如何通过UDP CFSocket发送数据包？ [英] How to send a packet via a UDP CFSocket?

问题描述

我是一个完整的新手到网络，但我是一个C / C ++程序员，在Objective-C我的工作（这是OSX / iPhone）。

我想学习如何发送魔术包用cfsocket UDP套接字。我见过有库，比如AsyncUDPSocket库，但是我不想用这些。

我试图来看看苹果UDPecho文件，但作为一个初学者它确实让我困惑。我GOOGLE了周围了很多，我有放在一起code以下，我有一个数据包嗅探器的运行，并没有任何注册被发送。我明白我的code丢失的错误捕获了很多，但我只是试图让基础知识第一。

这是code吧？ （道歉，如果这接缝暧昧），我的意思是我错过了code的某些阶段，如：CFSocketSetAddress

如果任何人知道任何真正好的教程，这将有助于。

任何帮助是极大AP preciated，正如我在这是一个完整的初学者。

感谢

  INT主（INT ARGC，为const char * argv的[]）
{    NSAutoreleasePool *池= [[NSAutoreleasePool的alloc]初始化];    CFSocketRef WOLsocket;
    WOLsocket = CFSocketCreate（kCFAllocatorDefault，PF_INET，SOCK_DGRAM，IPPROTO_UDP，0，NULL，NULL）;
    如果（插座== NULL）{
        的NSLog（@CfSocketCreate失败）;
    }其他{
        如果（插座）{
            的NSLog（@插座创造:)）;                结构sockaddr_in的地址;
                memset的（放，地址，0，sizeof的（地址））;
                addr.sin_len = sizeof的（地址）;
                addr.sin_family = AF_INET;
                addr.sin_port = htons（9）; //港口
                INET_ATON（255.255.255.255，＆放大器; addr.sin_addr）; // IP地址
                CHAR ethadd [] =HelloWorld的;
                CFDataRef数据= CFDataCreate（NULL，（常量UINT8 *）ethadd，sizeof的（ethadd））;
                CFSocketSendData（插座，NULL，数据，0）;}    }    [池排水]
    返回0;
}
 

解决方案

您的问题很简单：你不告诉你想让它发送数据CFSocket

您精心构建的地址地址，但不使用它。你要么需要调用 CFSocketSetAddress 来的目的地址在插座上（如果你希望所有的数据包发送给去同一个目的地），或通过地址作为第二参数 CFSocketSendData 。

I am a complete newbie to networking, however I am a c/c++ programmer, and am working in objective-c (This is for OSX/iPhone).

I am trying to learn how to send a magic packet with a UDP socket using cfsocket. I've seen there are libraries such as AsyncUDPSocket library, however I do not want to use these.

I attempted to look at apples UDPecho file but, as a beginner it did confuse me. I've googled around ALOT, and I have put together the code below, I have a packet sniffer running and it doesn't register anything being sent. I understand my code is missing alot of error catching, however I am just trying to get the basics in first.

Is this code right? (apologies if this seams ambiguous) What I mean is am I missing certain stages of the code such as: CFSocketSetAddress?

If anyone knows any really good tutorials it would help.

Any help is greatly appreciated, as I am a complete beginner at this.

Thanks

int main (int argc, const char * argv[])
{

    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    CFSocketRef WOLsocket;
    WOLsocket = CFSocketCreate(kCFAllocatorDefault, PF_INET, SOCK_DGRAM, IPPROTO_UDP, 0, NULL, NULL);
    if ( socket == NULL) {
        NSLog(@"CfSocketCreate Failed");
    }else{
        if( socket ) {
            NSLog(@"Socket created :)");

                struct sockaddr_in addr;
                memset(&addr, 0, sizeof(addr));
                addr.sin_len = sizeof(addr);
                addr.sin_family = AF_INET;
                addr.sin_port = htons(9); //port
                inet_aton("255.255.255.255", &addr.sin_addr); //ip adress


                char ethadd []= "helloworld";
                CFDataRef Data = CFDataCreate(NULL, (const UInt8*)ethadd, sizeof(ethadd));
                CFSocketSendData(socket,NULL, Data, 0);}

    }

    [pool drain];
    return 0;
}

解决方案

Your problem is very simple: you are not telling the CFSocket where you want it to send the data.

You carefully construct an address in addr, but then don't use it. You either need to call CFSocketSetAddress to set the destination address on the socket (if you want all packets you send to go to the same destination), or pass the address as the 2nd argument to CFSocketSendData.

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