3 from socket import inet_pton, inet_ntop
6 from traceback import format_exc, format_stack
9 from scapy.utils import wrpcap, rdpcap, PcapReader
10 from scapy.plist import PacketList
11 from vpp_interface import VppInterface
13 from scapy.layers.l2 import Ether, ARP
14 from scapy.layers.inet6 import IPv6, ICMPv6ND_NS, ICMPv6ND_NA,\
15 ICMPv6NDOptSrcLLAddr, ICMPv6NDOptDstLLAddr, ICMPv6ND_RA, RouterAlert, \
17 from util import ppp, ppc
18 from scapy.utils6 import in6_getnsma, in6_getnsmac, in6_ismaddr
21 class CaptureTimeoutError(Exception):
22 """ Exception raised if capture or packet doesn't appear within timeout """
27 """ Is packet one of uninteresting IPv6 broadcasts? """
28 if p.haslayer(ICMPv6ND_RA):
29 if in6_ismaddr(p[IPv6].dst):
31 if p.haslayer(IPv6ExtHdrHopByHop):
32 for o in p[IPv6ExtHdrHopByHop].options:
33 if isinstance(o, RouterAlert):
38 class VppPGInterface(VppInterface):
40 VPP packet-generator interface
45 """packet-generator interface index assigned by VPP"""
49 def gso_enabled(self):
50 """gso enabled on packet-generator interface"""
51 if self._gso_enabled == 0:
57 """gso size on packet-generator interface"""
61 def coalesce_is_enabled(self):
62 """coalesce enabled on packet-generator interface"""
63 if self._coalesce_enabled == 0:
64 return "coalesce-disabled"
65 return "coalesce-enabled"
69 """pcap file path - captured packets"""
72 def get_in_path(self, worker):
73 """ pcap file path - injected packets"""
74 if worker is not None:
75 return "%s/pg%u_wrk%u_in.pcap" % (self.test.tempdir, self.pg_index,
77 return "%s/pg%u_in.pcap" % (self.test.tempdir, self.pg_index)
80 def capture_cli(self):
81 """CLI string to start capture on this interface"""
82 return self._capture_cli
84 def get_cap_name(self, worker=None):
85 """return capture name for this interface and given worker"""
86 if worker is not None:
87 return self._cap_name + "-worker%d" % worker
90 def get_input_cli(self, nb_replays=None, worker=None):
91 """return CLI string to load the injected packets"""
92 input_cli = "packet-generator new pcap %s source pg%u name %s" % (
93 self.get_in_path(worker), self.pg_index, self.get_cap_name(worker))
94 if nb_replays is not None:
95 return "%s limit %d" % (input_cli, nb_replays)
96 if worker is not None:
97 return "%s worker %d" % (input_cli, worker)
101 def in_history_counter(self):
102 """Self-incrementing counter used when renaming old pcap files"""
103 v = self._in_history_counter
104 self._in_history_counter += 1
108 def out_history_counter(self):
109 """Self-incrementing counter used when renaming old pcap files"""
110 v = self._out_history_counter
111 self._out_history_counter += 1
114 def __init__(self, test, pg_index, gso, gso_size):
115 """ Create VPP packet-generator interface """
116 super().__init__(test)
118 r = test.vapi.pg_create_interface(pg_index, gso, gso_size)
119 self.set_sw_if_index(r.sw_if_index)
121 self._in_history_counter = 0
122 self._out_history_counter = 0
123 self._out_assert_counter = 0
124 self._pg_index = pg_index
125 self._gso_enabled = gso
126 self._gso_size = gso_size
127 self._coalesce_enabled = 0
128 self._out_file = "pg%u_out.pcap" % self.pg_index
129 self._out_path = self.test.tempdir + "/" + self._out_file
130 self._capture_cli = "packet-generator capture pg%u pcap %s" % (
131 self.pg_index, self.out_path)
132 self._cap_name = "pcap%u-sw_if_index-%s" % (
133 self.pg_index, self.sw_if_index)
135 def rename_previous_capture_file(self, path, counter):
136 # if a file from a previous capture exists, rename it.
137 filename = os.path.basename(path)
139 if os.path.isfile(path):
140 name = "%s/history.[timestamp:%f].[%s-counter:%04d].%s" % \
146 self.test.logger.debug("Renaming %s->%s" %
148 os.rename(path, name)
150 self.test.logger.debug("OSError: Could not rename %s %s" %
153 def enable_capture(self):
154 """ Enable capture on this packet-generator interface
155 of at most n packets.
