/*
** 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 "pp_error.h"
#include "zbxdbhigh.h"
#include "zbxstr.h"
#include "zbxvariant.h"
#include "zbxalgo.h"
#include "zbxdbschema.h"
/* mock field to estimate how much data can be stored in characters, bytes or both, */
/* depending on database backend */
typedef struct
{
int bytes_num;
int chars_num;
}
zbx_db_mock_field_t;
ZBX_PTR_VECTOR_IMPL(pp_result_ptr, zbx_pp_result_t *)
/******************************************************************************
* *
* Purpose: set result value *
* *
* Parameters: result - [OUT] result to set *
* value - [IN] field type in database schema *
* action - [IN] on fail action *
* value_raw - [IN] value before applying on fail action if *
* non-default action was applied. This value is *
* 'moved' over to result. *
* *
******************************************************************************/
void pp_result_set(zbx_pp_result_t *result, const zbx_variant_t *value, int action, zbx_variant_t *value_raw)
{
zbx_variant_copy(&result->value, value);
result->value_raw = *value_raw;
zbx_variant_set_none(value_raw);
result->action = action;
}
void zbx_pp_result_free(zbx_pp_result_t *result)
{
zbx_variant_clear(&result->value);
zbx_variant_clear(&result->value_raw);
zbx_free(result);
}
void pp_free_results(zbx_pp_result_t *results, int results_num)
{
for (int i = 0; i < results_num; i++)
{
zbx_variant_clear(&results[i].value);
zbx_variant_clear(&results[i].value_raw);
}
zbx_free(results);
}
/******************************************************************************
* *
* Purpose: initializes mock field *
* *
* Parameters: field - [OUT] field data *
* field_type - [IN] field type in database schema *
* field_len - [IN] field size in database schema *
* *
******************************************************************************/
static void zbx_db_mock_field_init(zbx_db_mock_field_t *field, int field_type, int field_len)
{
switch (field_type)
{
case ZBX_TYPE_CHAR:
field->chars_num = field_len;
field->bytes_num = -1;
return;
}
THIS_SHOULD_NEVER_HAPPEN;
field->chars_num = 0;
field->bytes_num = 0;
}
/******************************************************************************
* *
* Purpose: 'appends' text to the field, if successful the character/byte *
* limits are updated *
* *
* Parameters: field - [IN/OUT] mock field *
* text - [IN] text to append *
* *
* Return value: SUCCEED - the field had enough space to append the text *
* FAIL - otherwise *
* *
******************************************************************************/
static int zbx_db_mock_field_append(zbx_db_mock_field_t *field, const char *text)
{
int bytes_num, chars_num;
if (-1 != field->bytes_num)
{
bytes_num = (int)strlen(text);
if (bytes_num > field->bytes_num)
return FAIL;
}
else
bytes_num = 0;
if (-1 != field->chars_num)
{
chars_num = (int)zbx_strlen_utf8(text);
if (chars_num > field->chars_num)
return FAIL;
}
else
chars_num = 0;
field->bytes_num -= bytes_num;
field->chars_num -= chars_num;
return SUCCEED;
}
/******************************************************************************
* *
* Purpose: format value in text format *
* *
* Parameters: value - [IN] value to format *
* value_str - [OUT] formatted value *
* *
* Comments: Control characters are replaced with '.' and truncated if it's *
* larger than ZBX_PP_VALUE_PREVIEW_LEN characters. *
* *
******************************************************************************/
static void pp_error_format_value(const zbx_variant_t *value, char **value_str)
{
const char *value_desc;
size_t i, len;
#define ZBX_PP_VALUE_PREVIEW_LEN 100
value_desc = zbx_variant_value_desc(value);
if (ZBX_PP_VALUE_PREVIEW_LEN < zbx_strlen_utf8(value_desc))
{
/* truncate value and append '...' */
len = zbx_strlen_utf8_nchars(value_desc, ZBX_PP_VALUE_PREVIEW_LEN - ZBX_CONST_STRLEN("..."));
*value_str = zbx_malloc(NULL, len + ZBX_CONST_STRLEN("...") + 1);
memcpy(*value_str, value_desc, len);
memcpy(*value_str + len, "...", ZBX_CONST_STRLEN("...") + 1);
}
else
{
*value_str = zbx_malloc(NULL, (len = strlen(value_desc)) + 1);
memcpy(*value_str, value_desc, len + 1);
}
/* replace control characters */
for (i = 0; i < len; i++)
{
if (0 != iscntrl((*value_str)[i]))
(*value_str)[i] = '.';
}
#undef ZBX_PP_VALUE_PREVIEW_LEN
}
/******************************************************************************
* *
* Purpose: format one preprocessing step result *
* *
* Parameters: step - [IN] preprocessing step number *
