#!/bin/sh -e

# Hack to get the dpkg process' PID despite using debconf
if [ -z "$PARENT_PID" ]; then
  export PARENT_PID=$PPID
fi

. /usr/share/debconf/confmodule

supported_kernel() {
  local version
  if [ "$1" ]; then
    version="$1"
  else
    version="$(uname -r)"
  fi

  case "$version" in
    2.[012345].*|2.6.[0-9]|2.6.[0-9][!0-9]*) return 1 ;;
    2.6.1[0-4]|2.6.1[0-4][!0-9]*) return 1 ;;
  esac
  return 0
}

check_installed_kernel() {
  for ver in /lib/modules/*; do
    ver=${ver##*/}
    [ "$ver" = '*' ] && return 1
    supported_kernel "$ver" && return 0
  done
  return 1
}

check_installing_kernel() {
  for pkg in $(ps hp $PARENT_PID -o args); do
    ver=$(echo $pkg | sed -nr "s/^.*linux-image-(2\.6\.[0-9]+)-[0-9]+-.*_.*_.*\.deb$/\1/p")
    [ "$ver" ] && supported_kernel "$ver" && return 0
  done
  return 1
}

check_kernel_version() {
  # skip the check if udev is not already active
  [ -d /dev/.udev/ ] || return 0

  supported_kernel && return

  if [ -e /etc/udev/kernel-upgrade ]; then
    echo "This version of udev requires a kernel >= 2.6.15, but the upgrade was forced."
    # restart udevd which was killed by the old prerm
    /sbin/udevd -d || true
    return 0
  fi
  
  db_title Upgrading udev

  if check_installed_kernel || check_installing_kernel; then
    db_fset udev/reboot_needed seen false
    db_input high udev/reboot_needed || true
    db_go
    db_stop
    echo "A reboot is needed, but proceeding with the upgrade."
    touch /etc/udev/kernel-upgrade
    # restart udevd which was killed by the old prerm
    /sbin/udevd -d || true
    return 0
  fi

  db_fset udev/new_kernel_needed seen false
  db_reset udev/new_kernel_needed
  db_input critical udev/new_kernel_needed || true
  db_go
  db_get udev/new_kernel_needed
  if [ "$RET" = true ]; then
    db_stop
    echo "This version of udev requires a kernel >= 2.6.15, but the upgrade was forced."
    touch /etc/udev/kernel-upgrade
    # restart udevd which was killed by the old prerm
    /sbin/udevd -d || true
    return 0
  fi
  db_stop
  exit 1
}

have_rules_link() {
  local arg="$1"

  local link
  for link in /etc/udev/rules.d/*.rules; do
    test -L $link || continue
    local target=$(readlink --quiet --canonicalize $link)
    if [ "$target" = "/etc/udev/$arg" ]; then
      echo "$link"
      return
    fi
  done
}

# create a new link in rules.d/ if it does not already exist
add_rules_link() {
  local name=$1
  local target=${name#*_}

  [ -e /etc/udev/rules.d/$name -o -L /etc/udev/rules.d/$name ] || \
    ln -s ../$target /etc/udev/rules.d/$name
}

rm_conffile() {
  local name="$1"
  local oldmd5="$2"

  [ -e "$name" ] || return 0

  local md5="$(md5sum $name | sed -e 's/ .*//')"
  if [ "$md5" = "$oldmd5" ]; then
    rm -f $name
  fi
}

upgrade_generated_rules_098() {
  # suppress logging because the old udevd which does not understand the
  # new syntax is still running and will complain about it
  udevcontrol log_priority= 2> /dev/null || true

  local D=/etc/udev/rules.d/
  if [ -f $D/z25_persistent-cd.rules ]; then
    sed -e 's/BUS==/SUBSYSTEMS==/g' -e 's/ID==/KERNELS==/' \
	< $D/z25_persistent-cd.rules > $D/z25_persistent-cd.rules.tmp
    mv $D/z25_persistent-cd.rules.tmp $D/z25_persistent-cd.rules
  fi
  if [ -f $D/z25_persistent-net.rules ]; then
    sed -e 's/DRIVER==/DRIVERS==/' \
	< $D/z25_persistent-net.rules > $D/z25_persistent-net.rules.tmp
    mv $D/z25_persistent-net.rules.tmp $D/z25_persistent-net.rules
  fi
}

