1 /* $NetBSD: timer.c,v 1.20 2021/03/23 18:16:53 christos Exp $ */
2 /* $KAME: timer.c,v 1.11 2005/04/14 06:22:35 suz Exp $ */
3
4 /*
5 * Copyright (C) 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include <sys/queue.h>
34 #include <sys/time.h>
35
36 #include <assert.h>
37 #include <limits.h>
38 #include <unistd.h>
39 #include <syslog.h>
40 #include <stdbool.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <search.h>
44 #include "timer.h"
45 #include "logit.h"
46 #include "prog_ops.h"
47
48 struct rtadvd_timer_head_t ra_timer = TAILQ_HEAD_INITIALIZER(ra_timer);
49 static struct timespec tm_limit = { LONG_MAX, 1000000000L - 1 };
50 static struct timespec tm_max;
51
52 void
rtadvd_timer_init(void)53 rtadvd_timer_init(void)
54 {
55
56 TAILQ_INIT(&ra_timer);
57 tm_max = tm_limit;
58 }
59
60 struct rtadvd_timer *
rtadvd_add_timer(struct rtadvd_timer * (* timeout)(void *),void (* update)(void *,struct timespec *),void * timeodata,void * updatedata)61 rtadvd_add_timer(struct rtadvd_timer *(*timeout) (void *),
62 void (*update) (void *, struct timespec *),
63 void *timeodata, void *updatedata)
64 {
65 struct rtadvd_timer *newtimer;
66
67 assert(timeout != NULL);
68
69 if ((newtimer = malloc(sizeof(*newtimer))) == NULL) {
70 logit(LOG_ERR, "%s: malloc: %m", __func__);
71 exit(EXIT_FAILURE);
72 }
73
74 memset(newtimer, 0, sizeof(*newtimer));
75
76 newtimer->expire = timeout;
77 newtimer->update = update;
78 newtimer->expire_data = timeodata;
79 newtimer->update_data = updatedata;
80 newtimer->tm = tm_max;
81
82 /* link into chain */
83 TAILQ_INSERT_TAIL(&ra_timer, newtimer, next);
84
85 return(newtimer);
86 }
87
88 void
rtadvd_remove_timer(struct rtadvd_timer ** timer)89 rtadvd_remove_timer(struct rtadvd_timer **timer)
90 {
91
92 if (*timer) {
93 TAILQ_REMOVE(&ra_timer, *timer, next);
94 free(*timer);
95 *timer = NULL;
96 }
97 }
98
99 void
rtadvd_set_timer(struct timespec * tm,struct rtadvd_timer * timer)100 rtadvd_set_timer(struct timespec *tm, struct rtadvd_timer *timer)
101 {
102 struct timespec now;
103
104 /* reset the timer */
105 prog_clock_gettime(CLOCK_MONOTONIC, &now);
106 timespecadd(&now, tm, &timer->tm);
107
108 /* update the next expiration time */
109 if (timespeccmp(&timer->tm, &tm_max, <))
110 tm_max = timer->tm;
111
112 /* enable the timer */
113 timer->enabled = true;
114 }
115
116 /*
117 * Check expiration for each timer. If a timer expires,
118 * call the expire function for the timer and update the timer.
119 * Return the next interval for select() call.
120 */
121 struct timespec *
rtadvd_check_timer(void)122 rtadvd_check_timer(void)
123 {
124 static struct timespec returnval;
125 struct timespec now;
126 struct rtadvd_timer *tm, *tmn;
127
128 prog_clock_gettime(CLOCK_MONOTONIC, &now);
129 tm_max = tm_limit;
130
131 TAILQ_FOREACH_SAFE(tm, &ra_timer, next, tmn) {
132 if (!tm->enabled)
133 continue;
134 if (timespeccmp(&tm->tm, &now, <=)) {
135 if ((*tm->expire)(tm->expire_data) == NULL)
136 continue; /* the timer was removed */
137 if (tm->update)
138 (*tm->update)(tm->update_data, &tm->tm);
139 timespecadd(&tm->tm, &now, &tm->tm);
140 }
141 if (timespeccmp(&tm->tm, &tm_max, <))
142 tm_max = tm->tm;
143 }
144
145 if (timespeccmp(&tm_max, &tm_limit, ==))
146 return(NULL);
147 if (timespeccmp(&tm_max, &now, <)) {
148 /* this may occur when the interval is too small */
149 timespecclear(&returnval);
150 } else
151 timespecsub(&tm_max, &now, &returnval);
152 return(&returnval);
153 }
154
155 struct timespec *
rtadvd_timer_rest(struct rtadvd_timer * timer)156 rtadvd_timer_rest(struct rtadvd_timer *timer)
157 {
158 static struct timespec returnval;
159 struct timespec now;
160
161 prog_clock_gettime(CLOCK_MONOTONIC, &now);
162 if (timespeccmp(&timer->tm, &now, <=)) {
163 if (timer->enabled)
164 logit(LOG_DEBUG,
165 "%s: a timer must be expired, but not yet",
166 __func__);
167 returnval.tv_sec = 0;
168 returnval.tv_nsec = 0;
169 }
170 else
171 timespecsub(&timer->tm, &now, &returnval);
172
173 return(&returnval);
174 }
175