#!/bin/sh # # Xdummy: an LD_PRELOAD hack to run a stock Xorg(1) or XFree86(1) server # with the "dummy" video driver to make it avoid Linux VT switching, etc. # # Run "Xdummy -help" for more info. # install="" uninstall="" runit=1 prconf="" notweak="" root="" nosudo="" xserver="" geom="" depth="" debug="" strace="" cmdline_config="" PATH=$PATH:/bin:/usr/bin export PATH program=`basename "$0"` help () { ${PAGER:-more} << END $program: A hack to run a stock Xorg(1) or XFree86(1) X server with the "dummy" (RAM-only framebuffer) video driver such that it AVOIDS the Linux VT switching, opening device files in /dev, keyboard and mouse conflicts, and other problems associated with the normal use of "dummy". In other words, it tries to make Xorg/XFree86 with the "dummy" device driver act more like Xvfb(1). The primary motivation for the Xdummy script is to provide a virtual X server for x11vnc but with more features than Xvfb (or Xvnc); however it could be used for other reasons (e.g. better automated testing than with Xvfb.) One nice thing is the dummy server supports RANDR dynamic resizing while Xvfb does not. So, for example, x11vnc+Xdummy terminal services are a little better than x11vnc+Xvfb. To achieve this, while running the real Xserver $program intercepts system and library calls via the LD_PRELOAD method and modifies the behavior to make it work correctly (e.g. avoid the VT stuff.) LD_PRELOAD tricks are usually "clever hacks" and so might not work in all situations or break when something changes. This program does not need to be run as root as of 12/2009. However, if there are problems for certain situations (usually older servers) it may perform better if run as root (use the -root option.) Also, gcc/cc and other build tools are required for this script to be able to compile the LD_PRELOAD shared object. Be sure they are installed on the system. See -install and -uninstall described below. Your Linux distribution may not install the dummy driver by default, e.g: /usr/lib/xorg/modules/drivers/dummy_drv.so some have it in a package named xserver-xorg-video-dummy you that need to install. Usage: $program <${program}-args> (actually, the arguments can be supplied in any order.) Examples: $program -install $program :1 $program -debug :1 $program -tmpdir ~/mytmp :1 -nolisten tcp startx example: startx -e bash -- $program :2 -depth 16 (if startx needs to be run as root, you can su(1) to a normal user in the bash shell and then launch ~/.xinitrc or ~/.xsession, gnome-session, startkde, startxfce4, etc.) xdm example: xdm -config /usr/local/dummy/xdm-config -nodaemon where the xdm-config file has line: DisplayManager.servers: /usr/local/dummy/Xservers and /usr/local/dummy/Xservers has lines: :1 local /usr/local/dummy/Xdummy :1 -debug :2 local /usr/local/dummy/Xdummy :2 -debug (-debug is optional) gdm/kdm example: TBD. Root permission and x11vnc: Update: as of 12/2009 this program no longer must be run as root. So try it as non-root before running it as root and/or the following schemes. In some circumstances X server program may need to be run as root. If so, one could run x11vnc as root with -unixpw (it switches to the user that logs in) and that may be OK, some other ideas: - add this to sudo via visudo: ALL ALL = NOPASSWD: /usr/local/bin/Xdummy - use this little suid wrapper: /* * xdummy.c * cc -o ./xdummy xdummy.c sudo cp ./xdummy /usr/local/bin/xdummy sudo chown root:root /usr/local/bin/xdummy sudo chmod u+s /usr/local/bin/xdummy * */ #include #include #include #include int main (int argc, char *argv[]) { extern char **environ; char str[100]; sprintf(str, "XDUMMY_UID=%d", (int) getuid()); putenv(str); setuid(0); setgid(0); execv("/usr/local/bin/Xdummy", argv); exit(1); return 1; } Options: ${program}-args: -install Compile the LD_PRELOAD shared object and install it next to the $program script file as: $0.so When that file exists it is used as the LD_PRELOAD shared object without recompiling. Otherwise, each time $program is run the LD_PRELOAD shared object is compiled as a file in /tmp (or -tmpdir) If you set the environment variable INTERPOSE_GETUID=1 when building, then when $program is run as an ordinary user, the shared object will interpose getuid() calls and pretend to be root. Otherwise it doesn't pretend to be root. You can also set the CFLAGS environment variable to anything else you want on the compile cmdline. -uninstall Remove the file: $0.so The LD_PRELOAD shared object will then be compiled each time this program is run. The X server is not started under -install, -uninstall, or -prconf. :N