4 from traceback import format_exc
5 from scapy.utils import wrpcap, rdpcap, PcapReader
6 from vpp_interface import VppInterface
8 from scapy.layers.l2 import Ether, ARP
9 from scapy.layers.inet6 import IPv6, ICMPv6ND_NS, ICMPv6ND_NA,\
10 ICMPv6NDOptSrcLLAddr, ICMPv6NDOptDstLLAddr, ICMPv6ND_RA, RouterAlert, \
12 from util import ppp, ppc
13 from scapy.utils6 import in6_getnsma, in6_getnsmac
14 from scapy.utils import inet_pton, inet_ntop
17 """ Is packet one of uninteresting IPv6 broadcasts? """
18 if p.haslayer(ICMPv6ND_RA):
20 if p.haslayer(IPv6ExtHdrHopByHop):
21 for o in p[IPv6ExtHdrHopByHop].options:
22 if isinstance(o, RouterAlert):
27 class VppPGInterface(VppInterface):
29 VPP packet-generator interface
34 """packet-generator interface index assigned by VPP"""
39 """pcap file path - captured packets"""
44 """ pcap file path - injected packets"""
48 def capture_cli(self):
49 """CLI string to start capture on this interface"""
50 return self._capture_cli
54 """capture name for this interface"""
59 """CLI string to load the injected packets"""
60 return self._input_cli
63 def in_history_counter(self):
64 """Self-incrementing counter used when renaming old pcap files"""
65 v = self._in_history_counter
66 self._in_history_counter += 1
70 def out_history_counter(self):
71 """Self-incrementing counter used when renaming old pcap files"""
72 v = self._out_history_counter
73 self._out_history_counter += 1
76 def __init__(self, test, pg_index):
77 """ Create VPP packet-generator interface """
78 r = test.vapi.pg_create_interface(pg_index)
79 self._sw_if_index = r.sw_if_index
81 super(VppPGInterface, self).__init__(test)
83 self._in_history_counter = 0
84 self._out_history_counter = 0
85 self._pg_index = pg_index
86 self._out_file = "pg%u_out.pcap" % self.pg_index
87 self._out_path = self.test.tempdir + "/" + self._out_file
88 self._in_file = "pg%u_in.pcap" % self.pg_index
89 self._in_path = self.test.tempdir + "/" + self._in_file
90 self._capture_cli = "packet-generator capture pg%u pcap %s" % (
91 self.pg_index, self.out_path)
92 self._cap_name = "pcap%u" % self.sw_if_index
93 self._input_cli = "packet-generator new pcap %s source pg%u name %s" % (
94 self.in_path, self.pg_index, self.cap_name)
96 def rotate_out_file(self):
98 if os.path.isfile(self.out_path):
99 os.rename(self.out_path,
100 "%s/history.[timestamp:%f].[%s-counter:%04d].%s" %
104 self.out_history_counter,
109 def enable_capture(self):
110 """ Enable capture on this packet-generator interface"""
111 self.rotate_out_file()
112 # FIXME this should be an API, but no such exists atm
113 self.test.vapi.cli(self.capture_cli)
114 self._pcap_reader = None
116 def add_stream(self, pkts):
118 Add a stream of packets to this packet-generator
120 :param pkts: iterable packets
124 if os.path.isfile(self.in_path):
125 os.rename(self.in_path,
126 "%s/history.[timestamp:%f].[%s-counter:%04d].%s" %
130 self.in_history_counter,
134 wrpcap(self.in_path, pkts)
135 self.test.register_capture(self.cap_name)
136 # FIXME this should be an API, but no such exists atm
137 self.test.vapi.cli(self.input_cli)
139 def _get_capture(self, timeout, filter_out_fn=is_ipv6_misc):
140 """ Helper method to get capture and filter it """
142 if not self.wait_for_capture_file(timeout):
144 output = rdpcap(self.out_path)
145 self.test.logger.debug("Capture has %s packets" % len(output.res))
147 self.test.logger.debug("Exception in scapy.rdpcap(%s): %s" %
148 (self.out_path, format_exc()))
150 before = len(output.res)
152 output.res = [p for p in output.res if not filter_out_fn(p)]
153 removed = before - len(output.res)
155 self.test.logger.debug(
156 "Filtered out %s packets from capture (returning %s)" %
157 (removed, len(output.res)))
160 def get_capture(self, expected_count=None, remark=None, timeout=1,
161 filter_out_fn=is_ipv6_misc):
162 """ Get captured packets
