[3.10] gh-113171: gh-65056: Fix "private" (non-global) IP address ranges (GH-113179...

The _private_networks variables, used by various is_private
implementations, were missing some ranges and at the same time had
overly strict ranges (where there are more specific ranges considered
globally reachable by the IANA registries).

This patch updates the ranges with what was missing or otherwise
incorrect.

100.64.0.0/10 is left alone, for now, as it's been made special in [1].

The _address_exclude_many() call returns 8 networks for IPv4, 121
networks for IPv6.

[1] https://github.com/python/cpython/issues/61602

In 3.10 and below, is_private checks whether the network and broadcast
address are both private.
In later versions (where the test wss backported from), it checks
whether they both are in the same private network.

For 0.0.0.0/0, both 0.0.0.0 and 255.225.255.255 are private,
but one is in 0.0.0.0/8 ("This network") and the other in
255.255.255.255/32 ("Limited broadcast").

---------

Co-authored-by: Jakub Stasiak <jakub@stasiak.at>

diff --git a/Doc/library/ipaddress.rst b/Doc/library/ipaddress.rst
index 9c2dff55703273ffa21d86c113b4aa473b912652..6f4520e32da8416e7e007f490bab5849496dfcc8 100644 (file)
--- a/Doc/library/ipaddress.rst
+++ b/Doc/library/ipaddress.rst
@@ -188,18 +188,53 @@ write code that handles both IP versions correctly.  Address objects are
 
    .. attribute:: is_private
 
-      ``True`` if the address is allocated for private networks.  See
+      ``True`` if the address is defined as not globally reachable by
       iana-ipv4-special-registry_ (for IPv4) or iana-ipv6-special-registry_
-      (for IPv6).
+      (for IPv6) with the following exceptions:
+
+      * ``is_private`` is ``False`` for the shared address space (``100.64.0.0/10``)
+      * For IPv4-mapped IPv6-addresses the ``is_private`` value is determined by the
+        semantics of the underlying IPv4 addresses and the following condition holds
+        (see :attr:`IPv6Address.ipv4_mapped`)::
+
+            address.is_private == address.ipv4_mapped.is_private
+
+      ``is_private`` has value opposite to :attr:`is_global`, except for the shared address space
+      (``100.64.0.0/10`` range) where they are both ``False``.
+
+      .. versionchanged:: 3.10.15
+
+         Fixed some false positives and false negatives.
+
+         * ``192.0.0.0/24`` is considered private with the exception of ``192.0.0.9/32`` and
+           ``192.0.0.10/32`` (previously: only the ``192.0.0.0/29`` sub-range was considered private).
+         * ``64:ff9b:1::/48`` is considered private.
+         * ``2002::/16`` is considered private.
+         * There are exceptions within ``2001::/23`` (otherwise considered private): ``2001:1::1/128``,
+           ``2001:1::2/128``, ``2001:3::/32``, ``2001:4:112::/48``, ``2001:20::/28``, ``2001:30::/28``.
+           The exceptions are not considered private.
 
    .. attribute:: is_global
 
-      ``True`` if the address is allocated for public networks.  See
+      ``True`` if the address is defined as globally reachable by
       iana-ipv4-special-registry_ (for IPv4) or iana-ipv6-special-registry_
-      (for IPv6).
+      (for IPv6) with the following exception:
+
+      For IPv4-mapped IPv6-addresses the ``is_private`` value is determined by the
+      semantics of the underlying IPv4 addresses and the following condition holds
+      (see :attr:`IPv6Address.ipv4_mapped`)::
+
+         address.is_global == address.ipv4_mapped.is_global
+
+      ``is_global`` has value opposite to :attr:`is_private`, except for the shared address space
+      (``100.64.0.0/10`` range) where they are both ``False``.
 
       .. versionadded:: 3.4
 
+      .. versionchanged:: 3.10.15
+
+         Fixed some false positives and false negatives, see :attr:`is_private` for details.
+
    .. attribute:: is_unspecified
 
       ``True`` if the address is unspecified.  See :RFC:`5735` (for IPv4)

diff --git a/Doc/whatsnew/3.10.rst b/Doc/whatsnew/3.10.rst
index 43da72aece9dfd03dff38d088c32e2c8be950d57..d6ccf96a4cfec256eae02cc2ce523baa4fea39cc 100644 (file)
--- a/Doc/whatsnew/3.10.rst
+++ b/Doc/whatsnew/3.10.rst
@@ -2348,3 +2348,12 @@ tarfile
   :exc:`DeprecationWarning`.
   In Python 3.14, the default will switch to ``'data'``.
   (Contributed by Petr Viktorin in :pep:`706`.)
+
+Notable changes in 3.10.15
+==========================
+
+ipaddress
+---------
+
+* Fixed ``is_global`` and ``is_private`` behavior in ``IPv4Address``,
+  ``IPv6Address``, ``IPv4Network`` and ``IPv6Network``.

