| /*- |
| * Copyright (c) 2000-2004 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. |
| * |
| */ |
| |
| #include <sys/bsd_cdefs.h> |
| //__FBSDID("$FreeBSD$"); |
| |
| #include <sys/bsd_libkern.h> |
| #include <sys/bsd_param.h> |
| //#include <sys/bsd_kthread.h> |
| //#include <sys/bsd_lock.h> |
| #include <sys/bsd_malloc.h> |
| //#include <sys/bsd_mutex.h> |
| //#include <sys/bsd_poll.h> |
| //#include <sys/bsd_queue.h> |
| #include <sys/bsd_random.h> |
| //#include <sys/bsd_selinfo.h> |
| //#include <sys/bsd_systm.h> |
| //#include <sys/bsd_sysctl.h> |
| |
| #include <machine/bsd_cpufunc.h> |
| #include <machine/bsd_cpu.h> |
| #include <stdlib.h> |
| |
| |
| //#include <dev/random/bsd_randomdev_soft.h> |
| |
| static int read_random_phony(void *, int); |
| |
| /* Structure holding the desired entropy sources */ |
| struct harvest_select harvest = { 1, 1, 1, 0 }; |
| |
| /* hold the address of the routine which is actually called if |
| * the randomdev is loaded |
| */ |
| static void (*reap_func)(u_int64_t, const void *, u_int, u_int, u_int, |
| enum esource) = NULL; |
| static int (*read_func)(void *, int) = read_random_phony; |
| |
| /* Initialise the harvester at load time */ |
| void |
| random_yarrow_init_harvester(void (*reaper)(u_int64_t, const void *, u_int, |
| u_int, u_int, enum esource), int (*reader)(void *, int)) |
| { |
| reap_func = reaper; |
| read_func = reader; |
| } |
| |
| /* Deinitialise the harvester at unload time */ |
| void |
| random_yarrow_deinit_harvester(void) |
| { |
| reap_func = NULL; |
| read_func = read_random_phony; |
| } |
| |
| /* 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. |
| * |
| * XXXRW: get_cyclecount() is cheap on most modern hardware, where cycle |
| * counters are built in, but on older hardware it will do a real time clock |
| * read which can be quite expensive. |
| */ |
| void |
| random_harvest(void *entropy, u_int count, u_int bits, u_int frac, |
| enum esource origin) |
| { |
| if (reap_func) |
| (*reap_func)(get_cyclecount(), entropy, count, bits, frac, |
| origin); |
| } |
| |
| /* Userland-visible version of read_random */ |
| int |
| read_random(void *buf, int count) |
| { |
| return ((*read_func)(buf, count)); |
| } |
| |
| /* If the entropy device is not loaded, make a token effort to |
| * provide _some_ kind of randomness. This should only be used |
| * inside other RNG's, like arc4random(9). |
| */ |
| static int |
| read_random_phony(void *buf, int count) |
| { |
| u_long randval; |
| int size, i; |
| |
| /* srandom() is called in kern/init_main.c:proc0_post() */ |
| |
| /* Fill buf[] with random(9) output */ |
| for (i = 0; i < count; i+= (int)sizeof(u_long)) { |
| randval = random(); |
| size = MIN(count - i, sizeof(u_long)); |
| memcpy(&((char *)buf)[i], &randval, (size_t)size); |
| } |
| |
| return (count); |
| } |
| |
| /* Helper routine to enable kproc_exit() to work while the module is |
| * being (or has been) unloaded. |
| * This routine is in this file because it is always linked into the kernel, |
| * and will thus never be unloaded. This is critical for unloadable modules |
| * that have threads. |
| */ |
| void |
| random_set_wakeup_exit(void *control) |
| { |
| //wakeup(control); |
| //kproc_exit(0); |
| /* NOTREACHED */ |
| } |