#!/bin/sh
#
# Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
# Copyright (c) 2015 Xin LI <delphij@FreeBSD.org>
#
# 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"
desc="Generate a unique host ID"
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
}

valid_hostid()
{
	uuid=$1

	x="[0-9a-f]"
	y=$x$x$x$x

	# Check against a blacklist before
	# accepting the UUID.
	case "${uuid}" in
	00000000-0000-0000-0000-000000000000)
		;;
	00020003-0004-0005-0006-000700080009)
		;;
	03000200-0400-0500-0006-000700080009)
		;;
	07090201-0103-0301-0807-060504030201)
		;;
	11111111-1111-1111-1111-111111111111)
		;;
	11111111-2222-3333-4444-555555555555)
		;;
	4c4c4544-0000-2010-8020-80c04f202020)
		;;
	58585858-5858-5858-5858-585858585858)
		;;
	890e2d14-cacd-45d1-ae66-bc80e8bfeb0f)
		;;
	8e275844-178f-44a8-aceb-a7d7e5178c63)
		;;
	dc698397-fa54-4cf2-82c8-b1b5307a6a7f)
		;;
	fefefefe-fefe-fefe-fefe-fefefefefefe)
		;;
	*-ffff-ffff-ffff-ffffffffffff)
		;;
	$y$y-$y-$y-$y-$y$y$y)
		return 0
		;;
	esac

	return 1
}

hostid_hardware()
{
	uuid=`kenv -q smbios.system.uuid`

	if valid_hostid $uuid; then
		echo "${uuid}"
	fi
}

hostid_generate()
{
	# First look for UUID in hardware.
	uuid=`hostid_hardware`
	if [ -z "${uuid}" ]; then
		warn "hostid: unable to figure out a UUID from DMI data, generating a new one"
		sleep 2
		# 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
		read saved_hostid < ${hostid_file}
		if valid_hostid ${saved_hostid}; then
			hostid_set `cat ${hostid_file}`
			exit 0
		fi
	fi

	# No hostid file, generate UUID.
	hostid_generate
}

load_rc_config $name
run_rc_command "$1"