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"""
74 """ pcap file path - injected packets"""
78 def capture_cli(self):
79 """CLI string to start capture on this interface"""
80 return self._capture_cli
84 """capture name for this interface"""
89 """CLI string to load the injected packets"""
90 if self._nb_replays is not None:
91 return "%s limit %d" % (self._input_cli, self._nb_replays)
92 if self._worker is not None:
93 return "%s worker %d" % (self._input_cli, self._worker)
94 return self._input_cli
97 def in_history_counter(self):
98 """Self-incrementing counter used when renaming old pcap files"""
99 v = self._in_history_counter
100 self._in_history_counter += 1
104 def out_history_counter(self):
105 """Self-incrementing counter used when renaming old pcap files"""
106 v = self._out_history_counter
107 self._out_history_counter += 1
110 def __init__(self, test, pg_index, gso, gso_size):
111 """ Create VPP packet-generator interface """
112 super(VppPGInterface, self).__init__(test)
114 r = test.vapi.pg_create_interface(pg_index, gso, gso_size)
115 self.set_sw_if_index(r.sw_if_index)
117 self._in_history_counter = 0
118 self._out_history_counter = 0
119 self._out_assert_counter = 0
120 self._pg_index = pg_index
121 self._gso_enabled = gso
122 self._gso_size = gso_size
123 self._coalesce_enabled = 0
124 self._out_file = "pg%u_out.pcap" % self.pg_index
125 self._out_path = self.test.tempdir + "/" + self._out_file
126 self._in_file = "pg%u_in.pcap" % self.pg_index
127 self._in_path = self.test.tempdir + "/" + self._in_file
128 self._capture_cli = "packet-generator capture pg%u pcap %s" % (
129 self.pg_index, self.out_path)
130 self._cap_name = "pcap%u-sw_if_index-%s" % (
131 self.pg_index, self.sw_if_index)
133 "packet-generator new pcap %s source pg%u name %s" % (
134 self.in_path, self.pg_index, self.cap_name)
135 self._nb_replays = None
137 def _rename_previous_capture_file(self, path, counter, file):
138 # if a file from a previous capture exists, rename it.
140 if os.path.isfile(path):
141 name = "%s/history.[timestamp:%f].[%s-counter:%04d].%s" % \
147 self.test.logger.debug("Renaming %s->%s" %
149 os.rename(path, name)
151 self.test.logger.debug("OSError: Could not rename %s %s" %
154 def enable_capture(self):
155 """ Enable capture on this packet-generator interface
156 of at most n packets.
157 If n < 0, this is no limit
159 # disable the capture to flush the capture
160 self.disable_capture()
161 self._rename_previous_capture_file(self.out_path,
162 self.out_history_counter,
164 # FIXME this should be an API, but no such exists atm
165 self.test.vapi.cli(self.capture_cli)
166 self._pcap_reader = None
168 def disable_capture(self):
169 self.test.vapi.cli("%s disable" % self.capture_cli)
171 def coalesce_enable(self):
172 """ Enable packet coalesce on this packet-generator interface"""
173 self._coalesce_enabled = 1
174 self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index,
177 def coalesce_disable(self):
178 """ Disable packet coalesce on this packet-generator interface"""
179 self._coalesce_enabled = 0
180 self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index,
183 def add_stream(self, pkts, nb_replays=None, worker=None):
185 Add a stream of packets to this packet-generator
187 :param pkts: iterable packets
190 self._worker = worker
191 self._nb_replays = nb_replays
192 self._rename_previous_capture_file(self.in_path,
193 self.in_history_counter,
195 wrpcap(self.in_path, pkts)
196 self.test.register_capture(self.cap_name)
197 # FIXME this should be an API, but no such exists atm
198 self.test.vapi.cli(self.input_cli)
200 def generate_debug_aid(self, kind):
201 """ Create a hardlink to the out file with a counter and a file
202 containing stack trace to ease debugging in case of multiple capture
204 self.test.logger.debug("Generating debug aid for %s on %s" %
206 link_path, stack_path = ["%s/debug_%s_%s_%s.%s" %
207 (self.test.tempdir, self._name,
208 self._out_assert_counter, kind, suffix)
209 for suffix in ["pcap", "stack"]
211 os.link(self.out_path, link_path)
212 with open(stack_path, "w") as f:
213 f.writelines(format_stack())
214 self._out_assert_counter += 1
216 def _get_capture(self, timeout, filter_out_fn=is_ipv6_misc):
217 """ Helper method to get capture and filter it """
219 if not self.wait_for_capture_file(timeout):
221 output = rdpcap(self.out_path)
222 self.test.logger.debug("Capture has %s packets" % len(output.res))
