xserver-multidpi/os/utils.c

/*

Copyright 1987, 1998  The Open Group

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

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 OPEN GROUP 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 of The Open Group shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization
from The Open Group.


Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts,
Copyright 1994 Quarterdeck Office Systems.

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the names of Digital and
Quarterdeck not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior
permission.

DIGITAL AND QUARTERDECK DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS, IN NO EVENT SHALL DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT
OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE
OR PERFORMANCE OF THIS SOFTWARE.

*/

#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif

#ifdef __CYGWIN__
#include <stdlib.h>
#include <signal.h>
#endif

#if defined(WIN32) && !defined(__CYGWIN__)
#include <X11/Xwinsock.h>
#endif
#include <X11/Xos.h>
#include <stdio.h>
#include <time.h>
#if !defined(WIN32) || !defined(__MINGW32__)
#include <sys/time.h>
#include <sys/resource.h>
#endif
#include "misc.h"
#include <X11/X.h>
#define XSERV_t
#define TRANS_SERVER
#define TRANS_REOPEN
#include <X11/Xtrans/Xtrans.h>
#include "input.h"
#include "dixfont.h"
#include "osdep.h"
#include "extension.h"
#ifdef X_POSIX_C_SOURCE
#define _POSIX_C_SOURCE X_POSIX_C_SOURCE
#include <signal.h>
#undef _POSIX_C_SOURCE
#else
#if defined(_POSIX_SOURCE)
#include <signal.h>
#else
#define _POSIX_SOURCE
#include <signal.h>
#undef _POSIX_SOURCE
#endif
#endif
#ifndef WIN32
#include <sys/wait.h>
#endif
#if !defined(SYSV) && !defined(WIN32) 
#include <sys/resource.h>
#endif
#include <sys/stat.h>
#include <ctype.h>    /* for isspace */
#include <stdarg.h>

#include <stdlib.h>	/* for malloc() */

#if defined(TCPCONN) || defined(STREAMSCONN)
# ifndef WIN32
#  include <netdb.h>
# endif
#endif

#include "opaque.h"

#include "dixstruct.h"

#ifdef XKB
#include <xkbsrv.h>
#endif

#ifdef RENDER
#include "picture.h"
#endif

_X_EXPORT Bool noTestExtensions;
#ifdef COMPOSITE
_X_EXPORT Bool noCompositeExtension = FALSE;
#endif

#ifdef DAMAGE
_X_EXPORT Bool noDamageExtension = FALSE;
#endif
#ifdef DBE
_X_EXPORT Bool noDbeExtension = FALSE;
#endif
#ifdef DPMSExtension
_X_EXPORT Bool noDPMSExtension = FALSE;
#endif
#ifdef GLXEXT
_X_EXPORT Bool noGlxExtension = FALSE;
_X_EXPORT Bool noGlxVisualInit = FALSE;
#endif
#ifdef SCREENSAVER
_X_EXPORT Bool noScreenSaverExtension = FALSE;
#endif
#ifdef MITSHM
_X_EXPORT Bool noMITShmExtension = FALSE;
#endif
#ifdef MULTIBUFFER
_X_EXPORT Bool noMultibufferExtension = FALSE;
#endif
#ifdef RANDR
_X_EXPORT Bool noRRExtension = FALSE;
#endif
#ifdef RENDER
_X_EXPORT Bool noRenderExtension = FALSE;
#endif
#ifdef XCSECURITY
_X_EXPORT Bool noSecurityExtension = FALSE;
#endif
#ifdef RES
_X_EXPORT Bool noResExtension = FALSE;
#endif
#ifdef XF86BIGFONT
_X_EXPORT Bool noXFree86BigfontExtension = FALSE;
#endif
#ifdef XFreeXDGA
_X_EXPORT Bool noXFree86DGAExtension = FALSE;
#endif
#ifdef XF86DRI
_X_EXPORT Bool noXFree86DRIExtension = FALSE;
#endif
#ifdef XF86VIDMODE
_X_EXPORT Bool noXFree86VidModeExtension = FALSE;
#endif
#ifdef XFIXES
_X_EXPORT Bool noXFixesExtension = FALSE;
#endif
/* noXkbExtension is defined in xkb/xkbInit.c */
#ifdef PANORAMIX
/* Xinerama is disabled by default unless enabled via +xinerama */
_X_EXPORT Bool noPanoramiXExtension = TRUE;
#endif
#ifdef XSELINUX
_X_EXPORT Bool noSELinuxExtension = FALSE;
_X_EXPORT int selinuxEnforcingState = SELINUX_MODE_DEFAULT;
#endif
#ifdef XV
_X_EXPORT Bool noXvExtension = FALSE;
#endif
#ifdef DRI2
_X_EXPORT Bool noDRI2Extension = FALSE;
#endif

_X_EXPORT Bool noGEExtension = FALSE;

#define X_INCLUDE_NETDB_H
#include <X11/Xos_r.h>

#include <errno.h>

_X_EXPORT Bool CoreDump;

#ifdef PANORAMIX
_X_EXPORT Bool PanoramiXExtensionDisabledHack = FALSE;
#endif

_X_EXPORT int auditTrailLevel = 1;

#if defined(SVR4) || defined(__linux__) || defined(CSRG_BASED)
#define HAS_SAVED_IDS_AND_SETEUID
#endif

static char *dev_tty_from_init = NULL;	/* since we need to parse it anyway */

_X_EXPORT OsSigHandlerPtr
OsSignal(sig, handler)
    int sig;
    OsSigHandlerPtr handler;
{
    struct sigaction act, oact;

    sigemptyset(&act.sa_mask);
    if (handler != SIG_IGN)
	sigaddset(&act.sa_mask, sig);
    act.sa_flags = 0;
    act.sa_handler = handler;
    if (sigaction(sig, &act, &oact))
      perror("sigaction");
    return oact.sa_handler;
}

/*
 * Explicit support for a server lock file like the ones used for UUCP.
 * For architectures with virtual terminals that can run more than one
 * server at a time.  This keeps the servers from stomping on each other
 * if the user forgets to give them different display numbers.
 */
#define LOCK_DIR "/tmp"
#define LOCK_TMP_PREFIX "/.tX"
#define LOCK_PREFIX "/.X"
#define LOCK_SUFFIX "-lock"

#ifndef PATH_MAX
#include <sys/param.h>
#ifndef PATH_MAX
#ifdef MAXPATHLEN
#define PATH_MAX MAXPATHLEN
#else
#define PATH_MAX 1024
#endif
#endif
#endif

static Bool StillLocking = FALSE;
static char LockFile[PATH_MAX];
static Bool nolock = FALSE;

