5 from traceback import format_exc, format_stack
6 from scapy.utils import wrpcap, rdpcap, PcapReader
7 from scapy.plist import PacketList
8 from vpp_interface import VppInterface
10 from scapy.layers.l2 import Ether, ARP
11 from scapy.layers.inet6 import IPv6, ICMPv6ND_NS, ICMPv6ND_NA,\
12 ICMPv6NDOptSrcLLAddr, ICMPv6NDOptDstLLAddr, ICMPv6ND_RA, RouterAlert, \
14 from util import ppp, ppc
15 from scapy.utils6 import in6_getnsma, in6_getnsmac, in6_ismaddr
16 from scapy.utils import inet_pton, inet_ntop
20 """ Is packet one of uninteresting IPv6 broadcasts? """
21 if p.haslayer(ICMPv6ND_RA):
22 if in6_ismaddr(p[IPv6].dst):
24 if p.haslayer(IPv6ExtHdrHopByHop):
25 for o in p[IPv6ExtHdrHopByHop].options:
26 if isinstance(o, RouterAlert):
31 class VppPGInterface(VppInterface):
33 VPP packet-generator interface
38 """packet-generator interface index assigned by VPP"""
43 """pcap file path - captured packets"""
48 """ pcap file path - injected packets"""
52 def capture_cli(self):
53 """CLI string to start capture on this interface"""
54 return self._capture_cli
58 """capture name for this interface"""
63 """CLI string to load the injected packets"""
64 return self._input_cli
67 def in_history_counter(self):
68 """Self-incrementing counter used when renaming old pcap files"""
69 v = self._in_history_counter
70 self._in_history_counter += 1
74 def out_history_counter(self):
75 """Self-incrementing counter used when renaming old pcap files"""
76 v = self._out_history_counter
77 self._out_history_counter += 1
80 def __init__(self, test, pg_index):
81 """ Create VPP packet-generator interface """
82 r = test.vapi.pg_create_interface(pg_index)
83 self._sw_if_index = r.sw_if_index
85 super(VppPGInterface, self).__init__(test)
87 self._in_history_counter = 0
88 self._out_history_counter = 0
89 self._out_assert_counter = 0
90 self._pg_index = pg_index
91 self._out_file = "pg%u_out.pcap" % self.pg_index
92 self._out_path = self.test.tempdir + "/" + self._out_file
93 self._in_file = "pg%u_in.pcap" % self.pg_index
94 self._in_path = self.test.tempdir + "/" + self._in_file
95 self._capture_cli = "packet-generator capture pg%u pcap %s" % (
96 self.pg_index, self.out_path)
97 self._cap_name = "pcap%u" % self.sw_if_index
99 "packet-generator new pcap %s source pg%u name %s" % (
100 self.in_path, self.pg_index, self.cap_name)
102 def enable_capture(self):
103 """ Enable capture on this packet-generator interface"""
105 if os.path.isfile(self.out_path):
106 os.rename(self.out_path,
107 "%s/history.[timestamp:%f].[%s-counter:%04d].%s" %
111 self.out_history_counter,
115 # FIXME this should be an API, but no such exists atm
116 self.test.vapi.cli(self.capture_cli)
117 self._pcap_reader = None
119 def add_stream(self, pkts):
121 Add a stream of packets to this packet-generator
123 :param pkts: iterable packets
127 if os.path.isfile(self.in_path):
128 os.rename(self.in_path,
129 "%s/history.[timestamp:%f].[%s-counter:%04d].%s" %
133 self.in_history_counter,
137 wrpcap(self.in_path, pkts)
138 self.test.register_capture(self.cap_name)
139 # FIXME this should be an API, but no such exists atm
140 self.test.vapi.cli(self.input_cli)
142 def generate_debug_aid(self, kind):
143 """ Create a hardlink to the out file with a counter and a file
144 containing stack trace to ease debugging in case of multiple capture
146 self.test.logger.debug("Generating debug aid for %s on %s" %
148 link_path, stack_path = ["%s/debug_%s_%s_%s.%s" %
149 (self.test.tempdir, self._name,
150 self._out_assert_counter, kind, suffix)
151 for suffix in ["pcap", "stack"]
153 os.link(self.out_path, link_path)
154 with open(stack_path, "w") as f:
155 f.writelines(format_stack())
156 self._out_assert_counter += 1
158 def _get_capture(self, timeout, filter_out_fn=is_ipv6_misc):
159 """ Helper method to get capture and filter it """
161 if not self.wait_for_capture_file(timeout):
163 output = rdpcap(self.out_path)
