Indexed SNMP queries do not work with php-snmp

[rollodp]

I'm running Cacti 0.8.6g on Fedora Core 4. I am unable to perform indexed snmp queries.

I've found there's an issue with using php-snmp inside a exec()ed php script that means the @snmprealwalk function returns an empty array. Invoking the script directly works as expected from http or from a command line as cactiuser or root.

This affects lib/snmp.php, cacti_snmp_walk() and means that all my indexed snmp data queries return zero rows.

To prove this I did:

Create cacti/snmpwalktest.php:

Code: Select all

<?php
        /* invoke snmprealwalk */
        $temp_array = @snmprealwalk("host:161", "public",".1.3.6.1.2.1.25.2.3.1.3", 8000, 3);
        print("snmpresult size " . sizeof($temp_array) . "\n");
        print("snmprealwalk result: $temp_array\n");

        /* print the response from snmprealwalk */
        for (@reset($temp_array); $i = @key($temp_array); next($temp_array)) {
                $oid = ereg_replace("^\.", "", $i);
                $val = $temp_array[$i];
                print("$oid = $val \n");
        }
?>

Create exectest.php:

Code: Select all

<?php
        $cmd = "echo hello";
        print("Performing exec($cmd)\n");
        exec($cmd,$out,$err);
        print("Error code : $err\n");
        print("Output:\n");
        for($i=0; list($key, $value) = each($out); $i++) {
                print("out[$i]: $value\n");
        }


        $cmd = "/usr/bin/php -q /var/www/html/cacti/snmpwalktest.php";
        print("\nPerforming exec($cmd)\n");
        exec($cmd,$out,$err);
        print("Error code : $err\n");
        print("Output:\n");
        for($i=0; list($key, $value) = each($out); $i++) {
                print("out[$i]: $value\n");
        }
?>

http://host/cacti/snmpwalktest.php gives:

Code: Select all

snmpresult size 5
snmprealwalk result: Array
HOST-RESOURCES-MIB::hrStorageDescr.1 = STRING: C:\ Label:Win2k3  Serial Number 28851fff 
HOST-RESOURCES-MIB::hrStorageDescr.2 = STRING: D:\ Label:CVS  Serial Number beece64f 
HOST-RESOURCES-MIB::hrStorageDescr.3 = STRING: E:\ Label:Archives  Serial Number 74c82d2f 
HOST-RESOURCES-MIB::hrStorageDescr.4 = STRING: Virtual Memory 
HOST-RESOURCES-MIB::hrStorageDescr.5 = STRING: Physical Memory 

but http://host/cacti/exectest.php gives:

Code: Select all

Performing exec(echo hello)
Error code : 0
Output:
out[0]: hello

Performing exec(/usr/bin/php -q /var/www/html/cacti/snmpwalktest.php)
Error code : 0
Output:
out[0]: snmpresult size 1
out[1]: snmprealwalk result:

Note there is an empty response from @snmprealwalk from the exec()ed snmpwalktest.php

Am I barking up the wrong tree, or is there a problem with php-snmp here?

[rony]

What version of php?

[rollodp]

Sorry, forgot to say...

$> yum info php
[snip]
Installed Packages
Name : php
Arch : i386
Version: 5.0.4
Release: 10.5
Size : 5.9 M
Repo : installed
[snip]

[rollodp]

I just installed 0.8.6h on a fresh install of FC4 and it started working ok. Dunno why the above was causing problems but at least it works now.