/*
 * LockServer --
 *      Check if the server lock file exists.  If so, check if the PID
 *      contained inside is valid.  If so, then die.  Otherwise, create
 *      the lock file containing the PID.
 */
_X_EXPORT void
LockServer(void)
{
  char tmp[PATH_MAX], pid_str[12];
  int lfd, i, haslock, l_pid, t;
  char *tmppath = NULL;
  int len;
  char port[20];

  if (nolock) return;
  /*
   * Path names
   */
  tmppath = LOCK_DIR;

  sprintf(port, "%d", atoi(display));
  len = strlen(LOCK_PREFIX) > strlen(LOCK_TMP_PREFIX) ? strlen(LOCK_PREFIX) :
						strlen(LOCK_TMP_PREFIX);
  len += strlen(tmppath) + strlen(port) + strlen(LOCK_SUFFIX) + 1;
  if (len > sizeof(LockFile))
    FatalError("Display name `%s' is too long\n", port);
  (void)sprintf(tmp, "%s" LOCK_TMP_PREFIX "%s" LOCK_SUFFIX, tmppath, port);
  (void)sprintf(LockFile, "%s" LOCK_PREFIX "%s" LOCK_SUFFIX, tmppath, port);

  /*
   * Create a temporary file containing our PID.  Attempt three times
   * to create the file.
   */
  StillLocking = TRUE;
  i = 0;
  do {
    i++;
    lfd = open(tmp, O_CREAT | O_EXCL | O_WRONLY, 0644);
    if (lfd < 0)
       sleep(2);
    else
       break;
  } while (i < 3);
  if (lfd < 0) {
    unlink(tmp);
    i = 0;
    do {
      i++;
      lfd = open(tmp, O_CREAT | O_EXCL | O_WRONLY, 0644);
      if (lfd < 0)
         sleep(2);
      else
         break;
    } while (i < 3);
  }
  if (lfd < 0)
    FatalError("Could not create lock file in %s\n", tmp);
  (void) sprintf(pid_str, "%10ld\n", (long)getpid());
  (void) write(lfd, pid_str, 11);
  (void) chmod(tmp, 0444);
  (void) close(lfd);

  /*
   * OK.  Now the tmp file exists.  Try three times to move it in place
   * for the lock.
   */
  i = 0;
  haslock = 0;
  while ((!haslock) && (i++ < 3)) {
    haslock = (link(tmp,LockFile) == 0);
    if (haslock) {
      /*
       * We're done.
       */
      break;
    }
    else {
      /*
       * Read the pid from the existing file
       */
      lfd = open(LockFile, O_RDONLY);
      if (lfd < 0) {
        unlink(tmp);
        FatalError("Can't read lock file %s\n", LockFile);
      }
      pid_str[0] = '\0';
      if (read(lfd, pid_str, 11) != 11) {
        /*
         * Bogus lock file.
         */
        unlink(LockFile);
        close(lfd);
        continue;
      }
      pid_str[11] = '\0';
      sscanf(pid_str, "%d", &l_pid);
      close(lfd);

      /*
       * Now try to kill the PID to see if it exists.
       */
      errno = 0;
      t = kill(l_pid, 0);
      if ((t< 0) && (errno == ESRCH)) {
        /*
         * Stale lock file.
         */
        unlink(LockFile);
        continue;
      }
      else if (((t < 0) && (errno == EPERM)) || (t == 0)) {
        /*
         * Process is still active.
         */
        unlink(tmp);
	FatalError("Server is already active for display %s\n%s %s\n%s\n",
		   port, "\tIf this server is no longer running, remove",
		   LockFile, "\tand start again.");
      }
    }
  }
  unlink(tmp);
  if (!haslock)
    FatalError("Could not create server lock file: %s\n", LockFile);
  StillLocking = FALSE;
}

/*
 * UnlockServer --
 *      Remove the server lock file.
 */
_X_EXPORT void
UnlockServer(void)
{
  if (nolock) return;

  if (!StillLocking){

  (void) unlink(LockFile);
  }
}

/* Force connections to close on SIGHUP from init */

/*ARGSUSED*/
_X_EXPORT SIGVAL
AutoResetServer (int sig)
{
    int olderrno = errno;

    dispatchException |= DE_RESET;
    isItTimeToYield = TRUE;
    errno = olderrno;
}

/* Force connections to close and then exit on SIGTERM, SIGINT */

/*ARGSUSED*/
_X_EXPORT SIGVAL
GiveUp(int sig)
{
    int olderrno = errno;

    dispatchException |= DE_TERMINATE;
    isItTimeToYield = TRUE;
    errno = olderrno;
}

#if defined WIN32 && defined __MINGW32__
_X_EXPORT CARD32
GetTimeInMillis (void)
{
  return GetTickCount ();
}
#else
_X_EXPORT CARD32
GetTimeInMillis(void)
{
    struct timeval tv;

#ifdef MONOTONIC_CLOCK
    struct timespec tp;
    if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0)
        return (tp.tv_sec * 1000) + (tp.tv_nsec / 1000000L);
#endif

    X_GETTIMEOFDAY(&tv);
    return(tv.tv_sec * 1000) + (tv.tv_usec / 1000);
}
#endif

_X_EXPORT void
AdjustWaitForDelay (pointer waitTime, unsigned long newdelay)
{
    static struct timeval   delay_val;
    struct timeval	    **wt = (struct timeval **) waitTime;
    unsigned long	    olddelay;

    if (*wt == NULL)
    {
	delay_val.tv_sec = newdelay / 1000;
	delay_val.tv_usec = 1000 * (newdelay % 1000);
	*wt = &delay_val;
    }
    else
    {
	olddelay = (*wt)->tv_sec * 1000 + (*wt)->tv_usec / 1000;
	if (newdelay < olddelay)
	{
	    (*wt)->tv_sec = newdelay / 1000;
	    (*wt)->tv_usec = 1000 * (newdelay % 1000);
	}
    }
}

