xref: /freebsd/sys/sys/random.h (revision ce6a89e27cd190313be39bb479880aeda4778436)
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 /*
41  * In the loadable random world, there are set of dangling pointers left in the
42  * core kernel:
43  *   * read_random, read_random_uio, is_random_seeded are function pointers,
44  *     rather than functions.
45  *   * p_random_alg_context is a true pointer in loadable random kernels.
46  *
47  * These are initialized at SI_SUB_RANDOM:SI_ORDER_SECOND during boot.  The
48  * read-type pointers are initialized by random_alg_context_init() in
49  * randomdev.c and p_random_alg_context in the algorithm, e.g., fortuna.c's
50  * random_fortuna_init_alg().  The nice thing about function pointers is they
51  * have a similar calling convention to ordinary functions.
52  *
53  * (In !loadable, the read_random, etc, routines are just plain functions;
54  * p_random_alg_context is a macro for the public visibility
55  * &random_alg_context.)
56  */
57 #if defined(RANDOM_LOADABLE)
58 extern void (*_read_random)(void *, u_int);
59 extern int (*_read_random_uio)(struct uio *, bool);
60 extern bool (*_is_random_seeded)(void);
61 #define	read_random(a, b)	(*_read_random)(a, b)
62 #define	read_random_uio(a, b)	(*_read_random_uio)(a, b)
63 #define	is_random_seeded()	(*_is_random_seeded)()
64 #else
65 void read_random(void *, u_int);
66 int read_random_uio(struct uio *, bool);
67 bool is_random_seeded(void);
68 #endif
69 
70 /*
71  * Note: if you add or remove members of random_entropy_source, remember to
72  * also update the strings in the static array random_source_descr[] in
73  * random_harvestq.c.
74  */
75 enum random_entropy_source {
76 	RANDOM_START = 0,
77 	RANDOM_CACHED = 0,
78 	/* Environmental sources */
79 	RANDOM_ATTACH,
80 	RANDOM_KEYBOARD,
81 	RANDOM_MOUSE,
82 	RANDOM_NET_TUN,
83 	RANDOM_NET_ETHER,
84 	RANDOM_NET_NG,
85 	RANDOM_INTERRUPT,
86 	RANDOM_SWI,
87 	RANDOM_FS_ATIME,
88 	RANDOM_UMA,	/* Special!! UMA/SLAB Allocator */
89 	RANDOM_ENVIRONMENTAL_END = RANDOM_UMA,
90 	/* Fast hardware random-number sources from here on. */
91 	RANDOM_PURE_START,
92 	RANDOM_PURE_OCTEON = RANDOM_PURE_START,
93 	RANDOM_PURE_SAFE,
94 	RANDOM_PURE_GLXSB,
95 	RANDOM_PURE_UBSEC,
96 	RANDOM_PURE_HIFN,
97 	RANDOM_PURE_RDRAND,
98 	RANDOM_PURE_NEHEMIAH,
99 	RANDOM_PURE_RNDTEST,
100 	RANDOM_PURE_VIRTIO,
101 	RANDOM_PURE_BROADCOM,
102 	RANDOM_PURE_CCP,
103 	RANDOM_PURE_DARN,
104 	RANDOM_PURE_TPM,
105 	RANDOM_PURE_VMGENID,
106 	ENTROPYSOURCE
107 };
108 _Static_assert(ENTROPYSOURCE <= 32,
109     "hardcoded assumption that values fit in a typical word-sized bitset");
110 
111 #define RANDOM_CACHED_BOOT_ENTROPY_MODULE	"boot_entropy_cache"
112 
113 extern u_int hc_source_mask;
114 void random_harvest_queue_(const void *, u_int, enum random_entropy_source);
115 void random_harvest_fast_(const void *, u_int);
116 void random_harvest_direct_(const void *, u_int, enum random_entropy_source);
117 
118 static __inline void
119 random_harvest_queue(const void *entropy, u_int size, enum random_entropy_source origin)
120 {
121 
122 	if (hc_source_mask & (1 << origin))
123 		random_harvest_queue_(entropy, size, origin);
124 }
125 
126 static __inline void
127 random_harvest_fast(const void *entropy, u_int size, enum random_entropy_source origin)
128 {
129 
130 	if (hc_source_mask & (1 << origin))
131 		random_harvest_fast_(entropy, size);
132 }
133 
134 static __inline void
135 random_harvest_direct(const void *entropy, u_int size, enum random_entropy_source origin)
136 {
137 
138 	if (hc_source_mask & (1 << origin))
139 		random_harvest_direct_(entropy, size, origin);
140 }
141 
142 void random_harvest_register_source(enum random_entropy_source);
143 void random_harvest_deregister_source(enum random_entropy_source);
144 
145 #if defined(RANDOM_ENABLE_UMA)
146 #define random_harvest_fast_uma(a, b, c)	random_harvest_fast(a, b, c)
147 #else /* !defined(RANDOM_ENABLE_UMA) */
148 #define random_harvest_fast_uma(a, b, c)	do {} while (0)
149 #endif /* defined(RANDOM_ENABLE_UMA) */
150 
151 #if defined(RANDOM_ENABLE_ETHER)
152 #define random_harvest_queue_ether(a, b)	random_harvest_queue(a, b, RANDOM_NET_ETHER)
153 #else /* !defined(RANDOM_ENABLE_ETHER) */
154 #define random_harvest_queue_ether(a, b)	do {} while (0)
155 #endif /* defined(RANDOM_ENABLE_ETHER) */
156 
157 
158 #endif /* _KERNEL */
159 
160 #define GRND_NONBLOCK	0x1
161 #define GRND_RANDOM	0x2
162 #define GRND_INSECURE	0x4
163 
164 __BEGIN_DECLS
165 ssize_t getrandom(void *buf, size_t buflen, unsigned int flags);
166 __END_DECLS
167 
168 #endif /* _SYS_RANDOM_H_ */
169