test/vpp_pg_interface.py

   1 import os
   2 import shutil
   3 import socket
   4 from socket import inet_pton, inet_ntop
   5 import struct
   6 import time
   7 from traceback import format_exc, format_stack
   8 from sh import tshark
   9 from pathlib import Path
  10
  11 from config import config
  12 from scapy.utils import wrpcap, rdpcap, PcapReader
  13 from scapy.plist import PacketList
  14 from vpp_interface import VppInterface
  15 from vpp_papi import VppEnum
  16
  17 from scapy.layers.l2 import Ether, ARP
  18 from scapy.layers.inet6 import (
  19     IPv6,
  20     ICMPv6ND_NS,
  21     ICMPv6ND_NA,
  22     ICMPv6NDOptSrcLLAddr,
  23     ICMPv6NDOptDstLLAddr,
  24     ICMPv6ND_RA,
  25     RouterAlert,
  26     IPv6ExtHdrHopByHop,
  27 )
  28 from util import ppp, ppc, UnexpectedPacketError
  29 from scapy.utils6 import in6_getnsma, in6_getnsmac, in6_ismaddr
  30
  31
  32 class CaptureTimeoutError(Exception):
  33     """Exception raised if capture or packet doesn't appear within timeout"""
  34
  35     pass
  36
  37
  38 def is_ipv6_misc(p):
  39     """Is packet one of uninteresting IPv6 broadcasts?"""
  40     if p.haslayer(ICMPv6ND_RA):
  41         if in6_ismaddr(p[IPv6].dst):
  42             return True
  43     if p.haslayer(IPv6ExtHdrHopByHop):
  44         for o in p[IPv6ExtHdrHopByHop].options:
  45             if isinstance(o, RouterAlert):
  46                 return True
  47     return False
  48
  49
  50 class VppPGInterface(VppInterface):
  51     """
  52     VPP packet-generator interface
  53     """
  54
  55     @property
  56     def pg_index(self):
  57         """packet-generator interface index assigned by VPP"""
  58         return self._pg_index
  59
  60     @property
  61     def gso_enabled(self):
  62         """gso enabled on packet-generator interface"""
  63         if self._gso_enabled == 0:
  64             return "gso-disabled"
  65         return "gso-enabled"
  66
  67     @property
  68     def gso_size(self):
  69         """gso size on packet-generator interface"""
  70         return self._gso_size
  71
  72     @property
  73     def coalesce_is_enabled(self):
  74         """coalesce enabled on packet-generator interface"""
  75         if self._coalesce_enabled == 0:
  76             return "coalesce-disabled"
  77         return "coalesce-enabled"
  78
  79     @property
  80     def out_path(self):
  81         """pcap file path - captured packets"""
  82         return self._out_path
  83
  84     def get_in_path(self, worker):
  85         """pcap file path - injected packets"""
  86         if worker is not None:
  87             return "%s/pg%u_wrk%u_in.pcap" % (self.test.tempdir, self.pg_index, worker)
  88         return "%s/pg%u_in.pcap" % (self.test.tempdir, self.pg_index)
  89
  90     @property
  91     def capture_cli(self):
  92         """CLI string to start capture on this interface"""
  93         return self._capture_cli
  94
  95     def get_cap_name(self, worker=None):
  96         """return capture name for this interface and given worker"""
  97         if worker is not None:
  98             return self._cap_name + "-worker%d" % worker
  99         return self._cap_name
 100
 101     def get_input_cli(self, nb_replays=None, worker=None):
 102         """return CLI string to load the injected packets"""
 103         input_cli = "packet-generator new pcap %s source pg%u name %s" % (
 104             self.get_in_path(worker),
 105             self.pg_index,
 106             self.get_cap_name(worker),
 107         )
 108         if nb_replays is not None:
 109             return "%s limit %d" % (input_cli, nb_replays)
 110         if worker is not None:
 111             return "%s worker %d" % (input_cli, worker)
 112         return input_cli
 113
 114     @property
