external/bsd/ntp/dist/lib/isc/unix/stdtime.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
   5  * Copyright (C) 1999-2001  Internet Software Consortium.
   6  *
   7  * Permission to use, copy, modify, and/or distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  12  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  13  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  14  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  15  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  16  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  17  * PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 /* Id: stdtime.c,v 1.19 2007/06/19 23:47:18 tbox Exp */
  21
  22 /*! \file */
  23
  24 #include <config.h>
  25
  26 #include <stddef.h>     /* NULL */
  27 #include <stdlib.h>     /* NULL */
  28 #include <syslog.h>
  29
  30 #include <sys/time.h>
  31
  32 #include <isc/stdtime.h>
  33 #include <isc/util.h>
  34
  35 #ifndef ISC_FIX_TV_USEC
  36 #define ISC_FIX_TV_USEC 1
  37 #endif
  38
  39 #define US_PER_S 1000000
  40
  41 #if ISC_FIX_TV_USEC
  42 static inline void
  43 fix_tv_usec(struct timeval *tv) {
  44         isc_boolean_t fixed = ISC_FALSE;
  45
  46         if (tv->tv_usec < 0) {
  47                 fixed = ISC_TRUE;
  48                 do {
  49                         tv->tv_sec -= 1;
  50                         tv->tv_usec += US_PER_S;
  51                 } while (tv->tv_usec < 0);
  52         } else if (tv->tv_usec >= US_PER_S) {
  53                 fixed = ISC_TRUE;
  54                 do {
  55                         tv->tv_sec += 1;
  56                         tv->tv_usec -= US_PER_S;
  57                 } while (tv->tv_usec >=US_PER_S);
  58         }
  59         /*
  60          * Call syslog directly as we are called from the logging functions.
  61          */
  62         if (fixed)
  63                 (void)syslog(LOG_ERR, "gettimeofday returned bad tv_usec: corrected");
  64 }
  65 #endif
  66
  67 void
  68 isc_stdtime_get(isc_stdtime_t *t) {
  69         struct timeval tv;
  70
  71         /*
  72          * Set 't' to the number of seconds since 00:00:00 UTC, January 1,
  73          * 1970.
  74          */
  75
  76         REQUIRE(t != NULL);
  77
  78         RUNTIME_CHECK(gettimeofday(&tv, NULL) != -1);
  79
  80 #if ISC_FIX_TV_USEC
  81         fix_tv_usec(&tv);
  82         INSIST(tv.tv_usec >= 0);
  83 #else
  84         INSIST(tv.tv_usec >= 0 && tv.tv_usec < US_PER_S);
  85 #endif
  86
  87         *t = (unsigned int)tv.tv_sec;
  88 }