summaryrefslogtreecommitdiffstats
path: root/tests/helpers/c/prng.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-09 13:16:35 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-09 13:16:35 +0000
commite2bbf175a2184bd76f6c54ccf8456babeb1a46fc (patch)
treef0b76550d6e6f500ada964a3a4ee933a45e5a6f1 /tests/helpers/c/prng.c
parentInitial commit. (diff)
downloadfrr-e2bbf175a2184bd76f6c54ccf8456babeb1a46fc.tar.xz
frr-e2bbf175a2184bd76f6c54ccf8456babeb1a46fc.zip
Adding upstream version 9.1.upstream/9.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tests/helpers/c/prng.c')
-rw-r--r--tests/helpers/c/prng.c95
1 files changed, 95 insertions, 0 deletions
diff --git a/tests/helpers/c/prng.c b/tests/helpers/c/prng.c
new file mode 100644
index 0000000..612c433
--- /dev/null
+++ b/tests/helpers/c/prng.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * 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")
+ * Copyright (C) 2017 Christian Franke
+ *
+ * This file is part of Quagga
+ */
+
+#include <zebra.h>
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "prng.h"
+
+struct prng {
+ uint64_t state;
+};
+
+struct prng *prng_new(unsigned long long seed)
+{
+ struct prng *rv = calloc(sizeof(*rv), 1);
+ assert(rv);
+
+ rv->state = seed;
+
+ return rv;
+}
+
+/*
+ * This implementation has originally been provided to musl libc by
+ * Szabolcs Nagy <nsz at port70 dot net> in 2013 under the terms of
+ * the MIT license.
+ * It is a simple LCG which D.E. Knuth attributes to C.E. Haynes in
+ * TAOCP Vol2 3.3.4
+ */
+int prng_rand(struct prng *prng)
+{
+ prng->state = 6364136223846793005ULL * prng->state + 1;
+ return prng->state >> 33;
+}
+
+const char *prng_fuzz(struct prng *prng, const char *string,
+ const char *charset, unsigned int operations)
+{
+ static char buf[256];
+ unsigned int charset_len;
+ unsigned int i;
+ unsigned int offset;
+ unsigned int op;
+ unsigned int character;
+
+ assert(strlen(string) < sizeof(buf));
+
+ strncpy(buf, string, sizeof(buf));
+ charset_len = strlen(charset);
+
+ for (i = 0; i < operations; i++) {
+ offset = prng_rand(prng) % strlen(buf);
+ op = prng_rand(prng) % 3;
+
+ switch (op) {
+ case 0:
+ /* replace */
+ character = prng_rand(prng) % charset_len;
+ buf[offset] = charset[character];
+ break;
+ case 1:
+ /* remove */
+ memmove(buf + offset, buf + offset + 1,
+ strlen(buf) - offset);
+ break;
+ case 2:
+ /* insert */
+ assert(strlen(buf) + 1 < sizeof(buf));
+
+ memmove(buf + offset + 1, buf + offset,
+ strlen(buf) + 1 - offset);
+ character = prng_rand(prng) % charset_len;
+ buf[offset] = charset[character];
+ break;
+ }
+ }
+ return buf;
+}
+
+void prng_free(struct prng *prng)
+{
+ free(prng);
+}