3 from socket import inet_pton, inet_ntop
6 from traceback import format_exc, format_stack
8 from config import config
10 from scapy.utils import wrpcap, rdpcap, PcapReader
11 from scapy.plist import PacketList
12 from vpp_interface import VppInterface
13 from vpp_papi import VppEnum
15 from scapy.layers.l2 import Ether, ARP
16 from scapy.layers.inet6 import IPv6, ICMPv6ND_NS, ICMPv6ND_NA,\
17 ICMPv6NDOptSrcLLAddr, ICMPv6NDOptDstLLAddr, ICMPv6ND_RA, RouterAlert, \
19 from util import ppp, ppc, UnexpectedPacketError
20 from scapy.utils6 import in6_getnsma, in6_getnsmac, in6_ismaddr
23 class CaptureTimeoutError(Exception):
24 """ Exception raised if capture or packet doesn't appear within timeout """
29 """ Is packet one of uninteresting IPv6 broadcasts? """
30 if p.haslayer(ICMPv6ND_RA):
31 if in6_ismaddr(p[IPv6].dst):
33 if p.haslayer(IPv6ExtHdrHopByHop):
34 for o in p[IPv6ExtHdrHopByHop].options:
35 if isinstance(o, RouterAlert):
40 class VppPGInterface(VppInterface):
42 VPP packet-generator interface
47 """packet-generator interface index assigned by VPP"""
51 def gso_enabled(self):
52 """gso enabled on packet-generator interface"""
53 if self._gso_enabled == 0:
59 """gso size on packet-generator interface"""
63 def coalesce_is_enabled(self):
64 """coalesce enabled on packet-generator interface"""
65 if self._coalesce_enabled == 0:
66 return "coalesce-disabled"
67 return "coalesce-enabled"
71 """pcap file path - captured packets"""
74 def get_in_path(self, worker):
75 """ pcap file path - injected packets"""
76 if worker is not None:
77 return "%s/pg%u_wrk%u_in.pcap" % (self.test.tempdir, self.pg_index,
79 return "%s/pg%u_in.pcap" % (self.test.tempdir, self.pg_index)
82 def capture_cli(self):
83 """CLI string to start capture on this interface"""
84 return self._capture_cli
86 def get_cap_name(self, worker=None):
87 """return capture name for this interface and given worker"""
88 if worker is not None:
89 return self._cap_name + "-worker%d" % worker
92 def get_input_cli(self, nb_replays=None, worker=None):
93 """return CLI string to load the injected packets"""
94 input_cli = "packet-generator new pcap %s source pg%u name %s" % (
95 self.get_in_path(worker), self.pg_index, self.get_cap_name(worker))
96 if nb_replays is not None:
97 return "%s limit %d" % (input_cli, nb_replays)
98 if worker is not None:
99 return "%s worker %d" % (input_cli, worker)
103 def in_history_counter(self):
104 """Self-incrementing counter used when renaming old pcap files"""
105 v = self._in_history_counter
106 self._in_history_counter += 1
110 def out_history_counter(self):
111 """Self-incrementing counter used when renaming old pcap files"""
112 v = self._out_history_counter
113 self._out_history_counter += 1
116 def __init__(self, test, pg_index, gso, gso_size, mode):
117 """ Create VPP packet-generator interface """
118 super().__init__(test)
120 r = test.vapi.pg_create_interface_v2(pg_index, gso, gso_size, mode)
121 self.set_sw_if_index(r.sw_if_index)
123 self._in_history_counter = 0
124 self._out_history_counter = 0
125 self._out_assert_counter = 0
126 self._pg_index = pg_index
127 self._gso_enabled = gso
128 self._gso_size = gso_size
129 self._coalesce_enabled = 0
130 self._out_file = "pg%u_out.pcap" % self.pg_index
131 self._out_path = self.test.tempdir + "/" + self._out_file
132 self._capture_cli = "packet-generator capture pg%u pcap %s" % (
133 self.pg_index, self.out_path)
134 self._cap_name = "pcap%u-sw_if_index-%s" % (
135 self.pg_index, self.sw_if_index)
137 def handle_old_pcap_file(self, path, counter):
138 filename = os.path.basename(path)
140 if not config.keep_pcaps:
142 self.test.logger.debug(f"Removing {path}")
145 self.test.logger.debug(f"OSError: Could not remove {path}")
151 if os.path.isfile(path):
152 name = "%s/history.[timestamp:%f].[%s-counter:%04d].%s" % \
158 self.test.logger.debug("Renaming %s->%s" % (path, name))
159 os.rename(path, name)
161 self.test.logger.debug("OSError: Could not rename %s %s" %
164 def enable_capture(self):
165 """ Enable capture on this packet-generator interface
166 of at most n packets.
