# Sample dhcpcd hook script for NTP

# Sample dhcpcd hook script for NTP
# It will configure either one of NTP, OpenNTP or Chrony (in that order)
# and will default to NTP if no default config is found.

# Like our resolv.conf hook script, we store a database of ntp.conf files
# and merge into /etc/ntp.conf

# You can set the env var NTP_CONF to override the derived default on
# systems with >1 NTP client installed.
# Here is an example for OpenNTP
# dhcpcd -e NTP_CONF=/usr/pkg/etc/ntpd.conf
# or by adding this to /etc/dhcpcd.conf
# env NTP_CONF=/usr/pkg/etc/ntpd.conf
# or by adding this to /etc/dhcpcd.enter-hook
# NTP_CONF=/usr/pkg/etc/ntpd.conf
# To use Chrony instead, simply change ntpd.conf to chrony.conf in the
# above examples.

: ${ntp_confs:=ntp.conf ntpd.conf chrony.conf}
: ${ntp_conf_dirs=/etc /usr/pkg/etc /usr/local/etc}
ntp_conf_dir="$state_dir/ntp.conf"

# If NTP_CONF is not set, work out a good default
if [ -z "$NTP_CONF" ]; then
for d in ${ntp_conf_dirs}; do
for f in ${ntp_confs}; do
if [ -e "$d/$f" ]; then
NTP_CONF="$d/$f"
break 2
fi
done
done
[ -e "$NTP_CONF" ] || NTP_CONF=/etc/ntp.conf
fi

# Derive service name from configuration
if [ -z "$ntp_service" ]; then
case "$NTP_CONF" in
*chrony.conf) ntp_service=chronyd;;
*) ntp_service=ntpd;;
esac
fi

# Debian has a separate file for DHCP config to avoid stamping on
# the master.
if [ "$ntp_service" = ntpd ] && command -v invoke-rc.d >/dev/null 2>&1; then
[ -e /var/lib/ntp ] || mkdir /var/lib/ntp
: ${ntp_service:=ntp}
: ${NTP_DHCP_CONF:=/var/lib/ntp/ntp.conf.dhcp}
fi

: ${ntp_restart_cmd:=service_condcommand $ntp_service restart}

ntp_conf=${NTP_CONF}
NL="
"

build_ntp_conf()
{
cf="$state_dir/ntp.conf.$ifname"

# Build a list of interfaces
interfaces=$(list_interfaces "$ntp_conf_dir")

header=
servers=
if [ -n "$interfaces" ]; then
# Build the header
for x in ${interfaces}; do
header="$header${header:+, }$x"
done

# Build a server list
srvs=$(cd "$ntp_conf_dir";
key_get_value "server " $interfaces)
if [ -n "$srvs" ]; then
for x in $(uniqify $srvs); do
servers="${servers}server $x$NL"
done
fi
fi

# Merge our config into ntp.conf
[ -e "$cf" ] && rm -f "$cf"
[ -d "$ntp_conf_dir" ] || mkdir -p "$ntp_conf_dir"

if [ -n "$NTP_DHCP_CONF" ]; then
[ -e "$ntp_conf" ] && cp "$ntp_conf" "$cf"
ntp_conf="$NTP_DHCP_CONF"
elif [ -e "$ntp_conf" ]; then
remove_markers "$signature_base" "$signature_base_end" \
"$ntp_conf" > "$cf"
fi

if [ -n "$servers" ]; then
echo "$signature_base${header:+ $from }$header" >> "$cf"
printf %s "$servers" >> "$cf"
echo "$signature_base_end${header:+ $from }$header" >> "$cf"
else
[ -e "$ntp_conf" ] && [ -e "$cf" ] || return
fi

# If we changed anything, restart ntpd
if change_file "$ntp_conf" "$cf"; then
[ -n "$ntp_restart_cmd" ] && eval $ntp_restart_cmd
fi
}

add_ntp_conf()
{
cf="$ntp_conf_dir/$ifname"

[ -e "$cf" ] && rm "$cf"
[ -d "$ntp_conf_dir" ] || mkdir -p "$ntp_conf_dir"
if [ -n "$new_ntp_servers" ]; then
for x in $(uniqify $new_ntp_servers); do
echo "server $x" >> "$cf"
done
fi
build_ntp_conf
}

remove_ntp_conf()
{
if [ -e "$ntp_conf_dir/$ifname" ]; then
rm "$ntp_conf_dir/$ifname"
fi
build_ntp_conf
}

# For ease of use, map DHCP6 names onto our DHCP4 names
case "$reason" in
BOUND6|RENEW6|REBIND6|REBOOT6|INFORM6)
new_ntp_servers="$new_dhcp6_sntp_servers $new_dhcp6_ntp_server_addr $new_dhcp6_ntp_server_fqdn"
;;
esac

if $if_configured; then
if $if_up; then
add_ntp_conf
elif $if_down; then
remove_ntp_conf
fi
fi