librenms-librenms/includes/polling/customoid.inc.php

<?php

use LibreNMS\RRD\RrdDefinition;

foreach (dbFetchRows("SELECT * FROM `customoids` WHERE `customoid_passed` = 1 AND `device_id` = ?", array($device['device_id'])) as $customoid) {
    d_echo($customoid);

    $prev_oid_value = $customoid['customoid_current'];

    $rawdata = snmp_get($device, $customoid['customoid_oid'], '-Oqv');
    
    $user_funcs = array(
        "celsius_to_fahrenheit",
        "fahrenheit_to_celsius",
        "uw_to_dbm"
    );

    if (is_numeric($rawdata)) {
        $graphs['customoid'] = true;
        $oid_value = $rawdata;
    } else {
        $oid_value = 0;
        $error = "Invalid SNMP reply.";
    }

    if ($customoid['customoid_divisor'] && $oid_value !== 0) {
        $oid_value = ($oid_value / $customoid['customoid_divisor']);
    }
    if ($customoid['customoid_multiplier']) {
        $oid_value = ($oid_value * $customoid['customoid_multiplier']);
    }

    if (isset($customoid['user_func']) && in_array($customoid['user_func'], $user_funcs)) {
        $oid_value = $customoid['user_func']($oid_value);
    }

    echo 'Custom OID '.$customoid['customoid_descr'].': ';
    echo $oid_value.' '.$customoid['customoid_unit']."\n";

    $fields = array(
        'oid' => $oid_value,
    );

    $rrd_name = array('customoid', $customoid['customoid_descr']);
    if ($customoid['customoid_datatype'] == 'COUNTER') {
        $datatype = $customoid['customoid_datatype'];
    } else {
        $datatype = 'GAUGE';
    }
    $rrd_def = RrdDefinition::make()
        ->addDataset('oid_value', $datatype);

    $tags = compact('rrd_name', 'rrd_def');

    data_update($device, 'customoid', $tags, $fields);
    dbUpdate(array('customoid_current' => $oid_value, 'lastupdate' => array('NOW()'), 'customoid_prev' => $prev_oid_value), 'customoids', '`customoid_id` = ?', array($customoid['customoid_id']));
}//end foreach

unset($customoid, $prev_oid_value, $rawdata, $user_funcs, $oid_value, $error, $fields, $rrd_def, $rrd_name, $tags);