fs/ext2/xattr_trusted.c

   1 /*
   2  * linux/fs/ext2/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 <linux/ext2_fs.h>
  12 #include "xattr.h"
  13
  14 static size_t
  15 ext2_xattr_trusted_list(struct dentry *dentry, char *list, size_t list_size,
  16                 const char *name, size_t name_len, int type)
  17 {
  18         const int prefix_len = XATTR_TRUSTED_PREFIX_LEN;
  19         const size_t total_len = prefix_len + name_len + 1;
  20
  21         if (!capable(CAP_SYS_ADMIN))
  22                 return 0;
  23
  24         if (list && total_len <= list_size) {
  25                 memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
  26                 memcpy(list+prefix_len, name, name_len);
  27                 list[prefix_len + name_len] = '\0';
  28         }
  29         return total_len;
  30 }
  31
  32 static int
  33 ext2_xattr_trusted_get(struct dentry *dentry, const char *name,
  34                 void *buffer, size_t size, int type)
  35 {
  36         if (strcmp(name, "") == 0)
  37                 return -EINVAL;
  38         return ext2_xattr_get(dentry->d_inode, EXT2_XATTR_INDEX_TRUSTED, name,
  39                               buffer, size);
  40 }
  41
  42 static int
  43 ext2_xattr_trusted_set(struct dentry *dentry, const char *name,
  44                 const void *value, size_t size, int flags, int type)
  45 {
  46         if (strcmp(name, "") == 0)
  47                 return -EINVAL;
  48         return ext2_xattr_set(dentry->d_inode, EXT2_XATTR_INDEX_TRUSTED, name,
  49                               value, size, flags);
  50 }
  51
  52 const struct xattr_handler ext2_xattr_trusted_handler = {
  53         .prefix = XATTR_TRUSTED_PREFIX,
  54         .list   = ext2_xattr_trusted_list,
  55         .get    = ext2_xattr_trusted_get,
  56         .set    = ext2_xattr_trusted_set,
  57 };