You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
147 lines
3.7 KiB
147 lines
3.7 KiB
/* ebt_nat
|
|
*
|
|
* Authors:
|
|
* Bart De Schuymer <bdschuym@pandora.be>
|
|
*
|
|
* June, 2002
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <getopt.h>
|
|
#include <netinet/ether.h>
|
|
#include <xtables.h>
|
|
#include <linux/netfilter_bridge/ebt_nat.h>
|
|
#include "iptables/nft.h"
|
|
#include "iptables/nft-bridge.h"
|
|
|
|
#define NAT_S '1'
|
|
#define NAT_S_TARGET '2'
|
|
#define NAT_S_ARP '3'
|
|
static const struct option brsnat_opts[] =
|
|
{
|
|
{ "to-source" , required_argument, 0, NAT_S },
|
|
{ "to-src" , required_argument, 0, NAT_S },
|
|
{ "snat-target" , required_argument, 0, NAT_S_TARGET },
|
|
{ "snat-arp" , no_argument, 0, NAT_S_ARP },
|
|
{ 0 }
|
|
};
|
|
|
|
static void brsnat_print_help(void)
|
|
{
|
|
printf(
|
|
"snat options:\n"
|
|
" --to-src address : MAC address to map source to\n"
|
|
" --snat-target target : ACCEPT, DROP, RETURN or CONTINUE\n"
|
|
" --snat-arp : also change src address in arp msg\n");
|
|
}
|
|
|
|
static void brsnat_init(struct xt_entry_target *target)
|
|
{
|
|
struct ebt_nat_info *natinfo = (struct ebt_nat_info *)target->data;
|
|
|
|
natinfo->target = EBT_ACCEPT;
|
|
}
|
|
|
|
#define OPT_SNAT 0x01
|
|
#define OPT_SNAT_TARGET 0x02
|
|
#define OPT_SNAT_ARP 0x04
|
|
static int brsnat_parse(int c, char **argv, int invert, unsigned int *flags,
|
|
const void *entry, struct xt_entry_target **target)
|
|
{
|
|
struct ebt_nat_info *natinfo = (struct ebt_nat_info *)(*target)->data;
|
|
struct ether_addr *addr;
|
|
|
|
switch (c) {
|
|
case NAT_S:
|
|
EBT_CHECK_OPTION(flags, OPT_SNAT);
|
|
if (!(addr = ether_aton(optarg)))
|
|
xtables_error(PARAMETER_PROBLEM, "Problem with specified --to-source mac");
|
|
memcpy(natinfo->mac, addr, ETH_ALEN);
|
|
break;
|
|
case NAT_S_TARGET:
|
|
{ unsigned int tmp;
|
|
EBT_CHECK_OPTION(flags, OPT_SNAT_TARGET);
|
|
if (ebt_fill_target(optarg, &tmp))
|
|
xtables_error(PARAMETER_PROBLEM, "Illegal --snat-target target");
|
|
natinfo->target = (natinfo->target & ~EBT_VERDICT_BITS) | (tmp & EBT_VERDICT_BITS);
|
|
}
|
|
break;
|
|
case NAT_S_ARP:
|
|
EBT_CHECK_OPTION(flags, OPT_SNAT_ARP);
|
|
natinfo->target ^= NAT_ARP_BIT;
|
|
break;
|
|
default:
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static void brsnat_final_check(unsigned int flags)
|
|
{
|
|
if (!flags)
|
|
xtables_error(PARAMETER_PROBLEM,
|
|
"You must specify proper arguments");
|
|
}
|
|
|
|
static void brsnat_print(const void *ip, const struct xt_entry_target *target, int numeric)
|
|
{
|
|
struct ebt_nat_info *natinfo = (struct ebt_nat_info *)target->data;
|
|
|
|
printf("--to-src ");
|
|
xtables_print_mac(natinfo->mac);
|
|
if (!(natinfo->target&NAT_ARP_BIT))
|
|
printf(" --snat-arp");
|
|
printf(" --snat-target %s", ebt_target_name((natinfo->target|~EBT_VERDICT_BITS)));
|
|
}
|
|
|
|
static const char* brsnat_verdict(int verdict)
|
|
{
|
|
switch (verdict) {
|
|
case EBT_ACCEPT: return "accept";
|
|
case EBT_DROP: return "drop";
|
|
case EBT_CONTINUE: return "continue";
|
|
case EBT_RETURN: return "return";
|
|
}
|
|
|
|
return "";
|
|
}
|
|
|
|
static int brsnat_xlate(struct xt_xlate *xl,
|
|
const struct xt_xlate_tg_params *params)
|
|
{
|
|
const struct ebt_nat_info *natinfo = (const void*)params->target->data;
|
|
|
|
xt_xlate_add(xl, "ether saddr set %s ",
|
|
ether_ntoa((struct ether_addr *)natinfo->mac));
|
|
|
|
/* NAT_ARP_BIT set -> no arp mangling, not set -> arp mangling (yes, its inverted) */
|
|
if (!(natinfo->target&NAT_ARP_BIT))
|
|
return 0;
|
|
|
|
xt_xlate_add(xl, "%s ", brsnat_verdict(natinfo->target | ~EBT_VERDICT_BITS));
|
|
return 1;
|
|
}
|
|
|
|
static struct xtables_target brsnat_target =
|
|
{
|
|
.name = "snat",
|
|
.version = XTABLES_VERSION,
|
|
.family = NFPROTO_BRIDGE,
|
|
.size = XT_ALIGN(sizeof(struct ebt_nat_info)),
|
|
.userspacesize = XT_ALIGN(sizeof(struct ebt_nat_info)),
|
|
.help = brsnat_print_help,
|
|
.init = brsnat_init,
|
|
.parse = brsnat_parse,
|
|
.final_check = brsnat_final_check,
|
|
.print = brsnat_print,
|
|
.xlate = brsnat_xlate,
|
|
.extra_opts = brsnat_opts,
|
|
};
|
|
|
|
void _init(void)
|
|
{
|
|
xtables_register_target(&brsnat_target);
|
|
}
|