xref: /freebsd-10.0-release/usr.sbin/sysrc/sysrc

#!/bin/sh
#-
# Copyright (c) 2010-2013 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.
#
# $FreeBSD$
#
############################################################ INCLUDES

BSDCFG_SHARE="/usr/share/bsdconfig"
[ "$_COMMON_SUBR" ] || . $BSDCFG_SHARE/common.subr || exit 1
[ "$_SYSRC_SUBR"  ] || f_include $BSDCFG_SHARE/sysrc.subr

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

#
# Options
#
DELETE=
DESCRIBE=
IGNORE_UNKNOWNS=
JAIL=
QUIET=
ROOTDIR=
SHOW_ALL=
SHOW_EQUALS=
SHOW_FILE=
SHOW_NAME=1
SHOW_VALUE=1
SYSRC_VERBOSE=

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

# die [ $fmt [ $opts ... ]]
#
# Optionally print a message to stderr before exiting with failure status.
#
die()
{
	local fmt="$1"
	[ $# -gt 0 ] && shift 1
	[  "$fmt"  ] && f_err "$fmt\n" "$@"

	exit $FAILURE
}

# usage
#
# Prints a short syntax statement and exits.
#
usage()
{
	f_err "Usage: %s [OPTIONS] name[=value] ...\n" "$pgm"
	f_err "Try \`%s --help' for more information.\n" "$pgm"
	die
}

# help
#
# Prints a full syntax statement and exits.
#
help()
{
	local optfmt="\t%-11s%s\n"
	local envfmt="\t%-17s%s\n"

	f_err "Usage: %s [OPTIONS] name[=value] ...\n" "$pgm"

	f_err "OPTIONS:\n"
	f_err "$optfmt" "-a" \
	      "Dump a list of all non-default configuration variables."
	f_err "$optfmt" "-A" \
	      "Dump a list of all configuration variables (incl. defaults)."
	f_err "$optfmt" "-d" \
	      "Print a description of the given variable."
	f_err "$optfmt" "-D" \
	      "Show default value(s) only (this is the same as setting"
	f_err "$optfmt" "" \
	      "RC_CONFS to NULL or passing \`-f' with a NULL file-argument)."
	f_err "$optfmt" "-e" \
	      "Print query results as \`var=value' (useful for producing"
	f_err "$optfmt" "" \
	      "output to be fed back in). Ignored if \`-n' is specified."
	f_err "$optfmt" "-f file" \
	      "Operate on the specified file(s) instead of rc_conf_files."
	f_err "$optfmt" "" \
	      "Can be specified multiple times for additional files."
	f_err "$optfmt" "-F" \
	      "Show only the last rc.conf(5) file each directive is in."
	f_err "$optfmt" "-h" \
	      "Print a short usage statement to stderr and exit."
	f_err "$optfmt" "--help" \
	      "Print this message to stderr and exit."
	f_err "$optfmt" "-i" \
	      "Ignore unknown variables."
	f_err "$optfmt" "-j jail" \
	      "The jid or name of the jail to operate within (overrides"
	f_err "$optfmt" "" \
	      "\`-R dir'; requires jexec(8))."
	f_err "$optfmt" "-n" \
	      "Show only variable values, not their names."
	f_err "$optfmt" "-N" \
	      "Show only variable names, not their values."
	f_err "$optfmt" "-q" \
	      "Quiet. Ignore previous \`-v' and/or SYSRC_VERBOSE."
	f_err "$optfmt" "-R dir" \
	      "Operate within the root directory \`dir' rather than \`/'."
	f_err "$optfmt" "-v" \
	      "Verbose. Print the pathname of the specific rc.conf(5)"
	f_err "$optfmt" "" \
	      "file where the directive was found."
	f_err "$optfmt" "-x" \
	      "Remove variable(s) from specified file(s)."
	f_err "\n"

	f_err "ENVIRONMENT:\n"
	f_err "$envfmt" "RC_CONFS" \
	      "Override default rc_conf_files (even if set to NULL)."
	f_err "$envfmt" "RC_DEFAULTS" \
	      "Location of \`/etc/defaults/rc.conf' file."
	f_err "$envfmt" "SYSRC_VERBOSE" \
	      "Default verbosity. Set to non-NULL to enable."

	die
}

# jail_depend
#
# Dump dependencies such as language-file variables and include files to stdout
# to be piped-into sh(1) running via jexec(8)/chroot(8). As a security measure,
# this prevents existing language files and library files from being loaded in
# the jail. This also relaxes the requirement to have these files in every jail
# before sysrc can be used on said jail.
#
jail_depend()
{
	#
	# Indicate that we are jailed
	#
	echo export _SYSRC_JAILED=1

