test/util.py

   1 """ test framework utilities """
   2
   3 import socket
   4 import sys
   5 from abc import abstractmethod, ABCMeta
   6 from cStringIO import StringIO
   7 from scapy.layers.inet6 import in6_mactoifaceid
   8
   9 from scapy.layers.l2 import Ether
  10 from scapy.packet import Raw
  11 from scapy.layers.inet import IP
  12 from scapy.layers.inet6 import IPv6, IPv6ExtHdrFragment, IPv6ExtHdrRouting,\
  13     IPv6ExtHdrHopByHop
  14 from socket import AF_INET6
  15
  16
  17 def ppp(headline, packet):
  18     """ Return string containing the output of scapy packet.show() call. """
  19     o = StringIO()
  20     old_stdout = sys.stdout
  21     sys.stdout = o
  22     print(headline)
  23     packet.show()
  24     sys.stdout = old_stdout
  25     return o.getvalue()
  26
  27
  28 def ppc(headline, capture, limit=10):
  29     """ Return string containing ppp() printout for a capture.
  30
  31     :param headline: printed as first line of output
  32     :param capture: packets to print
  33     :param limit: limit the print to # of packets
  34     """
  35     if not capture:
  36         return headline
  37     tail = ""
  38     if limit < len(capture):
  39         tail = "\nPrint limit reached, %s out of %s packets printed" % (
  40             limit, len(capture))
  41     body = "".join([ppp("Packet #%s:" % count, p)
  42                     for count, p in zip(range(0, limit), capture)])
  43     return "%s\n%s%s" % (headline, body, tail)
  44
  45
  46 def ip4_range(ip4, s, e):
  47     tmp = ip4.rsplit('.', 1)[0]
  48     return ("%s.%d" % (tmp, i) for i in range(s, e))
  49
  50
  51 def ip4n_range(ip4n, s, e):
  52     ip4 = socket.inet_ntop(socket.AF_INET, ip4n)
  53     return (socket.inet_pton(socket.AF_INET, ip)
  54             for ip in ip4_range(ip4, s, e))
  55
  56
  57 def mactobinary(mac):
  58     """ Convert the : separated format into binary packet data for the API """
  59     return mac.replace(':', '').decode('hex')
  60
  61
  62 def mk_ll_addr(mac):
  63     euid = in6_mactoifaceid(mac)
  64     addr = "fe80::" + euid
  65     return addr
  66
  67
  68 class NumericConstant(object):
  69     __metaclass__ = ABCMeta
  70
  71     desc_dict = {}
  72
  73     @abstractmethod
  74     def __init__(self, value):
  75         self._value = value
  76
  77     def __int__(self):
  78         return self._value
  79
  80     def __long__(self):
  81         return self._value
  82
  83     def __str__(self):
  84         if self._value in self.desc_dict:
  85             return self.desc_dict[self._value]
  86         return ""
  87
  88
  89 class Host(object):
  90     """ Generic test host "connected" to VPPs interface. """
  91
  92     @property
  93     def mac(self):
  94         """ MAC address """
  95         return self._mac
  96
  97     @property
  98     def bin_mac(self):
  99         """ MAC address """
 100         return mactobinary(self._mac)
 101
 102     @property
 103     def ip4(self):
 104         """ IPv4 address - string """
 105         return self._ip4
 106
 107     @property
 108     def ip4n(self):
 109         """ IPv4 address of remote host - raw, suitable as API parameter."""
 110         return socket.inet_pton(socket.AF_INET, self._ip4)
 111
 112     @property
 113     def ip6(self):
 114         """ IPv6 address - string """
 115         return self._ip6
 116
 117     @property
 118     def ip6n(self):
 119         """ IPv6 address of remote host - raw, suitable as API parameter."""
 120         return socket.inet_pton(socket.AF_INET6, self._ip6)
 121
 122     @property
 123     def ip6_ll(self):
 124         """ IPv6 link-local address - string """
 125         return self._ip6_ll
 126
 127     @property
 128     def ip6n_ll(self):
 129         """ IPv6 link-local address of remote host -
 130         raw, suitable as API parameter."""