 115     def in_history_counter(self):
 116         """Self-incrementing counter used when renaming old pcap files"""
 117         v = self._in_history_counter
 118         self._in_history_counter += 1
 119         return v
 120
 121     @property
 122     def out_history_counter(self):
 123         """Self-incrementing counter used when renaming old pcap files"""
 124         v = self._out_history_counter
 125         self._out_history_counter += 1
 126         return v
 127
 128     def __init__(self, test, pg_index, gso, gso_size, mode):
 129         """Create VPP packet-generator interface"""
 130         super().__init__(test)
 131
 132         r = test.vapi.pg_create_interface_v2(pg_index, gso, gso_size, mode)
 133         self.set_sw_if_index(r.sw_if_index)
 134
 135         self._in_history_counter = 0
 136         self._out_history_counter = 0
 137         self._out_assert_counter = 0
 138         self._pg_index = pg_index
 139         self._gso_enabled = gso
 140         self._gso_size = gso_size
 141         self._coalesce_enabled = 0
 142         self._out_file = "pg%u_out.pcap" % self.pg_index
 143         self._out_path = self.test.tempdir + "/" + self._out_file
 144         self._capture_cli = "packet-generator capture pg%u pcap %s" % (
 145             self.pg_index,
 146             self.out_path,
 147         )
 148         self._cap_name = "pcap%u-sw_if_index-%s" % (self.pg_index, self.sw_if_index)
 149
 150     def link_pcap_file(self, path, direction, counter):
 151         if not config.keep_pcaps:
 152             return
 153         filename = os.path.basename(path)
 154         test_name = (
 155             self.test_name
 156             if hasattr(self, "test_name")
 157             else f"suite{self.test.__name__}"
 158         )
 159         name = f"{self.test.tempdir}/{test_name}.[timestamp:{time.time():.8f}].{self.name}-{direction}-{counter:04}.{filename}"
 160         if os.path.isfile(name):
 161             self.test.logger.debug(
 162                 f"Skipping hard link creation: {name} already exists!"
 163             )
 164             return
 165         try:
 166             if os.path.isfile(path):
 167                 self.test.logger.debug(f"Creating hard link {path}->{name}")
 168                 os.link(path, name)
 169         except OSError:
 170             self.test.logger.debug(
 171                 f"OSError: Could not create hard link {path}->{name}"
 172             )
 173
 174     def remove_old_pcap_file(self, path):
 175         try:
 176             self.test.logger.debug(f"Removing {path}")
 177             os.remove(path)
 178         except OSError:
 179             self.test.logger.debug(f"OSError: Could not remove {path}")
 180         return
 181
 182     def decode_pcap_files(self, pcap_dir, filename_prefix):
 183         # Generate tshark packet trace of testcase pcap files
 184         pg_decode = f"{pcap_dir}/pcap-decode-{filename_prefix}.txt"
 185         if os.path.isfile(pg_decode):
 186             self.test.logger.debug(
 187                 f"The pg streams decode file already exists: {pg_decode}"
 188             )
 189             return
 190         self.test.logger.debug(
 191             f"Generating testcase pg streams decode file: {pg_decode}"
 192         )
 193         ts_opts = "-Vr"
 194         for p in sorted(Path(pcap_dir).glob(f"{filename_prefix}*.pcap")):
 195             self.test.logger.debug(f"Decoding {p}")
 196             with open(f"{pg_decode}", "a", buffering=1) as f:
 197                 print(f"tshark {ts_opts} {p}", file=f)
 198                 tshark(ts_opts, f"{p}", _out=f)
 199                 print("", file=f)
 200
 201     def enable_capture(self):
 202         """Enable capture on this packet-generator interface
 203         of at most n packets.