_X_EXPORT void UseMsg(void)
{
    ErrorF("use: X [:<display>] [option]\n");
    ErrorF("-a #                   mouse acceleration (pixels)\n");
    ErrorF("-ac                    disable access control restrictions\n");
    ErrorF("-audit int             set audit trail level\n");	
    ErrorF("-auth file             select authorization file\n");	
    ErrorF("-br                    create root window with black background\n");
    ErrorF("+bs                    enable any backing store support\n");
    ErrorF("-bs                    disable any backing store support\n");
    ErrorF("-c                     turns off key-click\n");
    ErrorF("c #                    key-click volume (0-100)\n");
    ErrorF("-cc int                default color visual class\n");
    ErrorF("-core                  generate core dump on fatal error\n");
    ErrorF("-dpi int               screen resolution in dots per inch\n");
#ifdef DPMSExtension
    ErrorF("dpms                   enables VESA DPMS monitor control\n");
    ErrorF("-dpms                  disables VESA DPMS monitor control\n");
#endif
    ErrorF("-deferglyphs [none|all|16] defer loading of [no|all|16-bit] glyphs\n");
    ErrorF("-f #                   bell base (0-100)\n");
    ErrorF("-fc string             cursor font\n");
    ErrorF("-fn string             default font name\n");
    ErrorF("-fp string             default font path\n");
    ErrorF("-help                  prints message with these options\n");
    ErrorF("-I                     ignore all remaining arguments\n");
#ifdef RLIMIT_DATA
    ErrorF("-ld int                limit data space to N Kb\n");
#endif
#ifdef RLIMIT_NOFILE
    ErrorF("-lf int                limit number of open files to N\n");
#endif
#ifdef RLIMIT_STACK
    ErrorF("-ls int                limit stack space to N Kb\n");
#endif
#ifdef SERVER_LOCK
    ErrorF("-nolock                disable the locking mechanism\n");
#endif
#ifndef NOLOGOHACK
    ErrorF("-logo                  enable logo in screen saver\n");
    ErrorF("nologo                 disable logo in screen saver\n");
#endif
    ErrorF("-nolisten string       don't listen on protocol\n");
    ErrorF("-noreset               don't reset after last client exists\n");
    ErrorF("-reset                 reset after last client exists\n");
    ErrorF("-p #                   screen-saver pattern duration (minutes)\n");
    ErrorF("-pn                    accept failure to listen on all ports\n");
    ErrorF("-nopn                  reject failure to listen on all ports\n");
    ErrorF("-r                     turns off auto-repeat\n");
    ErrorF("r                      turns on auto-repeat \n");
#ifdef RENDER
    ErrorF("-render [default|mono|gray|color] set render color alloc policy\n");
#endif
    ErrorF("-retro                 start with classic stipple and cursor\n");
    ErrorF("-s #                   screen-saver timeout (minutes)\n");
    ErrorF("-t #                   mouse threshold (pixels)\n");
    ErrorF("-terminate             terminate at server reset\n");
    ErrorF("-to #                  connection time out\n");
    ErrorF("-tst                   disable testing extensions\n");
    ErrorF("ttyxx                  server started from init on /dev/ttyxx\n");
    ErrorF("v                      video blanking for screen-saver\n");
    ErrorF("-v                     screen-saver without video blanking\n");
    ErrorF("-wm                    WhenMapped default backing-store\n");
    ErrorF("-wr                    create root window with white background\n");
    ErrorF("-x string              loads named extension at init time \n");
    ErrorF("-maxbigreqsize         set maximal bigrequest size \n");
#ifdef PANORAMIX
    ErrorF("+xinerama              Enable XINERAMA extension\n");
    ErrorF("-xinerama              Disable XINERAMA extension\n");
#endif
    ErrorF("-dumbSched             Disable smart scheduling, enable old behavior\n");
    ErrorF("-schedInterval int     Set scheduler interval in msec\n");
    ErrorF("+extension name        Enable extension\n");
    ErrorF("-extension name        Disable extension\n");
#ifdef XDMCP
    XdmcpUseMsg();
#endif
#ifdef XKB
    XkbUseMsg();
#endif
    ddxUseMsg();
}

/*  This function performs a rudimentary sanity check
 *  on the display name passed in on the command-line,
 *  since this string is used to generate filenames.
 *  It is especially important that the display name
 *  not contain a "/" and not start with a "-".
 *                                            --kvajk
 */
static int 
VerifyDisplayName(const char *d)
{
    if ( d == (char *)0 ) return( 0 );  /*  null  */
    if ( *d == '\0' ) return( 0 );  /*  empty  */
    if ( *d == '-' ) return( 0 );  /*  could be confused for an option  */
    if ( *d == '.' ) return( 0 );  /*  must not equal "." or ".."  */
    if ( strchr(d, '/') != (char *)0 ) return( 0 );  /*  very important!!!  */
    return( 1 );
}

/*
 * This function parses the command line. Handles device-independent fields
 * and allows ddx to handle additional fields.  It is not allowed to modify
 * argc or any of the strings pointed to by argv.
 */
_X_EXPORT void
ProcessCommandLine(int argc, char *argv[])
{
    int i, skip;

    defaultKeyboardControl.autoRepeat = TRUE;

#ifdef NO_PART_NET
    PartialNetwork = FALSE;
#else
    PartialNetwork = TRUE;
#endif

