1 /* Test whether a file has a nontrivial access control list.
3 Copyright (C) 2002-2003, 2005-2013 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. */
20 /* Without this pragma, gcc 4.7.0 20120126 may suggest that the
21 file_has_acl function might be candidate for attribute 'const' */
22 #if (__GNUC__ == 4 && 6 <= __GNUC_MINOR__) || 4 < __GNUC__
23 # pragma GCC diagnostic ignored "-Wsuggest-attribute=const"
30 #include "acl-internal.h"
33 #if USE_ACL && HAVE_ACL_GET_FILE
35 # if HAVE_ACL_TYPE_EXTENDED /* Mac OS X */
37 /* ACL is an ACL, from a file, stored as type ACL_TYPE_EXTENDED.
38 Return 1 if the given ACL is non-trivial.
39 Return 0 if it is trivial. */
41 acl_extended_nontrivial (acl_t acl)
43 /* acl is non-trivial if it is non-empty. */
44 return (acl_entries (acl) > 0);
47 # else /* Linux, FreeBSD, IRIX, Tru64 */
49 /* ACL is an ACL, from a file, stored as type ACL_TYPE_ACCESS.
50 Return 1 if the given ACL is non-trivial.
51 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode.
52 Return -1 and set errno upon failure to determine it. */
54 acl_access_nontrivial (acl_t acl)
56 /* acl is non-trivial if it has some entries other than for "user::",
57 "group::", and "other::". Normally these three should be present
58 at least, allowing us to write
59 return (3 < acl_entries (acl));
60 but the following code is more robust. */
61 # if HAVE_ACL_FIRST_ENTRY /* Linux, FreeBSD */
66 for (got_one = acl_get_entry (acl, ACL_FIRST_ENTRY, &ace);
68 got_one = acl_get_entry (acl, ACL_NEXT_ENTRY, &ace))
71 if (acl_get_tag_type (ace, &tag) < 0)
73 if (!(tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ || tag == ACL_OTHER))
78 # else /* IRIX, Tru64 */
79 # if HAVE_ACL_TO_SHORT_TEXT /* IRIX */
80 /* Don't use acl_get_entry: it is undocumented. */
82 int count = acl->acl_cnt;
85 for (i = 0; i < count; i++)
87 acl_entry_t ace = &acl->acl_entry[i];
88 acl_tag_t tag = ace->ae_tag;
90 if (!(tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ
91 || tag == ACL_OTHER_OBJ))
97 # if HAVE_ACL_FREE_TEXT /* Tru64 */
98 /* Don't use acl_get_entry: it takes only one argument and does not work. */
100 int count = acl->acl_num;
103 for (ace = acl->acl_first; count > 0; ace = ace->next, count--)
108 tag = ace->entry->acl_type;
109 if (!(tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ || tag == ACL_OTHER))
112 perm = ace->entry->acl_perm;
113 /* On Tru64, perm can also contain non-standard bits such as
114 PERM_INSERT, PERM_DELETE, PERM_MODIFY, PERM_LOOKUP, ... */
115 if ((perm & ~(ACL_READ | ACL_WRITE | ACL_EXECUTE)) != 0)
127 #elif USE_ACL && HAVE_FACL && defined GETACL /* Solaris, Cygwin, not HP-UX */
129 /* Test an ACL retrieved with GETACL.
130 Return 1 if the given ACL, consisting of COUNT entries, is non-trivial.
131 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
133 acl_nontrivial (int count, aclent_t *entries)
137 for (i = 0; i < count; i++)
139 aclent_t *ace = &entries[i];
141 /* Note: If ace->a_type = USER_OBJ, ace->a_id is the st_uid from stat().