 204         If n < 0, this is no limit
 205         """
 206         # disable the capture to flush the capture
 207         self.disable_capture()
 208         self.remove_old_pcap_file(self.out_path)
 209         # FIXME this should be an API, but no such exists atm
 210         self.test.vapi.cli(self.capture_cli)
 211         self._pcap_reader = None
 212
 213     def disable_capture(self):
 214         self.test.vapi.cli("%s disable" % self.capture_cli)
 215
 216     def coalesce_enable(self):
 217         """Enable packet coalesce on this packet-generator interface"""
 218         self._coalesce_enabled = 1
 219         self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index, 1)
 220
 221     def coalesce_disable(self):
 222         """Disable packet coalesce on this packet-generator interface"""
 223         self._coalesce_enabled = 0
 224         self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index, 0)
 225
 226     def add_stream(self, pkts, nb_replays=None, worker=None):
 227         """
 228         Add a stream of packets to this packet-generator
 229
 230         :param pkts: iterable packets
 231
 232         """
 233         in_pcap = self.get_in_path(worker)
 234         if os.path.isfile(in_pcap):
 235             self.remove_old_pcap_file(in_pcap)
 236         wrpcap(in_pcap, pkts)
 237         self.test.register_pcap(self, worker)
 238         # FIXME this should be an API, but no such exists atm
 239         self.test.vapi.cli(self.get_input_cli(nb_replays, worker))
 240         self.link_pcap_file(self.get_in_path(worker), "inp", self.in_history_counter)
 241
 242     def generate_debug_aid(self, kind):
 243         """Create a hardlink to the out file with a counter and a file
 244         containing stack trace to ease debugging in case of multiple capture
 245         files present."""
 246         self.test.logger.debug("Generating debug aid for %s on %s" % (kind, self._name))
 247         link_path, stack_path = [
 248             "%s/debug_%s_%s_%s.%s"
 249             % (self.test.tempdir, self._name, self._out_assert_counter, kind, suffix)
 250             for suffix in ["pcap", "stack"]
 251         ]
 252         os.link(self.out_path, link_path)
 253         with open(stack_path, "w") as f:
 254             f.writelines(format_stack())
 255         self._out_assert_counter += 1
 256
 257     def _get_capture(self, timeout, filter_out_fn=is_ipv6_misc):
 258         """Helper method to get capture and filter it"""
 259         try:
 260             if not self.wait_for_capture_file(timeout):
 261                 return None
 262             output = rdpcap(self.out_path)
 263             self.test.logger.debug(f"Capture has {len(output.res)} packets")
 264         except:
 265             self.test.logger.debug(
 266                 "Exception in scapy.rdpcap (%s): %s" % (self.out_path, format_exc())
 267             )
 268             return None
 269         before = len(output.res)
 270         if filter_out_fn:
 271             output.res = [p for p in output.res if not filter_out_fn(p)]
 272         removed = before - len(output.res)
 273         if removed:
 274             self.test.logger.debug(
 275                 "Filtered out %s packets from capture (returning %s)"
 276                 % (removed, len(output.res))
 277             )
 278         return output
 279
 280     def get_capture(
 281         self, expected_count=None, remark=None, timeout=1, filter_out_fn=is_ipv6_misc
 282     ):
 283         """Get captured packets
 284
 285         :param expected_count: expected number of packets to capture, if None,
 286                                then self.test.packet_count_for_dst_pg_idx is
 287                                used to lookup the expected count
 288         :param remark: remark printed into debug logs
 289         :param timeout: how long to wait for packets
 290         :param filter_out_fn: filter applied to each packet, packets for which
 291                               the filter returns True are removed from capture
 292         :returns: iterable packets
 293         """
 294         remaining_time = timeout
 295         capture = None
 296         name = self.name if remark is None else "%s (%s)" % (self.name, remark)
 297         based_on = "based on provided argument"
 298         if expected_count is None:
 299             expected_count = self.test.get_packet_count_for_if_idx(self.sw_if_index)
 300             based_on = "based on stored packet_infos"
 301             if expected_count == 0:
 302                 raise Exception(
 303                     "Internal error, expected packet count for %s is 0!" % name
 304                 )
 305         self.test.logger.debug(
 306             "Expecting to capture %s (%s) packets on %s"
 307             % (expected_count, based_on, name)
 308         )
 309         while remaining_time > 0:
 310             before = time.time()
 311             capture = self._get_capture(remaining_time, filter_out_fn)
