Add CIDR for canonical format conversion

Currently, CIDR was not checked while converting address
to the canonical format in [1].
As most inputs to the neutron server would have CIDR, therefore
this patch handles this issue.

[1]:Ic9afa5f90fba783748f7c56e8fba02e06af69748

Change-Id: Ia5f0880ea2a4d76296c1ff9bc0abab71a6294007

neutron_lib/api/converters.py

@@ -185,6 +185,24 @@ def convert_ip_to_canonical_format(value):
     return value
 
 
+def convert_cidr_to_canonical_format(value):
+    """CIDR is validated and converted to canonical format.
+
+    :param value: The CIDR which needs to be checked.
+    :returns: - 'value' if 'value' is CIDR with IPv4 address,
+              - CIDR with canonical IPv6 address if 'value' is IPv6 CIDR.
+    :raises:  - InvalidInput if 'value' is None, not a valid CIDR or
+                invalid IP Format.
+    """
+    error_message = _("%s is not in a CIDR format") % value
+    try:
+        cidr = netaddr.IPNetwork(value)
+        return str(convert_ip_to_canonical_format(
+            cidr.ip)) + "/" + str(cidr.prefixlen)
+    except netaddr.core.AddrFormatError:
+        raise n_exc.InvalidInput(error_message=error_message)
+
+
 def convert_string_to_case_insensitive(data):
     """Convert a string value into a lower case string.
 

neutron_lib/tests/unit/api/test_conversions.py

@@ -171,7 +171,7 @@ class TestConvertToList(base.BaseTestCase):
             self.assertEqual([item], converters.convert_to_list(item))
 
 
-class TestConvertIPv6CanonicalFormat(base.BaseTestCase):
+class TestConvertIPv6AddrCanonicalFormat(base.BaseTestCase):
 
     def test_convert_ipv6_address_extended_add_with_zeroes(self):
         result = converters.convert_ip_to_canonical_format(
@@ -202,6 +202,23 @@ class TestConvertIPv6CanonicalFormat(base.BaseTestCase):
         self.assertEqual("on", result)
 
 
+class TestConvertIPv6CIDRCanonicalFormat(base.BaseTestCase):
+
+    def test_convert_ipv4_address_with_CIDR(self):
+        result = converters.convert_cidr_to_canonical_format(u'192.168.1.1/24')
+        self.assertEqual(u'192.168.1.1/24', result)
+
+    def test_convert_ipv6_extended_addr_withcidr_to_compressed(self):
+        result = converters.convert_cidr_to_canonical_format(
+            u'Fe80:0:0:0:0:0:0:1/64')
+        self.assertEqual(u'fe80::1/64', result)
+
+    def test_convert_non_ip_addr_with_slash(self):
+        with testtools.ExpectedException(n_exc.InvalidInput):
+            converters.convert_cidr_to_canonical_format(
+                u"Dormamu/DarkSeid/Vulture")
+
+
 class TestConvertStringToCaseInsensitive(base.BaseTestCase):
 
     def test_convert_string_to_lower(self):

releasenotes/notes/cidr_for_canonical_format-4e7925d76a27a19d.yaml

@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    A new converter is added to facilitate converting IPv6 CIDRs to canonical format. This way
+    IPv6 CIDRs can be specified in multiple formats but would be handled in their canonical format.