1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x.
4 *
5 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
6 * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
7 */
8
9#include <linux/module.h>
10#include <linux/moduleparam.h>
11#include <linux/netfilter_ipv6/ip6_tables.h>
12#include <linux/slab.h>
13
14MODULE_LICENSE("GPL");
15MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
16MODULE_DESCRIPTION("ip6tables filter table");
17
18#define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \
19 (1 << NF_INET_FORWARD) | \
20 (1 << NF_INET_LOCAL_OUT))
21
22static const struct xt_table packet_filter = {
23 .name = "filter",
24 .valid_hooks = FILTER_VALID_HOOKS,
25 .me = THIS_MODULE,
26 .af = NFPROTO_IPV6,
27 .priority = NF_IP6_PRI_FILTER,
28};
29
30static struct nf_hook_ops *filter_ops __read_mostly;
31
32/* Default to forward because I got too much mail already. */
33static bool forward = true;
34module_param(forward, bool, 0000);
35
36static int ip6table_filter_table_init(struct net *net)
37{
38 struct ip6t_replace *repl;
39 int err;
40
41 repl = ip6t_alloc_initial_table(&packet_filter);
42 if (repl == NULL)
43 return -ENOMEM;
44 /* Entry 1 is the FORWARD hook */
45 ((struct ip6t_standard *)repl->entries)[1].target.verdict =
46 forward ? -NF_ACCEPT - 1 : -NF_DROP - 1;
47
48 err = ip6t_register_table(net, table: &packet_filter, repl, ops: filter_ops);
49 kfree(objp: repl);
50 return err;
51}
52
53static int __net_init ip6table_filter_net_init(struct net *net)
54{
55 if (!forward)
56 return ip6table_filter_table_init(net);
57
58 return 0;
59}
60
61static void __net_exit ip6table_filter_net_pre_exit(struct net *net)
62{
63 ip6t_unregister_table_pre_exit(net, name: "filter");
64}
65
66static void __net_exit ip6table_filter_net_exit(struct net *net)
67{
68 ip6t_unregister_table_exit(net, name: "filter");
69}
70
71static struct pernet_operations ip6table_filter_net_ops = {
72 .init = ip6table_filter_net_init,
73 .pre_exit = ip6table_filter_net_pre_exit,
74 .exit = ip6table_filter_net_exit,
75};
76
77static int __init ip6table_filter_init(void)
78{
79 int ret = xt_register_template(t: &packet_filter,
80 table_init: ip6table_filter_table_init);
81
82 if (ret < 0)
83 return ret;
84
85 filter_ops = xt_hook_ops_alloc(&packet_filter, ip6t_do_table);
86 if (IS_ERR(ptr: filter_ops)) {
87 xt_unregister_template(t: &packet_filter);
88 return PTR_ERR(ptr: filter_ops);
89 }
90
91 ret = register_pernet_subsys(&ip6table_filter_net_ops);
92 if (ret < 0) {
93 xt_unregister_template(t: &packet_filter);
94 kfree(objp: filter_ops);
95 return ret;
96 }
97
98 return ret;
99}
100
101static void __exit ip6table_filter_fini(void)
102{
103 unregister_pernet_subsys(&ip6table_filter_net_ops);
104 xt_unregister_template(t: &packet_filter);
105 kfree(objp: filter_ops);
106}
107
108module_init(ip6table_filter_init);
109module_exit(ip6table_filter_fini);
110

source code of linux/net/ipv6/netfilter/ip6table_filter.c