#!/usr/bin/perl

#

#  Copyright (C) 2009-2010 D. R. Commander.  All Rights Reserved.

#  Copyright (C) 2005-2006 Sun Microsystems, Inc.  All Rights Reserved.

#  Copyright (C) 2002-2003 Constantin Kaplinsky.  All Rights Reserved.

#  Copyright (C) 2002-2005 RealVNC Ltd.

#  Copyright (C) 1999 AT&T Laboratories Cambridge.  All Rights Reserved.

#

#  This is free software; you can redistribute it and/or modify

#  it under the terms of the GNU General Public License as published by

#  the Free Software Foundation; either version 2 of the License, or

#  (at your option) any later version.

#

#  This software is distributed in the hope that it will be useful,

#  but WITHOUT ANY WARRANTY; without even the implied warranty of

#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

#  GNU General Public License for more details.

#

#  You should have received a copy of the GNU General Public License

#  along with this software; if not, write to the Free Software

#  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,

#  USA.

#

#

# vncserver - wrapper script to start an X VNC server.

#

# First make sure we're operating in a sane environment.

$exedir = "";

$slashndx = rindex($0, "/");

if($slashndx>=0) {

    $exedir = substr($0, 0, $slashndx+1);

}

&SanityCheck();

&NotifyAboutDeprecation();

#

# Global variables.  You may want to configure some of these for

# your site

#

$geometry = "1024x768";

#$depth = 16;

$vncUserDir = "$ENV{HOME}/.vnc";

$vncUserConfig = "$vncUserDir/config";

$vncSystemConfigDir = "/etc/tigervnc";

$vncSystemConfigDefaultsFile = "$vncSystemConfigDir/vncserver-config-defaults";

$vncSystemConfigMandatoryFile = "$vncSystemConfigDir/vncserver-config-mandatory";

$skipxstartup = 0;

$xauthorityFile = "$ENV{XAUTHORITY}" || "$ENV{HOME}/.Xauthority";

$xstartupFile = $vncUserDir . "/xstartup";

$defaultXStartup

    = ("#!/bin/sh\n\n".

       "unset SESSION_MANAGER\n".

       "unset DBUS_SESSION_BUS_ADDRESS\n".

       "/etc/X11/xinit/xinitrc\n".

       "# Assume either Gnome will be started by default when installed\n".

       "# We want to kill the session automatically in this case when user logs out. In case you modify\n".

       "# /etc/X11/xinit/Xclients or ~/.Xclients yourself to achieve a different result, then you should\n".

       "# be responsible to modify below code to avoid that your session will be automatically killed\n".

       "if [ -e /usr/bin/gnome-session ]; then\n".

       "    vncserver -kill \$DISPLAY\n".

       "fi\n");

$defaultConfig

    = ("## Supported server options to pass to vncserver upon invocation can be listed\n".

       "## in this file. See the following manpages for more: vncserver(1) Xvnc(1).\n".

       "## Several common ones are shown below. Uncomment and modify to your liking.\n".

       "##\n".

       "# securitytypes=vncauth,tlsvnc\n".

       "# desktop=sandbox\n".

       "# geometry=2000x1200\n".

       "# localhost\n".

       "# alwaysshared\n");

chop($host = `uname -n`);

if (-d "/etc/X11/fontpath.d") {

    $fontPath = "catalogue:/etc/X11/fontpath.d";

}

@fontpaths = ('/usr/share/X11/fonts', '/usr/share/fonts', '/usr/share/fonts/X11/');

if (! -l "/usr/lib/X11") {push(@fontpaths, '/usr/lib/X11/fonts');}

if (! -l "/usr/X11") {push(@fontpaths, '/usr/X11/lib/X11/fonts');}

if (! -l "/usr/X11R6") {push(@fontpaths, '/usr/X11R6/lib/X11/fonts');}

push(@fontpaths, '/usr/share/fonts/default');

