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 "eval.h"

​

#include "zbxexpr.h"

#include "zbxstr.h"

​

/* The tag expression token is virtual token used during item query filter processing. */

#define ZBX_EVAL_TOKEN_TAG_EXPRESSION       (1000)

​

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

 *                                                                            *

 * Purpose: parses item query /host/key?[filter] into host, key and filter    *

 *          components                                                        *

 *                                                                            *

 * Parameters: str   - [IN] item query                                        *

 *             len   - [IN] query length                                      *

 *             query - [IN] parsed item query                                 *

 *                                                                            *

 * Return value: number of parsed characters                                  *

 *                                                                            *

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

size_t  zbx_eval_parse_query(const char *str, size_t len, zbx_item_query_t *query)

{

    size_t      n;

    const char  *host, *key, *filter;

​

    if (0 == (n = eval_parse_query(str, &host, &key, &filter)) || n != len)

        return 0;

​

    query->host = (host != key - 1 ? zbx_substr(host, 0, key - host - 2) : NULL);

​

    if (NULL != filter)

    {

        query->key = zbx_substr(key, 0, (filter - key) - 3);

        query->filter = zbx_substr(filter, 0, (str + len - filter) - 2);

    }

    else

    {

        query->key = zbx_substr(key, 0, (str + len - key) - 1);

        query->filter = NULL;

    }

​

    return n;

}

​

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

 *                                                                            *

 * Purpose: frees resources allocated by item reference                       *

 *                                                                            *

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

void    zbx_eval_clear_query(zbx_item_query_t *query)

{

    zbx_free(query->host);

    zbx_free(query->key);

    zbx_free(query->filter);

}

​

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

 *                                                                            *

 * Purpose: Prepares filter expression by converting property comparisons     *

 *          prop =/<> "value" to prop("value")/not prop("value") function     *

 *          calls.                                                            *

 *                                                                            *

 * Parameters: ctx - [IN] evaluation context                                  *

 *                                                                            *

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

void    zbx_eval_prepare_filter(zbx_eval_context_t *ctx)

{

    int i, j;

​

    for (i = 0; i < ctx->stack.values_num; i++)

    {

        zbx_eval_token_t    *prop = &ctx->stack.values[i];

​

        if (0 == (prop->type & ZBX_EVAL_CLASS_PROPERTY))

            continue;

​

        for (j = i + 1; j < ctx->stack.values_num; j++)