From patchwork Fri Nov 2 02:52:34 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matt Weber X-Patchwork-Id: 992167 Return-Path: X-Original-To: incoming-buildroot@patchwork.ozlabs.org Delivered-To: patchwork-incoming-buildroot@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=busybox.net (client-ip=140.211.166.133; helo=hemlock.osuosl.org; envelope-from=buildroot-bounces@busybox.net; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=rockwellcollins.com Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 42mRSp6HJKz9sTV for ; Fri, 2 Nov 2018 13:52:42 +1100 (AEDT) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id DDD0087A2B; Fri, 2 Nov 2018 02:52:39 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id kKtnnsV9AdGq; Fri, 2 Nov 2018 02:52:39 +0000 (UTC) Received: from ash.osuosl.org (ash.osuosl.org [140.211.166.34]) by hemlock.osuosl.org (Postfix) with ESMTP id 3A02386D8A; Fri, 2 Nov 2018 02:52:39 +0000 (UTC) X-Original-To: buildroot@lists.busybox.net Delivered-To: buildroot@osuosl.org Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by ash.osuosl.org (Postfix) with ESMTP id 6D3541BF23F for ; Fri, 2 Nov 2018 02:52:37 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 6AC1286D8A for ; Fri, 2 Nov 2018 02:52:37 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id KlM5y5ZrWaZG for ; Fri, 2 Nov 2018 02:52:36 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from ch3vs04.rockwellcollins.com (ch3vs04.rockwellcollins.com [205.175.226.52]) by hemlock.osuosl.org (Postfix) with ESMTPS id 49AE086B64 for ; Fri, 2 Nov 2018 02:52:36 +0000 (UTC) Received: from ofwch3n02.rockwellcollins.com (HELO crulimr01.rockwellcollins.com) ([205.175.226.14]) by ch3vs04.rockwellcollins.com with ESMTP; 01 Nov 2018 21:52:35 -0500 X-Received: from largo.rockwellcollins.com (unknown [192.168.140.76]) by crulimr01.rockwellcollins.com (Postfix) with ESMTP id 321B4600B7; Thu, 1 Nov 2018 21:52:35 -0500 (CDT) From: Matt Weber To: buildroot@buildroot.org Date: Thu, 1 Nov 2018 21:52:34 -0500 Message-Id: <1541127154-45957-1-git-send-email-matthew.weber@rockwellcollins.com> X-Mailer: git-send-email 1.9.1 Subject: [Buildroot] [PATCH v4] package/ntp: sntp time sync script X-BeenThere: buildroot@busybox.net X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion and development of buildroot List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Oscar Gomez Fuente MIME-Version: 1.0 Errors-To: buildroot-bounces@busybox.net Sender: "buildroot" This patch adds the installation of a startup script if the sntp utility is selected as an option. The utility is design to do a one time step/slew adjustment of the system time (similar to the ntpdate tool http://support.ntp.org/bin/view/Dev/DeprecatingNtpdate). One nice benefit over ntpdate is that sntp can run while ntpd is still running. However, ntpd may still need to be restarted if the time step was large enough. The script provides the ability to override the arguments as part of a /etc/defaults/sntp file. On a local LAN, the initial large step adjustment took less then one second to be retrieved and system time updated. If a user already has a RTC maintaining the time and the system was powered off for a long period of time, the script assumes a slew adjustment when +/- 128ms, rather then a time step(jump). This could be further tuned by a user with the /etc/defaults/sntp configuration file. One NTP pool server is being set as sntp uses all of the servers provided when the DNS is resolved as servers to attempt to retrieve time from before timing out. It looks like currently that is 4 servers per *pool.ntp.org hostname. Cc: Oscar Gomez Fuente Signed-off-by: Matt Weber Tested-by: Oscar Gomez Fuente --- Major design/observations (v2) Originally an attempt was made to use the ntpd in one shot mode but it required more complex logic to handle the cases of a timeout