167 If n < 0, this is no limit
169 # disable the capture to flush the capture
170 self.disable_capture()
171 self.handle_old_pcap_file(self.out_path, self.out_history_counter)
172 # FIXME this should be an API, but no such exists atm
173 self.test.vapi.cli(self.capture_cli)
174 self._pcap_reader = None
176 def disable_capture(self):
177 self.test.vapi.cli("%s disable" % self.capture_cli)
179 def coalesce_enable(self):
180 """ Enable packet coalesce on this packet-generator interface"""
181 self._coalesce_enabled = 1
182 self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index,
185 def coalesce_disable(self):
186 """ Disable packet coalesce on this packet-generator interface"""
187 self._coalesce_enabled = 0
188 self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index,
191 def add_stream(self, pkts, nb_replays=None, worker=None):
193 Add a stream of packets to this packet-generator
195 :param pkts: iterable packets
198 wrpcap(self.get_in_path(worker), pkts)
199 self.test.register_pcap(self, worker)
200 # FIXME this should be an API, but no such exists atm
201 self.test.vapi.cli(self.get_input_cli(nb_replays, worker))
203 def generate_debug_aid(self, kind):
204 """ Create a hardlink to the out file with a counter and a file
205 containing stack trace to ease debugging in case of multiple capture
207 self.test.logger.debug("Generating debug aid for %s on %s" %
209 link_path, stack_path = ["%s/debug_%s_%s_%s.%s" %
210 (self.test.tempdir, self._name,
211 self._out_assert_counter, kind, suffix)
212 for suffix in ["pcap", "stack"]
214 os.link(self.out_path, link_path)
215 with open(stack_path, "w") as f:
216 f.writelines(format_stack())
217 self._out_assert_counter += 1
219 def _get_capture(self, timeout, filter_out_fn=is_ipv6_misc):
220 """ Helper method to get capture and filter it """
222 if not self.wait_for_capture_file(timeout):
224 output = rdpcap(self.out_path)
225 self.test.logger.debug("Capture has %s packets" % len(output.res))
227 self.test.logger.debug("Exception in scapy.rdpcap (%s): %s" %
228 (self.out_path, format_exc()))
230 before = len(output.res)
232 output.res = [p for p in output.res if not filter_out_fn(p)]
233 removed = before - len(output.res)
235 self.test.logger.debug(
236 "Filtered out %s packets from capture (returning %s)" %
237 (removed, len(output.res)))
240 def get_capture(self, expected_count=None, remark=None, timeout=1,
241 filter_out_fn=is_ipv6_misc):
242 """ Get captured packets
244 :param expected_count: expected number of packets to capture, if None,
245 then self.test.packet_count_for_dst_pg_idx is
246 used to lookup the expected count
247 :param remark: remark printed into debug logs
248 :param timeout: how long to wait for packets
249 :param filter_out_fn: filter applied to each packet, packets for which
250 the filter returns True are removed from capture
251 :returns: iterable packets
253 remaining_time = timeout
255 name = self.name if remark is None else "%s (%s)" % (self.name, remark)
256 based_on = "based on provided argument"
257 if expected_count is None:
259 self.test.get_packet_count_for_if_idx(self.sw_if_index)
260 based_on = "based on stored packet_infos"
261 if expected_count == 0:
263 "Internal error, expected packet count for %s is 0!" %
265 self.test.logger.debug("Expecting to capture %s (%s) packets on %s" % (
266 expected_count, based_on, name))
267 while remaining_time > 0:
269 capture = self._get_capture(remaining_time, filter_out_fn)
270 elapsed_time = time.time() - before
272 if len(capture.res) == expected_count:
273 # bingo, got the packets we expected
275 elif len(capture.res) > expected_count:
276 self.test.logger.error(
277 ppc("Unexpected packets captured:", capture))
280 self.test.logger.debug("Partial capture containing %s "
281 "packets doesn't match expected "
283 (len(capture.res), expected_count))
284 elif expected_count == 0:
285 # bingo, got None as we expected - return empty capture
287 remaining_time -= elapsed_time
289 self.generate_debug_aid("count-mismatch")
290 if len(capture) > 0 and 0 == expected_count:
