randomdev.h revision 74072 
1/*-
2 * Copyright (c) 2001 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 * $FreeBSD: head/sys/dev/random/randomdev.h 74072 2001-03-10 12:51:55Z markm $
27 */
28
29/* This header contains only those definitions that are global
30 * and non algorithm-specific for the entropy processor
31 */
32
33/* #define ENTROPYSOURCE nn	   entropy sources (actually classes)
34 *					This is properly defined in
35 *					an enum in sys/random.h
36 */
37
38/* Cryptographic block size in bits */
39#define	BLOCKSIZE	256
40
41/* The ring size _MUST_ be a power of 2 */
42#define HARVEST_RING_SIZE	1024	/* harvest ring buffer size */
43#define HARVEST_RING_MASK	(HARVEST_RING_SIZE - 1)
44
45#define HARVESTSIZE	16	/* max size of each harvested entropy unit */
46
47SYSCTL_DECL(_kern_random);
48
49/* These are used to queue harvested packets of entropy. The entropy
50 * buffer size is pretty arbitrary.
51 */
52struct harvest {
53	u_int64_t somecounter;		/* fast counter for clock jitter */
54	u_char entropy[HARVESTSIZE];	/* the harvested entropy */
55	u_int size, bits, frac;		/* stats about the entropy */
56	enum esource source;		/* stats about the entropy */
57};
58
59void random_init(void);
60void random_deinit(void);
61void random_init_harvester(void (*)(u_int64_t, void *, u_int, u_int, u_int, enum esource), u_int (*)(void *, u_int));
62void random_deinit_harvester(void);
63void random_set_wakeup_exit(void *);
64void random_process_event(struct harvest *event);
65void random_reseed(void);
66void random_unblock(void);
67
68u_int read_random_real(void *, u_int);
69
70/* If this was c++, this would be a template */
71#define RANDOM_CHECK_UINT(name, min, max)				\
72static int								\
73random_check_uint_##name##(SYSCTL_HANDLER_ARGS)				\
74{									\
75	if (oidp->oid_arg1 != NULL) {					\
76		 if (*(u_int *)(oidp->oid_arg1) < min)			\
77			*(u_int *)(oidp->oid_arg1) = min;		\
78		 else if (*(u_int *)(oidp->oid_arg1) > max)		\
79			*(u_int *)(oidp->oid_arg1) = max;		\
80	}								\
81        return sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2,	\
82		req);							\
83}
84