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Diffstat (limited to 'fs/xfs/xfs_acl.c')
-rw-r--r--fs/xfs/xfs_acl.c937
1 files changed, 937 insertions, 0 deletions
diff --git a/fs/xfs/xfs_acl.c b/fs/xfs/xfs_acl.c
new file mode 100644
index 00000000000..8d01dce8c53
--- /dev/null
+++ b/fs/xfs/xfs_acl.c
@@ -0,0 +1,937 @@
+/*
+ * Copyright (c) 2001-2002 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * Further, this software is distributed without any warranty that it is
+ * free of the rightful claim of any third person regarding infringement
+ * or the like. Any license provided herein, whether implied or
+ * otherwise, applies only to this software file. Patent licenses, if
+ * any, provided herein do not apply to combinations of this program with
+ * other software, or any other product whatsoever.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write the Free Software Foundation, Inc., 59
+ * Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
+ * Mountain View, CA 94043, or:
+ *
+ * http://www.sgi.com
+ *
+ * For further information regarding this notice, see:
+ *
+ * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
+ */
+
+#include "xfs.h"
+
+#include "xfs_inum.h"
+#include "xfs_dir.h"
+#include "xfs_dir2.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_btree.h"
+#include "xfs_attr_sf.h"
+#include "xfs_dir_sf.h"
+#include "xfs_dir2_sf.h"
+#include "xfs_dinode.h"
+#include "xfs_inode.h"
+#include "xfs_acl.h"
+#include "xfs_mac.h"
+#include "xfs_attr.h"
+
+#include <linux/posix_acl_xattr.h>
+
+STATIC int xfs_acl_setmode(vnode_t *, xfs_acl_t *, int *);
+STATIC void xfs_acl_filter_mode(mode_t, xfs_acl_t *);
+STATIC void xfs_acl_get_endian(xfs_acl_t *);
+STATIC int xfs_acl_access(uid_t, gid_t, xfs_acl_t *, mode_t, cred_t *);
+STATIC int xfs_acl_invalid(xfs_acl_t *);
+STATIC void xfs_acl_sync_mode(mode_t, xfs_acl_t *);
+STATIC void xfs_acl_get_attr(vnode_t *, xfs_acl_t *, int, int, int *);
+STATIC void xfs_acl_set_attr(vnode_t *, xfs_acl_t *, int, int *);
+STATIC int xfs_acl_allow_set(vnode_t *, int);
+
+kmem_zone_t *xfs_acl_zone;
+
+
+/*
+ * Test for existence of access ACL attribute as efficiently as possible.
+ */
+int
+xfs_acl_vhasacl_access(
+ vnode_t *vp)
+{
+ int error;
+
+ xfs_acl_get_attr(vp, NULL, _ACL_TYPE_ACCESS, ATTR_KERNOVAL, &error);
+ return (error == 0);
+}
+
+/*
+ * Test for existence of default ACL attribute as efficiently as possible.
+ */
+int
+xfs_acl_vhasacl_default(
+ vnode_t *vp)
+{
+ int error;
+
+ if (vp->v_type != VDIR)
+ return 0;
+ xfs_acl_get_attr(vp, NULL, _ACL_TYPE_DEFAULT, ATTR_KERNOVAL, &error);
+ return (error == 0);
+}
+
+/*
+ * Convert from extended attribute representation to in-memory for XFS.
+ */
+STATIC int
+posix_acl_xattr_to_xfs(
+ posix_acl_xattr_header *src,
+ size_t size,
+ xfs_acl_t *dest)
+{
+ posix_acl_xattr_entry *src_entry;
+ xfs_acl_entry_t *dest_entry;
+ int n;
+
+ if (!src || !dest)
+ return EINVAL;
+
+ if (size < sizeof(posix_acl_xattr_header))
+ return EINVAL;
+
+ if (src->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
+ return EOPNOTSUPP;
+
+ memset(dest, 0, sizeof(xfs_acl_t));
+ dest->acl_cnt = posix_acl_xattr_count(size);
+ if (dest->acl_cnt < 0 || dest->acl_cnt > XFS_ACL_MAX_ENTRIES)
+ return EINVAL;
+
+ /*
+ * acl_set_file(3) may request that we set default ACLs with
+ * zero length -- defend (gracefully) against that here.
