1 /* $NetBSD: hyperentropy.c,v 1.17 2020/04/30 03:41:20 riastradh Exp $ */
2
3 /*
4 * Copyright (c) 2014 Antti Kantee. 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 <sys/cdefs.h>
29 __KERNEL_RCSID(0, "$NetBSD: hyperentropy.c,v 1.17 2020/04/30 03:41:20 riastradh Exp $");
30
31 #include <sys/param.h>
32 #include <sys/kmem.h>
33 #include <sys/rndsource.h>
34
35 #include <rump-sys/kern.h>
36
37 #include <rump/rumpuser.h>
38
39 static krndsource_t rndsrc;
40
41 static void
feedrandom(size_t bytes,void * cookie __unused)42 feedrandom(size_t bytes, void *cookie __unused)
43 {
44 uint8_t *rnddata;
45 size_t n, nread;
46
47 rnddata = kmem_intr_alloc(bytes, KM_SLEEP);
48 n = 0;
49 while (n < bytes) {
50 if (rumpuser_getrandom(rnddata + n, bytes - n,
51 RUMPUSER_RANDOM_HARD|RUMPUSER_RANDOM_NOWAIT, &nread)
52 != 0)
53 break;
54 n += MIN(nread, bytes - n);
55 }
56 if (n) {
57 rnd_add_data_sync(&rndsrc, rnddata, n, NBBY*n);
58 }
59 kmem_intr_free(rnddata, bytes);
60 }
61
62 void
rump_hyperentropy_init(void)63 rump_hyperentropy_init(void)
64 {
65
66 rndsource_setcb(&rndsrc, &feedrandom, NULL);
67 rnd_attach_source(&rndsrc, "rump_hyperent", RND_TYPE_VM,
68 RND_FLAG_COLLECT_VALUE|RND_FLAG_HASCB);
69 }
70