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_old_pcap_file(self, path, counter):
136 filename = os.path.basename(path)
138 if os.path.isfile(path):
139 name = "%s/history.[timestamp:%f].[%s-counter:%04d].%s" % \
145 self.test.logger.debug("Renaming %s->%s" %
147 os.rename(path, name)
149 self.test.logger.debug("OSError: Could not rename %s %s" %
152 def enable_capture(self):
153 """ Enable capture on this packet-generator interface
154 of at most n packets.
155 If n < 0, this is no limit
157 # disable the capture to flush the capture
158 self.disable_capture()
159 self.rename_old_pcap_file(self.out_path, self.out_history_counter)
160 # FIXME this should be an API, but no such exists atm
161 self.test.vapi.cli(self.capture_cli)
162 self._pcap_reader = None
164 def disable_capture(self):
165 self.test.vapi.cli("%s disable" % self.capture_cli)
167 def coalesce_enable(self):
168 """ Enable packet coalesce on this packet-generator interface"""
169 self._coalesce_enabled = 1
170 self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index,
173 def coalesce_disable(self):
174 """ Disable packet coalesce on this packet-generator interface"""
175 self._coalesce_enabled = 0
176 self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index,
179 def add_stream(self, pkts, nb_replays=None, worker=None):
181 Add a stream of packets to this packet-generator
183 :param pkts: iterable packets
186 wrpcap(self.get_in_path(worker), pkts)
187 self.test.register_pcap(self, worker)
188 # FIXME this should be an API, but no such exists atm
189 self.test.vapi.cli(self.get_input_cli(nb_replays, worker))
191 def generate_debug_aid(self, kind):
192 """ Create a hardlink to the out file with a counter and a file
193 containing stack trace to ease debugging in case of multiple capture
195 self.test.logger.debug("Generating debug aid for %s on %s" %
197 link_path, stack_path = ["%s/debug_%s_%s_%s.%s" %
198 (self.test.tempdir, self._name,
199 self._out_assert_counter, kind, suffix)
200 for suffix in ["pcap", "stack"]
202 os.link(self.out_path, link_path)
203 with open(stack_path, "w") as f:
204 f.writelines(format_stack())
205 self._out_assert_counter += 1
207 def _get_capture(self, timeout, filter_out_fn=is_ipv6_misc):
208 """ Helper method to get capture and filter it """
210 if not self.wait_for_capture_file(timeout):
212 output = rdpcap(self.out_path)
213 self.test.logger.debug("Capture has %s packets" % len(output.res))
215 self.test.logger.debug("Exception in scapy.rdpcap (%s): %s" %
216 (self.out_path, format_exc()))
218 before = len(output.res)
220 output.res = [p for p in output.res if not filter_out_fn(p)]
221 removed = before - len(output.res)
223 self.test.logger.debug(
224 "Filtered out %s packets from capture (returning %s)" %
225 (removed, len(output.res)))
228 def get_capture(self, expected_count=None, remark=None, timeout=1,
229 filter_out_fn=is_ipv6_misc):
230 """ Get captured packets
232 :param expected_count: expected number of packets to capture, if None,
233 then self.test.packet_count_for_dst_pg_idx is
234 used to lookup the expected count
235 :param remark: remark printed into debug logs
236 :param timeout: how long to wait for packets
237 :param filter_out_fn: filter applied to each packet, packets for which
238 the filter returns True are removed from capture
239 :returns: iterable packets
241 remaining_time = timeout
243 name = self.name if remark is None else "%s (%s)" % (self.name, remark)
244 based_on = "based on provided argument"
245 if expected_count is None:
247 self.test.get_packet_count_for_if_idx(self.sw_if_index)
248 based_on = "based on stored packet_infos"
249 if expected_count == 0:
251 "Internal error, expected packet count for %s is 0!" %
253 self.test.logger.debug("Expecting to capture %s (%s) packets on %s" % (
254 expected_count, based_on, name))
255 while remaining_time > 0:
257 capture = self._get_capture(remaining_time, filter_out_fn)
258 elapsed_time = time.time() - before
260 if len(capture.res) == expected_count:
261 # bingo, got the packets we expected
263 elif len(capture.res) > expected_count:
264 self.test.logger.error(
