UDP Broadcast / Device Discovery on iOS?

I'm working on finding Logitech Harmony Hub device discovery tools on a local network from an iOS app. The concept is inspired by the NODE.JS project that seems to send broadcasts on UDP 255.255.255.255, and then buys the IP-address of the Logitech (that's all I need). When testing the NODE.JS project on my home network from my Mac, it successfully finds the Logitech Harmony hub.

I use CocoaASyncSocket, and I must admit, my understanding of how UDP translation / discovery works may be distorted here. That's what I'm doing:

import UIKit
import CocoaAsyncSocket

class ViewController: UIViewController, GCDAsyncUdpSocketDelegate {

var address = "255.255.255.255"
var port:UInt16 = 5224
var socket:GCDAsyncUdpSocket!
var socketReceive:GCDAsyncUdpSocket!
var error : NSError?

override func viewDidLoad() {
    super.viewDidLoad()

    let message = "_logitech-reverse-bonjour._tcp.local.\n61991".dataUsingEncoding(NSUTF8StringEncoding)

    socket = GCDAsyncUdpSocket(delegate: self, delegateQueue: dispatch_get_main_queue())
    socket.sendData(message, toHost: address, port: port, withTimeout: 1000, tag: 0)

    do {
        try socket.bindToPort(port)
    } catch {
        print(error)
    }

    do {
        try socket.enableBroadcast(true)
    } catch {
        print(error)
    }

    do {
        try socket.beginReceiving()
    } catch {
        print(error)
    }

}

    func udpSocket(sock: GCDAsyncUdpSocket!, didConnectToAddress address: NSData!) {
        print("didConnectToAddress");
    }

    func udpSocket(sock: GCDAsyncUdpSocket!, didNotConnect error: NSError!) {
        print("didNotConnect \(error)")
    }

    func udpSocket(sock: GCDAsyncUdpSocket!, didSendDataWithTag tag: Int) {
        print("didSendDataWithTag")
    } 

    func udpSocket(sock: GCDAsyncUdpSocket!, didNotSendDataWithTag tag: Int, dueToError error: NSError!) {
        print("didNotSendDataWithTag")
    }

func udpSocket(sock: GCDAsyncUdpSocket!, didReceiveData data: NSData!, fromAddress address: NSData!, withFilterContext filterContext: AnyObject!) {

    var host: NSString?
    var port1: UInt16 = 0
    GCDAsyncUdpSocket.getHost(&host, port: &port1, fromAddress: address)
    print("From \(host!)")

    let gotdata: NSString = NSString(data: data!, encoding: NSUTF8StringEncoding)!
    print(gotdata)

}

}

When I compile this, the only answer I get is the message I just sent,

didSendDataWithTag
From ::ffff:192.168.1.101
_logitech-reverse-bonjour._tcp.local.
61991
From 192.168.1.101
_logitech-reverse-bonjour._tcp.local.
61991

, , , - , .

!

+4
1

, . :

  • 5224 . logitech-reverse-bonjour._tcp.local. , Harmony, - 61991.
  • Harmony , , ( 61991).

, . responseCollector.js node.js

+2

Source: https://habr.com/ru/post/1628398/


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