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