4 from traceback import format_exc, format_stack
5 from scapy.utils import wrpcap, rdpcap, PcapReader
6 from scapy.plist import PacketList
7 from vpp_interface import VppInterface
9 from scapy.layers.l2 import Ether, ARP
10 from scapy.layers.inet6 import IPv6, ICMPv6ND_NS, ICMPv6ND_NA,\
11 ICMPv6NDOptSrcLLAddr, ICMPv6NDOptDstLLAddr, ICMPv6ND_RA, RouterAlert, \
13 from util import ppp, ppc
14 from scapy.utils6 import in6_getnsma, in6_getnsmac, in6_ismaddr
15 from scapy.utils import inet_pton, inet_ntop
19 """ Is packet one of uninteresting IPv6 broadcasts? """
20 if p.haslayer(ICMPv6ND_RA):
21 if in6_ismaddr(p[IPv6].dst):
23 if p.haslayer(IPv6ExtHdrHopByHop):
24 for o in p[IPv6ExtHdrHopByHop].options:
25 if isinstance(o, RouterAlert):
30 class VppPGInterface(VppInterface):
32 VPP packet-generator interface
37 """packet-generator interface index assigned by VPP"""
42 """pcap file path - captured packets"""
47 """ pcap file path - injected packets"""
51 def capture_cli(self):
52 """CLI string to start capture on this interface"""
53 return self._capture_cli
57 """capture name for this interface"""
62 """CLI string to load the injected packets"""
63 return self._input_cli
66 def in_history_counter(self):
67 """Self-incrementing counter used when renaming old pcap files"""
68 v = self._in_history_counter
69 self._in_history_counter += 1
73 def out_history_counter(self):
74 """Self-incrementing counter used when renaming old pcap files"""
75 v = self._out_history_counter
76 self._out_history_counter += 1
79 def __init__(self, test, pg_index):
80 """ Create VPP packet-generator interface """
81 r = test.vapi.pg_create_interface(pg_index)
82 self._sw_if_index = r.sw_if_index
84 super(VppPGInterface, self).__init__(test)
86 self._in_history_counter = 0
87 self._out_history_counter = 0
88 self._out_assert_counter = 0
89 self._pg_index = pg_index
90 self._out_file = "pg%u_out.pcap" % self.pg_index
91 self._out_path = self.test.tempdir + "/" + self._out_file
92 self._in_file = "pg%u_in.pcap" % self.pg_index
93 self._in_path = self.test.tempdir + "/" + self._in_file
94 self._capture_cli = "packet-generator capture pg%u pcap %s" % (
95 self.pg_index, self.out_path)
96 self._cap_name = "pcap%u" % self.sw_if_index
98 "packet-generator new pcap %s source pg%u name %s" % (
99 self.in_path, self.pg_index, self.cap_name)
101 def enable_capture(self):
102 """ Enable capture on this packet-generator interface"""
104 if os.path.isfile(self.out_path):
105 os.rename(self.out_path,
106 "%s/history.[timestamp:%f].[%s-counter:%04d].%s" %
110 self.out_history_counter,
114 # FIXME this should be an API, but no such exists atm
115 self.test.vapi.cli(self.capture_cli)
116 self._pcap_reader = None
118 def add_stream(self, pkts):
120 Add a stream of packets to this packet-generator
122 :param pkts: iterable packets
126 if os.path.isfile(self.in_path):
127 os.rename(self.in_path,
128 "%s/history.[timestamp:%f].[%s-counter:%04d].%s" %
132 self.in_history_counter,
136 wrpcap(self.in_path, pkts)
137 self.test.register_capture(self.cap_name)
138 # FIXME this should be an API, but no such exists atm
139 self.test.vapi.cli(self.input_cli)
141 def generate_debug_aid(self, kind):
142 """ Create a hardlink to the out file with a counter and a file
143 containing stack trace to ease debugging in case of multiple capture
145 self.test.logger.debug("Generating debug aid for %s on %s" %
147 link_path, stack_path = ["%s/debug_%s_%s_%s.%s" %
148 (self.test.tempdir, self._name,
149 self._out_assert_counter, kind, suffix)
150 for suffix in ["pcap", "stack"]
152 os.link(self.out_path, link_path)
153 with open(stack_path, "w") as f:
154 f.writelines(format_stack())
155 self._out_assert_counter += 1
157 def _get_capture(self, timeout, filter_out_fn=is_ipv6_misc):
158 """ Helper method to get capture and filter it """
160 if not self.wait_for_capture_file(timeout):
162 output = rdpcap(self.out_path)
163 self.test.logger.debug("Capture has %s packets" % len(output.res))
165 self.test.logger.debug("Exception in scapy.rdpcap (%s): %s" %
166 (self.out_path, format_exc()))
168 before = len(output.res)
