import os
import time
import socket
-from traceback import format_exc
+import struct
+from traceback import format_exc, format_stack
from scapy.utils import wrpcap, rdpcap, PcapReader
+from scapy.plist import PacketList
from vpp_interface import VppInterface
from scapy.layers.l2 import Ether, ARP
from scapy.utils6 import in6_getnsma, in6_getnsmac, in6_ismaddr
from scapy.utils import inet_pton, inet_ntop
+
+class CaptureTimeoutError(Exception):
+ """ Exception raised if capture or packet doesn't appear within timeout """
+ pass
+
+
def is_ipv6_misc(p):
""" Is packet one of uninteresting IPv6 broadcasts? """
if p.haslayer(ICMPv6ND_RA):
def __init__(self, test, pg_index):
""" Create VPP packet-generator interface """
- r = test.vapi.pg_create_interface(pg_index)
- self._sw_if_index = r.sw_if_index
-
super(VppPGInterface, self).__init__(test)
+ r = test.vapi.pg_create_interface(pg_index)
+ self.set_sw_if_index(r.sw_if_index)
+
self._in_history_counter = 0
self._out_history_counter = 0
+ self._out_assert_counter = 0
self._pg_index = pg_index
self._out_file = "pg%u_out.pcap" % self.pg_index
self._out_path = self.test.tempdir + "/" + self._out_file
self._capture_cli = "packet-generator capture pg%u pcap %s" % (
self.pg_index, self.out_path)
self._cap_name = "pcap%u" % self.sw_if_index
- self._input_cli = "packet-generator new pcap %s source pg%u name %s" % (
- self.in_path, self.pg_index, self.cap_name)
+ self._input_cli = \
+ "packet-generator new pcap %s source pg%u name %s" % (
+ self.in_path, self.pg_index, self.cap_name)
- def rotate_out_file(self):
+ def enable_capture(self):
+ """ Enable capture on this packet-generator interface"""
try:
if os.path.isfile(self.out_path):
- os.rename(self.out_path,
- "%s/history.[timestamp:%f].[%s-counter:%04d].%s" %
- (self.test.tempdir,
- time.time(),
- self.name,
- self.out_history_counter,
- self._out_file))
+ name = "%s/history.[timestamp:%f].[%s-counter:%04d].%s" % \
+ (self.test.tempdir,
+ time.time(),
+ self.name,
+ self.out_history_counter,
+ self._out_file)
+ self.test.logger.debug("Renaming %s->%s" %
+ (self.out_path, name))
+ os.rename(self.out_path, name)
except:
pass
-
- def enable_capture(self):
- """ Enable capture on this packet-generator interface"""
- self.rotate_out_file()
# FIXME this should be an API, but no such exists atm
self.test.vapi.cli(self.capture_cli)
self._pcap_reader = None
"""
try:
if os.path.isfile(self.in_path):
- os.rename(self.in_path,
- "%s/history.[timestamp:%f].[%s-counter:%04d].%s" %
- (self.test.tempdir,
- time.time(),
- self.name,
- self.in_history_counter,
- self._in_file))
+ name = "%s/history.[timestamp:%f].[%s-counter:%04d].%s" %\
+ (self.test.tempdir,
+ time.time(),
+ self.name,
+ self.in_history_counter,
+ self._in_file)
+ self.test.logger.debug("Renaming %s->%s" %
+ (self.in_path, name))
+ os.rename(self.in_path, name)
except:
pass
wrpcap(self.in_path, pkts)
# FIXME this should be an API, but no such exists atm
self.test.vapi.cli(self.input_cli)
+ def generate_debug_aid(self, kind):
+ """ Create a hardlink to the out file with a counter and a file
+ containing stack trace to ease debugging in case of multiple capture
+ files present. """
+ self.test.logger.debug("Generating debug aid for %s on %s" %
+ (kind, self._name))
+ link_path, stack_path = ["%s/debug_%s_%s_%s.%s" %
+ (self.test.tempdir, self._name,
+ self._out_assert_counter, kind, suffix)
+ for suffix in ["pcap", "stack"]