142 If ace->a_type = GROUP_OBJ, ace->a_id is the st_gid from stat().
143 We don't need to check ace->a_id in these cases. */
144 if (!(ace->a_type == USER_OBJ
145 || ace->a_type == GROUP_OBJ
146 || ace->a_type == OTHER_OBJ
147 /* Note: Cygwin does not return a CLASS_OBJ ("mask:") entry
149 || ace->a_type == CLASS_OBJ))
157 /* A shortcut for a bitmask. */
158 # define NEW_ACE_WRITEA_DATA (NEW_ACE_WRITE_DATA | NEW_ACE_APPEND_DATA)
160 /* Test an ACL retrieved with ACE_GETACL.
161 Return 1 if the given ACL, consisting of COUNT entries, is non-trivial.
162 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
164 acl_ace_nontrivial (int count, ace_t *entries)
168 /* The flags in the ace_t structure changed in a binary incompatible way
169 when ACL_NO_TRIVIAL etc. were introduced in <sys/acl.h> version 1.15.
170 How to distinguish the two conventions at runtime?
171 In the old convention, usually three ACEs have a_flags = ACE_OWNER /
172 ACE_GROUP / ACE_OTHER, in the range 0x0100..0x0400. In the new
173 convention, these values are not used. */
174 int old_convention = 0;
176 for (i = 0; i < count; i++)
177 if (entries[i].a_flags & (OLD_ACE_OWNER | OLD_ACE_GROUP | OLD_ACE_OTHER))
184 /* Running on Solaris 10. */
185 for (i = 0; i < count; i++)
187 ace_t *ace = &entries[i];
190 If ace->a_flags = ACE_OWNER, ace->a_who is the st_uid from stat().
191 If ace->a_flags = ACE_GROUP, ace->a_who is the st_gid from stat().
192 We don't need to check ace->a_who in these cases. */
193 if (!(ace->a_type == OLD_ALLOW
194 && (ace->a_flags == OLD_ACE_OWNER
195 || ace->a_flags == OLD_ACE_GROUP
196 || ace->a_flags == OLD_ACE_OTHER)))
201 /* Running on Solaris 10 (newer version) or Solaris 11. */
202 unsigned int access_masks[6] =
205 0, /* owner@ allow */
207 0, /* group@ allow */
208 0, /* everyone@ deny */
209 0 /* everyone@ allow */
212 for (i = 0; i < count; i++)
214 ace_t *ace = &entries[i];
218 if (ace->a_type == NEW_ACE_ACCESS_ALLOWED_ACE_TYPE)
220 else if (ace->a_type == NEW_ACE_ACCESS_DENIED_ACE_TYPE)
225 if (ace->a_flags == NEW_ACE_OWNER)
227 else if (ace->a_flags == (NEW_ACE_GROUP | NEW_ACE_IDENTIFIER_GROUP))
229 else if (ace->a_flags == NEW_ACE_EVERYONE)
234 access_masks[index1 + index2] |= ace->a_access_mask;
237 /* The same bit shouldn't be both allowed and denied. */
238 if (access_masks[0] & access_masks[1])
240 if (access_masks[2] & access_masks[3])
242 if (access_masks[4] & access_masks[5])
245 /* Check minimum masks. */
246 if ((NEW_ACE_WRITE_NAMED_ATTRS
247 | NEW_ACE_WRITE_ATTRIBUTES
249 | NEW_ACE_WRITE_OWNER)
252 access_masks[1] &= ~(NEW_ACE_WRITE_NAMED_ATTRS
253 | NEW_ACE_WRITE_ATTRIBUTES
255 | NEW_ACE_WRITE_OWNER);
256 if ((NEW_ACE_READ_NAMED_ATTRS
257 | NEW_ACE_READ_ATTRIBUTES
259 | NEW_ACE_SYNCHRONIZE)
262 access_masks[5] &= ~(NEW_ACE_READ_NAMED_ATTRS
263 | NEW_ACE_READ_ATTRIBUTES
265 | NEW_ACE_SYNCHRONIZE);
267 /* Check the allowed or denied bits. */
268 switch ((access_masks[0] | access_masks[1])
269 & ~(NEW_ACE_READ_NAMED_ATTRS
270 | NEW_ACE_READ_ATTRIBUTES
