vpp/test/vpp_pg_interface.py
Klement Sekera d9b0c6fbf7 tests: replace pycodestyle with black
Drop pycodestyle for code style checking in favor of black. Black is
much faster, stable PEP8 compliant code style checker offering also
automatic formatting. It aims to be very stable and produce smallest
diffs. It's used by many small and big projects.

Running checkstyle with black takes a few seconds with a terse output.
Thus, test-checkstyle-diff is no longer necessary.

Expand scope of checkstyle to all python files in the repo, replacing
test-checkstyle with checkstyle-python.

Also, fixstyle-python is now available for automatic style formatting.

Note: python virtualenv has been consolidated in test/Makefile,
test/requirements*.txt which will eventually be moved to a central
location.  This is required to simply the automated generation of
docker executor images in the CI.

Type: improvement
Change-Id: I022a326603485f58585e879ac0f697fceefbc9c8
Signed-off-by: Klement Sekera <klement.sekera@gmail.com>
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>
2022-05-10 18:52:08 +00:00

574 lines
21 KiB
Python

import os
import socket
from socket import inet_pton, inet_ntop
import struct
import time
from traceback import format_exc, format_stack
from config import config
import scapy.compat
from scapy.utils import wrpcap, rdpcap, PcapReader
from scapy.plist import PacketList
from vpp_interface import VppInterface
from vpp_papi import VppEnum
from scapy.layers.l2 import Ether, ARP
from scapy.layers.inet6 import (
IPv6,
ICMPv6ND_NS,
ICMPv6ND_NA,
ICMPv6NDOptSrcLLAddr,
ICMPv6NDOptDstLLAddr,
ICMPv6ND_RA,
RouterAlert,
IPv6ExtHdrHopByHop,
)
from util import ppp, ppc, UnexpectedPacketError
from scapy.utils6 import in6_getnsma, in6_getnsmac, in6_ismaddr
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):
"""
VPP packet-generator interface
"""
@property
def pg_index(self):
"""packet-generator interface index assigned by VPP"""
return self._pg_index
@property
def gso_enabled(self):
"""gso enabled on packet-generator interface"""
if self._gso_enabled == 0:
return "gso-disabled"
return "gso-enabled"
@property
def gso_size(self):
"""gso size on packet-generator interface"""
return self._gso_size
@property
def coalesce_is_enabled(self):
"""coalesce enabled on packet-generator interface"""
if self._coalesce_enabled == 0:
return "coalesce-disabled"
return "coalesce-enabled"
@property
def out_path(self):
"""pcap file path - captured packets"""
return self._out_path
def get_in_path(self, worker):
"""pcap file path - injected packets"""
if worker is not None:
return "%s/pg%u_wrk%u_in.pcap" % (self.test.tempdir, self.pg_index, worker)
return "%s/pg%u_in.pcap" % (self.test.tempdir, self.pg_index)
@property
def capture_cli(self):
"""CLI string to start capture on this interface"""
return self._capture_cli
def get_cap_name(self, worker=None):
"""return capture name for this interface and given worker"""
if worker is not None:
return self._cap_name + "-worker%d" % worker
return self._cap_name
def get_input_cli(self, nb_replays=None, worker=None):
"""return CLI string to load the injected packets"""
input_cli = "packet-generator new pcap %s source pg%u name %s" % (
self.get_in_path(worker),
self.pg_index,
self.get_cap_name(worker),
)
if nb_replays is not None:
return "%s limit %d" % (input_cli, nb_replays)
if worker is not None:
return "%s worker %d" % (input_cli, worker)
return 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, gso, gso_size, mode):
"""Create VPP packet-generator interface"""
super().__init__(test)
r = test.vapi.pg_create_interface_v2(pg_index, gso, gso_size, mode)
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._gso_enabled = gso
self._gso_size = gso_size
self._coalesce_enabled = 0
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-sw_if_index-%s" % (self.pg_index, self.sw_if_index)
def handle_old_pcap_file(self, path, counter):
filename = os.path.basename(path)
if not config.keep_pcaps:
try:
self.test.logger.debug(f"Removing {path}")
os.remove(path)
except OSError:
self.test.logger.debug(f"OSError: Could not remove {path}")
return
# keep
try:
if os.path.isfile(path):
name = "%s/history.[timestamp:%f].[%s-counter:%04d].%s" % (
self.test.tempdir,
time.time(),
self.name,
counter,
filename,
)
self.test.logger.debug("Renaming %s->%s" % (path, name))
