protect hostnames, readme

README

@@ -1,4 +1,4 @@
-## Simple DNS
+## Entry DNS
 
 A DNS users frontend.
 

app/models/a.rb

@@ -16,6 +16,17 @@ class A < Record
 
   attr_accessor :host_domain
   validates :host_domain, :inclusion => {:in => Settings.host_domains}, :allow_blank => true
+
+  validate do
+    if Settings.host_domains.include?(domain.name)
+      for hostname in Settings.protected_hostnames
+        if name =~ /^#{hostname}/i
+          errors[:name] << "cannot be used, please try another"
+          break
+        end
+      end
+    end
+  end
   
   before_validation do
     if host_domain.present? && Settings.host_domains.include?(host_domain)

config/settings.sample.yml

@@ -8,3 +8,9 @@ ns:
 default_prio: 10
 host_domains:
   - entrydns.org
+protected_hostnames:
+  - www
+  - mail
+  - smtp
+  - imap
+  - ns[0-9]*