@fonttypes = ('misc',

             '75dpi',

             '100dpi',

             'Speedo',

             'Type1');

foreach $_fpath (@fontpaths) {

    foreach $_ftype (@fonttypes) {

        if (-f "$_fpath/$_ftype/fonts.dir") {

            if (! -l "$_fpath/$_ftype") {

                $defFontPath .= "$_fpath/$_ftype,";

            }

        }

    }

}

if ($defFontPath) {

    if (substr($defFontPath, -1, 1) == ',') {

        chop $defFontPath;

    }

}

if ($fontPath eq "") {

    $fontPath = $defFontPath;

}

# Check command line options

&ParseOptions("-geometry",1,"-depth",1,"-pixelformat",1,"-name",1,"-kill",1,

	      "-help",0,"-h",0,"--help",0,"-fp",1,"-list",0,"-fg",0,"-autokill",0,"-noxstartup",0,"-xstartup",1);

&Usage() if ($opt{'-help'} || $opt{'-h'} || $opt{'--help'});

&Kill() if ($opt{'-kill'});

&List() if ($opt{'-list'});

# Uncomment this line if you want default geometry, depth and pixelformat

# to match the current X display:

# &GetXDisplayDefaults();

if ($opt{'-geometry'}) {

    $geometry = $opt{'-geometry'};

}

if ($opt{'-depth'}) {

    $depth = $opt{'-depth'};

    $pixelformat = "";

}

if ($opt{'-pixelformat'}) {

    $pixelformat = $opt{'-pixelformat'};

}

if ($opt{'-noxstartup'}) {

    $skipxstartup = 1;

}

if ($opt{'-xstartup'}) {

    $xstartupFile = $opt{'-xstartup'};

}

if ($opt{'-fp'}) {

    $fontPath = $opt{'-fp'};

    $fpArgSpecified = 1;

}

&CheckGeometryAndDepth();

# Create the user's vnc directory if necessary.

if (!(-e $vncUserDir)) {

    if (!mkdir($vncUserDir,0755)) {

	die "$prog: Could not create $vncUserDir.\n";

    }

}

# Find display number.

if ((@ARGV > 0) && ($ARGV[0] =~ /^:(\d+)$/)) {

    $displayNumber = $1;

    shift(@ARGV);

    if (!&CheckDisplayNumber($displayNumber)) {

        warn "A VNC server is already running as :$displayNumber\n";

        $displayNumber = &GetDisplayNumber();

    }

} elsif ((@ARGV > 0) && ($ARGV[0] !~ /^-/) && ($ARGV[0] !~ /^\+/)) {

    &Usage();

} else {

    $displayNumber = &GetDisplayNumber();

}

$vncPort = 5900 + $displayNumber;

if ($opt{'-name'}) {

    $desktopName = $opt{'-name'};

} else {

    $desktopName = "$host:$displayNumber ($ENV{USER})";

}

my %default_opts;

my %config;

# We set some reasonable defaults. Config file settings

# override these where present.

$default_opts{desktop} = &quotedString($desktopName);

$default_opts{auth} = &quotedString($xauthorityFile);

$default_opts{geometry} = $geometry if ($geometry);

$default_opts{depth} = $depth if ($depth);

$default_opts{pixelformat} = $pixelformat if ($pixelformat);

$default_opts{rfbauth} = "$vncUserDir/passwd";

$default_opts{rfbport} = $vncPort;

$default_opts{fp} = $fontPath if ($fontPath);

$default_opts{pn} = "";

# Load user-overrideable system defaults

LoadConfig($vncSystemConfigDefaultsFile);

# Then the user's settings

LoadConfig($vncUserConfig);

# And then override anything set above if mandatory settings exist.

# WARNING: "Mandatory" is used loosely here! As the man page says,

# there is nothing stopping someone from EASILY subverting the

# settings in $vncSystemConfigMandatoryFile by simply passing

# CLI args to vncserver, which trump config files! To properly

# hard force policy in a non-subvertible way would require major

# development work that touches Xvnc itself.

LoadConfig($vncSystemConfigMandatoryFile, 1);

#

# Check whether VNC authentication is enabled, and if so, prompt the user to

# create a VNC password if they don't already have one.

#

$securityTypeArgSpecified = 0;