+ ]
+ os.link(self.out_path, link_path)
+ with open(stack_path, "w") as f:
+ f.writelines(format_stack())
+ self._out_assert_counter += 1
+
def _get_capture(self, timeout, filter_out_fn=is_ipv6_misc):
""" Helper method to get capture and filter it """
try:
output = rdpcap(self.out_path)
self.test.logger.debug("Capture has %s packets" % len(output.res))
except:
- self.test.logger.debug("Exception in scapy.rdpcap(%s): %s" %
+ self.test.logger.debug("Exception in scapy.rdpcap (%s): %s" %
(self.out_path, format_exc()))
return None
before = len(output.res)
based_on = "based on stored packet_infos"
if expected_count == 0:
raise Exception(
- "Internal error, expected packet count for %s is 0!" % name)
- self.test.logger.debug("Expecting to capture %s(%s) packets on %s" % (
+ "Internal error, expected packet count for %s is 0!" %
+ name)
+ self.test.logger.debug("Expecting to capture %s (%s) packets on %s" % (
expected_count, based_on, name))
while remaining_time > 0:
before = time.time()
if len(capture.res) == expected_count:
# bingo, got the packets we expected
return capture
+ elif len(capture.res) > expected_count:
+ self.test.logger.error(
+ ppc("Unexpected packets captured:", capture))
+ break
+ else:
+ self.test.logger.debug("Partial capture containing %s "
+ "packets doesn't match expected "
+ "count %s (yet?)" %
+ (len(capture.res), expected_count))
elif expected_count == 0:
- return None
+ # bingo, got None as we expected - return empty capture
+ return PacketList()
remaining_time -= elapsed_time
if capture:
+ self.generate_debug_aid("count-mismatch")
raise Exception("Captured packets mismatch, captured %s packets, "
"expected %s packets on %s" %
(len(capture.res), expected_count, name))
try:
capture = self.get_capture(
0, remark=remark, filter_out_fn=filter_out_fn)
- if capture:
- if len(capture.res) == 0:
- # junk filtered out, we're good
- return
- self.test.logger.error(
- ppc("Unexpected packets captured:", capture))
+ if not capture or len(capture.res) == 0:
+ # junk filtered out, we're good
+ return
except:
pass
+ self.generate_debug_aid("empty-assert")
if remark:
raise AssertionError(
- "Non-empty capture file present for interface %s(%s)" %
+ "Non-empty capture file present for interface %s (%s)" %
(self.name, remark))
else:
- raise AssertionError(
- "Non-empty capture file present for interface %s" %
- self.name)
+ raise AssertionError("Capture file present for interface %s" %
+ self.name)
def wait_for_capture_file(self, timeout=1):
"""
:returns: True/False if the file is present or appears within timeout
"""
- limit = time.time() + timeout
+ deadline = time.time() + timeout
if not os.path.isfile(self.out_path):
self.test.logger.debug("Waiting for capture file %s to appear, "
"timeout is %ss" % (self.out_path, timeout))
self.test.logger.debug("Capture file %s already exists" %
self.out_path)
return True
- while time.time() < limit:
+ while time.time() < deadline:
if os.path.isfile(self.out_path):
break
time.sleep(0) # yield
if os.path.isfile(self.out_path):
self.test.logger.debug("Capture file appeared after %fs" %
- (time.time() - (limit - timeout)))
+ (time.time() - (deadline - timeout)))
else:
self.test.logger.debug("Timeout - capture file still nowhere")
return False
return True
+ def verify_enough_packet_data_in_pcap(self):
+ """
+ Check if enough data is available in file handled by internal pcap
+ reader so that a whole packet can be read.
