+#define MAC_HASH_BITS 10
+#define MAC_HASH_MASK (MAC_HASH_SIZE - 1)
+#define MAC_HASH_SIZE (1u << MAC_HASH_BITS)
+
+#define MAC_MAX 2048
+
+/* Time, in seconds, before expiring a mac_entry due to inactivity. */
+#define MAC_ENTRY_IDLE_TIME 60
+
+/* Time, in seconds, to lock an entry updated by a gratuitous ARP to avoid
+ * relearning based on a reflection from a bond slave. */
+#define MAC_GRAT_ARP_LOCK_TIME 5
+
+enum grat_arp_lock_type {
+ GRAT_ARP_LOCK_NONE,
+ GRAT_ARP_LOCK_SET,
+ GRAT_ARP_LOCK_CHECK
+};
+
+/* A MAC learning table entry. */
+struct mac_entry {
+ struct list hash_node; /* Element in a mac_learning 'table' list. */
+ struct list lru_node; /* Element in 'lrus' or 'free' list. */
+ time_t expires; /* Expiration time. */
+ time_t grat_arp_lock; /* Gratuitous ARP lock expiration time. */
+ uint8_t mac[ETH_ADDR_LEN]; /* Known MAC address. */
+ uint16_t vlan; /* VLAN tag. */
+ int port; /* Port on which MAC was most recently seen. */
+ tag_type tag; /* Tag for this learning entry. */
+};
+
+int mac_entry_age(const struct mac_entry *);
+
+/* MAC learning table. */
+struct mac_learning {
+ struct list free; /* Not-in-use entries. */
+ struct list lrus; /* In-use entries, least recently used at the
+ front, most recently used at the back. */
+ struct list table[MAC_HASH_SIZE]; /* Hash table. */
+ struct mac_entry entries[MAC_MAX]; /* All entries. */
+ uint32_t secret; /* Secret for randomizing hash table. */
+ unsigned long *flood_vlans; /* Bitmap of learning disabled VLANs. */
+};
+