[NETFILTER]: x_tables: return new table from {arp,ip,ip6}t_register_table()
[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 __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 struct xt_table __packet_filter = {
55         .name           = "filter",
56         .valid_hooks    = FILTER_VALID_HOOKS,
57         .lock           = RW_LOCK_UNLOCKED,
58         .me             = THIS_MODULE,
59         .af             = AF_INET6,
60 };
61 static struct xt_table *packet_filter;
62
63 /* The work comes in here from netfilter.c. */
64 static unsigned int
65 ip6t_hook(unsigned int hook,
66          struct sk_buff *skb,
67          const struct net_device *in,
68          const struct net_device *out,
69          int (*okfn)(struct sk_buff *))
70 {
71         return ip6t_do_table(skb, hook, in, out, packet_filter);
72 }
73
74 static unsigned int
75 ip6t_local_out_hook(unsigned int hook,
76                    struct sk_buff *skb,
77                    const struct net_device *in,
78                    const struct net_device *out,
79                    int (*okfn)(struct sk_buff *))
80 {
81 #if 0
82         /* root is playing with raw sockets. */
83         if (skb->len < sizeof(struct iphdr)
84             || ip_hdrlen(skb) < sizeof(struct iphdr)) {
85                 if (net_ratelimit())
86                         printk("ip6t_hook: happy cracking.\n");
87                 return NF_ACCEPT;
88         }
89 #endif
90
91         return ip6t_do_table(skb, hook, in, out, packet_filter);
92 }
93
94 static struct nf_hook_ops ip6t_ops[] __read_mostly = {
95         {
96                 .hook           = ip6t_hook,
97                 .owner          = THIS_MODULE,
98                 .pf             = PF_INET6,
99                 .hooknum        = NF_INET_LOCAL_IN,
100                 .priority       = NF_IP6_PRI_FILTER,
101         },
102         {
103                 .hook           = ip6t_hook,
104                 .owner          = THIS_MODULE,
105                 .pf             = PF_INET6,
106                 .hooknum        = NF_INET_FORWARD,
107                 .priority       = NF_IP6_PRI_FILTER,
108         },
109         {
110                 .hook           = ip6t_local_out_hook,
111                 .owner          = THIS_MODULE,
112                 .pf             = PF_INET6,
113                 .hooknum        = NF_INET_LOCAL_OUT,
114                 .priority       = NF_IP6_PRI_FILTER,
115         },
116 };
117
118 /* Default to forward because I got too much mail already. */
119 static int forward = NF_ACCEPT;
120 module_param(forward, bool, 0000);
121
122 static int __init ip6table_filter_init(void)
123 {
124         int ret;
125
126         if (forward < 0 || forward > NF_MAX_VERDICT) {
127                 printk("iptables forward must be 0 or 1\n");
128                 return -EINVAL;
129         }
130
131         /* Entry 1 is the FORWARD hook */
132         initial_table.entries[1].target.verdict = -forward - 1;
133
134         /* Register table */
135         packet_filter = ip6t_register_table(&__packet_filter, &initial_table.repl);
136         if (IS_ERR(packet_filter))
137                 return PTR_ERR(packet_filter);
138
139         /* Register hooks */
140         ret = nf_register_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
141         if (ret < 0)
142                 goto cleanup_table;
143
144         return ret;
145
146  cleanup_table:
147         ip6t_unregister_table(packet_filter);
148         return ret;
149 }
150
151 static void __exit ip6table_filter_fini(void)
152 {
153         nf_unregister_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
154         ip6t_unregister_table(packet_filter);
155 }
156
157 module_init(ip6table_filter_init);
158 module_exit(ip6table_filter_fini);