/*      $NetBSD: if_llatbl.h,v 1.20 2026/03/26 04:35:17 ozaki-r Exp $   */
/*
 * Copyright (c) 2004 Luigi Rizzo, Alessandro Cerri. All rights reserved.
 * Copyright (c) 2004-2008 Qing Li. All rights reserved.
 * Copyright (c) 2008 Kip Macy. All rights reserved.
 * Copyright (c) 2015 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#include <sys/cdefs.h>

#ifndef _NET_IF_LLATBL_H_
#define _NET_IF_LLATBL_H_

#if defined(_KERNEL_OPT)
#include "opt_gateway.h"
#include "opt_mbuftrace.h"
#endif

#include <sys/rwlock.h>
#include <sys/syslog.h>

#include <netinet/in.h>

struct ifnet;
struct sysctl_req;
struct rt_msghdr;
struct rt_addrinfo;
struct rt_walkarg;

struct llentry;
LIST_HEAD(llentries, llentry);

extern krwlock_t lltable_rwlock;
#define LLTABLE_RLOCK()         rw_enter(&lltable_rwlock, RW_READER)
#define LLTABLE_RUNLOCK()       rw_exit(&lltable_rwlock)
#define LLTABLE_WLOCK()         rw_enter(&lltable_rwlock, RW_WRITER)
#define LLTABLE_WUNLOCK()       rw_exit(&lltable_rwlock)
#define LLTABLE_LOCK_ASSERT()   KASSERT(rw_lock_held(&lltable_rwlock))

/*
 * Code referencing llentry must at least hold
 * a shared lock
 */
struct llentry {
        LIST_ENTRY(llentry)      lle_next;
        union l3addr {
                struct in_addr  addr4;
                struct in6_addr addr6;
        } r_l3addr;
        union {
                uint64_t        mac_aligned;
                uint16_t        mac16[3];
                uint8_t         mac8[20];       /* IB needs 20 bytes. */
        } ll_addr;
        uint32_t                spare0;
        uint64_t                spare1;

        struct lltable           *lle_tbl;
        struct llentries         *lle_head;
        void                    (*lle_free)(struct llentry *);
        void                    (*lle_ll_free)(struct llentry *);
        struct mbuf              *la_hold;
        int                      la_numheld;  /* # of packets currently held */
        time_t                   la_expire;
        uint16_t                 la_flags;
        uint16_t                 la_asked;
        uint16_t                 la_preempt;
        uint16_t                 ln_byhint;
        int16_t                  ln_state;      /* ND_LLINFO_NOSTATE == -2 */
        uint16_t                 ln_router;
        time_t                   ln_ntick;
        int                      lle_refcnt;

        LIST_ENTRY(llentry)     lle_chain;      /* chain of deleted items */
        struct callout          lle_timer;
        krwlock_t               lle_lock;

#ifdef __NetBSD__
#define la_timer        lle_timer
#define ln_timer_ch     lle_timer
#define ln_expire       la_expire
#define ln_asked        la_asked
#define ln_hold         la_hold
        void                    *la_opaque;     /* For tokenring */
#endif
};


#if 0
#define LLE_LOCK_TRACE(t, lle)  log(LOG_DEBUG, \
                                    "%s:%d: LOCK(" #t "): lle=%p\n", \
                                    __func__, __LINE__, (lle))
#else
#define LLE_LOCK_TRACE(t, lle)  do {} while (0)
#endif

#define LLE_WLOCK(lle)          do { \
                                        LLE_LOCK_TRACE(WL, (lle)); \
                                        rw_enter(&(lle)->lle_lock, RW_WRITER); \
                                } while (0)
#define LLE_RLOCK(lle)          do { \
                                        LLE_LOCK_TRACE(RL, (lle)); \
                                        rw_enter(&(lle)->lle_lock, RW_READER); \
                                } while (0)
#define LLE_WUNLOCK(lle)        do { \
                                        LLE_LOCK_TRACE(WU, (lle)); \
                                        rw_exit(&(lle)->lle_lock); \
                                } while (0)
#define LLE_RUNLOCK(lle)        do { \
                                        LLE_LOCK_TRACE(RU, (lle)); \
                                        rw_exit(&(lle)->lle_lock); \
                                } while (0)
#define LLE_DOWNGRADE(lle)      rw_downgrade(&(lle)->lle_lock)
#define LLE_TRY_UPGRADE(lle)    rw_tryupgrade(&(lle)->lle_lock)
#ifdef __FreeBSD__
#define LLE_LOCK_INIT(lle)      rw_init_flags(&(lle)->lle_lock, "lle", RW_DUPOK)
#else /* XXX */
#define LLE_LOCK_INIT(lle)      rw_init(&(lle)->lle_lock)
#endif
#define LLE_LOCK_DESTROY(lle)   rw_destroy(&(lle)->lle_lock)
#define LLE_WLOCK_ASSERT(lle)   KASSERT(rw_write_held(&(lle)->lle_lock))

