#! /bin/bash
# Copyright (c) 1996, 1997, 1998 S.u.S.E. GmbH
# Copyright (c) 1998, 1999, 2000, 2001 SuSE GmbH
# Copyright (c) 2002, 2003 SuSE Linux AG
# Copyright (c) 2004-2014 SUSE LINUX Products GmbH, Nuernberg, Germany.
#
# 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, see <http://www.gnu.org/licenses/>.
#
# Author: Rolf Haberrecker <rolf@suse.de>, 1997-1999
#         Peter Poeml <poeml@suse.de>, 2000-2006
#         Marius Tomaschewski <mt@suse.de>, 2006-2010
#
# /usr/lib/dhcp/dhcpd helper script, fromer /etc/init.d/dhcpd init script.
#
###
test -s /etc/sysconfig/dhcpd && . /etc/sysconfig/dhcpd

SUPPORTS_CHROOT="yes"
SUPPORTS_RUN_AS="yes"
SUPPORTS_HUP="no"

# note: $DAEMON_PIDFILE is a symlink to the
#       $DAEMON_STATE$DAEMON_PIDFILE (also
#       while DHCPD_RUN_CHROOTED=no) now,
#       as DHCPD_RUN_AS is not allowed to
#       create pid files in /run.

DHCPv_OPT=$1 ; shift
case $DHCPv_OPT in
-4)
	DAEMON='ISC DHCPv4 Server'
	DAEMON_BIN=/usr/sbin/dhcpd
	DAEMON_CONF=/etc/dhcpd.conf
	DAEMON_STATE=/var/lib/dhcp
	DAEMON_LEASES=dhcpd.leases
	DAEMON_PIDFILE=/run/dhcpd.pid
	STARTPROC_LOGFILE=/var/log/rc.dhcpd.log
	LDAP_CONF=/etc/openldap/ldap.conf

	test "$DHCPD_RUN_CHROOTED" = "yes" && \
	CHROOT_PREFIX="$DAEMON_STATE" || CHROOT_PREFIX=''

	DHCPD_CONF_INCLUDE_FILES=${DHCPD_CONF_INCLUDE_FILES:-/etc/dhcpd.d}
;;
-6)
	DAEMON='ISC DHCPv6 Server'
	DAEMON_BIN=/usr/sbin/dhcpd
	DAEMON_CONF=/etc/dhcpd6.conf
	DAEMON_STATE=/var/lib/dhcp6
	DAEMON_LEASES=dhcpd6.leases
	DAEMON_PIDFILE=/run/dhcpd6.pid
	STARTPROC_LOGFILE=/var/log/rc.dhcpd6.log
	LDAP_CONF=""

	test "$DHCPD6_RUN_CHROOTED" = "yes" && \
	CHROOT_PREFIX="$DAEMON_STATE" || CHROOT_PREFIX=''

	DHCPD_RUN_AS=$DHCPD6_RUN_AS
	DHCPD_INTERFACE=$DHCPD6_INTERFACE
	DHCPD_OTHER_ARGS=$DHCPD6_OTHER_ARGS
	DHCPD_CONF_INCLUDE_FILES=${DHCPD6_CONF_INCLUDE_FILES:-/etc/dhcpd6.d}
;;
*)
	echo >&2 "Usage: $0 <-4|-6> <action>"
	exit 2
;;
esac

# Return values acc. to LSB for all commands but status:
# 0 - success
# 1 - generic or unspecified error
# 2 - invalid or excess argument(s)
# 3 - unimplemented feature (e.g. "reload")
# 4 - insufficient privilege
# 5 - program is not installed
# 6 - program is not configured
# 7 - program is not running
# 
# Note that starting an already running service, stopping
# or restarting a not-running service as well as the restart
# with force-reload (in case signalling is not supported) are
# considered a success.

if ! [ -x "$DAEMON_BIN" ]; then
	case $1 in
	stop)   ;;
	*)	echo -n >&2 "\"$DAEMON_BIN\" is not an executable file. Exiting."
		case $1 in
		status) exit 4 ;;
		*)	exit 5 ;;
		esac
	;;
	esac
	exit
fi
if ! [ -r "$DAEMON_CONF" ] ; then
	case $1 in
	stop|status)
		if test ! -s /etc/sysconfig/dhcpd ; then
			test -e $DAEMON_STATE/$DAEMON_PIDFILE && \
			CHROOT_PREFIX="$DAEMON_STATE" || CHROOT_PREFIX=''
		fi
	;;
	*)
		echo -n >&2 "\"$DAEMON_CONF\" config file missed. Exiting."
		exit 6
	;;
	esac
fi

