2 * Copyright (c) 2001-2002 Silicon Graphics, Inc. All Rights Reserved.
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of version 2 of the GNU General Public License as
6 * published by the Free Software Foundation.
8 * This program is distributed in the hope that it would be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
12 * Further, this software is distributed without any warranty that it is
13 * free of the rightful claim of any third person regarding infringement
14 * or the like. Any license provided herein, whether implied or
15 * otherwise, applies only to this software file. Patent licenses, if
16 * any, provided herein do not apply to combinations of this program with
17 * other software, or any other product whatsoever.
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write the Free Software Foundation, Inc., 59
21 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
23 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
24 * Mountain View, CA 94043, or:
28 * For further information regarding this notice, see:
30 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
38 #include "xfs_alloc_btree.h"
39 #include "xfs_bmap_btree.h"
40 #include "xfs_ialloc_btree.h"
41 #include "xfs_btree.h"
42 #include "xfs_attr_sf.h"
43 #include "xfs_dir_sf.h"
44 #include "xfs_dir2_sf.h"
45 #include "xfs_dinode.h"
46 #include "xfs_inode.h"
51 #include <linux/posix_acl_xattr.h>
53 STATIC int xfs_acl_setmode(vnode_t *, xfs_acl_t *, int *);
54 STATIC void xfs_acl_filter_mode(mode_t, xfs_acl_t *);
55 STATIC void xfs_acl_get_endian(xfs_acl_t *);
56 STATIC int xfs_acl_access(uid_t, gid_t, xfs_acl_t *, mode_t, cred_t *);
57 STATIC int xfs_acl_invalid(xfs_acl_t *);
58 STATIC void xfs_acl_sync_mode(mode_t, xfs_acl_t *);
59 STATIC void xfs_acl_get_attr(vnode_t *, xfs_acl_t *, int, int, int *);
60 STATIC void xfs_acl_set_attr(vnode_t *, xfs_acl_t *, int, int *);
61 STATIC int xfs_acl_allow_set(vnode_t *, int);
63 kmem_zone_t *xfs_acl_zone;
67 * Test for existence of access ACL attribute as efficiently as possible.
70 xfs_acl_vhasacl_access(
75 xfs_acl_get_attr(vp, NULL, _ACL_TYPE_ACCESS, ATTR_KERNOVAL, &error);
80 * Test for existence of default ACL attribute as efficiently as possible.
83 xfs_acl_vhasacl_default(
88 if (vp->v_type != VDIR)
90 xfs_acl_get_attr(vp, NULL, _ACL_TYPE_DEFAULT, ATTR_KERNOVAL, &error);
95 * Convert from extended attribute representation to in-memory for XFS.
98 posix_acl_xattr_to_xfs(
99 posix_acl_xattr_header *src,
103 posix_acl_xattr_entry *src_entry;
104 xfs_acl_entry_t *dest_entry;
110 if (size < sizeof(posix_acl_xattr_header))
113 if (src->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
116 memset(dest, 0, sizeof(xfs_acl_t));
117 dest->acl_cnt = posix_acl_xattr_count(size);
118 if (dest->acl_cnt < 0 || dest->acl_cnt > XFS_ACL_MAX_ENTRIES)
122 * acl_set_file(3) may request that we set default ACLs with
123 * zero length -- defend (gracefully) against that here.
128 src_entry = (posix_acl_xattr_entry *)((char *)src + sizeof(*src));
129 dest_entry = &dest->acl_entry[0];
131 for (n = 0; n < dest->acl_cnt; n++, src_entry++, dest_entry++) {
132 dest_entry->ae_perm = le16_to_cpu(src_entry->e_perm);
133 if (_ACL_PERM_INVALID(dest_entry->ae_perm))
135 dest_entry->ae_tag = le16_to_cpu(src_entry->e_tag);
136 switch(dest_entry->ae_tag) {
139 dest_entry->ae_id = le32_to_cpu(src_entry->e_id);
145 dest_entry->ae_id = ACL_UNDEFINED_ID;
151 if (xfs_acl_invalid(dest))
158 * Comparison function called from qsort().
159 * Primary key is ae_tag, secondary key is ae_id.
162 xfs_acl_entry_compare(
166 xfs_acl_entry_t *a = (xfs_acl_entry_t *)va,
167 *b = (xfs_acl_entry_t *)vb;
169 if (a->ae_tag == b->ae_tag)
170 return (a->ae_id - b->ae_id);
171 return (a->ae_tag - b->ae_tag);
175 * Convert from in-memory XFS to extended attribute representation.
