1 /* Test whether a file has a nontrivial access control list.
3 Copyright (C) 2002-2003, 2005-2008 Free Software Foundation, Inc.
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
18 Written by Paul Eggert and Andreas Gruenbacher. */
24 #include "acl-internal.h"
27 #if USE_ACL && HAVE_ACL_GET_FILE
29 # if HAVE_ACL_TYPE_EXTENDED /* MacOS X */
31 /* ACL is an ACL, from a file, stored as type ACL_TYPE_EXTENDED.
32 Return 1 if the given ACL is non-trivial.
33 Return 0 if it is trivial. */
35 acl_extended_nontrivial (acl_t acl)
37 /* acl is non-trivial if it is non-empty. */
38 return (acl_entries (acl) > 0);
41 # else /* Linux, FreeBSD, IRIX, Tru64 */
43 /* ACL is an ACL, from a file, stored as type ACL_TYPE_ACCESS.
44 Return 1 if the given ACL is non-trivial.
45 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.
46 Return -1 and set errno upon failure to determine it. */
48 acl_access_nontrivial (acl_t acl)
50 /* acl is non-trivial if it has some entries other than for "user::",
51 "group::", and "other::". Normally these three should be present
52 at least, allowing us to write
53 return (3 < acl_entries (acl));
54 but the following code is more robust. */
55 # if HAVE_ACL_FIRST_ENTRY /* Linux, FreeBSD */
60 for (at_end = acl_get_entry (acl, ACL_FIRST_ENTRY, &ace);
62 at_end = acl_get_entry (acl, ACL_NEXT_ENTRY, &ace))
65 if (acl_get_tag_type (ace, &tag) < 0)
67 if (!(tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ || tag == ACL_OTHER))
72 # else /* IRIX, Tru64 */
73 # if HAVE_ACL_TO_SHORT_TEXT /* IRIX */
74 /* Don't use acl_get_entry: it is undocumented. */
76 int count = acl->acl_cnt;
79 for (i = 0; i < count; i++)
81 acl_entry_t ace = &acl->acl_entry[i];
82 acl_tag_t tag = ace->ae_tag;
84 if (!(tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ
85 || tag == ACL_OTHER_OBJ))
91 # if HAVE_ACL_FREE_TEXT /* Tru64 */
92 /* Don't use acl_get_entry: it takes only one argument and does not work. */
94 int count = acl->acl_num;
97 for (ace = acl->acl_first; count > 0; ace = ace->next, count--)
102 tag = ace->entry->acl_type;
103 if (!(tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ || tag == ACL_OTHER))
106 perm = ace->entry->acl_perm;
107 /* On Tru64, perm can also contain non-standard bits such as
108 PERM_INSERT, PERM_DELETE, PERM_MODIFY, PERM_LOOKUP, ... */
109 if ((perm & ~(ACL_READ | ACL_WRITE | ACL_EXECUTE)) != 0)
121 #elif USE_ACL && HAVE_ACL && defined GETACL /* Solaris, Cygwin, not HP-UX */
123 /* Test an ACL retrieved with GETACL.
124 Return 1 if the given ACL, consisting of COUNT entries, is non-trivial.
125 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
127 acl_nontrivial (int count, aclent_t *entries)
131 for (i = 0; i < count; i++)
133 aclent_t *ace = &entries[i];
135 /* Note: If ace->a_type = USER_OBJ, ace->a_id is the st_uid from stat().
136 If ace->a_type = GROUP_OBJ, ace->a_id is the st_gid from stat().
137 We don't need to check ace->a_id in these cases. */
138 if (!(ace->a_type == USER_OBJ
139 || ace->a_type == GROUP_OBJ
140 || ace->a_type == OTHER_OBJ
141 /* Note: Cygwin does not return a CLASS_OBJ ("mask:") entry
143 || ace->a_type == CLASS_OBJ))
151 /* Test an ACL retrieved with ACE_GETACL.
152 Return 1 if the given ACL, consisting of COUNT entries, is non-trivial.
153 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
155 acl_ace_nontrivial (int count, ace_t *entries)
159 for (i = 0; i < count; i++)
161 ace_t *ace = &entries[i];
163 /* Note: If ace->a_flags = ACE_OWNER, ace->a_who is the st_uid from
164 stat(). If ace->a_flags = ACE_GROUP, ace->a_who is the st_gid from
165 stat(). We don't need to check ace->a_who in these cases. */
166 if (!(ace->a_type == ALLOW
167 && (ace->a_flags == ACE_OWNER
168 || ace->a_flags == ACE_GROUP
169 || ace->a_flags == ACE_OTHER)))
177 #elif USE_ACL && HAVE_GETACL /* HP-UX */
179 /* Return 1 if the given ACL is non-trivial.
