[BusyBox] Patch for id with invalid username

[Erik Andersen]

On Thu Jul 27, 2000 at 04:43:44PM -0500, Ken Chalmers wrote:
> Here's a patch for id (requires patching id.c & utility.c) that allows 
> it to detect and print an error if you give an invalid username.  Note 
> that because of the way the information is passed, if you ever have a 
> user with a gid of (2^32)-1, they'll be told they don't exist.  
> Unlikely that one will ever have 4 billion groups on an embedded 
> system, though :)  
> 
> I don't even know if this kind of error checking is something people 
> consider important, but it only adds a few bytes so I just figured I'd 
> put it up for interest's sake.
> 
> The patches are against the current (as of Jul 27 2000) CVS source.
> 
> 	-Ken
> 
> -- 
> Do not meddle in the affairs of dragons, cuz, like,
> you are crunchy and taste good with ketchup.
> 
>  
> --- busybox/id.c	Thu Jul 27 16:29:00 2000
> +++ busybox.idpatch/id.c	Thu Jul 27 16:22:23 2000
> @@ -71,6 +71,10 @@
>  	} else {
>  		group = xmalloc(9);
>  	    gid = my_getpwnamegid(user);
> +		if(gid == -1) {
> +			fprintf(stderr, "id: %s: No such user\n", user);
> +			return(1);
> +		}
>  		my_getgrgid(group, gid);
>  	}

I've applied this, plus a few other cleanups.  We were using malloc, rather
then calloc which could result in unterminated strings (and segfaults).  Also,
error checking was lousy, so I moved your test and enhanced it a bit.

Could you poke at it now and see if you can make it misbehave?

 -Erik

--
Erik B. Andersen   email:  andersen at lineo.com
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