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 __FBSDID("$FreeBSD$"); 31 32 #include <sys/types.h> 33 #include "namespace.h" 34 #include <sys/acl.h> 35 #include "un-namespace.h" 36 37 #include <errno.h> 38 #include <stdio.h> 39 40 #include "acl_support.h" 41 42 /* 43 * acl_calc_mask() (23.4.2): calculate and set the permissions 44 * associated with the ACL_MASK ACL entry. If the ACL already 45 * contains an ACL_MASK entry, its permissions shall be 46 * overwritten; if not, one shall be added. 47 */ 48 int 49 acl_calc_mask(acl_t *acl_p) 50 { 51 struct acl *acl_int, *acl_int_new; 52 acl_t acl_new; 53 int i, mask_mode, mask_num; 54 55 /* 56 * (23.4.2.4) requires acl_p to point to a pointer to a valid ACL. 57 * Since one of the primary reasons to use this function would be 58 * to calculate the appropriate mask to obtain a valid ACL, we only 59 * perform sanity checks here and validate the ACL prior to 60 * returning. 61 */ 62 if (acl_p == NULL || *acl_p == NULL) { 63 errno = EINVAL; 64 return (-1); 65 } 66 67 if (!_acl_brand_may_be(*acl_p, ACL_BRAND_POSIX)) { 68 errno = EINVAL; 69 return (-1); 70 } 71 _acl_brand_as(*acl_p, ACL_BRAND_POSIX); 72 73 acl_int = &(*acl_p)->ats_acl; 74 if ((acl_int->acl_cnt < 3) || (acl_int->acl_cnt > ACL_MAX_ENTRIES)) { 75 errno = EINVAL; 76 return (-1); 77 } 78 79 acl_new = acl_dup(*acl_p); 80 if (acl_new == NULL) 81 return (-1); 82 acl_int_new = &acl_new->ats_acl; 83 84 mask_mode = 0; 85 mask_num = -1; 86 87 /* gather permissions and find a mask entry */ 88 for (i = 0; i < acl_int_new->acl_cnt; i++) { 89 switch(acl_int_new->acl_entry[i].ae_tag) { 90 case ACL_USER: 91 case ACL_GROUP: 92 case ACL_GROUP_OBJ: 93 mask_mode |= 94 acl_int_new->acl_entry[i].ae_perm & ACL_PERM_BITS; 95 break; 96 case ACL_MASK: 97 mask_num = i; 98 break; 99 } 100 } 101 102 /* if a mask entry already exists, overwrite the perms */ 103 if (mask_num != -1) 104 acl_int_new->acl_entry[mask_num].ae_perm = mask_mode; 105 else { 106 /* if no mask exists, check acl_cnt... */ 107 if (acl_int_new->acl_cnt == ACL_MAX_ENTRIES) { 108 errno = ENOMEM; 109 acl_free(acl_new); 110 return (-1); 111 } 112 /* ...and add the mask entry */ 113 acl_int_new->acl_entry[acl_int_new->acl_cnt].ae_tag = ACL_MASK; 114 acl_int_new->acl_entry[acl_int_new->acl_cnt].ae_id = 115 ACL_UNDEFINED_ID; 116 acl_int_new->acl_entry[acl_int_new->acl_cnt].ae_perm = 117 mask_mode; 118 acl_int_new->acl_cnt++; 119 } 120 121 if (acl_valid(acl_new) == -1) { 122 errno = EINVAL; 123 acl_free(acl_new); 124 return (-1); 125 } 126 127 **acl_p = *acl_new; 128 acl_free(acl_new); 129 130 return (0); 131 } 132