+
+ :returns: True if enough data present, else False
+ """
+ orig_pos = self._pcap_reader.f.tell() # save file position
+ enough_data = False
+ # read packet header from pcap
+ packet_header_size = 16
+ caplen = None
+ end_pos = None
+ hdr = self._pcap_reader.f.read(packet_header_size)
+ if len(hdr) == packet_header_size:
+ # parse the capture length - caplen
+ sec, usec, caplen, wirelen = struct.unpack(
+ self._pcap_reader.endian + "IIII", hdr)
+ self._pcap_reader.f.seek(0, 2) # seek to end of file
+ end_pos = self._pcap_reader.f.tell() # get position at end
+ if end_pos >= orig_pos + len(hdr) + caplen:
+ enough_data = True # yay, we have enough data
+ self._pcap_reader.f.seek(orig_pos, 0) # restore original position
+ return enough_data
+
def wait_for_packet(self, timeout, filter_out_fn=is_ipv6_misc):
"""
Wait for next packet captured with a timeout
deadline = time.time() + timeout
if self._pcap_reader is None:
if not self.wait_for_capture_file(timeout):
- raise Exception("Capture file %s did not appear within "
- "timeout" % self.out_path)
+ raise CaptureTimeoutError("Capture file %s did not appear "
+ "within timeout" % self.out_path)
while time.time() < deadline:
try:
self._pcap_reader = PcapReader(self.out_path)
break
except:
- self.test.logger.debug("Exception in scapy.PcapReader(%s): "
- "%s" % (self.out_path, format_exc()))
+ self.test.logger.debug(
+ "Exception in scapy.PcapReader(%s): %s" %
+ (self.out_path, format_exc()))
if not self._pcap_reader:
- raise Exception("Capture file %s did not appear within "
- "timeout" % self.out_path)
+ raise CaptureTimeoutError("Capture file %s did not appear within "
+ "timeout" % self.out_path)
- self.test.logger.debug("Waiting for packet")
- while time.time() < deadline:
+ poll = False
+ if timeout > 0:
+ self.test.logger.debug("Waiting for packet")
+ else:
+ poll = True
+ self.test.logger.debug("Polling for packet")
+ while time.time() < deadline or poll:
+ if not self.verify_enough_packet_data_in_pcap():
+ time.sleep(0) # yield
+ poll = False
+ continue
p = self._pcap_reader.recv()
if p is not None:
if filter_out_fn is not None and filter_out_fn(p):
"Packet received after %ss was filtered out" %
(time.time() - (deadline - timeout)))
else:
- self.test.logger.debug("Packet received after %fs" %
- (time.time() - (deadline - timeout)))
+ self.test.logger.debug(
+ "Packet received after %fs" %
+ (time.time() - (deadline - timeout)))
return p
time.sleep(0) # yield
+ poll = False
self.test.logger.debug("Timeout - no packets received")
- raise Exception("Packet didn't arrive within timeout")
+ raise CaptureTimeoutError("Packet didn't arrive within timeout")
def create_arp_req(self):
"""Create ARP request applicable for this interface"""
self.test.logger.info("No ARP received on port %s" %
pg_interface.name)
return
- self.rotate_out_file()
arp_reply = captured_packet.copy() # keep original for exception
# Make Dot1AD packet content recognizable to scapy
if arp_reply.type == 0x88a8:
captured_packet = pg_interface.wait_for_packet(
deadline - now, filter_out_fn=None)
except:
- self.test.logger.error("Timeout while waiting for NDP response")
+ self.test.logger.error(
+ "Timeout while waiting for NDP response")
raise
ndp_reply = captured_packet.copy() # keep original for exception
# Make Dot1AD packet content recognizable to scapy
self._local_mac = opt.lladdr
self.test.logger.debug(self.test.vapi.cli("show trace"))
# we now have the MAC we've been after
- self.rotate_out_file()
return
except:
self.test.logger.info(
- ppp("Unexpected response to NDP request:", captured_packet))
+ ppp("Unexpected response to NDP request:",
+ captured_packet))
now = time.time()
self.test.logger.debug(self.test.vapi.cli("show trace"))
- self.rotate_out_file()
raise Exception("Timeout while waiting for NDP response")
Code Review / vpp.git / blobdiff