freebsd-dev/libexec/rc/rc.d/ntpd
Ian Lepore 735c001b6b Allow opt-out of automatic ntpd leapfile checking/fetching.
When a system has no internet connection, or when it is configured to obtain
ntpd leapfiles from some source other than the internet, or even when the
sysadmin has decided for some reason to customize ntp.conf to eliminate use
of the leapfile, the rc.d/ntpd script emits various error messages related
to the file.

This change allows setting the rc var ntp_db_leapfile to NONE to disable all
automatic processing related to that file in rc.d/ntpd.

Differential Revision:	https://reviews.freebsd.org/D22461
2019-11-25 19:59:53 +00:00

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#!/bin/sh
#
# $FreeBSD$
#
# PROVIDE: ntpd
# REQUIRE: DAEMON ntpdate FILESYSTEMS devfs
# BEFORE: LOGIN
# KEYWORD: nojail shutdown
. /etc/rc.subr
name="ntpd"
desc="Network Time Protocol daemon"
rcvar="ntpd_enable"
command="/usr/sbin/${name}"
extra_commands="fetch needfetch"
fetch_cmd="ntpd_fetch_leapfile"
needfetch_cmd="ntpd_needfetch_leapfile"
start_precmd="ntpd_precmd"
_ntp_tmp_leapfile="/var/run/ntpd.leap-seconds.list"
_ntp_default_dir="/var/db/ntp"
_ntp_default_driftfile="${_ntp_default_dir}/ntpd.drift"
_ntp_old_driftfile="/var/db/ntpd.drift"
pidfile="${_ntp_default_dir}/${name}.pid"
load_rc_config $name
leapfile_is_disabled() {
# Return true (0) if automatic leapfile handling is disabled.
case "$ntp_db_leapfile" in
[Nn][Oo] | [Nn][Oo][Nn][Ee] )
return 0;;
* )
return 1;;
esac
}
can_run_nonroot()
{
# If the admin set what uid to use, we don't change it.
if [ -n "${ntpd_user}" ]; then
return 1
fi
# If the admin set any command line options involving files, we
# may not be able to access them as user ntpd.
case "${rc_flags}" in
*-f* | *--driftfile* | *-i* | *--jaildir* | \
*-k* | *--keyfile* | *-l* | *--logfile* | \
*-p* | *--pidfile* | *-s* | *--statsdir* )
return 1;;
esac
# If the admin set any options in ntp.conf involving files,
# we may not be able to access them as user ntpd.
local fileopts="^[ \t]*crypto|^[ \t]*driftfile|^[ \t]*key|^[ \t]*logfile|^[ \t]*statsdir"
grep -E -q "${fileopts}" "${ntpd_config}" && return 1
# Try to set up the the MAC ntpd policy so ntpd can run with reduced
# privileges. Detect whether MAC is compiled into the kernel, load
# the policy module if not already present, then check whether the
# policy has been disabled via tunable or sysctl.
[ -n "$(sysctl -qn security.mac.version)" ] || return 1
sysctl -qn security.mac.ntpd >/dev/null || kldload -qn mac_ntpd || return 1
[ "$(sysctl -qn security.mac.ntpd.enabled)" == "1" ] || return 1
# On older existing systems, the ntp dir may by owned by root, change
# it to ntpd to give the daemon create/write access to the driftfile.
if [ "$(stat -f %u ${_ntp_default_dir})" = "0" ]; then
chown ntpd:ntpd "${_ntp_default_dir}" || return 1
chmod 0755 "${_ntp_default_dir}" || return 1
logger -s -t "rc.d/ntpd" -p daemon.notice \
"${_ntp_default_dir} updated to owner ntpd:ntpd, mode 0755"
fi
# If the driftfile exists in the standard location for older existing
# systems, move it into the ntp dir and fix the ownership if we can.
if [ -f "${_ntp_old_driftfile}" ] && [ ! -L "${_ntp_old_driftfile}" ]; then
mv "${_ntp_old_driftfile}" "${_ntp_default_driftfile}" &&
chown ntpd:ntpd "${_ntp_default_driftfile}" || return 1
logger -s -t "rc.d/ntpd" -p daemon.notice \
"${_ntp_default_driftfile} updated to owner ntpd:ntpd"
logger -s -t "rc.d/ntpd" -p daemon.notice \
"${_ntp_old_driftfile} moved to ${_ntp_default_driftfile}"
fi
}
ntpd_precmd()
{
local driftopt
# If we can run as a non-root user, switch uid to ntpd and use the
# new default location for the driftfile inside the ntpd-owned dir.
# Otherwise, figure out what to do about the driftfile option. If set
# by the admin, we don't add the option. If the file exists in the old
# default location we use that, else we use the new default location.
if can_run_nonroot; then
