snmp.php

<?php
/*
 +-------------------------------------------------------------------------+
 | Copyright (C) 2004-2017 The Cacti Group                                 |
 |                                                                         |
 | 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.                            |
 +-------------------------------------------------------------------------+
 | Cacti: The Complete RRDTool-based Graphing Solution                     |
 +-------------------------------------------------------------------------+
 | This code is designed, written, and maintained by the Cacti Group. See  |
 | about.php and/or the AUTHORS file for specific developer information.   |
 +-------------------------------------------------------------------------+
 | http://www.cacti.net/                                                   |
 +-------------------------------------------------------------------------+
*/

define('REGEXP_SNMP_TRIM', '/(hex|counter(32|64)|gauge|gauge(32|64)|float|ipaddress|string|integer):/i');

define('SNMP_METHOD_PHP', 1);
define('SNMP_METHOD_BINARY', 2);

if (!isset($banned_snmp_strings)) {
	$banned_snmp_strings = array(
		'End of MIB',
		'No Such');
}

/* we must use an apostrophe to escape community names under Unix in case the user uses
characters that the shell might interpret. */
if ($config['cacti_server_os'] == 'unix') {
	define('SNMP_ESCAPE_CHARACTER', "'");
}else{
	define('SNMP_ESCAPE_CHARACTER', '"');
}

function cacti_snmp_get($hostname, $community, $oid, $version, $username, $password, $auth_proto, $priv_pass, 
	$priv_proto, $context, $port = 161, $timeout = 500, $retries = 0, $max_oids = 10, $method = SNMP_VALUE_LIBRARY, $environ = SNMP_POLLER) {

	global $config;

	/* determine default retries */
	if (($retries == 0) || (!is_numeric($retries))) {
		$retries = read_config_option('snmp_retries');
		if ($retries == '') $retries = 3;
	}

	/* do not attempt to poll invalid combinations */
	if (($version == 0) || (!is_numeric($version)) ||
		(!is_numeric($port)) ||
		(!is_numeric($retries)) ||
		(!is_numeric($timeout)) ||
		(($community == '') && ($version != 3))
		) {
		return 'U';
	}

	if ((snmp_get_method($version) == SNMP_METHOD_PHP) &&
		(!strlen($context) || ($version != 3))) {
		/* make sure snmp* is verbose so we can see what types of data
		we are getting back */
		snmp_set_quick_print(0);

		/* set the output format to numeric */
		snmp_set_valueretrieval($method);

		if ($version == '1') {
			$snmp_value = @snmpget("$hostname:$port", "$community", "$oid", ($timeout * 1000), $retries);
		}elseif ($version == '2') {
			$snmp_value = @snmp2_get("$hostname:$port", "$community", "$oid", ($timeout * 1000), $retries);
		}else{
			if ($priv_proto == '[None]') {
				$proto = 'authNoPriv';
				$priv_proto = '';
			}else{
				$proto = 'authPriv';
			}

			$snmp_value = @snmp3_get("$hostname:$port", "$username", $proto, $auth_proto, "$password", $priv_proto, "$priv_pass", "$oid", ($timeout * 1000), $retries);
		}

		if ($snmp_value === false) {
			cacti_log("WARNING: SNMP Get Timeout for Host:'$hostname', and OID:'$oid'", false);
		}
	}else {
		/* ucd/net snmp want the timeout in seconds */
		$timeout = ceil($timeout / 1000);

		if ($version == '1') {
			$snmp_auth = '-c ' . snmp_escape_string($community); /* v1/v2 - community string */
		}elseif ($version == '2') {
			$snmp_auth = '-c ' . snmp_escape_string($community); /* v1/v2 - community string */
			$version = '2c'; /* ucd/net snmp prefers this over '2' */
		}elseif ($version == '3') {
			if ($priv_proto == '[None]') {
				$proto = 'authNoPriv';
				$priv_proto = '';
			}else{
				$proto = 'authPriv';
			}

			if (strlen($priv_pass)) {
				$priv_pass = '-X ' . snmp_escape_string($priv_pass) . ' -x ' . snmp_escape_string($priv_proto);
			}else{
				$priv_pass = '';
			}

			if (strlen($context)) {
				$context = '-n ' . snmp_escape_string($context);
			}else{
				$context = '';
			}

