LibreNMS/Device/YamlDiscovery.php
<?php
/**
* YamlDiscovery.php
*
* -Description-
*
* 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 3 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, see <https://www.gnu.org/licenses/>.
*
* @link https://www.librenms.org
*
* @copyright 2017 Tony Murray
* @author Tony Murray <murraytony@gmail.com>
*/
namespace LibreNMS\Device;
use App\View\SimpleTemplate;
use Illuminate\Support\Arr;
use Illuminate\Support\Str;
use LibreNMS\Config;
use LibreNMS\Interfaces\Discovery\DiscoveryItem;
use LibreNMS\OS;
use LibreNMS\Util\Compare;
use LibreNMS\Util\IP;
use LibreNMS\Util\Oid;
class YamlDiscovery
{
/**
* @param OS $os
* @param DiscoveryItem|string $class
* @param array $yaml_data
* @return array
*/
public static function discover(OS $os, $class, $yaml_data)
{
$pre_cache = $os->preCache();
$device = $os->getDeviceArray();
$items = [];
// convert to class name for static call below
if (is_object($class)) {
$class = get_class($class);
}
d_echo('YAML Discovery Data: ');
d_echo($yaml_data);
foreach ($yaml_data as $first_key => $first_yaml) {
if ($first_key == 'pre-cache') {
continue;
}
$group_options = isset($first_yaml['options']) ? $first_yaml['options'] : [];
// find the data array, we could already be at for simple modules
if (isset($data['data'])) {
$first_yaml = $first_yaml['data'];
} elseif ($first_key !== 'data') {
continue;
}
foreach ($first_yaml as $data) {
$raw_data = (array) $pre_cache[$data['oid']];
d_echo("Data {$data['oid']}: ");
d_echo($raw_data);
$count = 0;
foreach ($raw_data as $index => $snmp_data) {
$count++;
$current_data = [];
// fall back to the fetched oid if value is not specified. Useful for non-tabular data.
if (! isset($data['value'])) {
$data['value'] = $data['oid'];
}
// determine numeric oid automatically if not specified
if (! isset($data['num_oid'])) {
try {
$data['num_oid'] = static::computeNumericalOID($os, $data);
} catch (\Exception $e) {
d_echo('Error: We cannot find a numerical OID for ' . $data['value'] . '. Skipping this one...');
continue;
}
}
foreach ($data as $name => $value) {
if (! in_array($name, ['oid', 'skip_values', 'snmp_flags', 'rrd_type'])) {
$current_data[$name] = self::fillValues($name, $index, $data, $count, $pre_cache, $value);
} else {
$current_data[$name] = $value;
}
}
if (static::canSkipItem($current_data['value'], $index, $current_data, $group_options, $snmp_data)) {
continue;
}
$item = $class::fromYaml($os, $index, $current_data);
if ($item->isValid()) {
$items[] = $item;
}
}
}
}
return $items;
}
/**
* @param string $name The oid of the value we are searching for
* @param int|string $index The index of the current entity we are searching from
* @param array $discovery_data The yaml discovery data
* @param int $count The count of where we are in the discovery data
* @param array $pre_cache Data that has been previously fetched (should contain all snmp data)
* @param int|string|null $value The current value of the data that we might need to transform (or return as is)
* @return mixed
*/
public static function fillValues($name, $index, $discovery_data, $count, $pre_cache, $value): mixed
{
if (str_contains($value, '{{')) {
// replace embedded values
return static::replaceValues($name, $index, $count, $discovery_data, $pre_cache);
} elseif (! str_contains($value, ' ')) {
// replace references to data
return static::getValueFromData($name, $index, $discovery_data, $pre_cache, $value);
}
return $value;
}
/**
* @param \LibreNMS\OS $os OS/device we areworking on
* @param array $data Array derived from YAML
* @return string
*
* @throws \LibreNMS\Exceptions\InvalidOidException
*/
public static function computeNumericalOID(OS $os, array $data): string
{
d_echo('Info: Trying to find a numerical OID for ' . $data['value'] . '.');
$search_mib = $os->getDiscovery()['mib'];
$mib_prefix_data_oid = Str::before($data['oid'], '::');
if (! empty($mib_prefix_data_oid) && empty(Str::before($data['value'], '::'))) {
// We should search value in this mib first, as it is explicitely specified
$search_mib = $mib_prefix_data_oid . ':' . $search_mib;
}
try {
$num_oid = Oid::toNumeric($data['value'], $search_mib);
} catch (\Exception $e) {
throw $e;
}
d_echo('Info: We found numerical oid for ' . $data['value'] . ': ' . $num_oid);
return $num_oid . '.{{ $index }}';
}
/**
* @param string $name Name of the field in yaml
* @param string $index index in the snmp table
* @param int $count current count of snmp table entries
* @param array $def yaml definition
* @param array $pre_cache snmp data fetched from device
* @return mixed|string|string[]|null
*/
public static function replaceValues($name, $index, $count, $def, $pre_cache)
{
$value = static::getValueFromData($name, $index, $def, $pre_cache);
if (is_null($value)) {
// basic replacements
$variables = [
'index' => $index,
'count' => $count,
// we compute a numOid compatible version of index
// string length followed by ASCII of each char.
