TFTP::Client retransmit lost data blocks on upload

Retransmit data blocks until we receieve a matching ACK.

lib/rex/proto/tftp/client.rb

@@ -302,21 +302,27 @@ def send_data(host,port)
       yield "Sending #{expected_size} bytes (#{expected_blocks} blocks)"
     end
     data_blocks.each_with_index do |data_block,idx|
-      req = [OpData, (idx + 1), data_block].pack("nnA*")
-      if self.server_sock.sendto(req, host, port) > 0
-        sent_data += data_block.size
-      end
-      res = self.server_sock.recvfrom(65535)
-      if res
-        code, type, msg = parse_tftp_response(res[0])
-        if code == 4
-          sent_blocks += 1
-          yield "Sent #{data_block.size} bytes in block #{sent_blocks}" if block_given?
-        else
-          if block_given?
-            yield "Got an unexpected response: Code:%d, Type:%d, Message:'%s'. Aborting." % [code, type, msg]
+      while true
+        req = [OpData, (idx + 1), data_block].pack("nnA*")
+        self.server_sock.sendto(req, host, port)
+        res = self.server_sock.recvfrom(65535)
+        if res
+          code, type, msg = parse_tftp_response(res[0])
+          if code == 4
+            if type == idx + 1
+              sent_blocks += 1
+              sent_data += data_block.size
+              yield "Sent #{data_block.size} bytes in block #{idx+1}" if block_given?
+	      break
+	    else
+              next
+	    end
+          else
+            if block_given?
+              yield "Got an unexpected response: Code:%d, Type:%d, Message:'%s'. Aborting." % [code, type, msg]
+            end
+            break
           end
-          break
         end
       end
     end