178 posix_acl_xfs_to_xattr(
180 posix_acl_xattr_header *dest,
184 size_t new_size = posix_acl_xattr_size(src->acl_cnt);
185 posix_acl_xattr_entry *dest_entry;
186 xfs_acl_entry_t *src_entry;
191 /* Need to sort src XFS ACL by <ae_tag,ae_id> */
192 qsort(src->acl_entry, src->acl_cnt, sizeof(src->acl_entry[0]),
193 xfs_acl_entry_compare);
195 dest->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
196 dest_entry = &dest->a_entries[0];
197 src_entry = &src->acl_entry[0];
198 for (n = 0; n < src->acl_cnt; n++, dest_entry++, src_entry++) {
199 dest_entry->e_perm = cpu_to_le16(src_entry->ae_perm);
200 if (_ACL_PERM_INVALID(src_entry->ae_perm))
202 dest_entry->e_tag = cpu_to_le16(src_entry->ae_tag);
203 switch (src_entry->ae_tag) {
206 dest_entry->e_id = cpu_to_le32(src_entry->ae_id);
212 dest_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
229 xfs_acl_t *xfs_acl = NULL;
230 posix_acl_xattr_header *ext_acl = acl;
234 if ((error = _MAC_VACCESS(vp, NULL, VREAD)))
237 if (!(_ACL_ALLOC(xfs_acl))) {
241 memset(xfs_acl, 0, sizeof(xfs_acl_t));
243 flags = ATTR_KERNOVAL;
245 xfs_acl_get_attr(vp, xfs_acl, kind, flags, &error);
250 error = -posix_acl_xattr_size(XFS_ACL_MAX_ENTRIES);
252 if (xfs_acl_invalid(xfs_acl)) {
256 if (kind == _ACL_TYPE_ACCESS) {
259 va.va_mask = XFS_AT_MODE;
260 VOP_GETATTR(vp, &va, 0, sys_cred, error);
263 xfs_acl_sync_mode(va.va_mode, xfs_acl);
265 error = -posix_acl_xfs_to_xattr(xfs_acl, ext_acl, size);
282 error = xfs_acl_allow_set(vp, kind);
284 VOP_ATTR_REMOVE(vp, kind == _ACL_TYPE_DEFAULT?
285 SGI_ACL_DEFAULT: SGI_ACL_FILE,
286 ATTR_ROOT, sys_cred, error);
287 if (error == ENOATTR)
288 error = 0; /* 'scool */
301 posix_acl_xattr_header *ext_acl = acl;
304 int basicperms = 0; /* more than std unix perms? */
309 if (!(_ACL_ALLOC(xfs_acl)))
312 error = posix_acl_xattr_to_xfs(ext_acl, size, xfs_acl);
317 if (!xfs_acl->acl_cnt) {
323 error = xfs_acl_allow_set(vp, kind);
327 /* Incoming ACL exists, set file mode based on its value */
328 if (kind == _ACL_TYPE_ACCESS)
329 xfs_acl_setmode(vp, xfs_acl, &basicperms);
332 * If we have more than std unix permissions, set up the actual attr.
333 * Otherwise, delete any existing attr. This prevents us from
334 * having actual attrs for permissions that can be stored in the
335 * standard permission bits.
338 xfs_acl_set_attr(vp, xfs_acl, kind, &error);
340 xfs_acl_vremove(vp, _ACL_TYPE_ACCESS);
358 if (!(_ACL_ALLOC(acl)))
361 /* If the file has no ACL return -1. */
362 rval = sizeof(xfs_acl_t);
363 if (xfs_attr_fetch(ip, SGI_ACL_FILE, SGI_ACL_FILE_SIZE,
364 (char *)acl, &rval, ATTR_ROOT | ATTR_KERNACCESS, cr)) {
368 xfs_acl_get_endian(acl);
370 /* If the file has an empty ACL return -1. */
371 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) {
376 /* Synchronize ACL with mode bits */
377 xfs_acl_sync_mode(ip->i_d.di_mode, acl);
379 rval = xfs_acl_access(ip->i_d.di_uid, ip->i_d.di_gid, acl, mode, cr);
392 if (vp->v_inode.i_flags & (S_IMMUTABLE|S_APPEND))
394 if (kind == _ACL_TYPE_DEFAULT && vp->v_type != VDIR)
396 if (vp->v_vfsp->vfs_flag & VFS_RDONLY)
398 if ((error = _MAC_VACCESS(vp, NULL, VWRITE)))
400 va.va_mask = XFS_AT_UID;
401 VOP_GETATTR(vp, &va, 0, NULL, error);
404 if (va.va_uid != current->fsuid && !capable(CAP_FOWNER))
410 * Look for any effective exec access, to allow CAP_DAC_OVERRIDE for exec.