164 :param expected_count: expected number of packets to capture, if None,
165 then self.test.packet_count_for_dst_pg_idx is
166 used to lookup the expected count
167 :param remark: remark printed into debug logs
168 :param timeout: how long to wait for packets
169 :param filter_out_fn: filter applied to each packet, packets for which
170 the filter returns True are removed from capture
171 :returns: iterable packets
173 remaining_time = timeout
175 name = self.name if remark is None else "%s (%s)" % (self.name, remark)
176 based_on = "based on provided argument"
177 if expected_count is None:
179 self.test.get_packet_count_for_if_idx(self.sw_if_index)
180 based_on = "based on stored packet_infos"
181 if expected_count == 0:
183 "Internal error, expected packet count for %s is 0!" % name)
184 self.test.logger.debug("Expecting to capture %s(%s) packets on %s" % (
185 expected_count, based_on, name))
186 while remaining_time > 0:
188 capture = self._get_capture(remaining_time, filter_out_fn)
189 elapsed_time = time.time() - before
191 if len(capture.res) == expected_count:
192 # bingo, got the packets we expected
194 elif expected_count == 0:
196 remaining_time -= elapsed_time
198 raise Exception("Captured packets mismatch, captured %s packets, "
199 "expected %s packets on %s" %
200 (len(capture.res), expected_count, name))
202 raise Exception("No packets captured on %s" % name)
204 def assert_nothing_captured(self, remark=None, filter_out_fn=is_ipv6_misc):
205 """ Assert that nothing unfiltered was captured on interface
207 :param remark: remark printed into debug logs
208 :param filter_out_fn: filter applied to each packet, packets for which
209 the filter returns True are removed from capture
211 if os.path.isfile(self.out_path):
213 capture = self.get_capture(
214 0, remark=remark, filter_out_fn=filter_out_fn)
216 if len(capture.res) == 0:
217 # junk filtered out, we're good
219 self.test.logger.error(
220 ppc("Unexpected packets captured:", capture))
224 raise AssertionError(
225 "Non-empty capture file present for interface %s(%s)" %
228 raise AssertionError(
229 "Non-empty capture file present for interface %s" %
232 def wait_for_capture_file(self, timeout=1):
234 Wait until pcap capture file appears
236 :param timeout: How long to wait for the packet (default 1s)
238 :returns: True/False if the file is present or appears within timeout
240 limit = time.time() + timeout
241 if not os.path.isfile(self.out_path):
242 self.test.logger.debug("Waiting for capture file %s to appear, "
243 "timeout is %ss" % (self.out_path, timeout))
245 self.test.logger.debug("Capture file %s already exists" %
248 while time.time() < limit:
249 if os.path.isfile(self.out_path):
251 time.sleep(0) # yield
252 if os.path.isfile(self.out_path):
253 self.test.logger.debug("Capture file appeared after %fs" %
254 (time.time() - (limit - timeout)))
256 self.test.logger.debug("Timeout - capture file still nowhere")
260 def wait_for_packet(self, timeout, filter_out_fn=is_ipv6_misc):
262 Wait for next packet captured with a timeout
264 :param timeout: How long to wait for the packet
266 :returns: Captured packet if no packet arrived within timeout
267 :raises Exception: if no packet arrives within timeout
269 deadline = time.time() + timeout
270 if self._pcap_reader is None:
271 if not self.wait_for_capture_file(timeout):
272 raise Exception("Capture file %s did not appear within "
273 "timeout" % self.out_path)
274 while time.time() < deadline:
276 self._pcap_reader = PcapReader(self.out_path)
279 self.test.logger.debug("Exception in scapy.PcapReader(%s): "
280 "%s" % (self.out_path, format_exc()))
281 if not self._pcap_reader:
282 raise Exception("Capture file %s did not appear within "
283 "timeout" % self.out_path)
285 self.test.logger.debug("Waiting for packet")
286 while time.time() < deadline:
287 p = self._pcap_reader.recv()
