static int socketpair_win32()

in folly/net/NetOps.cpp [550:653]

• 90 lines of code
• 23 McCabe index (conditional complexity)

static int socketpair_win32(
    int family, int type, int protocol, intptr_t fd[2]) {
  intptr_t listener = -1;
  intptr_t connector = -1;
  intptr_t acceptor = -1;
  struct sockaddr_in listen_addr;
  struct sockaddr_in connect_addr;
  int size;
  int saved_errno = -1;
  int family_test;

  family_test = family != AF_INET && (family != AF_UNIX);
  if (protocol || family_test) {
    WSASetLastError(WSAEAFNOSUPPORT);
    return -1;
  }

  if (!fd) {
    WSASetLastError(WSAEINVAL);
    return -1;
  }

  listener = ::socket(AF_INET, type, 0);
  if (listener < 0) {
    return -1;
  }
  memset(&listen_addr, 0, sizeof(listen_addr));
  listen_addr.sin_family = AF_INET;
  listen_addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  listen_addr.sin_port = 0; /* kernel chooses port.   */
  if (::bind(listener, (struct sockaddr*)&listen_addr, sizeof(listen_addr)) ==
      -1) {
    goto tidy_up_and_fail;
  }
  if (::listen(listener, 1) == -1) {
    goto tidy_up_and_fail;
  }

  connector = ::socket(AF_INET, type, 0);
  if (connector < 0) {
    goto tidy_up_and_fail;
  }

  memset(&connect_addr, 0, sizeof(connect_addr));

  /* We want to find out the port number to connect to.  */
  size = sizeof(connect_addr);
  if (::getsockname(listener, (struct sockaddr*)&connect_addr, &size) == -1) {
    goto tidy_up_and_fail;
  }
  if (size != sizeof(connect_addr)) {
    goto abort_tidy_up_and_fail;
  }
  if (::connect(
          connector, (struct sockaddr*)&connect_addr, sizeof(connect_addr)) ==
      -1) {
    goto tidy_up_and_fail;
  }

  size = sizeof(listen_addr);
  acceptor = ::accept(listener, (struct sockaddr*)&listen_addr, &size);
  if (acceptor < 0) {
    goto tidy_up_and_fail;
  }
  if (size != sizeof(listen_addr)) {
    goto abort_tidy_up_and_fail;
  }
  /* Now check we are talking to ourself by matching port and host on the
     two sockets.   */
  if (::getsockname(connector, (struct sockaddr*)&connect_addr, &size) == -1) {
    goto tidy_up_and_fail;
  }
  if (size != sizeof(connect_addr) ||
      listen_addr.sin_family != connect_addr.sin_family ||
      listen_addr.sin_addr.s_addr != connect_addr.sin_addr.s_addr ||
      listen_addr.sin_port != connect_addr.sin_port) {
    goto abort_tidy_up_and_fail;
  }
  ::closesocket(listener);
  fd[0] = connector;
  fd[1] = acceptor;

  return 0;

abort_tidy_up_and_fail:
  saved_errno = WSAECONNABORTED;

tidy_up_and_fail:
  if (saved_errno < 0) {
    saved_errno = WSAGetLastError();
  }
  if (listener != -1) {
    ::closesocket(listener);
  }
  if (connector != -1) {
    ::closesocket(connector);
  }
  if (acceptor != -1) {
    ::closesocket(acceptor);
  }

  WSASetLastError(saved_errno);
  return -1;
}