			$snmp_auth = trim('-u ' . snmp_escape_string($username) .
				' -l ' . snmp_escape_string($proto) .
				' -a ' . snmp_escape_string($auth_proto) .
				' -A ' . snmp_escape_string($password) .
				' '    . $priv_pass .
				' '    . $context); /* v3 - username/password */
		}

		/* no valid snmp version has been set, get out */
		if (empty($snmp_auth)) { return; }

		exec(cacti_escapeshellcmd(read_config_option('path_snmpget')) . ' -O fntevU ' . $snmp_auth . " -v $version -t $timeout -r $retries " . cacti_escapeshellarg($hostname) . ":$port " . cacti_escapeshellarg($oid), $snmp_value);

		/* fix for multi-line snmp output */
		if (is_array($snmp_value)) {
			$snmp_value = implode(' ', $snmp_value);
		}
	}

	/* fix for multi-line snmp output */
	if (isset($snmp_value)) {
		if (is_array($snmp_value)) {
			$snmp_value = implode(' ', $snmp_value);
		}
	}

	if (substr_count($snmp_value, 'Timeout:')) {
		cacti_log("WARNING: SNMP Get Timeout for Host:'$hostname', and OID:'$oid'", false);
	}

	/* strip out non-snmp data */
	$snmp_value = format_snmp_string($snmp_value, false);

	return $snmp_value;
}

function cacti_snmp_getnext($hostname, $community, $oid, $version, $username, $password, $auth_proto, $priv_pass, $priv_proto, $context, $port = 161, $timeout = 500, $retries = 0, $method = SNMP_VALUE_LIBRARY, $environ = SNMP_POLLER) {
	global $config;

	/* determine default retries */
	if (($retries == 0) || (!is_numeric($retries))) {
		$retries = read_config_option('snmp_retries');
		if ($retries == '') $retries = 3;
	}

	/* do not attempt to poll invalid combinations */
	if (($version == 0) || (!is_numeric($version)) ||
		(!is_numeric($port)) ||
		(!is_numeric($retries)) ||
		(!is_numeric($timeout)) ||
		(($community == '') && ($version != 3))
		) {
		return 'U';
	}

	if ((snmp_get_method($version) == SNMP_METHOD_PHP) &&
		(!strlen($context) || ($version != 3))) {
		/* make sure snmp* is verbose so we can see what types of data
		we are getting back */
		snmp_set_quick_print(0);

		/* set the output format to numeric */
		snmp_set_valueretrieval($method);

		if ($version == '1') {
			$snmp_value = @snmpgetnext("$hostname:$port", "$community", "$oid", ($timeout * 1000), $retries);
		}elseif ($version == '2') {
			$snmp_value = @snmp2_getnext("$hostname:$port", "$community", "$oid", ($timeout * 1000), $retries);
		}else{
			if ($priv_proto == '[None]') {
				$proto = 'authNoPriv';
				$priv_proto = '';
			}else{
				$proto = 'authPriv';
			}

			$snmp_value = @snmp3_getnext("$hostname:$port", "$username", $proto, $auth_proto, "$password", $priv_proto, "$priv_pass", "$oid", ($timeout * 1000), $retries);
		}

		if ($snmp_value === false) {
			cacti_log("WARNING: SNMP GetNext Timeout for Host:'$hostname', and OID:'$oid'", false);
		}
	}else {
		/* ucd/net snmp want the timeout in seconds */
		$timeout = ceil($timeout / 1000);

		if ($version == '1') {
			$snmp_auth = '-c ' . snmp_escape_string($community); /* v1/v2 - community string */
		}elseif ($version == '2') {
			$snmp_auth = '-c ' . snmp_escape_string($community); /* v1/v2 - community string */
			$version = '2c'; /* ucd/net snmp prefers this over '2' */
		}elseif ($version == '3') {
			if ($priv_proto == '[None]') {
				$proto = 'authNoPriv';
				$priv_proto = '';
			}else{
				$proto = 'authPriv';
			}

			if (strlen($priv_pass)) {
				$priv_pass = '-X ' . snmp_escape_string($priv_pass) . ' -x ' . snmp_escape_string($priv_proto);
			}else{
				$priv_pass = '';
			}

			if (strlen($context)) {
				$context = '-n ' . snmp_escape_string($context);
			}else{
				$context = '';
			}

