SnmpQuery, respect snmp.max_oid (#14894)

Previously, the code would query all the oids it received. Now it will split it up into multiple queries if too many are sent.

Prevents some devices snmp service from crashing.

LibreNMS/Data/Source/NetSnmpQuery.php

@@ -250,11 +250,7 @@ class NetSnmpQuery implements SnmpQueryInterface
      */
     public function get($oid): SnmpResponse
     {
-        if (empty($oid)) {
-            return new SnmpResponse('');
-        }
-
-        return $this->exec('snmpget', $this->parseOid($oid));
+        return $this->execMultiple('snmpget', $this->limitOids($this->parseOid($oid)));
     }
 
     /**
@@ -278,7 +274,7 @@ class NetSnmpQuery implements SnmpQueryInterface
      */
     public function next($oid): SnmpResponse
     {
-        return $this->exec('snmpgetnext', $this->parseOid($oid));
+        return $this->execMultiple('snmpgetnext', $this->limitOids($this->parseOid($oid)));
     }
 
     /**
@@ -374,7 +370,7 @@ class NetSnmpQuery implements SnmpQueryInterface
         $response = new SnmpResponse('');
 
         foreach ($oids as $oid) {
-            $response = $response->append($this->exec($command, [$oid]));
+            $response = $response->append($this->exec($command, Arr::wrap($oid)));
 
             // if abort on failure is set, return after first failure
             if ($this->abort && ! $response->isValid()) {
@@ -500,10 +496,20 @@ class NetSnmpQuery implements SnmpQueryInterface
         Log::debug($error);
     }
 
-    /**
-     * @param  array|string  $oid
-     */
-    private function parseOid($oid): array
+    private function limitOids(array $oids): array
+    {
+        // get max oids per query device attrib > os setting > global setting
+        $configured_max = $this->device->getAttrib('snmp_max_oid') ?: Config::getOsSetting($this->device->os, 'snmp_max_oid', Config::get('snmp.max_oid', 10));
+        $max_oids = max($configured_max, 1); // 0 or less would break things.
+
+        if (count($oids) > $max_oids) {
+            return array_chunk($oids, $max_oids);
+        }
+
+        return $oids;
+    }
+
+    private function parseOid(array|string $oid): array
     {
         return is_string($oid) ? explode(' ', $oid) : $oid;
     }

includes/definitions/hpe-mapdu.yaml

@@ -5,9 +5,9 @@ icon: hpe
 group: hpe
 mib_dir: hp
 over:
-    - {graph: device_power, text: Power}  
+    - {graph: device_power, text: Power}
     - {graph: device_current, text: Current}
-snmp_max_oid: '8'
+snmp_max_oid: 8
 discovery:
     -
         sysObjectID:

includes/definitions/tait-tnadmin.yaml

@@ -3,7 +3,7 @@ text: 'Tait TN Admin OS'
 type: network
 icon: tait
 mib_dir: tait
-snmp_max_oid: '1'
+snmp_max_oid: 1
 over:
     - { graph: device_temperature, text: 'Temperature' }
 discovery:

misc/config_definitions.json

@@ -5280,6 +5280,13 @@
             "type": "integer",
             "units": "seconds"
         },
+        "snmp.max_oid": {
+            "group": "poller",
+            "section": "snmp",
+            "order": 5,
+            "type": "integer",
+            "default": 10
+        },
         "snmp.max_repeaters": {
             "group": "poller",
             "section": "snmp",

misc/os_schema.json

@@ -391,7 +391,8 @@
             "type": "boolean"
         },
         "snmp_max_oid": {
-            "type": "string"
+            "type": "integer",
+            "minimum": 1
         },
         "ifXmcbc": {
             "type": "boolean"

resources/lang/en/settings.php

@@ -1413,6 +1413,10 @@ return [
                 'description' => 'Communities (priority)',
                 'help' => 'Enter community strings for v1 and v2c and order them as you want them to be tried',
             ],
+            'max_oid' => [
+                'description' => 'Max OIDs',
+                'help' => 'Maximum OIDs per query.  Can be overriden at OS and device levels.',
+            ],
             'max_repeaters' => [
                 'description' => 'Max Repeaters',
                 'help' => 'Set repeaters to use for SNMP bulk requests',