 131         return socket.inet_pton(socket.AF_INET6, self._ip6_ll)
 132
 133     def __eq__(self, other):
 134         if isinstance(other, Host):
 135             return (self.mac == other.mac and
 136                     self.ip4 == other.ip4 and
 137                     self.ip6 == other.ip6 and
 138                     self.ip6_ll == other.ip6_ll)
 139         else:
 140             return False
 141
 142     def __ne__(self, other):
 143         return not self.__eq__(other)
 144
 145     def __repr__(self):
 146         return "Host { mac:%s ip4:%s ip6:%s ip6_ll:%s }" % (self.mac,
 147                                                             self.ip4,
 148                                                             self.ip6,
 149                                                             self.ip6_ll)
 150
 151     def __hash__(self):
 152         return hash(self.__repr__())
 153
 154     def __init__(self, mac=None, ip4=None, ip6=None, ip6_ll=None):
 155         self._mac = mac
 156         self._ip4 = ip4
 157         self._ip6 = ip6
 158         self._ip6_ll = ip6_ll
 159
 160
 161 class ForeignAddressFactory(object):
 162     count = 0
 163     prefix_len = 24
 164     net_template = '10.10.10.{}'
 165     net = net_template.format(0) + '/' + str(prefix_len)
 166
 167     def get_ip4(self):
 168         if self.count > 255:
 169             raise Exception("Network host address exhaustion")
 170         self.count += 1
 171         return self.net_template.format(self.count)
 172
 173
 174 class L4_Conn():
 175     """ L4 'connection' tied to two VPP interfaces """
 176
 177     def __init__(self, testcase, if1, if2, af, l4proto, port1, port2):
 178         self.testcase = testcase
 179         self.ifs = [None, None]
 180         self.ifs[0] = if1
 181         self.ifs[1] = if2
 182         self.address_family = af
 183         self.l4proto = l4proto
 184         self.ports = [None, None]
 185         self.ports[0] = port1
 186         self.ports[1] = port2
 187         self
 188
 189     def pkt(self, side, l4args={}, payload="x"):
 190         is_ip6 = 1 if self.address_family == AF_INET6 else 0
 191         s0 = side
 192         s1 = 1 - side
 193         src_if = self.ifs[s0]
 194         dst_if = self.ifs[s1]
 195         layer_3 = [IP(src=src_if.remote_ip4, dst=dst_if.remote_ip4),
 196                    IPv6(src=src_if.remote_ip6, dst=dst_if.remote_ip6)]
 197         merged_l4args = {'sport': self.ports[s0], 'dport': self.ports[s1]}
 198         merged_l4args.update(l4args)
 199         p = (Ether(dst=src_if.local_mac, src=src_if.remote_mac) /
 200              layer_3[is_ip6] /
 201              self.l4proto(**merged_l4args) /
 202              Raw(payload))
 203         return p
 204
 205     def send(self, side, flags=None, payload=""):
 206         l4args = {}
 207         if flags is not None:
 208             l4args['flags'] = flags
 209         self.ifs[side].add_stream(self.pkt(side,
 210                                            l4args=l4args, payload=payload))
 211         self.ifs[1 - side].enable_capture()
 212         self.testcase.pg_start()
 213
 214     def recv(self, side):
 215         p = self.ifs[side].wait_for_packet(1)
 216         return p
 217
 218     def send_through(self, side, flags=None, payload=""):