_user="ntpd"
driftopt="-f ${_ntp_default_driftfile}"
elif grep -q "^[ \t]*driftfile" "${ntpd_config}" ||
[ -n "${rc_flags}" ] &&
( [ -z "${rc_flags##*-f*}" ] ||
[ -z "${rc_flags##*--driftfile*}" ] ); then
driftopt="" # admin set the option, we don't need to add it.
elif [ -f "${_ntp_old_driftfile}" ]; then
driftopt="-f ${_ntp_old_driftfile}"
else
driftopt="-f ${_ntp_default_driftfile}"
fi
# Set command_args based on the various config vars.
command_args="-p ${pidfile} -c ${ntpd_config} ${driftopt}"
if checkyesno ntpd_sync_on_start; then
command_args="${command_args} -g"
fi
# Make sure the leapfile is ready to use, unless leapfile
# handling is disabled.
if leapfile_is_disabled; then
return
fi
ntpd_init_leapfile
if [ ! -f "${ntp_db_leapfile}" ]; then
ntpd_fetch_leapfile
fi
}
current_ntp_ts() {
# Seconds between 1900-01-01 and 1970-01-01
# echo $(((70*365+17)*86400))
ntp_to_unix=2208988800
echo $(($(date -u +%s)+$ntp_to_unix))
}
get_ntp_leapfile_ver() {
# Leapfile update date (version number).
expr "$(awk '$1 == "#$" { print $2 }' "$1" 2>/dev/null)" : \
'^\([1-9][0-9]*\)$' \| 0
}
get_ntp_leapfile_expiry() {
# Leapfile expiry date.
expr "$(awk '$1 == "#@" { print $2 }' "$1" 2>/dev/null)" : \
'^\([1-9][0-9]*\)$' \| 0
}
ntpd_init_leapfile() {
if leapfile_is_disabled; then
return
fi
# Refresh working leapfile with an invalid hash due to
# FreeBSD id header. Ntpd will ignore leapfiles with a
# mismatch hash. The file must be the virgin file from
# the source.
if [ ! -f $ntp_db_leapfile ]; then
cp -p $ntp_src_leapfile $ntp_db_leapfile
fi
}
ntpd_needfetch_leapfile() {
local rc verbose
if leapfile_is_disabled; then
# Return code 1: ntp leapfile fetch not needed
return 1
fi
if checkyesno ntp_leapfile_fetch_verbose; then
verbose=echo
else
verbose=:
fi
ntp_ver_no_src=$(get_ntp_leapfile_ver $ntp_src_leapfile)
ntp_expiry_src=$(get_ntp_leapfile_expiry $ntp_src_leapfile)
ntp_ver_no_db=$(get_ntp_leapfile_ver $ntp_db_leapfile)
ntp_expiry_db=$(get_ntp_leapfile_expiry $ntp_db_leapfile)
$verbose ntp_src_leapfile version is $ntp_ver_no_src expires $ntp_expiry_src
$verbose ntp_db_leapfile version is $ntp_ver_no_db expires $ntp_expiry_db
if [ "$ntp_ver_no_src" -gt "$ntp_ver_no_db" -o \
"$ntp_ver_no_src" -eq "$ntp_ver_no_db" -a \
"$ntp_expiry_src" -gt "$ntp_expiry_db" ]; then
$verbose replacing $ntp_db_leapfile with $ntp_src_leapfile
cp -p $ntp_src_leapfile $ntp_db_leapfile
ntp_ver_no_db=$ntp_ver_no_src
else
$verbose not replacing $ntp_db_leapfile with $ntp_src_leapfile
fi
ntp_leapfile_expiry_seconds=$((ntp_leapfile_expiry_days*86400))
ntp_leap_expiry=$(get_ntp_leapfile_expiry $ntp_db_leapfile)
ntp_leap_fetch_date=$((ntp_leap_expiry-ntp_leapfile_expiry_seconds))
if [ $(current_ntp_ts) -ge $ntp_leap_fetch_date ]; then
$verbose Within ntp leapfile expiry limit, initiating fetch
# Return code 0: ntp leapfile fetch needed
return 0
fi
# Return code 1: ntp leapfile fetch not needed
return 1
}
ntpd_fetch_leapfile() {
if leapfile_is_disabled; then
return
fi
if checkyesno ntp_leapfile_fetch_verbose; then
verbose=echo
else
verbose=:
fi
if ntpd_needfetch_leapfile ; then
for url in $ntp_leapfile_sources ; do
$verbose fetching $url
fetch $ntp_leapfile_fetch_opts -o $_ntp_tmp_leapfile $url && break
done
ntp_ver_no_tmp=$(get_ntp_leapfile_ver $_ntp_tmp_leapfile)
ntp_expiry_tmp=$(get_ntp_leapfile_expiry $_ntp_tmp_leapfile)
if [ "$ntp_expiry_tmp" -gt "$ntp_expiry_db" -o \
"$ntp_expiry_tmp" -eq "$ntp_expiry_db" -a \
"$ntp_ver_no_tmp" -gt "$ntp_ver_no_db" ]; then
$verbose using $url as $ntp_db_leapfile
mv -f $_ntp_tmp_leapfile $ntp_db_leapfile ||
$verbose "warning: cannot replace $ntp_db_leapfile (read-only fs?)"
else
$verbose using existing $ntp_db_leapfile
fi
fi
}
run_rc_command "$1"