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/* Shared library add-on to iptables for ECN, $Version$
*
* (C) 2002 by Harald Welte <laforge@gnumonks.org>
*
* This program is distributed under the terms of GNU GPL v2, 1991
*
* libipt_ECN.c borrowed heavily from libipt_DSCP.c
*
* $Id$
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>
#include <xtables.h>
#include <linux/netfilter_ipv4/ipt_ECN.h>
static void ECN_help(void)
{
printf(
"ECN target options\n"
" --ecn-tcp-remove Remove all ECN bits from TCP header\n");
}
#if 0
"ECN target v%s EXPERIMENTAL options (use with extreme care!)\n"
" --ecn-ip-ect Set the IPv4 ECT codepoint (0 to 3)\n"
" --ecn-tcp-cwr Set the IPv4 CWR bit (0 or 1)\n"
" --ecn-tcp-ece Set the IPv4 ECE bit (0 or 1)\n",
#endif
static const struct option ECN_opts[] = {
{ "ecn-tcp-remove", 0, NULL, 'F' },
{ "ecn-tcp-cwr", 1, NULL, 'G' },
{ "ecn-tcp-ece", 1, NULL, 'H' },
{ "ecn-ip-ect", 1, NULL, '9' },
{ .name = NULL }
};
static int ECN_parse(int c, char **argv, int invert, unsigned int *flags,
const void *entry, struct xt_entry_target **target)
{
unsigned int result;
struct ipt_ECN_info *einfo
= (struct ipt_ECN_info *)(*target)->data;
switch (c) {
case 'F':
if (*flags)
xtables_error(PARAMETER_PROBLEM,
"ECN target: Only use --ecn-tcp-remove ONCE!");
einfo->operation = IPT_ECN_OP_SET_ECE | IPT_ECN_OP_SET_CWR;
einfo->proto.tcp.ece = 0;
einfo->proto.tcp.cwr = 0;
*flags = 1;
break;
case 'G':
if (*flags & IPT_ECN_OP_SET_CWR)
xtables_error(PARAMETER_PROBLEM,
"ECN target: Only use --ecn-tcp-cwr ONCE!");
if (!xtables_strtoui(optarg, NULL, &result, 0, 1))
xtables_error(PARAMETER_PROBLEM,
"ECN target: Value out of range");
einfo->operation |= IPT_ECN_OP_SET_CWR;
einfo->proto.tcp.cwr = result;
*flags |= IPT_ECN_OP_SET_CWR;
break;
case 'H':
if (*flags & IPT_ECN_OP_SET_ECE)
xtables_error(PARAMETER_PROBLEM,
"ECN target: Only use --ecn-tcp-ece ONCE!");
if (!xtables_strtoui(optarg, NULL, &result, 0, 1))
xtables_error(PARAMETER_PROBLEM,
"ECN target: Value out of range");
einfo->operation |= IPT_ECN_OP_SET_ECE;
einfo->proto.tcp.ece = result;
*flags |= IPT_ECN_OP_SET_ECE;
break;
case '9':
if (*flags & IPT_ECN_OP_SET_IP)
xtables_error(PARAMETER_PROBLEM,
"ECN target: Only use --ecn-ip-ect ONCE!");
if (!xtables_strtoui(optarg, NULL, &result, 0, 3))
xtables_error(PARAMETER_PROBLEM,
"ECN target: Value out of range");
einfo->operation |= IPT_ECN_OP_SET_IP;
einfo->ip_ect = result;
*flags |= IPT_ECN_OP_SET_IP;
break;
default:
return 0;
}
return 1;
}
static void ECN_check(unsigned int flags)
{
if (!flags)
xtables_error(PARAMETER_PROBLEM,
"ECN target: Parameter --ecn-tcp-remove is required");
}
static void ECN_print(const void *ip, const struct xt_entry_target *target,
int numeric)
{
const struct ipt_ECN_info *einfo =
(const struct ipt_ECN_info *)target->data;
printf("ECN ");
if (einfo->operation == (IPT_ECN_OP_SET_ECE|IPT_ECN_OP_SET_CWR)
&& einfo->proto.tcp.ece == 0
&& einfo->proto.tcp.cwr == 0)
printf("TCP remove ");
else {
if (einfo->operation & IPT_ECN_OP_SET_ECE)
printf("ECE=%u ", einfo->proto.tcp.ece);
if (einfo->operation & IPT_ECN_OP_SET_CWR)
printf("CWR=%u ", einfo->proto.tcp.cwr);
if (einfo->operation & IPT_ECN_OP_SET_IP)
printf("ECT codepoint=%u ", einfo->ip_ect);
}
}
static void ECN_save(const void *ip, const struct xt_entry_target *target)
{
const struct ipt_ECN_info *einfo =
(const struct ipt_ECN_info *)target->data;
if (einfo->operation == (IPT_ECN_OP_SET_ECE|IPT_ECN_OP_SET_CWR)
&& einfo->proto.tcp.ece == 0
&& einfo->proto.tcp.cwr == 0)
printf("--ecn-tcp-remove ");
else {
if (einfo->operation & IPT_ECN_OP_SET_ECE)
printf("--ecn-tcp-ece %d ", einfo->proto.tcp.ece);
if (einfo->operation & IPT_ECN_OP_SET_CWR)
printf("--ecn-tcp-cwr %d ", einfo->proto.tcp.cwr);
if (einfo->operation & IPT_ECN_OP_SET_IP)
printf("--ecn-ip-ect %d ", einfo->ip_ect);
}
}
static struct xtables_target ecn_tg_reg = {
.name = "ECN",
.version = XTABLES_VERSION,
.family = NFPROTO_IPV4,
.size = XT_ALIGN(sizeof(struct ipt_ECN_info)),
.userspacesize = XT_ALIGN(sizeof(struct ipt_ECN_info)),
.help = ECN_help,
.parse = ECN_parse,
.final_check = ECN_check,
.print = ECN_print,
.save = ECN_save,
.extra_opts = ECN_opts,
};
void _init(void)
{
xtables_register_target(&ecn_tg_reg);
}
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