From 3288539a0b3be6b69efd2630b79133b918bb079b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Herv=C3=A9=20Beraud?= <hberaud@redhat.com>
Date: Wed, 3 Feb 2021 10:50:50 +0100
Subject: [PATCH] Add a ``strict`` flag allowing users to restrict validation
 of IPv4 format

Add a ``strict`` flag allowing users to restrict validation to IP
addresses in presentation format (``a.b.c.d``) as opposed to address
format (``a.b.c.d``, ``a.b.c``, ``a.b``, ``a``).

https://github.com/netaddr/netaddr/issues/186
https://man7.org/linux/man-pages/man3/inet_pton.3.html
https://bugzilla.redhat.com/show_bug.cgi?id=1924436

Change-Id: I10fed16dad77ac17691a5d175c42b25916dc8bc4
Closes-Bug: #1914386
---
 oslo_utils/netutils.py                        | 31 +++++++++++++-
 oslo_utils/tests/test_netutils.py             | 41 ++++++++++++++++++-
 ...-from-text-to-binary-8c46ad2d9989e8c5.yaml |  6 +++
 3 files changed, 75 insertions(+), 3 deletions(-)
 create mode 100644 releasenotes/notes/allow-to-convert-ipv4-address-from-text-to-binary-8c46ad2d9989e8c5.yaml

diff --git a/oslo_utils/netutils.py b/oslo_utils/netutils.py
index 492c7268..8912f17e 100644
--- a/oslo_utils/netutils.py
+++ b/oslo_utils/netutils.py
@@ -24,6 +24,7 @@ import socket
 from urllib import parse
 
 import netaddr
+from netaddr.core import INET_PTON
 import netifaces
 
 from oslo_utils._i18n import _
@@ -81,17 +82,43 @@ def parse_host_port(address, default_port=None):
     return (host, None if port is None else int(port))
 
 
-def is_valid_ipv4(address):
+def is_valid_ipv4(address, strict=None):
     """Verify that address represents a valid IPv4 address.
 
     :param address: Value to verify
     :type address: string
+    :param strict: flag allowing users to restrict validation
+        to IP addresses in presentation format (``a.b.c.d``) as opposed to
+        address format (``a.b.c.d``, ``a.b.c``, ``a.b``, ``a``).
+    :type flags: bool
     :returns: bool
 
     .. versionadded:: 1.1
+    .. versionchanged:: 4.8.0
+       Allow to restrict validation to IP addresses in presentation format
+       (``a.b.c.d``) as opposed to address format
+       (``a.b.c.d``, ``a.b.c``, ``a.b``, ``a``).
     """
+    if strict is not None:
+        flag = INET_PTON if strict else 0
+        try:
+            return netaddr.valid_ipv4(address, flags=flag)
+        except netaddr.AddrFormatError:
+            return False
+
+    # non strict mode
     try:
-        return netaddr.valid_ipv4(address)
+        if netaddr.valid_ipv4(address, flags=INET_PTON):
+            return True
+        else:
+            if netaddr.valid_ipv4(address):
+                LOG.warn(
+                    'Converting in non strict mode is deprecated. '
+                    'You should pass strict=False if you want to '
+                    'preserve legacy behavior')
+                return True
+            else:
+                return False
     except netaddr.AddrFormatError:
         return False
 
diff --git a/oslo_utils/tests/test_netutils.py b/oslo_utils/tests/test_netutils.py
index 28bb1d9c..93fedf39 100644
--- a/oslo_utils/tests/test_netutils.py
+++ b/oslo_utils/tests/test_netutils.py
@@ -154,13 +154,52 @@ class NetworkUtilsTest(test_base.BaseTestCase):
         netutils.set_tcp_keepalive(mock_sock, False)
         self.assertEqual(1, len(mock_sock.mock_calls))
 
-    def test_is_valid_ipv4(self):
+    @mock.patch.object(netutils, 'LOG', autospec=True)
+    def test_is_valid_ipv4(self, mock_log):
+        expected_log = 'Converting in non strict mode is deprecated. ' \
+            'You should pass strict=False if you want to preserve ' \
+            'legacy behavior'
         self.assertTrue(netutils.is_valid_ipv4('42.42.42.42'))
 
         self.assertFalse(netutils.is_valid_ipv4('-1.11.11.11'))
 
         self.assertFalse(netutils.is_valid_ipv4(''))
 
+        self.assertTrue(netutils.is_valid_ipv4('10'))
+        mock_log.warn.assert_called_with(expected_log)
+        mock_log.reset_mock()
+        self.assertTrue(netutils.is_valid_ipv4('10.10'))
+        mock_log.warn.assert_called_with(expected_log)
+        mock_log.reset_mock()
+        self.assertTrue(netutils.is_valid_ipv4('10.10.10'))
+        mock_log.warn.assert_called_with(expected_log)
+        mock_log.reset_mock()
+        self.assertTrue(netutils.is_valid_ipv4('10.10.10.10'))
+        mock_log.warn.assert_not_called()
+        mock_log.reset_mock()
+        self.assertFalse(
+            netutils.is_valid_ipv4('10', strict=True)
+        )
+        self.assertFalse(
+            netutils.is_valid_ipv4('10.10', strict=True)
+        )
+        self.assertFalse(
+            netutils.is_valid_ipv4('10.10.10', strict=True)
+        )
+        mock_log.warn.assert_not_called()
+        mock_log.reset_mock()
+        self.assertTrue(
+            netutils.is_valid_ipv4('10', strict=False)
+        )
+        self.assertTrue(
+            netutils.is_valid_ipv4('10.10', strict=False)
+        )
+        self.assertTrue(
+            netutils.is_valid_ipv4('10.10.10', strict=False)
+        )
+        mock_log.warn.assert_not_called()
+        mock_log.reset_mock()
+
     def test_is_valid_ipv6(self):
         self.assertTrue(netutils.is_valid_ipv6('::1'))
 
diff --git a/releasenotes/notes/allow-to-convert-ipv4-address-from-text-to-binary-8c46ad2d9989e8c5.yaml b/releasenotes/notes/allow-to-convert-ipv4-address-from-text-to-binary-8c46ad2d9989e8c5.yaml
new file mode 100644
index 00000000..cca9c1b5
--- /dev/null
+++ b/releasenotes/notes/allow-to-convert-ipv4-address-from-text-to-binary-8c46ad2d9989e8c5.yaml
@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Add a ``strict`` flag to ``netutils.is_valid_ipv4`` to allowing users to
+    restrict validation to IP addresses in presentation format (``a.b.c.d``)
+    as opposed to address format (``a.b.c.d``, ``a.b.c``, ``a.b``, ``a``).