Function server_mpvio_write_packet

sql/sql_acl.cc:14696–14718

vio->write_packet() callback method for server authentication plugins This function is called by a server authentication plugin, when it wants to send data to the client. It transparently wraps the data into a handshake packet, and handles plugin negotiation with the client. If necessary, it escapes the plugin data, if it starts with a mysql protocol packet byte. */

  it escapes the plugin data, if it starts with a mysql protocol packet byte.
*/
static int server_mpvio_write_packet(MYSQL_PLUGIN_VIO *param,
                                   const uchar *packet, int packet_len)
{
  MPVIO_EXT *mpvio= (MPVIO_EXT *) param;
  int res;
  DBUG_ENTER("server_mpvio_write_packet");

  /* reset cached_client_reply */
  mpvio->cached_client_reply.pkt= 0;

  /* for the 1st packet we wrap plugin data into the handshake packet */
  if (mpvio->packets_written == 0)
    res= send_server_handshake_packet(mpvio, (char*) packet, packet_len);
  else if (mpvio->status == MPVIO_EXT::RESTART)
    res= send_plugin_request_packet(mpvio, packet, packet_len);
  else /* plugin data, prefixed with 1 */
    res= net_write_command(&mpvio->auth_info.thd->net, 1, (uchar*)"", 0,
                           packet, packet_len);
  mpvio->cached_client_reply.plugin= ""_LEX_CSTRING;
  mpvio->status= MPVIO_EXT::FAILURE; // the status is no longer RESTART
  mpvio->packets_written++;
  DBUG_RETURN(res);
}

/**
  vio->read_packet() callback method for server authentication plugins