| 1 | /* $NetBSD: rndsource.h,v 1.5 2016/02/17 00:43:43 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/null.h> |
| 42 | #include <sys/rndio.h> /* RND_TYPE_*, RND_FLAG_* */ |
| 43 | #include <sys/rngtest.h> |
| 44 | #include <sys/queue.h> |
| 45 | |
| 46 | typedef struct rnd_delta_estimator { |
| 47 | uint64_t x; |
| 48 | uint64_t dx; |
| 49 | uint64_t d2x; |
| 50 | uint64_t insamples; |
| 51 | uint64_t outbits; |
| 52 | } rnd_delta_t; |
| 53 | |
| 54 | typedef struct krndsource { |
| 55 | LIST_ENTRY(krndsource) list; /* the linked list */ |
| 56 | char name[16]; /* device name */ |
| 57 | rnd_delta_t time_delta; /* time delta estimator */ |
| 58 | rnd_delta_t value_delta; /* value delta estimator */ |
| 59 | uint32_t total; /* entropy from this source */ |
| 60 | uint32_t type; /* type */ |
| 61 | uint32_t flags; /* flags */ |
| 62 | void *state; /* state information */ |
| 63 | size_t test_cnt; /* how much test data accumulated? */ |
| 64 | void (*get)(size_t, void *); /* pool wants N bytes (badly) */ |
| 65 | void *getarg; /* argument to get-function */ |
| 66 | void (*enable)(struct krndsource *, bool); /* turn on/off */ |
| 67 | rngtest_t *test; /* test data for RNG type sources */ |
| 68 | unsigned refcnt; |
| 69 | } krndsource_t; |
| 70 | |
| 71 | static inline void |
| 72 | rndsource_setcb(struct krndsource *const rs, void (*const cb)(size_t, void *), |
| 73 | void *const arg) |
| 74 | { |
| 75 | rs->get = cb; |
| 76 | rs->getarg = arg; |
| 77 | } |
| 78 | |
| 79 | static inline void |
| 80 | rndsource_setenable(struct krndsource *const rs, void *const cb) |
| 81 | { |
| 82 | rs->enable = cb; |
| 83 | } |
| 84 | |
| 85 | #define RND_ENABLED(rp) \ |
| 86 | (((rp)->flags & RND_FLAG_NO_COLLECT) == 0) |
| 87 | |
| 88 | void _rnd_add_uint32(krndsource_t *, uint32_t); |
| 89 | void _rnd_add_uint64(krndsource_t *, uint64_t); |
| 90 | void rnd_add_data(krndsource_t *, const void *const, uint32_t, |
| 91 | uint32_t); |
| 92 | void rnd_add_data_sync(krndsource_t *, const void *, uint32_t, |
| 93 | uint32_t); |
| 94 | void rnd_attach_source(krndsource_t *, const char *, |
| 95 | uint32_t, uint32_t); |
| 96 | void rnd_detach_source(krndsource_t *); |
| 97 | |
| 98 | static inline void |
| 99 | rnd_add_uint32(krndsource_t *kr, uint32_t val) |
| 100 | { |
| 101 | if (__predict_true(kr)) { |
| 102 | if (RND_ENABLED(kr)) { |
| 103 | _rnd_add_uint32(kr, val); |
| 104 | } |
| 105 | } else { |
| 106 | rnd_add_data(NULL, &val, sizeof(val), 0); |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | static inline void |
| 111 | rnd_add_uint64(krndsource_t *kr, uint64_t val) |
| 112 | { |
| 113 | if (__predict_true(kr)) { |
| 114 | if (RND_ENABLED(kr)) { |
| 115 | _rnd_add_uint64(kr, val); |
| 116 | } |
| 117 | } else { |
| 118 | rnd_add_data(NULL, &val, sizeof(val), 0); |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | #endif /* _SYS_RNDSOURCE_H */ |
| 123 | |