1/*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2001-2002 Chris D. Faulhaber 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29#include <sys/cdefs.h> 30#if 0 31__FBSDID("$FreeBSD: head/lib/libc/posix1e/acl_calc_mask.c 326193 2017-11-25 17:12:48Z pfg $"); 32#else 33__RCSID("$NetBSD: acl_calc_mask.c,v 1.2 2024/01/20 14:52:48 christos Exp $"); 34#endif 35 36#include "namespace.h" 37 38#include <sys/types.h> 39#include <sys/acl.h> 40 41#include <errno.h> 42#include <stdio.h> 43 44#include "acl_support.h" 45 46/* 47 * acl_calc_mask() (23.4.2): calculate and set the permissions 48 * associated with the ACL_MASK ACL entry. If the ACL already 49 * contains an ACL_MASK entry, its permissions shall be 50 * overwritten; if not, one shall be added. 51 */ 52int 53acl_calc_mask(acl_t *acl_p) 54{ 55 struct acl *acl_int, *acl_int_new; 56 acl_t acl_new; 57 size_t i; 58 int mask_mode, mask_num; 59 60 /* 61 * (23.4.2.4) requires acl_p to point to a pointer to a valid ACL. 62 * Since one of the primary reasons to use this function would be 63 * to calculate the appropriate mask to obtain a valid ACL, we only 64 * perform sanity checks here and validate the ACL prior to 65 * returning. 66 */ 67 if (acl_p == NULL || *acl_p == NULL) { 68 errno = EINVAL; 69 return (-1); 70 } 71 72 if (!_acl_brand_may_be(*acl_p, ACL_BRAND_POSIX)) { 73 errno = EINVAL; 74 return (-1); 75 } 76 _acl_brand_as(*acl_p, ACL_BRAND_POSIX); 77 78 acl_int = &(*acl_p)->ats_acl; 79 if ((acl_int->acl_cnt < 3) || (acl_int->acl_cnt > ACL_MAX_ENTRIES)) { 80 errno = EINVAL; 81 return (-1); 82 } 83 84 acl_new = acl_dup(*acl_p); 85 if (acl_new == NULL) 86 return (-1); 87 acl_int_new = &acl_new->ats_acl; 88 89 mask_mode = 0; 90 mask_num = -1; 91 92 /* gather permissions and find a mask entry */ 93 for (i = 0; i < acl_int_new->acl_cnt; i++) { 94 switch(acl_int_new->acl_entry[i].ae_tag) { 95 case ACL_USER: 96 case ACL_GROUP: 97 case ACL_GROUP_OBJ: 98 mask_mode |= 99 acl_int_new->acl_entry[i].ae_perm & ACL_PERM_BITS; 100 break; 101 case ACL_MASK: 102 mask_num = (int)i; 103 break; 104 } 105 } 106 107 /* if a mask entry already exists, overwrite the perms */ 108 if (mask_num != -1) 109 acl_int_new->acl_entry[mask_num].ae_perm = mask_mode; 110 else { 111 /* if no mask exists, check acl_cnt... */ 112 if (acl_int_new->acl_cnt == ACL_MAX_ENTRIES) { 113 errno = ENOMEM; 114 acl_free(acl_new); 115 return (-1); 116 } 117 /* ...and add the mask entry */ 118 acl_int_new->acl_entry[acl_int_new->acl_cnt].ae_tag = ACL_MASK; 119 acl_int_new->acl_entry[acl_int_new->acl_cnt].ae_id = 120 ACL_UNDEFINED_ID; 121 acl_int_new->acl_entry[acl_int_new->acl_cnt].ae_perm = 122 mask_mode; 123 acl_int_new->acl_cnt++; 124 } 125 126 if (acl_valid(acl_new) == -1) { 127 errno = EINVAL; 128 acl_free(acl_new); 129 return (-1); 130 } 131 132 **acl_p = *acl_new; 133 acl_free(acl_new); 134 135 return (0); 136} 137