acl_calc_mask.c revision 75185
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 75185 2001-04-04 18:00:52Z tmm $ 27 */ 28 29#include <sys/types.h> 30#include "namespace.h" 31#include <sys/acl.h> 32#include "un-namespace.h" 33 34#include <errno.h> 35 36/* 37 * acl_calc_mask() calculates and set the permissions associated 38 * with the ACL_MASK ACL entry. If the ACL already contains an 39 * ACL_MASK entry, its permissions shall be overwritten; if not, 40 * one shall be added. 41 */ 42int 43acl_calc_mask(acl_t *acl_p) 44{ 45 acl_t acl_new; 46 int group_obj, i, mask_mode, mask_num, other_obj, user_obj; 47 48 /* check args */ 49 if (!acl_p || !*acl_p || ((*acl_p)->acl_cnt < 3) || 50 ((*acl_p)->acl_cnt > ACL_MAX_ENTRIES)) { 51 errno = EINVAL; 52 return -1; 53 } 54 55 acl_new = acl_dup(*acl_p); 56 if (!acl_new) 57 return -1; 58 59 user_obj = group_obj = other_obj = mask_mode = 0; 60 mask_num = -1; 61 62 /* gather permissions and find a mask entry */ 63 for (i = 0; i < acl_new->acl_cnt; i++) { 64 switch(acl_new->acl_entry[i].ae_tag) { 65 case ACL_USER_OBJ: 66 user_obj++; 67 break; 68 case ACL_OTHER: 69 other_obj++; 70 break; 71 case ACL_GROUP_OBJ: 72 group_obj++; 73 /* FALLTHROUGH */ 74 case ACL_GROUP: 75 case ACL_USER: 76 mask_mode |= 77 acl_new->acl_entry[i].ae_perm & ACL_PERM_BITS; 78 break; 79 case ACL_MASK: 80 mask_num = i; 81 break; 82 default: 83 errno = EINVAL; 84 acl_free(acl_new); 85 return -1; 86 /* NOTREACHED */ 87 } 88 } 89 if ((user_obj != 1) || (group_obj != 1) || (other_obj != 1)) { 90 errno = EINVAL; 91 acl_free(acl_new); 92 return -1; 93 } 94 /* if a mask entry already exists, overwrite the perms */ 95 if (mask_num != -1) { 96 acl_new->acl_entry[mask_num].ae_perm = mask_mode; 97 } else { 98 /* if no mask exists, check acl_cnt... */ 99 if (acl_new->acl_cnt == ACL_MAX_ENTRIES) { 100 errno = EINVAL; 101 acl_free(acl_new); 102 return -1; 103 } 104 /* ...and add the mask entry */ 105 acl_new->acl_entry[acl_new->acl_cnt].ae_tag = ACL_MASK; 106 acl_new->acl_entry[acl_new->acl_cnt].ae_id = 0; 107 acl_new->acl_entry[acl_new->acl_cnt].ae_perm = mask_mode; 108 acl_new->acl_cnt++; 109 } 110 111 if (acl_valid(acl_new) == -1) { 112 errno = EINVAL; 113 acl_free(acl_new); 114 return -1; 115 } 116 117 **acl_p = *acl_new; 118 acl_free(acl_new); 119 120 return 0; 121} 122