1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2020 Alexander V. Chernikov
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28/*
29 * This file contains code responsible for expiring temporal routes
30 * (typically, redirect-originated) from the route tables.
31 */
32
33#include <sys/param.h>
34#include <sys/systm.h>
35#include <sys/socket.h>
36#include <sys/kernel.h>
37#include <sys/lock.h>
38#include <sys/ck.h>
39#include <sys/rmlock.h>
40#include <sys/callout.h>
41
42#include <net/if.h>
43#include <net/route.h>
44#include <net/route/route_ctl.h>
45#include <net/route/route_var.h>
46#include <net/vnet.h>
47
48/*
49 * Callback returning 1 for the expired routes.
50 * Updates time of the next nearest route expiration as a side effect.
51 */
52static int
53expire_route(const struct rtentry *rt, const struct nhop_object *nh, void *arg)
54{
55	uint32_t nh_expire = nhop_get_expire(nh);
56	time_t *next_callout;
57
58	if (nh_expire == 0)
59		return (0);
60
61	if (nh_expire <= time_uptime)
62		return (1);
63
64	next_callout = (time_t *)arg;
65
66	/*
67	 * Update next_callout to determine the next ts to
68	 * run the callback at.
69	 */
70	if (*next_callout == 0 || *next_callout > nh_expire)
71		*next_callout = nh_expire;
72
73	return (0);
74}
75
76/*
77 * Per-rnh callout function traversing the tree and deleting
78 * expired routes. Calculates next callout run by looking at
79 * the nh_expire time for the remaining temporal routes.
80 */
81static void
82expire_callout(void *arg)
83{
84	struct rib_head *rnh;
85	time_t next_expire;
86	int seconds;
87
88	rnh = (struct rib_head *)arg;
89
90	CURVNET_SET(rnh->rib_vnet);
91	next_expire = 0;
92
93	rib_walk_del(rnh->rib_fibnum, rnh->rib_family, expire_route,
94	    (void *)&next_expire, 1);
95
96	RIB_WLOCK(rnh);
97	if (next_expire > 0) {
98		seconds = (next_expire - time_uptime);
99		if (seconds < 0)
100			seconds = 0;
101		callout_reset_sbt(&rnh->expire_callout, SBT_1S * seconds,
102		    SBT_1MS * 500, expire_callout, rnh, 0);
103		rnh->next_expire = next_expire;
104	} else {
105		/*
106		 * Before resetting next_expire, check that tmproutes_update()
107		 * has not kicked in and scheduled another invocation.
108		 */
109		if (callout_pending(&rnh->expire_callout) == 0)
110			rnh->next_expire = 0;
111	}
112	RIB_WUNLOCK(rnh);
113	CURVNET_RESTORE();
114}
115
116/*
117 * Function responsible for updating the time of the next calllout
118 * w.r.t. new temporal routes insertion.
119 *
120 * Called by the routing code upon adding new temporal route
121 * to the tree. RIB_WLOCK must be held.
122 */
123void
124tmproutes_update(struct rib_head *rnh, struct rtentry *rt, struct nhop_object *nh)
125{
126	int seconds;
127	uint32_t nh_expire = nhop_get_expire(nh);
128
129	RIB_WLOCK_ASSERT(rnh);
130
131	if (rnh->next_expire == 0 || rnh->next_expire > nh_expire) {
132		/*
133		 * Callback is not scheduled, is executing,
134		 * or is scheduled for a later time than we need.
135		 *
136		 * Schedule the one for the current @rt expiration time.
137		 */
138		seconds = (nh_expire - time_uptime);
139		if (seconds < 0)
140			seconds = 0;
141		callout_reset_sbt(&rnh->expire_callout, SBT_1S * seconds,
142		    SBT_1MS * 500, expire_callout, rnh, 0);
143
144		rnh->next_expire = nh_expire;
145	}
146}
147
148void
149tmproutes_init(struct rib_head *rh)
150{
151
152	callout_init(&rh->expire_callout, 1);
153}
154
155void
156tmproutes_destroy(struct rib_head *rh)
157{
158
159	callout_drain(&rh->expire_callout);
160}
161