check_version() {
  [ "$2" ] || return 0

  # This needs to be checked first to allow aborting before changing anything
  if dpkg --compare-versions $2 lt 0.092-1; then
    check_kernel_version
  fi

  dpkg --compare-versions $2 lt 0.098-1 || return 0
  upgrade_generated_rules_098

  dpkg --compare-versions $2 lt 0.097-1 || return 0
  CD_RULES=$(have_rules_link cd-aliases.rules)
  if [ "$CD_RULES" ]; then
    rm -f $CD_RULES
    add_rules_link z75_cd-aliases-generator.rules
  fi
  rm -f /etc/udev/cd-aliases.rules

  HOTPLUGD_RULES=$(have_rules_link hotplugd.rules)
  if [ "$HOTPLUGD_RULES" ]; then
    rm -f $HOTPLUGD_RULES
  fi

  dpkg --compare-versions $2 lt 0.090-1 || return 0
  if [ "$(dpkg --print-architecture)" != s390 ]; then
    add_rules_link z45_persistent-net-generator.rules
    : > /etc/udev/run-write_net_rules
  fi

  dpkg --compare-versions $2 lt 0.088-1 || return 0
  add_rules_link z20_persistent-input.rules

  dpkg --compare-versions $2 lt 0.084-4 || return 0
  # delete an example conffile which was installed by some old versions
  rm_conffile /etc/scsi_id.config a1e107dda17adaa2063b139ef50a428c

  dpkg --compare-versions $2 lt 0.080-1 || return 0
  [ -e /etc/rcS.d/S04udev ] && mv /etc/rcS.d/S04udev /etc/rcS.d/S03udev

  dpkg --compare-versions $2 lt 0.076-1 || return 0
  if [ -d /dev/.udevdb/ -a ! -d /dev/.udev/db/ ]; then
    mkdir -p /dev/.udev/
    mv /dev/.udevdb /dev/.udev/db
    mkdir -p /dev/.udevdb/
  fi

  dpkg --compare-versions $2 lt 0.072-1 || return 0
  rm -f /etc/udev/scripts/scsi-devfs.sh /etc/udev/scripts/ide-devfs.sh \
	/etc/udev/scripts/raid-devfs.sh /etc/udev/scripts/inputdev.sh

  dpkg --compare-versions $2 lt 0.070-3 || return 0
  add_rules_link z55_hotplug.rules

  dpkg --compare-versions $2 lt 0.070-1 || return 0
  CD_RULES=$(have_rules_link simple-cd-aliases.rules)
  if [ "$CD_RULES" ]; then
    rm -f $CD_RULES
  fi
  rm -f /etc/udev/scripts/dvb.sh /etc/udev/scripts/ide-model.sh \
	/etc/udev/cdsymlinks.conf /etc/udev/scripts/cdsymlinks.sh \
	/etc/udev/simple-cd-aliases.rules

  dpkg --compare-versions $2 lt 0.066-1 || return 0
  add_rules_link z20_persistent.rules

  dpkg --compare-versions $2 lt 0.060-1 || return 0
  add_rules_link z50_run.rules
  rm -f /etc/dev.d/net/hotplug.dev /etc/udev/udev.permissions

  if dpkg --compare-versions $2 lt 0.056-3; then
    echo 'Upgrading from packages older than 0.056-3 is not supported.'
    echo 'Please purge udev before installing this package.'
    exit 1
  fi
}

disable_hotplug() {
    # ugly, but what else could I do?
    if [ -e /etc/hotplug.d/default/default.hotplug ]; then
	rm -f /etc/hotplug.d/default/default.hotplug
    fi
    if [ -e /etc/init.d/hotplug ]; then
	echo
	echo "**************************************************************"
	echo "* Please purge the hotplug package!"
        echo "* (/etc/init.d/hotplug has been found on this system)"
	echo "**************************************************************"
	echo
    fi
}

case "$1" in
    install)
    # $2 is non-empty when installing from the "config-files" state
    check_version "$@"
    disable_hotplug
    ;;

    upgrade|abort-upgrade)
    check_version "$@"
    disable_hotplug
    ;;

    *)
    echo "$0 called with unknown argument '$1'" >&2
    exit 1
    ;;
esac

#DEBHELPER#