/*

 *  Portable interface to the CPU cycle counter

 *

 *  Copyright The Mbed TLS Contributors

 *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later

 */

#include <string.h>

#include "common.h"

#include "mbedtls/platform.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

/* *INDENT-OFF* */

#ifndef asm

#define asm __asm

#endif

/* *INDENT-ON* */

#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 <signal.h>

/* time.h should be included independently of MBEDTLS_HAVE_TIME. If the

 * platform matches the ifdefs above, it will be used. */

#include <time.h>

#include <sys/time.h>

struct _hr_time {

    struct timeval start;

};

#endif /* _WIN32 && !EFIX64 && !EFI32 */

#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \

    (defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)

#define HAVE_HARDCLOCK

unsigned long mbedtls_timing_hardclock(void)

{

    unsigned long tsc;

    __asm   rdtsc

    __asm   mov[tsc], eax

    return tsc;

}

#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&

          ( _MSC_VER && _M_IX86 ) || __WATCOMC__ */

/* some versions of mingw-64 have 32-bit longs even on x84_64 */

#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \

    defined(__GNUC__) && (defined(__i386__) || (                       \

    (defined(__amd64__) || defined(__x86_64__)) && __SIZEOF_LONG__ == 4))

#define HAVE_HARDCLOCK

unsigned long mbedtls_timing_hardclock(void)

{

    unsigned long lo, hi;

    asm volatile ("rdtsc" : "=a" (lo), "=d" (hi));

    return lo;

}

#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&

          __GNUC__ && __i386__ */

#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \

    defined(__GNUC__) && (defined(__amd64__) || defined(__x86_64__))

#define HAVE_HARDCLOCK

unsigned long mbedtls_timing_hardclock(void)

{

    unsigned long lo, hi;

    asm volatile ("rdtsc" : "=a" (lo), "=d" (hi));

    return lo | (hi << 32);

}

#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&

          __GNUC__ && ( __amd64__ || __x86_64__ ) */

#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \

    defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))

#define HAVE_HARDCLOCK

unsigned long mbedtls_timing_hardclock(void)

{

    unsigned long tbl, tbu0, tbu1;

    do {

        asm volatile ("mftbu %0" : "=r" (tbu0));

        asm volatile ("mftb  %0" : "=r" (tbl));

        asm volatile ("mftbu %0" : "=r" (tbu1));

    } while (tbu0 != tbu1);

    return tbl;

}

#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&

          __GNUC__ && ( __powerpc__ || __ppc__ ) */

#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \

    defined(__GNUC__) && defined(__sparc64__)

#if defined(__OpenBSD__)

#warning OpenBSD does not allow access to tick register using software version instead

#else

#define HAVE_HARDCLOCK

unsigned long mbedtls_timing_hardclock(void)

{

    unsigned long tick;

    asm volatile ("rdpr %%tick, %0;" : "=&r" (tick));

    return tick;

}

#endif /* __OpenBSD__ */

#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&

          __GNUC__ && __sparc64__ */

#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&  \

    defined(__GNUC__) && defined(__sparc__) && !defined(__sparc64__)

#define HAVE_HARDCLOCK

unsigned long mbedtls_timing_hardclock(void)

{

    unsigned long tick;

    asm volatile (".byte 0x83, 0x41, 0x00, 0x00");

    asm volatile ("mov   %%g1, %0" : "=r" (tick));

    return tick;

}

#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&

          __GNUC__ && __sparc__ && !__sparc64__ */

#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&      \

    defined(__GNUC__) && defined(__alpha__)

#define HAVE_HARDCLOCK

unsigned long mbedtls_timing_hardclock(void)

{

    unsigned long cc;

    asm volatile ("rpcc %0" : "=r" (cc));

    return cc & 0xFFFFFFFF;

}

#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&

          __GNUC__ && __alpha__ */

#if !defined(HAVE_HARDCLOCK) && defined(MBEDTLS_HAVE_ASM) &&      \

    defined(__GNUC__) && defined(__ia64__)

#define HAVE_HARDCLOCK

unsigned long mbedtls_timing_hardclock(void)

{

    unsigned long itc;

    asm volatile ("mov %0 = ar.itc" : "=r" (itc));

    return itc;

}

#endif /* !HAVE_HARDCLOCK && MBEDTLS_HAVE_ASM &&

          __GNUC__ && __ia64__ */

#if !defined(HAVE_HARDCLOCK) && defined(_MSC_VER) && \

    !defined(EFIX64) && !defined(EFI32)

