freebsd/etc/rc.d/hostid

#!/bin/sh
#
# Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
# 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 AUTHORS 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 AUTHORS 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.
#
# $FreeBSD$
#

# PROVIDE: hostid
# REQUIRE: sysctl
# KEYWORD: nojail

. /etc/rc.subr

name="hostid"
start_cmd="hostid_start"
stop_cmd=":"
reset_cmd="hostid_reset"
extra_commands="reset"
rcvar="hostid_enable"

hostid_set()
{
	uuid=$1
	# Generate hostid based on hostuuid - take first four bytes from md5(uuid).
	id=`echo -n $uuid | /sbin/md5`
	id="0x${id%????????????????????????}"

	# Set both kern.hostuuid and kern.hostid.
	#
	check_startmsgs && echo "Setting hostuuid: ${uuid}."
	${SYSCTL} kern.hostuuid="${uuid}" >/dev/null
	check_startmsgs && echo "Setting hostid: ${id}."
	${SYSCTL} kern.hostid=${id} >/dev/null
}

hostid_hardware()
{
	uuid=`kenv -q smbios.system.uuid`
	x="[0-9a-f]"
	y=$x$x$x$x
	case "${uuid}" in
	$y$y-$y-$y-$y-$y$y$y)
		echo "${uuid}"
		;;
	esac
}

hostid_generate()
{
	# First look for UUID in hardware.
	uuid=`hostid_hardware`
	if [ -z ${uuid} ]; then
		# If not found, fall back to software-generated UUID.
		uuid=`uuidgen`
	fi
	hostid_set $uuid
}

hostid_reset()
{
	hostid_generate
	# Store newly generated UUID in ${hostid_file}.
	echo $uuid > ${hostid_file}
	if [ $? -ne 0 ]; then
		warn "could not store hostuuid in ${hostid_file}."
	fi
}

hostid_start()
{
	# If ${hostid_file} already exists, we take UUID from there.
	if [ -r ${hostid_file} ]; then
		hostid_set `cat ${hostid_file}`
	else
		# No hostid file, generate UUID.
		hostid_generate
	fi
}

load_rc_config $name
run_rc_command "$1"