1 /* Test whether a file has a nontrivial access control list.
3 Copyright (C) 2002-2003, 2005-2011 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, Andreas Grünbacher, and Bruno Haible. */
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 (got_one = acl_get_entry (acl, ACL_FIRST_ENTRY, &ace);
62 got_one = 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_FACL && defined GETACL /* Solaris, Cygwin, not HP-UX */
123 # if !(defined ACL_NO_TRIVIAL && 0) /* Solaris <= 10, Cygwin */
125 /* Test an ACL retrieved with GETACL.
126 Return 1 if the given ACL, consisting of COUNT entries, is non-trivial.
127 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
129 acl_nontrivial (int count, aclent_t *entries)
133 for (i = 0; i < count; i++)
135 aclent_t *ace = &entries[i];
137 /* Note: If ace->a_type = USER_OBJ, ace->a_id is the st_uid from stat().
138 If ace->a_type = GROUP_OBJ, ace->a_id is the st_gid from stat().
139 We don't need to check ace->a_id in these cases. */
140 if (!(ace->a_type == USER_OBJ
141 || ace->a_type == GROUP_OBJ
142 || ace->a_type == OTHER_OBJ
143 /* Note: Cygwin does not return a CLASS_OBJ ("mask:") entry
145 || ace->a_type == CLASS_OBJ))
153 /* Test an ACL retrieved with ACE_GETACL.
154 Return 1 if the given ACL, consisting of COUNT entries, is non-trivial.
155 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
157 acl_ace_nontrivial (int count, ace_t *entries)
161 /* The flags in the ace_t structure changed in a binary incompatible way
162 when ACL_NO_TRIVIAL etc. were introduced in <sys/acl.h> version 1.15.
163 How to distinguish the two conventions at runtime?
164 In the old convention, usually three ACEs have a_flags = ACE_OWNER /
165 ACE_GROUP / ACE_OTHER, in the range 0x0100..0x0400. In the new
166 convention, these values are not used. */
167 int old_convention = 0;
169 for (i = 0; i < count; i++)
170 if (entries[i].a_flags & (OLD_ACE_OWNER | OLD_ACE_GROUP | OLD_ACE_OTHER))
177 /* Running on Solaris 10. */
178 for (i = 0; i < count; i++)
180 ace_t *ace = &entries[i];
183 If ace->a_flags = ACE_OWNER, ace->a_who is the st_uid from stat().
184 If ace->a_flags = ACE_GROUP, ace->a_who is the st_gid from stat().
185 We don't need to check ace->a_who in these cases. */
186 if (!(ace->a_type == OLD_ALLOW
187 && (ace->a_flags == OLD_ACE_OWNER
188 || ace->a_flags == OLD_ACE_GROUP
189 || ace->a_flags == OLD_ACE_OTHER)))
194 /* Running on Solaris 10 (newer version) or Solaris 11. */
195 unsigned int access_masks[6] =
198 0, /* owner@ allow */
200 0, /* group@ allow */
201 0, /* everyone@ deny */
202 0 /* everyone@ allow */
205 for (i = 0; i < count; i++)
207 ace_t *ace = &entries[i];
211 if (ace->a_type == NEW_ACE_ACCESS_ALLOWED_ACE_TYPE)
213 else if (ace->a_type == NEW_ACE_ACCESS_DENIED_ACE_TYPE)
218 if (ace->a_flags == NEW_ACE_OWNER)
220 else if (ace->a_flags == (NEW_ACE_GROUP | NEW_ACE_IDENTIFIER_GROUP))
222 else if (ace->a_flags == ACE_EVERYONE)
227 access_masks[index1 + index2] |= ace->a_access_mask;
230 /* The same bit shouldn't be both allowed and denied. */
231 if (access_masks[0] & access_masks[1])
233 if (access_masks[2] & access_masks[3])
235 if (access_masks[4] & access_masks[5])
238 /* Check minimum masks. */
239 if ((NEW_ACE_WRITE_NAMED_ATTRS
240 | NEW_ACE_WRITE_ATTRIBUTES
242 | NEW_ACE_WRITE_OWNER)
245 access_masks[1] &= ~(NEW_ACE_WRITE_NAMED_ATTRS
246 | NEW_ACE_WRITE_ATTRIBUTES
248 | NEW_ACE_WRITE_OWNER);
249 if ((NEW_ACE_WRITE_NAMED_ATTRS
250 | NEW_ACE_WRITE_ATTRIBUTES
252 | NEW_ACE_WRITE_OWNER)
255 access_masks[4] &= ~(NEW_ACE_WRITE_NAMED_ATTRS
256 | NEW_ACE_WRITE_ATTRIBUTES
258 | NEW_ACE_WRITE_OWNER);
