63edd2efc3
to dummy,yarrow and break the usability of /dev/random. Fix the name of the tunable to something logical that 'sysctl kern.random' emits. Submitted by: des@ (the idea, code by me)
125 lines
3.2 KiB
C
125 lines
3.2 KiB
C
/*-
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* Copyright (c) 2013 Arthur Mesh <arthurmesh@gmail.com>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer
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* in this position and unchanged.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/fcntl.h>
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#include <sys/kernel.h>
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#include <sys/malloc.h>
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#include <sys/module.h>
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#include <sys/random.h>
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#include <sys/selinfo.h>
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#include <sys/systm.h>
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#include <sys/time.h>
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#include <dev/random/random_adaptors.h>
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#include <dev/random/randomdev.h>
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static struct mtx dummy_random_mtx;
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/* Used to fake out unused random calls in random_adaptor */
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static void
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random_null_func(void)
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{
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}
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static int
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dummy_random_poll(int events __unused, struct thread *td __unused)
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{
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return (0);
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}
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static int
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dummy_random_block(int flag)
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{
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int error = 0;
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mtx_lock(&dummy_random_mtx);
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/* Blocking logic */
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while (!error) {
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if (flag & O_NONBLOCK)
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error = EWOULDBLOCK;
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else {
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printf("random: dummy device blocking on read.\n");
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error = msleep(&dummy_random_block,
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&dummy_random_mtx,
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PUSER | PCATCH, "block", 0);
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}
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}
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mtx_unlock(&dummy_random_mtx);
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return (error);
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}
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static void
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dummy_random_init(void)
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{
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mtx_init(&dummy_random_mtx, "sleep mtx for dummy_random",
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NULL, MTX_DEF);
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}
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static void
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dummy_random_deinit(void)
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{
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mtx_destroy(&dummy_random_mtx);
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}
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struct random_adaptor dummy_random = {
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.ident = "Dummy entropy device that always blocks",
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.init = dummy_random_init,
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.deinit = dummy_random_deinit,
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.block = dummy_random_block,
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.poll = dummy_random_poll,
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.read = (random_read_func_t *)random_null_func,
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.reseed = (random_reseed_func_t *)random_null_func,
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.seeded = 0, /* This device can never be seeded */
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.priority = 1, /* Bottom priority, so goes to last position */
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};
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static int
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dummy_random_modevent(module_t mod __unused, int type, void *unused __unused)
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{
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switch (type) {
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case MOD_LOAD:
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random_adaptor_register("dummy", &dummy_random);
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EVENTHANDLER_INVOKE(random_adaptor_attach,
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&dummy_random);
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return (0);
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}
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return (EINVAL);
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}
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RANDOM_ADAPTOR_MODULE(dummy, dummy_random_modevent, 1);
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