#define LLE_IS_VALID(lle)       (((lle) != NULL) && ((lle) != (void *)-1))

#if 0
#define LLE_REF_TRACE(t, lle, n) \
        log(LOG_DEBUG, "%s:%d: %p REF(" #t "): refcnt=%d\n", \
            __func__, __LINE__, (lle), (n))
#else
#define LLE_REF_TRACE(t, lle, n)        do {} while (0)
#endif

#define LLE_ADDREF(lle) do {                                    \
        LLE_WLOCK_ASSERT(lle);                                  \
        LLE_REF_TRACE(ADD, (lle), (lle)->lle_refcnt);           \
        KASSERTMSG((lle)->lle_refcnt >= 0,                      \
            "negative refcnt %d on lle %p",                     \
            (lle)->lle_refcnt, (lle));                          \
        (lle)->lle_refcnt++;                                    \
} while (0)

#define LLE_REMREF(lle) do {                                    \
        LLE_WLOCK_ASSERT(lle);                                  \
        LLE_REF_TRACE(REM, (lle), (lle)->lle_refcnt);           \
        KASSERTMSG((lle)->lle_refcnt > 0,                       \
            "bogus refcnt %d on lle %p",                        \
            (lle)->lle_refcnt, (lle));                          \
        (lle)->lle_refcnt--;                                    \
        if ((lle)->lle_refcnt == 0)                             \
                LLE_REF_TRACE(ZERO, (lle), (lle)->lle_refcnt);  \
} while (0)

#define LLE_FREE_LOCKED(lle) do {                               \
        if ((lle)->lle_refcnt == 1) {                           \
                if ((lle)->lle_ll_free != NULL)                 \
                        (lle)->lle_ll_free(lle);                \
                (lle)->lle_free(lle);                           \
        } else {                                                \
                LLE_REMREF(lle);                                \
                LLE_WUNLOCK(lle);                               \
        }                                                       \
        /* guard against invalid refs */                        \
        (lle) = NULL;                                           \
} while (0)

#define LLE_FREE(lle) do {                                      \
        LLE_WLOCK(lle);                                         \
        LLE_FREE_LOCKED(lle);                                   \
} while (0)


typedef struct llentry *(llt_lookup_t)(struct lltable *, u_int flags,
    const struct sockaddr *l3addr);
typedef struct llentry *(llt_create_t)(struct lltable *, u_int flags,
    const struct sockaddr *l3addr, const struct rtentry *);
typedef int (llt_delete_t)(struct lltable *, u_int flags,
    const struct sockaddr *l3addr);
typedef void (llt_prefix_free_t)(struct lltable *,
    const struct sockaddr *prefix, const struct sockaddr *mask, u_int flags);
typedef int (llt_dump_entry_t)(struct lltable *, struct llentry *,
    struct rt_walkarg *);
typedef uint32_t (llt_hash_t)(const struct llentry *, uint32_t);
typedef int (llt_match_prefix_t)(const struct sockaddr *,
    const struct sockaddr *, u_int, struct llentry *);
typedef void (llt_free_entry_t)(struct lltable *, struct llentry *);
typedef void (llt_fill_sa_entry_t)(const struct llentry *, struct sockaddr *);
typedef void (llt_free_tbl_t)(struct lltable *);
typedef void (llt_link_entry_t)(struct lltable *, struct llentry *);
typedef void (llt_unlink_entry_t)(struct llentry *);

