IPC fails between user process and root process
I am using a CGI process to spawn a new process using execl system call. Both the CGI and the spawned processes are owned by user "www". The spawned process need to communicate with a system process owned by "root". The user "www" has lower privileges than the "root".
I have tried pipes and msg queues for IPC between the root process and the www process, but unfortunately both fail.
Am I doing something wrong? Generally speaking can a process with lower privilege send messages to a higher privilege process or to root process in Linux? If yes, is there a method that I am unaware of.