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/* Shared library add-on to iptables for ECN matching
*
* (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
*
*/
#include <stdio.h>
#include <xtables.h>
#include <linux/netfilter_ipv4/ipt_ecn.h>
enum {
O_ECN_TCP_CWR = 0,
O_ECN_TCP_ECE,
O_ECN_IP_ECT,
};
static void ecn_help(void)
{
printf(
"ECN match options\n"
"[!] --ecn-tcp-cwr Match CWR bit of TCP header\n"
"[!] --ecn-tcp-ece Match ECE bit of TCP header\n"
"[!] --ecn-ip-ect [0..3] Match ECN codepoint in IPv4 header\n");
}
static const struct xt_option_entry ecn_opts[] = {
{.name = "ecn-tcp-cwr", .id = O_ECN_TCP_CWR, .type = XTTYPE_NONE,
.flags = XTOPT_INVERT},
{.name = "ecn-tcp-ece", .id = O_ECN_TCP_ECE, .type = XTTYPE_NONE,
.flags = XTOPT_INVERT},
{.name = "ecn-ip-ect", .id = O_ECN_IP_ECT, .type = XTTYPE_UINT8,
.min = 0, .max = 3, .flags = XTOPT_INVERT},
XTOPT_TABLEEND,
};
static void ecn_parse(struct xt_option_call *cb)
{
struct ipt_ecn_info *einfo = cb->data;
xtables_option_parse(cb);
switch (cb->entry->id) {
case O_ECN_TCP_CWR:
einfo->operation |= IPT_ECN_OP_MATCH_CWR;
if (cb->invert)
einfo->invert |= IPT_ECN_OP_MATCH_CWR;
break;
case O_ECN_TCP_ECE:
einfo->operation |= IPT_ECN_OP_MATCH_ECE;
if (cb->invert)
einfo->invert |= IPT_ECN_OP_MATCH_ECE;
break;
case O_ECN_IP_ECT:
if (cb->invert)
einfo->invert |= IPT_ECN_OP_MATCH_IP;
einfo->operation |= IPT_ECN_OP_MATCH_IP;
einfo->ip_ect = cb->val.u8;
break;
}
}
static void ecn_check(struct xt_fcheck_call *cb)
{
if (cb->xflags == 0)
xtables_error(PARAMETER_PROBLEM,
"ECN match: some option required");
}
static void ecn_print(const void *ip, const struct xt_entry_match *match,
int numeric)
{
const struct ipt_ecn_info *einfo =
(const struct ipt_ecn_info *)match->data;
printf(" ECN match");
if (einfo->operation & IPT_ECN_OP_MATCH_ECE) {
printf(" %sECE",
(einfo->invert & IPT_ECN_OP_MATCH_ECE) ? "!" : "");
}
if (einfo->operation & IPT_ECN_OP_MATCH_CWR) {
printf(" %sCWR",
(einfo->invert & IPT_ECN_OP_MATCH_CWR) ? "!" : "");
}
if (einfo->operation & IPT_ECN_OP_MATCH_IP) {
printf(" %sECT=%d",
(einfo->invert & IPT_ECN_OP_MATCH_IP) ? "!" : "",
einfo->ip_ect);
}
}
static void ecn_save(const void *ip, const struct xt_entry_match *match)
{
const struct ipt_ecn_info *einfo =
(const struct ipt_ecn_info *)match->data;
if (einfo->operation & IPT_ECN_OP_MATCH_ECE) {
if (einfo->invert & IPT_ECN_OP_MATCH_ECE)
printf(" !");
printf(" --ecn-tcp-ece");
}
if (einfo->operation & IPT_ECN_OP_MATCH_CWR) {
if (einfo->invert & IPT_ECN_OP_MATCH_CWR)
printf(" !");
printf(" --ecn-tcp-cwr");
}
if (einfo->operation & IPT_ECN_OP_MATCH_IP) {
if (einfo->invert & IPT_ECN_OP_MATCH_IP)
printf(" !");
printf(" --ecn-ip-ect %d", einfo->ip_ect);
}
}
static struct xtables_match ecn_mt_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,
.print = ecn_print,
.save = ecn_save,
.x6_parse = ecn_parse,
.x6_fcheck = ecn_check,
.x6_options = ecn_opts,
};
void _init(void)
{
xtables_register_match(&ecn_mt_reg);
}
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