What if listen returns 10022?

Question

C++ / C#

I am writing a TCP server in MFC.
I initialize like this:

CCYBERRMSDlg* dlg = (CCYBERRMSDlg*)Param;
  
  CString ip, port;
  dlg->GetDlgItem(IDC_EDIT2)->GetWindowTextA(ip);
  dlg->GetDlgItem(IDC_EDIT3)->GetWindowTextA(port);

  string IP, PORT;
  IP = string(CT2CA(ip));
  PORT = string(CT2CA(port));

  WSAData wsaData;
  WORD DllVersion = MAKEWORD(2, 1);
  if (WSAStartup(DllVersion, &wsaData) != 0) {
    return false;
  }

  SOCKADDR_IN addr;
  int sizeofaddr = sizeof(addr);
  addr.sin_family = AF_INET;
  addr.sin_addr.s_addr = inet_addr(IP.c_str());
  addr.sin_port = atoi(PORT.c_str());
  
  SOCKET sListen = socket(AF_INET, SOCK_STREAM, NULL);
  bind(sListen, (SOCKADDR*)&addr, sizeof(addr));
  if (WSAGetLastError() != 0) {
    dlg->AddLog("bind error");
    return -1;
  }
  if (listen(sListen, SOMAXCONN) != 0) {
    dlg->AddLog("listen error");
    return -1;
  }

It all starts and runs in a separate thread.
As a result, "listen error" is displayed in the log box.
Initially, everything worked fine, but then I changed something, I don’t remember what, and everything stopped working. The magic of programming...

Answer 1

I did not understand what the problem was, but it seems to me that it was necessary to use ::bindand not bind
Found a working code here: https://www.binarytides.com/code-tcp-socket-server...

WSACleanup();
  WSADATA wsaData;
  SOCKET sListen, newConnection;
  struct sockaddr_in server, client;
  int c;
  
  if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
    dlg->AddLog("Error WSAStartup");
    return -1;
  }

  if ((sListen = socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET) {
    dlg->AddLog("Error create socket sListen");
    return -1;
  }

  server.sin_family = AF_INET;
  server.sin_addr.s_addr = inet_addr(IP.c_str());
  server.sin_port = htons(atoi(PORT.c_str()));

  int result = ::bind(sListen, (struct sockaddr*)&server, sizeof(server));
  if (result != 0) {
    string code = to_string(WSAGetLastError());
    dlg->AddLog(string("Bind error: " + code).c_str());
  }

  listen(sListen, 256);

  dlg->AddLog("Waiting for connections...");

  c = sizeof(struct sockaddr_in);

  newConnection = accept(sListen, (struct sockaddr*)&client, &c);
  if (newConnection == INVALID_SOCKET) {
    dlg->AddLog("Error accept");
  }

  dlg->AddLog("Connected new user!");

  closesocket(sListen);