freebsd-skq/lib/libc/posix1e/acl_calc_mask.c

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/*
* Copyright (c) 2001 Chris D. Faulhaber
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR THE VOICES IN HIS HEAD BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/types.h>
#include "namespace.h"
#include <sys/acl.h>
#include "un-namespace.h"
#include <errno.h>
#include <stdio.h>
/*
* acl_calc_mask() (23.4.2): calculate and set the permissions
* associated with the ACL_MASK ACL entry. If the ACL already
* contains an ACL_MASK entry, its permissions shall be
* overwritten; if not, one shall be added.
*/
int
acl_calc_mask(acl_t *acl_p)
{
struct acl *acl_int, *acl_int_new;
acl_t acl_new;
int i, mask_mode, mask_num;
/*
* (23.4.2.4) requires acl_p to point to a pointer to a valid ACL.
* Since one of the primary reasons to use this function would be
* to calculate the appropriate mask to obtain a valid ACL, we only
* perform sanity checks here and validate the ACL prior to
* returning.
*/
if (!acl_p || !*acl_p) {
errno = EINVAL;
return -1;
}
acl_int = &(*acl_p)->ats_acl;
if ((acl_int->acl_cnt < 3) || (acl_int->acl_cnt > ACL_MAX_ENTRIES)) {
errno = EINVAL;
return -1;
}
acl_new = acl_dup(*acl_p);
if (!acl_new)
return -1;
acl_int_new = &acl_new->ats_acl;
mask_mode = 0;
mask_num = -1;
/* gather permissions and find a mask entry */
for (i = 0; i < acl_int_new->acl_cnt; i++) {
switch(acl_int_new->acl_entry[i].ae_tag) {
case ACL_USER:
case ACL_GROUP:
case ACL_GROUP_OBJ:
mask_mode |=
acl_int_new->acl_entry[i].ae_perm & ACL_PERM_BITS;
break;
case ACL_MASK:
mask_num = i;
break;
}
}
/* if a mask entry already exists, overwrite the perms */
if (mask_num != -1)
acl_int_new->acl_entry[mask_num].ae_perm = mask_mode;
else {
/* if no mask exists, check acl_cnt... */
if (acl_int_new->acl_cnt == ACL_MAX_ENTRIES) {
errno = ENOMEM;
return -1;
}
/* ...and add the mask entry */
acl_int_new->acl_entry[acl_int_new->acl_cnt].ae_tag = ACL_MASK;
acl_int_new->acl_entry[acl_int_new->acl_cnt].ae_id =
ACL_UNDEFINED_ID;
acl_int_new->acl_entry[acl_int_new->acl_cnt].ae_perm =
mask_mode;
acl_int_new->acl_cnt++;
}
if (acl_valid(acl_new) == -1) {
errno = EINVAL;
acl_free(acl_new);
return -1;
}
**acl_p = *acl_new;
acl_free(acl_new);
return 0;
}