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 "zbxip.h"

​

#include "zbxnum.h"

#include "zbxstr.h"

​

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

 *                                                                            *

 * Purpose: checks if string is IPv4 address                                  *

 *                                                                            *

 * Parameters: ip - [IN]                                                      *

 *                                                                            *

 * Return value: SUCCEED - input is IPv4 address                              *

 *               FAIL    - otherwise                                          *

 *                                                                            *

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

int zbx_is_ip4(const char *ip)

{

    const char  *p = ip;

    int     digits = 0, dots = 0, res = FAIL, octet = 0;

​

    zabbix_log(LOG_LEVEL_DEBUG, "In %s() ip:'%s'", __func__, ip);

​

    while ('\0' != *p)

    {

        if (0 != isdigit(*p))

        {

            octet = octet * 10 + (*p - '0');

            digits++;

        }

        else if ('.' == *p)

        {

            if (0 == digits || 3 < digits || 255 < octet)

                break;

​

            digits = 0;

            octet = 0;

            dots++;

        }

        else

        {

            digits = 0;

            break;

        }

​

        p++;

    }

    if (3 == dots && 1 <= digits && 3 >= digits && 255 >= octet)

        res = SUCCEED;

​