1 // SPDX-License-Identifier: GPL-2.0-only
6 * Bart De Schuymer <bdschuym@pandora.be>
12 #include <linux/netfilter_bridge/ebtables.h>
13 #include <uapi/linux/netfilter_bridge.h>
14 #include <linux/module.h>
16 #define NAT_VALID_HOOKS ((1 << NF_BR_PRE_ROUTING) | (1 << NF_BR_LOCAL_OUT) | \
17 (1 << NF_BR_POST_ROUTING))
19 static struct ebt_entries initial_chains[] = {
29 .name = "POSTROUTING",
34 static struct ebt_replace_kernel initial_table = {
36 .valid_hooks = NAT_VALID_HOOKS,
37 .entries_size = 3 * sizeof(struct ebt_entries),
39 [NF_BR_PRE_ROUTING] = &initial_chains[0],
40 [NF_BR_LOCAL_OUT] = &initial_chains[1],
41 [NF_BR_POST_ROUTING] = &initial_chains[2],
43 .entries = (char *)initial_chains,
46 static int check(const struct ebt_table_info *info, unsigned int valid_hooks)
48 if (valid_hooks & ~NAT_VALID_HOOKS)
53 static const struct ebt_table frame_nat = {
55 .table = &initial_table,
56 .valid_hooks = NAT_VALID_HOOKS,
62 ebt_nat_in(void *priv, struct sk_buff *skb,
63 const struct nf_hook_state *state)
65 return ebt_do_table(skb, state, state->net->xt.frame_nat);
69 ebt_nat_out(void *priv, struct sk_buff *skb,
70 const struct nf_hook_state *state)
72 return ebt_do_table(skb, state, state->net->xt.frame_nat);
75 static const struct nf_hook_ops ebt_ops_nat[] = {
79 .hooknum = NF_BR_LOCAL_OUT,
80 .priority = NF_BR_PRI_NAT_DST_OTHER,
85 .hooknum = NF_BR_POST_ROUTING,
86 .priority = NF_BR_PRI_NAT_SRC,
91 .hooknum = NF_BR_PRE_ROUTING,
92 .priority = NF_BR_PRI_NAT_DST_BRIDGED,
96 static int __net_init frame_nat_net_init(struct net *net)
98 return ebt_register_table(net, &frame_nat, ebt_ops_nat,
102 static void __net_exit frame_nat_net_exit(struct net *net)
104 ebt_unregister_table(net, net->xt.frame_nat, ebt_ops_nat);
107 static struct pernet_operations frame_nat_net_ops = {
108 .init = frame_nat_net_init,
109 .exit = frame_nat_net_exit,
112 static int __init ebtable_nat_init(void)
114 return register_pernet_subsys(&frame_nat_net_ops);
117 static void __exit ebtable_nat_fini(void)
119 unregister_pernet_subsys(&frame_nat_net_ops);
122 module_init(ebtable_nat_init);
123 module_exit(ebtable_nat_fini);
124 MODULE_LICENSE("GPL");