	#
	# Print i18n language variables (their current values are sanitized
	# and re-printed for interpretation so that the i18n language files
	# do not need to exist within the jail).
	#
	local var val
	for var in \
		msg_cannot_create_permission_denied \
		msg_permission_denied \
		msg_previous_syntax_errors \
	; do
		val=$( eval echo \"\$$var\" |
			awk '{ gsub(/'\''/, "'\''\\'\'\''"); print }' )
		echo $var="'$val'"
	done

	#
	# Print include dependencies
	#
	cat $BSDCFG_SHARE/common.subr
	cat $BSDCFG_SHARE/sysrc.subr
}

############################################################ MAIN SOURCE

#
# Perform sanity checks
#
[ $# -gt 0 ] || usage

#
# Check for `--help' command-line option
#
( # Operate in sub-shell to protect $@ in parent
	while [ $# -gt 0 ]; do
		case "$1" in
		--help) exit 1;;
		-[fRj]) # These flags take an argument
			shift 1;;
		esac
		shift 1
	done
	exit 0
) || help

#
# Process command-line flags
#
while getopts aAdDef:Fhij:nNqR:vxX flag; do
	case "$flag" in
	a) SHOW_ALL=${SHOW_ALL:-1};;
	A) SHOW_ALL=2;;
	d) DESCRIBE=1;;
	D) RC_CONFS=;;
	e) SHOW_EQUALS=1;;
	f) RC_CONFS="$RC_CONFS${RC_CONFS:+ }$OPTARG";;
	F) SHOW_FILE=1;;
	h) usage;;
	i) IGNORE_UNKNOWNS=1;;
	j) [ "$OPTARG" ] || die \
	   	"%s: Missing or null argument to \`-j' flag" "$pgm"
	   JAIL="$OPTARG";;
	n) SHOW_NAME=;;
	N) SHOW_VALUE=;;
	q) QUIET=1 SYSRC_VERBOSE=;;
	R) [ "$OPTARG" ] || die \
	   	"%s: Missing or null argument to \`-R' flag" "$pgm"
	   ROOTDIR="$OPTARG";;
	v) SYSRC_VERBOSE=1 QUIET=;;
	x) DELETE=${DELETE:-1};;
	X) DELETE=2;;
	\?) usage;;
	esac
done
shift $(( $OPTIND - 1 ))

#
# [More] Sanity checks (e.g., "sysrc --")
#
[ $# -eq 0 -a ! "$SHOW_ALL" ] && usage

#
# Taint-check all rc.conf(5) files
#
errmsg="$pgm: Exiting due to previous syntax errors"
if [ "${RC_CONFS+set}" ]; then
	( for i in $RC_CONFS; do
	  	[ -e "$i" ] || continue
	  	/bin/sh -n "$i" || exit $FAILURE
	  done
	  exit $SUCCESS
	) || die "$errmsg"
else
	/bin/sh -n "$RC_DEFAULTS" || die "$errmsg"
	( . "$RC_DEFAULTS"
	  for i in $rc_conf_files; do
	  	[ -e "$i" ] || continue
	  	/bin/sh -n "$i" || exit $FAILURE
	  done
	  exit $SUCCESS
	) || die "$errmsg"
fi

#
# Process `-x' (and secret `-X') command-line options
#
errmsg="$pgm: \`-x' option incompatible with \`-a'/\`-A' options"
errmsg="$errmsg (use \`-X' to override)"
if [ "$DELETE" -a "$SHOW_ALL" ]; then
	[ "$DELETE" = "2" ] || die "$errmsg"
fi

#
# Process `-e', `-n', and `-N' command-line options
#
SEP=': '
[ "$SHOW_EQUALS" ] && SEP='="'
[ "$SHOW_NAME" ] || SHOW_EQUALS=
[ "$SYSRC_VERBOSE" = "0" ] && SYSRC_VERBOSE=
if [ ! "$SHOW_VALUE" ]; then
	SHOW_NAME=1
	SHOW_EQUALS=
fi

#
# Process `-j jail' and `-R dir' command-line options
#
if [ "$JAIL" -o "$ROOTDIR" ]; then
	#
	# Reconstruct the arguments that we want to carry-over
	#
	args="
		${SYSRC_VERBOSE:+-v}
		${QUIET:+-q}
		$( [ "$DELETE" = "1" ] && echo \ -x )
		$( [ "$DELETE" = "2" ] && echo \ -X )
		$( [ "$SHOW_ALL" = "1" ] && echo \ -a )
		$( [ "$SHOW_ALL" = "2" ] && echo \ -A )
		${DESCRIBE:+-d}
		${SHOW_EQUALS:+-e}
		${IGNORE_UNKNOWNS:+-i}
		$( [ "$SHOW_NAME"  ] || echo \ -n )
		$( [ "$SHOW_VALUE" ] || echo \ -N )
		$( [ "$SHOW_FILE"  ] && echo \ -F )
	"
	if [ "${RC_CONFS+set}" ]; then
		args="$args -f '$RC_CONFS'"
	fi
	for arg in "$@"; do
		args="$args '$arg'"
	done