289 if filter_out_fn is not None and filter_out_fn(p):
290 self.test.logger.debug(
291 "Packet received after %ss was filtered out" %
292 (time.time() - (deadline - timeout)))
294 self.test.logger.debug("Packet received after %fs" %
295 (time.time() - (deadline - timeout)))
297 time.sleep(0) # yield
298 self.test.logger.debug("Timeout - no packets received")
299 raise Exception("Packet didn't arrive within timeout")
301 def create_arp_req(self):
302 """Create ARP request applicable for this interface"""
303 return (Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) /
304 ARP(op=ARP.who_has, pdst=self.local_ip4,
305 psrc=self.remote_ip4, hwsrc=self.remote_mac))
307 def create_ndp_req(self):
308 """Create NDP - NS applicable for this interface"""
309 nsma = in6_getnsma(inet_pton(socket.AF_INET6, self.local_ip6))
310 d = inet_ntop(socket.AF_INET6, nsma)
312 return (Ether(dst=in6_getnsmac(nsma)) /
313 IPv6(dst=d, src=self.remote_ip6) /
314 ICMPv6ND_NS(tgt=self.local_ip6) /
315 ICMPv6NDOptSrcLLAddr(lladdr=self.remote_mac))
317 def resolve_arp(self, pg_interface=None):
318 """Resolve ARP using provided packet-generator interface
320 :param pg_interface: interface used to resolve, if None then this
324 if pg_interface is None:
326 self.test.logger.info("Sending ARP request for %s on port %s" %
327 (self.local_ip4, pg_interface.name))
328 arp_req = self.create_arp_req()
329 pg_interface.add_stream(arp_req)
330 pg_interface.enable_capture()
332 self.test.logger.info(self.test.vapi.cli("show trace"))
334 captured_packet = pg_interface.wait_for_packet(1)
336 self.test.logger.info("No ARP received on port %s" %
339 self.rotate_out_file()
340 arp_reply = captured_packet.copy() # keep original for exception
341 # Make Dot1AD packet content recognizable to scapy
342 if arp_reply.type == 0x88a8:
343 arp_reply.type = 0x8100
344 arp_reply = Ether(str(arp_reply))
346 if arp_reply[ARP].op == ARP.is_at:
347 self.test.logger.info("VPP %s MAC address is %s " %
348 (self.name, arp_reply[ARP].hwsrc))
349 self._local_mac = arp_reply[ARP].hwsrc
351 self.test.logger.info("No ARP received on port %s" %
354 self.test.logger.error(
355 ppp("Unexpected response to ARP request:", captured_packet))
358 def resolve_ndp(self, pg_interface=None, timeout=1):
359 """Resolve NDP using provided packet-generator interface
361 :param pg_interface: interface used to resolve, if None then this
363 :param timeout: how long to wait for response before giving up
366 if pg_interface is None:
368 self.test.logger.info("Sending NDP request for %s on port %s" %
369 (self.local_ip6, pg_interface.name))
370 ndp_req = self.create_ndp_req()
371 pg_interface.add_stream(ndp_req)
372 pg_interface.enable_capture()
375 deadline = now + timeout
376 # Enabling IPv6 on an interface can generate more than the
377 # ND reply we are looking for (namely MLD). So loop through
378 # the replies to look for want we want.
379 while now < deadline:
381 captured_packet = pg_interface.wait_for_packet(
382 deadline - now, filter_out_fn=None)
384 self.test.logger.error("Timeout while waiting for NDP response")
386 ndp_reply = captured_packet.copy() # keep original for exception
387 # Make Dot1AD packet content recognizable to scapy
388 if ndp_reply.type == 0x88a8:
389 ndp_reply.type = 0x8100
390 ndp_reply = Ether(str(ndp_reply))
392 ndp_na = ndp_reply[ICMPv6ND_NA]
393 opt = ndp_na[ICMPv6NDOptDstLLAddr]
394 self.test.logger.info("VPP %s MAC address is %s " %
395 (self.name, opt.lladdr))
396 self._local_mac = opt.lladdr
397 self.test.logger.debug(self.test.vapi.cli("show trace"))
398 # we now have the MAC we've been after
399 self.rotate_out_file()
402 self.test.logger.info(
403 ppp("Unexpected response to NDP request:", captured_packet))
406 self.test.logger.debug(self.test.vapi.cli("show trace"))
407 self.rotate_out_file()
408 raise Exception("Timeout while waiting for NDP response")