180 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
182 acl_nontrivial (int count, struct acl_entry *entries, struct stat *sb)
186 for (i = 0; i < count; i++)
188 struct acl_entry *ace = &entries[i];
190 if (!((ace->uid == sb->st_uid && ace->gid == ACL_NSGROUP)
191 || (ace->uid == ACL_NSUSER && ace->gid == sb->st_gid)
192 || (ace->uid == ACL_NSUSER && ace->gid == ACL_NSGROUP)))
201 /* Return 1 if NAME has a nontrivial access control list, 0 if NAME
202 only has no or a base access control list, and -1 (setting errno)
203 on error. SB must be set to the stat buffer of FILE. */
206 file_has_acl (char const *name, struct stat const *sb)
209 if (! S_ISLNK (sb->st_mode))
211 # if HAVE_ACL_GET_FILE
213 /* POSIX 1003.1e (draft 17 -- abandoned) specific version. */
214 /* Linux, FreeBSD, MacOS X, IRIX, Tru64 */
217 if (HAVE_ACL_EXTENDED_FILE) /* Linux */
219 /* On Linux, acl_extended_file is an optimized function: It only
220 makes two calls to getxattr(), one for ACL_TYPE_ACCESS, one for
222 ret = acl_extended_file (name);
224 else /* FreeBSD, MacOS X, IRIX, Tru64 */
226 # if HAVE_ACL_TYPE_EXTENDED /* MacOS X */
227 /* On MacOS X, acl_get_file (name, ACL_TYPE_ACCESS)
228 and acl_get_file (name, ACL_TYPE_DEFAULT)
229 always return NULL / EINVAL. There is no point in making
230 these two useless calls. The real ACL is retrieved through
231 acl_get_file (name, ACL_TYPE_EXTENDED). */
232 acl_t acl = acl_get_file (name, ACL_TYPE_EXTENDED);
235 ret = acl_extended_nontrivial (acl);
240 # else /* FreeBSD, IRIX, Tru64 */
241 acl_t acl = acl_get_file (name, ACL_TYPE_ACCESS);
246 ret = acl_access_nontrivial (acl);
250 # if HAVE_ACL_FREE_TEXT /* Tru64 */
251 /* On OSF/1, acl_get_file (name, ACL_TYPE_DEFAULT) always
252 returns NULL with errno not set. There is no point in
254 # else /* FreeBSD, IRIX */
255 /* On Linux, FreeBSD, IRIX, acl_get_file (name, ACL_TYPE_ACCESS)
256 and acl_get_file (name, ACL_TYPE_DEFAULT) on a directory
257 either both succeed or both fail; it depends on the
258 filesystem. Therefore there is no point in making the second
259 call if the first one already failed. */
260 if (ret == 0 && S_ISDIR (sb->st_mode))
262 acl = acl_get_file (name, ACL_TYPE_DEFAULT);
265 ret = (0 < acl_entries (acl));
278 return ACL_NOT_WELL_SUPPORTED (errno) ? 0 : -1;
281 # elif HAVE_ACL && defined GETACLCNT /* Solaris, Cygwin, not HP-UX */
283 # if HAVE_ACL_TRIVIAL
285 /* Solaris 10 (newer version), which has additional API declared in
286 <sys/acl.h> (acl_t) and implemented in libsec (acl_set, acl_trivial,
287 acl_fromtext, ...). */
288 return acl_trivial (name);
290 # else /* Solaris, Cygwin, general case */
292 /* Solaris 2.5 through Solaris 10, Cygwin, and contemporaneous versions
293 of Unixware. The acl() call returns the access and default ACL both
301 count = acl (name, GETACLCNT, 0, NULL);
305 if (errno == ENOSYS || errno == ENOTSUP)
314 /* Don't use MIN_ACL_ENTRIES: It's set to 4 on Cygwin, but Cygwin
315 returns only 3 entries for files with no ACL. But this is safe:
316 If there are more than 4 entries, there cannot be only the
317 "user::", "group::", "other:", and "mask:" entries. */
321 entries = (aclent_t *) malloc (count * sizeof (aclent_t));
327 if (acl (name, GETACL, count, entries) == count)
329 if (acl_nontrivial (count, entries))
337 /* Huh? The number of ACL entries changed since the last call.
344 /* Solaris also has a different variant of ACLs, used in ZFS and NFSv4
345 file systems (whereas the other ones are used in UFS file systems). */
351 count = acl (name, ACE_GETACLCNT, 0, NULL);
355 if (errno == ENOSYS || errno == EINVAL)
364 /* If there are more than 3 entries, there cannot be only the
365 ACE_OWNER, ACE_GROUP, ACE_OTHER entries. */
369 entries = (ace_t *) malloc (count * sizeof (ace_t));
375 if (acl (name, ACE_GETACL, count, entries) == count)
377 if (acl_ace_nontrivial (count, entries))
385 /* Huh? The number of ACL entries changed since the last call.
395 # elif HAVE_GETACL /* HP-UX */
398 struct acl_entry entries[NACLENTRIES];
402 count = getacl (name, 0, NULL);
405 return (errno == ENOSYS || errno == EOPNOTSUPP ? 0 : -1);
410 if (count > NACLENTRIES)
411 /* If NACLENTRIES cannot be trusted, use dynamic memory
415 /* If there are more than 3 entries, there cannot be only the
416 (uid,%), (%,gid), (%,%) entries. */
420 if (getacl (name, count, entries) == count)
424 if (stat (name, &statbuf) < 0)
427 return acl_nontrivial (count, entries, &statbuf);
429 /* Huh? The number of ACL entries changed since the last call.
437 /* FIXME: Add support for AIX. Please see Samba's
438 source/lib/sysacls.c file for fix-related ideas. */