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         self.wait_for_pg_stop()
 176         self.test.unlink_testcase_file(self.test, Path(path))
 177         return
 178
 179     def decode_pcap_files(self, pcap_dir, filename_prefix):
 180         # Generate tshark packet trace of testcase pcap files
 181         pg_decode = f"{pcap_dir}/pcap-decode-{filename_prefix}.txt"
 182         if os.path.isfile(pg_decode):
 183             self.test.logger.debug(
 184                 f"The pg streams decode file already exists: {pg_decode}"
 185             )
 186             return
 187         self.test.logger.debug(
 188             f"Generating testcase pg streams decode file: {pg_decode}"
 189         )
 190         ts_opts = "-Vr"
 191         for p in sorted(Path(pcap_dir).glob(f"{filename_prefix}*.pcap")):
 192             self.test.logger.debug(f"Decoding {p}")
 193             with open(f"{pg_decode}", "a", buffering=1) as f:
 194                 print(f"tshark {ts_opts} {p}", file=f)
 195                 tshark(ts_opts, f"{p}", _out=f)
 196                 print("", file=f)
 197
 198     def enable_capture(self):
 199         """Enable capture on this packet-generator interface
 200         of at most n packets.
 201         If n < 0, this is no limit
 202         """
 203         # disable the capture to flush the capture
 204         self.disable_capture()
 205         self.remove_old_pcap_file(self.out_path)
 206         # FIXME this should be an API, but no such exists atm
 207         self.test.vapi.cli(self.capture_cli)
 208         self._pcap_reader = None
 209
 210     def disable_capture(self):
 211         self.test.vapi.cli("%s disable" % self.capture_cli)
 212
 213     def coalesce_enable(self):
 214         """Enable packet coalesce on this packet-generator interface"""
 215         self._coalesce_enabled = 1
 216         self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index, 1)
 217
 218     def coalesce_disable(self):
 219         """Disable packet coalesce on this packet-generator interface"""
 220         self._coalesce_enabled = 0
 221         self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index, 0)
 222
 223     def add_stream(self, pkts, nb_replays=None, worker=None):
 224         """
 225         Add a stream of packets to this packet-generator
 226
 227         :param pkts: iterable packets
 228
 229         """
 230         in_pcap = self.get_in_path(worker)
 231         if os.path.isfile(in_pcap):
 232             self.remove_old_pcap_file(in_pcap)
 233         wrpcap(in_pcap, pkts)
 234         self.test.register_pcap(self, worker)
 235         # FIXME this should be an API, but no such exists atm
 236         self.test.vapi.cli(self.get_input_cli(nb_replays, worker))
 237         self.link_pcap_file(self.get_in_path(worker), "inp", self.in_history_counter)
 238
 239     def generate_debug_aid(self, kind):
 240         """Create a hardlink to the out file with a counter and a file
 241         containing stack trace to ease debugging in case of multiple capture
 242         files present."""
 243         self.test.logger.debug("Generating debug aid for %s on %s" % (kind, self._name))
 244         link_path, stack_path = [
 245             "%s/debug_%s_%s_%s.%s"
 246             % (self.test.tempdir, self._name, self._out_assert_counter, kind, suffix)
 247             for suffix in ["pcap", "stack"]
 248         ]
 249         os.link(self.out_path, link_path)
 250         with open(stack_path, "w") as f:
 251             f.writelines(format_stack())
 252         self._out_assert_counter += 1
 253
 254     def _get_capture(self, timeout, filter_out_fn=is_ipv6_misc):
 255         """Helper method to get capture and filter it"""
 256         try:
 257             if not self.wait_for_capture_file(timeout):
 258                 return None
 259             output = rdpcap(self.out_path)
 260             self.test.logger.debug(f"Capture has {len(output.res)} packets")
 261         except:
 262             self.test.logger.debug(
 263                 "Exception in scapy.rdpcap (%s): %s" % (self.out_path, format_exc())
 264             )
 265             return None
 266         before = len(output.res)
 267         if filter_out_fn:
 268             output.res = [p for p in output.res if not filter_out_fn(p)]
 269         removed = before - len(output.res)
 270         if removed:
 271             self.test.logger.debug(
 272                 "Filtered out %s packets from capture (returning %s)"
 273                 % (removed, len(output.res))
 274             )
 275         return output
 276
 277     def get_capture(
