#!/bin/sh -e

PATH="/sbin:/bin"

UDEVSTART=/sbin/udevstart

# default maximum size of the /dev tmpfs
tmpfs_size="1M"

[ -x $UDEVSTART ] || exit 0

. /etc/udev/udev.conf

case "$(uname -r)" in
  2.[012345].*)
    echo "udev requires a 2.6.x kernel, not started."
    exit 0
    ;;
esac

if ! grep -q '[[:space:]]tmpfs$' /proc/filesystems; then
    echo "udev requires tmpfs support, not started."
    exit 0
fi

if [ ! -e /proc/sys/kernel/hotplug ]; then
    echo "udev requires hotplug support, not started."
    exit 0
fi

if [ "$udev_root" != "/dev/" ]; then
    echo "udev_root != /dev/, not started. Please check /etc/udev/udev.conf."
    exit 0
fi

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

# we need to unmount /dev/pts/ and remount it later over the tmpfs
unmount_devpts() {
  if mountpoint -q /dev/pts/; then
    umount -l /dev/pts/
  fi

  if mountpoint -q /dev/shm/; then
    umount -l /dev/shm/
  fi
}

# mount a tmpfs over /dev, if somebody did not already do it
mount_tmpfs() {
  if grep -E -q "^[^[:space:]]+ /dev tmpfs" /proc/mounts; then
    return 0
  fi

  # /.dev is used by /sbin/MAKEDEV to access the real /dev directory.
  # if you don't like it just remove it.
  [ -d /.dev ] && mount --bind /dev /.dev

  echo -n "Mounting a tmpfs over /dev..."
  mount -n -o fscontext=system_u:object_r:device_t,size=$tmpfs_size,mode=0755 -t tmpfs none /dev
  echo "done."
}

# I hate this hack.  -- Md
make_extra_nodes () {
  grep '^[^#]' /etc/udev/links.conf | \
  while read type name arg1; do
    [ "$type" -a "$name" -a ! -e "/dev/$name" -a ! -L "/dev/$name" ] ||continue
    case "$type" in
    L)
      ln -s $arg1 /dev/$name
      ;;
    D)
      mkdir -p /dev/$name
      ;;
    M)
      mknod --mode=600 /dev/$name $arg1
      ;;
    *)
      echo "unparseable line ($type $name $arg1)"
      ;;
    esac
  done
}

# When modifying this script, do not forget that between the time that
# the new /dev has been mounted and udevstart has been run there will be
# no /dev/null. This also means that you cannot use the "&" shell command.

##############################################################################
case "$1" in
  start)
    unmount_devpts
    mount_tmpfs
    ACTION=add
    echo -n "Creating initial device nodes..."
    $UDEVSTART
    make_extra_nodes
    # all extra nodes created we must do the security contexts on them, oh dear.
    if [ -x /sbin/restoredevicefiles ]; then
      /sbin/restoredevicefiles
    fi

    echo "done."
    ;;
  remove)
    # I'm not sure this is useful
    ACTION=remove
    echo -n "Removing device nodes..."
    old_synthesize_events
    echo "done."
    ;;
  stop)
    start-stop-daemon --stop --exec /sbin/udevd --oknodo --quiet
    unmount_devpts
    echo -n "Unmounting /dev..."
    # unmounting with -l should never fail
    if umount -l /dev; then
      echo "done."
      umount -l /.dev || true
      /etc/init.d/mountvirtfs start
    else
      echo "failed."
    fi
    ;;
  restart|force-reload)
    echo -n "Recreating device nodes..."
    ACTION=add
    $UDEVSTART
    make_extra_nodes
    echo "done."
    ;;
  *)
    echo "Usage: /etc/init.d/udev {start|stop|restart|force-reload}"
    exit 1
    ;;
esac

exit 0