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

14 files changed, 254 insertions, 29 deletions

diff --git a/docs/libcurl/curl_share_setopt.3 b/docs/libcurl/curl_share_setopt.3
index 85349ab00..6c209eb00 100644
--- a/docs/libcurl/curl_share_setopt.3
+++ b/docs/libcurl/curl_share_setopt.3
@@ -87,6 +87,15 @@ existed before this.
 
 Note that when you use the multi interface, all easy handles added to the same
 multi handle will share connection cache by default without using this option.
+.IP CURL_LOCK_DATA_PSL
+The Public Suffix List stored in the share object is made available to all
+easy handle bound to the later. Since the Public Suffix List is periodically
+refreshed, this avoids updates in too many different contexts.
+
+\fBCURL_LOCK_DATA_PSL\fP exists since 7.61.0.
+
+Note that when you use the multi interface, all easy handles added to the same
+multi handle will share PSL cache by default without using this option.
 .RE
 .IP CURLSHOPT_UNSHARE
 This option does the opposite of \fICURLSHOPT_SHARE\fP. It specifies that
diff --git a/docs/libcurl/symbols-in-versions b/docs/libcurl/symbols-in-versions
index f98609e1d..f3ad33510 100644
--- a/docs/libcurl/symbols-in-versions
+++ b/docs/libcurl/symbols-in-versions
@@ -780,6 +780,7 @@ CURL_LOCK_DATA_CONNECT          7.10.3
 CURL_LOCK_DATA_COOKIE           7.10.3
 CURL_LOCK_DATA_DNS              7.10.3
 CURL_LOCK_DATA_NONE             7.10.3
+CURL_LOCK_DATA_PSL              7.61.0
 CURL_LOCK_DATA_SHARE            7.10.4
 CURL_LOCK_DATA_SSL_SESSION      7.10.3
 CURL_LOCK_TYPE_CONNECT          7.10          -           7.10.2
diff --git a/include/curl/curl.h b/include/curl/curl.h
index 3ebaa019a..b7f75da75 100644
--- a/include/curl/curl.h
+++ b/include/curl/curl.h
@@ -2582,6 +2582,7 @@ typedef enum {
   CURL_LOCK_DATA_DNS,
   CURL_LOCK_DATA_SSL_SESSION,
   CURL_LOCK_DATA_CONNECT,
+  CURL_LOCK_DATA_PSL,
   CURL_LOCK_DATA_LAST
 } curl_lock_data;
 
diff --git a/lib/Makefile.inc b/lib/Makefile.inc
index 61c23411d..76ca6d041 100644
--- a/lib/Makefile.inc
+++ b/lib/Makefile.inc
@@ -54,7 +54,7 @@ LIB_CFILES = file.c timeval.c base64.c hostip.c progress.c formdata.c   \
   http_ntlm.c curl_ntlm_wb.c curl_ntlm_core.c curl_sasl.c rand.c        \
   curl_multibyte.c hostcheck.c conncache.c pipeline.c dotdot.c          \
   x509asn1.c http2.c smb.c curl_endian.c curl_des.c system_win32.c      \
-  mime.c sha256.c setopt.c curl_path.c curl_ctype.c curl_range.c
+  mime.c sha256.c setopt.c curl_path.c curl_ctype.c curl_range.c psl.c
 
 LIB_HFILES = arpa_telnet.h netrc.h file.h timeval.h hostip.h progress.h \
   formdata.h cookie.h http.h sendf.h ftp.h url.h dict.h if2ip.h         \
@@ -74,7 +74,7 @@ LIB_HFILES = arpa_telnet.h netrc.h file.h timeval.h hostip.h progress.h \
   curl_setup_once.h multihandle.h setup-vms.h pipeline.h dotdot.h       \
   x509asn1.h http2.h sigpipe.h smb.h curl_endian.h curl_des.h           \
   curl_printf.h system_win32.h rand.h mime.h curl_sha256.h setopt.h     \
-  curl_path.h curl_ctype.h curl_range.h
+  curl_path.h curl_ctype.h curl_range.h psl.h
 
 LIB_RCFILES = libcurl.rc
 
diff --git a/lib/cookie.c b/lib/cookie.c
index 29f627fd4..a8d8f485e 100644
--- a/lib/cookie.c
+++ b/lib/cookie.c
@@ -84,12 +84,9 @@ Example set of cookies:
 
 #if !defined(CURL_DISABLE_HTTP) && !defined(CURL_DISABLE_COOKIES)
 
-#ifdef USE_LIBPSL
-# include <libpsl.h>
-#endif
-
 #include "urldata.h"
 #include "cookie.h"
+#include "psl.h"
 #include "strtok.h"
 #include "sendf.h"
 #include "slist.h"
@@ -406,6 +403,12 @@ static void remove_expired(struct CookieInfo *cookies)
   }
 }
 
