Improved handling of exceptions during Resolver message decode (fixes socketry#10).

Author: ioquatix

lib/rubydns/message.rb

@@ -35,6 +35,7 @@ def self.decode_message(data)
 data.force_encoding("BINARY")
 end
 
+# This may throw Resolv::DNS::DecodeError.
 Message.decode(data)
 end
 end

lib/rubydns/resolver.rb

@@ -111,12 +111,22 @@ def run!
 end
 
 def process_response!(response)
-if response.tc != 0
+if Exception === response
+@logger.warn "[#{@message.id}] Failure while processing response #{exception}!" if @logger
+RubyDNS.log_exception(@logger, response) if @logger
+
+try_next_server!
+elsif response.tc != 0
 @logger.warn "[#{@message.id}] Received truncated response!" if @logger
-# We hardcode this behaviour for now.
+
+try_next_server!
+elsif response.id != @message.id
+@logger.warn "[#{@message.id}] Received response with incorrect message id: #{response.id}" if @request.logger
+
 try_next_server!
 else
 @logger.warn "[#{@message.id}] Received valid response #{response.inspect}" if @logger
+
 succeed response
 end
 end
@@ -175,13 +185,11 @@ def post_init
 def receive_data(data)
 # Receiving response from remote DNS server...
 message = RubyDNS::decode_message(data)
-
+
 # The message id must match, and it can't be truncated:
-if message.id == @request.message.id
-@request.process_response!(message)
-else
-@request.logger.warn "[#{@request.message.id}] Received response with incorrect message id: #{message.id}" if @request.logger
-end
+@request.process_response!(message)
+rescue Resolv::DNS::DecodeError => error
+@request.process_response!(error)
 end
 end
 
@@ -220,12 +228,10 @@ def receive_data(data)
 
 message = RubyDNS::decode_message(data)
 
-if message.id == @request.message.id
-@request.process_response!(message)
-else
-@request.logger.warn "[#{@request.message.id}] Received response with incorrect message id: #{message.id}" if @request.logger
-end
+@request.process_response!(message)
 end
+rescue Resolv::DNS::DecodeError => error
+@request.process_response!(error)
 end
 end
 end