# remove empty pid files to avoid disturbing warnings by checkproc/killproc
# (these can occur if dhcpd does not start correctly)
test -e $DAEMON_PIDFILE && ! test -s $DAEMON_PIDFILE && rm $DAEMON_PIDFILE
test -e $DAEMON_STATE/$DAEMON_PIDFILE && ! test -s $DAEMON_STATE/$DAEMON_PIDFILE && rm $DAEMON_STATE/$DAEMON_PIDFILE

case "$1" in
    start)
	echo -n "Starting $DAEMON "

        ## If there is no conf file, skip starting of dhcpd
        ## and return with "program not configured"
	if ! [ -f $DAEMON_CONF ]; then
		echo -n "... no configuration file found";
		# service is not configured
		exit 6;
	fi

        ## If the interfaces are not set, skip starting of dhcpd
        ## and return with "program not configured"
	if [ -z "$DHCPD_INTERFACE" ]; then
		var="DHCPD_INTERFACE"
		case $DHCPv_OPT in -6) var=DHCPD6_INTERFACE ;; esac
		echo -n "... set $var in /etc/sysconfig/dhcpd"
		# service is not configured
		exit 6;
	fi
	
	if [ "$DHCPD_INTERFACE" = "ANY" ]; then
		DHCPD_INTERFACE=""
	fi

	jail=${CHROOT_PREFIX:-${DAEMON_STATE}}; leases=$DAEMON_LEASES
	if ! [ -e $jail/db/$leases ]; then
		# until 9.0, the lease file was in /var/lib/dhcp and part of the package
		if test -e $jail/$leases -a '!' -L $jail/$leases; then
			# this is the case where the %post script runs _before_ the old package is 
			# removed (i.e., dhcpd.leases has not renamed to .rpmsave yet)
			mv $jail/$leases $jail/db/$leases && \
			ln -s db/$leases $jail/
		elif test -e $jail/$leases.rpmsave; then
			# this is what's left when the package is already gone.
			mv $jail/$leases.rpmsave $jail/db/$leases && \
			ln -s db/$leases $jail/
		else
			# fresh installation:
			# a lease file must be present. the server won't start without
			touch $jail/db/$leases
		fi
	fi

	if test "$DHCPD_RUN_CHROOTED" = "yes" ; then 
		## copy the conf file to the chroot jail (dhcpd has to be restarted anyway, 
		## when it has changed) and change path to leases file
		for i in $DAEMON_CONF $DHCPD_CONF_INCLUDE_FILES $LDAP_CONF /etc /dev; do
			if test -d "${i}" ; then
				test -d "$CHROOT_PREFIX/${i}" || \
				mkdir -p "$CHROOT_PREFIX/${i}"
			elif test -e "${i}" ; then
				test -d "$CHROOT_PREFIX/${i%/*}" || \
				mkdir -p "$CHROOT_PREFIX/${i%/*}"
			fi
		done
		rm -f $CHROOT_PREFIX/dev/urandom
		for i in $DAEMON_CONF $DHCPD_CONF_INCLUDE_FILES $LDAP_CONF /etc/{gai.conf,nsswitch.conf,resolv.conf,host.conf,hosts,localtime,bindresvport.blacklist} /dev/urandom; do
			if ! test -e "$i"; then continue; fi # neither of them is absolutely necessary
			cp -aL "$i" "${CHROOT_PREFIX}/${i%/*}/" &>/dev/null \
				|| { echo "...$0:$LINENO: could not copy $i to chroot jail"; exit 6; }
		done
		libdir=@LIBDIR@
		if test -x /usr/bin/ldd ; then
			get_ldd_deps()
			{
				ldd_wl="\/${libdir}\/lib"
				ldd_bl="\/${libdir}\/libc\."
				/usr/bin/ldd "$1" | \
				while read -sr a b c d ; do
					[ -n "$c" ] || continue
					[[ $c =~ $ldd_wl ]] || continue
					[[ $c =~ $ldd_bl ]] && continue
					echo $c
				done
			}
		else
			get_ldd_deps() { :; }
		fi
		cplibs=`for i in /$libdir/{libresolv.so.*,libnss_*.so.*} \
			         /$libdir/{libpthread.so.0,libdl.so.2,libgcc_s.so.*} ;
			do
				if [ -s "$i" ] ; then
					echo "$i"
					get_ldd_deps "$i"
				fi
			done | sort -u`
		for i in $cplibs ; do
			if [ -s "$i" ]; then
				cp -pL "$i" "${CHROOT_PREFIX}/$libdir/" \
				|| { echo "...$0:$LINENO: could not copy $i to chroot jail"; exit 6; }
			fi
		done

		# mount /proc into the chroot; the server fails if unable to read /proc/net/{dev,if_inet6}
		mkdir -p ${CHROOT_PREFIX}/proc
		mount -t proc -o ro proc ${CHROOT_PREFIX}/proc 2>/dev/null