+/* Make sure domain contains a dot or is localhost. */
+static bool bad_domain(const char *domain)
+{
+  return !strchr(domain, '.') && !strcasecompare(domain, "localhost");
+}
+
 /****************************************************************************
  *
  * Curl_cookie_add()
@@ -442,10 +445,6 @@ Curl_cookie_add(struct Curl_easy *data,
   bool badcookie = FALSE; /* cookies are good by default. mmmmm yummy */
   size_t myhash;
 
-#ifdef USE_LIBPSL
-  const psl_ctx_t *psl;
-#endif
-
 #ifdef CURL_DISABLE_VERBOSE_STRINGS
   (void)data;
 #endif
@@ -585,13 +584,8 @@ Curl_cookie_add(struct Curl_easy *data,
            * TLD or otherwise "protected" suffix. To reduce risk, we require a
            * dot OR the exact host name being "localhost".
            */
-          {
-            const char *dotp;
-            /* check for more dots */
-            dotp = strchr(whatptr, '.');
-            if(!dotp && !strcasecompare("localhost", whatptr))
-              domain = ":";
-          }
+          if(bad_domain(whatptr))
+            domain = ":";
 #endif
 
           is_ip = isip(domain ? domain : whatptr);
@@ -890,14 +884,21 @@ Curl_cookie_add(struct Curl_easy *data,
     remove_expired(c);
 
 #ifdef USE_LIBPSL
-  /* Check if the domain is a Public Suffix and if yes, ignore the cookie.
-     This needs a libpsl compiled with builtin data. */
+  /* Check if the domain is a Public Suffix and if yes, ignore the cookie. */
   if(domain && co->domain && !isip(co->domain)) {
-    psl = psl_builtin();
-    if(psl && !psl_is_cookie_domain_acceptable(psl, domain, co->domain)) {
-      infof(data,
-            "cookie '%s' dropped, domain '%s' must not set cookies for '%s'\n",
-            co->name, domain, co->domain);
+    const psl_ctx_t *psl = Curl_psl_use(data);
+    int acceptable;
+
+    if(psl) {
+      acceptable = psl_is_cookie_domain_acceptable(psl, domain, co->domain);
+      Curl_psl_release(data);
+    }
+    else
+      acceptable = !bad_domain(domain);
+
+    if(!acceptable) {
+      infof(data, "cookie '%s' dropped, domain '%s' must not "
+                  "set cookies for '%s'\n", co->name, domain, co->domain);
       freecookie(co);
       return NULL;
     }
diff --git a/lib/multi.c b/lib/multi.c
index f85284695..b6f5b796d 100644
--- a/lib/multi.c
+++ b/lib/multi.c
@@ -31,6 +31,7 @@
 #include "progress.h"
 #include "easyif.h"
 #include "share.h"
+#include "psl.h"
 #include "multiif.h"
 #include "sendf.h"
 #include "timeval.h"
@@ -409,6 +410,14 @@ CURLMcode curl_multi_add_handle(struct Curl_multi *multi,
   else
     data->state.conn_cache = &multi->conn_cache;
 
+#ifdef USE_LIBPSL
+  /* Do the same for PSL. */
+  if(data->share && (data->share->specifier & (1 << CURL_LOCK_DATA_PSL)))
+    data->psl = &data->share->psl;
+  else
+    data->psl = &multi->psl;
+#endif
+
   /* This adds the new entry at the 'end' of the doubly-linked circular
      list of Curl_easy structs to try and maintain a FIFO queue so
      the pipelined requests are in order. */
@@ -727,6 +736,12 @@ CURLMcode curl_multi_remove_handle(struct Curl_multi *multi,
     data->easy_conn = NULL;
   }
 
+#ifdef USE_LIBPSL
+  /* Remove the PSL association. */
+  if(data->psl == &multi->psl)
+    data->psl = NULL;
+#endif
+
   data->multi = NULL; /* clear the association to this multi handle */
 
   /* make sure there's no pending message in the queue sent from this easy
@@ -2220,6 +2235,11 @@ CURLMcode curl_multi_cleanup(struct Curl_multi *multi)
       data->state.conn_cache = NULL;
       data->multi = NULL; /* clear the association */
 
+#ifdef USE_LIBPSL
+      if(data->psl == &multi->psl)
+        data->psl = NULL;
+#endif
+
       data = nextdata;
     }
 
@@ -2232,6 +2252,7 @@ CURLMcode curl_multi_cleanup(struct Curl_multi *multi)
     Curl_llist_destroy(&multi->pending, NULL);
 