$vncAuthEnabled = 0;

$passwordArgSpecified = 0;

@vncAuthStrings = ("vncauth", "tlsvnc", "x509vnc");

# ...first we check our configuration files' settings

if ($config{'securitytypes'}) {

  $securityTypeArgSpecified = 1;

  foreach $arg2 (split(',', $config{'securitytypes'})) {

    if (grep {$_ eq lc($arg2)} @vncAuthStrings) {

      $vncAuthEnabled = 1;

    }

  }

}

# ...and finally we check CLI args, which in the case of the topic at

# hand (VNC auth or not), override anything found in configuration files

# (even so-called "mandatory" settings).

for ($i = 0; $i < @ARGV; ++$i) {

    # -SecurityTypes can be followed by a space or "="

    my @splitargs = split('=', $ARGV[$i]);

    if (@splitargs <= 1 && $i < @ARGV - 1) {

        push(@splitargs, $ARGV[$i + 1]);

    }

    if (lc(@splitargs[0]) eq "-securitytypes") {

        if (@splitargs > 1) {

            $securityTypeArgSpecified = 1;

        }

        foreach $arg2 (split(',', @splitargs[1])) {

            if (grep {$_ eq lc($arg2)} @vncAuthStrings) {

                $vncAuthEnabled = 1;

            }

        }

    }

    if ((lc(@splitargs[0]) eq "-password")

     || (lc(@splitargs[0]) eq "-passwordfile"

     || (lc(@splitargs[0]) eq "-rfbauth"))) {

        $passwordArgSpecified = 1;

    }

}

if ((!$securityTypeArgSpecified || $vncAuthEnabled) && !$passwordArgSpecified) {

    ($z,$z,$mode) = stat("$vncUserDir/passwd");

    if (!(-e "$vncUserDir/passwd") || ($mode & 077)) {

        warn "\nYou will require a password to access your desktops.\n\n";

        system($exedir."vncpasswd -q $vncUserDir/passwd");

        if (($? >> 8) != 0) {

            exit 1;

        }

    }

}

$desktopLog = "$vncUserDir/$host:$displayNumber.log";

unlink($desktopLog);

# Make an X server cookie and set up the Xauthority file

# mcookie is a part of util-linux, usually only GNU/Linux systems have it.

$cookie = `mcookie`;

# Fallback for non GNU/Linux OS - use /dev/urandom on systems that have it,

# otherwise use perl's random number generator, seeded with the sum

# of the current time, our PID and part of the encrypted form of the password.

if ($cookie eq "" && open(URANDOM, '<', '/dev/urandom')) {

  my $randata;

  if (sysread(URANDOM, $randata, 16) == 16) {

    $cookie = unpack 'h*', $randata;

  }

  close(URANDOM);

}

if ($cookie eq "") {

  srand(time+$$+unpack("L",`cat $vncUserDir/passwd`));

  for (1..16) {

    $cookie .= sprintf("%02x", int(rand(256)) % 256);

  }

}

open(XAUTH, "|xauth -f $xauthorityFile source -");

print XAUTH "add $host:$displayNumber . $cookie\n";

print XAUTH "add $host/unix:$displayNumber . $cookie\n";

close(XAUTH);

# Now start the X VNC Server

# We build up our Xvnc command with options

$cmd = $exedir."Xvnc :$displayNumber";

foreach my $k (sort keys %config) {

  $cmd .= " -$k $config{$k}";

  delete $default_opts{$k}; # file options take precedence

}

foreach my $k (sort keys %default_opts) {

  $cmd .= " -$k $default_opts{$k}";

}

# Add color database stuff here, e.g.:

# $cmd .= " -co /usr/lib/X11/rgb";

foreach $arg (@ARGV) {

  $cmd .= " " . &quotedString($arg);

}

$cmd .= " >> " . &quotedString($desktopLog) . " 2>&1;;

# Run $cmd and record the process ID.

$pidFile = "$vncUserDir/$host:$displayNumber.pid";

system("$cmd & echo \$! >$pidFile");

