xref: /freebsd/usr.sbin/bsdconfig/startup/share/rcvar.subr (revision d0b2dbfa)

if [ ! "$_STARTUP_RCVAR_SUBR" ]; then _STARTUP_RCVAR_SUBR=1
#
# Copyright (c) 2006-2013 Devin Teske
# All rights reserved.
#
# 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.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
#
#
############################################################ INCLUDES

BSDCFG_SHARE="/usr/share/bsdconfig"
. $BSDCFG_SHARE/common.subr || exit 1
f_dprintf "%s: loading includes..." startup/rcvar.subr
f_include $BSDCFG_SHARE/sysrc.subr

############################################################ CONFIGURATION

#
# Default path to the `/etc/rc.d' directory where service(8) scripts are stored
#
: ${ETC_RC_D:=/etc/rc.d}

#
# Default path to `/etc/rc.subr' (for find_local_scripts_new())
#
: ${ETC_RC_SUBR:=/etc/rc.subr}

############################################################ GLOBALS

#
# Initialize in-memory cache variables
#
STARTUP_RCVAR_MAP=
_STARTUP_RCVAR_MAP=

#
# Define what an rcvar looks like
#
STARTUP_RCVAR_REGEX='[[:alpha:]_][[:alnum:]_]*="([Yy][Ee][Ss]|[Nn][Oo])"'

#
# Default path to on-disk cache file(s)
#
STARTUP_RCVAR_MAP_CACHEFILE="/var/run/bsdconfig/startup_rcvar_map.cache"

############################################################ FUNCTIONS

# f_startup_rcvar_map [$var_to_set]
#
# Produce a map (beit from in-memory cache or on-disk cache) of rc.d scripts
# and their associated rcvar's. The map returned has the following format:
#
# 	rcvar default script description
#
# With each as follows:
#
# 	rcvar         the variable used to enable this rc.d script
# 	default       default value for this variable
# 	script        the rc.d script in-question
# 	description   description of the variable from rc.conf(5) defaults
#
# If $var_to_set is missing or NULL, the map is printed to standard output for
# capturing in a sub-shell (which is less-recommended because of performance
# degredation; for example, when called in a loop).
#
f_startup_rcvar_map()
{
	local __funcname=f_startup_rcvar_map
	local __var_to_set="$1"

	# If the in-memory cached value is available, return it immediately
	if [ "$_STARTUP_RCVAR_MAP" ]; then
		if [ "$__var_to_set" ]; then
			setvar "$__var_to_set" "$STARTUP_RCVAR_MAP"
		else
			echo "$STARTUP_RCVAR_MAP"
		fi
		return $SUCCESS
	fi

	#
	# create the in-memory cache (potentially from validated on-disk cache)
	#

	# Get a list of /etc/rc.d scripts ...
	local __file __rc_script_list=
	for __file in "$ETC_RC_D"/*; do
		[ -f "$__file" ] || continue
		[ -x "$__file" ] || continue
		__rc_script_list="$__rc_script_list $__file"
	done
	# ... and /usr/local/etc/rc.d scripts
	__rc_script_list="$__rc_script_list $(
		local_startup=$( f_sysrc_get local_startup )
		f_include "$ETC_RC_SUBR"
		find_local_scripts_new
		echo $local_rc
	)"
	__rc_script_list="${__rc_script_list# }" # Trim leading space

	#
	# Calculate a digest given the checksums of all dependencies (scripts
	# and the defaults file). This digest will be used to determine if an
	# on-disk global persistent cache file (containg this digest on the
	# first line) is valid and can be used to quickly populate the cache
	# value for immediate return.
	#
	local __rc_script_list_digest
	__rc_script_list_digest=$( cd "$ETC_RC_D" 2> /dev/null &&
		cksum "$RC_DEFAULTS" $__rc_script_list 2> /dev/null | md5 )

	#
	# Check to see if the global persistent cache file exists
	#
	if [ -f "$STARTUP_RCVAR_MAP_CACHEFILE" ]; then
		#
		# Attempt to populate the in-memory cache with the (soon to be)
		# validated on-disk cache. If validation fails, fall-back to
		# the current value and return error.
		#
		STARTUP_RCVAR_MAP=$(
			(	# Get digest as first word on first line
				read digest rest_ignored

				#
				# If the stored digest matches the calculated-
				# one populate the in-memory cache from the on-
				# disk cache and return success.
				#
				if [ "$digest" = "$__rc_script_list_digest" ]
				then
					cat
					exit $SUCCESS
				else
					# Otherwise, return the current value
					echo "$STARTUP_RCVAR_MAP"
					exit $FAILURE
				fi
			) < "$STARTUP_RCVAR_MAP_CACHEFILE"
		)
		local __retval=$?
		export STARTUP_RCVAR_MAP # Make children faster (export cache)
		if [ $__retval -eq $SUCCESS ]; then
			export _STARTUP_RCVAR_MAP=1
			if [ "$__var_to_set" ]; then
				setvar "$__var_to_set" "$STARTUP_RCVAR_MAP"
			else
				echo "$STARTUP_RCVAR_MAP"
			fi
			return $SUCCESS
		fi
		# Otherwise, fall-thru to create in-memory cache from scratch
	fi

	#
	# If we reach this point, we need to generate the data from scratch
	# (and after we do, we'll attempt to create the global persistent
	# cache file to speed up future executions).
	#

	STARTUP_RCVAR_MAP=$(
		for script in $__rc_script_list; do
			rcvar_list=$( $script rcvar 2> /dev/null | awk -F= \
				-v script="$script" '
		              	/^'"$STARTUP_RCVAR_REGEX"'/ {
		              		if ( $2 ~ /^"[Yy][Ee][Ss]"$/ )
		              			print $1 ",YES"
		              		else
		              			print $1 ",NO"
		              	}' )
			for entry in $rcvar_list; do
				rcvar="${entry%%,*}"
				rcvar_default=$( f_sysrc_get_default "$rcvar" )
				[ "$rcvar_default" ] ||
					rcvar_default="${entry#*,}"
				rcvar_desc=$( f_sysrc_desc "$rcvar" )
				echo $rcvar ${rcvar_default:-NO} \
				     $script "$rcvar_desc"
			done
		done | sort -u
	)
	export STARTUP_RCVAR_MAP
	export _STARTUP_RCVAR_MAP=1
	if [ "$__var_to_set" ]; then
		setvar "$__var_to_set" "$STARTUP_RCVAR_MAP"
	else
		echo "$STARTUP_RCVAR_MAP"
	fi

	#
	# Attempt to create/update the persistent global cache
	#

	# Create a new temporary file to write to
	local __tmpfile
	f_eval_catch -dk __tmpfile $__funcname mktemp \
		'mktemp -t "%s"' "$__tmpfile" || return $FAILURE

	# Write the temporary file contents
	echo "$__rc_script_list_digest" > "$__tmpfile"
	echo "$STARTUP_RCVAR_MAP" >> "$__tmpfile"

	# Finally, move the temporary file into place
	case "$STARTUP_RCVAR_MAP_CACHEFILE" in
	*/*) f_eval_catch -d $__funcname mkdir \
		'mkdir -p "%s"' "${STARTUP_RCVAR_MAP_CACHEFILE%/*}"
	esac
	f_eval_catch -d $__funcname mv \
		'mv "%s" "%s"' "$__tmpfile" "$STARTUP_RCVAR_MAP_CACHEFILE"
}

############################################################ MAIN

f_dprintf "%s: Successfully loaded." startup/rcvar.subr

fi # ! $_STARTUP_RCVAR_SUBR