     Curl_hash_destroy(&multi->hostcache);
+    Curl_psl_destroy(&multi->psl);
 
     /* Free the blacklists by setting them to NULL */
     Curl_pipeline_set_site_blacklist(NULL, &multi->pipelining_site_bl);
diff --git a/lib/multihandle.h b/lib/multihandle.h
index 1a5017f4a..ea2bf352d 100644
--- a/lib/multihandle.h
+++ b/lib/multihandle.h
@@ -7,7 +7,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * 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
@@ -23,6 +23,7 @@
  ***************************************************************************/
 
 #include "conncache.h"
+#include "psl.h"
 
 struct Curl_message {
   struct curl_llist_element list;
@@ -97,6 +98,11 @@ struct Curl_multi {
   /* Hostname cache */
   struct curl_hash hostcache;
 
+#ifdef USE_LIBPSL
+  /* PSL cache. */
+  struct PslCache psl;
+#endif
+
   /* timetree points to the splay-tree of time nodes to figure out expire
      times of all currently set timers */
   struct Curl_tree *timetree;
diff --git a/lib/psl.c b/lib/psl.c
new file mode 100644
index 000000000..568baff03
--- /dev/null
+++ b/lib/psl.c
@@ -0,0 +1,111 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  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.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#include <curl/curl.h>
+
+#ifdef USE_LIBPSL
+
+#include "psl.h"
+#include "share.h"
+
+/* The last 3 #include files should be in this order */
+#include "curl_printf.h"
+#include "curl_memory.h"
+#include "memdebug.h"
+
+void Curl_psl_destroy(struct PslCache *pslcache)
+{
+  if(pslcache->psl) {
+    if(pslcache->dynamic)
+      psl_free((psl_ctx_t *) pslcache->psl);
+    pslcache->psl = NULL;
+    pslcache->dynamic = FALSE;
+  }
+}
+
+static time_t now_seconds(void)
+{
+  struct curltime now = Curl_now();
+
+  return now.tv_sec;
+}
+
+const psl_ctx_t *Curl_psl_use(struct Curl_easy *easy)
+{
+  struct PslCache *pslcache = easy->psl;
+  const psl_ctx_t *psl;
+  time_t now;
+
+  if(!pslcache)
+    return NULL;
+
+  Curl_share_lock(easy, CURL_LOCK_DATA_PSL, CURL_LOCK_ACCESS_SHARED);
+  now = now_seconds();
+  if(!pslcache->psl || pslcache->expires <= now) {
+    /* Let a chance to other threads to do the job: avoids deadlock. */
+    Curl_share_unlock(easy, CURL_LOCK_DATA_PSL);
+
+    /* Update cache: this needs an exclusive lock. */
+    Curl_share_lock(easy, CURL_LOCK_DATA_PSL, CURL_LOCK_ACCESS_SINGLE);
+
+    /* Recheck in case another thread did the job. */
+    now = now_seconds();
+    if(!pslcache->psl || pslcache->expires <= now) {
+      bool dynamic = FALSE;
+      time_t expires = TIME_T_MAX;
+
+#if defined(PSL_VERSION_NUMBER) && PSL_VERSION_NUMBER >= 0x001000
+      psl = psl_latest(NULL);
+      dynamic = psl != NULL;
+      /* Take care of possible time computation overflow. */
+      expires = now < TIME_T_MAX - PSL_TTL? now + PSL_TTL: TIME_T_MAX;
+
+      /* Only get the built-in PSL if we do not already have the "latest". */
+      if(!psl && !pslcache->dynamic)
+#endif
+
+        psl = psl_builtin();
+
+      if(psl) {
+        Curl_psl_destroy(pslcache);
+        pslcache->psl = psl;
+        pslcache->dynamic = dynamic;
+        pslcache->expires = expires;
+      }
+    }
+    Curl_share_unlock(easy, CURL_LOCK_DATA_PSL);  /* Release exclusive lock. */
+    Curl_share_lock(easy, CURL_LOCK_DATA_PSL, CURL_LOCK_ACCESS_SHARED);
+  }
+  psl = pslcache->psl;
+  if(!psl)
+    Curl_share_unlock(easy, CURL_LOCK_DATA_PSL);
+  return psl;
+}
+
+void Curl_psl_release(struct Curl_easy *easy)
+{
+  Curl_share_unlock(easy, CURL_LOCK_DATA_PSL);
+}
+
+#endif /* USE_LIBPSL */
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 */
diff --git a/lib/setopt.c b/lib/setopt.c
index af53ee3ef..c1f6bd97e 100644
--- a/lib/setopt.c
+++ b/lib/setopt.c
@@ -1942,6 +1942,11 @@ CURLcode Curl_vsetopt(struct Curl_easy *data, CURLoption option,
       if(data->share->sslsession == data->state.session)
         data->state.session = NULL;
 
