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| author | Donald Sharp <sharpd@cumulusnetworks.com> | 2017-02-09 09:38:37 -0500 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2017-02-09 09:38:37 -0500 |
| commit | 9c3a235e8a8bbfc0c4465bb26bf36981bd387899 (patch) | |
| tree | d8e32ef1321154cd766b5ba38d291bde45ed512f /tests/helpers/c/prng.c | |
| parent | bae44e4b7653f91408044764d206d2415fc38d9f (diff) | |
| parent | a4b74d05fca0ff19c04cc2fef432d5fde9469c45 (diff) | |
Merge pull request #164 from opensourcerouting/pytest2
Rework test runners to use pytest
Diffstat (limited to 'tests/helpers/c/prng.c')
| -rw-r--r-- | tests/helpers/c/prng.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/tests/helpers/c/prng.c b/tests/helpers/c/prng.c new file mode 100644 index 0000000000..bdcfb07af1 --- /dev/null +++ b/tests/helpers/c/prng.c @@ -0,0 +1,132 @@ +/* + * 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 <zebra.h> + +#include <assert.h> +#include <stdlib.h> +#include <string.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; +} + +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); +} |
