fix: Use snmpv3 username even when NoAuthNoPriv is selected #4677

AUTHORS.md

@@ -135,6 +135,7 @@ LibreNMS contributors:
 - Florent Bruchez <ftbz@me.com> (ftbz)
 - Bartosz Radwan <b.radwan@citypartner.pl> (bartoszradwan)
 - Kate Gerry <kate@fansubber.com> (kate66)
+- Johan Zaxmy <johan@zaxmy.com> (Zaxmy)
 - Ryan Gibbons <rtgibbons23@gmail.com> (rtgibbons)
 
 [1]: http://observium.org/ "Observium web site"

includes/snmp.inc.php

@@ -560,8 +560,8 @@ function snmp_gen_auth(&$device)
         
         if ($device['authlevel'] === 'noAuthNoPriv') {
             // We have to provide a username anyway (see Net-SNMP doc)
-            // FIXME: There are two other places this is set - why are they ignored here?
-            $cmd .= ' -u root';
+            $username = !empty($device['authname']) ? $device['authname'] : 'root';
+            $cmd .= " -u '".$username."'";
         } elseif ($device['authlevel'] === 'authNoPriv') {
             $cmd .= " -a '".$device['authalgo']."'";
             $cmd .= " -A '".$device['authpass']."'";