1/*
  2 * linux/fs/hfsplus/posix_acl.c
  3 *
  4 * Vyacheslav Dubeyko <slava@dubeyko.com>
  5 *
  6 * Handler for Posix Access Control Lists (ACLs) support.
  7 */
  8
  9#include "hfsplus_fs.h"
 10#include "xattr.h"
 11#include "acl.h"
 12
 13struct posix_acl *hfsplus_get_posix_acl(struct inode *inode, int type)
 14{
 15	struct posix_acl *acl;
 16	char *xattr_name;
 17	char *value = NULL;
 18	ssize_t size;
 19
 20	hfs_dbg(ACL_MOD, "[%s]: ino %lu\n", __func__, inode->i_ino);
 21
 22	switch (type) {
 23	case ACL_TYPE_ACCESS:
 24		xattr_name = XATTR_NAME_POSIX_ACL_ACCESS;
 25		break;
 26	case ACL_TYPE_DEFAULT:
 27		xattr_name = XATTR_NAME_POSIX_ACL_DEFAULT;
 28		break;
 29	default:
 30		return ERR_PTR(-EINVAL);
 31	}
 32
 33	size = __hfsplus_getxattr(inode, xattr_name, NULL, 0);
 34
 35	if (size > 0) {
 36		value = (char *)hfsplus_alloc_attr_entry();
 37		if (unlikely(!value))
 38			return ERR_PTR(-ENOMEM);
 39		size = __hfsplus_getxattr(inode, xattr_name, value, size);
 40	}
 41
 42	if (size > 0)
 43		acl = posix_acl_from_xattr(&init_user_ns, value, size);
 44	else if (size == -ENODATA)
 45		acl = NULL;
 46	else
 47		acl = ERR_PTR(size);
 48
 49	hfsplus_destroy_attr_entry((hfsplus_attr_entry *)value);
 50
 51	if (!IS_ERR(acl))
 52		set_cached_acl(inode, type, acl);
 53
 54	return acl;
 55}
 56
 57int hfsplus_set_posix_acl(struct inode *inode, struct posix_acl *acl,
 58		int type)
 59{
 60	int err;
 61	char *xattr_name;
 62	size_t size = 0;
 63	char *value = NULL;
 64
 65	hfs_dbg(ACL_MOD, "[%s]: ino %lu\n", __func__, inode->i_ino);
 66
 67	switch (type) {
 68	case ACL_TYPE_ACCESS:
 69		xattr_name = XATTR_NAME_POSIX_ACL_ACCESS;
 70		if (acl) {
 71			err = posix_acl_equiv_mode(acl, &inode->i_mode);
 72			if (err < 0)
 73				return err;
 74		}
 75		err = 0;
 76		break;
 77
 78	case ACL_TYPE_DEFAULT:
 79		xattr_name = XATTR_NAME_POSIX_ACL_DEFAULT;
 80		if (!S_ISDIR(inode->i_mode))
 81			return acl ? -EACCES : 0;
 82		break;
 83
 84	default:
 85		return -EINVAL;
 86	}
 87
 88	if (acl) {
 89		size = posix_acl_xattr_size(acl->a_count);
 90		if (unlikely(size > HFSPLUS_MAX_INLINE_DATA_SIZE))
 91			return -ENOMEM;
 92		value = (char *)hfsplus_alloc_attr_entry();
 93		if (unlikely(!value))
 94			return -ENOMEM;
 95		err = posix_acl_to_xattr(&init_user_ns, acl, value, size);
 96		if (unlikely(err < 0))
 97			goto end_set_acl;
 98	}
 99
100	err = __hfsplus_setxattr(inode, xattr_name, value, size, 0);
101
102end_set_acl:
103	hfsplus_destroy_attr_entry((hfsplus_attr_entry *)value);
104
105	if (!err)
106		set_cached_acl(inode, type, acl);
107
108	return err;
109}
110
111int hfsplus_init_posix_acl(struct inode *inode, struct inode *dir)
112{
113	int err = 0;
114	struct posix_acl *default_acl, *acl;
115
116	hfs_dbg(ACL_MOD,
117		"[%s]: ino %lu, dir->ino %lu\n",
118		__func__, inode->i_ino, dir->i_ino);
119
120	if (S_ISLNK(inode->i_mode))
121		return 0;
122
123	err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
124	if (err)
125		return err;
126
127	if (default_acl) {
128		err = hfsplus_set_posix_acl(inode, default_acl,
129					    ACL_TYPE_DEFAULT);
130		posix_acl_release(default_acl);
131	}
132
133	if (acl) {
134		if (!err)
135			err = hfsplus_set_posix_acl(inode, acl,
136						    ACL_TYPE_ACCESS);
137		posix_acl_release(acl);
138	}
139	return err;
140}