| # Copyright (C) 2006, 2007, 2009 Nominum, Inc. |
| # |
| # Permission to use, copy, modify, and distribute this software and its |
| # documentation for any purpose with or without fee is hereby granted, |
| # provided that the above copyright notice and this permission notice |
| # appear in all copies. |
| # |
| # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES |
| # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR |
| # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT |
| # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| |
| """DNS E.164 helpers |
| |
| @var public_enum_domain: The DNS public ENUM domain, e164.arpa. |
| @type public_enum_domain: dns.name.Name object |
| """ |
| |
| import dns.exception |
| import dns.name |
| import dns.resolver |
| |
| public_enum_domain = dns.name.from_text('e164.arpa.') |
| |
| def from_e164(text, origin=public_enum_domain): |
| """Convert an E.164 number in textual form into a Name object whose |
| value is the ENUM domain name for that number. |
| @param text: an E.164 number in textual form. |
| @type text: str |
| @param origin: The domain in which the number should be constructed. |
| The default is e164.arpa. |
| @type: dns.name.Name object or None |
| @rtype: dns.name.Name object |
| """ |
| parts = [d for d in text if d.isdigit()] |
| parts.reverse() |
| return dns.name.from_text('.'.join(parts), origin=origin) |
| |
| def to_e164(name, origin=public_enum_domain, want_plus_prefix=True): |
| """Convert an ENUM domain name into an E.164 number. |
| @param name: the ENUM domain name. |
| @type name: dns.name.Name object. |
| @param origin: A domain containing the ENUM domain name. The |
| name is relativized to this domain before being converted to text. |
| @type: dns.name.Name object or None |
| @param want_plus_prefix: if True, add a '+' to the beginning of the |
| returned number. |
| @rtype: str |
| """ |
| if not origin is None: |
| name = name.relativize(origin) |
| dlabels = [d for d in name.labels if (d.isdigit() and len(d) == 1)] |
| if len(dlabels) != len(name.labels): |
| raise dns.exception.SyntaxError('non-digit labels in ENUM domain name') |
| dlabels.reverse() |
| text = ''.join(dlabels) |
| if want_plus_prefix: |
| text = '+' + text |
| return text |
| |
| def query(number, domains, resolver=None): |
| """Look for NAPTR RRs for the specified number in the specified domains. |
| |
| e.g. lookup('16505551212', ['e164.dnspython.org.', 'e164.arpa.']) |
| """ |
| if resolver is None: |
| resolver = dns.resolver.get_default_resolver() |
| for domain in domains: |
| if isinstance(domain, (str, unicode)): |
| domain = dns.name.from_text(domain) |
| qname = dns.e164.from_e164(number, domain) |
| try: |
| return resolver.query(qname, 'NAPTR') |
| except dns.resolver.NXDOMAIN: |
| pass |
| raise dns.resolver.NXDOMAIN |