psl: use latest psl and refresh it periodically

The latest psl is cached in the multi or share handle. It is refreshed
before use after 72 hours.
New share lock CURL_LOCK_DATA_PSL controls the psl cache sharing.
If the latest psl is not available, the builtin psl is used.

Reported-by: Yaakov Selkowitz
Fixes #2553
Closes #2601

1 files changed, 47 insertions, 0 deletions

diff --git a/lib/psl.h b/lib/psl.h
new file mode 100644
index 000000000..e9f99d03e
--- /dev/null
+++ b/lib/psl.h
@@ -0,0 +1,47 @@
+#ifndef HEADER_PSL_H
+#define HEADER_PSL_H
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#ifdef USE_LIBPSL
+#include <libpsl.h>
+
+#define PSL_TTL (72 * 3600)     /* PSL time to live before a refresh. */
+
+struct PslCache {
+  const psl_ctx_t *psl; /* The PSL. */
+  time_t expires; /* Time this PSL life expires. */
+  bool dynamic; /* PSL should be released when no longer needed. */
+};
+
+const psl_ctx_t *Curl_psl_use(struct Curl_easy *easy);
+void Curl_psl_release(struct Curl_easy *easy);
+void Curl_psl_destroy(struct PslCache *pslcache);
+
+#else
+
+#define Curl_psl_use(easy) NULL
+#define Curl_psl_release(easy)
+#define Curl_psl_destroy(pslcache)
+
+#endif /* USE_LIBPSL */
+#endif /* HEADER_PSL_H */