			$snmp_auth = trim('-u ' . snmp_escape_string($username) .
				' -l ' . snmp_escape_string($proto) .
				' -a ' . snmp_escape_string($auth_proto) .
				' -A ' . snmp_escape_string($password) .
				' '    . $priv_pass .
				' '    . $context); /* v3 - username/password */
		}

		/* no valid snmp version has been set, get out */
		if (empty($snmp_auth)) { return; }

		exec(cacti_escapeshellcmd(read_config_option('path_snmpgetnext')) . " -O fntevU $snmp_auth -v $version -t $timeout -r $retries " . cacti_escapeshellarg($hostname) . ":$port " . cacti_escapeshellarg($oid), $snmp_value);
	}

	if (isset($snmp_value)) {
		/* fix for multi-line snmp output */
		if (is_array($snmp_value)) {
			$snmp_value = implode(' ', $snmp_value);
		}
	}

	if (substr_count($snmp_value, 'Timeout:')) {
		cacti_log("WARNING: SNMP GetNext Timeout for Host:'$hostname', and OID:'$oid'", false);
	}

	/* strip out non-snmp data */
	$snmp_value = format_snmp_string($snmp_value, false);

	return $snmp_value;
}

function cacti_snmp_walk($hostname, $community, $oid, $version, $username, $password, $auth_proto, $priv_pass, $priv_proto, $context, $port = 161, $timeout = 500, $retries = 0, $max_oids = 10, $method = SNMP_VALUE_LIBRARY, $environ = SNMP_POLLER) {
	global $config, $banned_snmp_strings;

	$snmp_oid_included = true;
	$snmp_auth	       = '';
	$snmp_array        = array();
	$temp_array        = array();

	/* determine default retries */
	if (($retries == 0) || (!is_numeric($retries))) {
		$retries = read_config_option('snmp_retries');
		if ($retries == '') $retries = 3;
	}

	/* do not attempt to poll invalid combinations */
	if (($version == 0) || (!is_numeric($version)) ||
		(!is_numeric($max_oids)) ||
		(!is_numeric($port)) ||
		(!is_numeric($retries)) ||
		(!is_numeric($timeout)) ||
		(($community == '') && ($version != 3))
		) {
		return array();
	}

	$path_snmpbulkwalk = read_config_option('path_snmpbulkwalk');

	if ((snmp_get_method($version) == SNMP_METHOD_PHP) &&
		(!strlen($context) || ($version != 3)) &&
		(($version == 1) ||
		(version_compare(phpversion(), '5.1') >= 0) ||
		(!file_exists($path_snmpbulkwalk)))) {
		/* make sure snmp* is verbose so we can see what types of data
		we are getting back */

		/* force php to return numeric oid's */
		cacti_oid_numeric_format();

		snmp_set_quick_print(0);

		/* set the output format to numeric */
		snmp_set_valueretrieval($method);

		if ($version == '1') {
			$temp_array = @snmprealwalk("$hostname:$port", "$community", "$oid", ($timeout * 1000), $retries);
		}elseif ($version == '2') {
			$temp_array = @snmp2_real_walk("$hostname:$port", "$community", "$oid", ($timeout * 1000), $retries);
		}else{
			if ($priv_proto == '[None]') {
				$proto = 'authNoPriv';
				$priv_proto = '';
			}else{
				$proto = 'authPriv';
			}

			$temp_array = @snmp3_real_walk("$hostname:$port", "$username", $proto, $auth_proto, "$password", $priv_proto, "$priv_pass", "$oid", ($timeout * 1000), $retries);
		}

		if ($temp_array === false) {
			cacti_log("WARNING: SNMP Walk Timeout for Host:'$hostname', and OID:'$oid'", false);
		}

		/* check for bad entries */
		if (is_array($temp_array) && sizeof($temp_array)) {
			foreach($temp_array as $key => $value) {
				foreach($banned_snmp_strings as $item) {
					if(strstr($value, $item) != '') {
						unset($temp_array[$key]);
						continue 2;
					}
				}
			}

