1 /* $NetBSD: rndsource.h,v 1.3 2015/04/21 03:53:07 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/rndio.h> /* RND_TYPE_*, RND_FLAG_* */
42 #include <sys/rngtest.h>
43
44 typedef struct rnd_delta_estimator {
45 uint64_t x;
46 uint64_t dx;
47 uint64_t d2x;
48 uint64_t insamples;
49 uint64_t outbits;
50 } rnd_delta_t;
51
52 typedef struct krndsource {
53 LIST_ENTRY(krndsource) list; /* the linked list */
54 char name[16]; /* device name */
55 rnd_delta_t time_delta; /* time delta estimator */
56 rnd_delta_t value_delta; /* value delta estimator */
57 uint32_t total; /* entropy from this source */
58 uint32_t type; /* type */
59 uint32_t flags; /* flags */
60 void *state; /* state information */
61 size_t test_cnt; /* how much test data accumulated? */
62 void (*get)(size_t, void *); /* pool wants N bytes (badly) */
63 void *getarg; /* argument to get-function */
64 void (*enable)(struct krndsource *, bool); /* turn on/off */
65 rngtest_t *test; /* test data for RNG type sources */
66 unsigned refcnt;
67 } krndsource_t;
68
69 static inline void
rndsource_setcb(struct krndsource * const rs,void (* const cb)(size_t,void *),void * const arg)70 rndsource_setcb(struct krndsource *const rs, void (*const cb)(size_t, void *),
71 void *const arg)
72 {
73 rs->get = cb;
74 rs->getarg = arg;
75 }
76
77 static inline void
rndsource_setenable(struct krndsource * const rs,void * const cb)78 rndsource_setenable(struct krndsource *const rs, void *const cb)
79 {
80 rs->enable = cb;
81 }
82
83 #define RND_ENABLED(rp) \
84 (((rp)->flags & RND_FLAG_NO_COLLECT) == 0)
85
86 void _rnd_add_uint32(krndsource_t *, uint32_t);
87 void _rnd_add_uint64(krndsource_t *, uint64_t);
88 void rnd_add_data(krndsource_t *, const void *const, uint32_t,
89 uint32_t);
90 void rnd_attach_source(krndsource_t *, const char *,
91 uint32_t, uint32_t);
92 void rnd_detach_source(krndsource_t *);
93
94 static inline void
rnd_add_uint32(krndsource_t * kr,uint32_t val)95 rnd_add_uint32(krndsource_t *kr, uint32_t val)
96 {
97 if (__predict_true(kr)) {
98 if (RND_ENABLED(kr)) {
99 _rnd_add_uint32(kr, val);
100 }
101 } else {
102 rnd_add_data(NULL, &val, sizeof(val), 0);
103 }
104 }
105
106 static inline void
rnd_add_uint64(krndsource_t * kr,uint64_t val)107 rnd_add_uint64(krndsource_t *kr, uint64_t val)
108 {
109 if (__predict_true(kr)) {
110 if (RND_ENABLED(kr)) {
111 _rnd_add_uint64(kr, val);
112 }
113 } else {
114 rnd_add_data(NULL, &val, sizeof(val), 0);
115 }
116 }
117
118 #endif /* _SYS_RNDSOURCE_H */
119