md5_or_sha1_used), |
| ConditionalField(StrField("auth_key_hash", "0" * 16), bfd_is_md5_used), |
| ConditionalField(StrField("auth_key_hash", "0" * 20), bfd_is_sha1_used), |
| ] |
| |
| def mysummary(self): |
| return self.sprintf( |
| "BFD(my_disc=%BFD.my_discriminator%, your_disc=%BFD.your_discriminator%)" |
| ) |
| |
| |
| # glue the BFD packet class to scapy parser |
| bind_layers(UDP, BFD, dport=BFD_UDP_SH_PORT) |
| bind_layers(UDP, BFD, dport=BFD_UDP_MH_PORT) |
| |
| |
| class BFD_vpp_echo(Packet): |
| """BFD echo packet as used by VPP (non-rfc, as rfc doesn't define one)""" |
| |
| udp_dport = 3785 #: BFD echo destination port per RFC 5881 |
| name = "BFD_VPP_ECHO" |
| |
| fields_desc = [ |
| BitField("discriminator", 0, 32), |
| BitField("expire_time_clocks", 0, 64), |
| BitField("checksum", 0, 64), |
| ] |
| |
| def mysummary(self): |
| return self.sprintf( |
| "BFD_VPP_ECHO(disc=%BFD_VPP_ECHO.discriminator%," |
| "expire_time_clocks=%BFD_VPP_ECHO.expire_time_clocks%)" |
| ) |
| |
| |
| # glue the BFD echo packet class to scapy parser |
| bind_layers(UDP, BFD_vpp_echo, dport=BFD_vpp_echo.udp_dport) |
| |
| |
| class VppBFDAuthKey(VppObject): |
| """Represents BFD authentication key in VPP""" |
| |
| def __init__(self, test, conf_key_id, auth_type, key): |
| self._test = test |
| self._key = key |
| self._auth_type = auth_type |
| test.assertIn(auth_type, BFDAuthType.desc_dict) |
| self._conf_key_id = conf_key_id |
| |
| @property |
| def test(self): |
| """Test which created this key""" |
| return self._test |
| |
| @property |
| def auth_type(self): |
| """Authentication type for this key""" |
| return self._auth_type |
| |
| @property |
| def key(self): |
| """key data""" |
| return self._key |
| |
| @key.setter |
| def key(self, value): |
| self._key = value |
| |
| @property |
| def conf_key_id(self): |
| """configuration key ID""" |
| return self._conf_key_id |
| |
| def add_vpp_config(self): |
| self.test.vapi.bfd_auth_set_key( |
| conf_key_id=self._conf_key_id, |
| auth_type=self._auth_type, |
| key=self._key, |
| key_len=len(self._key), |
| ) |
| self._test.registry.register(self, self.test.logger) |
| |
| def get_bfd_auth_keys_dump_entry(self): |
| """get the entry in the auth keys dump corresponding to this key""" |
| result = self.test.vapi.bfd_auth_keys_dump() |
| for k in result: |
| if k.conf_key_id == self._conf_key_id: |
| return k |
| return None |
| |
| def query_vpp_config(self): |
| return self.get_bfd_auth_keys_dump_entry() is not None |
| |
| def remove_vpp_config(self): |
| self.test.vapi.bfd_auth_del_key(conf_key_id=self._conf_key_id) |
| |
| def object_id(self): |
| return "bfd-auth-key-%s" % self._conf_key_id |
| |
| |
| class VppBFDUDPSession(VppObject): |
| """Represents BFD UDP session in VPP""" |
| |
| def __init__( |
| self, |
| test, |
| interface, |
| peer_addr, |
| multihop=False, |
| local_addr=None, |
| af=AF_INET, |
| desired_min_tx=300000, |
| required_min_rx=300000, |
| detect_mult=3, |
| sha1_key=None, |
| bfd_key_id=None, |
| is_tunnel=False, |
| ): |
| self._test = test |
| self._multihop = multihop |
| self._interface = interface |
| self._af = af |
| |
| if multihop: |
| self._sw_if_index = 0xFFFFFFFF |
| self.test.vapi.bfd_udp_enable_multihop() |
| else: |
