1 files changed, 60 insertions, 0 deletions
diff --git a/pimd/pim_rand.c b/pimd/pim_rand.c
new file mode 100644
index 00000000..df2a1111
--- /dev/null
+++ b/pimd/pim_rand.c
@@ -0,0 +1,60 @@
+/*
+  PIM for Quagga
+  Copyright (C) 2008  Everton da Silva Marques
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  General Public License for more details.
+  
+  You should have received a copy of the GNU General Public License
+  along with this program; see the file COPYING; if not, write to the
+  Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+  MA 02110-1301 USA
+  
+  $QuaggaId: $Format:%an, %ai, %h$ $
+*/
+
+#include "pim_rand.h"
+#include "pim_time.h"
+
+/* Quick and dirty random number generator from NUMERICAL RECIPES IN C:
+   THE ART OF SCIENTIFIC COMPUTING (ISBN 0-521-43108-5). */
+/* BEWARE: '_qseed_' is assigned! */
+#define QRANDOM(_qseed_)  ((_qseed_) = (((_qseed_) * 1664525L) + 1013904223L))
+
+static long qpim_rand_seed;
+
+void pim_rand_init()
+{
+  qpim_rand_seed = pim_time_monotonic_sec() ^ getpid();
+}
+
+long pim_rand()
+{
+  return QRANDOM(qpim_rand_seed);
+}
+
+int pim_rand_next(int min, int max)
+{
+  long rand;
+
+  assert(min <= max);
+
+  /* FIXME better random generator ? */
+
+  rand = QRANDOM(qpim_rand_seed); 
+  if (rand < 0)
+    rand = -rand;
+  rand = rand % (1 + max - min) + min;
+
+  assert(rand >= min);
+  assert(rand <= max);
+
+  return rand;
+}