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
12 from vpp_papi import VppEnum
14 from scapy.layers.l2 import Ether, ARP
15 from scapy.layers.inet6 import IPv6, ICMPv6ND_NS, ICMPv6ND_NA,\
16 ICMPv6NDOptSrcLLAddr, ICMPv6NDOptDstLLAddr, ICMPv6ND_RA, RouterAlert, \
18 from util import ppp, ppc
19 from scapy.utils6 import in6_getnsma, in6_getnsmac, in6_ismaddr
22 class CaptureTimeoutError(Exception):
23 """ Exception raised if capture or packet doesn't appear within timeout """
28 """ Is packet one of uninteresting IPv6 broadcasts? """
29 if p.haslayer(ICMPv6ND_RA):
30 if in6_ismaddr(p[IPv6].dst):
32 if p.haslayer(IPv6ExtHdrHopByHop):
33 for o in p[IPv6ExtHdrHopByHop].options:
34 if isinstance(o, RouterAlert):
39 class VppPGInterface(VppInterface):
41 VPP packet-generator interface
46 """packet-generator interface index assigned by VPP"""
50 def gso_enabled(self):
51 """gso enabled on packet-generator interface"""
52 if self._gso_enabled == 0:
58 """gso size on packet-generator interface"""
62 def coalesce_is_enabled(self):
63 """coalesce enabled on packet-generator interface"""
64 if self._coalesce_enabled == 0:
65 return "coalesce-disabled"
66 return "coalesce-enabled"
70 """pcap file path - captured packets"""
73 def get_in_path(self, worker):
74 """ pcap file path - injected packets"""
75 if worker is not None:
76 return "%s/pg%u_wrk%u_in.pcap" % (self.test.tempdir, self.pg_index,
78 return "%s/pg%u_in.pcap" % (self.test.tempdir, self.pg_index)
81 def capture_cli(self):
82 """CLI string to start capture on this interface"""
83 return self._capture_cli
85 def get_cap_name(self, worker=None):
86 """return capture name for this interface and given worker"""
87 if worker is not None:
88 return self._cap_name + "-worker%d" % worker
91 def get_input_cli(self, nb_replays=None, worker=None):
92 """return CLI string to load the injected packets"""
93 input_cli = "packet-generator new pcap %s source pg%u name %s" % (
94 self.get_in_path(worker), self.pg_index, self.get_cap_name(worker))
95 if nb_replays is not None:
96 return "%s limit %d" % (input_cli, nb_replays)
97 if worker is not None:
98 return "%s worker %d" % (input_cli, worker)
102 def in_history_counter(self):
103 """Self-incrementing counter used when renaming old pcap files"""
104 v = self._in_history_counter
105 self._in_history_counter += 1
109 def out_history_counter(self):
110 """Self-incrementing counter used when renaming old pcap files"""
111 v = self._out_history_counter
112 self._out_history_counter += 1
115 def __init__(self, test, pg_index, gso, gso_size, mode):
116 """ Create VPP packet-generator interface """
117 super().__init__(test)
119 r = test.vapi.pg_create_interface_v2(pg_index, gso, gso_size, mode)
120 self.set_sw_if_index(r.sw_if_index)
122 self._in_history_counter = 0
123 self._out_history_counter = 0
124 self._out_assert_counter = 0
125 self._pg_index = pg_index
126 self._gso_enabled = gso
127 self._gso_size = gso_size
128 self._coalesce_enabled = 0
129 self._out_file = "pg%u_out.pcap" % self.pg_index
130 self._out_path = self.test.tempdir + "/" + self._out_file
131 self._capture_cli = "packet-generator capture pg%u pcap %s" % (
132 self.pg_index, self.out_path)
133 self._cap_name = "pcap%u-sw_if_index-%s" % (
134 self.pg_index, self.sw_if_index)
136 def rename_old_pcap_file(self, path, counter):
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_old_pcap_file(self.out_path, self.out_history_counter)
161 # FIXME this should be an API, but no such exists atm
162 self.test.vapi.cli(self.capture_cli)
163 self._pcap_reader = None
165 def disable_capture(self):
166 self.test.vapi.cli("%s disable" % self.capture_cli)
168 def coalesce_enable(self):
169 """ Enable packet coalesce on this packet-generator interface"""
170 self._coalesce_enabled = 1
171 self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index,
174 def coalesce_disable(self):
175 """ Disable packet coalesce on this packet-generator interface"""
176 self._coalesce_enabled = 0
177 self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index,
180 def add_stream(self, pkts, nb_replays=None, worker=None):
182 Add a stream of packets to this packet-generator
184 :param pkts: iterable packets
