NetBSD/etc/rc.subr

# $NetBSD: rc.subr,v 1.18 2000/05/13 03:07:17 lukem Exp $
#
# Copyright (c) 1997-2000 The NetBSD Foundation, Inc.
# All rights reserved.
#
# This code is derived from software contributed to The NetBSD Foundation
# by Luke Mewburn.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. All advertising materials mentioning features or use of this software
#    must display the following acknowledgement:
#        This product includes software developed by the NetBSD
#        Foundation, Inc. and its contributors.
# 4. Neither the name of The NetBSD Foundation nor the names of its
#    contributors may be used to endorse or promote products derived
#    from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
# rc.subr
#	functions used by various rc scripts
#

#
#	functions
#	---------

#
# checkyesno var
#	Test $1 variable, and warn if not set to YES or NO.
#	Return 0 if it's "yes" (et al), nonzero otherwise.
#
checkyesno()
{
	eval _value=\$${1}
	case $_value in

		#	"yes", "true", "on", or "1"
	[Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1)
		return 0
		;;

		#	"no", "false", "off", or "0"
	[Nn][Oo]|[Ff][Aa][Ll][Ss][Ee]|[Oo][Ff][Ff]|0)
		return 1
		;;
	*)
		warn "\$${1} is not set properly."
		return 1
		;;
	esac
}

#
# mount_critical_filesystems
#	Go through the list of critical filesystems, checking each one
#	to see if it is mounted, and if it is not, mounting it.
#
mount_critical_filesystems()
{
	if [ $1 = local ]; then
		_fslist=$critical_filesystems_beforenet
	else
		_fslist=$critical_filesystems
	fi
	for _fs in $_fslist; do
		mount | (
			_ismounted=no
			while read what _on on _type type; do
				if [ $on = $_fs ]; then
					_ismounted=yes
				fi
			done
			if [ $_ismounted = no ]; then 
				mount $_fs >/dev/null 2>&1
			fi
		)  
	done
}

#
# check_pidfile pidfile procname
#	Parses the first line of pidfile for a pid, and ensures
#	that the process is running and matches procname.
#	Prints the matching pid upon success, nothing otherwise.
#
check_pidfile()
{
	_pidfile=$1
	_procname=$2
	if [ -z "$_pidfile" -o -z "$_procname" ]; then
		err 3 'USAGE: check_pidfile pidfile procname'
	fi
	if [ ! -f $_pidfile ]; then
		return
	fi
	read _pid _junk < $_pidfile
	if [ -z "$_pid" ]; then
		return
	fi
	_procnamebn=`basename $_procname`
	ps -p $_pid -o 'pid,command' | while read _npid _arg0 _argv; do
		if [ "$_npid" = "PID" ]; then
			continue
		fi
		if [   "$_arg0" = "$_procname" \
		    -o "$_arg0" = "$_procnamebn" \
		    -o "$_arg0" = "${_procnamebn}:" \
		    -o "$_arg0" = "(${_procnamebn})" ]; then
			echo $_npid
			return
		fi
	done
}

#
# check_process procname
#	Ensures that a process (or processes) named procname is running.
#	Prints a list of matching pids.
#
check_process()
{
	_procname=$1
	if [ -z "$_procname" ]; then
		err 3 'USAGE: check_process procname'
	fi
	_procnamebn=`basename $_procname`
	_pref=
	ps -ax -o 'pid,command' | while read _npid _arg0 _argv; do
		if [ "$_npid" = "PID" ]; then
			continue
		fi
		if [   "$_arg0" = "$_procname" \
		    -o "$_arg0" = "$_procnamebn" \
		    -o "$_arg0" = "${_procnamebn}:" \
		    -o "$_arg0" = "(${_procnamebn})" ]; then
			echo -n "$_pref$_npid"
			_pref=" "
		fi
	done
}

