NetBSD/etc/rc.subr

# $NetBSD: rc.subr,v 1.38 2001/11/19 03:18:32 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
}

# reverse_list list
#	print the list in reverse order
#
reverse_list()
{
	_revlist=
	for _revfile in $*; do
		_revlist="$_revfile $_revlist"
	done
	echo $_revlist
}

#
# 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=${_procname##*/}
	ps -p $_pid -o 'pid,command' | while read _npid _arg0 _argv; do
		case "$_npid" in
		    PID)
			continue ;;
		esac
		case "$_arg0" in
		    $_procname|$_procnamebn|${_procnamebn}:|"(${_procnamebn})")
			echo $_npid
			return
			;;
		esac
	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=${_procname##*/}
	_pref=
	ps -ax -o 'pid,command' | while read _npid _arg0 _argv; do
		case "$_npid" in
		    PID)
			continue ;;
		esac
		case "$_arg0" in
		    $_procname|$_procnamebn|${_procnamebn}:|"(${_procnamebn})")
			echo -n "$_pref$_npid"
			_pref=" "
			;;
		esac
	done
}

#
# wait_for_pids pid [pid ...]
#	spins until none of the pids exist
#
wait_for_pids()
{
	_list=$*
	if [ -z "$_list" ]; then
		return
	fi
	_prefix=
	while true; do
		_nlist="";
		for _j in $_list; do
			if kill -0 $_j 2>/dev/null; then
				_nlist="${_nlist}${_nlist:+ }$_j"
			fi
		done
		if [ -z "$_nlist" ]; then
			break
		fi
		_list=$_nlist
		echo -n ${_prefix:-"Waiting for PIDS: "}$_list
		_prefix=", "
		sleep 2
	done
	if [ -n "$_prefix" ]; then
		echo "."
	fi
}

#
# run_rc_command arg
#	Search for arg in the list of supported commands, which is:
#		"start stop restart rcvar status poll ${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	This is checked with checkyesno to determine
#				if the action should be run.
#
#	${name}_chroot	n	Directory to chroot to before running ${command}
#
#	${name}_chdir	n	Directory to cd to before running ${command}
#				(if not using ${name}_chroot).
#
#	${name}_flags	n	Arguments to call ${command} with.
#				NOTE:	$flags from the parent environment
#					can be used to override this.
#
#	${name}_nice	n	Nice level to run ${command} at.
#
#	${name}_user	n	User to run ${command} as, using su(1) if not
#				using ${name}_chroot.
#
#	${name}_group	n	Group to run chrooted ${command} as.
#
#	${name}_groups	n	Comma separated list of supplementary groups
#				to run the chrooted ${command} with.
#
#	${_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)
#
#	${_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
#	---		-------
#	start		if !running && checkyesno ${rcvar}
#				${command}
#
#	stop		if ${pidfile}
#				_pid=`check_pidfile $pidfile`
#			else
#				_pid=`check_process $command`
#			kill $sig_stop $_pid
#			wait_for_pids $_pid
#			($sig_stop defaults to TERM.)
#
#	reload		Similar to stop, except use $sig_reload instead,
#			and doesn't wait_for_pids.
#			$sig_reload defaults to HUP.
#
#	restart		Run `stop' then `start'.
#
#	status		Show if ${command} is running, etc.
#
#	poll		Wait for ${command} to exit.
#
#	rcvar		Display what rc.conf variable is used (if any).
#
#
#
run_rc_command()
{
	_arg=$1
	if [ -z "$name" ]; then
		err 3 'run_rc_command: $name is not set.'
	fi

	case "$_arg" in
	fast*)				# "fast" prefix; don't check pid
		_arg=${_arg#fast}
		_rc_fast_run=YES
		;;
	force*)				# "force prefix; always start
		_arg=${_arg#force}
		_rc_force_run=YES
		if [ -n "${rcvar}" ]; then
			eval ${rcvar}=YES
		fi
		;;
	esac

