| 1 | /** |
| 2 | * \file timing.h |
| 3 | * |
| 4 | * \brief Portable interface to timeouts and to the CPU cycle counter |
| 5 | */ |
| 6 | /* |
| 7 | * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved |
| 8 | * SPDX-License-Identifier: GPL-2.0 |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or modify |
| 11 | * it under the terms of the GNU General Public License as published by |
| 12 | * the Free Software Foundation; either version 2 of the License, or |
| 13 | * (at your option) any later version. |
| 14 | * |
| 15 | * This program is distributed in the hope that it will be useful, |
| 16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | * GNU General Public License for more details. |
| 19 | * |
| 20 | * You should have received a copy of the GNU General Public License along |
| 21 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 22 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 23 | * |
| 24 | * This file is part of mbed TLS (https://tls.mbed.org) |
| 25 | */ |
| 26 | #ifndef MBEDTLS_TIMING_H |
| 27 | #define MBEDTLS_TIMING_H |
| 28 | |
| 29 | #if !defined(MBEDTLS_CONFIG_FILE) |
| 30 | #include "config.h" |
| 31 | #else |
| 32 | #include MBEDTLS_CONFIG_FILE |
| 33 | #endif |
| 34 | |
| 35 | #include <stdint.h> |
| 36 | |
| 37 | #ifdef __cplusplus |
| 38 | extern "C" { |
| 39 | #endif |
| 40 | |
| 41 | #if !defined(MBEDTLS_TIMING_ALT) |
| 42 | // Regular implementation |
| 43 | // |
| 44 | |
| 45 | /** |
| 46 | * \brief timer structure |
| 47 | */ |
| 48 | struct mbedtls_timing_hr_time |
| 49 | { |
| 50 | unsigned char opaque[32]; |
| 51 | }; |
| 52 | |
| 53 | /** |
| 54 | * \brief Context for mbedtls_timing_set/get_delay() |
| 55 | */ |
| 56 | typedef struct mbedtls_timing_delay_context |
| 57 | { |
| 58 | struct mbedtls_timing_hr_time timer; |
| 59 | uint32_t int_ms; |
| 60 | uint32_t fin_ms; |
| 61 | } mbedtls_timing_delay_context; |
| 62 | |
| 63 | #else /* MBEDTLS_TIMING_ALT */ |
| 64 | #include "timing_alt.h" |
| 65 | #endif /* MBEDTLS_TIMING_ALT */ |
| 66 | |
| 67 | extern volatile int mbedtls_timing_alarmed; |
| 68 | |
| 69 | /** |
| 70 | * \brief Return the CPU cycle counter value |
| 71 | * |
| 72 | * \warning This is only a best effort! Do not rely on this! |
| 73 | * In particular, it is known to be unreliable on virtual |
| 74 | * machines. |
| 75 | * |
| 76 | * \note This value starts at an unspecified origin and |
| 77 | * may wrap around. |
| 78 | */ |
| 79 | unsigned long mbedtls_timing_hardclock( void ); |
| 80 | |
| 81 | /** |
| 82 | * \brief Return the elapsed time in milliseconds |
| 83 | * |
| 84 | * \param val points to a timer structure |
| 85 | * \param reset If 0, query the elapsed time. Otherwise (re)start the timer. |
| 86 | * |
| 87 | * \return Elapsed time since the previous reset in ms. When |
| 88 | * restarting, this is always 0. |
| 89 | * |
| 90 | * \note To initialize a timer, call this function with reset=1. |
| 91 | * |
| 92 | * Determining the elapsed time and resetting the timer is not |
| 93 | * atomic on all platforms, so after the sequence |
| 94 | * `{ get_timer(1); ...; time1 = get_timer(1); ...; time2 = |
| 95 | * get_timer(0) }` the value time1+time2 is only approximately |
| 96 | * the delay since the first reset. |
| 97 | */ |
| 98 | unsigned long mbedtls_timing_get_timer( struct mbedtls_timing_hr_time *val, int reset ); |
| 99 | |
| 100 | /** |
| 101 | * \brief Setup an alarm clock |
| 102 | * |
| 103 | * \param seconds delay before the "mbedtls_timing_alarmed" flag is set |
| 104 | * (must be >=0) |
| 105 | * |
| 106 | * \warning Only one alarm at a time is supported. In a threaded |
| 107 | * context, this means one for the whole process, not one per |
| 108 | * thread. |
| 109 | */ |
| 110 | void mbedtls_set_alarm( int seconds ); |
| 111 | |
| 112 | /** |
| 113 | * \brief Set a pair of delays to watch |
| 114 | * (See \c mbedtls_timing_get_delay().) |
| 115 | * |
| 116 | * \param data Pointer to timing data. |
| 117 | * Must point to a valid \c mbedtls_timing_delay_context struct. |
| 118 | * \param int_ms First (intermediate) delay in milliseconds. |
| 119 | * The effect if int_ms > fin_ms is unspecified. |
| 120 | * \param fin_ms Second (final) delay in milliseconds. |
| 121 | * Pass 0 to cancel the current delay. |
| 122 | * |
| 123 | * \note To set a single delay, either use \c mbedtls_timing_set_timer |
| 124 | * directly or use this function with int_ms == fin_ms. |
| 125 | */ |
| 126 | void mbedtls_timing_set_delay( void *data, uint32_t int_ms, uint32_t fin_ms ); |
| 127 | |
| 128 | /** |
| 129 | * \brief Get the status of delays |
| 130 | * (Memory helper: number of delays passed.) |
| 131 | * |
| 132 | * \param data Pointer to timing data |
| 133 | * Must point to a valid \c mbedtls_timing_delay_context struct. |
| 134 | * |
| 135 | * \return -1 if cancelled (fin_ms = 0), |
| 136 | * 0 if none of the delays are passed, |
| 137 | * 1 if only the intermediate delay is passed, |
| 138 | * 2 if the final delay is passed. |
| 139 | */ |
| 140 | int mbedtls_timing_get_delay( void *data ); |
| 141 | |
| 142 | #if defined(MBEDTLS_SELF_TEST) |
| 143 | /** |
| 144 | * \brief Checkup routine |
| 145 | * |
| 146 | * \return 0 if successful, or 1 if a test failed |
| 147 | */ |
| 148 | int mbedtls_timing_self_test( int verbose ); |
| 149 | #endif |
| 150 | |
| 151 | #ifdef __cplusplus |
| 152 | } |
| 153 | #endif |
| 154 | |
| 155 | #endif /* timing.h */ |