259 if ((NEW_ACE_READ_NAMED_ATTRS
260 | NEW_ACE_READ_ATTRIBUTES
262 | NEW_ACE_SYNCHRONIZE)
265 access_masks[5] &= ~(NEW_ACE_READ_NAMED_ATTRS
266 | NEW_ACE_READ_ATTRIBUTES
268 | NEW_ACE_SYNCHRONIZE);
270 /* Check the allowed or denied bits. */
271 if ((access_masks[0] | access_masks[1])
272 != (NEW_ACE_READ_DATA
273 | NEW_ACE_WRITE_DATA | NEW_ACE_APPEND_DATA
276 if ((access_masks[2] | access_masks[3])
277 != (NEW_ACE_READ_DATA
278 | NEW_ACE_WRITE_DATA | NEW_ACE_APPEND_DATA
281 if ((access_masks[4] | access_masks[5])
282 != (NEW_ACE_READ_DATA
283 | NEW_ACE_WRITE_DATA | NEW_ACE_APPEND_DATA
287 /* Check that the NEW_ACE_WRITE_DATA and NEW_ACE_APPEND_DATA bits are
288 either both allowed or both denied. */
289 if (((access_masks[0] & NEW_ACE_WRITE_DATA) != 0)
290 != ((access_masks[0] & NEW_ACE_APPEND_DATA) != 0))
292 if (((access_masks[2] & NEW_ACE_WRITE_DATA) != 0)
293 != ((access_masks[2] & NEW_ACE_APPEND_DATA) != 0))
295 if (((access_masks[4] & NEW_ACE_WRITE_DATA) != 0)
296 != ((access_masks[4] & NEW_ACE_APPEND_DATA) != 0))
307 #elif USE_ACL && HAVE_GETACL /* HP-UX */
309 /* Return 1 if the given ACL is non-trivial.
310 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
312 acl_nontrivial (int count, struct acl_entry *entries, struct stat *sb)
316 for (i = 0; i < count; i++)
318 struct acl_entry *ace = &entries[i];
320 if (!((ace->uid == sb->st_uid && ace->gid == ACL_NSGROUP)
321 || (ace->uid == ACL_NSUSER && ace->gid == sb->st_gid)
322 || (ace->uid == ACL_NSUSER && ace->gid == ACL_NSGROUP)))
328 # if HAVE_ACLV_H /* HP-UX >= 11.11 */
330 /* Return 1 if the given ACL is non-trivial.
331 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
333 aclv_nontrivial (int count, struct acl *entries)
337 for (i = 0; i < count; i++)
339 struct acl *ace = &entries[i];
341 /* Note: If ace->a_type = USER_OBJ, ace->a_id is the st_uid from stat().
342 If ace->a_type = GROUP_OBJ, ace->a_id is the st_gid from stat().
343 We don't need to check ace->a_id in these cases. */
344 if (!(ace->a_type == USER_OBJ /* no need to check ace->a_id here */
345 || ace->a_type == GROUP_OBJ /* no need to check ace->a_id here */
346 || ace->a_type == CLASS_OBJ
347 || ace->a_type == OTHER_OBJ))
355 #elif USE_ACL && (HAVE_ACLX_GET || HAVE_STATACL) /* AIX */
357 /* Return 1 if the given ACL is non-trivial.
358 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
360 acl_nontrivial (struct acl *a)
362 /* The normal way to iterate through an ACL is like this:
363 struct acl_entry *ace;
364 for (ace = a->acl_ext; ace != acl_last (a); ace = acl_nxt (ace))
367 switch (ace->ace_type)
374 for (aei = ace->ace_id; aei != id_last (ace); aei = id_nxt (aei))
378 return (acl_last (a) != a->acl_ext ? 1 : 0);
381 # if HAVE_ACLX_GET && defined ACL_AIX_WIP /* newer AIX */
383 /* Return 1 if the given ACL is non-trivial.
384 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
386 acl_nfs4_nontrivial (nfs4_acl_int_t *a)
388 # if 1 /* let's try this first */
389 return (a->aclEntryN > 0 ? 1 : 0);
391 int count = a->aclEntryN;
394 for (i = 0; i < count; i++)
396 nfs4_ace_int_t *ace = &a->aclEntry[i];
398 if (!((ace->flags & ACE4_ID_SPECIAL) != 0
399 && (ace->aceWho.special_whoid == ACE4_WHO_OWNER
400 || ace->aceWho.special_whoid == ACE4_WHO_GROUP
401 || ace->aceWho.special_whoid == ACE4_WHO_EVERYONE)
402 && ace->aceType == ACE4_ACCESS_ALLOWED_ACE_TYPE
403 && ace->aceFlags == 0
404 && (ace->aceMask & ~(ACE4_READ_DATA | ACE4_LIST_DIRECTORY
405 | ACE4_WRITE_DATA | ACE4_ADD_FILE
406 | ACE4_EXECUTE)) == 0))
415 #elif USE_ACL && HAVE_ACLSORT /* NonStop Kernel */
417 /* Test an ACL retrieved with ACL_GET.
