# ssdpscan.ps1 - Multicast SSDP-Discovery
#

[CmdletBinding()]
param (
   $mcastip = "192.168.178.255",
   $sourceudpport = 0,
   $remoteudpport = 1900,
   $timeout = 5000
)

Write-Verbose "Multicast SSDP-Discovery Start"

Write-Verbose "Create UDP-Client"
$udpClient = new-Object system.Net.Sockets.Udpclient($sourceudpport)
Write-Host "using UDP SourcePort: $($udpclient.client.localendpoint.port)"

Write-Verbose "Prepare Payload"
[string]$buffer = "M-SEARCH * HTTP/1.1`r`nHost: 239.255.255.250:1900`r`nST: upnp:rootdevice`r`nMan: ""ssdp:discover""`r`nMX: 3`r`n`r`n"
$byteBuffer  = [System.Text.Encoding]::ASCII.GetBytes($Buffer)

Write-Verbose "Send Multicast SSDP-Discovery Paket to $($mcastip):$($remoteudpport)"
$sendbytes = $udpClient.Send($byteBuffer, $byteBuffer.length, $mcastip, $remoteudpport)
if ($sendbytes -eq $byteBuffer.length) {
   Write-Verbose " SSDP-Discovery Paket sent"
}
else {
   Write-Error "Error sending SSDP-Discovery Paket"
}

Write-Verbose "Receive Multicast SSDP-Discovery Answers with ($Timeout) Sec timeout"
$udpclient.Client.ReceiveTimeout = $timeout 
$IPEndpoint = new-object net.ipendpoint([net.ipaddress]::any, 0) 
do {
    Write-Verbose "Reading pending packets"
    try {
        $data = $udpclient.receive([ref]$IPEndpoint)
    }
    catch {
        Write-Verbose "No more SSDP-Discovery Pakets to process"
        break
    }

    Write-Verbose "Received SSDP-Discovery Paket from $($IPEndpoint.Address):$($IPEndpoint.Port)"
    $ssdpanswer = ([system.text.encoding]::ASCII.GetString($data))
    #$result = @{}
    $result = New-Object PSObject
    $result | Add-Member -Membertype NoteProperty -Name "RemoteIPAddress" -Value $IPEndpoint.Address
    $result | Add-Member -Membertype NoteProperty -Name "RemotePort" -Value $IPEndpoint.Port

    foreach ($line in ($ssdpanswer -split "`r`n")) {
        Write-Verbose "Parsing Line: $($line)"
        $firstcolon = $line.IndexOf(":")
        if ($firstcolon -gt 0) {
            $result | Add-Member `
                        -Membertype NoteProperty `
                        -Name $line.Substring(0,$firstcolon).trim() `
                        -Value $line.Substring($firstcolon+1).trim()
        }
    }
    $result
}
while ($true) 

Write-Verbose "Close UDP-Client"
$Udpclient.Close()
Write-Verbose "Multicast SSDP-Discovery End"