	_keywords="start stop restart rcvar $extra_commands"
	_pid=
	_pidcmd=
					# setup pid check command if not fast
	if [ -z "$_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 poll"
		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	_chroot=\$${name}_chroot \
	    _nice=\$${name}_nice	_user=\$${name}_user \
	    _group=\$${name}_group	_groups=\$${name}_groups

					# if ${rcvar} is set, and $1 is not
					# "rcvar" or "status", then run
					#	checkyesno ${rcvar}
					# and return if that failed
					#
	# XXXX use case?
	if [ -n "${rcvar}" -a "$_arg" != "rcvar" -a "$_arg" != "status" ]; then
		if ! checkyesno ${rcvar}; then
			return 0
		fi
	fi

	eval $_pidcmd			# determine the pid if necessary

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

					# if there's a custom ${XXX_cmd},
					# run that instead of the default
					#
		eval _cmd=\$${_arg}_cmd _precmd=\$${_arg}_precmd
		if [ -n "$_cmd" ]; then
					# if the precmd failed and force
					# isn't set, exit
					#
			if ! eval $_precmd && [ -z "$_rc_force_run" ]; then
				return 1
			fi

			eval $_cmd
			return 0
		fi

		case "$_arg" in		# default operations...

		status)
			if [ -n "$_pid" ]; then
				echo "${name} is running as pid $_pid."
			else
				echo "${name} is not running."
				return 1
			fi
			;;

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

			if [ ! -x $command ]; then
				return 0
			fi

					# check for required variables,
					# directories, and files
					#
			for _f in $required_vars; do
				if ! checkyesno $_f; then
					warn "\$${_f} is not set."
					if [ -z "$_rc_force_run" ]; then
						return 1
					fi
				fi
			done
			for _f in $required_dirs; do
				if [ ! -d "${_f}/." ]; then
					warn "${_f} is not a directory."
					if [ -z "$_rc_force_run" ]; then
						return 1
					fi
				fi
			done
			for _f in $required_files; do
				if [ ! -r "${_f}" ]; then
					warn "${_f} is not readable."
					if [ -z "$_rc_force_run" ]; then
						return 1
					fi
				fi
			done

					# if the precmd failed and force
					# isn't set, exit
					#
			if ! eval $_precmd && [ -z "$_rc_force_run" ]; then
				return 1
			fi


					# setup the command to run, and run it
					#
			echo "Starting ${name}."
			if [ -n "$_chroot" ]; then
				_doit="\
${_nice:+nice -n $_nice }\
chroot ${_user:+-u $_user }${_group:+-g $_group }${_groups:+-G $_groups }\
$_chroot $command $_flags $command_args"
			else
				_doit="\
${_chdir:+cd $_chdir; }\
${_nice:+nice -n $_nice }\
$command $_flags $command_args"
				if [ -n "$_user" ]; then
				    _doit="su -m $_user -c 'sh -c \"$_doit\"'"
				fi
			fi
			eval $_doit
			;;

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

			if ! eval $_precmd && [ -z "$_rc_force_run" ]; then
				return 1
			fi
			echo "Stopping ${name}."
			_doit="kill -${sig_stop:-TERM} $_pid"
			if [ -n "$_user" ]; then
				_doit="su -m $_user -c 'sh -c \"$_doit\"'"
			fi
			eval $_doit
			wait_for_pids $_pid
			;;

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

		restart)
			if ! eval $_precmd && [ -z "$_rc_force_run" ]; then
				return 1
			fi
					# prevent restart being called more
					# than once by any given script
					#
			if [ -n "$_rc_restart_done" ]; then
				return 0
			fi
			_rc_restart_done=YES

