/*
 * ip2location.c - IP2Location dlfunc for Exim
 * https://mta.org.ua/exim-4.94-conf/dlfunc/ip2location/ip2location.c
 *
 * Copyright (C) 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.
 */

#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <IP2Location.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);

#define string_sprintf(fmt, ...) \
	string_sprintf_trc(fmt, US __FUNCTION__, __LINE__, __VA_ARGS__)
extern uschar *string_sprintf_trc(const char *, const uschar *, unsigned, ...) ALMOST_PRINTF(1,4);


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

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

/* default code returned on lookup failures: */
#define RESULT_LOOKUP_FAILED	US"--"

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

int ip2location(uschar **yield, int argc, uschar *argv[])
{
	char *filename = (char *)argv[0];
	char *ip_address = (char *)argv[1];
	int defer_ok = 0;
	int status;
	IP2LocationRecord *record = NULL;

	if (argc < 2) {
		debug_printf("ip2location dlfunc: Invalid number of arguments\n");
		*yield = string_copy(US"Invalid number of arguments");
		return ERROR;
	}

	if (argc < 3) {
		defer_ok = 0;
	} else if (
		(strcmpic(argv[2], US"1") == 0)
		|| (strcmpic(argv[2], US"yes") == 0)
		|| (strcmpic(argv[2], US"true") == 0)
		|| (strcmpic(argv[2], US"defer_ok") == 0)
	) {
		defer_ok = 1;
	} else {
		defer_ok = 0;
	}
	debug_printf("ip2location dlfunc: defer_ok: %d\n", defer_ok);

	debug_printf("ip2location dlfunc: IP2Location API version: %s (%lu)\n", IP2Location_api_version_string(), IP2Location_api_version_num());

	debug_printf("ip2location dlfunc: try to find country for the host address %s in the %s database\n", ip_address, filename);

	IP2Location *IP2LocationObj = IP2Location_open(filename);
	if (IP2LocationObj == NULL) {
		if (defer_ok) {
			debug_printf("ip2location dlfunc: Call to IP2Location_open_mem failed\n");
			log_write(0, LOG_PANIC, "ip2location dlfunc: Call to IP2Location_open_mem failed");
			goto LOOKUP_FAILED_DEFER_OK;
		} else {
			*yield = string_sprintf("Call to IP2Location_open_mem failed", "");
			return ERROR;
		}
	}

	if(IP2Location_open_mem(IP2LocationObj, IP2LOCATION_SHARED_MEMORY) == -1) {
		if (defer_ok) {
			debug_printf("ip2location dlfunc: Can't open %s\n", filename);
			log_write(0, LOG_PANIC, "ip2location dlfunc: Can't open %s", filename);
			goto LOOKUP_FAILED_DEFER_OK;
		} else {
			*yield = string_sprintf("Can't open %s", filename);
			goto LOOKUP_FAILED;
		}
	}

	record = IP2Location_get_all(IP2LocationObj, ip_address);
	if (record != NULL) {
		*yield = string_sprintf("%s", (record->country_short == NULL ? (char *)RESULT_UNKNOWN : record->country_short));
		IP2Location_free_record(record);
	} else {
		*yield = string_sprintf("%s", RESULT_UNKNOWN);
	}
	IP2Location_close(IP2LocationObj);
	IP2Location_delete_shm();
	return OK;

LOOKUP_FAILED_DEFER_OK:
	*yield = string_sprintf("%s", RESULT_LOOKUP_FAILED);
LOOKUP_FAILED:
	if (IP2LocationObj != NULL) IP2Location_close(IP2LocationObj);
	return ERROR;
}