Fix #439 - Detect if the target goes down during the scan

lib/common/common_helper.rb

@@ -64,6 +64,14 @@ end
 
 require_files_from_directory(COMMON_LIB_DIR, '**/*.rb')
 
+# Hook to check if the target if down during the scan
+# The target is considered down after 10 request with status = 0
+down = 0
+Typhoeus.on_complete do |response|
+  down += 1 if response.code == 0
+  fail 'The target seems to be down' if down >= 10
+end
+
 # Add protocol
 def add_http_protocol(url)
   url =~ /^https?:/ ? url : "http://#{url}"