#
# run_rc_command arg
#	Search for arg in the list of supported commands, which is:
#		"start stop restart rcvar status ${extra_commands}"
#	If there's a match, run ${arg}_cmd or the default command (see below).
#
#	If arg has a given prefix, then change the operation as follows:
#		prefix	operation
#		------	---------
#		fast	Skip the pid check.
#		force	Set ${rcvar} to YES.
#
#	The following globals are used:
#	name		needed	function
#	----		------	--------
#	name		y	Name of script.
#	command		n	Full path to command.
#				Not needed if ${arg}_cmd is set for
#				each keyword.
#	command_args	n	Optional args/shell directives for command.
#	extra_commands	n	List of extra commands supported.
#	pidfile		n	If set, use check_pidfile $pidfile, else if
#				$command is set, use check_process $command.
#	rcvar		n	If the default command is being run, this is
#				checked with checkyesno to determine if
#				the action should be run.
#				If this variable isn't set, ${name} is checked 
#				instead.
#	${name}_chdir	n	Directory to cd to before running ${command}.
#	${name}_flags	n	Arguments to call ${command} with.
#				NOTE:	if $flags is set (e.g, from the parent
#					environment), it overrides this.
#	${name}_nice	n	Nice level to run ${command} at.
#	${name}_user	n	User to run ${command} as.
#	${_arg}_cmd	n	If set, use this as the action when invoked;
#				$_arg is available to the action to use.
#				Otherwise, use default command (see below)
#				NOTE:	checkyesno ${rcvar} is NOT performed
#					for ${_arg}_cmd; use ${_arg}_precmd to
#					do this.
#	${_arg}_precmd	n	If set, run just before performing the main
#				action in the default command (i.e, after
#				checking for required bits and process
#				(non)existance).
#				If this completes with a non-zero exit code,
#				don't run ${_arg}_cmd.
#	required_dirs	n	If set, check for the existence of the given
#				directories before running the default
#				(re)start command.
#	required_files	n	If set, check for the readability of the given
#				files before running the default (re)start
#				command.
#	required_vars	n	If set, perform checkyesno on each of the
#				listed variables before running the default
#				(re)start command.
#
#	Default commands for a given arg:
#	arg		default
#	---		-------
#	status		Show if ${command} is running, etc.
#	start		if !running && checkyesno ${rcvar}
#				${command}
#	stop		if ${pidfile}
#				kill $sig_stop `check_pidfile $pidfile`
#			else
#				kill $sig_stop `check_process $command`
#			$sig_stop defaults to TERM.
#	reload		As stop, except use $sig_reload instead.
#			$sig_reload defaults to HUP.
#	restart		Run `stop' then `start'.
#
run_rc_command()
{
	_arg=$1
	_ckvar=${rcvar:-$name}
	if [ -z "$_ckvar" ]; then
		err 3 'neither $rcvar or $name is set.'
	fi

	case "$_arg" in
	fast*)
		_arg=${_arg#fast}
		_rc_fast_run=YES
		;;
	force*)
		_arg=${_arg#force}
		eval ${_ckvar}=YES
		;;
	esac

	_keywords="start stop restart rcvar $extra_commands"
	_pid=
	_pidcmd=
	if [ -z "$_rc_fast_run" ]; then
		if [ -n "$pidfile" ]; then
			_pidcmd='_pid=`check_pidfile '$pidfile' '$command'`'
		elif [ -n "$command" ]; then
			_pidcmd='_pid=`check_process '$command'`'
		fi
		if [ -n "$_pidcmd" ]; then
			_keywords="${_keywords} status"
		fi
	fi

	if [ -z "$_arg" ]; then
		rc_usage "$_keywords"
	fi

	if [ -n "$flags" ]; then	# allow override from environment
		_flags=$flags
	else
		eval _flags=\$${name}_flags
	fi
	eval _chdir=\$${name}_chdir
	eval _nice=\$${name}_nice
	eval _user=\$${name}_user

	eval $_pidcmd

	for _elem in $_keywords; do
		if [ "$_elem" != "$_arg" ]; then
			continue
		fi

		eval _cmd=\$${_arg}_cmd
		eval _precmd=\$${_arg}_precmd
		if [ -n "$_cmd" ]; then
			eval $_precmd || return 1
			eval $_cmd
			return 0
		fi

		case "$_arg" in

		status)
			if [ -n "$_pid" ]; then
				echo "${name} is running as pid $_pid."
			else
				echo "${name} is not running."
			fi
			;;

		start)
			if [ -n "$_pid" ]; then
				echo "${name} already running? (pid=$_pid)."
				exit 1
			fi