156 If n < 0, this is no limit
158 # disable the capture to flush the capture
159 self.disable_capture()
160 self.rename_previous_capture_file(self.out_path,
161 self.out_history_counter)
162 # FIXME this should be an API, but no such exists atm
163 self.test.vapi.cli(self.capture_cli)
164 self._pcap_reader = None
166 def disable_capture(self):
167 self.test.vapi.cli("%s disable" % self.capture_cli)
169 def coalesce_enable(self):
170 """ Enable packet coalesce on this packet-generator interface"""
171 self._coalesce_enabled = 1
172 self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index,
175 def coalesce_disable(self):
176 """ Disable packet coalesce on this packet-generator interface"""
177 self._coalesce_enabled = 0
178 self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index,
181 def add_stream(self, pkts, nb_replays=None, worker=None):
183 Add a stream of packets to this packet-generator
185 :param pkts: iterable packets
188 wrpcap(self.get_in_path(worker), pkts)
189 self.test.register_capture(self, worker)
190 # FIXME this should be an API, but no such exists atm
191 self.test.vapi.cli(self.get_input_cli(nb_replays, worker))
193 def generate_debug_aid(self, kind):
194 """ Create a hardlink to the out file with a counter and a file
195 containing stack trace to ease debugging in case of multiple capture
197 self.test.logger.debug("Generating debug aid for %s on %s" %
199 link_path, stack_path = ["%s/debug_%s_%s_%s.%s" %
200 (self.test.tempdir, self._name,
201 self._out_assert_counter, kind, suffix)
202 for suffix in ["pcap", "stack"]
204 os.link(self.out_path, link_path)
205 with open(stack_path, "w") as f:
206 f.writelines(format_stack())
207 self._out_assert_counter += 1
209 def _get_capture(self, timeout, filter_out_fn=is_ipv6_misc):
210 """ Helper method to get capture and filter it """
212 if not self.wait_for_capture_file(timeout):
214 output = rdpcap(self.out_path)
215 self.test.logger.debug("Capture has %s packets" % len(output.res))
217 self.test.logger.debug("Exception in scapy.rdpcap (%s): %s" %
218 (self.out_path, format_exc()))
220 before = len(output.res)
222 output.res = [p for p in output.res if not filter_out_fn(p)]
223 removed = before - len(output.res)
225 self.test.logger.debug(
226 "Filtered out %s packets from capture (returning %s)" %
227 (removed, len(output.res)))
230 def get_capture(self, expected_count=None, remark=None, timeout=1,
231 filter_out_fn=is_ipv6_misc):
232 """ Get captured packets
234 :param expected_count: expected number of packets to capture, if None,
235 then self.test.packet_count_for_dst_pg_idx is
236 used to lookup the expected count
237 :param remark: remark printed into debug logs
238 :param timeout: how long to wait for packets
239 :param filter_out_fn: filter applied to each packet, packets for which
240 the filter returns True are removed from capture
241 :returns: iterable packets
243 remaining_time = timeout
245 name = self.name if remark is None else "%s (%s)" % (self.name, remark)
246 based_on = "based on provided argument"
247 if expected_count is None:
249 self.test.get_packet_count_for_if_idx(self.sw_if_index)
250 based_on = "based on stored packet_infos"
251 if expected_count == 0:
253 "Internal error, expected packet count for %s is 0!" %
255 self.test.logger.debug("Expecting to capture %s (%s) packets on %s" % (
256 expected_count, based_on, name))
257 while remaining_time > 0:
259 capture = self._get_capture(remaining_time, filter_out_fn)
260 elapsed_time = time.time() - before
262 if len(capture.res) == expected_count:
263 # bingo, got the packets we expected
265 elif len(capture.res) > expected_count:
266 self.test.logger.error(
267 ppc("Unexpected packets captured:", capture))
270 self.test.logger.debug("Partial capture containing %s "
271 "packets doesn't match expected "
273 (len(capture.res), expected_count))
274 elif expected_count == 0:
275 # bingo, got None as we expected - return empty capture
277 remaining_time -= elapsed_time
279 self.generate_debug_aid("count-mismatch")
280 raise Exception("Captured packets mismatch, captured %s packets, "
281 "expected %s packets on %s" %
282 (len(capture.res), expected_count, name))
284 raise Exception("No packets captured on %s" % name)
286 def assert_nothing_captured(self, remark=None, filter_out_fn=is_ipv6_misc):
287 """ Assert that nothing unfiltered was captured on interface
289 :param remark: remark printed into debug logs
290 :param filter_out_fn: filter applied to each packet, packets for which
291 the filter returns True are removed from capture
293 if os.path.isfile(self.out_path):
295 capture = self.get_capture(
296 0, remark=remark, filter_out_fn=filter_out_fn)
297 if not capture or len(capture.res) == 0:
298 # junk filtered out, we're good
302 self.generate_debug_aid("empty-assert")
304 raise AssertionError(
305 "Non-empty capture file present for interface %s (%s)" %
308 raise AssertionError("Capture file present for interface %s" %
311 def wait_for_pg_stop(self):
312 # wait till packet-generator is stopped
313 # "show packet-generator" while it is still running gives this:
314 # Name Enabled Count Parameters
315 # pcap0-sw_if_inde Yes 64 limit 64, ...
