Files
xtables-addons/extensions/libxt_dhcpmac.c

102 lines
2.5 KiB
C

/*
* "dhcpmac" match extension for iptables
* Copyright © Jan Engelhardt, 2008
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License; either
* version 2 of the License, or any later version, as published by the
* Free Software Foundation.
*/
#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <netdb.h>
#include <net/ethernet.h>
#include <xtables.h>
#include "xt_DHCPMAC.h"
#include "mac.c"
#include "compat_user.h"
enum {
F_MAC = 1 << 0,
};
static const struct option dhcpmac_mt_opts[] = {
{.name = "mac", .has_arg = true, .val = 'M'},
{NULL},
};
static void dhcpmac_mt_help(void)
{
printf(
"dhcpmac match options:\n"
"[!] --mac lladdr[/mask] Match on MAC address in DHCP Client Host field\n"
);
}
static int dhcpmac_mt_parse(int c, char **argv, int invert,
unsigned int *flags, const void *entry, struct xt_entry_match **match)
{
struct dhcpmac_info *info = (void *)(*match)->data;
switch (c) {
case 'M':
xtables_param_act(XTF_ONLY_ONCE, "dhcpmac", "--mac", *flags & F_MAC);
xtables_param_act(XTF_NO_INVERT, "dhcpmac", "--mac", invert);
if (!mac_parse(optarg, info->addr, &info->mask))
xtables_param_act(XTF_BAD_VALUE, "dhcpmac", "--mac", optarg);
if (invert)
info->invert = true;
*flags |= F_MAC;
return true;
}
return false;
}
static void dhcpmac_mt_check(unsigned int flags)
{
if (flags == 0)
xtables_error(PARAMETER_PROBLEM, "dhcpmac match: "
"--mac parameter required");
}
static void dhcpmac_mt_save(const void *ip,
const struct xt_entry_match *match)
{
const struct dhcpmac_info *info = (void *)match->data;
if (info->invert)
printf(" !");
printf(" --mac " DH_MAC_FMT "/%u ",
DH_MAC_HEX(info->addr), info->mask);
}
static void dhcpmac_mt_print(const void *ip,
const struct xt_entry_match *match, int numeric)
{
printf(" -m dhcpmac");
dhcpmac_mt_save(ip, match);
}
static struct xtables_match dhcpmac_mt_reg = {
.version = XTABLES_VERSION,
.name = "dhcpmac",
.revision = 0,
.family = NFPROTO_IPV4,
.size = XT_ALIGN(sizeof(struct dhcpmac_info)),
.userspacesize = XT_ALIGN(sizeof(struct dhcpmac_info)),
.help = dhcpmac_mt_help,
.parse = dhcpmac_mt_parse,
.final_check = dhcpmac_mt_check,
.print = dhcpmac_mt_print,
.save = dhcpmac_mt_save,
.extra_opts = dhcpmac_mt_opts,
};
static __attribute__((constructor)) void dhcpmac_mt_ldr(void)
{
xtables_register_match(&dhcpmac_mt_reg);
}