RFC: Optionally hide MIT-SHM from clients with different UID
This is kind of a workaround for #125 (closed). Since apps and toolkits tend to do the paranoid thing and set their shm segments 0600, there's no way to do (pre-1.2) MIT-SHM operations if the client and server have different UIDs. So it might be preferable to have the shm dispatch code treat clients with a different uid as "non-local" for this case and reply with BadRequest. Note that the MIT-SHM 1.2 requests work via file descriptor passing and would not have this permission issue, so you would likely want to continue to allow those.