#!/bin/sh

# This program 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 program 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

# This script converts all db files of a cyrus installation from their
# existing format to the format required by the current installation.
# The format of current db files is determined using the 'file' command
# with a magic file added for skiplist db, the new format is read from
# a config file usually in /usr/share/cyrus-imapd/rpm/db.cfg, which is
# created while compiling. After converting, the db.cfg file is
# copied to a cache file usually at /var/lib/imap/rpm/db.cfg.cache to
# allow bypassing this converting script if both files are identical.
# While this is a bit less secure, it may be useful on big server where
# db converting is done automatically.
#
# This script can safely be run as root, it will reexec itself as user
# cyrus if needed.
#
# author: Simon Matter, Invoca Systems <simon.matter@invoca.ch>

# changelog
# v1.0.1, Oct 22 2002 Simon Matter <simon.matter@invoca.ch>
# - added two-step conversion method
#
# v1.0.2, Jan 10 2003 Simon Matter <simon.matter@invoca.ch>
# - fixed a bug where cvt_cyrusdb was called to convert empty or
#   nonexistent files
#
# v1.0.3, Mar 14 2003 Simon Matter <simon.matter@invoca.ch>
# - fixed a problem with new versions of the file command
#
# v1.0.4
# - added GPL license
#
# v1.0.5, May 02 2003 Simon Matter <simon.matter@invoca.ch>
# - modified exec path
#
# v1.0.6, Jul 18 2003 Simon Matter <simon.matter@invoca.ch>
# - changed db3 to berkeley
# - added new db backends for 2.2
#
# v1.0.7, Jan 23 2004 Simon Matter <simon.matter@invoca.ch>
# - included some modifications from Luca Olivetti <luca@olivetti.cjb.net>
# - added masssievec functionality
#
# v1.0.8, Jan 28 2004 Simon Matter <simon.matter@invoca.ch>
# - convert sieve scripts to UTF-8 before calling masssievec
#
# v1.0.9, Jan 29 2004 Simon Matter <simon.matter@invoca.ch>
# - convert sieve scripts to UTF-8 only if sievec failed before
#
# v1.0.10, Feb 24 2004 Simon Matter <simon.matter@invoca.ch>
# - change su within init script to get input from
#   /dev/null, this prevents hang when running in SELinux
#
# v1.0.11, Mar 02 2004 Simon Matter <simon.matter@invoca.ch>
# - fixed SELinux fix
#
# v1.0.12, Dec 16 2004 Simon Matter <simon.matter@invoca.ch>
# - use runuser instead of su if available

if [ -n "$(/sbin/pidof cyrus-master)" ]; then
  echo "ERROR: cyrus-master is running, unable to convert mailboxes!"
  exit 1
fi

if [ ! -f /etc/imapd.conf ]; then
  echo "ERROR: configuration file not found."
  exit 1
fi

# fallback to su if runuser not available
if [ -x /sbin/runuser ]; then
  RUNUSER=runuser
else
  RUNUSER=su
fi

# force cyrus user for security reasons
if [ ! $(whoami) = "cyrus" ]; then
  exec $RUNUSER - cyrus -c "cd $PWD < /dev/null ; $0"
fi

# files get mode 0600
umask 166

# get_config [config default]
# extracts config option from config file
get_config() {
  if config=$(grep "^$1" /etc/imapd.conf); then
    echo $config | cut -d: -f2 | sed -e 's/^ *//' -e 's/-nosync//' -e 's/ *$//'
  else
    echo $2
  fi
}

# where to find files and directories
system_magic=$(file --version | awk '/magic file/ {print $4}')
cyrus_magic=/usr/share/cyrus-imapd/rpm/magic
cvt_cyrusdb=/usr/lib/cyrus-imapd/cvt_cyrusdb
sievec=/usr/lib/cyrus-imapd/sievec
imap_prefix=$(get_config configdirectory /var/lib/imap)
sieve_dir=$(get_config sievedir /var/lib/imap/sieve)
db_cfg=/usr/share/cyrus-imapd/rpm/db.cfg
db_current=${imap_prefix}/rpm/db.cfg.current
db_cache=${imap_prefix}/rpm/db.cfg.cache

# source default db backend config
. $db_cfg

# get configured db backend config
CONFIG_DB_DUPLICATE=$(get_config duplicate_db $CONFIG_DB_DUPLICATE)
CONFIG_DB_MBOX=$(get_config mboxlist_db $CONFIG_DB_MBOX)
CONFIG_DB_SEEN=$(get_config seenstate_db $CONFIG_DB_SEEN)
CONFIG_DB_SUBS=$(get_config subscription_db $CONFIG_DB_SUBS)
CONFIG_DB_TLS=$(get_config tlscache_db $CONFIG_DB_TLS)
CONFIG_DB_ANNOTATION=$(get_config annotation_db $CONFIG_DB_ANNOTATION)

