test/vpp_pg_interface.py

   1 import os
   2 import time
   3 from scapy.utils import wrpcap, rdpcap, PcapReader
   4 from vpp_interface import VppInterface
   5
   6 from scapy.layers.l2 import Ether, ARP
   7 from scapy.layers.inet6 import IPv6, ICMPv6ND_NS, ICMPv6ND_NA,\
   8     ICMPv6NDOptSrcLLAddr, ICMPv6NDOptDstLLAddr, ICMPv6ND_RA, RouterAlert, \
   9     IPv6ExtHdrHopByHop
  10 from util import ppp, ppc
  11
  12
  13 def is_ipv6_misc(p):
  14     """ Is packet one of uninteresting IPv6 broadcasts? """
  15     if p.haslayer(ICMPv6ND_RA):
  16         return True
  17     if p.haslayer(IPv6ExtHdrHopByHop):
  18         for o in p[IPv6ExtHdrHopByHop].options:
  19             if isinstance(o, RouterAlert):
  20                 return True
  21     return False
  22
  23
  24 class VppPGInterface(VppInterface):
  25     """
  26     VPP packet-generator interface
  27     """
  28
  29     @property
  30     def pg_index(self):
  31         """packet-generator interface index assigned by VPP"""
  32         return self._pg_index
  33
  34     @property
  35     def out_path(self):
  36         """pcap file path - captured packets"""
  37         return self._out_path
  38
  39     @property
  40     def in_path(self):
  41         """ pcap file path - injected packets"""
  42         return self._in_path
  43
  44     @property
  45     def capture_cli(self):
  46         """CLI string to start capture on this interface"""
  47         return self._capture_cli
  48
  49     @property
  50     def cap_name(self):
  51         """capture name for this interface"""
  52         return self._cap_name
  53
  54     @property
  55     def input_cli(self):
  56         """CLI string to load the injected packets"""
  57         return self._input_cli
  58
  59     @property
  60     def in_history_counter(self):
  61         """Self-incrementing counter used when renaming old pcap files"""
  62         v = self._in_history_counter
  63         self._in_history_counter += 1
  64         return v
  65
  66     @property
  67     def out_history_counter(self):
  68         """Self-incrementing counter used when renaming old pcap files"""
  69         v = self._out_history_counter
  70         self._out_history_counter += 1
  71         return v
  72
  73     def __init__(self, test, pg_index):
  74         """ Create VPP packet-generator interface """
  75         r = test.vapi.pg_create_interface(pg_index)
  76         self._sw_if_index = r.sw_if_index
  77
  78         super(VppPGInterface, self).__init__(test)
  79
  80         self._in_history_counter = 0
  81         self._out_history_counter = 0
  82         self._pg_index = pg_index
  83         self._out_file = "pg%u_out.pcap" % self.pg_index
  84         self._out_path = self.test.tempdir + "/" + self._out_file
  85         self._in_file = "pg%u_in.pcap" % self.pg_index
  86         self._in_path = self.test.tempdir + "/" + self._in_file
  87         self._capture_cli = "packet-generator capture pg%u pcap %s" % (
  88             self.pg_index, self.out_path)
  89         self._cap_name = "pcap%u" % self.sw_if_index
  90         self._input_cli = "packet-generator new pcap %s source pg%u name %s" % (
  91             self.in_path, self.pg_index, self.cap_name)
  92
  93     def enable_capture(self):
  94         """ Enable capture on this packet-generator interface"""
  95         try:
  96             if os.path.isfile(self.out_path):
  97                 os.rename(self.out_path,
  98                           "%s/history.[timestamp:%f].[%s-counter:%04d].%s" %
  99                           (self.test.tempdir,
 100                            time.time(),
 101                            self.name,
 102                            self.out_history_counter,
 103                            self._out_file))
 104         except:
 105             pass
 106         # FIXME this should be an API, but no such exists atm
 107         self.test.vapi.cli(self.capture_cli)
 108         self._pcap_reader = None
 109
 110     def add_stream(self, pkts):
 111         """
 112         Add a stream of packets to this packet-generator
 113
 114         :param pkts: iterable packets
 115
 116         """
 117         try:
 118             if os.path.isfile(self.in_path):
 119                 os.rename(self.in_path,
 120                           "%s/history.[timestamp:%f].[%s-counter:%04d].%s" %
 121                           (self.test.tempdir,
 122                            time.time(),
 123                            self.name,
 124                            self.in_history_counter,
 125                            self._in_file))