187 wrpcap(self.get_in_path(worker), pkts)
188 self.test.register_pcap(self, worker)
189 # FIXME this should be an API, but no such exists atm
190 self.test.vapi.cli(self.get_input_cli(nb_replays, worker))
192 def generate_debug_aid(self, kind):
193 """ Create a hardlink to the out file with a counter and a file
194 containing stack trace to ease debugging in case of multiple capture
196 self.test.logger.debug("Generating debug aid for %s on %s" %
198 link_path, stack_path = ["%s/debug_%s_%s_%s.%s" %
199 (self.test.tempdir, self._name,
200 self._out_assert_counter, kind, suffix)
201 for suffix in ["pcap", "stack"]
203 os.link(self.out_path, link_path)
204 with open(stack_path, "w") as f:
205 f.writelines(format_stack())
206 self._out_assert_counter += 1
208 def _get_capture(self, timeout, filter_out_fn=is_ipv6_misc):
209 """ Helper method to get capture and filter it """
211 if not self.wait_for_capture_file(timeout):
213 output = rdpcap(self.out_path)
214 self.test.logger.debug("Capture has %s packets" % len(output.res))
216 self.test.logger.debug("Exception in scapy.rdpcap (%s): %s" %
217 (self.out_path, format_exc()))
219 before = len(output.res)
221 output.res = [p for p in output.res if not filter_out_fn(p)]
222 removed = before - len(output.res)
224 self.test.logger.debug(
225 "Filtered out %s packets from capture (returning %s)" %
226 (removed, len(output.res)))
229 def get_capture(self, expected_count=None, remark=None, timeout=1,
230 filter_out_fn=is_ipv6_misc):
231 """ Get captured packets
233 :param expected_count: expected number of packets to capture, if None,
234 then self.test.packet_count_for_dst_pg_idx is
235 used to lookup the expected count
236 :param remark: remark printed into debug logs
237 :param timeout: how long to wait for packets
238 :param filter_out_fn: filter applied to each packet, packets for which
239 the filter returns True are removed from capture
240 :returns: iterable packets
242 remaining_time = timeout
244 name = self.name if remark is None else "%s (%s)" % (self.name, remark)
245 based_on = "based on provided argument"
246 if expected_count is None:
248 self.test.get_packet_count_for_if_idx(self.sw_if_index)
249 based_on = "based on stored packet_infos"
250 if expected_count == 0:
252 "Internal error, expected packet count for %s is 0!" %
254 self.test.logger.debug("Expecting to capture %s (%s) packets on %s" % (
255 expected_count, based_on, name))
256 while remaining_time > 0:
258 capture = self._get_capture(remaining_time, filter_out_fn)
259 elapsed_time = time.time() - before
261 if len(capture.res) == expected_count:
262 # bingo, got the packets we expected
264 elif len(capture.res) > expected_count:
265 self.test.logger.error(
266 ppc("Unexpected packets captured:", capture))
269 self.test.logger.debug("Partial capture containing %s "
270 "packets doesn't match expected "
272 (len(capture.res), expected_count))
273 elif expected_count == 0:
274 # bingo, got None as we expected - return empty capture
276 remaining_time -= elapsed_time
278 self.generate_debug_aid("count-mismatch")
279 raise Exception("Captured packets mismatch, captured %s packets, "
280 "expected %s packets on %s" %
281 (len(capture.res), expected_count, name))
283 raise Exception("No packets captured on %s" % name)
285 def assert_nothing_captured(self, remark=None, filter_out_fn=is_ipv6_misc):
286 """ Assert that nothing unfiltered was captured on interface
288 :param remark: remark printed into debug logs
289 :param filter_out_fn: filter applied to each packet, packets for which
290 the filter returns True are removed from capture
292 if os.path.isfile(self.out_path):
294 capture = self.get_capture(
295 0, remark=remark, filter_out_fn=filter_out_fn)
296 if not capture or len(capture.res) == 0:
297 # junk filtered out, we're good
301 self.generate_debug_aid("empty-assert")
303 raise AssertionError(
304 "Non-empty capture file present for interface %s (%s)" %
307 raise AssertionError("Capture file present for interface %s" %
310 def wait_for_pg_stop(self):
311 # wait till packet-generator is stopped
312 # "show packet-generator" while it is still running gives this:
313 # Name Enabled Count Parameters
314 # pcap0-sw_if_inde Yes 64 limit 64, ...
