crypto/engine/eng_init.c

   1 /*
   2  * Copyright 2001-2017 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include "e_os.h"
  11 #include "eng_local.h"
  12
  13 /*
  14  * Initialise a engine type for use (or up its functional reference count if
  15  * it's already in use). This version is only used internally.
  16  */
  17 int engine_unlocked_init(ENGINE *e)
  18 {
  19     int to_return = 1;
  20
  21     if ((e->funct_ref == 0) && e->init)
  22         /*
  23          * This is the first functional reference and the engine requires
  24          * initialisation so we do it now.
  25          */
  26         to_return = e->init(e);
  27     if (to_return) {
  28         /*
  29          * OK, we return a functional reference which is also a structural
  30          * reference.
  31          */
  32         e->struct_ref++;
  33         e->funct_ref++;
  34         engine_ref_debug(e, 0, 1);
  35         engine_ref_debug(e, 1, 1);
  36     }
  37     return to_return;
  38 }
  39
  40 /*
  41  * Free a functional reference to a engine type. This version is only used
  42  * internally.
  43  */
  44 int engine_unlocked_finish(ENGINE *e, int unlock_for_handlers)
  45 {
  46     int to_return = 1;
  47
  48     /*
  49      * Reduce the functional reference count here so if it's the terminating
  50      * case, we can release the lock safely and call the finish() handler
  51      * without risk of a race. We get a race if we leave the count until
  52      * after and something else is calling "finish" at the same time -
  53      * there's a chance that both threads will together take the count from 2
  54      * to 0 without either calling finish().
  55      */
  56     e->funct_ref--;
  57     engine_ref_debug(e, 1, -1);
  58     if ((e->funct_ref == 0) && e->finish) {
  59         if (unlock_for_handlers)
  60             CRYPTO_THREAD_unlock(global_engine_lock);
  61         to_return = e->finish(e);
  62         if (unlock_for_handlers)
  63             CRYPTO_THREAD_write_lock(global_engine_lock);
  64         if (!to_return)
  65             return 0;
  66     }
  67     REF_ASSERT_ISNT(e->funct_ref < 0);
  68     /* Release the structural reference too */
  69     if (!engine_free_util(e, 0)) {
  70         ENGINEerr(ENGINE_F_ENGINE_UNLOCKED_FINISH, ENGINE_R_FINISH_FAILED);
  71         return 0;
  72     }
  73     return to_return;
  74 }
  75
  76 /* The API (locked) version of "init" */
  77 int ENGINE_init(ENGINE *e)
  78 {
  79     int ret;
  80     if (e == NULL) {
  81         ENGINEerr(ENGINE_F_ENGINE_INIT, ERR_R_PASSED_NULL_PARAMETER);
  82         return 0;
  83     }
  84     if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) {
  85         ENGINEerr(ENGINE_F_ENGINE_INIT, ERR_R_MALLOC_FAILURE);
  86         return 0;
  87     }
  88     CRYPTO_THREAD_write_lock(global_engine_lock);
  89     ret = engine_unlocked_init(e);
  90     CRYPTO_THREAD_unlock(global_engine_lock);
  91     return ret;
  92 }
  93
  94 /* The API (locked) version of "finish" */
  95 int ENGINE_finish(ENGINE *e)
  96 {
  97     int to_return = 1;
  98
  99     if (e == NULL)
 100         return 1;
 101     CRYPTO_THREAD_write_lock(global_engine_lock);
 102     to_return = engine_unlocked_finish(e, 1);
 103     CRYPTO_THREAD_unlock(global_engine_lock);
 104     if (!to_return) {
 105         ENGINEerr(ENGINE_F_ENGINE_FINISH, ENGINE_R_FINISH_FAILED);
 106         return 0;
 107     }
 108     return to_return;
 109 }