1 files changed, 82 insertions, 0 deletions
diff --git a/tests/prng.c b/tests/prng.c
new file mode 100644
index 00000000..7b1b4282
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+++ b/tests/prng.c
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+/*
+ * Very simple prng to allow for randomized tests with reproducable
+ * results.
+ *
+ * Copyright (C) 2012 by Open Source Routing.
+ * Copyright (C) 2012 by Internet Systems Consortium, Inc. ("ISC")
+ *
+ * This file is part of Quagga
+ *
+ * Quagga 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, or (at your option) any
+ * later version.
+ *
+ * Quagga 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 Quagga; see the file COPYING.  If not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+
+#include "prng.h"
+
+struct prng
+{
+  unsigned long long state1;
+  unsigned long long state2;
+};
+
+static char
+prng_bit(struct prng *prng)
+{
+  prng->state1 *= 2416;
+  prng->state1 += 374441;
+  prng->state1 %= 1771875;
+
+  if (prng->state1 % 2)
+    {
+      prng->state2 *= 84589;
+      prng->state2 += 45989;
+      prng->state2 %= 217728;
+    }
+
+  return prng->state2 % 2;
+}
+
+struct prng*
+prng_new(unsigned long long seed)
+{
+  struct prng *rv = calloc(sizeof(*rv), 1);
+  assert(rv);
+
+  rv->state1 = rv->state2 = seed;
+
+  return rv;
+}
+
+unsigned int
+prng_rand(struct prng *prng)
+{
+  unsigned int i, rv = 0;
+
+  for (i = 0; i < 32; i++)
+    {
+      rv |= prng_bit(prng);
+      rv <<= 1;
+    }
+  return rv;
+}
+
+void
+prng_free(struct prng *prng)
+{
+  free(prng);
+}