 278         self, expected_count=None, remark=None, timeout=1, filter_out_fn=is_ipv6_misc
 279     ):
 280         """Get captured packets
 281
 282         :param expected_count: expected number of packets to capture, if None,
 283                                then self.test.packet_count_for_dst_pg_idx is
 284                                used to lookup the expected count
 285         :param remark: remark printed into debug logs
 286         :param timeout: how long to wait for packets
 287         :param filter_out_fn: filter applied to each packet, packets for which
 288                               the filter returns True are removed from capture
 289         :returns: iterable packets
 290         """
 291         remaining_time = timeout
 292         capture = None
 293         name = self.name if remark is None else "%s (%s)" % (self.name, remark)
 294         based_on = "based on provided argument"
 295         if expected_count is None:
 296             expected_count = self.test.get_packet_count_for_if_idx(self.sw_if_index)
 297             based_on = "based on stored packet_infos"
 298             if expected_count == 0:
 299                 raise Exception(
 300                     "Internal error, expected packet count for %s is 0!" % name
 301                 )
 302         self.test.logger.debug(
 303             "Expecting to capture %s (%s) packets on %s"
 304             % (expected_count, based_on, name)
 305         )
 306         while remaining_time > 0:
 307             before = time.time()
 308             capture = self._get_capture(remaining_time, filter_out_fn)
 309             elapsed_time = time.time() - before
 310             if capture:
 311                 if len(capture.res) == expected_count:
 312                     # bingo, got the packets we expected
 313                     return capture
 314                 elif len(capture.res) > expected_count:
 315                     self.test.logger.error(
 316                         ppc(
 317                             f"Unexpected packets captured, got {len(capture.res)}, expected {expected_count}:",
 318                             capture,
 319                         )
 320                     )
 321                     break
 322                 else:
 323                     self.test.logger.debug(
 324                         "Partial capture containing %s "
 325                         "packets doesn't match expected "
 326                         "count %s (yet?)" % (len(capture.res), expected_count)
 327                     )
 328             elif expected_count == 0:
 329                 # bingo, got None as we expected - return empty capture
 330                 return PacketList()
 331             remaining_time -= elapsed_time
 332         if capture:
 333             self.generate_debug_aid("count-mismatch")
 334             if len(capture) > 0 and 0 == expected_count:
 335                 rem = f"\n{remark}" if remark else ""
 336                 raise UnexpectedPacketError(
 337                     capture[0],
 338                     f"\n({len(capture)} packets captured in total){rem} on {name}",
 339                 )
 340             msg = f"Captured packets mismatch, captured {len(capture.res)} packets, expected {expected_count} packets on {name}:"
 341             raise Exception(f"{ppc(msg, capture)}")
 342         else:
 343             if 0 == expected_count:
 344                 return
 345             raise Exception(f"No packets captured on {name} (timeout = {timeout}s)")
 346
 347     def assert_nothing_captured(
 348         self, timeout=1, remark=None, filter_out_fn=is_ipv6_misc
 349     ):
 350         """Assert that nothing unfiltered was captured on interface
 351
 352         :param remark: remark printed into debug logs
 353         :param filter_out_fn: filter applied to each packet, packets for which
 354                               the filter returns True are removed from capture
 355         """
 356         capture = self.get_capture(
 357             0, timeout=timeout, remark=remark, filter_out_fn=filter_out_fn
 358         )
 359         if not capture or len(capture.res) == 0:
 360             # junk filtered out, we're good
 361             return
 362
 363     def wait_for_pg_stop(self):
 364         # wait till packet-generator is stopped
 365         # "show packet-generator" while it is still running gives this:
 366         # Name               Enabled        Count     Parameters
 367         # pcap0-sw_if_inde     Yes           64       limit 64, ...
 368         #
 369         # also have a 5-minute timeout just in case things go terribly wrong...
