IPv4 and IPv6 CIDR validators (#125)

* validators: Add IPv4, v6 CIDR validators

Closes #117.

* tests: Add IPv4, v6 CIDR tests

* validators: Update imports

* validators: Better split handling, isdigit

* tests: Fix tests

* validators: Use single quotes

Author: woodruffw

tests/test_ipv4_cidr.py

@@ -0,0 +1,25 @@
+# -*- coding: utf-8 -*-
+import pytest
+
+from validators import ipv4_cidr, ipv6_cidr, ValidationFailure
+
+
+@pytest.mark.parametrize(('cidr',), [
+    ('127.0.0.1/0',),
+    ('123.5.77.88/8',),
+    ('12.12.12.12/32',),
+])
+def test_returns_true_on_valid_ipv4_cidr(cidr):
+    assert ipv4_cidr(cidr)
+    assert not ipv6_cidr(cidr)
+
+
+@pytest.mark.parametrize(('cidr',), [
+    ('abc.0.0.1',),
+    ('1.1.1.1',),
+    ('1.1.1.1/-1',),
+    ('1.1.1.1/33',),
+    ('1.1.1.1/foo',),
+])
+def test_returns_failed_validation_on_invalid_ipv4_cidr(cidr):
+    assert isinstance(ipv4_cidr(cidr), ValidationFailure)

tests/test_ipv6_cidr.py

@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+import pytest
+
+from validators import ipv4_cidr, ipv6_cidr, ValidationFailure
+
+
+@pytest.mark.parametrize(('cidr',), [
+    ('::1/0',),
+    ('dead:beef:0:0:0:0:42:1/8',),
+    ('abcd:ef::42:1/32',),
+    ('0:0:0:0:0:ffff:1.2.3.4/64',),
+    ('::192.168.30.2/128',),
+])
+def test_returns_true_on_valid_ipv6_cidr(cidr):
+    assert ipv6_cidr(cidr)
+    assert not ipv4_cidr(cidr)
+
+
+@pytest.mark.parametrize(('cidr',), [
+    ('abc.0.0.1',),
+    ('abcd:1234::123::1',),
+    ('1:2:3:4:5:6:7:8:9',),
+    ('abcd::1ffff',),
+    ('1.1.1.1',),
+    ('::1',),
+    ('::1/129',),
+    ('::1/-1',),
+    ('::1/foo',),
+])
+def test_returns_failed_validation_on_invalid_ipv6_cidr(cidr):
+    assert isinstance(ipv6_cidr(cidr), ValidationFailure)

validators/__init__.py

@@ -5,7 +5,7 @@
 from .hashes import md5, sha1, sha224, sha256, sha512
 from .i18n import fi_business_id, fi_ssn
 from .iban import iban
-from .ip_address import ipv4, ipv6
+from .ip_address import ipv4, ipv4_cidr, ipv6, ipv6_cidr
 from .length import length
 from .mac_address import mac_address
 from .slug import slug
@@ -16,7 +16,7 @@
 
 __all__ = ('between', 'domain', 'email', 'Max', 'Min', 'md5', 'sha1', 'sha224',
            'sha256', 'sha512', 'fi_business_id', 'fi_ssn', 'iban', 'ipv4',
-           'ipv6', 'length', 'mac_address', 'slug', 'truthy', 'url',
-           'ValidationFailure', 'validator', 'uuid')
+           'ipv4_cidr', 'ipv6', 'ipv6_cidr', 'length', 'mac_address', 'slug',
+           'truthy', 'url', 'ValidationFailure', 'validator', 'uuid')
 
 __version__ = '0.13.0'

validators/ip_address.py

@@ -29,6 +29,31 @@ def ipv4(value):
     return all(0 <= int(part) < 256 for part in groups)
 
 
+@validator
+def ipv4_cidr(value):
+    """
+    Return whether or not given value is a valid CIDR-notated IP version 4
+    address range.
+
+    This validator is based on RFC4632 3.1.
+
+    Examples::
+
+        >>> ipv4_cidr('1.1.1.1/8')
+        True
+
+        >>> ipv4_cidr('1.1.1.1')
+        ValidationFailure(func=ipv4_cidr, args={'value': '1.1.1.1'})
+    """
+    try:
+        prefix, suffix = value.split('/', 2)
+    except ValueError:
+        return False
+    if not ipv4(prefix) or not suffix.isdigit():
+        return False
+    return 0 <= int(suffix) <= 32
+
+
 @validator
 def ipv6(value):
     """
@@ -92,3 +117,28 @@ def ipv6(value):
     elif count_blank == 2 and not ipv6_groups[0] and not ipv6_groups[1]:
         return True
     return False
+
+
+@validator
+def ipv6_cidr(value):
+    """
+    Returns whether or not given value is a valid CIDR-notated IP version 6
+    address range.
+
+    This validator is based on RFC4632 3.1.
+
+    Examples::
+
+        >>> ipv6_cidr('::1/128')
+        True
+
+        >>> ipv6_cidr('::1')
+        ValidationFailure(func=ipv6_cidr, args={'value': '::1'})
+    """
+    try:
+        prefix, suffix = value.split('/', 2)
+    except ValueError:
+        return False
+    if not ipv6(prefix) or not suffix.isdigit():
+        return False
+    return 0 <= int(suffix) <= 128