From 5255da80ff43903ac5053018629ffd4fafcc77e1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tuomas=20Riihim=C3=A4ki?= <tuomas@iudex.fi>
Date: Wed, 12 Oct 2022 17:17:33 +0300
Subject: [PATCH] Improve LinkUp and LinkDown trap handling incomplete traps
 (#14385)

* fix LinkUp and LinkDown trap parsing
These traps do not always include 'ifAdminStatus' and 'ifOperStatus' from IF-MIB,
which causes the fields to become NULL when traps are received.

Add checks that values exist, and add default value for ifOperStatus.

* Fix styleci complaint

* Update LinkDown.php

* Update LinkUp.php

* Update LinkUp.php

Co-authored-by: Tony Murray <murraytony@gmail.com>
---
 LibreNMS/Snmptrap/Handlers/LinkDown.php | 7 +++++--
 LibreNMS/Snmptrap/Handlers/LinkUp.php   | 4 ++--
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/LibreNMS/Snmptrap/Handlers/LinkDown.php b/LibreNMS/Snmptrap/Handlers/LinkDown.php
index 24c059f9e035..5f1ba110f5a6 100644
--- a/LibreNMS/Snmptrap/Handlers/LinkDown.php
+++ b/LibreNMS/Snmptrap/Handlers/LinkDown.php
@@ -52,9 +52,12 @@ public function handle(Device $device, Trap $trap)
             return;
         }
 
-        $port->ifOperStatus = $trap->getOidData("IF-MIB::ifOperStatus.$ifIndex");
-        $port->ifAdminStatus = $trap->getOidData("IF-MIB::ifAdminStatus.$ifIndex");
+        $port->ifOperStatus = $trap->getOidData("IF-MIB::ifOperStatus.$ifIndex") ?: 'down';
 
+        $trapAdminStatus = $trap->getOidData("IF-MIB::ifAdminStatus.$ifIndex");
+        if ($trapAdminStatus) {
+            $port->ifAdminStatus = $trapAdminStatus;
+        }
         Log::event("SNMP Trap: linkDown $port->ifAdminStatus/$port->ifOperStatus " . $port->ifDescr, $device->device_id, 'interface', 5, $port->port_id);
 
         if ($port->isDirty('ifAdminStatus')) {
diff --git a/LibreNMS/Snmptrap/Handlers/LinkUp.php b/LibreNMS/Snmptrap/Handlers/LinkUp.php
index dc5d1eab2645..9cf85c2b98ce 100644
--- a/LibreNMS/Snmptrap/Handlers/LinkUp.php
+++ b/LibreNMS/Snmptrap/Handlers/LinkUp.php
@@ -52,8 +52,8 @@ public function handle(Device $device, Trap $trap)
             return;
         }
 
-        $port->ifOperStatus = $trap->getOidData("IF-MIB::ifAdminStatus.$ifIndex");
-        $port->ifAdminStatus = $trap->getOidData("IF-MIB::ifOperStatus.$ifIndex");
+        $port->ifOperStatus = $trap->getOidData("IF-MIB::ifOperStatus.$ifIndex") ?: 'up';
+        $port->ifAdminStatus = $trap->getOidData("IF-MIB::ifAdminStatus.$ifIndex") ?: 'up'; // If we receive LinkUp trap, we can safely assume that the ifAdminStatus is also up.
 
         Log::event("SNMP Trap: linkUp $port->ifAdminStatus/$port->ifOperStatus " . $port->ifDescr, $device->device_id, 'interface', 1, $port->port_id);