helpers: refactor for simple functions

lib/dyndnsd/helper.rb

@@ -0,0 +1,23 @@
+
+require 'ipaddr'
+
+module Dyndnsd
+  class Helper
+    def self.is_fqdn_valid?(hostname, domain)
+      return false if hostname.length < domain.length + 2
+      return false if not hostname.end_with?(domain)
+      name = hostname.chomp(domain)
+      return false if not name.match(/^[a-zA-Z0-9_-]+\.$/)
+      true
+    end
+
+    def self.is_ip_valid?(ip)
+      begin
+        IPAddr.new(ip)
+        return true
+      rescue ArgumentError
+        return false
+      end
+    end
+  end
+end