quary dns use swift 3

querydns.swift

func query(domain:String) ->[String] {
    var results:[String] = []
    //dispatch_async(q) { [weak self] in
    let host = CFHostCreateWithName(nil,domain as CFString).takeRetainedValue()
    //NSLog("getIPFromDNS %@", hostName)
    //let d = NSDate()
    
    CFHostStartInfoResolution(host, .addresses, nil)
    var success: DarwinBoolean = false
    if let addresses = CFHostGetAddressing(host, &success)?.takeUnretainedValue() as NSArray? {
        
        for s in  addresses{
            let theAddress =  s as! NSData
            var hostname = [CChar](repeating: 0, count: Int(256))
            print(theAddress)
            let p = theAddress as Data
            let value = p.withUnsafeBytes { (ptr: UnsafePointer<sockaddr>)  in
                return ptr
            }
            if getnameinfo(value, socklen_t(theAddress.length),
                           &hostname, socklen_t(hostname.count), nil, 0, NI_NUMERICHOST) == 0 {
                let numAddress = String(cString:hostname)
                    
                results.append(numAddress)
                
            }
            
            
        }
        
        
    }
    return results
}
print(query(domain: "www.freebsdchina.org"))