    for ( i = 1; i < argc; i++ )
    {
	/* call ddx first, so it can peek/override if it wants */
        if((skip = ddxProcessArgument(argc, argv, i)))
	{
	    i += (skip - 1);
	}
	else if(argv[i][0] ==  ':')  
	{
	    /* initialize display */
	    display = argv[i];
	    display++;
            if( ! VerifyDisplayName( display ) ) {
                ErrorF("Bad display name: %s\n", display);
                UseMsg();
		FatalError("Bad display name, exiting: %s\n", display);
            }
	}
	else if ( strcmp( argv[i], "-a") == 0)
	{
	    if(++i < argc)
	        defaultPointerControl.num = atoi(argv[i]);
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-ac") == 0)
	{
	    defeatAccessControl = TRUE;
	}
	else if ( strcmp( argv[i], "-audit") == 0)
	{
	    if(++i < argc)
	        auditTrailLevel = atoi(argv[i]);
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-auth") == 0)
	{
	    if(++i < argc)
	        InitAuthorization (argv[i]);
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-br") == 0) ; /* default */
	else if ( strcmp( argv[i], "+bs") == 0)
	    enableBackingStore = TRUE;
	else if ( strcmp( argv[i], "-bs") == 0)
	    disableBackingStore = TRUE;
	else if ( strcmp( argv[i], "c") == 0)
	{
	    if(++i < argc)
	        defaultKeyboardControl.click = atoi(argv[i]);
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-c") == 0)
	{
	    defaultKeyboardControl.click = 0;
	}
	else if ( strcmp( argv[i], "-cc") == 0)
	{
	    if(++i < argc)
	        defaultColorVisualClass = atoi(argv[i]);
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-core") == 0)
	{
	    CoreDump = TRUE;
#if !defined(WIN32) || !defined(__MINGW32__)
	    struct rlimit   core_limit;
	    getrlimit (RLIMIT_CORE, &core_limit);
	    core_limit.rlim_cur = core_limit.rlim_max;
	    setrlimit (RLIMIT_CORE, &core_limit);
#endif
	}
	else if ( strcmp( argv[i], "-dpi") == 0)
	{
	    if(++i < argc)
	        monitorResolution = atoi(argv[i]);
	    else
		UseMsg();
	}
#ifdef DPMSExtension
	else if ( strcmp( argv[i], "dpms") == 0)
	    DPMSEnabledSwitch = TRUE;
	else if ( strcmp( argv[i], "-dpms") == 0)
	    DPMSDisabledSwitch = TRUE;
#endif
	else if ( strcmp( argv[i], "-deferglyphs") == 0)
	{
	    if(++i >= argc || !ParseGlyphCachingMode(argv[i]))
		UseMsg();
	}
	else if ( strcmp( argv[i], "-f") == 0)
	{
	    if(++i < argc)
	        defaultKeyboardControl.bell = atoi(argv[i]);
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-fc") == 0)
	{
	    if(++i < argc)
	        defaultCursorFont = argv[i];
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-fn") == 0)
	{
	    if(++i < argc)
	        defaultTextFont = argv[i];
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-fp") == 0)
	{
	    if(++i < argc)
	    {
	        defaultFontPath = argv[i];
	    }
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-help") == 0)
	{
	    UseMsg();
	    exit(0);
	}
#ifdef XKB
        else if ( (skip=XkbProcessArguments(argc,argv,i))!=0 ) {
	    if (skip>0)
		 i+= skip-1;
	    else UseMsg();
	}
#endif
#ifdef RLIMIT_DATA
	else if ( strcmp( argv[i], "-ld") == 0)
	{
	    if(++i < argc)
	    {
	        limitDataSpace = atoi(argv[i]);
		if (limitDataSpace > 0)
		    limitDataSpace *= 1024;
	    }
	    else
		UseMsg();
	}
#endif
#ifdef RLIMIT_NOFILE
	else if ( strcmp( argv[i], "-lf") == 0)
	{
	    if(++i < argc)
	        limitNoFile = atoi(argv[i]);
	    else
		UseMsg();
	}
#endif
#ifdef RLIMIT_STACK
	else if ( strcmp( argv[i], "-ls") == 0)
	{
	    if(++i < argc)
	    {
	        limitStackSpace = atoi(argv[i]);
		if (limitStackSpace > 0)
		    limitStackSpace *= 1024;
	    }
	    else
		UseMsg();
	}
#endif
#ifdef SERVER_LOCK
	else if ( strcmp ( argv[i], "-nolock") == 0)
	{
#if !defined(WIN32) && !defined(__CYGWIN__)
	  if (getuid() != 0)
	    ErrorF("Warning: the -nolock option can only be used by root\n");
	  else
#endif
	    nolock = TRUE;
	}
#endif
#ifndef NOLOGOHACK
	else if ( strcmp( argv[i], "-logo") == 0)
	{
	    logoScreenSaver = 1;
	}
	else if ( strcmp( argv[i], "nologo") == 0)
	{
	    logoScreenSaver = 0;
	}
#endif
	else if ( strcmp( argv[i], "-nolisten") == 0)
	{
            if(++i < argc) {
		if (_XSERVTransNoListen(argv[i])) 
		    FatalError ("Failed to disable listen for %s transport",
				argv[i]);
	   } else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-noreset") == 0)
	{
	    dispatchExceptionAtReset = 0;
	}
	else if ( strcmp( argv[i], "-reset") == 0)
	{
	    dispatchExceptionAtReset = DE_RESET;
	}
	else if ( strcmp( argv[i], "-p") == 0)
	{
	    if(++i < argc)
	        defaultScreenSaverInterval = ((CARD32)atoi(argv[i])) *
					     MILLI_PER_MIN;
	    else
		UseMsg();
	}
	else if (strcmp(argv[i], "-pogo") == 0)
	{
	    dispatchException = DE_TERMINATE;
	}
	else if ( strcmp( argv[i], "-pn") == 0)
	    PartialNetwork = TRUE;
	else if ( strcmp( argv[i], "-nopn") == 0)
	    PartialNetwork = FALSE;
	else if ( strcmp( argv[i], "r") == 0)
	    defaultKeyboardControl.autoRepeat = TRUE;
	else if ( strcmp( argv[i], "-r") == 0)
	    defaultKeyboardControl.autoRepeat = FALSE;
	else if ( strcmp( argv[i], "-retro") == 0)
	    party_like_its_1989 = TRUE;
	else if ( strcmp( argv[i], "-s") == 0)
	{
	    if(++i < argc)
	        defaultScreenSaverTime = ((CARD32)atoi(argv[i])) *
					 MILLI_PER_MIN;
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-t") == 0)
	{
	    if(++i < argc)
	        defaultPointerControl.threshold = atoi(argv[i]);
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-terminate") == 0)
	{
	    dispatchExceptionAtReset = DE_TERMINATE;
	}
	else if ( strcmp( argv[i], "-to") == 0)
	{
	    if(++i < argc)
		TimeOutValue = ((CARD32)atoi(argv[i])) * MILLI_PER_SECOND;
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-tst") == 0)
	{
	    noTestExtensions = TRUE;
	}
	else if ( strcmp( argv[i], "v") == 0)
	    defaultScreenSaverBlanking = PreferBlanking;
	else if ( strcmp( argv[i], "-v") == 0)
	    defaultScreenSaverBlanking = DontPreferBlanking;
	else if ( strcmp( argv[i], "-wm") == 0)
	    defaultBackingStore = WhenMapped;
        else if ( strcmp( argv[i], "-wr") == 0)
            whiteRoot = TRUE;
        else if ( strcmp( argv[i], "-maxbigreqsize") == 0) {
             if(++i < argc) {
                 long reqSizeArg = atol(argv[i]);

