stdtime.c revision 290001 
1/*
2 * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1999-2001  Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/* $Id: stdtime.c,v 1.19 2007/06/19 23:47:18 tbox Exp $ */
19
20/*! \file */
21
22#include <config.h>
23
24#include <stddef.h>	/* NULL */
25#include <stdlib.h>	/* NULL */
26#include <syslog.h>
27
28#include <sys/time.h>
29
30#include <isc/stdtime.h>
31#include <isc/util.h>
32
33#ifndef ISC_FIX_TV_USEC
34#define ISC_FIX_TV_USEC 1
35#endif
36
37#define US_PER_S 1000000
38
39#if ISC_FIX_TV_USEC
40static inline void
41fix_tv_usec(struct timeval *tv) {
42	isc_boolean_t fixed = ISC_FALSE;
43
44	if (tv->tv_usec < 0) {
45		fixed = ISC_TRUE;
46		do {
47			tv->tv_sec -= 1;
48			tv->tv_usec += US_PER_S;
49		} while (tv->tv_usec < 0);
50	} else if (tv->tv_usec >= US_PER_S) {
51		fixed = ISC_TRUE;
52		do {
53			tv->tv_sec += 1;
54			tv->tv_usec -= US_PER_S;
55		} while (tv->tv_usec >=US_PER_S);
56	}
57	/*
58	 * Call syslog directly as we are called from the logging functions.
59	 */
60	if (fixed)
61		(void)syslog(LOG_ERR, "gettimeofday returned bad tv_usec: corrected");
62}
63#endif
64
65void
66isc_stdtime_get(isc_stdtime_t *t) {
67	struct timeval tv;
68
69	/*
70	 * Set 't' to the number of seconds since 00:00:00 UTC, January 1,
71	 * 1970.
72	 */
73
74	REQUIRE(t != NULL);
75
76	RUNTIME_CHECK(gettimeofday(&tv, NULL) != -1);
77
78#if ISC_FIX_TV_USEC
79	fix_tv_usec(&tv);
80	INSIST(tv.tv_usec >= 0);
81#else
82	INSIST(tv.tv_usec >= 0 && tv.tv_usec < US_PER_S);
83#endif
84
85	*t = (unsigned int)tv.tv_sec;
86}
87