 312             elapsed_time = time.time() - before
 313             if capture:
 314                 if len(capture.res) == expected_count:
 315                     # bingo, got the packets we expected
 316                     return capture
 317                 elif len(capture.res) > expected_count:
 318                     self.test.logger.error(
 319                         ppc(
 320                             f"Unexpected packets captured, got {len(capture.res)}, expected {expected_count}:",
 321                             capture,
 322                         )
 323                     )
 324                     break
 325                 else:
 326                     self.test.logger.debug(
 327                         "Partial capture containing %s "
 328                         "packets doesn't match expected "
 329                         "count %s (yet?)" % (len(capture.res), expected_count)
 330                     )
 331             elif expected_count == 0:
 332                 # bingo, got None as we expected - return empty capture
 333                 return PacketList()
 334             remaining_time -= elapsed_time
 335         if capture:
 336             self.generate_debug_aid("count-mismatch")
 337             if len(capture) > 0 and 0 == expected_count:
 338                 rem = f"\n{remark}" if remark else ""
 339                 raise UnexpectedPacketError(
 340                     capture[0],
 341                     f"\n({len(capture)} packets captured in total){rem} on {name}",
 342                 )
 343             msg = f"Captured packets mismatch, captured {len(capture.res)} packets, expected {expected_count} packets on {name}:"
 344             raise Exception(f"{ppc(msg, capture)}")
 345         else:
 346             if 0 == expected_count:
 347                 return
 348             raise Exception(f"No packets captured on {name} (timeout = {timeout}s)")
 349
 350     def assert_nothing_captured(
 351         self, timeout=1, remark=None, filter_out_fn=is_ipv6_misc
 352     ):
 353         """Assert that nothing unfiltered was captured on interface
 354
 355         :param remark: remark printed into debug logs
 356         :param filter_out_fn: filter applied to each packet, packets for which
 357                               the filter returns True are removed from capture
 358         """
 359         capture = self.get_capture(
 360             0, timeout=timeout, remark=remark, filter_out_fn=filter_out_fn
 361         )
 362         if not capture or len(capture.res) == 0:
 363             # junk filtered out, we're good
 364             return
 365
 366     def wait_for_pg_stop(self):
 367         # wait till packet-generator is stopped
 368         # "show packet-generator" while it is still running gives this:
 369         # Name               Enabled        Count     Parameters
 370         # pcap0-sw_if_inde     Yes           64       limit 64, ...
 371         #
 372         # also have a 5-minute timeout just in case things go terribly wrong...
 373         deadline = time.time() + 300
 374         while self.test.vapi.cli("show packet-generator").find("Yes") != -1:
 375             self._test.sleep(0.01)  # yield
 376             if time.time() > deadline:
 377                 self.test.logger.debug("Timeout waiting for pg to stop")
 378                 break
 379
 380     def wait_for_capture_file(self, timeout=1):
 381         """
 382         Wait until pcap capture file appears
 383
 384         :param timeout: How long to wait for the packet (default 1s)
 385
 386         :returns: True/False if the file is present or appears within timeout
 387         """
 388         self.wait_for_pg_stop()
 389         deadline = time.time() + timeout
 390         if not os.path.isfile(self.out_path):
 391             self.test.logger.debug(
 392                 f"Waiting for capture file {self.out_path} to appear, timeout is {timeout}s\n"
 393                 f"{' '.join(format_stack(limit=10))}"
 394             )
 395         else:
 396             self.test.logger.debug("Capture file %s already exists" % self.out_path)
 397             self.link_pcap_file(self.out_path, "out", self.out_history_counter)
 398             return True
 399         while time.time() < deadline:
 400             if os.path.isfile(self.out_path):
 401                 break
 402             self._test.sleep(0)  # yield
 403         if os.path.isfile(self.out_path):
 404             self.test.logger.debug(
 405                 "Capture file appeared after %fs" % (time.time() - (deadline - timeout))
 406             )
 407         else:
 408             self.test.logger.debug("Timeout - capture file still nowhere")
 409             return False
 410         self.link_pcap_file(self.out_path, "out", self.out_history_counter)
 411         return True
 412
 413     def verify_enough_packet_data_in_pcap(self):
 414         """
 415         Check if enough data is available in file handled by internal pcap
 416         reader so that a whole packet can be read.
