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import os
import time
from scapy.utils import wrpcap, rdpcap, PcapReader
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 util import ppp, ppc
class VppPGInterface(VppInterface):
"""
VPP packet-generator interface
"""
@property
def pg_index(self):
"""packet-generator interface index assigned by VPP"""
return self._pg_index
@property
def out_path(self):
"""pcap file path - captured packets"""
return self._out_path
@property
def in_path(self):
""" pcap file path - injected packets"""
return self._in_path
@property
def capture_cli(self):
"""CLI string to start capture on this interface"""
return self._capture_cli
@property
def cap_name(self):
"""capture name for this interface"""
return self._cap_name
@property
def input_cli(self):
"""CLI string to load the injected packets"""
return self._input_cli
@property
def in_history_counter(self):
"""Self-incrementing counter used when renaming old pcap files"""
v = self._in_history_counter
self._in_history_counter += 1
return v
@property
def out_history_counter(self):
"""Self-incrementing counter used when renaming old pcap files"""
v = self._out_history_counter
self._out_history_counter += 1
return v
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)
self._in_history_counter = 0
self._out_history_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._in_path = self.test.tempdir + "/" + self._in_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)
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))
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):
"""
Add a stream of packets to this packet-generator
:param pkts: iterable packets
"""
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))
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)
def get_capture(self, remark=None):
"""
Get captured packets
:returns: iterable packets
"""
try:
self.wait_for_capture_file()
output = rdpcap(self.out_path)
except IOError: # TODO
self.test.logger.debug("File %s does not exist, probably because no"
" packets arrived" % self.out_path)
if remark:
raise Exception("No packets captured on %s(%s)" %
(self.name, remark))
else:
raise Exception("No packets captured on %s" % self.name)
return output
def assert_nothing_captured(self, remark=None):
if os.path.isfile(self.out_path):
try:
capture = self.get_capture()
self.test.logger.error(
ppc("Unexpected packets captured:", capture))
except:
pass
if remark:
raise AssertionError(
"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)
:raises Exception: if the capture file does not appear within timeout
"""
limit = time.time() + timeout
if not os.path.isfile(self.out_path):
self.test.logger.debug(
"Waiting for capture file to appear, timeout is %ss", timeout)
else:
self.test.logger.debug("Capture file already exists")
return
while time.time() < limit:
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)))
else:
self.test.logger.debug("Timeout - capture file still nowhere")
raise Exception("Capture file did not appear within timeout")
def wait_for_packet(self, timeout):
"""
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
"""
limit = time.time() + timeout
if self._pcap_reader is None:
self.wait_for_capture_file(timeout)
self._pcap_reader = PcapReader(self.out_path)
self.test.logger.debug("Waiting for packet")
while time.time() < limit:
p = self._pcap_reader.recv()
if p is not None:
self.test.logger.debug("Packet received after %fs",
(time.time() - (limit - timeout)))
return p
time.sleep(0) # yield
self.test.logger.debug("Timeout - no packets received")
raise Exception("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) /
ARP(op=ARP.who_has, pdst=self.local_ip4,
psrc=self.remote_ip4, hwsrc=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) /
ICMPv6ND_NS(tgt=self.local_ip6) /
ICMPv6NDOptSrcLLAddr(lladdr=self.remote_mac))
def resolve_arp(self, pg_interface=None):
"""Resolve ARP using provided packet-generator interface
:param pg_interface: interface used to resolve, if None then this
interface is used
"""
if pg_interface is None:
pg_interface = self
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()
self.test.logger.info(self.test.vapi.cli("show trace"))
try:
arp_reply = pg_interface.get_capture()
except:
self.test.logger.info("No ARP received on port %s" %
pg_interface.name)
return
arp_reply = arp_reply[0]
# 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:
self.test.logger.info("VPP %s MAC address is %s " %
(self.name, arp_reply[ARP].hwsrc))
self._local_mac = arp_reply[ARP].hwsrc
else:
self.test.logger.info(
"No ARP received on port %s" %
pg_interface.name)
except:
self.test.logger.error(
ppp("Unexpected response to ARP request:", arp_reply))
raise
def resolve_ndp(self, pg_interface=None):
"""Resolve NDP using provided packet-generator interface
:param pg_interface: interface used to resolve, if None then this
interface is used
"""
if pg_interface is None:
pg_interface = self
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()
self.test.logger.info(self.test.vapi.cli("show trace"))
replies = pg_interface.get_capture()
if replies is None or len(replies) == 0:
self.test.logger.info(
"No NDP received on port %s" %
pg_interface.name)
return
# 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.
for ndp_reply in replies:
# 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
except:
self.test.logger.info(
ppp("Unexpected response to NDP request:", ndp_reply))
# if no packets above provided the local MAC, then this failed.
if not hasattr(self, '_local_mac'):
raise
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