#define HAVE_HARDCLOCK

unsigned long mbedtls_timing_hardclock(void)

{

    LARGE_INTEGER offset;

    QueryPerformanceCounter(&offset);

    return (unsigned long) (offset.QuadPart);

}

#endif /* !HAVE_HARDCLOCK && _MSC_VER && !EFIX64 && !EFI32 */

#if !defined(HAVE_HARDCLOCK)

#define HAVE_HARDCLOCK

static int hardclock_init = 0;

static struct timeval tv_init;

unsigned long mbedtls_timing_hardclock(void)

{

    struct timeval tv_cur;

    if (hardclock_init == 0) {

        gettimeofday(&tv_init, NULL);

        hardclock_init = 1;

    }

    gettimeofday(&tv_cur, NULL);

    return (tv_cur.tv_sec  - tv_init.tv_sec) * 1000000U

           + (tv_cur.tv_usec - tv_init.tv_usec);

}

#endif /* !HAVE_HARDCLOCK */

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;

    if (reset) {

        QueryPerformanceCounter(&t.start);

        memcpy(val, &t, sizeof(struct _hr_time));

        return 0;

    } else {

        unsigned long delta;

        LARGE_INTEGER now, hfreq;

        /* We can't safely cast val because it may not be aligned, so use memcpy */

        memcpy(&t, val, sizeof(struct _hr_time));

        QueryPerformanceCounter(&now);

        QueryPerformanceFrequency(&hfreq);

        delta = (unsigned long) ((now.QuadPart - t.start.QuadPart) * 1000ul

                                 / hfreq.QuadPart);

        return delta;

    }

}

/* It's OK to use a global because alarm() is supposed to be global anyway */

static DWORD alarmMs;

static void TimerProc(void *TimerContext)

{

    (void) TimerContext;

    Sleep(alarmMs);

    mbedtls_timing_alarmed = 1;

    /* _endthread will be called implicitly on return

     * That ensures execution of thread function's epilogue */

}

void mbedtls_set_alarm(int seconds)

{

    if (seconds == 0) {

        /* No need to create a thread for this simple case.

         * Also, this shorcut is more reliable at least on MinGW32 */

        mbedtls_timing_alarmed = 1;

        return;

    }

    mbedtls_timing_alarmed = 0;

    alarmMs = seconds * 1000;

    (void) _beginthread(TimerProc, 0, NULL);

}

#else /* _WIN32 && !EFIX64 && !EFI32 */

unsigned long mbedtls_timing_get_timer(struct mbedtls_timing_hr_time *val, int reset)

{

    struct _hr_time t;

    if (reset) {

        gettimeofday(&t.start, NULL);

        memcpy(val, &t, sizeof(struct _hr_time));

        return 0;

    } else {

        unsigned long delta;

        struct timeval now;

        /* We can't safely cast val because it may not be aligned, so use memcpy */

        memcpy(&t, val, sizeof(struct _hr_time));

        gettimeofday(&now, NULL);

        delta = (now.tv_sec  - t.start.tv_sec) * 1000ul

                + (now.tv_usec - t.start.tv_usec) / 1000;

        return delta;

    }

}

static void sighandler(int signum)

{

    mbedtls_timing_alarmed = 1;

    signal(signum, sighandler);

}

void mbedtls_set_alarm(int seconds)

{

    mbedtls_timing_alarmed = 0;

    signal(SIGALRM, sighandler);

    alarm(seconds);

    if (seconds == 0) {

        /* alarm(0) cancelled any previous pending alarm, but the

           handler won't fire, so raise the flag straight away. */

        mbedtls_timing_alarmed = 1;

    }

}

#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 */

#if defined(MBEDTLS_SELF_TEST)

/*

 * Busy-waits for the given number of milliseconds.

 * Used for testing mbedtls_timing_hardclock.

