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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-09 13:16:35 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-09 13:16:35 +0000 |
commit | e2bbf175a2184bd76f6c54ccf8456babeb1a46fc (patch) | |
tree | f0b76550d6e6f500ada964a3a4ee933a45e5a6f1 /tests/helpers/c/prng.c | |
parent | Initial commit. (diff) | |
download | frr-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.c | 95 |
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); +} |