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      1 /***************************************************************************
      2  *                                  _   _ ____  _
      3  *  Project                     ___| | | |  _ \| |
      4  *                             / __| | | | |_) | |
      5  *                            | (__| |_| |  _ <| |___
      6  *                             \___|\___/|_| \_\_____|
      7  *
      8  * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel (at) haxx.se>, et al.
      9  *
     10  * This software is licensed as described in the file COPYING, which
     11  * you should have received as part of this distribution. The terms
     12  * are also available at https://curl.haxx.se/docs/copyright.html.
     13  *
     14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
     15  * copies of the Software, and permit persons to whom the Software is
     16  * furnished to do so, under the terms of the COPYING file.
     17  *
     18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
     19  * KIND, either express or implied.
     20  *
     21  ***************************************************************************/
     22 /* <DESC>
     23  * one way to set the necessary OpenSSL locking callbacks if you want to do
     24  * multi-threaded transfers with HTTPS/FTPS with libcurl built to use OpenSSL.
     25  * </DESC>
     26  */
     27 /*
     28  * This is not a complete stand-alone example.
     29  *
     30  * Author: Jeremy Brown
     31  */
     32 
     33 #include <stdio.h>
     34 #include <pthread.h>
     35 #include <openssl/err.h>
     36 
     37 #define MUTEX_TYPE       pthread_mutex_t
     38 #define MUTEX_SETUP(x)   pthread_mutex_init(&(x), NULL)
     39 #define MUTEX_CLEANUP(x) pthread_mutex_destroy(&(x))
     40 #define MUTEX_LOCK(x)    pthread_mutex_lock(&(x))
     41 #define MUTEX_UNLOCK(x)  pthread_mutex_unlock(&(x))
     42 #define THREAD_ID        pthread_self()
     43 
     44 
     45 void handle_error(const char *file, int lineno, const char *msg)
     46 {
     47   fprintf(stderr, "** %s:%d %s\n", file, lineno, msg);
     48   ERR_print_errors_fp(stderr);
     49   /* exit(-1); */
     50 }
     51 
     52 /* This array will store all of the mutexes available to OpenSSL. */
     53 static MUTEX_TYPE *mutex_buf = NULL;
     54 
     55 static void locking_function(int mode, int n, const char *file, int line)
     56 {
     57   if(mode & CRYPTO_LOCK)
     58     MUTEX_LOCK(mutex_buf[n]);
     59   else
     60     MUTEX_UNLOCK(mutex_buf[n]);
     61 }
     62 
     63 static unsigned long id_function(void)
     64 {
     65   return ((unsigned long)THREAD_ID);
     66 }
     67 
     68 int thread_setup(void)
     69 {
     70   int i;
     71 
     72   mutex_buf = malloc(CRYPTO_num_locks() * sizeof(MUTEX_TYPE));
     73   if(!mutex_buf)
     74     return 0;
     75   for(i = 0;  i < CRYPTO_num_locks();  i++)
     76     MUTEX_SETUP(mutex_buf[i]);
     77   CRYPTO_set_id_callback(id_function);
     78   CRYPTO_set_locking_callback(locking_function);
     79   return 1;
     80 }
     81 
     82 int thread_cleanup(void)
     83 {
     84   int i;
     85 
     86   if(!mutex_buf)
     87     return 0;
     88   CRYPTO_set_id_callback(NULL);
     89   CRYPTO_set_locking_callback(NULL);
     90   for(i = 0;  i < CRYPTO_num_locks();  i++)
     91     MUTEX_CLEANUP(mutex_buf[i]);
     92   free(mutex_buf);
     93   mutex_buf = NULL;
     94   return 1;
     95 }
     96