/*

 * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#include "e_os.h"

#include "internal/cryptlib.h"

#include "crypto/cryptlib.h"

#include <stdio.h>

#include <stdlib.h>

#include <limits.h>

#include <openssl/crypto.h>

#ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE

# include <execinfo.h>

#endif

/*

 * the following pointers may be changed as long as 'allow_customize' is set

 */

static int allow_customize = 1;

static void *(*malloc_impl)(size_t, const char *, int)

    = CRYPTO_malloc;

static void *(*realloc_impl)(void *, size_t, const char *, int)

    = CRYPTO_realloc;

static void (*free_impl)(void *, const char *, int)

    = CRYPTO_free;

#ifndef OPENSSL_NO_CRYPTO_MDEBUG

# include "internal/tsan_assist.h"

static TSAN_QUALIFIER int malloc_count;

static TSAN_QUALIFIER int realloc_count;

static TSAN_QUALIFIER int free_count;

# define INCREMENT(x) tsan_counter(&(x))

static char *md_failstring;

static long md_count;

static int md_fail_percent = 0;

static int md_tracefd = -1;

static int call_malloc_debug = 1;

static void parseit(void);

static int shouldfail(void);

# define FAILTEST() if (shouldfail()) return NULL

#else

static int call_malloc_debug = 0;

# define INCREMENT(x) /* empty */

# define FAILTEST() /* empty */

#endif

int CRYPTO_set_mem_functions(

        void *(*m)(size_t, const char *, int),

        void *(*r)(void *, size_t, const char *, int),

        void (*f)(void *, const char *, int))

{

    if (!allow_customize)

        return 0;

    if (m)

        malloc_impl = m;

    if (r)

        realloc_impl = r;

    if (f)

        free_impl = f;

    return 1;

}

int CRYPTO_set_mem_debug(int flag)

{

    if (!allow_customize)

        return 0;

    call_malloc_debug = flag;

    return 1;

}

void CRYPTO_get_mem_functions(

        void *(**m)(size_t, const char *, int),

        void *(**r)(void *, size_t, const char *, int),

        void (**f)(void *, const char *, int))

{

    if (m != NULL)

        *m = malloc_impl;

    if (r != NULL)

        *r = realloc_impl;

    if (f != NULL)

        *f = free_impl;

}

#ifndef OPENSSL_NO_CRYPTO_MDEBUG

void CRYPTO_get_alloc_counts(int *mcount, int *rcount, int *fcount)

{

    if (mcount != NULL)

        *mcount = tsan_load(&malloc_count);

    if (rcount != NULL)

        *rcount = tsan_load(&realloc_count);

    if (fcount != NULL)

        *fcount = tsan_load(&free_count);

}

/*

 * Parse a "malloc failure spec" string.  This likes like a set of fields

 * separated by semicolons.  Each field has a count and an optional failure

 * percentage.  For example:

 *          100@0;100@25;0@0

 *    or    100;100@25;0

 * This means 100 mallocs succeed, then next 100 fail 25% of the time, and

 * all remaining (count is zero) succeed.

 */

static void parseit(void)

{

    char *semi = strchr(md_failstring, ';');

    char *atsign;

    if (semi != NULL)

        *semi++ = '\0';

    /* Get the count (atol will stop at the @ if there), and percentage */

    md_count = atol(md_failstring);

    atsign = strchr(md_failstring, '@');

    md_fail_percent = atsign == NULL ? 0 : atoi(atsign + 1);

    if (semi != NULL)

        md_failstring = semi;

}

/*

 * Windows doesn't have random(), but it has rand()

 * Some rand() implementations aren't good, but we're not

 * dealing with secure randomness here.

 */

# ifdef _WIN32

#  define random() rand()

# endif

/*

 * See if the current malloc should fail.

