diff options
Diffstat (limited to 'sys/dev/random/random_adaptors.c')
| -rw-r--r-- | sys/dev/random/random_adaptors.c | 483 |
1 files changed, 0 insertions, 483 deletions
diff --git a/sys/dev/random/random_adaptors.c b/sys/dev/random/random_adaptors.c deleted file mode 100644 index 5a67f50..0000000 --- a/sys/dev/random/random_adaptors.c +++ /dev/null @@ -1,483 +0,0 @@ -/*- - * Copyright (c) 2013 Mark R V Murray - * Copyright (c) 2013 Arthur Mesh <arthurmesh@gmail.com> - * Copyright (c) 2013 David E. O'Brien <obrien@NUXI.org> - * 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/param.h> -__FBSDID("$FreeBSD$"); - -#include "opt_random.h" - -#include <sys/systm.h> -#include <sys/conf.h> -#include <sys/fcntl.h> -#include <sys/kernel.h> -#include <sys/kthread.h> -#include <sys/libkern.h> -#include <sys/lock.h> -#include <sys/malloc.h> -#include <sys/module.h> -#include <sys/mutex.h> -#include <sys/poll.h> -#include <sys/queue.h> -#include <sys/random.h> -#include <sys/sbuf.h> -#include <sys/selinfo.h> -#include <sys/sx.h> -#include <sys/sysctl.h> -#include <sys/uio.h> -#include <sys/unistd.h> - -#include <dev/random/randomdev.h> -#include <dev/random/random_adaptors.h> -#include <dev/random/live_entropy_sources.h> - -/* The random_adaptors_lock protects random_adaptors_list and friends and random_adaptor. - * We need a sleepable lock for uiomove/block/poll/sbuf/sysctl. - */ -static struct sx random_adaptors_lock; -LIST_HEAD(adaptors_head, random_adaptors); -static struct adaptors_head random_adaptors_list = LIST_HEAD_INITIALIZER(random_adaptors_list); -static struct random_adaptor *random_adaptor = NULL; /* Currently active adaptor */ -/* End of data items requiring random_adaptors_lock protection */ - -/* The random_readrate_mtx mutex protects the read-rate estimator. - */ -static struct mtx random_read_rate_mtx; -static int random_adaptor_read_rate_cache; -/* End of data items requiring random_readrate_mtx mutex protection */ - -static struct selinfo rsel; - -/* Utility routine to change active adaptor when the random_adaptors_list - * gets modified. - * - * Walk a list of registered random(4) adaptors and pick either a requested - * one or the highest priority one, whichever comes first. Panic on failure - * as the fallback must always be the "dummy" adaptor. - */ -static void -random_adaptor_choose(void) -{ - char rngs[128], *token, *cp; - struct random_adaptors *rra, *rrai; - struct random_adaptor *random_adaptor_previous; - int primax; - - /* We are going to be messing with random_adaptor. - * Exclusive lock is mandatory. - */ - sx_assert(&random_adaptors_lock, SA_XLOCKED); - - random_adaptor_previous = random_adaptor; - - random_adaptor = NULL; - if (TUNABLE_STR_FETCH("kern.random.active_adaptor", rngs, sizeof(rngs))) { - cp = rngs; - - /* XXX: FIX!! (DES): - * - fetch tunable once, at boot - * - make sysctl r/w - * - when fetching tunable or processing a sysctl - * write, parse into list of strings so we don't - * have to do it here again and again - * - sysctl read should return a reconstructed string - */ - while ((token = strsep(&cp, ",")) != NULL) { - LIST_FOREACH(rra, &random_adaptors_list, rra_entries) - if (strcmp(rra->rra_name, token) == 0) { - random_adaptor = rra->rra_ra; - break; - } - if (random_adaptor != NULL) { - printf("random: selecting requested adaptor <%s>\n", - random_adaptor->ra_ident); - break; - } - else - printf("random: requested adaptor <%s> not available\n", - token); - } - } - - primax = 0; - if (random_adaptor == NULL) { - /* - * Fall back to the highest priority item on the available - * RNG list. - */ - LIST_FOREACH(rrai, &random_adaptors_list, rra_entries) { - if (rrai->rra_ra->ra_priority >= primax) { - random_adaptor = rrai->rra_ra; - primax = rrai->rra_ra->ra_priority; - } - } - if (random_adaptor != NULL) - printf("random: selecting highest priority adaptor <%s>\n", - random_adaptor->ra_ident); - } - - KASSERT(random_adaptor != NULL, ("adaptor not found")); - - /* If we are changing adaptors, deinit the old and init the new. */ - if (random_adaptor != random_adaptor_previous) { -#ifdef RANDOM_DEBUG - printf("random: %s - changing from %s to %s\n", __func__, - (random_adaptor_previous == NULL ? "NULL" : random_adaptor_previous->ra_ident), - random_adaptor->ra_ident); -#endif - if (random_adaptor_previous != NULL) { - randomdev_deinit_reader(); - (random_adaptor_previous->ra_deinit)(); - } - (random_adaptor->ra_init)(); - } - - randomdev_init_reader(random_adaptor->ra_read); -} - - -/* XXX: FIX!! Make sure we are not inserting a duplicate */ -void -random_adaptor_register(const char *name, struct random_adaptor *ra) -{ - struct random_adaptors *rra; - - KASSERT(name != NULL && ra != NULL, ("invalid input to %s", __func__)); - - rra = malloc(sizeof(*rra), M_ENTROPY, M_WAITOK); - rra->rra_name = name; - rra->rra_ra = ra; - - sx_xlock(&random_adaptors_lock); - LIST_INSERT_HEAD(&random_adaptors_list, rra, rra_entries); - random_adaptor_choose(); - KASSERT(random_adaptor != NULL, ("No active random adaptor in %s", __func__)); - sx_xunlock(&random_adaptors_lock); -} - -void -random_adaptor_deregister(const char *name) -{ - struct random_adaptors *rra; - - KASSERT(name != NULL, ("invalid input to %s", __func__)); - - sx_xlock(&random_adaptors_lock); - KASSERT(random_adaptor != NULL, ("No active random adaptor in %s", __func__)); - LIST_FOREACH(rra, &random_adaptors_list, rra_entries) - if (strcmp(rra->rra_name, name) == 0) { - LIST_REMOVE(rra, rra_entries); - break; - } - random_adaptor_choose(); - sx_xunlock(&random_adaptors_lock); - - free(rra, M_ENTROPY); -} - -/* ARGSUSED */ -int -random_adaptor_read(struct cdev *dev __unused, struct uio *uio, int flags) -{ - void *random_buf; - int c, error; - ssize_t nbytes; - -#ifdef RANDOM_DEBUG_VERBOSE - printf("random: %s %ld\n", __func__, uio->uio_resid); -#endif - - random_buf = malloc(PAGE_SIZE, M_ENTROPY, M_WAITOK); - - sx_slock(&random_adaptors_lock); - - KASSERT(random_adaptor != NULL, ("No active random adaptor in %s", __func__)); - - /* Let the entropy source do any pre-read setup. */ - (random_adaptor->ra_read)(NULL, 0); - - /* (Un)Blocking logic */ - error = 0; - while (!random_adaptor->ra_seeded() && error == 0) { - if (flags & O_NONBLOCK) { - error = EWOULDBLOCK; - break; - } - - /* Sleep instead of going into a spin-frenzy */ - error = sx_sleep(&random_adaptor, &random_adaptors_lock, - PUSER | PCATCH, "randrd", hz/10); - KASSERT(random_adaptor != NULL, ("No active random adaptor in %s", - __func__)); - - /* keep tapping away at the pre-read until we seed/unblock. */ - (random_adaptor->ra_read)(NULL, 0); - } - - mtx_lock(&random_read_rate_mtx); - - /* The read-rate stuff is a rough indication of the instantaneous read rate, - * used to increase the use of 'live' entropy sources when lots of