'index_string' => implode('.', array_map(function ($index) {
return strlen($index) . '.' . implode('.', unpack('c*', $index));
}, explode('.', $index))),
];
foreach (explode('.', $index) as $pos => $subindex) {
$variables['subindex' . $pos] = $subindex;
}
$value = (string) (new SimpleTemplate($def[$name] ?? '', $variables))->keepEmptyTemplates();
// search discovery data for values
$template = new SimpleTemplate($value);
$template->replaceWith(function ($matches) use ($index, $def, $pre_cache) {
$replace = static::getValueFromData($matches[1], $index, $def, $pre_cache);
if (is_null($replace)) {
// allow parsing of InetAddress hex data representing ipv4 or ipv6
// using {{ $InetAddress_varNameContainingHexIpAddrOfTypeInetAddress }}
// -Ih flag screew up HEX string that contain only printable chars, use at minimum -Ox, and remove -Ih use for exemple:
// snmp_flags: '-OteQUsax'
// snmp_no_Ih_flag: ''
if (str_starts_with($matches[1], 'InetAddress_')) {
$inetaddr = explode('_', $matches[1]);
if (count($inetaddr) == 2) {
return IP::fromHexString(static::getValueFromData($inetaddr[1], $index, $def, $pre_cache), true);
}
}
\Log::warning('YamlDiscovery: No variable available to replace ' . $matches[1] . ' index: ' . $index);
return ''; // remove the unavailable variable
}
return $replace;
});
$value = (string) $template;
}
return $value;
}
/**
* Helper function for dynamic discovery to search for data from pre_cached snmp data
*
* @param string $name The name of the field from the discovery data or just an oid
* @param string|int $index The index of the current sensor
* @param array $discovery_data The discovery data for the current sensor
* @param array $pre_cache all pre-cached snmp data
* @param mixed $default The default value to return if data is not found
* @return mixed
*/
public static function getValueFromData($name, $index, $discovery_data, $pre_cache, $default = null)
{
if (isset($discovery_data[$name])) {
$name = $discovery_data[$name];
}
if (isset($discovery_data['oid']) && ! is_array($discovery_data['oid']) && isset($pre_cache[$discovery_data['oid']][$index]) && isset($pre_cache[$discovery_data['oid']][$index][$name])) {
return $pre_cache[$discovery_data['oid']][$index][$name];
}
if (isset($pre_cache[$index][$name])) {
return $pre_cache[$index][$name];
}
// parse sub_index options name with trailing colon and index
if (preg_match('/^(.+):(\d+)(?:-(\d+))?$/', $name, $matches)) {
// subindex found
$name = $matches[1];
//create the sub-index values in order to try to match them with precache
$sub_indexes = explode('.', $index);
// if subindex is a range, get them all, otherwise just get the first
$index = isset($matches[3])
? implode('.', array_slice($sub_indexes, (int) $matches[2], (int) $matches[3]))
: $sub_indexes[(int) $matches[2]];
}
// look for the data in pre_cache
if (isset($pre_cache[$name]) && ! is_numeric($name)) {
if (is_array($pre_cache[$name])) {
if (isset($pre_cache[$name][$index][$name])) {
return $pre_cache[$name][$index][$name];
} elseif (isset($pre_cache[$name][$index])) {
return $pre_cache[$name][$index];
} elseif (count($pre_cache[$name]) === 1 && ! is_array(current($pre_cache[$name]))) {
return current($pre_cache[$name]);
}
} else {
return $pre_cache[$name];
}
}
// search for name inside walked tables if oid is fully qualified
if (str_contains($name, '::')) {
foreach ($pre_cache as $table_name => $table) {
if (is_array($table) && isset($table[$index][$name])) {
return $table[$index][$name];
}
}
}
return $default;
}
public static function preCache(OS $os)
{