 */

static int shouldfail(void)

{

    int roll = (int)(random() % 100);

    int shoulditfail = roll < md_fail_percent;

# ifndef _WIN32

/* suppressed on Windows as POSIX-like file descriptors are non-inheritable */

    int len;

    char buff[80];

    if (md_tracefd > 0) {

        BIO_snprintf(buff, sizeof(buff),

                     "%c C%ld %%%d R%d\n",

                     shoulditfail ? '-' : '+', md_count, md_fail_percent, roll);

        len = strlen(buff);

        if (write(md_tracefd, buff, len) != len)

            perror("shouldfail write failed");

#  ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE

        if (shoulditfail) {

            void *addrs[30];

            int num = backtrace(addrs, OSSL_NELEM(addrs));

            backtrace_symbols_fd(addrs, num, md_tracefd);

        }

#  endif

    }

# endif

    if (md_count) {

        /* If we used up this one, go to the next. */

        if (--md_count == 0)

            parseit();

    }

    return shoulditfail;

}

void ossl_malloc_setup_failures(void)

{

    const char *cp = getenv("OPENSSL_MALLOC_FAILURES");

    if (cp != NULL && (md_failstring = strdup(cp)) != NULL)

        parseit();

    if ((cp = getenv("OPENSSL_MALLOC_FD")) != NULL)

        md_tracefd = atoi(cp);

}

#endif

void *CRYPTO_malloc(size_t num, const char *file, int line)

{

    void *ret = NULL;

    INCREMENT(malloc_count);

    if (malloc_impl != NULL && malloc_impl != CRYPTO_malloc)

        return malloc_impl(num, file, line);

    if (num == 0)

        return NULL;

    FAILTEST();

    if (allow_customize) {

        /*

         * Disallow customization after the first allocation. We only set this

         * if necessary to avoid a store to the same cache line on every

         * allocation.

         */

        allow_customize = 0;

    }

#ifndef OPENSSL_NO_CRYPTO_MDEBUG

    if (call_malloc_debug) {

        CRYPTO_mem_debug_malloc(NULL, num, 0, file, line);

        ret = malloc(num);

        CRYPTO_mem_debug_malloc(ret, num, 1, file, line);

    } else {

        ret = malloc(num);

    }

#else

    (void)(file); (void)(line);

    ret = malloc(num);

#endif

    return ret;

}

void *CRYPTO_zalloc(size_t num, const char *file, int line)

{

    void *ret = CRYPTO_malloc(num, file, line);

    FAILTEST();

    if (ret != NULL)

        memset(ret, 0, num);

    return ret;

}

void *CRYPTO_realloc(void *str, size_t num, const char *file, int line)

{

    INCREMENT(realloc_count);

    if (realloc_impl != NULL && realloc_impl != &CRYPTO_realloc)

        return realloc_impl(str, num, file, line);

    FAILTEST();

    if (str == NULL)

        return CRYPTO_malloc(num, file, line);

    if (num == 0) {

        CRYPTO_free(str, file, line);

        return NULL;

    }

#ifndef OPENSSL_NO_CRYPTO_MDEBUG

    if (call_malloc_debug) {

        void *ret;

        CRYPTO_mem_debug_realloc(str, NULL, num, 0, file, line);

        ret = realloc(str, num);

        CRYPTO_mem_debug_realloc(str, ret, num, 1, file, line);

        return ret;

    }

#else

    (void)(file); (void)(line);

#endif

    return realloc(str, num);

}

void *CRYPTO_clear_realloc(void *str, size_t old_len, size_t num,

                           const char *file, int line)

{

    void *ret = NULL;

    if (str == NULL)

        return CRYPTO_malloc(num, file, line);

    if (num == 0) {

        CRYPTO_clear_free(str, old_len, file, line);

        return NULL;

    }

    /* Can't shrink the buffer since memcpy below copies |old_len| bytes. */

    if (num < old_len) {

        OPENSSL_cleanse((char*)str + num, old_len - num);

        return str;

    }

    ret = CRYPTO_malloc(num, file, line);

    if (ret != NULL) {

        memcpy(ret, str, old_len);

        CRYPTO_clear_free(str, old_len, file, line);

    }

    return ret;

}

void CRYPTO_free(void *str, const char *file, int line)

{

    INCREMENT(free_count);

    if (free_impl != NULL && free_impl != &CRYPTO_free) {

        free_impl(str, file, line);

        return;

    }

#ifndef OPENSSL_NO_CRYPTO_MDEBUG

    if (call_malloc_debug) {

        CRYPTO_mem_debug_free(str, 0, file, line);

        free(str);

        CRYPTO_mem_debug_free(str, 1, file, line);

    } else {

        free(str);

    }

#else

    free(str);

#endif

}

void CRYPTO_clear_free(void *str, size_t num, const char *file, int line)

{

    if (str == NULL)

        return;

    if (num)

        OPENSSL_cleanse(str, num);

    CRYPTO_free(str, file, line);

}