sys/net/route.h

/*
 * Copyright (c) 1980, 1986 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *      @(#)route.h     7.4 (Berkeley) 6/27/88
 */

/*
 * Kernel resident routing tables.
 *
 * The routing tables are initialized when interface addresses
 * are set by making entries for all directly connected interfaces.
 */

/*
 * A route consists of a destination address and a reference
 * to a routing entry.  These are often held by protocols
 * in their control blocks, e.g. inpcb.
 */
struct route {
        struct  rtentry *ro_rt;
        struct  sockaddr ro_dst;
};

/*
 * We distinguish between routes to hosts and routes to networks,
 * preferring the former if available.  For each route we infer
 * the interface to use from the gateway address supplied when
 * the route was entered.  Routes that forward packets through
 * gateways are marked so that the output routines know to address the
 * gateway rather than the ultimate destination.
 */
struct rtentry {
        u_long  rt_hash;                /* to speed lookups */
        struct  sockaddr rt_dst;        /* key */
        struct  sockaddr rt_gateway;    /* value */
        short   rt_flags;               /* up/down?, host/net */
        short   rt_refcnt;              /* # held references */
        u_long  rt_use;                 /* raw # packets forwarded */
        struct  ifnet *rt_ifp;          /* the answer: interface to use */
};

#define RTF_UP          0x1             /* route useable */
#define RTF_GATEWAY     0x2             /* destination is a gateway */
#define RTF_HOST        0x4             /* host entry (net otherwise) */
#define RTF_DYNAMIC     0x10            /* created dynamically (by redirect) */
#define RTF_MODIFIED    0x20            /* modified dynamically (by redirect) */

/*
 * Routing statistics.
 */
struct  rtstat {
        short   rts_badredirect;        /* bogus redirect calls */
        short   rts_dynamic;            /* routes created by redirects */
        short   rts_newgateway;         /* routes modified by redirects */
        short   rts_unreach;            /* lookups which failed */
        short   rts_wildcard;           /* lookups satisfied by a wildcard */
};

#ifdef KERNEL
#define RTFREE(rt) \
        if ((rt)->rt_refcnt == 1) \
                rtfree(rt); \
        else \
                (rt)->rt_refcnt--;

#ifdef  GATEWAY
#define RTHASHSIZ       64
#else
#define RTHASHSIZ       8
#endif
#if     (RTHASHSIZ & (RTHASHSIZ - 1)) == 0
#define RTHASHMOD(h)    ((h) & (RTHASHSIZ - 1))
#else
#define RTHASHMOD(h)    ((h) % RTHASHSIZ)
#endif
struct  mbuf *rthost[RTHASHSIZ];
struct  mbuf *rtnet[RTHASHSIZ];
struct  rtstat  rtstat;
#endif