4 from socket import inet_pton, inet_ntop
7 from traceback import format_exc, format_stack
9 from config import config
11 from scapy.utils import wrpcap, rdpcap, PcapReader
12 from scapy.plist import PacketList
13 from vpp_interface import VppInterface
14 from vpp_papi import VppEnum
16 from scapy.layers.l2 import Ether, ARP
17 from scapy.layers.inet6 import (
27 from util import ppp, ppc, UnexpectedPacketError
28 from scapy.utils6 import in6_getnsma, in6_getnsmac, in6_ismaddr
31 class CaptureTimeoutError(Exception):
32 """Exception raised if capture or packet doesn't appear within timeout"""
38 """Is packet one of uninteresting IPv6 broadcasts?"""
39 if p.haslayer(ICMPv6ND_RA):
40 if in6_ismaddr(p[IPv6].dst):
42 if p.haslayer(IPv6ExtHdrHopByHop):
43 for o in p[IPv6ExtHdrHopByHop].options:
44 if isinstance(o, RouterAlert):
49 class VppPGInterface(VppInterface):
51 VPP packet-generator interface
56 """packet-generator interface index assigned by VPP"""
60 def gso_enabled(self):
61 """gso enabled on packet-generator interface"""
62 if self._gso_enabled == 0:
68 """gso size on packet-generator interface"""
72 def coalesce_is_enabled(self):
73 """coalesce enabled on packet-generator interface"""
74 if self._coalesce_enabled == 0:
75 return "coalesce-disabled"
76 return "coalesce-enabled"
80 """pcap file path - captured packets"""
83 def get_in_path(self, worker):
84 """pcap file path - injected packets"""
85 if worker is not None:
86 return "%s/pg%u_wrk%u_in.pcap" % (self.test.tempdir, self.pg_index, worker)
87 return "%s/pg%u_in.pcap" % (self.test.tempdir, self.pg_index)
90 def capture_cli(self):
91 """CLI string to start capture on this interface"""
92 return self._capture_cli
94 def get_cap_name(self, worker=None):
95 """return capture name for this interface and given worker"""
96 if worker is not None:
97 return self._cap_name + "-worker%d" % worker
100 def get_input_cli(self, nb_replays=None, worker=None):
101 """return CLI string to load the injected packets"""
102 input_cli = "packet-generator new pcap %s source pg%u name %s" % (
103 self.get_in_path(worker),
105 self.get_cap_name(worker),
107 if nb_replays is not None:
108 return "%s limit %d" % (input_cli, nb_replays)
109 if worker is not None:
110 return "%s worker %d" % (input_cli, worker)
114 def in_history_counter(self):
115 """Self-incrementing counter used when renaming old pcap files"""
116 v = self._in_history_counter
117 self._in_history_counter += 1
121 def out_history_counter(self):
122 """Self-incrementing counter used when renaming old pcap files"""
123 v = self._out_history_counter
124 self._out_history_counter += 1
127 def __init__(self, test, pg_index, gso, gso_size, mode):
128 """Create VPP packet-generator interface"""
129 super().__init__(test)
131 r = test.vapi.pg_create_interface_v2(pg_index, gso, gso_size, mode)
132 self.set_sw_if_index(r.sw_if_index)
134 self._in_history_counter = 0
135 self._out_history_counter = 0
136 self._out_assert_counter = 0
137 self._pg_index = pg_index
138 self._gso_enabled = gso
139 self._gso_size = gso_size
140 self._coalesce_enabled = 0
141 self._out_file = "pg%u_out.pcap" % self.pg_index
142 self._out_path = self.test.tempdir + "/" + self._out_file
143 self._capture_cli = "packet-generator capture pg%u pcap %s" % (
147 self._cap_name = "pcap%u-sw_if_index-%s" % (self.pg_index, self.sw_if_index)
149 def handle_old_pcap_file(self, path, counter):
150 filename = os.path.basename(path)
152 if not config.keep_pcaps:
154 self.test.logger.debug(f"Removing {path}")
157 self.test.logger.debug(f"OSError: Could not remove {path}")
163 if os.path.isfile(path):
164 name = "%s/history.[timestamp:%f].[%s-counter:%04d].%s" % (
171 self.test.logger.debug("Renaming %s->%s" % (path, name))
172 shutil.move(path, name)
174 self.test.logger.debug("OSError: Could not rename %s %s" % (path, filename))
176 def enable_capture(self):
177 """Enable capture on this packet-generator interface
178 of at most n packets.
