crypto/sleep.c

   1 /*
   2  * Copyright 2022-2024 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <openssl/crypto.h>
  11 #include "internal/e_os.h"
  12
  13 /* system-specific variants defining OSSL_sleep() */
  14 #if defined(OPENSSL_SYS_UNIX) || defined(__DJGPP__)
  15 #include <unistd.h>
  16
  17 void OSSL_sleep(uint64_t millis)
  18 {
  19 # ifdef OPENSSL_SYS_VXWORKS
  20     struct timespec ts;
  21
  22     ts.tv_sec = (long int) (millis / 1000);
  23     ts.tv_nsec = (long int) (millis % 1000) * 1000000ul;
  24     nanosleep(&ts, NULL);
  25 # elif defined(__TANDEM) && !defined(_REENTRANT)
  26 #   include <cextdecs.h(PROCESS_DELAY_)>
  27
  28     /* HPNS does not support usleep for non threaded apps */
  29     PROCESS_DELAY_(millis * 1000);
  30 # else
  31     unsigned int s = (unsigned int)(millis / 1000);
  32     unsigned int us = (unsigned int)((millis % 1000) * 1000);
  33
  34     if (s > 0)
  35         sleep(s);
  36     usleep(us);
  37 # endif
  38 }
  39 #elif defined(_WIN32) && !defined(OPENSSL_SYS_UEFI)
  40 # include <windows.h>
  41
  42 void OSSL_sleep(uint64_t millis)
  43 {
  44     /*
  45      * Windows' Sleep() takes a DWORD argument, which is smaller than
  46      * a uint64_t, so we need to limit it to 49 days, which should be enough.
  47      */
  48     DWORD limited_millis = (DWORD)-1;
  49
  50     if (millis < limited_millis)
  51         limited_millis = (DWORD)millis;
  52     Sleep(limited_millis);
  53 }
  54
  55 #else
  56 /* Fallback to a busy wait */
  57 # include "internal/time.h"
  58
  59 static void ossl_sleep_secs(uint64_t secs)
  60 {
  61     /*
  62      * sleep() takes an unsigned int argument, which is smaller than
  63      * a uint64_t, so it needs to be limited to 136 years which
  64      * should be enough even for Sleeping Beauty.
  65      */
  66     unsigned int limited_secs = UINT_MAX;
  67
  68     if (secs < limited_secs)
  69         limited_secs = (unsigned int)secs;
  70     sleep(limited_secs);
  71 }
  72
  73 static void ossl_sleep_millis(uint64_t millis)
  74 {
  75     const OSSL_TIME finish
  76         = ossl_time_add(ossl_time_now(), ossl_ms2time(millis));
  77
  78     while (ossl_time_compare(ossl_time_now(), finish) < 0)
  79         /* busy wait */ ;
  80 }
  81
  82 void OSSL_sleep(uint64_t millis)
  83 {
  84     ossl_sleep_secs(millis / 1000);
  85     ossl_sleep_millis(millis % 1000);
  86 }
  87 #endif /* defined(OPENSSL_SYS_UNIX) || defined(__DJGPP__) */