/*

 * Copyright (c) 2013 Patrick McHardy <kaber@trash.net>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */

#include <stdbool.h>

#include <stdio.h>

#include <xtables.h>

#include <linux/netfilter/xt_SYNPROXY.h>

enum {

	O_SACK_PERM = 0,

	O_TIMESTAMP,

	O_WSCALE,

	O_MSS,

	O_ECN,

};

static void SYNPROXY_help(void)

{

	printf(

"SYNPROXY target options:\n"

"  --sack-perm                        Set SACK_PERM\n"

"  --timestamp                        Set TIMESTAMP\n"

"  --wscale value                     Set window scaling factor\n"

"  --mss value                        Set MSS value\n"

"  --ecn                              Set ECN\n");

}

static const struct xt_option_entry SYNPROXY_opts[] = {

	{.name = "sack-perm", .id = O_SACK_PERM, .type = XTTYPE_NONE, },

	{.name = "timestamp", .id = O_TIMESTAMP, .type = XTTYPE_NONE, },

	{.name = "wscale",    .id = O_WSCALE,    .type = XTTYPE_UINT32, },

	{.name = "mss",       .id = O_MSS,       .type = XTTYPE_UINT32, },

	{.name = "ecn",       .id = O_ECN,	 .type = XTTYPE_NONE, },

	XTOPT_TABLEEND,

};

static void SYNPROXY_parse(struct xt_option_call *cb)

{

	struct xt_synproxy_info *info = cb->data;

	xtables_option_parse(cb);

	switch (cb->entry->id) {

	case O_SACK_PERM:

		info->options |= XT_SYNPROXY_OPT_SACK_PERM;

		break;

	case O_TIMESTAMP:

		info->options |= XT_SYNPROXY_OPT_TIMESTAMP;

		break;

	case O_WSCALE:

		info->options |= XT_SYNPROXY_OPT_WSCALE;

		info->wscale = cb->val.u32;

		break;

	case O_MSS:

		info->options |= XT_SYNPROXY_OPT_MSS;

		info->mss = cb->val.u32;

		break;

	case O_ECN:

		info->options |= XT_SYNPROXY_OPT_ECN;

		break;

	}

}

static void SYNPROXY_check(struct xt_fcheck_call *cb)

{

}

static void SYNPROXY_print(const void *ip, const struct xt_entry_target *target,

                           int numeric)

{

	const struct xt_synproxy_info *info =

		(const struct xt_synproxy_info *)target->data;

	printf(" SYNPROXY ");

	if (info->options & XT_SYNPROXY_OPT_SACK_PERM)

		printf("sack-perm ");

	if (info->options & XT_SYNPROXY_OPT_TIMESTAMP)

		printf("timestamp ");

	if (info->options & XT_SYNPROXY_OPT_WSCALE)

		printf("wscale %u ", info->wscale);

	if (info->options & XT_SYNPROXY_OPT_MSS)

		printf("mss %u ", info->mss);

	if (info->options & XT_SYNPROXY_OPT_ECN)

		printf("ecn ");

}

static void SYNPROXY_save(const void *ip, const struct xt_entry_target *target)

{

	const struct xt_synproxy_info *info =

		(const struct xt_synproxy_info *)target->data;

	if (info->options & XT_SYNPROXY_OPT_SACK_PERM)

		printf(" --sack-perm");

	if (info->options & XT_SYNPROXY_OPT_TIMESTAMP)

		printf(" --timestamp");

	if (info->options & XT_SYNPROXY_OPT_WSCALE)

		printf(" --wscale %u", info->wscale);

	if (info->options & XT_SYNPROXY_OPT_MSS)

		printf(" --mss %u", info->mss);

	if (info->options & XT_SYNPROXY_OPT_ECN)

		printf(" --ecn");

}

static int SYNPROXY_xlate(struct xt_xlate *xl,

		          const struct xt_xlate_tg_params *params)

{

	const struct xt_synproxy_info *info =

		(const struct xt_synproxy_info *)params->target->data;

	xt_xlate_add(xl, "synproxy ");

	if (info->options & XT_SYNPROXY_OPT_SACK_PERM)

		xt_xlate_add(xl, "sack-perm ");

	if (info->options & XT_SYNPROXY_OPT_TIMESTAMP)

		xt_xlate_add(xl, "timestamp ");

	if (info->options & XT_SYNPROXY_OPT_WSCALE)

		xt_xlate_add(xl, "wscale %u ", info->wscale);

	if (info->options & XT_SYNPROXY_OPT_MSS)

		xt_xlate_add(xl, "mss %u ", info->mss);

	if (info->options & XT_SYNPROXY_OPT_ECN)

		xt_xlate_add(xl, "ecn ");

	return 1;

}

static struct xtables_target synproxy_tg_reg = {

	.family        = NFPROTO_UNSPEC,

	.name          = "SYNPROXY",

	.version       = XTABLES_VERSION,

	.revision      = 0,

	.size          = XT_ALIGN(sizeof(struct xt_synproxy_info)),

	.userspacesize = XT_ALIGN(sizeof(struct xt_synproxy_info)),

	.help          = SYNPROXY_help,

	.print         = SYNPROXY_print,

	.save          = SYNPROXY_save,

	.x6_parse      = SYNPROXY_parse,

	.x6_fcheck     = SYNPROXY_check,

	.x6_options    = SYNPROXY_opts,

	.xlate         = SYNPROXY_xlate,

};

void _init(void)

{

	xtables_register_target(&synproxy_tg_reg);

}