dns.rdatatype

Source Code for Module dns.rdatatype

1 # Copyright (C) 2001-2007, 2009-2011 Nominum, Inc. 2 # 3 # Permission to use, copy, modify, and distribute this software and its 4 # documentation for any purpose with or without fee is hereby granted, 5 # provided that the above copyright notice and this permission notice 6 # appear in all copies. 7 # 8 # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES 9 # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 10 # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR 11 # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 12 # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 13 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 14 # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 15 16 """DNS Rdata Types. 17 18 @var _by_text: The rdata type textual name to value mapping 19 @type _by_text: dict 20 @var _by_value: The rdata type value to textual name mapping 21 @type _by_value: dict 22 @var _metatypes: If an rdatatype is a metatype, there will be a mapping 23 whose key is the rdatatype value and whose value is True in this dictionary. 24 @type _metatypes: dict 25 @var _singletons: If an rdatatype is a singleton, there will be a mapping 26 whose key is the rdatatype value and whose value is True in this dictionary. 27 @type _singletons: dict""" 28 29 import re 30 31 import dns.exception 32 33 NONE = 0 34 A = 1 35 NS = 2 36 MD = 3 37 MF = 4 38 CNAME = 5 39 SOA = 6 40 MB = 7 41 MG = 8 42 MR = 9 43 NULL = 10 44 WKS = 11 45 PTR = 12 46 HINFO = 13 47 MINFO = 14 48 MX = 15 49 TXT = 16 50 RP = 17 51 AFSDB = 18 52 X25 = 19 53 ISDN = 20 54 RT = 21 55 NSAP = 22 56 NSAP_PTR = 23 57 SIG = 24 58 KEY = 25 59 PX = 26 60 GPOS = 27 61 AAAA = 28 62 LOC = 29 63 NXT = 30 64 SRV = 33 65 NAPTR = 35 66 KX = 36 67 CERT = 37 68 A6 = 38 69 DNAME = 39 70 OPT = 41 71 APL = 42 72 DS = 43 73 SSHFP = 44 74 IPSECKEY = 45 75 RRSIG = 46 76 NSEC = 47 77 DNSKEY = 48 78 DHCID = 49 79 NSEC3 = 50 80 NSEC3PARAM = 51 81 TLSA = 52 82 HIP = 55 83 CDS = 59 84 CDNSKEY = 60 85 CSYNC = 62 86 SPF = 99 87 UNSPEC = 103 88 EUI48 = 108 89 EUI64 = 109 90 TKEY = 249 91 TSIG = 250 92 IXFR = 251 93 AXFR = 252 94 MAILB = 253 95 MAILA = 254 96 ANY = 255 97 URI = 256 98 CAA = 257 99 AVC = 258 100 TA = 32768 101 DLV = 32769 102 103 _by_text = { 104 'NONE': NONE, 105 'A': A, 106 'NS': NS, 107 'MD': MD, 108 'MF': MF, 109 'CNAME': CNAME, 110 'SOA': SOA, 111 'MB': MB, 112 'MG': MG, 113 'MR': MR, 114 'NULL': NULL, 115 'WKS': WKS, 116 'PTR': PTR, 117 'HINFO': HINFO, 118 'MINFO': MINFO, 119 'MX': MX, 120 'TXT': TXT, 121 'RP': RP, 122 'AFSDB': AFSDB, 123 'X25': X25, 124 'ISDN': ISDN, 125 'RT': RT, 126 'NSAP': NSAP, 127 'NSAP-PTR': NSAP_PTR, 128 'SIG': SIG, 129 'KEY': KEY, 130 'PX': PX, 131 'GPOS': GPOS, 132 'AAAA': AAAA, 133 'LOC': LOC, 134 'NXT': NXT, 135 'SRV': SRV, 136 'NAPTR': NAPTR, 137 'KX': KX, 138 'CERT': CERT, 139 'A6': A6, 140 'DNAME': DNAME, 141 'OPT': OPT, 142 'APL': APL, 143 'DS': DS, 144 'SSHFP': SSHFP, 145 'IPSECKEY': IPSECKEY, 146 'RRSIG': RRSIG, 147 'NSEC': NSEC, 148 'DNSKEY': DNSKEY, 149 'DHCID': DHCID, 150 'NSEC3': NSEC3, 151 'NSEC3PARAM': NSEC3PARAM, 152 'TLSA': TLSA, 153 'HIP': HIP, 154 'CDS': CDS, 155 'CDNSKEY': CDNSKEY, 156 'CSYNC': CSYNC, 157 'SPF': SPF, 158 'UNSPEC': UNSPEC, 159 'EUI48': EUI48, 160 'EUI64': EUI64, 161 'TKEY': TKEY, 162 'TSIG': TSIG, 163 'IXFR': IXFR, 164 'AXFR': AXFR, 165 'MAILB': MAILB, 166 'MAILA': MAILA, 167 'ANY': ANY, 168 'URI': URI, 169 'CAA': CAA, 170 'AVC': AVC, 171 'TA': TA, 172 'DLV': DLV, 173 } 174 175 # We construct the inverse mapping programmatically to ensure that we 176 # cannot make any mistakes (e.g. omissions, cut-and-paste errors) that 177 # would cause the mapping not to be true inverse. 178 179 _by_value = dict((y, x) for x, y in _by_text.items()) 180 181 182 _metatypes = { 183 OPT: True 184 } 185 186 _singletons = { 187 SOA: True, 188 NXT: True, 189 DNAME: True, 190 NSEC: True, 191 # CNAME is technically a singleton, but we allow multiple CNAMEs. 192 } 193 194 _unknown_type_pattern = re.compile('TYPE([0-9]+)$', re.I) 195 196

197 -class UnknownRdatatype(dns.exception.DNSException):

198 199 """DNS resource record type is unknown."""

200 201

202 -def from_text(text):

203 """Convert text into a DNS rdata type value. 204 @param text: the text 205 @type text: string 206 @raises dns.rdatatype.UnknownRdatatype: the type is unknown 207 @raises ValueError: the rdata type value is not >= 0 and <= 65535 208 @rtype: int""" 209 210 value = _by_text.get(text.upper()) 211 if value is None: 212 match = _unknown_type_pattern.match(text) 213 if match is None: 214 raise UnknownRdatatype 215 value = int(match.group(1)) 216 if value < 0 or value > 65535: 217 raise ValueError("type must be between >= 0 and <= 65535") 218 return value

219 220

221 -def to_text(value):

222 """Convert a DNS rdata type to text. 223 @param value: the rdata type value 224 @type value: int 225 @raises ValueError: the rdata type value is not >= 0 and <= 65535 226 @rtype: string""" 227 228 if value < 0 or value > 65535: 229 raise ValueError("type must be between >= 0 and <= 65535") 230 text = _by_value.get(value) 231 if text is None: 232 text = 'TYPE' + repr(value) 233 return text

234 235

236 -def is_metatype(rdtype):

237 """True if the type is a metatype. 238 @param rdtype: the type 239 @type rdtype: int 240 @rtype: bool""" 241 242 if rdtype >= TKEY and rdtype <= ANY or rdtype in _metatypes: 243 return True 244 return False

245 246

247 -def is_singleton(rdtype):

248 """True if the type is a singleton. 249 @param rdtype: the type 250 @type rdtype: int 251 @rtype: bool""" 252 253 if rdtype in _singletons: 254 return True 255 return False

256