launch_chk.cpp

/* Copyright (c) 2008 Apple Inc.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT.  IN NO EVENT SHALL THE ABOVE LISTED COPYRIGHT
 * HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * Except as contained in this notice, the name(s) of the above
 * copyright holders shall not be used in advertising or otherwise to
 * promote the sale, use or other dealings in this Software without
 * prior written authorization.
 */
/* Copied from http://www.opensource.apple.com/source/X11server/X11server-106.3/kdrive/xorg-server-1.6.5-apple3/hw/xquartz/mach-startup/launchd_fd.c
 */
#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif

#include <launch.h>
#include <stdio.h>
#include <errno.h>

#include "launchd_fd.h"

int launchd_display_fd(void) {
  launch_data_t sockets_dict, checkin_request, checkin_response;
  launch_data_t listening_fd_array, listening_fd;

  /* Get launchd fd */
  if ((checkin_request = launch_data_new_string(LAUNCH_KEY_CHECKIN)) == NULL) {
    fprintf(stderr,"launch_data_new_string(\"" LAUNCH_KEY_CHECKIN "\") Unable to create string.\n");
    return ERROR_FD;
  }
    
  if ((checkin_response = launch_msg(checkin_request)) == NULL) {
    fprintf(stderr,"launch_msg(\"" LAUNCH_KEY_CHECKIN "\") IPC failure: %s\n",strerror(errno));
    return ERROR_FD;
  }
    
  if (LAUNCH_DATA_ERRNO == launch_data_get_type(checkin_response)) {
    // ignore EACCES, which is common if we weren't started by launchd
    if (launch_data_get_errno(checkin_response) != EACCES)
      fprintf(stderr,"launchd check-in failed: %s\n", strerror(launch_data_get_errno(checkin_response)));
    return ERROR_FD;
  } 

  /**********************************************************/
  /* Start of code - not Apple copyright                    */  

  // I had a lot of trouble getting the code below working, so
  // eventually went to an iteration based solution.
#if ! defined( LAUNCHD_ID_PREFIX )
#define LAUNCHD_ID_PREFIX "x"
#endif


  bool launch_find_socket( launch_data_t, int * );
  {
    int fd_result = -1;
    if( launch_find_socket( checkin_response, &fd_result ) == true )
      {
	return fd_result;
      }
  }
  /* End of code - not Apple copyright                      */  
  /**********************************************************/

  sockets_dict = launch_data_dict_lookup(checkin_response, LAUNCH_JOBKEY_SOCKETS);
  if (NULL == sockets_dict) {
    fprintf(stderr,"launchd check-in: no sockets found to answer requests on!\n");
    return ERROR_FD;
  }
    
  if (launch_data_dict_get_count(sockets_dict) > 1) {
    fprintf(stderr,"launchd check-in: some sockets will be ignored!\n");
    return ERROR_FD;
  }
    
  listening_fd_array = launch_data_dict_lookup(sockets_dict, LAUNCHD_ID_PREFIX":0");
  if (NULL == listening_fd_array) {
    listening_fd_array = launch_data_dict_lookup(sockets_dict, ":0");
    if (NULL == listening_fd_array) {
      fprintf(stderr,"launchd check-in: No known sockets found to answer requests on! \"%s:0\" and \":0\" failed.\n", LAUNCHD_ID_PREFIX);
      return ERROR_FD;
    }
  }
    
  if (launch_data_array_get_count(listening_fd_array)!=1) {
    fprintf(stderr,"launchd check-in: Expected 1 socket from launchd, got %u)\n",
	    (unsigned)launch_data_array_get_count(listening_fd_array));
    return ERROR_FD;
  }
    
  listening_fd=launch_data_array_get_index(listening_fd_array, 0);
  return launch_data_get_fd(listening_fd);
  }