security.c

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/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2006  NEC Corporation
 *
 * Created by KaiGai Kohei <[email protected]>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/time.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/crc32.h>
#include <linux/jffs2.h>
#include <linux/xattr.h>
#include <linux/mtd/mtd.h>
#include <linux/security.h>
#include "nodelist.h"

/* ---- Initial Security Label(s) Attachment callback --- */
static int jffs2_initxattrs(struct inode *inode,
                const struct xattr *xattr_array, void *fs_info)
{
    const struct xattr *xattr;
    int err = 0;

    for (xattr = xattr_array; xattr->name != NULL; xattr++) {
        err = do_jffs2_setxattr(inode, JFFS2_XPREFIX_SECURITY,
                    xattr->name, xattr->value,
                    xattr->value_len, 0);
        if (err < 0)
            break;
    }
    return err;
}

/* ---- Initial Security Label(s) Attachment ----------- */
int jffs2_init_security(struct inode *inode, struct inode *dir,
            const struct qstr *qstr)
{
    return security_inode_init_security(inode, dir, qstr,
                        &jffs2_initxattrs, NULL);
}

/* ---- XATTR Handler for "security.*" ----------------- */
static int jffs2_security_getxattr(struct dentry *dentry, const char *name,
                   void *buffer, size_t size, int type)
{
    if (!strcmp(name, ""))
        return -EINVAL;

    return do_jffs2_getxattr(dentry->d_inode, JFFS2_XPREFIX_SECURITY,
                 name, buffer, size);
}

static int jffs2_security_setxattr(struct dentry *dentry, const char *name,
        const void *buffer, size_t size, int flags, int type)
{
    if (!strcmp(name, ""))
        return -EINVAL;

    return do_jffs2_setxattr(dentry->d_inode, JFFS2_XPREFIX_SECURITY,
                 name, buffer, size, flags);
}

static size_t jffs2_security_listxattr(struct dentry *dentry, char *list,
        size_t list_size, const char *name, size_t name_len, int type)
{
    size_t retlen = XATTR_SECURITY_PREFIX_LEN + name_len + 1;

    if (list && retlen <= list_size) {
        strcpy(list, XATTR_SECURITY_PREFIX);
        strcpy(list + XATTR_SECURITY_PREFIX_LEN, name);
    }

    return retlen;
}

const struct xattr_handler jffs2_security_xattr_handler = {
    .prefix = XATTR_SECURITY_PREFIX,
    .list = jffs2_security_listxattr,
    .set = jffs2_security_setxattr,
    .get = jffs2_security_getxattr
};