140 lines
3.0 KiB
C
140 lines
3.0 KiB
C
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/*
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* ebtable_nat
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*
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* Authors:
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* Bart De Schuymer <bdschuym@pandora.be>
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*
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* April, 2002
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*
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*/
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#include <linux/netfilter_bridge/ebtables.h>
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#include <linux/module.h>
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#define NAT_VALID_HOOKS ((1 << NF_BR_PRE_ROUTING) | (1 << NF_BR_LOCAL_OUT) | \
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(1 << NF_BR_POST_ROUTING))
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static struct ebt_entries initial_chains[] =
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{
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{
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.name = "PREROUTING",
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.policy = EBT_ACCEPT,
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},
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{
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.name = "OUTPUT",
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.policy = EBT_ACCEPT,
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},
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{
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.name = "POSTROUTING",
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.policy = EBT_ACCEPT,
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}
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};
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static struct ebt_replace_kernel initial_table =
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{
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.name = "nat",
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.valid_hooks = NAT_VALID_HOOKS,
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.entries_size = 3 * sizeof(struct ebt_entries),
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.hook_entry = {
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[NF_BR_PRE_ROUTING] = &initial_chains[0],
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[NF_BR_LOCAL_OUT] = &initial_chains[1],
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[NF_BR_POST_ROUTING] = &initial_chains[2],
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},
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.entries = (char *)initial_chains,
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};
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static int check(const struct ebt_table_info *info, unsigned int valid_hooks)
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{
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if (valid_hooks & ~NAT_VALID_HOOKS)
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return -EINVAL;
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return 0;
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}
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static struct ebt_table frame_nat =
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{
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.name = "nat",
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.table = &initial_table,
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.valid_hooks = NAT_VALID_HOOKS,
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.check = check,
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.me = THIS_MODULE,
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};
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static unsigned int
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ebt_nat_in(unsigned int hook, struct sk_buff *skb, const struct net_device *in
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, const struct net_device *out, int (*okfn)(struct sk_buff *))
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{
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return ebt_do_table(hook, skb, in, out, dev_net(in)->xt.frame_nat);
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}
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static unsigned int
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ebt_nat_out(unsigned int hook, struct sk_buff *skb, const struct net_device *in
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, const struct net_device *out, int (*okfn)(struct sk_buff *))
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{
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return ebt_do_table(hook, skb, in, out, dev_net(out)->xt.frame_nat);
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}
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static struct nf_hook_ops ebt_ops_nat[] __read_mostly = {
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{
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.hook = ebt_nat_out,
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.owner = THIS_MODULE,
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.pf = NFPROTO_BRIDGE,
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.hooknum = NF_BR_LOCAL_OUT,
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.priority = NF_BR_PRI_NAT_DST_OTHER,
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},
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{
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.hook = ebt_nat_out,
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.owner = THIS_MODULE,
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.pf = NFPROTO_BRIDGE,
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.hooknum = NF_BR_POST_ROUTING,
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.priority = NF_BR_PRI_NAT_SRC,
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},
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{
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.hook = ebt_nat_in,
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.owner = THIS_MODULE,
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.pf = NFPROTO_BRIDGE,
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.hooknum = NF_BR_PRE_ROUTING,
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.priority = NF_BR_PRI_NAT_DST_BRIDGED,
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},
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};
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static int __net_init frame_nat_net_init(struct net *net)
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{
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net->xt.frame_nat = ebt_register_table(net, &frame_nat);
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if (IS_ERR(net->xt.frame_nat))
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return PTR_ERR(net->xt.frame_nat);
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return 0;
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}
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static void __net_exit frame_nat_net_exit(struct net *net)
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{
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ebt_unregister_table(net->xt.frame_nat);
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}
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static struct pernet_operations frame_nat_net_ops = {
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.init = frame_nat_net_init,
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.exit = frame_nat_net_exit,
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};
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static int __init ebtable_nat_init(void)
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{
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int ret;
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ret = register_pernet_subsys(&frame_nat_net_ops);
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if (ret < 0)
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return ret;
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ret = nf_register_hooks(ebt_ops_nat, ARRAY_SIZE(ebt_ops_nat));
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if (ret < 0)
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unregister_pernet_subsys(&frame_nat_net_ops);
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return ret;
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}
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static void __exit ebtable_nat_fini(void)
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{
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nf_unregister_hooks(ebt_ops_nat, ARRAY_SIZE(ebt_ops_nat));
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unregister_pernet_subsys(&frame_nat_net_ops);
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}
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module_init(ebtable_nat_init);
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module_exit(ebtable_nat_fini);
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MODULE_LICENSE("GPL");
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