diff --git a/Lib/ipaddress.py b/Lib/ipaddress.py index 9cef275f7ae..c165505a533 100644 --- a/Lib/ipaddress.py +++ b/Lib/ipaddress.py @@ -1970,12 +1970,21 @@ class IPv6Address(_BaseV6, _BaseAddress): def _explode_shorthand_ip_string(self): ipv4_mapped = self.ipv4_mapped if ipv4_mapped is None: - long_form = super()._explode_shorthand_ip_string() - else: - prefix_len = 30 - raw_exploded_str = super()._explode_shorthand_ip_string() - long_form = "%s%s" % (raw_exploded_str[:prefix_len], str(ipv4_mapped)) - return long_form + return super()._explode_shorthand_ip_string() + prefix_len = 30 + raw_exploded_str = super()._explode_shorthand_ip_string() + return f"{raw_exploded_str[:prefix_len]}{ipv4_mapped!s}" + + def _reverse_pointer(self): + ipv4_mapped = self.ipv4_mapped + if ipv4_mapped is None: + return super()._reverse_pointer() + prefix_len = 30 + raw_exploded_str = super()._explode_shorthand_ip_string()[:prefix_len] + # ipv4 encoded using hexadecimal nibbles instead of decimals + ipv4_int = ipv4_mapped._ip + reverse_chars = f"{raw_exploded_str}{ipv4_int:008x}"[::-1].replace(':', '') + return '.'.join(reverse_chars) + '.ip6.arpa' def _ipv4_mapped_ipv6_to_str(self): """Return convenient text representation of IPv4-mapped IPv6 address diff --git a/Lib/test/test_ipaddress.py b/Lib/test/test_ipaddress.py index c3ecf2a7429..bd8d5d220e9 100644 --- a/Lib/test/test_ipaddress.py +++ b/Lib/test/test_ipaddress.py @@ -2585,12 +2585,42 @@ class IpaddrUnitTest(unittest.TestCase): self.assertEqual('192.168.178.1', addr4.exploded) def testReversePointer(self): - addr1 = ipaddress.IPv4Address('127.0.0.1') - addr2 = ipaddress.IPv6Address('2001:db8::1') - self.assertEqual('1.0.0.127.in-addr.arpa', addr1.reverse_pointer) - self.assertEqual('1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.' + - 'b.d.0.1.0.0.2.ip6.arpa', - addr2.reverse_pointer) + for addr_v4, expected in [ + ('127.0.0.1', '1.0.0.127.in-addr.arpa'), + # test vector: https://www.rfc-editor.org/rfc/rfc1035, §3.5 + ('10.2.0.52', '52.0.2.10.in-addr.arpa'), + ]: + with self.subTest('ipv4_reverse_pointer', addr=addr_v4): + addr = ipaddress.IPv4Address(addr_v4) + self.assertEqual(addr.reverse_pointer, expected) + + for addr_v6, expected in [ + ( + '2001:db8::1', ( + '1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.' + '0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.' + 'ip6.arpa' + ) + ), + ( + '::FFFF:192.168.1.35', ( + '3.2.1.0.8.a.0.c.f.f.f.f.0.0.0.0.' + '0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.' + 'ip6.arpa' + ) + ), + # test vector: https://www.rfc-editor.org/rfc/rfc3596, §2.5 + ( + '4321:0:1:2:3:4:567:89ab', ( + 'b.a.9.8.7.6.5.0.4.0.0.0.3.0.0.0.' + '2.0.0.0.1.0.0.0.0.0.0.0.1.2.3.4.' + 'ip6.arpa' + ) + ) + ]: + with self.subTest('ipv6_reverse_pointer', addr=addr_v6): + addr = ipaddress.IPv6Address(addr_v6) + self.assertEqual(addr.reverse_pointer, expected) def testIntRepresentation(self): self.assertEqual(16909060, int(self.ipv4_address)) diff --git a/Misc/NEWS.d/next/Library/2024-08-28-13-03-36.gh-issue-123409.lW0YF-.rst b/Misc/NEWS.d/next/Library/2024-08-28-13-03-36.gh-issue-123409.lW0YF-.rst new file mode 100644 index 00000000000..7c6aab632b6 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-08-28-13-03-36.gh-issue-123409.lW0YF-.rst @@ -0,0 +1,2 @@ +Fix :attr:`ipaddress.IPv6Address.reverse_pointer` output according to +:rfc:`RFC 3596, §2.5 <3596#section-2.5>`. Patch by Bénédikt Tran.