# Give Xvnc a chance to start up

sleep(3);

if ($fontPath ne $defFontPath) {

    unless (kill 0, `cat $pidFile`) {

        if ($fpArgSpecified) {

	    warn "\nWARNING: The first attempt to start Xvnc failed, probably because the font\n";

	    warn "path you specified using the -fp argument is incorrect.  Attempting to\n";

	    warn "determine an appropriate font path for this system and restart Xvnc using\n";

	    warn "that font path ...\n";

        } else {

	    warn "\nWARNING: The first attempt to start Xvnc failed, possibly because the font\n";

	    warn "catalog is not properly configured.  Attempting to determine an appropriate\n";

	    warn "font path for this system and restart Xvnc using that font path ...\n";

        }

	$cmd =~ s@-fp [^ ]+@@;

	$cmd .= " -fp $defFontPath" if ($defFontPath);

	system("$cmd & echo \$! >$pidFile");

	sleep(3);

    }

}

unless (kill 0, `cat $pidFile`) {

    warn "Could not start Xvnc.\n\n";

    unlink $pidFile;

    open(LOG, "<$desktopLog");

    while (<LOG>) { print; }

    close(LOG);

    die "\n";

}

warn "\nNew '$desktopName' desktop is $host:$displayNumber\n\n";

# Create the user's xstartup script if necessary.

if (! $skipxstartup) {

    if (!(-e "$xstartupFile")) {

	warn "Creating default startup script $xstartupFile\n";

	open(XSTARTUP, ">$xstartupFile");

        print XSTARTUP $defaultXStartup;

        close(XSTARTUP);

        chmod 0755, "$xstartupFile";

    }

}

# Create the user's config file if necessary.

if (!(-e "$vncUserDir/config")) {

    warn "Creating default config $vncUserDir/config\n";

    open(VNCUSERCONFIG, ">$vncUserDir/config");

    print VNCUSERCONFIG $defaultConfig;

    close(VNCUSERCONFIG);

    chmod 0644, "$vncUserDir/config";

}

# Run the X startup script.

if (! $skipxstartup) {

    warn "Starting applications specified in $xstartupFile\n";

}

warn "Log file is $desktopLog\n\n";

# If the unix domain socket exists then use that (DISPLAY=:n) otherwise use

# TCP (DISPLAY=host:n)

if (-e "/tmp/.X11-unix/X$displayNumber" ||

    -e "/usr/spool/sockets/X11/$displayNumber")

{

    $ENV{DISPLAY}= ":$displayNumber";

} else {

    $ENV{DISPLAY}= "$host:$displayNumber";

}

$ENV{VNCDESKTOP}= $desktopName;

if ($opt{'-fg'}) {

    if (! $skipxstartup) {

        system("$xstartupFile >> " . &quotedString($desktopLog) . " 2>&1");

    }

    if (kill 0, `cat $pidFile`) {

        $opt{'-kill'} = ':'.$displayNumber;

        &Kill();

    }

} else {

    if ($opt{'-autokill'}) {

    	if (! $skipxstartup) {

            system("($xstartupFile; $0 -kill :$displayNumber) >> "

	     . &quotedString($desktopLog) . " 2>&1 &";;

    	}

    } else {

    	if (! $skipxstartup) {

            system("$xstartupFile >> " . &quotedString($desktopLog)

	     . " 2>&1 &";;

    	}

    }

}

exit;

###############################################################################

# Functions

###############################################################################

#

# Populate the global %config hash with settings from a specified

# vncserver configuration file if it exists

#

# Args: 1. file path

#       2. optional boolean flag to enable warning when a previously

#          set configuration setting is being overridden

#

sub LoadConfig {

  local ($configFile, $warnoverride) = @_;

  local ($toggle) = undef;

  if (stat($configFile)) {

    if (open(IN, $configFile)) {

      while (<IN>) {

        next if /^#/;

        if (my ($k, $v) = /^\s*(\w+)\s*=\s*(.+)$/) {

          $k = lc($k); # must normalize key case

          if ($k eq "session") {

            next;

