Mirror rsync IP: allow netmask specification

Noticed this was necessary while trying to get all the rsync IPs into the
database.

Signed-off-by: Dan McGee <dan@archlinux.org>

main/admin.py

@@ -1,3 +1,4 @@
+import re
 from django import forms
 from django.contrib import admin
 from django.contrib.auth.models import User
@@ -31,8 +32,24 @@ class MirrorUrlInlineAdmin(admin.TabularInline):
     form = MirrorUrlForm
     extra = 3
 
+# ripped off from django.forms.fields, adding netmask ability
+ipv4nm_re = re.compile(r'^(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}(/(\d|[1-2]\d|3[0-2])){0,1}$')
+class IPAddressNetmaskField(forms.fields.RegexField):
+    default_error_messages = {
+        'invalid': u'Enter a valid IPv4 address, possibly including netmask.',
+    }
+
+    def __init__(self, *args, **kwargs):
+        super(IPAddressNetmaskField, self).__init__(ipv4nm_re, *args, **kwargs)
+
+class MirrorRsyncForm(forms.ModelForm):
+    class Meta:
+        model = MirrorRsync
+    ip = IPAddressNetmaskField(label='IP')
+
 class MirrorRsyncInlineAdmin(admin.TabularInline):
     model = MirrorRsync
+    form = MirrorRsyncForm
     extra = 2
 
 class MirrorAdmin(admin.ModelAdmin):