1/* $NetBSD: rndsource.h,v 1.5 2016/02/17 00:43:43 riastradh Exp $ */
2
3/*-
4 * Copyright (c) 1997 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Michael Graff <explorer@flame.org>. This code uses ideas and
9 * algorithms from the Linux driver written by Ted Ts'o.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33#ifndef _SYS_RNDSOURCE_H
34#define _SYS_RNDSOURCE_H
35
36#ifndef _KERNEL /* XXX */
37#error <sys/rndsource.h> is meant for kernel consumers only.
38#endif
39
40#include <sys/types.h>
41#include <sys/null.h>
42#include <sys/rndio.h> /* RND_TYPE_*, RND_FLAG_* */
43#include <sys/rngtest.h>
44#include <sys/queue.h>
45
46typedef struct rnd_delta_estimator {
47 uint64_t x;
48 uint64_t dx;
49 uint64_t d2x;
50 uint64_t insamples;
51 uint64_t outbits;
52} rnd_delta_t;
53
54typedef struct krndsource {
55 LIST_ENTRY(krndsource) list; /* the linked list */
56 char name[16]; /* device name */
57 rnd_delta_t time_delta; /* time delta estimator */
58 rnd_delta_t value_delta; /* value delta estimator */
59 uint32_t total; /* entropy from this source */
60 uint32_t type; /* type */
61 uint32_t flags; /* flags */
62 void *state; /* state information */
63 size_t test_cnt; /* how much test data accumulated? */
64 void (*get)(size_t, void *); /* pool wants N bytes (badly) */
65 void *getarg; /* argument to get-function */
66 void (*enable)(struct krndsource *, bool); /* turn on/off */
67 rngtest_t *test; /* test data for RNG type sources */
68 unsigned refcnt;
69} krndsource_t;
70
71static inline void
72rndsource_setcb(struct krndsource *const rs, void (*const cb)(size_t, void *),
73 void *const arg)
74{
75 rs->get = cb;
76 rs->getarg = arg;
77}
78
79static inline void
80rndsource_setenable(struct krndsource *const rs, void *const cb)
81{
82 rs->enable = cb;
83}
84
85#define RND_ENABLED(rp) \
86 (((rp)->flags & RND_FLAG_NO_COLLECT) == 0)
87
88void _rnd_add_uint32(krndsource_t *, uint32_t);
89void _rnd_add_uint64(krndsource_t *, uint64_t);
90void rnd_add_data(krndsource_t *, const void *const, uint32_t,
91 uint32_t);
92void rnd_add_data_sync(krndsource_t *, const void *, uint32_t,
93 uint32_t);
94void rnd_attach_source(krndsource_t *, const char *,
95 uint32_t, uint32_t);
96void rnd_detach_source(krndsource_t *);
97
98static inline void
99rnd_add_uint32(krndsource_t *kr, uint32_t val)
100{
101 if (__predict_true(kr)) {
102 if (RND_ENABLED(kr)) {
103 _rnd_add_uint32(kr, val);
104 }
105 } else {
106 rnd_add_data(NULL, &val, sizeof(val), 0);
107 }
108}
109
110static inline void
111rnd_add_uint64(krndsource_t *kr, uint64_t val)
112{
113 if (__predict_true(kr)) {
114 if (RND_ENABLED(kr)) {
115 _rnd_add_uint64(kr, val);
116 }
117 } else {
118 rnd_add_data(NULL, &val, sizeof(val), 0);
119 }
120}
121
122#endif /* _SYS_RNDSOURCE_H */
123