import os
import time
-from logging import error, info
-from scapy.utils import wrpcap, rdpcap
+import socket
+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.layers.inet6 import IPv6, ICMPv6ND_NS, ICMPv6ND_NA, \
- ICMPv6NDOptSrcLLAddr, ICMPv6NDOptDstLLAddr
+from scapy.layers.inet6 import IPv6, ICMPv6ND_NS, ICMPv6ND_NA,\
+ ICMPv6NDOptSrcLLAddr, ICMPv6NDOptDstLLAddr, ICMPv6ND_RA, RouterAlert, \
+ IPv6ExtHdrHopByHop
+from util import ppp, ppc
+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):
+ if in6_ismaddr(p[IPv6].dst):
+ return True
+ if p.haslayer(IPv6ExtHdrHopByHop):
+ for o in p[IPv6ExtHdrHopByHop].options:
+ if isinstance(o, RouterAlert):
+ return True
+ return False
class VppPGInterface(VppInterface):
self._out_history_counter += 1
return v
- def post_init_setup(self):
- """ Perform post-init setup for super class and add our own setup """
- super(VppPGInterface, self).post_init_setup()
+ def __init__(self, test, pg_index):
+ """ Create VPP packet-generator interface """
+ 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._in_file = "pg%u_in.pcap" % self.pg_index
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)
-
- def __init__(self, test, pg_index):
- """ Create VPP packet-generator interface """
- self._in_history_counter = 0
- self._out_history_counter = 0
- self._pg_index = pg_index
- self._test = test
- r = self.test.vapi.pg_create_interface(self.pg_index)
- self._sw_if_index = r.sw_if_index
- self.post_init_setup()
+ self._input_cli = \
+ "packet-generator new pcap %s source pg%u name %s" % (
+ self.in_path, self.pg_index, self.cap_name)
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
# FIXME this should be an API, but no such exists atm
self.test.vapi.cli(self.capture_cli)
+ self._pcap_reader = None
def add_stream(self, pkts):
"""
"""
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)
+ self.test.register_capture(self.cap_name)
# FIXME this should be an API, but no such exists atm
self.test.vapi.cli(self.input_cli)
- self.test.pg_streams.append(self.cap_name)
- self.test.vapi.cli("trace add pg-input %d" % len(pkts))
- def get_capture(self):
- """
- Get captured packets
+ 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
- :returns: iterable packets
- """
+ def _get_capture(self, timeout, filter_out_fn=is_ipv6_misc):
+ """ Helper method to get capture and filter it """
try:
+ if not self.wait_for_capture_file(timeout):
+ return None
output = rdpcap(self.out_path)
- except IOError: # TODO
- error("File %s does not exist, probably because no"
- " packets arrived" % self.out_path)
- return []
+ self.test.logger.debug("Capture has %s packets" % len(output.res))
+ except:
+ self.test.logger.debug("Exception in scapy.rdpcap (%s): %s" %
+ (self.out_path, format_exc()))
+ return None
+ before = len(output.res)
+ if filter_out_fn:
+ output.res = [p for p in output.res if not filter_out_fn(p)]
+ removed = before - len(output.res)
+ if removed:
+ self.test.logger.debug(
+ "Filtered out %s packets from capture (returning %s)" %
+ (removed, len(output.res)))
return output
+ def get_capture(self, expected_count=None, remark=None, timeout=1,
+ filter_out_fn=is_ipv6_misc):
+ """ Get captured packets
+
+ :param expected_count: expected number of packets to capture, if None,
+ then self.test.packet_count_for_dst_pg_idx is
+ used to lookup the expected count
+ :param remark: remark printed into debug logs
+ :param timeout: how long to wait for packets
+ :param filter_out_fn: filter applied to each packet, packets for which
+ the filter returns True are removed from capture
+ :returns: iterable packets
+ """
+ remaining_time = timeout
+ capture = None
+ name = self.name if remark is None else "%s (%s)" % (self.name, remark)
+ based_on = "based on provided argument"
+ if expected_count is None:
+ expected_count = \
+ self.test.get_packet_count_for_if_idx(self.sw_if_index)
+ 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" % (
+ expected_count, based_on, name))
+ while remaining_time > 0:
+ before = time.time()
+ capture = self._get_capture(remaining_time, filter_out_fn)
+ elapsed_time = time.time() - before
+ if capture:
+ 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:
+ # 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))
+ else:
+ raise Exception("No packets captured on %s" % name)
+
+ def assert_nothing_captured(self, remark=None, filter_out_fn=is_ipv6_misc):
+ """ Assert that nothing unfiltered was captured on interface
+
+ :param remark: remark printed into debug logs
+ :param filter_out_fn: filter applied to each packet, packets for which
+ the filter returns True are removed from capture
+ """
+ if os.path.isfile(self.out_path):
+ try:
+ capture = self.get_capture(
+ 0, remark=remark, filter_out_fn=filter_out_fn)
+ 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)" %
+ (self.name, remark))
+ else:
+ raise AssertionError("Capture file present for interface %s" %
+ self.name)
+
+ def wait_for_capture_file(self, timeout=1):
+ """
+ Wait until pcap capture file appears
+
+ :param timeout: How long to wait for the packet (default 1s)
+
+ :returns: True/False if the file is present or appears within 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))
+ else:
+ self.test.logger.debug("Capture file %s already exists" %
+ self.out_path)
+ return True
