lib/reversed.rb in reversed-0.2.0 vs lib/reversed.rb in reversed-0.2.1

@@ -1,13 +1,24 @@
 require "reversed/version"
 require "net/dns"
 
 module Reversed
-  def self.lookup(ip)
+  def self.lookup(ip, timeout: 5, nameservers: nil)
     ip = ip.to_s
     unless ip.empty?
-      resolver = Net::DNS::Resolver.new(retry: 3).search(ip)
-      answer = resolver.answer.first || resolver.authority.first
-      answer.value.split(" ").first[0..-2] if answer
+      options = {
+        retry: 3,
+        udp_timeout: timeout
+      }
+      options[:nameservers] = nameservers if nameservers
+      begin
+        resolver = Net::DNS::Resolver.new(options).search(ip)
+        answer = resolver.answer.first || resolver.authority.first
+        if answer && !answer.value.empty?
+          answer.value.split(" ").first[0..-2]
+        end
+      rescue Net::DNS::Resolver::NoResponseError
+        nil
+      end
     end
   end
 end