通过所有可用的网络接口使用GCDAsyncUdpSocket进行UDP广播

Question

我正在使用GCDAsyncUdpSocket广播UDP数据包以搜索我的NAS设备。

以下是用于发送和接收UDP数据包的代码段

NSString *broadCastAddress = @"255.255.255.255";
NSInteger udpPort =  8097;

GCDAsyncUdpSocket  *gcdAsyncUdpSocket = [[GCDAsyncUdpSocket alloc]  initWithDelegate:selfdelegateQueue:dispatch_get_main_queue()];
[gcdAsyncUdpSocket bindToPort:udpPort error:&error];
[gcdAsyncUdpSocket setPreferIPv4];

NSData *data = @“Hi there”; // Sample data
[gcdAsyncUdpSocket  enableBroadcast:YES error:&error];
[gcdAsyncUdpSocket  beginReceiving:&error];

[gcdAsyncUdpSocket  sendData:data toHost:broadCastAddress port:udpPort withTimeout:-1 tag:1];

上面的代码只能通过单个网络接口（即Wifi或以太网或Thunderbolt）发送数据包，但我想通过所有可用的网络接口进行广播。 （以太网，WiFi，Thunderbolt等）。

我有什么办法可以同时使用同一端口通过所有可用的网络接口（以太网，WiFi，Thunderbolt等）进行广播。

任何帮助表示赞赏，在此先感谢。

Answer 1

唷！ 经过大量使用Google搜索和反复试验方法后，我找到了解决方案。 解决方案在这里。

1. 首先使用以下功能枚举所有可用的网络接口。

    - (NSMutableArray *) enumerateAndGetDetailsOfAllNetworkInterfaces { NSMutableArray *interfaceArray = [[NSMutableArray alloc] init]; struct ifaddrs *ifap, *ifa; struct sockaddr_in *sa; char *addr; getifaddrs (&ifap); for (ifa = ifap; ifa; ifa = ifa->ifa_next) { if (ifa->ifa_addr->sa_family==AF_INET) { QNInterfaceModel *interfaceModel = [[QNInterfaceModel alloc] init]; sa = (struct sockaddr_in *) ifa->ifa_addr; addr = inet_ntoa(sa->sin_addr); printf("Interface: %s\\tAddress: %s\\n", ifa->ifa_name, addr); interfaceModel.interfaceName = [NSString stringWithCString:ifa->ifa_name encoding:NSUTF8StringEncoding]; interfaceModel.interfaceIPAddress = [NSString stringWithCString:addr encoding:NSUTF8StringEncoding]; [interfaceArray addObject:interfaceModel]; } } freeifaddrs(ifap); return interfaceArray; } 

我创建了存储接口名称及其地址的InterfaceModel。

步骤2：为每个接口创建一个套接字

    NSMutableArray *interfaceArray = [self enumerateAndGetDetailsOfAllNetworkInterfaces];

    for(QNInterfaceModel *interfaceModel in interfaceArray)
    {
       NSError *error;

       NSInteger udpPort =  8097;

       GCDAsyncUdpSocket *gcdAsyncUdpSocket = [[GCDAsyncUdpSocket alloc] initWithDelegate:self
                                                                         delegateQueue:dispatch_get_main_queue()];
       [gcdAsyncUdpSocket bindToPort:udpPort interface:interfaceModel.interfaceName error:&error];

       gcdAsyncUdpSocket.delegate = self;

       if(error == nil)
       {
         [_socketArray addObject:gcdAsyncUdpSocket];
       }
    }

步骤3：将所有创建的套接字存储在一个数组中，并通过每个套接字进行广播，如下所示，但是在广播之前，我们需要创建一个侦听器套接字以接收响应数据包。

     NSError *error;

     NSString *broadCastString = @"255.255.255.255";

     NSInteger udpPort =  8097;
     GCDAsyncUdpSocket *listenerGCDAsyncUdpSocket = [[GCDAsyncUdpSocket alloc] initWithDelegate:self
                                                                  delegateQueue:dispatch_get_main_queue()];
    [listenerGCDAsyncUdpSocket bindToPort:udpPort error:&error];
    [listenerGCDAsyncUdpSocket setPreferIPv4];
    [listenerGCDAsyncUdpSocket  enableBroadcast:YES error:&error];
    [listenerGCDAsyncUdpSocket  beginReceiving:&error];


   // Send Packets through all the available Interfaces
   for(NSInteger i =0 ; i<_socketArray.count ;i++)
   {
    GCDAsyncUdpSocket *gcdAsyncUdpSocket = [_socketArray objectAtIndex:i];
    gcdAsyncUdpSocket.delegate = self;

    if(error)
    {
       // Error connecting
    }
    else
    {
        [gcdAsyncUdpSocket setPreferIPv4];

        NSData *data = @"Hi There";

        if (![gcdAsyncUdpSocket enableBroadcast:YES error:&error]) {

            QNDLog(@"Error enableBroadcast:%@",error);
            return;
        }

        [gcdAsyncUdpSocket  beginReceiving:&error];

        [gcdAsyncUdpSocket  sendData:data toHost:broadCastString port:udpPort withTimeout:-1 tag:i];
    }
}