		DHCPD_ARGS="-chroot $CHROOT_PREFIX -lf /db/$DAEMON_LEASES"

		## If there is a pid file containing a pid, the machine might have crashed. pid files in
		## /run are always cleaned up at boot time, but this is not the case for the pid file in 
		## the chroot jail. Therefore, and old pid file may exist. This is only a problem if it 
		## incidentally contains the pid of a running process. If this process is not a 'dhcpd', 
		## we remove the pid. (dhcpd itself only checks whether the pid is alive or not.)
		if test -s $DAEMON_STATE/$DAEMON_PIDFILE; then
			p=$(<$DAEMON_STATE/$DAEMON_PIDFILE)
			if test -n "$p" && grep -qsE "^${DAEMON_BIN}" "/proc/$p/cmdline" ; then
				echo -n '(already running) '
			else
				rm -f $DAEMON_STATE/$DAEMON_PIDFILE
			fi
		fi
		PID_FILE_ARG="$DAEMON_PIDFILE"
	else
		DHCPD_ARGS="-lf ${DAEMON_STATE}/db/$DAEMON_LEASES"
		PID_FILE_ARG="$DAEMON_STATE$DAEMON_PIDFILE"
	fi

	if [ -n "$DHCPD_RUN_AS" ]; then
		DHCPD_RUN_AS_GROUP="$(getent group $(getent passwd $DHCPD_RUN_AS | cut -d: -f4) | cut -d: -f1)"
		DHCPD_ARGS="$DHCPD_ARGS -user $DHCPD_RUN_AS -group $DHCPD_RUN_AS_GROUP"

		chown	"${DHCPD_RUN_AS}:${DHCPD_RUN_AS_GROUP}" \
			"$DAEMON_STATE/${DAEMON_PIDFILE%/*}"
	fi


	## check syntax with -t (output to log file) and start only when the syntax is okay
	rm -f $STARTPROC_LOGFILE # start log
	error=0
	if ! $DAEMON_BIN $DHCPv_OPT -t -cf $CHROOT_PREFIX/$DAEMON_CONF -pf $PID_FILE_ARG > $STARTPROC_LOGFILE 2>&1 ; then
		error=1
	else
		## Start daemon. If this fails the return value is set appropriate.
		## The init script should return 0, even if service is already running, 
		## to match the LSB spec.

		test "$2" = "-v" && echo -en \
			"\nexecuting '$DAEMON_BIN $DHCPv_OPT -cf $DAEMON_CONF -pf $PID_FILE_ARG $DHCPD_ARGS $DHCPD_OTHER_ARGS $DHCPD_INTERFACE'"

		$DAEMON_BIN $DHCPv_OPT -cf $DAEMON_CONF -pf $PID_FILE_ARG $DHCPD_ARGS $DHCPD_OTHER_ARGS $DHCPD_INTERFACE &> $STARTPROC_LOGFILE
		ret=$?
	fi	

	if [ $error -gt 0 -o ${ret:-0} -gt 0 ]; then
		## be verbose
		echo ""
		echo -n "  please see $STARTPROC_LOGFILE for details "
		## set status to failed
		exit 1
	else
		ln -sf "$DAEMON_STATE$DAEMON_PIDFILE" "$DAEMON_PIDFILE"
		[ "$DHCPD_RUN_CHROOTED" = "yes" ] && echo -n "[chroot]" || :
	fi
	;;
    stop)
	echo -n "Shutting down $DAEMON "

	# Catch the case where daemon is running without chroot,
	# but sysconfig/dhcp has been changed to use chroot (and
	# another way around).
	# In this case is there is no $chroot/$pidfile, but there
	# should be a /pidfile that we use instead.
	# We can not kill without pid file or dhcp4 kills dhcp6.
	PID_FILE="$DAEMON_STATE$DAEMON_PIDFILE"
	if test "$DHCPD_RUN_CHROOTED" = "yes" ; then
		if test ! -s "$DAEMON_STATE$DAEMON_PIDFILE" -a \
		          -s "$DAEMON_PIDFILE" ; then
			PID_FILE="$DAEMON_PIDFILE"
		fi
	else
		if test ! -s "$DAEMON_PIDFILE" -a \
		          -s "$DAEMON_STATE$DAEMON_PIDFILE" ; then
			PID_FILE="$DAEMON_STATE$DAEMON_PIDFILE"
		fi
	fi

	## Stop daemon with killproc(8) and if this fails
	## set echo the echo return value.
	killproc -p "$PID_FILE" $DAEMON_BIN
	ret=$?

