/*
 * Copyright (c) 2008, 2009 Nicira Networks.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef MAC_LEARNING_H
#define MAC_LEARNING_H 1

#include <time.h>
#include "list.h"
#include "packets.h"
#include "tag.h"

#define MAC_HASH_BITS 10
#define MAC_HASH_MASK (MAC_HASH_SIZE - 1)
#define MAC_HASH_SIZE (1u << MAC_HASH_BITS)

#define MAC_MAX 1024

/* 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. */
    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. */
};

/* 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  */
};

struct mac_learning *mac_learning_create(void);
void mac_learning_destroy(struct mac_learning *);
tag_type mac_learning_learn(struct mac_learning *,
                            const uint8_t src[ETH_ADDR_LEN], uint16_t vlan,
                            uint16_t src_port);
int mac_learning_lookup(const struct mac_learning *,
                        const uint8_t dst[ETH_ADDR_LEN], uint16_t vlan);
int mac_learning_lookup_tag(const struct mac_learning *,
                            const uint8_t dst[ETH_ADDR_LEN],
                            uint16_t vlan, tag_type *tag);
void mac_learning_flush(struct mac_learning *);
void mac_learning_run(struct mac_learning *, struct tag_set *);
void mac_learning_wait(struct mac_learning *);

#endif /* mac-learning.h */