/*
 * ip2country_v6 - MaxMind GeoIP dlfunc for Exim
 * https://mta.org.ua/exim-4.94-conf/dlfunc/ip2country_v6/ip2country_v6.c
 *
 * Copyright (C) 2018-2020 Victor Ustugov <corvax+dlfunc@mta.org.ua>
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Based on source code from https://github.com/snabb/exim-geoipv6-dlfunc
 * by Janne Snabb <snabb@epipe.com>
 */

/* Headers for inet_pton(3): */
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

/* MaxMind GeoIP C API header: */
#include "GeoIP.h"

//#define DLFUNC_IMPL
/* Exim4 dlfunc API header: */
//#include "local_scan.h"
//#include "macros.h"
#include "exim.h"

//# define string_copy(s) string_copy_function(s)
//# define string_copyn(s, n) string_copyn_function((s), (n))
//# define string_copy_taint(s, t) string_copy_taint_function((s), (t))

extern uschar * string_copy_function(const uschar *);
extern uschar * string_copyn_function(const uschar *, int n);
extern uschar * string_copy_taint_function(const uschar *, BOOL tainted);


/*****************************************************************************
 * Configuration settings:
 *****************************************************************************/

/* GeoIP database edition selection: */
#define EDITION_V4	GEOIP_COUNTRY_EDITION
#define EDITION_V6	GEOIP_COUNTRY_EDITION_V6

/* default code returned when country is unknown: */
#define COUNTRY_CODE_UNKNOWN		US"--"

/* default code returned on lookup failures due to missing database: */
#define COUNTRY_CODE_LOOKUP_FAILED	US"--"

//-------------------------------------------------------------------------

int ip2country_v6(uschar **yield, int argc, uschar *argv[]) {
	GeoIP *gi;
	const char *res;
	union {
		struct in_addr buf4;
		struct in6_addr buf6;
	} buf;

	if (argc != 1) {
		*yield = string_copy(US"Invalid number of arguments");
		return ERROR;
        }

	if (inet_pton(AF_INET, (char *) argv[0], &buf) == 1) {
		/* IPv4 address: */

		gi = GeoIP_open_type(EDITION_V4, GEOIP_STANDARD);

		if (gi == NULL) {
			log_write(0, LOG_MAIN, "ip2country_v6: Failed to open IPv4 GeoIP database");
			*yield = string_copy(COUNTRY_CODE_LOOKUP_FAILED);
			return OK;
		}

		res = GeoIP_country_code_by_addr(gi, (char *) argv[0]);

	} else if (inet_pton(AF_INET6, (char *) argv[0], &buf) == 1) {
		/* IPv6 address: */

		gi = GeoIP_open_type(EDITION_V6, GEOIP_STANDARD);

		if (gi == NULL) {
			log_write(0, LOG_MAIN, "ip2country_v6: Failed to open IPv6 GeoIP database");
			*yield = string_copy(COUNTRY_CODE_LOOKUP_FAILED);
			return OK;
		}

		res = GeoIP_country_code_by_addr_v6(gi, (char *) argv[0]);

	} else {
		/* Unrecognized address format: */

		*yield = string_copy(US"Unrecognized address format");
		return FAIL;
	}
	GeoIP_delete(gi);

	if (res == NULL)
		*yield = string_copy(COUNTRY_CODE_UNKNOWN);
	else
		*yield = string_copy(US res);

	return OK;
}

int ip2continent_v6(uschar **yield, int argc, uschar *argv[]) {
	GeoIP *gi;
	const char *res;
	union {
		struct in_addr buf4;
		struct in6_addr buf6;
	} buf;
	const char *country;

	if (argc != 1) {
		*yield = string_copy(US"Invalid number of arguments");
		return ERROR;
        }

	if (inet_pton(AF_INET, (char *) argv[0], &buf) == 1) {
		/* IPv4 address: */

		gi = GeoIP_open_type(EDITION_V4, GEOIP_STANDARD);

		if (gi == NULL) {
			log_write(0, LOG_MAIN, "ip2country_v6: Failed to open IPv4 GeoIP database");
			*yield = string_copy(COUNTRY_CODE_LOOKUP_FAILED);
			return OK;
		}

		country = GeoIP_country_code_by_addr(gi, (char *) argv[0]);
		if (country == NULL) {
			*yield = string_copy(COUNTRY_CODE_UNKNOWN);
			return OK;
		}
		res = GeoIP_continent_by_id(GeoIP_id_by_code(country));

	} else if (inet_pton(AF_INET6, (char *) argv[0], &buf) == 1) {
		/* IPv6 address: */

		gi = GeoIP_open_type(EDITION_V6, GEOIP_STANDARD);

		if (gi == NULL) {
			log_write(0, LOG_MAIN, "ip2country_v6: Failed to open IPv6 GeoIP database");
			*yield = string_copy(COUNTRY_CODE_LOOKUP_FAILED);
			return OK;
		}

		country = GeoIP_country_code_by_addr_v6(gi, (char *) argv[0]);
		if (country == NULL) {
			*yield = string_copy(COUNTRY_CODE_UNKNOWN);
			return OK;
		}
		res = GeoIP_continent_by_id(GeoIP_id_by_code(country));

	} else {
		/* Unrecognized address format: */

		*yield = string_copy(US"Unrecognized address format");
		return FAIL;
	}
	GeoIP_delete(gi);

	if (res == NULL)
		*yield = string_copy(COUNTRY_CODE_UNKNOWN);
	else
		*yield = string_copy(US res);

	return OK;
}

/*****************************************************************************
 * eof
 *****************************************************************************/