DNSMASQ_DHCP_VER=4
-dnsmasq_features="$(dnsmasq --version | grep -m1 'Compile time options:' | cut -d: -f2) "
-[ "${dnsmasq_features#* DHCP }" = "$dnsmasq_features" ] || dnsmasq_has_dhcp=1
-[ "${dnsmasq_features#* DHCPv6 }" = "$dnsmasq_features" ] || dnsmasq_has_dhcp6=1
-[ "${dnsmasq_features#* DNSSEC }" = "$dnsmasq_features" ] || dnsmasq_has_dnssec=1
-[ "${dnsmasq_features#* TFTP }" = "$dnsmasq_features" ] || dnsmasq_has_tftp=1
-[ "${dnsmasq_features#* ipset }" = "$dnsmasq_features" ] || dnsmasq_has_ipset=1
dnsmasq_ignore_opt() {
local opt="$1"
+ if [ -z "$dnsmasq_features" ]; then
+ dnsmasq_features="$(dnsmasq --version | grep -m1 'Compile time options:' | cut -d: -f2) "
+ [ "${dnsmasq_features#* DHCP }" = "$dnsmasq_features" ] || dnsmasq_has_dhcp=1
+ [ "${dnsmasq_features#* DHCPv6 }" = "$dnsmasq_features" ] || dnsmasq_has_dhcp6=1
+ [ "${dnsmasq_features#* DNSSEC }" = "$dnsmasq_features" ] || dnsmasq_has_dnssec=1
+ [ "${dnsmasq_features#* TFTP }" = "$dnsmasq_features" ] || dnsmasq_has_tftp=1
+ [ "${dnsmasq_features#* ipset }" = "$dnsmasq_features" ] || dnsmasq_has_ipset=1
+ fi
+
case "$opt" in
dhcp-duid|\
ra-param)