+ */
+ if (!dest->acl_cnt)
+ return 0;
+
+ src_entry = (posix_acl_xattr_entry *)((char *)src + sizeof(*src));
+ dest_entry = &dest->acl_entry[0];
+
+ for (n = 0; n < dest->acl_cnt; n++, src_entry++, dest_entry++) {
+ dest_entry->ae_perm = le16_to_cpu(src_entry->e_perm);
+ if (_ACL_PERM_INVALID(dest_entry->ae_perm))
+ return EINVAL;
+ dest_entry->ae_tag = le16_to_cpu(src_entry->e_tag);
+ switch(dest_entry->ae_tag) {
+ case ACL_USER:
+ case ACL_GROUP:
+ dest_entry->ae_id = le32_to_cpu(src_entry->e_id);
+ break;
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ dest_entry->ae_id = ACL_UNDEFINED_ID;
+ break;
+ default:
+ return EINVAL;
+ }
+ }
+ if (xfs_acl_invalid(dest))
+ return EINVAL;
+
+ return 0;
+}
+
+/*
+ * Comparison function called from qsort().
+ * Primary key is ae_tag, secondary key is ae_id.
+ */
+STATIC int
+xfs_acl_entry_compare(
+ const void *va,
+ const void *vb)
+{
+ xfs_acl_entry_t *a = (xfs_acl_entry_t *)va,
+ *b = (xfs_acl_entry_t *)vb;
+
+ if (a->ae_tag == b->ae_tag)
+ return (a->ae_id - b->ae_id);
+ return (a->ae_tag - b->ae_tag);
+}
+
+/*
+ * Convert from in-memory XFS to extended attribute representation.
+ */
+STATIC int
+posix_acl_xfs_to_xattr(
+ xfs_acl_t *src,
+ posix_acl_xattr_header *dest,
+ size_t size)
+{
+ int n;
+ size_t new_size = posix_acl_xattr_size(src->acl_cnt);
+ posix_acl_xattr_entry *dest_entry;
+ xfs_acl_entry_t *src_entry;
+
+ if (size < new_size)
+ return -ERANGE;
+
+ /* Need to sort src XFS ACL by <ae_tag,ae_id> */
+ qsort(src->acl_entry, src->acl_cnt, sizeof(src->acl_entry[0]),
+ xfs_acl_entry_compare);
+
+ dest->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
+ dest_entry = &dest->a_entries[0];
+ src_entry = &src->acl_entry[0];
+ for (n = 0; n < src->acl_cnt; n++, dest_entry++, src_entry++) {
+ dest_entry->e_perm = cpu_to_le16(src_entry->ae_perm);
+ if (_ACL_PERM_INVALID(src_entry->ae_perm))
+ return -EINVAL;
+ dest_entry->e_tag = cpu_to_le16(src_entry->ae_tag);
+ switch (src_entry->ae_tag) {
+ case ACL_USER:
+ case ACL_GROUP:
+ dest_entry->e_id = cpu_to_le32(src_entry->ae_id);
+ break;
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ dest_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
+ break;
+ default:
+ return -EINVAL;
