/* * Copyright (C) 1999-2001 Internet Software Consortium. * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* $Id: random.c,v 1.1.1.1 2003/01/10 00:48:39 bbraun Exp $ */ #include <config.h> #include <stdlib.h> #include <time.h> /* Required for time(). */ #include <isc/mutex.h> #include <isc/once.h> #include <isc/random.h> #include <isc/string.h> #include <isc/util.h> static isc_once_t once = ISC_ONCE_INIT; static void initialize_rand(void) { srand(time(NULL)); } static void initialize(void) { RUNTIME_CHECK(isc_once_do(&once, initialize_rand) == ISC_R_SUCCESS); } void isc_random_seed(isc_uint32_t seed) { initialize(); srand(seed); } void isc_random_get(isc_uint32_t *val) { REQUIRE(val != NULL); initialize(); *val = rand(); } isc_uint32_t isc_random_jitter(isc_uint32_t max, isc_uint32_t jitter) { REQUIRE(jitter < max); if (jitter == 0) return (max); else return (max - rand() % jitter); }