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 def ip6_normalize(ip6):
  69     return socket.inet_ntop(socket.AF_INET6,
  70                             socket.inet_pton(socket.AF_INET6, ip6))
  71
  72
  73 class NumericConstant(object):
  74     __metaclass__ = ABCMeta
  75
  76     desc_dict = {}
  77
  78     @abstractmethod
  79     def __init__(self, value):
  80         self._value = value
  81
  82     def __int__(self):
  83         return self._value
  84
  85     def __long__(self):
  86         return self._value
  87
  88     def __str__(self):
  89         if self._value in self.desc_dict:
  90             return self.desc_dict[self._value]
  91         return ""
  92
  93
  94 class Host(object):
  95     """ Generic test host "connected" to VPPs interface. """
  96
  97     @property
  98     def mac(self):
  99         """ MAC address """
 100         return self._mac
 101
 102     @property
 103     def bin_mac(self):
 104         """ MAC address """
 105         return mactobinary(self._mac)
 106
 107     @property
 108     def ip4(self):
 109         """ IPv4 address - string """
 110         return self._ip4
 111
 112     @property
 113     def ip4n(self):
 114         """ IPv4 address of remote host - raw, suitable as API parameter."""
 115         return socket.inet_pton(socket.AF_INET, self._ip4)
 116
 117     @property
 118     def ip6(self):
 119         """ IPv6 address - string """
 120         return self._ip6
 121
 122     @property
 123     def ip6n(self):
 124         """ IPv6 address of remote host - raw, suitable as API parameter."""
 125         return socket.inet_pton(socket.AF_INET6, self._ip6)
 126
 127     @property
 128     def ip6_ll(self):
 129         """ IPv6 link-local address - string """
 130         return self._ip6_ll
 131
 132     @property
 133     def ip6n_ll(self):
 134         """ IPv6 link-local address of remote host -
 135         raw, suitable as API parameter."""
 136         return socket.inet_pton(socket.AF_INET6, self._ip6_ll)
 137
 138     def __eq__(self, other):
 139         if isinstance(other, Host):
 140             return (self.mac == other.mac and
 141                     self.ip4 == other.ip4 and
 142                     self.ip6 == other.ip6 and
 143                     self.ip6_ll == other.ip6_ll)
 144         else:
 145             return False
 146
 147     def __ne__(self, other):
 148         return not self.__eq__(other)
 149
 150     def __repr__(self):
 151         return "Host { mac:%s ip4:%s ip6:%s ip6_ll:%s }" % (self.mac,
 152                                                             self.ip4,
 153                                                             self.ip6,
 154                                                             self.ip6_ll)
 155
 156     def __hash__(self):
 157         return hash(self.__repr__())
 158
 159     def __init__(self, mac=None, ip4=None, ip6=None, ip6_ll=None):
 160         self._mac = mac
 161         self._ip4 = ip4
 162         self._ip6 = ip6
 163         self._ip6_ll = ip6_ll
 164
 165
 166 class ForeignAddressFactory(object):
 167     count = 0
 168     prefix_len = 24
 169     net_template = '10.10.10.{}'
 170     net = net_template.format(0) + '/' + str(prefix_len)
 171
 172     def get_ip4(self):
 173         if self.count > 255:
 174             raise Exception("Network host address exhaustion")
 175         self.count += 1
 176         return self.net_template.format(self.count)
 177
 178
 179 class L4_Conn():
 180     """ L4 'connection' tied to two VPP interfaces """
 181
 182     def __init__(self, testcase, if1, if2, af, l4proto, port1, port2):
 183         self.testcase = testcase
 184         self.ifs = [None, None]
 185         self.ifs[0] = if1
 186         self.ifs[1] = if2
 187         self.address_family = af
 188         self.l4proto = l4proto
 189         self.ports = [None, None]
 190         self.ports[0] = port1
 191         self.ports[1] = port2
 192         self
 193
 194     def pkt(self, side, l4args={}, payload="x"):
 195         is_ip6 = 1 if self.address_family == AF_INET6 else 0
 196         s0 = side
 197         s1 = 1 - side
 198         src_if = self.ifs[s0]
 199         dst_if = self.ifs[s1]
 200         layer_3 = [IP(src=src_if.remote_ip4, dst=dst_if.remote_ip4),