The DISPLAY (e.g. :15) is often the first argument. It is passed to the real X server and also used by the Xdummy script as an identifier. -geom geom1[,geom2...] Take the geometry (e.g. 1024x768) or list of geometries and insert them into the Screen section of the tweaked X server config file. Use this to have a smaller geometry than the one in the system config file. -depth n Use pixel color depth n (e.g. 8, 16, or 24). This makes sure the X config file has a Screen.Display subsection of this depth. Note this option is ALSO passed to the X server. -DEPTH n Same as -depth, except not passed to X server. -tmpdir dir Specify a temporary directory, owned by you and only writable by you. This is used in place of /tmp/Xdummy.\$USER/.. to place the $program.so shared object, tweaked config files, etc. -nonroot Run in non-root mode (working 12/2009, now default) -root Run as root (may still be needed in some environments.) Same as XDUMMY_RUN_AS_ROOT=1. -nosudo Do not try to use sudo(1) when re-running as root, use su(1) instead. -xserver path Specify the path to the Xserver to use. Default is to try "Xorg" first and then "XFree86". If those are not in \$PATH, it tries these locations: /usr/bin/Xorg /usr/X11R6/bin/Xorg /usr/X11R6/bin/XFree86 -n Do not run the command to start the X server, just show the command that $program would run. The LD_PRELOAD shared object will be built, if needed. Also note any XDUMMY* environment variables that need to be set. -prconf Print, to stdout, the tweaked Xorg/XFree86 config file (-config and -xf86config server options, respectively.) The Xserver is not started. -notweak Do not tweak (modify) the Xorg/XFree86 config file (system or server command line) at all. The -geom and similar config file modifications are ignored. It is up to you to make sure it is a working config file (e.g. "dummy" driver, etc.) Perhaps you want to use a file based on the -prconf output. -debug Extra debugging output. -strace strace(1) the Xserver process (for troubleshooting.) -ltrace ltrace(1) instead of strace (can be slow.) -h, -help Print out this help. Xserver-args: Most of the Xorg and XFree86 options will work and are simply passed along if you supply them. Important ones that may be supplied if missing: :N X Display number for server to use. vtNN Linux virtual terminal (VT) to use (a VT is currently still used, just not switched to and from.) -config file Driver "dummy" tweaked config file, a -xf86config file number of settings are tweaked besides Driver. If -config/-xf86config is not given, the system one (e.g. /etc/X11/xorg.conf) is used. If the system one cannot be found, a built-in one is used. Any settings in the config file that are not consistent with "dummy" mode will be overwritten (unless -notweak is specified.) If "file" is only a basename (e.g. "xorg.dummy.conf") with no /'s, then no tweaking of it is done: the X server will look for that basename via its normal search algorithm. If the found file does not refer to the "dummy" driver, etc, then the X server will fail. Notes: The Xorg/XFree86 "dummy" driver is currently undocumented. It works well in this mode, but it is evidently not intended for end-users. So it could be removed or broken at any time. If the display Xserver-arg (e.g. :1) is not given, or ":" is given that indicates $program should try to find a free one (based on tcp ports.) If the display virtual terminal, VT, (e.g. vt9) is not given that indicates $program should try to find a free one (or guess a high one.) This program is not completely secure WRT files in /tmp (but it tries to a good degree.) Better is to use the -tmpdir option to supply a directory only writable by you. Even better is to get rid of users on the local machine you do not trust :-) Set XDUMMY_SET_XV=1 to turn on debugging output for this script. END } warn() { echo "$*" 1>&2 } if [ "X$XDUMMY_SET_XV" != "X" ]; then set -xv fi if [ "X$XDUMMY_UID" = "X" ]; then XDUMMY_UID=`id -u` export XDUMMY_UID fi if [ "X$XDUMMY_UID" = "X0" ]; then if [ "X$SUDO_UID" != "X" ]; then XDUMMY_UID=$SUDO_UID export XDUMMY_UID fi fi # check if root=1 first: # if [ "X$XDUMMY_RUN_AS_ROOT" = "X1" ]; then root=1 fi for arg in $* do if [ "X$arg" = "X-nonroot" ]; then root="" elif [ "X$arg" = "X-root" ]; then root=1 fi done # See if it really needs to be run as root: # if [ "X$XDUMMY_SU_EXEC" = "X" -a "X$root" = "X1" -a "X`id -u`" != "X0" ]; then # this is to prevent infinite loop in case su/sudo doesn't work: XDUMMY_SU_EXEC=1 export XDUMMY_SU_EXEC dosu=1 nosudo="" for arg in $* do if [ "X$arg" = "X-nonroot" ]; then