/*

 * IPv6 Hop Limit Target module

 * Maciej Soltysiak <solt@dns.toxicfilms.tv>

 * Based on HW's ttl target

 * This program is distributed under the terms of GNU GPL

 */

#include <stdio.h>

#include <xtables.h>

#include <linux/netfilter_ipv6/ip6t_HL.h>

enum {

	O_HL_SET = 0,

	O_HL_INC,

	O_HL_DEC,

	F_HL_SET = 1 << O_HL_SET,

	F_HL_INC = 1 << O_HL_INC,

	F_HL_DEC = 1 << O_HL_DEC,

	F_ANY    = F_HL_SET | F_HL_INC | F_HL_DEC,

};

#define s struct ip6t_HL_info

static const struct xt_option_entry HL_opts[] = {

	{.name = "hl-set", .type = XTTYPE_UINT8, .id = O_HL_SET,

	 .excl = F_ANY, .flags = XTOPT_PUT, XTOPT_POINTER(s, hop_limit)},

	{.name = "hl-dec", .type = XTTYPE_UINT8, .id = O_HL_DEC,

	 .excl = F_ANY, .flags = XTOPT_PUT, XTOPT_POINTER(s, hop_limit),

	 .min = 1},

	{.name = "hl-inc", .type = XTTYPE_UINT8, .id = O_HL_INC,

	 .excl = F_ANY, .flags = XTOPT_PUT, XTOPT_POINTER(s, hop_limit),

	 .min = 1},

	XTOPT_TABLEEND,

};

#undef s

static void HL_help(void)

{

	printf(

"HL target options\n"

"  --hl-set value		Set HL to <value 0-255>\n"

"  --hl-dec value		Decrement HL by <value 1-255>\n"

"  --hl-inc value		Increment HL by <value 1-255>\n");

}

static void HL_parse(struct xt_option_call *cb)

{

	struct ip6t_HL_info *info = cb->data;

	xtables_option_parse(cb);

	switch (cb->entry->id) {

	case O_HL_SET:

		info->mode = IP6T_HL_SET;

		break;

	case O_HL_INC:

		info->mode = IP6T_HL_INC;

		break;

	case O_HL_DEC:

		info->mode = IP6T_HL_DEC;

		break;

	}

}

static void HL_check(struct xt_fcheck_call *cb)

{

	if (!(cb->xflags & F_ANY))

		xtables_error(PARAMETER_PROBLEM,

				"HL: You must specify an action");

}

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

{

	const struct ip6t_HL_info *info = 

		(struct ip6t_HL_info *) target->data;

	switch (info->mode) {

		case IP6T_HL_SET:

			printf(" --hl-set");

			break;

		case IP6T_HL_DEC:

			printf(" --hl-dec");

			break;

		case IP6T_HL_INC:

			printf(" --hl-inc");

			break;

	}

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

}

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

                     int numeric)

{

	const struct ip6t_HL_info *info =

		(struct ip6t_HL_info *) target->data;

	printf(" HL ");

	switch (info->mode) {

		case IP6T_HL_SET:

			printf("set to");

			break;

		case IP6T_HL_DEC:

			printf("decrement by");

			break;

		case IP6T_HL_INC:

			printf("increment by");

			break;

	}

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

}

static struct xtables_target hl_tg6_reg = {

	.name 		= "HL",

	.version	= XTABLES_VERSION,

	.family		= NFPROTO_IPV6,

	.size		= XT_ALIGN(sizeof(struct ip6t_HL_info)),

	.userspacesize	= XT_ALIGN(sizeof(struct ip6t_HL_info)),

	.help		= HL_help,

	.print		= HL_print,

	.save		= HL_save,

	.x6_parse	= HL_parse,

	.x6_fcheck	= HL_check,

	.x6_options	= HL_opts,

};

void _init(void)

{

	xtables_register_target(&hl_tg6_reg);

}