cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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arptable_filter.c (2144B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Filtering ARP tables module.
      4 *
      5 * Copyright (C) 2002 David S. Miller (davem@redhat.com)
      6 *
      7 */
      8
      9#include <linux/module.h>
     10#include <linux/netfilter/x_tables.h>
     11#include <linux/netfilter_arp/arp_tables.h>
     12#include <linux/slab.h>
     13
     14MODULE_LICENSE("GPL");
     15MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
     16MODULE_DESCRIPTION("arptables filter table");
     17
     18#define FILTER_VALID_HOOKS ((1 << NF_ARP_IN) | (1 << NF_ARP_OUT) | \
     19			   (1 << NF_ARP_FORWARD))
     20
     21static const struct xt_table packet_filter = {
     22	.name		= "filter",
     23	.valid_hooks	= FILTER_VALID_HOOKS,
     24	.me		= THIS_MODULE,
     25	.af		= NFPROTO_ARP,
     26	.priority	= NF_IP_PRI_FILTER,
     27};
     28
     29static struct nf_hook_ops *arpfilter_ops __read_mostly;
     30
     31static int arptable_filter_table_init(struct net *net)
     32{
     33	struct arpt_replace *repl;
     34	int err;
     35
     36	repl = arpt_alloc_initial_table(&packet_filter);
     37	if (repl == NULL)
     38		return -ENOMEM;
     39	err = arpt_register_table(net, &packet_filter, repl, arpfilter_ops);
     40	kfree(repl);
     41	return err;
     42}
     43
     44static void __net_exit arptable_filter_net_pre_exit(struct net *net)
     45{
     46	arpt_unregister_table_pre_exit(net, "filter");
     47}
     48
     49static void __net_exit arptable_filter_net_exit(struct net *net)
     50{
     51	arpt_unregister_table(net, "filter");
     52}
     53
     54static struct pernet_operations arptable_filter_net_ops = {
     55	.exit = arptable_filter_net_exit,
     56	.pre_exit = arptable_filter_net_pre_exit,
     57};
     58
     59static int __init arptable_filter_init(void)
     60{
     61	int ret = xt_register_template(&packet_filter,
     62				       arptable_filter_table_init);
     63
     64	if (ret < 0)
     65		return ret;
     66
     67	arpfilter_ops = xt_hook_ops_alloc(&packet_filter, arpt_do_table);
     68	if (IS_ERR(arpfilter_ops)) {
     69		xt_unregister_template(&packet_filter);
     70		return PTR_ERR(arpfilter_ops);
     71	}
     72
     73	ret = register_pernet_subsys(&arptable_filter_net_ops);
     74	if (ret < 0) {
     75		xt_unregister_template(&packet_filter);
     76		kfree(arpfilter_ops);
     77		return ret;
     78	}
     79
     80	return ret;
     81}
     82
     83static void __exit arptable_filter_fini(void)
     84{
     85	unregister_pernet_subsys(&arptable_filter_net_ops);
     86	xt_unregister_template(&packet_filter);
     87	kfree(arpfilter_ops);
     88}
     89
     90module_init(arptable_filter_init);
     91module_exit(arptable_filter_fini);