265 ppc("Unexpected packets captured:", capture))
268 self.test.logger.debug("Partial capture containing %s "
269 "packets doesn't match expected "
271 (len(capture.res), expected_count))
272 elif expected_count == 0:
273 # bingo, got None as we expected - return empty capture
275 remaining_time -= elapsed_time
277 self.generate_debug_aid("count-mismatch")
278 raise Exception("Captured packets mismatch, captured %s packets, "
279 "expected %s packets on %s" %
280 (len(capture.res), expected_count, name))
282 raise Exception("No packets captured on %s" % name)
284 def assert_nothing_captured(self, remark=None, filter_out_fn=is_ipv6_misc):
285 """ Assert that nothing unfiltered was captured on interface
287 :param remark: remark printed into debug logs
288 :param filter_out_fn: filter applied to each packet, packets for which
289 the filter returns True are removed from capture
291 if os.path.isfile(self.out_path):
293 capture = self.get_capture(
294 0, remark=remark, filter_out_fn=filter_out_fn)
295 if not capture or len(capture.res) == 0:
296 # junk filtered out, we're good
300 self.generate_debug_aid("empty-assert")
302 raise AssertionError(
303 "Non-empty capture file present for interface %s (%s)" %
306 raise AssertionError("Capture file present for interface %s" %
309 def wait_for_pg_stop(self):
310 # wait till packet-generator is stopped
311 # "show packet-generator" while it is still running gives this:
312 # Name Enabled Count Parameters
313 # pcap0-sw_if_inde Yes 64 limit 64, ...
315 # also have a 5-minute timeout just in case things go terribly wrong...
316 deadline = time.time() + 300
317 while self.test.vapi.cli('show packet-generator').find("Yes") != -1:
318 self._test.sleep(0.01) # yield
319 if time.time() > deadline:
320 self.test.logger.debug("Timeout waiting for pg to stop")
323 def wait_for_capture_file(self, timeout=1):
325 Wait until pcap capture file appears
327 :param timeout: How long to wait for the packet (default 1s)
329 :returns: True/False if the file is present or appears within timeout
331 self.wait_for_pg_stop()
332 deadline = time.time() + timeout
333 if not os.path.isfile(self.out_path):
334 self.test.logger.debug("Waiting for capture file %s to appear, "
335 "timeout is %ss" % (self.out_path, timeout))
337 self.test.logger.debug("Capture file %s already exists" %
340 while time.time() < deadline:
341 if os.path.isfile(self.out_path):
343 self._test.sleep(0) # yield
344 if os.path.isfile(self.out_path):
345 self.test.logger.debug("Capture file appeared after %fs" %
346 (time.time() - (deadline - timeout)))
348 self.test.logger.debug("Timeout - capture file still nowhere")
352 def verify_enough_packet_data_in_pcap(self):
354 Check if enough data is available in file handled by internal pcap
355 reader so that a whole packet can be read.
357 :returns: True if enough data present, else False
359 orig_pos = self._pcap_reader.f.tell() # save file position
361 # read packet header from pcap
362 packet_header_size = 16
365 hdr = self._pcap_reader.f.read(packet_header_size)
366 if len(hdr) == packet_header_size:
367 # parse the capture length - caplen
368 sec, usec, caplen, wirelen = struct.unpack(
369 self._pcap_reader.endian + "IIII", hdr)
370 self._pcap_reader.f.seek(0, 2) # seek to end of file
371 end_pos = self._pcap_reader.f.tell() # get position at end
372 if end_pos >= orig_pos + len(hdr) + caplen:
373 enough_data = True # yay, we have enough data
374 self._pcap_reader.f.seek(orig_pos, 0) # restore original position
377 def wait_for_packet(self, timeout, filter_out_fn=is_ipv6_misc):
379 Wait for next packet captured with a timeout
381 :param timeout: How long to wait for the packet
383 :returns: Captured packet if no packet arrived within timeout
384 :raises Exception: if no packet arrives within timeout
386 deadline = time.time() + timeout
387 if self._pcap_reader is None:
388 if not self.wait_for_capture_file(timeout):
389 raise CaptureTimeoutError("Capture file %s did not appear "
390 "within timeout" % self.out_path)
391 while time.time() < deadline:
393 self._pcap_reader = PcapReader(self.out_path)
396 self.test.logger.debug(
397 "Exception in scapy.PcapReader(%s): %s" %
