twisted/names/common.py

   1 # -*- test-case-name: twisted.names.test -*-
   2 # Copyright (c) Twisted Matrix Laboratories.
   3 # See LICENSE for details.
   4
   5 """
   6 Base functionality useful to various parts of Twisted Names.
   7 """
   8
   9 import socket
  10
  11 from twisted.names import dns
  12 from twisted.names.error import DNSFormatError, DNSServerError, DNSNameError
  13 from twisted.names.error import DNSNotImplementedError, DNSQueryRefusedError
  14 from twisted.names.error import DNSUnknownError
  15
  16 from twisted.internet import defer, error
  17 from twisted.python import failure
  18
  19 EMPTY_RESULT = (), (), ()
  20
  21 class ResolverBase:
  22     """
  23     L{ResolverBase} is a base class for L{IResolver} implementations which
  24     deals with a lot of the boilerplate of implementing all of the lookup
  25     methods.
  26
  27     @cvar _errormap: A C{dict} mapping DNS protocol failure response codes
  28         to exception classes which will be used to represent those failures.
  29     """
  30     _errormap = {
  31         dns.EFORMAT: DNSFormatError,
  32         dns.ESERVER: DNSServerError,
  33         dns.ENAME: DNSNameError,
  34         dns.ENOTIMP: DNSNotImplementedError,
  35         dns.EREFUSED: DNSQueryRefusedError}
  36
  37     typeToMethod = None
  38
  39     def __init__(self):
  40         self.typeToMethod = {}
  41         for (k, v) in typeToMethod.items():
  42             self.typeToMethod[k] = getattr(self, v)
  43
  44
  45     def exceptionForCode(self, responseCode):
  46         """
  47         Convert a response code (one of the possible values of
  48         L{dns.Message.rCode} to an exception instance representing it.
  49
  50         @since: 10.0
  51         """
  52         return self._errormap.get(responseCode, DNSUnknownError)
  53
  54
  55     def query(self, query, timeout = None):
  56         try:
  57             return self.typeToMethod[query.type](str(query.name), timeout)
  58         except KeyError, e:
  59             return defer.fail(failure.Failure(NotImplementedError(str(self.__class__) + " " + str(query.type))))
  60
  61     def _lookup(self, name, cls, type, timeout):
  62         return defer.fail(NotImplementedError("ResolverBase._lookup"))
  63
  64     def lookupAddress(self, name, timeout = None):
  65         """
  66         @see: twisted.names.client.lookupAddress
  67         """
  68         return self._lookup(name, dns.IN, dns.A, timeout)
  69
  70     def lookupIPV6Address(self, name, timeout = None):
  71         """
  72         @see: twisted.names.client.lookupIPV6Address
  73         """
  74         return self._lookup(name, dns.IN, dns.AAAA, timeout)
  75
  76     def lookupAddress6(self, name, timeout = None):
  77         """
  78         @see: twisted.names.client.lookupAddress6
  79         """
  80         return self._lookup(name, dns.IN, dns.A6, timeout)
  81
  82     def lookupMailExchange(self, name, timeout = None):
  83         """
  84         @see: twisted.names.client.lookupMailExchange
  85         """
  86         return self._lookup(name, dns.IN, dns.MX, timeout)
  87
  88     def lookupNameservers(self, name, timeout = None):
  89         """
  90         @see: twisted.names.client.lookupNameservers
  91         """
  92         return self._lookup(name, dns.IN, dns.NS, timeout)
  93
  94     def lookupCanonicalName(self, name, timeout = None):
  95         """
  96         @see: twisted.names.client.lookupCanonicalName
  97         """
  98         return self._lookup(name, dns.IN, dns.CNAME, timeout)
  99
 100     def lookupMailBox(self, name, timeout = None):
 101         """
 102         @see: twisted.names.client.lookupMailBox
 103         """
 104         return self._lookup(name, dns.IN, dns.MB, timeout)
 105
 106     def lookupMailGroup(self, name, timeout = None):
 107         """
 108         @see: twisted.names.client.lookupMailGroup
 109         """
 110         return self._lookup(name, dns.IN, dns.MG, timeout)
 111
 112     def lookupMailRename(self, name, timeout = None):
 113         """
 114         @see: twisted.names.client.lookupMailRename
 115         """
 116         return self._lookup(name, dns.IN, dns.MR, timeout)
 117
 118     def lookupPointer(self, name, timeout = None):
 119         """
 120         @see: twisted.names.client.lookupPointer
 121         """
 122         return self._lookup(name, dns.IN, dns.PTR, timeout)
 123
 124     def lookupAuthority(self, name, timeout = None):
 125         """
 126         @see: twisted.names.client.lookupAuthority
 127         """
 128         return self._lookup(name, dns.IN, dns.SOA, timeout)
 129
 130     def lookupNull(self, name, timeout = None):
 131         """
 132         @see: twisted.names.client.lookupNull
 133         """
 134         return self._lookup(name, dns.IN, dns.NULL, timeout)
 135
 136     def lookupWellKnownServices(self, name, timeout = None):
 137         """
 138         @see: twisted.names.client.lookupWellKnownServices
 139         """
 140         return self._lookup(name, dns.IN, dns.WKS, timeout)
 141
 142     def lookupService(self, name, timeout = None):
 143         """
