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/*
* Filtering ARP tables module.
*
* Copyright (C) 2002 David S. Miller (davem@redhat.com)
*
*/
#include <linux/module.h>
#include <linux/netfilter_arp/arp_tables.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
MODULE_DESCRIPTION("arptables filter table");
#define FILTER_VALID_HOOKS ((1 << NF_ARP_IN) | (1 << NF_ARP_OUT) | \
(1 << NF_ARP_FORWARD))
static struct
{
struct arpt_replace repl;
struct arpt_standard entries[3];
struct arpt_error term;
} initial_table __net_initdata = {
.repl = {
.name = "filter",
.valid_hooks = FILTER_VALID_HOOKS,
.num_entries = 4,
.size = sizeof(struct arpt_standard) * 3 + sizeof(struct arpt_error),
.hook_entry = {
[NF_ARP_IN] = 0,
[NF_ARP_OUT] = sizeof(struct arpt_standard),
[NF_ARP_FORWARD] = 2 * sizeof(struct arpt_standard),
},
.underflow = {
[NF_ARP_IN] = 0,
[NF_ARP_OUT] = sizeof(struct arpt_standard),
[NF_ARP_FORWARD] = 2 * sizeof(struct arpt_standard),
},
},
.entries = {
ARPT_STANDARD_INIT(NF_ACCEPT), /* ARP_IN */
ARPT_STANDARD_INIT(NF_ACCEPT), /* ARP_OUT */
ARPT_STANDARD_INIT(NF_ACCEPT), /* ARP_FORWARD */
},
.term = ARPT_ERROR_INIT,
};
static struct xt_table packet_filter = {
.name = "filter",
.valid_hooks = FILTER_VALID_HOOKS,
.me = THIS_MODULE,
.af = NFPROTO_ARP,
};
/* The work comes in here from netfilter.c */
static unsigned int arpt_in_hook(unsigned int hook,
struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
return arpt_do_table(skb, hook, in, out,
dev_net(in)->ipv4.arptable_filter);
}
static unsigned int arpt_out_hook(unsigned int hook,
struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
return arpt_do_table(skb, hook, in, out,
dev_net(out)->ipv4.arptable_filter);
}
static struct nf_hook_ops arpt_ops[] __read_mostly = {
{
.hook = arpt_in_hook,
.owner = THIS_MODULE,
.pf = NFPROTO_ARP,
.hooknum = NF_ARP_IN,
.priority = NF_IP_PRI_FILTER,
},
{
.hook = arpt_out_hook,
.owner = THIS_MODULE,
.pf = NFPROTO_ARP,
.hooknum = NF_ARP_OUT,
.priority = NF_IP_PRI_FILTER,
},
{
.hook = arpt_in_hook,
.owner = THIS_MODULE,
.pf = NFPROTO_ARP,
.hooknum = NF_ARP_FORWARD,
.priority = NF_IP_PRI_FILTER,
},
};
static int __net_init arptable_filter_net_init(struct net *net)
{
/* Register table */
net->ipv4.arptable_filter =
arpt_register_table(net, &packet_filter, &initial_table.repl);
if (IS_ERR(net->ipv4.arptable_filter))
return PTR_ERR(net->ipv4.arptable_filter);
return 0;
}
static void __net_exit arptable_filter_net_exit(struct net *net)
{
arpt_unregister_table(net->ipv4.arptable_filter);
}
static struct pernet_operations arptable_filter_net_ops = {
.init = arptable_filter_net_init,
.exit = arptable_filter_net_exit,
};
static int __init arptable_filter_init(void)
{
int ret;
ret = register_pernet_subsys(&arptable_filter_net_ops);
if (ret < 0)
return ret;
ret = nf_register_hooks(arpt_ops, ARRAY_SIZE(arpt_ops));
if (ret < 0)
goto cleanup_table;
return ret;
cleanup_table:
unregister_pernet_subsys(&arptable_filter_net_ops);
return ret;
}
static void __exit arptable_filter_fini(void)
{
nf_unregister_hooks(arpt_ops, ARRAY_SIZE(arpt_ops));
unregister_pernet_subsys(&arptable_filter_net_ops);
}
module_init(arptable_filter_init);
module_exit(arptable_filter_fini);
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