224 self.test.logger.debug("Exception in scapy.rdpcap (%s): %s" %
225 (self.out_path, format_exc()))
227 before = len(output.res)
229 output.res = [p for p in output.res if not filter_out_fn(p)]
230 removed = before - len(output.res)
232 self.test.logger.debug(
233 "Filtered out %s packets from capture (returning %s)" %
234 (removed, len(output.res)))
237 def get_capture(self, expected_count=None, remark=None, timeout=1,
238 filter_out_fn=is_ipv6_misc):
239 """ Get captured packets
241 :param expected_count: expected number of packets to capture, if None,
242 then self.test.packet_count_for_dst_pg_idx is
243 used to lookup the expected count
244 :param remark: remark printed into debug logs
245 :param timeout: how long to wait for packets
246 :param filter_out_fn: filter applied to each packet, packets for which
247 the filter returns True are removed from capture
248 :returns: iterable packets
250 remaining_time = timeout
252 name = self.name if remark is None else "%s (%s)" % (self.name, remark)
253 based_on = "based on provided argument"
254 if expected_count is None:
256 self.test.get_packet_count_for_if_idx(self.sw_if_index)
257 based_on = "based on stored packet_infos"
258 if expected_count == 0:
260 "Internal error, expected packet count for %s is 0!" %
262 self.test.logger.debug("Expecting to capture %s (%s) packets on %s" % (
263 expected_count, based_on, name))
264 while remaining_time > 0:
266 capture = self._get_capture(remaining_time, filter_out_fn)
267 elapsed_time = time.time() - before
269 if len(capture.res) == expected_count:
270 # bingo, got the packets we expected
272 elif len(capture.res) > expected_count:
273 self.test.logger.error(
274 ppc("Unexpected packets captured:", capture))
277 self.test.logger.debug("Partial capture containing %s "
278 "packets doesn't match expected "
280 (len(capture.res), expected_count))
281 elif expected_count == 0:
282 # bingo, got None as we expected - return empty capture
284 remaining_time -= elapsed_time
286 self.generate_debug_aid("count-mismatch")
287 raise Exception("Captured packets mismatch, captured %s packets, "
288 "expected %s packets on %s" %
289 (len(capture.res), expected_count, name))
291 raise Exception("No packets captured on %s" % name)
293 def assert_nothing_captured(self, remark=None, filter_out_fn=is_ipv6_misc):
294 """ Assert that nothing unfiltered was captured on interface
296 :param remark: remark printed into debug logs
297 :param filter_out_fn: filter applied to each packet, packets for which
298 the filter returns True are removed from capture
300 if os.path.isfile(self.out_path):
302 capture = self.get_capture(
303 0, remark=remark, filter_out_fn=filter_out_fn)
304 if not capture or len(capture.res) == 0:
305 # junk filtered out, we're good
309 self.generate_debug_aid("empty-assert")
311 raise AssertionError(
312 "Non-empty capture file present for interface %s (%s)" %
315 raise AssertionError("Capture file present for interface %s" %
318 def wait_for_pg_stop(self):
319 # wait till packet-generator is stopped
320 # "show packet-generator" while it is still running gives this:
321 # Name Enabled Count Parameters
322 # pcap0-sw_if_inde Yes 64 limit 64, ...
324 # also have a 5-minute timeout just in case things go terribly wrong...
325 deadline = time.time() + 300
326 while self.test.vapi.cli('show packet-generator').find("Yes") != -1:
327 self._test.sleep(0.01) # yield
328 if time.time() > deadline:
329 self.test.logger.debug("Timeout waiting for pg to stop")
332 def wait_for_capture_file(self, timeout=1):
334 Wait until pcap capture file appears
336 :param timeout: How long to wait for the packet (default 1s)
338 :returns: True/False if the file is present or appears within timeout
340 self.wait_for_pg_stop()
341 deadline = time.time() + timeout
342 if not os.path.isfile(self.out_path):
343 self.test.logger.debug("Waiting for capture file %s to appear, "
344 "timeout is %ss" % (self.out_path, timeout))
346 self.test.logger.debug("Capture file %s already exists" %
349 while time.time() < deadline:
350 if os.path.isfile(self.out_path):
352 self._test.sleep(0) # yield
353 if os.path.isfile(self.out_path):
354 self.test.logger.debug("Capture file appeared after %fs" %
355 (time.time() - (deadline - timeout)))
357 self.test.logger.debug("Timeout - capture file still nowhere")
361 def verify_enough_packet_data_in_pcap(self):
363 Check if enough data is available in file handled by internal pcap
364 reader so that a whole packet can be read.