+#ifdef USE_LIBPSL
+      if(data->psl == &data->share->psl)
+        data->psl = data->multi? &data->multi->psl: NULL;
+#endif
+
       data->share->dirty--;
 
       Curl_share_unlock(data, CURL_LOCK_DATA_SHARE);
@@ -1973,8 +1978,12 @@ CURLcode Curl_vsetopt(struct Curl_easy *data, CURLoption option,
         data->set.general_ssl.max_ssl_sessions = data->share->max_ssl_sessions;
         data->state.session = data->share->sslsession;
       }
-      Curl_share_unlock(data, CURL_LOCK_DATA_SHARE);
+#ifdef USE_LIBPSL
+      if(data->share->specifier & (1 << CURL_LOCK_DATA_PSL))
+        data->psl = &data->share->psl;
+#endif
 
+      Curl_share_unlock(data, CURL_LOCK_DATA_SHARE);
     }
     /* check for host cache not needed,
      * it will be done by curl_easy_perform */
diff --git a/lib/share.c b/lib/share.c
index 870b191fc..3d5108610 100644
--- a/lib/share.c
+++ b/lib/share.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * 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
@@ -25,6 +25,7 @@
 #include <curl/curl.h>
 #include "urldata.h"
 #include "share.h"
+#include "psl.h"
 #include "vtls/vtls.h"
 #include "curl_memory.h"
 
@@ -106,6 +107,12 @@ curl_share_setopt(struct Curl_share *share, CURLSHoption option, ...)
         res = CURLSHE_NOMEM;
       break;
 
+    case CURL_LOCK_DATA_PSL:
+#ifndef USE_LIBPSL
+      res = CURLSHE_NOT_BUILT_IN;
+#endif
+      break;
+
     default:
       res = CURLSHE_BAD_OPTION;
     }
@@ -205,6 +212,8 @@ curl_share_cleanup(struct Curl_share *share)
   }
 #endif
 
+  Curl_psl_destroy(&share->psl);
+
   if(share->unlockfunc)
     share->unlockfunc(NULL, CURL_LOCK_DATA_SHARE, share->clientdata);
   free(share);
diff --git a/lib/share.h b/lib/share.h
index 4b13406d9..a7dea41ad 100644
--- a/lib/share.h
+++ b/lib/share.h
@@ -7,7 +7,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * 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
@@ -25,6 +25,7 @@
 #include "curl_setup.h"
 #include <curl/curl.h>
 #include "cookie.h"
+#include "psl.h"
 #include "urldata.h"
 #include "conncache.h"
 
@@ -49,6 +50,9 @@ struct Curl_share {
 #if !defined(CURL_DISABLE_HTTP) && !defined(CURL_DISABLE_COOKIES)
   struct CookieInfo *cookies;
 #endif
+#ifdef USE_LIBPSL
+  struct PslCache psl;
+#endif
 
   struct curl_ssl_session *sslsession;
   size_t max_ssl_sessions;
diff --git a/lib/urldata.h b/lib/urldata.h
index b8e9ddd9b..9a821aa5a 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -80,6 +80,7 @@
 #define RESP_TIMEOUT (1800*1000)
 
 #include "cookie.h"
+#include "psl.h"
 #include "formdata.h"
 
 #ifdef HAVE_NETINET_IN_H
@@ -1736,6 +1737,9 @@ struct Curl_easy {
                                     struct to which this "belongs" when used
                                     by the easy interface */
   struct Curl_share *share;    /* Share, handles global variable mutexing */
+#ifdef USE_LIBPSL
+  struct PslCache *psl;        /* The associated PSL cache. */
+#endif
   struct SingleRequest req;    /* Request-specific data */
   struct UserDefined set;      /* values set by the libcurl user */
   struct DynamicStatic change; /* possibly modified userdefined data */
diff --git a/packages/OS400/curl.inc.in b/packages/OS400/curl.inc.in
index b2ff6d6fb..915fef7c4 100644
--- a/packages/OS400/curl.inc.in
+++ b/packages/OS400/curl.inc.in
@@ -1591,8 +1591,10 @@
      d                 c                   4
      d  CURL_LOCK_DATA_CONNECT...
      d                 c                   5
-     d  CURL_LOCK_DATA_LAST...
+     d  CURL_LOCK_DATA_PSL...
      d                 c                   6
+     d  CURL_LOCK_DATA_LAST...
+     d                 c                   7
       *
      d curl_lock_access...
      d                 s             10i 0 based(######ptr######)               Enum