                 /* Request size > 128MB does not make much sense... */
                 if( reqSizeArg > 0L && reqSizeArg < 128L ) {
                     maxBigRequestSize = (reqSizeArg * 1048576L) - 1L;
                 }
                 else
                 {
                     UseMsg();
                 }
             }
             else
             {
                 UseMsg();
             }
         }
#ifdef PANORAMIX
	else if ( strcmp( argv[i], "+xinerama") == 0){
	    noPanoramiXExtension = FALSE;
	}
	else if ( strcmp( argv[i], "-xinerama") == 0){
	    noPanoramiXExtension = TRUE;
	}
	else if ( strcmp( argv[i], "-disablexineramaextension") == 0){
	    PanoramiXExtensionDisabledHack = TRUE;
	}
#endif
	else if ( strcmp( argv[i], "-x") == 0)
	{
	    if(++i >= argc)
		UseMsg();
	    /* For U**x, which doesn't support dynamic loading, there's nothing
	     * to do when we see a -x.  Either the extension is linked in or
	     * it isn't */
	}
	else if ( strcmp( argv[i], "-I") == 0)
	{
	    /* ignore all remaining arguments */
	    break;
	}
	else if (strncmp (argv[i], "tty", 3) == 0)
	{
	    /* just in case any body is interested */
	    dev_tty_from_init = argv[i];
	}
#ifdef XDMCP
	else if ((skip = XdmcpOptions(argc, argv, i)) != i)
	{
	    i = skip - 1;
	}
#endif
	else if ( strcmp( argv[i], "-dumbSched") == 0)
	{
	    SmartScheduleDisable = TRUE;
	}
	else if ( strcmp( argv[i], "-schedInterval") == 0)
	{
	    if (++i < argc)
	    {
		SmartScheduleInterval = atoi(argv[i]);
		SmartScheduleSlice = SmartScheduleInterval;
	    }
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-schedMax") == 0)
	{
	    if (++i < argc)
	    {
		SmartScheduleMaxSlice = atoi(argv[i]);
	    }
	    else
		UseMsg();
	}
#ifdef RENDER
	else if ( strcmp( argv[i], "-render" ) == 0)
	{
	    if (++i < argc)
	    {
		int policy = PictureParseCmapPolicy (argv[i]);

		if (policy != PictureCmapPolicyInvalid)
		    PictureCmapPolicy = policy;
		else
		    UseMsg ();
	    }
	    else
		UseMsg ();
	}
#endif
	else if ( strcmp( argv[i], "+extension") == 0)
	{
	    if (++i < argc)
	    {
		if (!EnableDisableExtension(argv[i], TRUE))
		    EnableDisableExtensionError(argv[i], TRUE);
	    }
	    else
		UseMsg();
	}
	else if ( strcmp( argv[i], "-extension") == 0)
	{
	    if (++i < argc)
	    {
		if (!EnableDisableExtension(argv[i], FALSE))
		    EnableDisableExtensionError(argv[i], FALSE);
	    }
	    else
		UseMsg();
	}
 	else
 	{
	    ErrorF("Unrecognized option: %s\n", argv[i]);
	    UseMsg();
	    FatalError("Unrecognized option: %s\n", argv[i]);
        }
    }
}

/* Implement a simple-minded font authorization scheme.  The authorization
   name is "hp-hostname-1", the contents are simply the host name. */
_X_EXPORT int
set_font_authorizations(char **authorizations, int *authlen, pointer client)
{
#define AUTHORIZATION_NAME "hp-hostname-1"
#if defined(TCPCONN) || defined(STREAMSCONN)
    static char *result = NULL;
    static char *p = NULL;

    if (p == NULL)
    {
	char hname[1024], *hnameptr;
	unsigned int len;
#if defined(IPv6) && defined(AF_INET6)
	struct addrinfo hints, *ai = NULL;
#else
	struct hostent *host;
#ifdef XTHREADS_NEEDS_BYNAMEPARAMS
	_Xgethostbynameparams hparams;
#endif
#endif

	gethostname(hname, 1024);
#if defined(IPv6) && defined(AF_INET6)
	bzero(&hints, sizeof(hints));
	hints.ai_flags = AI_CANONNAME;
	if (getaddrinfo(hname, NULL, &hints, &ai) == 0) {
	    hnameptr = ai->ai_canonname;
	} else {
	    hnameptr = hname;
	}
#else
	host = _XGethostbyname(hname, hparams);
	if (host == NULL)
	    hnameptr = hname;
	else
	    hnameptr = host->h_name;
#endif

	len = strlen(hnameptr) + 1;
	result = xalloc(len + sizeof(AUTHORIZATION_NAME) + 4);

	p = result;
        *p++ = sizeof(AUTHORIZATION_NAME) >> 8;
        *p++ = sizeof(AUTHORIZATION_NAME) & 0xff;
        *p++ = (len) >> 8;
        *p++ = (len & 0xff);

	memmove(p, AUTHORIZATION_NAME, sizeof(AUTHORIZATION_NAME));
	p += sizeof(AUTHORIZATION_NAME);
	memmove(p, hnameptr, len);
	p += len;
#if defined(IPv6) && defined(AF_INET6)
	if (ai) {
	    freeaddrinfo(ai);
	}
#endif
    }
    *authlen = p - result;
    *authorizations = result;
    return 1;
#else /* TCPCONN */
    return 0;
#endif /* TCPCONN */
}

#ifndef INTERNAL_MALLOC

_X_EXPORT void * 
Xalloc(unsigned long amount)
{
    void *ptr;

    if ((long)amount <= 0) {
	return NULL;
    }
    /* aligned extra on long word boundary */
    amount = (amount + (sizeof(long) - 1)) & ~(sizeof(long) - 1);
    ptr = malloc(amount);
    return ptr;
}

/*****************
 * XNFalloc 
 * "no failure" realloc
 *****************/

_X_EXPORT void *
XNFalloc(unsigned long amount)
{
    void *ptr;

    if ((long)amount <= 0)
        return NULL;
    /* aligned extra on long word boundary */
    amount = (amount + (sizeof(long) - 1)) & ~(sizeof(long) - 1);
    ptr = malloc(amount);
    if (!ptr)
        FatalError("Out of memory");
    return ptr;
}

/*****************
 * Xcalloc
 *****************/

_X_EXPORT void *
Xcalloc(unsigned long amount)
{
    void *ret;

    ret = Xalloc (amount);
    if (ret)
	bzero (ret, (int) amount);
    return ret;
}

/*****************
 * XNFcalloc
 *****************/

_X_EXPORT void *
XNFcalloc(unsigned long amount)
{
    void *ret;

    ret = Xalloc (amount);
    if (ret)
	bzero (ret, (int) amount);
    else if ((long)amount > 0)
        FatalError("Out of memory");
    return ret;
}

/*****************
 * Xrealloc
 *****************/

_X_EXPORT void *
Xrealloc(pointer ptr, unsigned long amount)
{
    if ((long)amount <= 0)
    {
	if (ptr && !amount)
	    free(ptr);
	return NULL;
    }
    amount = (amount + (sizeof(long) - 1)) & ~(sizeof(long) - 1);
    if (ptr)
        ptr = realloc(ptr, amount);
    else
	ptr = malloc(amount);

    return ptr;
}
                    
/*****************
 * XNFrealloc 
 * "no failure" realloc
 *****************/

_X_EXPORT void *
XNFrealloc(pointer ptr, unsigned long amount)
{
    if ((ptr = Xrealloc(ptr, amount)) == NULL)
    {
	if ((long)amount > 0)
            FatalError( "Out of memory" );
    }
    return ptr;
}