 201                    IPv6(src=src_if.remote_ip6, dst=dst_if.remote_ip6)]
 202         merged_l4args = {'sport': self.ports[s0], 'dport': self.ports[s1]}
 203         merged_l4args.update(l4args)
 204         p = (Ether(dst=src_if.local_mac, src=src_if.remote_mac) /
 205              layer_3[is_ip6] /
 206              self.l4proto(**merged_l4args) /
 207              Raw(payload))
 208         return p
 209
 210     def send(self, side, flags=None, payload=""):
 211         l4args = {}
 212         if flags is not None:
 213             l4args['flags'] = flags
 214         self.ifs[side].add_stream(self.pkt(side,
 215                                            l4args=l4args, payload=payload))
 216         self.ifs[1 - side].enable_capture()
 217         self.testcase.pg_start()
 218
 219     def recv(self, side):
 220         p = self.ifs[side].wait_for_packet(1)
 221         return p
 222
 223     def send_through(self, side, flags=None, payload=""):
 224         self.send(side, flags, payload)
 225         p = self.recv(1 - side)
 226         return p
 227
 228     def send_pingpong(self, side, flags1=None, flags2=None):
 229         p1 = self.send_through(side, flags1)
 230         p2 = self.send_through(1 - side, flags2)
 231         return [p1, p2]
 232
 233
 234 class L4_CONN_SIDE:
 235     L4_CONN_SIDE_ZERO = 0
 236     L4_CONN_SIDE_ONE = 1
 237
 238
 239 class LoggerWrapper(object):
 240     def __init__(self, logger=None):
 241         self._logger = logger
 242
 243     def debug(self, *args, **kwargs):
 244         if self._logger:
 245             self._logger.debug(*args, **kwargs)
 246
 247     def error(self, *args, **kwargs):
 248         if self._logger:
 249             self._logger.error(*args, **kwargs)
 250
 251
 252 def fragment_rfc791(packet, fragsize, _logger=None):
 253     """
 254     Fragment an IPv4 packet per RFC 791
 255     :param packet: packet to fragment
 256     :param fragsize: size at which to fragment
 257     :note: IP options are not supported
 258     :returns: list of fragments
 259     """
 260     logger = LoggerWrapper(_logger)
 261     logger.debug(ppp("Fragmenting packet:", packet))
 262     packet = packet.__class__(str(packet))  # recalculate all values
 263     if len(packet[IP].options) > 0:
 264         raise Exception("Not implemented")
 265     if len(packet) <= fragsize:
 266         return [packet]
 267
 268     pre_ip_len = len(packet) - len(packet[IP])
 269     ip_header_len = packet[IP].ihl * 4
 270     hex_packet = str(packet)
 271     hex_headers = hex_packet[:(pre_ip_len + ip_header_len)]
 272     hex_payload = hex_packet[(pre_ip_len + ip_header_len):]
 273
 274     pkts = []
 275     ihl = packet[IP].ihl
 276     otl = len(packet[IP])
 277     nfb = (fragsize - pre_ip_len - ihl * 4) / 8
 278     fo = packet[IP].frag
 279
 280     p = packet.__class__(hex_headers + hex_payload[:nfb * 8])
 281     p[IP].flags = "MF"
 282     p[IP].frag = fo
 283     p[IP].len = ihl * 4 + nfb * 8
 284     del p[IP].chksum
 285     pkts.append(p)
 286
 287     p = packet.__class__(hex_headers + hex_payload[nfb * 8:])
 288     p[IP].len = otl - nfb * 8
 289     p[IP].frag = fo + nfb
 290     del p[IP].chksum
 291
 292     more_fragments = fragment_rfc791(p, fragsize, _logger)
 293     pkts.extend(more_fragments)
 294
 295     return pkts
 296
 297
 298 def fragment_rfc8200(packet, identification, fragsize, _logger=None):
 299     """
 300     Fragment an IPv6 packet per RFC 8200
 301     :param packet: packet to fragment
 302     :param fragsize: size at which to fragment
 303     :note: IP options are not supported
 304     :returns: list of fragments
 305     """
 306     logger = LoggerWrapper(_logger)
 307     packet = packet.__class__(str(packet))  # recalculate all values
 308     if len(packet) <= fragsize:
 309         return [packet]
 310     logger.debug(ppp("Fragmenting packet:", packet))
 311     pkts = []
 312     counter = 0
 313     routing_hdr = None
 314     hop_by_hop_hdr = None
 315     upper_layer = None
 316     seen_ipv6 = False
 317     ipv6_nr = -1
 318     l = packet.getlayer(counter)
 319     while l is not None:
 320         if l.__class__ is IPv6:
 321             if seen_ipv6:
 322                 # ignore 2nd IPv6 header and everything below..
