1 /* $NetBSD: getentropy.c,v 1.1 2020/05/06 16:17:36 nia Exp $ */ 2 3 /*- 4 * Copyright (c) 2020 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Nia Alarie. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __RCSID("$NetBSD: getentropy.c,v 1.1 2020/05/06 16:17:36 nia Exp $"); 34 35 #include "namespace.h" 36 37 #include <sys/param.h> 38 #include <sys/sysctl.h> 39 40 #include <errno.h> 41 #include <unistd.h> 42 43 #ifdef __weak_alias 44 __weak_alias(getentropy,_getentropy) 45 #endif 46 47 int 48 getentropy(void *buf, size_t buflen) 49 { 50 size_t len = buflen; 51 int name[2] = { CTL_KERN, KERN_ARND }; 52 53 if (buf == NULL && buflen > 0) { 54 errno = EFAULT; 55 return -1; 56 } 57 58 if (buflen > 256) { 59 errno = EIO; 60 return -1; 61 } 62 63 return sysctl(name, 2, buf, &len, NULL, 0); 64 } 65