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NetBSD/sys/netinet/in_route.h

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Here are various changes designed to protect against bad IPv4 routing caused by stale route caches (struct route). Route caches are sprinkled throughout PCBs, the IP fast-forwarding table, and IP tunnel interfaces (gre, gif, stf). Stale IPv6 and ISO route caches will be treated by separate patches. Thank you to Christoph Badura for suggesting the general approach to invalidating route caches that I take here. Here are the details: Add hooks to struct domain for tracking and for invalidating each domain's route caches: dom_rtcache, dom_rtflush, and dom_rtflushall. Introduce helper subroutines, rtflush(ro) for invalidating a route cache, rtflushall(family) for invalidating all route caches in a routing domain, and rtcache(ro) for notifying the domain of a new cached route. Chain together all IPv4 route caches where ro_rt != NULL. Provide in_rtcache() for adding a route to the chain. Provide in_rtflush() and in_rtflushall() for invalidating IPv4 route caches. In in_rtflush(), set ro_rt to NULL, and remove the route from the chain. In in_rtflushall(), walk the chain and remove every route cache. In rtrequest1(), call rtflushall() to invalidate route caches when a route is added. In gif(4), discard the workaround for stale caches that involves expiring them every so often. Replace the pattern 'RTFREE(ro->ro_rt); ro->ro_rt = NULL;' with a call to rtflush(ro). Update ipflow_fastforward() and all other users of route caches so that they expect a cached route, ro->ro_rt, to turn to NULL. Take care when moving a 'struct route' to rtflush() the source and to rtcache() the destination. In domain initializers, use .dom_xxx tags. KNF here and there.
2006-12-09 08:33:04 +03:00
/* $NetBSD: in_route.h,v 1.1 2006/12/09 05:33:04 dyoung Exp $ */
/*
* Copyright (c) 2006 David Young. 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. The name of David Young may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY David Young ``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 David
* Young 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 _NETINET_IN_ROUTE_H_
#define _NETINET_IN_ROUTE_H_
struct route;
void in_rtcache(struct route *);
void in_rtflush(struct route *);
void in_rtflushall(void);
#endif /* !_NETINET_IN_ROUTE_H_ */