Merge branch 'fixes-davem' of master.kernel.org:/pub/scm/linux/kernel/git/linville...
[linux-2.6] / 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_IP6_LOCAL_IN) | (1 << NF_IP6_FORWARD) | (1 << NF_IP6_LOCAL_OUT))
21
22 static struct
23 {
24         struct ip6t_replace repl;
25         struct ip6t_standard entries[3];
26         struct ip6t_error term;
27 } initial_table __initdata = {
28         .repl = {
29                 .name = "filter",
30                 .valid_hooks = FILTER_VALID_HOOKS,
31                 .num_entries = 4,
32                 .size = sizeof(struct ip6t_standard) * 3 + sizeof(struct ip6t_error),
33                 .hook_entry = {
34                         [NF_IP6_LOCAL_IN] = 0,
35                         [NF_IP6_FORWARD] = sizeof(struct ip6t_standard),
36                         [NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 2
37                 },
38                 .underflow = {
39                         [NF_IP6_LOCAL_IN] = 0,
40                         [NF_IP6_FORWARD] = sizeof(struct ip6t_standard),
41                         [NF_IP6_LOCAL_OUT] = sizeof(struct ip6t_standard) * 2
42                 },
43         },
44         .entries = {
45                 IP6T_STANDARD_INIT(NF_ACCEPT),  /* LOCAL_IN */
46                 IP6T_STANDARD_INIT(NF_ACCEPT),  /* FORWARD */
47                 IP6T_STANDARD_INIT(NF_ACCEPT),  /* LOCAL_OUT */
48         },
49         .term = IP6T_ERROR_INIT,                /* ERROR */
50 };
51
52 static struct xt_table packet_filter = {
53         .name           = "filter",
54         .valid_hooks    = FILTER_VALID_HOOKS,
55         .lock           = RW_LOCK_UNLOCKED,
56         .me             = THIS_MODULE,
57         .af             = AF_INET6,
58 };
59
60 /* The work comes in here from netfilter.c. */
61 static unsigned int
62 ip6t_hook(unsigned int hook,
63          struct sk_buff *skb,
64          const struct net_device *in,
65          const struct net_device *out,
66          int (*okfn)(struct sk_buff *))
67 {
68         return ip6t_do_table(skb, hook, in, out, &packet_filter);
69 }
70
71 static unsigned int
72 ip6t_local_out_hook(unsigned int hook,
73                    struct sk_buff *skb,
74                    const struct net_device *in,
75                    const struct net_device *out,
76                    int (*okfn)(struct sk_buff *))
77 {
78 #if 0
79         /* root is playing with raw sockets. */
80         if (skb->len < sizeof(struct iphdr)
81             || ip_hdrlen(skb) < sizeof(struct iphdr)) {
82                 if (net_ratelimit())
83                         printk("ip6t_hook: happy cracking.\n");
84                 return NF_ACCEPT;
85         }
86 #endif
87
88         return ip6t_do_table(skb, hook, in, out, &packet_filter);
89 }
90
91 static struct nf_hook_ops ip6t_ops[] = {
92         {
93                 .hook           = ip6t_hook,
94                 .owner          = THIS_MODULE,
95                 .pf             = PF_INET6,
96                 .hooknum        = NF_IP6_LOCAL_IN,
97                 .priority       = NF_IP6_PRI_FILTER,
98         },
99         {
100                 .hook           = ip6t_hook,
101                 .owner          = THIS_MODULE,
102                 .pf             = PF_INET6,
103                 .hooknum        = NF_IP6_FORWARD,
104                 .priority       = NF_IP6_PRI_FILTER,
105         },
106         {
107                 .hook           = ip6t_local_out_hook,
108                 .owner          = THIS_MODULE,
109                 .pf             = PF_INET6,
110                 .hooknum        = NF_IP6_LOCAL_OUT,
111                 .priority       = NF_IP6_PRI_FILTER,
112         },
113 };
114
115 /* Default to forward because I got too much mail already. */
116 static int forward = NF_ACCEPT;
117 module_param(forward, bool, 0000);
118
119 static int __init ip6table_filter_init(void)
120 {
121         int ret;
122
123         if (forward < 0 || forward > NF_MAX_VERDICT) {
124                 printk("iptables forward must be 0 or 1\n");
125                 return -EINVAL;
126         }
127
128         /* Entry 1 is the FORWARD hook */
129         initial_table.entries[1].target.verdict = -forward - 1;
130
131         /* Register table */
132         ret = ip6t_register_table(&packet_filter, &initial_table.repl);
133         if (ret < 0)
134                 return ret;
135
136         /* Register hooks */
137         ret = nf_register_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
138         if (ret < 0)
139                 goto cleanup_table;
140
141         return ret;
142
143  cleanup_table:
144         ip6t_unregister_table(&packet_filter);
145         return ret;
146 }
147
148 static void __exit ip6table_filter_fini(void)
149 {
150         nf_unregister_hooks(ip6t_ops, ARRAY_SIZE(ip6t_ops));
151         ip6t_unregister_table(&packet_filter);
152 }
153
154 module_init(ip6table_filter_init);
155 module_exit(ip6table_filter_fini);