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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
*/
#include <stdio.h>
#include <xtables.h>
#include <linux/netfilter_ipv4/ipt_ECN.h>
enum {
O_ECN_TCP_REMOVE = 0,
O_ECN_TCP_CWR,
O_ECN_TCP_ECE,
O_ECN_IP_ECT,
F_ECN_TCP_REMOVE = 1 << O_ECN_TCP_REMOVE,
F_ECN_TCP_CWR = 1 << O_ECN_TCP_CWR,
F_ECN_TCP_ECE = 1 << O_ECN_TCP_ECE,
};
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 xt_option_entry ECN_opts[] = {
{.name = "ecn-tcp-remove", .id = O_ECN_TCP_REMOVE, .type = XTTYPE_NONE,
.excl = F_ECN_TCP_CWR | F_ECN_TCP_ECE},
{.name = "ecn-tcp-cwr", .id = O_ECN_TCP_CWR, .type = XTTYPE_UINT8,
.min = 0, .max = 1, .excl = F_ECN_TCP_REMOVE},
{.name = "ecn-tcp-ece", .id = O_ECN_TCP_ECE, .type = XTTYPE_UINT8,
.min = 0, .max = 1, .excl = F_ECN_TCP_REMOVE},
{.name = "ecn-ip-ect", .id = O_ECN_IP_ECT, .type = XTTYPE_UINT8,
.min = 0, .max = 3},
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_REMOVE:
einfo->operation = IPT_ECN_OP_SET_ECE | IPT_ECN_OP_SET_CWR;
einfo->proto.tcp.ece = 0;
einfo->proto.tcp.cwr = 0;
break;
case O_ECN_TCP_CWR:
einfo->operation |= IPT_ECN_OP_SET_CWR;
einfo->proto.tcp.cwr = cb->val.u8;
break;
case O_ECN_TCP_ECE:
einfo->operation |= IPT_ECN_OP_SET_ECE;
einfo->proto.tcp.ece = cb->val.u8;
break;
case O_ECN_IP_ECT:
einfo->operation |= IPT_ECN_OP_SET_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 target: An operation 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,
.print = ECN_print,
.save = ECN_save,
.x6_parse = ECN_parse,
.x6_fcheck = ECN_check,
.x6_options = ECN_opts,
};
void _init(void)
{
xtables_register_target(&ecn_tg_reg);
}
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