tests/topotests/bgp_remove_private_as/test_bgp_remove_private_as.py

   1 #!/usr/bin/env python
   2
   3 #
   4 # test_bgp_remove_private_as.py
   5 #
   6 # Copyright (C) 2022  NVIDIA Corporation
   7 # Trey Aspelund
   8 #
   9 # Permission to use, copy, modify, and/or distribute this software
  10 # for any purpose with or without fee is hereby granted, provided
  11 # that the above copyright notice and this permission notice appear
  12 # in all copies.
  13 #
  14 # THE SOFTWARE IS PROVIDED "AS IS" AND NVIDIA DISCLAIMS ALL WARRANTIES
  15 # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  16 # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NVIDIA BE LIABLE FOR
  17 # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY
  18 # DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  19 # WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  20 # ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  21 # OF THIS SOFTWARE.
  22 #
  23
  24 """
  25 test_bgp_remove_private_as.py tests the following conditions:
  26 1. "remove-private-AS" strips all private ASNs from the AS-path unless:
  27     a. the ASN belongs to the peer
  28     b. the ASN is both local + private
  29     c. the AS-path is not completely comprised of public ASNs
  30 2. "remove-private-AS all" strips all private ASNs from the AS-path unless:
  31     a. the ASN belongs to the peer
  32     b. the ASN is both local + private
  33 3. "remove-private-AS replace-AS" swaps private ASNs with local ASN unless:
  34     a. the ASN belongs to the peer
  35     b. the AS-path is not completely comprised of public ASNs
  36 4. "remove-private-AS all replace-AS" swaps private ASNs with local ASN unless:
  37     a. the ASN belongs to the peer
  38
  39 All conditions are tested while the local ASN is private.
  40 All conditions are tested while the local ASN is public.
  41 All conditions are tested against an eBGP peer in a private ASN.
  42 All conditions are tested against an eBGP peer in a public ASN.
  43 """
  44
  45 import os
  46 import sys
  47 import json
  48 import time
  49 import pytest
  50
  51 CWD = os.path.dirname(os.path.realpath(__file__))
  52 sys.path.append(os.path.join(CWD, "../"))
  53
  54 # pylint: disable=C0413
  55 from lib import topotest
  56 from lib.topogen import Topogen, TopoRouter, get_topogen
  57 from functools import partial
  58
  59 pytestmark = [pytest.mark.bgpd]
  60
  61
  62 def build_topo(tgen):
  63     """
  64     We are effectively creating two hub/spoke topologies with r2 and r5 acting
  65     as hubs. "remove-private-AS" will be configured on r2/r5 towards r3/r4, and
  66     r1 will act as the originator of the test prefixes. AS-Path validation will
  67     be done on r3/r4.
  68
  69     Topology:
  70     +-----+      +-----+     +-----+
  71     | r1  |----->|r2/r5|---->| r3  |
  72     +-----+      +-----+     +-----+
  73                     |
  74                     v
  75                  +-----+
  76                  | r4  |
  77                  +-----+
  78     ASNs:
  79      - r1: 65001
  80      - r2: 65002
  81      - r3: 65003
  82      - r4: 4444
  83      - r5: 5555
  84     """
  85     for routern in range(1, 6):
  86         tgen.add_router(f"r{routern}")
  87
  88     #######################
  89     # Connections to r2
  90     #######################
  91     switch = tgen.add_switch("s1")
  92     switch.add_link(tgen.gears["r1"])
  93     switch.add_link(tgen.gears["r2"])
  94
  95     switch = tgen.add_switch("s2")
  96     switch.add_link(tgen.gears["r2"])
  97     switch.add_link(tgen.gears["r3"])
  98