272 | NEW_ACE_SYNCHRONIZE))
275 case NEW_ACE_READ_DATA:
276 case NEW_ACE_WRITEA_DATA:
277 case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA:
278 case NEW_ACE_EXECUTE:
279 case NEW_ACE_READ_DATA | NEW_ACE_EXECUTE:
280 case NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE:
281 case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE:
286 switch ((access_masks[2] | access_masks[3])
287 & ~(NEW_ACE_READ_NAMED_ATTRS
288 | NEW_ACE_READ_ATTRIBUTES
290 | NEW_ACE_SYNCHRONIZE))
293 case NEW_ACE_READ_DATA:
294 case NEW_ACE_WRITEA_DATA:
295 case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA:
296 case NEW_ACE_EXECUTE:
297 case NEW_ACE_READ_DATA | NEW_ACE_EXECUTE:
298 case NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE:
299 case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE:
304 switch ((access_masks[4] | access_masks[5])
305 & ~(NEW_ACE_WRITE_NAMED_ATTRS
306 | NEW_ACE_WRITE_ATTRIBUTES
308 | NEW_ACE_WRITE_OWNER))
311 case NEW_ACE_READ_DATA:
312 case NEW_ACE_WRITEA_DATA:
313 case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA:
314 case NEW_ACE_EXECUTE:
315 case NEW_ACE_READ_DATA | NEW_ACE_EXECUTE:
316 case NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE:
317 case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE:
323 /* Check that the NEW_ACE_WRITE_DATA and NEW_ACE_APPEND_DATA bits are
324 either both allowed or both denied. */
325 if (((access_masks[0] & NEW_ACE_WRITE_DATA) != 0)
326 != ((access_masks[0] & NEW_ACE_APPEND_DATA) != 0))
328 if (((access_masks[2] & NEW_ACE_WRITE_DATA) != 0)
329 != ((access_masks[2] & NEW_ACE_APPEND_DATA) != 0))
331 if (((access_masks[4] & NEW_ACE_WRITE_DATA) != 0)
332 != ((access_masks[4] & NEW_ACE_APPEND_DATA) != 0))
341 #elif USE_ACL && HAVE_GETACL /* HP-UX */
343 /* Return 1 if the given ACL is non-trivial.
344 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
346 acl_nontrivial (int count, struct acl_entry *entries, struct stat *sb)
350 for (i = 0; i < count; i++)
352 struct acl_entry *ace = &entries[i];
354 if (!((ace->uid == sb->st_uid && ace->gid == ACL_NSGROUP)
355 || (ace->uid == ACL_NSUSER && ace->gid == sb->st_gid)
356 || (ace->uid == ACL_NSUSER && ace->gid == ACL_NSGROUP)))
362 # if HAVE_ACLV_H /* HP-UX >= 11.11 */
364 /* Return 1 if the given ACL is non-trivial.
365 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
367 aclv_nontrivial (int count, struct acl *entries)
371 for (i = 0; i < count; i++)
373 struct acl *ace = &entries[i];
375 /* Note: If ace->a_type = USER_OBJ, ace->a_id is the st_uid from stat().
376 If ace->a_type = GROUP_OBJ, ace->a_id is the st_gid from stat().
377 We don't need to check ace->a_id in these cases. */
378 if (!(ace->a_type == USER_OBJ /* no need to check ace->a_id here */
379 || ace->a_type == GROUP_OBJ /* no need to check ace->a_id here */
380 || ace->a_type == CLASS_OBJ
381 || ace->a_type == OTHER_OBJ))
389 #elif USE_ACL && (HAVE_ACLX_GET || HAVE_STATACL) /* AIX */
391 /* Return 1 if the given ACL is non-trivial.