170 output.res = [p for p in output.res if not filter_out_fn(p)]
171 removed = before - len(output.res)
173 self.test.logger.debug(
174 "Filtered out %s packets from capture (returning %s)" %
175 (removed, len(output.res)))
178 def get_capture(self, expected_count=None, remark=None, timeout=1,
179 filter_out_fn=is_ipv6_misc):
180 """ Get captured packets
182 :param expected_count: expected number of packets to capture, if None,
183 then self.test.packet_count_for_dst_pg_idx is
184 used to lookup the expected count
185 :param remark: remark printed into debug logs
186 :param timeout: how long to wait for packets
187 :param filter_out_fn: filter applied to each packet, packets for which
188 the filter returns True are removed from capture
189 :returns: iterable packets
191 remaining_time = timeout
193 name = self.name if remark is None else "%s (%s)" % (self.name, remark)
194 based_on = "based on provided argument"
195 if expected_count is None:
197 self.test.get_packet_count_for_if_idx(self.sw_if_index)
198 based_on = "based on stored packet_infos"
199 if expected_count == 0:
201 "Internal error, expected packet count for %s is 0!" %
203 self.test.logger.debug("Expecting to capture %s (%s) packets on %s" % (
204 expected_count, based_on, name))
205 while remaining_time > 0:
207 capture = self._get_capture(remaining_time, filter_out_fn)
208 elapsed_time = time.time() - before
210 if len(capture.res) == expected_count:
211 # bingo, got the packets we expected
214 self.test.logger.debug("Partial capture containing %s "
215 "packets doesn't match expected "
217 (len(capture.res), expected_count))
218 elif expected_count == 0:
219 # bingo, got None as we expected - return empty capture
221 remaining_time -= elapsed_time
223 self.generate_debug_aid("count-mismatch")
224 raise Exception("Captured packets mismatch, captured %s packets, "
225 "expected %s packets on %s" %
226 (len(capture.res), expected_count, name))
228 raise Exception("No packets captured on %s" % name)
230 def assert_nothing_captured(self, remark=None, filter_out_fn=is_ipv6_misc):
231 """ Assert that nothing unfiltered was captured on interface
233 :param remark: remark printed into debug logs
234 :param filter_out_fn: filter applied to each packet, packets for which
235 the filter returns True are removed from capture
237 if os.path.isfile(self.out_path):
239 capture = self.get_capture(
240 0, remark=remark, filter_out_fn=filter_out_fn)
241 if not capture or len(capture.res) == 0:
242 # junk filtered out, we're good
244 self.test.logger.error(
245 ppc("Unexpected packets captured:", capture))
248 self.generate_debug_aid("empty-assert")
250 raise AssertionError(
251 "Non-empty capture file present for interface %s (%s)" %
254 raise AssertionError("Capture file present for interface %s" %
257 def wait_for_capture_file(self, timeout=1):
259 Wait until pcap capture file appears
261 :param timeout: How long to wait for the packet (default 1s)
263 :returns: True/False if the file is present or appears within timeout
265 limit = time.time() + timeout
266 if not os.path.isfile(self.out_path):
267 self.test.logger.debug("Waiting for capture file %s to appear, "
268 "timeout is %ss" % (self.out_path, timeout))
270 self.test.logger.debug(
271 "Capture file %s already exists" %
274 while time.time() < limit:
275 if os.path.isfile(self.out_path):
277 time.sleep(0) # yield
278 if os.path.isfile(self.out_path):
279 self.test.logger.debug("Capture file appeared after %fs" %
280 (time.time() - (limit - timeout)))
282 self.test.logger.debug("Timeout - capture file still nowhere")
286 def wait_for_packet(self, timeout, filter_out_fn=is_ipv6_misc):
288 Wait for next packet captured with a timeout
290 :param timeout: How long to wait for the packet
292 :returns: Captured packet if no packet arrived within timeout
293 :raises Exception: if no packet arrives within timeout
295 deadline = time.time() + timeout
296 if self._pcap_reader is None:
297 if not self.wait_for_capture_file(timeout):
298 raise Exception("Capture file %s did not appear within "
299 "timeout" % self.out_path)
300 while time.time() < deadline:
302 self._pcap_reader = PcapReader(self.out_path)