| self._sw_if_index = self._interface.sw_if_index |
| |
| if local_addr: |
| self._local_addr = local_addr |
| else: |
| if self.af == AF_INET: |
| self._local_addr = self.interface.local_ip4 |
| else: |
| self._local_addr = self.interface.local_ip6 |
| |
| self._peer_addr = peer_addr |
| self._desired_min_tx = desired_min_tx |
| self._required_min_rx = required_min_rx |
| self._detect_mult = detect_mult |
| self._sha1_key = sha1_key |
| if bfd_key_id is not None: |
| self._bfd_key_id = bfd_key_id |
| else: |
| self._bfd_key_id = randint(0, 255) |
| self._is_tunnel = is_tunnel |
| |
| @property |
| def test(self): |
| """Test which created this session""" |
| return self._test |
| |
| @property |
| def interface(self): |
| """Interface on which this session lives""" |
| return self._interface |
| |
| @property |
| def af(self): |
| """Address family - AF_INET or AF_INET6""" |
| return self._af |
| |
| @property |
| def local_addr(self): |
| """BFD session local address (VPP address)""" |
| if self._local_addr is None: |
| if self.af == AF_INET: |
| return self._interface.local_ip4 |
| elif self.af == AF_INET6: |
| return self._interface.local_ip6 |
| else: |
| raise Exception("Unexpected af '%s'" % self.af) |
| return self._local_addr |
| |
| @property |
| def peer_addr(self): |
| """BFD session peer address""" |
| return self._peer_addr |
| |
| def get_bfd_udp_session_dump_entry(self): |
| """get the namedtuple entry from bfd udp session dump""" |
| result = self.test.vapi.bfd_udp_session_dump() |
| for s in result: |
| self.test.logger.debug("session entry: %s" % str(s)) |
| multihop = s.sw_if_index == ~0 |
| if multihop or s.sw_if_index == self._sw_if_index: |
| if self._local_addr == str(s.local_addr) and self._peer_addr == str( |
| s.peer_addr |
| ): |
| return s |
| return None |
| |
| @property |
| def state(self): |
| """BFD session state""" |
| session = self.get_bfd_udp_session_dump_entry() |
| if session is None: |
| raise Exception("Could not find BFD session in VPP response") |
| return session.state |
| |
| @property |
| def desired_min_tx(self): |
| """desired minimum tx interval""" |
| return self._desired_min_tx |
| |
| @property |
| def required_min_rx(self): |
| """required minimum rx interval""" |
| return self._required_min_rx |
| |
| @property |
| def detect_mult(self): |
| """detect multiplier""" |
| return self._detect_mult |
| |
| @property |
| def sha1_key(self): |
| """sha1 key""" |
| return self._sha1_key |
| |
| @property |
| def bfd_key_id(self): |
| """bfd key id in use""" |
| return self._bfd_key_id |
| |
| @property |
| def is_tunnel(self): |
| return self._is_tunnel |
| |
| def activate_auth(self, key, bfd_key_id=None, delayed=False): |
| """activate authentication for this session""" |
| self._bfd_key_id = bfd_key_id if bfd_key_id else randint(0, 255) |
| self._sha1_key = key |
| conf_key_id = self._sha1_key.conf_key_id |
| is_delayed = 1 if delayed else 0 |
| self.test.vapi.bfd_udp_auth_activate( |
| sw_if_index=self._sw_if_index, |
| local_addr=self.local_addr, |
| peer_addr=self.peer_addr, |
| bfd_key_id=self._bfd_key_id, |
| conf_key_id=conf_key_id, |
| is_delayed=is_delayed, |
| ) |
| |
| def deactivate_auth(self, delayed=False): |
| """deactivate authentication""" |
| self._bfd_key_id = None |
| self._sha1_key = None |
