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/*
* '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 __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,
.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, &packet_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) ||
ip_hdrlen(skb) < sizeof(struct iphdr)) {
if (net_ratelimit())
printk("iptable_raw: ignoring short SOCK_RAW "
"packet.\n");
return NF_ACCEPT;
}
return ipt_do_table(skb, hook, in, out, &packet_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 __init iptable_raw_init(void)
{
int ret;
/* Register table */
ret = ipt_register_table(&packet_raw, &initial_table.repl);
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:
ipt_unregister_table(&packet_raw);
return ret;
}
static void __exit iptable_raw_fini(void)
{
nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
ipt_unregister_table(&packet_raw);
}
module_init(iptable_raw_init);
module_exit(iptable_raw_fini);
MODULE_LICENSE("GPL");
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