  99     switch = tgen.add_switch("s3")
 100     switch.add_link(tgen.gears["r2"])
 101     switch.add_link(tgen.gears["r4"])
 102
 103     #######################
 104     # Connections to r5
 105     #######################
 106     switch = tgen.add_switch("s4")
 107     switch.add_link(tgen.gears["r1"])
 108     switch.add_link(tgen.gears["r5"])
 109
 110     switch = tgen.add_switch("s5")
 111     switch.add_link(tgen.gears["r3"])
 112     switch.add_link(tgen.gears["r5"])
 113
 114     switch = tgen.add_switch("s6")
 115     switch.add_link(tgen.gears["r4"])
 116     switch.add_link(tgen.gears["r5"])
 117
 118
 119 def setup_module(mod):
 120     tgen = Topogen(build_topo, mod.__name__)
 121     tgen.start_topology()
 122
 123     router_list = tgen.routers()
 124
 125     for i, (rname, router) in enumerate(router_list.items(), 1):
 126         router.load_config(
 127             TopoRouter.RD_ZEBRA, os.path.join(CWD, f"{rname}/zebra.conf")
 128         )
 129         router.load_config(TopoRouter.RD_BGP, os.path.join(CWD, f"{rname}/bgpd.conf"))
 130
 131     tgen.start_router()
 132
 133
 134 def teardown_module(mod):
 135     tgen = get_topogen()
 136     tgen.stop_topology()
 137
 138
 139 def test_bgp_remove_private_as():
 140     tgen = get_topogen()
 141
 142     if tgen.routers_have_failure():
 143         pytest.skip(tgen.errors)
 144
 145     # Test routes
 146     prefixes = [
 147         "100.64.0.0/32",
 148         "100.64.0.1/32",
 149         "100.64.0.2/32",
 150         "100.64.0.3/32",
 151         "100.64.0.4/32",
 152     ]
 153
 154     # r2/r5 are setup with remove-private-AS configs.
 155     tx_routers = ["r2", "r5"]
 156
 157     # We will validate the paths received by r3/r4.
 158     rx_routers = ["r3", "r4"]
 159
 160     # Config options for remove-private-AS
 161     remove_types = [
 162         "remove-private-AS",
 163         "remove-private-AS all",
 164         "remove-private-AS replace-AS",
 165         "remove-private-AS all replace-AS",
 166     ]
 167
 168     # Expected as-paths for each test route from the perspective of each
 169     # rx_router, accounting for each variation of remove-private-AS.
 170     #
 171     # Structure:
 172     # expected_paths = {
 173     #     rx_router: {
 174     #         remove_type: {
 175     #             tx_router: {
 176     #                 prefix: "path"
 177     #             }
 178     #         }
 179     #     }
 180     # }
 181     expected_paths = {
 182         "r3": {
 183             "remove-private-AS": {
 184                 "r2": {
 185                     "100.64.0.0/32": "65002",
 186                     "100.64.0.1/32": "65002 65003 65003",
 187                     "100.64.0.2/32": "65002 65001 4200000000 1000 4200000001 2000 4200000002",
 188                     "100.64.0.3/32": "65002 65001 65003 4200000000 1000 4200000001 2000 4200000002 65003",
 189                     "100.64.0.4/32": "65002 65001 1000 2000 2000 3000",
 190                 },
 191                 "r5": {
 192                     "100.64.0.0/32": "5555",
 193                     "100.64.0.1/32": "5555 65003 65003",
 194                     "100.64.0.2/32": "5555 65001 4200000000 1000 4200000001 2000 4200000002",
 195                     "100.64.0.3/32": "5555 65001 65003 4200000000 1000 4200000001 2000 4200000002 65003",
 196                     "100.64.0.4/32": "5555 65001 1000 2000 2000 3000",
 197                 },
 198             },
 199             "remove-private-AS all": {
 200                 "r2": {
 201                     "100.64.0.0/32": "65002",
 202                     "100.64.0.1/32": "65002 65003 65003",
