Re: [gpsd-users] gpsd/udev behavior

[Eric S. Raymond]

Paul Fox <address@hidden>:
> manually changing the device permissions from 660 to 666 makes
> everything work.
> 
> the machine is an OLPC XO laptop, so it's entirely possible that it's
> a problem with our version of F17, but we don't really touch udev
> much.  (i say "we", because my work address is @laptop.org.)  any tips
> how this _should_ be working?

This is probably a distro-specific issue brought about by the choice
of default ownership or default permissions on the TTY devices.  Or it
could be the result of a minor packaging error. See the code near the
the following comment in gpsd.c

        /*
         * Drop privileges.  Up to now we've been running as root.  Instead,
         * set the user ID to 'nobody' (or whatever the --enable-gpsd-user
         * is) and the group ID to the owning group of a prototypical TTY
         * device. This limits the scope of any compromises in the code.
         * It requires that all GPS devices have their group read/write
         * permissions set.
         */

I'd explain in detail, but I think the comment and code are clear enough.
-- 
                <a href="http://www.catb.org/~esr/";>Eric S. Raymond</a>