+ }
+ }
+ return new_size;
+}
+
+int
+xfs_acl_vget(
+ vnode_t *vp,
+ void *acl,
+ size_t size,
+ int kind)
+{
+ int error;
+ xfs_acl_t *xfs_acl = NULL;
+ posix_acl_xattr_header *ext_acl = acl;
+ int flags = 0;
+
+ VN_HOLD(vp);
+ if(size) {
+ if (!(_ACL_ALLOC(xfs_acl))) {
+ error = ENOMEM;
+ goto out;
+ }
+ memset(xfs_acl, 0, sizeof(xfs_acl_t));
+ } else
+ flags = ATTR_KERNOVAL;
+
+ xfs_acl_get_attr(vp, xfs_acl, kind, flags, &error);
+ if (error)
+ goto out;
+
+ if (!size) {
+ error = -posix_acl_xattr_size(XFS_ACL_MAX_ENTRIES);
+ } else {
+ if (xfs_acl_invalid(xfs_acl)) {
+ error = EINVAL;
+ goto out;
+ }
+ if (kind == _ACL_TYPE_ACCESS) {
+ vattr_t va;
+
+ va.va_mask = XFS_AT_MODE;
+ VOP_GETATTR(vp, &va, 0, sys_cred, error);
+ if (error)
+ goto out;
+ xfs_acl_sync_mode(va.va_mode, xfs_acl);
+ }
+ error = -posix_acl_xfs_to_xattr(xfs_acl, ext_acl, size);
+ }
+out:
+ VN_RELE(vp);
+ if(xfs_acl)
+ _ACL_FREE(xfs_acl);
+ return -error;
+}
+
+int
+xfs_acl_vremove(
+ vnode_t *vp,
+ int kind)
+{
+ int error;
+
+ VN_HOLD(vp);
+ error = xfs_acl_allow_set(vp, kind);
+ if (!error) {
+ VOP_ATTR_REMOVE(vp, kind == _ACL_TYPE_DEFAULT?
+ SGI_ACL_DEFAULT: SGI_ACL_FILE,
+ ATTR_ROOT, sys_cred, error);
+ if (error == ENOATTR)
+ error = 0; /* 'scool */
+ }
+ VN_RELE(vp);
+ return -error;
+}
+
+int
+xfs_acl_vset(
+ vnode_t *vp,
+ void *acl,
+ size_t size,
+ int kind)
+{
+ posix_acl_xattr_header *ext_acl = acl;
+ xfs_acl_t *xfs_acl;
+ int error;
+ int basicperms = 0; /* more than std unix perms? */
+
+ if (!acl)
+ return -EINVAL;
+
+ if (!(_ACL_ALLOC(xfs_acl)))
+ return -ENOMEM;
+
+ error = posix_acl_xattr_to_xfs(ext_acl, size, xfs_acl);
+ if (error) {
+ _ACL_FREE(xfs_acl);
+ return -error;
+ }
+ if (!xfs_acl->acl_cnt) {
+ _ACL_FREE(xfs_acl);
+ return 0;
+ }
+
+ VN_HOLD(vp);
+ error = xfs_acl_allow_set(vp, kind);
+ if (error)
+ goto out;
+
+ /* Incoming ACL exists, set file mode based on its value */
+ if (kind == _ACL_TYPE_ACCESS)
+ xfs_acl_setmode(vp, xfs_acl, &basicperms);
+
+ /*
+ * If we have more than std unix permissions, set up the actual attr.
+ * Otherwise, delete any existing attr. This prevents us from
+ * having actual attrs for permissions that can be stored in the
+ * standard permission bits.
