#include <stdbool.h>

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <getopt.h>

#include <xtables.h>

#include <linux/netfilter/x_tables.h>

#include <linux/netfilter/xt_NFLOG.h>

enum {

	O_GROUP = 0,

	O_PREFIX,

	O_RANGE,

	O_SIZE,

	O_THRESHOLD,

	F_RANGE = 1 << O_RANGE,

	F_SIZE = 1 << O_SIZE,

};

#define s struct xt_nflog_info

static const struct xt_option_entry NFLOG_opts[] = {

	{.name = "nflog-group", .id = O_GROUP, .type = XTTYPE_UINT16,

	 .flags = XTOPT_PUT, XTOPT_POINTER(s, group)},

	{.name = "nflog-prefix", .id = O_PREFIX, .type = XTTYPE_STRING,

	 .min = 1, .flags = XTOPT_PUT, XTOPT_POINTER(s, prefix)},

	{.name = "nflog-range", .id = O_RANGE, .type = XTTYPE_UINT32,

	 .excl = F_SIZE, .flags = XTOPT_PUT, XTOPT_POINTER(s, len)},

	{.name = "nflog-size", .id = O_SIZE, .type = XTTYPE_UINT32,

	 .excl = F_RANGE, .flags = XTOPT_PUT, XTOPT_POINTER(s, len)},

	{.name = "nflog-threshold", .id = O_THRESHOLD, .type = XTTYPE_UINT16,

	 .flags = XTOPT_PUT, XTOPT_POINTER(s, threshold)},

	XTOPT_TABLEEND,

};

#undef s

static void NFLOG_help(void)

{

	printf("NFLOG target options:\n"

	       " --nflog-group NUM		NETLINK group used for logging\n"

	       " --nflog-range NUM		This option has no effect, use --nflog-size\n"

	       " --nflog-size NUM		Number of bytes to copy\n"

	       " --nflog-threshold NUM		Message threshold of in-kernel queue\n"

	       " --nflog-prefix STRING		Prefix string for log messages\n");

}

static void NFLOG_init(struct xt_entry_target *t)

{

	struct xt_nflog_info *info = (struct xt_nflog_info *)t->data;

	info->threshold	= XT_NFLOG_DEFAULT_THRESHOLD;

}

static void NFLOG_parse(struct xt_option_call *cb)

{

	xtables_option_parse(cb);

	switch (cb->entry->id) {

	case O_PREFIX:

		if (strchr(cb->arg, '\n') != NULL)

			xtables_error(PARAMETER_PROBLEM,

				   "Newlines not allowed in --log-prefix");

		break;

	}

}

static void NFLOG_check(struct xt_fcheck_call *cb)

{

	struct xt_nflog_info *info = cb->data;

	if (cb->xflags & F_RANGE)

		fprintf(stderr, "warn: --nflog-range has never worked and is no"

			" longer supported, please use --nflog-size insted\n");

	if (cb->xflags & F_SIZE)

		info->flags |= XT_NFLOG_F_COPY_LEN;

}

static void nflog_print(const struct xt_nflog_info *info, char *prefix)

{

	if (info->prefix[0] != '\0') {

		printf(" %snflog-prefix ", prefix);

		xtables_save_string(info->prefix);

	}

	if (info->group)

		printf(" %snflog-group %u", prefix, info->group);

	if (info->flags & XT_NFLOG_F_COPY_LEN)

		printf(" %snflog-size %u", prefix, info->len);

	else if (info->len)

		printf(" %snflog-range %u", prefix, info->len);

	if (info->threshold != XT_NFLOG_DEFAULT_THRESHOLD)

		printf(" %snflog-threshold %u", prefix, info->threshold);

}

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

			int numeric)

{

	const struct xt_nflog_info *info = (struct xt_nflog_info *)target->data;

	nflog_print(info, "");

}

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

{

	const struct xt_nflog_info *info = (struct xt_nflog_info *)target->data;

	nflog_print(info, "--");

}

static void nflog_print_xlate(const struct xt_nflog_info *info,

			      struct xt_xlate *xl, bool escape_quotes)

{

	xt_xlate_add(xl, "log ");

	if (info->prefix[0] != '\0') {

		if (escape_quotes)

			xt_xlate_add(xl, "prefix \\\"%s\\\" ", info->prefix);

		else

			xt_xlate_add(xl, "prefix \"%s\" ", info->prefix);

	}

	if (info->flags & XT_NFLOG_F_COPY_LEN)

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

	if (info->threshold != XT_NFLOG_DEFAULT_THRESHOLD)

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

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

}

static int NFLOG_xlate(struct xt_xlate *xl,

		       const struct xt_xlate_tg_params *params)

{

	const struct xt_nflog_info *info =

		(struct xt_nflog_info *)params->target->data;

	nflog_print_xlate(info, xl, params->escape_quotes);

	return 1;

}

static struct xtables_target nflog_target = {

	.family		= NFPROTO_UNSPEC,

	.name		= "NFLOG",

	.version	= XTABLES_VERSION,

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

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

	.help		= NFLOG_help,

	.init		= NFLOG_init,

	.x6_fcheck	= NFLOG_check,

	.x6_parse	= NFLOG_parse,

	.print		= NFLOG_print,

	.save		= NFLOG_save,

	.x6_options	= NFLOG_opts,

	.xlate		= NFLOG_xlate,

};

void _init(void)

{

	xtables_register_target(&nflog_target);

}