root/net/bridge/netfilter/ebt_802_3.c

DEFINITIONS

1. ebt_802_3_mt
2. ebt_802_3_mt_check
3. ebt_802_3_init
4. ebt_802_3_fini

/*
 * 802_3
 *
 * Author:
 * Chris Vitale csv@bluetail.com
 *
 * May 2003
 *
 */
#include <linux/module.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_bridge/ebtables.h>
#include <linux/netfilter_bridge/ebt_802_3.h>

static bool
ebt_802_3_mt(const struct sk_buff *skb, const struct xt_match_param *par)
{
        const struct ebt_802_3_info *info = par->matchinfo;
        const struct ebt_802_3_hdr *hdr = ebt_802_3_hdr(skb);
        __be16 type = hdr->llc.ui.ctrl & IS_UI ? hdr->llc.ui.type : hdr->llc.ni.type;

        if (info->bitmask & EBT_802_3_SAP) {
                if (FWINV(info->sap != hdr->llc.ui.ssap, EBT_802_3_SAP))
                        return false;
                if (FWINV(info->sap != hdr->llc.ui.dsap, EBT_802_3_SAP))
                        return false;
        }

        if (info->bitmask & EBT_802_3_TYPE) {
                if (!(hdr->llc.ui.dsap == CHECK_TYPE && hdr->llc.ui.ssap == CHECK_TYPE))
                        return false;
                if (FWINV(info->type != type, EBT_802_3_TYPE))
                        return false;
        }

        return true;
}

static bool ebt_802_3_mt_check(const struct xt_mtchk_param *par)
{
        const struct ebt_802_3_info *info = par->matchinfo;

        if (info->bitmask & ~EBT_802_3_MASK || info->invflags & ~EBT_802_3_MASK)
                return false;

        return true;
}

static struct xt_match ebt_802_3_mt_reg __read_mostly = {
        .name           = "802_3",
        .revision       = 0,
        .family         = NFPROTO_BRIDGE,
        .match          = ebt_802_3_mt,
        .checkentry     = ebt_802_3_mt_check,
        .matchsize      = XT_ALIGN(sizeof(struct ebt_802_3_info)),
        .me             = THIS_MODULE,
};

static int __init ebt_802_3_init(void)
{
        return xt_register_match(&ebt_802_3_mt_reg);
}

static void __exit ebt_802_3_fini(void)
{
        xt_unregister_match(&ebt_802_3_mt_reg);
}

module_init(ebt_802_3_init);
module_exit(ebt_802_3_fini);
MODULE_DESCRIPTION("Ebtables: DSAP/SSAP field and SNAP type matching");
MODULE_LICENSE("GPL");