291 rem = f"\n{remark}" if remark else ""
292 raise UnexpectedPacketError(
294 f"\n({len(capture)} packets captured in total){rem}")
295 raise Exception("Captured packets mismatch, captured %s packets, "
296 "expected %s packets on %s" %
297 (len(capture.res), expected_count, name))
299 raise Exception("No packets captured on %s" % name)
301 def assert_nothing_captured(self, timeout=1, remark=None,
302 filter_out_fn=is_ipv6_misc):
303 """ Assert that nothing unfiltered was captured on interface
305 :param remark: remark printed into debug logs
306 :param filter_out_fn: filter applied to each packet, packets for which
307 the filter returns True are removed from capture
309 if os.path.isfile(self.out_path):
311 capture = self.get_capture(
312 0, timeout=timeout, remark=remark,
313 filter_out_fn=filter_out_fn)
314 if not capture or len(capture.res) == 0:
315 # junk filtered out, we're good
319 self.generate_debug_aid("empty-assert")
321 raise UnexpectedPacketError(
323 f" ({len(capture)} packets captured in total) ({remark})")
325 raise UnexpectedPacketError(
326 capture[0], f" ({len(capture)} packets captured in total)")
328 def wait_for_pg_stop(self):
329 # wait till packet-generator is stopped
330 # "show packet-generator" while it is still running gives this:
331 # Name Enabled Count Parameters
332 # pcap0-sw_if_inde Yes 64 limit 64, ...
334 # also have a 5-minute timeout just in case things go terribly wrong...
335 deadline = time.time() + 300
336 while self.test.vapi.cli('show packet-generator').find("Yes") != -1:
337 self._test.sleep(0.01) # yield
338 if time.time() > deadline:
339 self.test.logger.debug("Timeout waiting for pg to stop")
342 def wait_for_capture_file(self, timeout=1):
344 Wait until pcap capture file appears
346 :param timeout: How long to wait for the packet (default 1s)
348 :returns: True/False if the file is present or appears within timeout
350 self.wait_for_pg_stop()
351 deadline = time.time() + timeout
352 if not os.path.isfile(self.out_path):
353 self.test.logger.debug("Waiting for capture file %s to appear, "
354 "timeout is %ss" % (self.out_path, timeout))
356 self.test.logger.debug("Capture file %s already exists" %
359 while time.time() < deadline:
360 if os.path.isfile(self.out_path):
362 self._test.sleep(0) # yield
363 if os.path.isfile(self.out_path):
364 self.test.logger.debug("Capture file appeared after %fs" %
365 (time.time() - (deadline - timeout)))
367 self.test.logger.debug("Timeout - capture file still nowhere")
371 def verify_enough_packet_data_in_pcap(self):
373 Check if enough data is available in file handled by internal pcap
374 reader so that a whole packet can be read.
376 :returns: True if enough data present, else False
378 orig_pos = self._pcap_reader.f.tell() # save file position
380 # read packet header from pcap
381 packet_header_size = 16
384 hdr = self._pcap_reader.f.read(packet_header_size)
385 if len(hdr) == packet_header_size:
386 # parse the capture length - caplen
387 sec, usec, caplen, wirelen = struct.unpack(
388 self._pcap_reader.endian + "IIII", hdr)
389 self._pcap_reader.f.seek(0, 2) # seek to end of file
390 end_pos = self._pcap_reader.f.tell() # get position at end
391 if end_pos >= orig_pos + len(hdr) + caplen:
392 enough_data = True # yay, we have enough data
393 self._pcap_reader.f.seek(orig_pos, 0) # restore original position
396 def wait_for_packet(self, timeout, filter_out_fn=is_ipv6_misc):
398 Wait for next packet captured with a timeout
400 :param timeout: How long to wait for the packet
402 :returns: Captured packet if no packet arrived within timeout
403 :raises Exception: if no packet arrives within timeout
405 deadline = time.time() + timeout
406 if self._pcap_reader is None:
407 if not self.wait_for_capture_file(timeout):
408 raise CaptureTimeoutError("Capture file %s did not appear "
409 "within timeout" % self.out_path)
410 while time.time() < deadline:
412 self._pcap_reader = PcapReader(self.out_path)
415 self.test.logger.debug(
416 "Exception in scapy.PcapReader(%s): %s" %
417 (self.out_path, format_exc()))