| is_delayed = 1 if delayed else 0 |
| self.test.vapi.bfd_udp_auth_deactivate( |
| sw_if_index=self._sw_if_index, |
| local_addr=self.local_addr, |
| peer_addr=self.peer_addr, |
| is_delayed=is_delayed, |
| ) |
| |
| def modify_parameters( |
| self, detect_mult=None, desired_min_tx=None, required_min_rx=None |
| ): |
| """modify session parameters""" |
| if detect_mult: |
| self._detect_mult = detect_mult |
| if desired_min_tx: |
| self._desired_min_tx = desired_min_tx |
| if required_min_rx: |
| self._required_min_rx = required_min_rx |
| self.test.vapi.bfd_udp_mod( |
| sw_if_index=self._sw_if_index, |
| desired_min_tx=self.desired_min_tx, |
| required_min_rx=self.required_min_rx, |
| detect_mult=self.detect_mult, |
| local_addr=self.local_addr, |
| peer_addr=self.peer_addr, |
| ) |
| |
| def add_vpp_config(self): |
| bfd_key_id = self._bfd_key_id if self._sha1_key else None |
| conf_key_id = self._sha1_key.conf_key_id if self._sha1_key else None |
| is_authenticated = True if self._sha1_key else False |
| self.test.vapi.bfd_udp_add( |
| sw_if_index=self._sw_if_index, |
| desired_min_tx=self.desired_min_tx, |
| required_min_rx=self.required_min_rx, |
| detect_mult=self.detect_mult, |
| local_addr=self.local_addr, |
| peer_addr=self.peer_addr, |
| bfd_key_id=bfd_key_id, |
| conf_key_id=conf_key_id, |
| is_authenticated=is_authenticated, |
| ) |
| self._test.registry.register(self, self.test.logger) |
| |
| def upd_vpp_config( |
| self, detect_mult=None, desired_min_tx=None, required_min_rx=None |
| ): |
| if desired_min_tx: |
| self._desired_min_tx = desired_min_tx |
| if required_min_rx: |
| self._required_min_rx = required_min_rx |
| if detect_mult: |
| self._detect_mult = detect_mult |
| bfd_key_id = self._bfd_key_id if self._sha1_key else None |
| conf_key_id = self._sha1_key.conf_key_id if self._sha1_key else None |
| is_authenticated = True if self._sha1_key else False |
| self.test.vapi.bfd_udp_upd( |
| sw_if_index=self._sw_if_index, |
| desired_min_tx=self.desired_min_tx, |
| required_min_rx=self.required_min_rx, |
| detect_mult=self.detect_mult, |
| local_addr=self.local_addr, |
| peer_addr=self.peer_addr, |
| bfd_key_id=bfd_key_id, |
| conf_key_id=conf_key_id, |
| is_authenticated=is_authenticated, |
| ) |
| self._test.registry.register(self, self.test.logger) |
| |
| def query_vpp_config(self): |
| session = self.get_bfd_udp_session_dump_entry() |
| return session is not None |
| |
| def remove_vpp_config(self): |
| self.test.vapi.bfd_udp_del( |
| sw_if_index=self._sw_if_index, |
| local_addr=self.local_addr, |
| peer_addr=self.peer_addr, |
| ) |
| |
| def object_id(self): |
| return "bfd-udp-%s-%s-%s-%s-%s" % ( |
| self._multihop, |
| self._sw_if_index, |
| self.local_addr, |
| self.peer_addr, |
| self.af, |
| ) |
| |
| def admin_up(self): |
| """set bfd session admin-up""" |
| self.test.vapi.bfd_udp_session_set_flags( |
| flags=VppEnum.vl_api_if_status_flags_t.IF_STATUS_API_FLAG_ADMIN_UP, |
| sw_if_index=self._sw_if_index, |
| local_addr=self.local_addr, |
| peer_addr=self.peer_addr, |
| ) |
| |
| def admin_down(self): |
| """set bfd session admin-down""" |
| self.test.vapi.bfd_udp_session_set_flags( |
| flags=0, |
| sw_if_index=self._sw_if_index, |
| local_addr=self.local_addr, |
| peer_addr=self.peer_addr, |
| ) |