366 :returns: True if enough data present, else False
368 orig_pos = self._pcap_reader.f.tell() # save file position
370 # read packet header from pcap
371 packet_header_size = 16
374 hdr = self._pcap_reader.f.read(packet_header_size)
375 if len(hdr) == packet_header_size:
376 # parse the capture length - caplen
377 sec, usec, caplen, wirelen = struct.unpack(
378 self._pcap_reader.endian + "IIII", hdr)
379 self._pcap_reader.f.seek(0, 2) # seek to end of file
380 end_pos = self._pcap_reader.f.tell() # get position at end
381 if end_pos >= orig_pos + len(hdr) + caplen:
382 enough_data = True # yay, we have enough data
383 self._pcap_reader.f.seek(orig_pos, 0) # restore original position
386 def wait_for_packet(self, timeout, filter_out_fn=is_ipv6_misc):
388 Wait for next packet captured with a timeout
390 :param timeout: How long to wait for the packet
392 :returns: Captured packet if no packet arrived within timeout
393 :raises Exception: if no packet arrives within timeout
395 deadline = time.time() + timeout
396 if self._pcap_reader is None:
397 if not self.wait_for_capture_file(timeout):
398 raise CaptureTimeoutError("Capture file %s did not appear "
399 "within timeout" % self.out_path)
400 while time.time() < deadline:
402 self._pcap_reader = PcapReader(self.out_path)
405 self.test.logger.debug(
406 "Exception in scapy.PcapReader(%s): %s" %
407 (self.out_path, format_exc()))
408 if not self._pcap_reader:
409 raise CaptureTimeoutError("Capture file %s did not appear within "
410 "timeout" % self.out_path)
414 self.test.logger.debug("Waiting for packet")
417 self.test.logger.debug("Polling for packet")
418 while time.time() < deadline or poll:
419 if not self.verify_enough_packet_data_in_pcap():
420 self._test.sleep(0) # yield
423 p = self._pcap_reader.recv()
425 if filter_out_fn is not None and filter_out_fn(p):
426 self.test.logger.debug(
427 "Packet received after %ss was filtered out" %
428 (time.time() - (deadline - timeout)))
430 self.test.logger.debug(
431 "Packet received after %fs" %
432 (time.time() - (deadline - timeout)))
434 self._test.sleep(0) # yield
436 self.test.logger.debug("Timeout - no packets received")
437 raise CaptureTimeoutError("Packet didn't arrive within timeout")
439 def create_arp_req(self):
440 """Create ARP request applicable for this interface"""
441 return (Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) /
442 ARP(op=ARP.who_has, pdst=self.local_ip4,
443 psrc=self.remote_ip4, hwsrc=self.remote_mac))
445 def create_ndp_req(self):
446 """Create NDP - NS applicable for this interface"""
447 nsma = in6_getnsma(inet_pton(socket.AF_INET6, self.local_ip6))
448 d = inet_ntop(socket.AF_INET6, nsma)
450 return (Ether(dst=in6_getnsmac(nsma)) /
451 IPv6(dst=d, src=self.remote_ip6) /
452 ICMPv6ND_NS(tgt=self.local_ip6) /
453 ICMPv6NDOptSrcLLAddr(lladdr=self.remote_mac))
455 def resolve_arp(self, pg_interface=None):
456 """Resolve ARP using provided packet-generator interface
458 :param pg_interface: interface used to resolve, if None then this
462 if pg_interface is None:
464 self.test.logger.info("Sending ARP request for %s on port %s" %
465 (self.local_ip4, pg_interface.name))
466 arp_req = self.create_arp_req()
467 pg_interface.add_stream(arp_req)
468 pg_interface.enable_capture()
470 self.test.logger.info(self.test.vapi.cli("show trace"))
472 captured_packet = pg_interface.wait_for_packet(1)
474 self.test.logger.info("No ARP received on port %s" %
477 arp_reply = captured_packet.copy() # keep original for exception
479 if arp_reply[ARP].op == ARP.is_at:
480 self.test.logger.info("VPP %s MAC address is %s " %
481 (self.name, arp_reply[ARP].hwsrc))
482 self._local_mac = arp_reply[ARP].hwsrc
484 self.test.logger.info("No ARP received on port %s" %
487 self.test.logger.error(
488 ppp("Unexpected response to ARP request:", captured_packet))
491 def resolve_ndp(self, pg_interface=None, timeout=1):
492 """Resolve NDP using provided packet-generator interface
494 :param pg_interface: interface used to resolve, if None then this
496 :param timeout: how long to wait for response before giving up
499 if pg_interface is None:
501 self.test.logger.info("Sending NDP request for %s on port %s" %
502 (self.local_ip6, pg_interface.name))
503 ndp_req = self.create_ndp_req()
504 pg_interface.add_stream(ndp_req)
505 pg_interface.enable_capture()
508 deadline = now + timeout
509 # Enabling IPv6 on an interface can generate more than the
510 # ND reply we are looking for (namely MLD). So loop through
511 # the replies to look for want we want.
512 while now < deadline:
514 captured_packet = pg_interface.wait_for_packet(
515 deadline - now, filter_out_fn=None)
517 self.test.logger.error(
518 "Timeout while waiting for NDP response")
520 ndp_reply = captured_packet.copy() # keep original for exception
522 ndp_na = ndp_reply[ICMPv6ND_NA]
523 opt = ndp_na[ICMPv6NDOptDstLLAddr]
524 self.test.logger.info("VPP %s MAC address is %s " %
525 (self.name, opt.lladdr))
526 self._local_mac = opt.lladdr
527 self.test.logger.debug(self.test.vapi.cli("show trace"))
528 # we now have the MAC we've been after
531 self.test.logger.info(
532 ppp("Unexpected response to NDP request:",
536 self.test.logger.debug(self.test.vapi.cli("show trace"))
537 raise Exception("Timeout while waiting for NDP response")