/*****************
 *  Xfree
 *    calls free 
 *****************/    

_X_EXPORT void
Xfree(pointer ptr)
{
    if (ptr)
	free(ptr); 
}
#endif /* !INTERNAL_MALLOC */


_X_EXPORT char *
Xstrdup(const char *s)
{
    char *sd;

    if (s == NULL)
	return NULL;

    sd = Xalloc(strlen(s) + 1);
    if (sd != NULL)
	strcpy(sd, s);
    return sd;
}


_X_EXPORT char *
XNFstrdup(const char *s)
{
    char *sd;

    if (s == NULL)
	return NULL;

    sd = XNFalloc(strlen(s) + 1);
    strcpy(sd, s);
    return sd;
}


#ifdef SIGVTALRM
#define SMART_SCHEDULE_POSSIBLE
#endif

#ifdef SMART_SCHEDULE_POSSIBLE
#define SMART_SCHEDULE_SIGNAL		SIGALRM
#define SMART_SCHEDULE_TIMER		ITIMER_REAL
#endif

_X_EXPORT void
SmartScheduleStopTimer (void)
{
#ifdef SMART_SCHEDULE_POSSIBLE
    struct itimerval	timer;
    
    if (SmartScheduleDisable)
	return;
    timer.it_interval.tv_sec = 0;
    timer.it_interval.tv_usec = 0;
    timer.it_value.tv_sec = 0;
    timer.it_value.tv_usec = 0;
    (void) setitimer (ITIMER_REAL, &timer, 0);
#endif
}

_X_EXPORT void
SmartScheduleStartTimer (void)
{
#ifdef SMART_SCHEDULE_POSSIBLE
    struct itimerval	timer;
    
    if (SmartScheduleDisable)
	return;
    timer.it_interval.tv_sec = 0;
    timer.it_interval.tv_usec = SmartScheduleInterval * 1000;
    timer.it_value.tv_sec = 0;
    timer.it_value.tv_usec = SmartScheduleInterval * 1000;
    setitimer (ITIMER_REAL, &timer, 0);
#endif
}

#ifdef SMART_SCHEDULE_POSSIBLE
static void
SmartScheduleTimer (int sig)
{
    SmartScheduleTime += SmartScheduleInterval;
}
#endif

_X_EXPORT Bool
SmartScheduleInit (void)
{
#ifdef SMART_SCHEDULE_POSSIBLE
    struct sigaction	act;

    if (SmartScheduleDisable)
	return TRUE;
    
    bzero ((char *) &act, sizeof(struct sigaction));

    /* Set up the timer signal function */
    act.sa_handler = SmartScheduleTimer;
    sigemptyset (&act.sa_mask);
    sigaddset (&act.sa_mask, SMART_SCHEDULE_SIGNAL);
    if (sigaction (SMART_SCHEDULE_SIGNAL, &act, 0) < 0)
    {
	perror ("sigaction for smart scheduler");
	return FALSE;
    }
    return TRUE;
#else
    return FALSE;
#endif
}

#ifdef SIG_BLOCK
static sigset_t	PreviousSignalMask;
static int	BlockedSignalCount;
#endif

_X_EXPORT void
OsBlockSignals (void)
{
#ifdef SIG_BLOCK
    if (BlockedSignalCount++ == 0)
    {
	sigset_t    set;
	
	sigemptyset (&set);
#ifdef SIGALRM
	sigaddset (&set, SIGALRM);
#endif
#ifdef SIGVTALRM
	sigaddset (&set, SIGVTALRM);
#endif
#ifdef SIGWINCH
	sigaddset (&set, SIGWINCH);
#endif
#ifdef SIGIO
	sigaddset (&set, SIGIO);
#endif
#ifdef SIGTSTP
	sigaddset (&set, SIGTSTP);
#endif
#ifdef SIGTTIN
	sigaddset (&set, SIGTTIN);
#endif
#ifdef SIGTTOU
	sigaddset (&set, SIGTTOU);
#endif
#ifdef SIGCHLD
	sigaddset (&set, SIGCHLD);
#endif
	sigprocmask (SIG_BLOCK, &set, &PreviousSignalMask);
    }
#endif
}

_X_EXPORT void
OsReleaseSignals (void)
{
#ifdef SIG_BLOCK
    if (--BlockedSignalCount == 0)
    {
	sigprocmask (SIG_SETMASK, &PreviousSignalMask, 0);
    }
#endif
}

#if !defined(WIN32)
/*
 * "safer" versions of system(3), popen(3) and pclose(3) which give up
 * all privs before running a command.
 *
 * This is based on the code in FreeBSD 2.2 libc.
 *
 * XXX It'd be good to redirect stderr so that it ends up in the log file
 * as well.  As it is now, xkbcomp messages don't end up in the log file.
 */

_X_EXPORT int
System(char *command)
{
    int pid, p;
#ifdef SIGCHLD
    void (*csig)(int);
#endif
    int status;

    if (!command)
	return(1);

#ifdef SIGCHLD
    csig = signal(SIGCHLD, SIG_DFL);
    if (csig == SIG_ERR) {
      perror("signal");
      return -1;
    }
#endif

#ifdef DEBUG
    ErrorF("System: `%s'\n", command);
#endif

    switch (pid = fork()) {
    case -1:	/* error */
	p = -1;
    case 0:	/* child */
	if (setgid(getgid()) == -1)
	    _exit(127);
	if (setuid(getuid()) == -1)
	    _exit(127);
	execl("/bin/sh", "sh", "-c", command, (char *)NULL);
	_exit(127);
    default:	/* parent */
	do {
	    p = waitpid(pid, &status, 0);
	} while (p == -1 && errno == EINTR);
	
    }

#ifdef SIGCHLD
    if (signal(SIGCHLD, csig) == SIG_ERR) {
      perror("signal");
      return -1;
    }
#endif

    return p == -1 ? -1 : status;
}

static struct pid {
    struct pid *next;
    FILE *fp;
    int pid;
} *pidlist;

