ts-bacnet/lib/bvlc.js

The BACnet protocol library written in pure JavaScript.

"use strict";
var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
    if (k2 === undefined) k2 = k;
    var desc = Object.getOwnPropertyDescriptor(m, k);
    if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
      desc = { enumerable: true, get: function() { return m[k]; } };
    }
    Object.defineProperty(o, k2, desc);
}) : (function(o, m, k, k2) {
    if (k2 === undefined) k2 = k;
    o[k2] = m[k];
}));
var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
    Object.defineProperty(o, "default", { enumerable: true, value: v });
}) : function(o, v) {
    o["default"] = v;
});
var __importStar = (this && this.__importStar) || function (mod) {
    if (mod && mod.__esModule) return mod;
    var result = {};
    if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k);
    __setModuleDefault(result, mod);
    return result;
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.decode = exports.encode = void 0;
const baEnum = __importStar(require("./enum"));
const DEFAULT_BACNET_PORT = 47808;
const encode = (buffer, func, msgLength, originatingIP) => {
    buffer[0] = baEnum.BVLL_TYPE_BACNET_IP;
    buffer[1] = func;
    buffer[2] = (msgLength & 0xff00) >> 8;
    buffer[3] = (msgLength & 0x00ff) >> 0;
    if (originatingIP) {
        // This is always a FORWARDED_NPDU regardless of the 'func' parameter.
        if (func !== baEnum.BvlcResultPurpose.FORWARDED_NPDU) {
            throw new Error("Cannot specify originatingIP unless " +
                "BvlcResultPurpose.FORWARDED_NPDU is used.");
        }
        // Encode the IP address and optional port into bytes.
        const [ipstr, portstr] = originatingIP.split(":");
        const port = parseInt(portstr, 10) || DEFAULT_BACNET_PORT;
        const ip = ipstr.split(".");
        buffer[4] = parseInt(ip[0], 10);
        buffer[5] = parseInt(ip[1], 10);
        buffer[6] = parseInt(ip[2], 10);
        buffer[7] = parseInt(ip[3], 10);
        buffer[8] = (port & 0xff00) >> 8;
        buffer[9] = (port & 0x00ff) >> 0;
        return 6 + baEnum.BVLC_HEADER_LENGTH;
    }
    else {
        if (func === baEnum.BvlcResultPurpose.FORWARDED_NPDU) {
            throw new Error("Must specify originatingIP if " +
                "BvlcResultPurpose.FORWARDED_NPDU is used.");
        }
    }
    return baEnum.BVLC_HEADER_LENGTH;
};
exports.encode = encode;
const decode = (buffer, _offset) => {
    let len;
    const func = buffer[1];
    const msgLength = (buffer[2] << 8) | (buffer[3] << 0);
    if (buffer[0] !== baEnum.BVLL_TYPE_BACNET_IP || buffer.length !== msgLength) {
        return undefined;
    }
    let originatingIP = null;
    switch (func) {
        case baEnum.BvlcResultPurpose.BVLC_RESULT:
        case baEnum.BvlcResultPurpose.ORIGINAL_UNICAST_NPDU:
        case baEnum.BvlcResultPurpose.ORIGINAL_BROADCAST_NPDU:
        case baEnum.BvlcResultPurpose.DISTRIBUTE_BROADCAST_TO_NETWORK:
        case baEnum.BvlcResultPurpose.REGISTER_FOREIGN_DEVICE:
        case baEnum.BvlcResultPurpose.READ_FOREIGN_DEVICE_TABLE:
        case baEnum.BvlcResultPurpose.DELETE_FOREIGN_DEVICE_TABLE_ENTRY:
        case baEnum.BvlcResultPurpose.READ_BROADCAST_DISTRIBUTION_TABLE:
        case baEnum.BvlcResultPurpose.WRITE_BROADCAST_DISTRIBUTION_TABLE:
        case baEnum.BvlcResultPurpose.READ_BROADCAST_DISTRIBUTION_TABLE_ACK:
        case baEnum.BvlcResultPurpose.READ_FOREIGN_DEVICE_TABLE_ACK:
            len = 4;
            break;
        case baEnum.BvlcResultPurpose.FORWARDED_NPDU:
            // Work out where the packet originally came from before the BBMD
            // forwarded it to us, so we can tell the BBMD where to send any reply to.
            const port = (buffer[8] << 8) | buffer[9];
            originatingIP = buffer.slice(4, 8).join(".");
            // Only add the port if it's not the usual one.
            if (port !== DEFAULT_BACNET_PORT) {
                originatingIP += ":" + port;
            }
            len = 10;
            break;
        case baEnum.BvlcResultPurpose.SECURE_BVLL:
            // unimplemented
            return undefined;
        default:
            return undefined;
    }
    return {
        len,
        func,
        msgLength,
        // Originating IP is set to the IP address of the node that originally
        // sent the packet, when it has been forwarded to us by a BBMD (since the
        // BBMD's IP address will be in the sender field.
        originatingIP,
    };
};
exports.decode = decode;