+ */
+ if (!basicperms) {
+ xfs_acl_set_attr(vp, xfs_acl, kind, &error);
+ } else {
+ xfs_acl_vremove(vp, _ACL_TYPE_ACCESS);
+ }
+
+out:
+ VN_RELE(vp);
+ _ACL_FREE(xfs_acl);
+ return -error;
+}
+
+int
+xfs_acl_iaccess(
+ xfs_inode_t *ip,
+ mode_t mode,
+ cred_t *cr)
+{
+ xfs_acl_t *acl;
+ int rval;
+
+ if (!(_ACL_ALLOC(acl)))
+ return -1;
+
+ /* If the file has no ACL return -1. */
+ rval = sizeof(xfs_acl_t);
+ if (xfs_attr_fetch(ip, SGI_ACL_FILE, SGI_ACL_FILE_SIZE,
+ (char *)acl, &rval, ATTR_ROOT | ATTR_KERNACCESS, cr)) {
+ _ACL_FREE(acl);
+ return -1;
+ }
+ xfs_acl_get_endian(acl);
+
+ /* If the file has an empty ACL return -1. */
+ if (acl->acl_cnt == XFS_ACL_NOT_PRESENT) {
+ _ACL_FREE(acl);
+ return -1;
+ }
+
+ /* Synchronize ACL with mode bits */
+ xfs_acl_sync_mode(ip->i_d.di_mode, acl);
+
+ rval = xfs_acl_access(ip->i_d.di_uid, ip->i_d.di_gid, acl, mode, cr);
+ _ACL_FREE(acl);
+ return rval;
+}
+
+STATIC int
+xfs_acl_allow_set(
+ vnode_t *vp,
+ int kind)
+{
+ vattr_t va;
+ int error;
+
+ if (vp->v_inode.i_flags & (S_IMMUTABLE|S_APPEND))
+ return EPERM;
+ if (kind == _ACL_TYPE_DEFAULT && vp->v_type != VDIR)
+ return ENOTDIR;
+ if (vp->v_vfsp->vfs_flag & VFS_RDONLY)
+ return EROFS;
+ va.va_mask = XFS_AT_UID;
+ VOP_GETATTR(vp, &va, 0, NULL, error);
+ if (error)
+ return error;
+ if (va.va_uid != current->fsuid && !capable(CAP_FOWNER))
+ return EPERM;
+ return error;
+}
+
+/*
+ * The access control process to determine the access permission:
+ * if uid == file owner id, use the file owner bits.
+ * if gid == file owner group id, use the file group bits.
+ * scan ACL for a maching user or group, and use matched entry
+ * permission. Use total permissions of all matching group entries,
+ * until all acl entries are exhausted. The final permission produced
+ * by matching acl entry or entries needs to be & with group permission.
+ * if not owner, owning group, or matching entry in ACL, use file
+ * other bits.
+ */
+STATIC int
+xfs_acl_capability_check(
+ mode_t mode,
+ cred_t *cr)
+{
+ if ((mode & ACL_READ) && !capable_cred(cr, CAP_DAC_READ_SEARCH))
+ return EACCES;
+ if ((mode & ACL_WRITE) && !capable_cred(cr, CAP_DAC_OVERRIDE))
+ return EACCES;
+ if ((mode & ACL_EXECUTE) && !capable_cred(cr, CAP_DAC_OVERRIDE))
+ return EACCES;
+
+ return 0;
+}
+
+/*
+ * Note: cr is only used here for the capability check if the ACL test fails.
+ * It is not used to find out the credentials uid or groups etc, as was
+ * done in IRIX. It is assumed that the uid and groups for the current
+ * thread are taken from "current" instead of the cr parameter.
+ */
+STATIC int
+xfs_acl_access(
+ uid_t fuid,
+ gid_t fgid,
+ xfs_acl_t *fap,
+ mode_t md,
+ cred_t *cr)
+{
+ xfs_acl_entry_t matched;
+ int i, allows;
+ int maskallows = -1; /* true, but not 1, either */
+ int seen_userobj = 0;
+
+ matched.ae_tag = 0; /* Invalid type */
+ md >>= 6; /* Normalize the bits for comparison */
+
+ for (i = 0; i < fap->acl_cnt; i++) {
+ /*
+ * Break out if we've got a user_obj entry or
+ * a user entry and the mask (and have processed USER_OBJ)
+ */
+ if (matched.ae_tag == ACL_USER_OBJ)
+ break;
+ if (matched.ae_tag == ACL_USER) {
+ if (maskallows != -1 && seen_userobj)
+ break;
+ if (fap->acl_entry[i].ae_tag != ACL_MASK &&
