Re: Forking Java GUI Apps

From: Sadrul H C (imadil_at_gmail.com)
Date: 09/30/04

  • Next message: Joseph: "ASCII to binary and /proc" 
    Date: 29 Sep 2004 22:20:08 -0700

    Kasper Dupont <kasperd@daimi.au.dk> wrote in message
    news:<415AA4FF.6D5986BF@daimi.au.dk>...
    > Sadrul H C wrote:
    > >
    > > you can set the uid of the forked child process to another user. that
    > > should prevent the child from making any successful X-server calls.
    >
    > This is a misunderstanding. You don't communicate
    > with the X-server through function calls. You
    > communicate over a socket.
    thanks for clearing that up :)

    >
    > To prevent a process from communicating with the
    > X-server you must do two things. Prevent it from
    > using an already established socket, that would
    > usually just mean close it. And you must prevent
    > it from getting the cookie. Usually you read the
    > cookie from ~/.Xauthority unless overriden by a
    > XAUTHORITY environment variable. But even if it
    > does not have read access to that file, it may
    > still find the cookie if it exist in the process
    > address space. A successfull execve call will
    > remove it from address space.
    if from root, i wanted to run a child process which
    communicates with the X server as a low-privileged
    user, then i change the permission levels to that
    ~/.Xauthority file so that the user can read from it.
    is that a good way of doing things?

    -- Adil

  • Next message: Joseph: "ASCII to binary and /proc"

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