 370         deadline = time.time() + 300
 371         while self.test.vapi.cli("show packet-generator").find("Yes") != -1:
 372             self._test.sleep(0.01)  # yield
 373             if time.time() > deadline:
 374                 self.test.logger.debug("Timeout waiting for pg to stop")
 375                 break
 376
 377     def wait_for_capture_file(self, timeout=1):
 378         """
 379         Wait until pcap capture file appears
 380
 381         :param timeout: How long to wait for the packet (default 1s)
 382
 383         :returns: True/False if the file is present or appears within timeout
 384         """
 385         self.wait_for_pg_stop()
 386         deadline = time.time() + timeout
 387         if not os.path.isfile(self.out_path):
 388             self.test.logger.debug(
 389                 f"Waiting for capture file {self.out_path} to appear, timeout is {timeout}s\n"
 390                 f"{' '.join(format_stack(limit=10))}"
 391             )
 392         else:
 393             self.test.logger.debug("Capture file %s already exists" % self.out_path)
 394             self.link_pcap_file(self.out_path, "out", self.out_history_counter)
 395             return True
 396         while time.time() < deadline:
 397             if os.path.isfile(self.out_path):
 398                 break
 399             self._test.sleep(0)  # yield
 400         if os.path.isfile(self.out_path):
 401             self.test.logger.debug(
 402                 "Capture file appeared after %fs" % (time.time() - (deadline - timeout))
 403             )
 404         else:
 405             self.test.logger.debug("Timeout - capture file still nowhere")
 406             return False
 407         self.link_pcap_file(self.out_path, "out", self.out_history_counter)
 408         return True
 409
 410     def verify_enough_packet_data_in_pcap(self):
 411         """
 412         Check if enough data is available in file handled by internal pcap
 413         reader so that a whole packet can be read.
 414
 415         :returns: True if enough data present, else False
 416         """
 417         orig_pos = self._pcap_reader.f.tell()  # save file position
 418         enough_data = False
 419         # read packet header from pcap
 420         packet_header_size = 16
 421         caplen = None
 422         end_pos = None
 423         hdr = self._pcap_reader.f.read(packet_header_size)
 424         if len(hdr) == packet_header_size:
 425             # parse the capture length - caplen
 426             sec, usec, caplen, wirelen = struct.unpack(
 427                 self._pcap_reader.endian + "IIII", hdr
 428             )
 429             self._pcap_reader.f.seek(0, 2)  # seek to end of file
 430             end_pos = self._pcap_reader.f.tell()  # get position at end
 431             if end_pos >= orig_pos + len(hdr) + caplen:
 432                 enough_data = True  # yay, we have enough data
 433         self._pcap_reader.f.seek(orig_pos, 0)  # restore original position
 434         return enough_data
 435
 436     def wait_for_packet(self, timeout, filter_out_fn=is_ipv6_misc):
 437         """
 438         Wait for next packet captured with a timeout
 439
 440         :param timeout: How long to wait for the packet
 441
 442         :returns: Captured packet if no packet arrived within timeout
 443         :raises Exception: if no packet arrives within timeout
 444         """
 445         deadline = time.time() + timeout
 446         if self._pcap_reader is None:
 447             if not self.wait_for_capture_file(timeout):
 448                 raise CaptureTimeoutError(
 449                     "Capture file %s did not appear within timeout" % self.out_path
 450                 )
 451             while time.time() < deadline:
 452                 try:
 453                     self._pcap_reader = PcapReader(self.out_path)
 454                     break
 455                 except:
 456                     self.test.logger.debug(
 457                         "Exception in scapy.PcapReader(%s): %s"
 458                         % (self.out_path, format_exc())
 459                     )
 460         if not self._pcap_reader:
 461             raise CaptureTimeoutError(
 462                 "Capture file %s did not appear within timeout" % self.out_path
 463             )
 464
 465         poll = False
 466         if timeout > 0:
 467             self.test.logger.debug("Waiting for packet")
 468         else:
 469             poll = True
 470             self.test.logger.debug("Polling for packet")
 471         while time.time() < deadline or poll:
 472             if not self.verify_enough_packet_data_in_pcap():
 473                 self._test.sleep(0)  # yield
 474                 poll = False
 475                 continue
 476             p = self._pcap_reader.recv()
 477             if p is not None:
 478                 if filter_out_fn is not None and filter_out_fn(p):
 479                     self.test.logger.debug(
 480                         "Packet received after %ss was filtered out"
 481                         % (time.time() - (deadline - timeout))
 482                     )
 483                 else:
 484                     self.test.logger.debug(
 485                         "Packet received after %fs"
 486                         % (time.time() - (deadline - timeout))
