// SPDX-License-Identifier: GPL-2.0-only
/*
 *  ebt_mark_m
 *
 *      Authors:
 *      Bart De Schuymer <bdschuym@pandora.be>
 *
 *  July, 2002
 *
 */
#include <linux/module.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_bridge/ebtables.h>
#include <linux/netfilter_bridge/ebt_mark_m.h>

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

        if (info->bitmask & EBT_MARK_OR)
                return !!(skb->mark & info->mask) ^ info->invert;
        return ((skb->mark & info->mask) == info->mark) ^ info->invert;
}

static int ebt_mark_mt_check(const struct xt_mtchk_param *par)
{
        const struct ebt_mark_m_info *info = par->matchinfo;

        if (info->bitmask & ~EBT_MARK_MASK)
                return -EINVAL;
        if ((info->bitmask & EBT_MARK_OR) && (info->bitmask & EBT_MARK_AND))
                return -EINVAL;
        if (!info->bitmask)
                return -EINVAL;
        return 0;
}


#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
struct compat_ebt_mark_m_info {
        compat_ulong_t mark, mask;
        uint8_t invert, bitmask;
};

static void mark_mt_compat_from_user(void *dst, const void *src)
{
        const struct compat_ebt_mark_m_info *user = src;
        struct ebt_mark_m_info *kern = dst;

        kern->mark = user->mark;
        kern->mask = user->mask;
        kern->invert = user->invert;
        kern->bitmask = user->bitmask;
}

static int mark_mt_compat_to_user(void __user *dst, const void *src)
{
        struct compat_ebt_mark_m_info __user *user = dst;
        const struct ebt_mark_m_info *kern = src;

        if (put_user(kern->mark, &user->mark) ||
            put_user(kern->mask, &user->mask) ||
            put_user(kern->invert, &user->invert) ||
            put_user(kern->bitmask, &user->bitmask))
                return -EFAULT;
        return 0;
}
#endif

static struct xt_match ebt_mark_mt_reg __read_mostly = {
        .name           = "mark_m",
        .revision       = 0,
        .family         = NFPROTO_BRIDGE,
        .match          = ebt_mark_mt,
        .checkentry     = ebt_mark_mt_check,
        .matchsize      = sizeof(struct ebt_mark_m_info),
#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
        .compatsize     = sizeof(struct compat_ebt_mark_m_info),
        .compat_from_user = mark_mt_compat_from_user,
        .compat_to_user = mark_mt_compat_to_user,
#endif
        .me             = THIS_MODULE,
};

static int __init ebt_mark_m_init(void)
{
        return xt_register_match(&ebt_mark_mt_reg);
}

static void __exit ebt_mark_m_fini(void)
{
        xt_unregister_match(&ebt_mark_mt_reg);
}

module_init(ebt_mark_m_init);
module_exit(ebt_mark_m_fini);
MODULE_DESCRIPTION("Ebtables: Packet mark match");
MODULE_LICENSE("GPL");