1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 #include <sys/types.h> 31 #include "namespace.h" 32 #include <sys/acl.h> 33 #include "un-namespace.h" 34 35 #include <errno.h> 36 #include <stdio.h> 37 38 #include "acl_support.h" 39 40 /* 41 * acl_calc_mask() (23.4.2): calculate and set the permissions 42 * associated with the ACL_MASK ACL entry. If the ACL already 43 * contains an ACL_MASK entry, its permissions shall be 44 * overwritten; if not, one shall be added. 45 */ 46 int 47 acl_calc_mask(acl_t *acl_p) 48 { 49 struct acl *acl_int, *acl_int_new; 50 acl_t acl_new; 51 int i, mask_mode, mask_num; 52 53 /* 54 * (23.4.2.4) requires acl_p to point to a pointer to a valid ACL. 55 * Since one of the primary reasons to use this function would be 56 * to calculate the appropriate mask to obtain a valid ACL, we only 57 * perform sanity checks here and validate the ACL prior to 58 * returning. 59 */ 60 if (acl_p == NULL || *acl_p == NULL) { 61 errno = EINVAL; 62 return (-1); 63 } 64 65 if (!_acl_brand_may_be(*acl_p, ACL_BRAND_POSIX)) { 66 errno = EINVAL; 67 return (-1); 68 } 69 _acl_brand_as(*acl_p, ACL_BRAND_POSIX); 70 71 acl_int = &(*acl_p)->ats_acl; 72 if ((acl_int->acl_cnt < 3) || (acl_int->acl_cnt > ACL_MAX_ENTRIES)) { 73 errno = EINVAL; 74 return (-1); 75 } 76 77 acl_new = acl_dup(*acl_p); 78 if (acl_new == NULL) 79 return (-1); 80 acl_int_new = &acl_new->ats_acl; 81 82 mask_mode = 0; 83 mask_num = -1; 84 85 /* gather permissions and find a mask entry */ 86 for (i = 0; i < acl_int_new->acl_cnt; i++) { 87 switch(acl_int_new->acl_entry[i].ae_tag) { 88 case ACL_USER: 89 case ACL_GROUP: 90 case ACL_GROUP_OBJ: 91 mask_mode |= 92 acl_int_new->acl_entry[i].ae_perm & ACL_PERM_BITS; 93 break; 94 case ACL_MASK: 95 mask_num = i; 96 break; 97 } 98 } 99 100 /* if a mask entry already exists, overwrite the perms */ 101 if (mask_num != -1) 102 acl_int_new->acl_entry[mask_num].ae_perm = mask_mode; 103 else { 104 /* if no mask exists, check acl_cnt... */ 105 if (acl_int_new->acl_cnt == ACL_MAX_ENTRIES) { 106 errno = ENOMEM; 107 acl_free(acl_new); 108 return (-1); 109 } 110 /* ...and add the mask entry */ 111 acl_int_new->acl_entry[acl_int_new->acl_cnt].ae_tag = ACL_MASK; 112 acl_int_new->acl_entry[acl_int_new->acl_cnt].ae_id = 113 ACL_UNDEFINED_ID; 114 acl_int_new->acl_entry[acl_int_new->acl_cnt].ae_perm = 115 mask_mode; 116 acl_int_new->acl_cnt++; 117 } 118 119 if (acl_valid(acl_new) == -1) { 120 errno = EINVAL; 121 acl_free(acl_new); 122 return (-1); 123 } 124 125 **acl_p = *acl_new; 126 acl_free(acl_new); 127 128 return (0); 129 } 130