lib/reversed.rb in reversed-0.2.1 vs lib/reversed.rb in reversed-0.3.0

@@ -1,24 +1,36 @@
 require "reversed/version"
 require "net/dns"
+require "ipaddr"
 
 module Reversed
   def self.lookup(ip, timeout: 5, nameservers: nil)
     ip = ip.to_s
     unless ip.empty?
+      begin
+        # ensure valid ip
+        ip = IPAddr.new(ip)
+      rescue IPAddr::InvalidAddressError
+        raise ArgumentError, "Invalid IP"
+      end
+
       options = {
-        retry: 3,
+        retry_number: 3,
         udp_timeout: timeout
       }
       options[:nameservers] = nameservers if nameservers
       begin
-        resolver = Net::DNS::Resolver.new(options).search(ip)
+        resolver = Net::DNS::Resolver.new(options).search(ip.reverse, Net::DNS::PTR)
         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
+      rescue Errno::EAFNOSUPPORT
+        options[:use_tcp] = true
+        options[:tcp_timeout] = timeout
+        retry
       end
     end
   end
 end