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
rumpuser__random_init(void)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
rumpuser__random_init(void)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
rumpuser_getrandom(void * buf,size_t buflen,int flags,size_t * retp)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