305 self.test.logger.debug(
306 "Exception in scapy.PcapReader(%s): %s" %
307 (self.out_path, format_exc()))
308 if not self._pcap_reader:
309 raise Exception("Capture file %s did not appear within "
310 "timeout" % self.out_path)
312 self.test.logger.debug("Waiting for packet")
313 while time.time() < deadline:
314 p = self._pcap_reader.recv()
316 if filter_out_fn is not None and filter_out_fn(p):
317 self.test.logger.debug(
318 "Packet received after %ss was filtered out" %
319 (time.time() - (deadline - timeout)))
321 self.test.logger.debug(
322 "Packet received after %fs" %
323 (time.time() - (deadline - timeout)))
325 time.sleep(0) # yield
326 self.test.logger.debug("Timeout - no packets received")
327 raise Exception("Packet didn't arrive within timeout")
329 def create_arp_req(self):
330 """Create ARP request applicable for this interface"""
331 return (Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) /
332 ARP(op=ARP.who_has, pdst=self.local_ip4,
333 psrc=self.remote_ip4, hwsrc=self.remote_mac))
335 def create_ndp_req(self):
336 """Create NDP - NS applicable for this interface"""
337 nsma = in6_getnsma(inet_pton(socket.AF_INET6, self.local_ip6))
338 d = inet_ntop(socket.AF_INET6, nsma)
340 return (Ether(dst=in6_getnsmac(nsma)) /
341 IPv6(dst=d, src=self.remote_ip6) /
342 ICMPv6ND_NS(tgt=self.local_ip6) /
343 ICMPv6NDOptSrcLLAddr(lladdr=self.remote_mac))
345 def resolve_arp(self, pg_interface=None):
346 """Resolve ARP using provided packet-generator interface
348 :param pg_interface: interface used to resolve, if None then this
352 if pg_interface is None:
354 self.test.logger.info("Sending ARP request for %s on port %s" %
355 (self.local_ip4, pg_interface.name))
356 arp_req = self.create_arp_req()
357 pg_interface.add_stream(arp_req)
358 pg_interface.enable_capture()
360 self.test.logger.info(self.test.vapi.cli("show trace"))
362 captured_packet = pg_interface.wait_for_packet(1)
364 self.test.logger.info("No ARP received on port %s" %
367 arp_reply = captured_packet.copy() # keep original for exception
368 # Make Dot1AD packet content recognizable to scapy
369 if arp_reply.type == 0x88a8:
370 arp_reply.type = 0x8100
371 arp_reply = Ether(str(arp_reply))
373 if arp_reply[ARP].op == ARP.is_at:
374 self.test.logger.info("VPP %s MAC address is %s " %
375 (self.name, arp_reply[ARP].hwsrc))
376 self._local_mac = arp_reply[ARP].hwsrc
378 self.test.logger.info("No ARP received on port %s" %
381 self.test.logger.error(
382 ppp("Unexpected response to ARP request:", captured_packet))
385 def resolve_ndp(self, pg_interface=None, timeout=1):
386 """Resolve NDP using provided packet-generator interface
388 :param pg_interface: interface used to resolve, if None then this
390 :param timeout: how long to wait for response before giving up
393 if pg_interface is None:
395 self.test.logger.info("Sending NDP request for %s on port %s" %
396 (self.local_ip6, pg_interface.name))
397 ndp_req = self.create_ndp_req()
398 pg_interface.add_stream(ndp_req)
399 pg_interface.enable_capture()
402 deadline = now + timeout
403 # Enabling IPv6 on an interface can generate more than the
404 # ND reply we are looking for (namely MLD). So loop through
405 # the replies to look for want we want.
406 while now < deadline:
408 captured_packet = pg_interface.wait_for_packet(
409 deadline - now, filter_out_fn=None)
411 self.test.logger.error(
412 "Timeout while waiting for NDP response")
414 ndp_reply = captured_packet.copy() # keep original for exception
415 # Make Dot1AD packet content recognizable to scapy
416 if ndp_reply.type == 0x88a8:
417 ndp_reply.type = 0x8100
418 ndp_reply = Ether(str(ndp_reply))
420 ndp_na = ndp_reply[ICMPv6ND_NA]
421 opt = ndp_na[ICMPv6NDOptDstLLAddr]
422 self.test.logger.info("VPP %s MAC address is %s " %
423 (self.name, opt.lladdr))
424 self._local_mac = opt.lladdr
425 self.test.logger.debug(self.test.vapi.cli("show trace"))
426 # we now have the MAC we've been after
429 self.test.logger.info(
430 ppp("Unexpected response to NDP request:",
434 self.test.logger.debug(self.test.vapi.cli("show trace"))
435 raise Exception("Timeout while waiting for NDP response")