crypto/engine/eng_init.c

   1 /* ====================================================================
   2  * Copyright (c) 1999-2001 The OpenSSL Project.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  *
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in
  13  *    the documentation and/or other materials provided with the
  14  *    distribution.
  15  *
  16  * 3. All advertising materials mentioning features or use of this
  17  *    software must display the following acknowledgment:
  18  *    "This product includes software developed by the OpenSSL Project
  19  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  20  *
  21  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  22  *    endorse or promote products derived from this software without
  23  *    prior written permission. For written permission, please contact
  24  *    licensing@OpenSSL.org.
  25  *
  26  * 5. Products derived from this software may not be called "OpenSSL"
  27  *    nor may "OpenSSL" appear in their names without prior written
  28  *    permission of the OpenSSL Project.
  29  *
  30  * 6. Redistributions of any form whatsoever must retain the following
  31  *    acknowledgment:
  32  *    "This product includes software developed by the OpenSSL Project
  33  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  34  *
  35  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  36  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  37  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  38  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  39  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  40  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  41  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  42  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  44  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  45  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  46  * OF THE POSSIBILITY OF SUCH DAMAGE.
  47  * ====================================================================
  48  *
  49  * This product includes cryptographic software written by Eric Young
  50  * (eay@cryptsoft.com).  This product includes software written by Tim
  51  * Hudson (tjh@cryptsoft.com).
  52  *
  53  */
  54
  55 #include "eng_int.h"
  56
  57 /*
  58  * Initialise a engine type for use (or up its functional reference count if
  59  * it's already in use). This version is only used internally.
  60  */
  61 int engine_unlocked_init(ENGINE *e)
  62 {
  63     int to_return = 1;
  64
  65     if ((e->funct_ref == 0) && e->init)
  66         /*
  67          * This is the first functional reference and the engine requires
  68          * initialisation so we do it now.
  69          */
  70         to_return = e->init(e);
  71     if (to_return) {
  72         /*
  73          * OK, we return a functional reference which is also a structural
  74          * reference.
  75          */
  76         e->struct_ref++;
  77         e->funct_ref++;
  78         engine_ref_debug(e, 0, 1);
  79         engine_ref_debug(e, 1, 1);
  80     }
  81     return to_return;
  82 }
  83
  84 /*
  85  * Free a functional reference to a engine type. This version is only used
  86  * internally.
  87  */
  88 int engine_unlocked_finish(ENGINE *e, int unlock_for_handlers)
  89 {
  90     int to_return = 1;
  91
  92     /*
  93      * Reduce the functional reference count here so if it's the terminating
  94      * case, we can release the lock safely and call the finish() handler
  95      * without risk of a race. We get a race if we leave the count until
  96      * after and something else is calling "finish" at the same time -
  97      * there's a chance that both threads will together take the count from 2
  98      * to 0 without either calling finish().
  99      */
 100     e->funct_ref--;
 101     engine_ref_debug(e, 1, -1);
 102     if ((e->funct_ref == 0) && e->finish) {
 103         if (unlock_for_handlers)
 104             CRYPTO_THREAD_unlock(global_engine_lock);
 105         to_return = e->finish(e);
 106         if (unlock_for_handlers)
 107             CRYPTO_THREAD_write_lock(global_engine_lock);
 108         if (!to_return)
 109             return 0;
 110     }
 111     REF_ASSERT_ISNT(e->funct_ref < 0);
 112     /* Release the structural reference too */
 113     if (!engine_free_util(e, 0)) {
 114         ENGINEerr(ENGINE_F_ENGINE_UNLOCKED_FINISH, ENGINE_R_FINISH_FAILED);
 115         return 0;
 116     }
 117     return to_return;
 118 }
 119
 120 /* The API (locked) version of "init" */
 121 int ENGINE_init(ENGINE *e)
 122 {
 123     int ret;
 124     if (e == NULL) {
 125         ENGINEerr(ENGINE_F_ENGINE_INIT, ERR_R_PASSED_NULL_PARAMETER);
 126         return 0;
 127     }
 128     CRYPTO_THREAD_run_once(&engine_lock_init, do_engine_lock_init);
 129     CRYPTO_THREAD_write_lock(global_engine_lock);
 130     ret = engine_unlocked_init(e);
 131     CRYPTO_THREAD_unlock(global_engine_lock);
 132     return ret;
 133 }
 134
 135 /* The API (locked) version of "finish" */
 136 int ENGINE_finish(ENGINE *e)
 137 {
 138     int to_return = 1;
 139
 140     if (e == NULL)
 141         return 1;
 142     CRYPTO_THREAD_write_lock(global_engine_lock);
 143     to_return = engine_unlocked_finish(e, 1);
 144     CRYPTO_THREAD_unlock(global_engine_lock);
 145     if (!to_return) {
 146         ENGINEerr(ENGINE_F_ENGINE_FINISH, ENGINE_R_FINISH_FAILED);
 147         return 0;
 148     }
 149     return to_return;
 150 }