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 */
52 static int
expire_route(const struct rtentry * rt,const struct nhop_object * nh,void * arg)53 expire_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 */
81 static void
expire_callout(void * arg)82 expire_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 */
123 void
tmproutes_update(struct rib_head * rnh,struct rtentry * rt,struct nhop_object * nh)124 tmproutes_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
148 void
tmproutes_init(struct rib_head * rh)149 tmproutes_init(struct rib_head *rh)
150 {
151
152 callout_init(&rh->expire_callout, 1);
153 }
154
155 void
tmproutes_destroy(struct rib_head * rh)156 tmproutes_destroy(struct rib_head *rh)
157 {
158
159 callout_drain(&rh->expire_callout);
160 }
161