 203                     "100.64.0.2/32": "65002 1000 2000",
 204                     "100.64.0.3/32": "65002 65003 1000 2000 65003",
 205                     "100.64.0.4/32": "65002 1000 2000 2000 3000",
 206                 },
 207                 "r5": {
 208                     "100.64.0.0/32": "5555",
 209                     "100.64.0.1/32": "5555 65003 65003",
 210                     "100.64.0.2/32": "5555 1000 2000",
 211                     "100.64.0.3/32": "5555 65003 1000 2000 65003",
 212                     "100.64.0.4/32": "5555 1000 2000 2000 3000",
 213                 },
 214             },
 215             "remove-private-AS replace-AS": {
 216                 "r2": {
 217                     "100.64.0.0/32": "65002 65002 65002 65002 65002",
 218                     "100.64.0.1/32": "65002 65002 65003 65002 65002 65002 65003",
 219                     "100.64.0.2/32": "65002 65001 4200000000 1000 4200000001 2000 4200000002",
 220                     "100.64.0.3/32": "65002 65001 65003 4200000000 1000 4200000001 2000 4200000002 65003",
 221                     "100.64.0.4/32": "65002 65001 1000 2000 2000 3000",
 222                 },
 223                 "r5": {
 224                     "100.64.0.0/32": "5555 5555 5555 5555 5555",
 225                     "100.64.0.1/32": "5555 5555 65003 5555 5555 5555 65003",
 226                     "100.64.0.2/32": "5555 65001 4200000000 1000 4200000001 2000 4200000002",
 227                     "100.64.0.3/32": "5555 65001 65003 4200000000 1000 4200000001 2000 4200000002 65003",
 228                     "100.64.0.4/32": "5555 65001 1000 2000 2000 3000",
 229                 },
 230             },
 231             "remove-private-AS all replace-AS": {
 232                 "r2": {
 233                     "100.64.0.0/32": "65002 65002 65002 65002 65002",
 234                     "100.64.0.1/32": "65002 65002 65003 65002 65002 65002 65003",
 235                     "100.64.0.2/32": "65002 65002 65002 1000 65002 2000 65002",
 236                     "100.64.0.3/32": "65002 65002 65003 65002 1000 65002 2000 65002 65003",
 237                     "100.64.0.4/32": "65002 65002 1000 2000 2000 3000",
 238                 },
 239                 "r5": {
 240                     "100.64.0.0/32": "5555 5555 5555 5555 5555",
 241                     "100.64.0.1/32": "5555 5555 65003 5555 5555 5555 65003",
 242                     "100.64.0.2/32": "5555 5555 5555 1000 5555 2000 5555",
 243                     "100.64.0.3/32": "5555 5555 65003 5555 1000 5555 2000 5555 65003",
 244                     "100.64.0.4/32": "5555 5555 1000 2000 2000 3000",
 245                 },
 246             },
 247         },
 248         "r4": {
 249             "remove-private-AS": {
 250                 "r2": {
 251                     "100.64.0.0/32": "65002",
 252                     "100.64.0.1/32": "65002",
 253                     "100.64.0.2/32": "65002 65001 4200000000 1000 4200000001 2000 4200000002",
 254                     "100.64.0.3/32": "65002 65001 65003 4200000000 1000 4200000001 2000 4200000002 65003",
 255                     "100.64.0.4/32": "65002 65001 1000 2000 2000 3000",
 256                 },
 257                 "r5": {
 258                     "100.64.0.0/32": "5555",
 259                     "100.64.0.1/32": "5555",
 260                     "100.64.0.2/32": "5555 65001 4200000000 1000 4200000001 2000 4200000002",
 261                     "100.64.0.3/32": "5555 65001 65003 4200000000 1000 4200000001 2000 4200000002 65003",
 262                     "100.64.0.4/32": "5555 65001 1000 2000 2000 3000",
