1 // SPDX-License-Identifier: GPL-2.0-only
3 * Filtering ARP tables module.
5 * Copyright (C) 2002 David S. Miller (davem@redhat.com)
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>
14 MODULE_LICENSE("GPL");
15 MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
16 MODULE_DESCRIPTION("arptables filter table");
18 #define FILTER_VALID_HOOKS ((1 << NF_ARP_IN) | (1 << NF_ARP_OUT) | \
19 (1 << NF_ARP_FORWARD))
21 static const struct xt_table packet_filter = {
23 .valid_hooks = FILTER_VALID_HOOKS,
26 .priority = NF_IP_PRI_FILTER,
29 static struct nf_hook_ops *arpfilter_ops __read_mostly;
31 static int arptable_filter_table_init(struct net *net)
33 struct arpt_replace *repl;
36 repl = arpt_alloc_initial_table(&packet_filter);
39 err = arpt_register_table(net, &packet_filter, repl, arpfilter_ops);
44 static void __net_exit arptable_filter_net_pre_exit(struct net *net)
46 arpt_unregister_table_pre_exit(net, "filter");
49 static void __net_exit arptable_filter_net_exit(struct net *net)
51 arpt_unregister_table(net, "filter");
54 static struct pernet_operations arptable_filter_net_ops = {
55 .exit = arptable_filter_net_exit,
56 .pre_exit = arptable_filter_net_pre_exit,
59 static int __init arptable_filter_init(void)
61 int ret = xt_register_template(&packet_filter,
62 arptable_filter_table_init);
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);
73 ret = register_pernet_subsys(&arptable_filter_net_ops);
75 xt_unregister_template(&packet_filter);
83 static void __exit arptable_filter_fini(void)
85 unregister_pernet_subsys(&arptable_filter_net_ops);
86 xt_unregister_template(&packet_filter);
90 module_init(arptable_filter_init);
91 module_exit(arptable_filter_fini);