Add warning to collect-wsl-logs.ps1 to be displayed when tool is missing

diagnostics/collect-wsl-logs.ps1

@@ -9,6 +9,44 @@ Param (
 
 Set-StrictMode -Version Latest
 
+function Test-WslApplication {
+    param (
+        $Name
+    )
+
+    # Log warning when tool is not present in WSL
+
+    # Capture any output/error from wsl.exe so we can distinguish
+    # between "command not found" and "WSL invocation failed".
+    $wslOutput = & wsl.exe -e sh -lc "command -v $Name >/dev/null 2>&1" 2>&1
+    $exitCode = $LASTEXITCODE
+
+    if ($exitCode -eq 0)
+    {
+        return $true
+    }
+
+    # POSIX shells typically return 1 when command -v does not find the command, but we have seen sh returning 127.
+    if ($exitCode -eq 1 -or $exitCode -eq 127)
+    {
+        Write-Warning "$Name not found in WSL. For a more complete log collection install $Name."
+        return $false
+    }
+
+    # Any other exit code is assumed to indicate WSL itself failed
+    # (e.g., no distro installed, WSL disabled, or other startup error).
+    if (-not [string]::IsNullOrWhiteSpace($wslOutput))
+    {
+        Write-Warning "Unable to check for $Name in WSL. wsl.exe exited with code $exitCode. Output: $wslOutput"
+    }
+    else
+    {
+        Write-Warning "Unable to check for $Name in WSL. wsl.exe exited with code $exitCode."
+    }
+
+    return $false
+}
+
 function Collect-WindowsNetworkState {
     param (
         $Folder,
@@ -89,6 +127,9 @@ else
 # Networking-specific setup
 if ($LogProfile -eq "networking")
 {
+    Test-WslApplication -Name "tcpdump" | Out-Null
+    Test-WslApplication -Name "iptables" | Out-Null
+
     # Copy/download networking.sh script
     $networkingBashScript = "$folder/networking.sh"
     if (Test-Path "$PSScriptRoot/networking.sh")