OsSigHandlerPtr old_alarm = NULL; /* XXX horrible awful hack */

_X_EXPORT pointer
Popen(char *command, char *type)
{
    struct pid *cur;
    FILE *iop;
    int pdes[2], pid;

    if (command == NULL || type == NULL)
	return NULL;

    if ((*type != 'r' && *type != 'w') || type[1])
	return NULL;

    if ((cur = (struct pid *)xalloc(sizeof(struct pid))) == NULL)
	return NULL;

    if (pipe(pdes) < 0) {
	xfree(cur);
	return NULL;
    }

    /* Ignore the smart scheduler while this is going on */
    old_alarm = OsSignal(SIGALRM, SIG_IGN);
    if (old_alarm == SIG_ERR) {
      perror("signal");
      return NULL;
    }

    switch (pid = fork()) {
    case -1: 	/* error */
	close(pdes[0]);
	close(pdes[1]);
	xfree(cur);
	if (OsSignal(SIGALRM, old_alarm) == SIG_ERR)
	  perror("signal");
	return NULL;
    case 0:	/* child */
	if (setgid(getgid()) == -1)
	    _exit(127);
	if (setuid(getuid()) == -1)
	    _exit(127);
	if (*type == 'r') {
	    if (pdes[1] != 1) {
		/* stdout */
		dup2(pdes[1], 1);
		close(pdes[1]);
	    }
	    close(pdes[0]);
	} else {
	    if (pdes[0] != 0) {
		/* stdin */
		dup2(pdes[0], 0);
		close(pdes[0]);
	    }
	    close(pdes[1]);
	}
	execl("/bin/sh", "sh", "-c", command, (char *)NULL);
	_exit(127);
    }

    /* Avoid EINTR during stdio calls */
    OsBlockSignals ();
    
    /* parent */
    if (*type == 'r') {
	iop = fdopen(pdes[0], type);
	close(pdes[1]);
    } else {
	iop = fdopen(pdes[1], type);
	close(pdes[0]);
    }

    cur->fp = iop;
    cur->pid = pid;
    cur->next = pidlist;
    pidlist = cur;

#ifdef DEBUG
    ErrorF("Popen: `%s', fp = %p\n", command, iop);
#endif

    return iop;
}

/* fopen that drops privileges */
_X_EXPORT pointer
Fopen(char *file, char *type)
{
    FILE *iop;
#ifndef HAS_SAVED_IDS_AND_SETEUID
    struct pid *cur;
    int pdes[2], pid;

    if (file == NULL || type == NULL)
	return NULL;

    if ((*type != 'r' && *type != 'w') || type[1])
	return NULL;

    if ((cur = (struct pid *)xalloc(sizeof(struct pid))) == NULL)
	return NULL;

    if (pipe(pdes) < 0) {
	xfree(cur);
	return NULL;
    }

    switch (pid = fork()) {
    case -1: 	/* error */
	close(pdes[0]);
	close(pdes[1]);
	xfree(cur);
	return NULL;
    case 0:	/* child */
	if (setgid(getgid()) == -1)
	    _exit(127);
	if (setuid(getuid()) == -1)
	    _exit(127);
	if (*type == 'r') {
	    if (pdes[1] != 1) {
		/* stdout */
		dup2(pdes[1], 1);
		close(pdes[1]);
	    }
	    close(pdes[0]);
	} else {
	    if (pdes[0] != 0) {
		/* stdin */
		dup2(pdes[0], 0);
		close(pdes[0]);
	    }
	    close(pdes[1]);
	}
	execl("/bin/cat", "cat", file, (char *)NULL);
	_exit(127);
    }

    /* Avoid EINTR during stdio calls */
    OsBlockSignals ();
    
    /* parent */
    if (*type == 'r') {
	iop = fdopen(pdes[0], type);
	close(pdes[1]);
    } else {
	iop = fdopen(pdes[1], type);
	close(pdes[0]);
    }

    cur->fp = iop;
    cur->pid = pid;
    cur->next = pidlist;
    pidlist = cur;

#ifdef DEBUG
    ErrorF("Fopen(%s), fp = %p\n", file, iop);
#endif

    return iop;
#else
    int ruid, euid;

    ruid = getuid();
    euid = geteuid();
    
    if (seteuid(ruid) == -1) {
	    return NULL;
    }
    iop = fopen(file, type);

    if (seteuid(euid) == -1) {
	    fclose(iop);
	    return NULL;
    }
    return iop;
#endif /* HAS_SAVED_IDS_AND_SETEUID */
}

_X_EXPORT int
Pclose(pointer iop)
{
    struct pid *cur, *last;
    int pstat;
    int pid;

#ifdef DEBUG
    ErrorF("Pclose: fp = %p\n", iop);
#endif

    fclose(iop);

    for (last = NULL, cur = pidlist; cur; last = cur, cur = cur->next)
	if (cur->fp == iop)
	    break;
    if (cur == NULL)
	return -1;

    do {
	pid = waitpid(cur->pid, &pstat, 0);
    } while (pid == -1 && errno == EINTR);

    if (last == NULL)
	pidlist = cur->next;
    else
	last->next = cur->next;
    xfree(cur);

    /* allow EINTR again */
    OsReleaseSignals ();
    
    if (old_alarm && OsSignal(SIGALRM, old_alarm) == SIG_ERR) {
      perror("signal");
      return -1;
    }

    return pid == -1 ? -1 : pstat;
}

_X_EXPORT int 
Fclose(pointer iop)
{
#ifdef HAS_SAVED_IDS_AND_SETEUID
    return fclose(iop);
#else
    return Pclose(iop);
#endif
}

#endif /* !WIN32 */


/*
 * CheckUserParameters: check for long command line arguments and long
 * environment variables.  By default, these checks are only done when
 * the server's euid != ruid.  In 3.3.x, these checks were done in an
 * external wrapper utility.
 */

/* Consider LD* variables insecure? */
#ifndef REMOVE_ENV_LD
#define REMOVE_ENV_LD 1
#endif

/* Remove long environment variables? */
#ifndef REMOVE_LONG_ENV
#define REMOVE_LONG_ENV 1
#endif

/*
 * Disallow stdout or stderr as pipes?  It's possible to block the X server
 * when piping stdout+stderr to a pipe.
 *
 * Don't enable this because it looks like it's going to cause problems.
 */
#ifndef NO_OUTPUT_PIPES
#define NO_OUTPUT_PIPES 0
#endif


/* Check args and env only if running setuid (euid == 0 && euid != uid) ? */
#ifndef CHECK_EUID
#ifndef WIN32
#define CHECK_EUID 1
#else
#define CHECK_EUID 0
#endif
#endif

/*
 * Maybe the locale can be faked to make isprint(3) report that everything
 * is printable?  Avoid it by default.
 */
#ifndef USE_ISPRINT
#define USE_ISPRINT 0
#endif

#define MAX_ARG_LENGTH          128
#define MAX_ENV_LENGTH          256
#define MAX_ENV_PATH_LENGTH     2048	/* Limit for *PATH and TERMCAP */

#if USE_ISPRINT
#include <ctype.h>
#define checkPrintable(c) isprint(c)
#else
#define checkPrintable(c) (((c) & 0x7f) >= 0x20 && ((c) & 0x7f) != 0x7f)
#endif

enum BadCode {
    NotBad = 0,
    UnsafeArg,
    ArgTooLong,
    UnprintableArg,
    EnvTooLong,
    OutputIsPipe,
    InternalError
};

