+typedef u_int (*if_ndo_printer)(struct netdissect_options *ndo,
+ const struct pcap_pkthdr *, const u_char *);
+typedef u_int (*if_printer)(const struct pcap_pkthdr *, const u_char *);
+
+extern if_ndo_printer lookup_ndo_printer(int);
+extern if_printer lookup_printer(int);
+
+