| 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") |