316 # also have a 5-minute timeout just in case things go terribly wrong...
317 deadline = time.time() + 300
318 while self.test.vapi.cli('show packet-generator').find("Yes") != -1:
319 self._test.sleep(0.01) # yield
320 if time.time() > deadline:
321 self.test.logger.debug("Timeout waiting for pg to stop")
324 def wait_for_capture_file(self, timeout=1):
326 Wait until pcap capture file appears
328 :param timeout: How long to wait for the packet (default 1s)
330 :returns: True/False if the file is present or appears within timeout
332 self.wait_for_pg_stop()
333 deadline = time.time() + timeout
334 if not os.path.isfile(self.out_path):
335 self.test.logger.debug("Waiting for capture file %s to appear, "
336 "timeout is %ss" % (self.out_path, timeout))
338 self.test.logger.debug("Capture file %s already exists" %
341 while time.time() < deadline:
342 if os.path.isfile(self.out_path):
344 self._test.sleep(0) # yield
345 if os.path.isfile(self.out_path):
346 self.test.logger.debug("Capture file appeared after %fs" %
347 (time.time() - (deadline - timeout)))
349 self.test.logger.debug("Timeout - capture file still nowhere")
353 def verify_enough_packet_data_in_pcap(self):
355 Check if enough data is available in file handled by internal pcap
356 reader so that a whole packet can be read.
358 :returns: True if enough data present, else False
360 orig_pos = self._pcap_reader.f.tell() # save file position
362 # read packet header from pcap
363 packet_header_size = 16
366 hdr = self._pcap_reader.f.read(packet_header_size)
367 if len(hdr) == packet_header_size:
368 # parse the capture length - caplen
369 sec, usec, caplen, wirelen = struct.unpack(
370 self._pcap_reader.endian + "IIII", hdr)
371 self._pcap_reader.f.seek(0, 2) # seek to end of file
372 end_pos = self._pcap_reader.f.tell() # get position at end
373 if end_pos >= orig_pos + len(hdr) + caplen:
374 enough_data = True # yay, we have enough data
375 self._pcap_reader.f.seek(orig_pos, 0) # restore original position
378 def wait_for_packet(self, timeout, filter_out_fn=is_ipv6_misc):
380 Wait for next packet captured with a timeout
382 :param timeout: How long to wait for the packet
384 :returns: Captured packet if no packet arrived within timeout
385 :raises Exception: if no packet arrives within timeout
387 deadline = time.time() + timeout
388 if self._pcap_reader is None:
389 if not self.wait_for_capture_file(timeout):
390 raise CaptureTimeoutError("Capture file %s did not appear "
391 "within timeout" % self.out_path)
392 while time.time() < deadline:
394 self._pcap_reader = PcapReader(self.out_path)
397 self.test.logger.debug(
398 "Exception in scapy.PcapReader(%s): %s" %
399 (self.out_path, format_exc()))
400 if not self._pcap_reader:
401 raise CaptureTimeoutError("Capture file %s did not appear within "
402 "timeout" % self.out_path)
406 self.test.logger.debug("Waiting for packet")
409 self.test.logger.debug("Polling for packet")
410 while time.time() < deadline or poll:
411 if not self.verify_enough_packet_data_in_pcap():
412 self._test.sleep(0) # yield
415 p = self._pcap_reader.recv()
417 if filter_out_fn is not None and filter_out_fn(p):
418 self.test.logger.debug(
419 "Packet received after %ss was filtered out" %
420 (time.time() - (deadline - timeout)))
422 self.test.logger.debug(
423 "Packet received after %fs" %
424 (time.time() - (deadline - timeout)))
426 self._test.sleep(0) # yield