          }

          if ($warnoverride && $config{$k}) {

            print("Warning: $configFile is overriding previously defined '$k' to be '$v'\n");

          }

          $config{$k} = $v;

        } elsif ($_ =~ m/^\s*(\S+)/) {

          # We can't reasonably warn on override of toggles (e.g. AlwaysShared)

          # because it would get crazy to do so. We'd have to check if the

          # current config file being loaded defined the logical opposite setting

          # (NeverShared vs. AlwaysShared, etc etc).

          $toggle = lc($1); # must normalize key case

          $config{$toggle} = $k;

        }

      }

      close(IN);

    }

  }

}

#

# CheckGeometryAndDepth simply makes sure that the geometry and depth values

# are sensible.

#

sub CheckGeometryAndDepth

{

    if ($geometry =~ /^(\d+)x(\d+)$/) {

	$width = $1; $height = $2;

	if (($width<1) || ($height<1)) {

	    die "$prog: geometry $geometry is invalid\n";

	}

	$geometry = "${width}x$height";

    } else {

	die "$prog: geometry $geometry is invalid\n";

    }

    if ($depth && (($depth < 8) || ($depth > 32))) {

	die "Depth must be between 8 and 32\n";

    }

}

#

# GetDisplayNumber gets the lowest available display number.  A display number

# n is taken if something is listening on the VNC server port (5900+n) or the

# X server port (6000+n).

#

sub GetDisplayNumber

{

    foreach $n (1..99) {

	if (&CheckDisplayNumber($n)) {

	    return $n+0; # Bruce Mah's workaround for bug in perl 5.005_02

	}

    }

    die "$prog: no free display number on $host.\n";

}

#

# CheckDisplayNumber checks if the given display number is available.  A

# display number n is taken if something is listening on the VNC server port

# (5900+n) or the X server port (6000+n).

#

sub CheckDisplayNumber

{

    local ($n) = @_;

    socket(S, $AF_INET, $SOCK_STREAM, 0) || die "$prog: socket failed: $!\n";

    eval 'setsockopt(S, &SOL_SOCKET, &SO_REUSEADDR, pack("l", 1))';

    if (!bind(S, pack('S n x12', $AF_INET, 6000 + $n))) {

	close(S);

	return 0;

    }

    close(S);

    socket(S, $AF_INET, $SOCK_STREAM, 0) || die "$prog: socket failed: $!\n";

    eval 'setsockopt(S, &SOL_SOCKET, &SO_REUSEADDR, pack("l", 1))';

    if (!bind(S, pack('S n x12', $AF_INET, 5900 + $n))) {

	close(S);

	return 0;

    }

    close(S);

    if (-e "/tmp/.X$n-lock") {

	warn "\nWarning: $host:$n is taken because of /tmp/.X$n-lock\n";

	warn "Remove this file if there is no X server $host:$n\n";

	return 0;

    }

    if (-e "/tmp/.X11-unix/X$n") {

	warn "\nWarning: $host:$n is taken because of /tmp/.X11-unix/X$n\n";

	warn "Remove this file if there is no X server $host:$n\n";

	return 0;

    }

    if (-e "/usr/spool/sockets/X11/$n") {

	warn("\nWarning: $host:$n is taken because of ".

             "/usr/spool/sockets/X11/$n\n");

	warn "Remove this file if there is no X server $host:$n\n";

	return 0;

    }

    return 1;

}

#

# GetXDisplayDefaults uses xdpyinfo to find out the geometry, depth and pixel

# format of the current X display being used.  If successful, it sets the

# options as appropriate so that the X VNC server will use the same settings

# (minus an allowance for window manager decorations on the geometry).  Using

# the same depth and pixel format means that the VNC server won't have to

# translate pixels when the desktop is being viewed on this X display (for

# TrueColor displays anyway).

#

sub GetXDisplayDefaults

{

    local (@lines, @matchlines, $width, $height, $defaultVisualId, $i,

	   $red, $green, $blue);

    $wmDecorationWidth = 4;	# a guess at typical size for window manager

    $wmDecorationHeight = 24;	# decoration size

    return if (!defined($ENV{DISPLAY}));