317 # also have a 5-minute timeout just in case things go terribly wrong...
318 deadline = time.time() + 300
319 while self.test.vapi.cli('show packet-generator').find("Yes") != -1:
320 self._test.sleep(0.01) # yield
321 if time.time() > deadline:
322 self.test.logger.debug("Timeout waiting for pg to stop")
325 def wait_for_capture_file(self, timeout=1):
327 Wait until pcap capture file appears
329 :param timeout: How long to wait for the packet (default 1s)
331 :returns: True/False if the file is present or appears within timeout
333 self.wait_for_pg_stop()
334 deadline = time.time() + timeout
335 if not os.path.isfile(self.out_path):
336 self.test.logger.debug("Waiting for capture file %s to appear, "
337 "timeout is %ss" % (self.out_path, timeout))
339 self.test.logger.debug("Capture file %s already exists" %
342 while time.time() < deadline:
343 if os.path.isfile(self.out_path):
345 self._test.sleep(0) # yield
346 if os.path.isfile(self.out_path):
347 self.test.logger.debug("Capture file appeared after %fs" %
348 (time.time() - (deadline - timeout)))
350 self.test.logger.debug("Timeout - capture file still nowhere")
354 def verify_enough_packet_data_in_pcap(self):
356 Check if enough data is available in file handled by internal pcap
357 reader so that a whole packet can be read.
359 :returns: True if enough data present, else False
361 orig_pos = self._pcap_reader.f.tell() # save file position
363 # read packet header from pcap
364 packet_header_size = 16
367 hdr = self._pcap_reader.f.read(packet_header_size)
368 if len(hdr) == packet_header_size:
369 # parse the capture length - caplen
370 sec, usec, caplen, wirelen = struct.unpack(
371 self._pcap_reader.endian + "IIII", hdr)
372 self._pcap_reader.f.seek(0, 2) # seek to end of file
373 end_pos = self._pcap_reader.f.tell() # get position at end
374 if end_pos >= orig_pos + len(hdr) + caplen:
375 enough_data = True # yay, we have enough data
376 self._pcap_reader.f.seek(orig_pos, 0) # restore original position
379 def wait_for_packet(self, timeout, filter_out_fn=is_ipv6_misc):
381 Wait for next packet captured with a timeout
383 :param timeout: How long to wait for the packet
385 :returns: Captured packet if no packet arrived within timeout
386 :raises Exception: if no packet arrives within timeout
388 deadline = time.time() + timeout
389 if self._pcap_reader is None:
390 if not self.wait_for_capture_file(timeout):
391 raise CaptureTimeoutError("Capture file %s did not appear "
392 "within timeout" % self.out_path)
393 while time.time() < deadline:
395 self._pcap_reader = PcapReader(self.out_path)
398 self.test.logger.debug(
399 "Exception in scapy.PcapReader(%s): %s" %
400 (self.out_path, format_exc()))
401 if not self._pcap_reader:
402 raise CaptureTimeoutError("Capture file %s did not appear within "
403 "timeout" % self.out_path)
407 self.test.logger.debug("Waiting for packet")
410 self.test.logger.debug("Polling for packet")
411 while time.time() < deadline or poll:
412 if not self.verify_enough_packet_data_in_pcap():
413 self._test.sleep(0) # yield
416 p = self._pcap_reader.recv()
418 if filter_out_fn is not None and filter_out_fn(p):
419 self.test.logger.debug(
420 "Packet received after %ss was filtered out" %
421 (time.time() - (deadline - timeout)))
423 self.test.logger.debug(
424 "Packet received after %fs" %
425 (time.time() - (deadline - timeout)))
427 self._test.sleep(0) # yield
