/usr/src/xtables-addons-3.0/extensions/libxt_dhcpmac.c is in xtables-addons-dkms 3.0-0.1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 | /*
* "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);
}
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