1995-08-19 21:30:30 +00:00
|
|
|
|
/* uid.c
|
|
|
|
|
|
Switch back and forth between UUCP and user permissions.
|
|
|
|
|
|
|
|
|
|
|
|
Copyright (C) 1992, 1995 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
|
|
|
|
|
|
|
|
|
|
The author of the program may be contacted at ian@airs.com or
|
|
|
|
|
|
c/o Cygnus Support, 48 Grove Street, Somerville, MA 02144.
|
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
|
|
#include "uucp.h"
|
|
|
|
|
|
|
|
|
|
|
|
#include "uudefs.h"
|
|
|
|
|
|
#include "sysdep.h"
|
|
|
|
|
|
|
|
|
|
|
|
#include <errno.h>
|
1995-08-21 11:28:26 +00:00
|
|
|
|
|
|
|
|
|
|
/* NetBSD apparently does not support setuid as required by POSIX when
|
|
|
|
|
|
using saved setuid, so use seteuid instead. */
|
|
|
|
|
|
|
|
|
|
|
|
#if HAVE_SETEUID
|
|
|
|
|
|
#define setuid seteuid
|
|
|
|
|
|
#endif
|
1995-08-19 21:30:30 +00:00
|
|
|
|
|
|
|
|
|
|
/* Switch to permissions of the invoking user. */
|
|
|
|
|
|
|
|
|
|
|
|
boolean
|
|
|
|
|
|
fsuser_perms (pieuid)
|
|
|
|
|
|
uid_t *pieuid;
|
|
|
|
|
|
{
|
|
|
|
|
|
uid_t ieuid, iuid;
|
|
|
|
|
|
|
|
|
|
|
|
ieuid = geteuid ();
|
|
|
|
|
|
iuid = getuid ();
|
|
|
|
|
|
if (pieuid != NULL)
|
|
|
|
|
|
*pieuid = ieuid;
|
|
|
|
|
|
|
|
|
|
|
|
#if HAVE_SETREUID
|
|
|
|
|
|
/* Swap the effective user id and the real user id. We can then
|
|
|
|
|
|
swap them back again when we want to return to the uucp user's
|
|
|
|
|
|
permissions. */
|
|
|
|
|
|
if (setreuid (ieuid, iuid) < 0)
|
|
|
|
|
|
{
|
|
|
|
|
|
ulog (LOG_ERROR, "setreuid (%ld, %ld): %s",
|
|
|
|
|
|
(long) ieuid, (long) iuid, strerror (errno));
|
|
|
|
|
|
return FALSE;
|
|
|
|
|
|
}
|
|
|
|
|
|
#else /* ! HAVE_SETREUID */
|
|
|
|
|
|
#if HAVE_SAVED_SETUID
|
|
|
|
|
|
/* Set the effective user id to the real user id. Since the
|
|
|
|
|
|
effective user id is saved (it's the saved setuid) we will able
|
|
|
|
|
|
to set back to it later. If the real user id is root we will not
|
|
|
|
|
|
be able to switch back and forth, so don't even try. */
|
|
|
|
|
|
if (iuid != 0)
|
|
|
|
|
|
{
|
|
|
|
|
|
if (setuid (iuid) < 0)
|
|
|
|
|
|
{
|
|
|
|
|
|
ulog (LOG_ERROR, "setuid (%ld): %s", (long) iuid, strerror (errno));
|
|
|
|
|
|
return FALSE;
|
|
|
|
|
|
}
|
|
|
|
|
|
}
|
|
|
|
|
|
#else /* ! HAVE_SAVED_SETUID */
|
|
|
|
|
|
/* There's no way to switch between real permissions and effective
|
|
|
|
|
|
permissions. Just try to open the file with the uucp
|
|
|
|
|
|
permissions. */
|
|
|
|
|
|
#endif /* ! HAVE_SAVED_SETUID */
|
|
|
|
|
|
#endif /* ! HAVE_SETREUID */
|
|
|
|
|
|
|
|
|
|
|
|
return TRUE;
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* Restore the uucp permissions. */
|
|
|
|
|
|
|
|
|
|
|
|
/*ARGSUSED*/
|
|
|
|
|
|
boolean
|
|
|
|
|
|
fsuucp_perms (ieuid)
|
|
|
|
|
|
long ieuid;
|
|
|
|
|
|
{
|
|
|
|
|
|
#if HAVE_SETREUID
|
|
|
|
|
|
/* Swap effective and real user id's back to what they were. */
|
|
|
|
|
|
if (! fsuser_perms ((uid_t *) NULL))
|
|
|
|
|
|
return FALSE;
|
|
|
|
|
|
#else /* ! HAVE_SETREUID */
|
|
|
|
|
|
#if HAVE_SAVED_SETUID
|
|
|
|
|
|
/* Set ourselves back to our original effective user id. */
|
|
|
|
|
|
if (setuid ((uid_t) ieuid) < 0)
|
|
|
|
|
|
{
|
|
|
|
|
|
ulog (LOG_ERROR, "setuid (%ld): %s", (long) ieuid, strerror (errno));
|
|
|
|
|
|
/* Is this error message helpful or confusing? */
|
|
|
|
|
|
if (errno == EPERM)
|
|
|
|
|
|
ulog (LOG_ERROR,
|
|
|
|
|
|
"Probably HAVE_SAVED_SETUID in policy.h should be set to 0");
|
|
|
|
|
|
return FALSE;
|
|
|
|
|
|
}
|
|
|
|
|
|
#else /* ! HAVE_SAVED_SETUID */
|
|
|
|
|
|
/* We didn't switch, no need to switch back. */
|
|
|
|
|
|
#endif /* ! HAVE_SAVED_SETUID */
|
|
|
|
|
|
#endif /* ! HAVE_SETREUID */
|
|
|
|
|
|
|
|
|
|
|
|
return TRUE;
|
|
|
|
|
|
}
|