+ 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() - (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
+
+ :param timeout: How long to wait for the packet
+
+ :returns: Captured packet if no packet arrived within timeout
+ :raises Exception: if no packet arrives within timeout
+ """
+ deadline = time.time() + timeout
+ if self._pcap_reader is None:
+ if not self.wait_for_capture_file(timeout):
+ 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()))
+ if not self._pcap_reader:
+ raise CaptureTimeoutError("Capture file %s did not appear within "
+ "timeout" % self.out_path)
+
+ 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):
+ self.test.logger.debug(
+ "Packet received after %ss was filtered out" %
+ (time.time() - (deadline - timeout)))
+ else:
+ 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 CaptureTimeoutError("Packet didn't arrive within timeout")
+
def create_arp_req(self):
"""Create ARP request applicable for this interface"""
return (Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) /
def create_ndp_req(self):
"""Create NDP - NS applicable for this interface"""
- return (Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) /
- IPv6(src=self.remote_ip6, dst=self.local_ip6) /
+ nsma = in6_getnsma(inet_pton(socket.AF_INET6, self.local_ip6))
+ d = inet_ntop(socket.AF_INET6, nsma)
+
+ return (Ether(dst=in6_getnsmac(nsma)) /
+ IPv6(dst=d, src=self.remote_ip6) /
ICMPv6ND_NS(tgt=self.local_ip6) /
ICMPv6NDOptSrcLLAddr(lladdr=self.remote_mac))
"""
if pg_interface is None:
pg_interface = self
- info("Sending ARP request for %s on port %s" %
- (self.local_ip4, pg_interface.name))
+ self.test.logger.info("Sending ARP request for %s on port %s" %
+ (self.local_ip4, pg_interface.name))
arp_req = self.create_arp_req()
pg_interface.add_stream(arp_req)
pg_interface.enable_capture()
self.test.pg_start()
- info(self.test.vapi.cli("show trace"))
- arp_reply = pg_interface.get_capture()
- if arp_reply is None or len(arp_reply) == 0:
- info("No ARP received on port %s" % pg_interface.name)
+ self.test.logger.info(self.test.vapi.cli("show trace"))
+ try:
+ captured_packet = pg_interface.wait_for_packet(1)
+ except:
+ self.test.logger.info("No ARP received on port %s" %
+ pg_interface.name)
return
- arp_reply = arp_reply[0]
+ arp_reply = captured_packet.copy() # keep original for exception
# Make Dot1AD packet content recognizable to scapy
if arp_reply.type == 0x88a8:
arp_reply.type = 0x8100
arp_reply = Ether(str(arp_reply))
try:
if arp_reply[ARP].op == ARP.is_at:
- info("VPP %s MAC address is %s " %
- (self.name, arp_reply[ARP].hwsrc))
+ self.test.logger.info("VPP %s MAC address is %s " %
+ (self.name, arp_reply[ARP].hwsrc))
self._local_mac = arp_reply[ARP].hwsrc
else:
- info("No ARP received on port %s" % pg_interface.name)
+ self.test.logger.info("No ARP received on port %s" %
+ pg_interface.name)
except:
- error("Unexpected response to ARP request:")
- error(arp_reply.show())
+ self.test.logger.error(
+ ppp("Unexpected response to ARP request:", captured_packet))
raise
- def resolve_ndp(self, pg_interface=None):
+ def resolve_ndp(self, pg_interface=None, timeout=1):
"""Resolve NDP using provided packet-generator interface
:param pg_interface: interface used to resolve, if None then this
interface is used
+ :param timeout: how long to wait for response before giving up
"""
if pg_interface is None:
pg_interface = self
- info("Sending NDP request for %s on port %s" %
- (self.local_ip6, pg_interface.name))
+ self.test.logger.info("Sending NDP request for %s on port %s" %
+ (self.local_ip6, pg_interface.name))
ndp_req = self.create_ndp_req()
pg_interface.add_stream(ndp_req)
pg_interface.enable_capture()
self.test.pg_start()
- info(self.test.vapi.cli("show trace"))
- ndp_reply = pg_interface.get_capture()
- if ndp_reply is None or len(ndp_reply) == 0:
- info("No NDP received on port %s" % pg_interface.name)
- return
- ndp_reply = ndp_reply[0]
- # Make Dot1AD packet content recognizable to scapy
- if ndp_reply.type == 0x88a8:
- ndp_reply.type = 0x8100
- ndp_reply = Ether(str(ndp_reply))
- try:
- ndp_na = ndp_reply[ICMPv6ND_NA]
- opt = ndp_na[ICMPv6NDOptDstLLAddr]
- info("VPP %s MAC address is %s " %
- (self.name, opt.lladdr))
- self._local_mac = opt.lladdr
- except:
- error("Unexpected response to NDP request:")
- error(ndp_reply.show())
- raise
+ now = time.time()
+ deadline = now + timeout
+ # Enabling IPv6 on an interface can generate more than the
+ # ND reply we are looking for (namely MLD). So loop through
+ # the replies to look for want we want.
+ while now < deadline:
+ try:
+ captured_packet = pg_interface.wait_for_packet(
+ deadline - now, filter_out_fn=None)
+ except:
+ 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
+ if ndp_reply.type == 0x88a8:
+ ndp_reply.type = 0x8100
+ ndp_reply = Ether(str(ndp_reply))
+ try:
+ ndp_na = ndp_reply[ICMPv6ND_NA]
+ opt = ndp_na[ICMPv6NDOptDstLLAddr]
+ self.test.logger.info("VPP %s MAC address is %s " %
+ (self.name, opt.lladdr))
+ self._local_mac = opt.lladdr
+ self.test.logger.debug(self.test.vapi.cli("show trace"))
+ # we now have the MAC we've been after
+ return
+ except:
+ self.test.logger.info(
+ ppp("Unexpected response to NDP request:",
+ captured_packet))
+ now = time.time()
+
+ self.test.logger.debug(self.test.vapi.cli("show trace"))
+ raise Exception("Timeout while waiting for NDP response")
Code Review / vpp.git / blobdiff