418 Return 1 if the given ACL, consisting of COUNT entries, is non-trivial.
419 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
421 acl_nontrivial (int count, struct acl *entries)
425 for (i = 0; i < count; i++)
427 struct acl *ace = &entries[i];
429 /* Note: If ace->a_type = USER_OBJ, ace->a_id is the st_uid from stat().
430 If ace->a_type = GROUP_OBJ, ace->a_id is the st_gid from stat().
431 We don't need to check ace->a_id in these cases. */
432 if (!(ace->a_type == USER_OBJ /* no need to check ace->a_id here */
433 || ace->a_type == GROUP_OBJ /* no need to check ace->a_id here */
434 || ace->a_type == CLASS_OBJ
435 || ace->a_type == OTHER_OBJ))
444 /* Return 1 if NAME has a nontrivial access control list, 0 if NAME
445 only has no or a base access control list, and -1 (setting errno)
446 on error. SB must be set to the stat buffer of FILE. */
449 file_has_acl (char const *name, struct stat const *sb)
452 if (! S_ISLNK (sb->st_mode))
454 # if HAVE_ACL_GET_FILE
456 /* POSIX 1003.1e (draft 17 -- abandoned) specific version. */
457 /* Linux, FreeBSD, MacOS X, IRIX, Tru64 */
460 if (HAVE_ACL_EXTENDED_FILE || HAVE_ACL_EXTENDED_FILE_NOFOLLOW) /* Linux */
462 # if HAVE_ACL_EXTENDED_FILE_NOFOLLOW
463 /* acl_extended_file_nofollow() uses lgetxattr() in order to prevent
464 unnecessary mounts, but it returns the same result as we already
465 know that NAME is not a symbolic link at this point (modulo the
466 TOCTTOU race condition). */
467 ret = acl_extended_file_nofollow (name);
469 /* On Linux, acl_extended_file is an optimized function: It only
470 makes two calls to getxattr(), one for ACL_TYPE_ACCESS, one for
472 ret = acl_extended_file (name);
475 else /* FreeBSD, MacOS X, IRIX, Tru64 */
477 # if HAVE_ACL_TYPE_EXTENDED /* MacOS X */
478 /* On MacOS X, acl_get_file (name, ACL_TYPE_ACCESS)
479 and acl_get_file (name, ACL_TYPE_DEFAULT)
480 always return NULL / EINVAL. There is no point in making
481 these two useless calls. The real ACL is retrieved through
482 acl_get_file (name, ACL_TYPE_EXTENDED). */
483 acl_t acl = acl_get_file (name, ACL_TYPE_EXTENDED);
486 ret = acl_extended_nontrivial (acl);
491 # else /* FreeBSD, IRIX, Tru64 */
492 acl_t acl = acl_get_file (name, ACL_TYPE_ACCESS);
497 ret = acl_access_nontrivial (acl);
501 # if HAVE_ACL_FREE_TEXT /* Tru64 */
502 /* On OSF/1, acl_get_file (name, ACL_TYPE_DEFAULT) always
503 returns NULL with errno not set. There is no point in
505 # else /* FreeBSD, IRIX */
506 /* On Linux, FreeBSD, IRIX, acl_get_file (name, ACL_TYPE_ACCESS)
507 and acl_get_file (name, ACL_TYPE_DEFAULT) on a directory
508 either both succeed or both fail; it depends on the
509 file system. Therefore there is no point in making the second
510 call if the first one already failed. */
511 if (ret == 0 && S_ISDIR (sb->st_mode))
513 acl = acl_get_file (name, ACL_TYPE_DEFAULT);
516 ret = (0 < acl_entries (acl));
529 return ACL_NOT_WELL_SUPPORTED (errno) ? 0 : -1;
532 # elif HAVE_FACL && defined GETACLCNT /* Solaris, Cygwin, not HP-UX */
534 # if defined ACL_NO_TRIVIAL
536 /* Solaris 10 (newer version), which has additional API declared in
537 <sys/acl.h> (acl_t) and implemented in libsec (acl_set, acl_trivial,
538 acl_fromtext, ...). */
539 return acl_trivial (name);
541 # else /* Solaris, Cygwin, general case */
543 /* Solaris 2.5 through Solaris 10, Cygwin, and contemporaneous versions
544 of Unixware. The acl() call returns the access and default ACL both
552 count = acl (name, GETACLCNT, 0, NULL);
556 if (errno == ENOSYS || errno == ENOTSUP)
565 /* Don't use MIN_ACL_ENTRIES: It's set to 4 on Cygwin, but Cygwin
566 returns only 3 entries for files with no ACL. But this is safe:
567 If there are more than 4 entries, there cannot be only the
568 "user::", "group::", "other:", and "mask:" entries. */
572 entries = (aclent_t *) malloc (count * sizeof (aclent_t));
578 if (acl (name, GETACL, count, entries) == count)
580 if (acl_nontrivial (count, entries))
588 /* Huh? The number of ACL entries changed since the last call.
