gsocket.cpp

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*  don't have access to the GSocket struct information.
*  Returns true if the flag was set correctly, false if an error occurred
*  (ie, if the parameter was NULL)
*/
bool GSocket::SetReusable()
{
    /* socket must not be null, and must not be in use/already bound */
    if (this && m_fd == INVALID_SOCKET) {
        m_reusable = true;
        return true;
    }
    return false;
}

/* Client specific parts */

/* GSocket_Connect:
 *  For stream (connection oriented) sockets, GSocket_Connect() tries
 *  to establish a client connection to a server using the peer address
 *  as established with GSocket_SetPeer(). Returns GSOCK_NOERROR if the
 *  connection has been successfully established, or one of the error
 *  codes listed below. Note that for nonblocking sockets, a return
 *  value of GSOCK_WOULDBLOCK doesn't mean a failure. The connection
 *  request can be completed later; you should use GSocket_Select()
 *  to poll for GSOCK_CONNECTION | GSOCK_LOST, or wait for the
 *  corresponding asynchronous events.
 *
 *  For datagram (non connection oriented) sockets, GSocket_Connect()
 *  just sets the peer address established with GSocket_SetPeer() as
 *  default destination.
 *
 *  Error codes:
 *    GSOCK_INVSOCK    - the socket is in use or not valid.
 *    GSOCK_INVADDR    - the peer address has not been established.
 *    GSOCK_TIMEDOUT   - timeout, the connection failed.
 *    GSOCK_WOULDBLOCK - connection in progress (nonblocking sockets only)
 *    GSOCK_MEMERR     - couldn't allocate memory.
 *    GSOCK_IOERR      - low-level error.
 */
GSocketError GSocket::Connect(GSocketStream stream)
{
  int ret, err;
  u_long arg = 1;

  assert(this);

  /* Enable CONNECTION events (needed for nonblocking connections) */
  m_detected &= ~GSOCK_CONNECTION_FLAG;

  if (m_fd != INVALID_SOCKET)
  {
    m_error = GSOCK_INVSOCK;
    return GSOCK_INVSOCK;
  }

  if (!m_peer)
  {
    m_error = GSOCK_INVADDR;
    return GSOCK_INVADDR;
  }

  /* Streamed or dgram socket? */
  m_stream   = (stream == GSOCK_STREAMED);
  m_server   = false;
  m_establishing = false;

  /* Create the socket */
  m_fd = socket(m_peer->m_realfamily,
                     m_stream? SOCK_STREAM : SOCK_DGRAM, 0);

  if (m_fd == INVALID_SOCKET)
  {
    m_error = GSOCK_IOERR;
    return GSOCK_IOERR;
  }

  ioctlsocket(m_fd, FIONBIO, (u_long FAR *) &arg);
  gs_gui_functions->Enable_Events(this);

  /* Connect it to the peer address, with a timeout (see below) */
  ret = connect(m_fd, m_peer->m_addr, m_peer->m_len);

  if (ret == SOCKET_ERROR)
  {
    err = WSAGetLastError();

    /* If connect failed with EWOULDBLOCK and the GSocket object
     * is in blocking mode, we select() for the specified timeout
     * checking for writability to see if the connection request
     * completes.
     */
    if ((err == WSAEWOULDBLOCK) && (!m_non_blocking))
    {
      err = Connect_Timeout();

      if (err != GSOCK_NOERROR)
      {
        Close();
        /* m_error is set in _GSocket_Connect_Timeout */
      }

      return (GSocketError) err;
    }

    /* If connect failed with EWOULDBLOCK and the GSocket object
     * is set to nonblocking, we set m_error to GSOCK_WOULDBLOCK
     * (and return GSOCK_WOULDBLOCK) but we don't close the socket;
     * this way if the connection completes, a GSOCK_CONNECTION
     * event will be generated, if enabled.
     */
    if ((err == WSAEWOULDBLOCK) && (m_non_blocking))
    {
      m_establishing = true;
      m_error = GSOCK_WOULDBLOCK;
      return GSOCK_WOULDBLOCK;
    }

    /* If connect failed with an error other than EWOULDBLOCK,
     * then the call to GSocket_Connect() has failed.
     */
    Close();
    m_error = GSOCK_IOERR;
    return GSOCK_IOERR;
  }

  return GSOCK_NOERROR;
}

/* Datagram sockets */

/* GSocket_SetNonOriented:
 *  Sets up this socket as a non-connection oriented (datagram) socket.
 *  Before using this function, the local address must have been set
 *  with GSocket_SetLocal(), or the call will fail. Returns GSOCK_NOERROR
 *  on success, or one of the following otherwise.
 *
 *  Error codes:
 *    GSOCK_INVSOCK - the socket is in use.
 *    GSOCK_INVADDR - the local address has not been set.
 *    GSOCK_IOERR   - low-level error.
 */
GSocketError GSocket::SetNonOriented()
{
  u_long arg = 1;

  assert(this);

  if (m_fd != INVALID_SOCKET)
  {
    m_error = GSOCK_INVSOCK;
    return GSOCK_INVSOCK;
  }

  if (!m_local)
  {
    m_error = GSOCK_INVADDR;
    return GSOCK_INVADDR;
  }

  /* Initialize all fields */
  m_stream   = false;
  m_server   = false;

