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/cdefs.h>
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/socket.h>
37 #include <sys/kernel.h>
38 #include <sys/lock.h>
39 #include <sys/ck.h>
40 #include <sys/rmlock.h>
41 #include <sys/callout.h>
42
43 #include <net/if.h>
44 #include <net/route.h>
45 #include <net/route/route_ctl.h>
46 #include <net/route/route_var.h>
47 #include <net/vnet.h>
48
49 /*
50 * Callback returning 1 for the expired routes.
51 * Updates time of the next nearest route expiration as a side effect.
52 */
53 static int
expire_route(const struct rtentry * rt,const struct nhop_object * nh,void * arg)54 expire_route(const struct rtentry *rt, const struct nhop_object *nh, void *arg)
55 {
56 uint32_t nh_expire = nhop_get_expire(nh);
57 time_t *next_callout;
58
59 if (nh_expire == 0)
60 return (0);
61
62 if (nh_expire <= time_uptime)
63 return (1);
64
65 next_callout = (time_t *)arg;
66
67 /*
68 * Update next_callout to determine the next ts to
69 * run the callback at.
70 */
71 if (*next_callout == 0 || *next_callout > nh_expire)
72 *next_callout = nh_expire;
73
74 return (0);
75 }
76
77 /*
78 * Per-rnh callout function traversing the tree and deleting
79 * expired routes. Calculates next callout run by looking at
80 * the nh_expire time for the remaining temporal routes.
81 */
82 static void
expire_callout(void * arg)83 expire_callout(void *arg)
84 {
85 struct rib_head *rnh;
86 time_t next_expire;
87 int seconds;
88
89 rnh = (struct rib_head *)arg;
90
91 CURVNET_SET(rnh->rib_vnet);
92 next_expire = 0;
93
94 rib_walk_del(rnh->rib_fibnum, rnh->rib_family, expire_route,
95 (void *)&next_expire, 1);
96
97 RIB_WLOCK(rnh);
98 if (next_expire > 0) {
99 seconds = (next_expire - time_uptime);
100 if (seconds < 0)
101 seconds = 0;
102 callout_reset_sbt(&rnh->expire_callout, SBT_1S * seconds,
103 SBT_1MS * 500, expire_callout, rnh, 0);
104 rnh->next_expire = next_expire;
105 } else {
106 /*
107 * Before resetting next_expire, check that tmproutes_update()
108 * has not kicked in and scheduled another invocation.
109 */
110 if (callout_pending(&rnh->expire_callout) == 0)
111 rnh->next_expire = 0;
112 }
113 RIB_WUNLOCK(rnh);
114 CURVNET_RESTORE();
115 }
116
117 /*
118 * Function responsible for updating the time of the next calllout
119 * w.r.t. new temporal routes insertion.
120 *
121 * Called by the routing code upon adding new temporal route
122 * to the tree. RIB_WLOCK must be held.
123 */
124 void
tmproutes_update(struct rib_head * rnh,struct rtentry * rt,struct nhop_object * nh)125 tmproutes_update(struct rib_head *rnh, struct rtentry *rt, struct nhop_object *nh)
126 {
127 int seconds;
128 uint32_t nh_expire = nhop_get_expire(nh);
129
130 RIB_WLOCK_ASSERT(rnh);
131
132 if (rnh->next_expire == 0 || rnh->next_expire > nh_expire) {
133 /*
134 * Callback is not scheduled, is executing,
135 * or is scheduled for a later time than we need.
136 *
137 * Schedule the one for the current @rt expiration time.
138 */
139 seconds = (nh_expire - time_uptime);
140 if (seconds < 0)
141 seconds = 0;
142 callout_reset_sbt(&rnh->expire_callout, SBT_1S * seconds,
143 SBT_1MS * 500, expire_callout, rnh, 0);
144
145 rnh->next_expire = nh_expire;
146 }
147 }
148
149 void
tmproutes_init(struct rib_head * rh)150 tmproutes_init(struct rib_head *rh)
151 {
152
153 callout_init(&rh->expire_callout, 1);
154 }
155
156 void
tmproutes_destroy(struct rib_head * rh)157 tmproutes_destroy(struct rib_head *rh)
158 {
159
160 callout_drain(&rh->expire_callout);
161 }
162