1 /* $KAME: timer.c,v 1.4 2000/05/27 11:30:43 jinmei Exp $ */ 2 3 /* 4 * Copyright (C) 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $FreeBSD: src/usr.sbin/rtadvd/timer.c,v 1.1.2.3 2002/06/29 18:59:53 ume Exp $ 32 * $DragonFly: src/usr.sbin/rtadvd/timer.c,v 1.4 2005/02/17 14:00:10 joerg Exp $ 33 */ 34 35 #include <sys/time.h> 36 37 #include <unistd.h> 38 #include <syslog.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #if defined(__NetBSD__) || defined(__OpenBSD__) 42 #include <search.h> 43 #endif 44 #include "timer.h" 45 46 static struct rtadvd_timer timer_head; 47 48 #define MILLION 1000000 49 #define TIMEVAL_EQUAL(t1,t2) ((t1)->tv_sec == (t2)->tv_sec &&\ 50 (t1)->tv_usec == (t2)->tv_usec) 51 52 static struct timeval tm_max = {0x7fffffff, 0x7fffffff}; 53 54 void 55 rtadvd_timer_init() 56 { 57 memset(&timer_head, 0, sizeof(timer_head)); 58 59 timer_head.next = timer_head.prev = &timer_head; 60 timer_head.tm = tm_max; 61 } 62 63 struct rtadvd_timer * 64 rtadvd_add_timer(struct rtadvd_timer *(*timeout)(void *), 65 void (*update)(void *, struct timeval *), 66 void *timeodata, void *updatedata) 67 { 68 struct rtadvd_timer *newtimer; 69 70 if ((newtimer = malloc(sizeof(*newtimer))) == NULL) { 71 syslog(LOG_ERR, 72 "<%s> can't allocate memory", __func__); 73 exit(1); 74 } 75 76 memset(newtimer, 0, sizeof(*newtimer)); 77 78 if (timeout == NULL) { 79 syslog(LOG_ERR, 80 "<%s> timeout function unspecfied", __func__); 81 exit(1); 82 } 83 newtimer->expire = timeout; 84 newtimer->update = update; 85 newtimer->expire_data = timeodata; 86 newtimer->update_data = updatedata; 87 newtimer->tm = tm_max; 88 89 /* link into chain */ 90 insque(newtimer, &timer_head); 91 92 return(newtimer); 93 } 94 95 void 96 rtadvd_remove_timer(struct rtadvd_timer **timer) 97 { 98 remque(*timer); 99 free(*timer); 100 *timer = NULL; 101 } 102 103 void 104 rtadvd_set_timer(struct timeval *tm, struct rtadvd_timer *timer) 105 { 106 struct timeval now; 107 108 /* reset the timer */ 109 gettimeofday(&now, NULL); 110 111 TIMEVAL_ADD(&now, tm, &timer->tm); 112 113 /* update the next expiration time */ 114 if (TIMEVAL_LT(timer->tm, timer_head.tm)) 115 timer_head.tm = timer->tm; 116 117 return; 118 } 119 120 /* 121 * Check expiration for each timer. If a timer expires, 122 * call the expire function for the timer and update the timer. 123 * Return the next interval for select() call. 124 */ 125 struct timeval * 126 rtadvd_check_timer() 127 { 128 static struct timeval returnval; 129 struct timeval now; 130 struct rtadvd_timer *tm = timer_head.next, *tm_next; 131 132 gettimeofday(&now, NULL); 133 134 timer_head.tm = tm_max; 135 136 for (tm = timer_head.next; tm != &timer_head; tm = tm_next) { 137 tm_next = tm->next; 138 139 if (TIMEVAL_LEQ(tm->tm, now)) { 140 if (((*tm->expire)(tm->expire_data) == NULL)) 141 continue; /* the timer was removed */ 142 if (tm->update) 143 (*tm->update)(tm->update_data, &tm->tm); 144 TIMEVAL_ADD(&tm->tm, &now, &tm->tm); 145 } 146 147 if (TIMEVAL_LT(tm->tm, timer_head.tm)) 148 timer_head.tm = tm->tm; 149 } 150 151 if (TIMEVAL_EQUAL(&tm_max, &timer_head.tm)) { 152 /* no need to timeout */ 153 return(NULL); 154 } 155 else if (TIMEVAL_LT(timer_head.tm, now)) { 156 /* this may occur when the interval is too small */ 157 returnval.tv_sec = returnval.tv_usec = 0; 158 } 159 else 160 TIMEVAL_SUB(&timer_head.tm, &now, &returnval); 161 return(&returnval); 162 } 163 164 struct timeval * 165 rtadvd_timer_rest(struct rtadvd_timer *timer) 166 { 167 static struct timeval returnval, now; 168 169 gettimeofday(&now, NULL); 170 if (TIMEVAL_LEQ(timer->tm, now)) { 171 syslog(LOG_DEBUG, 172 "<%s> a timer must be expired, but not yet", 173 __func__); 174 returnval.tv_sec = returnval.tv_usec = 0; 175 } 176 else 177 TIMEVAL_SUB(&timer->tm, &now, &returnval); 178 179 return(&returnval); 180 } 181 182 /* result = a + b */ 183 void 184 TIMEVAL_ADD(struct timeval *a, struct timeval *b, struct timeval *result) 185 { 186 long l; 187 188 if ((l = a->tv_usec + b->tv_usec) < MILLION) { 189 result->tv_usec = l; 190 result->tv_sec = a->tv_sec + b->tv_sec; 191 } 192 else { 193 result->tv_usec = l - MILLION; 194 result->tv_sec = a->tv_sec + b->tv_sec + 1; 195 } 196 } 197 198 /* 199 * result = a - b 200 * XXX: this function assumes that a >= b. 201 */ 202 void 203 TIMEVAL_SUB(struct timeval *a, struct timeval *b, struct timeval *result) 204 { 205 long l; 206 207 if ((l = a->tv_usec - b->tv_usec) >= 0) { 208 result->tv_usec = l; 209 result->tv_sec = a->tv_sec - b->tv_sec; 210 } 211 else { 212 result->tv_usec = MILLION + l; 213 result->tv_sec = a->tv_sec - b->tv_sec - 1; 214 } 215 } 216