	# umount proc and remove libraries from the chroot jail,
	# so they are not left over if the server is deinstalled
	if [ "$DHCPD_RUN_CHROOTED" = yes -a -n "$CHROOT_PREFIX" ]; then
		umount ${CHROOT_PREFIX}/proc 2>/dev/null
		rm -f $CHROOT_PREFIX/lib*/*
	fi

	exit $ret
	;;
    try-restart)
	## Do a restart only if the service was active before.
	## Note: try-restart is now part of LSB (as of 1.9).
	## RH has a similar command named condrestart.
	$0 $DHCPv_OPT status
	if test $? = 0; then
		$0 $DHCPv_OPT restart
	fi
	;;
    restart)
	## Check syntax and when it is OK, stop the service
	## and regardless of whether it was running or not,
	## start it again.
	if ! $0 $DHCPv_OPT check-syntax &>/dev/null ; then
		echo -n "Syntax check reports errors, see log messages"
		exit 1
	else
		$0 $DHCPv_OPT stop
		sleep 3
		$0 $DHCPv_OPT start
	fi
	;;
    force-reload)
	## Signal the daemon to reload its config. Most daemons
	## do this on signal 1 (SIGHUP).
	## If it does not support it, restart.

	if [ "$SUPPORTS_HUP" = "yes" ]; then 
		echo -n "Reload service $DAEMON"
		killproc -p $DAEMON_STATE/$DAEMON_PIDFILE -HUP $DAEMON_BIN
		#touch $DAEMON_STATE/$DAEMON_PIDFILE
	elif ! $0 $DHCPv_OPT check-syntax &>/dev/null ; then
		echo -n "Syntax check reports errors, see log messages"
		exit 1
	else
		$0 $DHCPv_OPT stop  &&  sleep 3  &&  $0 $DHCPv_OPT start
	fi
	;;
    reload)
	## Like force-reload, but if daemon does not support
	## signalling, do nothing (!)

	echo -n "Reload service $DAEMON"
	if [ "$SUPPORTS_HUP" = "yes" ]; then
		# If it supports signalling:
		killproc -p $DAEMON_STATE/$DAEMON_PIDFILE -HUP $DAEMON_BIN
		#touch $DAEMON_STATE/$DAEMON_PIDFILE
	else
		## Otherwise if it does not support reload:
		exit 3
	fi
	;;
    status)
	echo -n "Checking for $DAEMON: "
	## Check status with checkproc(8), if process is running
	## checkproc will return with exit status 0.

	# Status has a slightly different for the status command:
	# 0 - service running
	# 1 - service dead, but /run/ pid file exists
	# 2 - service dead, but /var/lock/ lock file exists
	# 3 - service not running

	# NOTE: checkproc returns LSB compliant status values.
	checkproc -p $DAEMON_STATE/$DAEMON_PIDFILE $DAEMON_BIN
	;;
    probe)
	## Optional: Probe for the necessity of a reload,
	## give out the argument which is required for a reload.

	rc=0
	for i in /etc/sysconfig/dhcpd $DAEMON_CONF $DHCPD_CONF_INCLUDE_FILES; do
		test $i -nt $DAEMON_STATE/$DAEMON_PIDFILE && rc=1
	done
	test $rc = 1 && echo restart
	;;
    check-syntax|syntax-check)
	echo -n "Checking syntax of $DAEMON_CONF: "

	## this nice bit is from Edwin Groothuis:
	## check syntax (quiet)
	$DAEMON_BIN $DHCPv_OPT -q -t -cf $DAEMON_CONF
	if [ $? -ne 0 ]; then 
		echo ""
		## check syntax (verbose)
		$DAEMON_BIN $DHCPv_OPT -t -cf $DAEMON_CONF
		echo -ne '\nConfig is NOT okay'
		exit 1
	fi
	;;
    check-lease|check-lease-file)
	echo -n "Checking lease file $DAEMON_LEASES: "

	if [ -s ${DAEMON_STATE}/db/$DAEMON_LEASES ] ; then
		## check leases file (quiet)
		$DAEMON_BIN $DHCPv_OPT -q -T -cf /dev/null -lf ${DAEMON_STATE}/db/$DAEMON_LEASES
		if [ $? -ne 0 ]; then
			echo ""
			## check leases file (verbose)
			$DAEMON_BIN $DHCPv_OPT -T -cf $DAEMON_CONF -lf ${DAEMON_STATE}/db/$DAEMON_LEASES
			echo -ne '\nLease file is NOT okay'
			exit 1
		fi
	fi
	;;
    *)
	SCRIPT="${SCRIPT:-${0##*/} $DHCPv_OPT}"
	echo "Usage: $SCRIPT {start|stop|status|try-restart|restart|force-reload|reload|probe|check-syntax} [-v]"
	exit 1
esac