From: Brian Wellington Date: Wed, 29 Apr 2020 20:47:10 +0000 (-0700) Subject: Add alternate origin support to dns.reversename. X-Git-Tag: v2.0.0rc1~295^2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4f46f0bc4209c61b350f09b54b685f51cecdb833;p=thirdparty%2Fdnspython.git Add alternate origin support to dns.reversename. --- diff --git a/dns/reversename.py b/dns/reversename.py index 0e10bec0..fd382a55 100644 --- a/dns/reversename.py +++ b/dns/reversename.py @@ -27,13 +27,22 @@ ipv4_reverse_domain = dns.name.from_text('in-addr.arpa.') ipv6_reverse_domain = dns.name.from_text('ip6.arpa.') -def from_address(text): +def from_address(text, v4_origin=ipv4_reverse_domain, + v6_origin=ipv6_reverse_domain): """Convert an IPv4 or IPv6 address in textual form into a Name object whose value is the reverse-map domain name of the address. *text*, a ``text``, is an IPv4 or IPv6 address in textual form (e.g. '127.0.0.1', '::1') + *v4_origin*, a ``dns.name.Name`` to append to the labels corresponding to + the address if the address is an IPv4 address, instead of the default + (in-addr.arpa.) + + *v6_origin*, a ``dns.name.Name`` to append to the labels corresponding to + the address if the address is an IPv6 address, instead of the default + (ip6.arpa.) + Raises ``dns.exception.SyntaxError`` if the address is badly formed. Returns a ``dns.name.Name``. @@ -43,49 +52,49 @@ def from_address(text): v6 = dns.ipv6.inet_aton(text) if dns.ipv6.is_mapped(v6): parts = ['%d' % byte for byte in v6[12:]] - origin = ipv4_reverse_domain + origin = v4_origin else: parts = [x for x in str(binascii.hexlify(v6).decode())] - origin = ipv6_reverse_domain + origin = v6_origin except Exception: parts = ['%d' % byte for byte in dns.ipv4.inet_aton(text)] - origin = ipv4_reverse_domain - parts.reverse() - return dns.name.from_text('.'.join(parts), origin=origin) + origin = v4_origin + return dns.name.from_text('.'.join(reversed(parts)), origin=origin) -def to_address(name): +def to_address(name, v4_origin=ipv4_reverse_domain, + v6_origin=ipv6_reverse_domain): """Convert a reverse map domain name into textual address form. *name*, a ``dns.name.Name``, an IPv4 or IPv6 address in reverse-map name form. + *v4_origin*, a ``dns.name.Name`` representing the top-level domain for + IPv4 addresses, instead of the default (in-addr.arpa.) + + *v6_origin*, a ``dns.name.Name`` representing the top-level domain for + IPv4 addresses, instead of the default (ip6.arpa.) + Raises ``dns.exception.SyntaxError`` if the name does not have a reverse-map form. Returns a ``text``. """ - if name.is_subdomain(ipv4_reverse_domain): - name = name.relativize(ipv4_reverse_domain) - labels = list(name.labels) - labels.reverse() - text = b'.'.join(labels) - # run through inet_aton() to check syntax and make pretty. + if name.is_subdomain(v4_origin): + name = name.relativize(v4_origin) + text = b'.'.join(reversed(name.labels)) + # run through inet_ntoa() to check syntax and make pretty. return dns.ipv4.inet_ntoa(dns.ipv4.inet_aton(text)) - elif name.is_subdomain(ipv6_reverse_domain): - name = name.relativize(ipv6_reverse_domain) - labels = list(name.labels) - labels.reverse() + elif name.is_subdomain(v6_origin): + name = name.relativize(v6_origin) + labels = list(reversed(name.labels)) parts = [] - i = 0 - l = len(labels) - while i < l: + for i in range(0, len(labels), 4): parts.append(b''.join(labels[i:i + 4])) - i += 4 text = b':'.join(parts) - # run through inet_aton() to check syntax and make pretty. + # run through inet_ntoa() to check syntax and make pretty. return dns.ipv6.inet_ntoa(dns.ipv6.inet_aton(text)) else: raise dns.exception.SyntaxError('unknown reverse-map address family') diff --git a/tests/test_name.py b/tests/test_name.py index 0f08e870..47cea187 100644 --- a/tests/test_name.py +++ b/tests/test_name.py @@ -804,6 +804,18 @@ class NameTestCase(unittest.TestCase): dns.reversename.from_address('::1::1') self.assertRaises(dns.exception.SyntaxError, bad) + def testReverseIPv4AlternateOrigin(self): + e = dns.name.from_text('1.0.0.127.foo.bar.') + origin = dns.name.from_text('foo.bar') + n = dns.reversename.from_address('127.0.0.1', v4_origin=origin) + self.assertEqual(e, n) + + def testReverseIPv6AlternateOrigin(self): + e = dns.name.from_text('1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.foo.bar.') + origin = dns.name.from_text('foo.bar') + n = dns.reversename.from_address(b'::1', v6_origin=origin) + self.assertEqual(e, n) + def testForwardIPv4(self): n = dns.name.from_text('1.0.0.127.in-addr.arpa.') e = '127.0.0.1' @@ -816,6 +828,20 @@ class NameTestCase(unittest.TestCase): text = dns.reversename.to_address(n) self.assertEqual(text, e) + def testForwardIPv4AlternateOrigin(self): + n = dns.name.from_text('1.0.0.127.foo.bar.') + e = '127.0.0.1' + origin = dns.name.from_text('foo.bar') + text = dns.reversename.to_address(n, v4_origin=origin) + self.assertEqual(text, e) + + def testForwardIPv6AlternateOrigin(self): + n = dns.name.from_text('1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.foo.bar.') + e = '::1' + origin = dns.name.from_text('foo.bar') + text = dns.reversename.to_address(n, v6_origin=origin) + self.assertEqual(text, e) + def testE164ToEnum(self): text = '+1 650 555 1212' e = dns.name.from_text('2.1.2.1.5.5.5.0.5.6.1.e164.arpa.')