output.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 155 行

#ifndef lint
static	char	*sccsid = "@(#)output.c	4.1	(ULTRIX)	7/2/90";
#endif lint

/************************************************************************
 *									*
 *			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) 1983 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */
/*
#ifndef lint
static char sccsid[] = "@(#)output.c	4.1 (Berkeley) 7/2/90";
#endif not lint
*/
/*
 * Routing Table Management Daemon
 */
#include "defs.h"

/*
 * Apply the function "f" to all non-passive
 * interfaces.  If the interface supports the
 * use of broadcasting use it, otherwise address
 * the output to the known router.
 */
toall(f)
	int (*f)();
{
	register struct interface *ifp;
	register struct sockaddr *dst;
	register int flags;
	extern struct interface *ifnet;

	for (ifp = ifnet; ifp; ifp = ifp->int_next) {
		printf("toall %x\n", ifp);
		if (ifp->int_flags & IFF_PASSIVE)
			continue;
		dst = ifp->int_flags & IFF_BROADCAST ? &ifp->int_broadaddr :
		      ifp->int_flags & IFF_POINTOPOINT ? &ifp->int_dstaddr :
		      &ifp->int_addr;
		flags = ifp->int_flags & IFF_INTERFACE ? MSG_DONTROUTE : 0;
		(*f)(dst, flags, ifp);
	}
}

/*
 * Output a preformed packet.
 */
/*ARGSUSED*/
sendmsg(dst, flags, ifp)
	struct sockaddr *dst;
	int flags;
	struct interface *ifp;
{

	(*afswitch[dst->sa_family].af_output)(s, flags,
		dst, sizeof (struct rip));
	TRACE_OUTPUT(ifp, dst, sizeof (struct rip));
}

/*
 * Supply dst with the contents of the routing tables.
 * If this won't fit in one packet, chop it up into several.
 */
supply(dst, flags, ifp)
	struct sockaddr *dst;
	int flags;
	register struct interface *ifp;
{
	register struct rt_entry *rt;
	register struct netinfo *n = msg->rip_nets;
	register struct rthash *rh;
	struct rthash *base = hosthash;
	int doinghost = 1, size;
	int (*output)() = afswitch[dst->sa_family].af_output;
	int (*sendroute)() = afswitch[dst->sa_family].af_sendroute;
	int npackets = 0;

	msg->rip_cmd = RIPCMD_RESPONSE;
	msg->rip_vers = RIPVERSION;
	bzero(msg->rip_res1, sizeof(msg->rip_res1));
again:
	for (rh = base; rh < &base[ROUTEHASHSIZ]; rh++)
	for (rt = rh->rt_forw; rt != (struct rt_entry *)rh; rt = rt->rt_forw) {
		/*
		 * Don't resend the information on the network
		 * from which it was received (unless sending
		 * in response to a query).
		 */
		if (ifp && rt->rt_ifp == ifp &&
		    (rt->rt_state & RTS_INTERFACE) == 0)
			continue;
		if (rt->rt_state & RTS_EXTERNAL)
			continue;
		/*
		 * Limit the spread of subnet information
		 * to those who are interested.
		 */
		if (doinghost == 0 && rt->rt_state & RTS_SUBNET) {
			if (rt->rt_dst.sa_family != dst->sa_family)
				continue;
			if ((*sendroute)(rt, dst) == 0)
				continue;
		}
		size = (char *)n - packet;
		if (size > MAXPACKETSIZE - sizeof (struct netinfo)) {
			(*output)(s, flags, dst, size);
			TRACE_OUTPUT(ifp, dst, size);
			n = msg->rip_nets;
			npackets++;
		}
		n->rip_dst = rt->rt_dst;
		n->rip_dst.sa_family = htons(n->rip_dst.sa_family);
		n->rip_metric = htonl(min(rt->rt_metric + 1, HOPCNT_INFINITY));
		n++;
	}
	if (doinghost) {
		doinghost = 0;
		base = nethash;
		goto again;
	}
	if (n != msg->rip_nets || npackets == 0) {
		size = (char *)n - packet;
		(*output)(s, flags, dst, size);
		TRACE_OUTPUT(ifp, dst, size);
	}
}