LXR linux/fs/ext4/xattr

   1/*
   2 * linux/fs/ext4/xattr_trusted.c
   3 * Handler for trusted extended attributes.
   4 *
   5 * Copyright (C) 2003 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
   6 */
   7
   8#include <linux/string.h>
   9#include <linux/capability.h>
  10#include <linux/fs.h>
  11#include "ext4_jbd2.h"
  12#include "ext4.h"
  13#include "xattr.h"
  14
  15static size_t
  16ext4_xattr_trusted_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_TRUSTED_PREFIX_LEN;
  20        const size_t total_len = prefix_len + name_len + 1;
  21
  22        if (!capable(CAP_SYS_ADMIN))
  23                return 0;
  24
  25        if (list && total_len <= list_size) {
  26                memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
  27                memcpy(list+prefix_len, name, name_len);
  28                list[prefix_len + name_len] = '\0';
  29        }
  30        return total_len;
  31}
  32
  33static int
  34ext4_xattr_trusted_get(struct dentry *dentry, const char *name, void *buffer,
  35                size_t size, int type)
  36{
  37        if (strcmp(name, "") == 0)
  38                return -EINVAL;
  39        return ext4_xattr_get(dentry->d_inode, EXT4_XATTR_INDEX_TRUSTED,
  40                              name, buffer, size);
  41}
  42
  43static int
  44ext4_xattr_trusted_set(struct dentry *dentry, const char *name,
  45                const void *value, size_t size, int flags, int type)
  46{
  47        if (strcmp(name, "") == 0)
  48                return -EINVAL;
  49        return ext4_xattr_set(dentry->d_inode, EXT4_XATTR_INDEX_TRUSTED,
  50                              name, value, size, flags);
  51}
  52
  53const struct xattr_handler ext4_xattr_trusted_handler = {
  54        .prefix = XATTR_TRUSTED_PREFIX,
  55        .list   = ext4_xattr_trusted_list,
  56        .get    = ext4_xattr_trusted_get,
  57        .set    = ext4_xattr_trusted_set,
  58};
  59