4 from socket import inet_pton, inet_ntop
7 from traceback import format_exc, format_stack
9 from pathlib import Path
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
17 from scapy.layers.l2 import Ether, ARP
18 from scapy.layers.inet6 import (
28 from util import ppp, ppc, UnexpectedPacketError
29 from scapy.utils6 import in6_getnsma, in6_getnsmac, in6_ismaddr
32 class CaptureTimeoutError(Exception):
33 """Exception raised if capture or packet doesn't appear within timeout"""
39 """Is packet one of uninteresting IPv6 broadcasts?"""
40 if p.haslayer(ICMPv6ND_RA):
41 if in6_ismaddr(p[IPv6].dst):
43 if p.haslayer(IPv6ExtHdrHopByHop):
44 for o in p[IPv6ExtHdrHopByHop].options:
45 if isinstance(o, RouterAlert):
50 class VppPGInterface(VppInterface):
52 VPP packet-generator interface
57 """packet-generator interface index assigned by VPP"""
61 def gso_enabled(self):
62 """gso enabled on packet-generator interface"""
63 if self._gso_enabled == 0:
69 """gso size on packet-generator interface"""
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"
81 """pcap file path - captured packets"""
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)
91 def capture_cli(self):
92 """CLI string to start capture on this interface"""
93 return self._capture_cli
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
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),
106 self.get_cap_name(worker),
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)
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
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
128 def __init__(self, test, pg_index, gso, gso_size, mode):
129 """Create VPP packet-generator interface"""
130 super().__init__(test)
132 r = test.vapi.pg_create_interface_v2(pg_index, gso, gso_size, mode)
133 self.set_sw_if_index(r.sw_if_index)
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" % (
148 self._cap_name = "pcap%u-sw_if_index-%s" % (self.pg_index, self.sw_if_index)
150 def link_pcap_file(self, path, direction, counter):
151 if not config.keep_pcaps:
153 filename = os.path.basename(path)
156 if hasattr(self, "test_name")
157 else f"suite{self.test.__name__}"
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!"
166 if os.path.isfile(path):
167 self.test.logger.debug(f"Creating hard link {path}->{name}")
170 self.test.logger.debug(
171 f"OSError: Could not create hard link {path}->{name}"
174 def remove_old_pcap_file(self, path):
175 self.wait_for_pg_stop()
176 self.test.unlink_testcase_file(self.test, Path(path))
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}"
187 self.test.logger.debug(
188 f"Generating testcase pg streams decode file: {pg_decode}"
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)
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
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
210 def disable_capture(self):
211 self.test.vapi.cli("%s disable" % self.capture_cli)
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)
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)
223 def add_stream(self, pkts, nb_replays=None, worker=None):
225 Add a stream of packets to this packet-generator
227 :param pkts: iterable packets
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)
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
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"]
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
254 def _get_capture(self, timeout, filter_out_fn=is_ipv6_misc):
255 """Helper method to get capture and filter it"""
257 if not self.wait_for_capture_file(timeout):
259 output = rdpcap(self.out_path)
260 self.test.logger.debug(f"Capture has {len(output.res)} packets")
262 self.test.logger.debug(
263 "Exception in scapy.rdpcap (%s): %s" % (self.out_path, format_exc())
266 before = len(output.res)
268 output.res = [p for p in output.res if not filter_out_fn(p)]
269 removed = before - len(output.res)
271 self.test.logger.debug(
272 "Filtered out %s packets from capture (returning %s)"
273 % (removed, len(output.res))
278 self, expected_count=None, remark=None, timeout=1, filter_out_fn=is_ipv6_misc
280 """Get captured packets
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
291 remaining_time = timeout
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:
300 "Internal error, expected packet count for %s is 0!" % name
302 self.test.logger.debug(
303 "Expecting to capture %s (%s) packets on %s"
304 % (expected_count, based_on, name)
306 while remaining_time > 0:
308 capture = self._get_capture(remaining_time, filter_out_fn)
309 elapsed_time = time.time() - before
311 if len(capture.res) == expected_count:
312 # bingo, got the packets we expected
314 elif len(capture.res) > expected_count:
315 self.test.logger.error(
317 f"Unexpected packets captured, got {len(capture.res)}, expected {expected_count}:",
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)
328 elif expected_count == 0:
329 # bingo, got None as we expected - return empty capture
331 remaining_time -= elapsed_time
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(
338 f"\n({len(capture)} packets captured in total){rem} on {name}",
340 msg = f"Captured packets mismatch, captured {len(capture.res)} packets, expected {expected_count} packets on {name}:"
341 raise Exception(f"{ppc(msg, capture)}")
343 if 0 == expected_count:
345 raise Exception(f"No packets captured on {name} (timeout = {timeout}s)")
347 def assert_nothing_captured(
348 self, timeout=1, remark=None, filter_out_fn=is_ipv6_misc
350 """Assert that nothing unfiltered was captured on interface
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
356 capture = self.get_capture(
357 0, timeout=timeout, remark=remark, filter_out_fn=filter_out_fn
359 if not capture or len(capture.res) == 0:
360 # junk filtered out, we're good
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, ...
