1/*	$Id: timer.c,v 1.1.1.1 2006/12/04 00:45:30 Exp $	*/
2/*	ported from KAME: timer.c,v 1.3 2002/09/24 14:20:50 itojun Exp	*/
3
4/*
5 * Copyright (C) 2002 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#include <sys/types.h>
33#include <sys/time.h>
34#include <sys/socket.h>
35
36#include <netinet/in.h>
37
38#include <unistd.h>
39#include <syslog.h>
40#include <stdlib.h>
41#include <string.h>
42#if defined(__NetBSD__) || defined(__OpenBSD__)
43#include <search.h>
44#endif
45
46#include "queue.h"
47#include "dhcp6.h"
48#include "config.h"
49#include "common.h"
50#include "timer.h"
51
52#define MILLION 1000000
53
54LIST_HEAD(, dhcp6_timer) timer_head;
55static struct timeval tm_sentinel;
56static struct timeval tm_max = {0x7fffffff, 0x7fffffff};
57
58/* result = a + b */
59static void
60timeval_add(struct timeval *a, struct timeval *b, struct timeval *result)
61{
62	long l;
63
64	if ((l = a->tv_usec + b->tv_usec) < MILLION) {
65		result->tv_usec = l;
66		result->tv_sec = a->tv_sec + b->tv_sec;
67	}
68	else {
69		result->tv_usec = l - MILLION;
70		result->tv_sec = a->tv_sec + b->tv_sec + 1;
71	}
72}
73
74void
75timeval_sub(struct timeval *a, struct timeval *b, struct timeval *result)
76{
77	long l;
78
79	if ((l = a->tv_usec - b->tv_usec) >= 0) {
80		result->tv_usec = l;
81		result->tv_sec = a->tv_sec - b->tv_sec;
82	}
83	else {
84		result->tv_usec = MILLION + l;
85		result->tv_sec = a->tv_sec - b->tv_sec - 1;
86	}
87}
88
89void
90dhcp6_timer_init(void)
91{
92	LIST_INIT(&timer_head);
93	tm_sentinel = tm_max;
94}
95
96struct dhcp6_timer *
97dhcp6_add_timer(struct dhcp6_timer *(*timeout)(void *),
98		void *timeodata)
99{
100	struct dhcp6_timer *newtimer;
101	if ((newtimer = malloc(sizeof(*newtimer))) == NULL) {
102		dprintf(LOG_ERR, "%s" "can't allocate memory", FNAME);
103		return (NULL);
104	}
105
106	memset(newtimer, 0, sizeof(*newtimer));
107
108	if (timeout == NULL) {
109		dprintf(LOG_ERR, "%s" "timeout function unspecified", FNAME);
110		return (NULL);
111	}
112	newtimer->expire = timeout;
113	newtimer->expire_data = timeodata;
114	newtimer->tm = tm_max;
115
116	LIST_INSERT_HEAD(&timer_head, newtimer, link);
117
118	return (newtimer);
119}
120
121void
122dhcp6_remove_timer(struct dhcp6_timer *timer)
123{
124	timer->flag |= MARK_REMOVE;
125}
126
127void
128dhcp6_set_timer(struct timeval *tm,
129		struct dhcp6_timer *timer)
130{
131	struct timeval now;
132	timer->flag |= MARK_CLEAR;
133	/* reset the timer */
134	gettimeofday(&now, NULL);
135
136	timeval_add(&now, tm, &timer->tm);
137
138	/* update the next expiration time */
139	if (TIMEVAL_LT(timer->tm, tm_sentinel))
140		tm_sentinel = timer->tm;
141	return;
142}
143
144/*
145 * Check expiration for each timer. If a timer is expired,
146 * call the expire function for the timer and update the timer.
147 * Return the next interval for select() call.
148 */
149struct timeval *
150dhcp6_check_timer(void)
151{
152	static struct timeval returnval;
153	struct timeval now;
154	struct dhcp6_timer *tm, *tm_next;
155
156	gettimeofday(&now, NULL);
157
158	tm_sentinel = tm_max;
159
160	for (tm = LIST_FIRST(&timer_head); tm; tm = tm_next) {
161		tm_next = LIST_NEXT(tm, link);
162		if (tm->flag & MARK_REMOVE) {
163			LIST_REMOVE(tm, link);
164			free(tm);
165			tm = NULL;
166			continue;
167		}
168		if (TIMEVAL_LEQ(tm->tm, now)) {
169			if ((*tm->expire)(tm->expire_data) == NULL)
170				continue; /* timer has been freed */
171		}
172
173		if (TIMEVAL_LT(tm->tm, tm_sentinel))
174			tm_sentinel = tm->tm;
175	}
176
177	if (TIMEVAL_EQUAL(tm_max, tm_sentinel)) {
178		/* no need to timeout */
179		return (NULL);
180	} else if (TIMEVAL_LT(tm_sentinel, now)) {
181		/* this may occur when the interval is too small */
182		returnval.tv_sec = returnval.tv_usec = 0;
183	} else
184		timeval_sub(&tm_sentinel, &now, &returnval);
185	return (&returnval);
186}
187
188struct timeval *
189dhcp6_timer_rest(struct dhcp6_timer *timer)
190{
191	struct timeval now;
192	static struct timeval returnval;
193
194	gettimeofday(&now, NULL);
195	if (TIMEVAL_LEQ(timer->tm, now)) {
196		syslog(LOG_DEBUG,
197		       "<%s> a timer must be expired, but not yet",
198		       __FUNCTION__);
199		returnval.tv_sec = returnval.tv_usec = 0;
200	} else
201		timeval_sub(&timer->tm, &now, &returnval);
202
203	return (&returnval);
204}
205