knxultimate/src/protocol/TunnelCRI.ts

KNX IP protocol implementation for Node. This is the ENGINE of Node-Red KNX-Ultimate node.

import { KNX_CONSTANTS } from './KNXConstants'
import CRI from './CRI'

const TUNNEL_CRI_LENGTH: number = 4

export enum TunnelTypes {
	TUNNEL_LINKLAYER = KNX_CONSTANTS.TUNNEL_LINKLAYER,
	TUNNEL_RAW = KNX_CONSTANTS.TUNNEL_RAW,
	TUNNEL_BUSMONITOR = KNX_CONSTANTS.TUNNEL_BUSMONITOR,
}

export default class TunnelCRI extends CRI {
	private knxLayer: number

	constructor(knxLayer: number) {
		super(KNX_CONSTANTS.TUNNEL_CONNECTION)
		this.knxLayer = knxLayer
	}

	get length(): number {
		return TUNNEL_CRI_LENGTH
	}

	static createFromBuffer(buffer: Buffer, offset: number = 0): TunnelCRI {
		const knxLayer: number = buffer.readUInt8(offset++)
		buffer.readUInt8(offset)
		return new TunnelCRI(knxLayer)
	}

	toBuffer(): Buffer {
		const buffer: Buffer = Buffer.alloc(this.length)
		let offset: number = 0
		buffer.writeUInt8(this.length, offset++)
		buffer.writeUInt8(KNX_CONSTANTS.TUNNEL_CONNECTION, offset++)
		buffer.writeUInt8(this.knxLayer, offset++)
		buffer.writeUInt8(0x00, offset)
		return buffer
	}
}