netfilter: xtables: use xt_table for hook instantiation
[linux-2.6.git] / net / ipv6 / netfilter / ip6table_filter.c
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
16 MODULE_LICENSE("GPL");
17 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
18 MODULE_DESCRIPTION("ip6tables filter table");
19
20 #define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \
21                             (1 << NF_INET_FORWARD) | \
22                             (1 << NF_INET_LOCAL_OUT))
23
24 static struct
25 {
26         struct ip6t_replace repl;
27         struct ip6t_standard entries[3];
28         struct ip6t_error term;
29 } initial_table __net_initdata = {
30         .repl = {
31                 .name = "filter",
32                 .valid_hooks = FILTER_VALID_HOOKS,
33                 .num_entries = 4,
34                 .size = sizeof(struct ip6t_standard) * 3 + sizeof(struct ip6t_error),
35                 .hook_entry = {
36                         [NF_INET_LOCAL_IN] = 0,
37                         [NF_INET_FORWARD] = sizeof(struct ip6t_standard),
38                         [NF_INET_LOCAL_OUT] = sizeof(struct ip6t_standard) * 2
39                 },
40                 .underflow = {
41                         [NF_INET_LOCAL_IN] = 0,
42                         [NF_INET_FORWARD] = sizeof(struct ip6t_standard),
43                         [NF_INET_LOCAL_OUT] = sizeof(struct ip6t_standard) * 2
44                 },
45         },
46         .entries = {
47                 IP6T_STANDARD_INIT(NF_ACCEPT),  /* LOCAL_IN */
48                 IP6T_STANDARD_INIT(NF_ACCEPT),  /* FORWARD */
49                 IP6T_STANDARD_INIT(NF_ACCEPT),  /* LOCAL_OUT */
50         },
51         .term = IP6T_ERROR_INIT,                /* ERROR */
52 };
53
54 static const struct xt_table packet_filter = {
55         .name           = "filter",
56         .valid_hooks    = FILTER_VALID_HOOKS,
57         .me             = THIS_MODULE,
58         .af             = NFPROTO_IPV6,
59         .priority       = NF_IP6_PRI_FILTER,
60 };
61
62 /* The work comes in here from netfilter.c. */
63 static unsigned int
64 ip6table_filter_hook(unsigned int hook, struct sk_buff *skb,
65                      const struct net_device *in, const struct net_device *out,
66                      int (*okfn)(struct sk_buff *))
67 {
68         const struct net *net = dev_net((in != NULL) ? in : out);
69
70         return ip6t_do_table(skb, hook, in, out, net->ipv6.ip6table_filter);
71 }
72
73 static struct nf_hook_ops *filter_ops __read_mostly;
74
75 /* Default to forward because I got too much mail already. */
76 static int forward = NF_ACCEPT;
77 module_param(forward, bool, 0000);
78
79 static int __net_init ip6table_filter_net_init(struct net *net)
80 {
81         /* Register table */
82         net->ipv6.ip6table_filter =
83                 ip6t_register_table(net, &packet_filter, &initial_table.repl);
84         if (IS_ERR(net->ipv6.ip6table_filter))
85                 return PTR_ERR(net->ipv6.ip6table_filter);
86         return 0;
87 }
88
89 static void __net_exit ip6table_filter_net_exit(struct net *net)
90 {
91         ip6t_unregister_table(net, net->ipv6.ip6table_filter);
92 }
93
94 static struct pernet_operations ip6table_filter_net_ops = {
95         .init = ip6table_filter_net_init,
96         .exit = ip6table_filter_net_exit,
97 };
98
99 static int __init ip6table_filter_init(void)
100 {
101         int ret;
102
103         if (forward < 0 || forward > NF_MAX_VERDICT) {
104                 printk("iptables forward must be 0 or 1\n");
105                 return -EINVAL;
106         }
107
108         /* Entry 1 is the FORWARD hook */
109         initial_table.entries[1].target.verdict = -forward - 1;
110
111         ret = register_pernet_subsys(&ip6table_filter_net_ops);
112         if (ret < 0)
113                 return ret;
114
115         /* Register hooks */
116         filter_ops = xt_hook_link(&packet_filter, ip6table_filter_hook);
117         if (IS_ERR(filter_ops)) {
118                 ret = PTR_ERR(filter_ops);
119                 goto cleanup_table;
120         }
121
122         return ret;
123
124  cleanup_table:
125         unregister_pernet_subsys(&ip6table_filter_net_ops);
126         return ret;
127 }
128
129 static void __exit ip6table_filter_fini(void)
130 {
131         xt_hook_unlink(&packet_filter, filter_ops);
132         unregister_pernet_subsys(&ip6table_filter_net_ops);
133 }
134
135 module_init(ip6table_filter_init);
136 module_exit(ip6table_filter_fini);