root/src/add-ons/kernel/network/stack/radix.h
/*
 * Copyright 2006, Haiku, Inc. All Rights Reserved.
 * Distributed under the terms of the MIT License.
 */

/*
 * 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.
 * 4. 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_


#include <SupportDefs.h>


/*
 * 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*/
        uint8   rn_flags;               /* enumerated next */
        union {
                struct {                        /* leaf only data: */
                        uint8   *rn_Key;                /* object of search */
                        uint8   *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 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) */

#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 */
        uint8   rm_flags;               /* cf. rn_flags */
        struct  radix_mask *rm_mklist;  /* more masks to try */
        union   {
                uint8   *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 */

typedef int walktree_f_t(struct radix_node *, void *);

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_addaddr)      /* add based on sockaddr */
                (void *v, void *mask,
                     struct radix_node_head *head, struct radix_node nodes[]);
        struct  radix_node *(*rnh_addpkt)       /* add based on packet hdr */
                (void *v, void *mask,
                     struct radix_node_head *head, struct radix_node nodes[]);
        struct  radix_node *(*rnh_deladdr)      /* remove based on sockaddr */
                (void *v, void *mask, struct radix_node_head *head);
        struct  radix_node *(*rnh_delpkt)       /* remove based on packet hdr */
                (void *v, void *mask, struct radix_node_head *head);
        struct  radix_node *(*rnh_matchaddr)    /* locate based on sockaddr */
                (void *v, struct radix_node_head *head);
        struct  radix_node *(*rnh_lookup)       /* locate based on sockaddr */
                (void *v, void *mask, struct radix_node_head *head);
        struct  radix_node *(*rnh_matchpkt)     /* locate based on packet hdr */
                (void *v, struct radix_node_head *head);
        int     (*rnh_walktree)                 /* traverse tree */
                (struct radix_node_head *head, walktree_f_t *f, void *w);
        int     (*rnh_walktree_from)            /* traverse tree below a */
                (struct radix_node_head *head, void *a, void *m,
                     walktree_f_t *f, void *w);
        void    (*rnh_close)    /* do something when the last ref drops */
                (struct radix_node *rn, struct radix_node_head *head);
        struct  radix_node rnh_nodes[3];        /* empty tree for common case */
};


#ifdef __cplusplus
extern "{"
#endif

void    rn_init(void);
int             rn_inithead(void **, int);
int             rn_refines(void *, void *);
struct radix_node *rn_addmask(void *, int, int);
struct radix_node *rn_addroute (void *, void *, struct radix_node_head *,
                        struct radix_node [2]);
struct radix_node *rn_delete(void *, void *, struct radix_node_head *);
struct radix_node *rn_lookup (void *v_arg, void *m_arg,
                        struct radix_node_head *head);
struct radix_node *rn_match(void *, struct radix_node_head *);

#ifdef __cplusplus
}
#endif

#endif /* _RADIX_H_ */