acl_calc_mask.c revision 74432
1/* 2 * Copyright (c) 2001 Chris D. Faulhaber 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR THE VOICES IN HIS HEAD BE 18 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 19 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 20 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 21 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 22 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 23 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 24 * POSSIBILITY OF SUCH DAMAGE. 25 * 26 * $FreeBSD: head/lib/libc/posix1e/acl_calc_mask.c 74432 2001-03-19 03:19:51Z jedgar $ 27 */ 28 29#include <sys/types.h> 30#include <sys/acl.h> 31 32#include <errno.h> 33 34/* 35 * acl_calc_mask() calculates and set the permissions associated 36 * with the ACL_MASK ACL entry. If the ACL already contains an 37 * ACL_MASK entry, its permissions shall be overwritten; if not, 38 * one shall be added. 39 */ 40int 41acl_calc_mask(acl_t *acl_p) 42{ 43 acl_t acl_new; 44 int group_obj, i, mask_mode, mask_num, other_obj, user_obj; 45 46 /* check args */ 47 if (!acl_p || !*acl_p || ((*acl_p)->acl_cnt < 3) || 48 ((*acl_p)->acl_cnt > ACL_MAX_ENTRIES)) { 49 errno = EINVAL; 50 return -1; 51 } 52 53 acl_new = acl_dup(*acl_p); 54 if (!acl_new) 55 return -1; 56 57 user_obj = group_obj = other_obj = mask_mode = 0; 58 mask_num = -1; 59 60 /* gather permissions and find a mask entry */ 61 for (i = 0; i < acl_new->acl_cnt; i++) { 62 switch(acl_new->acl_entry[i].ae_tag) { 63 case ACL_USER_OBJ: 64 user_obj++; 65 break; 66 case ACL_OTHER: 67 other_obj++; 68 break; 69 case ACL_GROUP_OBJ: 70 group_obj++; 71 /* FALLTHROUGH */ 72 case ACL_GROUP: 73 case ACL_USER: 74 mask_mode |= 75 acl_new->acl_entry[i].ae_perm & ACL_PERM_BITS; 76 break; 77 case ACL_MASK: 78 mask_num = i; 79 break; 80 default: 81 errno = EINVAL; 82 acl_free(acl_new); 83 return -1; 84 /* NOTREACHED */ 85 } 86 } 87 if ((user_obj != 1) || (group_obj != 1) || (other_obj != 1)) { 88 errno = EINVAL; 89 acl_free(acl_new); 90 return -1; 91 } 92 /* if a mask entry already exists, overwrite the perms */ 93 if (mask_num != -1) { 94 acl_new->acl_entry[mask_num].ae_perm = mask_mode; 95 } else { 96 /* if no mask exists, check acl_cnt... */ 97 if (acl_new->acl_cnt == ACL_MAX_ENTRIES) { 98 errno = EINVAL; 99 acl_free(acl_new); 100 return -1; 101 } 102 /* ...and add the mask entry */ 103 acl_new->acl_entry[acl_new->acl_cnt].ae_tag = ACL_MASK; 104 acl_new->acl_entry[acl_new->acl_cnt].ae_id = 0; 105 acl_new->acl_entry[acl_new->acl_cnt].ae_perm = mask_mode; 106 acl_new->acl_cnt++; 107 } 108 109 if (acl_valid(acl_new) == -1) { 110 errno = EINVAL; 111 acl_free(acl_new); 112 return -1; 113 } 114 115 **acl_p = *acl_new; 116 acl_free(acl_new); 117 118 return 0; 119} 120