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/* Shared library add-on to xtables for CHECKSUM
*
* (C) 2002 by Harald Welte <laforge@gnumonks.org>
* (C) 2010 by Red Hat, Inc
* Author: Michael S. Tsirkin <mst@redhat.com>
*
* This program is distributed under the terms of GNU GPL v2, 1991
*
* libxt_CHECKSUM.c borrowed some bits from libipt_ECN.c
*/
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>
#include <xtables.h>
#include <linux/netfilter/xt_CHECKSUM.h>
static void CHECKSUM_help(void)
{
printf(
"CHECKSUM target options\n"
" --checksum-fill Fill in packet checksum.\n");
}
static const struct option CHECKSUM_opts[] = {
{.name = "checksum-fill", .has_arg = false, .val = 'F'},
XT_GETOPT_TABLEEND,
};
static int CHECKSUM_parse(int c, char **argv, int invert, unsigned int *flags,
const void *entry, struct xt_entry_target **target)
{
struct xt_CHECKSUM_info *einfo
= (struct xt_CHECKSUM_info *)(*target)->data;
switch (c) {
case 'F':
xtables_param_act(XTF_ONLY_ONCE, "CHECKSUM", "--checksum-fill",
*flags & XT_CHECKSUM_OP_FILL);
einfo->operation = XT_CHECKSUM_OP_FILL;
*flags |= XT_CHECKSUM_OP_FILL;
break;
default:
return 0;
}
return 1;
}
static void CHECKSUM_check(unsigned int flags)
{
if (!flags)
xtables_error(PARAMETER_PROBLEM,
"CHECKSUM target: Parameter --checksum-fill is required");
}
static void CHECKSUM_print(const void *ip, const struct xt_entry_target *target,
int numeric)
{
const struct xt_CHECKSUM_info *einfo =
(const struct xt_CHECKSUM_info *)target->data;
printf("CHECKSUM ");
if (einfo->operation & XT_CHECKSUM_OP_FILL)
printf("fill ");
}
static void CHECKSUM_save(const void *ip, const struct xt_entry_target *target)
{
const struct xt_CHECKSUM_info *einfo =
(const struct xt_CHECKSUM_info *)target->data;
if (einfo->operation & XT_CHECKSUM_OP_FILL)
printf("--checksum-fill ");
}
static struct xtables_target checksum_tg_reg = {
.name = "CHECKSUM",
.version = XTABLES_VERSION,
.family = NFPROTO_UNSPEC,
.size = XT_ALIGN(sizeof(struct xt_CHECKSUM_info)),
.userspacesize = XT_ALIGN(sizeof(struct xt_CHECKSUM_info)),
.help = CHECKSUM_help,
.parse = CHECKSUM_parse,
.final_check = CHECKSUM_check,
.print = CHECKSUM_print,
.save = CHECKSUM_save,
.extra_opts = CHECKSUM_opts,
};
void _init(void)
{
xtables_register_target(&checksum_tg_reg);
}
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