dosu="" elif [ "X$arg" = "X-nosudo" ]; then nosudo="1" elif [ "X$arg" = "X-help" ]; then dosu="" elif [ "X$arg" = "X-h" ]; then dosu="" elif [ "X$arg" = "X-install" ]; then dosu="" elif [ "X$arg" = "X-uninstall" ]; then dosu="" elif [ "X$arg" = "X-n" ]; then dosu="" elif [ "X$arg" = "X-prconf" ]; then dosu="" fi done if [ $dosu ]; then # we need to restart it with su/sudo: if type sudo > /dev/null 2>&1; then : else nosudo=1 fi if [ "X$nosudo" = "X" ]; then warn "$program: supply the sudo password to restart as root:" if [ "X$XDUMMY_UID" != "X" ]; then exec sudo $0 -uid $XDUMMY_UID "$@" else exec sudo $0 "$@" fi else warn "$program: supply the root password to restart as root:" if [ "X$XDUMMY_UID" != "X" ]; then exec su -c "$0 -uid $XDUMMY_UID $*" else exec su -c "$0 $*" fi fi # DONE: exit fi fi # This will hold the X display, e.g. :20 # disp="" args="" cmdline_config="" # Process Xdummy args: # while [ "X$1" != "X" ] do if [ "X$1" = "X-config" -o "X$1" = "X-xf86config" ]; then cmdline_config="$2" fi case $1 in ":"*) disp=$1 ;; "-install") install=1; runit="" ;; "-uninstall") uninstall=1; runit="" ;; "-n") runit="" ;; "-no") runit="" ;; "-norun") runit="" ;; "-prconf") prconf=1; runit="" ;; "-notweak") notweak=1 ;; "-noconf") notweak=1 ;; "-nonroot") root="" ;; "-root") root=1 ;; "-nosudo") nosudo=1 ;; "-xserver") xserver="$2"; shift ;; "-uid") XDUMMY_UID="$2"; shift export XDUMMY_UID ;; "-geom") geom="$2"; shift ;; "-depth") depth="$2"; args="$args -depth $2"; shift ;; "-DEPTH") depth="$2"; shift ;; "-tmpdir") XDUMMY_TMPDIR="$2"; shift ;; "-debug") debug=1 ;; "-nodebug") debug="" ;; "-strace") strace=1 ;; "-ltrace") strace=2 ;; "-h") help; exit 0 ;; "-help") help; exit 0 ;; *) args="$args $1" ;; esac shift done # Try to get a username for use in our tmp directory, etc. # user="" if [ X`id -u` = "X0" ]; then user=root # this will also be used below for id=0 elif [ "X$USER" != "X" ]; then user=$USER elif [ "X$LOGNAME" != "X" ]; then user=$LOGNAME fi # Keep trying... # if [ "X$user" = "X" ]; then user=`whoami 2>/dev/null` fi if [ "X$user" = "X" ]; then user=`basename "$HOME"` fi if [ "X$user" = "X" -o "X$user" = "X." ]; then user="u$$" fi if [ "X$debug" = "X1" -a "X$runit" != "X" ]; then echo "" echo "/usr/bin/env:" env | egrep -v '^(LS_COLORS|TERMCAP)' | sort echo "" fi # Function to compile the LD_PRELOAD shared object: # make_so() { # extract code embedded in this script into a tmp C file: n1=`grep -n '^#code_begin' $0 | head -1 | awk -F: '{print $1}'` n2=`grep -n '^#code_end' $0 | head -1 | awk -F: '{print $1}'` n1=`expr $n1 + 1` dn=`expr $n2 - $n1` tmp=$tdir/Xdummy.$RANDOM$$.c rm -f $tmp if [ -e $tmp -o -h $tmp ]; then warn "$tmp still exists." exit 1 fi touch $tmp || exit 1 tail -n +$n1 $0 | head -n $dn > $tmp # compile it to Xdummy.so: if [ -f $SO ]; then mv $SO $SO.$$ rm -f $SO.$$ fi rm -f $SO touch $SO if [ ! -f $SO ]; then SO=$tdir/Xdummy.$user.so warn "warning switching LD_PRELOAD shared object to: $SO" fi if [ -f $SO ]; then mv $SO $SO.$$ rm -f $SO.$$ fi rm -f $SO # we assume gcc: if [ "X$INTERPOSE_GETUID" = "X1" ]; then CFLAGS="$CFLAGS -DINTERPOSE_GETUID" fi echo "$program:" cc -shared -fPIC $CFLAGS -o $SO $tmp cc -shared -fPIC $CFLAGS -o $SO $tmp rc=$? rm -f $tmp if [ $rc != 0 ]; then warn "$program: cannot build $SO" exit 1 fi if [ "X$debug" != "X" -o "X$install" != "X" ]; then warn "$program: created $SO" ls -l "$SO" fi } # Set tdir to tmp dir for make_so(): if [ "X$XDUMMY_TMPDIR" != "X" ]; then tdir=$XDUMMY_TMPDIR mkdir -p $tdir else tdir="/tmp" fi # Handle -install/-uninstall case: SO=$0.so if [ "X$install" != "X" -o "X$uninstall" != "X" ]; then if [ -e $SO -o -h $SO ]; then warn "$program: removing $SO" fi if [ -f $SO ]; then mv $SO $SO.$$ rm -f $SO.$$ fi rm -f $SO if [ -e $SO -o -h $SO ]; then warn "warning: $SO still exists." exit 1 fi if [ $install ]; then make_so if [ ! -f $SO ]; then exit 1 fi fi exit 0 fi # We need a tmp directory for the .so, tweaked config file, and for # redirecting filenames we cannot create (under -nonroot) # tack="" if [ "X$XDUMMY_TMPDIR" = "X" ]; then XDUMMY_TMPDIR="/tmp/Xdummy.$user" # try to tack on a unique subdir (display number or pid) # to allow multiple instances # if [ "X$disp" != "X" ]; then t0=$disp else t0=$1 fi tack=`echo "$t0" | sed -e 's/^.