From: Fabian Keil <fk@fabiankeil.de>
Date: Tue, 26 Dec 2006 17:31:41 +0000 (+0000)
Subject: Mutex protect rand() if POSIX threading
X-Git-Tag: v_3_0_7~429
X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=commitdiff_plain;h=23a960241804eb0d73d845acdfcce0bf0e5ebd9c

Mutex protect rand() if POSIX threading
is used, warn the user if that's not possible
and stop using it on _WIN32 where it could
cause crashes.
---

diff --git a/jcc.c b/jcc.c
index 2dc0718e..76fa1c34 100644
--- a/jcc.c
+++ b/jcc.c
@@ -1,4 +1,4 @@
-const char jcc_rcs[] = "$Id: jcc.c,v 1.110 2006/12/13 14:52:53 etresoft Exp $";
+const char jcc_rcs[] = "$Id: jcc.c,v 1.111 2006/12/23 16:15:06 fabiankeil Exp $";
 /*********************************************************************
  *
  * File        :  $Source: /cvsroot/ijbswa/current/jcc.c,v $
@@ -33,6 +33,10 @@ const char jcc_rcs[] = "$Id: jcc.c,v 1.110 2006/12/13 14:52:53 etresoft Exp $";
  *
  * Revisions   :
  *    $Log: jcc.c,v $
+ *    Revision 1.111  2006/12/23 16:15:06  fabiankeil
+ *    Don't prevent core dumps by catching SIGABRT.
+ *    It's rude and makes debugging unreasonable painful.
+ *
  *    Revision 1.110  2006/12/13 14:52:53  etresoft
  *    Fix build failure on MacOS X. Global symbols can be either static or extern, but not both.
  *
@@ -844,6 +848,11 @@ pthread_mutex_t gethostbyaddr_mutex;
 #ifndef HAVE_GETHOSTBYNAME_R
 pthread_mutex_t gethostbyname_mutex;
 #endif /* ndef HAVE_GETHOSTBYNAME_R */
+
+#ifndef HAVE_RANDOM
+pthread_mutex_t rand_mutex;
+#endif /* ndef HAVE_RANDOM */
+
 #endif /* FEATURE_PTHREAD */
 
 #if defined(unix) || defined(__EMX__)
@@ -899,7 +908,7 @@ const char MISSING_DESTINATION_RESPONSE[] =
  * Function    :  sig_handler 
  *
  * Description :  Signal handler for different signals.
- *                Exit gracefully on ABRT, TERM and  INT
+ *                Exit gracefully on TERM and INT
  *                or set a flag that will cause the errlog
  *                to be reopened by the main thread on HUP.
  *
@@ -2069,9 +2078,7 @@ int main(int argc, const char *argv[])
 #endif
 {
    int argc_pos = 0;
-#ifdef HAVE_RANDOM
-   unsigned int random_seed;
-#endif /* ifdef HAVE_RANDOM */
+   int random_seed;
 #ifdef unix
    struct passwd *pw = NULL;
    struct group *grp = NULL;
@@ -2238,11 +2245,18 @@ int main(int argc, const char *argv[])
 #ifndef HAVE_GETHOSTBYNAME_R
    pthread_mutex_init(&gethostbyname_mutex,0);
 #endif /* ndef HAVE_GETHOSTBYNAME_R */
+
+#ifndef HAVE_RANDOM
+   pthread_mutex_init(&rand_mutex,0);
+#endif /* ndef HAVE_RANDOM */
+
 #endif /* FEATURE_PTHREAD */
 
+   random_seed = (int)time(NULL);
 #ifdef HAVE_RANDOM
-   random_seed = (unsigned int)time(NULL);
    srandom(random_seed);
+#else
+   srand(random_seed);
 #endif /* ifdef HAVE_RANDOM */
 