 417
 418         :returns: True if enough data present, else False
 419         """
 420         orig_pos = self._pcap_reader.f.tell()  # save file position
 421         enough_data = False
 422         # read packet header from pcap
 423         packet_header_size = 16
 424         caplen = None
 425         end_pos = None
 426         hdr = self._pcap_reader.f.read(packet_header_size)
 427         if len(hdr) == packet_header_size:
 428             # parse the capture length - caplen
 429             sec, usec, caplen, wirelen = struct.unpack(
 430                 self._pcap_reader.endian + "IIII", hdr
 431             )
 432             self._pcap_reader.f.seek(0, 2)  # seek to end of file
 433             end_pos = self._pcap_reader.f.tell()  # get position at end
 434             if end_pos >= orig_pos + len(hdr) + caplen:
 435                 enough_data = True  # yay, we have enough data
 436         self._pcap_reader.f.seek(orig_pos, 0)  # restore original position
 437         return enough_data
 438
 439     def wait_for_packet(self, timeout, filter_out_fn=is_ipv6_misc):
 440         """
 441         Wait for next packet captured with a timeout
 442
 443         :param timeout: How long to wait for the packet
 444
 445         :returns: Captured packet if no packet arrived within timeout
 446         :raises Exception: if no packet arrives within timeout
 447         """
 448         deadline = time.time() + timeout
 449         if self._pcap_reader is None:
 450             if not self.wait_for_capture_file(timeout):
 451                 raise CaptureTimeoutError(
 452                     "Capture file %s did not appear within timeout" % self.out_path
 453                 )
 454             while time.time() < deadline:
 455                 try:
 456                     self._pcap_reader = PcapReader(self.out_path)
 457                     break
 458                 except:
 459                     self.test.logger.debug(
 460                         "Exception in scapy.PcapReader(%s): %s"
 461                         % (self.out_path, format_exc())
 462                     )
 463         if not self._pcap_reader:
 464             raise CaptureTimeoutError(
 465                 "Capture file %s did not appear within timeout" % self.out_path
 466             )
 467
 468         poll = False
 469         if timeout > 0:
 470             self.test.logger.debug("Waiting for packet")
 471         else:
 472             poll = True
 473             self.test.logger.debug("Polling for packet")
 474         while time.time() < deadline or poll:
 475             if not self.verify_enough_packet_data_in_pcap():
 476                 self._test.sleep(0)  # yield
 477                 poll = False
 478                 continue
 479             p = self._pcap_reader.recv()
 480             if p is not None:
 481                 if filter_out_fn is not None and filter_out_fn(p):
 482                     self.test.logger.debug(
 483                         "Packet received after %ss was filtered out"
 484                         % (time.time() - (deadline - timeout))
 485                     )
 486                 else:
 487                     self.test.logger.debug(
 488                         "Packet received after %fs"
 489                         % (time.time() - (deadline - timeout))
 490                     )
 491                     return p
 492             self._test.sleep(0)  # yield
 493             poll = False
 494         self.test.logger.debug(f"Timeout ({timeout}) - no packets received")
 495         raise CaptureTimeoutError(f"Packet didn't arrive within timeout ({timeout})")
 496
 497     def create_arp_req(self):
 498         """Create ARP request applicable for this interface"""
 499         return Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) / ARP(
 500             op=ARP.who_has,
 501             pdst=self.local_ip4,
 502             psrc=self.remote_ip4,
 503             hwsrc=self.remote_mac,
 504         )
 505
 506     def create_ndp_req(self, addr=None):
 507         """Create NDP - NS applicable for this interface"""
 508         if not addr:
 509             addr = self.local_ip6
 510         nsma = in6_getnsma(inet_pton(socket.AF_INET6, addr))
 511         d = inet_ntop(socket.AF_INET6, nsma)
 512
 513         return (
