#! /bin/sh

# /etc/logbackup.d/sysklogd
#   logbackup fragment for system logs
#
#   This script allows rotation and backup of all system logs, on systems
#   where /var/log is mounted as tmpfs.
#
#   It is called by /etc/init.d/logbackup:
#    - at system startup to retreive backed-up logs to /var/log
#    - on a daily basis to rotate and back-up the logs on the hard-drive
#    - at system halt or reboot to back-up the logs before the
#      tmpfs is unmounted
#
#   This script handles all sysklogd-managed logs and login-related logs
#   (wtmp, btmp, and lastlog).
#
#   This script was written by François Févotte, but is largely adapted
#   from Debian's default /etc/cron.daily/sysklogd file, which was
#   originally written by Martin Schulze <joey@debian.org>.

NAME="syslog"
DIR_LOG="/var/log"
DIR_BAK="/var/log.real"

LOGS=`syslogd-listfiles --all`
LOGS="$LOGS
  $DIR_LOG/wtmp
  $DIR_LOG/btmp
"

[ -r /etc/logbackup.conf ] && . /etc/logbackup.conf
if [ "$LOGBACKUP_INCLUDED" != "" ]; then
    echo $LOGS $DIR_LOG/lastlog | xargs -n 1 echo >> $LOGBACKUP_INCLUDED
fi

test -x /usr/sbin/syslogd-listfiles || exit 0
test -x /sbin/syslogd || exit 0
test -f /usr/share/sysklogd/dummy || exit 0

set -e

do_retrieve()
{
    logger -i -t "logbackup" "($NAME) Retrieve backed-up logs"
    cd $DIR_LOG
    for LOG in $LOGS; do
	LOGNAME=`basename $LOG`
	[ -r $DIR_BAK/$LOGNAME.0 ] && cp -a $DIR_BAK/$LOGNAME.* $DIR_LOG
    done

    # If there exists /var/log/lastlog, this is the newest version
    if [ ! -r $DIR_LOG/lastlog ]; then
        # retrieve the backed-up version if possible
	if [ -r $DIR_BAK/lastlog ]; then
	    cp -a $DIR_BAK/lastlog $DIR_LOG
	fi
    fi

    # Ensure login-related files exist and have the right permissions
    # and ownership
    touch $DIR_LOG/lastlog $DIR_LOG/wtmp $DIR_LOG/btmp
    chmod 0644 $DIR_LOG/lastlog $DIR_LOG/wtmp
    chmod 0640 $DIR_LOG/btmp
    chown root.utmp $DIR_LOG/lastlog $DIR_LOG/wtmp $DIR_LOG/btmp

    return 0
}

do_backup()
{
    logger -i -t "logbackup" "($NAME) Back-up logs"
    cd $DIR_LOG
    for LOG in $LOGS; do
	LOGNAME=`basename $LOG`
	[ -r $DIR_LOG/$LOGNAME.0 ] && cp -a $DIR_LOG/$LOGNAME.* $DIR_BAK
    done

    [ -r $DIR_LOG/lastlog ] && cp -a $DIR_LOG/lastlog $DIR_BAK

    return 0
}

do_rotate()
{
    logger -i -t "logbackup" "($NAME) Rotate logs"
    cd $DIR_LOG
    for LOG in $LOGS; do
	if [ -s $LOG ]; then
	    savelog -g adm -m 640 -u root -c 7 $LOG >/dev/null
	fi
    done

    for LOG in `syslogd-listfiles --auth`; do
	if [ -f $LOG ]; then
	    chown root:adm $LOG
	    chmod o-rwx $LOG
	fi
    done

    /usr/sbin/logrotate --force /etc/logrotate.d/login

    /etc/init.d/sysklogd reload-or-restart > /dev/null
    return 0
}

case "$1" in
    retrieve)
        do_retrieve
        ;;
    backup)
        do_retrieve
	do_rotate
        do_backup
	;;
    *)
	echo "Usage: $SCRIPTNAME {retrieve|backup}" >&2
	exit 3
	;;
esac