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 SPF = 99 84 UNSPEC = 103 85 TKEY = 249 86 TSIG = 250 87 IXFR = 251 88 AXFR = 252 89 MAILB = 253 90 MAILA = 254 91 ANY = 255 92 URI = 256 93 CAA = 257 94 TA = 32768 95 DLV = 32769 96 97 _by_text = { 98 'NONE' : NONE, 99 'A' : A, 100 'NS' : NS, 101 'MD' : MD, 102 'MF' : MF, 103 'CNAME' : CNAME, 104 'SOA' : SOA, 105 'MB' : MB, 106 'MG' : MG, 107 'MR' : MR, 108 'NULL' : NULL, 109 'WKS' : WKS, 110 'PTR' : PTR, 111 'HINFO' : HINFO, 112 'MINFO' : MINFO, 113 'MX' : MX, 114 'TXT' : TXT, 115 'RP' : RP, 116 'AFSDB' : AFSDB, 117 'X25' : X25, 118 'ISDN' : ISDN, 119 'RT' : RT, 120 'NSAP' : NSAP, 121 'NSAP-PTR' : NSAP_PTR, 122 'SIG' : SIG, 123 'KEY' : KEY, 124 'PX' : PX, 125 'GPOS' : GPOS, 126 'AAAA' : AAAA, 127 'LOC' : LOC, 128 'NXT' : NXT, 129 'SRV' : SRV, 130 'NAPTR' : NAPTR, 131 'KX' : KX, 132 'CERT' : CERT, 133 'A6' : A6, 134 'DNAME' : DNAME, 135 'OPT' : OPT, 136 'APL' : APL, 137 'DS' : DS, 138 'SSHFP' : SSHFP, 139 'IPSECKEY' : IPSECKEY, 140 'RRSIG' : RRSIG, 141 'NSEC' : NSEC, 142 'DNSKEY' : DNSKEY, 143 'DHCID' : DHCID, 144 'NSEC3' : NSEC3, 145 'NSEC3PARAM' : NSEC3PARAM, 146 'TLSA' : TLSA, 147 'HIP' : HIP, 148 'SPF' : SPF, 149 'UNSPEC' : UNSPEC, 150 'TKEY' : TKEY, 151 'TSIG' : TSIG, 152 'IXFR' : IXFR, 153 'AXFR' : AXFR, 154 'MAILB' : MAILB, 155 'MAILA' : MAILA, 156 'ANY' : ANY, 157 'URI' : URI, 158 'CAA' : CAA, 159 'TA' : TA, 160 'DLV' : DLV, 161 } 162 163 # We construct the inverse mapping programmatically to ensure that we 164 # cannot make any mistakes (e.g. omissions, cut-and-paste errors) that 165 # would cause the mapping not to be true inverse. 166 167 _by_value = dict([(y, x) for x, y in _by_text.iteritems()]) 168 169 170 _metatypes = { 171 OPT : True 172 } 173 174 _singletons = { 175 SOA : True, 176 NXT : True, 177 DNAME : True, 178 NSEC : True, 179 # CNAME is technically a singleton, but we allow multiple CNAMEs. 180 } 181 182 _unknown_type_pattern = re.compile('TYPE([0-9]+)$', re.I); 183

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

185 """DNS resource record type is unknown."""

186

187 -def from_text(text):

188 """Convert text into a DNS rdata type value. 189 @param text: the text 190 @type text: string 191 @raises dns.rdatatype.UnknownRdatatype: the type is unknown 192 @raises ValueError: the rdata type value is not >= 0 and <= 65535 193 @rtype: int""" 194 195 value = _by_text.get(text.upper()) 196 if value is None: 197 match = _unknown_type_pattern.match(text) 198 if match == None: 199 raise UnknownRdatatype 200 value = int(match.group(1)) 201 if value < 0 or value > 65535: 202 raise ValueError("type must be between >= 0 and <= 65535") 203 return value

204

205 -def to_text(value):

206 """Convert a DNS rdata type to text. 207 @param value: the rdata type value 208 @type value: int 209 @raises ValueError: the rdata type value is not >= 0 and <= 65535 210 @rtype: string""" 211 212 if value < 0 or value > 65535: 213 raise ValueError("type must be between >= 0 and <= 65535") 214 text = _by_value.get(value) 215 if text is None: 216 text = 'TYPE' + `value` 217 return text

218

219 -def is_metatype(rdtype):

220 """True if the type is a metatype. 221 @param rdtype: the type 222 @type rdtype: int 223 @rtype: bool""" 224 225 if rdtype >= TKEY and rdtype <= ANY or _metatypes.has_key(rdtype): 226 return True 227 return False

228

229 -def is_singleton(rdtype):

230 """True if the type is a singleton. 231 @param rdtype: the type 232 @type rdtype: int 233 @rtype: bool""" 234 235 if _singletons.has_key(rdtype): 236 return True 237 return False

238