  /* Create the socket */
  m_fd = socket(m_local->m_realfamily, SOCK_DGRAM, 0);

  if (m_fd == INVALID_SOCKET)
  {
    m_error = GSOCK_IOERR;
    return GSOCK_IOERR;
  }

  ioctlsocket(m_fd, FIONBIO, (u_long FAR *) &arg);
  gs_gui_functions->Enable_Events(this);

  /* Bind to the local address,
   * and retrieve the actual address bound.
   */
  if ((bind(m_fd, m_local->m_addr, m_local->m_len) != 0) ||
      (getsockname(m_fd,
                   m_local->m_addr,
                   (WX_SOCKLEN_T *)&m_local->m_len) != 0))
  {
    Close();
    m_error = GSOCK_IOERR;
    return GSOCK_IOERR;
  }

  return GSOCK_NOERROR;
}

/* Generic IO */

/* Like recv(), send(), ... */
int GSocket::Read(char *buffer, int size)
{
  int ret;

  assert(this);

  /* Reenable INPUT events */
  m_detected &= ~GSOCK_INPUT_FLAG;

  if (m_fd == INVALID_SOCKET || m_server)
  {
    m_error = GSOCK_INVSOCK;
    return -1;
  }

  /* If the socket is blocking, wait for data (with a timeout) */
  if (Input_Timeout() == GSOCK_TIMEDOUT)
    return -1;

  /* Read the data */
  if (m_stream)
    ret = Recv_Stream(buffer, size);
  else
    ret = Recv_Dgram(buffer, size);

  if (ret == SOCKET_ERROR)
  {
    if (WSAGetLastError() != WSAEWOULDBLOCK)
      m_error = GSOCK_IOERR;
    else
      m_error = GSOCK_WOULDBLOCK;
    return -1;
  }

  return ret;
}

int GSocket::Write(const char *buffer, int size)
{
  int ret;

  assert(this);

  if (m_fd == INVALID_SOCKET || m_server)
  {
    m_error = GSOCK_INVSOCK;
    return -1;
  }

  /* If the socket is blocking, wait for writability (with a timeout) */
  if (Output_Timeout() == GSOCK_TIMEDOUT)
    return -1;

  /* Write the data */
  if (m_stream)
    ret = Send_Stream(buffer, size);
  else
    ret = Send_Dgram(buffer, size);

  if (ret == SOCKET_ERROR)
  {
    if (WSAGetLastError() != WSAEWOULDBLOCK)
      m_error = GSOCK_IOERR;
    else
      m_error = GSOCK_WOULDBLOCK;

    /* Only reenable OUTPUT events after an error (just like WSAAsyncSelect
     * does). Once the first OUTPUT event is received, users can assume
     * that the socket is writable until a read operation fails. Only then
     * will further OUTPUT events be posted.
     */
    m_detected &= ~GSOCK_OUTPUT_FLAG;
    return -1;
  }

  return ret;
}

/* GSocket_Select:
 *  Polls the socket to determine its status. This function will
 *  check for the events specified in the 'flags' parameter, and
 *  it will return a mask indicating which operations can be
 *  performed. This function won't block, regardless of the
 *  mode (blocking | nonblocking) of the socket.
 */
GSocketEventFlags GSocket::Select(GSocketEventFlags flags)
{
  if (!gs_gui_functions->CanUseEventLoop())
  {
    GSocketEventFlags result = 0;
    fd_set readfds;
    fd_set writefds;
    fd_set exceptfds;

    assert(this);

    FD_ZERO(&readfds);
    FD_ZERO(&writefds);
    FD_ZERO(&exceptfds);
    FD_SET(m_fd, &readfds);
    if (flags & GSOCK_OUTPUT_FLAG || flags & GSOCK_CONNECTION_FLAG)
      FD_SET(m_fd, &writefds);
    FD_SET(m_fd, &exceptfds);

    /* Check 'sticky' CONNECTION flag first */
    result |= (GSOCK_CONNECTION_FLAG & m_detected);

    /* If we have already detected a LOST event, then don't try
     * to do any further processing.
     */
    if ((m_detected & GSOCK_LOST_FLAG) != 0)
    {
      m_establishing = false;

      return (GSOCK_LOST_FLAG & flags);
    }

    /* Try select now */
    if (select(m_fd + 1, &readfds, &writefds, &exceptfds,
        &m_timeout) <= 0)
    {
      /* What to do here? */
      return (result & flags);
    }

    /* Check for exceptions and errors */
    if (FD_ISSET(m_fd, &exceptfds))
    {
      m_establishing = false;
      m_detected = GSOCK_LOST_FLAG;

      /* LOST event: Abort any further processing */
      return (GSOCK_LOST_FLAG & flags);
    }

