NSPOSIXErrorDomain when binding to socket on macOS 10.12

Question

I am playing with CocoaAsyncSocket in Swift to bind to a UDP socket and receive messages over the local network.

I am initialising a socket, and trying to bind to a port but am getting a NSPOSIXErrorDomain error. Perhaps indicating some sort of permissions issue?

My code:

import Cocoa
import CocoaAsyncSocket

@NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate, GCDAsyncUdpSocketDelegate {
    func applicationDidFinishLaunching(_ aNotification: Notification) {
        let socket = GCDAsyncUdpSocket.init(delegate: self, delegateQueue: DispatchQueue.main)
        do {
            try socket.bind(toPort: 53401)
        } catch let msg {
            NSLog("Error....\(msg)")
        }
    }
}

Full error:

Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted" UserInfo={NSLocalizedDescription=Operation not permitted, NSLocalizedFailureReason=Error in bind() function}

Answer 1

I believe it's the generated Xcode entitlements that prevent from binding. I changed those values to false and now the bind works

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>com.apple.security.app-sandbox</key>
    <false/>
    <key>com.apple.security.files.user-selected.read-only</key>
    <false/>
</dict>
</plist>