/*      $OpenBSD: radix.h,v 1.30 2017/06/19 09:42:45 mpi Exp $  */
/*      $NetBSD: radix.h,v 1.8 1996/02/13 22:00:37 christos Exp $       */

/*
 * 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.
 *
 *      @(#)radix.h     8.2 (Berkeley) 10/31/94
 */

#ifndef _NET_RADIX_H_
#define _NET_RADIX_H_

/*
 * Radix search tree node layout.
 */

struct radix_node {
        struct  radix_mask *rn_mklist;  /* list of masks contained in subtree */
        struct  radix_node *rn_p;       /* parent */
        short   rn_b;                   /* 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;
};

#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_off rn_u.rn_node.rn_Off
#define rn_l rn_u.rn_node.rn_L
#define rn_r rn_u.rn_node.rn_R

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

struct radix_mask {
        short   rm_b;                   /* 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_node_head {
        struct  radix_node *rnh_treetop;
        int     rnh_addrsize;           /* permit, but not require fixed keys */
        int     rnh_pktsize;            /* permit, but not require fixed keys */
        struct  radix_node rnh_nodes[3];/* empty tree for common case */
        u_int   rnh_rtableid;
};

void    rn_init(unsigned int);
int     rn_inithead(void **, int);

int     rn_walktree(struct radix_node_head *,
            int (*)(struct radix_node *, void *, u_int), void *);

struct radix_node       *rn_addroute(void *, void *, struct radix_node_head *,
                            struct radix_node [2], u_int8_t);
struct radix_node       *rn_delete(void *, void *, struct radix_node_head *,
                            struct radix_node *);
struct radix_node       *rn_lookup(void *, void *, struct radix_node_head *);
struct radix_node       *rn_match(void *, struct radix_node_head *);

#endif /* _NET_RADIX_H_ */