/*

 * 'raw' table, which is the very first hooked in at PRE_ROUTING and LOCAL_OUT .

 *

 * Copyright (C) 2003 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

 */

#include <linux/module.h>

#include <linux/netfilter_ipv4/ip_tables.h>

#include <net/ip.h>

#define RAW_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_OUT))

static struct

{

	struct ipt_replace repl;

	struct ipt_standard entries[2];

	struct ipt_error term;

} initial_table __net_initdata = {

	.repl = {

		.name = "raw",

		.valid_hooks = RAW_VALID_HOOKS,

		.num_entries = 3,

		.size = sizeof(struct ipt_standard) * 2 + sizeof(struct ipt_error),

		.hook_entry = {

			[NF_INET_PRE_ROUTING] = 0,

			[NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard)

		},

		.underflow = {

			[NF_INET_PRE_ROUTING] = 0,

			[NF_INET_LOCAL_OUT]  = sizeof(struct ipt_standard)

		},

	},

	.entries = {

		IPT_STANDARD_INIT(NF_ACCEPT),	/* PRE_ROUTING */

		IPT_STANDARD_INIT(NF_ACCEPT),	/* LOCAL_OUT */

	},

	.term = IPT_ERROR_INIT,			/* ERROR */

};

static struct xt_table packet_raw = {

	.name = "raw",

	.valid_hooks =  RAW_VALID_HOOKS,

	.lock = __RW_LOCK_UNLOCKED(packet_raw.lock),

	.me = THIS_MODULE,

	.af = AF_INET,

};

/* The work comes in here from netfilter.c. */

static unsigned int

ipt_hook(unsigned int hook,

	 struct sk_buff *skb,

	 const struct net_device *in,

	 const struct net_device *out,

	 int (*okfn)(struct sk_buff *))

{

	return ipt_do_table(skb, hook, in, out,

			    dev_net(in)->ipv4.iptable_raw);

}

static unsigned int

ipt_local_hook(unsigned int hook,

	       struct sk_buff *skb,

	       const struct net_device *in,

	       const struct net_device *out,

	       int (*okfn)(struct sk_buff *))

{

	/* root is playing with raw sockets. */

	if (skb->len < sizeof(struct iphdr) ||

		return NF_ACCEPT;

	return ipt_do_table(skb, hook, in, out,

			    dev_net(out)->ipv4.iptable_raw);

}

/* 'raw' is the very first table. */

static struct nf_hook_ops ipt_ops[] __read_mostly = {

	{

		.hook = ipt_hook,

		.pf = PF_INET,

		.hooknum = NF_INET_PRE_ROUTING,

		.priority = NF_IP_PRI_RAW,

		.owner = THIS_MODULE,

	},

	{

		.hook = ipt_local_hook,

		.pf = PF_INET,

		.hooknum = NF_INET_LOCAL_OUT,

		.priority = NF_IP_PRI_RAW,

		.owner = THIS_MODULE,

	},

};

static int __net_init iptable_raw_net_init(struct net *net)

{

	/* Register table */

	net->ipv4.iptable_raw =

		ipt_register_table(net, &packet_raw, &initial_table.repl);

	if (IS_ERR(net->ipv4.iptable_raw))

		return PTR_ERR(net->ipv4.iptable_raw);

	return 0;

}

static void __net_exit iptable_raw_net_exit(struct net *net)

{

	ipt_unregister_table(net->ipv4.iptable_raw);

}

static struct pernet_operations iptable_raw_net_ops = {

	.init = iptable_raw_net_init,

	.exit = iptable_raw_net_exit,

};

static int __init iptable_raw_init(void)

{

	int ret;

	ret = register_pernet_subsys(&iptable_raw_net_ops);

	if (ret < 0)

		return ret;

	/* Register hooks */

	ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));

	if (ret < 0)

		goto cleanup_table;

	return ret;

 cleanup_table:

	unregister_pernet_subsys(&iptable_raw_net_ops);

	return ret;

}

static void __exit iptable_raw_fini(void)

{

	nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));

	unregister_pernet_subsys(&iptable_raw_net_ops);

}

module_init(iptable_raw_init);

module_exit(iptable_raw_fini);

MODULE_LICENSE("GPL");