main.c

ipp打印机服务器原代码 注意：请将ipp.gz改为ipp.tar.gz 然后使用tar zxvf ipp.tar.gz解压 站长注意

/*
 * "$Id: main.c,v 1.128 2005/01/03 19:29:59 mike Exp $"
 *
 *   Scheduler main loop for the Common UNIX Printing System (CUPS).
 *
 *   Copyright 1997-2005 by Easy Software Products, all rights reserved.
 *
 *   These coded instructions, statements, and computer programs are the
 *   property of Easy Software Products and are protected by Federal
 *   copyright law.  Distribution and use rights are outlined in the file
 *   "LICENSE" which should have been included with this file.  If this
 *   file is missing or damaged please contact Easy Software Products
 *   at:
 *
 *       Attn: CUPS Licensing Information
 *       Easy Software Products
 *       44141 Airport View Drive, Suite 204
 *       Hollywood, Maryland 20636 USA
 *
 *       Voice: [phone]
 *       EMail: [e-mail]
 *         WWW: http://www.cups.org
 *
 * Contents:
 *
 *   main()               - Main entry for the CUPS scheduler.
 *   cupsdClosePipe()     - Close a pipe as necessary.
 *   cupsdOpenPipe()      - Create a pipe which is closed on exec.
 *   CatchChildSignals()  - Catch SIGCHLD signals...
 *   HoldSignals()        - Hold child and termination signals.
 *   IgnoreChildSignals() - Ignore SIGCHLD signals...
 *   ReleaseSignals()     - Release signals for delivery.
 *   SetString()          - Set a string value.
 *   SetStringf()         - Set a formatted string value.
 *   parent_handler()     - Catch USR1/CHLD signals...
 *   process_children()   - Process all dead children...
 *   sigchld_handler()    - Handle 'child' signals from old processes.
 *   sighup_handler()     - Handle 'hangup' signals to reconfigure the scheduler.
 *   sigterm_handler()    - Handle 'terminate' signals that stop the scheduler.
 *   select_timeout()     - Calculate the select timeout value.
 *   usage()              - Show scheduler usage.
 */

/*
 * Include necessary headers...
 */

#define _MAIN_C_
#include "cupsd.h"
#include <sys/resource.h>
#include <syslog.h>
#include <grp.h>
#if defined(HAVE_MALLOC_H) && defined(HAVE_MALLINFO)
#  include <malloc.h>
#endif /* HAVE_MALLOC_H && HAVE_MALLINFO */
#include <stdio.h>

/*
 * Local functions...
 */

static void	parent_handler(int sig);
#if	0
static void	process_children(void);
#endif
static void	sigchld_handler(int sig);
static void	sighup_handler(int sig);
static void	sigterm_handler(int sig);
static long	select_timeout(int fds);
static void	usage(void);


/*
 * Local globals...
 */

static int	parent_signal = 0;	/* Set to signal number from child */
static int	holdcount = 0;		/* Number of times "hold" was called */
#if defined(HAVE_SIGACTION) && !defined(HAVE_SIGSET)
static sigset_t	holdmask;		/* Old POSIX signal mask */
#endif /* HAVE_SIGACTION && !HAVE_SIGSET */
static int	dead_children = 0;	/* Dead children? */
static int	stop_scheduler = 0;	/* Should the scheduler stop? */


/*
 * 'main()' - Main entry for the CUPS scheduler.
 */

int					/* O - Exit status */
main(int  argc,				/* I - Number of command-line arguments */
     char *argv[])			/* I - Command-line arguments */
{
  int			i;		/* Looping var */
  char			*opt;		/* Option character */
  int			fg;		/* Run in the foreground */
  int			fds;		/* Number of ready descriptors select returns */
  fd_set		*input,		/* Input set for select() */
			*output;	/* Output set for select() */
  client_t		*con;		/* Current client */

#if	0
  job_t			*job,		/* Current job */
			*next;		/* Next job */

#endif
  listener_t		*lis;		/* Current listener */
  time_t		activity;	/* Activity timer */
  time_t		browse_time;	/* Next browse send time */
  time_t		senddoc_time;	/* Send-Document time */
#ifdef HAVE_MALLINFO
  time_t		mallinfo_time;	/* Malloc information time */
#endif /* HAVE_MALLINFO */
  struct timeval	timeout;	/* select() timeout */
  struct rlimit		limit;		/* Runtime limit */
#if defined(HAVE_SIGACTION) && !defined(HAVE_SIGSET)
  struct sigaction	action;		/* Actions for POSIX signals */
#endif /* HAVE_SIGACTION && !HAVE_SIGSET */
#ifdef __sgi
  cups_file_t		*fp;		/* Fake lpsched lock file */
  struct stat		statbuf;	/* Needed for checking lpsched FIFO */
#endif /* __sgi */