# remember current db backend config
{
echo "CONFIG_DB_DUPLICATE=$CONFIG_DB_DUPLICATE"
echo "CONFIG_DB_MBOX=$CONFIG_DB_MBOX"
echo "CONFIG_DB_SEEN=$CONFIG_DB_SEEN"
echo "CONFIG_DB_SUBS=$CONFIG_DB_SUBS"
echo "CONFIG_DB_TLS=$CONFIG_DB_TLS"
echo "CONFIG_DB_ANNOTATION=$CONFIG_DB_ANNOTATION"
echo "CONFIG_DB_SIEVE=$CONFIG_DB_SIEVE"
} > $db_current

# file_type [file]
file_type() {
  this_type=$(file -b -m "$system_magic:$cyrus_magic" "$1" 2> /dev/null)
  if echo "$this_type" | grep -qi skip > /dev/null 2>&1; then
    echo skiplist
  elif echo "$this_type" | grep -qi text > /dev/null 2>&1; then
    echo flat
  else
    echo berkeley
  fi
}

# cvt_file [file] [db]
cvt_file() {
  target="$1"
  new_db="$2"
  if [ -s "$target" ]; then
    old_db=$(file_type "$target")
    if [ ! "$old_db" = "$new_db" ]; then
      # The two-step conversion is paranoia against the filenames being encoded
      # inside the database or logfiles (berkeley does this, for example).
      rm -f "${target}.flat"
      if [ "$old_db" = "flat" ]; then
        cp -a "$target" "${target}.flat"
      else
        $cvt_cyrusdb "$target" "$old_db" "${target}.flat" flat
      fi
      RETVAL=$?
      ERRVAL=$[ $ERRVAL + $RETVAL ]
      if [ $RETVAL -eq 0 ]; then
        rm -f "$target"
        if [ -s "${target}.flat" ]; then
          if [ "$new_db" = "flat" ]; then
            cp -a "${target}.flat" "$target"
          else
            $cvt_cyrusdb "${target}.flat" flat "$target" "$new_db"
          fi
        fi
        RETVAL=$?
        ERRVAL=$[ $ERRVAL + $RETVAL ]
        if [ $RETVAL -eq 0 ]; then
          rm -f "${target}.flat"
        else
          echo "ERROR: unable to convert ${target}.flat from flat to $new_db"
        fi
      else
        echo "ERROR: unable to convert $target from $old_db to flat"
      fi
    fi
  fi
}

# cvt_to_utf8 [file]
cvt_to_utf8() {
  target="$1"
  if [ -s "$target" ]; then
    if ! $sievec "$target" "${target}.sievec"; then
      iconv --from-code=ISO-8859-1 --to-code=UTF-8 --output="${target}.UTF-8" "$target"
      if [ -s "${target}.UTF-8" ]; then
        # preserve timestamp
        touch --reference="$target" "${target}.UTF-8"
        mv -f "${target}.UTF-8" "$target"
      else
        ERRVAL=$[ $ERRVAL + 1 ]
      fi
    fi
    rm -f "${target}.sievec"
  fi
}

ERRVAL=0

# do we need to convert databases ?
if ! cmp -s $db_current $db_cache; then
  # we treat sieve scripts the same way like db files
  find ${sieve_dir}/ -name "*.script" -type f | while read db_file trash; do
    cvt_to_utf8 "$db_file"
  done
  /usr/lib/cyrus-imapd/masssievec /usr/lib/cyrus-imapd/sievec
  # convert all db files
  cvt_file $imap_prefix/deliver.db           "$CONFIG_DB_DUPLICATE"
  cvt_file $imap_prefix/mailboxes.db         "$CONFIG_DB_MBOX"
  cvt_file $imap_prefix/tls_sessions.db      "$CONFIG_DB_TLS"
  cvt_file $imap_prefix/annotations.db       "$CONFIG_DB_ANNOTATION"
  find ${imap_prefix}/user/ -name "*.seen" -type f | while read db_file trash; do
    cvt_file "$db_file" "$CONFIG_DB_SEEN"
  done
  find ${imap_prefix}/user/ -name "*.sub" -type f | while read db_file trash; do
    cvt_file "$db_file" "$CONFIG_DB_SUBS"
  done
fi

# copy the current config file so we can check whether something has changed
if [ $ERRVAL -eq 0 ]; then
  mv -f $db_current $db_cache
else
  rm -f $db_cache
  rm -f $db_current
fi

exit $ERRVAL