// Pre-cache data for later use
$pre_cache = [];
$device = $os->getDeviceArray();
$pre_cache_file = 'includes/discovery/sensors/pre-cache/' . $device['os'] . '.inc.php';
if (is_file($pre_cache_file)) {
echo "Pre-cache {$device['os']}: ";
include $pre_cache_file;
echo PHP_EOL;
d_echo($pre_cache);
}
// TODO change to exclude os with pre-cache php file, but just exclude them by hand for now (like avtech)
if ($device['os'] == 'avtech') {
return $pre_cache;
}
if (! empty($os->getDiscovery()['modules'])) {
echo 'Caching data: ';
foreach ($os->getDiscovery()['modules'] as $module => $discovery_data) {
echo "$module ";
foreach ($discovery_data as $key => $data_array) {
// find the data array, we could already be at for simple modules
if (isset($data_array['data'])) {
$data_array = $data_array['data'];
} elseif ($key !== 'data') {
continue;
}
$saved_nobulk = Config::getOsSetting($os->getName(), 'snmp_bulk', true);
foreach ($data_array as $data) {
foreach (Arr::wrap($data['oid'] ?? []) as $oid) {
if (! array_key_exists($oid, $pre_cache)) {
if (isset($data['snmp_flags'])) {
$snmp_flag = Arr::wrap($data['snmp_flags']);
} elseif (str_contains($oid, '::')) {
$snmp_flag = ['-OteQUSa'];
} else {
$snmp_flag = ['-OteQUsa'];
}
if (! isset($data['snmp_no_Ih_flag'])) {
$snmp_flag[] = '-Ih';
}
// disable bulk request for specific data
if (isset($data['snmp_bulk'])) {
Config::set('os.' . $os->getName() . '.snmp_bulk', (bool) $data['snmp_bulk']);
}
$mib = $os->getDiscovery()['mib'] ?? null;
$pre_cache[$oid] = snmpwalk_cache_oid($device, $oid, $pre_cache[$oid] ?? [], $mib, null, $snmp_flag);
Config::set('os.' . $os->getName() . '.snmp_bulk', $saved_nobulk);
}
}
}
}
}
echo PHP_EOL;
}
return $pre_cache;
}
/**
* Check to see if we should skip this discovery item
*
* @param mixed $value
* @param int|string $index
* @param array $yaml_item_data The data key from this item
* @param array $group_options The options key from this group of items
* @param array $pre_cache The pre-cache data array
* @return bool
*/
public static function canSkipItem($value, $index, array $yaml_item_data, array $group_options, array $pre_cache = []): bool
{
$skip_values = array_replace((array) ($group_options['skip_values'] ?? []), (array) ($yaml_item_data['skip_values'] ?? []));
foreach ($skip_values as $skip_value) {
if (is_array($skip_value) && $pre_cache) {
// Dynamic skipping of data
$op = $skip_value['op'] ?? '!=';
if (isset($skip_value['device'])) {
// field from device model
$tmp_value = \DeviceCache::getPrimary()[$skip_value['device']] ?? null;
} elseif ($skip_value['oid'] == 'index') {
$tmp_value = $index;
} else {
// oid previously fetched from the device
$tmp_value = static::getValueFromData($skip_value['oid'], $index, $yaml_item_data, $pre_cache);
if (str_contains($skip_value['oid'], '.')) {
[$skip_value['oid'], $targeted_index] = explode('.', $skip_value['oid'], 2);
$tmp_value = static::getValueFromData($skip_value['oid'], $targeted_index, $yaml_item_data, $pre_cache);
}
}
if (Compare::values($tmp_value, $skip_value['value'], $op)) {
return true;
}
}
if ($value == $skip_value) {
return true;
}
}
$skip_value_lt = array_replace((array) ($group_options['skip_value_lt'] ?? []), (array) ($yaml_item_data['skip_value_lt'] ?? []));
foreach ($skip_value_lt as $skip_value) {
if ($value < $skip_value) {
return true;
}
}
$skip_value_gt = array_replace((array) ($group_options['skip_value_gt'] ?? []), (array) ($yaml_item_data['skip_value_gt'] ?? []));
foreach ($skip_value_gt as $skip_value) {
if ($value > $skip_value) {
return true;
}
}
return false;
}
}