xref: /freebsd/contrib/ntp/libntp/lib/isc/unix/stdtime.c (revision a466cc55373fc3cf86837f09da729535b57e69a1)
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
40 static inline void
fix_tv_usec(struct timeval * tv)41 fix_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 
65 void
isc_stdtime_get(isc_stdtime_t * t)66 isc_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