NetBSD/gnu/libexec/uucp/uudir.c

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1993-03-21 12:45:37 +03:00
/* uudir.c
Create a directory owned by uucp. This is Unix specific.
Copyright (C) 1992 Ian Lance Taylor
This file is part of the Taylor UUCP package.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
The author of the program may be contacted at ian@airs.com or
c/o AIRS, P.O. Box 520, Waltham, MA 02254.
$Log: uudir.c,v $
Revision 1.1.1.1 1993/03/21 09:45:37 cgd
initial import of 386bsd-0.1 sources
Revision 1.1 1992/02/09 05:11:42 ian
Initial revision
*/
#include "uucp.h"
#if USE_RCS_ID
char uudir_rcsid[] = "$Id: uudir.c,v 1.1.1.1 1993/03/21 09:45:37 cgd Exp $";
#endif
#include <pwd.h>
#if USE_STDIO && HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "sysdep.h"
/* External functions. */
extern int setuid ();
extern struct passwd *getpwnam ();
/* This is a simple program which sets its real uid to uucp and then
invokes /bin/mkdir. It is only used if the system does not support
the mkdir system call. It must be installed suid to root.
This program is needed because the UUCP programs will be run suid
to uucp. On a system without the mkdir system call, /bin/mkdir is
a suid root program. This means that /bin/mkdir always creates
directories using the real uid, rather than the effective uid.
This is wrong, since the UUCP programs always want to create
directories that are owned by uucp. Therefore, this simple suid
root program is used to force /bin/mkdir into making a directory
owned by uucp.
If we made the program publically executable, this would mean that
anybody could create a directory owned by uucp. This is probably
not a good thing, but since the program must be owned by root we
can't simply make it executable only by uucp. Therefore, the
Makefile hides the program away in /usr/lib/uucp/util, and makes
that directory searchable only by uucp. This should prevent
anybody else from getting to the program.
This is not a perfect solution, since any suid root program is by
definition a potential security hole. I really can't see any way
to avoid this, though. */
int
main (argc, argv)
int argc;
char **argv;
{
struct passwd *q;
const char *zprog, *zname;
/* We don't print any error messages, since this program should
never be run directly by a user. */
if (argc != 2)
exit (EXIT_FAILURE);
/* OWNER is passed in from the Makefile. It will normally be
"uucp". */
q = getpwnam (OWNER);
if (q == NULL)
exit (EXIT_FAILURE);
if (setuid (q->pw_uid) < 0)
exit (EXIT_FAILURE);
zprog = MKDIR_PROGRAM;
zname = strrchr (zprog, '/');
if (zname == NULL)
zname = zprog;
else
++zname;
(void) execl (zprog, zname, argv[1], (char *) NULL);
exit (EXIT_FAILURE);
}