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// SPDX-License-Identifier: GPL-2.0-only
/*
* ebtable_nat
*
* Authors:
* Bart De Schuymer <bdschuym@pandora.be>
*
* April, 2002
*
*/
#include <linux/netfilter_bridge/ebtables.h>
#include <uapi/linux/netfilter_bridge.h>
#include <linux/module.h>
#define NAT_VALID_HOOKS ((1 << NF_BR_PRE_ROUTING) | (1 << NF_BR_LOCAL_OUT) | \
(1 << NF_BR_POST_ROUTING))
static struct ebt_entries initial_chains[] = {
{
.name = "PREROUTING",
.policy = EBT_ACCEPT,
},
{
.name = "OUTPUT",
.policy = EBT_ACCEPT,
},
{
.name = "POSTROUTING",
.policy = EBT_ACCEPT,
}
};
static struct ebt_replace_kernel initial_table = {
.name = "nat",
.valid_hooks = NAT_VALID_HOOKS,
.entries_size = 3 * sizeof(struct ebt_entries),
.hook_entry = {
[NF_BR_PRE_ROUTING] = &initial_chains[0],
[NF_BR_LOCAL_OUT] = &initial_chains[1],
[NF_BR_POST_ROUTING] = &initial_chains[2],
},
.entries = (char *)initial_chains,
};
static int check(const struct ebt_table_info *info, unsigned int valid_hooks)
{
if (valid_hooks & ~NAT_VALID_HOOKS)
return -EINVAL;
return 0;
}
static const struct ebt_table frame_nat = {
.name = "nat",
.table = &initial_table,
.valid_hooks = NAT_VALID_HOOKS,
.check = check,
.me = THIS_MODULE,
};
static unsigned int
ebt_nat_in(void *priv, struct sk_buff *skb,
const struct nf_hook_state *state)
{
return ebt_do_table(skb, state, state->net->xt.frame_nat);
}
static unsigned int
ebt_nat_out(void *priv, struct sk_buff *skb,
const struct nf_hook_state *state)
{
return ebt_do_table(skb, state, state->net->xt.frame_nat);
}
static const struct nf_hook_ops ebt_ops_nat[] = {
{
.hook = ebt_nat_out,
.pf = NFPROTO_BRIDGE,
.hooknum = NF_BR_LOCAL_OUT,
.priority = NF_BR_PRI_NAT_DST_OTHER,
},
{
.hook = ebt_nat_out,
.pf = NFPROTO_BRIDGE,
.hooknum = NF_BR_POST_ROUTING,
.priority = NF_BR_PRI_NAT_SRC,
},
{
.hook = ebt_nat_in,
.pf = NFPROTO_BRIDGE,
.hooknum = NF_BR_PRE_ROUTING,
.priority = NF_BR_PRI_NAT_DST_BRIDGED,
},
};
static int __net_init frame_nat_net_init(struct net *net)
{
return ebt_register_table(net, &frame_nat, ebt_ops_nat,
&net->xt.frame_nat);
}
static void __net_exit frame_nat_net_pre_exit(struct net *net)
{
ebt_unregister_table_pre_exit(net, "nat", ebt_ops_nat);
}
static void __net_exit frame_nat_net_exit(struct net *net)
{
ebt_unregister_table(net, net->xt.frame_nat);
}
static struct pernet_operations frame_nat_net_ops = {
.init = frame_nat_net_init,
.exit = frame_nat_net_exit,
.pre_exit = frame_nat_net_pre_exit,
};
static int __init ebtable_nat_init(void)
{
return register_pernet_subsys(&frame_nat_net_ops);
}
static void __exit ebtable_nat_fini(void)
{
unregister_pernet_subsys(&frame_nat_net_ops);
}
module_init(ebtable_nat_init);
module_exit(ebtable_nat_fini);
MODULE_LICENSE("GPL");
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