#if defined(VENDORSUPPORT)
#define BUGADDRESS VENDORSUPPORT
#elif defined(BUILDERADDR)
#define BUGADDRESS BUILDERADDR
#else
#define BUGADDRESS "xorg@freedesktop.org"
#endif

void
_X_EXPORT CheckUserParameters(int argc, char **argv, char **envp)
{
    enum BadCode bad = NotBad;
    int i = 0, j;
    char *a, *e = NULL;

#if CHECK_EUID
    if (geteuid() == 0 && getuid() != geteuid())
#endif
    {
	/* Check each argv[] */
	for (i = 1; i < argc; i++) {
	    if (strcmp(argv[i], "-fp") == 0)
	    {
		i++; /* continue with next argument. skip the length check */
		if (i >= argc)
		    break;
	    } else
	    {
		if (strlen(argv[i]) > MAX_ARG_LENGTH) {
		    bad = ArgTooLong;
		    break;
		}
	    }
	    a = argv[i];
	    while (*a) {
		if (checkPrintable(*a) == 0) {
		    bad = UnprintableArg;
		    break;
		}
		a++;
	    }
	    if (bad)
		break;
	}
	if (!bad) {
	    /* Check each envp[] */
	    for (i = 0; envp[i]; i++) {

		/* Check for bad environment variables and values */
#if REMOVE_ENV_LD
		while (envp[i] && (strncmp(envp[i], "LD", 2) == 0)) {
		    for (j = i; envp[j]; j++) {
			envp[j] = envp[j+1];
		    }
		}
#endif   
		if (envp[i] && (strlen(envp[i]) > MAX_ENV_LENGTH)) {
#if REMOVE_LONG_ENV
		    for (j = i; envp[j]; j++) {
			envp[j] = envp[j+1];
		    }
		    i--;
#else
		    char *eq;
		    int len;

		    eq = strchr(envp[i], '=');
		    if (!eq)
			continue;
		    len = eq - envp[i];
		    e = malloc(len + 1);
		    if (!e) {
			bad = InternalError;
			break;
		    }
		    strncpy(e, envp[i], len);
		    e[len] = 0;
		    if (len >= 4 &&
			(strcmp(e + len - 4, "PATH") == 0 ||
			 strcmp(e, "TERMCAP") == 0)) {
			if (strlen(envp[i]) > MAX_ENV_PATH_LENGTH) {
			    bad = EnvTooLong;
			    break;
			} else {
			    free(e);
			}
		    } else {
			bad = EnvTooLong;
			break;
		    }
#endif
		}
	    }
	}
#if NO_OUTPUT_PIPES
	if (!bad) {
	    struct stat buf;

	    if (fstat(fileno(stdout), &buf) == 0 && S_ISFIFO(buf.st_mode))
		bad = OutputIsPipe;
	    if (fstat(fileno(stderr), &buf) == 0 && S_ISFIFO(buf.st_mode))
		bad = OutputIsPipe;
	}
#endif
    }
    switch (bad) {
    case NotBad:
	return;
    case UnsafeArg:
	ErrorF("Command line argument number %d is unsafe\n", i);
	break;
    case ArgTooLong:
	ErrorF("Command line argument number %d is too long\n", i);
	break;
    case UnprintableArg:
	ErrorF("Command line argument number %d contains unprintable"
		" characters\n", i);
	break;
    case EnvTooLong:
	ErrorF("Environment variable `%s' is too long\n", e);
	break;
    case OutputIsPipe:
	ErrorF("Stdout and/or stderr is a pipe\n");
	break;
    case InternalError:
	ErrorF("Internal Error\n");
	break;
    default:
	ErrorF("Unknown error\n");
	break;
    }
    FatalError("X server aborted because of unsafe environment\n");
}

/*
 * CheckUserAuthorization: check if the user is allowed to start the
 * X server.  This usually means some sort of PAM checking, and it is
 * usually only done for setuid servers (uid != euid).
 */

#ifdef USE_PAM
#include <security/pam_appl.h>
#include <security/pam_misc.h>
#include <pwd.h>
#endif /* USE_PAM */

_X_EXPORT void
CheckUserAuthorization(void)
{
#ifdef USE_PAM
    static struct pam_conv conv = {
	misc_conv,
	NULL
    };

    pam_handle_t *pamh = NULL;
    struct passwd *pw;
    int retval;

    if (getuid() != geteuid()) {
	pw = getpwuid(getuid());
	if (pw == NULL)
	    FatalError("getpwuid() failed for uid %d\n", getuid());

	retval = pam_start("xserver", pw->pw_name, &conv, &pamh);
	if (retval != PAM_SUCCESS)
	    FatalError("pam_start() failed.\n"
			"\tMissing or mangled PAM config file or module?\n");

	retval = pam_authenticate(pamh, 0);
	if (retval != PAM_SUCCESS) {
	    pam_end(pamh, retval);
	    FatalError("PAM authentication failed, cannot start X server.\n"
			"\tPerhaps you do not have console ownership?\n");
	}

	retval = pam_acct_mgmt(pamh, 0);
	if (retval != PAM_SUCCESS) {
	    pam_end(pamh, retval);
	    FatalError("PAM authentication failed, cannot start X server.\n"
			"\tPerhaps you do not have console ownership?\n");
	}

	/* this is not a session, so do not do session management */
	pam_end(pamh, PAM_SUCCESS);
    }
#endif
}

#ifdef __SCO__
#include <fcntl.h>

static void
lockit (int fd, short what)
{
  struct flock lck;

  lck.l_whence = 0;
  lck.l_start = 0;
  lck.l_len = 1;
  lck.l_type = what;

  (void)fcntl (fd, F_SETLKW, &lck);
}

/* SCO OpenServer 5 lacks pread/pwrite. Emulate them. */
ssize_t
pread (int fd, void *buf, size_t nbytes, off_t offset)
{
  off_t saved;
  ssize_t ret;

  lockit (fd, F_RDLCK);
  saved = lseek (fd, 0, SEEK_CUR);
  lseek (fd, offset, SEEK_SET);
  ret = read (fd, buf, nbytes);
  lseek (fd, saved, SEEK_SET);
  lockit (fd, F_UNLCK);

  return ret;
}

ssize_t
pwrite (int fd, const void *buf, size_t nbytes, off_t offset)
{
  off_t saved;
  ssize_t ret;

  lockit (fd, F_WRLCK);
  saved = lseek (fd, 0, SEEK_CUR);
  lseek (fd, offset, SEEK_SET);
  ret = write (fd, buf, nbytes);
  lseek (fd, saved, SEEK_SET);
  lockit (fd, F_UNLCK);

  return ret;
}
#endif /* __SCO__ */