1 /* $NetBSD: rumpuser_random.c,v 1.4 2014/11/04 19:05:17 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 1.4 2014/11/04 19:05:17 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 49 static const size_t random_maxread = 32; 50 51 #ifdef HAVE_ARC4RANDOM_BUF 52 int 53 rumpuser__random_init(void) 54 { 55 56 return 0; 57 } 58 #else 59 static const char *random_device = "/dev/urandom"; 60 static int random_fd = -1; 61 62 int 63 rumpuser__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 75 int 76 rumpuser_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