Zabbix

/*

** Copyright (C) 2001-2025 Zabbix SIA

**

** This program is free software: you can redistribute it and/or modify it under the terms of

** the GNU Affero General Public License as published by the Free Software Foundation, version 3.

**

** This program 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 Affero General Public License for more details.

**

** You should have received a copy of the GNU Affero General Public License along with this program.

** If not, see <https://www.gnu.org/licenses/>.

**/

​

#include "ip_reverse.h"

​

#include "zbxip.h"

#include "zbxcomms.h"

​

static void reverse_digits(short unsigned int a, char s2[8])

{

    char    s[8];

​

    zbx_snprintf(s, 8, "%04x", a);

​

    for (int i = 0; i <= 3; i++)

    {

        (s2)[i * 2] = s[3 - i];

        (s2)[i * 2 + 1] = '.';

    }

}

​

/******************************************************************************

 *                                                                            *

 * Purpose: Creates a new IP, from the provided one, that is suitabe for the  *

 *          reverse DNS lookup (PTR record type). IP needs to be reversed and *

 *          supplied in the special format for such queries. If the IP        *

 *          already is in the acceptable format - this will be detected, and  *

 *          new IP copy will not be changed, the returned IP will be          *

 *          identical to the supplied one. Otherwise, this functions attempts *

 *          to reverse and format it.                                         *

 *                                                                            *

 * Parameters:                                                                *

 *         src_ip - [IN]                                                      *

 *         dst_ip - [OUT] newly allocated string IP that is suitable to be    *

 *                        supplied to reverse DNS lookup                      *

 *         error  - [OUT]                                                     *

 *                                                                            *

 * Return value: SUCCEED or FAIL                                              *

 *                                                                            *

 * Comments: allocates memory                                                 *

 *                                                                            *

 ******************************************************************************/

int zbx_ip_reverse(const char *src_ip, char **dst_ip, char **error)

{

    if (NULL != strstr(src_ip, ".ip6.arpa") || NULL != strstr(src_ip, ".in-addr.arpa"))

    {

        *dst_ip = zbx_strdup(*dst_ip, src_ip);

​

        return SUCCEED;

    }

​

    if (SUCCEED == zbx_is_ip6(src_ip))