From 2c7cac91ed6e7db0f6937923d2b57f97dbdbc337 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 28 Apr 2024 11:53:30 +0200 Subject: Adding upstream version 8.4.4. Signed-off-by: Daniel Baumann --- tests/helpers/c/prng.c | 108 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 108 insertions(+) create mode 100644 tests/helpers/c/prng.c (limited to 'tests/helpers/c/prng.c') diff --git a/tests/helpers/c/prng.c b/tests/helpers/c/prng.c new file mode 100644 index 0000000..e2173d4 --- /dev/null +++ b/tests/helpers/c/prng.c @@ -0,0 +1,108 @@ +/* + * 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 + * + * 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 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 + */ + +#include + +#include +#include +#include + +#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 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); +} -- cgit v1.2.3