// SPDX-License-Identifier: GPL-2.0-only
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/*
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* 802_3
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*
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* Author:
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* Chris Vitale csv@bluetail.com
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*
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* May 2003
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*
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*/
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#include <linux/module.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter_bridge/ebtables.h>
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#include <linux/skbuff.h>
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#include <uapi/linux/netfilter_bridge/ebt_802_3.h>
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static struct ebt_802_3_hdr *ebt_802_3_hdr(const struct sk_buff *skb)
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{
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return (struct ebt_802_3_hdr *)skb_mac_header(skb);
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}
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static bool
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ebt_802_3_mt(const struct sk_buff *skb, struct xt_action_param *par)
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{
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const struct ebt_802_3_info *info = par->matchinfo;
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const struct ebt_802_3_hdr *hdr = ebt_802_3_hdr(skb);
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__be16 type = hdr->llc.ui.ctrl & IS_UI ? hdr->llc.ui.type : hdr->llc.ni.type;
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if (info->bitmask & EBT_802_3_SAP) {
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if (NF_INVF(info, EBT_802_3_SAP, info->sap != hdr->llc.ui.ssap))
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return false;
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if (NF_INVF(info, EBT_802_3_SAP, info->sap != hdr->llc.ui.dsap))
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return false;
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}
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if (info->bitmask & EBT_802_3_TYPE) {
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if (!(hdr->llc.ui.dsap == CHECK_TYPE && hdr->llc.ui.ssap == CHECK_TYPE))
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return false;
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if (NF_INVF(info, EBT_802_3_TYPE, info->type != type))
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return false;
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}
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return true;
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}
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static int ebt_802_3_mt_check(const struct xt_mtchk_param *par)
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{
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const struct ebt_802_3_info *info = par->matchinfo;
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if (info->bitmask & ~EBT_802_3_MASK || info->invflags & ~EBT_802_3_MASK)
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return -EINVAL;
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return 0;
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}
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static struct xt_match ebt_802_3_mt_reg __read_mostly = {
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.name = "802_3",
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.revision = 0,
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.family = NFPROTO_BRIDGE,
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.match = ebt_802_3_mt,
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.checkentry = ebt_802_3_mt_check,
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.matchsize = sizeof(struct ebt_802_3_info),
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.me = THIS_MODULE,
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};
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static int __init ebt_802_3_init(void)
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{
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return xt_register_match(&ebt_802_3_mt_reg);
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}
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static void __exit ebt_802_3_fini(void)
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{
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xt_unregister_match(&ebt_802_3_mt_reg);
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}
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module_init(ebt_802_3_init);
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module_exit(ebt_802_3_fini);
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MODULE_DESCRIPTION("Ebtables: DSAP/SSAP field and SNAP type matching");
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MODULE_LICENSE("GPL");
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