-add_executable(odhcpd src/odhcpd.c src/config.c src/router.c src/dhcpv6.c src/ndp.c src/dhcpv6-ia.c src/dhcpv4.c ${EXT_SRC})
-target_link_libraries(odhcpd resolv ubox uci ${EXT_LINK})
+if(${DHCPV4_SUPPORT})
+ add_definitions(-DDHCPV4_SUPPORT)
+ set(EXT_SRC ${EXT_SRC} src/dhcpv4.c)
+endif(${DHCPV4_SUPPORT})
+
+add_executable(odhcpd src/odhcpd.c src/config.c src/router.c src/dhcpv6.c src/ndp.c src/dhcpv6-ia.c src/netlink.c ${EXT_SRC})
+target_link_libraries(odhcpd resolv ubox uci ${libnl} ${EXT_LINK})