+ fap->acl_entry[i].ae_tag != ACL_USER_OBJ)
+ continue;
+ }
+ /* True if this entry allows the requested access */
+ allows = ((fap->acl_entry[i].ae_perm & md) == md);
+
+ switch (fap->acl_entry[i].ae_tag) {
+ case ACL_USER_OBJ:
+ seen_userobj = 1;
+ if (fuid != current->fsuid)
+ continue;
+ matched.ae_tag = ACL_USER_OBJ;
+ matched.ae_perm = allows;
+ break;
+ case ACL_USER:
+ if (fap->acl_entry[i].ae_id != current->fsuid)
+ continue;
+ matched.ae_tag = ACL_USER;
+ matched.ae_perm = allows;
+ break;
+ case ACL_GROUP_OBJ:
+ if ((matched.ae_tag == ACL_GROUP_OBJ ||
+ matched.ae_tag == ACL_GROUP) && !allows)
+ continue;
+ if (!in_group_p(fgid))
+ continue;
+ matched.ae_tag = ACL_GROUP_OBJ;
+ matched.ae_perm = allows;
+ break;
+ case ACL_GROUP:
+ if ((matched.ae_tag == ACL_GROUP_OBJ ||
+ matched.ae_tag == ACL_GROUP) && !allows)
+ continue;
+ if (!in_group_p(fap->acl_entry[i].ae_id))
+ continue;
+ matched.ae_tag = ACL_GROUP;
+ matched.ae_perm = allows;
+ break;
+ case ACL_MASK:
+ maskallows = allows;
+ break;
+ case ACL_OTHER:
+ if (matched.ae_tag != 0)
+ continue;
+ matched.ae_tag = ACL_OTHER;
+ matched.ae_perm = allows;
+ break;
+ }
+ }
+ /*
+ * First possibility is that no matched entry allows access.
+ * The capability to override DAC may exist, so check for it.
+ */
+ switch (matched.ae_tag) {
+ case ACL_OTHER:
+ case ACL_USER_OBJ:
+ if (matched.ae_perm)
+ return 0;
+ break;
+ case ACL_USER:
+ case ACL_GROUP_OBJ:
+ case ACL_GROUP:
+ if (maskallows && matched.ae_perm)
+ return 0;
+ break;
+ case 0:
+ break;
+ }
+
+ return xfs_acl_capability_check(md, cr);
+}
+
+/*
+ * ACL validity checker.
+ * This acl validation routine checks each ACL entry read in makes sense.
+ */
+STATIC int
+xfs_acl_invalid(
+ xfs_acl_t *aclp)
+{
+ xfs_acl_entry_t *entry, *e;
+ int user = 0, group = 0, other = 0, mask = 0;
+ int mask_required = 0;
+ int i, j;
+
+ if (!aclp)
+ goto acl_invalid;
+
+ if (aclp->acl_cnt > XFS_ACL_MAX_ENTRIES)
+ goto acl_invalid;
+
+ for (i = 0; i < aclp->acl_cnt; i++) {
+ entry = &aclp->acl_entry[i];
+ switch (entry->ae_tag) {
+ case ACL_USER_OBJ:
+ if (user++)
+ goto acl_invalid;
+ break;
+ case ACL_GROUP_OBJ:
+ if (group++)
+ goto acl_invalid;
+ break;
+ case ACL_OTHER:
+ if (other++)
+ goto acl_invalid;
+ break;
+ case ACL_USER:
+ case ACL_GROUP:
+ for (j = i + 1; j < aclp->acl_cnt; j++) {
+ e = &aclp->acl_entry[j];
+ if (e->ae_id == entry->ae_id &&
+ e->ae_tag == entry->ae_tag)
+ goto acl_invalid;
+ }
+ mask_required++;
+ break;
+ case ACL_MASK:
+ if (mask++)
+ goto acl_invalid;
+ break;
+ default:
+ goto acl_invalid;
+ }
+ }
+ if (!user || !group || !other || (mask_required && !mask))
+ goto acl_invalid;
+ else
+ return 0;
+acl_invalid:
+ return EINVAL;
+}
+
+/*
+ * Do ACL endian conversion.
+ */
+STATIC void
+xfs_acl_get_endian(
+ xfs_acl_t *aclp)
+{
+ xfs_acl_entry_t *ace, *end;
+
+ INT_SET(aclp->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
+ end = &aclp->acl_entry[0]+aclp->acl_cnt;
+ for (ace = &aclp->acl_entry[0]; ace < end; ace++) {
+ INT_SET(ace->ae_tag, ARCH_CONVERT, ace->ae_tag);
+ INT_SET(ace->ae_id, ARCH_CONVERT, ace->ae_id);
+ INT_SET(ace->ae_perm, ARCH_CONVERT, ace->ae_perm);
+ }
+}
+
+/*
+ * Get the ACL from the EA and do endian conversion.