    /*
diff --git a/jcc.h b/jcc.h
index 9da00cf1..3e08911d 100644
--- a/jcc.h
+++ b/jcc.h
@@ -1,6 +1,6 @@
 #ifndef JCC_H_INCLUDED
 #define JCC_H_INCLUDED
-#define JCC_H_VERSION "$Id: jcc.h,v 1.18 2006/11/13 19:05:51 fabiankeil Exp $"
+#define JCC_H_VERSION "$Id: jcc.h,v 1.19 2006/12/06 19:41:39 fabiankeil Exp $"
 /*********************************************************************
  *
  * File        :  $Source: /cvsroot/ijbswa/current/jcc.h,v $
@@ -35,6 +35,16 @@
  *
  * Revisions   :
  *    $Log: jcc.h,v $
+ *    Revision 1.19  2006/12/06 19:41:39  fabiankeil
+ *    Privoxy is now able to run as intercepting
+ *    proxy in combination with any packet filter
+ *    that does the port redirection. The destination
+ *    is extracted from the "Host:" header which
+ *    should be available for nearly all requests.
+ *
+ *    Moved HTTP snipplets into jcc.c.
+ *    Added error message for gopher proxy requests.
+ *
  *    Revision 1.18  2006/11/13 19:05:51  fabiankeil
  *    Make pthread mutex locking more generic. Instead of
  *    checking for OSX and OpenBSD, check for FEATURE_PTHREAD
@@ -181,6 +191,11 @@ extern pthread_mutex_t gethostbyaddr_mutex;
 #ifndef HAVE_GETHOSTBYNAME_R
 extern pthread_mutex_t gethostbyname_mutex;
 #endif /* ndef HAVE_GETHOSTBYNAME_R */
+
+#ifndef HAVE_RANDOM
+extern pthread_mutex_t rand_mutex;
+#endif /* ndef HAVE_RANDOM */
+
 #endif /* FEATURE_PTHREAD */
 
 /* Functions */
diff --git a/miscutil.c b/miscutil.c
index 5167546d..fe19582a 100644
--- a/miscutil.c
+++ b/miscutil.c
@@ -1,4 +1,4 @@
-const char miscutil_rcs[] = "$Id: miscutil.c,v 1.43 2006/09/23 13:26:38 roro Exp $";
+const char miscutil_rcs[] = "$Id: miscutil.c,v 1.44 2006/11/07 12:46:43 fabiankeil Exp $";
 /*********************************************************************
  *
  * File        :  $Source: /cvsroot/ijbswa/current/miscutil.c,v $
@@ -36,6 +36,9 @@ const char miscutil_rcs[] = "$Id: miscutil.c,v 1.43 2006/09/23 13:26:38 roro Exp
  *
  * Revisions   :
  *    $Log: miscutil.c,v $
+ *    Revision 1.44  2006/11/07 12:46:43  fabiankeil
+ *    Silence compiler warning on NetBSD 3.1.
+ *
  *    Revision 1.43  2006/09/23 13:26:38  roro
  *    Replace TABs by spaces in source code.
  *
@@ -1081,25 +1084,37 @@ char * make_path(const char * dir, const char * file)
 long int pick_from_range(long int range)
 {
    long int number;
-#ifndef HAVE_RANDOM
-   unsigned int weak_seed;
-
-   weak_seed = (unsigned int)((unsigned int)time(NULL) | (unsigned int)range);
-   srand(weak_seed);
+#ifdef HAVE_RANDOM
+   number = random() % range + 1; 
+#elif defined(FEATURE_PTHREAD)
+   pthread_mutex_lock(&rand_mutex);
+   number = rand() % (long int)(range + 1);
+   pthread_mutex_unlock(&rand_mutex);
+#else
+#ifdef _WIN32
    /*
-    * Some rand implementations aren't that random and return mostly
-    * lower numbers. Low entropy doesn't matter for the header times, 
-    * but higher "random" factors are prefered.
+    * On Windows and mingw32 srand() has to be called in every
+    * rand()-using thread, but can cause crashes if it's not
+    * mutex protected.
+    *
+    * Currently we don't have mutexes for mingw32, and for
+    * our purpose this cludge is probably preferable to crashes.
     */
-   number = (rand() * 12345) % (long int)(range + 1);
-   /* Overflows don't matter either, positive numbers do. */
-   if(number<0)
-   {
-      number*= -1;
-   }
+   log_error(LOG_LEVEL_INFO, "No thread-safe PRNG available? Using weak \'randomization\' factor.");
+   number = (range + GetCurrentThreadId() % range) / 2;
 #else
-   number = random() % range + 1; 
-#endif /* (ifndef HAVE_RANDOM) */
+   /*
+    * XXX: Which platforms reach this and are there
+    * better options than just using rand() and hoping
+    * that it's safe?
+    */
+   log_error(LOG_LEVEL_INFO, "No thread-safe PRNG available? Header time randomization might cause "
+      "crashes, predictable results or even combine these fine options.");
+   number = rand() % (long int)(range + 1);
+#endif /* def _WIN32 */ 
+
+#endif /* (def HAVE_RANDOM) */
+
    return (number);
 }