392 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
394 acl_nontrivial (struct acl *a)
396 /* The normal way to iterate through an ACL is like this:
397 struct acl_entry *ace;
398 for (ace = a->acl_ext; ace != acl_last (a); ace = acl_nxt (ace))
401 switch (ace->ace_type)
408 for (aei = ace->ace_id; aei != id_last (ace); aei = id_nxt (aei))
412 return (acl_last (a) != a->acl_ext ? 1 : 0);
415 # if HAVE_ACLX_GET && defined ACL_AIX_WIP /* newer AIX */
417 /* Return 1 if the given ACL is non-trivial.
418 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
420 acl_nfs4_nontrivial (nfs4_acl_int_t *a)
422 # if 1 /* let's try this first */
423 return (a->aclEntryN > 0 ? 1 : 0);
425 int count = a->aclEntryN;
428 for (i = 0; i < count; i++)
430 nfs4_ace_int_t *ace = &a->aclEntry[i];
432 if (!((ace->flags & ACE4_ID_SPECIAL) != 0
433 && (ace->aceWho.special_whoid == ACE4_WHO_OWNER
434 || ace->aceWho.special_whoid == ACE4_WHO_GROUP
435 || ace->aceWho.special_whoid == ACE4_WHO_EVERYONE)
436 && ace->aceType == ACE4_ACCESS_ALLOWED_ACE_TYPE
437 && ace->aceFlags == 0
438 && (ace->aceMask & ~(ACE4_READ_DATA | ACE4_LIST_DIRECTORY
439 | ACE4_WRITE_DATA | ACE4_ADD_FILE
440 | ACE4_EXECUTE)) == 0))
449 #elif USE_ACL && HAVE_ACLSORT /* NonStop Kernel */
451 /* Test an ACL retrieved with ACL_GET.
452 Return 1 if the given ACL, consisting of COUNT entries, is non-trivial.
453 Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */
455 acl_nontrivial (int count, struct acl *entries)
459 for (i = 0; i < count; i++)
461 struct acl *ace = &entries[i];
463 /* Note: If ace->a_type = USER_OBJ, ace->a_id is the st_uid from stat().
464 If ace->a_type = GROUP_OBJ, ace->a_id is the st_gid from stat().
465 We don't need to check ace->a_id in these cases. */
466 if (!(ace->a_type == USER_OBJ /* no need to check ace->a_id here */
467 || ace->a_type == GROUP_OBJ /* no need to check ace->a_id here */
468 || ace->a_type == CLASS_OBJ
469 || ace->a_type == OTHER_OBJ))
478 /* Return 1 if NAME has a nontrivial access control list, 0 if NAME
479 only has no or a base access control list, and -1 (setting errno)
480 on error. SB must be set to the stat buffer of NAME, obtained
481 through stat() or lstat(). */
484 file_has_acl (char const *name, struct stat const *sb)
487 if (! S_ISLNK (sb->st_mode))
489 # if HAVE_ACL_GET_FILE
491 /* POSIX 1003.1e (draft 17 -- abandoned) specific version. */
492 /* Linux, FreeBSD, Mac OS X, IRIX, Tru64 */
495 if (HAVE_ACL_EXTENDED_FILE) /* Linux */
497 /* On Linux, acl_extended_file is an optimized function: It only
498 makes two calls to getxattr(), one for ACL_TYPE_ACCESS, one for
500 ret = acl_extended_file (name);
502 else /* FreeBSD, Mac OS X, IRIX, Tru64 */
504 # if HAVE_ACL_TYPE_EXTENDED /* Mac OS X */
505 /* On Mac OS X, acl_get_file (name, ACL_TYPE_ACCESS)
506 and acl_get_file (name, ACL_TYPE_DEFAULT)
507 always return NULL / EINVAL. There is no point in making
508 these two useless calls. The real ACL is retrieved through
509 acl_get_file (name, ACL_TYPE_EXTENDED). */
510 acl_t acl = acl_get_file (name, ACL_TYPE_EXTENDED);
513 ret = acl_extended_nontrivial (acl);
