4 from socket import inet_pton, inet_ntop
7 from traceback import format_exc, format_stack
9 from config import config
11 from scapy.utils import wrpcap, rdpcap, PcapReader
12 from scapy.plist import PacketList
13 from vpp_interface import VppInterface
14 from vpp_papi import VppEnum
16 from scapy.layers.l2 import Ether, ARP
17 from scapy.layers.inet6 import (
27 from util import ppp, ppc, UnexpectedPacketError
28 from scapy.utils6 import in6_getnsma, in6_getnsmac, in6_ismaddr
31 class CaptureTimeoutError(Exception):
32 """Exception raised if capture or packet doesn't appear within timeout"""
38 """Is packet one of uninteresting IPv6 broadcasts?"""
39 if p.haslayer(ICMPv6ND_RA):
40 if in6_ismaddr(p[IPv6].dst):
42 if p.haslayer(IPv6ExtHdrHopByHop):
43 for o in p[IPv6ExtHdrHopByHop].options:
44 if isinstance(o, RouterAlert):
49 class VppPGInterface(VppInterface):
51 VPP packet-generator interface
56 """packet-generator interface index assigned by VPP"""
60 def gso_enabled(self):
61 """gso enabled on packet-generator interface"""
62 if self._gso_enabled == 0:
68 """gso size on packet-generator interface"""
72 def coalesce_is_enabled(self):
73 """coalesce enabled on packet-generator interface"""
74 if self._coalesce_enabled == 0:
75 return "coalesce-disabled"
76 return "coalesce-enabled"
80 """pcap file path - captured packets"""
83 def get_in_path(self, worker):
84 """pcap file path - injected packets"""
85 if worker is not None:
86 return "%s/pg%u_wrk%u_in.pcap" % (self.test.tempdir, self.pg_index, worker)
87 return "%s/pg%u_in.pcap" % (self.test.tempdir, self.pg_index)
90 def capture_cli(self):
91 """CLI string to start capture on this interface"""
92 return self._capture_cli
94 def get_cap_name(self, worker=None):
95 """return capture name for this interface and given worker"""
96 if worker is not None:
97 return self._cap_name + "-worker%d" % worker
100 def get_input_cli(self, nb_replays=None, worker=None):
101 """return CLI string to load the injected packets"""
102 input_cli = "packet-generator new pcap %s source pg%u name %s" % (
103 self.get_in_path(worker),
105 self.get_cap_name(worker),
107 if nb_replays is not None:
108 return "%s limit %d" % (input_cli, nb_replays)
109 if worker is not None:
110 return "%s worker %d" % (input_cli, worker)
114 def in_history_counter(self):
115 """Self-incrementing counter used when renaming old pcap files"""
116 v = self._in_history_counter
117 self._in_history_counter += 1
121 def out_history_counter(self):
122 """Self-incrementing counter used when renaming old pcap files"""
123 v = self._out_history_counter
124 self._out_history_counter += 1
127 def __init__(self, test, pg_index, gso, gso_size, mode):
128 """Create VPP packet-generator interface"""
129 super().__init__(test)
131 r = test.vapi.pg_create_interface_v2(pg_index, gso, gso_size, mode)
132 self.set_sw_if_index(r.sw_if_index)
134 self._in_history_counter = 0
135 self._out_history_counter = 0
136 self._out_assert_counter = 0
137 self._pg_index = pg_index
138 self._gso_enabled = gso
139 self._gso_size = gso_size
140 self._coalesce_enabled = 0
141 self._out_file = "pg%u_out.pcap" % self.pg_index
142 self._out_path = self.test.tempdir + "/" + self._out_file
143 self._capture_cli = "packet-generator capture pg%u pcap %s" % (
147 self._cap_name = "pcap%u-sw_if_index-%s" % (self.pg_index, self.sw_if_index)
149 def handle_old_pcap_file(self, path, counter):
150 filename = os.path.basename(path)
152 if not config.keep_pcaps:
154 self.test.logger.debug(f"Removing {path}")
157 self.test.logger.debug(f"OSError: Could not remove {path}")
162 if os.path.isfile(path):
163 name = "%s/history.[timestamp:%f].[%s-counter:%04d].%s" % (
170 self.test.logger.debug("Renaming %s->%s" % (path, name))
171 shutil.move(path, name)
173 self.test.logger.debug("OSError: Could not rename %s %s" % (path, filename))
175 def enable_capture(self):
176 """Enable capture on this packet-generator interface
177 of at most n packets.
