101 lines
2.3 KiB
C
101 lines
2.3 KiB
C
/*
|
|
* '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 <linux/slab.h>
|
|
#include <net/ip.h>
|
|
|
|
#define RAW_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_OUT))
|
|
|
|
static int __net_init iptable_raw_table_init(struct net *net);
|
|
|
|
static const struct xt_table packet_raw = {
|
|
.name = "raw",
|
|
.valid_hooks = RAW_VALID_HOOKS,
|
|
.me = THIS_MODULE,
|
|
.af = NFPROTO_IPV4,
|
|
.priority = NF_IP_PRI_RAW,
|
|
.table_init = iptable_raw_table_init,
|
|
};
|
|
|
|
/* The work comes in here from netfilter.c. */
|
|
static unsigned int
|
|
iptable_raw_hook(void *priv, struct sk_buff *skb,
|
|
const struct nf_hook_state *state)
|
|
{
|
|
if (state->hook == NF_INET_LOCAL_OUT &&
|
|
(skb->len < sizeof(struct iphdr) ||
|
|
ip_hdrlen(skb) < sizeof(struct iphdr)))
|
|
/* root is playing with raw sockets. */
|
|
return NF_ACCEPT;
|
|
|
|
return ipt_do_table(skb, state, state->net->ipv4.iptable_raw);
|
|
}
|
|
|
|
static struct nf_hook_ops *rawtable_ops __read_mostly;
|
|
|
|
static int __net_init iptable_raw_table_init(struct net *net)
|
|
{
|
|
struct ipt_replace *repl;
|
|
int ret;
|
|
|
|
if (net->ipv4.iptable_raw)
|
|
return 0;
|
|
|
|
repl = ipt_alloc_initial_table(&packet_raw);
|
|
if (repl == NULL)
|
|
return -ENOMEM;
|
|
ret = ipt_register_table(net, &packet_raw, repl, rawtable_ops,
|
|
&net->ipv4.iptable_raw);
|
|
kfree(repl);
|
|
return ret;
|
|
}
|
|
|
|
static void __net_exit iptable_raw_net_exit(struct net *net)
|
|
{
|
|
if (!net->ipv4.iptable_raw)
|
|
return;
|
|
ipt_unregister_table(net, net->ipv4.iptable_raw, rawtable_ops);
|
|
net->ipv4.iptable_raw = NULL;
|
|
}
|
|
|
|
static struct pernet_operations iptable_raw_net_ops = {
|
|
.exit = iptable_raw_net_exit,
|
|
};
|
|
|
|
static int __init iptable_raw_init(void)
|
|
{
|
|
int ret;
|
|
|
|
rawtable_ops = xt_hook_ops_alloc(&packet_raw, iptable_raw_hook);
|
|
if (IS_ERR(rawtable_ops))
|
|
return PTR_ERR(rawtable_ops);
|
|
|
|
ret = register_pernet_subsys(&iptable_raw_net_ops);
|
|
if (ret < 0) {
|
|
kfree(rawtable_ops);
|
|
return ret;
|
|
}
|
|
|
|
ret = iptable_raw_table_init(&init_net);
|
|
if (ret) {
|
|
unregister_pernet_subsys(&iptable_raw_net_ops);
|
|
kfree(rawtable_ops);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void __exit iptable_raw_fini(void)
|
|
{
|
|
unregister_pernet_subsys(&iptable_raw_net_ops);
|
|
kfree(rawtable_ops);
|
|
}
|
|
|
|
module_init(iptable_raw_init);
|
|
module_exit(iptable_raw_fini);
|
|
MODULE_LICENSE("GPL");
|