fields: support subnet masks via ip_address

Author: johnnyapol

mirrors/fields.py

@@ -3,7 +3,12 @@
 from django.core.exceptions import ValidationError
 from django.db import models
 
-from ipaddress import ip_address as IP
+from ipaddress import ip_address, ip_interface
+
+def IP(address):
+    if '/' not in address:
+        return ip_address(address)
+    return ip_interface(address)
 
 class IPNetworkFormField(forms.Field):
     def to_python(self, value):