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 = POSIX_ACL_XATTR_ACCESS;
25		break;
26	case ACL_TYPE_DEFAULT:
27		xattr_name = POSIX_ACL_XATTR_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 = POSIX_ACL_XATTR_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 = POSIX_ACL_XATTR_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}
141