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")
377 def wait_for_capture_file(self, timeout=1):
379 Wait until pcap capture file appears
381 :param timeout: How long to wait for the packet (default 1s)
383 :returns: True/False if the file is present or appears within timeout
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))}"
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)
396 while time.time() < deadline:
397 if os.path.isfile(self.out_path):
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))
405 self.test.logger.debug("Timeout - capture file still nowhere")
407 self.link_pcap_file(self.out_path, "out", self.out_history_counter)
410 def verify_enough_packet_data_in_pcap(self):
412 Check if enough data is available in file handled by internal pcap
413 reader so that a whole packet can be read.
415 :returns: True if enough data present, else False
417 orig_pos = self._pcap_reader.f.tell() # save file position
419 # read packet header from pcap
420 packet_header_size = 16
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
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
436 def wait_for_packet(self, timeout, filter_out_fn=is_ipv6_misc):
438 Wait for next packet captured with a timeout
440 :param timeout: How long to wait for the packet
442 :returns: Captured packet if no packet arrived within timeout
443 :raises Exception: if no packet arrives within timeout
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
451 while time.time() < deadline:
453 self._pcap_reader = PcapReader(self.out_path)
456 self.test.logger.debug(
457 "Exception in scapy.PcapReader(%s): %s"
458 % (self.out_path, format_exc())
460 if not self._pcap_reader:
461 raise CaptureTimeoutError(
462 "Capture file %s did not appear within timeout" % self.out_path
467 self.test.logger.debug("Waiting for packet")
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
476 p = self._pcap_reader.recv()
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))
484 self.test.logger.debug(
485 "Packet received after %fs"
486 % (time.time() - (deadline - timeout))
489 self._test.sleep(0) # yield
491 self.test.logger.debug(f"Timeout ({timeout}) - no packets received")
492 raise CaptureTimeoutError(f"Packet didn't arrive within timeout ({timeout})")
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(
499 psrc=self.remote_ip4,
500 hwsrc=self.remote_mac,
503 def create_ndp_req(self, addr=None):
504 """Create NDP - NS applicable for this interface"""
506 addr = self.local_ip6
507 nsma = in6_getnsma(inet_pton(socket.AF_INET6, addr))
508 d = inet_ntop(socket.AF_INET6, nsma)
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)
517 def resolve_arp(self, pg_interface=None):
518 """Resolve ARP using provided packet-generator interface
520 :param pg_interface: interface used to resolve, if None then this
524 if pg_interface is None:
526 self.test.logger.info(
527 "Sending ARP request for %s on port %s"
528 % (self.local_ip4, pg_interface.name)
530 arp_req = self.create_arp_req()
531 pg_interface.add_stream(arp_req)
532 pg_interface.enable_capture()
534 self.test.logger.info(self.test.vapi.cli("show trace"))
536 captured_packet = pg_interface.wait_for_packet(1)
538 self.test.logger.info("No ARP received on port %s" % pg_interface.name)
540 arp_reply = captured_packet.copy() # keep original for exception
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)
546 self._local_mac = arp_reply[ARP].hwsrc
548 self.test.logger.info("No ARP received on port %s" % pg_interface.name)
550 self.test.logger.error(
551 ppp("Unexpected response to ARP request:", captured_packet)
555 def resolve_ndp(self, pg_interface=None, timeout=1, link_layer=False):
556 """Resolve NDP using provided packet-generator interface
558 :param pg_interface: interface used to resolve, if None then this
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
565 if pg_interface is None:
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)
571 ndp_req = self.create_ndp_req(addr)
572 pg_interface.add_stream(ndp_req)
573 pg_interface.enable_capture()
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:
582 captured_packet = pg_interface.wait_for_packet(
583 deadline - now, filter_out_fn=None
586 self.test.logger.error("Timeout while waiting for NDP response")
588 ndp_reply = captured_packet.copy() # keep original for exception
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)
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
600 self.test.logger.info(
601 ppp("Unexpected response to NDP request:", captured_packet)
605 self.test.logger.debug(self.test.vapi.cli("show trace"))
606 raise Exception("Timeout while waiting for NDP response")