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/* setresuid -- set real user ID, effective user ID, and saved-set user ID
Copyright (C) 2002-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <unistd.h>
#include <hurd.h>
#include <hurd/id.h>
/* Set the real user ID, effective user ID, and saved-set user ID,
of the calling process to RUID, EUID, and SUID, respectively. */
int
__setresuid (uid_t ruid, uid_t euid, uid_t suid)
{
auth_t newauth;
error_t err;
retry:
HURD_CRITICAL_BEGIN;
__mutex_lock (&_hurd_id.lock);
err = _hurd_check_ids ();
if (!err)
{
/* Make a new auth handle which has EUID as the first element in the
list of effective uids. */
uid_t *newgen, *newaux;
uid_t auxs[2] = { ruid, suid };
size_t ngen, naux;
newgen = _hurd_id.gen.uids;
ngen = _hurd_id.gen.nuids;
if (euid != -1)
{
if (_hurd_id.gen.nuids == 0)
{
/* No effective uids now. The new set will be just UID. */
newgen = &euid;
ngen = 1;
}
else
{
_hurd_id.gen.uids[0] = euid;
_hurd_id.valid = 0;
}
}
newaux = _hurd_id.aux.uids;
naux = _hurd_id.aux.nuids;
if (ruid != -1)
{
if (_hurd_id.aux.nuids == 0)
{
newaux = &ruid;
naux = 1;
}
else
{
_hurd_id.aux.uids[0] = ruid;
_hurd_id.valid = 0;
}
}
if (suid != -1)
{
if (ruid == -1)
{
if (_hurd_id.aux.nuids >= 1)
auxs[0] = _hurd_id.aux.uids[0];
else if (_hurd_id.gen.nuids >= 1)
auxs[0] = _hurd_id.gen.uids[0];
else
/* Not even an effective UID.
Fall back to the only UID we have. */
auxs[0] = suid;
}
if (_hurd_id.aux.nuids <= 1)
{
/* No saved uids now. The new set will be just UID. */
newaux = auxs;
naux = 2;
}
else
{
_hurd_id.aux.uids[1] = suid;
_hurd_id.valid = 0;
}
}
err = __USEPORT (AUTH, __auth_makeauth
(port, NULL, MACH_MSG_TYPE_COPY_SEND, 0,
newgen, ngen, newaux, naux,
_hurd_id.gen.gids, _hurd_id.gen.ngids,
_hurd_id.aux.gids, _hurd_id.aux.ngids,
&newauth));
}
__mutex_unlock (&_hurd_id.lock);
HURD_CRITICAL_END;
if (err == EINTR)
/* Got a signal while inside an RPC of the critical section, retry again */
goto retry;
if (err)
return __hurd_fail (err);
/* Install the new handle and reauthenticate everything. */
err = __setauth (newauth);
__mach_port_deallocate (__mach_task_self (), newauth);
return err;
}
libc_hidden_def (__setresuid)
weak_alias (__setresuid, setresuid)
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