Differential D22988 Diff 66228 sys/net/route_temporal.c

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sys/net/route_temporal.c

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				/*-
				* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
				*
				* Copyright (c) 2020 Alexander V. Chernikov
				*
				* 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.
				*
				* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
				*
				* $FreeBSD$
				*/

				/*
				* This file contains code responsible for expiring temporal routes
				* (typically, redirect-originated) from the route tables.
				*/

				#include <sys/cdefs.h>
				#include <sys/param.h>
				#include <sys/systm.h>
				#include <sys/socket.h>
				#include <sys/kernel.h>
				#include <sys/lock.h>
				#include <sys/rmlock.h>

				#include <net/if.h>
				#include <net/route.h>
				#include <net/route_var.h>
				#include <net/vnet.h>

				/*
				* Callback returning 1 for the expired routes.
				* Updates time of the next nearest route expiration
				* as a side effect.
				*/
				static int
				expire_route(const struct rtentry rt, void arg)
				{
				time_t next_callout = (time_t )arg;

				if (rt->rt_expire == 0)
				return (0);

				if (rt->rt_expire <= time_uptime) {
				printf("expiring %p, ts %lu\n", rt, rt->rt_expire);
				return (1);
				}

				/*
				* Update next_callout to determine the next ts to
				* run the callback at.
				*/
				if (next_callout == 0 \|\| next_callout > rt->rt_expire)
				*next_callout = rt->rt_expire;

				return (0);
				}

				/*
				* Per-rnh callout function traversing the tree and deleting
				* expired routes. Calculates next callout run by looking at
				* the rt_expire time for the remaining temporal routes.
				*/
				static void
				expire_callout(void *arg)
				{
				struct rib_head rnh = (struct rib_head )arg;
				time_t next_expire = 0;
				int ticks;

				CURVNET_SET(rnh->rib_vnet);

				rib_walk_del(rnh->rib_fibnum, rnh->rib_family, expire_route,
				(void *)&next_expire, 1);

				RIB_WLOCK(rnh);
				if (next_expire > 0) {
				ticks = (next_expire - time_uptime) * hz;
				if (ticks < 0)
				ticks = 0;
				callout_reset(&rnh->expire_callout, ticks, expire_callout, rnh);
				rnh->next_expire = next_expire;
				} else {
				/*
				* Before resetting next_expire, check that tmproutes_update()
				* has not kicked in and scheduled another invocation.
				*/
				if (callout_pending(&rnh->expire_callout) == 0)
				rnh->next_expire = 0;
				}
				RIB_WUNLOCK(rnh);
				CURVNET_RESTORE();
				}

				/*
				* Function responsible for updating the time of the next calllout
				* w.r.t. new temporal routes insertion.
				*
				* Called by the routing code upon adding new temporal route
				* to the tree. RIB_WLOCK must be held.
				*/
				void
				tmproutes_update(struct rib_head rnh, struct rtentry rt)
				{
				int ticks;

				RIB_WLOCK_ASSERT(rnh);

				if (rnh->next_expire == 0 \|\| rnh->next_expire > rt->rt_expire) {
				/*
				* Callback is not scheduled, is executing,
				* or is scheduled for a later time than we need.
				*
				* Schedule the one for the current @rt expiration time.
				*/
				ticks = (rt->rt_expire - time_uptime) * hz;
				if (ticks < 0)
				ticks = 0;
				callout_reset(&rnh->expire_callout, ticks, expire_callout, rnh);

				rnh->next_expire = rt->rt_expire;
				}
				}

				void
				tmproutes_init(struct rib_head *rh)
				{

				callout_init(&rh->expire_callout, 1);
				}


				void
				tmproutes_destroy(struct rib_head *rh)
				{

				callout_drain(&rh->expire_callout);
				}