* result - [IN] preprocessing step result *
* out - [OUT] formatted string *
* *
******************************************************************************/
static void pp_error_format_result(int step, const zbx_pp_result_t *result, char **out)
{
char *actions[] = {"", " (discard value)", " (set value)", " (set error)"};
if (ZBX_VARIANT_ERR != result->value.type)
{
char *value_str;
pp_error_format_value(&result->value, &value_str);
*out = zbx_dsprintf(NULL, "%d. Result%s: %s\n", step, actions[result->action], value_str);
zbx_free(value_str);
}
else
{
*out = zbx_dsprintf(NULL, "%d. Failed%s: %s\n", step, actions[result->action],
zbx_variant_value_desc(&result->value));
}
}
/******************************************************************************
* *
* Purpose: format preprocessing error message *
* *
* Parameters: value - [IN] input value *
* results - [IN] preprocessing step results *
* results_num - [IN] number of executed steps *
* error - [OUT] formatted error message *
* *
******************************************************************************/
void pp_format_error(const zbx_variant_t *value, zbx_pp_result_t *results, int results_num, char **error)
{
char *value_str, *err_step;
int i;
size_t error_alloc = 512, error_offset = 0;
zbx_vector_str_t results_str;
zbx_db_mock_field_t field;
zbx_vector_str_create(&results_str);
/* add header to error message */
*error = zbx_malloc(NULL, error_alloc);
pp_error_format_value(value, &value_str);
zbx_snprintf_alloc(error, &error_alloc, &error_offset, "Preprocessing failed for: %s\n", value_str);
zbx_free(value_str);
zbx_db_mock_field_init(&field, ZBX_TYPE_CHAR, ZBX_ITEM_ERROR_LEN);
zbx_db_mock_field_append(&field, *error);
zbx_db_mock_field_append(&field, "...\n");
/* format the last (failed) step */
pp_error_format_result(results_num, &results[results_num - 1], &err_step);
zbx_vector_str_append(&results_str, err_step);
if (SUCCEED == zbx_db_mock_field_append(&field, err_step))
{
/* format the first steps */
for (i = results_num - 2; i >= 0; i--)
{
pp_error_format_result(i + 1, &results[i], &err_step);
if (SUCCEED != zbx_db_mock_field_append(&field, err_step))
{
zbx_free(err_step);
break;
}
zbx_vector_str_append(&results_str, err_step);
}
}
/* add steps to error message */
if (results_str.values_num < results_num)
zbx_strcpy_alloc(error, &error_alloc, &error_offset, "...\n");
for (i = results_str.values_num - 1; i >= 0; i--)
zbx_strcpy_alloc(error, &error_alloc, &error_offset, results_str.values[i]);
zbx_rtrim(*error, ZBX_WHITESPACE);
/* truncate formatted error if necessary */
if (ZBX_ITEM_ERROR_LEN < zbx_strlen_utf8(*error))
{
char *ptr;
ptr = (*error) + zbx_strlen_utf8_nchars(*error, ZBX_ITEM_ERROR_LEN - 3);
for (i = 0; i < 3; i++)
*ptr++ = '.';
*ptr = '\0';
}
zbx_vector_str_clear_ext(&results_str, zbx_str_free);
zbx_vector_str_destroy(&results_str);
}
/******************************************************************************
* *
* Purpose: apply 'on fail' preprocessing error handler *
* *
* Parameters: value - [IN/OUT] *
* step - [IN] preprocessing operation that produced error *
* *
******************************************************************************/
int pp_error_on_fail(zbx_dc_um_shared_handle_t *um_handle, zbx_uint64_t hostid, zbx_variant_t *value,
const zbx_pp_step_t *step)
{
char *error_handler_params;
zabbix_log(LOG_LEVEL_DEBUG, "In %s()", __func__);
switch (step->error_handler)
{
case ZBX_PREPROC_FAIL_DISCARD_VALUE:
zbx_variant_clear(value);
break;
case ZBX_PREPROC_FAIL_SET_VALUE:
case ZBX_PREPROC_FAIL_SET_ERROR:
zbx_variant_clear(value);
error_handler_params = zbx_strdup(NULL, step->error_handler_params);
if (NULL != um_handle)
{
char *error = NULL;
if (SUCCEED != zbx_dc_expand_user_and_func_macros_from_cache(um_handle->um_cache,
&error_handler_params, &hostid, 1, ZBX_MACRO_ENV_NONSECURE, &error))
{
zabbix_log(LOG_LEVEL_DEBUG, "cannot resolve user macros: %s", error);
zbx_free(error);
}
}
if (ZBX_PREPROC_FAIL_SET_VALUE == step->error_handler)
{
zbx_variant_set_str(value, error_handler_params);
}
else if (ZBX_PREPROC_FAIL_SET_ERROR == step->error_handler)
{
zbx_variant_set_error(value, error_handler_params);
}
else
{
THIS_SHOULD_NEVER_HAPPEN;
zabbix_log(LOG_LEVEL_ERR, "unexpected \"custom on fail\" handler type %d",
step->error_handler);
zbx_free(error_handler_params);
}
break;
}
zabbix_log(LOG_LEVEL_DEBUG, "End of %s() value:%s", __func__, zbx_variant_value_desc(value));
return step->error_handler;
}