xref: /third_party/curl/lib/psl.c (revision 13498266)
1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) Daniel Stenberg, <daniel@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.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 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24
25#include "curl_setup.h"
26
27#include <curl/curl.h>
28
29#ifdef USE_LIBPSL
30
31#include "psl.h"
32#include "share.h"
33
34/* The last 3 #include files should be in this order */
35#include "curl_printf.h"
36#include "curl_memory.h"
37#include "memdebug.h"
38
39void Curl_psl_destroy(struct PslCache *pslcache)
40{
41  if(pslcache->psl) {
42    if(pslcache->dynamic)
43      psl_free((psl_ctx_t *) pslcache->psl);
44    pslcache->psl = NULL;
45    pslcache->dynamic = FALSE;
46  }
47}
48
49static time_t now_seconds(void)
50{
51  struct curltime now = Curl_now();
52
53  return now.tv_sec;
54}
55
56const psl_ctx_t *Curl_psl_use(struct Curl_easy *easy)
57{
58  struct PslCache *pslcache = easy->psl;
59  const psl_ctx_t *psl;
60  time_t now;
61
62  if(!pslcache)
63    return NULL;
64
65  Curl_share_lock(easy, CURL_LOCK_DATA_PSL, CURL_LOCK_ACCESS_SHARED);
66  now = now_seconds();
67  if(!pslcache->psl || pslcache->expires <= now) {
68    /* Let a chance to other threads to do the job: avoids deadlock. */
69    Curl_share_unlock(easy, CURL_LOCK_DATA_PSL);
70
71    /* Update cache: this needs an exclusive lock. */
72    Curl_share_lock(easy, CURL_LOCK_DATA_PSL, CURL_LOCK_ACCESS_SINGLE);
73
74    /* Recheck in case another thread did the job. */
75    now = now_seconds();
76    if(!pslcache->psl || pslcache->expires <= now) {
77      bool dynamic = FALSE;
78      time_t expires = TIME_T_MAX;
79
80#if defined(PSL_VERSION_NUMBER) && PSL_VERSION_NUMBER >= 0x001000
81      psl = psl_latest(NULL);
82      dynamic = psl != NULL;
83      /* Take care of possible time computation overflow. */
84      expires = now < TIME_T_MAX - PSL_TTL? now + PSL_TTL: TIME_T_MAX;
85
86      /* Only get the built-in PSL if we do not already have the "latest". */
87      if(!psl && !pslcache->dynamic)
88#endif
89
90        psl = psl_builtin();
91
92      if(psl) {
93        Curl_psl_destroy(pslcache);
94        pslcache->psl = psl;
95        pslcache->dynamic = dynamic;
96        pslcache->expires = expires;
97      }
98    }
99    Curl_share_unlock(easy, CURL_LOCK_DATA_PSL);  /* Release exclusive lock. */
100    Curl_share_lock(easy, CURL_LOCK_DATA_PSL, CURL_LOCK_ACCESS_SHARED);
101  }
102  psl = pslcache->psl;
103  if(!psl)
104    Curl_share_unlock(easy, CURL_LOCK_DATA_PSL);
105  return psl;
106}
107
108void Curl_psl_release(struct Curl_easy *easy)
109{
110  Curl_share_unlock(easy, CURL_LOCK_DATA_PSL);
111}
112
113#endif /* USE_LIBPSL */
114