remarkable-linux/net/bridge/netfilter/ebt_dnat.c
Florian Westphal fc0e3df4f0 netfilter: ebtables: avoid explicit XT_ALIGN() in match/targets
This will cause trouble once CONFIG_COMPAT support is added to ebtables.
xt_compat_*_offset() calculate the kernel/userland structure size delta
using:

XT_ALIGN(size) - COMPAT_XT_ALIGN(size)

If the match/target sizes are aligned at registration time,
delta is always zero.

Should have zero effect for existing systems: xtables uses
XT_ALIGN() whenever it deals with match/target sizes.

Signed-off-by: Florian Westphal <fwestphal@astaro.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-02-15 18:16:26 +01:00

75 lines
1.8 KiB
C

/*
* ebt_dnat
*
* Authors:
* Bart De Schuymer <bdschuym@pandora.be>
*
* June, 2002
*
*/
#include <linux/module.h>
#include <net/sock.h>
#include <linux/netfilter.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_bridge/ebtables.h>
#include <linux/netfilter_bridge/ebt_nat.h>
static unsigned int
ebt_dnat_tg(struct sk_buff *skb, const struct xt_target_param *par)
{
const struct ebt_nat_info *info = par->targinfo;
if (!skb_make_writable(skb, 0))
return EBT_DROP;
memcpy(eth_hdr(skb)->h_dest, info->mac, ETH_ALEN);
return info->target;
}
static bool ebt_dnat_tg_check(const struct xt_tgchk_param *par)
{
const struct ebt_nat_info *info = par->targinfo;
unsigned int hook_mask;
if (BASE_CHAIN && info->target == EBT_RETURN)
return false;
hook_mask = par->hook_mask & ~(1 << NF_BR_NUMHOOKS);
if ((strcmp(par->table, "nat") != 0 ||
(hook_mask & ~((1 << NF_BR_PRE_ROUTING) |
(1 << NF_BR_LOCAL_OUT)))) &&
(strcmp(par->table, "broute") != 0 ||
hook_mask & ~(1 << NF_BR_BROUTING)))
return false;
if (INVALID_TARGET)
return false;
return true;
}
static struct xt_target ebt_dnat_tg_reg __read_mostly = {
.name = "dnat",
.revision = 0,
.family = NFPROTO_BRIDGE,
.hooks = (1 << NF_BR_NUMHOOKS) | (1 << NF_BR_PRE_ROUTING) |
(1 << NF_BR_LOCAL_OUT) | (1 << NF_BR_BROUTING),
.target = ebt_dnat_tg,
.checkentry = ebt_dnat_tg_check,
.targetsize = sizeof(struct ebt_nat_info),
.me = THIS_MODULE,
};
static int __init ebt_dnat_init(void)
{
return xt_register_target(&ebt_dnat_tg_reg);
}
static void __exit ebt_dnat_fini(void)
{
xt_unregister_target(&ebt_dnat_tg_reg);
}
module_init(ebt_dnat_init);
module_exit(ebt_dnat_fini);
MODULE_DESCRIPTION("Ebtables: Destination MAC address translation");
MODULE_LICENSE("GPL");