Hi all, I have a question regarding how to set up a UDP listener on iOS 14. I have a UDP listener which has worked in the past, but after updating to iOS 14 it works sporadically/not at all.
This lives in an NSObject, and listens for a UDP broadcast across the local network on port 15000 (no specific IP address). It uses the CocoaAsyncSocket library. When I call setUpSocket() local network permissions are not triggered, but the app is able to sporadically pick up UDP packets.
var socket: GCDAsyncUdpSocket?
var broadcastPort: UInt16 = 15000
var broadcastAddress: String = ""
var connectAddress = ""
var connectPort = 0
func setUpSocket() {
findUDP()
let socket = GCDAsyncUdpSocket(delegate: self, delegateQueue: DispatchQueue.main)
socket.setIPv4Enabled(true)
socket.setIPv6Enabled(false)
do {
try socket.bind(toPort: broadcastPort) /*15000*/
try socket.enableBroadcast(false)
try socket.beginReceiving()
} catch let error as NSError {
print("Issue with setting up listener \(error)")
}
}
/*Called when UDP packets are received.*/
func udpSocket(_ sock: GCDAsyncUdpSocket, didReceive data: Data, fromAddress: Data, withFilterContext filterContext: Any?) {
do {
let jsonDictionary = try JSONSerialization.jsonObject(with: data, options: []) as! [String : Any]
if (connected == false) {
if (jsonDictionary["Addresses"] != nil) {
if (jsonDictionary["Addresses"] is NSArray) {
let addresses = jsonDictionary["Addresses"] as! NSArray
for i in addresses {
let ipAddress:String = i as! String
if (ipAddress.range(of: "^([0-9]{1,3}\\.){3}[0-9]{1,3}(\\/([0-9]|[1-2][0-9]|3[0-2]))?$", options: .regularExpression) != nil) {
connectAddress = ipAddress
}
}
connectPort = jsonDictionary["Port"] as! Int
}
			/*Sets up a TCP connection on the IP and Port provided in the UDP broadcast.*/
			setupNetworkCommunication(ip: connectAddress, port: connectPort)
closeSocket()
}
}
} catch let error {
return print(error)
}
}
How can I update this to comply with iOS 14? If I need to update to use Bonjour services, how can I listen on a port without specifying an address (and without having to look for a specific Bonjour service broadcast, because the broadcast I'm looking for doesn't use Bonjour).
Is it acceptable to quickly open and close a Bonjour NWBrowser in order to trigger the network permissions, and then use my code as-is? This seems to work but seems hacky at best.
Thanks in advance.