518 # else /* FreeBSD, IRIX, Tru64 */
519 acl_t acl = acl_get_file (name, ACL_TYPE_ACCESS);
524 ret = acl_access_nontrivial (acl);
528 # if HAVE_ACL_FREE_TEXT /* Tru64 */
529 /* On OSF/1, acl_get_file (name, ACL_TYPE_DEFAULT) always
530 returns NULL with errno not set. There is no point in
532 # else /* FreeBSD, IRIX */
533 /* On Linux, FreeBSD, IRIX, acl_get_file (name, ACL_TYPE_ACCESS)
534 and acl_get_file (name, ACL_TYPE_DEFAULT) on a directory
535 either both succeed or both fail; it depends on the
536 file system. Therefore there is no point in making the second
537 call if the first one already failed. */
538 if (ret == 0 && S_ISDIR (sb->st_mode))
540 acl = acl_get_file (name, ACL_TYPE_DEFAULT);
543 ret = (0 < acl_entries (acl));
556 return ACL_NOT_WELL_SUPPORTED (errno) ? 0 : -1;
559 # elif HAVE_FACL && defined GETACL /* Solaris, Cygwin, not HP-UX */
561 # if defined ACL_NO_TRIVIAL
563 /* Solaris 10 (newer version), which has additional API declared in
564 <sys/acl.h> (acl_t) and implemented in libsec (acl_set, acl_trivial,
565 acl_fromtext, ...). */
566 return acl_trivial (name);
568 # else /* Solaris, Cygwin, general case */
570 /* Solaris 2.5 through Solaris 10, Cygwin, and contemporaneous versions
571 of Unixware. The acl() call returns the access and default ACL both
574 /* Initially, try to read the entries into a stack-allocated buffer.
575 Use malloc if it does not fit. */
578 alloc_init = 4000 / sizeof (aclent_t), /* >= 3 */
579 alloc_max = MIN (INT_MAX, SIZE_MAX / sizeof (aclent_t))
581 aclent_t buf[alloc_init];
582 size_t alloc = alloc_init;
583 aclent_t *entries = buf;
584 aclent_t *malloced = NULL;
589 count = acl (name, GETACL, alloc, entries);
590 if (count < 0 && errno == ENOSPC)
592 /* Increase the size of the buffer. */
594 if (alloc > alloc_max / 2)
599 alloc = 2 * alloc; /* <= alloc_max */
601 (aclent_t *) malloc (alloc * sizeof (aclent_t));
613 if (errno == ENOSYS || errno == ENOTSUP)
617 int saved_errno = errno;
627 /* Don't use MIN_ACL_ENTRIES: It's set to 4 on Cygwin, but Cygwin
628 returns only 3 entries for files with no ACL. But this is safe:
629 If there are more than 4 entries, there cannot be only the
630 "user::", "group::", "other:", and "mask:" entries. */
637 if (acl_nontrivial (count, entries))
647 /* Solaris also has a different variant of ACLs, used in ZFS and NFSv4
648 file systems (whereas the other ones are used in UFS file systems). */
650 /* Initially, try to read the entries into a stack-allocated buffer.
651 Use malloc if it does not fit. */
654 alloc_init = 4000 / sizeof (ace_t), /* >= 3 */
655 alloc_max = MIN (INT_MAX, SIZE_MAX / sizeof (ace_t))
657 ace_t buf[alloc_init];
658 size_t alloc = alloc_init;
659 ace_t *entries = buf;
660 ace_t *malloced = NULL;
665 count = acl (name, ACE_GETACL, alloc, entries);
666 if (count < 0 && errno == ENOSPC)
668 /* Increase the size of the buffer. */
670 if (alloc > alloc_max / 2)
675 alloc = 2 * alloc; /* <= alloc_max */
676 entries = malloced = (ace_t *) malloc (alloc * sizeof (ace_t));
688 if (errno == ENOSYS || errno == EINVAL)
692 int saved_errno = errno;
702 /* In the old (original Solaris 10) convention:
703 If there are more than 3 entries, there cannot be only the
704 ACE_OWNER, ACE_GROUP, ACE_OTHER entries.
705 In the newer Solaris 10 and Solaris 11 convention:
706 If there are more than 6 entries, there cannot be only the
707 ACE_OWNER, ACE_GROUP, ACE_EVERYONE entries, each once with
708 NEW_ACE_ACCESS_ALLOWED_ACE_TYPE and once with
709 NEW_ACE_ACCESS_DENIED_ACE_TYPE. */
716 if (acl_ace_nontrivial (count, entries))
729 # elif HAVE_GETACL /* HP-UX */
732 struct acl_entry entries[NACLENTRIES];
735 count = getacl (name, NACLENTRIES, entries);
739 /* ENOSYS is seen on newer HP-UX versions.
740 EOPNOTSUPP is typically seen on NFS mounts.
741 ENOTSUP was seen on Quantum StorNext file systems (cvfs). */
742 if (errno == ENOSYS || errno == EOPNOTSUPP || errno == ENOTSUP)
751 if (count > NACLENTRIES)
752 /* If NACLENTRIES cannot be trusted, use dynamic memory
756 /* If there are more than 3 entries, there cannot be only the
757 (uid,%), (%,gid), (%,%) entries. */
764 if (stat (name, &statbuf) < 0)
767 return acl_nontrivial (count, entries, &statbuf);
772 # if HAVE_ACLV_H /* HP-UX >= 11.11 */
775 struct acl entries[NACLVENTRIES];
778 count = acl ((char *) name, ACL_GET, NACLVENTRIES, entries);
782 /* EOPNOTSUPP is seen on NFS in HP-UX 11.11, 11.23.
783 EINVAL is seen on NFS in HP-UX 11.31. */
784 if (errno == ENOSYS || errno == EOPNOTSUPP || errno == EINVAL)
793 if (count > NACLVENTRIES)
794 /* If NACLVENTRIES cannot be trusted, use dynamic memory
798 /* If there are more than 4 entries, there cannot be only the
799 four base ACL entries. */
803 return aclv_nontrivial (count, entries);
809 # elif HAVE_ACLX_GET && defined ACL_AIX_WIP /* AIX */
814 size_t aclsize = sizeof (aclbuf);
819 /* The docs say that type being 0 is equivalent to ACL_ANY, but it
820 is not true, in AIX 5.3. */
822 if (aclx_get (name, 0, &type, aclbuf, &aclsize, &mode) >= 0)
830 int saved_errno = errno;
836 aclsize = 2 * aclsize;
839 acl = malloc (aclsize);
847 if (type.u64 == ACL_AIXC)
849 int result = acl_nontrivial ((struct acl *) acl);
854 else if (type.u64 == ACL_NFS4)
856 int result = acl_nfs4_nontrivial ((nfs4_acl_int_t *) acl);
863 /* A newer type of ACL has been introduced in the system.
864 We should better support it. */
871 # elif HAVE_STATACL /* older AIX */
873 union { struct acl a; char room[4096]; } u;
875 if (statacl (name, STX_NORMAL, &u.a, sizeof (u)) < 0)
878 return acl_nontrivial (&u.a);
880 # elif HAVE_ACLSORT /* NonStop Kernel */
883 struct acl entries[NACLENTRIES];
886 count = acl ((char *) name, ACL_GET, NACLENTRIES, entries);
890 if (errno == ENOSYS || errno == ENOTSUP)
899 if (count > NACLENTRIES)
900 /* If NACLENTRIES cannot be trusted, use dynamic memory
904 /* If there are more than 4 entries, there cannot be only the
905 four base ACL entries. */
909 return acl_nontrivial (count, entries);