			( $0 ${_rc_force_run:+force}stop )
			$0 ${_rc_force_run:+force}start

			;;

		poll)
			if [ -n "$_pid" ]; then
				wait_for_pids $_pid
			fi
			;;

		rcvar)
			echo "# $name"
			if [ -n "$rcvar" ]; then
				if checkyesno ${rcvar}; then
					echo "\$${rcvar}=YES"
				else
					echo "\$${rcvar}=NO"
				fi
			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.  If `file' appears to be
#	a backup or scratch file, ignore it.  Otherwise if it's
#	executable 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

	if [ -n "$rc_fast_and_loose" ]; then
		unset name command command_args extra_commands pidfile rcvar
		unset required_dirs required_files required_vars
		eval unset ${_arg}_cmd ${_arg}_precmd
		set $_arg ; . $_file
	else
		case "$_file" in
		*.sh)				# run in current shell
			set $_arg ; . $_file
			;;
		*[~#]|*.OLD|*.orig)		# scratch file; skip
			warn "Ignoring scratch file $_file"
			;;
		*)				# run in subshell
			if [ -x $_file ]; then
				( set $_arg ; . $_file )
			fi
			;;
		esac
	fi
}

#
# load_rc_config
#	Source in the configuration file for a given command.
#
load_rc_config()
{
	_command=$1
	if [ -z "$_command" ]; then
		err 3 'USAGE: load_rc_config command'
	fi

	if [ -z "$_rc_conf_loaded" ]; then
		. /etc/rc.conf
		_rc_conf_loaded=YES
	fi
	if [ -f /etc/rc.conf.d/"$_command" ]; then
		. /etc/rc.conf.d/"$_command"
	fi
}


#
# 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: $*"
}

#
# backup_file action file cur backup
#	Make a backup copy of `file' into `cur', and save the previous
#	version of `cur' as `backup' or use rcs for archiving.
#
#	This routine checks the value of the backup_uses_rcs variable,
#	which can be either YES or NO.
#
#	The `action' keyword can be one of the following:
#
#	add		`file' is now being backed up (and is possibly
#			being reentered into the backups system).  `cur'
#			is created and RCS files, if necessary, are
#			created as well.
#
#	update		`file' has changed and needs to be backed up.
#			If `cur' exists, it is copied to to `back' or
#			checked into RCS (if the repository file is old),
#			and then `file' is copied to `cur'.  Another RCS
#			check in done here if RCS is being used.
#
#	remove		`file' is no longer being tracked by the backups
#			system.  If RCS is not being used, `cur' is moved
#			to `back', otherwise an empty file is checked in,
#			and then `cur' is removed.
#
#
backup_file()
{
	_action=$1
	_file=$2
	_cur=$3
	_back=$4

	if checkyesno backup_uses_rcs; then
		_msg0="backup archive"
		_msg1="update"

		# ensure that history file is not locked
		if [ -f $_cur,v ]; then
			rcs -q -u -U -M $_cur
		fi

		# ensure after switching to rcs that the
		# current backup is not lost
		if [ -f $_cur ]; then
			# no archive, or current newer than archive
			if [ ! -f $_cur,v -o $_cur -nt $_cur,v ]; then
				ci -q -f -u -t-"$_msg0" -m"$_msg1" $_cur
				rcs -q -kb -U $_cur
			fi
		fi

		case $_action in
		add|update)
			cp -p $_file $_cur
			ci -q -f -u -t-"$_msg0" -m"$_msg1" $_cur
			rcs -q -kb -U $_cur
			chown root:wheel $_cur $_cur,v
			;;
		remove)
			cp /dev/null $_cur
			ci -q -f -u -t-"$_msg0" -m"$_msg1" $_cur
			rcs -q -kb -U $_cur
			chown root:wheel $_cur $_cur,v
			rm $_cur
			;;
		esac
	else
		case $_action in
		add|update)
			if [ -f $_cur ]; then
				cp -p $_cur $_back
			fi
			cp -p $_file $_cur
			chown root:wheel $_cur
			;;
		remove)
			mv -f $_cur $_back
			;;
		esac
	fi
}