ebt_mark_m.c

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/*
 *  ebt_mark_m
 *
 *  Authors:
 *  Bart De Schuymer <[email protected]>
 *
 *  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_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_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");