mirror of
git://git.code.sf.net/p/xtables-addons/xtables-addons
synced 2025-09-06 12:45:13 +02:00
aab8dd360f
Xtables-addons's extensions will always be built as modules, so it is safe to use __attribute__((constructor)).
103 lines
2.6 KiB
C
103 lines
2.6 KiB
C
/*
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* "dhcpaddr" match extension for iptables
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* Copyright © Jan Engelhardt <jengelh [at] medozas de>, 2008
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License; either
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* version 2 of the License, or any later version, as published by the
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* Free Software Foundation.
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*/
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#include <getopt.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <netdb.h>
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#include <net/ethernet.h>
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#include <xtables.h>
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#include "xt_DHCPADDR.h"
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#include "mac.c"
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enum {
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F_MAC = 1 << 0,
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};
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static const struct option dhcpaddr_mt_opts[] = {
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{.name = "mac", .has_arg = true, .val = 'M'},
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{NULL},
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};
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static void dhcpaddr_mt_help(void)
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{
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printf(
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"dhcpaddr match options:\n"
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"[!] --mac lladdr[/mask] Match on MAC address in DHCP Client Host field\n"
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);
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}
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static int dhcpaddr_mt_parse(int c, char **argv, int invert,
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unsigned int *flags, const void *entry, struct xt_entry_match **match)
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{
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struct dhcpaddr_info *info = (void *)(*match)->data;
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switch (c) {
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case 'M':
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param_act(P_ONLY_ONCE, "dhcpaddr", "--mac", *flags & F_MAC);
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param_act(P_NO_INVERT, "dhcpaddr", "--mac", invert);
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if (!mac_parse(optarg, info->addr, &info->mask))
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param_act(P_BAD_VALUE, "dhcpaddr", "--mac", optarg);
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if (invert)
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info->invert = true;
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*flags |= F_MAC;
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return true;
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}
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return false;
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}
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static void dhcpaddr_mt_check(unsigned int flags)
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{
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if (flags == 0)
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exit_error(PARAMETER_PROBLEM, "dhcpaddr match: "
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"--mac parameter required");
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}
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static void dhcpaddr_mt_print(const void *ip,
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const struct xt_entry_match *match, int numeric)
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{
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const struct dhcpaddr_info *info = (void *)match->data;
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printf("dhcpaddr %s" DH_MAC_FMT "/%u ",
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info->invert ? "!" : "", DH_MAC_HEX(info->addr), info->mask);
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}
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static void dhcpaddr_mt_save(const void *ip,
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const struct xt_entry_match *match)
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{
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const struct dhcpaddr_info *info = (void *)match->data;
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if (info->invert)
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printf("! ");
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printf("--mac " DH_MAC_FMT "/%u ",
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DH_MAC_HEX(info->addr), info->mask);
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}
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static struct xtables_match dhcpaddr_mt_reg = {
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.version = XTABLES_VERSION,
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.name = "dhcpaddr",
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.revision = 0,
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.family = PF_INET,
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.size = XT_ALIGN(sizeof(struct dhcpaddr_info)),
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.userspacesize = XT_ALIGN(sizeof(struct dhcpaddr_info)),
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.help = dhcpaddr_mt_help,
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.parse = dhcpaddr_mt_parse,
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.final_check = dhcpaddr_mt_check,
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.print = dhcpaddr_mt_print,
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.save = dhcpaddr_mt_save,
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.extra_opts = dhcpaddr_mt_opts,
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};
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static __attribute__((constructor)) void dhcpaddr_mt_ldr(void)
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{
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xtables_register_match(&dhcpaddr_mt_reg);
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}
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