/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* 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.
*/
/*
* 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/ck.h>
#include <sys/rmlock.h>
#include <sys/callout.h>
#include <net/if.h>
#include <net/route.h>
#include <net/route/route_ctl.h>
#include <net/route/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, const struct nhop_object *nh, void *arg)
{
uint32_t nh_expire = nhop_get_expire(nh);
time_t *next_callout;
if (nh_expire == 0)
return (0);
if (nh_expire <= time_uptime)
return (1);
next_callout = (time_t *)arg;
/*
* Update next_callout to determine the next ts to
* run the callback at.
*/
if (*next_callout == 0 || *next_callout > nh_expire)
*next_callout = nh_expire;
return (0);
}
/*
* Per-rnh callout function traversing the tree and deleting
* expired routes. Calculates next callout run by looking at
* the nh_expire time for the remaining temporal routes.
*/
static void
expire_callout(void *arg)
{
struct rib_head *rnh;
time_t next_expire;
int seconds;
rnh = (struct rib_head *)arg;
CURVNET_SET(rnh->rib_vnet);
next_expire = 0;
rib_walk_del(rnh->rib_fibnum, rnh->rib_family, expire_route,
(void *)&next_expire, 1);
RIB_WLOCK(rnh);
if (next_expire > 0) {
seconds = (next_expire - time_uptime);
if (seconds < 0)
seconds = 0;
callout_reset_sbt(&rnh->expire_callout, SBT_1S * seconds,
SBT_1MS * 500, expire_callout, rnh, 0);
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, struct nhop_object *nh)
{
int seconds;
uint32_t nh_expire = nhop_get_expire(nh);
RIB_WLOCK_ASSERT(rnh);
if (rnh->next_expire == 0 || rnh->next_expire > nh_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.
*/
seconds = (nh_expire - time_uptime);
if (seconds < 0)
seconds = 0;
callout_reset_sbt(&rnh->expire_callout, SBT_1S * seconds,
SBT_1MS * 500, expire_callout, rnh, 0);
rnh->next_expire = nh_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);
}
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