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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.
**/
/**
* Class is used to validate and parse a trigger function.
*/
class C10FunctionParser extends CParser {
const STATE_NEW = 0;
const STATE_END = 1;
const STATE_UNQUOTED = 2;
const STATE_QUOTED = 3;
const STATE_END_OF_PARAMS = 4;
const PARAM_ARRAY = 0;
const PARAM_UNQUOTED = 1;
const PARAM_QUOTED = 2;
private $function = '';
private $parameters = '';
private $params_raw = [];
/**
* Returns true if the char is allowed in the function name, false otherwise.
*
* @param string $c
*
* @return bool
*/
protected function isFunctionChar($c) {
return ($c >= 'a' && $c <= 'z');
}
/**
* Parse a trigger function and parameters and put them into $this->params_raw array.
*
* @param string $source
* @param int $pos
*/
public function parse($source, $pos = 0) {
$this->length = 0;
$this->match = '';
$this->function = '';
$this->parameters = '';
$this->params_raw = [];
for ($p = $pos; isset($source[$p]) && $this->isFunctionChar($source[$p]); $p++) {
}
if ($p == $pos) {
return self::PARSE_FAIL;
}
$p2 = $p;
$params_raw = [
'type' => self::PARAM_ARRAY,
'raw' => '',
'pos' => $p - $pos,
'parameters' => []
];
if (!$this->parseFunctionParameters($source, $p, $params_raw['parameters'])) {
return self::PARSE_FAIL;
}
$params_raw['raw'] = substr($source, $p2, $p - $p2);
$this->length = $p - $pos;
$this->match = substr($source, $pos, $this->length);
$this->function = substr($source, $pos, $p2 - $pos);
$this->parameters = substr($source, $p2 + 1, $p - $p2 - 2);
$this->params_raw = $params_raw;
return isset($source[$p]) ? self::PARSE_SUCCESS_CONT : self::PARSE_SUCCESS;
}
private function parseFunctionParameters($source, &$pos, array &$parameters) {
if (!isset($source[$pos]) || $source[$pos] != '(') {
return false;
}
$_parameters = [];
$state = self::STATE_NEW;
$num = 0;
for ($p = $pos + 1; isset($source[$p]); $p++) {
switch ($state) {
// a new parameter started
case self::STATE_NEW:
switch ($source[$p]) {
case ' ':
break;
case ',':
$_parameters[$num++] = [
'type' => self::PARAM_UNQUOTED,
'raw' => '',
'pos' => $p - $pos
];
break;
case ')':
$_parameters[$num] = [
'type' => self::PARAM_UNQUOTED,
'raw' => '',
'pos' => $p - $pos
];
$state = self::STATE_END_OF_PARAMS;
break;
case '"':
$_parameters[$num] = [
'type' => self::PARAM_QUOTED,
'raw' => $source[$p],
'pos' => $p - $pos
];
$state = self::STATE_QUOTED;
break;
default:
$_parameters[$num] = [
'type' => self::PARAM_UNQUOTED,
'raw' => $source[$p],
'pos' => $p - $pos
];
$state = self::STATE_UNQUOTED;
}
break;
// end of parameter
case self::STATE_END:
switch ($source[$p]) {
case ' ':
break;
case ',':
$state = self::STATE_NEW;
$num++;
break;
case ')':
$state = self::STATE_END_OF_PARAMS;
break;
default:
break 3;
}
break;
// an unquoted parameter
case self::STATE_UNQUOTED:
switch ($source[$p]) {
case ')':
$state = self::STATE_END_OF_PARAMS;
break;
case ',':
$state = self::STATE_NEW;
$num++;
break;
default:
$_parameters[$num]['raw'] .= $source[$p];
}
break;
// a quoted parameter
case self::STATE_QUOTED:
$_parameters[$num]['raw'] .= $source[$p];
if ($source[$p] == '"' && $source[$p - 1] != '\\') {
$state = self::STATE_END;
}
break;
// end of parameters
case self::STATE_END_OF_PARAMS:
break 2;
}
}
if ($state == self::STATE_END_OF_PARAMS) {
$parameters = $_parameters;
$pos = $p;
return true;
}
return false;
}
/**
* Returns the left part of the trigger function without parameters.
*
* @return string
*/
public function getFunction() {
return $this->function;
}
/**
* Returns the parameters of the function.
*
* @return string
*/
public function getParameters() {
return $this->parameters;
}
/**
* Returns the list of the parameters.
*
* @return array
*/
public function getParamsRaw() {
return $this->params_raw;
}
/**
* Returns the number of the parameters.
*
* @return int
*/
public function getParamsNum() {
return array_key_exists('parameters', $this->params_raw) ? count($this->params_raw['parameters']) : 0;
}
/*
* Unquotes special symbols in item the parameter
*
* @param string $param
*
* @return string
*/
private static function unquoteParam($param) {
$unquoted = '';
for ($p = 1; isset($param[$p]); $p++) {
if ($param[$p] == '\\' && $param[$p + 1] == '"') {
continue;
}
$unquoted .= $param[$p];
}
return substr($unquoted, 0, -1);
}
/**
* Returns an unquoted parameter.
*
* @param int $n the number of the requested parameter
*
* @return string|null
*/
public function getParam($n) {
$num = 0;
foreach ($this->params_raw['parameters'] as $param) {
if ($num++ == $n) {
switch ($param['type']) {
case self::PARAM_UNQUOTED:
// return parameter without any changes
return $param['raw'];
case self::PARAM_QUOTED:
return $this->unquoteParam($param['raw']);
}
}
}
return null;
}
/**
* Returns unquoted parameters.
*
* @return array
*/
public function getParams(): array {
if (!array_key_exists('parameters', $this->params_raw)) {
return [];
}
$parameters = [];
foreach ($this->params_raw['parameters'] as $param) {
$parameters[] = $param['type'] == self::PARAM_QUOTED ? $this->unquoteParam($param['raw']) : $param['raw'];
}
return $parameters;
}
}