Root/fs/ext3/xattr_security.c

1/*
2 * linux/fs/ext3/xattr_security.c
3 * Handler for storing security labels as extended attributes.
4 */
5
6#include <linux/module.h>
7#include <linux/slab.h>
8#include <linux/string.h>
9#include <linux/fs.h>
10#include <linux/ext3_jbd.h>
11#include <linux/ext3_fs.h>
12#include <linux/security.h>
13#include "xattr.h"
14
15static size_t
16ext3_xattr_security_list(struct dentry *dentry, char *list, size_t list_size,
17             const char *name, size_t name_len, int type)
18{
19    const size_t prefix_len = XATTR_SECURITY_PREFIX_LEN;
20    const size_t total_len = prefix_len + name_len + 1;
21
22
23    if (list && total_len <= list_size) {
24        memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
25        memcpy(list+prefix_len, name, name_len);
26        list[prefix_len + name_len] = '\0';
27    }
28    return total_len;
29}
30
31static int
32ext3_xattr_security_get(struct dentry *dentry, const char *name,
33        void *buffer, size_t size, int type)
34{
35    if (strcmp(name, "") == 0)
36        return -EINVAL;
37    return ext3_xattr_get(dentry->d_inode, EXT3_XATTR_INDEX_SECURITY,
38                  name, buffer, size);
39}
40
41static int
42ext3_xattr_security_set(struct dentry *dentry, const char *name,
43        const void *value, size_t size, int flags, int type)
44{
45    if (strcmp(name, "") == 0)
46        return -EINVAL;
47    return ext3_xattr_set(dentry->d_inode, EXT3_XATTR_INDEX_SECURITY,
48                  name, value, size, flags);
49}
50
51int
52ext3_init_security(handle_t *handle, struct inode *inode, struct inode *dir,
53           const struct qstr *qstr)
54{
55    int err;
56    size_t len;
57    void *value;
58    char *name;
59
60    err = security_inode_init_security(inode, dir, qstr, &name, &value, &len);
61    if (err) {
62        if (err == -EOPNOTSUPP)
63            return 0;
64        return err;
65    }
66    err = ext3_xattr_set_handle(handle, inode, EXT3_XATTR_INDEX_SECURITY,
67                    name, value, len, 0);
68    kfree(name);
69    kfree(value);
70    return err;
71}
72
73const struct xattr_handler ext3_xattr_security_handler = {
74    .prefix = XATTR_SECURITY_PREFIX,
75    .list = ext3_xattr_security_list,
76    .get = ext3_xattr_security_get,
77    .set = ext3_xattr_security_set,
78};
79

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