S50date

#!/bin/bash

PROG_DATE="/bin/date"
PROG_NTPD="/usr/sbin/chronyd"
PROG_SNTP="/usr/bin/sntp"
LOG_SNTP="/var/log/sntp.log"

SYS_CONF="/etc/date.conf"
BOOT_CONF="/boot/date.conf"
CONF="/data/etc/date.conf"

SYS_NTP_CONF="/etc/ntp.conf"
BOOT_NTP_CONF="/boot/ntp.conf"
NTP_CONF="/data/etc/ntp.conf"

SAVED_DATE_FILE="/var/lib/saved_date"


test -n "${OS_VERSION}" || source /etc/init.d/base

prepare_conf ${CONF} ${SYS_CONF} ${BOOT_CONF}
prepare_conf ${NTP_CONF} ${SYS_NTP_CONF} ${BOOT_NTP_CONF}

test -s ${CONF} || exit 0

test "${OS_NETWORKLESS}" == "true" && exit 0

DATE_TIMEOUT=10
DATE_METHOD=sntp
DATE_HOST="google.com"
DATE_INTERVAL="900"
DATE_NTP_SERVER=""

source ${CONF}


set_current_date_http() {
    curl_args="-v -s -m ${DATE_TIMEOUT} -H \"Cache-Control: no-cache\" -X GET"
    url="http://${DATE_HOST}?_=${RANDOM}"
    date_str=$(curl ${curl_args} ${url} 2>&1 | grep Date | sed -e 's/< Date: //')
    if [[ -n "${date_str}" ]]; then
        ${PROG_DATE} -u -D "%a, %d %b %Y %H:%M:%S" -s "${date_str}" > /dev/null
        logger -t date "current system date/time set to $(date) via HTTP"
        return 0
    else
        logger -t date "failed to set current system date/time via HTTP"
        return 1
    fi
}

set_current_date_ntp() {
    if [[ -n "${DATE_NTP_SERVER}" ]]; then
        sed -i "s/pool .*/pool ${DATE_NTP_SERVER} iburst/" ${NTP_CONF}
    fi

    ${PROG_NTPD} -f ${NTP_CONF} -q -t ${DATE_TIMEOUT} &>/dev/null
    if [[ $? == 0 ]]; then
        logger -t date "current system date/time set to $(date) via NTP"
        return 0
    else
        logger -t date "failed to set current system date/time via NTP"
        return 1
    fi
}

set_current_date_sntp() {
    sntp_args="-t ${DATE_TIMEOUT} -K /dev/null -Ss"
    server=$(cat ${NTP_CONF} | grep pool | head -n 1 | cut -d ' ' -f 2)
    
    # Retry command 3 times
    truncate -s0 ${LOG_SNTP}
    ok=false
    for (( i = 0; i < 3; i++ )); do
        ${PROG_SNTP} ${sntp_args} ${server} &>>${LOG_SNTP} && { ok=true; break; }
        sleep 1
    done
    if [[ ${ok} == true ]]; then
        logger -t date "current system date/time set to $(date) via SNTP"
        return 0
    else
        logger -t date "failed to set current system date/time via SNTP"
        return 1
    fi
}


start_http() {
    msg_begin "Setting current date using HTTP"
    if set_current_date_http; then
        sleep_interval=${DATE_INTERVAL}
        msg_done "$(${PROG_DATE})"
    else
        sleep_interval=${DATE_TIMEOUT}
        msg_fail
    fi
    
    msg_begin "Starting http date updater"
    while true; do
        sleep ${sleep_interval}
        if set_current_date_http; then
            sleep_interval=${DATE_INTERVAL}
        else
            sleep_interval=${DATE_TIMEOUT}
        fi
    done &
    msg_done
}

start_ntp() {
    if [[ -n "${DATE_NTP_SERVER}" ]]; then
        sed -i "s/pool .*/pool ${DATE_NTP_SERVER} iburst/" ${NTP_CONF}
    fi

    if [[ "${DATE_METHOD}" == "sntp" ]]; then
        msg_begin "Setting current date using SNTP"
        set_current_date_sntp
        test $? == 0 && msg_done "$(${PROG_DATE})" || msg_fail
    else # assuming ntp
        msg_begin "Setting current date using NTP"
        set_current_date_ntp
        test $? == 0 && msg_done "$(${PROG_DATE})" || msg_fail
    fi

    msg_begin "Starting ntpd"
    ${PROG_NTPD} -f ${NTP_CONF}
    test $? == 0 && msg_done || msg_fail
}

stop_http() {
    msg_begin "Stopping date updater"
    ps | grep S50date | grep -v $$ | grep -v grep | tr -s ' ' | sed -e 's/^\s//' | cut -d ' ' -f 1 | xargs -r kill
    test $? == 0 && msg_done || msg_fail
}

stop_ntp() {
    msg_begin "Stopping ntpd"
    killall -q $(basename ${PROG_NTPD})
    test $? == 0 && msg_done || msg_fail
}

start() {
    # Load saved date first
    test -s ${SAVED_DATE_FILE} && date -s $(cat ${SAVED_DATE_FILE}) -D%s >/dev/null

    if [[ "${DATE_METHOD}" == "http" ]]; then
        start_http
    else # ntp or sntp
        start_ntp
    fi

    echo "system date is $(${PROG_DATE} '+%Y-%m-%d %H:%M:%S')" > /dev/kmsg
}

stop() {
    if [[ "${DATE_METHOD}" == "http" ]]; then
        stop_http
    else # ntp or sntp
        stop_ntp
    fi
    
    # Save current date to disk for next time
    date +%s > ${SAVED_DATE_FILE}
}

case "$1" in
    start)
        start
        ;;

    stop)
        stop
        ;;

    restart)
        stop
        start
        ;;

    *)
        echo "Usage: $0 {start|stop|restart}"
        exit 1
esac

exit $?