where the app had to be killed before the actual ntpd was started. Similarly bad server addreses or network connection being down had to be handled with the timeout case as the app in one shot mode wouldn't exit. http://lists.ntp.org/pipermail/questions/2011-July/030041.html (post v2) An attempt was made to use the wait -w feature of ntpd but it seems that approach requires a longer period of stability. I believe the -w actually means to wait for good stable time vs time being set with the possibility of slewing required. So apps could pend on ntp-wait to get good time before proceeding. This doesn't work for a quick initial time set. (v3+) So the approach in this series uses ntpd to cleanup the time after a quick initial set. Plus using the feature of the sntp to manage do we time jump or do some minor slewing. Changes v3 -> v4 - Updated S48sntp script to just use a single pool host which provides 4 NTP servers sntp will query before timing out v2 -> v3 - Moved initial time set to a S48sntp script as originally suggested by Oscar and preferred by Arnout - Switched to sntp tool as it simplified the logic around when and how do we call the tool to perform this time sync (it handles when to slew/step and multiple servers at once) v1 -> v2 [Arnout - Moved NTP_WAIT_DELAY above sourcing of configuration file - Switched to using unix time for current time check - Added comment on why redirection of stdout and stderr - Attempted to use the pid file but found it added more calls to the shell then using a variable, so switched back - Adjusted printout so the actual ntpd service start was aligned with the respecting Ok/Fail. - Dropped -g from the main service call as the "big" time jump should have already occurred with the one-shot ntpd -gq. v1 Based on Oscar's v1 patch to add a ntpdate startup script. http://patchwork.ozlabs.org/patch/986852/ --- package/ntp/S48sntp | 42 ++++++++++++++++++++++++++++++++++++++++++ package/ntp/ntp.mk | 9 +++++++++ 2 files changed, 51 insertions(+) create mode 100755 package/ntp/S48sntp diff --git a/package/ntp/S48sntp b/package/ntp/S48sntp new file mode 100755 index 0000000..cc0948e --- /dev/null +++ b/package/ntp/S48sntp @@ -0,0 +1,42 @@ +#! /bin/sh + +NAME=sntp +# sntp uses all the IPs resolved for the hostname (i.e. pool.ntp.org has 4). +# It will try each until they either all timeout or time has been set. Thus +# default to only providing one NTP pool host. +SNTP_SERVERS="pool.ntp.org" +# Step if time delta is greater then 128ms, otherwise slew +SNTP_ARGS="-Ss -M 128" +SNTP_KEY_CACHE="/tmp/kod" + +# Read config file if it is present. +if [ -r /etc/default/$NAME ] +then + . /etc/default/$NAME +fi + +# Create key cache file to prevents warning that file is missing +touch $SNTP_KEY_CACHE + +case "$1" in + start) + echo "Starting $NAME: " + $NAME $SNTP_ARGS -K $SNTP_KEY_CACHE $SNTP_SERVERS + [ $? = 0 ] && echo "OK" || echo "FAIL" + ;; + stop) + echo "Stopping $NAME: OK" + ;; + restart|reload) + echo "Restarting $NAME: " + $0 stop + sleep 1 + $0 start + ;; + *) + echo "Usage: $0 {start|stop|restart|reload}" >&2 + exit 1 + ;; +esac + +exit 0 diff --git a/package/ntp/ntp.mk b/package/ntp/ntp.mk index af3c1aa..aad1cdd 100644 --- a/package/ntp/ntp.mk +++ b/package/ntp/ntp.mk @@ -93,9 +93,18 @@ define NTP_INSTALL_TARGET_CMDS $(INSTALL) -m 644 package/ntp/ntpd.etc.conf $(TARGET_DIR)/etc/ntp.conf endef +# This script will step the time if there is a large difference +# before ntpd takes over the necessary slew adjustments +ifeq ($(BR2_PACKAGE_NTP_SNTP),y) +define NTP_INSTALL_INIT_SYSV_SNTP + $(INSTALL) -D -m 755 package/ntp/S48sntp $(TARGET_DIR)/etc/init.d/S48sntp +endef +endif + ifeq ($(BR2_PACKAGE_NTP_NTPD),y) define NTP_INSTALL_INIT_SYSV $(INSTALL) -D -m 755 package/ntp/S49ntp $(TARGET_DIR)/etc/init.d/S49ntp + $(NTP_INSTALL_INIT_SYSV_SNTP) endef define NTP_INSTALL_INIT_SYSTEMD