1 /*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/types.h> 31 #include <stdlib.h> 32 33 static int rand_deterministic; 34 static u_int next = 1; 35 36 int 37 rand_r(u_int *seed) 38 { 39 *seed = *seed * 1103515245 + 12345; 40 return (*seed % ((u_int)RAND_MAX + 1)); 41 } 42 43 #if defined(APIWARN) 44 __warn_references(rand_r, 45 "warning: rand_r() is not random, it is deterministic."); 46 #endif 47 48 int 49 rand(void) 50 { 51 if (rand_deterministic == 0) 52 return (arc4random() % ((u_int)RAND_MAX + 1)); 53 return (rand_r(&next)); 54 } 55 56 #if defined(APIWARN) 57 __warn_references(rand, 58 "warning: rand() may return deterministic values, is that what you want?"); 59 #endif 60 61 void 62 srand(u_int seed) 63 { 64 rand_deterministic = 0; 65 } 66 67 void 68 srand_deterministic(u_int seed) 69 { 70 rand_deterministic = 1; 71 next = seed; 72 } 73