Creating and binding socket on Mac OS Hight Sierra

Question

I have serious and strange problem with creating socket in my application for Hight Sierra. If I create command Line tool, everything is ok! I create socket, bind socket. But If I trying to create Cocoa App, I can't binding my socket! :(

If I use CFSockets in Cocoa App,

    char punchline[] = "MESSAGE from Server!";
    int yes = 1;

    CFSocketContext CTX = {0, punchline, NULL, NULL, NULL};

    CFSocketRef TCPServer = CFSocketCreate(kCFAllocatorDefault, PF_INET, SOCK_STREAM, IPPROTO_TCP, kCFSocketAcceptCallBack, (CFSocketCallBack) &AcceptCallBack, &CTX);


    if (TCPServer == NULL) return;

    setsockopt(CFSocketGetNative(TCPServer), SOL_SOCKET, SO_REUSEADDR, (void *) &yes, sizeof(yes));

    struct sockaddr_in addr;
    memset(&addr, 0, sizeof(addr));
    addr.sin_len = sizeof(addr);
    addr.sin_family = AF_INET;
    addr.sin_port = htons(33000);
    addr.sin_addr.s_addr = htonl(INADDR_ANY);

    NSData *address = [NSData dataWithBytes:&addr length:sizeof(addr)];

    if (CFSocketSetAddress(TCPServer, (CFDataRef) address) != kCFSocketSuccess) {
        CFRelease(TCPServer);
        return;
    }

I get this message:

CFSocketSetAddress bind failure: 1

If I use low level C function in Cocoa App, like this:

  sockfd = socket(AF_INET, SOCK_STREAM, 0);

  bzero((char *) &serv_addr, sizeof(serv_addr));
  portno = atoi(argv[1]);

  serv_addr.sin_family = AF_INET;
  serv_addr.sin_addr.s_addr = INADDR_ANY;
  serv_addr.sin_port = htons(portno);

  if (bind(sockfd, (struct sockaddr *) &serv_addr,
             sizeof(serv_addr)) < 0) error("ERROR on binding");

    listen(sockfd,5);
    clilen = sizeof(cli_addr);
    newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);

...it's not work too, and I get error on binding and also this message in console:

ERROR: Operation not permitted

But in command line tool everything is working well!

What kind of project settings (may be in info.plist) I need to fix? Where is a trouble? :(

Help me! :(((

Answer 1

The problem was that the application was sandboxed and did not have the Network: Incoming Connections entitlement. That entitlement can be added in Xcode under the App Sandbox details in the Capabilities tab of the target settings.