typedef int (llt_foreach_cb_t)(struct lltable *, struct llentry *, void *);
typedef int (llt_foreach_entry_t)(struct lltable *, llt_foreach_cb_t *, void *);

struct lltable {
        SLIST_ENTRY(lltable)    llt_link;
        int                     llt_af;
        int                     llt_hsize;
        struct llentries        *lle_head;
        unsigned int            llt_lle_count;
        struct ifnet            *llt_ifp;

        llt_lookup_t            *llt_lookup;
        llt_create_t            *llt_create;
        llt_delete_t            *llt_delete;
        llt_prefix_free_t       *llt_prefix_free;
        llt_dump_entry_t        *llt_dump_entry;
        llt_hash_t              *llt_hash;
        llt_match_prefix_t      *llt_match_prefix;
        llt_free_entry_t        *llt_free_entry;
        llt_foreach_entry_t     *llt_foreach_entry;
        llt_link_entry_t        *llt_link_entry;
        llt_unlink_entry_t      *llt_unlink_entry;
        llt_fill_sa_entry_t     *llt_fill_sa_entry;
        llt_free_tbl_t          *llt_free_tbl;
#ifdef MBUFTRACE
        struct mowner           *llt_mowner;
#endif
};

MALLOC_DECLARE(M_LLTABLE);

/*
 * LLentry flags
 */
#define LLE_DELETED     0x0001  /* entry must be deleted */
#define LLE_STATIC      0x0002  /* entry is static */
#define LLE_IFADDR      0x0004  /* entry is interface addr */
#define LLE_VALID       0x0008  /* ll_addr is valid */
#define LLE_PUB         0x0020  /* publish entry ??? */
#define LLE_LINKED      0x0040  /* linked to lookup structure */
#define LLE_UNRESOLVED  0x0080  /* address unresolved */
/* LLE request flags */
#define LLE_EXCLUSIVE   0x2000  /* return lle xlocked  */

#define LLATBL_HASH(key, mask) \
        (((((((key >> 8) ^ key) >> 8) ^ key) >> 8) ^ key) & mask)

void lltableinit(void);

struct lltable *lltable_allocate_htbl(uint32_t hsize);
void            lltable_free(struct lltable *);
void            lltable_link(struct lltable *llt);
void            lltable_prefix_free(const int, const struct sockaddr *,
                    const struct sockaddr *, const u_int);
void            lltable_drain(int);
void            lltable_purge_entries(struct lltable *);
int             lltable_sysctl_dump(int, struct rt_walkarg *);
int             lltable_dump_entry(struct lltable *, struct llentry *,
                    struct rt_walkarg *, struct sockaddr *);

size_t          llentry_free(struct llentry *);
struct llentry  *llentry_alloc(struct ifnet *, struct lltable *,
                    struct sockaddr_storage *);

struct llentry  *llentry_pool_get(int);
void            llentry_pool_put(struct llentry *);

/* helper functions */
size_t lltable_drop_entry_queue(struct llentry *);

struct llentry *lltable_create_lle(struct lltable *llt, u_int flags,
    const void *paddr);
void lltable_link_entry(struct lltable *llt, struct llentry *lle);
void lltable_unlink_entry(struct lltable *llt, struct llentry *lle);
void lltable_free_entry(struct lltable *llt, struct llentry *lle);
void lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa);
struct ifnet *lltable_get_ifp(const struct lltable *llt);
int lltable_get_af(const struct lltable *llt);

static __inline unsigned int
lltable_get_entry_count(struct lltable *llt)
{
        return llt->llt_lle_count;
}

int lltable_foreach_lle(struct lltable *llt, llt_foreach_cb_t *f,
    void *farg);
/*
 * Generic link layer address lookup function.
 */
static __inline struct llentry *
lla_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
{

        return (llt->llt_lookup(llt, flags, l3addr));
}

static __inline struct llentry *
lla_create(struct lltable *llt, u_int flags, const struct sockaddr *l3addr,
    const struct rtentry *rt)
{

        return (llt->llt_create(llt, flags, l3addr, rt));
}

static __inline int
lla_delete(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
{

        return (llt->llt_delete(llt, flags, l3addr));
}


int lla_rt_output(const u_char, const int, const time_t,
    struct rt_addrinfo *info, int);

#endif  /* _NET_IF_LLATBL_H_ */