diff --git a/Lib/ipaddress.py b/Lib/ipaddress.py
index 756f1bc38c97fdb5d0d1124512960d9d0e38198a..94b1761b5f7bf80b2efb4f64e692fe509fbcc9d2 100644 (file)
--- a/Lib/ipaddress.py
+++ b/Lib/ipaddress.py
@@ -1323,18 +1323,41 @@ class IPv4Address(_BaseV4, _BaseAddress):
     @property
     @functools.lru_cache()
     def is_private(self):
-        """Test if this address is allocated for private networks.
+        """``True`` if the address is defined as not globally reachable by
+        iana-ipv4-special-registry_ (for IPv4) or iana-ipv6-special-registry_
+        (for IPv6) with the following exceptions:
 
-        Returns:
-            A boolean, True if the address is reserved per
-            iana-ipv4-special-registry.
+        * ``is_private`` is ``False`` for ``100.64.0.0/10``
+        * For IPv4-mapped IPv6-addresses the ``is_private`` value is determined by the
+            semantics of the underlying IPv4 addresses and the following condition holds
+            (see :attr:`IPv6Address.ipv4_mapped`)::
+
+                address.is_private == address.ipv4_mapped.is_private
 
+        ``is_private`` has value opposite to :attr:`is_global`, except for the ``100.64.0.0/10``
+        IPv4 range where they are both ``False``.
         """
-        return any(self in net for net in self._constants._private_networks)
+        return (
+            any(self in net for net in self._constants._private_networks)
+            and all(self not in net for net in self._constants._private_networks_exceptions)
+        )
 
     @property
     @functools.lru_cache()
     def is_global(self):
+        """``True`` if the address is defined as globally reachable by
+        iana-ipv4-special-registry_ (for IPv4) or iana-ipv6-special-registry_
+        (for IPv6) with the following exception:
+
+        For IPv4-mapped IPv6-addresses the ``is_private`` value is determined by the
+        semantics of the underlying IPv4 addresses and the following condition holds
+        (see :attr:`IPv6Address.ipv4_mapped`)::
+
+            address.is_global == address.ipv4_mapped.is_global
+
+        ``is_global`` has value opposite to :attr:`is_private`, except for the ``100.64.0.0/10``
+        IPv4 range where they are both ``False``.
+        """
         return self not in self._constants._public_network and not self.is_private
 
     @property
@@ -1538,13 +1561,15 @@ class _IPv4Constants:
 
     _public_network = IPv4Network('100.64.0.0/10')
 
+    # Not globally reachable address blocks listed on
+    # https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml
     _private_networks = [
         IPv4Network('0.0.0.0/8'),
         IPv4Network('10.0.0.0/8'),
         IPv4Network('127.0.0.0/8'),
         IPv4Network('169.254.0.0/16'),
         IPv4Network('172.16.0.0/12'),
-        IPv4Network('192.0.0.0/29'),
+        IPv4Network('192.0.0.0/24'),
         IPv4Network('192.0.0.170/31'),
         IPv4Network('192.0.2.0/24'),
         IPv4Network('192.168.0.0/16'),
@@ -1555,6 +1580,11 @@ class _IPv4Constants:
         IPv4Network('255.255.255.255/32'),
         ]
 
+    _private_networks_exceptions = [
+        IPv4Network('192.0.0.9/32'),
+        IPv4Network('192.0.0.10/32'),
+    ]
+
     _reserved_network = IPv4Network('240.0.0.0/4')
 
     _unspecified_address = IPv4Address('0.0.0.0')
@@ -1996,27 +2026,42 @@ class IPv6Address(_BaseV6, _BaseAddress):
     @property
     @functools.lru_cache()
     def is_private(self):
-        """Test if this address is allocated for private networks.
+        """``True`` if the address is defined as not globally reachable by
+        iana-ipv4-special-registry_ (for IPv4) or iana-ipv6-special-registry_
+        (for IPv6) with the following exceptions:
 
-        Returns:
-            A boolean, True if the address is reserved per
-            iana-ipv6-special-registry, or is ipv4_mapped and is
-            reserved in the iana-ipv4-special-registry.
+        * ``is_private`` is ``False`` for ``100.64.0.0/10``
+        * For IPv4-mapped IPv6-addresses the ``is_private`` value is determined by the
+            semantics of the underlying IPv4 addresses and the following condition holds
+            (see :attr:`IPv6Address.ipv4_mapped`)::
+
+                address.is_private == address.ipv4_mapped.is_private
 
