#!/bin/bash

# Copyright (C) 2012 by Debian Edu project, http://wiki.debian.org/DebianEdu
#       Mike Gabriel <mike.gabriel@das-netzwerkteam.de>

# Internet Kiosk 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.
#
# Internet Kiosk 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 program; if not, write to the
# Free Software Foundation, Inc.,
# 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.

set -e

if echo $0 | egrep "^./bin/.*$" >/dev/null; then
    ETCDIR="etc/"
elif echo $0 | egrep "^./ik_.*$" >/dev/null; then
    ETCDIR="../etc/"
else
    ETCDIR=/etc/internet-kiosk/
fi

source $ETCDIR/ik_settings

IK_SHELL="${IK_SHELL:-bash}"
IK_CHROOT="${IK_CHROOT:-/opt/internet-kiosk}"

test -e "$IK_CHROOT" || { 
    echo "ERROR: Internet Kiosk Terminal chroot does not exist at $IK_CHROOT."
    echo "Run ik_create to create it..."
    exit -1
}

[ "x$USER" == "xroot" ] || { 
    echo "ERROR: Internet Kiosk Diskless Terminal management scripts have to run"
    echo "as super-user root."
    exit -2
}

cat > "$IK_CHROOT/ik_dte_shell.sh" <<EOF
#!/bin/bash
export HOME=/root

# export the proxy server (if any) to the shell.
export http_proxy=$IK_HTTP_PROXY
export https_proxy=$IK_HTTPS_PROXY
export ftp_proxy=$IK_FTP_PROXY

echo "This shell has been started in your Internet Kiosk Terminal's chroot environment."
echo 'All changes performed here will take effect on your Internet Kiosk Terminals'
echo 'after their next (re)boot. So be careful!!!'
echo
echo "To return from this chroot shell hit STRG+D or type ,,exit'' on the"
echo 'command line...'
echo

# migrate start-stop-daemon to wrapper & variable based start-stop-daemon execution
if [ \$(stat --format '%s' /sbin/start-stop-daemon) -gt 200 ]; then
        cp /sbin/start-stop-daemon /sbin/start-stop-daemon.real
        echo '#!/bin/sh'                                                                       > /sbin/start-stop-daemon
        echo '#'                                                                               >> /sbin/start-stop-daemon
        echo '# Internet Kiosk Wrapper to avoid running daemons while performing maintenance.' >> /sbin/start-stop-daemon
        echo '#'                                                                               >> /sbin/start-stop-daemon
        echo                                                                                   >> /sbin/start-stop-daemon
        echo 'if [ "\$IK_HANDLE_DAEMONS" != "false" ]; then'                                   >> /sbin/start-stop-daemon
        echo '        /sbin/start-stop-daemon.real "\$@"'                                      >> /sbin/start-stop-daemon
        echo 'fi'                                                                              >> /sbin/start-stop-daemon
        chmod a+x /sbin/start-stop-daemon
fi

export IK_HANDLE_DAEMONS=false

/bin/$IK_SHELL

echo
echo "Internet Kiosk Terminal Shell has exited."
echo
EOF
chmod u+x "$IK_CHROOT/ik_dte_shell.sh"

mkdir -p $IK_CHROOT/{proc,dev/pts,sys}
mount | grep $IK_CHROOT/proc >/dev/null || mount -tproc proc $IK_CHROOT/proc || true
mount | grep $IK_CHROOT/sys >/dev/null || mount -tsysfs sys $IK_CHROOT/sys || true
mount | grep $IK_CHROOT/dev/pts >/dev/null || mount -tdevpts devts $IK_CHROOT/dev/pts || true

chroot "$IK_CHROOT" /ik_dte_shell.sh

for mountpoint in proc dev/pts sys; do
        while true; do
                cat /proc/mounts | grep $IK_CHROOT/$mountpoint >/dev/null && umount $IK_CHROOT/$mountpoint || break
        done
done