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 <linux/slab.h>
9#include <net/ip.h>
10
11#define RAW_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_OUT))
12
13static const struct xt_table packet_raw = {
14	.name = "raw",
15	.valid_hooks =  RAW_VALID_HOOKS,
16	.me = THIS_MODULE,
17	.af = NFPROTO_IPV4,
18	.priority = NF_IP_PRI_RAW,
19};
20
21/* The work comes in here from netfilter.c. */
22static unsigned int
23iptable_raw_hook(const struct nf_hook_ops *ops, struct sk_buff *skb,
24		 const struct nf_hook_state *state)
25{
26	const struct net *net;
27
28	if (ops->hooknum == NF_INET_LOCAL_OUT &&
29	    (skb->len < sizeof(struct iphdr) ||
30	     ip_hdrlen(skb) < sizeof(struct iphdr)))
31		/* root is playing with raw sockets. */
32		return NF_ACCEPT;
33
34	net = dev_net(state->in ? state->in : state->out);
35	return ipt_do_table(skb, ops->hooknum, state, net->ipv4.iptable_raw);
36}
37
38static struct nf_hook_ops *rawtable_ops __read_mostly;
39
40static int __net_init iptable_raw_net_init(struct net *net)
41{
42	struct ipt_replace *repl;
43
44	repl = ipt_alloc_initial_table(&packet_raw);
45	if (repl == NULL)
46		return -ENOMEM;
47	net->ipv4.iptable_raw =
48		ipt_register_table(net, &packet_raw, repl);
49	kfree(repl);
50	return PTR_ERR_OR_ZERO(net->ipv4.iptable_raw);
51}
52
53static void __net_exit iptable_raw_net_exit(struct net *net)
54{
55	ipt_unregister_table(net, net->ipv4.iptable_raw);
56}
57
58static struct pernet_operations iptable_raw_net_ops = {
59	.init = iptable_raw_net_init,
60	.exit = iptable_raw_net_exit,
61};
62
63static int __init iptable_raw_init(void)
64{
65	int ret;
66
67	ret = register_pernet_subsys(&iptable_raw_net_ops);
68	if (ret < 0)
69		return ret;
70
71	/* Register hooks */
72	rawtable_ops = xt_hook_link(&packet_raw, iptable_raw_hook);
73	if (IS_ERR(rawtable_ops)) {
74		ret = PTR_ERR(rawtable_ops);
75		unregister_pernet_subsys(&iptable_raw_net_ops);
76	}
77
78	return ret;
79}
80
81static void __exit iptable_raw_fini(void)
82{
83	xt_hook_unlink(&packet_raw, rawtable_ops);
84	unregister_pernet_subsys(&iptable_raw_net_ops);
85}
86
87module_init(iptable_raw_init);
88module_exit(iptable_raw_fini);
89MODULE_LICENSE("GPL");
90