			$o = 0;
			for (reset($temp_array); $i = key($temp_array); next($temp_array)) {
				if ($temp_array[$i] != 'NULL') {
					$snmp_array[$o]['oid'] = preg_replace('/^\./', '', $i);
					$snmp_array[$o]['value'] = format_snmp_string($temp_array[$i], $snmp_oid_included);
				}
				$o++;
			}
		}
	}else{
		/* ucd/net snmp want the timeout in seconds */
		$timeout = ceil($timeout / 1000);

		if ($version == '1') {
			$snmp_auth = '-c ' . snmp_escape_string($community); /* v1/v2 - community string */
		}elseif ($version == '2') {
			$snmp_auth = '-c ' . snmp_escape_string($community); /* v1/v2 - community string */
			$version = '2c'; /* ucd/net snmp prefers this over '2' */
		}elseif ($version == '3') {
			if ($priv_proto == '[None]') {
				$proto = 'authNoPriv';
				$priv_proto = '';
			}else{
				$proto = 'authPriv';
			}

			if (strlen($priv_pass)) {
				$priv_pass = '-X ' . snmp_escape_string($priv_pass) . ' -x ' . snmp_escape_string($priv_proto);
			}else{
				$priv_pass = '';
			}

			if (strlen($context)) {
				$context = '-n ' . snmp_escape_string($context);
			}else{
				$context = '';
			}

			$snmp_auth = trim('-u ' . snmp_escape_string($username) .
				' -l ' . snmp_escape_string($proto) .
				' -a ' . snmp_escape_string($auth_proto) .
				' -A ' . snmp_escape_string($password) .
				' '    . $priv_pass .
				' '    . $context); /* v3 - username/password */
		}

		if (file_exists($path_snmpbulkwalk) && ($version > 1) && ($max_oids > 1)) {
			$temp_array = exec_into_array(cacti_escapeshellcmd($path_snmpbulkwalk) . " -O eQnU $snmp_auth -v $version -t $timeout -r $retries -Cr$max_oids " . cacti_escapeshellarg($hostname) . ":$port " . cacti_escapeshellarg($oid));
		}else{
			$temp_array = exec_into_array(cacti_escapeshellcmd(read_config_option('path_snmpwalk')) . " -O eQnU $snmp_auth -v $version -t $timeout -r $retries " . cacti_escapeshellarg($hostname) . ":$port " . cacti_escapeshellarg($oid));
		}

		if (substr_count(implode(' ', $temp_array), 'Timeout:')) {
			cacti_log("WARNING: SNMP Walk Timeout for Host:'$hostname', and OID:'$oid'", false);
		}

		/* check for bad entries */
		if (is_array($temp_array) && sizeof($temp_array)) {
			foreach($temp_array as $key => $value) {
				foreach($banned_snmp_strings as $item) {
					if(strstr($value, $item) != '') {
						unset($temp_array[$key]);
						continue 2;
					}
				}
			}

			for ($i=0; $i < count($temp_array); $i++) {
				if ($temp_array[$i] != 'NULL') {
					$snmp_array[$i]['oid']   = trim(preg_replace('/(.*) =.*/', "\\1", $temp_array[$i]));
					$snmp_array[$i]['value'] = format_snmp_string($temp_array[$i], true);
				}
			}
		}
	}

	return $snmp_array;
}

function format_snmp_string($string, $snmp_oid_included) {
	global $banned_snmp_strings;

	$string = preg_replace(REGEXP_SNMP_TRIM, '', trim($string));

	if (substr($string, 0, 7) == 'No Such') {
		return '';
	}

	if ($snmp_oid_included) {
		/* strip off all leading junk (the oid and stuff) */
		$string_array = explode('=', $string);
		if (sizeof($string_array) == 1) {
			/* trim excess first */
			$string = trim($string);
		}else if ((substr($string, 0, 1) == '.') || (strpos($string, '::') !== false)) {
			/* drop the OID from the array */
			array_shift($string_array);
			$string = trim(implode('=', $string_array));
		}else {
			$string = trim(implode('=', $string_array));
		}
	}

	/* trim quoting and other oddities */
	$string = trim($string, " \r\n\0\x0B\t\"'");

	/* search for a hex string */
	if (substr_count($string, ':')) {
		$newstr = '';
		$fail   = false;
		$pieces = explode(':', $string);
		foreach($pieces AS $p) {
			if (strlen($p) > 2) {
				$fail = true;
				break;
			}
			$newstr .= chr(hexdec($p));
		}

		if (!$fail) {
			$string = $newstr;
		}
	}

	/* return the easiest value */
	if ($string == '') {
		return $string;
	}

	/* now check for the second most obvious */
	if (is_numeric($string)) {
		return trim($string);
	}

