Fixes exceptions during interface discovery

Fix #38

Author: LordHepipud

lib/core/tools/ConvertTo-IcingaIPBinaryString.psm1

@@ -22,21 +22,16 @@
 function ConvertTo-IcingaIPBinaryString()
 {
    param(
-      [string]$IP
+      $IP
    );
 
-   $IPArray = $IP.Split(' ');
-   $IPList  = @();
-
-   foreach ($entry in $IPArray) {
-      if ($entry -like '*.*') {
-         $IPList += ConvertTo-IcingaIPv4BinaryString -IP $entry;
-      } elseif ($entry -like '*:*') {
-         $IPList += ConvertTo-IcingaIPv6BinaryString -IP $entry;
-      } else {
-         return 'Invalid IP was provided!';
-      }
+   if ($IP -like '*.*') {
+      $IP = ConvertTo-IcingaIPv4BinaryString -IP $IP;
+   } elseif ($IP -like '*:*') {
+      $IP = ConvertTo-IcingaIPv6BinaryString -IP $IP;
+   } else {
+      return 'Invalid IP was provided!';
    }
 
-    return $IPList;
+   return $IP;
 }

lib/core/tools/ConvertTo-IcingaIPv4BinaryString.psm1

@@ -21,18 +21,24 @@
 
 function ConvertTo-IcingaIPv4BinaryString()
 {
-    param(
-        [string]$IP
-    );
+   param(
+      [string]$IP
+   );
 
-    $IP = $IP -split '\.' | ForEach-Object {    
-        [System.Convert]::ToString($_, 2).PadLeft(8, '0');
-    }
-    $IP = $IP -join '';
-    $IP = $IP -replace '\s','';
-    
-    return @{
-       'value' = $IP;
-       'name' = 'IPv4'
+   try {
+      $IP = $IP -split '\.' | ForEach-Object {    
+         [System.Convert]::ToString($_, 2).PadLeft(8, '0');
+      }
+      $IP = $IP -join '';
+      $IP = $IP -replace '\s','';
+   } catch {
+       # Todo: Should we handle errors? It might happen due to faulty routes or unhandled route config
+       #       we throw errors which should have no effect at all
+       return $null;
+   }
+
+   return @{
+      'value' = $IP;
+      'name' = 'IPv4'
    }
 }

lib/core/tools/Get-IcingaNetworkInterface.psm1

@@ -113,11 +113,21 @@ function Get-IcingaNetworkInterface()
         foreach ($destinationIP in $IPBinStringMaster) {
             [string]$RegexPattern = [string]::Format("^.{{{0}}}", $Route.Value.Mask);
             [string]$ToBeMatched = $Route.Value."Binary IP String";
+            if ($null -eq $ToBeMatched) {
+                continue;
+            }
+
             $Match1=[regex]::Matches($ToBeMatched, $RegexPattern).Value;
             $Match2=[regex]::Matches($destinationIP.Value, $RegexPattern).Value;
 
             If ($Match1 -like $Match2) {
-                $ExternalInterface = ((Get-NetIPAddress -InterfaceIndex $Route.Value.Interface -AddressFamily $destinationIP.Name).IPAddress);
+                $ExternalInterface = ((Get-NetIPAddress -InterfaceIndex $Route.Value.Interface -AddressFamily $destinationIP.Name -ErrorAction SilentlyContinue).IPAddress);
+
+                # If no interface was found -> skip this entry
+                if ($null -eq $ExternalInterface) {
+                    continue;
+                }
+
                 if ($ExternalInterfaces.ContainsKey($ExternalInterface)) {
                     $ExternalInterfaces[$ExternalInterface].count += 1;
                 } else {