1/* $NetBSD: rumpuser_random.c,v 1.3 2014/08/24 14:37:31 pooka Exp $ */ 2 3/* 4 * Copyright (c) 2014 Justin Cormack. All Rights Reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28#include "rumpuser_port.h" 29 30#if !defined(lint) 31__RCSID("$NetBSD: rumpuser_random.c,v 1.3 2014/08/24 14:37:31 pooka Exp $"); 32#endif /* !lint */ 33 34#include <sys/types.h> 35 36#include <assert.h> 37#include <errno.h> 38#include <fcntl.h> 39#include <stdint.h> 40#include <stdio.h> 41#include <stdlib.h> 42#include <string.h> 43#include <unistd.h> 44 45#include <rump/rumpuser.h> 46 47#include "rumpuser_int.h" 48 49static const size_t random_maxread = 32; 50 51#ifdef HAVE_ARC4RANDOM_BUF 52int 53rumpuser__random_init(void) 54{ 55 56 return 0; 57} 58#else 59static const char *random_device = "/dev/urandom"; 60static int random_fd = -1; 61 62int 63rumpuser__random_init(void) 64{ 65 66 random_fd = open(random_device, O_RDONLY); 67 if (random_fd < 0) { 68 fprintf(stderr, "random init open failed\n"); 69 return errno; 70 } 71 return 0; 72} 73#endif 74 75int 76rumpuser_getrandom(void *buf, size_t buflen, int flags, size_t *retp) 77{ 78#ifndef HAVE_ARC4RANDOM_BUF 79 ssize_t rv; 80 81 rv = read(random_fd, buf, buflen > random_maxread ? random_maxread : buflen); 82 if (rv < 0) { 83 ET(errno); 84 } 85 *retp = rv; 86#else 87 buflen = buflen > random_maxread ? random_maxread : buflen; 88 arc4random_buf(buf, buflen); 89 *retp = buflen; 90#endif 91 92 return 0; 93} 94