 514             Ether(dst=in6_getnsmac(nsma))
 515             / IPv6(dst=d, src=self.remote_ip6)
 516             / ICMPv6ND_NS(tgt=addr)
 517             / ICMPv6NDOptSrcLLAddr(lladdr=self.remote_mac)
 518         )
 519
 520     def resolve_arp(self, pg_interface=None):
 521         """Resolve ARP using provided packet-generator interface
 522
 523         :param pg_interface: interface used to resolve, if None then this
 524             interface is used
 525
 526         """
 527         if pg_interface is None:
 528             pg_interface = self
 529         self.test.logger.info(
 530             "Sending ARP request for %s on port %s"
 531             % (self.local_ip4, pg_interface.name)
 532         )
 533         arp_req = self.create_arp_req()
 534         pg_interface.add_stream(arp_req)
 535         pg_interface.enable_capture()
 536         self.test.pg_start()
 537         self.test.logger.info(self.test.vapi.cli("show trace"))
 538         try:
 539             captured_packet = pg_interface.wait_for_packet(1)
 540         except:
 541             self.test.logger.info("No ARP received on port %s" % pg_interface.name)
 542             return
 543         arp_reply = captured_packet.copy()  # keep original for exception
 544         try:
 545             if arp_reply[ARP].op == ARP.is_at:
 546                 self.test.logger.info(
 547                     "VPP %s MAC address is %s " % (self.name, arp_reply[ARP].hwsrc)
 548                 )
 549                 self._local_mac = arp_reply[ARP].hwsrc
 550             else:
 551                 self.test.logger.info("No ARP received on port %s" % pg_interface.name)
 552         except:
 553             self.test.logger.error(
 554                 ppp("Unexpected response to ARP request:", captured_packet)
 555             )
 556             raise
 557
 558     def resolve_ndp(self, pg_interface=None, timeout=1, link_layer=False):
 559         """Resolve NDP using provided packet-generator interface
 560
 561         :param pg_interface: interface used to resolve, if None then this
 562             interface is used
 563         :param timeout: how long to wait for response before giving up
 564         :param link_layer: resolve for global address if False (default)
 565             or for link-layer address if True
 566
 567         """
 568         if pg_interface is None:
 569             pg_interface = self
 570         addr = self.local_ip6_ll if link_layer else self.local_ip6
 571         self.test.logger.info(
 572             "Sending NDP request for %s on port %s" % (addr, pg_interface.name)
 573         )
 574         ndp_req = self.create_ndp_req(addr)
 575         pg_interface.add_stream(ndp_req)
 576         pg_interface.enable_capture()
 577         self.test.pg_start()
 578         now = time.time()
 579         deadline = now + timeout
 580         # Enabling IPv6 on an interface can generate more than the
 581         # ND reply we are looking for (namely MLD). So loop through
 582         # the replies to look for want we want.
 583         while now < deadline:
 584             try:
 585                 captured_packet = pg_interface.wait_for_packet(
 586                     deadline - now, filter_out_fn=None
 587                 )
 588             except:
 589                 self.test.logger.error("Timeout while waiting for NDP response")
 590                 raise
 591             ndp_reply = captured_packet.copy()  # keep original for exception
 592             try:
 593                 ndp_na = ndp_reply[ICMPv6ND_NA]
 594                 opt = ndp_na[ICMPv6NDOptDstLLAddr]
 595                 self.test.logger.info(
 596                     "VPP %s MAC address is %s " % (self.name, opt.lladdr)
 597                 )
 598                 self._local_mac = opt.lladdr
 599                 self.test.logger.debug(self.test.vapi.cli("show trace"))
 600                 # we now have the MAC we've been after
 601                 return
 602             except:
 603                 self.test.logger.info(
 604                     ppp("Unexpected response to NDP request:", captured_packet)
 605                 )
 606             now = time.time()
 607
 608         self.test.logger.debug(self.test.vapi.cli("show trace"))
 609         raise Exception("Timeout while waiting for NDP response")