Transpilers/Protocols/UDP.Protocol.psx.ps1
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<# .SYNOPSIS udp protocol .DESCRIPTION Converts a UDP protocol command to PowerShell .EXAMPLE udp://127.0.0.1:8568 # Creates a UDP Client .EXAMPLE udp:// -Host [ipaddress]::broadcast -port 911 -Send "It's an emergency!" .EXAMPLE {send udp:// -Host [ipaddress]::broadcast -Port 911 "It's an emergency!"}.Transpile() .EXAMPLE Invoke-PipeScript { receive udp://*:911 } Invoke-PipeScript { send udp:// -Host [ipaddress]::broadcast -Port 911 "It's an emergency!" } Invoke-PipeScript { receive udp://*:911 -Keep } #> using namespace System.Management.Automation.Language [ValidateScript({ $commandAst = $_ if ($commandAst -isnot [CommandAst]) { return $false } if ($commandAst.CommandElements[0..1] -match '^udp://' -ne $null) { if ($commandAst.CommandElements[0] -notmatch '^udp://') { if ($commandAst.CommandElements[0].value -notin 'send', 'receive') { return $false } } return $true } return $false })] param( # The URI. [Parameter(Mandatory,ValueFromPipeline)] [uri] $CommandUri, # The Command's Abstract Syntax Tree [Parameter(Mandatory)] [Management.Automation.Language.CommandAST] $CommandAst ) process { $commandParameters = [Ordered]@{} + $CommandAst.Parameter $commandArguments = @() + $CommandAst.ArgumentList $methodName = '' $commandName = if ($CommandAst.CommandElements[0].Value -match '://') { $CommandAst.CommandElements[0].Value } elseif ($commandArguments.Length -ge 1 -and $commandArguments[0] -is [string] -and $commandArguments[0] -match '://') { $methodName = $CommandAst.CommandElements[0].Value $commandArguments[0] $commandArguments = $commandArguments[1..$($commandArguments.Count)] } $udpIP, $udpPort = $null, $null $constructorArgs = @(if ($CommandUri.Host) { $udpIP = $commandUri.Host $commandUri.Host if ($commandUri.Port) { $udpPort = $CommandUri.Port $commandUri.Port } } elseif ($commandParameters.Port -and -not $commandParameters.Host) { $udpPort = $commandParameters.Port $commandParameters.Port } elseif ($commandParameters.Host -and $commandParameters.Port) { $udpIP = $commandParameters.Host $udpIP $udpPort = $commandParameters.Port $udpPort }) # We will always need to construct a client # so prepare that code now that we know the host and port. $constructUdp = "new Net.Sockets.UdpClient $constructorArgs" if ($udpIP -is [string] -and $udpIP -notmatch '^\[') { $udpIP = "'$($udpIP -replace "'", "''")'" } # If the method name is send or -Send was provided if ($methodName -eq 'send' -or $commandParameters.Send) { # ensure we have both and IP and a port if (-not $udpIP -or -not $udpPort) { Write-Error "Must provide both IP and port to send" return } # If we don't have a -Send parameter, try to bind positionally. if (-not $commandParameters.Send -and $commandArguments[0]) { $commandParameters.Send = $commandArguments[0] } # If we still don't have a -Send parameter, error out. if (-not $commandParameters.Send) { Write-Error "Nothing to $(if ($methodName -ne 'Send') {'-'})Send" return } # prepare send to be embedded $embedSend = if ($commandParameters.Send -is [ScriptBlock]) { "& {$($commandParameters.Send)}" } elseif ($commandParameters.Send -is [string]) { "[text.Encoding]::utf8.GetBytes('$($commandParameters.Send -replace "'","''")')" } else { $commandParameters.Send } # Create a UDP client and send the datagram. [ScriptBlock]::Create(" `$udpClient = $constructUDP `$datagram = @($embedSend) -as [byte[]] `$bytesSent = `$udpClient.Send(`$datagram, `$datagram.Length) ").Transpile() } # If the method name is receive or -Receive was passed, we'll want to receive results elseif ($methodName -eq 'Receive' -or $commandParameters.Receive) { # If -Receive was not passed, try to bind it positionally. if (-not $commandParameters.Receive) { $commandParameters.Receive = $commandArguments[0] } # If -Receive was passed and was not a [ScriptBlock], error out. if ($commandParameters.Receive -and $commandParameters.Receive -isnot [ScriptBlock]) { Write-Error "UDP -Receive must be a [ScriptBlock]" return } # If -Receive was not provided, default it to creating an event. if (-not $commandParameters.Receive) { $commandParameters.Receive = { New-Event "$udpEventName" -MessageData $datagram } } # If we do not have an IP and port, we cannot receive. if (-not $udpIP -or -not $udpPort) { Write-Error "Must provide both IP and port to receive" return } # Receiving UDP results must be run in a background job. # Thus we start by creating that script. $jobScript = [ScriptBlock]::Create(@" `$udpClient = [Net.Sockets.UdpClient]::new() `$udpEndpoint = [Net.IpEndpoint]::new( ([ipaddress]$udpIP), $udpPort ) `$udpEventName = "udp://`$udpEndPoint" Register-EngineEvent -SourceIdentifier `$udpEventName -Forward `$udpClientBound = `$false try { `$udpClient.Client.Bind(`$udpEndpoint) `$udpClientBound = `$true } catch { Write-Error -Message `$_.Message -Exception `$_.Exception } :udpReceive while (`$udpClientBound) { `$datagram = `$udpClient.Receive([ref]`$udpEndpoint) & { $($commandParameters.Receive) } `$datagram } `$udpClient.Close() "@).Transpile() # Now we construct the job name. $jobName = "'${udpIP}:${udpPort}'" -replace "['`"]" # Then we set the jobCommand. # It would be nice to be able to use Start-ThreadJob, but Start-ThreadJob will not forward events. # (also, Starting a ThreadJob and then doing a blocking call on that thread makes a job that cannot be stopped) $jobCommand = "Start-Job " $outputScript = [ScriptBlock]::create(@" `$jobName = '$jobName' `$jobScript = { $jobScript } `$JobExists = Get-Job | Where-Object Name -eq `$JobName if (-not (`$JobExists)) { $( if (-not $CommandAst.IsAssigned) { '$null = ' } )$($jobCommand + '-Name "$jobName" -ScriptBlock $jobScript') } else { `$JobExists | Receive-Job$(if ($commandParameters.Keep) { ' -Keep'}) } "@) # If the command is assigned, wrap it in $() so that only one thing is returned. if ($CommandAst.IsAssigned) { [ScriptBlock]::create("`$($outputScript)") } else { $outputScript } } else { [scriptblock]::Create($constructUdp).Transpile() } } |