428 self.test.logger.debug("Timeout - no packets received")
429 raise CaptureTimeoutError("Packet didn't arrive within timeout")
431 def create_arp_req(self):
432 """Create ARP request applicable for this interface"""
433 return (Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) /
434 ARP(op=ARP.who_has, pdst=self.local_ip4,
435 psrc=self.remote_ip4, hwsrc=self.remote_mac))
437 def create_ndp_req(self, addr=None):
438 """Create NDP - NS applicable for this interface"""
440 addr = self.local_ip6
441 nsma = in6_getnsma(inet_pton(socket.AF_INET6, addr))
442 d = inet_ntop(socket.AF_INET6, nsma)
444 return (Ether(dst=in6_getnsmac(nsma)) /
445 IPv6(dst=d, src=self.remote_ip6) /
446 ICMPv6ND_NS(tgt=addr) /
447 ICMPv6NDOptSrcLLAddr(lladdr=self.remote_mac))
449 def resolve_arp(self, pg_interface=None):
450 """Resolve ARP using provided packet-generator interface
452 :param pg_interface: interface used to resolve, if None then this
456 if pg_interface is None:
458 self.test.logger.info("Sending ARP request for %s on port %s" %
459 (self.local_ip4, pg_interface.name))
460 arp_req = self.create_arp_req()
461 pg_interface.add_stream(arp_req)
462 pg_interface.enable_capture()
464 self.test.logger.info(self.test.vapi.cli("show trace"))
466 captured_packet = pg_interface.wait_for_packet(1)
468 self.test.logger.info("No ARP received on port %s" %
471 arp_reply = captured_packet.copy() # keep original for exception
473 if arp_reply[ARP].op == ARP.is_at:
474 self.test.logger.info("VPP %s MAC address is %s " %
475 (self.name, arp_reply[ARP].hwsrc))
476 self._local_mac = arp_reply[ARP].hwsrc
478 self.test.logger.info("No ARP received on port %s" %
481 self.test.logger.error(
482 ppp("Unexpected response to ARP request:", captured_packet))
485 def resolve_ndp(self, pg_interface=None, timeout=1, link_layer=False):
486 """Resolve NDP using provided packet-generator interface
488 :param pg_interface: interface used to resolve, if None then this
490 :param timeout: how long to wait for response before giving up
491 :param link_layer: resolve for global address if False (default)
492 or for link-layer address if True
495 if pg_interface is None:
497 addr = self.local_ip6_ll if link_layer else self.local_ip6
498 self.test.logger.info("Sending NDP request for %s on port %s" %
499 (addr, pg_interface.name))
500 ndp_req = self.create_ndp_req(addr)
501 pg_interface.add_stream(ndp_req)
502 pg_interface.enable_capture()
505 deadline = now + timeout
506 # Enabling IPv6 on an interface can generate more than the
507 # ND reply we are looking for (namely MLD). So loop through
508 # the replies to look for want we want.
509 while now < deadline:
511 captured_packet = pg_interface.wait_for_packet(
512 deadline - now, filter_out_fn=None)
514 self.test.logger.error(
515 "Timeout while waiting for NDP response")
517 ndp_reply = captured_packet.copy() # keep original for exception
519 ndp_na = ndp_reply[ICMPv6ND_NA]
520 opt = ndp_na[ICMPv6NDOptDstLLAddr]
521 self.test.logger.info("VPP %s MAC address is %s " %
522 (self.name, opt.lladdr))
523 self._local_mac = opt.lladdr
524 self.test.logger.debug(self.test.vapi.cli("show trace"))
525 # we now have the MAC we've been after
528 self.test.logger.info(
529 ppp("Unexpected response to NDP request:",
533 self.test.logger.debug(self.test.vapi.cli("show trace"))
534 raise Exception("Timeout while waiting for NDP response")