#!/bin/bash

### BEGIN INIT INFO
# Provides:          nfs-kernel-server
# Required-Start:    $remote_fs nfs-common $portmap $time
# Required-Stop:     $remote_fs nfs-common $portmap $time
# Should-Start:      $named
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Kernel NFS server support
# Description:       NFS is a popular protocol for file sharing across
#		     TCP/IP networks. This service provides NFS server
#                    functionality, which is configured via the
#                    /etc/exports file.
### END INIT INFO

# What is this?
DESC="NFS kernel daemon"
PREFIX=/usr

# Exit if required binaries are missing.
[ -x $PREFIX/sbin/rpc.nfsd    ] || exit 0
[ -x $PREFIX/sbin/rpc.mountd  ] || exit 0
[ -x $PREFIX/sbin/exportfs    ] || exit 0

# Read config
DEFAULTFILE=/etc/default/nfs-kernel-server
RPCNFSDPRIORITY=0
NEED_SVCGSSD=no
PROCNFSD_MOUNTPOINT=/proc/fs/nfsd
if [ -f $DEFAULTFILE ]; then
    . $DEFAULTFILE
fi

. /lib/lsb/init-functions

do_modprobe() {
    if [ -x /sbin/modprobe ] && [ -f /proc/modules ]
    then
        modprobe -q "$1" || true
    fi
}

do_mount() {
    if ! grep -E -qs "$1\$" /proc/filesystems
    then
	return 1
    fi
    if ! mountpoint -q "$2"
    then
	mount -t "$1" "$1" "$2"
	return
    fi
    return 0
}

# See how we were called.
case "$1" in
  start)
	export_files="/etc/exports"
	for file in /etc/exports.d/*.exports ; do
		if [ -f "$file" ]; then
			export_files="$export_files $file"
		fi
	done
	# shellcheck disable=SC2086
	if [ -f /etc/exports ] && grep -q '^[[:space:]]*[^#]*/' $export_files
	then
		do_modprobe nfsd

		# See if our running kernel supports the NFS kernel server
		if ! grep -E -qs "[[:space:]]nfsd\$" /proc/filesystems; then
			log_warning_msg "Not starting $DESC: no support in current kernel"
			exit 0
		fi
		
		do_mount nfsd $PROCNFSD_MOUNTPOINT || NEED_SVCGSSD=no
		log_action_begin_msg "Exporting directories for $DESC"
		$PREFIX/sbin/exportfs -r
		RET=$?
		if [ $RET != 0 ]; then
			log_action_end_msg $RET
			exit $RET
		fi
		log_action_end_msg 0

		log_daemon_msg "Starting $DESC"
		log_progress_msg "nfsd"
		
		# See if rpcbind is running
		$PREFIX/sbin/rpcinfo -p >/dev/null 2>&1
		RET=$?
		if [ $RET != 0 ]; then
		    echo
		    log_warning_msg "Not starting: portmapper is not running"
		    exit 0
		fi

		start-stop-daemon --start --oknodo --quiet \
		    --nicelevel $RPCNFSDPRIORITY \
		    --exec $PREFIX/sbin/rpc.nfsd
		RET=$?
		if [ $RET != 0 ]; then
			log_end_msg $RET
			exit $RET
		fi

		# make sure 127.0.0.1 is a valid source for requests
		ClearAddr=
		if [ -f /proc/net/rpc/auth.unix.ip/channel ]
		then
		    grep -Fqs 127.0.0.1 /proc/net/rpc/auth.unix.ip/content || {
			echo "nfsd 127.0.0.1 2147483647 localhost" >/proc/net/rpc/auth.unix.ip/channel
			ClearAddr=yes
		    }
		fi

		[ -z "$ClearAddr" ] || echo "nfsd 127.0.0.1 1" >/proc/net/rpc/auth.unix.ip/channel
	
	        if [ "$NEED_SVCGSSD" = "yes" ]; then
			do_modprobe rpcsec_gss_krb5
			log_progress_msg "svcgssd"
			start-stop-daemon --start --oknodo --quiet \
			    --exec $PREFIX/sbin/rpc.svcgssd
			RET=$?
			if [ $RET != 0 ]; then
				log_end_msg $RET
				exit $RET
			fi
		fi

		log_progress_msg "mountd"
		start-stop-daemon --start --oknodo --quiet \
		    --exec $PREFIX/sbin/rpc.mountd
		RET=$?
		if [ $RET != 0 ]; then
			log_end_msg $RET
			exit $RET
		fi

		log_end_msg 0
	else
		log_warning_msg "Not starting $DESC: no exports"
	fi
	;;

  stop)
	log_daemon_msg "Stopping $DESC"

	log_progress_msg "mountd"
	start-stop-daemon --stop --oknodo --quiet \
	    --name rpc.mountd --user 0
	RET=$?
	if [ $RET != 0 ]; then
		log_end_msg $RET
		exit $RET
	fi

	if [ "$NEED_SVCGSSD" = "yes" ]; then
		log_progress_msg "svcgssd"
		start-stop-daemon --stop --oknodo --quiet \
		    --name rpc.svcgssd --user 0
		RET=$?
		if [ $RET != 0 ]; then
			log_end_msg $RET
			exit $RET
		fi
	fi

	log_progress_msg "nfsd"
	start-stop-daemon --stop --oknodo --quiet \
	    --name nfsd --user 0 --signal 2
	RET=$?
	if [ $RET != 0 ]; then
		log_end_msg $RET
		exit $RET
	fi

	log_end_msg 0

	log_action_begin_msg "Unexporting directories for $DESC"
	$PREFIX/sbin/exportfs -au
	RET=$?
	if [ $RET != 0 ]; then
		log_action_end_msg $RET
		exit $RET
	fi
	log_action_end_msg 0

	if mountpoint -q $PROCNFSD_MOUNTPOINT
	then
	    $PREFIX/sbin/exportfs -f
	fi
	;;

  status)
	status_of_proc nfsd nfsd
	exit $?
	;;

  reload | force-reload)
	log_begin_msg "Re-exporting directories for $DESC..."
	$PREFIX/sbin/exportfs -r
	RET=$?
	log_end_msg $RET
	exit $RET
	;;

  restart)
	$0 stop
	sleep 1
	$0 start
	;;

  *)
	log_success_msg "Usage: nfs-kernel-server {start|stop|status|reload|force-reload|restart}"
	exit 1
	;;
esac

exit 0