vpp/test/vpp_pg_interface.py
Mohsin Kazmi 0b1bd9df33 pg: add support to delete pg interface
Type: improvement

Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>
Change-Id: I3102fded415c644673fb79a0fdb7a7448ce20f26
2024-10-07 08:39:23 +00:00

612 lines
23 KiB
Python

import os
import shutil
import socket
from socket import inet_pton, inet_ntop
import struct
import time
from traceback import format_exc, format_stack
from sh import tshark
from pathlib import Path
from config import config
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 remove_vpp_config(self):
"""delete Pg interface"""
self.disable_capture()
self.test.vapi.pg_delete_interface(sw_if_index=self.sw_if_index)
def link_pcap_file(self, path, direction, counter):
if not config.keep_pcaps:
return
filename = os.path.basename(path)
test_name = (
self.test_name
if hasattr(self, "test_name")
else f"suite{self.test.__name__}"
)
name = f"{self.test.tempdir}/{test_name}.[timestamp:{time.time():.8f}].{self.name}-{direction}-{counter:04}.{filename}"
if os.path.isfile(name):
self.test.logger.debug(
f"Skipping hard link creation: {name} already exists!"
)
return
try:
if os.path.isfile(path):
self.test.logger.debug(f"Creating hard link {path}->{name}")
os.link(path, name)
except OSError:
self.test.logger.debug(
f"OSError: Could not create hard link {path}->{name}"
)
def remove_old_pcap_file(self, path):
self.wait_for_pg_stop()
self.test.unlink_testcase_file(self.test, Path(path))
return
def decode_pcap_files(self, pcap_dir, filename_prefix):
# Generate tshark packet trace of testcase pcap files
pg_decode = f"{pcap_dir}/pcap-decode-{filename_prefix}.txt"
if os.path.isfile(pg_decode):
self.test.logger.debug(
f"The pg streams decode file already exists: {pg_decode}"
)
return
self.test.logger.debug(
f"Generating testcase pg streams decode file: {pg_decode}"
)
ts_opts = "-Vxr"
for p in sorted(Path(pcap_dir).glob(f"{filename_prefix}*.pcap")):
self.test.logger.debug(f"Decoding {p}")
with open(f"{pg_decode}", "a", buffering=1) as f:
print(f"tshark {ts_opts} {p}", file=f)
tshark(ts_opts, f"{p}", _out=f)
print("", file=f)
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.remove_old_pcap_file(self.out_path)
# 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
"""
in_pcap = self.get_in_path(worker)
if os.path.isfile(in_pcap):
self.remove_old_pcap_file(in_pcap)
wrpcap(in_pcap, 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))
self.link_pcap_file(self.get_in_path(worker), "inp", self.in_history_counter)
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(f"Capture has {len(output.res)} packets")
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(
f"Unexpected packets captured, got {len(capture.res)}, expected {expected_count}:",
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} on {name}",
)
msg = f"Captured packets mismatch, captured {len(capture.res)} packets, expected {expected_count} packets on {name}:"
raise Exception(f"{ppc(msg, capture)}")
else:
if 0 == expected_count:
return
raise Exception(f"No packets captured on {name} (timeout = {timeout}s)")
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(
f"Waiting for capture file {self.out_path} to appear, timeout is {timeout}s\n"
f"{' '.join(format_stack(limit=10))}"
)
else:
self.test.logger.debug("Capture file %s already exists" % self.out_path)
self.link_pcap_file(self.out_path, "out", self.out_history_counter)
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
self.link_pcap_file(self.out_path, "out", self.out_history_counter)
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(f"Timeout ({timeout}) - no packets received")
raise CaptureTimeoutError(f"Packet didn't arrive within timeout ({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")