add E.164 helpers

diff --git a/dns/__init__.py b/dns/__init__.py
index 5d4ee2ca9da6613ddd30f15e9fc10323ef1b97ef..b4036afd34f509c3c180d268a555695dc59c70a4 100644 (file)
--- a/dns/__init__.py
+++ b/dns/__init__.py
@@ -17,6 +17,7 @@
 
 __all__ = [
     'dnssec',
+    'e164',
     'exception',
     'flags',
     'inet',

diff --git a/dns/e164.py b/dns/e164.py
new file mode 100644 (file)
index 0000000..bcc7c47
--- /dev/null
+++ b/dns/e164.py
@@ -0,0 +1,61 @@
+# Copyright (C) 2005 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 Names.
+
+@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
+
+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