mbedtls/library/timing.c
TRodziewicz 15a7b73708 Documentation rewording
Signed-off-by: TRodziewicz <tomasz.rodziewicz@mobica.com>
2021-06-16 11:22:53 +02:00

164 lines
4.2 KiB
C

/*
* Portable interface to the CPU cycle counter
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "common.h"
#if defined(MBEDTLS_TIMING_C)
#include "mbedtls/timing.h"
#if !defined(MBEDTLS_TIMING_ALT)
#if !defined(unix) && !defined(__unix__) && !defined(__unix) && \
!defined(__APPLE__) && !defined(_WIN32) && !defined(__QNXNTO__) && \
!defined(__HAIKU__) && !defined(__midipix__)
#error "This module only works on Unix and Windows, see MBEDTLS_TIMING_C in config.h"
#endif
#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
#include <windows.h>
#include <process.h>
struct _hr_time
{
LARGE_INTEGER start;
};
#else
#include <unistd.h>
#include <sys/types.h>
#include <sys/time.h>
#include <signal.h>
#include <time.h>
struct _hr_time
{
struct timeval start;
};
#endif /* _WIN32 && !EFIX64 && !EFI32 */
volatile int mbedtls_timing_alarmed = 0;
#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
unsigned long mbedtls_timing_get_timer( struct mbedtls_timing_hr_time *val, int reset )
{
struct _hr_time *t = (struct _hr_time *) val;
if( reset )
{
QueryPerformanceCounter( &t->start );
return( 0 );
}
else
{
unsigned long delta;
LARGE_INTEGER now, hfreq;
QueryPerformanceCounter( &now );
QueryPerformanceFrequency( &hfreq );
delta = (unsigned long)( ( now.QuadPart - t->start.QuadPart ) * 1000ul
/ hfreq.QuadPart );
return( delta );
}
}
#else /* _WIN32 && !EFIX64 && !EFI32 */
/**
* \brief Return the elapsed time in milliseconds
*
* \warning May change without notice
*
* \param val points to a timer structure
* \param reset If 0, query the elapsed time. Otherwise (re)start the timer.
*
* \return Elapsed time since the previous reset in ms. When
* restarting, this is always 0.
*
* \note To initialize a timer, call this function with reset=1.
*
* Determining the elapsed time and resetting the timer is not
* atomic on all platforms, so after the sequence
* `{ get_timer(1); ...; time1 = get_timer(1); ...; time2 =
* get_timer(0) }` the value time1+time2 is only approximately
* the delay since the first reset.
*/
unsigned long mbedtls_timing_get_timer( struct mbedtls_timing_hr_time *val, int reset )
{
struct _hr_time *t = (struct _hr_time *) val;
if( reset )
{
gettimeofday( &t->start, NULL );
return( 0 );
}
else
{
unsigned long delta;
struct timeval now;
gettimeofday( &now, NULL );
delta = ( now.tv_sec - t->start.tv_sec ) * 1000ul
+ ( now.tv_usec - t->start.tv_usec ) / 1000;
return( delta );
}
}
#endif /* _WIN32 && !EFIX64 && !EFI32 */
/*
* Set delays to watch
*/
void mbedtls_timing_set_delay( void *data, uint32_t int_ms, uint32_t fin_ms )
{
mbedtls_timing_delay_context *ctx = (mbedtls_timing_delay_context *) data;
ctx->int_ms = int_ms;
ctx->fin_ms = fin_ms;
if( fin_ms != 0 )
(void) mbedtls_timing_get_timer( &ctx->timer, 1 );
}
/*
* Get number of delays expired
*/
int mbedtls_timing_get_delay( void *data )
{
mbedtls_timing_delay_context *ctx = (mbedtls_timing_delay_context *) data;
unsigned long elapsed_ms;
if( ctx->fin_ms == 0 )
return( -1 );
elapsed_ms = mbedtls_timing_get_timer( &ctx->timer, 0 );
if( elapsed_ms >= ctx->fin_ms )
return( 2 );
if( elapsed_ms >= ctx->int_ms )
return( 1 );
return( 0 );
}
#endif /* !MBEDTLS_TIMING_ALT */
#endif /* MBEDTLS_TIMING_C */