*://'` if echo "$tack" | grep '^[0-9][0-9]*$' > /dev/null; then : else tack=$$ fi if [ "X$tack" != "X" ]; then XDUMMY_TMPDIR="$XDUMMY_TMPDIR/$tack" fi fi tmp=$XDUMMY_TMPDIR if echo "$tmp" | grep '^/tmp' > /dev/null; then if [ "X$tmp" != "X/tmp" -a "X$tmp" != "X/tmp/" ]; then # clean this subdir of /tmp out, otherwise leave it... rm -rf $XDUMMY_TMPDIR if [ -e $XDUMMY_TMPDIR ]; then warn "$XDUMMY_TMPDIR still exists" exit 1 fi fi fi mkdir -p $XDUMMY_TMPDIR chmod 700 $XDUMMY_TMPDIR if [ "X$tack" != "X" ]; then chmod 700 `dirname "$XDUMMY_TMPDIR"` 2>/dev/null fi # See if we can write something there: # tfile="$XDUMMY_TMPDIR/test.file" touch $tfile if [ ! -f $tfile ]; then XDUMMY_TMPDIR="/tmp/Xdummy.$$.$USER" warn "warning: setting tmpdir to $XDUMMY_TMPDIR ..." rm -rf $XDUMMY_TMPDIR || exit 1 mkdir -p $XDUMMY_TMPDIR || exit 1 fi rm -f $tfile export XDUMMY_TMPDIR # Compile the LD_PRELOAD shared object if needed (needs XDUMMY_TMPDIR) # if [ ! -f $SO ]; then SO="$XDUMMY_TMPDIR/Xdummy.so" make_so fi # Decide which X server to use: # if [ "X$xserver" = "X" ]; then if type Xorg >/dev/null 2>&1; then xserver="Xorg" elif type XFree86 >/dev/null 2>&1; then xserver="XFree86" elif -x /usr/bin/Xorg; then xserver="/usr/bin/Xorg" elif -x /usr/X11R6/bin/Xorg; then xserver="/usr/X11R6/bin/Xorg" elif -x /usr/X11R6/bin/XFree86; then xserver="/usr/X11R6/bin/XFree86" fi if [ "X$xserver" = "X" ]; then # just let it fail below. xserver="/usr/bin/Xorg" warn "$program: cannot locate a stock Xserver... assuming $xserver" fi fi # See if the binary is suid or not readable under -nonroot mode: # if [ "X$BASH_VERSION" != "X" ]; then xserver_path=`type -p $xserver 2>/dev/null` else xserver_path=`type $xserver 2>/dev/null | awk '{print $NF}'` fi if [ -e "$xserver_path" -a "X$root" = "X" -a "X$runit" != "X" ]; then if [ ! -r $xserver_path -o -u $xserver_path -o -g $xserver_path ]; then # XXX not quite correct with rm -rf $XDUMMY_TMPDIR ... # we keep on a filesystem we know root can write to. base=`basename "$xserver_path"` new="/tmp/$base.$user.bin" if [ -e $new ]; then snew=`ls -l $new | awk '{print $5}' | grep '^[0-9][0-9]*$'` sold=`ls -l $xserver_path | awk '{print $5}' | grep '^[0-9][0-9]*$'` if [ "X$snew" != "X" -a "X$sold" != "X" -a "X$sold" != "X$snew" ]; then warn "removing different sized copy:" ls -l $new $xserver_path rm -f $new fi fi if [ ! -e $new -o ! -s $new ]; then rm -f $new touch $new || exit 1 chmod 700 $new || exit 1 if [ ! -r $xserver_path ]; then warn "" warn "NEED TO COPY UNREADABLE $xserver_path to $new as root:" warn "" ls -l $xserver_path 1>&2 warn "" warn "This only needs to be done once:" warn " cat $xserver_path > $new" warn "" nos=$nosudo if type sudo > /dev/null 2>&1; then : else nos=1 fi if [ "X$nos" = "X1" ]; then warn "Please supply root passwd to 'su -c'" su -c "cat $xserver_path > $new" else warn "Please supply the sudo passwd if asked:" sudo /bin/sh -c "cat $xserver_path > $new" fi else warn "" warn "COPYING SETUID $xserver_path to $new" warn "" ls -l $xserver_path 1>&2 warn "" cat $xserver_path > $new fi ls -l $new if [ -s $new ]; then : else rm -f $new ls -l $new exit 1 fi warn "" warn "Please restart Xdummy now." exit 0 fi if [ ! -O $new ]; then warn "file \"$new\" not owned by us!" ls -l $new exit 1 fi xserver=$new fi fi # Work out display: # if [ "X$disp" != "X" ]; then : elif [ "X$1" != "X" ]; then if echo "$1" | grep '^:[0-9]' > /dev/null; then disp=$1 shift elif [ "X$1" = "X:" ]; then # ":" means for us to find one. shift fi fi if [ "X$disp" = "X" -o "X$disp" = "X:" ]; then # try to find an open display port: # (tcp outdated...) ports=`netstat -ant | grep LISTEN | awk '{print $4}' | sed -e 's/^.*://'` n=0 while [ $n -le 20 ] do port=`printf "60%02d" $n` if echo "$ports" | grep "^${port}\$" > /dev/null; then : else disp=":$n" warn "$program: auto-selected DISPLAY $disp" break fi n=`expr $n + 1` done fi # Work out which vt to use, try to find/guess an open one if necessary. # vt="" for arg in $* do if echo "$arg" | grep '^vt' > /dev/null; then vt=$arg break fi done if [ "X$vt" = "X" ]; then if [ "X$user" = "Xroot" ]; then # root can user fuser(1) to see if it is in use: if type fuser >/dev/null 2>&1; then # try /dev/tty17 thru /dev/tty32 n=17 while [ $n -le 32 ] do dev="/dev/tty$n" if fuser $dev >/dev/null 2>&1; then : else vt="vt$n" warn "$program: auto-selected VT $vt => $dev" break fi n=`expr $n + 1` done fi fi if [ "X$vt" = "X" ]; then # take a wild guess... vt=vt16 warn "$program: selected fallback VT $vt" fi else vt="" fi # Decide flavor of Xserver: # stype=`basename "$xserver"` if echo "$stype" | grep -i xfree86 > /dev/null; then stype=xfree86 else stype=xorg fi tweak_config() { in="$1" config2="$XDUMMY_TMPDIR/xdummy_modified_xconfig.conf" if [ "X$disp" != "X" ]; then d=`echo "$disp" | sed -e 's,/,,g' -e 's/:/_/g'` config2="$config2$d" fi # perl script to tweak the config file... add/delete options, etc. # env XDUMMY_GEOM=$geom \ XDUMMY_DEPTH=$depth \ perl > $config2 < $in -e ' $n = 0; $geom = $ENV{XDUMMY_GEOM}; $depth = $ENV{XDUMMY_DEPTH}; $videoram = "24000"; $HorizSync = "30.0 - 130.0"; $VertRefresh = "50.0 - 250.0"; if ($geom ne "") { my $tmp = ""; foreach $g (split(/,/, $geom)) { $tmp .