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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))
/* Standard entry. */
struct arpt_standard
{
struct arpt_entry entry;
struct arpt_standard_target target;
};
struct arpt_error_target
{
struct arpt_entry_target target;
char errorname[ARPT_FUNCTION_MAXNAMELEN];
};
struct arpt_error
{
struct arpt_entry entry;
struct arpt_error_target target;
};
static struct
{
struct arpt_replace repl;
struct arpt_standard entries[3];
struct arpt_error term;
} initial_table __initdata
= { { "filter", FILTER_VALID_HOOKS, 4,
sizeof(struct arpt_standard) * 3 + sizeof(struct arpt_error),
{ [NF_ARP_IN] = 0,
[NF_ARP_OUT] = sizeof(struct arpt_standard),
[NF_ARP_FORWARD] = 2 * sizeof(struct arpt_standard), },
{ [NF_ARP_IN] = 0,
[NF_ARP_OUT] = sizeof(struct arpt_standard),
[NF_ARP_FORWARD] = 2 * sizeof(struct arpt_standard), },
0, NULL, { } },
{
/* ARP_IN */
{
{
{
{ 0 }, { 0 }, { 0 }, { 0 },
0, 0,
{ { 0, }, { 0, } },
{ { 0, }, { 0, } },
0, 0,
0, 0,
0, 0,
"", "", { 0 }, { 0 },
0, 0
},
sizeof(struct arpt_entry),
sizeof(struct arpt_standard),
0,
{ 0, 0 }, { } },
{ { { { ARPT_ALIGN(sizeof(struct arpt_standard_target)), "" } }, { } },
-NF_ACCEPT - 1 }
},
/* ARP_OUT */
{
{
{
{ 0 }, { 0 }, { 0 }, { 0 },
0, 0,
{ { 0, }, { 0, } },
{ { 0, }, { 0, } },
0, 0,
0, 0,
0, 0,
"", "", { 0 }, { 0 },
0, 0
},
sizeof(struct arpt_entry),
sizeof(struct arpt_standard),
0,
{ 0, 0 }, { } },
{ { { { ARPT_ALIGN(sizeof(struct arpt_standard_target)), "" } }, { } },
-NF_ACCEPT - 1 }
},
/* ARP_FORWARD */
{
{
{
{ 0 }, { 0 }, { 0 }, { 0 },
0, 0,
{ { 0, }, { 0, } },
{ { 0, }, { 0, } },
0, 0,
0, 0,
0, 0,
"", "", { 0 }, { 0 },
0, 0
},
sizeof(struct arpt_entry),
sizeof(struct arpt_standard),
0,
{ 0, 0 }, { } },
{ { { { ARPT_ALIGN(sizeof(struct arpt_standard_target)), "" } }, { } },
-NF_ACCEPT - 1 }
}
},
/* ERROR */
{
{
{
{ 0 }, { 0 }, { 0 }, { 0 },
0, 0,
{ { 0, }, { 0, } },
{ { 0, }, { 0, } },
0, 0,
0, 0,
0, 0,
"", "", { 0 }, { 0 },
0, 0
},
sizeof(struct arpt_entry),
sizeof(struct arpt_error),
0,
{ 0, 0 }, { } },
{ { { { ARPT_ALIGN(sizeof(struct arpt_error_target)), ARPT_ERROR_TARGET } },
{ } },
"ERROR"
}
}
};
static struct arpt_table packet_filter = {
.name = "filter",
.valid_hooks = FILTER_VALID_HOOKS,
.lock = RW_LOCK_UNLOCKED,
.private = NULL,
.me = THIS_MODULE,
.af = NF_ARP,
};
/* The work comes in here from netfilter.c */
static unsigned int arpt_hook(unsigned int hook,
struct sk_buff **pskb,
const struct net_device *in,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
return arpt_do_table(pskb, hook, in, out, &packet_filter, NULL);
}
static struct nf_hook_ops arpt_ops[] = {
{
.hook = arpt_hook,
.owner = THIS_MODULE,
.pf = NF_ARP,
.hooknum = NF_ARP_IN,
},
{
.hook = arpt_hook,
.owner = THIS_MODULE,
.pf = NF_ARP,
.hooknum = NF_ARP_OUT,
},
{
.hook = arpt_hook,
.owner = THIS_MODULE,
.pf = NF_ARP,
.hooknum = NF_ARP_FORWARD,
},
};
static int __init arptable_filter_init(void)
{
int ret;
/* Register table */
ret = arpt_register_table(&packet_filter, &initial_table.repl);
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:
arpt_unregister_table(&packet_filter);
return ret;
}
static void __exit arptable_filter_fini(void)
{
nf_unregister_hooks(arpt_ops, ARRAY_SIZE(arpt_ops));
arpt_unregister_table(&packet_filter);
}
module_init(arptable_filter_init);
module_exit(arptable_filter_fini);
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