429 self.test.logger.debug("Timeout - no packets received")
430 raise CaptureTimeoutError("Packet didn't arrive within timeout")
432 def create_arp_req(self):
433 """Create ARP request applicable for this interface"""
434 return (Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) /
435 ARP(op=ARP.who_has, pdst=self.local_ip4,
436 psrc=self.remote_ip4, hwsrc=self.remote_mac))
438 def create_ndp_req(self, addr=None):
439 """Create NDP - NS applicable for this interface"""
441 addr = self.local_ip6
442 nsma = in6_getnsma(inet_pton(socket.AF_INET6, addr))
443 d = inet_ntop(socket.AF_INET6, nsma)
445 return (Ether(dst=in6_getnsmac(nsma)) /
446 IPv6(dst=d, src=self.remote_ip6) /
447 ICMPv6ND_NS(tgt=addr) /
448 ICMPv6NDOptSrcLLAddr(lladdr=self.remote_mac))
450 def resolve_arp(self, pg_interface=None):
451 """Resolve ARP using provided packet-generator interface
453 :param pg_interface: interface used to resolve, if None then this
457 if pg_interface is None:
459 self.test.logger.info("Sending ARP request for %s on port %s" %
460 (self.local_ip4, pg_interface.name))
461 arp_req = self.create_arp_req()
462 pg_interface.add_stream(arp_req)
463 pg_interface.enable_capture()
465 self.test.logger.info(self.test.vapi.cli("show trace"))
467 captured_packet = pg_interface.wait_for_packet(1)
469 self.test.logger.info("No ARP received on port %s" %
472 arp_reply = captured_packet.copy() # keep original for exception
474 if arp_reply[ARP].op == ARP.is_at:
475 self.test.logger.info("VPP %s MAC address is %s " %
476 (self.name, arp_reply[ARP].hwsrc))
477 self._local_mac = arp_reply[ARP].hwsrc
479 self.test.logger.info("No ARP received on port %s" %
482 self.test.logger.error(
483 ppp("Unexpected response to ARP request:", captured_packet))
486 def resolve_ndp(self, pg_interface=None, timeout=1, link_layer=False):
487 """Resolve NDP using provided packet-generator interface
489 :param pg_interface: interface used to resolve, if None then this
491 :param timeout: how long to wait for response before giving up
492 :param link_layer: resolve for global address if False (default)
493 or for link-layer address if True
496 if pg_interface is None:
498 addr = self.local_ip6_ll if link_layer else self.local_ip6
499 self.test.logger.info("Sending NDP request for %s on port %s" %
500 (addr, pg_interface.name))
501 ndp_req = self.create_ndp_req(addr)
502 pg_interface.add_stream(ndp_req)
503 pg_interface.enable_capture()
506 deadline = now + timeout
507 # Enabling IPv6 on an interface can generate more than the
508 # ND reply we are looking for (namely MLD). So loop through
509 # the replies to look for want we want.
510 while now < deadline:
512 captured_packet = pg_interface.wait_for_packet(
513 deadline - now, filter_out_fn=None)
515 self.test.logger.error(
516 "Timeout while waiting for NDP response")
518 ndp_reply = captured_packet.copy() # keep original for exception
520 ndp_na = ndp_reply[ICMPv6ND_NA]
521 opt = ndp_na[ICMPv6NDOptDstLLAddr]
522 self.test.logger.info("VPP %s MAC address is %s " %
523 (self.name, opt.lladdr))
524 self._local_mac = opt.lladdr
525 self.test.logger.debug(self.test.vapi.cli("show trace"))
526 # we now have the MAC we've been after
529 self.test.logger.info(
530 ppp("Unexpected response to NDP request:",
534 self.test.logger.debug(self.test.vapi.cli("show trace"))
535 raise Exception("Timeout while waiting for NDP response")