| /* |
| * 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_action_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 int 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 -EINVAL; |
| |
| 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 -EINVAL; |
| if (INVALID_TARGET) |
| return -EINVAL; |
| return 0; |
| } |
| |
| 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"); |