如何在 Swift 中从 DNS 查询中获取真实的 IP 地址？

我想从 Swift 中的 DNS 查询获取 IP 地址（如 192.168.0.1 或 87.12.56.50）。我用 100 种不同的方法尝试了 100 次……没有任何帮助，所以我不得不寻求帮助。 到目前为止，这是我的代码：

let host = CFHostCreateWithName(nil,"subdomain.of.stackoverflow.com").takeUnretainedValue();
CFHostStartInfoResolution(host, .Addresses, nil);
var success: Boolean = 0;
let addresses = CFHostGetAddressing(host, &success).takeUnretainedValue() as NSArray;
if(addresses.count > 0){
   let theAddress = addresses[0] as NSData;
   println(theAddress);
}

好的...这些是我尝试实现但没有成功的代码的链接：https://gist.github.com/mikeash/bca3a341db74221625f5 https://gist.github.com/mikeash/bca3a341db74221625f5
如何在iOS上进行DNS查询 https://stackoverflow.com/questions/5000441/how-to-perform-dns-query-on-ios
在 Swift 中从 NSData 对象创建数组 https://stackoverflow.com/questions/24516170/create-an-array-in-swift-from-an-nsdata-object
CFHostGetAddressing() 是否支持 ipv6 DNS 条目？ https://stackoverflow.com/questions/24796142/does-cfhostgetaddressing-support-ipv6-dns-entries
在 Swift 中进行简单的 DNS 查找 https://stackoverflow.com/questions/24898001/do-a-simple-dns-lookup-in-swift

您的代码以“套接字地址”结构的形式检索地址。getnameinfo()可用于将地址转换为数字 IP 字符串 （代码回收自https://stackoverflow.com/a/25627545/1187415 https://stackoverflow.com/a/25627545/1187415, 现在更新为Swift 2):

let host = CFHostCreateWithName(nil,"www.google.com").takeRetainedValue()
CFHostStartInfoResolution(host, .Addresses, nil)
var success: DarwinBoolean = false
if let addresses = CFHostGetAddressing(host, &success)?.takeUnretainedValue() as NSArray?,
    let theAddress = addresses.firstObject as? NSData {
    var hostname = [CChar](count: Int(NI_MAXHOST), repeatedValue: 0)
    if getnameinfo(UnsafePointer(theAddress.bytes), socklen_t(theAddress.length),
        &hostname, socklen_t(hostname.count), nil, 0, NI_NUMERICHOST) == 0 {
            if let numAddress = String.fromCString(hostname) {
                print(numAddress)
            }
    }
}

输出（示例）：173.194.112.147

另请注意使用takeRetainedValue()在第一行，因为CFHostCreateWithName()其名称中包含“Create”，因此返回 (+1) 保留 目的。

Swift 3/Xcode 8 更新：

let host = CFHostCreateWithName(nil,"www.google.com" as CFString).takeRetainedValue()
CFHostStartInfoResolution(host, .addresses, nil)
var success: DarwinBoolean = false
if let addresses = CFHostGetAddressing(host, &success)?.takeUnretainedValue() as NSArray?,
    let theAddress = addresses.firstObject as? NSData {
    var hostname = [CChar](repeating: 0, count: Int(NI_MAXHOST))
    if getnameinfo(theAddress.bytes.assumingMemoryBound(to: sockaddr.self), socklen_t(theAddress.length),
                   &hostname, socklen_t(hostname.count), nil, 0, NI_NUMERICHOST) == 0 {
        let numAddress = String(cString: hostname)
        print(numAddress)
    }
}

或者，为了得到all主机的 IP 地址：

let host = CFHostCreateWithName(nil,"www.google.com" 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))
        if getnameinfo(theAddress.bytes.assumingMemoryBound(to: sockaddr.self), socklen_t(theAddress.length),
                       &hostname, socklen_t(hostname.count), nil, 0, NI_NUMERICHOST) == 0 {
            let numAddress = String(cString: hostname)
            print(numAddress)
        }
    }
}