[Feat] Disclose decoded network details of the source device.

[SamuelToh]

Node Version: 12.4.0

Node BACstack Version: 0.2.4

• Bug Report
• Feature Request
• Question

Feature Request / Question

• It is not uncommon to have more than one bacnet devices sitting on the same ip address because the target address could be like a subnet which can house many other devices.

In order to reach out to a specific device, commands like the read property will have to be explicit. Unicasting to an address is not sufficient as there can be more than 1 devices responding to the call. Hence to narrow down to a specific target device the parametersnet and adr must be set. At the moment whoIs does not disclose this.

We will need to decode these information and make it available.

Current Behaviour (Bug Report)

N/A

Expected Behaviour (Bug Report)

• I would like the WhoIs response to include the following data.

"header": {
    "func": 10,
    "sender": {
      "address": "10.1.201.53",
      "forwardedFrom": null,
      "type": 0,
      "net": 7778,
      "adr": [
        127,
        0,
        0,
        1,
        180,
        196
      ]
    },

The structure is recommended as this will make things easier for the lib user. All they need to do here would be to pass on the 'sender' object into the api like readProp and not care about the details.

Steps to reproduce Issue (Bug Report)

[eabinga]

Seems to work:

bacnetClient.on('listening', () => {
    bacnetClient.whoIs({address: '192.168.1.255', net: 65535}); // broadcast & global whois
    
    setTimeout(() => {
        bacnetClient.close();
    }, 5000);

Results in:

{
   "len":2,
   "type":16,
   "service":0,
   "header":{
      "func":10,
      "sender":{
         "address":"192.168.1.10:64359",
         "forwardedFrom":null,
         "type":0,
         "net":20,
         "adr":[
            192,
            168,
            1,
            200,
            186,
            192
         ]
      },
      "apduType":16,
      "expectingReply":false,
      "confirmedService":false
   },
   "payload":{
      "len":0,
      "deviceId":1000,
      "maxApdu":1440,
      "segmentation":0,
      "vendorId":35
   }
}

Where this device is not on the local network