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