178 If n < 0, this is no limit
180 # disable the capture to flush the capture
181 self.disable_capture()
182 self.handle_old_pcap_file(self.out_path, self.out_history_counter)
183 # FIXME this should be an API, but no such exists atm
184 self.test.vapi.cli(self.capture_cli)
185 self._pcap_reader = None
187 def disable_capture(self):
188 self.test.vapi.cli("%s disable" % self.capture_cli)
190 def coalesce_enable(self):
191 """Enable packet coalesce on this packet-generator interface"""
192 self._coalesce_enabled = 1
193 self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index, 1)
195 def coalesce_disable(self):
196 """Disable packet coalesce on this packet-generator interface"""
197 self._coalesce_enabled = 0
198 self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index, 0)
200 def add_stream(self, pkts, nb_replays=None, worker=None):
202 Add a stream of packets to this packet-generator
204 :param pkts: iterable packets
207 wrpcap(self.get_in_path(worker), pkts)
208 self.test.register_pcap(self, worker)
209 # FIXME this should be an API, but no such exists atm
210 self.test.vapi.cli(self.get_input_cli(nb_replays, worker))
212 def generate_debug_aid(self, kind):
213 """Create a hardlink to the out file with a counter and a file
214 containing stack trace to ease debugging in case of multiple capture
216 self.test.logger.debug("Generating debug aid for %s on %s" % (kind, self._name))
217 link_path, stack_path = [
218 "%s/debug_%s_%s_%s.%s"
219 % (self.test.tempdir, self._name, self._out_assert_counter, kind, suffix)
220 for suffix in ["pcap", "stack"]
222 os.link(self.out_path, link_path)
223 with open(stack_path, "w") as f:
224 f.writelines(format_stack())
225 self._out_assert_counter += 1
227 def _get_capture(self, timeout, filter_out_fn=is_ipv6_misc):
228 """Helper method to get capture and filter it"""
230 if not self.wait_for_capture_file(timeout):
232 output = rdpcap(self.out_path)
233 self.test.logger.debug("Capture has %s packets" % len(output.res))
235 self.test.logger.debug(
236 "Exception in scapy.rdpcap (%s): %s" % (self.out_path, format_exc())
239 before = len(output.res)
241 output.res = [p for p in output.res if not filter_out_fn(p)]
242 removed = before - len(output.res)
244 self.test.logger.debug(
245 "Filtered out %s packets from capture (returning %s)"
246 % (removed, len(output.res))
251 self, expected_count=None, remark=None, timeout=1, filter_out_fn=is_ipv6_misc
253 """Get captured packets
255 :param expected_count: expected number of packets to capture, if None,
256 then self.test.packet_count_for_dst_pg_idx is
257 used to lookup the expected count
258 :param remark: remark printed into debug logs
259 :param timeout: how long to wait for packets
260 :param filter_out_fn: filter applied to each packet, packets for which
261 the filter returns True are removed from capture
262 :returns: iterable packets
264 remaining_time = timeout
266 name = self.name if remark is None else "%s (%s)" % (self.name, remark)
267 based_on = "based on provided argument"
268 if expected_count is None:
269 expected_count = self.test.get_packet_count_for_if_idx(self.sw_if_index)
270 based_on = "based on stored packet_infos"
271 if expected_count == 0:
273 "Internal error, expected packet count for %s is 0!" % name
275 self.test.logger.debug(
276 "Expecting to capture %s (%s) packets on %s"
277 % (expected_count, based_on, name)
279 while remaining_time > 0:
281 capture = self._get_capture(remaining_time, filter_out_fn)
282 elapsed_time = time.time() - before
284 if len(capture.res) == expected_count:
285 # bingo, got the packets we expected
287 elif len(capture.res) > expected_count:
288 self.test.logger.error(ppc("Unexpected packets captured:", capture))
291 self.test.logger.debug(
292 "Partial capture containing %s "
293 "packets doesn't match expected "
294 "count %s (yet?)" % (len(capture.res), expected_count)
296 elif expected_count == 0:
297 # bingo, got None as we expected - return empty capture
299 remaining_time -= elapsed_time
301 self.generate_debug_aid("count-mismatch")
302 if len(capture) > 0 and 0 == expected_count:
303 rem = f"\n{remark}" if remark else ""
304 raise UnexpectedPacketError(
305 capture[0], f"\n({len(capture)} packets captured in total){rem}"
308 "Captured packets mismatch, captured %s packets, "
309 "expected %s packets on %s" % (len(capture.res), expected_count, name)
312 if 0 == expected_count:
314 raise Exception("No packets captured on %s" % name)
316 def assert_nothing_captured(
317 self, timeout=1, remark=None, filter_out_fn=is_ipv6_misc
319 """Assert that nothing unfiltered was captured on interface
321 :param remark: remark printed into debug logs
322 :param filter_out_fn: filter applied to each packet, packets for which
323 the filter returns True are removed from capture
325 capture = self.get_capture(
326 0, timeout=timeout, remark=remark, filter_out_fn=filter_out_fn
328 if not capture or len(capture.res) == 0:
329 # junk filtered out, we're good
332 def wait_for_pg_stop(self):
333 # wait till packet-generator is stopped
334 # "show packet-generator" while it is still running gives this:
335 # Name Enabled Count Parameters
336 # pcap0-sw_if_inde Yes 64 limit 64, ...
