XPAMacros(3) Server Callback Macros


#include <xpa.h>
xpa_class, xpa_name, xpa_method, xpa_cmdfd, xpa_datafd,
xpa_sendian, xpa_cendian


Server routines have access to information about the XPA being called via the following macros (each of which takes the xpa handle as an argument):

  macro                 explanation
  ------                -----------
  xpa_class             class of this xpa
  xpa_name              name of this xpa
  xpa_method            method string (inet or local connect info)
  xpa_cmdfd             fd of command socket
  xpa_datafd            fd of data socket
  xpa_sendian           endian-ness of server ("little" or "big")
  xpa_cendian           endian-ness of client ("little" or "big"

The argument to these macros is the call_data pointer that is passed to the server procedure. This pointer should be type case to XPA in the server routine:

  XPA xpa = (XPA)call_data;

The most important of these macros is xpa_datafd(). A server routine that sets ``fillbuf=false'' in receive_mode or send_mode can use this macro to perform I/O directly to/from the client, rather than using buf.

The xpa_cendian and xpa_sendian macros can be used together to determine if the data transferred from the client is byte swapped with respect to the server. Values for these macros are: ``little'', ``big'', or ``?''. In order to do a proper conversion, you still need to know the format of the data (i.e., byte swapping is dependent on the size of the data element being converted).