418 if not self._pcap_reader:
419 raise CaptureTimeoutError("Capture file %s did not appear within "
420 "timeout" % self.out_path)
424 self.test.logger.debug("Waiting for packet")
427 self.test.logger.debug("Polling for packet")
428 while time.time() < deadline or poll:
429 if not self.verify_enough_packet_data_in_pcap():
430 self._test.sleep(0) # yield
433 p = self._pcap_reader.recv()
435 if filter_out_fn is not None and filter_out_fn(p):
436 self.test.logger.debug(
437 "Packet received after %ss was filtered out" %
438 (time.time() - (deadline - timeout)))
440 self.test.logger.debug(
441 "Packet received after %fs" %
442 (time.time() - (deadline - timeout)))
444 self._test.sleep(0) # yield
446 self.test.logger.debug("Timeout - no packets received")
447 raise CaptureTimeoutError("Packet didn't arrive within timeout")
449 def create_arp_req(self):
450 """Create ARP request applicable for this interface"""
451 return (Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) /
452 ARP(op=ARP.who_has, pdst=self.local_ip4,
453 psrc=self.remote_ip4, hwsrc=self.remote_mac))
455 def create_ndp_req(self, addr=None):
456 """Create NDP - NS applicable for this interface"""
458 addr = self.local_ip6
459 nsma = in6_getnsma(inet_pton(socket.AF_INET6, addr))
460 d = inet_ntop(socket.AF_INET6, nsma)
462 return (Ether(dst=in6_getnsmac(nsma)) /
463 IPv6(dst=d, src=self.remote_ip6) /
464 ICMPv6ND_NS(tgt=addr) /
465 ICMPv6NDOptSrcLLAddr(lladdr=self.remote_mac))
467 def resolve_arp(self, pg_interface=None):
468 """Resolve ARP using provided packet-generator interface
470 :param pg_interface: interface used to resolve, if None then this
474 if pg_interface is None:
476 self.test.logger.info("Sending ARP request for %s on port %s" %
477 (self.local_ip4, pg_interface.name))
478 arp_req = self.create_arp_req()
479 pg_interface.add_stream(arp_req)
480 pg_interface.enable_capture()
482 self.test.logger.info(self.test.vapi.cli("show trace"))
484 captured_packet = pg_interface.wait_for_packet(1)
486 self.test.logger.info("No ARP received on port %s" %
489 arp_reply = captured_packet.copy() # keep original for exception
491 if arp_reply[ARP].op == ARP.is_at:
492 self.test.logger.info("VPP %s MAC address is %s " %
493 (self.name, arp_reply[ARP].hwsrc))
494 self._local_mac = arp_reply[ARP].hwsrc
496 self.test.logger.info("No ARP received on port %s" %
499 self.test.logger.error(
500 ppp("Unexpected response to ARP request:", captured_packet))
503 def resolve_ndp(self, pg_interface=None, timeout=1, link_layer=False):
504 """Resolve NDP using provided packet-generator interface
506 :param pg_interface: interface used to resolve, if None then this
508 :param timeout: how long to wait for response before giving up
509 :param link_layer: resolve for global address if False (default)
510 or for link-layer address if True
513 if pg_interface is None:
515 addr = self.local_ip6_ll if link_layer else self.local_ip6
516 self.test.logger.info("Sending NDP request for %s on port %s" %
517 (addr, pg_interface.name))
518 ndp_req = self.create_ndp_req(addr)
519 pg_interface.add_stream(ndp_req)
520 pg_interface.enable_capture()
523 deadline = now + timeout
524 # Enabling IPv6 on an interface can generate more than the
525 # ND reply we are looking for (namely MLD). So loop through
526 # the replies to look for want we want.
527 while now < deadline:
529 captured_packet = pg_interface.wait_for_packet(
530 deadline - now, filter_out_fn=None)
532 self.test.logger.error(
533 "Timeout while waiting for NDP response")
535 ndp_reply = captured_packet.copy() # keep original for exception
537 ndp_na = ndp_reply[ICMPv6ND_NA]
538 opt = ndp_na[ICMPv6NDOptDstLLAddr]
539 self.test.logger.info("VPP %s MAC address is %s " %
540 (self.name, opt.lladdr))
541 self._local_mac = opt.lladdr
542 self.test.logger.debug(self.test.vapi.cli("show trace"))
543 # we now have the MAC we've been after
546 self.test.logger.info(
547 ppp("Unexpected response to NDP request:",
551 self.test.logger.debug(self.test.vapi.cli("show trace"))
552 raise Exception("Timeout while waiting for NDP response")