338 # also have a 5-minute timeout just in case things go terribly wrong...
339 deadline = time.time() + 300
340 while self.test.vapi.cli("show packet-generator").find("Yes") != -1:
341 self._test.sleep(0.01) # yield
342 if time.time() > deadline:
343 self.test.logger.debug("Timeout waiting for pg to stop")
346 def wait_for_capture_file(self, timeout=1):
348 Wait until pcap capture file appears
350 :param timeout: How long to wait for the packet (default 1s)
352 :returns: True/False if the file is present or appears within timeout
354 self.wait_for_pg_stop()
355 deadline = time.time() + timeout
356 if not os.path.isfile(self.out_path):
357 self.test.logger.debug(
358 "Waiting for capture file %s to appear, "
359 "timeout is %ss" % (self.out_path, timeout)
362 self.test.logger.debug("Capture file %s already exists" % self.out_path)
364 while time.time() < deadline:
365 if os.path.isfile(self.out_path):
367 self._test.sleep(0) # yield
368 if os.path.isfile(self.out_path):
369 self.test.logger.debug(
370 "Capture file appeared after %fs" % (time.time() - (deadline - timeout))
373 self.test.logger.debug("Timeout - capture file still nowhere")
377 def verify_enough_packet_data_in_pcap(self):
379 Check if enough data is available in file handled by internal pcap
380 reader so that a whole packet can be read.
382 :returns: True if enough data present, else False
384 orig_pos = self._pcap_reader.f.tell() # save file position
386 # read packet header from pcap
387 packet_header_size = 16
390 hdr = self._pcap_reader.f.read(packet_header_size)
391 if len(hdr) == packet_header_size:
392 # parse the capture length - caplen
393 sec, usec, caplen, wirelen = struct.unpack(
394 self._pcap_reader.endian + "IIII", hdr
396 self._pcap_reader.f.seek(0, 2) # seek to end of file
397 end_pos = self._pcap_reader.f.tell() # get position at end
398 if end_pos >= orig_pos + len(hdr) + caplen:
399 enough_data = True # yay, we have enough data
400 self._pcap_reader.f.seek(orig_pos, 0) # restore original position
403 def wait_for_packet(self, timeout, filter_out_fn=is_ipv6_misc):
405 Wait for next packet captured with a timeout
407 :param timeout: How long to wait for the packet
409 :returns: Captured packet if no packet arrived within timeout
410 :raises Exception: if no packet arrives within timeout
412 deadline = time.time() + timeout
413 if self._pcap_reader is None:
414 if not self.wait_for_capture_file(timeout):
415 raise CaptureTimeoutError(
416 "Capture file %s did not appear within timeout" % self.out_path
418 while time.time() < deadline:
420 self._pcap_reader = PcapReader(self.out_path)
423 self.test.logger.debug(
424 "Exception in scapy.PcapReader(%s): %s"
425 % (self.out_path, format_exc())
427 if not self._pcap_reader:
428 raise CaptureTimeoutError(
429 "Capture file %s did not appear within timeout" % self.out_path
434 self.test.logger.debug("Waiting for packet")
437 self.test.logger.debug("Polling for packet")
438 while time.time() < deadline or poll:
439 if not self.verify_enough_packet_data_in_pcap():
440 self._test.sleep(0) # yield
443 p = self._pcap_reader.recv()
445 if filter_out_fn is not None and filter_out_fn(p):
446 self.test.logger.debug(
447 "Packet received after %ss was filtered out"
448 % (time.time() - (deadline - timeout))
451 self.test.logger.debug(
452 "Packet received after %fs"
453 % (time.time() - (deadline - timeout))
456 self._test.sleep(0) # yield
