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From: karish@mindcraft.com (Chuck Karish)
Newsgroups: news.software.b
Subject: Re: (C News) limit filesize and inews
Message-ID: <663302894.24807@mindcraft.com>
Date: 8 Jan 91 02:48:13 GMT
References: <1991Jan6.073729.21354@zoo.toronto.edu> <3464@gazette.bcm.tmc.edu> <1991Jan7.182907.13583@zoo.toronto.edu> <3480@gazette.bcm.tmc.edu>
Organization: Mindcraft, Inc.
Lines: 51

In article <3480@gazette.bcm.tmc.edu> sob@tmc.edu (Stan Barber) writes:
>Okey, WHAT IS THE SOLUTION THEN?

First, to restrain our petulence just a little.

>Just for fun, let's eliminate the "Get the OS fixed" answer.

That's the only real answer.  Workaround follows.

"Get the OS fixed" isn't even enough.  Per-user limits management is
done in different ways on different systems, because the standards
don't specify the behavior.  The choices are to (a) make c-news look
like c-kermit inside, or (b) to use a workaround until vendors converge
on a reasonable way of specifying the limit.

>For even more fun, let's eliminate "change the system wide parameters"
>answer, too.

Okay.

>Now, what's the answer?

For SysV-based systems:

Call relaynews and expire from a wrapper that runs with root's
effective UID, uses ulimit() to set a usable file size, does setuid()
and setgid() to the news user's ID, values, and execs its argument.

#define	NEWSUID	55
#define	NEWSGID	56
#define	FILESIZE	204800	/* 512-byte blocks; this is 1 GB */

main(argc, argv)
int argc;
char **argv;
{
	if(argc < 2)
		exit(1);

	++ argv;
	if((ulimit(2, FILESIZE) >= 0)
	  && (setgid(NEWSGID) == 0)
	  && (setuid(NEWSUID) == 0))
		exit(execvp(*argv, argv));
	else
		exit(1);
}
-- 

	Chuck Karish		karish@mindcraft.com
	Mindcraft, Inc.		(415) 323-9000