398 (self.out_path, format_exc()))
399 if not self._pcap_reader:
400 raise CaptureTimeoutError("Capture file %s did not appear within "
401 "timeout" % self.out_path)
405 self.test.logger.debug("Waiting for packet")
408 self.test.logger.debug("Polling for packet")
409 while time.time() < deadline or poll:
410 if not self.verify_enough_packet_data_in_pcap():
411 self._test.sleep(0) # yield
414 p = self._pcap_reader.recv()
416 if filter_out_fn is not None and filter_out_fn(p):
417 self.test.logger.debug(
418 "Packet received after %ss was filtered out" %
419 (time.time() - (deadline - timeout)))
421 self.test.logger.debug(
422 "Packet received after %fs" %
423 (time.time() - (deadline - timeout)))
425 self._test.sleep(0) # yield
427 self.test.logger.debug("Timeout - no packets received")
428 raise CaptureTimeoutError("Packet didn't arrive within timeout")
430 def create_arp_req(self):
431 """Create ARP request applicable for this interface"""
432 return (Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) /
433 ARP(op=ARP.who_has, pdst=self.local_ip4,
434 psrc=self.remote_ip4, hwsrc=self.remote_mac))
436 def create_ndp_req(self, addr=None):
437 """Create NDP - NS applicable for this interface"""
439 addr = self.local_ip6
440 nsma = in6_getnsma(inet_pton(socket.AF_INET6, addr))
441 d = inet_ntop(socket.AF_INET6, nsma)
443 return (Ether(dst=in6_getnsmac(nsma)) /
444 IPv6(dst=d, src=self.remote_ip6) /
445 ICMPv6ND_NS(tgt=addr) /
446 ICMPv6NDOptSrcLLAddr(lladdr=self.remote_mac))
448 def resolve_arp(self, pg_interface=None):
449 """Resolve ARP using provided packet-generator interface
451 :param pg_interface: interface used to resolve, if None then this
455 if pg_interface is None:
457 self.test.logger.info("Sending ARP request for %s on port %s" %
458 (self.local_ip4, pg_interface.name))
459 arp_req = self.create_arp_req()
460 pg_interface.add_stream(arp_req)
461 pg_interface.enable_capture()
463 self.test.logger.info(self.test.vapi.cli("show trace"))
465 captured_packet = pg_interface.wait_for_packet(1)
467 self.test.logger.info("No ARP received on port %s" %
470 arp_reply = captured_packet.copy() # keep original for exception
472 if arp_reply[ARP].op == ARP.is_at:
473 self.test.logger.info("VPP %s MAC address is %s " %
474 (self.name, arp_reply[ARP].hwsrc))
475 self._local_mac = arp_reply[ARP].hwsrc
477 self.test.logger.info("No ARP received on port %s" %
480 self.test.logger.error(
481 ppp("Unexpected response to ARP request:", captured_packet))
484 def resolve_ndp(self, pg_interface=None, timeout=1, link_layer=False):
485 """Resolve NDP using provided packet-generator interface
487 :param pg_interface: interface used to resolve, if None then this
489 :param timeout: how long to wait for response before giving up
490 :param link_layer: resolve for global address if False (default)
491 or for link-layer address if True
494 if pg_interface is None:
496 addr = self.local_ip6_ll if link_layer else self.local_ip6
497 self.test.logger.info("Sending NDP request for %s on port %s" %
498 (addr, pg_interface.name))
499 ndp_req = self.create_ndp_req(addr)
500 pg_interface.add_stream(ndp_req)
501 pg_interface.enable_capture()
504 deadline = now + timeout
505 # Enabling IPv6 on an interface can generate more than the
506 # ND reply we are looking for (namely MLD). So loop through
507 # the replies to look for want we want.
508 while now < deadline:
510 captured_packet = pg_interface.wait_for_packet(
511 deadline - now, filter_out_fn=None)
513 self.test.logger.error(
514 "Timeout while waiting for NDP response")
516 ndp_reply = captured_packet.copy() # keep original for exception
518 ndp_na = ndp_reply[ICMPv6ND_NA]
519 opt = ndp_na[ICMPv6NDOptDstLLAddr]
520 self.test.logger.info("VPP %s MAC address is %s " %
521 (self.name, opt.lladdr))
522 self._local_mac = opt.lladdr
523 self.test.logger.debug(self.test.vapi.cli("show trace"))
524 # we now have the MAC we've been after
527 self.test.logger.info(
528 ppp("Unexpected response to NDP request:",
532 self.test.logger.debug(self.test.vapi.cli("show trace"))
533 raise Exception("Timeout while waiting for NDP response")