xt_mark.c

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/*
 *  xt_mark - Netfilter module to match NFMARK value
 *
 *  (C) 1999-2001 Marc Boucher <[email protected]>
 *  Copyright © CC Computer Consultants GmbH, 2007 - 2008
 *  Jan Engelhardt <[email protected]>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/skbuff.h>

#include <linux/netfilter/xt_mark.h>
#include <linux/netfilter/x_tables.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marc Boucher <[email protected]>");
MODULE_DESCRIPTION("Xtables: packet mark operations");
MODULE_ALIAS("ipt_mark");
MODULE_ALIAS("ip6t_mark");
MODULE_ALIAS("ipt_MARK");
MODULE_ALIAS("ip6t_MARK");

static unsigned int
mark_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
    const struct xt_mark_tginfo2 *info = par->targinfo;

    skb->mark = (skb->mark & ~info->mask) ^ info->mark;
    return XT_CONTINUE;
}

static bool
mark_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
    const struct xt_mark_mtinfo1 *info = par->matchinfo;

    return ((skb->mark & info->mask) == info->mark) ^ info->invert;
}

static struct xt_target mark_tg_reg __read_mostly = {
    .name           = "MARK",
    .revision       = 2,
    .family         = NFPROTO_UNSPEC,
    .target         = mark_tg,
    .targetsize     = sizeof(struct xt_mark_tginfo2),
    .me             = THIS_MODULE,
};

static struct xt_match mark_mt_reg __read_mostly = {
    .name           = "mark",
    .revision       = 1,
    .family         = NFPROTO_UNSPEC,
    .match          = mark_mt,
    .matchsize      = sizeof(struct xt_mark_mtinfo1),
    .me             = THIS_MODULE,
};

static int __init mark_mt_init(void)
{
    int ret;

    ret = xt_register_target(&mark_tg_reg);
    if (ret < 0)
        return ret;
    ret = xt_register_match(&mark_mt_reg);
    if (ret < 0) {
        xt_unregister_target(&mark_tg_reg);
        return ret;
    }
    return 0;
}

static void __exit mark_mt_exit(void)
{
    xt_unregister_match(&mark_mt_reg);
    xt_unregister_target(&mark_tg_reg);
}

module_init(mark_mt_init);
module_exit(mark_mt_exit);