 263                 },
 264             },
 265             "remove-private-AS all": {
 266                 "r2": {
 267                     "100.64.0.0/32": "65002",
 268                     "100.64.0.1/32": "65002",
 269                     "100.64.0.2/32": "65002 1000 2000",
 270                     "100.64.0.3/32": "65002 1000 2000",
 271                     "100.64.0.4/32": "65002 1000 2000 2000 3000",
 272                 },
 273                 "r5": {
 274                     "100.64.0.0/32": "5555",
 275                     "100.64.0.1/32": "5555",
 276                     "100.64.0.2/32": "5555 1000 2000",
 277                     "100.64.0.3/32": "5555 1000 2000",
 278                     "100.64.0.4/32": "5555 1000 2000 2000 3000",
 279                 },
 280             },
 281             "remove-private-AS replace-AS": {
 282                 "r2": {
 283                     "100.64.0.0/32": "65002 65002 65002 65002 65002",
 284                     "100.64.0.1/32": "65002 65002 65002 65002 65002 65002 65002",
 285                     "100.64.0.2/32": "65002 65001 4200000000 1000 4200000001 2000 4200000002",
 286                     "100.64.0.3/32": "65002 65001 65003 4200000000 1000 4200000001 2000 4200000002 65003",
 287                     "100.64.0.4/32": "65002 65001 1000 2000 2000 3000",
 288                 },
 289                 "r5": {
 290                     "100.64.0.0/32": "5555 5555 5555 5555 5555",
 291                     "100.64.0.1/32": "5555 5555 5555 5555 5555 5555 5555",
 292                     "100.64.0.2/32": "5555 65001 4200000000 1000 4200000001 2000 4200000002",
 293                     "100.64.0.3/32": "5555 65001 65003 4200000000 1000 4200000001 2000 4200000002 65003",
 294                     "100.64.0.4/32": "5555 65001 1000 2000 2000 3000",
 295                 },
 296             },
 297             "remove-private-AS all replace-AS": {
 298                 "r2": {
 299                     "100.64.0.0/32": "65002 65002 65002 65002 65002",
 300                     "100.64.0.1/32": "65002 65002 65002 65002 65002 65002 65002",
 301                     "100.64.0.2/32": "65002 65002 65002 1000 65002 2000 65002",
 302                     "100.64.0.3/32": "65002 65002 65002 65002 1000 65002 2000 65002 65002",
 303                     "100.64.0.4/32": "65002 65002 1000 2000 2000 3000",
 304                 },
 305                 "r5": {
 306                     "100.64.0.0/32": "5555 5555 5555 5555 5555",
 307                     "100.64.0.1/32": "5555 5555 5555 5555 5555 5555 5555",
 308                     "100.64.0.2/32": "5555 5555 5555 1000 5555 2000 5555",
 309                     "100.64.0.3/32": "5555 5555 5555 5555 1000 5555 2000 5555 5555",
 310                     "100.64.0.4/32": "5555 5555 1000 2000 2000 3000",
 311                 },
 312             },
 313         },
 314     }
 315
 316     # Simple lookup of remote peer ip by routers in session (local --> remote).
 317     #
 318     # Structure:
 319     # peer_to_ip = {
 320     #     local_rtr: {
 321     #         peer_rtr: peer_ip
 322     #     }
 323     # }
 324     peer_to_ip = {
 325         "r1": {"r2": "203.0.113.1", "r5": "203.0.113.3"},
 326         "r2": {"r1": "203.0.113.0", "r3": "203.0.113.4", "r4": "203.0.113.8"},
 327         "r3": {"r2": "203.0.113.5", "r5": "203.0.113.7"},
 328         "r4": {"r2": "203.0.113.9", "r5": "203.0.113.11"},
 329         "r5": {"r1": "203.0.113.2", "r3": "203.0.113.6", "r4": "203.0.113.10"},
 330     }
 331
 332     def __bgp_up():
 333         """Return True if all configured peers are Established."""
