From 9fcf415711585993525e35ff1e6b225f0deb5f20 Mon Sep 17 00:00:00 2001
From: Pablo Rincon <pablo.rincon.crespo@gmail.com>
Date: Thu, 31 Dec 2009 02:22:06 +0100
Subject: [PATCH] Adding preseending to rands

---
 src/defrag.c    |    6 +++++-
 src/flow.c      |    4 +++-
 src/util-time.c |   16 ++++++++++++++++
 src/util-time.h |    2 ++
 4 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/src/defrag.c b/src/defrag.c
index 242764c..7da47ba 100644
--- a/src/defrag.c
+++ b/src/defrag.c
@@ -26,6 +26,7 @@
 #include "decode-ipv6.h"
 #include "util-hashlist.h"
 #include "util-pool.h"
+#include "util-time.h"
 #include "util-print.h"
 #include "util-debug.h"
 #include "util-fix_checksum.h"
@@ -1235,7 +1236,10 @@ void
 DefragInit(void)
 {
     /* Initialize random value for hashing and hash table size. */
-    defrag_hash_rand = rand();
+    unsigned int seed = TimeRandPreseed();
+    /* set defaults */
+    defrag_hash_rand = (int)( DEFAULT_DEFRAG_HASH_SIZE * (rand_r(&seed) / RAND_MAX + 1.0)) ; /* XXX seed rand */
+
     defrag_hash_size = DEFAULT_DEFRAG_HASH_SIZE;
 
     /* Allocate the DefragContext. */
diff --git a/src/flow.c b/src/flow.c
index ca6eb59..c4cb34d 100644
--- a/src/flow.c
+++ b/src/flow.c
@@ -436,8 +436,10 @@ void FlowInitConfig (char quiet)
     }
     SCMutexInit(&flow_memuse_mutex, NULL);
 
+    unsigned int seed = TimeRandPreseed();
     /* set defaults */
-    flow_config.hash_rand   = rand(); /* XXX seed rand */
+    flow_config.hash_rand   = (int)( FLOW_DEFAULT_HASHSIZE * (rand_r(&seed) / RAND_MAX + 1.0)) ; /* XXX seed rand */
+
     flow_config.hash_size   = FLOW_DEFAULT_HASHSIZE;
     flow_config.memcap      = FLOW_DEFAULT_MEMCAP;
     flow_config.prealloc    = FLOW_DEFAULT_PREALLOC;
diff --git a/src/util-time.c b/src/util-time.c
index f789cc8..6e9764d 100644
--- a/src/util-time.c
+++ b/src/util-time.c
@@ -79,3 +79,19 @@ void TimeSetIncrementTime(uint32_t tv_sec) {
     TimeSet(&tv);
 }
 
+/** 
+ * \brief create a seed number to pass to rand() , rand_r(), and similars
+ */
+unsigned int TimeRandPreseed(void) {
+    /* preseed rand() */
+    time_t now = time ( 0 );
+    unsigned char *p = (unsigned char *)&now;
+    unsigned seed = 0;
+    size_t ind;
+
+    for ( ind = 0; ind < sizeof now; ind++ )
+      seed = seed * ( UCHAR_MAX + 2U ) + p[ind];
+
+    return seed;
+}
+
diff --git a/src/util-time.h b/src/util-time.h
index 5597e70..82f1459 100644
--- a/src/util-time.h
+++ b/src/util-time.h
@@ -10,5 +10,7 @@ void TimeSetIncrementTime(uint32_t);
 void TimeModeSetLive(void);
 void TimeModeSetOffline (void);
 
+unsigned int TimeRandPreseed(void);
+
 #endif /* __UTIL_TIME_H__ */
 
-- 
1.6.5