Manage CS GO dedicated server using RCON protocol

CSGODedicatedServerManager.psm1

using namespace System.IO
using namespace System.Net
using namespace System.Net.Sockets

class RconClient {
	hidden [Socket]$_socket
	hidden [int]$_id = 1

	RconClient([Socket]$socket) {
		$this._socket = $socket
	}

	[void]Close() {
		$this._socket.Disconnect($false)
		$this._socket.Dispose()
	}
}

class RconResponsePacket {
	static [int]$MaxPacketLength = 4096
	[int]$Id
	[string]$Type
	[string]$Body

	RconResponsePacket([int]$id, [string]$type, [string]$body) {
		$this.Id = $id
		$this.Type = $type
		$this.Body = $body
	}
}

Function Connect-ServerPort {
	[OutputType([System.Net.Sockets.Socket])]
	param(
		# Server address, can be IPv4 or DNS name
		[Parameter(Mandatory=$True)]
		[string]
		[ValidateNotNull()]
		$Address,

		# Server port
		[Parameter(Mandatory=$True)]
		[int]
		$Port
	)

	$ServerAddress = If ($Address -match '^(\d{1,3}\.){3}\d{1,3}$') { 
		[ipaddress]::Parse($Address)
	} Else { 
		[Dns]::GetHostAddresses($Address) | ?{ $_.AddressFamily -eq [AddressFamily]::InterNetwork } | select -First 1
	}
	$Endpoint = [IPEndpoint]::new($ServerAddress, $Port)
	$Socket = [Socket]::new([AddressFamily]::InterNetwork, [SocketType]::Stream, [ProtocolType]::Tcp)
	$Socket.Connect($Endpoint)

	Return $Socket
}

Function ConvertTo-CSGOPacket {
	[OutputType([byte[]])]
	param(
		# packet ID
		[Parameter(Mandatory=$True)]
		[int]
		$Id,

		# packet type
		[Parameter(Mandatory=$True)]
		[ValidateSet('Auth', 'Command')]
		[string]
		$Type,

		# packet body
		[Parameter(Mandatory=$True)]
		[ValidateNotNull()]
		[string]
		$Body
	)

	$BodyBytes = [System.Text.Encoding]::UTF8.GetBytes($Body + "\0")
	$BodyLength = $BodyBytes.Length

	$TypeId = If ('Auth' -eq $Type) { 3 } Else { 2 }
	$Stream = [MemoryStream]::new(12 + $BodyLength)
	try {
		$Stream.Write([System.BitConverter]::GetBytes(9 + $BodyLength), 0, 4)
		$Stream.Write([System.BitConverter]::GetBytes($Id), 0, 4)
		$Stream.Write([System.BitConverter]::GetBytes(($TypeId)), 0, 4)
		$Stream.Write($BodyBytes, 0, $BodyLength)
		$Stream.Write(([byte]0), 0, 1)

		Return $Stream.ToArray()
	}
	finally {
		$Stream.Dispose()
	}
}

Function ConvertFrom-CSGOPacket {
	[OutputType('RconResponsePacket')]
	param(
		# packet bytes
		[Parameter(Mandatory=$True)]
		[byte[]]
		$Buffer
	)

	$Size = [System.BitConverter]::ToInt32($Buffer, 0)
	If ($Size -lt 10) {
		Write-Error 'Invalid packet received' -ErrorAction Stop
	}

	$Id = [System.BitConverter]::ToInt32($Buffer, 4)
	switch ([System.BitConverter]::ToInt32($Buffer, 8)) {
		0 { $Type = 'Command' }
		2 { $Type = 'Auth'}
		Default { $Type = 'Unknown' }
	}
	try {
		$RawBody = [System.Text.Encoding]::UTF8.GetChars($Buffer, 12, ($Size - 10))
		$Body = ([string]::new($RawBody, 0, ($Size - 10))).TrimEnd()
		$Body = $Body -replace "\r\n|\n\r|\n|\r", "`r`n"
		Return [RconResponsePacket]::new($Id, $Type, $Body)
	}
	catch {
		Write-Warning 'Error reading RCON packet: ' + $_.Exception.Message
		Return [RconResponsePacket]::new($Id, $Type, [string]::Empty)
	}
}

Function Connect-CSGODedicatedServer {
	[OutputType('RconClient')]
	param(
		# server address, can be IPv4 or DNS name
		[Parameter(Mandatory=$True)]
		[string]
		[ValidateNotNull()]
		$Address,

		# Port (default: 27015)
		[Parameter(Mandatory=$False)]
		[int]
		$Port = 27015,

		# RCON server password
		[Parameter(Mandatory=$True, Position=1)]
		[ValidateNotNull()]
		[string]
		$Password
	)

	$Socket = Connect-ServerPort -Address $Address -Port $Port
	$Client = [RconClient]::new($Socket)
	$AuthPacket = ConvertTo-CSGOPacket -Id $Client._id -Type Auth -Body $Password
	$Socket.Send($AuthPacket, [SocketFlags]::None)
	$Buffer = [byte[]]::new([RconResponsePacket]::MaxPacketLength)
	$Socket.Receive($Buffer, 0, $Socket.Available, [SocketFlags]::None)
	$Response = [RconResponsePacket](ConvertFrom-CSGOPacket -Buffer $Buffer)
	$Client._id = $Client._id + 1

	Return $Client
}

Function Start-CSGODedicatedServer {
	[OutputType([RconClient])]
	param(
		# server port (default: 27015)
		[Parameter(Mandatory=$False)]
		[int]
		$Port = 27015
	)
}