    /* Check for readability */
    if (FD_ISSET(m_fd, &readfds))
    {
      result |= GSOCK_INPUT_FLAG;

      if (m_server && m_stream)
      { 
        /* This is a TCP server socket that detected a connection. 
           While the INPUT_FLAG is also set, it doesn't matter on 
           this kind of  sockets, as we can only Accept() from them. */
        result |= GSOCK_CONNECTION_FLAG;
        m_detected |= GSOCK_CONNECTION_FLAG;
      }
    }

    /* Check for writability */
    if (FD_ISSET(m_fd, &writefds))
    {
      if (m_establishing && !m_server)
      {
        int error;
        WX_SOCKLEN_T len = sizeof(error);

        m_establishing = false;

        getsockopt(m_fd, SOL_SOCKET, SO_ERROR, (char*)&error, &len);

        if (error)
        {
          m_detected = GSOCK_LOST_FLAG;

          /* LOST event: Abort any further processing */
          return (GSOCK_LOST_FLAG & flags);
        }
        else
        {
          result |= GSOCK_CONNECTION_FLAG;
          m_detected |= GSOCK_CONNECTION_FLAG;
        }
      }
      else
      {
        result |= GSOCK_OUTPUT_FLAG;
      }
    }

    return (result & flags);
  }
  else /* USE_GUI() */
  {
    assert(this);
    return flags & m_detected;
  }
}

/* Attributes */

/* GSocket_SetNonBlocking:
 *  Sets the socket to non-blocking mode. All IO calls will return
 *  immediately.
 */
void GSocket::SetNonBlocking(bool non_block)
{
  assert(this);

  m_non_blocking = non_block;
}

/* GSocket_SetTimeout:
 *  Sets the timeout for blocking calls. Time is expressed in
 *  milliseconds.
 */
void GSocket::SetTimeout(unsigned long millis)
{
  assert(this);

  m_timeout.tv_sec  = (millis / 1000);
  m_timeout.tv_usec = (millis % 1000) * 1000;
}

/* GSocket_GetError:
 *  Returns the last error occurred for this socket. Note that successful
 *  operations do not clear this back to GSOCK_NOERROR, so use it only
 *  after an error.
 */
GSocketError WXDLLIMPEXP_NET GSocket::GetError()
{
  assert(this);

  return m_error;
}

/* Callbacks */

/* GSOCK_INPUT:
 *   There is data to be read in the input buffer. If, after a read
 *   operation, there is still data available, the callback function will
 *   be called again.
 * GSOCK_OUTPUT:
 *   The socket is available for writing. That is, the next write call
 *   won't block. This event is generated only once, when the connection is
 *   first established, and then only if a call failed with GSOCK_WOULDBLOCK,
 *   when the output buffer empties again. This means that the app should
 *   assume that it can write since the first OUTPUT event, and no more
 *   OUTPUT events will be generated unless an error occurs.
 * GSOCK_CONNECTION:
 *   Connection successfully established, for client sockets, or incoming
 *   client connection, for server sockets. Wait for this event (also watch
 *   out for GSOCK_LOST) after you issue a nonblocking GSocket_Connect() call.
 * GSOCK_LOST:
 *   The connection is lost (or a connection request failed); this could
 *   be due to a failure, or due to the peer closing it gracefully.
 */

/* GSocket_SetCallback:
 *  Enables the callbacks specified by 'flags'. Note that 'flags'
 *  may be a combination of flags OR'ed toghether, so the same
 *  callback function can be made to accept different events.
 *  The callback function must have the following prototype:
 *
 *  void function(GSocket *socket, GSocketEvent event, char *cdata)
 */
void GSocket::SetCallback(GSocketEventFlags flags,
                         GSocketCallback callback, char *cdata)
{
  int count;

  assert(this);

  for (count = 0; count < GSOCK_MAX_EVENT; count++)
  {
    if ((flags & (1 << count)) != 0)
    {
      m_cbacks[count] = callback;
      m_data[count] = cdata;
    }
  }
}

/* GSocket_UnsetCallback:
 *  Disables all callbacks specified by 'flags', which may be a
 *  combination of flags OR'ed toghether.
 */
void GSocket::UnsetCallback(GSocketEventFlags flags)
{
  int count;

  assert(this);

  for (count = 0; count < GSOCK_MAX_EVENT; count++)
  {
    if ((flags & (1 << count)) != 0)
    {
      m_cbacks[count] = NULL;
      m_data[count] = NULL;
    }
  }
}

GSocketError GSocket::GetSockOpt(int level, int optname,
                                void *optval, int *optlen)
{
    if (getsockopt(m_fd, level, optname, (char*)optval, optlen) == 0)
    {
        return GSOCK_NOERROR;
    }
    return GSOCK_OPTERR;
}

GSocketError GSocket::SetSockOpt(int level, int optname,
                                const void *optval, int optlen)
{
    if (setsockopt(m_fd, level, optname, (char*)optval, optlen) == 0)
    {
        return GSOCK_NOERROR;
    }
    return GSOCK_OPTERR;
}

/* Internals (IO) */

/* _GSocket_Input_Timeout:
 *  For blocking sockets, wait until data is available or
 *  until timeout ellapses.
 */
GSocketError GSocket::Input_Timeout()
{
  fd_set readfds;