	#
	# If both are supplied, `-j jail' supercedes `-R dir'
	#
	if [ "$JAIL" ]; then
		#
		# Re-execute ourselves with sh(1) via jexec(8)
		#
		( echo set -- $args
		  jail_depend
		  cat $0
		) | env - RC_DEFAULTS="$RC_DEFAULTS" \
		    	/usr/sbin/jexec "$JAIL" /bin/sh
		exit $?
	elif [ "$ROOTDIR" ]; then
		#
		# Make sure that the root directory specified is not to any
		# running jails.
		#
		# NOTE: To maintain backward compatibility with older jails on
		# older systems, we will not perform this check if either the
		# jls(1) or jexec(8) utilities are missing.
		#
		if f_have jexec && f_have jls; then
			jid="`jls jid path | \
			(
				while read JID JROOT; do
					[ "$JROOT" = "$ROOTDIR" ] || continue
					echo $JID
				done
			)`"

			#
			# If multiple running jails match the specified root
			# directory, exit with error.
			#
			if [ "$jid" -a "${jid%[$IFS]*}" != "$jid" ]; then
				die "%s: %s: %s" "$pgm" "$ROOTDIR" \
				    "$( echo "Multiple jails claim this" \
				             "directory as their root." \
				             "(use \`-j jail' instead)" )"
			fi

			#
			# If only a single running jail matches the specified
			# root directory, implicitly use `-j jail'.
			#
			if [ "$jid" ]; then
				#
				# Re-execute outselves with sh(1) via jexec(8)
				#
				( echo set -- $args
				  jail_depend
				  cat $0
				) | env - RC_DEFAULTS="$RC_DEFAULTS" \
					/usr/sbin/jexec "$jid" /bin/sh
				exit $?
			fi

			# Otherwise, fall through and allow chroot(8)
		fi

		#
		# Re-execute ourselves with sh(1) via chroot(8)
		#
		( echo set -- $args
		  jail_depend
		  cat $0
		) | env - RC_DEFAULTS="$RC_DEFAULTS" \
		    	/usr/sbin/chroot "$ROOTDIR" /bin/sh
		exit $?
	fi
fi

#
# Process `-a' or `-A' command-line options
#
if [ "$SHOW_ALL" ]; then
	#
	# Get a list of variables that are currently set in the rc.conf(5)
	# files (included `/etc/defaults/rc.conf') by performing a call to
	# source_rc_confs() in a clean environment.
	#
	( # Operate in a sub-shell to protect the parent environment
		#
		# Set which variables we want to preserve in the environment.
		# Append the pipe-character (|) to the list of internal field
		# separation (IFS) characters, allowing us to use the below
		# list both as an extended grep (-E) pattern and argument list
		# (required to first get f_clean_env() to preserve these in the
		# environment and then later to prune them from the list of
		# variables produced by set(1)).
		#
		IFS="$IFS|"
		EXCEPT="IFS|EXCEPT|PATH|RC_DEFAULTS|OPTIND|DESCRIBE|SEP"
		EXCEPT="$EXCEPT|DELETE|SHOW_ALL|SHOW_EQUALS|SHOW_NAME"
		EXCEPT="$EXCEPT|SHOW_VALUE|SHOW_FILE|SYSRC_VERBOSE|RC_CONFS"
		EXCEPT="$EXCEPT|pgm|SUCCESS|FAILURE"
		EXCEPT="$EXCEPT|f_sysrc_desc_awk|f_sysrc_delete_awk"

		#
		# Clean the environment (except for our required variables)
		# and then source the required files.
		#
		f_clean_env --except $EXCEPT
		if [ -f "$RC_DEFAULTS" -a -r "$RC_DEFAULTS" ]; then
			. "$RC_DEFAULTS"

			#
			# If passed `-a' (rather than `-A'), re-purge the
			# environment, removing the rc.conf(5) defaults.
			#
			[ "$SHOW_ALL" = "1" ] \
				&& f_clean_env --except rc_conf_files $EXCEPT

