freebsd-dev/sys/dev/randomdev/harvest.c
markm 9555e6c41f Large upgrade to the entropy device; mainly inspired by feedback
from many folk.

o The reseed process is now a kthread. With SMPng, kthreads are
  pre-emptive, so the annoying jerkiness of the mouse is gone.

o The data structures are protected by mutexes now, not splfoo()/splx().

o The cryptographic routines are broken out into their own subroutines.
  this facilitates review, and possible replacement if that is ever
  found necessary.

Thanks to:		kris, green, peter, jasone, grog, jhb
Forgotten to thank:	You know who you are; no offense intended.
2000-09-10 13:52:19 +00:00

95 lines
2.8 KiB
C

/*-
* Copyright (c) 2000 Mark R V Murray
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer
* in this position and unchanged.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/queue.h>
#include <sys/kthread.h>
#include <sys/linker.h>
#include <sys/libkern.h>
#include <sys/mbuf.h>
#include <sys/random.h>
#include <sys/time.h>
#include <crypto/blowfish/blowfish.h>
#include <dev/randomdev/hash.h>
#include <dev/randomdev/yarrow.h>
/* hold the address of the routine which is actually called if
* the ramdomdev is loaded
*/
static void (*reap)(struct timespec *, void *, u_int, u_int, u_int, u_int) = NULL;
/* Initialise the harvester at load time */
void
random_init_harvester(void (*reaper)(struct timespec *, void *, u_int, u_int, u_int, u_int))
{
reap = reaper;
}
/* Deinitialise the harvester at unload time */
void
random_deinit_harvester(void)
{
reap = NULL;
}
/* Entropy harvesting routine. This is supposed to be fast; do
* not do anything slow in here!
* Implemented as in indirect call to allow non-inclusion of
* the entropy device.
*/
void
random_harvest(void *entropy, u_int count, u_int bits, u_int frac, u_int origin)
{
struct timespec timebuf;
if (reap) {
nanotime(&timebuf);
(*reap)(&timebuf, entropy, count, bits, frac, origin);
}
}
/* Helper routines to enable kthread_exit() to work while the module is
* being (or has been) unloaded.
*/
void
random_set_wakeup(int *var, int value)
{
*var = value;
wakeup(var);
}
void
random_set_wakeup_exit(int *var, int value, int exitval)
{
random_set_wakeup(var, value);
kthread_exit(exitval);
}