595 /* Solaris also has a different variant of ACLs, used in ZFS and NFSv4
596 file systems (whereas the other ones are used in UFS file systems). */
602 count = acl (name, ACE_GETACLCNT, 0, NULL);
606 if (errno == ENOSYS || errno == EINVAL)
615 /* If there are more than 3 entries, there cannot be only the
616 ACE_OWNER, ACE_GROUP, ACE_OTHER entries. */
620 entries = (ace_t *) malloc (count * sizeof (ace_t));
626 if (acl (name, ACE_GETACL, count, entries) == count)
628 if (acl_ace_nontrivial (count, entries))
636 /* Huh? The number of ACL entries changed since the last call.
646 # elif HAVE_GETACL /* HP-UX */
651 struct acl_entry entries[NACLENTRIES];
653 count = getacl (name, 0, NULL);
657 /* ENOSYS is seen on newer HP-UX versions.
658 EOPNOTSUPP is typically seen on NFS mounts.
659 ENOTSUP was seen on Quantum StorNext file systems (cvfs). */
660 if (errno == ENOSYS || errno == EOPNOTSUPP || errno == ENOTSUP)
669 if (count > NACLENTRIES)
670 /* If NACLENTRIES cannot be trusted, use dynamic memory
674 /* If there are more than 3 entries, there cannot be only the
675 (uid,%), (%,gid), (%,%) entries. */
679 if (getacl (name, count, entries) == count)
683 if (stat (name, &statbuf) < 0)
686 return acl_nontrivial (count, entries, &statbuf);
688 /* Huh? The number of ACL entries changed since the last call.
692 # if HAVE_ACLV_H /* HP-UX >= 11.11 */
697 struct acl entries[NACLVENTRIES];
699 count = acl ((char *) name, ACL_CNT, NACLVENTRIES, entries);
703 /* EOPNOTSUPP is seen on NFS in HP-UX 11.11, 11.23.
704 EINVAL is seen on NFS in HP-UX 11.31. */
705 if (errno == ENOSYS || errno == EOPNOTSUPP || errno == EINVAL)
714 if (count > NACLVENTRIES)
715 /* If NACLVENTRIES cannot be trusted, use dynamic memory
719 /* If there are more than 4 entries, there cannot be only the
720 four base ACL entries. */
724 if (acl ((char *) name, ACL_GET, count, entries) == count)
725 return aclv_nontrivial (count, entries);
726 /* Huh? The number of ACL entries changed since the last call.
732 # elif HAVE_ACLX_GET && defined ACL_AIX_WIP /* AIX */
737 size_t aclsize = sizeof (aclbuf);
742 /* The docs say that type being 0 is equivalent to ACL_ANY, but it
743 is not true, in AIX 5.3. */
745 if (aclx_get (name, 0, &type, aclbuf, &aclsize, &mode) >= 0)
751 int saved_errno = errno;
757 aclsize = 2 * aclsize;
760 acl = malloc (aclsize);
768 if (type.u64 == ACL_AIXC)
770 int result = acl_nontrivial ((struct acl *) acl);
775 else if (type.u64 == ACL_NFS4)
777 int result = acl_nfs4_nontrivial ((nfs4_acl_int_t *) acl);
784 /* A newer type of ACL has been introduced in the system.
785 We should better support it. */
792 # elif HAVE_STATACL /* older AIX */
794 union { struct acl a; char room[4096]; } u;
796 if (statacl (name, STX_NORMAL, &u.a, sizeof (u)) < 0)
799 return acl_nontrivial (&u.a);
801 # elif HAVE_ACLSORT /* NonStop Kernel */
804 struct acl entries[NACLENTRIES];
808 count = acl ((char *) name, ACL_CNT, NACLENTRIES, NULL);
816 if (count > NACLENTRIES)
817 /* If NACLENTRIES cannot be trusted, use dynamic memory
821 /* If there are more than 4 entries, there cannot be only the
822 four base ACL entries. */
826 if (acl ((char *) name, ACL_GET, count, entries) == count)
827 return acl_nontrivial (count, entries);
828 /* Huh? The number of ACL entries changed since the last call.