			#
			# If `-f file' was passed, set $rc_conf_files to an
			# explicit value, modifying the default behavior of
			# source_rc_confs().
			#
			[ "${RC_CONFS+set}" ] && rc_conf_files="$RC_CONFS"

			source_rc_confs

			#
			# If passed `-a' (rather than `-A'), remove
			# `rc_conf_files' unless it was defined somewhere
			# other than rc.conf(5) defaults.
			#
			[ "$SHOW_ALL" = "1" -a \
			  "$( f_sysrc_find rc_conf_files )" = "$RC_DEFAULTS" \
			] \
			&& unset rc_conf_files
		fi

		for NAME in $( set |
			awk -F= '/^[[:alpha:]_][[:alnum:]_]*=/ {print $1}' |
			grep -Ev "^($EXCEPT)$"
		); do
			#
			# If enabled, describe rather than expand value
			#
			if [ "$DESCRIBE" ]; then
				echo "$NAME: $( f_sysrc_desc "$NAME" )"
				continue
			fi

			#
			# If `-F' is passed, find it and move on
			#
			if [ "$SHOW_FILE" ]; then
				[ "$SHOW_NAME" ] && echo -n "$NAME: "
				f_sysrc_find "$NAME"
				continue
			fi

			#
			# If `-X' is passed, delete the variables
			#
			if [ "$DELETE" = "2" ]; then
				f_sysrc_delete "$NAME"
				continue
			fi

			[ "$SYSRC_VERBOSE" ] && \
				echo -n "$( f_sysrc_find "$NAME" ): "

			#
			# If `-N' is passed, simplify the output
			#
			if [ ! "$SHOW_VALUE" ]; then
				echo "$NAME"
				continue
			fi

			echo "${SHOW_NAME:+$NAME$SEP}$(
			      f_sysrc_get "$NAME" )${SHOW_EQUALS:+\"}"

		done
	)

	#
	# Ignore the remainder of positional arguments.
	#
	exit $SUCCESS
fi

#
# Process command-line arguments
#
while [ $# -gt 0 ]; do
	NAME="${1%%=*}"

	[ "$DESCRIBE" ] && \
		echo "$NAME: $( f_sysrc_desc "$NAME" )"

	case "$1" in
	*=*)
		#
		# Like sysctl(8), if both `-d' AND "name=value" is passed,
		# first describe, then attempt to set
		#

		if [ "$SYSRC_VERBOSE" ]; then
			file=$( f_sysrc_find "$NAME" )
			[ "$file" = "$RC_DEFAULTS" -o ! "$file" ] && \
				file=$( f_sysrc_get 'rc_conf_files%%[$IFS]*' )
			echo -n "$file: "
		fi

		#
		# If `-x' or `-X' is passed, delete the variable and ignore the
		# desire to set some value
		#
		if [ "$DELETE" ]; then
			f_sysrc_delete "$NAME"
			shift 1
			continue
		fi

		#
		# If `-N' is passed, simplify the output
		#
		if [ ! "$SHOW_VALUE" ]; then
			echo "$NAME"
			f_sysrc_set "$NAME" "${1#*}"
		else
			if [ "$SHOW_FILE" ]; then
				before=$( f_sysrc_find "$NAME" )
			else
				before=$( f_sysrc_get "$NAME" )
			fi
			if f_sysrc_set "$NAME" "${1#*=}"; then
				if [ "$SHOW_FILE" ]; then
					after=$( f_sysrc_find "$NAME" )
					echo -n "${SHOW_NAME:+$NAME$SEP}"
					echo -n "$before${SHOW_EQUALS:+\"}"
					echo " -> $after"
				else
					after=$( f_sysrc_get "$NAME" )
					echo -n "${SHOW_NAME:+$NAME$SEP}"
					echo "$before -> $after"
				fi
			fi
		fi
		;;
	*)
		if ! IGNORED="$( f_sysrc_get "$NAME?" )"; then
			[ "$IGNORE_UNKNOWNS" ] \
				|| echo "$pgm: unknown variable '$NAME'"
			shift 1
			continue
		fi

		#
		# Like sysctl(8), when `-d' is passed,
		# desribe it rather than expanding it
		#

		if [ "$DESCRIBE" ]; then
			shift 1
			continue
		fi

		#
		# If `-x' or `-X' is passed, delete the variable
		#
		if [ "$DELETE" ]; then
			f_sysrc_delete "$NAME"
			shift 1
			continue
		fi

		#
		# If `-F' is passed, find it and move on
		#
		if [ "$SHOW_FILE" ]; then
			[ "$SHOW_NAME" ] && echo -n "$NAME: "
			f_sysrc_find "$NAME"
			shift 1
			continue
		fi

		[ "$SYSRC_VERBOSE" ] && \
			echo -n "$( f_sysrc_find "$NAME" ): "

		#
		# If `-N' is passed, simplify the output
		#
		if [ ! "$SHOW_VALUE" ]; then
			echo "$NAME"
		else
			echo "${SHOW_NAME:+$NAME$SEP}$(
			      f_sysrc_get "$NAME" )${SHOW_EQUALS:+\"}"
		fi
	esac
	shift 1
done