 144         @see: twisted.names.client.lookupService
 145         """
 146         return self._lookup(name, dns.IN, dns.SRV, timeout)
 147
 148     def lookupHostInfo(self, name, timeout = None):
 149         """
 150         @see: twisted.names.client.lookupHostInfo
 151         """
 152         return self._lookup(name, dns.IN, dns.HINFO, timeout)
 153
 154     def lookupMailboxInfo(self, name, timeout = None):
 155         """
 156         @see: twisted.names.client.lookupMailboxInfo
 157         """
 158         return self._lookup(name, dns.IN, dns.MINFO, timeout)
 159
 160     def lookupText(self, name, timeout = None):
 161         """
 162         @see: twisted.names.client.lookupText
 163         """
 164         return self._lookup(name, dns.IN, dns.TXT, timeout)
 165
 166     def lookupSenderPolicy(self, name, timeout = None):
 167         """
 168         @see: twisted.names.client.lookupSenderPolicy
 169         """
 170         return self._lookup(name, dns.IN, dns.SPF, timeout)
 171
 172     def lookupResponsibility(self, name, timeout = None):
 173         """
 174         @see: twisted.names.client.lookupResponsibility
 175         """
 176         return self._lookup(name, dns.IN, dns.RP, timeout)
 177
 178     def lookupAFSDatabase(self, name, timeout = None):
 179         """
 180         @see: twisted.names.client.lookupAFSDatabase
 181         """
 182         return self._lookup(name, dns.IN, dns.AFSDB, timeout)
 183
 184     def lookupZone(self, name, timeout = None):
 185         """
 186         @see: twisted.names.client.lookupZone
 187         """
 188         return self._lookup(name, dns.IN, dns.AXFR, timeout)
 189
 190
 191     def lookupNamingAuthorityPointer(self, name, timeout=None):
 192         """
 193         @see: twisted.names.client.lookupNamingAuthorityPointer
 194         """
 195         return self._lookup(name, dns.IN, dns.NAPTR, timeout)
 196
 197
 198     def lookupAllRecords(self, name, timeout = None):
 199         """
 200         @see: twisted.names.client.lookupAllRecords
 201         """
 202         return self._lookup(name, dns.IN, dns.ALL_RECORDS, timeout)
 203
 204     def getHostByName(self, name, timeout = None, effort = 10):
 205         """
 206         @see: twisted.names.client.getHostByName
 207         """
 208         # XXX - respect timeout
 209         return self.lookupAllRecords(name, timeout
 210             ).addCallback(self._cbRecords, name, effort
 211             )
 212
 213     def _cbRecords(self, (ans, auth, add), name, effort):
 214         result = extractRecord(self, dns.Name(name), ans + auth + add, effort)
 215         if not result:
 216             raise error.DNSLookupError(name)
 217         return result
 218
 219
 220 def extractRecord(resolver, name, answers, level=10):
 221     if not level:
 222         return None
 223     if hasattr(socket, 'inet_ntop'):
 224         for r in answers:
 225             if r.name == name and r.type == dns.A6:
 226                 return socket.inet_ntop(socket.AF_INET6, r.payload.address)
 227         for r in answers:
 228             if r.name == name and r.type == dns.AAAA:
 229                 return socket.inet_ntop(socket.AF_INET6, r.payload.address)
 230     for r in answers:
 231         if r.name == name and r.type == dns.A:
 232             return socket.inet_ntop(socket.AF_INET, r.payload.address)
 233     for r in answers:
 234         if r.name == name and r.type == dns.CNAME:
 235             result = extractRecord(
 236                 resolver, r.payload.name, answers, level - 1)
 237             if not result:
 238                 return resolver.getHostByName(
 239                     str(r.payload.name), effort=level - 1)
 240             return result
 241     # No answers, but maybe there's a hint at who we should be asking about
 242     # this
 243     for r in answers:
 244         if r.type == dns.NS:
 245             from twisted.names import client
 246             r = client.Resolver(servers=[(str(r.payload.name), dns.PORT)])
 247             return r.lookupAddress(str(name)
 248                 ).addCallback(
 249                     lambda (ans, auth, add):
 250                         extractRecord(r, name, ans + auth + add, level - 1))
 251
 252
 253 typeToMethod = {
 254     dns.A:     'lookupAddress',
 255     dns.AAAA:  'lookupIPV6Address',
 256     dns.A6:    'lookupAddress6',
 257     dns.NS:    'lookupNameservers',
 258     dns.CNAME: 'lookupCanonicalName',
 259     dns.SOA:   'lookupAuthority',
 260     dns.MB:    'lookupMailBox',
 261     dns.MG:    'lookupMailGroup',
 262     dns.MR:    'lookupMailRename',
 263     dns.NULL:  'lookupNull',
 264     dns.WKS:   'lookupWellKnownServices',
 265     dns.PTR:   'lookupPointer',
 266     dns.HINFO: 'lookupHostInfo',
 267     dns.MINFO: 'lookupMailboxInfo',
 268     dns.MX:    'lookupMailExchange',
 269     dns.TXT:   'lookupText',
 270     dns.SPF:   'lookupSenderPolicy',
 271
 272     dns.RP:    'lookupResponsibility',
 273     dns.AFSDB: 'lookupAFSDatabase',
 274     dns.SRV:   'lookupService',
 275     dns.NAPTR: 'lookupNamingAuthorityPointer',
 276     dns.AXFR:         'lookupZone',
 277     dns.ALL_RECORDS:  'lookupAllRecords',
 278 }