Commands/Protocols/UDP-Protocol.ps1
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function Protocol.UDP { <# .SYNOPSIS UDP protocol .DESCRIPTION Converts a UDP protocol command to PowerShell. .EXAMPLE # Creates the code to create a UDP Client {udp://127.0.0.1:8568} | Use-PipeScript .EXAMPLE # Creates the code to broadast a message. {udp:// -Host [ipaddress]::broadcast -port 911 -Send "It's an emergency!"} | Use-PipeScript .EXAMPLE {send udp:// -Host [ipaddress]::broadcast -Port 911 "It's an emergency!"} | Use-PipeScript .EXAMPLE Use-PipeScript { watch udp://*:911 send udp:// -Host [ipaddress]::broadcast -Port 911 "It's an emergency!" receive udp://*:911 } #> [ValidateScript({ $commandAst = $_ if ($commandAst -isnot [Management.Automation.Language.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', 'watch') { return $false } } return $true } return $false })] [Alias('UDP','UDP://')] param( # The URI. [Parameter(Mandatory,ValueFromPipeline,ParameterSetName='Protocol',Position=0)] [Parameter(ValueFromPipeline,ParameterSetName='Interactive',Position=0)] [Parameter(Mandatory,ParameterSetName='ScriptBlock',Position=0)] [uri] $CommandUri, [ValidateSet('Send','Receive','Watch')] [Parameter(Position=1)] [string] $Method, # The Command's Abstract Syntax Tree [Parameter(Mandatory,ParameterSetName='Protocol')] [Management.Automation.Language.CommandAST] $CommandAst, # If the UDP protocol is used as an attribute, this will be the existing script block. [Parameter(Mandatory,ParameterSetName='ScriptBlock')] [ScriptBlock] $ScriptBlock = {}, # The script or message sent via UDP. $Send, # If set, will receive result events. [switch] $Receive, # A ScriptBlock used to watch the UDP socket. [scriptblock] $Watch, # The host name. This can be provided via parameter if it is not present in the URI. [Alias('Host')] [string] $HostName, # The port. This can be provided via parameter if it is not present in the URI. [int] $Port, # Any remaining arguments. [Parameter(ValueFromRemainingArguments)] [PSObject[]] $ArgumentList ) process { $commandParameters = if ($PSCmdlet.ParameterSetName -eq 'Protocol') { [Ordered]@{} + $CommandAst.Parameter } else { [Ordered]@{} + $PSBoundParameters } $commandArguments = if ($PSCmdlet.ParameterSetName -eq 'Protocol') { @() + $CommandAst.ArgumentList } else { @() + $args } if (-not $CommandUri.Scheme) { $commandUri = [uri]"udp://$($commandUri.OriginalString -replace '://')" } $methodName = $Method $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 -or $commandParameters.HostName)) { $udpPort = $commandParameters.Port $commandParameters.Port } elseif (($commandParameters.Host -or $commandParameters.HostName) -and $commandParameters.Port) { $udpIP = if ($commandParameters.Host) { $commandParameters.Host } else { $commandParameters.HostName } $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 "'", "''")'" } $UdpOperationScript = # If the method name is send or -Send was provided if ($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 -and $commandArguments[0]) { $commandParameters.Send = $commandArguments[0] } elseif (-not $commandParameters.Send -and $argumentList -and $ArgumentList[0]) { $commandParameters.Send = $ArgumentList[0] } # If we still don't have a -Send parameter, error out. if (-not $commandParameters.Send) { Write-Verbose "Nothing to $(if ($methodName -ne 'Send') {'-'} else {"Send"})" return } # prepare send to be embedded $embedSend = if ($commandParameters.Send -is [ScriptBlock]) { "& {$($commandParameters.Send)}" } elseif ($commandParameters.Send -is [string]) { "[text.Encoding]::utf8.GetBytes('$($commandParameters.Send -replace "'","''")')" } elseif ($commandParameters.Send -as [byte[]]) { "[Convert]::FromBase64String('$([Convert]::ToBase64String($commandParameters.Send))')" } else { $commandParameters.Send } # Create a UDP client and send the datagram. [ScriptBlock]::Create(" `$udpClient = $constructUDP `$datagram = @($embedSend) -as [byte[]] `$bytesSent = `$udpClient.Send(`$datagram, `$datagram.Length) ").Transpile() } # If the method name is Watch or -Watch was passed, we'll want to watch for results elseif ($methodName -eq 'Watch' -or $commandParameters.Watch) { # If -Watch was not passed, try to bind it positionally. if (-not $commandParameters.Watch) { $commandParameters.Watch = $commandArguments[0] } # If -Watch was passed and was not a [ScriptBlock], unset it. if ($commandParameters.Watch -and $commandParameters.Watch -isnot [ScriptBlock]) { $commandParameters.Watch = $null } # If -Watch was not provided, default it to creating an event. if (-not $commandParameters.Watch) { $commandParameters.Watch = { New-Event "$udpEventName" -MessageData $datagram } } # If we do not have an IP and port, we cannot watch. if (-not $udpIP -or -not $udpPort) { Write-Error "Must provide both IP and port to Watch" 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) `$watchOutput = & { $($commandParameters.Watch) } `$datagram if (`$watchOutput -isnot [Management.Automation.PSEvent]) { New-Event -SourceIdentifier `$udpEventName -MessageData `$watchOutput } } `$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) -or (`$jobExists.State -ne 'Running')) { $( if (-not $CommandAst.IsAssigned) { '$null = ' } )$($jobCommand + '-Name "$jobName" -ScriptBlock $jobScript') } "@) # If the command is assigned, wrap it in $() so that only one thing is returned. if ($CommandAst.IsAssigned) { [ScriptBlock]::create("`$($outputScript)") } else { $outputScript } } elseif ($methodName -eq 'Receive' -or $commandParameters.Receive) { $jobName = "${udpIP}:${udpPort}" -replace "['`"]" $eventName = "udp://${udpIP}:${udpPort}" -replace "['`"]" [scriptblock]::Create(" `$( `$udpEvents = @(Get-Event -SourceIdentifier '$eventName' -ErrorAction Ignore) [Array]::Reverse(`$udpEvents) `$udpEvents ) ") } else { [scriptblock]::Create($constructUdp).Transpile() } switch ($PSCmdlet.ParameterSetName) { Protocol { $UdpOperationScript } ScriptBlock { # join the existing script with the schema information Join-PipeScript -ScriptBlock $ScriptBlock, $UdpOperationScript } Interactive { . $UdpOperationScript } } } } |