 /*
  * Check for command-line arguments...
  */

  fg = 0;

  for (i = 1; i < argc; i ++)
    if (argv[i][0] == '-')
      for (opt = argv[i] + 1; *opt != '\0'; opt ++)
        switch (*opt)
	{
	  case 'c' : /* Configuration file */
	      i ++;
	      if (i >= argc)
	        usage();

              if (argv[i][0] == '/')
	      {
	       /*
	        * Absolute directory...
		*/

		SetString(&ConfigurationFile, argv[i]);
              }
	      else
	      {
	       /*
	        * Relative directory...
		*/

                char current[1024];	/* Current directory */


                getcwd(current, sizeof(current));
		SetStringf(&ConfigurationFile, "%s/%s", current, argv[i]);
              }
	      break;

          case 'f' : /* Run in foreground... */
	      fg = 1;
	      break;

          case 'F' : /* Run in foreground, but still disconnect from terminal... */
	      fg = -1;
	      break;

	  default : /* Unknown option */
              fprintf(stderr, "cupsd: Unknown option \'%c\' - aborting!\n", *opt);
	      usage();
	      break;
	}
    else
    {
      fprintf(stderr, "cupsd: Unknown argument \'%s\' - aborting!\n", argv[i]);
      usage();
    }

  if (!ConfigurationFile)
    SetString(&ConfigurationFile, CUPS_SERVERROOT "/cupsd.conf");
    DEBUG_printf(("Value ConfigurationFile:%s\n", ConfigurationFile)); 

 /*
  * If the user hasn't specified "-f", run in the background...
  */

  if (!fg)
  {
   /*
    * Setup signal handlers for the parent...
    */

#ifdef HAVE_SIGSET /* Use System V signals over POSIX to avoid bugs */
    sigset(SIGUSR1, parent_handler);
    sigset(SIGCHLD, parent_handler);

    sigset(SIGHUP, SIG_IGN);
#elif defined(HAVE_SIGACTION)
    memset(&action, 0, sizeof(action));
    sigemptyset(&action.sa_mask);
    sigaddset(&action.sa_mask, SIGUSR1);
    action.sa_handler = parent_handler;
    sigaction(SIGUSR1, &action, NULL);
    sigaction(SIGCHLD, &action, NULL);

    sigemptyset(&action.sa_mask);
    action.sa_handler = SIG_IGN;
    sigaction(SIGHUP, &action, NULL);
#else
    signal(SIGUSR1, parent_handler);
    signal(SIGCLD, parent_handler);

    signal(SIGHUP, SIG_IGN);
#endif /* HAVE_SIGSET */

    if (fork() > 0)
    {
     /*
      * OK, wait for the child to startup and send us SIGUSR1 or to crash
      * and the OS send us SIGCHLD...  We also need to ignore SIGHUP which
      * might be sent by the init script to restart the scheduler...
      */

      for (; parent_signal == 0;)
        sleep(1);

      if (parent_signal == SIGUSR1)
        return (0);

      if (wait(&i) < 0)
      {
        perror("cupsd");
	return (1);
      }
      else if (WIFEXITED(i))
      {
        fprintf(stderr, "cupsd: Child exited with status %d!\n", WEXITSTATUS(i));
	return (2);
      }
      else
      {
        fprintf(stderr, "cupsd: Child exited on signal %d!\n", WTERMSIG(i));
	return (3);
      }
    }
  }

  if (fg < 1)
  {
   /*
    * Make sure we aren't tying up any filesystems...
    */

    chdir("/");

#ifndef DEBUG
   /*
    * Disable core dumps...
    */

    getrlimit(RLIMIT_CORE, &limit);
    limit.rlim_cur = 0;
    setrlimit(RLIMIT_CORE, &limit);

   /*
    * Disconnect from the controlling terminal...
    */
    close(0);
    close(1);
    close(2);

    setsid();
#endif /* DEBUG */

  }

 /*
  * Set the timezone info...
  */

  if (getenv("TZ") != NULL)
    SetStringf(&TZ, "TZ=%s", getenv("TZ"));
  else
    SetString(&TZ, "");

  tzset();

#ifdef LC_TIME
  setlocale(LC_TIME, "");
#endif /* LC_TIME */

 /*
  * Set the maximum number of files...
  */

  getrlimit(RLIMIT_NOFILE, &limit);

  if (limit.rlim_max > CUPS_MAX_FDS)
    MaxFDs = CUPS_MAX_FDS;
  else
    MaxFDs = limit.rlim_max;

  limit.rlim_cur = MaxFDs;

  setrlimit(RLIMIT_NOFILE, &limit);

