1/*	$OpenBSD: timer.c,v 1.7 2018/04/10 15:58:21 cheloha Exp $	*/
2
3/*
4 * Copyright (c) 2005 H�kan Olsson.  All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
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 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28/*
29 * This code was written under funding by Multicom Security AB.
30 */
31
32
33#include <sys/types.h>
34#include <sys/queue.h>
35#include <sys/time.h>
36
37#include <stdlib.h>
38#include <string.h>
39#include <time.h>
40
41#include "sasyncd.h"
42
43/*
44 * All events have a name, an expiration time and a function to be called
45 * at this time. The queue is always sorted so the next event to happen is
46 * first in the queue.
47 */
48struct event {
49	TAILQ_ENTRY (event) next;
50	struct timespec	 expire;
51	char		*name;
52	void		(*fun) (void *);
53	void		*arg;
54};
55
56static TAILQ_HEAD (event_head, event) events;
57
58/* Initialize timer event queue. */
59void
60timer_init(void)
61{
62	TAILQ_INIT(&events);
63}
64
65/*
66 * Return the number of seconds until the next event happens. Used for
67 * the select() call in the main loop.
68 */
69void
70timer_next_event(struct timespec *ts)
71{
72	struct timespec	 now;
73	struct event	*e = TAILQ_FIRST(&events);
74
75	if (e) {
76		clock_gettime(CLOCK_MONOTONIC, &now);
77		if (timespeccmp(&now, &e->expire, >=))
78			timespecclear(ts);
79		else
80			timespecsub(&e->expire, &now, ts);
81	} else {
82		ts->tv_sec = 60;	/* "Best guess". */
83		ts->tv_nsec = 0;
84	}
85}
86
87/*
88 * Whenever select() times out, we have an event that should happen and this
89 * routine gets called. Handle and remove all pending events.
90 */
91void
92timer_run(void)
93{
94	struct timespec	 now;
95	struct event	*e;
96
97	clock_gettime(CLOCK_MONOTONIC, &now);
98	for (e = TAILQ_FIRST(&events); e && timespeccmp(&now, &e->expire, >=);
99	     e = TAILQ_FIRST(&events)) {
100		TAILQ_REMOVE(&events, e, next);
101		log_msg(2, "timer_run: event \"%s\"",
102		    e->name ? e->name : "<unknown>");
103		(*e->fun)(e->arg);
104		if (e->name)
105			free(e->name);
106		free(e);
107	}
108}
109
110/* Add a new event. */
111int
112timer_add(char *name, u_int32_t when, void (*function)(void *), void *arg)
113{
114	struct timespec	 now, tmp;
115	struct event	*e, *new;
116
117	new = calloc(1, sizeof *new);
118	if (!new) {
119		log_err("timer_add: calloc (1, %zu) failed", sizeof *new);
120		return -1;
121	}
122
123	new->name = strdup(name); /* We handle failures here. */
124	new->fun = function;
125	new->arg = arg;
126
127	tmp.tv_sec = when;
128	tmp.tv_nsec = 0;
129	clock_gettime(CLOCK_MONOTONIC, &now);
130	timespecadd(&now, &tmp, &new->expire);
131
132	log_msg(2, "timer_add: new event \"%s\" (expiring in %us)",
133	    name ? name : "<unknown>", when);
134
135	/* Insert the new event in the queue so it's always sorted. */
136	for (e = TAILQ_FIRST(&events); e; e = TAILQ_NEXT(e, next)) {
137		if (timespeccmp(&new->expire, &e->expire, >=))
138			continue;
139		TAILQ_INSERT_BEFORE(e, new, next);
140		return 0;
141	}
142	TAILQ_INSERT_TAIL(&events, new, next);
143	return 0;
144}
145