+        ``is_private`` has value opposite to :attr:`is_global`, except for the ``100.64.0.0/10``
+        IPv4 range where they are both ``False``.
         """
         ipv4_mapped = self.ipv4_mapped
         if ipv4_mapped is not None:
             return ipv4_mapped.is_private
-        return any(self in net for net in self._constants._private_networks)
+        return (
+            any(self in net for net in self._constants._private_networks)
+            and all(self not in net for net in self._constants._private_networks_exceptions)
+        )
 
     @property
     def is_global(self):
-        """Test if this address is allocated for public networks.
+        """``True`` if the address is defined as globally reachable by
+        iana-ipv4-special-registry_ (for IPv4) or iana-ipv6-special-registry_
+        (for IPv6) with the following exception:
 
-        Returns:
-            A boolean, true if the address is not reserved per
-            iana-ipv6-special-registry.
+        For IPv4-mapped IPv6-addresses the ``is_private`` value is determined by the
+        semantics of the underlying IPv4 addresses and the following condition holds
+        (see :attr:`IPv6Address.ipv4_mapped`)::
+
+            address.is_global == address.ipv4_mapped.is_global
 
+        ``is_global`` has value opposite to :attr:`is_private`, except for the ``100.64.0.0/10``
+        IPv4 range where they are both ``False``.
         """
         return not self.is_private
 
@@ -2257,19 +2302,31 @@ class _IPv6Constants:
 
     _multicast_network = IPv6Network('ff00::/8')
 
+    # Not globally reachable address blocks listed on
+    # https://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml
     _private_networks = [
         IPv6Network('::1/128'),
         IPv6Network('::/128'),
         IPv6Network('::ffff:0:0/96'),
+        IPv6Network('64:ff9b:1::/48'),
         IPv6Network('100::/64'),
         IPv6Network('2001::/23'),
-        IPv6Network('2001:2::/48'),
         IPv6Network('2001:db8::/32'),
-        IPv6Network('2001:10::/28'),
+        # IANA says N/A, let's consider it not globally reachable to be safe
+        IPv6Network('2002::/16'),
         IPv6Network('fc00::/7'),
         IPv6Network('fe80::/10'),
         ]
 
+    _private_networks_exceptions = [
+        IPv6Network('2001:1::1/128'),
+        IPv6Network('2001:1::2/128'),
+        IPv6Network('2001:3::/32'),
+        IPv6Network('2001:4:112::/48'),
+        IPv6Network('2001:20::/28'),
+        IPv6Network('2001:30::/28'),
+    ]
+
     _reserved_networks = [
         IPv6Network('::/8'), IPv6Network('100::/8'),
         IPv6Network('200::/7'), IPv6Network('400::/6'),

diff --git a/Lib/test/test_ipaddress.py b/Lib/test/test_ipaddress.py
index f1ef87f7d589b1c49862a9865377b13025e2c802..86f3bb504a23ba32963391ac30c7eb166e8673d3 100644 (file)
--- a/Lib/test/test_ipaddress.py
+++ b/Lib/test/test_ipaddress.py
@@ -2263,6 +2263,10 @@ class IpaddrUnitTest(unittest.TestCase):
         self.assertEqual(True, ipaddress.ip_address(
                 '172.31.255.255').is_private)
         self.assertEqual(False, ipaddress.ip_address('172.32.0.0').is_private)
+        self.assertFalse(ipaddress.ip_address('192.0.0.0').is_global)
+        self.assertTrue(ipaddress.ip_address('192.0.0.9').is_global)
+        self.assertTrue(ipaddress.ip_address('192.0.0.10').is_global)
+        self.assertFalse(ipaddress.ip_address('192.0.0.255').is_global)
 
         self.assertEqual(True,
                          ipaddress.ip_address('169.254.100.200').is_link_local)
@@ -2278,6 +2282,40 @@ class IpaddrUnitTest(unittest.TestCase):
         self.assertEqual(False, ipaddress.ip_address('128.0.0.0').is_loopback)
         self.assertEqual(True, ipaddress.ip_network('0.0.0.0').is_unspecified)
 
