#!/bin/sh
# Copyright © 2001, 2002, 2003, 2004, 2005 Jamie Zawinski <jwz@dnalounge.com>
#
# 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.  No representations are made about the suitability of this
# software for any purpose.  It is provided "as is" without express or 
# implied warranty.
#
# Created: 10-Jun-2001
#
# This script does a bunch of clean-up on the kiosks, to try and reset things
# to a usable state without necessarily resorting to restarting X.
#
#   - First, it checks whether the window manager and panel are running.
#     If they aren't, then it gives up and kills X (letting init restart it.)
#
#   - Next, it checks to see whether xscreensaver is running.  If it's not,
#     then it launches it, and exits.
#
#   - Next, it checks to see whether Firefox is running and responsive.
#     If it's running but wedged, it is killed (hard.)
#
#   - Next, it checks to see whether the screen saver is active (blanked.)
#     If the screen is not blanked, then someone is using the machine, and
#     we leave them alone.
#
#   - If the screen is blanked, then we run kiosk-ps-reaper to kill off any
#     processes that shouldn't be running.
#
#   - Finally, if Firefox is not running, it is launched.
#

progname=kiosk-nanny
export DISPLAY=:0.0
export PATH=/bin:/usr/bin:/sbin:/usr/local/bin:/usr/local/sbin:/usr/bin/X11

hourly=false
daily=false
debug=false
immunity=false

usage() {
  echo "usage: $progname [ -hourly | -daily ] [ -debug ]" >&2
  exit 1
}

# process command line
#
while [ $# != 0 ]; do
  case "$1" in
    -hourly ) hourly=true ; shift ;;
    -daily )  daily=true  ; shift ;;
    -debug )  debug=true  ; shift ;;
    * )       usage ;;
  esac
done

if [ "$hourly" = true -a "$daily" = true ]; then
  usage
fi

# If /etc/nox exists, then we're not running X by default on this box,
# so don't do anything here.
#
if [ -f /rw/etc/nox ]; then
  exit 0
fi


# to avoid all the kiosks hammering the NFS server at once, this
# script sleeps a custom amount of time for each.  It does this
# by finding the last byte of our IP address, subtracting 64,
# and sleeping that number of quarter-minutes.
#
n=`ifconfig eth0 |
   sed -n 's/.* inet addr:[0-9]*\.[0-9]*\.[0-9]*\.\([0-9]*\).*$/\1/p'`
if [ -z "$n" ]; then
  echo "$progname: can't find IP address?" >&2
  exit 1
fi
n=`echo "($n-64) * 15" | bc`

if [ "$debug" = true ]; then
  echo "debug: not sleeping ($n)" >&2
else
  sleep $n
fi


# set some important environment variables
. /usr/local/sbin/kiosk-env


# log all stdout/stderr text to syslog
log_lines() {
  while read line ; do
    if [ "$debug" = true ]; then
      echo "$line"
    else
      logger -t "$progname" "$line"
    fi
  done
}

(

##############################################################################
##
##   Check to see if the basic requirements are still running.
##
##############################################################################

if [ "$daily" = true ]; then
  echo "daily reset: restarting X." >&2
  killall X >/dev/null 2>&1
  exit 1
fi

xping() {
 ( 
   xprop -root -len 1 _XKB_RULES_NAMES >/dev/null 2>&1 &
   pid=$!
   ( sleep 10 ; kill $pid ) &
   wait $pid
 ) 2>/dev/null
}


if ! xping; then
  if [ "$debug" = true ]; then
    echo "X server not responding; checking again." >&2
  fi
  if ! xping; then   # try one more time, just in case
    echo "X server not responding: restarting X." >&2

    saver=`ls -l /proc/*/exe 2>/dev/null | grep /lib/xscreensaver/ | \
           sed 's@.*/@@'`
    if [ "$saver" = "" ]; then saver="(none)"; fi
    echo "active screen saver: $saver" >&2

    # perhaps provide a clue as to why X is not responding
    #/usr/bin/top -bn1 | head -19 | grep .
    w | head -1

    killall X >/dev/null 2>&1
    sleep 2
    killall -9 X >/dev/null 2>&1
    exit 1
  elif [ "$debug" = true ]; then
    echo "debug: X server is responding (on second try)" >&2
  fi
elif [ "$debug" = true ]; then
  echo "debug: X server is responding" >&2
fi

critical_app() {
  p=$1
  if [ '' = "`pidof $p`" ]; then
    # uh oh.  wait a bit and check again in case it's still starting up.
    sleep 5
    if [ '' = "`pidof $p`" ]; then
      echo "$p is not running!  killing X." >&2
      killall X >/dev/null 2>&1
      exit 1
    elif [ "$debug" = true ]; then
      echo "debug: $p is alive (just started?)" >&2
    fi
  elif [ "$debug" = true ]; then
    echo "debug: $p is alive" >&2
  fi
}

critical_app metacity
critical_app gnome-panel
critical_app multiload-applet-2

##############################################################################
##
##   Make sure xscreensaver is running.
##
##############################################################################

running=`xscreensaver-command -time 2>&-`

# if it's not running, maybe we're racing with it, and it just hasn't
# started yet.  Wait a few seconds and check again.
#
if [ -z "$running" ]; then
  sleep 5
  running=`xscreensaver-command -time 2>&-`
fi

