add unknown command override, see #2793

git-svn-id: file:///home/svn/framework3/trunk@10542 4d416f70-5f16-0410-b530-b9f4589650da

lib/msf/core/exploit/ftpserver.rb

@@ -125,6 +125,11 @@ module Exploit::Remote::FtpServer
 			return
 
 		else
+			# Allow per-command overrides
+			if(self.respond_to?("on_client_unknown_command"))
+				return self.send("on_client_unknown_command", c, cmd.upcase, arg)
+			end
+
 			print_status("#{@state[c][:name]} UNKNOWN '#{cmd} #{arg}'")
 			c.put("500 '#{cmd} #{arg}': command not understood.\r\n")
 			return