411 * Ignore checking for exec in USER_OBJ when there is no mask, because
412 * in this "minimal acl" case we don't have any actual acls, and we
413 * won't even be here.
416 xfs_acl_find_any_exec(
423 for (i = 0; i < fap->acl_cnt; i++) {
424 if (fap->acl_entry[i].ae_perm & ACL_EXECUTE) {
425 if (fap->acl_entry[i].ae_tag & (ACL_USER_OBJ|ACL_OTHER))
428 if (fap->acl_entry[i].ae_tag == ACL_MASK)
429 mask = fap->acl_entry[i].ae_perm;
431 masked_aces |= fap->acl_entry[i].ae_perm;
433 if ((mask & masked_aces) & ACL_EXECUTE)
442 * The access control process to determine the access permission:
443 * if uid == file owner id, use the file owner bits.
444 * if gid == file owner group id, use the file group bits.
445 * scan ACL for a maching user or group, and use matched entry
446 * permission. Use total permissions of all matching group entries,
447 * until all acl entries are exhausted. The final permission produced
448 * by matching acl entry or entries needs to be & with group permission.
449 * if not owner, owning group, or matching entry in ACL, use file
450 * other bits. Don't allow CAP_DAC_OVERRIDE on exec access unless
451 * there is some effective exec access somewhere.
454 xfs_acl_capability_check(
459 if ((mode & ACL_READ) && !capable_cred(cr, CAP_DAC_READ_SEARCH))
461 if ((mode & ACL_WRITE) && !capable_cred(cr, CAP_DAC_OVERRIDE))
463 if ((mode & ACL_EXECUTE) &&
464 (!capable_cred(cr, CAP_DAC_OVERRIDE) ||
465 !xfs_acl_find_any_exec(fap))) {
473 * Note: cr is only used here for the capability check if the ACL test fails.
474 * It is not used to find out the credentials uid or groups etc, as was
475 * done in IRIX. It is assumed that the uid and groups for the current
476 * thread are taken from "current" instead of the cr parameter.
486 xfs_acl_entry_t matched;
488 int maskallows = -1; /* true, but not 1, either */
489 int seen_userobj = 0;
491 matched.ae_tag = 0; /* Invalid type */
492 md >>= 6; /* Normalize the bits for comparison */
494 for (i = 0; i < fap->acl_cnt; i++) {
496 * Break out if we've got a user_obj entry or
497 * a user entry and the mask (and have processed USER_OBJ)
499 if (matched.ae_tag == ACL_USER_OBJ)
501 if (matched.ae_tag == ACL_USER) {
502 if (maskallows != -1 && seen_userobj)
504 if (fap->acl_entry[i].ae_tag != ACL_MASK &&
505 fap->acl_entry[i].ae_tag != ACL_USER_OBJ)
508 /* True if this entry allows the requested access */
509 allows = ((fap->acl_entry[i].ae_perm & md) == md);
511 switch (fap->acl_entry[i].ae_tag) {
514 if (fuid != current->fsuid)
516 matched.ae_tag = ACL_USER_OBJ;
517 matched.ae_perm = allows;
520 if (fap->acl_entry[i].ae_id != current->fsuid)
522 matched.ae_tag = ACL_USER;
523 matched.ae_perm = allows;
526 if ((matched.ae_tag == ACL_GROUP_OBJ ||
527 matched.ae_tag == ACL_GROUP) && !allows)
529 if (!in_group_p(fgid))
531 matched.ae_tag = ACL_GROUP_OBJ;
532 matched.ae_perm = allows;
535 if ((matched.ae_tag == ACL_GROUP_OBJ ||
536 matched.ae_tag == ACL_GROUP) && !allows)
538 if (!in_group_p(fap->acl_entry[i].ae_id))
540 matched.ae_tag = ACL_GROUP;
541 matched.ae_perm = allows;
547 if (matched.ae_tag != 0)
549 matched.ae_tag = ACL_OTHER;
550 matched.ae_perm = allows;
555 * First possibility is that no matched entry allows access.
556 * The capability to override DAC may exist, so check for it.
558 switch (matched.ae_tag) {
567 if (maskallows && matched.ae_perm)
574 return xfs_acl_capability_check(md, cr, fap);
578 * ACL validity checker.
579 * This acl validation routine checks each ACL entry read in makes sense.
