snmp.unescape setting (librenms#13590)

* snmp.unescape setting Works around issue with (I think net-snmp < 5.8.0) where it adds backslashes. * Updated test data
sunblade · Dec 1, 2021 · 5ce7a5a · 5ce7a5a
1 parent d69674b
commit 5ce7a5a
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Showing 5 changed files with 38 additions and 4 deletions.
diff --git a/LibreNMS/Config.php b/LibreNMS/Config.php
@@ -33,6 +33,7 @@
 use LibreNMS\Data\Store\Rrd;
 use LibreNMS\DB\Eloquent;
 use LibreNMS\Util\Debug;
+use LibreNMS\Util\Version;
 use Log;
 
 class Config
@@ -473,6 +474,9 @@ private static function processConfig()
         if (! self::has('rrdtool_version')) {
             self::persist('rrdtool_version', Rrd::version());
         }
+        if (! self::has('snmp.unescape')) {
+            self::persist('snmp.unescape', version_compare(Version::get()->netSnmp(), '5.8.0', '<'));
+        }
 
         self::populateTime();
 

diff --git a/LibreNMS/Data/Source/SnmpResponse.php b/LibreNMS/Data/Source/SnmpResponse.php
@@ -28,6 +28,7 @@
 use Illuminate\Support\Arr;
 use Illuminate\Support\Collection;
 use Illuminate\Support\Str;
+use LibreNMS\Config;
 use Log;
 
 class SnmpResponse
@@ -130,6 +131,11 @@ public function values(): array
                 $line = strtok(PHP_EOL);
             }
 
+            // remove extra escapes
+            if (Config::get('snmp.unescape')) {
+                $value = stripslashes($value);
+            }
+
             if (Str::startsWith($value, '"') && Str::endsWith($value, '"')) {
                 // unformatted string from net-snmp, remove extra escapes
                 $values[$oid] = trim(stripslashes($value), "\" \n\r");

diff --git a/misc/config_definitions.json b/misc/config_definitions.json
@@ -5130,6 +5130,9 @@
                 "public"
             ]
         },
+        "snmp.unescape": {
+            "type": "boolean"
+        },
         "snmp.exec_timeout": {
             "default": 1200,
             "type": "integer",

diff --git a/tests/Unit/SnmpResponseTest.php b/tests/Unit/SnmpResponseTest.php
@@ -25,6 +25,7 @@
 
 namespace LibreNMS\Tests\Unit;
 
+use LibreNMS\Config;
 use LibreNMS\Data\Source\SnmpResponse;
 use LibreNMS\Tests\TestCase;
 
@@ -49,11 +50,31 @@ public function testSimple(): void
         $this->assertEquals(['IF-MIB::ifDescr'], $response->table());
 
         // unescaped strings
-        $response = new SnmpResponse("Q-BRIDGE-MIB::dot1qVlanStaticName[1] = \"default\"\nQ-BRIDGE-MIB::dot1qVlanStaticName[9] = \"\\\\Surrounded\\\\\"");
+        $response = new SnmpResponse("Q-BRIDGE-MIB::dot1qVlanStaticName[1] = \"\\default\\\"\nQ-BRIDGE-MIB::dot1qVlanStaticName[6] = \\single\\\nQ-BRIDGE-MIB::dot1qVlanStaticName[9] = \\\\double\\\\\n");
         $this->assertTrue($response->isValid());
         $this->assertEquals('default', $response->value());
-        $this->assertEquals(['Q-BRIDGE-MIB::dot1qVlanStaticName[1]' => 'default', 'Q-BRIDGE-MIB::dot1qVlanStaticName[9]' => '\\Surrounded\\'], $response->values());
-        $this->assertEquals(['Q-BRIDGE-MIB::dot1qVlanStaticName' => [1 => 'default', 9 => '\\Surrounded\\']], $response->table());
+        Config::set('snmp.unescape', false);
+        $this->assertEquals([
+            'Q-BRIDGE-MIB::dot1qVlanStaticName[1]' => 'default',
+            'Q-BRIDGE-MIB::dot1qVlanStaticName[6]' => '\\single\\',
+            'Q-BRIDGE-MIB::dot1qVlanStaticName[9]' => '\\\\double\\\\',
+        ], $response->values());
+        $this->assertEquals(['Q-BRIDGE-MIB::dot1qVlanStaticName' => [
+            1 => 'default',
+            6 => '\\single\\',
+            9 => '\\\\double\\\\',
+        ]], $response->table());
+        Config::set('snmp.unescape', true); // for buggy versions of net-snmp
+        $this->assertEquals([
+            'Q-BRIDGE-MIB::dot1qVlanStaticName[1]' => 'default',
+            'Q-BRIDGE-MIB::dot1qVlanStaticName[6]' => 'single',
+            'Q-BRIDGE-MIB::dot1qVlanStaticName[9]' => '\\double\\',
+        ], $response->values());
+        $this->assertEquals(['Q-BRIDGE-MIB::dot1qVlanStaticName' => [
+            1 => 'default',
+            6 => 'single',
+            9 => '\\double\\',
+        ]], $response->table());
     }
 
     public function testMultiLine(): void

diff --git a/tests/data/arista-mos_metamux48.json b/tests/data/arista-mos_metamux48.json
@@ -5,7 +5,7 @@
                 {
                     "sysName": "<private>",
                     "sysObjectID": ".1.3.6.1.4.1.43191.1.6.7",
-                    "sysDescr": "Metamako MOS release 0.32.0 \\\\\\\\(build mos-0.32+22\\\\\\\\) running on a MetaMux 48 with L-Series",
+                    "sysDescr": "Metamako MOS release 0.32.0 \\\\(build mos-0.32+22\\\\) running on a MetaMux 48 with L-Series",
                     "sysContact": "<private>",
                     "version": "0.32.0",
                     "hardware": null,