 219         self.send(side, flags, payload)
 220         p = self.recv(1 - side)
 221         return p
 222
 223     def send_pingpong(self, side, flags1=None, flags2=None):
 224         p1 = self.send_through(side, flags1)
 225         p2 = self.send_through(1 - side, flags2)
 226         return [p1, p2]
 227
 228
 229 class L4_CONN_SIDE:
 230     L4_CONN_SIDE_ZERO = 0
 231     L4_CONN_SIDE_ONE = 1
 232
 233
 234 class LoggerWrapper(object):
 235     def __init__(self, logger=None):
 236         self._logger = logger
 237
 238     def debug(self, *args, **kwargs):
 239         if self._logger:
 240             self._logger.debug(*args, **kwargs)
 241
 242     def error(self, *args, **kwargs):
 243         if self._logger:
 244             self._logger.error(*args, **kwargs)
 245
 246
 247 def fragment_rfc791(packet, fragsize, _logger=None):
 248     """
 249     Fragment an IPv4 packet per RFC 791
 250     :param packet: packet to fragment
 251     :param fragsize: size at which to fragment
 252     :note: IP options are not supported
 253     :returns: list of fragments
 254     """
 255     logger = LoggerWrapper(_logger)
 256     logger.debug(ppp("Fragmenting packet:", packet))
 257     packet = packet.__class__(str(packet))  # recalculate all values
 258     if len(packet[IP].options) > 0:
 259         raise Exception("Not implemented")
 260     if len(packet) <= fragsize:
 261         return [packet]
 262
 263     pre_ip_len = len(packet) - len(packet[IP])
 264     ip_header_len = packet[IP].ihl * 4
 265     hex_packet = str(packet)
 266     hex_headers = hex_packet[:(pre_ip_len + ip_header_len)]
 267     hex_payload = hex_packet[(pre_ip_len + ip_header_len):]
 268
 269     pkts = []
 270     ihl = packet[IP].ihl
 271     otl = len(packet[IP])
 272     nfb = (fragsize - pre_ip_len - ihl * 4) / 8
 273     fo = packet[IP].frag
 274
 275     p = packet.__class__(hex_headers + hex_payload[:nfb * 8])
 276     p[IP].flags = "MF"
 277     p[IP].frag = fo
 278     p[IP].len = ihl * 4 + nfb * 8
 279     del p[IP].chksum
 280     pkts.append(p)
 281
 282     p = packet.__class__(hex_headers + hex_payload[nfb * 8:])
 283     p[IP].len = otl - nfb * 8
 284     p[IP].frag = fo + nfb
 285     del p[IP].chksum
 286
 287     more_fragments = fragment_rfc791(p, fragsize, _logger)
 288     pkts.extend(more_fragments)
 289
 290     return pkts
 291
 292
 293 def fragment_rfc8200(packet, identification, fragsize, _logger=None):
 294     """
 295     Fragment an IPv6 packet per RFC 8200
 296     :param packet: packet to fragment
 297     :param fragsize: size at which to fragment
 298     :note: IP options are not supported
 299     :returns: list of fragments
 300     """
 301     logger = LoggerWrapper(_logger)
 302     packet = packet.__class__(str(packet))  # recalculate all values
 303     if len(packet) <= fragsize:
 304         return [packet]
 305     logger.debug(ppp("Fragmenting packet:", packet))
 306     pkts = []
 307     counter = 0
 308     routing_hdr = None
 309     hop_by_hop_hdr = None
 310     upper_layer = None
 311     seen_ipv6 = False
 312     ipv6_nr = -1
 313     l = packet.getlayer(counter)
 314     while l is not None:
 315         if l.__class__ is IPv6:
 316             if seen_ipv6:
 317                 # ignore 2nd IPv6 header and everything below..
