-extern const char ovs_pkgdatadir[]; /* /usr/local/share/openvswitch */
-extern const char ovs_rundir[]; /* /usr/local/var/run/openvswitch */
-extern const char ovs_logdir[]; /* /usr/local/var/log/openvswitch */
-extern const char ovs_bindir[]; /* /usr/local/bin */
+const char *ovs_pkgdatadir(void); /* /usr/local/share/openvswitch */
+const char *ovs_rundir(void); /* /usr/local/var/run/openvswitch */
+const char *ovs_logdir(void); /* /usr/local/var/log/openvswitch */
+const char *ovs_bindir(void); /* /usr/local/bin */