stropdale

import Foundation



func reverseDNS(ip: String) -> String {
    var results: UnsafeMutablePointer<addrinfo>? = nil
    defer {
        if let results = results {
            freeaddrinfo(results)

stropdale

// Needs to be run on async otherwise you will get a crash.
// Make sure you have the internet permission added to the app manifest if this is going in an Anrdoid app...

    <uses-permission android:name="android.permission.INTERNET" />

public class DnsLookup extends AsyncTask<ArrayList<String>, Integer, ArrayList<HostIpDetails>> {

    private static String TAG = "DnsLookup";

    public interface DnsLookUpCompletionListener {

stropdale

import UIKit

// You many want to run this in the background
func getIPs(dnsName: String) -> String? {
    let host = CFHostCreateWithName(nil, dnsName as CFString).takeRetainedValue()
    CFHostStartInfoResolution(host, .addresses, nil)
    var success: DarwinBoolean = false
    if let addresses = CFHostGetAddressing(host, &success)?.takeUnretainedValue() as NSArray? {
        for case let theAddress as NSData in addresses {
            var hostname = [CChar](repeating: 0, count: Int(NI_MAXHOST))