 318                 break
 319             ipv6_nr = counter
 320             seen_ipv6 = True
 321         elif l.__class__ is IPv6ExtHdrFragment:
 322             raise Exception("Already fragmented")
 323         elif l.__class__ is IPv6ExtHdrRouting:
 324             routing_hdr = counter
 325         elif l.__class__ is IPv6ExtHdrHopByHop:
 326             hop_by_hop_hdr = counter
 327         elif seen_ipv6 and not upper_layer and \
 328                 not l.__class__.__name__.startswith('IPv6ExtHdr'):
 329             upper_layer = counter
 330         counter = counter + 1
 331         l = packet.getlayer(counter)
 332
 333     logger.debug(
 334         "Layers seen: IPv6(#%s), Routing(#%s), HopByHop(#%s), upper(#%s)" %
 335         (ipv6_nr, routing_hdr, hop_by_hop_hdr, upper_layer))
 336
 337     if upper_layer is None:
 338         raise Exception("Upper layer header not found in IPv6 packet")
 339
 340     last_per_fragment_hdr = ipv6_nr
 341     if routing_hdr is None:
 342         if hop_by_hop_hdr is not None:
 343             last_per_fragment_hdr = hop_by_hop_hdr
 344     else:
 345         last_per_fragment_hdr = routing_hdr
 346     logger.debug("Last per-fragment hdr is #%s" % (last_per_fragment_hdr))
 347
 348     per_fragment_headers = packet.copy()
 349     per_fragment_headers[last_per_fragment_hdr].remove_payload()
 350     logger.debug(ppp("Per-fragment headers:", per_fragment_headers))
 351
 352     ext_and_upper_layer = packet.getlayer(last_per_fragment_hdr)[1]
 353     hex_payload = str(ext_and_upper_layer)
 354     logger.debug("Payload length is %s" % len(hex_payload))
 355     logger.debug(ppp("Ext and upper layer:", ext_and_upper_layer))
 356
 357     fragment_ext_hdr = IPv6ExtHdrFragment()
 358     logger.debug(ppp("Fragment header:", fragment_ext_hdr))
 359
 360     if len(per_fragment_headers) + len(fragment_ext_hdr) +\
 361             len(ext_and_upper_layer) - len(ext_and_upper_layer.payload)\
 362             > fragsize:
 363         raise Exception("Cannot fragment this packet - MTU too small "
 364                         "(%s, %s, %s, %s, %s)" % (
 365                             len(per_fragment_headers), len(fragment_ext_hdr),
 366                             len(ext_and_upper_layer),
 367                             len(ext_and_upper_layer.payload), fragsize))
 368
 369     orig_nh = packet[IPv6].nh
 370     p = per_fragment_headers
 371     del p[IPv6].plen
 372     del p[IPv6].nh
 373     p = p / fragment_ext_hdr
 374     del p[IPv6ExtHdrFragment].nh
 375     first_payload_len_nfb = (fragsize - len(p)) / 8
 376     p = p / Raw(hex_payload[:first_payload_len_nfb * 8])
 377     del p[IPv6].plen
 378     p[IPv6ExtHdrFragment].nh = orig_nh
 379     p[IPv6ExtHdrFragment].id = identification
 380     p[IPv6ExtHdrFragment].offset = 0
 381     p[IPv6ExtHdrFragment].m = 1
 382     p = p.__class__(str(p))
 383     logger.debug(ppp("Fragment %s:" % len(pkts), p))
 384     pkts.append(p)
 385     offset = first_payload_len_nfb * 8
 386     logger.debug("Offset after first fragment: %s" % offset)
 387     while len(hex_payload) > offset:
 388         p = per_fragment_headers
 389         del p[IPv6].plen
 390         del p[IPv6].nh
 391         p = p / fragment_ext_hdr
 392         del p[IPv6ExtHdrFragment].nh
 393         l_nfb = (fragsize - len(p)) / 8
 394         p = p / Raw(hex_payload[offset:offset + l_nfb * 8])
 395         p[IPv6ExtHdrFragment].nh = orig_nh
 396         p[IPv6ExtHdrFragment].id = identification
 397         p[IPv6ExtHdrFragment].offset = offset / 8
 398         p[IPv6ExtHdrFragment].m = 1
 399         p = p.__class__(str(p))
 400         logger.debug(ppp("Fragment %s:" % len(pkts), p))
 401         pkts.append(p)
 402         offset = offset + l_nfb * 8
 403
 404     pkts[-1][IPv6ExtHdrFragment].m = 0  # reset more-flags in last fragment
 405
 406     return pkts