 323                 break
 324             ipv6_nr = counter
 325             seen_ipv6 = True
 326         elif l.__class__ is IPv6ExtHdrFragment:
 327             raise Exception("Already fragmented")
 328         elif l.__class__ is IPv6ExtHdrRouting:
 329             routing_hdr = counter
 330         elif l.__class__ is IPv6ExtHdrHopByHop:
 331             hop_by_hop_hdr = counter
 332         elif seen_ipv6 and not upper_layer and \
 333                 not l.__class__.__name__.startswith('IPv6ExtHdr'):
 334             upper_layer = counter
 335         counter = counter + 1
 336         l = packet.getlayer(counter)
 337
 338     logger.debug(
 339         "Layers seen: IPv6(#%s), Routing(#%s), HopByHop(#%s), upper(#%s)" %
 340         (ipv6_nr, routing_hdr, hop_by_hop_hdr, upper_layer))
 341
 342     if upper_layer is None:
 343         raise Exception("Upper layer header not found in IPv6 packet")
 344
 345     last_per_fragment_hdr = ipv6_nr
 346     if routing_hdr is None:
 347         if hop_by_hop_hdr is not None:
 348             last_per_fragment_hdr = hop_by_hop_hdr
 349     else:
 350         last_per_fragment_hdr = routing_hdr
 351     logger.debug("Last per-fragment hdr is #%s" % (last_per_fragment_hdr))
 352
 353     per_fragment_headers = packet.copy()
 354     per_fragment_headers[last_per_fragment_hdr].remove_payload()
 355     logger.debug(ppp("Per-fragment headers:", per_fragment_headers))
 356
 357     ext_and_upper_layer = packet.getlayer(last_per_fragment_hdr)[1]
 358     hex_payload = str(ext_and_upper_layer)
 359     logger.debug("Payload length is %s" % len(hex_payload))
 360     logger.debug(ppp("Ext and upper layer:", ext_and_upper_layer))
 361
 362     fragment_ext_hdr = IPv6ExtHdrFragment()
 363     logger.debug(ppp("Fragment header:", fragment_ext_hdr))
 364
 365     if len(per_fragment_headers) + len(fragment_ext_hdr) +\
 366             len(ext_and_upper_layer) - len(ext_and_upper_layer.payload)\
 367             > fragsize:
 368         raise Exception("Cannot fragment this packet - MTU too small "
 369                         "(%s, %s, %s, %s, %s)" % (
 370                             len(per_fragment_headers), len(fragment_ext_hdr),
 371                             len(ext_and_upper_layer),
 372                             len(ext_and_upper_layer.payload), fragsize))
 373
 374     orig_nh = packet[IPv6].nh
 375     p = per_fragment_headers
 376     del p[IPv6].plen
 377     del p[IPv6].nh
 378     p = p / fragment_ext_hdr
 379     del p[IPv6ExtHdrFragment].nh
 380     first_payload_len_nfb = (fragsize - len(p)) / 8
 381     p = p / Raw(hex_payload[:first_payload_len_nfb * 8])
 382     del p[IPv6].plen
 383     p[IPv6ExtHdrFragment].nh = orig_nh
 384     p[IPv6ExtHdrFragment].id = identification
 385     p[IPv6ExtHdrFragment].offset = 0
 386     p[IPv6ExtHdrFragment].m = 1
 387     p = p.__class__(str(p))
 388     logger.debug(ppp("Fragment %s:" % len(pkts), p))
 389     pkts.append(p)
 390     offset = first_payload_len_nfb * 8
 391     logger.debug("Offset after first fragment: %s" % offset)
 392     while len(hex_payload) > offset:
 393         p = per_fragment_headers
 394         del p[IPv6].plen
 395         del p[IPv6].nh
 396         p = p / fragment_ext_hdr
 397         del p[IPv6ExtHdrFragment].nh
 398         l_nfb = (fragsize - len(p)) / 8
 399         p = p / Raw(hex_payload[offset:offset + l_nfb * 8])
 400         p[IPv6ExtHdrFragment].nh = orig_nh
 401         p[IPv6ExtHdrFragment].id = identification
 402         p[IPv6ExtHdrFragment].offset = offset / 8
 403         p[IPv6ExtHdrFragment].m = 1
 404         p = p.__class__(str(p))
 405         logger.debug(ppp("Fragment %s:" % len(pkts), p))
 406         pkts.append(p)
 407         offset = offset + l_nfb * 8
 408
 409     pkts[-1][IPv6ExtHdrFragment].m = 0  # reset more-flags in last fragment
 410
 411     return pkts