acl_strip.c revision 279962
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 CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: head/lib/libc/posix1e/acl_strip.c 279962 2015-03-13 18:42:43Z pfg $"); 29 30#include <errno.h> 31#include <stdio.h> 32#include <assert.h> 33#include <sys/acl.h> 34#include <sys/stat.h> 35 36#include "acl_support.h" 37 38/* 39 * These routines from sys/kern/subr_acl_nfs4.c are used by both kernel 40 * and libc. 41 */ 42void acl_nfs4_sync_mode_from_acl(mode_t *_mode, const struct acl *aclp); 43void acl_nfs4_trivial_from_mode_libc(struct acl *aclp, int file_owner_id, 44 int canonical_six); 45 46static acl_t 47_nfs4_acl_strip_np(const acl_t aclp, int canonical_six) 48{ 49 acl_t newacl; 50 mode_t mode = 0; 51 52 newacl = acl_init(ACL_MAX_ENTRIES); 53 if (newacl == NULL) { 54 errno = ENOMEM; 55 return (NULL); 56 } 57 58 _acl_brand_as(newacl, ACL_BRAND_NFS4); 59 60 acl_nfs4_sync_mode_from_acl(&mode, &(aclp->ats_acl)); 61 acl_nfs4_trivial_from_mode_libc(&(newacl->ats_acl), mode, canonical_six); 62 63 return (newacl); 64} 65 66static acl_t 67_posix1e_acl_strip_np(const acl_t aclp, int recalculate_mask) 68{ 69 acl_t acl_new, acl_old; 70 acl_entry_t entry, entry_new; 71 acl_permset_t perm; 72 acl_tag_t tag; 73 int entry_id, have_mask_entry; 74 75 assert(_acl_brand(aclp) == ACL_BRAND_POSIX); 76 77 acl_old = acl_dup(aclp); 78 if (acl_old == NULL) 79 return (NULL); 80 81 assert(_acl_brand(acl_old) == ACL_BRAND_POSIX); 82 83 have_mask_entry = 0; 84 acl_new = acl_init(ACL_MAX_ENTRIES); 85 if (acl_new == NULL) { 86 acl_free(acl_old); 87 return (NULL); 88 } 89 tag = ACL_UNDEFINED_TAG; 90 91 /* only save the default user/group/other entries */ 92 entry_id = ACL_FIRST_ENTRY; 93 while (acl_get_entry(acl_old, entry_id, &entry) == 1) { 94 entry_id = ACL_NEXT_ENTRY; 95 96 assert(_entry_brand(entry) == ACL_BRAND_POSIX); 97 98 if (acl_get_tag_type(entry, &tag) == -1) 99 goto fail; 100 101 switch(tag) { 102 case ACL_USER_OBJ: 103 case ACL_GROUP_OBJ: 104 case ACL_OTHER: 105 if (acl_get_tag_type(entry, &tag) == -1) 106 goto fail; 107 if (acl_get_permset(entry, &perm) == -1) 108 goto fail; 109 if (acl_create_entry(&acl_new, &entry_new) == -1) 110 return (NULL); 111 if (acl_set_tag_type(entry_new, tag) == -1) 112 return (NULL); 113 if (acl_set_permset(entry_new, perm) == -1) 114 return (NULL); 115 if (acl_copy_entry(entry_new, entry) == -1) 116 return (NULL); 117 assert(_entry_brand(entry_new) == ACL_BRAND_POSIX); 118 break; 119 case ACL_MASK: 120 have_mask_entry = 1; 121 break; 122 default: 123 break; 124 } 125fail: 126 acl_free(acl_new); 127 acl_free(acl_old); 128 return (NULL); 129 } 130 131 assert(_acl_brand(acl_new) == ACL_BRAND_POSIX); 132 133 if (have_mask_entry && recalculate_mask) { 134 if (acl_calc_mask(&acl_new) == -1) 135 return (NULL); 136 } 137 138 return (acl_new); 139} 140 141acl_t 142acl_strip_np(const acl_t aclp, int recalculate_mask) 143{ 144 switch (_acl_brand(aclp)) { 145 case ACL_BRAND_NFS4: 146 return (_nfs4_acl_strip_np(aclp, 0)); 147 148 case ACL_BRAND_POSIX: 149 return (_posix1e_acl_strip_np(aclp, recalculate_mask)); 150 151 default: 152 errno = EINVAL; 153 return (NULL); 154 } 155} 156 157/* 158 * Return 1, if ACL is trivial, 0 otherwise. 159 * 160 * ACL is trivial, iff its meaning could be fully expressed using just file 161 * mode. In other words, ACL is trivial iff it doesn't have "+" to the right 162 * of the mode bits in "ls -l" output ;-) 163 */ 164int 165acl_is_trivial_np(const acl_t aclp, int *trivialp) 166{ 167 acl_t tmpacl; 168 int differs; 169 170 if (aclp == NULL || trivialp == NULL) { 171 errno = EINVAL; 172 return (-1); 173 } 174 175 switch (_acl_brand(aclp)) { 176 case ACL_BRAND_POSIX: 177 if (aclp->ats_acl.acl_cnt == 3) 178 *trivialp = 1; 179 else 180 *trivialp = 0; 181 182 return (0); 183 184 case ACL_BRAND_NFS4: 185 /* 186 * If the ACL has more than canonical six entries, 187 * it's non trivial by definition. 188 */ 189 if (aclp->ats_acl.acl_cnt > 6) { 190 *trivialp = 0; 191 return (0); 192 } 193 194 /* 195 * Calculate trivial ACL - using acl_strip_np(3) - and compare 196 * with the original. 197 */ 198 tmpacl = _nfs4_acl_strip_np(aclp, 0); 199 if (tmpacl == NULL) 200 return (-1); 201 202 differs = _acl_differs(aclp, tmpacl); 203 acl_free(tmpacl); 204 205 if (differs == 0) { 206 *trivialp = 1; 207 return (0); 208 } 209 210 /* 211 * Try again with an old-style, "canonical six" trivial ACL. 212 */ 213 tmpacl = _nfs4_acl_strip_np(aclp, 1); 214 if (tmpacl == NULL) 215 return (-1); 216 217 differs = _acl_differs(aclp, tmpacl); 218 acl_free(tmpacl); 219 220 if (differs) 221 *trivialp = 0; 222 else 223 *trivialp = 1; 224 225 return (0); 226 227 default: 228 errno = EINVAL; 229 return (-1); 230 } 231} 232