179 If n < 0, this is no limit
181 # disable the capture to flush the capture
182 self.disable_capture()
183 self.handle_old_pcap_file(self.out_path, self.out_history_counter)
184 # FIXME this should be an API, but no such exists atm
185 self.test.vapi.cli(self.capture_cli)
186 self._pcap_reader = None
188 def disable_capture(self):
189 self.test.vapi.cli("%s disable" % self.capture_cli)
191 def coalesce_enable(self):
192 """Enable packet coalesce on this packet-generator interface"""
193 self._coalesce_enabled = 1
194 self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index, 1)
196 def coalesce_disable(self):
197 """Disable packet coalesce on this packet-generator interface"""
198 self._coalesce_enabled = 0
199 self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index, 0)
201 def add_stream(self, pkts, nb_replays=None, worker=None):
203 Add a stream of packets to this packet-generator
205 :param pkts: iterable packets
208 wrpcap(self.get_in_path(worker), pkts)
209 self.test.register_pcap(self, worker)
210 # FIXME this should be an API, but no such exists atm
211 self.test.vapi.cli(self.get_input_cli(nb_replays, worker))
213 def generate_debug_aid(self, kind):
214 """Create a hardlink to the out file with a counter and a file
215 containing stack trace to ease debugging in case of multiple capture
217 self.test.logger.debug("Generating debug aid for %s on %s" % (kind, self._name))
218 link_path, stack_path = [
219 "%s/debug_%s_%s_%s.%s"
220 % (self.test.tempdir, self._name, self._out_assert_counter, kind, suffix)
221 for suffix in ["pcap", "stack"]
223 os.link(self.out_path, link_path)
224 with open(stack_path, "w") as f:
225 f.writelines(format_stack())
226 self._out_assert_counter += 1
228 def _get_capture(self, timeout, filter_out_fn=is_ipv6_misc):
229 """Helper method to get capture and filter it"""
231 if not self.wait_for_capture_file(timeout):
233 output = rdpcap(self.out_path)
234 self.test.logger.debug("Capture has %s packets" % len(output.res))
236 self.test.logger.debug(
237 "Exception in scapy.rdpcap (%s): %s" % (self.out_path, format_exc())
240 before = len(output.res)
242 output.res = [p for p in output.res if not filter_out_fn(p)]
243 removed = before - len(output.res)
245 self.test.logger.debug(
246 "Filtered out %s packets from capture (returning %s)"
247 % (removed, len(output.res))
252 self, expected_count=None, remark=None, timeout=1, filter_out_fn=is_ipv6_misc
254 """Get captured packets
256 :param expected_count: expected number of packets to capture, if None,
257 then self.test.packet_count_for_dst_pg_idx is
258 used to lookup the expected count
259 :param remark: remark printed into debug logs
260 :param timeout: how long to wait for packets
261 :param filter_out_fn: filter applied to each packet, packets for which
262 the filter returns True are removed from capture
263 :returns: iterable packets
265 remaining_time = timeout
267 name = self.name if remark is None else "%s (%s)" % (self.name, remark)
268 based_on = "based on provided argument"
269 if expected_count is None:
270 expected_count = self.test.get_packet_count_for_if_idx(self.sw_if_index)
271 based_on = "based on stored packet_infos"
272 if expected_count == 0:
274 "Internal error, expected packet count for %s is 0!" % name
276 self.test.logger.debug(
277 "Expecting to capture %s (%s) packets on %s"
278 % (expected_count, based_on, name)
280 while remaining_time > 0:
282 capture = self._get_capture(remaining_time, filter_out_fn)
283 elapsed_time = time.time() - before
285 if len(capture.res) == expected_count:
286 # bingo, got the packets we expected
288 elif len(capture.res) > expected_count:
289 self.test.logger.error(ppc("Unexpected packets captured:", capture))
292 self.test.logger.debug(
293 "Partial capture containing %s "
294 "packets doesn't match expected "
295 "count %s (yet?)" % (len(capture.res), expected_count)
297 elif expected_count == 0:
298 # bingo, got None as we expected - return empty capture
300 remaining_time -= elapsed_time
302 self.generate_debug_aid("count-mismatch")
303 if len(capture) > 0 and 0 == expected_count:
304 rem = f"\n{remark}" if remark else ""
305 raise UnexpectedPacketError(
306 capture[0], f"\n({len(capture)} packets captured in total){rem}"
309 "Captured packets mismatch, captured %s packets, "
310 "expected %s packets on %s" % (len(capture.res), expected_count, name)
313 if 0 == expected_count:
315 raise Exception("No packets captured on %s" % name)
317 def assert_nothing_captured(
318 self, timeout=1, remark=None, filter_out_fn=is_ipv6_misc
320 """Assert that nothing unfiltered was captured on interface
322 :param remark: remark printed into debug logs
323 :param filter_out_fn: filter applied to each packet, packets for which
324 the filter returns True are removed from capture
326 capture = self.get_capture(
327 0, timeout=timeout, remark=remark, filter_out_fn=filter_out_fn
329 if not capture or len(capture.res) == 0:
330 # junk filtered out, we're good
333 def wait_for_pg_stop(self):
334 # wait till packet-generator is stopped
335 # "show packet-generator" while it is still running gives this:
336 # Name Enabled Count Parameters
337 # pcap0-sw_if_inde Yes 64 limit 64, ...
