src/lib/wallclock/tor_gettimeofday.c

   1 /* Copyright (c) 2003-2004, Roger Dingledine
   2  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
   3  * Copyright (c) 2007-2019, The Tor Project, Inc. */
   4 /* See LICENSE for licensing information */
   5
   6 /**
   7  * \file tor_gettimeofday.c
   8  * \brief Implementat gettimeofday() for windows, and other platforms without
   9  *   it.
  10  **/
  11
  12 #include "orconfig.h"
  13 #include "lib/err/torerr.h"
  14 #include "lib/wallclock/tor_gettimeofday.h"
  15 #include "lib/cc/torint.h"
  16
  17 #include <stddef.h>
  18 #include <stdlib.h>
  19
  20 #ifdef HAVE_SYS_TIME_H
  21 #include <sys/time.h>
  22 #endif
  23
  24 #ifdef _WIN32
  25 #include <windows.h>
  26 #endif
  27
  28 #ifdef HAVE_SYS_TYPES_H
  29 #include <sys/types.h>
  30 #endif
  31
  32 #ifndef HAVE_GETTIMEOFDAY
  33 #ifdef HAVE_FTIME
  34 #include <sys/timeb.h>
  35 #endif
  36 #endif
  37
  38 /** Set *timeval to the current time of day.  On error, log and terminate.
  39  * (Same as gettimeofday(timeval,NULL), but never returns -1.)
  40  */
  41 MOCK_IMPL(void,
  42 tor_gettimeofday, (struct timeval *timeval))
  43 {
  44 #ifdef _WIN32
  45   /* Epoch bias copied from perl: number of units between windows epoch and
  46    * Unix epoch. */
  47 #define EPOCH_BIAS UINT64_C(116444736000000000)
  48 #define UNITS_PER_SEC UINT64_C(10000000)
  49 #define USEC_PER_SEC UINT64_C(1000000)
  50 #define UNITS_PER_USEC UINT64_C(10)
  51   union {
  52     uint64_t ft_64;
  53     FILETIME ft_ft;
  54   } ft;
  55   /* number of 100-nsec units since Jan 1, 1601 */
  56   GetSystemTimeAsFileTime(&ft.ft_ft);
  57   if (ft.ft_64 < EPOCH_BIAS) {
  58     /* LCOV_EXCL_START */
  59     raw_assert_unreached_msg("System time is before 1970; failing.");
  60     /* LCOV_EXCL_STOP */
  61   }
  62   ft.ft_64 -= EPOCH_BIAS;
  63   timeval->tv_sec = (unsigned) (ft.ft_64 / UNITS_PER_SEC);
  64   timeval->tv_usec = (unsigned) ((ft.ft_64 / UNITS_PER_USEC) % USEC_PER_SEC);
  65 #elif defined(HAVE_GETTIMEOFDAY)
  66   if (gettimeofday(timeval, NULL)) {
  67     /* LCOV_EXCL_START */
  68     /* If gettimeofday dies, we have either given a bad timezone (we didn't),
  69        or segfaulted.*/
  70     raw_assert_unreached_msg("gettimeofday failed");
  71     /* LCOV_EXCL_STOP */
  72   }
  73 #elif defined(HAVE_FTIME)
  74   struct timeb tb;
  75   ftime(&tb);
  76   timeval->tv_sec = tb.time;
  77   timeval->tv_usec = tb.millitm * 1000;
  78 #else
  79 #error "No way to get time."
  80 #endif /* defined(_WIN32) || ... */
  81   return;
  82 }