= "\"$g\" "; } $tmp =~ s/\s*$//; $geom = $tmp; } while (<>) { if ($ENV{XDUMMY_NOTWEAK}) { print $_; next; } $n++; if (/^\s*#/) { # pass comments straight thru print; next; } if (/^\s*Section\s+(\S+)/i) { # start of Section $sect = $1; $sect =~ s/\W//g; $sect =~ y/A-Z/a-z/; $sects{$sect} = 1; print; next; } if (/^\s*EndSection/i) { # end of Section if ($sect eq "serverflags") { if (!$got_DontVTSwitch) { print " ##Xdummy:##\n"; print " Option \"DontVTSwitch\" \"true\"\n"; } if (!$got_AllowMouseOpenFail) { print " ##Xdummy:##\n"; print " Option \"AllowMouseOpenFail\" \"true\"\n"; } if (!$got_PciForceNone) { print " ##Xdummy:##\n"; print " Option \"PciForceNone\" \"true\"\n"; } } elsif ($sect eq "device") { if (!$got_Driver) { print " ##Xdummy:##\n"; print " Driver \"dummy\"\n"; } if (!$got_VideoRam) { print " ##Xdummy:##\n"; print " VideoRam $videoram\n"; } } elsif ($sect eq "screen") { if ($depth ne "" && !got_DefaultDepth) { print " ##Xdummy:##\n"; print " DefaultDepth $depth\n"; } if ($got_Monitor eq "") { print " ##Xdummy:##\n"; print " Monitor \"Monitor0\"\n"; } } elsif ($sect eq "monitor") { if (!got_HorizSync) { print " ##Xdummy:##\n"; print " HorizSync $HorizSync\n"; } if (!got_VertRefresh) { print " ##Xdummy:##\n"; print " VertRefresh $VertRefresh\n"; } } $sect = ""; print; next; } if (/^\s*SubSection\s+(\S+)/i) { # start of Section $subsect = $1; $subsect =~ s/\W//g; $subsect =~ y/A-Z/a-z/; $subsects{$subsect} = 1; if ($sect eq "screen" && $subsect eq "display") { $got_Mode = 0; } print; next; } if (/^\s*EndSubSection/i) { # end of SubSection if ($sect eq "screen") { if ($subsect eq "display") { if ($depth ne "" && !$set_Depth) { print " ##Xdummy:##\n"; print " Depth\t$depth\n"; } if ($geom ne "" && ! $got_Mode) { print " ##Xdummy:##\n"; print " Modes\t$geom\n"; } } } $subsect = ""; print; next; } $l = $_; $l =~ s/#.*$//; if ($sect eq "serverflags") { if ($l =~ /^\s*Option.*DontVTSwitch/i) { $_ =~ s/false/true/ig; $got_DontVTSwitch = 1; } if ($l =~ /^\s*Option.*AllowMouseOpenFail/i) { $_ =~ s/false/true/ig; $got_AllowMouseOpenFail = 1; } if ($l =~ /^\s*Option.*PciForceNone/i) { $_ =~ s/false/true/ig; $got_PciForceNone= 1; } } if ($sect eq "module") { if ($l =~ /^\s*Load.*\b(dri|fbdevhw)\b/i) { $_ = "##Xdummy## $_"; } } if ($sect eq "monitor") { if ($l =~ /^\s*HorizSync/i) { $got_HorizSync = 1; } if ($l =~ /^\s*VertRefresh/i) { $got_VertRefresh = 1; } } if ($sect eq "device") { if ($l =~ /^(\s*Driver)\b/i) { $_ = "$1 \"dummy\"\n"; $got_Driver = 1; } if ($l =~ /^\s*VideoRam/i) { $got_VideoRam= 1; } } if ($sect eq "inputdevice") { if ($l =~ /^\s*Option.*\bDevice\b/i) { print " ##Xdummy:##\n"; $_ = " Option \"Device\" \"/dev/dilbert$n\"\n"; } } if ($sect eq "screen") { if ($l =~ /^\s*DefaultDepth\s+(\d+)/i) { if ($depth ne "") { print " ##Xdummy:##\n"; $_ = " DefaultDepth\t$depth\n"; } $got_DefaultDepth = 1; } if ($l =~ /^\s*Monitor\s+(\S+)/i) { $got_Monitor = $1; $got_Monitor =~ s/"//g; } if ($subsect eq "display") { if ($geom ne "") { if ($l =~ /^(\s*Modes)\b/i) { print " ##Xdummy:##\n"; $_ = "$1 $geom\n"; $got_Modes = 1; } } if ($l =~ /^\s*Depth\s+(\d+)/i) { my $d = $1; if (!$set_Depth && $depth ne "") { $set_Depth = 1; if ($depth != $d) { print " ##Xdummy:##\n"; $_ = " Depth\t$depth\n"; } } } } } print; } if ($ENV{XDUMMY_NOTWEAK}) { exit; } # create any crucial sections that are missing: if (! exists($sects{serverflags})) { print "\n##Xdummy:##\n"; print "Section \"ServerFlags\"\n"; print " Option \"DontVTSwitch\" \"true\"\n"; print " Option \"AllowMouseOpenFail\" \"true\"\n"; print " Option \"PciForceNone\" \"true\"\n"; print "EndSection\n"; } if (! exists($sects{device})) { print "\n##Xdummy:##\n"; print "Section \"Device\"\n"; print " Identifier \"Videocard0\"\n"; print " Driver \"dummy\"\n"; print " VideoRam $videoram\n"; print "EndSection\n"; } if (! exists($sects{monitor})) { print "\n##Xdummy:##\n"; print "Section \"Monitor\"\n"; print " Identifier \"Monitor0\"\n"; print " HorizSync $HorizSync\n"; print " VertRefresh $VertRefresh\n"; print "EndSection\n"; } if (! exists($sects{screen})) { print "\n##Xdummy:##\n"; print "Section \"Screen\"\n"; print " Identifier \"Screen0\"\n"; print " Device \"Videocard0\"\n"; if ($got_Monitor ne "") { print " Monitor \"$got_Monitor\"\n"; } else { print " Monitor \"Monitor0\"\n"; } if ($depth ne "") { print " DefaultDepth $depth\n"; } else { print " DefaultDepth 24\n"; } print " SubSection \"Display\"\n"; print " Viewport 0 0\n"; print " Depth 24\n"; if ($geom ne "") { print " Modes $geom\n"; } else { print " Modes \"1280x1024\" \"1024x768\" \"800x600\"\n"; } print " EndSubSection\n"; print "EndSection\n"; } '; } # Work out config file and tweak it. # if [ "X$cmdline_config" = "X" ]; then : elif echo "$cmdline_config" | grep '/' > /dev/null; then : else # ignore basename only case (let server handle it) cmdline_config="" notweak=1 fi config=$cmdline_config if [ "X$notweak" = "X1" -a "X$root" = "X" -a -f "$cmdline_config" ]; then # if not root we need to copy (but not tweak) the specified config. XDUMMY_NOTWEAK=1 export XDUMMY_NOTWEAK notweak="" fi if [ ! $notweak ]; then # tweaked config will be put in $config2: config2="" if [ "X$config" = "X" ]; then # use the default one: if [ "X$stype" = "Xxorg" ]; then config=/etc/X11/xorg.conf else if [ -f "/etc/X11/XF86Config-4" ]; then config="/etc/X11/XF86Config-4" else config="/etc/X11/XF86Config" fi fi if [ ! -f $config ]; then for c in /etc/X11/xorg.conf /etc/X11/XF86Config-4 /etc/X11/XF86Config do if [ -f $c ]; then config=$c break fi done fi fi if [ ! -f $config ]; then config="$XDUMMY_TMPDIR/xorg.conf" warn "$program: using minimal built-in xorg.conf settings." cat > $config < /dev/null; then so=`echo "$so" | sed -e "s,^\.,$pwd,"` fi if echo "$so" | grep '/' > /dev/null; then : else so="$pwd/$so" fi warn "env LD_PRELOAD=$so $xserver $disp $args $vt" warn "" if [ ! $runit ]; then exit 0 fi fi if [ $strace ]; then if [ "X$strace" = "X2" ]; then ltrace -f env LD_PRELOAD=$SO $xserver $disp $args $vt else strace -f env LD_PRELOAD=$SO $xserver $disp $args $vt fi else exec env LD_PRELOAD=$SO $xserver $disp $args $vt fi exit $? ######################################################################### code() { #code_begin #include #define O_ACCMODE 0003 #define O_RDONLY 00 #define O_WRONLY 01 #define O_RDWR 02 #define O_CREAT 0100 /* not fcntl */ #define O_EXCL 0200 /* not fcntl */ #define O_NOCTTY 0400 /* not fcntl */ #define O_TRUNC 01000 /* not fcntl */ #define O_APPEND 02000 #define O_NONBLOCK 04000 #define O_NDELAY O_NONBLOCK #define O_SYNC 010000 #define O_FSYNC O_SYNC #define O_ASYNC 020000 #include #include #include #include #include #define __USE_GNU #include static char tmpdir[4096]; static char str1[4096]; static char str2[4096]; static char devs[256][1024]; static int debug = -1; static int root = -1; static int changed_uid = 0; static int saw_fonts = 0; static int saw_lib_modules = 0; static time_t start = 0; void check_debug(void) { if (debug < 0) { if (getenv("XDUMMY_DEBUG") != NULL) { debug = 1; } else { debug = 0; } /* prevent other processes using the preload: */ putenv("LD_PRELOAD="); } } void check_root(void) { if (root < 0) { /* script tells us if we are root */ if (getenv("XDUMMY_ROOT") != NULL) { root = 1; } else { root = 0; } } } void check_uid(void) { if (start == 0) { start = time(NULL); if (debug) fprintf(stderr, "START: %u\n", (unsigned int) start); return; } else if (changed_uid == 0) { if (saw_fonts || time(NULL) > start + 20) { if (getenv("XDUMMY_UID")) { int uid = atoi(getenv("XDUMMY_UID")); if (debug) fprintf(stderr, "SETREUID: %d saw_fonts=%d\n", uid, saw_fonts); if (uid >= 0) { /* this will simply fail in -nonroot mode: */ setreuid(uid, -1); } } changed_uid = 1; } } } #define CHECKIT if (debug < 0) check_debug(); \ if (root < 0) check_root(); \ check_uid(); static void set_tmpdir(void) { char *s; static int didset = 0; if (didset) { return; } s = getenv("XDUMMY_TMPDIR"); if (! s) { s = "/tmp"; } tmpdir[0] = '\0'; strcat(tmpdir, s); strcat(tmpdir, "/"); didset = 1; } static char *tmpdir_path(const char *path) { char *str; set_tmpdir(); strcpy(str2, path); str = str2; while (*str) { if (*str == '/') { *str = '_'; } str++; } strcpy(str1, tmpdir); strcat(str1, str2); return str1; } int open(const char *pathname, int flags, unsigned short mode) { int fd; char *store_dev = NULL; static int (*real_open)(const char *, int , unsigned short) = NULL; CHECKIT if (! real_open) { real_open = (int (*)(const char *, int , unsigned short)) dlsym(RTLD_NEXT, "open"); } if (strstr(pathname, "lib/modules/")) { /* not currently used. */ saw_lib_modules = 1; } if (!root) { if (strstr(pathname, "/dev/") == pathname) { store_dev = strdup(pathname); } if (strstr(pathname, "/dev/tty") == pathname && strcmp(pathname, "/dev/tty")) { pathname = tmpdir_path(pathname); if (debug) fprintf(stderr, "OPEN: %s -> %s (as