root/fs/ext4/xattr_trusted.c

DEFINITIONS

1. ext4_xattr_trusted_list
2. ext4_xattr_trusted_get
3. ext4_xattr_trusted_set

/*
 * linux/fs/ext4/xattr_trusted.c
 * Handler for trusted extended attributes.
 *
 * Copyright (C) 2003 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
 */

#include <linux/module.h>
#include <linux/string.h>
#include <linux/capability.h>
#include <linux/fs.h>
#include "ext4_jbd2.h"
#include "ext4.h"
#include "xattr.h"

static size_t
ext4_xattr_trusted_list(struct inode *inode, char *list, size_t list_size,
                        const char *name, size_t name_len)
{
        const size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN;
        const size_t total_len = prefix_len + name_len + 1;

        if (!capable(CAP_SYS_ADMIN))
                return 0;

        if (list && total_len <= list_size) {
                memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
                memcpy(list+prefix_len, name, name_len);
                list[prefix_len + name_len] = '\0';
        }
        return total_len;
}

static int
ext4_xattr_trusted_get(struct inode *inode, const char *name,
                       void *buffer, size_t size)
{
        if (strcmp(name, "") == 0)
                return -EINVAL;
        return ext4_xattr_get(inode, EXT4_XATTR_INDEX_TRUSTED, name,
                              buffer, size);
}

static int
ext4_xattr_trusted_set(struct inode *inode, const char *name,
                       const void *value, size_t size, int flags)
{
        if (strcmp(name, "") == 0)
                return -EINVAL;
        return ext4_xattr_set(inode, EXT4_XATTR_INDEX_TRUSTED, name,
                              value, size, flags);
}

struct xattr_handler ext4_xattr_trusted_handler = {
        .prefix = XATTR_TRUSTED_PREFIX,
        .list   = ext4_xattr_trusted_list,
        .get    = ext4_xattr_trusted_get,
        .set    = ext4_xattr_trusted_set,
};