# Copyright (C) 2006, 2007, 2009, 2011 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 origin: 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 origin: 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