route.h

<B>Digital的Unix操作系统VAX 4.2源码</B>

/* static	char	*sccsid = "@(#)route.h	4.1	(ULTRIX)	7/2/90"; */
/************************************************************************
 *									*
 *			Copyright (c) 1984,1988 by			*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/
/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 *	route.h	7.1 (Berkeley) 6/4/86
 */

/*
 *	27-MAR-89	U. Sinkewicz
 *		Added lp routing changes from 3/16/89.
 *	
 *	15-Jan-88	lp
 *		Merge of final 43BSD changes. Use new memory allocation
 *	scheme for mbufs.
 *
 */ 

/*
 * Kernel resident routing tables.
 * 
 * The routing tables are initialized at boot time 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 */
	struct rtentry *rt_next;	/* next in list */
};

#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		/* changed 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 RTLOCK() smp_lock(&lk_rtentry, LK_RETRY)
#define RTUNLOCK() smp_unlock(&lk_rtentry)

#ifdef old
#define	RTFREE(rt) \
	if ((rt)->rt_refcnt == 1) \
		rtfree(rt); \
	else \
		(rt)->rt_refcnt--;
#endif /* old */

#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	rtentry *rthost[RTHASHSIZ];
struct	rtentry *rtnet[RTHASHSIZ];
struct	rtstat	rtstat;
#endif