 334         for router in tx_routers:
 335             output = json.loads(
 336                 tgen.gears[router].vtysh_cmd("show ip bgp summary json")
 337             )
 338             numPeers = output["ipv4Unicast"]["totalPeers"]
 339             numConverged = 0
 340             for peer_data in output["ipv4Unicast"]["peers"].values():
 341                 if peer_data["state"] == "Established":
 342                     numConverged += 1
 343             if numConverged == numPeers:
 344                 return True
 345         return False
 346
 347     def __bgp_converged():
 348         """Return True if all prefixes have been received from tx_routers."""
 349         for router in rx_routers:
 350             output = json.loads(
 351                 tgen.gears[router].vtysh_cmd("show ip bgp summary json")
 352             )
 353             numPeers = output["ipv4Unicast"]["totalPeers"]
 354             numConverged = 0
 355             for peer in tx_routers:
 356                 peer_ip = peer_to_ip[router][peer]
 357                 numPrefixes = output["ipv4Unicast"]["peers"][peer_ip]["pfxRcd"]
 358                 if numPrefixes == len(prefixes):
 359                     numConverged += 1
 360             if numConverged == numPeers:
 361                 return True
 362         return False
 363
 364     def _routers_up(tx_rtrs, rx_rtrs):
 365         """Ensure all BGP sessions are up and all routes are installed."""
 366         # all sessions go through tx_routers, so ensure all their peers are up
 367         test_func = partial(__bgp_up)
 368         _, result = topotest.run_and_expect(test_func, True, count=60, wait=0.5)
 369         assert result == True, "Not all peers in Established state!"
 370
 371         # ensure correct number of routes are installed
 372         test_func = partial(__bgp_converged)
 373         _, result = topotest.run_and_expect(test_func, True, count=60, wait=0.5)
 374         assert result == True, "Not all routes installed in time!"
 375
 376     def _change_remove_type(new_type, op):
 377         """Update config with next remove-private-AS config variant."""
 378         no = "no" if op == "del" else ""
 379         for tr in tx_routers:
 380             for rr in rx_routers:
 381                 p_ip = peer_to_ip[tr][rr]
 382                 tgen.gears[tr].vtysh_multicmd(
 383                     f"""
 384                     configure terminal
 385                     router bgp
 386                     address-family ipv4 unicast
 387                     {no} neighbor {p_ip} {new_type}
 388                     """
 389                 )
 390
 391     def _validate_paths(remove_type):
 392         """Compare actual AS-Path against expected AS-Path."""
 393         for rtr in rx_routers:
 394             for peer in tx_routers:
 395                 p_ip = peer_to_ip[rtr][peer]
 396                 adj_rib_in = json.loads(
 397                     tgen.gears[rtr].vtysh_cmd(
 398                         f"show ip bgp neighbor {p_ip} received-routes json"
 399                     )
 400                 )
 401                 for pfx in prefixes:
 402                     good_path = expected_paths[rtr][remove_type][peer][pfx]
 403                     real_path = adj_rib_in["receivedRoutes"][pfx]["path"]
 404                     return real_path == good_path
 405
 406     #######################
 407     # Begin Test
 408     #######################
 409
 410     # make sure all peers come up and exchange routes
 411     _routers_up(tx_routers, rx_routers)
 412
 413     # test each variation of remove-private-AS
 414     for rmv_type in remove_types:
 415         _change_remove_type(rmv_type, "add")
 416
 417         test_func = partial(_validate_paths, rmv_type)
 418         _, result = topotest.run_and_expect(test_func, True, count=60, wait=0.5)
 419         assert result == True, "Not all routes have correct AS-Path values!"
 420
 421         # each variation sets a separate peer flag in bgpd. we need to clear
 422         # the old flag after each iteration so we only test the flags we expect.
 423         _change_remove_type(rmv_type, "del")
 424
 425     return True
 426
 427
 428 if __name__ == "__main__":
 429     args = ["-s"] + sys.argv[1:]
 430     sys.exit(pytest.main(args))