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 TA = 32768 100 DLV = 32769 101 102 _by_text = { 103 'NONE': NONE, 104 'A': A, 105 'NS': NS, 106 'MD': MD, 107 'MF': MF, 108 'CNAME': CNAME, 109 'SOA': SOA, 110 'MB': MB, 111 'MG': MG, 112 'MR': MR, 113 'NULL': NULL, 114 'WKS': WKS, 115 'PTR': PTR, 116 'HINFO': HINFO, 117 'MINFO': MINFO, 118 'MX': MX, 119 'TXT': TXT, 120 'RP': RP, 121 'AFSDB': AFSDB, 122 'X25': X25, 123 'ISDN': ISDN, 124 'RT': RT, 125 'NSAP': NSAP, 126 'NSAP-PTR': NSAP_PTR, 127 'SIG': SIG, 128 'KEY': KEY, 129 'PX': PX, 130 'GPOS': GPOS, 131 'AAAA': AAAA, 132 'LOC': LOC, 133 'NXT': NXT, 134 'SRV': SRV, 135 'NAPTR': NAPTR, 136 'KX': KX, 137 'CERT': CERT, 138 'A6': A6, 139 'DNAME': DNAME, 140 'OPT': OPT, 141 'APL': APL, 142 'DS': DS, 143 'SSHFP': SSHFP, 144 'IPSECKEY': IPSECKEY, 145 'RRSIG': RRSIG, 146 'NSEC': NSEC, 147 'DNSKEY': DNSKEY, 148 'DHCID': DHCID, 149 'NSEC3': NSEC3, 150 'NSEC3PARAM': NSEC3PARAM, 151 'TLSA': TLSA, 152 'HIP': HIP, 153 'CDS': CDS, 154 'CDNSKEY': CDNSKEY, 155 'CSYNC': CSYNC, 156 'SPF': SPF, 157 'UNSPEC': UNSPEC, 158 'EUI48': EUI48, 159 'EUI64': EUI64, 160 'TKEY': TKEY, 161 'TSIG': TSIG, 162 'IXFR': IXFR, 163 'AXFR': AXFR, 164 'MAILB': MAILB, 165 'MAILA': MAILA, 166 'ANY': ANY, 167 'URI': URI, 168 'CAA': CAA, 169 'TA': TA, 170 'DLV': DLV, 171 } 172 173 # We construct the inverse mapping programmatically to ensure that we 174 # cannot make any mistakes (e.g. omissions, cut-and-paste errors) that 175 # would cause the mapping not to be true inverse. 176 177 _by_value = dict((y, x) for x, y in _by_text.items()) 178 179 180 _metatypes = { 181 OPT: True 182 } 183 184 _singletons = { 185 SOA: True, 186 NXT: True, 187 DNAME: True, 188 NSEC: True, 189 # CNAME is technically a singleton, but we allow multiple CNAMEs. 190 } 191 192 _unknown_type_pattern = re.compile('TYPE([0-9]+)$', re.I) 193 194

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

196 197 """DNS resource record type is unknown."""

198 199

200 -def from_text(text):

201 """Convert text into a DNS rdata type value. 202 @param text: the text 203 @type text: string 204 @raises dns.rdatatype.UnknownRdatatype: the type is unknown 205 @raises ValueError: the rdata type value is not >= 0 and <= 65535 206 @rtype: int""" 207 208 value = _by_text.get(text.upper()) 209 if value is None: 210 match = _unknown_type_pattern.match(text) 211 if match is None: 212 raise UnknownRdatatype 213 value = int(match.group(1)) 214 if value < 0 or value > 65535: 215 raise ValueError("type must be between >= 0 and <= 65535") 216 return value

217 218

219 -def to_text(value):

220 """Convert a DNS rdata type to text. 221 @param value: the rdata type value 222 @type value: int 223 @raises ValueError: the rdata type value is not >= 0 and <= 65535 224 @rtype: string""" 225 226 if value < 0 or value > 65535: 227 raise ValueError("type must be between >= 0 and <= 65535") 228 text = _by_value.get(value) 229 if text is None: 230 text = 'TYPE' + repr(value) 231 return text

232 233

234 -def is_metatype(rdtype):

235 """True if the type is a metatype. 236 @param rdtype: the type 237 @type rdtype: int 238 @rtype: bool""" 239 240 if rdtype >= TKEY and rdtype <= ANY or rdtype in _metatypes: 241 return True 242 return False

243 244

245 -def is_singleton(rdtype):

246 """True if the type is a singleton. 247 @param rdtype: the type 248 @type rdtype: int 249 @rtype: bool""" 250 251 if rdtype in _singletons: 252 return True 253 return False

254