ios - 在 Swift 中使用 CocoaAsyncSocket 接收 SSDP 响应

Question

我正在尝试使用带有库 CocoaAsyncSocket ( https://github.com/robbiehanson/CocoaAsyncSocket ) 的 swift 接收 SSDP 响应

我可以成功地将 M-Search 命令发送到多播组并获得响应，我查看了 wireshark ( http://i.imgur.com/pn6LB7R.png ):我可以看到 M-Search 数据包发出并且响应返回但是我从来没有在我的应用程序中收到 NSData。 (顺便说一句，我现在正在寻找 Roku)

我已经实现了 GCDAsyncUdpSocketDelegate Delegate 并添加了 didReceiveData 函数，但是我从来没有得到数据。

我怀疑这部分有问题:

ssdpSocket = GCDAsyncUdpSocket(delegate: self, delegateQueue: dispatch_get_main_queue()) 
ssdpSocket.bindToPort(ssdpPort, error: &error)
ssdpSocket.beginReceiving(&error)
ssdpSocket.enableBroadcast(true, error: &error)
ssdpSocket.connectToHost(ssdpAddres, onPort: ssdpPort, error: &error)
ssdpSocket.joinMulticastGroup(ssdpAddres, error: &error)

请看下面的示例代码:

import UIKit
class ViewController: UIViewController, GCDAsyncUdpSocketDelegate {

//ssdp stuff
var ssdpAddres          = "239.255.255.250"
var ssdpPort:UInt16     = 1900
var ssdpSocket:GCDAsyncUdpSocket!
var ssdpSocketRec:GCDAsyncUdpSocket!
var error : NSError?

override func viewDidLoad() {
    super.viewDidLoad()

    ssdpSocket = GCDAsyncUdpSocket(delegate: self, delegateQueue: dispatch_get_main_queue())
    ssdpSocket.bindToPort(ssdpPort, error: &error)
    ssdpSocket.beginReceiving(&error)
    ssdpSocket.enableBroadcast(true, error: &error)
    ssdpSocket.connectToHost(ssdpAddres, onPort: ssdpPort, error: &error)
    ssdpSocket.joinMulticastGroup(ssdpAddres, error: &error)

    //replace ST:roku:ecp with ST:ssdp:all to view all devices
    let data = "M-SEARCH * HTTP/1.1\r\nHOST: 239.255.255.250:1900\r\nMAN: \"ssdp:discover\"\r\nMX: 3\r\nST: roku:ecp\r\nUSER-AGENT: iOS UPnP/1.1 TestApp/1.0\r\n\r\n".dataUsingEncoding(NSUTF8StringEncoding)
    ssdpSocket.sendData(data, withTimeout: 1, tag: 0)
}


func udpSocket(sock:GCDAsyncUdpSocket!,didConnectToAddress data : NSData!){
    println("didConnectToAddress")
    println(data)
}

func udpSocket(sock: GCDAsyncUdpSocket!, didReceiveData data: NSData!, fromAddress address: NSData!, withFilterContext filterContext: AnyObject!) {
    println("didReceiveData")
    println(data)
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

}

Answer 1

在反复研究代码之后，我已经开始工作了，我将代码发布在这里以帮助其他人解决这个问题。

当我删除时:

ssdpSocket.connectToHost(ssdpAddres, onPort: ssdpPort, error: &error)

我能够接收数据，我怀疑这是以某种方式阻止了它.. 不确定如何或为什么，我猜我不需要连接到主机作为它的多播

现在可以使用以下代码:

let mSearchData = "M-SEARCH * HTTP/1.1\r\nHOST: 239.255.255.250:1900\r\nMAN: \"ssdp:discover\"\r\nMX: 3\r\nST: ssdp:all\r\nUSER-AGENT: iOS UPnP/1.1 TestApp/1.0\r\n\r\n".dataUsingEncoding(NSUTF8StringEncoding) //all devices

override func viewDidLoad() {
    super.viewDidLoad()

    //send M-Search
    ssdpSocket = GCDAsyncUdpSocket(delegate: self, delegateQueue: dispatch_get_main_queue())
    ssdpSocket.sendData(mSearchData, toHost: ssdpAddres, port: ssdpPort, withTimeout: 1, tag: 0)

    //bind for responses
    ssdpSocket.bindToPort(ssdpPort, error: &error)
    ssdpSocket.joinMulticastGroup(ssdpAddres, error: &error)
    ssdpSocket.beginReceiving(&error)

}

didReceiveData 函数现在被调用，我可以打印响应:

 func udpSocket(sock: GCDAsyncUdpSocket!, didReceiveData data: NSData!, fromAddress address: NSData!, withFilterContext filterContext: AnyObject!) {

    var host: NSString?
    var port1: UInt16 = 0
    GCDAsyncUdpSocket.getHost(&host, port: &port1, fromAddress: address)
    println("From \(host!)")


    let gotdata: NSString = NSString(data: data!, encoding: NSUTF8StringEncoding)!
    println(gotdata)

 }