Socket.m

void ListeningSocketCallback(CFSocketRef sock,
                             CFSocketCallBackType type, CFDataRef address, const void *data,
                             void *info)
{
    int fd = * (const int *) data;
    CFReadStreamRef   readStream;
    CFWriteStreamRef  writeStream;
    NSInputStream  *  inputStream;
    NSOutputStream *  outputStream;
    CFStreamCreatePairWithSocket(NULL, fd, &readStream,
                                 &writeStream);
    
    inputStream  = [NSMakeCollectable(readStream ) autorelease];
    outputStream = [NSMakeCollectable(writeStream) autorelease];
    [inputStream setProperty:(id)kCFBooleanTrue
                      forKey:(NSString *)kCFStreamPropertyShouldCloseNativeSocket];
}

- (void)createSocket {
    int fd4;
    struct sockaddr_in sin;
    
    fd4 = socket(AF_INET, SOCK_STREAM, 0);
    
    memset(&sin, 0, sizeof(sin));
    sin.sin_family = AF_INET;
    sin.sin_len = sizeof(sin);
    sin.sin_port = 0;

    int err = bind(fd4, (const struct sockaddr *) &sin, sin.sin_len);
    
    socklen_t addrLen = sizeof(sin);
    err = getsockname(fd4, (struct sockaddr *) &sin, &addrLen);
    
    err = listen(fd4, 5);
    
    CFSocketContext     context = {0, NULL, NULL, NULL, NULL};
    CFSocketRef         sock;
    CFRunLoopSourceRef  rls;
    
    sock = CFSocketCreateWithNative(NULL,
                                    fd4,
                                    kCFSocketAcceptCallBack,
                                    ListeningSocketCallback,
                                    &context);
    rls = CFSocketCreateRunLoopSource(NULL, sock, 0);
    CFRunLoopAddSource(CFRunLoopGetCurrent(),
                       rls,
                       kCFRunLoopCommonModes);
    
    CFRelease(rls);
    CFRelease(sock);
    
    NSNetService *service = [[NSNetService alloc]
                             initWithDomain:@""
                             type:@"_http._tcp."
                             name:@""
                             port:ntohs(sin.sin_port)];
    
    myService = service;
    self.port = sin.sin_port;
    
    [service scheduleInRunLoop: [NSRunLoop currentRunLoop]
                       forMode: NSRunLoopCommonModes];
    [service setDelegate: self];
    [service publish];
    isRunning = YES;
    
    NSMutableDictionary *txtDict = [NSMutableDictionary dictionaryWithCapacity:2];
    [txtDict setObject:@"moo" forKey:@"cow"];
    [txtDict setObject:@"quack" forKey:@"duck"];
    [self sendTxtData:service withDict:txtDict];
}

- (void)sendTxtData:(NSNetService *)service withDict:(NSMutableDictionary *)dict {
    NSData *txtData = [NSNetService dataFromTXTRecordDictionary:dict];
    [service setTXTRecordData:txtData];
}