Home | History | Annotate | Line # | Download | only in rtadvd 
      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
     53 rtadvd_timer_init(void)
     54 {
     55 
     56 	TAILQ_INIT(&ra_timer);
     57 	tm_max = tm_limit;
     58 }
     59 
     60 struct rtadvd_timer *
     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
     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
    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 *
    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 *
    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