xfs: validate acl count
[linux-2.6.git] / fs / ext3 / acl.h
1 /*
2   File: fs/ext3/acl.h
3
4   (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
5 */
6
7 #include <linux/posix_acl_xattr.h>
8
9 #define EXT3_ACL_VERSION        0x0001
10
11 typedef struct {
12         __le16          e_tag;
13         __le16          e_perm;
14         __le32          e_id;
15 } ext3_acl_entry;
16
17 typedef struct {
18         __le16          e_tag;
19         __le16          e_perm;
20 } ext3_acl_entry_short;
21
22 typedef struct {
23         __le32          a_version;
24 } ext3_acl_header;
25
26 static inline size_t ext3_acl_size(int count)
27 {
28         if (count <= 4) {
29                 return sizeof(ext3_acl_header) +
30                        count * sizeof(ext3_acl_entry_short);
31         } else {
32                 return sizeof(ext3_acl_header) +
33                        4 * sizeof(ext3_acl_entry_short) +
34                        (count - 4) * sizeof(ext3_acl_entry);
35         }
36 }
37
38 static inline int ext3_acl_count(size_t size)
39 {
40         ssize_t s;
41         size -= sizeof(ext3_acl_header);
42         s = size - 4 * sizeof(ext3_acl_entry_short);
43         if (s < 0) {
44                 if (size % sizeof(ext3_acl_entry_short))
45                         return -1;
46                 return size / sizeof(ext3_acl_entry_short);
47         } else {
48                 if (s % sizeof(ext3_acl_entry))
49                         return -1;
50                 return s / sizeof(ext3_acl_entry) + 4;
51         }
52 }
53
54 #ifdef CONFIG_EXT3_FS_POSIX_ACL
55
56 /* acl.c */
57 extern struct posix_acl *ext3_get_acl(struct inode *inode, int type);
58 extern int ext3_acl_chmod (struct inode *);
59 extern int ext3_init_acl (handle_t *, struct inode *, struct inode *);
60
61 #else  /* CONFIG_EXT3_FS_POSIX_ACL */
62 #include <linux/sched.h>
63 #define ext3_get_acl NULL
64
65 static inline int
66 ext3_acl_chmod(struct inode *inode)
67 {
68         return 0;
69 }
70
71 static inline int
72 ext3_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
73 {
74         return 0;
75 }
76 #endif  /* CONFIG_EXT3_FS_POSIX_ACL */
77