os.rename(path, name)
except OSError:
self.test.logger.debug("OSError: Could not rename %s %s" % (path, filename))
def enable_capture(self):
"""Enable capture on this packet-generator interface
of at most n packets.
If n < 0, this is no limit
"""
# disable the capture to flush the capture
self.disable_capture()
self.handle_old_pcap_file(self.out_path, self.out_history_counter)
# FIXME this should be an API, but no such exists atm
self.test.vapi.cli(self.capture_cli)
self._pcap_reader = None
def disable_capture(self):
self.test.vapi.cli("%s disable" % self.capture_cli)
def coalesce_enable(self):
"""Enable packet coalesce on this packet-generator interface"""
self._coalesce_enabled = 1
self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index, 1)
def coalesce_disable(self):
"""Disable packet coalesce on this packet-generator interface"""
self._coalesce_enabled = 0
self.test.vapi.pg_interface_enable_disable_coalesce(self.sw_if_index, 0)
def add_stream(self, pkts, nb_replays=None, worker=None):
"""
Add a stream of packets to this packet-generator
:param pkts: iterable packets
"""
wrpcap(self.get_in_path(worker), pkts)
self.test.register_pcap(self, worker)
# FIXME this should be an API, but no such exists atm
self.test.vapi.cli(self.get_input_cli(nb_replays, worker))
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:
if not self.wait_for_capture_file(timeout):
return None
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.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")
if len(capture) > 0 and 0 == expected_count:
rem = f"\n{remark}" if remark else ""
raise UnexpectedPacketError(
capture[0], f"\n({len(capture)} packets captured in total){rem}"
)
raise Exception(
"Captured packets mismatch, captured %s packets, "
"expected %s packets on %s" % (len(capture.res), expected_count, name)
)
else:
if 0 == expected_count:
return
raise Exception("No packets captured on %s" % name)
def assert_nothing_captured(
self, timeout=1, 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
"""
capture = self.get_capture(
0, timeout=timeout, remark=remark, filter_out_fn=filter_out_fn
)
if not capture or len(capture.res) == 0:
# junk filtered out, we're good
return
def wait_for_pg_stop(self):
# wait till packet-generator is stopped
# "show packet-generator" while it is still running gives this:
# Name Enabled Count Parameters
# pcap0-sw_if_inde Yes 64 limit 64, ...
#
# also have a 5-minute timeout just in case things go terribly wrong...
deadline = time.time() + 300
while self.test.vapi.cli("show packet-generator").find("Yes") != -1:
self._test.sleep(0.01) # yield
if time.time() > deadline:
self.test.logger.debug("Timeout waiting for pg to stop")
break
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
"""
self.wait_for_pg_stop()
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
self._test.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():
self._test.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
self._test.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) / ARP(
op=ARP.who_has,
pdst=self.local_ip4,
psrc=self.remote_ip4,
hwsrc=self.remote_mac,
)
def create_ndp_req(self, addr=None):
"""Create NDP - NS applicable for this interface"""
if not addr:
addr = self.local_ip6
nsma = in6_getnsma(inet_pton(socket.AF_INET6, addr))
d = inet_ntop(socket.AF_INET6, nsma)
return (
Ether(dst=in6_getnsmac(nsma))
/ IPv6(dst=d, src=self.remote_ip6)
/ ICMPv6ND_NS(tgt=addr)
/ 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:
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 = captured_packet.copy() # keep original for exception
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:", captured_packet)
)
raise
def resolve_ndp(self, pg_interface=None, timeout=1, link_layer=False):
"""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
:param link_layer: resolve for global address if False (default)
or for link-layer address if True
"""
if pg_interface is None:
pg_interface = self
addr = self.local_ip6_ll if link_layer else self.local_ip6
self.test.logger.info(
"Sending NDP request for %s on port %s" % (addr, pg_interface.name)
)
ndp_req = self.create_ndp_req(addr)
pg_interface.add_stream(ndp_req)
pg_interface.enable_capture()
self.test.pg_start()
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
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")