usr.sbin/rtadvd/timer.c

   1 /*      $NetBSD: timer.c,v 1.12 2015/06/05 14:09:20 roy 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 <limits.h>
  37 #include <unistd.h>
  38 #include <syslog.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41 #include <search.h>
  42 #include "timer.h"
  43
  44 struct rtadvd_timer_head_t ra_timer = TAILQ_HEAD_INITIALIZER(ra_timer);
  45 static struct timespec tm_limit = { LONG_MAX, 1000000000L - 1 };
  46 static struct timespec tm_max;
  47
  48 void
  49 rtadvd_timer_init(void)
  50 {
  51
  52         TAILQ_INIT(&ra_timer);
  53         tm_max = tm_limit;
  54 }
  55
  56 struct rtadvd_timer *
  57 rtadvd_add_timer(struct rtadvd_timer *(*timeout) (void *),
  58     void (*update) (void *, struct timespec *),
  59     void *timeodata, void *updatedata)
  60 {
  61         struct rtadvd_timer *newtimer;
  62
  63         if ((newtimer = malloc(sizeof(*newtimer))) == NULL) {
  64                 syslog(LOG_ERR,
  65                        "<%s> can't allocate memory", __func__);
  66                 exit(1);
  67         }
  68
  69         memset(newtimer, 0, sizeof(*newtimer));
  70
  71         if (timeout == NULL) {
  72                 syslog(LOG_ERR,
  73                        "<%s> timeout function unspecified", __func__);
  74                 exit(1);
  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         clock_gettime(CLOCK_MONOTONIC, &now);
 106         timespecadd(&now, tm, &timer->tm);
 107
 108         /* upate the next expiration time */
 109         if (timespeccmp(&timer->tm, &tm_max, <))
 110                 tm_max = timer->tm;
 111 }
 112
 113 /*
 114  * Check expiration for each timer. If a timer expires,
 115  * call the expire function for the timer and update the timer.
 116  * Return the next interval for select() call.
 117  */
 118 struct timespec *
 119 rtadvd_check_timer(void)
 120 {
 121         static struct timespec returnval;
 122         struct timespec now;
 123         struct rtadvd_timer *tm, *tmn;
 124
 125         clock_gettime(CLOCK_MONOTONIC, &now);
 126         tm_max = tm_limit;
 127
 128         TAILQ_FOREACH_SAFE(tm, &ra_timer, next, tmn) {
 129                 if (timespeccmp(&tm->tm, &now, <=)) {
 130                         if ((*tm->expire)(tm->expire_data) == NULL)
 131                                 continue; /* the timer was removed */
 132                         if (tm->update)
 133                                 (*tm->update)(tm->update_data, &tm->tm);
 134                         timespecadd(&tm->tm, &now, &tm->tm);
 135                 }
 136                 if (timespeccmp(&tm->tm, &tm_max, <))
 137                         tm_max = tm->tm;
 138         }
 139
 140         if (timespeccmp(&tm_max, &tm_limit, ==))
 141                 return(NULL);
 142         if (timespeccmp(&tm_max, &now, <)) {
 143                 /* this may occur when the interval is too small */
 144                 timespecclear(&returnval);
 145         } else
 146                 timespecsub(&tm_max, &now, &returnval);
 147         return(&returnval);
 148 }
 149
 150 struct timespec *
 151 rtadvd_timer_rest(struct rtadvd_timer *timer)
 152 {
 153         static struct timespec returnval;
 154         struct timespec now;
 155
 156         clock_gettime(CLOCK_MONOTONIC, &now);
 157         if (timespeccmp(&timer->tm, &now, <=)) {
 158                 syslog(LOG_DEBUG,
 159                        "<%s> a timer must be expired, but not yet",
 160                        __func__);
 161                 returnval.tv_sec = 0;
 162                 returnval.tv_nsec = 0;
 163         }
 164         else
 165                 timespecsub(&timer->tm, &now, &returnval);
 166
 167         return(&returnval);
 168 }