xref: /freebsd/sys/sys/random.h (revision cc426dd31990b8b50b210efc450e404596548ca1)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2000-2015, 2017 Mark R. V. Murray
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer
12  *    in this position and unchanged.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 #ifndef	_SYS_RANDOM_H_
32 #define	_SYS_RANDOM_H_
33 
34 #include <sys/types.h>
35 
36 #ifdef _KERNEL
37 
38 struct uio;
39 
40 #if defined(DEV_RANDOM)
41 u_int read_random(void *, u_int);
42 int read_random_uio(struct uio *, bool);
43 #else
44 static __inline int
45 read_random_uio(void *a __unused, u_int b __unused)
46 {
47 	return (0);
48 }
49 static __inline u_int
50 read_random(void *a __unused, u_int b __unused)
51 {
52 	return (0);
53 }
54 #endif
55 
56 /*
57  * Note: if you add or remove members of random_entropy_source, remember to
58  * also update the strings in the static array random_source_descr[] in
59  * random_harvestq.c.
60  */
61 enum random_entropy_source {
62 	RANDOM_START = 0,
63 	RANDOM_CACHED = 0,
64 	/* Environmental sources */
65 	RANDOM_ATTACH,
66 	RANDOM_KEYBOARD,
67 	RANDOM_MOUSE,
68 	RANDOM_NET_TUN,
69 	RANDOM_NET_ETHER,
70 	RANDOM_NET_NG,
71 	RANDOM_INTERRUPT,
72 	RANDOM_SWI,
73 	RANDOM_FS_ATIME,
74 	RANDOM_UMA,	/* Special!! UMA/SLAB Allocator */
75 	RANDOM_ENVIRONMENTAL_END = RANDOM_UMA,
76 	/* Fast hardware random-number sources from here on. */
77 	RANDOM_PURE_START,
78 	RANDOM_PURE_OCTEON = RANDOM_PURE_START,
79 	RANDOM_PURE_SAFE,
80 	RANDOM_PURE_GLXSB,
81 	RANDOM_PURE_UBSEC,
82 	RANDOM_PURE_HIFN,
83 	RANDOM_PURE_RDRAND,
84 	RANDOM_PURE_NEHEMIAH,
85 	RANDOM_PURE_RNDTEST,
86 	RANDOM_PURE_VIRTIO,
87 	RANDOM_PURE_BROADCOM,
88 	RANDOM_PURE_CCP,
89 	RANDOM_PURE_DARN,
90 	ENTROPYSOURCE
91 };
92 _Static_assert(ENTROPYSOURCE <= 32,
93     "hardcoded assumption that values fit in a typical word-sized bitset");
94 
95 #define RANDOM_LEGACY_BOOT_ENTROPY_MODULE	"/boot/entropy"
96 #define RANDOM_CACHED_BOOT_ENTROPY_MODULE	"boot_entropy_cache"
97 #define	RANDOM_CACHED_SKIP_START	256
98 
99 #if defined(DEV_RANDOM)
100 extern u_int hc_source_mask;
101 void random_harvest_queue_(const void *, u_int, enum random_entropy_source);
102 void random_harvest_fast_(const void *, u_int);
103 void random_harvest_direct_(const void *, u_int, enum random_entropy_source);
104 
105 static __inline void
106 random_harvest_queue(const void *entropy, u_int size, enum random_entropy_source origin)
107 {
108 
109 	if (hc_source_mask & (1 << origin))
110 		random_harvest_queue_(entropy, size, origin);
111 }
112 
113 static __inline void
114 random_harvest_fast(const void *entropy, u_int size, enum random_entropy_source origin)
115 {
116 
117 	if (hc_source_mask & (1 << origin))
118 		random_harvest_fast_(entropy, size);
119 }
120 
121 static __inline void
122 random_harvest_direct(const void *entropy, u_int size, enum random_entropy_source origin)
123 {
124 
125 	if (hc_source_mask & (1 << origin))
126 		random_harvest_direct_(entropy, size, origin);
127 }
128 
129 void random_harvest_register_source(enum random_entropy_source);
130 void random_harvest_deregister_source(enum random_entropy_source);
131 #else
132 #define random_harvest_queue(a, b, c) do {} while (0)
133 #define random_harvest_fast(a, b, c) do {} while (0)
134 #define random_harvest_direct(a, b, c) do {} while (0)
135 #define random_harvest_register_source(a) do {} while (0)
136 #define random_harvest_deregister_source(a) do {} while (0)
137 #endif
138 
139 #if defined(RANDOM_ENABLE_UMA)
140 #define random_harvest_fast_uma(a, b, c)	random_harvest_fast(a, b, c)
141 #else /* !defined(RANDOM_ENABLE_UMA) */
142 #define random_harvest_fast_uma(a, b, c)	do {} while (0)
143 #endif /* defined(RANDOM_ENABLE_UMA) */
144 
145 #if defined(RANDOM_ENABLE_ETHER)
146 #define random_harvest_queue_ether(a, b)	random_harvest_queue(a, b, RANDOM_NET_ETHER)
147 #else /* !defined(RANDOM_ENABLE_ETHER) */
148 #define random_harvest_queue_ether(a, b)	do {} while (0)
149 #endif /* defined(RANDOM_ENABLE_ETHER) */
150 
151 
152 #endif /* _KERNEL */
153 
154 #define GRND_NONBLOCK	0x1
155 #define GRND_RANDOM	0x2
156 ssize_t getrandom(void *buf, size_t buflen, unsigned int flags);
157 
158 #endif /* _SYS_RANDOM_H_ */
159