585 xfs_acl_entry_t *entry, *e;
586 int user = 0, group = 0, other = 0, mask = 0;
587 int mask_required = 0;
593 if (aclp->acl_cnt > XFS_ACL_MAX_ENTRIES)
596 for (i = 0; i < aclp->acl_cnt; i++) {
597 entry = &aclp->acl_entry[i];
598 switch (entry->ae_tag) {
613 for (j = i + 1; j < aclp->acl_cnt; j++) {
614 e = &aclp->acl_entry[j];
615 if (e->ae_id == entry->ae_id &&
616 e->ae_tag == entry->ae_tag)
629 if (!user || !group || !other || (mask_required && !mask))
638 * Do ACL endian conversion.
644 xfs_acl_entry_t *ace, *end;
646 INT_SET(aclp->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
647 end = &aclp->acl_entry[0]+aclp->acl_cnt;
648 for (ace = &aclp->acl_entry[0]; ace < end; ace++) {
649 INT_SET(ace->ae_tag, ARCH_CONVERT, ace->ae_tag);
650 INT_SET(ace->ae_id, ARCH_CONVERT, ace->ae_id);
651 INT_SET(ace->ae_perm, ARCH_CONVERT, ace->ae_perm);
656 * Get the ACL from the EA and do endian conversion.
666 int len = sizeof(xfs_acl_t);
668 ASSERT((flags & ATTR_KERNOVAL) ? (aclp == NULL) : 1);
671 kind == _ACL_TYPE_ACCESS ? SGI_ACL_FILE : SGI_ACL_DEFAULT,
672 (char *)aclp, &len, flags, sys_cred, *error);
673 if (*error || (flags & ATTR_KERNOVAL))
675 xfs_acl_get_endian(aclp);
679 * Set the EA with the ACL and do endian conversion.
688 xfs_acl_entry_t *ace, *newace, *end;
692 if (!(_ACL_ALLOC(newacl))) {
697 len = sizeof(xfs_acl_t) -
698 (sizeof(xfs_acl_entry_t) * (XFS_ACL_MAX_ENTRIES - aclp->acl_cnt));
699 end = &aclp->acl_entry[0]+aclp->acl_cnt;
700 for (ace = &aclp->acl_entry[0], newace = &newacl->acl_entry[0];
703 INT_SET(newace->ae_tag, ARCH_CONVERT, ace->ae_tag);
704 INT_SET(newace->ae_id, ARCH_CONVERT, ace->ae_id);
705 INT_SET(newace->ae_perm, ARCH_CONVERT, ace->ae_perm);
707 INT_SET(newacl->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
709 kind == _ACL_TYPE_ACCESS ? SGI_ACL_FILE: SGI_ACL_DEFAULT,
710 (char *)newacl, len, ATTR_ROOT, sys_cred, *error);
717 xfs_acl_t *access_acl,
718 xfs_acl_t *default_acl)
725 * Get the Access ACL and the mode. If either cannot
726 * be obtained for some reason, invalidate the access ACL.
728 xfs_acl_get_attr(vp, access_acl, _ACL_TYPE_ACCESS, 0, &error);
730 /* Got the ACL, need the mode... */
731 va.va_mask = XFS_AT_MODE;
732 VOP_GETATTR(vp, &va, 0, sys_cred, error);
736 access_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
737 else /* We have a good ACL and the file mode, synchronize. */
738 xfs_acl_sync_mode(va.va_mode, access_acl);
742 xfs_acl_get_attr(vp, default_acl, _ACL_TYPE_DEFAULT, 0, &error);
744 default_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
750 * This function retrieves the parent directory's acl, processes it
751 * and lets the child inherit the acl(s) that it should.
764 * If the parent does not have a default ACL, or it's an
765 * invalid ACL, we're done.
769 if (!pdaclp || xfs_acl_invalid(pdaclp))
773 * Copy the default ACL of the containing directory to
774 * the access ACL of the new file and use the mode that
775 * was passed in to set up the correct initial values for
776 * the u::,g::[m::], and o:: entries. This is what makes
777 * umask() "work" with ACL's.
780 if (!(_ACL_ALLOC(cacl)))
783 memcpy(cacl, pdaclp, sizeof(xfs_acl_t));
784 xfs_acl_filter_mode(vap->va_mode, cacl);
785 xfs_acl_setmode(vp, cacl, &basicperms);
788 * Set the Default and Access ACL on the file. The mode is already
789 * set on the file, so we don't need to worry about that.
791 * If the new file is a directory, its default ACL is a copy of
792 * the containing directory's default ACL.
