+
+/* XXX These probably belong elsewhere */
+void in_arpinput __P((struct mbuf *));
+void arpwhohas __P((struct arpcom *, struct in_addr *));
+
+#ifdef MULTICAST
+/*
+ * Ethernet multicast address structure. There is one of these for each
+ * multicast address or range of multicast addresses that we are supposed
+ * to listen to on a particular interface. They are kept in a linked list,
+ * rooted in the interface's arpcom structure. (This really has nothing to
+ * do with ARP, or with the Internet address family, but this appears to be
+ * the minimally-disrupting place to put it.)
+ */
+struct ether_multi {
+ u_char enm_addrlo[6]; /* low or only address of range */
+ u_char enm_addrhi[6]; /* high or only address of range */
+ struct arpcom *enm_ac; /* back pointer to arpcom */
+ u_int enm_refcount; /* no. claims to this addr/range */
+ struct ether_multi *enm_next; /* ptr to next ether_multi */
+};
+
+#ifdef KERNEL
+/*
+ * Structure used by macros below to remember position when stepping through
+ * all of the ether_multi records.
+ */
+struct ether_multistep {
+ struct ether_multi *e_enm;
+};
+
+/*
+ * Macro for looking up the ether_multi record for a given range of Ethernet
+ * multicast addresses connected to a given arpcom structure. If no matching
+ * record is found, "enm" returns NULL.
+ */
+#define ETHER_LOOKUP_MULTI(addrlo, addrhi, ac, enm) \
+ /* u_char addrlo[6]; */ \
+ /* u_char addrhi[6]; */ \
+ /* struct arpcom *ac; */ \
+ /* struct ether_multi *enm; */ \
+{ \
+ for ((enm) = (ac)->ac_multiaddrs; \
+ (enm) != NULL && \
+ (bcmp((enm)->enm_addrlo, (addrlo), 6) != 0 || \
+ bcmp((enm)->enm_addrhi, (addrhi), 6) != 0); \
+ (enm) = (enm)->enm_next); \
+}
+
+/*
+ * Macro to step through all of the ether_multi records, one at a time.
+ * The current position is remembered in "step", which the caller must
+ * provide. ETHER_FIRST_MULTI(), below, must be called to initialize "step"
+ * and get the first record. Both macros return a NULL "enm" when there
+ * are no remaining records.
+ */
+#define ETHER_NEXT_MULTI(step, enm) \
+ /* struct ether_multistep step; */ \
+ /* struct ether_multi *enm; */ \
+{ \
+ if (((enm) = (step).e_enm) != NULL) \
+ (step).e_enm = (enm)->enm_next; \
+}
+
+#define ETHER_FIRST_MULTI(step, ac, enm) \
+ /* struct ether_multistep step; */ \
+ /* struct arpcom *ac; */ \
+ /* struct ether_multi *enm; */ \
+{ \
+ (step).e_enm = (ac)->ac_multiaddrs; \
+ ETHER_NEXT_MULTI((step), (enm)); \
+}
+#endif
+#endif