netfilter: xtables: use xt_table for hook instantiation
[linux-2.6.git] / net / ipv4 / netfilter / iptable_raw.c
1 /*
2  * 'raw' table, which is the very first hooked in at PRE_ROUTING and LOCAL_OUT .
3  *
4  * Copyright (C) 2003 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
5  */
6 #include <linux/module.h>
7 #include <linux/netfilter_ipv4/ip_tables.h>
8 #include <net/ip.h>
9
10 #define RAW_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_OUT))
11
12 static const struct
13 {
14         struct ipt_replace repl;
15         struct ipt_standard entries[2];
16         struct ipt_error term;
17 } initial_table __net_initdata = {
18         .repl = {
19                 .name = "raw",
20                 .valid_hooks = RAW_VALID_HOOKS,
21                 .num_entries = 3,
22                 .size = sizeof(struct ipt_standard) * 2 + sizeof(struct ipt_error),
23                 .hook_entry = {
24                         [NF_INET_PRE_ROUTING] = 0,
25                         [NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard)
26                 },
27                 .underflow = {
28                         [NF_INET_PRE_ROUTING] = 0,
29                         [NF_INET_LOCAL_OUT]  = sizeof(struct ipt_standard)
30                 },
31         },
32         .entries = {
33                 IPT_STANDARD_INIT(NF_ACCEPT),   /* PRE_ROUTING */
34                 IPT_STANDARD_INIT(NF_ACCEPT),   /* LOCAL_OUT */
35         },
36         .term = IPT_ERROR_INIT,                 /* ERROR */
37 };
38
39 static const struct xt_table packet_raw = {
40         .name = "raw",
41         .valid_hooks =  RAW_VALID_HOOKS,
42         .me = THIS_MODULE,
43         .af = NFPROTO_IPV4,
44         .priority = NF_IP_PRI_RAW,
45 };
46
47 /* The work comes in here from netfilter.c. */
48 static unsigned int
49 iptable_raw_hook(unsigned int hook, struct sk_buff *skb,
50                  const struct net_device *in, const struct net_device *out,
51                  int (*okfn)(struct sk_buff *))
52 {
53         const struct net *net;
54
55         if (hook == NF_INET_LOCAL_OUT && 
56             (skb->len < sizeof(struct iphdr) ||
57              ip_hdrlen(skb) < sizeof(struct iphdr)))
58                 /* root is playing with raw sockets. */
59                 return NF_ACCEPT;
60
61         net = dev_net((in != NULL) ? in : out);
62         return ipt_do_table(skb, hook, in, out, net->ipv4.iptable_raw);
63 }
64
65 static struct nf_hook_ops *rawtable_ops __read_mostly;
66
67 static int __net_init iptable_raw_net_init(struct net *net)
68 {
69         /* Register table */
70         net->ipv4.iptable_raw =
71                 ipt_register_table(net, &packet_raw, &initial_table.repl);
72         if (IS_ERR(net->ipv4.iptable_raw))
73                 return PTR_ERR(net->ipv4.iptable_raw);
74         return 0;
75 }
76
77 static void __net_exit iptable_raw_net_exit(struct net *net)
78 {
79         ipt_unregister_table(net, net->ipv4.iptable_raw);
80 }
81
82 static struct pernet_operations iptable_raw_net_ops = {
83         .init = iptable_raw_net_init,
84         .exit = iptable_raw_net_exit,
85 };
86
87 static int __init iptable_raw_init(void)
88 {
89         int ret;
90
91         ret = register_pernet_subsys(&iptable_raw_net_ops);
92         if (ret < 0)
93                 return ret;
94
95         /* Register hooks */
96         rawtable_ops = xt_hook_link(&packet_raw, iptable_raw_hook);
97         if (IS_ERR(rawtable_ops)) {
98                 ret = PTR_ERR(rawtable_ops);
99                 goto cleanup_table;
100         }
101
102         return ret;
103
104  cleanup_table:
105         unregister_pernet_subsys(&iptable_raw_net_ops);
106         return ret;
107 }
108
109 static void __exit iptable_raw_fini(void)
110 {
111         xt_hook_unlink(&packet_raw, rawtable_ops);
112         unregister_pernet_subsys(&iptable_raw_net_ops);
113 }
114
115 module_init(iptable_raw_init);
116 module_exit(iptable_raw_fini);
117 MODULE_LICENSE("GPL");