/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1988, 1989, 1993
 *      The Regents of the University of California.  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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 THE REGENTS 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.
 */

#ifndef _RADIX_H_
#define _RADIX_H_

#ifdef _KERNEL
#include <sys/_lock.h>
#include <sys/_mutex.h>
#include <sys/_rmlock.h>
#endif

#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_RTABLE);
#endif

/*
 * Radix search tree node layout.
 */

struct radix_node {
        struct  radix_mask *rn_mklist;  /* list of masks contained in subtree */
        struct  radix_node *rn_parent;  /* parent */
        short   rn_bit;                 /* bit offset; -1-index(netmask) */
        char    rn_bmask;               /* node: mask for bit test*/
        u_char  rn_flags;               /* enumerated next */
#define RNF_NORMAL      1               /* leaf contains normal route */
#define RNF_ROOT        2               /* leaf is root leaf for tree */
#define RNF_ACTIVE      4               /* This node is alive (for rtfree) */
        union {
                struct {                        /* leaf only data: */
                        caddr_t rn_Key;         /* object of search */
                        caddr_t rn_Mask;        /* netmask, if present */
                        struct  radix_node *rn_Dupedkey;
                } rn_leaf;
                struct {                        /* node only data: */
                        int     rn_Off;         /* where to start compare */
                        struct  radix_node *rn_L;/* progeny */
                        struct  radix_node *rn_R;/* progeny */
                } rn_node;
        }               rn_u;
#ifdef RN_DEBUG
        int rn_info;
        struct radix_node *rn_twin;
        struct radix_node *rn_ybro;
#endif
};

#define rn_dupedkey     rn_u.rn_leaf.rn_Dupedkey
#define rn_key          rn_u.rn_leaf.rn_Key
#define rn_mask         rn_u.rn_leaf.rn_Mask
#define rn_offset       rn_u.rn_node.rn_Off
#define rn_left         rn_u.rn_node.rn_L
#define rn_right        rn_u.rn_node.rn_R

/*
 * Annotations to tree concerning potential routes applying to subtrees.
 */

struct radix_mask {
        short   rm_bit;                 /* bit offset; -1-index(netmask) */
        char    rm_unused;              /* cf. rn_bmask */
        u_char  rm_flags;               /* cf. rn_flags */
        struct  radix_mask *rm_mklist;  /* more masks to try */
        union   {
                caddr_t rmu_mask;               /* the mask */
                struct  radix_node *rmu_leaf;   /* for normal routes */
        }       rm_rmu;
        int     rm_refs;                /* # of references to this struct */
};

#define rm_mask rm_rmu.rmu_mask
#define rm_leaf rm_rmu.rmu_leaf         /* extra field would make 32 bytes */

struct radix_head;

typedef int walktree_f_t(struct radix_node *, void *);
typedef struct radix_node *rn_matchaddr_f_t(const void *v,
    struct radix_head *head);
typedef struct radix_node *rn_addaddr_f_t(void *v, const void *mask,
    struct radix_head *head, struct radix_node nodes[]);
typedef struct radix_node *rn_deladdr_f_t(const void *v, const void *mask,
    struct radix_head *head);
typedef struct radix_node *rn_lookup_f_t(const void *v, const void *mask,
    struct radix_head *head);
typedef int rn_walktree_t(struct radix_head *head, walktree_f_t *f,
    void *w);
typedef int rn_walktree_from_t(struct radix_head *head,
    void *a, void *m, walktree_f_t *f, void *w);
typedef void rn_close_t(struct radix_node *rn, struct radix_head *head);
struct radix_node *rn_nextprefix(struct radix_node *rn);

struct radix_mask_head;

struct radix_head {
        struct  radix_node *rnh_treetop;
        struct  radix_mask_head *rnh_masks;     /* Storage for our masks */
};

struct radix_node_head {
        struct radix_head rh;
        rn_matchaddr_f_t        *rnh_matchaddr; /* longest match for sockaddr */
        rn_addaddr_f_t  *rnh_addaddr;   /* add based on sockaddr*/
        rn_deladdr_f_t  *rnh_deladdr;   /* remove based on sockaddr */
        rn_lookup_f_t   *rnh_lookup;    /* exact match for sockaddr */
        rn_walktree_t   *rnh_walktree;  /* traverse tree */
        rn_walktree_from_t      *rnh_walktree_from; /* traverse tree below a */
        rn_close_t      *rnh_close;     /*do something when the last ref drops*/
        struct  radix_node rnh_nodes[3];        /* empty tree for common case */
#ifdef _KERNEL
        struct  rmlock rnh_lock;                /* locks entire radix tree */
#endif
};

struct radix_mask_head {
        struct radix_head head;
        struct radix_node mask_nodes[3];
};

void rn_inithead_internal(struct radix_head *rh, struct radix_node *base_nodes,
    int off);

#ifndef _KERNEL
#define R_Malloc(p, t, n) (p = (t) malloc((unsigned int)(n)))
#define R_Zalloc(p, t, n) (p = (t) calloc(1,(unsigned int)(n)))
#define R_Free(p) free((char *)p);
#else
#define R_Malloc(p, t, n) (p = (t) malloc((unsigned long)(n), M_RTABLE, M_NOWAIT))
#define R_Zalloc(p, t, n) (p = (t) malloc((unsigned long)(n), M_RTABLE, M_NOWAIT | M_ZERO))
#define R_Free(p) free((caddr_t)p, M_RTABLE);

#define RADIX_NODE_HEAD_RLOCK_TRACKER   struct rm_priotracker _rnh_tracker
#define RADIX_NODE_HEAD_LOCK_INIT(rnh)  \
    rm_init(&(rnh)->rnh_lock, "radix node head")
#define RADIX_NODE_HEAD_LOCK(rnh)       rm_wlock(&(rnh)->rnh_lock)
#define RADIX_NODE_HEAD_UNLOCK(rnh)     rm_wunlock(&(rnh)->rnh_lock)
#define RADIX_NODE_HEAD_RLOCK(rnh)      rm_rlock(&(rnh)->rnh_lock,\
    &_rnh_tracker)
#define RADIX_NODE_HEAD_RUNLOCK(rnh)    rm_runlock(&(rnh)->rnh_lock,\
    &_rnh_tracker)
#define RADIX_NODE_HEAD_DESTROY(rnh)    rm_destroy(&(rnh)->rnh_lock)
#define RADIX_NODE_HEAD_LOCK_ASSERT(rnh) rm_assert(&(rnh)->rnh_lock, RA_LOCKED)
#define RADIX_NODE_HEAD_WLOCK_ASSERT(rnh) rm_assert(&(rnh)->rnh_lock, RA_WLOCKED)
#endif /* _KERNEL */

int      rn_inithead(void **, int);
int      rn_detachhead(void **);
int      rn_refines(const void *, const void *);
struct radix_node *rn_addroute(void *, const void *, struct radix_head *,
    struct radix_node[2]);
struct radix_node *rn_delete(const void *, const void *, struct radix_head *);
struct radix_node *rn_lookup (const void *v_arg, const void *m_arg,
    struct radix_head *head);
struct radix_node *rn_match(const void *, struct radix_head *);
int rn_walktree_from(struct radix_head *h, void *a, void *m,
    walktree_f_t *f, void *w);
int rn_walktree(struct radix_head *, walktree_f_t *, void *);

#endif /* _RADIX_H_ */