FIFO)\n", store_dev, pathname); /* we make it a FIFO so ioctl on it does not fail */ unlink(pathname); mkfifo(pathname, 0666); } else if (0) { /* we used to handle more /dev files ... */ fd = real_open(pathname, O_WRONLY|O_CREAT, 0777); close(fd); } } fd = real_open(pathname, flags, mode); if (debug) fprintf(stderr, "OPEN: %s %d %d fd=%d\n", pathname, flags, mode, fd); if (! root) { if (store_dev) { if (fd < 256) { strcpy(devs[fd], store_dev); } free(store_dev); } } return(fd); } int open64(const char *pathname, int flags, unsigned short mode) { int fd; CHECKIT if (debug) fprintf(stderr, "OPEN64: %s %d %d\n", pathname, flags, mode); fd = open(pathname, flags, mode); return(fd); } int rename(const char *oldpath, const char *newpath) { static int (*real_rename)(const char *, const char *) = NULL; CHECKIT if (! real_rename) { real_rename = (int (*)(const char *, const char *)) dlsym(RTLD_NEXT, "rename"); } if (debug) fprintf(stderr, "RENAME: %s %s\n", oldpath, newpath); if (root) { return(real_rename(oldpath, newpath)); } if (strstr(oldpath, "/var/log") == oldpath) { if (debug) fprintf(stderr, "RENAME: returning 0\n"); return 0; } return(real_rename(oldpath, newpath)); } FILE *fopen(const char *pathname, const char *mode) { static FILE* (*real_fopen)(const char *, const char *) = NULL; char *str; if (! saw_fonts) { if (strstr(pathname, "/fonts/")) { if (strstr(pathname, "fonts.dir")) { saw_fonts = 1; } else if (strstr(pathname, "fonts.alias")) { saw_fonts = 1; } } } CHECKIT if (! real_fopen) { real_fopen = (FILE* (*)(const char *, const char *)) dlsym(RTLD_NEXT, "fopen"); } if (debug) fprintf(stderr, "FOPEN: %s %s\n", pathname, mode); if (strstr(pathname, "xdummy_modified_xconfig.conf")) { /* make our config appear to be in /etc/X11, etc. */ char *q = strrchr(pathname, '/'); if (q != NULL && getenv("XDUMMY_TMPDIR") != NULL) { strcpy(str1, getenv("XDUMMY_TMPDIR")); strcat(str1, q); if (debug) fprintf(stderr, "FOPEN: %s -> %s\n", pathname, str1); pathname = str1; } } if (root) { return(real_fopen(pathname, mode)); } str = (char *) pathname; if (strstr(pathname, "/var/log") == pathname) { str = tmpdir_path(pathname); if (debug) fprintf(stderr, "FOPEN: %s -> %s\n", pathname, str); } return(real_fopen(str, mode)); } #define RETURN0 if (debug) \ {fprintf(stderr, "IOCTL: covered %d 0x%x\n", fd, req);} return 0; #define RETURN1 if (debug) \ {fprintf(stderr, "IOCTL: covered %d 0x%x\n", fd, req);} return -1; int ioctl(int fd, int req, void *ptr) { static int closed_xf86Info_consoleFd = 0; static int (*real_ioctl)(int, int , void *) = NULL; CHECKIT if (! real_ioctl) { real_ioctl = (int (*)(int, int , void *)) dlsym(RTLD_NEXT, "open"); } if (debug) fprintf(stderr, "IOCTL: %d 0x%x %p\n", fd, req, ptr); /* based on xorg-x11-6.8.1-dualhead.patch */ if (req == VT_GETMODE) { /* close(xf86Info.consoleFd) */ if (0 && ! closed_xf86Info_consoleFd) { /* I think better not to close it... */ close(fd); closed_xf86Info_consoleFd = 1; } RETURN0 } else if (req == VT_SETMODE) { RETURN0 } else if (req == VT_GETSTATE) { RETURN0 } else if (req == KDSETMODE) { RETURN0 } else if (req == KDSETLED) { RETURN0 } else if (req == KDGKBMODE) { RETURN0 } else if (req == KDSKBMODE) { RETURN0 } else if (req == VT_ACTIVATE) { RETURN0 } else if (req == VT_WAITACTIVE) { RETURN0 } else if (req == VT_RELDISP) { if (ptr == (void *) 1) { RETURN1 } else if (ptr == (void *) VT_ACKACQ) { RETURN0 } } return(real_ioctl(fd, req, ptr)); } typedef void (*sighandler_t)(int); #define SIGUSR1 10 #define SIG_DFL ((sighandler_t)0) sighandler_t signal(int signum, sighandler_t handler) { static sighandler_t (*real_signal)(int, sighandler_t) = NULL; CHECKIT if (! real_signal) { real_signal = (sighandler_t (*)(int, sighandler_t)) dlsym(RTLD_NEXT, "signal"); } if (debug) fprintf(stderr, "SIGNAL: %d %p\n", signum, handler); if (signum == SIGUSR1) { if (debug) fprintf(stderr, "SIGNAL: skip SIGUSR1\n"); return SIG_DFL; } return(real_signal(signum, handler)); } int close(int fd) { static int (*real_close)(int) = NULL; CHECKIT if (! real_close) { real_close = (int (*)(int)) dlsym(RTLD_NEXT, "close"); } if (debug) fprintf(stderr, "CLOSE: %d\n", fd); if (!root) { if (fd < 256) { devs[fd][0] = '\0'; } } return(real_close(fd)); } struct stat { int foo; }; int stat(const char *path, struct stat *buf) { static int (*real_stat)(const char *, struct stat *) = NULL; CHECKIT if (! real_stat) { real_stat = (int (*)(const char *, struct stat *)) dlsym(RTLD_NEXT, "stat"); } if (debug) fprintf(stderr, "STAT: %s\n", path); return(real_stat(path, buf)); } int stat64(const char *path, struct stat *buf) { static int (*real_stat64)(const char *, struct stat *) = NULL; CHECKIT if (! real_stat64) { real_stat64 = (int (*)(const char *, struct stat *)) dlsym(RTLD_NEXT, "stat64"); } if (debug) fprintf(stderr, "STAT64: %s\n", path); return(real_stat64(path, buf)); } int chown(const char *path, uid_t owner, gid_t group) { static int (*real_chown)(const char *, uid_t, gid_t) = NULL; CHECKIT if (! real_chown) { real_chown = (int (*)(const char *, uid_t, gid_t)) dlsym(RTLD_NEXT, "chown"); } if (root) { return(real_chown(path, owner, group)); } if (debug) fprintf(stderr, "CHOWN: %s %d %d\n", path, owner, group); if (strstr(path, "/dev") == path) { if (debug) fprintf(stderr, "CHOWN: return 0\n"); return 0; } return(real_chown(path, owner, group)); } extern int *__errno_location (void); #ifndef ENODEV #define ENODEV 19 #endif int ioperm(unsigned long from, unsigned long num, int turn_on) { static int (*real_ioperm)(unsigned long, unsigned long, int) = NULL; CHECKIT if (! real_ioperm) { real_ioperm = (int (*)(unsigned long, unsigned long, int)) dlsym(RTLD_NEXT, "ioperm"); } if (debug) fprintf(stderr, "IOPERM: %d %d %d\n", (int) from, (int) num, turn_on); if (root) { return(real_ioperm(from, num, turn_on)); } if (from == 0 && num == 1024 && turn_on == 1) { /* we want xf86EnableIO to fail */ if (debug) fprintf(stderr, "IOPERM: setting ENODEV.\n"); *__errno_location() = ENODEV; return -1; } return 0; } int iopl(int level) { static int (*real_iopl)(int) = NULL; CHECKIT if (! real_iopl) { real_iopl = (int (*)(int)) dlsym(RTLD_NEXT, "iopl"); } if (debug) fprintf(stderr, "IOPL: %d\n", level); if (root) { return(real_iopl(level)); } return 0; } #ifdef INTERPOSE_GETUID /* * we got things to work w/o pretending to be root. * so we no longer interpose getuid(), etc. */ uid_t getuid(void) { static uid_t (*real_getuid)(void) = NULL; CHECKIT if (! real_getuid) { real_getuid = (uid_t (*)(void)) dlsym(RTLD_NEXT, "getuid"); } if (root) { return(real_getuid()); } if (debug) fprintf(stderr, "GETUID: 0\n"); return 0; } uid_t geteuid(void) { static uid_t (*real_geteuid)(void) = NULL; CHECKIT if (! real_geteuid) { real_geteuid = (uid_t (*)(void)) dlsym(RTLD_NEXT, "geteuid"); } if (root) { return(real_geteuid()); } if (debug) fprintf(stderr, "GETEUID: 0\n"); return 0; } uid_t geteuid_kludge1(void) { static uid_t (*real_geteuid)(void) = NULL; CHECKIT if (! real_geteuid) { real_geteuid = (uid_t (*)(void)) dlsym(RTLD_NEXT, "geteuid"); } if (debug) fprintf(stderr, "GETEUID: 0 saw_libmodules=%d\n", saw_lib_modules); if (root && !saw_lib_modules) { return(real_geteuid()); } else { saw_lib_modules = 0; return 0; } } uid_t getuid32(void) { static uid_t (*real_getuid32)(void) = NULL; CHECKIT if (! real_getuid32) { real_getuid32 = (uid_t (*)(void)) dlsym(RTLD_NEXT, "getuid32"); } if (root) { return(real_getuid32()); } if (debug) fprintf(stderr, "GETUID32: 0\n"); return 0; } uid_t geteuid32(void) { static uid_t (*real_geteuid32)(void) = NULL; CHECKIT if (! real_geteuid32) { real_geteuid32 = (uid_t (*)(void)) dlsym(RTLD_NEXT, "geteuid32"); } if (root) { return(real_geteuid32()); } if (debug) fprintf(stderr, "GETEUID32: 0\n"); return 0; } gid_t getgid(void) { static gid_t (*real_getgid)(void) = NULL; CHECKIT if (! real_getgid) { real_getgid = (gid_t (*)(void)) dlsym(RTLD_NEXT, "getgid"); } if (root) { return(real_getgid()); } if (debug) fprintf(stderr, "GETGID: 0\n"); return 0; } gid_t getegid(void) { static gid_t (*real_getegid)(void) = NULL; CHECKIT if (! real_getegid) { real_getegid = (gid_t (*)(void)) dlsym(RTLD_NEXT, "getegid"); } if (root) { return(real_getegid()); } if (debug) fprintf(stderr, "GETEGID: 0\n"); return 0; } gid_t getgid32(void) { static gid_t (*real_getgid32)(void) = NULL; CHECKIT if (! real_getgid32) { real_getgid32 = (gid_t (*)(void)) dlsym(RTLD_NEXT, "getgid32"); } if (root) { return(real_getgid32()); } if (debug) fprintf(stderr, "GETGID32: 0\n"); return 0; } gid_t getegid32(void) { static gid_t (*real_getegid32)(void) = NULL; CHECKIT if (! real_getegid32) { real_getegid32 = (gid_t (*)(void)) dlsym(RTLD_NEXT, "getegid32"); } if (root) { return(real_getegid32()); } if (debug) fprintf(stderr, "GETEGID32: 0\n"); return 0; } #endif #if 0 /* maybe we need to interpose on strcmp someday... here is the template */ int strcmp(const char *s1, const char *s2) { static int (*real_strcmp)(const char *, const char *) = NULL; CHECKIT if (! real_strcmp) { real_strcmp = (int (*)(const char *, const char *)) dlsym(RTLD_NEXT, "strcmp"); } if (debug) fprintf(stderr, "STRCMP: '%s' '%s'\n", s1, s2); return(real_strcmp(s1, s2)); } #endif #code_end }