+ */
+STATIC void
+xfs_acl_get_attr(
+ vnode_t *vp,
+ xfs_acl_t *aclp,
+ int kind,
+ int flags,
+ int *error)
+{
+ int len = sizeof(xfs_acl_t);
+
+ ASSERT((flags & ATTR_KERNOVAL) ? (aclp == NULL) : 1);
+ flags |= ATTR_ROOT;
+ VOP_ATTR_GET(vp,
+ kind == _ACL_TYPE_ACCESS ? SGI_ACL_FILE : SGI_ACL_DEFAULT,
+ (char *)aclp, &len, flags, sys_cred, *error);
+ if (*error || (flags & ATTR_KERNOVAL))
+ return;
+ xfs_acl_get_endian(aclp);
+}
+
+/*
+ * Set the EA with the ACL and do endian conversion.
+ */
+STATIC void
+xfs_acl_set_attr(
+ vnode_t *vp,
+ xfs_acl_t *aclp,
+ int kind,
+ int *error)
+{
+ xfs_acl_entry_t *ace, *newace, *end;
+ xfs_acl_t *newacl;
+ int len;
+
+ if (!(_ACL_ALLOC(newacl))) {
+ *error = ENOMEM;
+ return;
+ }
+
+ len = sizeof(xfs_acl_t) -
+ (sizeof(xfs_acl_entry_t) * (XFS_ACL_MAX_ENTRIES - aclp->acl_cnt));
+ end = &aclp->acl_entry[0]+aclp->acl_cnt;
+ for (ace = &aclp->acl_entry[0], newace = &newacl->acl_entry[0];
+ ace < end;
+ ace++, newace++) {
+ INT_SET(newace->ae_tag, ARCH_CONVERT, ace->ae_tag);
+ INT_SET(newace->ae_id, ARCH_CONVERT, ace->ae_id);
+ INT_SET(newace->ae_perm, ARCH_CONVERT, ace->ae_perm);
+ }
+ INT_SET(newacl->acl_cnt, ARCH_CONVERT, aclp->acl_cnt);
+ VOP_ATTR_SET(vp,
+ kind == _ACL_TYPE_ACCESS ? SGI_ACL_FILE: SGI_ACL_DEFAULT,
+ (char *)newacl, len, ATTR_ROOT, sys_cred, *error);
+ _ACL_FREE(newacl);
+}
+
+int
+xfs_acl_vtoacl(
+ vnode_t *vp,
+ xfs_acl_t *access_acl,
+ xfs_acl_t *default_acl)
+{
+ vattr_t va;
+ int error = 0;
+
+ if (access_acl) {
+ /*
+ * Get the Access ACL and the mode. If either cannot
+ * be obtained for some reason, invalidate the access ACL.
+ */
+ xfs_acl_get_attr(vp, access_acl, _ACL_TYPE_ACCESS, 0, &error);
+ if (!error) {
+ /* Got the ACL, need the mode... */
+ va.va_mask = XFS_AT_MODE;
+ VOP_GETATTR(vp, &va, 0, sys_cred, error);
+ }
+
+ if (error)
+ access_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
+ else /* We have a good ACL and the file mode, synchronize. */
+ xfs_acl_sync_mode(va.va_mode, access_acl);
+ }
+
+ if (default_acl) {
+ xfs_acl_get_attr(vp, default_acl, _ACL_TYPE_DEFAULT, 0, &error);
+ if (error)
+ default_acl->acl_cnt = XFS_ACL_NOT_PRESENT;
+ }
+ return error;
+}
+
+/*
+ * This function retrieves the parent directory's acl, processes it
+ * and lets the child inherit the acl(s) that it should.
