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<?php
/*
** Zabbix
** Copyright (C) 2001-2023 Zabbix SIA
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** 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 General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
**/
/**
* A parser for Prometheus pattern.
*/
class CPrometheusPatternParser extends CParser {
private $options = [
'usermacros' => false,
'lldmacros' => false
];
private $user_macro_parser;
private $lld_macro_parser;
private $lld_macro_function_parser;
public function __construct($options = []) {
if (array_key_exists('usermacros', $options)) {
$this->options['usermacros'] = $options['usermacros'];
}
if (array_key_exists('lldmacros', $options)) {
$this->options['lldmacros'] = $options['lldmacros'];
}
if ($this->options['usermacros']) {
$this->user_macro_parser = new CUserMacroParser();
}
if ($this->options['lldmacros']) {
$this->lld_macro_parser = new CLLDMacroParser();
$this->lld_macro_function_parser = new CLLDMacroFunctionParser();
}
}
/**
* Parse the given source string.
*
* metric { label1 =~ "value1" , label2 =" value2" } == number
*
* @param string $source Source string that needs to be parsed.
* @param int $pos Position offset.
*/
public function parse($source, $pos = 0) {
$this->length = 0;
$this->match = '';
$has_metric_name = false;
$p = $pos;
if ($this->parseMetric($source, $p)) {
$has_metric_name = true;
}
$p_tmp = $p;
if ($has_metric_name) {
self::skipWhitespaces($source, $p_tmp);
}
if ($this->parseLabelsValues($source, $p_tmp, $has_metric_name)) {
$p = $p_tmp;
}
elseif (!$has_metric_name) {
return self::PARSE_FAIL;
}
$p_tmp = $p;
self::skipWhitespaces($source, $p_tmp);
if ($this->parseComparisonOperator($source, $p_tmp)) {
self::skipWhitespaces($source, $p_tmp);
if ($this->parseNumber($source, $p_tmp)) {
$p = $p_tmp;
}
}
$this->length = $p - $pos;
$this->match = substr($source, $pos, $this->length);
return isset($source[$p]) ? self::PARSE_SUCCESS_CONT : self::PARSE_SUCCESS;
}
/**
* Move pointer at the end of whitespaces.
*
* @param string $source [IN] Source string that needs to be parsed.
* @param int $pos [IN/OUT] Position offset.
*
* @return bool
*/
private static function skipWhitespaces($source, &$pos) {
while (isset($source[$pos]) && ($source[$pos] === ' ' || $source[$pos] === "\t")) {
$pos++;
}
}
/**
* Parse metric parameter. Must follow the [a-zA-Z_:][a-zA-Z0-9_:]* regular expression. User macros and LLD macros
* are allowed.
*
* @param string $source [IN] Source string that needs to be parsed.
* @param int $pos [IN/OUT] Position offset.
*
* @return bool
*/
private function parseMetric($source, &$pos) {
if (preg_match('/^[a-zA-Z_:][a-zA-Z0-9_:]*/', substr($source, $pos), $matches)) {
$pos += strlen($matches[0]);
return true;
}
elseif ($this->options['usermacros'] && $this->user_macro_parser->parse($source, $pos) != self::PARSE_FAIL) {
$pos += $this->user_macro_parser->getLength();
return true;
}
elseif ($this->options['lldmacros'] && $this->lld_macro_parser->parse($source, $pos) != self::PARSE_FAIL) {
$pos += $this->lld_macro_parser->getLength();
return true;
}
elseif ($this->options['lldmacros']
&& $this->lld_macro_function_parser->parse($source, $pos) != self::PARSE_FAIL) {
$pos += $this->lld_macro_function_parser->getLength();
return true;
}
return false;
}
/**
* Parse label names and label values. Label name must follow the [a-zA-Z_][a-zA-Z0-9_]* regular expression. After
* label name, an operator must follow. Allowed operators are: = and =~ After operator a quoted value must follow.
* Value can contain any string and can be empty. Each label name and label value pair can be separated by a comma.
* Trailing comma is allowed. Spaces are trimmed before and after each unit (label name, operator, label value
* and comma).
*
* @param string $source [IN] Source string that needs to be parsed.
* @param int $pos [IN/OUT] Position offset.
* @param bool $has_metric_label [IN/OUT] Returns true if __name__ is present.