 126         except:
 127             pass
 128         wrpcap(self.in_path, pkts)
 129         self.test.register_capture(self.cap_name)
 130         # FIXME this should be an API, but no such exists atm
 131         self.test.vapi.cli(self.input_cli)
 132
 133     def get_capture(self, remark=None, filter_fn=is_ipv6_misc):
 134         """
 135         Get captured packets
 136
 137         :param remark: remark printed into debug logs
 138         :param filter_fn: filter applied to each packet, packets for which
 139                           the filter returns True are removed from capture
 140         :returns: iterable packets
 141         """
 142         try:
 143             self.wait_for_capture_file()
 144             output = rdpcap(self.out_path)
 145             self.test.logger.debug("Capture has %s packets" % len(output.res))
 146         except IOError:  # TODO
 147             self.test.logger.debug("File %s does not exist, probably because no"
 148                                    " packets arrived" % self.out_path)
 149             if remark:
 150                 raise Exception("No packets captured on %s(%s)" %
 151                                 (self.name, remark))
 152             else:
 153                 raise Exception("No packets captured on %s" % self.name)
 154         before = len(output.res)
 155         if filter_fn:
 156             output.res = [p for p in output.res if not filter_fn(p)]
 157         removed = len(output.res) - before
 158         if removed:
 159             self.test.logger.debug(
 160                 "Filtered out %s packets from capture (returning %s)" %
 161                 (removed, len(output.res)))
 162         return output
 163
 164     def assert_nothing_captured(self, remark=None):
 165         if os.path.isfile(self.out_path):
 166             try:
 167                 capture = self.get_capture(remark=remark)
 168                 self.test.logger.error(
 169                     ppc("Unexpected packets captured:", capture))
 170             except:
 171                 pass
 172             if remark:
 173                 raise AssertionError(
 174                     "Capture file present for interface %s(%s)" %
 175                     (self.name, remark))
 176             else:
 177                 raise AssertionError("Capture file present for interface %s" %
 178                                      self.name)
 179
 180     def wait_for_capture_file(self, timeout=1):
 181         """
 182         Wait until pcap capture file appears
 183
 184         :param timeout: How long to wait for the packet (default 1s)
 185
 186         :raises Exception: if the capture file does not appear within timeout
 187         """
 188         limit = time.time() + timeout
 189         if not os.path.isfile(self.out_path):
 190             self.test.logger.debug(
 191                 "Waiting for capture file to appear, timeout is %ss", timeout)
 192         else:
 193             self.test.logger.debug("Capture file already exists")
 194             return
 195         while time.time() < limit:
 196             if os.path.isfile(self.out_path):
 197                 break
 198             time.sleep(0)  # yield
 199         if os.path.isfile(self.out_path):
 200             self.test.logger.debug("Capture file appeared after %fs" %
 201                                    (time.time() - (limit - timeout)))
 202         else:
 203             self.test.logger.debug("Timeout - capture file still nowhere")
 204             raise Exception("Capture file did not appear within timeout")
 205
 206     def wait_for_packet(self, timeout):
 207         """
 208         Wait for next packet captured with a timeout
 209
 210         :param timeout: How long to wait for the packet
 211
 212         :returns: Captured packet if no packet arrived within timeout
 213         :raises Exception: if no packet arrives within timeout
 214         """
 215         limit = time.time() + timeout
 216         if self._pcap_reader is None:
 217             self.wait_for_capture_file(timeout)
 218             self._pcap_reader = PcapReader(self.out_path)
 219
 220         self.test.logger.debug("Waiting for packet")
 221         while time.time() < limit:
 222             p = self._pcap_reader.recv()
 223             if p is not None:
 224                 self.test.logger.debug("Packet received after %fs",
 225                                        (time.time() - (limit - timeout)))
 226                 return p
 227             time.sleep(0)  # yield
 228         self.test.logger.debug("Timeout - no packets received")