+ */
+int
+xfs_acl_inherit(
+ vnode_t *vp,
+ vattr_t *vap,
+ xfs_acl_t *pdaclp)
+{
+ xfs_acl_t *cacl;
+ int error = 0;
+ int basicperms = 0;
+
+ /*
+ * If the parent does not have a default ACL, or it's an
+ * invalid ACL, we're done.
+ */
+ if (!vp)
+ return 0;
+ if (!pdaclp || xfs_acl_invalid(pdaclp))
+ return 0;
+
+ /*
+ * Copy the default ACL of the containing directory to
+ * the access ACL of the new file and use the mode that
+ * was passed in to set up the correct initial values for
+ * the u::,g::[m::], and o:: entries. This is what makes
+ * umask() "work" with ACL's.
+ */
+
+ if (!(_ACL_ALLOC(cacl)))
+ return ENOMEM;
+
+ memcpy(cacl, pdaclp, sizeof(xfs_acl_t));
+ xfs_acl_filter_mode(vap->va_mode, cacl);
+ xfs_acl_setmode(vp, cacl, &basicperms);
+
+ /*
+ * Set the Default and Access ACL on the file. The mode is already
+ * set on the file, so we don't need to worry about that.
+ *
+ * If the new file is a directory, its default ACL is a copy of
+ * the containing directory's default ACL.
+ */
+ if (vp->v_type == VDIR)
+ xfs_acl_set_attr(vp, pdaclp, _ACL_TYPE_DEFAULT, &error);
+ if (!error && !basicperms)
+ xfs_acl_set_attr(vp, cacl, _ACL_TYPE_ACCESS, &error);
+ _ACL_FREE(cacl);
+ return error;
+}
+
+/*
+ * Set up the correct mode on the file based on the supplied ACL. This
+ * makes sure that the mode on the file reflects the state of the
+ * u::,g::[m::], and o:: entries in the ACL. Since the mode is where
+ * the ACL is going to get the permissions for these entries, we must
+ * synchronize the mode whenever we set the ACL on a file.
+ */
+STATIC int
+xfs_acl_setmode(
+ vnode_t *vp,
+ xfs_acl_t *acl,
+ int *basicperms)
+{
+ vattr_t va;
+ xfs_acl_entry_t *ap;
+ xfs_acl_entry_t *gap = NULL;
+ int i, error, nomask = 1;
+
+ *basicperms = 1;
+
+ if (acl->acl_cnt == XFS_ACL_NOT_PRESENT)
+ return 0;
+
+ /*
+ * Copy the u::, g::, o::, and m:: bits from the ACL into the
+ * mode. The m:: bits take precedence over the g:: bits.
+ */
+ va.va_mask = XFS_AT_MODE;
+ VOP_GETATTR(vp, &va, 0, sys_cred, error);
+ if (error)
+ return error;
+
+ va.va_mask = XFS_AT_MODE;
+ va.va_mode &= ~(S_IRWXU|S_IRWXG|S_IRWXO);
+ ap = acl->acl_entry;
+ for (i = 0; i < acl->acl_cnt; ++i) {
+ switch (ap->ae_tag) {
+ case ACL_USER_OBJ:
+ va.va_mode |= ap->ae_perm << 6;
+ break;
+ case ACL_GROUP_OBJ:
+ gap = ap;
+ break;
+ case ACL_MASK: /* more than just standard modes */
+ nomask = 0;
+ va.va_mode |= ap->ae_perm << 3;
+ *basicperms = 0;
+ break;
+ case ACL_OTHER:
+ va.va_mode |= ap->ae_perm;
+ break;
+ default: /* more than just standard modes */
+ *basicperms = 0;
+ break;
+ }
+ ap++;
+ }
+
+ /* Set the group bits from ACL_GROUP_OBJ if there's no ACL_MASK */
+ if (gap && nomask)
+ va.va_mode |= gap->ae_perm << 3;
+
+ VOP_SETATTR(vp, &va, 0, sys_cred, error);
+ return error;
+}
+
+/*
+ * The permissions for the special ACL entries (u::, g::[m::], o::) are
+ * actually stored in the file mode (if there is both a group and a mask,
+ * the group is stored in the ACL entry and the mask is stored on the file).