794 if (vp->v_type == VDIR)
795 xfs_acl_set_attr(vp, pdaclp, _ACL_TYPE_DEFAULT, &error);
796 if (!error && !basicperms)
797 xfs_acl_set_attr(vp, cacl, _ACL_TYPE_ACCESS, &error);
803 * Set up the correct mode on the file based on the supplied ACL. This
804 * makes sure that the mode on the file reflects the state of the
805 * u::,g::[m::], and o:: entries in the ACL. Since the mode is where
806 * the ACL is going to get the permissions for these entries, we must
807 * synchronize the mode whenever we set the ACL on a file.
817 xfs_acl_entry_t *gap = NULL;
818 int i, error, nomask = 1;
822 if (acl->acl_cnt == XFS_ACL_NOT_PRESENT)
826 * Copy the u::, g::, o::, and m:: bits from the ACL into the
827 * mode. The m:: bits take precedence over the g:: bits.
829 va.va_mask = XFS_AT_MODE;
830 VOP_GETATTR(vp, &va, 0, sys_cred, error);
834 va.va_mask = XFS_AT_MODE;
835 va.va_mode &= ~(S_IRWXU|S_IRWXG|S_IRWXO);
837 for (i = 0; i < acl->acl_cnt; ++i) {
838 switch (ap->ae_tag) {
840 va.va_mode |= ap->ae_perm << 6;
845 case ACL_MASK: /* more than just standard modes */
847 va.va_mode |= ap->ae_perm << 3;
851 va.va_mode |= ap->ae_perm;
853 default: /* more than just standard modes */
860 /* Set the group bits from ACL_GROUP_OBJ if there's no ACL_MASK */
862 va.va_mode |= gap->ae_perm << 3;
864 VOP_SETATTR(vp, &va, 0, sys_cred, error);
869 * The permissions for the special ACL entries (u::, g::[m::], o::) are
870 * actually stored in the file mode (if there is both a group and a mask,
871 * the group is stored in the ACL entry and the mask is stored on the file).
872 * This allows the mode to remain automatically in sync with the ACL without
873 * the need for a call-back to the ACL system at every point where the mode
874 * could change. This function takes the permissions from the specified mode
875 * and places it in the supplied ACL.
877 * This implementation draws its validity from the fact that, when the ACL
878 * was assigned, the mode was copied from the ACL.
879 * If the mode did not change, therefore, the mode remains exactly what was
880 * taken from the special ACL entries at assignment.
881 * If a subsequent chmod() was done, the POSIX spec says that the change in
882 * mode must cause an update to the ACL seen at user level and used for
883 * access checks. Before and after a mode change, therefore, the file mode
884 * most accurately reflects what the special ACL entries should permit/deny.
886 * CAVEAT: If someone sets the SGI_ACL_FILE attribute directly,
887 * the existing mode bits will override whatever is in the
888 * ACL. Similarly, if there is a pre-existing ACL that was
889 * never in sync with its mode (owing to a bug in 6.5 and
890 * before), it will now magically (or mystically) be
891 * synchronized. This could cause slight astonishment, but
892 * it is better than inconsistent permissions.
894 * The supplied ACL is a template that may contain any combination
895 * of special entries. These are treated as place holders when we fill
896 * out the ACL. This routine does not add or remove special entries, it
897 * simply unites each special entry with its associated set of permissions.
906 xfs_acl_entry_t *gap = NULL;
909 * Set ACL entries. POSIX1003.1eD16 requires that the MASK
910 * be set instead of the GROUP entry, if there is a MASK.
912 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
913 switch (ap->ae_tag) {
915 ap->ae_perm = (mode >> 6) & 0x7;
922 ap->ae_perm = (mode >> 3) & 0x7;
925 ap->ae_perm = mode & 0x7;
931 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
933 gap->ae_perm = (mode >> 3) & 0x7;
937 * When inheriting an Access ACL from a directory Default ACL,
938 * the ACL bits are set to the intersection of the ACL default
939 * permission bits and the file permission bits in mode. If there
940 * are no permission bits on the file then we must not give them
941 * the ACL. This is what what makes umask() work with ACLs.
950 xfs_acl_entry_t *gap = NULL;
953 * Set ACL entries. POSIX1003.1eD16 requires that the MASK
954 * be merged with GROUP entry, if there is a MASK.
956 for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
957 switch (ap->ae_tag) {
959 ap->ae_perm &= (mode >> 6) & 0x7;
966 ap->ae_perm &= (mode >> 3) & 0x7;
969 ap->ae_perm &= mode & 0x7;
975 /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
977 gap->ae_perm &= (mode >> 3) & 0x7;