*
* @return bool
*/
private function parseLabelValuePair($source, &$pos, &$has_metric_label) {
$p = $pos;
// Parse label name.
if (preg_match('/^[a-zA-Z_][a-zA-Z0-9_]*/', substr($source, $p), $matches)) {
if ($matches[0] === '__name__') {
if ($has_metric_label) {
return false;
}
$has_metric_label = true;
}
$p += strlen($matches[0]);
}
elseif ($this->options['usermacros'] && $this->user_macro_parser->parse($source, $p) != self::PARSE_FAIL) {
$p += $this->user_macro_parser->getLength();
}
elseif ($this->options['lldmacros'] && $this->lld_macro_parser->parse($source, $pos) != self::PARSE_FAIL) {
$p += $this->lld_macro_parser->getLength();
}
elseif ($this->options['lldmacros']
&& $this->lld_macro_function_parser->parse($source, $pos) != self::PARSE_FAIL) {
$p += $this->lld_macro_function_parser->getLength();
}
else {
return false;
}
self::skipWhitespaces($source, $p);
// Parse operator.
if (!isset($source[$p]) || !isset($source[$p + 1])) {
// Even if $p + 1 is not part of the operator, we still must have a character there
return false;
}
if ($source[$p] === '=') {
if ($source[$p + 1] === '~') {
$p += 2; // =~
} else {
$p += 1; // =
}
}
elseif ($source[$p] === '!') {
if ($source[$p + 1] !== '=' && $source[$p + 1] !== '~') {
return false;
}
$p += 2; // != or !~
}
else {
return false;
}
self::skipWhitespaces($source, $p);
// Parse label value.
if (!isset($source[$p]) || $source[$p] !== '"') {
return false;
}
$p++;
while (isset($source[$p])) {
switch ($source[$p]) {
case '\\':
switch (isset($source[$p + 1]) ? $source[$p + 1] : null) {
case '\\':
case '"':
case 'n':
$p++;
break;
default:
return false;
}
break;
case '"':
break 2;
}
$p++;
}
if (!isset($source[$p]) || $source[$p] !== '"') {
return false;
}
$p++;
$pos = $p;
return true;
}
/**
* Parse label names and label value pairs as one parameter that is wrapped in curly braces. Spaces are trimmed
* before and after each curly braces and label value pairs. Two __name__ labels are not allowed.
*
* @param string $source [IN] Source string that needs to be parsed.
* @param int $pos [IN/OUT] Position offset.
* @param bool $has_metric_name [IN] Metric name is present in the pattern.
*
* @return bool
*/
private function parseLabelsValues($source, &$pos, $has_metric_name) {
$p = $pos;
if (!isset($source[$p]) || $source[$p] !== '{') {
return false;
}
$p++;
$has_metric_label = false;
while (true) {
self::skipWhitespaces($source, $p);
if (!$this->parseLabelValuePair($source, $p, $has_metric_label)) {
break;
}
self::skipWhitespaces($source, $p);
if (!isset($source[$p]) || $source[$p] !== ',') {
break;
}
$p++;
}
if ($has_metric_name && $has_metric_label) {
return false;
}
if (!isset($source[$p]) || $source[$p] !== '}') {
return false;
}
$p++;
$pos = $p;
return true;
}
/**
* Parse number. It can be with plus or minus sign, can use scientific notation, decimals points, can even be
* not a number or infinity. User and LLD macros are allowed.
*
* @param string $source [IN] Source string that needs to be parsed.
* @param int $pos [IN/OUT] Position offset.
*
* @return bool
*/
private function parseNumber($source, &$pos) {
$pattern_num = '[+-]?([0-9]+(\.[0-9]*)?|\.[0-9]+)(e[+-]?[0-9]+)?';
$pattern_inf = '[+-]?inf';
$pattern_nan = 'nan';
if (preg_match('/^('.$pattern_num.'|'.$pattern_inf.'|'.$pattern_nan.')/i', substr($source, $pos), $matches)) {
$pos += strlen($matches[0]);
return true;
}
elseif ($this->options['usermacros'] && $this->user_macro_parser->parse($source, $pos) != self::PARSE_FAIL) {
$pos += $this->user_macro_parser->getLength();
return true;
}
elseif ($this->options['lldmacros'] && $this->lld_macro_parser->parse($source, $pos) != self::PARSE_FAIL) {
$pos += $this->lld_macro_parser->getLength();
return true;
}
elseif ($this->options['lldmacros']
&& $this->lld_macro_function_parser->parse($source, $pos) != self::PARSE_FAIL) {
$pos += $this->lld_macro_function_parser->getLength();
return true;
}
return false;
}
/**
* Parse the comparison operator. Currently only one comparison operator is allowed: ==
*
* @param string $source [IN] Source string that needs to be parsed.
* @param int $pos [IN/OUT] Position offset.
*
* @return bool
*/
private function parseComparisonOperator($source, &$pos) {
if (isset($source[$pos]) && substr($source, $pos, 2) === '==') {
$pos += 2;
return true;
}
return false;
}
}