// SPDX-License-Identifier: GPL-2.0-only
/*
* 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/skbuff.h>
#include <uapi/linux/netfilter_bridge/ebt_802_3.h>
static struct ebt_802_3_hdr *ebt_802_3_hdr(const struct sk_buff *skb)
{
return (struct ebt_802_3_hdr *)skb_mac_header(skb);
}
static bool
ebt_802_3_mt(const struct sk_buff *skb, struct xt_action_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 (NF_INVF(info, EBT_802_3_SAP, info->sap != hdr->llc.ui.ssap))
return false;
if (NF_INVF(info, EBT_802_3_SAP, info->sap != hdr->llc.ui.dsap))
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 (NF_INVF(info, EBT_802_3_TYPE, info->type != type))
return false;
}
return true;
}
static int 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 -EINVAL;
return 0;
}
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 = 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");