164 self.test.logger.debug("Capture has %s packets" % len(output.res))
166 self.test.logger.debug("Exception in scapy.rdpcap (%s): %s" %
167 (self.out_path, format_exc()))
169 before = len(output.res)
171 output.res = [p for p in output.res if not filter_out_fn(p)]
172 removed = before - len(output.res)
174 self.test.logger.debug(
175 "Filtered out %s packets from capture (returning %s)" %
176 (removed, len(output.res)))
179 def get_capture(self, expected_count=None, remark=None, timeout=1,
180 filter_out_fn=is_ipv6_misc):
181 """ Get captured packets
183 :param expected_count: expected number of packets to capture, if None,
184 then self.test.packet_count_for_dst_pg_idx is
185 used to lookup the expected count
186 :param remark: remark printed into debug logs
187 :param timeout: how long to wait for packets
188 :param filter_out_fn: filter applied to each packet, packets for which
189 the filter returns True are removed from capture
190 :returns: iterable packets
192 remaining_time = timeout
194 name = self.name if remark is None else "%s (%s)" % (self.name, remark)
195 based_on = "based on provided argument"
196 if expected_count is None:
198 self.test.get_packet_count_for_if_idx(self.sw_if_index)
199 based_on = "based on stored packet_infos"
200 if expected_count == 0:
202 "Internal error, expected packet count for %s is 0!" %
204 self.test.logger.debug("Expecting to capture %s (%s) packets on %s" % (
205 expected_count, based_on, name))
206 while remaining_time > 0:
208 capture = self._get_capture(remaining_time, filter_out_fn)
209 elapsed_time = time.time() - before
211 if len(capture.res) == expected_count:
212 # bingo, got the packets we expected
215 self.test.logger.debug("Partial capture containing %s "
216 "packets doesn't match expected "
218 (len(capture.res), expected_count))
219 elif expected_count == 0:
220 # bingo, got None as we expected - return empty capture
222 remaining_time -= elapsed_time
224 self.generate_debug_aid("count-mismatch")
225 raise Exception("Captured packets mismatch, captured %s packets, "
226 "expected %s packets on %s" %
227 (len(capture.res), expected_count, name))
229 raise Exception("No packets captured on %s" % name)
231 def assert_nothing_captured(self, remark=None, filter_out_fn=is_ipv6_misc):
232 """ Assert that nothing unfiltered was captured on interface
234 :param remark: remark printed into debug logs
235 :param filter_out_fn: filter applied to each packet, packets for which
236 the filter returns True are removed from capture
238 if os.path.isfile(self.out_path):
240 capture = self.get_capture(
241 0, remark=remark, filter_out_fn=filter_out_fn)
242 if not capture or len(capture.res) == 0:
243 # junk filtered out, we're good
245 self.test.logger.error(
246 ppc("Unexpected packets captured:", capture))
249 self.generate_debug_aid("empty-assert")
251 raise AssertionError(
252 "Non-empty capture file present for interface %s (%s)" %
255 raise AssertionError("Capture file present for interface %s" %
258 def wait_for_capture_file(self, timeout=1):
260 Wait until pcap capture file appears
262 :param timeout: How long to wait for the packet (default 1s)
264 :returns: True/False if the file is present or appears within timeout
266 limit = time.time() + timeout
267 if not os.path.isfile(self.out_path):
268 self.test.logger.debug("Waiting for capture file %s to appear, "
269 "timeout is %ss" % (self.out_path, timeout))
271 self.test.logger.debug(
272 "Capture file %s already exists" %
275 while time.time() < limit:
276 if os.path.isfile(self.out_path):
278 time.sleep(0) # yield
279 if os.path.isfile(self.out_path):
280 self.test.logger.debug("Capture file appeared after %fs" %
281 (time.time() - (limit - timeout)))
283 self.test.logger.debug("Timeout - capture file still nowhere")
287 def wait_for_packet_data(self, deadline):
289 Wait until enough data is available in the file handled by internal
290 pcap reader so that a whole packet can be read.