	/* account for invalid MIB files */
	if (substr_count($string, 'Wrong Type')) {
		$string = strrev($string);
		if ($position = strpos($string, ':')) {
			$string = trim(strrev(substr($string, 0, $position)));
		}else{
			$string = trim(strrev($string));
		}
	}

	/* Remove invalid chars */
	$k = strlen($string);
	for ($i=0; $i < $k; $i++) {
		if ((ord($string[$i]) <= 31) || (ord($string[$i]) >= 127)) {
			$string[$i] = ' ';
		}
	}
	$string = trim($string);

	if ((substr_count($string, 'Hex-STRING:')) ||
		(substr_count($string, 'Hex-')) ||
		(substr_count($string, 'Hex:'))) {
		/* strip of the 'Hex-STRING:' */
		$string = preg_replace('/Hex-STRING: ?/i', '', $string);
		$string = preg_replace('/Hex: ?/i', '', $string);
		$string = preg_replace('/Hex- ?/i', '', $string);

		$string_array = explode(' ', $string);

		/* loop through each string character and make ascii */
		$string = '';
		$hexval = '';
		$ishex  = false;
		for ($i=0;($i<sizeof($string_array));$i++) {
			if (strlen($string_array[$i])) {
				$string .= chr(hexdec($string_array[$i]));

				$hexval .= str_pad($string_array[$i], 2, '0', STR_PAD_LEFT);

				if (($i+1) < count($string_array)) {
					$hexval .= ':';
				}

				if ((hexdec($string_array[$i]) <= 31) || (hexdec($string_array[$i]) >= 127)) {
					if ((($i+1) == sizeof($string_array)) && ($string_array[$i] == 0)) {
						/* do nothing */
					}else{
						$ishex = true;
					}
				}
			}
		}

		if ($ishex) $string = $hexval;
	}elseif (preg_match("/(hex:\?)?([a-fA-F0-9]{1,2}(:|\s)){5}/", $string)) {
		$octet = '';

		/* strip of the 'hex:' */
		$string = preg_replace('/hex: ?/i', '', $string);

		/* split the hex on the delimiter */
		$octets = preg_split('/\s|:/', $string);

		/* loop through each octet and format it accordingly */
		for ($i=0;($i<count($octets));$i++) {
			$octet .= str_pad($octets[$i], 2, '0', STR_PAD_LEFT);

			if (($i+1) < count($octets)) {
				$octet .= ':';
			}
		}

		/* copy the final result and make it upper case */
		$string = strtoupper($octet);
	}elseif (preg_match('/Timeticks:\s\((\d+)\)\s/', $string, $matches)) {
		$string = $matches[1];
	}

	foreach($banned_snmp_strings as $item) {
		if(strstr($string, $item) != '') {
			$string = '';
			break;
		}
	}

	return $string;
}

function snmp_escape_string($string) {
	if (substr_count($string, SNMP_ESCAPE_CHARACTER)) {
		$string = substr_replace(SNMP_ESCAPE_CHARACTER, "\\" . SNMP_ESCAPE_CHARACTER, $string);
	}

	return SNMP_ESCAPE_CHARACTER . $string . SNMP_ESCAPE_CHARACTER;
}

function snmp_get_method($version = 1) {
	if ((function_exists('snmpget')) && ($version == 1)) {
		return SNMP_METHOD_PHP;
	}else if ((function_exists('snmp2_get')) && ($version == 2)) {
		return SNMP_METHOD_PHP;
	}else if ((function_exists('snmp3_get')) && ($version == 3)) {
		return SNMP_METHOD_PHP;
	}else if ((($version == 2) || ($version == 3)) && (file_exists(read_config_option('path_snmpget')))) {
		return SNMP_METHOD_BINARY;
	}else if (function_exists('snmpget')) {
		/* last resort (hopefully it isn't a 64-bit result) */
		return SNMP_METHOD_PHP;
	}else if (file_exists(read_config_option('path_snmpget'))) {
		return SNMP_METHOD_BINARY;
	}else{
		/* looks like snmp is broken */
		return SNMP_METHOD_BINARY;
	}
}

?>