 */

static void busy_msleep(unsigned long msec)

{

    struct mbedtls_timing_hr_time hires;

    unsigned long i = 0; /* for busy-waiting */

    volatile unsigned long j; /* to prevent optimisation */

    (void) mbedtls_timing_get_timer(&hires, 1);

    while (mbedtls_timing_get_timer(&hires, 0) < msec) {

        i++;

    }

    j = i;

    (void) j;

}

#define FAIL    do                                                      \

    {                                                                   \

        if (verbose != 0)                                              \

        {                                                               \

            mbedtls_printf("failed at line %d\n", __LINE__);          \

            mbedtls_printf(" cycles=%lu ratio=%lu millisecs=%lu secs=%lu hardfail=%d a=%lu b=%lu\n", \

                           cycles, ratio, millisecs, secs, hardfail,   \

                           (unsigned long) a, (unsigned long) b);     \

            mbedtls_printf(" elapsed(hires)=%lu status(ctx)=%d\n", \

                           mbedtls_timing_get_timer(&hires, 0),      \

                           mbedtls_timing_get_delay(&ctx));         \

        }                                                               \

        return 1;                                                    \

    } while (0)

/*

 * Checkup routine

 *

 * Warning: this is work in progress, some tests may not be reliable enough

 * yet! False positives may happen.

 */

int mbedtls_timing_self_test(int verbose)

{

    unsigned long cycles = 0, ratio = 0;

    unsigned long millisecs = 0, secs = 0;

    int hardfail = 0;

    struct mbedtls_timing_hr_time hires;

    uint32_t a = 0, b = 0;

    mbedtls_timing_delay_context ctx;

    memset(&ctx, 0, sizeof(ctx));

    if (verbose != 0) {

        mbedtls_printf("  TIMING tests note: will take some time!\n");

    }

    if (verbose != 0) {

        mbedtls_printf("  TIMING test #1 (set_alarm / get_timer): ");

    }

    {

        secs = 1;

        (void) mbedtls_timing_get_timer(&hires, 1);

        mbedtls_set_alarm((int) secs);

        while (!mbedtls_timing_alarmed) {

            ;

        }

        millisecs = mbedtls_timing_get_timer(&hires, 0);

        /* For some reason on Windows it looks like alarm has an extra delay

         * (maybe related to creating a new thread). Allow some room here. */

        if (millisecs < 800 * secs || millisecs > 1200 * secs + 300) {

            FAIL;

        }

    }

    if (verbose != 0) {

        mbedtls_printf("passed\n");

    }

    if (verbose != 0) {

        mbedtls_printf("  TIMING test #2 (set/get_delay        ): ");

    }

    {

        a = 800;

        b = 400;

        mbedtls_timing_set_delay(&ctx, a, a + b);            /* T = 0 */

        busy_msleep(a - a / 4);                        /* T = a - a/4 */

        if (mbedtls_timing_get_delay(&ctx) != 0) {

            FAIL;

        }

        busy_msleep(a / 4 + b / 4);                    /* T = a + b/4 */

        if (mbedtls_timing_get_delay(&ctx) != 1) {

            FAIL;

        }

        busy_msleep(b);                            /* T = a + b + b/4 */

        if (mbedtls_timing_get_delay(&ctx) != 2) {

            FAIL;

        }

    }

    mbedtls_timing_set_delay(&ctx, 0, 0);

    busy_msleep(200);

    if (mbedtls_timing_get_delay(&ctx) != -1) {

        FAIL;

    }

    if (verbose != 0) {

        mbedtls_printf("passed\n");

    }

    if (verbose != 0) {

        mbedtls_printf("  TIMING test #3 (hardclock / get_timer): ");

    }

    /*

     * Allow one failure for possible counter wrapping.

     * On a 4Ghz 32-bit machine the cycle counter wraps about once per second;

     * since the whole test is about 10ms, it shouldn't happen twice in a row.

     */

hard_test:

    if (hardfail > 1) {

        if (verbose != 0) {

            mbedtls_printf("failed (ignored)\n");

        }

        goto hard_test_done;

    }

    /* Get a reference ratio cycles/ms */

    millisecs = 1;

    cycles = mbedtls_timing_hardclock();

    busy_msleep(millisecs);

    cycles = mbedtls_timing_hardclock() - cycles;

    ratio = cycles / millisecs;

    /* Check that the ratio is mostly constant */

    for (millisecs = 2; millisecs <= 4; millisecs++) {

        cycles = mbedtls_timing_hardclock();

        busy_msleep(millisecs);

        cycles = mbedtls_timing_hardclock() - cycles;

        /* Allow variation up to 20% */

        if (cycles / millisecs < ratio - ratio / 5 ||

            cycles / millisecs > ratio + ratio / 5) {

            hardfail++;

            goto hard_test;

        }

    }

    if (verbose != 0) {

        mbedtls_printf("passed\n");

    }

hard_test_done:

    if (verbose != 0) {

        mbedtls_printf("\n");

    }

    return 0;

}

#endif /* MBEDTLS_SELF_TEST */

#endif /* MBEDTLS_TIMING_C */