    @lines = `xdpyinfo 2>/dev/null`;

    return if ($? != 0);

    @matchlines = grep(/dimensions/, @lines);

    if (@matchlines) {

	($width, $height) = ($matchlines[0] =~ /(\d+)x(\d+) pixels/);

	$width -= $wmDecorationWidth;

	$height -= $wmDecorationHeight;

	$geometry = "${width}x$height";

    }

    @matchlines = grep(/default visual id/, @lines);

    if (@matchlines) {

	($defaultVisualId) = ($matchlines[0] =~ /id:\s+(\S+)/);

	for ($i = 0; $i < @lines; $i++) {

	    if ($lines[$i] =~ /^\s*visual id:\s+$defaultVisualId$/) {

		if (($lines[$i+1] !~ /TrueColor/) ||

		    ($lines[$i+2] !~ /depth/) ||

		    ($lines[$i+4] !~ /red, green, blue masks/))

		{

		    return;

		}

		last;

	    }

	}

	return if ($i >= @lines);

	($depth) = ($lines[$i+2] =~ /depth:\s+(\d+)/);

	($red,$green,$blue)

	    = ($lines[$i+4]

	       =~ /masks:\s+0x([0-9a-f]+), 0x([0-9a-f]+), 0x([0-9a-f]+)/);

	$red = hex($red);

	$green = hex($green);

	$blue = hex($blue);

	if ($red > $blue) {

	    $red = int(log($red) / log(2)) - int(log($green) / log(2));

	    $green = int(log($green) / log(2)) - int(log($blue) / log(2));

	    $blue = int(log($blue) / log(2)) + 1;

	    $pixelformat = "rgb$red$green$blue";

	} else {

	    $blue = int(log($blue) / log(2)) - int(log($green) / log(2));

	    $green = int(log($green) / log(2)) - int(log($red) / log(2));

	    $red = int(log($red) / log(2)) + 1;

	    $pixelformat = "bgr$blue$green$red";

	}

    }

}

#

# quotedString returns a string which yields the original string when parsed

# by a shell.

#

sub quotedString

{

    local ($in) = @_;

    $in =~ s/\'/\'\"\'\"\'/g;

    return "'$in'";

}

#

# removeSlashes turns slashes into underscores for use as a file name.

#

sub removeSlashes

{

    local ($in) = @_;

    $in =~ s|/|_|g;

    return "$in";

}

#

# Usage

#

sub Usage

{

    die("\nusage: $prog [:<number>] [-name <desktop-name>] [-depth <depth>]\n".

	"                 [-geometry <width>x<height>]\n".

	"                 [-pixelformat rgbNNN|bgrNNN]\n".

	"                 [-fp <font-path>]\n".

	"                 [-cc <visual>]\n".            

	"                 [-fg]\n".

	"                 [-autokill]\n".

	"                 [-noxstartup]\n".

	"                 [-xstartup <file>]\n".

	"                 <Xvnc-options>...\n\n".

	"       $prog -kill <X-display>\n\n".

	"       $prog -list\n\n");

}

#

# List

#

sub List

{

    opendir(dir, $vncUserDir);

    my @filelist = readdir(dir);

    closedir(dir);

    print "\nTigerVNC server sessions:\n\n";

    print "X DISPLAY #\tPROCESS ID\n";

    foreach my $file (@filelist) {

	if ($file =~ /$host:(\d+)$\.pid/) {

	    chop($tmp_pid = `cat $vncUserDir/$file`);

	    if (kill 0, $tmp_pid) {

		print ":".$1."\t\t".`cat $vncUserDir/$file`;

	    } else {

		unlink ($vncUserDir . "/" . $file);

	    }

	}

    }

    exit;

}

#

# Kill

#

sub Kill

{

    $opt{'-kill'} =~ s/(:\d+)\.\d+$/$1/; # e.g. turn :1.0 into :1

    if ($opt{'-kill'} =~ /^:\d+$/) {

	$pidFile = "$vncUserDir/$host$opt{'-kill'}.pid";

    } else {