# ok, it's really not running.  launch it, and exit (because we know
# the saver isn't active right now: it just started.)
#
if [ -z "$running" ]; then
  if [ "$debug" = true ]; then
    echo "xscreensaver died!  re-launching..." >&2
  fi
  su guest -s /bin/sh -c "xscreensaver >/dev/null 2>&1 &"
  exit 0
fi

##############################################################################
##
##   If Firefox is running, but wedged, kill it.
##
##############################################################################

killed_firefox=false

reset_firefox_prefs() {

  if [ "$debug" = true ]; then
    echo "debug: resetting firefox prefs..." >&2
  fi

  foxslt=`sed -n 's/^Path=\(.*\)$/\1/p' \
          /home/guest-ro/.mozilla/firefox/profiles.ini`

  # fuck locks
  rm -f /home/guest/.mozilla/firefox/$foxslt/lock

  cp -p /home/guest-ro/.mozilla/firefox/$foxslt/*.{js,rdf} \
           /home/guest/.mozilla/firefox/$foxslt/
}


kill_firefox() {

  if [ "$debug" = true ]; then
    echo "debug: killing firefox..." >&2
  fi

  killall firefox-bin >/dev/null 2>&1
  sleep 3
  killall -9 firefox-bin >/dev/null 2>&1
  reset_firefox_prefs
  killed_firefox=true
}

if [ '' != "`pidof firefox-bin`" ]; then
  if ( mozilla-ping --timeout 10 ); then
    if [ "$debug" = true ]; then
      echo "debug: firefox is alive" >&2
    fi
  else
    if [ "$debug" = true ]; then
      echo "debug: firefox is wedged..." >&2
    fi
    kill_firefox
  fi
fi


##############################################################################
##
##   If the screen is blanked, reset things.
##
##############################################################################


if ( echo "$running" | grep -q ' blanked ' ); then
  # the screen is blank.

  # turn on host-based access control:
  /usr/bin/X11/xhost - >/dev/null 2>&1
  # allow access from server (telomere aka kiosk)
  /usr/bin/X11/xhost kiosk >/dev/null 2>&1

  # if any hosts have been explicitly allowed, disallow them:
  hosts=`xhost 2>/dev/null | sed -n -e 's/^INET:/-/p' |
       sed 's/^-\(kiosk[^.]*\|localhost\)\(\..*\|\)$//'`
  if [ ! -z "$hosts" ]; then
    xhost $hosts >/dev/null 2>&1
  fi

  # Make sure the X console is selected.
  # Usually this is VT 7, but sometimes (why?) it's VT 8.
  #
  xlog=/var/log/XFree86.0.log
  vt=`sed -n 's/^.* using VT number \([0-9][0-9]*\).*$/\1/p' $xlog`
  chvt ${vt:-7}

  if [ "$hourly" = true -a "$killed_firefox" = false ]; then
#    echo "hourly reset: restarting firefox." >&2
    kill_firefox
  else
    # reset the firefox prefs constantly.
    reset_firefox_prefs
  fi

  if [ "$hourly" = true ]; then
    # once an hour, reset the background picture
    # use xsri because it doesn't use vroot.h
    # (for some reason xsri now gets an X error when xscreensaver
    # is running, sigh...)
    /usr/bin/xsri /usr/local/etc/images/kioskbg.jpg >/dev/null 2>&1
  fi


  # now kill off any unknown processes.
  if [ "$immunity" = false ]; then
    kiosk-ps-reaper -v
  fi
fi

##############################################################################
##
##   If Firefox is not running, launch it.
##   (It takes so long to start up that people get confused...)
##
##############################################################################

if [ '' = "`pidof firefox-bin`" ]; then

#  if [ "$killed_firefox" = false ]; then
#    echo "firefox is dead: launching it." >&2
#  fi

  if [ "$debug" = true ]; then
    echo "launching firefox..." >&2
  fi

  su guest -c "exec firefox" >/dev/null 2>&1 &

fi

) 2>&1 | log_lines

exit 0