/*

 * Copyright 2001-2017 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 "eng_local.h"

/*

 * Initialise a engine type for use (or up its functional reference count if

 * it's already in use). This version is only used internally.

 */

int engine_unlocked_init(ENGINE *e)

{

    int to_return = 1;

    if ((e->funct_ref == 0) && e->init)

        /*

         * This is the first functional reference and the engine requires

         * initialisation so we do it now.

         */

        to_return = e->init(e);

    if (to_return) {

        /*

         * OK, we return a functional reference which is also a structural

         * reference.

         */

        e->struct_ref++;

        e->funct_ref++;

        engine_ref_debug(e, 0, 1);

        engine_ref_debug(e, 1, 1);

    }

    return to_return;

}

/*

 * Free a functional reference to a engine type. This version is only used

 * internally.

 */

int engine_unlocked_finish(ENGINE *e, int unlock_for_handlers)

{

    int to_return = 1;

    /*

     * Reduce the functional reference count here so if it's the terminating

     * case, we can release the lock safely and call the finish() handler

     * without risk of a race. We get a race if we leave the count until

     * after and something else is calling "finish" at the same time -

     * there's a chance that both threads will together take the count from 2

     * to 0 without either calling finish().

     */

    e->funct_ref--;

    engine_ref_debug(e, 1, -1);

    if ((e->funct_ref == 0) && e->finish) {

        if (unlock_for_handlers)

            CRYPTO_THREAD_unlock(global_engine_lock);

        to_return = e->finish(e);

        if (unlock_for_handlers)

            CRYPTO_THREAD_write_lock(global_engine_lock);

        if (!to_return)

            return 0;

    }

    REF_ASSERT_ISNT(e->funct_ref < 0);

    /* Release the structural reference too */

    if (!engine_free_util(e, 0)) {

        ENGINEerr(ENGINE_F_ENGINE_UNLOCKED_FINISH, ENGINE_R_FINISH_FAILED);

        return 0;

    }

    return to_return;

}

/* The API (locked) version of "init" */

int ENGINE_init(ENGINE *e)

{

    int ret;

    if (e == NULL) {

        ENGINEerr(ENGINE_F_ENGINE_INIT, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) {

        ENGINEerr(ENGINE_F_ENGINE_INIT, ERR_R_MALLOC_FAILURE);

        return 0;

    }

    CRYPTO_THREAD_write_lock(global_engine_lock);

    ret = engine_unlocked_init(e);

    CRYPTO_THREAD_unlock(global_engine_lock);

    return ret;

}

/* The API (locked) version of "finish" */

int ENGINE_finish(ENGINE *e)

{

    int to_return = 1;

    if (e == NULL)

        return 1;

    CRYPTO_THREAD_write_lock(global_engine_lock);

    to_return = engine_unlocked_finish(e, 1);

    CRYPTO_THREAD_unlock(global_engine_lock);

    if (!to_return) {

        ENGINEerr(ENGINE_F_ENGINE_FINISH, ENGINE_R_FINISH_FAILED);

        return 0;

    }

    return to_return;

}