/*

 * Bart De Schuymer <bdschuym@pandora.be>

 *

 * 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.

 *

 * Giuseppe Longo <giuseppelng@gmail.com> adapted the original code to the

 * xtables-compat environment in 2015.

 *

 */

#include <stdio.h>

#include <stdlib.h>

#include <syslog.h>

#include <string.h>

#include <getopt.h>

#include <xtables.h>

#include <linux/netfilter_bridge/ebt_log.h>

#define LOG_DEFAULT_LEVEL LOG_INFO

#define LOG_PREFIX '1'

#define LOG_LEVEL  '2'

#define LOG_ARP    '3'

#define LOG_IP     '4'

#define LOG_LOG    '5'

#define LOG_IP6    '6'

struct code {

	char *c_name;

	int c_val;

};

static struct code eight_priority[] = {

	{ "emerg", LOG_EMERG },

	{ "alert", LOG_ALERT },

	{ "crit", LOG_CRIT },

	{ "error", LOG_ERR },

	{ "warning", LOG_WARNING },

	{ "notice", LOG_NOTICE },

	{ "info", LOG_INFO },

	{ "debug", LOG_DEBUG }

};

static int name_to_loglevel(const char *arg)

{

	int i;

	for (i = 0; i < 8; i++)

		if (!strcmp(arg, eight_priority[i].c_name))

			return eight_priority[i].c_val;

	/* return bad loglevel */

	return 9;

}

static const struct option brlog_opts[] = {

	{ .name = "log-prefix",		.has_arg = true,  .val = LOG_PREFIX },

	{ .name = "log-level",		.has_arg = true,  .val = LOG_LEVEL  },

	{ .name = "log-arp",		.has_arg = false, .val = LOG_ARP    },

	{ .name = "log-ip",		.has_arg = false, .val = LOG_IP     },

	{ .name = "log",		.has_arg = false, .val = LOG_LOG    },

	{ .name = "log-ip6",		.has_arg = false, .val = LOG_IP6    },

	XT_GETOPT_TABLEEND,

};

static void brlog_help(void)

{

	int i;

	printf(

"log options:\n"

"--log               : use this if you're not specifying anything\n"

"--log-level level   : level = [1-8] or a string\n"

"--log-prefix prefix : max. %d chars.\n"

"--log-ip            : put ip info. in the log for ip packets\n"

"--log-arp           : put (r)arp info. in the log for (r)arp packets\n"

"--log-ip6           : put ip6 info. in the log for ip6 packets\n"

	, EBT_LOG_PREFIX_SIZE - 1);

	for (i = 0; i < 8; i++)

		printf("%d = %s\n", eight_priority[i].c_val,

				    eight_priority[i].c_name);

}

static void brlog_init(struct xt_entry_target *t)

{

	struct ebt_log_info *loginfo = (struct ebt_log_info *)t->data;

	loginfo->bitmask = 0;

	loginfo->prefix[0] = '\0';

	loginfo->loglevel = LOG_NOTICE;

}

static unsigned int log_chk_inv(int inv, unsigned int bit, const char *suffix)

{

	if (inv)

		xtables_error(PARAMETER_PROBLEM,

			      "Unexpected `!' after --log%s", suffix);

	return bit;

}

static int brlog_parse(int c, char **argv, int invert, unsigned int *flags,

		       const void *entry, struct xt_entry_target **target)

{

	struct ebt_log_info *loginfo = (struct ebt_log_info *)(*target)->data;

	long int i;

	char *end;

	switch (c) {

	case LOG_PREFIX:

		if (invert)

			xtables_error(PARAMETER_PROBLEM,

				      "Unexpected `!` after --log-prefix");

		if (strlen(optarg) > sizeof(loginfo->prefix) - 1)

			xtables_error(PARAMETER_PROBLEM,

				      "Prefix too long");

		if (strchr(optarg, '\"'))

			xtables_error(PARAMETER_PROBLEM,

				      "Use of \\\" is not allowed"

				      " in the prefix");

		strcpy((char *)loginfo->prefix, (char *)optarg);

		break;

	case LOG_LEVEL:

		i = strtol(optarg, &end, 16);

		if (*end != '\0' || i < 0 || i > 7)

			loginfo->loglevel = name_to_loglevel(optarg);

		else

			loginfo->loglevel = i;

		if (loginfo->loglevel == 9)

			xtables_error(PARAMETER_PROBLEM,

				      "Problem with the log-level");

		break;

	case LOG_IP:

		loginfo->bitmask |= log_chk_inv(invert, EBT_LOG_IP, "-ip");

		break;

	case LOG_ARP:

		loginfo->bitmask |= log_chk_inv(invert, EBT_LOG_ARP, "-arp");

		break;

	case LOG_LOG:

		loginfo->bitmask |= log_chk_inv(invert, 0, "");

		break;

	case LOG_IP6:

		loginfo->bitmask |= log_chk_inv(invert, EBT_LOG_IP6, "-ip6");

		break;

	default:

		return 0;

	}

	*flags |= loginfo->bitmask;

	return 1;

}

static void brlog_final_check(unsigned int flags)

{

}

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

			int numeric)

{

	struct ebt_log_info *loginfo = (struct ebt_log_info *)target->data;

	printf("--log-level %s --log-prefix \"%s\"",

		eight_priority[loginfo->loglevel].c_name,

		loginfo->prefix);

	if (loginfo->bitmask & EBT_LOG_IP)

		printf(" --log-ip");

	if (loginfo->bitmask & EBT_LOG_ARP)

		printf(" --log-arp");

	if (loginfo->bitmask & EBT_LOG_IP6)

		printf(" --log-ip6");

	printf(" ");

}

static int brlog_xlate(struct xt_xlate *xl,

		       const struct xt_xlate_tg_params *params)

{

	const struct ebt_log_info *loginfo = (const void *)params->target->data;

	xt_xlate_add(xl, "log");

	if (loginfo->prefix[0]) {

		if (params->escape_quotes)

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

		else

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

	}

	if (loginfo->loglevel != LOG_DEFAULT_LEVEL)

		xt_xlate_add(xl, " level %s", eight_priority[loginfo->loglevel].c_name);

	xt_xlate_add(xl, " flags ether ");

	return 1;

}

static struct xtables_target brlog_target = {

	.name		= "log",

	.revision	= 0,

	.version	= XTABLES_VERSION,

	.family		= NFPROTO_BRIDGE,

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

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

	.init		= brlog_init,

	.help		= brlog_help,

	.parse		= brlog_parse,

	.final_check	= brlog_final_check,

	.print		= brlog_print,

	.xlate		= brlog_xlate,

	.extra_opts	= brlog_opts,

};

void _init(void)

{

	xtables_register_target(&brlog_target);

}