117 lines
3.3 KiB
C
117 lines
3.3 KiB
C
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/* uid.c
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Switch back and forth between UUCP and user permissions.
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Copyright (C) 1992, 1995 Ian Lance Taylor
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This file is part of the Taylor UUCP package.
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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The author of the program may be contacted at ian@airs.com or
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c/o Cygnus Support, 48 Grove Street, Somerville, MA 02144.
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*/
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#include "uucp.h"
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#include "uudefs.h"
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#include "sysdep.h"
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#include <errno.h>
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/* NetBSD apparently does not support setuid as required by POSIX when
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using saved setuid, so use seteuid instead. */
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#if HAVE_SETEUID
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#define setuid seteuid
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#endif
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/* Switch to permissions of the invoking user. */
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boolean
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fsuser_perms (pieuid)
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uid_t *pieuid;
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{
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uid_t ieuid, iuid;
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ieuid = geteuid ();
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iuid = getuid ();
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if (pieuid != NULL)
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*pieuid = ieuid;
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#if HAVE_SETREUID
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/* Swap the effective user id and the real user id. We can then
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swap them back again when we want to return to the uucp user's
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permissions. */
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if (setreuid (ieuid, iuid) < 0)
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{
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ulog (LOG_ERROR, "setreuid (%ld, %ld): %s",
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(long) ieuid, (long) iuid, strerror (errno));
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return FALSE;
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}
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#else /* ! HAVE_SETREUID */
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#if HAVE_SAVED_SETUID
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/* Set the effective user id to the real user id. Since the
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effective user id is saved (it's the saved setuid) we will able
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to set back to it later. If the real user id is root we will not
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be able to switch back and forth, so don't even try. */
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if (iuid != 0)
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{
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if (setuid (iuid) < 0)
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{
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ulog (LOG_ERROR, "setuid (%ld): %s", (long) iuid, strerror (errno));
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return FALSE;
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}
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}
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#else /* ! HAVE_SAVED_SETUID */
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/* There's no way to switch between real permissions and effective
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permissions. Just try to open the file with the uucp
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permissions. */
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#endif /* ! HAVE_SAVED_SETUID */
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#endif /* ! HAVE_SETREUID */
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return TRUE;
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}
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/* Restore the uucp permissions. */
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/*ARGSUSED*/
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boolean
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fsuucp_perms (ieuid)
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long ieuid;
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{
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#if HAVE_SETREUID
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/* Swap effective and real user id's back to what they were. */
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if (! fsuser_perms ((uid_t *) NULL))
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return FALSE;
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#else /* ! HAVE_SETREUID */
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#if HAVE_SAVED_SETUID
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/* Set ourselves back to our original effective user id. */
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if (setuid ((uid_t) ieuid) < 0)
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{
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ulog (LOG_ERROR, "setuid (%ld): %s", (long) ieuid, strerror (errno));
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/* Is this error message helpful or confusing? */
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if (errno == EPERM)
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ulog (LOG_ERROR,
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"Probably HAVE_SAVED_SETUID in policy.h should be set to 0");
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return FALSE;
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}
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#else /* ! HAVE_SAVED_SETUID */
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/* We didn't switch, no need to switch back. */
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#endif /* ! HAVE_SAVED_SETUID */
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#endif /* ! HAVE_SETREUID */
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return TRUE;
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}
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