LXR linux/fs/ext2/xattr

   1/*
   2 * linux/fs/ext2/xattr_security.c
   3 * Handler for storing security labels as extended attributes.
   4 */
   5
   6#include <linux/module.h>
   7#include <linux/string.h>
   8#include <linux/fs.h>
   9#include <linux/ext2_fs.h>
  10#include <linux/security.h>
  11#include "xattr.h"
  12
  13static size_t
  14ext2_xattr_security_list(struct inode *inode, char *list, size_t list_size,
  15                         const char *name, size_t name_len)
  16{
  17        const int prefix_len = XATTR_SECURITY_PREFIX_LEN;
  18        const size_t total_len = prefix_len + name_len + 1;
  19
  20        if (list && total_len <= list_size) {
  21                memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
  22                memcpy(list+prefix_len, name, name_len);
  23                list[prefix_len + name_len] = '\0';
  24        }
  25        return total_len;
  26}
  27
  28static int
  29ext2_xattr_security_get(struct inode *inode, const char *name,
  30                       void *buffer, size_t size)
  31{
  32        if (strcmp(name, "") == 0)
  33                return -EINVAL;
  34        return ext2_xattr_get(inode, EXT2_XATTR_INDEX_SECURITY, name,
  35                              buffer, size);
  36}
  37
  38static int
  39ext2_xattr_security_set(struct inode *inode, const char *name,
  40                       const void *value, size_t size, int flags)
  41{
  42        if (strcmp(name, "") == 0)
  43                return -EINVAL;
  44        return ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY, name,
  45                              value, size, flags);
  46}
  47
  48int
  49ext2_init_security(struct inode *inode, struct inode *dir)
  50{
  51        int err;
  52        size_t len;
  53        void *value;
  54        char *name;
  55
  56        err = security_inode_init_security(inode, dir, &name, &value, &len);
  57        if (err) {
  58                if (err == -EOPNOTSUPP)
  59                        return 0;
  60                return err;
  61        }
  62        err = ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY,
  63                             name, value, len, 0);
  64        kfree(name);
  65        kfree(value);
  66        return err;
  67}
  68
  69struct xattr_handler ext2_xattr_security_handler = {
  70        .prefix = XATTR_SECURITY_PREFIX,
  71        .list   = ext2_xattr_security_list,
  72        .get    = ext2_xattr_security_get,
  73        .set    = ext2_xattr_security_set,
  74};
  75