339 # also have a 5-minute timeout just in case things go terribly wrong...
340 deadline = time.time() + 300
341 while self.test.vapi.cli("show packet-generator").find("Yes") != -1:
342 self._test.sleep(0.01) # yield
343 if time.time() > deadline:
344 self.test.logger.debug("Timeout waiting for pg to stop")
347 def wait_for_capture_file(self, timeout=1):
349 Wait until pcap capture file appears
351 :param timeout: How long to wait for the packet (default 1s)
353 :returns: True/False if the file is present or appears within timeout
355 self.wait_for_pg_stop()
356 deadline = time.time() + timeout
357 if not os.path.isfile(self.out_path):
358 self.test.logger.debug(
359 "Waiting for capture file %s to appear, "
360 "timeout is %ss" % (self.out_path, timeout)
363 self.test.logger.debug("Capture file %s already exists" % self.out_path)
365 while time.time() < deadline:
366 if os.path.isfile(self.out_path):
368 self._test.sleep(0) # yield
369 if os.path.isfile(self.out_path):
370 self.test.logger.debug(
371 "Capture file appeared after %fs" % (time.time() - (deadline - timeout))
374 self.test.logger.debug("Timeout - capture file still nowhere")
378 def verify_enough_packet_data_in_pcap(self):
380 Check if enough data is available in file handled by internal pcap
381 reader so that a whole packet can be read.
383 :returns: True if enough data present, else False
385 orig_pos = self._pcap_reader.f.tell() # save file position
387 # read packet header from pcap
388 packet_header_size = 16
391 hdr = self._pcap_reader.f.read(packet_header_size)
392 if len(hdr) == packet_header_size:
393 # parse the capture length - caplen
394 sec, usec, caplen, wirelen = struct.unpack(
395 self._pcap_reader.endian + "IIII", hdr
397 self._pcap_reader.f.seek(0, 2) # seek to end of file
398 end_pos = self._pcap_reader.f.tell() # get position at end
399 if end_pos >= orig_pos + len(hdr) + caplen:
400 enough_data = True # yay, we have enough data
401 self._pcap_reader.f.seek(orig_pos, 0) # restore original position
404 def wait_for_packet(self, timeout, filter_out_fn=is_ipv6_misc):
406 Wait for next packet captured with a timeout
408 :param timeout: How long to wait for the packet
410 :returns: Captured packet if no packet arrived within timeout
411 :raises Exception: if no packet arrives within timeout
413 deadline = time.time() + timeout
414 if self._pcap_reader is None:
415 if not self.wait_for_capture_file(timeout):
416 raise CaptureTimeoutError(
417 "Capture file %s did not appear within timeout" % self.out_path
419 while time.time() < deadline:
421 self._pcap_reader = PcapReader(self.out_path)
424 self.test.logger.debug(
425 "Exception in scapy.PcapReader(%s): %s"
426 % (self.out_path, format_exc())
428 if not self._pcap_reader:
429 raise CaptureTimeoutError(
430 "Capture file %s did not appear within timeout" % self.out_path
435 self.test.logger.debug("Waiting for packet")
438 self.test.logger.debug("Polling for packet")
439 while time.time() < deadline or poll:
440 if not self.verify_enough_packet_data_in_pcap():
441 self._test.sleep(0) # yield
444 p = self._pcap_reader.recv()
446 if filter_out_fn is not None and filter_out_fn(p):
447 self.test.logger.debug(
448 "Packet received after %ss was filtered out"
449 % (time.time() - (deadline - timeout))
452 self.test.logger.debug(
453 "Packet received after %fs"
454 % (time.time() - (deadline - timeout))
457 self._test.sleep(0) # yield