 487                     )
 488                     return p
 489             self._test.sleep(0)  # yield
 490             poll = False
 491         self.test.logger.debug(f"Timeout ({timeout}) - no packets received")
 492         raise CaptureTimeoutError(f"Packet didn't arrive within timeout ({timeout})")
 493
 494     def create_arp_req(self):
 495         """Create ARP request applicable for this interface"""
 496         return Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) / ARP(
 497             op=ARP.who_has,
 498             pdst=self.local_ip4,
 499             psrc=self.remote_ip4,
 500             hwsrc=self.remote_mac,
 501         )
 502
 503     def create_ndp_req(self, addr=None):
 504         """Create NDP - NS applicable for this interface"""
 505         if not addr:
 506             addr = self.local_ip6
 507         nsma = in6_getnsma(inet_pton(socket.AF_INET6, addr))
 508         d = inet_ntop(socket.AF_INET6, nsma)
 509
 510         return (
 511             Ether(dst=in6_getnsmac(nsma))
 512             / IPv6(dst=d, src=self.remote_ip6)
 513             / ICMPv6ND_NS(tgt=addr)
 514             / ICMPv6NDOptSrcLLAddr(lladdr=self.remote_mac)
 515         )
 516
 517     def resolve_arp(self, pg_interface=None):
 518         """Resolve ARP using provided packet-generator interface
 519
 520         :param pg_interface: interface used to resolve, if None then this
 521             interface is used
 522
 523         """
 524         if pg_interface is None:
 525             pg_interface = self
 526         self.test.logger.info(
 527             "Sending ARP request for %s on port %s"
 528             % (self.local_ip4, pg_interface.name)
 529         )
 530         arp_req = self.create_arp_req()
 531         pg_interface.add_stream(arp_req)
 532         pg_interface.enable_capture()
 533         self.test.pg_start()
 534         self.test.logger.info(self.test.vapi.cli("show trace"))
 535         try:
 536             captured_packet = pg_interface.wait_for_packet(1)
 537         except:
 538             self.test.logger.info("No ARP received on port %s" % pg_interface.name)
 539             return
 540         arp_reply = captured_packet.copy()  # keep original for exception
 541         try:
 542             if arp_reply[ARP].op == ARP.is_at:
 543                 self.test.logger.info(
 544                     "VPP %s MAC address is %s " % (self.name, arp_reply[ARP].hwsrc)
 545                 )
 546                 self._local_mac = arp_reply[ARP].hwsrc
 547             else:
 548                 self.test.logger.info("No ARP received on port %s" % pg_interface.name)
 549         except:
 550             self.test.logger.error(
 551                 ppp("Unexpected response to ARP request:", captured_packet)
 552             )
 553             raise
 554
 555     def resolve_ndp(self, pg_interface=None, timeout=1, link_layer=False):
 556         """Resolve NDP using provided packet-generator interface
 557
 558         :param pg_interface: interface used to resolve, if None then this
 559             interface is used
 560         :param timeout: how long to wait for response before giving up
 561         :param link_layer: resolve for global address if False (default)
 562             or for link-layer address if True
 563
 564         """
 565         if pg_interface is None:
 566             pg_interface = self
 567         addr = self.local_ip6_ll if link_layer else self.local_ip6
 568         self.test.logger.info(
 569             "Sending NDP request for %s on port %s" % (addr, pg_interface.name)
 570         )
 571         ndp_req = self.create_ndp_req(addr)
 572         pg_interface.add_stream(ndp_req)
 573         pg_interface.enable_capture()
 574         self.test.pg_start()
 575         now = time.time()
 576         deadline = now + timeout
 577         # Enabling IPv6 on an interface can generate more than the
 578         # ND reply we are looking for (namely MLD). So loop through
 579         # the replies to look for want we want.
 580         while now < deadline:
 581             try:
 582                 captured_packet = pg_interface.wait_for_packet(
 583                     deadline - now, filter_out_fn=None
 584                 )
 585             except:
 586                 self.test.logger.error("Timeout while waiting for NDP response")
 587                 raise
 588             ndp_reply = captured_packet.copy()  # keep original for exception
 589             try:
 590                 ndp_na = ndp_reply[ICMPv6ND_NA]
 591                 opt = ndp_na[ICMPv6NDOptDstLLAddr]
 592                 self.test.logger.info(
 593                     "VPP %s MAC address is %s " % (self.name, opt.lladdr)
 594                 )
 595                 self._local_mac = opt.lladdr
 596                 self.test.logger.debug(self.test.vapi.cli("show trace"))
 597                 # we now have the MAC we've been after
 598                 return
 599             except:
 600                 self.test.logger.info(
 601                     ppp("Unexpected response to NDP request:", captured_packet)
 602                 )
 603             now = time.time()
 604
 605         self.test.logger.debug(self.test.vapi.cli("show trace"))
 606         raise Exception("Timeout while waiting for NDP response")