fs/9p/xattr_trusted.c

   1 /*
   2  * Copyright IBM Corporation, 2010
   3  * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of version 2.1 of the GNU Lesser General Public License
   7  * as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  12  *
  13  */
  14
  15
  16 #include <linux/module.h>
  17 #include <linux/string.h>
  18 #include <linux/fs.h>
  19 #include <linux/slab.h>
  20 #include "xattr.h"
  21
  22 static int v9fs_xattr_trusted_get(struct dentry *dentry, const char *name,
  23                         void *buffer, size_t size, int type)
  24 {
  25         int retval;
  26         char *full_name;
  27         size_t name_len;
  28         size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN;
  29
  30         if (name == NULL)
  31                 return -EINVAL;
  32
  33         if (strcmp(name, "") == 0)
  34                 return -EINVAL;
  35
  36         name_len = strlen(name);
  37         full_name = kmalloc(prefix_len + name_len + 1 , GFP_KERNEL);
  38         if (!full_name)
  39                 return -ENOMEM;
  40         memcpy(full_name, XATTR_TRUSTED_PREFIX, prefix_len);
  41         memcpy(full_name+prefix_len, name, name_len);
  42         full_name[prefix_len + name_len] = '\0';
  43
  44         retval = v9fs_xattr_get(dentry, full_name, buffer, size);
  45         kfree(full_name);
  46         return retval;
  47 }
  48
  49 static int v9fs_xattr_trusted_set(struct dentry *dentry, const char *name,
  50                         const void *value, size_t size, int flags, int type)
  51 {
  52         int retval;
  53         char *full_name;
  54         size_t name_len;
  55         size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN;
  56
  57         if (name == NULL)
  58                 return -EINVAL;
  59
  60         if (strcmp(name, "") == 0)
  61                 return -EINVAL;
  62
  63         name_len = strlen(name);
  64         full_name = kmalloc(prefix_len + name_len + 1 , GFP_KERNEL);
  65         if (!full_name)
  66                 return -ENOMEM;
  67         memcpy(full_name, XATTR_TRUSTED_PREFIX, prefix_len);
  68         memcpy(full_name + prefix_len, name, name_len);
  69         full_name[prefix_len + name_len] = '\0';
  70
  71         retval = v9fs_xattr_set(dentry, full_name, value, size, flags);
  72         kfree(full_name);
  73         return retval;
  74 }
  75
  76 struct xattr_handler v9fs_xattr_trusted_handler = {
  77         .prefix = XATTR_TRUSTED_PREFIX,
  78         .get    = v9fs_xattr_trusted_get,
  79         .set    = v9fs_xattr_trusted_set,
  80 };