[svn] Use the new function `random_number' that doesn't depend on RAND_MAX

being defined.
Published in <sxsheqqq6xb.fsf@florida.arsdigita.de>.

diff --git a/src/ChangeLog b/src/ChangeLog
index 9dbe68383a5cc140cc9dadf960908e3bda074376..974ba611965eaf13b32881a44adb681c522735a9 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,16 @@
+2001-12-17  Hrvoje Niksic  <hniksic@arsdigita.com>
+
+       * gen_sslfunc.c (ssl_init_prng): Use random_number to get a byte
+       of "randomness" at a time.
+       (ssl_init_prng): Don't seed the PRNG; random_number will do that.
+
+       * retr.c (sleep_between_retrievals): Use it.  Make sure that the
+       random amount averages in opt.wait.
+       (sleep_between_retrievals): Don't seed the PRNG; random_number
+       will do that.
+
+       * utils.c (random_number): New function.
+

 2001-12-14  Hrvoje Niksic  <hniksic@arsdigita.com>
 
        * url.c (path_simplify): Move here from utils.c, and make static.
 2001-12-14  Hrvoje Niksic  <hniksic@arsdigita.com>
 
        * url.c (path_simplify): Move here from utils.c, and make static.

diff --git a/src/gen_sslfunc.c b/src/gen_sslfunc.c
index d28f1ad8f8b0cff7d75445b597594347182b3959..1f97edcc38b315c083bb8fde959b7e450dee302f 100644 (file)
--- a/src/gen_sslfunc.c
+++ b/src/gen_sslfunc.c
@@ -42,6 +42,7 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 #include <openssl/rand.h>
 
 #include "wget.h"
 #include <openssl/rand.h>
 
 #include "wget.h"

+#include "utils.h"

 #include "connect.h"
 #include "url.h"
 
 #include "connect.h"
 #include "url.h"
 


@@ -96,11 +97,10 @@ ssl_init_prng (void)
      security will use /dev/random or their own source of randomness
      anyway.  */
 
      security will use /dev/random or their own source of randomness
      anyway.  */
 

-  srand (time (NULL));

   while (RAND_status () == 0 && maxrand-- > 0)
     {
   while (RAND_status () == 0 && maxrand-- > 0)
     {

-      int rnd = rand ();
-      RAND_seed ((unsigned char *)&rnd, sizeof (rnd));
+      unsigned char rnd = random_number (256);
+      RAND_seed (&rnd, sizeof (rnd));

     }
 
   if (RAND_status () == 0)
     }
 
   if (RAND_status () == 0)

diff --git a/src/retr.c b/src/retr.c
index 44229cba9f492dd5dbc2a915f7850d38d9076576..6bd885894c429a0ce7f86897541ba51d1701ed42 100644 (file)
--- a/src/retr.c
+++ b/src/retr.c
@@ -653,10 +653,6 @@ sleep_between_retrievals (int count)
 {
   static int first_retrieval = 1;
 
 {
   static int first_retrieval = 1;
 

-  if (first_retrieval && opt.random_wait)
-    /* --random-wait uses the RNG, so seed it. */
-    srand (time (NULL));
-

   if (!first_retrieval && (opt.wait || opt.waitretry))
     {
       if (opt.waitretry && count > 1)
   if (!first_retrieval && (opt.wait || opt.waitretry))
     {
       if (opt.waitretry && count > 1)


@@ -676,10 +672,10 @@ sleep_between_retrievals (int count)
            sleep (opt.wait);
          else
            {
            sleep (opt.wait);
          else
            {

-             int waitmax = 2 * opt.wait;
-             /* This is equivalent to rand() % waitmax, but uses the
-                high-order bits for better randomness.  */
-             int waitsecs = (double)waitmax * rand () / (RAND_MAX + 1.0);
+             /* Sleep a random amount of time averaging in opt.wait
+                seconds.  The sleeping amount ranges from 0 to
+                opt.wait*2, inclusive.  */
+             int waitsecs = random_number (opt.wait * 2 + 1);

 
              DEBUGP (("sleep_between_retrievals: norm=%ld,fuzz=%ld,sleep=%d\n",
                       opt.wait, waitsecs - opt.wait, waitsecs));
 
              DEBUGP (("sleep_between_retrievals: norm=%ld,fuzz=%ld,sleep=%d\n",
                       opt.wait, waitsecs - opt.wait, waitsecs));

diff --git a/src/utils.c b/src/utils.c
index f6f736183ab5e363ed4ce89338cd18b699fe2063..69f0bdc0090b20e832c5cca9ebf3cc55854314e8 100644 (file)
--- a/src/utils.c
+++ b/src/utils.c
@@ -1654,6 +1654,49 @@ determine_screen_width (void)
 #endif /* TIOCGWINSZ */
 }
 
 #endif /* TIOCGWINSZ */
 }
 

+/* Return a random number between 0 and MAX-1, inclusive.
+
+   If MAX is greater than the value of RAND_MAX+1 on the system, the
+   returned value will be in the range [0, RAND_MAX].  This may be
+   fixed in a future release.
+
+   The random number generator is seeded automatically the first time
+   it is called.
+
+   This uses rand() for portability.  It has been suggested that
+   random() offers better randomness, but this is not required for
+   Wget, so I chose to go for simplicity and use rand
+   unconditionally.  */
+
+int
+random_number (int max)
+{
+  static int seeded;
+  double bounded;
+  int rnd;
+
+  if (!seeded)
+    {
+      srand (time (NULL));
+      seeded = 1;
+    }
+  rnd = rand ();
+
+  /* On systems that don't define RAND_MAX, assume it to be 2**15 - 1,
+     and enforce that assumption by masking other bits.  */
+#ifndef RAND_MAX
+# define RAND_MAX 32767
+  rnd &= RAND_MAX;
+#endif
+
+  /* This is equivalent to rand() % max, but uses the high-order bits
+     for better randomness on architecture where rand() is implemented
+     using a simple congruential generator.  */
+
+  bounded = (double)max * rnd / (RAND_MAX + 1.0);
+  return (int)bounded;
+}
+

 #if 0
 /* A debugging function for checking whether an MD5 library works. */
 
 #if 0
 /* A debugging function for checking whether an MD5 library works. */
 

diff --git a/src/utils.h b/src/utils.h
index e4c636894ffea94e56d0973e3ea38460b93a6da2..0cba30187311fc2b1659750700c84f12e15f5662 100644 (file)
--- a/src/utils.h
+++ b/src/utils.h
@@ -102,5 +102,6 @@ long wtimer_granularity PARAMS ((void));
 char *html_quote_string PARAMS ((const char *));
 
 int determine_screen_width PARAMS ((void));
 char *html_quote_string PARAMS ((const char *));
 
 int determine_screen_width PARAMS ((void));

+int random_number PARAMS ((int));

 
 #endif /* UTILS_H */
 
 #endif /* UTILS_H */