xref: /freebsd/sys/dev/random/randomdev.h (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
1 /*-
2  * Copyright (c) 2000-2015 Mark R V Murray
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer
10  *    in this position and unchanged.
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 OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #ifndef SYS_DEV_RANDOM_RANDOMDEV_H_INCLUDED
28 #define	SYS_DEV_RANDOM_RANDOMDEV_H_INCLUDED
29 
30 #ifdef _KERNEL
31 
32 /* This header contains only those definitions that are global
33  * and non algorithm-specific for the entropy processor
34  */
35 
36 #ifdef SYSCTL_DECL	/* from sysctl.h */
37 SYSCTL_DECL(_kern_random);
38 SYSCTL_DECL(_kern_random_initial_seeding);
39 
40 #define	RANDOM_CHECK_UINT(name, min, max)				\
41 static int								\
42 random_check_uint_##name(SYSCTL_HANDLER_ARGS)				\
43 {									\
44 	if (oidp->oid_arg1 != NULL) {					\
45 		if (*(u_int *)(oidp->oid_arg1) <= (min))		\
46 			*(u_int *)(oidp->oid_arg1) = (min);		\
47 		else if (*(u_int *)(oidp->oid_arg1) > (max))		\
48 			*(u_int *)(oidp->oid_arg1) = (max);		\
49 	}								\
50 	return (sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2,	\
51 		req));							\
52 }
53 #endif /* SYSCTL_DECL */
54 
55 MALLOC_DECLARE(M_ENTROPY);
56 
57 extern bool random_bypass_before_seeding;
58 extern bool read_random_bypassed_before_seeding;
59 extern bool arc4random_bypassed_before_seeding;
60 extern bool random_bypass_disable_warnings;
61 
62 #endif /* _KERNEL */
63 
64 struct harvest_event;
65 
66 typedef void random_alg_pre_read_t(void);
67 typedef void random_alg_read_t(uint8_t *, size_t);
68 typedef bool random_alg_seeded_t(void);
69 typedef void random_alg_eventprocessor_t(struct harvest_event *);
70 
71 typedef u_int random_source_read_t(void *, u_int);
72 
73 /*
74  * Random Algorithm is a processor of randomness for the kernel
75  * and for userland.
76  */
77 struct random_algorithm {
78 	const char			*ra_ident;
79 	u_int				 ra_poolcount;
80 	random_alg_pre_read_t		*ra_pre_read;
81 	random_alg_read_t		*ra_read;
82 	random_alg_seeded_t		*ra_seeded;
83 	random_alg_eventprocessor_t	*ra_event_processor;
84 };
85 
86 #if defined(RANDOM_LOADABLE)
87 extern const struct random_algorithm *p_random_alg_context;
88 #else
89 extern const struct random_algorithm random_alg_context;
90 #define	p_random_alg_context (&random_alg_context)
91 #endif
92 
93 #ifdef _KERNEL
94 
95 /*
96  * Random Source is a source of entropy that can provide
97  * specified or approximate amount of entropy immediately
98  * upon request.
99  */
100 struct random_source {
101 	const char			*rs_ident;
102 	enum random_entropy_source	 rs_source;
103 	random_source_read_t		*rs_read;
104 };
105 
106 void random_source_register(struct random_source *);
107 void random_source_deregister(struct random_source *);
108 
109 #endif /* _KERNEL */
110 
111 void randomdev_unblock(void);
112 
113 #endif /* SYS_DEV_RANDOM_RANDOMDEV_H_INCLUDED */
114