+    def testPrivateNetworks(self):
+        self.assertEqual(True, ipaddress.ip_network("0.0.0.0/0").is_private)
+        self.assertEqual(False, ipaddress.ip_network("1.0.0.0/8").is_private)
+
+        self.assertEqual(True, ipaddress.ip_network("0.0.0.0/8").is_private)
+        self.assertEqual(True, ipaddress.ip_network("10.0.0.0/8").is_private)
+        self.assertEqual(True, ipaddress.ip_network("127.0.0.0/8").is_private)
+        self.assertEqual(True, ipaddress.ip_network("169.254.0.0/16").is_private)
+        self.assertEqual(True, ipaddress.ip_network("172.16.0.0/12").is_private)
+        self.assertEqual(True, ipaddress.ip_network("192.0.0.0/29").is_private)
+        self.assertEqual(False, ipaddress.ip_network("192.0.0.9/32").is_private)
+        self.assertEqual(True, ipaddress.ip_network("192.0.0.170/31").is_private)
+        self.assertEqual(True, ipaddress.ip_network("192.0.2.0/24").is_private)
+        self.assertEqual(True, ipaddress.ip_network("192.168.0.0/16").is_private)
+        self.assertEqual(True, ipaddress.ip_network("198.18.0.0/15").is_private)
+        self.assertEqual(True, ipaddress.ip_network("198.51.100.0/24").is_private)
+        self.assertEqual(True, ipaddress.ip_network("203.0.113.0/24").is_private)
+        self.assertEqual(True, ipaddress.ip_network("240.0.0.0/4").is_private)
+        self.assertEqual(True, ipaddress.ip_network("255.255.255.255/32").is_private)
+
+        self.assertEqual(False, ipaddress.ip_network("::/0").is_private)
+        self.assertEqual(False, ipaddress.ip_network("::ff/128").is_private)
+
+        self.assertEqual(True, ipaddress.ip_network("::1/128").is_private)
+        self.assertEqual(True, ipaddress.ip_network("::/128").is_private)
+        self.assertEqual(True, ipaddress.ip_network("::ffff:0:0/96").is_private)
+        self.assertEqual(True, ipaddress.ip_network("100::/64").is_private)
+        self.assertEqual(True, ipaddress.ip_network("2001:2::/48").is_private)
+        self.assertEqual(False, ipaddress.ip_network("2001:3::/48").is_private)
+        self.assertEqual(True, ipaddress.ip_network("2001:db8::/32").is_private)
+        self.assertEqual(True, ipaddress.ip_network("2001:10::/28").is_private)
+        self.assertEqual(True, ipaddress.ip_network("fc00::/7").is_private)
+        self.assertEqual(True, ipaddress.ip_network("fe80::/10").is_private)
+
     def testReservedIpv6(self):
 
         self.assertEqual(True, ipaddress.ip_network('ffff::').is_multicast)
@@ -2351,6 +2389,20 @@ class IpaddrUnitTest(unittest.TestCase):
         self.assertEqual(True, ipaddress.ip_address('0::0').is_unspecified)
         self.assertEqual(False, ipaddress.ip_address('::1').is_unspecified)
 
+        self.assertFalse(ipaddress.ip_address('64:ff9b:1::').is_global)
+        self.assertFalse(ipaddress.ip_address('2001::').is_global)
+        self.assertTrue(ipaddress.ip_address('2001:1::1').is_global)
+        self.assertTrue(ipaddress.ip_address('2001:1::2').is_global)
+        self.assertFalse(ipaddress.ip_address('2001:2::').is_global)
+        self.assertTrue(ipaddress.ip_address('2001:3::').is_global)
+        self.assertFalse(ipaddress.ip_address('2001:4::').is_global)
+        self.assertTrue(ipaddress.ip_address('2001:4:112::').is_global)
+        self.assertFalse(ipaddress.ip_address('2001:10::').is_global)
+        self.assertTrue(ipaddress.ip_address('2001:20::').is_global)
+        self.assertTrue(ipaddress.ip_address('2001:30::').is_global)
+        self.assertFalse(ipaddress.ip_address('2001:40::').is_global)
+        self.assertFalse(ipaddress.ip_address('2002::').is_global)
+
         # some generic IETF reserved addresses
         self.assertEqual(True, ipaddress.ip_address('100::').is_reserved)
         self.assertEqual(True, ipaddress.ip_network('4000::1/128').is_reserved)

diff --git a/Misc/NEWS.d/next/Library/2024-03-14-01-38-44.gh-issue-113171.VFnObz.rst b/Misc/NEWS.d/next/Library/2024-03-14-01-38-44.gh-issue-113171.VFnObz.rst
new file mode 100644 (file)
index 0000000..f9a7247
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-03-14-01-38-44.gh-issue-113171.VFnObz.rst
@@ -0,0 +1,9 @@
+Fixed various false positives and false negatives in
+
+* :attr:`ipaddress.IPv4Address.is_private` (see these docs for details)
+* :attr:`ipaddress.IPv4Address.is_global`
+* :attr:`ipaddress.IPv6Address.is_private`
+* :attr:`ipaddress.IPv6Address.is_global`
+
+Also in the corresponding :class:`ipaddress.IPv4Network` and :class:`ipaddress.IPv6Network`
+attributes.