292 :param deadline: timestamp by which the data must arrive
293 :raises Exception: if not enough data by deadline
295 orig_pos = self._pcap_reader.f.tell() # save file position
297 while time.time() < deadline:
298 # read packet header from pcap
299 hdr = self._pcap_reader.f.read(16)
301 time.sleep(0) # yield
302 continue # cannot read full header, continue looping
303 # find the capture length - caplen
304 sec, usec, caplen, wirelen = struct.unpack(
305 self._pcap_reader.endian + "IIII", hdr)
306 self._pcap_reader.f.seek(0, 2) # seek to end of file
307 end_pos = self._pcap_reader.f.tell() # get position at end
308 if end_pos >= orig_pos + len(hdr) + caplen:
309 enough_data = True # yay, we have enough data
311 self.test.logger.debug("Partial packet data in pcap")
312 time.sleep(0) # yield
313 self._pcap_reader.f.seek(orig_pos, 0) # restore original position
316 "Not enough data to read a full packet within deadline")
318 def wait_for_packet(self, timeout, filter_out_fn=is_ipv6_misc):
320 Wait for next packet captured with a timeout
322 :param timeout: How long to wait for the packet
324 :returns: Captured packet if no packet arrived within timeout
325 :raises Exception: if no packet arrives within timeout
327 deadline = time.time() + timeout
328 if self._pcap_reader is None:
329 if not self.wait_for_capture_file(timeout):
330 raise Exception("Capture file %s did not appear within "
331 "timeout" % self.out_path)
332 while time.time() < deadline:
334 self._pcap_reader = PcapReader(self.out_path)
337 self.test.logger.debug(
338 "Exception in scapy.PcapReader(%s): %s" %
339 (self.out_path, format_exc()))
340 if not self._pcap_reader:
341 raise Exception("Capture file %s did not appear within "
342 "timeout" % self.out_path)
344 self.test.logger.debug("Waiting for packet")
345 while time.time() < deadline:
346 self.wait_for_packet_data(deadline)
347 p = self._pcap_reader.recv()
349 if filter_out_fn is not None and filter_out_fn(p):
350 self.test.logger.debug(
351 "Packet received after %ss was filtered out" %
352 (time.time() - (deadline - timeout)))
354 self.test.logger.debug(
355 "Packet received after %fs" %
356 (time.time() - (deadline - timeout)))
358 time.sleep(0) # yield
359 self.test.logger.debug("Timeout - no packets received")
360 raise Exception("Packet didn't arrive within timeout")
362 def create_arp_req(self):
363 """Create ARP request applicable for this interface"""
364 return (Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) /
365 ARP(op=ARP.who_has, pdst=self.local_ip4,
366 psrc=self.remote_ip4, hwsrc=self.remote_mac))
368 def create_ndp_req(self):
369 """Create NDP - NS applicable for this interface"""
370 nsma = in6_getnsma(inet_pton(socket.AF_INET6, self.local_ip6))
371 d = inet_ntop(socket.AF_INET6, nsma)
373 return (Ether(dst=in6_getnsmac(nsma)) /
374 IPv6(dst=d, src=self.remote_ip6) /
375 ICMPv6ND_NS(tgt=self.local_ip6) /
376 ICMPv6NDOptSrcLLAddr(lladdr=self.remote_mac))
378 def resolve_arp(self, pg_interface=None):
379 """Resolve ARP using provided packet-generator interface
381 :param pg_interface: interface used to resolve, if None then this
385 if pg_interface is None:
387 self.test.logger.info("Sending ARP request for %s on port %s" %
388 (self.local_ip4, pg_interface.name))
389 arp_req = self.create_arp_req()
390 pg_interface.add_stream(arp_req)
391 pg_interface.enable_capture()
393 self.test.logger.info(self.test.vapi.cli("show trace"))
395 captured_packet = pg_interface.wait_for_packet(1)
397 self.test.logger.info("No ARP received on port %s" %
400 arp_reply = captured_packet.copy() # keep original for exception
401 # Make Dot1AD packet content recognizable to scapy
402 if arp_reply.type == 0x88a8:
403 arp_reply.type = 0x8100
404 arp_reply = Ether(str(arp_reply))
406 if arp_reply[ARP].op == ARP.is_at:
407 self.test.logger.info("VPP %s MAC address is %s " %
408 (self.name, arp_reply[ARP].hwsrc))
409 self._local_mac = arp_reply[ARP].hwsrc
411 self.test.logger.info("No ARP received on port %s" %
414 self.test.logger.error(
415 ppp("Unexpected response to ARP request:", captured_packet))
418 def resolve_ndp(self, pg_interface=None, timeout=1):
419 """Resolve NDP using provided packet-generator interface
421 :param pg_interface: interface used to resolve, if None then this
423 :param timeout: how long to wait for response before giving up
426 if pg_interface is None:
428 self.test.logger.info("Sending NDP request for %s on port %s" %
429 (self.local_ip6, pg_interface.name))
430 ndp_req = self.create_ndp_req()
431 pg_interface.add_stream(ndp_req)
432 pg_interface.enable_capture()
435 deadline = now + timeout
436 # Enabling IPv6 on an interface can generate more than the
437 # ND reply we are looking for (namely MLD). So loop through
438 # the replies to look for want we want.
439 while now < deadline:
441 captured_packet = pg_interface.wait_for_packet(
442 deadline - now, filter_out_fn=None)
444 self.test.logger.error(
445 "Timeout while waiting for NDP response")
447 ndp_reply = captured_packet.copy() # keep original for exception
448 # Make Dot1AD packet content recognizable to scapy
449 if ndp_reply.type == 0x88a8:
450 ndp_reply.type = 0x8100
451 ndp_reply = Ether(str(ndp_reply))
453 ndp_na = ndp_reply[ICMPv6ND_NA]
454 opt = ndp_na[ICMPv6NDOptDstLLAddr]
455 self.test.logger.info("VPP %s MAC address is %s " %
456 (self.name, opt.lladdr))
457 self._local_mac = opt.lladdr
458 self.test.logger.debug(self.test.vapi.cli("show trace"))
459 # we now have the MAC we've been after
462 self.test.logger.info(
463 ppp("Unexpected response to NDP request:",
467 self.test.logger.debug(self.test.vapi.cli("show trace"))
468 raise Exception("Timeout while waiting for NDP response")