Re: RPI4 + ntpdate + unbound

On 7/6/22 11:47, Peter Jeremy wrote:
> On 2022-Jul-01 21:02:05 -0700, John Kennedy <[email protected]> wrote:
>>   So I've got a RPI4 (no system time stored in NVRAM) that I did a stock
>> type FreeBSD install on setting the time with ntpdate and the unbound
>> DNS server (aiming for DNSSEC).  As many people have noted before me,
>> that setup is sort of broken because you can't look up DNSSEC hosts if
>> you think it's 1970.  No NTP time servers == no date reset == no DNS.
> 
> If you're running UFS, the system clock should get set to the timestamp
> in the superblock.   That will be the last sync before the previous
> shutdown so it'll be minutes to hours out of date but that should be
> recent enough for DNSSEC to work.
> 
> Note that this only works on UFS - see
> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=254058
> 
> As an alternative option, the RTC in both the Rock64 and RockPro64
> are supported.
> 


Based on this idea I created a /etc/rc.d/fakertc script. It saves the datetime on shutdown and restores it early on boot.

Not polished yet. But it works on my RPI4 14-CURRENT.
With this script the time does not go backwards in the logs anymore. And it should provide a more reasonable time for validating certificates in DNSSEC/ipsec or similar processes before ntpdate kicks in.

Regards,
Ronald.

#!/bin/sh
#

# PROVIDE: rtc
# REQUIRE: FILESYSTEMS
# BEFORE: netif
# KEYWORD: nojail shutdown

. /etc/rc.subr

name="fakertc"
desc="Restore RTC date and time"
start_cmd="fakertc_start"
stop_cmd="fakertc_stop"

extra_commands="savertc"
savertc_cmd="${name}_stop"

rtc_file="/var/db/${name}"

rtc_format="+%Y%m%d%H%M.%S"

save_rtc()
{
	oumask=`umask`
	umask 077
	debug "saving rtc to ${rtc_file}"
	date -Iseconds > "${rtc_file}"
	umask ${oumask}
}

fakertc_start()
{

	echo -n "Set RTC from: ${rtc_file}: "

	if [ ! -r ${rtc_file} ] ; then
		warn "${rtc_file} is not readable"
		return 1
	fi

	case ${rtc_file:=/${name}} in
	[Nn][Oo])
		;;
	*)
		date -u $( cat "${rtc_file}" )
		;;
	esac

	echo '.'
}

fakertc_stop()
{
	# Write some entropy so when the machine reboots /dev/random
	# can be reseeded
	#
	case ${rtc_file:=/${name}} in
	[Nn][Oo])
		;;
	*)
		echo -n "Writing RTC file: ${rtc_file}"
		oumask=`umask`
		umask 077
		date -u "${rtc_format}" > "${rtc_file}" || warn 'write failed (read-only fs?)'
		umask ${oumask}
		echo '.'
		;;
	esac
}

load_rc_config $name
run_rc_command "$1"