458 self.test.logger.debug("Timeout - no packets received")
459 raise CaptureTimeoutError("Packet didn't arrive within timeout")
461 def create_arp_req(self):
462 """Create ARP request applicable for this interface"""
463 return Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) / ARP(
466 psrc=self.remote_ip4,
467 hwsrc=self.remote_mac,
470 def create_ndp_req(self, addr=None):
471 """Create NDP - NS applicable for this interface"""
473 addr = self.local_ip6
474 nsma = in6_getnsma(inet_pton(socket.AF_INET6, addr))
475 d = inet_ntop(socket.AF_INET6, nsma)
478 Ether(dst=in6_getnsmac(nsma))
479 / IPv6(dst=d, src=self.remote_ip6)
480 / ICMPv6ND_NS(tgt=addr)
481 / ICMPv6NDOptSrcLLAddr(lladdr=self.remote_mac)
484 def resolve_arp(self, pg_interface=None):
485 """Resolve ARP using provided packet-generator interface
487 :param pg_interface: interface used to resolve, if None then this
491 if pg_interface is None:
493 self.test.logger.info(
494 "Sending ARP request for %s on port %s"
495 % (self.local_ip4, pg_interface.name)
497 arp_req = self.create_arp_req()
498 pg_interface.add_stream(arp_req)
499 pg_interface.enable_capture()
501 self.test.logger.info(self.test.vapi.cli("show trace"))
503 captured_packet = pg_interface.wait_for_packet(1)
505 self.test.logger.info("No ARP received on port %s" % pg_interface.name)
507 arp_reply = captured_packet.copy() # keep original for exception
509 if arp_reply[ARP].op == ARP.is_at:
510 self.test.logger.info(
511 "VPP %s MAC address is %s " % (self.name, arp_reply[ARP].hwsrc)
513 self._local_mac = arp_reply[ARP].hwsrc
515 self.test.logger.info("No ARP received on port %s" % pg_interface.name)
517 self.test.logger.error(
518 ppp("Unexpected response to ARP request:", captured_packet)
522 def resolve_ndp(self, pg_interface=None, timeout=1, link_layer=False):
523 """Resolve NDP using provided packet-generator interface
525 :param pg_interface: interface used to resolve, if None then this
527 :param timeout: how long to wait for response before giving up
528 :param link_layer: resolve for global address if False (default)
529 or for link-layer address if True
532 if pg_interface is None:
534 addr = self.local_ip6_ll if link_layer else self.local_ip6
535 self.test.logger.info(
536 "Sending NDP request for %s on port %s" % (addr, pg_interface.name)
538 ndp_req = self.create_ndp_req(addr)
539 pg_interface.add_stream(ndp_req)
540 pg_interface.enable_capture()
543 deadline = now + timeout
544 # Enabling IPv6 on an interface can generate more than the
545 # ND reply we are looking for (namely MLD). So loop through
546 # the replies to look for want we want.
547 while now < deadline:
549 captured_packet = pg_interface.wait_for_packet(
550 deadline - now, filter_out_fn=None
553 self.test.logger.error("Timeout while waiting for NDP response")
555 ndp_reply = captured_packet.copy() # keep original for exception
557 ndp_na = ndp_reply[ICMPv6ND_NA]
558 opt = ndp_na[ICMPv6NDOptDstLLAddr]
559 self.test.logger.info(
560 "VPP %s MAC address is %s " % (self.name, opt.lladdr)
562 self._local_mac = opt.lladdr
563 self.test.logger.debug(self.test.vapi.cli("show trace"))
564 # we now have the MAC we've been after
567 self.test.logger.info(
568 ppp("Unexpected response to NDP request:", captured_packet)
572 self.test.logger.debug(self.test.vapi.cli("show trace"))
573 raise Exception("Timeout while waiting for NDP response")