459 self.test.logger.debug("Timeout - no packets received")
460 raise CaptureTimeoutError("Packet didn't arrive within timeout")
462 def create_arp_req(self):
463 """Create ARP request applicable for this interface"""
464 return Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) / ARP(
467 psrc=self.remote_ip4,
468 hwsrc=self.remote_mac,
471 def create_ndp_req(self, addr=None):
472 """Create NDP - NS applicable for this interface"""
474 addr = self.local_ip6
475 nsma = in6_getnsma(inet_pton(socket.AF_INET6, addr))
476 d = inet_ntop(socket.AF_INET6, nsma)
479 Ether(dst=in6_getnsmac(nsma))
480 / IPv6(dst=d, src=self.remote_ip6)
481 / ICMPv6ND_NS(tgt=addr)
482 / ICMPv6NDOptSrcLLAddr(lladdr=self.remote_mac)
485 def resolve_arp(self, pg_interface=None):
486 """Resolve ARP using provided packet-generator interface
488 :param pg_interface: interface used to resolve, if None then this
492 if pg_interface is None:
494 self.test.logger.info(
495 "Sending ARP request for %s on port %s"
496 % (self.local_ip4, pg_interface.name)
498 arp_req = self.create_arp_req()
499 pg_interface.add_stream(arp_req)
500 pg_interface.enable_capture()
502 self.test.logger.info(self.test.vapi.cli("show trace"))
504 captured_packet = pg_interface.wait_for_packet(1)
506 self.test.logger.info("No ARP received on port %s" % pg_interface.name)
508 arp_reply = captured_packet.copy() # keep original for exception
510 if arp_reply[ARP].op == ARP.is_at:
511 self.test.logger.info(
512 "VPP %s MAC address is %s " % (self.name, arp_reply[ARP].hwsrc)
514 self._local_mac = arp_reply[ARP].hwsrc
516 self.test.logger.info("No ARP received on port %s" % pg_interface.name)
518 self.test.logger.error(
519 ppp("Unexpected response to ARP request:", captured_packet)
523 def resolve_ndp(self, pg_interface=None, timeout=1, link_layer=False):
524 """Resolve NDP using provided packet-generator interface
526 :param pg_interface: interface used to resolve, if None then this
528 :param timeout: how long to wait for response before giving up
529 :param link_layer: resolve for global address if False (default)
530 or for link-layer address if True
533 if pg_interface is None:
535 addr = self.local_ip6_ll if link_layer else self.local_ip6
536 self.test.logger.info(
537 "Sending NDP request for %s on port %s" % (addr, pg_interface.name)
539 ndp_req = self.create_ndp_req(addr)
540 pg_interface.add_stream(ndp_req)
541 pg_interface.enable_capture()
544 deadline = now + timeout
545 # Enabling IPv6 on an interface can generate more than the
546 # ND reply we are looking for (namely MLD). So loop through
547 # the replies to look for want we want.
548 while now < deadline:
550 captured_packet = pg_interface.wait_for_packet(
551 deadline - now, filter_out_fn=None
554 self.test.logger.error("Timeout while waiting for NDP response")
556 ndp_reply = captured_packet.copy() # keep original for exception
558 ndp_na = ndp_reply[ICMPv6ND_NA]
559 opt = ndp_na[ICMPv6NDOptDstLLAddr]
560 self.test.logger.info(
561 "VPP %s MAC address is %s " % (self.name, opt.lladdr)
563 self._local_mac = opt.lladdr
564 self.test.logger.debug(self.test.vapi.cli("show trace"))
565 # we now have the MAC we've been after
568 self.test.logger.info(
569 ppp("Unexpected response to NDP request:", captured_packet)
573 self.test.logger.debug(self.test.vapi.cli("show trace"))
574 raise Exception("Timeout while waiting for NDP response")