			if ! checkyesno ${_ckvar} || [ ! -x $command ]; then
				return 0
			fi

			for _f in $required_vars; do
				if ! checkyesno $_f; then
					warn \
			    "\$${_f} is not set; ${name} not started."
					return 1
				fi
			done
			for _f in $required_dirs; do
				if [ ! -d "${_f}/." ]; then
					warn \
			    "${_f} is not a directory; ${name} not started."
					return 1
				fi
			done
			for _f in $required_files; do
				if [ ! -r "${_f}" ]; then
					warn \
			"${_f} is not readable; ${name} not started."
					return 1
				fi
			done

			eval $_precmd || return 1
			echo "Starting ${name}."
			_doit="\
${_user:+su -m $_user -c 'sh -c \"}\
${_chdir:+cd $_chdir; }\
${_nice:+nice -n $_nice }\
$command $_flags $command_args\
${_user:+\"'}"
			eval $_doit
			;;

		stop)
			if [ -z "$_pid" ]; then
				if checkyesno ${_ckvar}; then
					if [ -n "$pidfile" ]; then
						echo \
					"${name} not running? (check $pidfile)."
					else
						echo "${name} not running?"
					fi
					exit 1
				fi
				return 0
			fi

			eval $_precmd || return 1
			echo "Stopping ${name}."
			_doit=\
"${_user:+su -m $_user -c '}kill -${sig_stop:-TERM} $_pid${_user:+'}"
			eval $_doit
			;;

		reload)
			if [ -z "$_pid" ]; then
				if checkyesno ${_ckvar}; then
					if [ -n "$pidfile" ]; then
						echo \
				    "${name} not running? (check $pidfile)."
					else
						echo "${name} not running?"
					fi
					exit 1
				fi
				return 0
			fi
			echo "Reloading ${name} config files."
			eval $_precmd || return 1
			_doit=\
"${_user:+su -m $_user -c '}kill -${sig_reload:-HUP} $_pid${_user:+'}"
			eval $_doit
			;;

		restart)
			if ! checkyesno ${_ckvar}; then
				return 0
			fi
			eval $_precmd || return 1
			( $0 stop )
			sleep 1
			$0 start

			;;

		rcvar)
			echo "# $name"
			if checkyesno ${_ckvar}; then
				echo "\$${_ckvar}=YES"
			else
				echo "\$${_ckvar}=NO"
			fi
			;;

		*)
			rc_usage "$_keywords"
			;;

		esac
		return 0
	done

	echo 1>&2 "$0: unknown directive '$_arg'."
	rc_usage "$_keywords"
	exit 1
}

#
# run_rc_script file arg
#	Start the script `file' with `arg', and correctly handle the
#	return value from the script.  If `file' ends with `.sh', it's
#	sourced into the current environment.  Otherwise it's run as
#	a child process.
#
#	Note: because `.sh' files are sourced into the current environment
#	run_rc_command shouldn't be used because its difficult to ensure
#	that the global variable state before and after the sourcing of 
#	the .sh file won't adversely affect other scripts.
#
run_rc_script()
{
	_file=$1
	_arg=$2
	if [ -z "$_file" -o -z "$_arg" ]; then
		err 3 'USAGE: run_rc_script file arg'
	fi

	case "$_file" in
	*.sh)				# run in current shell
		set $_arg ; . $_file
		;;
	*)				# run in subshell
		( set $_arg ; . $_file )
		;;
	esac
}

#
# rc_usage commands
#	Print a usage string for $0, with `commands' being a list of
#	valid commands.
#
rc_usage()
{
	echo -n 1>&2 "Usage: $0 [fast|force]("

	_sep=
	for _elem in $*; do
		echo -n 1>&2 "$_sep$_elem"
		_sep="|"
	done
	echo 1>&2 ")"
	exit 1
}

#
# err exitval message
#	Display message to stderr and log to the syslog, and exit with exitval.
#
err()
{
	exitval=$1
	shift

	logger "$0: ERROR $*"
	echo 1>&2 "$0: ERROR $*"
	exit $exitval
}

#
# warn message
#	Display message to stderr and log to the syslog.
#
warn()
{
	logger "$0: WARNING $*"
	echo 1>&2 "$0: WARNING $*"
}