 229         raise Exception("Packet didn't arrive within timeout")
 230
 231     def create_arp_req(self):
 232         """Create ARP request applicable for this interface"""
 233         return (Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) /
 234                 ARP(op=ARP.who_has, pdst=self.local_ip4,
 235                     psrc=self.remote_ip4, hwsrc=self.remote_mac))
 236
 237     def create_ndp_req(self):
 238         """Create NDP - NS applicable for this interface"""
 239         return (Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) /
 240                 IPv6(src=self.remote_ip6, dst=self.local_ip6) /
 241                 ICMPv6ND_NS(tgt=self.local_ip6) /
 242                 ICMPv6NDOptSrcLLAddr(lladdr=self.remote_mac))
 243
 244     def resolve_arp(self, pg_interface=None):
 245         """Resolve ARP using provided packet-generator interface
 246
 247         :param pg_interface: interface used to resolve, if None then this
 248             interface is used
 249
 250         """
 251         if pg_interface is None:
 252             pg_interface = self
 253         self.test.logger.info("Sending ARP request for %s on port %s" %
 254                               (self.local_ip4, pg_interface.name))
 255         arp_req = self.create_arp_req()
 256         pg_interface.add_stream(arp_req)
 257         pg_interface.enable_capture()
 258         self.test.pg_start()
 259         self.test.logger.info(self.test.vapi.cli("show trace"))
 260         try:
 261             arp_reply = pg_interface.get_capture(filter_fn=None)
 262         except:
 263             self.test.logger.info("No ARP received on port %s" %
 264                                   pg_interface.name)
 265             return
 266         arp_reply = arp_reply[0]
 267         # Make Dot1AD packet content recognizable to scapy
 268         if arp_reply.type == 0x88a8:
 269             arp_reply.type = 0x8100
 270             arp_reply = Ether(str(arp_reply))
 271         try:
 272             if arp_reply[ARP].op == ARP.is_at:
 273                 self.test.logger.info("VPP %s MAC address is %s " %
 274                                       (self.name, arp_reply[ARP].hwsrc))
 275                 self._local_mac = arp_reply[ARP].hwsrc
 276             else:
 277                 self.test.logger.info(
 278                     "No ARP received on port %s" %
 279                     pg_interface.name)
 280         except:
 281             self.test.logger.error(
 282                 ppp("Unexpected response to ARP request:", arp_reply))
 283             raise
 284
 285     def resolve_ndp(self, pg_interface=None):
 286         """Resolve NDP using provided packet-generator interface
 287
 288         :param pg_interface: interface used to resolve, if None then this
 289             interface is used
 290
 291         """
 292         if pg_interface is None:
 293             pg_interface = self
 294         self.test.logger.info("Sending NDP request for %s on port %s" %
 295                               (self.local_ip6, pg_interface.name))
 296         ndp_req = self.create_ndp_req()
 297         pg_interface.add_stream(ndp_req)
 298         pg_interface.enable_capture()
 299         self.test.pg_start()
 300         self.test.logger.info(self.test.vapi.cli("show trace"))
 301         replies = pg_interface.get_capture(filter_fn=None)
 302         if replies is None or len(replies) == 0:
 303             self.test.logger.info(
 304                 "No NDP received on port %s" %
 305                 pg_interface.name)
 306             return
 307         # Enabling IPv6 on an interface can generate more than the
 308         # ND reply we are looking for (namely MLD). So loop through
 309         # the replies to look for want we want.
 310         for ndp_reply in replies:
 311             # Make Dot1AD packet content recognizable to scapy
 312             if ndp_reply.type == 0x88a8:
 313                 ndp_reply.type = 0x8100
 314                 ndp_reply = Ether(str(ndp_reply))
 315             try:
 316                 ndp_na = ndp_reply[ICMPv6ND_NA]
 317                 opt = ndp_na[ICMPv6NDOptDstLLAddr]
 318                 self.test.logger.info("VPP %s MAC address is %s " %
 319                                       (self.name, opt.lladdr))
 320                 self._local_mac = opt.lladdr
 321             except:
 322                 self.test.logger.info(
 323                     ppp("Unexpected response to NDP request:", ndp_reply))
 324         # if no packets above provided the local MAC, then this failed.
 325         if not hasattr(self, '_local_mac'):
 326             raise