1 /*
2 * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x.
3 *
4 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
5 * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12 #include <linux/module.h>
13 #include <linux/moduleparam.h>
14 #include <linux/netfilter_ipv6/ip6_tables.h>
15 #include <linux/slab.h>
16
17 MODULE_LICENSE("GPL");
18 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
19 MODULE_DESCRIPTION("ip6tables filter table");
20
21 #define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \
22 (1 << NF_INET_FORWARD) | \
23 (1 << NF_INET_LOCAL_OUT))
24
25 static const struct xt_table packet_filter = {
26 .name = "filter",
27 .valid_hooks = FILTER_VALID_HOOKS,
28 .me = THIS_MODULE,
29 .af = NFPROTO_IPV6,
30 .priority = NF_IP6_PRI_FILTER,
31 };
32
33 /* The work comes in here from netfilter.c. */
34 static unsigned int
ip6table_filter_hook(unsigned int hook,struct sk_buff * skb,const struct net_device * in,const struct net_device * out,int (* okfn)(struct sk_buff *))35 ip6table_filter_hook(unsigned int hook, struct sk_buff *skb,
36 const struct net_device *in, const struct net_device *out,
37 int (*okfn)(struct sk_buff *))
38 {
39 const struct net *net = dev_net((in != NULL) ? in : out);
40
41 return ip6t_do_table(skb, hook, in, out, net->ipv6.ip6table_filter);
42 }
43
44 static struct nf_hook_ops *filter_ops __read_mostly;
45
46 /* Default to forward because I got too much mail already. */
47 static bool forward = NF_ACCEPT;
48 module_param(forward, bool, 0000);
49
ip6table_filter_net_init(struct net * net)50 static int __net_init ip6table_filter_net_init(struct net *net)
51 {
52 struct ip6t_replace *repl;
53
54 repl = ip6t_alloc_initial_table(&packet_filter);
55 if (repl == NULL)
56 return -ENOMEM;
57 /* Entry 1 is the FORWARD hook */
58 ((struct ip6t_standard *)repl->entries)[1].target.verdict =
59 -forward - 1;
60
61 net->ipv6.ip6table_filter =
62 ip6t_register_table(net, &packet_filter, repl);
63 kfree(repl);
64 if (IS_ERR(net->ipv6.ip6table_filter))
65 return PTR_ERR(net->ipv6.ip6table_filter);
66 return 0;
67 }
68
ip6table_filter_net_exit(struct net * net)69 static void __net_exit ip6table_filter_net_exit(struct net *net)
70 {
71 ip6t_unregister_table(net, net->ipv6.ip6table_filter);
72 }
73
74 static struct pernet_operations ip6table_filter_net_ops = {
75 .init = ip6table_filter_net_init,
76 .exit = ip6table_filter_net_exit,
77 };
78
ip6table_filter_init(void)79 static int __init ip6table_filter_init(void)
80 {
81 int ret;
82
83 if (forward < 0 || forward > NF_MAX_VERDICT) {
84 pr_err("iptables forward must be 0 or 1\n");
85 return -EINVAL;
86 }
87
88 ret = register_pernet_subsys(&ip6table_filter_net_ops);
89 if (ret < 0)
90 return ret;
91
92 /* Register hooks */
93 filter_ops = xt_hook_link(&packet_filter, ip6table_filter_hook);
94 if (IS_ERR(filter_ops)) {
95 ret = PTR_ERR(filter_ops);
96 goto cleanup_table;
97 }
98
99 return ret;
100
101 cleanup_table:
102 unregister_pernet_subsys(&ip6table_filter_net_ops);
103 return ret;
104 }
105
ip6table_filter_fini(void)106 static void __exit ip6table_filter_fini(void)
107 {
108 xt_hook_unlink(&packet_filter, filter_ops);
109 unregister_pernet_subsys(&ip6table_filter_net_ops);
110 }
111
112 module_init(ip6table_filter_init);
113 module_exit(ip6table_filter_fini);
114