 /*
  * Allocate memory for the input and output sets...
  */

  SetSize = (MaxFDs + 31) / 8 + 4;
  if (SetSize < sizeof(fd_set))
    SetSize = sizeof(fd_set);

  InputSet  = (fd_set *)calloc(1, SetSize);
  OutputSet = (fd_set *)calloc(1, SetSize);
  input     = (fd_set *)calloc(1, SetSize);
  output    = (fd_set *)calloc(1, SetSize);

  if (InputSet == NULL || OutputSet == NULL || input == NULL || output == NULL)
  {
    DEBUG_printf(("Unable to allocate memory for select() sets - exiting!\n"));
    syslog(LOG_LPR, "Unable to allocate memory for select() sets - exiting!");
    return (1);
  }

 /*
  * Read configuration...
  */

  if (!ReadConfiguration())
  {
    syslog(LOG_LPR, "Unable to read configuration file \'%s\' - exiting!",
           ConfigurationFile);
    return (1);
  }

 /*
  * Catch hangup and child signals and ignore broken pipes...
  */

#ifdef HAVE_SIGSET /* Use System V signals over POSIX to avoid bugs */
  if (RunAsUser)
    sigset(SIGHUP, sigterm_handler);
  else
    sigset(SIGHUP, sighup_handler);

  sigset(SIGPIPE, SIG_IGN);
  sigset(SIGTERM, sigterm_handler);
#elif defined(HAVE_SIGACTION)
  memset(&action, 0, sizeof(action));

  sigemptyset(&action.sa_mask);
  sigaddset(&action.sa_mask, SIGHUP);

  if (RunAsUser)
    action.sa_handler = sigterm_handler;
  else
    action.sa_handler = sighup_handler;

  sigaction(SIGHUP, &action, NULL);

  sigemptyset(&action.sa_mask);
  action.sa_handler = SIG_IGN;
  sigaction(SIGPIPE, &action, NULL);

  sigemptyset(&action.sa_mask);
  sigaddset(&action.sa_mask, SIGTERM);
  sigaddset(&action.sa_mask, SIGCHLD);
  action.sa_handler = sigterm_handler;
  sigaction(SIGTERM, &action, NULL);
#else
  if (RunAsUser)
    signal(SIGHUP, sigterm_handler);
  else
    signal(SIGHUP, sighup_handler);

  signal(SIGPIPE, SIG_IGN);
  signal(SIGTERM, sigterm_handler);
#endif /* HAVE_SIGSET */

#ifdef __sgi
 /*
  * Try to create a fake lpsched lock file if one is not already there.
  * Some Adobe applications need it under IRIX in order to enable
  * printing...
  */

  if ((fp = cupsFileOpen("/var/spool/lp/SCHEDLOCK", "w")) == NULL)
  {
    syslog(LOG_LPR, "Unable to create fake lpsched lock file "
                    "\"/var/spool/lp/SCHEDLOCK\"\' - %s!",
           strerror(errno));
  }
  else
  {
    fchmod(cupsFileNumber(fp), 0644);
    fchown(cupsFileNumber(fp), User, Group);

    cupsFileClose(fp);
  }
#endif /* __sgi */

#if	0
 /*
  * Initialize authentication certificates...
  */


  InitCerts();
#endif

 /*
  * If we are running in the background, signal the parent process that
  * we are up and running...
  */

  if (!fg)
    kill(getppid(), SIGUSR1);

 /*
  * If the administrator has configured the server to run as an unpriviledged
  * user, change to that user now...
  */

  if (RunAsUser)
  {
    setgid(Group);
    setgroups(1, &Group);
    setuid(User);
  }
  
#if 	0
 /*
  * Start any pending print jobs...
  */

  CheckJobs();
#endif

 /*
  * Loop forever...
  */

#ifdef HAVE_MALLINFO
  mallinfo_time = 0;
#endif /* HAVE_MALLINFO */
  browse_time   = time(NULL);
  senddoc_time  = time(NULL);
  fds           = 1;

  while (!stop_scheduler)
  {
#ifdef DEBUG
    LogMessage(L_DEBUG2, "main: Top of loop, dead_children=%d, NeedReload=%d",
               dead_children, NeedReload);
#endif /* DEBUG */

#if	0
   /*
    * Check if there are dead children to handle...
    */

    if (dead_children)
      process_children();


   /*
    * Check if we need to load the server configuration file...
    */

    if (NeedReload)
    {

      job_t	*job;			/* Current job */


     /*
      * Close any idle clients...
      */

      if (NumClients > 0)