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/*
* Arturo Borrero Gonzalez <arturo@debian.org> adapted
* this code to libxtables for arptables-compat in 2015
*/
#include <stdio.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <limits.h>
#include <getopt.h>
#include <netinet/ether.h>
#include <xtables.h>
#include <linux/netfilter_arp/arpt_mangle.h>
#include "iptables/nft.h"
#include "iptables/nft-arp.h"
static void arpmangle_print_help(void)
{
printf(
"mangle target options:\n"
"--mangle-ip-s IP address\n"
"--mangle-ip-d IP address\n"
"--mangle-mac-s MAC address\n"
"--mangle-mac-d MAC address\n"
"--mangle-target target (DROP, CONTINUE or ACCEPT -- default is ACCEPT)\n");
}
#define MANGLE_IPS '1'
#define MANGLE_IPT '2'
#define MANGLE_DEVS '3'
#define MANGLE_DEVT '4'
#define MANGLE_TARGET '5'
static const struct option arpmangle_opts[] = {
{ .name = "mangle-ip-s", .has_arg = true, .val = MANGLE_IPS },
{ .name = "mangle-ip-d", .has_arg = true, .val = MANGLE_IPT },
{ .name = "mangle-mac-s", .has_arg = true, .val = MANGLE_DEVS },
{ .name = "mangle-mac-d", .has_arg = true, .val = MANGLE_DEVT },
{ .name = "mangle-target", .has_arg = true, .val = MANGLE_TARGET },
XT_GETOPT_TABLEEND,
};
static void arpmangle_init(struct xt_entry_target *target)
{
struct arpt_mangle *mangle = (struct arpt_mangle *)target->data;
mangle->target = NF_ACCEPT;
}
static int
arpmangle_parse(int c, char **argv, int invert, unsigned int *flags,
const void *entry, struct xt_entry_target **target)
{
struct arpt_mangle *mangle = (struct arpt_mangle *)(*target)->data;
struct in_addr *ipaddr, mask;
struct ether_addr *macaddr;
const struct arpt_entry *e = (const struct arpt_entry *)entry;
unsigned int nr;
int ret = 1;
memset(&mask, 0, sizeof(mask));
switch (c) {
case MANGLE_IPS:
xtables_ipparse_any(optarg, &ipaddr, &mask, &nr);
mangle->u_s.src_ip.s_addr = ipaddr->s_addr;
free(ipaddr);
mangle->flags |= ARPT_MANGLE_SIP;
break;
case MANGLE_IPT:
xtables_ipparse_any(optarg, &ipaddr, &mask, &nr);
mangle->u_t.tgt_ip.s_addr = ipaddr->s_addr;
free(ipaddr);
mangle->flags |= ARPT_MANGLE_TIP;
break;
case MANGLE_DEVS:
if (e->arp.arhln_mask == 0)
xtables_error(PARAMETER_PROBLEM,
"no --h-length defined");
if (e->arp.invflags & ARPT_INV_ARPHLN)
xtables_error(PARAMETER_PROBLEM,
"! --h-length not allowed for "
"--mangle-mac-s");
if (e->arp.arhln != 6)
xtables_error(PARAMETER_PROBLEM,
"only --h-length 6 supported");
macaddr = ether_aton(optarg);
if (macaddr == NULL)
xtables_error(PARAMETER_PROBLEM,
"invalid source MAC");
memcpy(mangle->src_devaddr, macaddr, e->arp.arhln);
mangle->flags |= ARPT_MANGLE_SDEV;
break;
case MANGLE_DEVT:
if (e->arp.arhln_mask == 0)
xtables_error(PARAMETER_PROBLEM,
"no --h-length defined");
if (e->arp.invflags & ARPT_INV_ARPHLN)
xtables_error(PARAMETER_PROBLEM,
"! hln not allowed for --mangle-mac-d");
if (e->arp.arhln != 6)
xtables_error(PARAMETER_PROBLEM,
"only --h-length 6 supported");
macaddr = ether_aton(optarg);
if (macaddr == NULL)
xtables_error(PARAMETER_PROBLEM, "invalid target MAC");
memcpy(mangle->tgt_devaddr, macaddr, e->arp.arhln);
mangle->flags |= ARPT_MANGLE_TDEV;
break;
case MANGLE_TARGET:
if (!strcmp(optarg, "DROP"))
mangle->target = NF_DROP;
else if (!strcmp(optarg, "ACCEPT"))
mangle->target = NF_ACCEPT;
else if (!strcmp(optarg, "CONTINUE"))
mangle->target = XT_CONTINUE;
else
xtables_error(PARAMETER_PROBLEM,
"bad target for --mangle-target");
break;
default:
ret = 0;
}
return ret;
}
static void arpmangle_final_check(unsigned int flags)
{
}
static void print_mac(const unsigned char *mac, int l)
{
int j;
for (j = 0; j < l; j++)
printf("%02x%s", mac[j],
(j==l-1) ? "" : ":");
}
static void
arpmangle_print(const void *ip, const struct xt_entry_target *target,
int numeric)
{
struct arpt_mangle *m = (struct arpt_mangle *)(target->data);
char buf[100];
if (m->flags & ARPT_MANGLE_SIP) {
if (numeric)
sprintf(buf, "%s",
xtables_ipaddr_to_numeric(&(m->u_s.src_ip)));
else
sprintf(buf, "%s",
xtables_ipaddr_to_anyname(&(m->u_s.src_ip)));
printf("--mangle-ip-s %s ", buf);
}
if (m->flags & ARPT_MANGLE_SDEV) {
printf("--mangle-mac-s ");
print_mac((unsigned char *)m->src_devaddr, 6);
printf(" ");
}
if (m->flags & ARPT_MANGLE_TIP) {
if (numeric)
sprintf(buf, "%s",
xtables_ipaddr_to_numeric(&(m->u_t.tgt_ip)));
else
sprintf(buf, "%s",
xtables_ipaddr_to_anyname(&(m->u_t.tgt_ip)));
printf("--mangle-ip-d %s ", buf);
}
if (m->flags & ARPT_MANGLE_TDEV) {
printf("--mangle-mac-d ");
print_mac((unsigned char *)m->tgt_devaddr, 6);
printf(" ");
}
if (m->target != NF_ACCEPT) {
printf("--mangle-target ");
if (m->target == NF_DROP)
printf("DROP ");
else
printf("CONTINUE ");
}
}
static struct xtables_target arpmangle_target = {
.name = "mangle",
.revision = 0,
.version = XTABLES_VERSION,
.family = NFPROTO_ARP,
.size = XT_ALIGN(sizeof(struct arpt_mangle)),
.userspacesize = XT_ALIGN(sizeof(struct arpt_mangle)),
.help = arpmangle_print_help,
.init = arpmangle_init,
.parse = arpmangle_parse,
.final_check = arpmangle_final_check,
.print = arpmangle_print,
.extra_opts = arpmangle_opts,
};
void _init(void)
{
xtables_register_target(&arpmangle_target);
}
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