+ * This allows the mode to remain automatically in sync with the ACL without
+ * the need for a call-back to the ACL system at every point where the mode
+ * could change. This function takes the permissions from the specified mode
+ * and places it in the supplied ACL.
+ *
+ * This implementation draws its validity from the fact that, when the ACL
+ * was assigned, the mode was copied from the ACL.
+ * If the mode did not change, therefore, the mode remains exactly what was
+ * taken from the special ACL entries at assignment.
+ * If a subsequent chmod() was done, the POSIX spec says that the change in
+ * mode must cause an update to the ACL seen at user level and used for
+ * access checks. Before and after a mode change, therefore, the file mode
+ * most accurately reflects what the special ACL entries should permit/deny.
+ *
+ * CAVEAT: If someone sets the SGI_ACL_FILE attribute directly,
+ * the existing mode bits will override whatever is in the
+ * ACL. Similarly, if there is a pre-existing ACL that was
+ * never in sync with its mode (owing to a bug in 6.5 and
+ * before), it will now magically (or mystically) be
+ * synchronized. This could cause slight astonishment, but
+ * it is better than inconsistent permissions.
+ *
+ * The supplied ACL is a template that may contain any combination
+ * of special entries. These are treated as place holders when we fill
+ * out the ACL. This routine does not add or remove special entries, it
+ * simply unites each special entry with its associated set of permissions.
+ */
+STATIC void
+xfs_acl_sync_mode(
+ mode_t mode,
+ xfs_acl_t *acl)
+{
+ int i, nomask = 1;
+ xfs_acl_entry_t *ap;
+ xfs_acl_entry_t *gap = NULL;
+
+ /*
+ * Set ACL entries. POSIX1003.1eD16 requires that the MASK
+ * be set instead of the GROUP entry, if there is a MASK.
+ */
+ for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
+ switch (ap->ae_tag) {
+ case ACL_USER_OBJ:
+ ap->ae_perm = (mode >> 6) & 0x7;
+ break;
+ case ACL_GROUP_OBJ:
+ gap = ap;
+ break;
+ case ACL_MASK:
+ nomask = 0;
+ ap->ae_perm = (mode >> 3) & 0x7;
+ break;
+ case ACL_OTHER:
+ ap->ae_perm = mode & 0x7;
+ break;
+ default:
+ break;
+ }
+ }
+ /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
+ if (gap && nomask)
+ gap->ae_perm = (mode >> 3) & 0x7;
+}
+
+/*
+ * When inheriting an Access ACL from a directory Default ACL,
+ * the ACL bits are set to the intersection of the ACL default
+ * permission bits and the file permission bits in mode. If there
+ * are no permission bits on the file then we must not give them
+ * the ACL. This is what what makes umask() work with ACLs.
+ */
+STATIC void
+xfs_acl_filter_mode(
+ mode_t mode,
+ xfs_acl_t *acl)
+{
+ int i, nomask = 1;
+ xfs_acl_entry_t *ap;
+ xfs_acl_entry_t *gap = NULL;
+
+ /*
+ * Set ACL entries. POSIX1003.1eD16 requires that the MASK
+ * be merged with GROUP entry, if there is a MASK.
+ */
+ for (ap = acl->acl_entry, i = 0; i < acl->acl_cnt; ap++, i++) {
+ switch (ap->ae_tag) {
+ case ACL_USER_OBJ:
+ ap->ae_perm &= (mode >> 6) & 0x7;
+ break;
+ case ACL_GROUP_OBJ:
+ gap = ap;
+ break;
+ case ACL_MASK:
+ nomask = 0;
+ ap->ae_perm &= (mode >> 3) & 0x7;
+ break;
+ case ACL_OTHER:
+ ap->ae_perm &= mode & 0x7;
+ break;
+ default:
+ break;
+ }
+ }
+ /* Set the ACL_GROUP_OBJ if there's no ACL_MASK */
+ if (gap && nomask)
+ gap->ae_perm &= (mode >> 3) & 0x7;
+}
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-11-22 18:35:22 +0000