reads are done. - */ - nbytes = (uio->uio_resid + 32 - 1)/32; /* Round up to units of 32 */ - random_adaptor_read_rate_cache += nbytes*32; - random_adaptor_read_rate_cache = MIN(random_adaptor_read_rate_cache, 32); - - mtx_unlock(&random_read_rate_mtx); - - if (error == 0) { - nbytes = uio->uio_resid; - - /* The actual read */ - while (uio->uio_resid && !error) { - c = MIN(uio->uio_resid, PAGE_SIZE); - (random_adaptor->ra_read)(random_buf, c); - error = uiomove(random_buf, c, uio); - } - - /* Let the entropy source do any post-read cleanup. */ - (random_adaptor->ra_read)(NULL, 1); - - if (nbytes != uio->uio_resid && (error == ERESTART || - error == EINTR) ) - error = 0; /* Return partial read, not error. */ - - } - sx_sunlock(&random_adaptors_lock); - - free(random_buf, M_ENTROPY); - - return (error); -} - -int -random_adaptor_read_rate(void) -{ - int ret; - - mtx_lock(&random_read_rate_mtx); - - ret = random_adaptor_read_rate_cache; - random_adaptor_read_rate_cache = 1; - - mtx_unlock(&random_read_rate_mtx); - - return (ret); -} - -/* ARGSUSED */ -int -random_adaptor_write(struct cdev *dev __unused, struct uio *uio, int flags __unused) -{ - int c, error = 0; - void *random_buf; - ssize_t nbytes; - -#ifdef RANDOM_DEBUG - printf("random: %s %zd\n", __func__, uio->uio_resid); -#endif - - random_buf = malloc(PAGE_SIZE, M_ENTROPY, M_WAITOK); - - sx_slock(&random_adaptors_lock); - - KASSERT(random_adaptor != NULL, ("No active random adaptor in %s", __func__)); - - nbytes = uio->uio_resid; - while (uio->uio_resid > 0 && error == 0) { - c = MIN(uio->uio_resid, PAGE_SIZE); - error = uiomove(random_buf, c, uio); - if (error) - break; - (random_adaptor->ra_write)(random_buf, c); - - /* Introduce an annoying delay to stop swamping */ - error = sx_sleep(&random_adaptor, &random_adaptors_lock, - PUSER | PCATCH, "randwr", hz/10); - KASSERT(random_adaptor != NULL, ("No active random adaptor in %s", - __func__)); - } - - sx_sunlock(&random_adaptors_lock); - - if (nbytes != uio->uio_resid && (error == ERESTART || - error == EINTR) ) - error = 0; /* Partial write, not error. */ - - free(random_buf, M_ENTROPY); - - return (error); -} - -/* ARGSUSED */ -int -random_adaptor_poll(struct cdev *dev __unused, int events, struct thread *td __unused) -{ - -#ifdef RANDOM_DEBUG - printf("random: %s\n", __func__); -#endif - - sx_slock(&random_adaptors_lock); - - KASSERT(random_adaptor != NULL, ("No active random adaptor in %s", __func__)); - - if (events & (POLLIN | POLLRDNORM)) { - if (random_adaptor->ra_seeded()) - events &= (POLLIN | POLLRDNORM); - else - selrecord(td, &rsel); - } - - sx_sunlock(&random_adaptors_lock); - - return (events); -} - -/* This will be called by the entropy processor when it seeds itself and becomes secure */ -void -random_adaptor_unblock(void) -{ - - selwakeuppri(&rsel, PUSER); - wakeup(&random_adaptor); - printf("random: unblocking device.\n"); - - /* Do arc4random(9) a favour while we are about it. */ - (void)atomic_cmpset_int(&arc4rand_iniseed_state, ARC4_ENTR_NONE, ARC4_ENTR_HAVE); -} - -static int -random_sysctl_adaptors_handler(SYSCTL_HANDLER_ARGS) -{ - struct random_adaptors *rra; - struct sbuf sbuf; - int error, count; - - sx_slock(&random_adaptors_lock); - sbuf_new_for_sysctl(&sbuf, NULL, 64, req); - count = 0; - LIST_FOREACH(rra, &random_adaptors_list, rra_entries) - sbuf_printf(&sbuf, "%s%s(%d)", - (count++ ? "," : ""), rra->rra_name, rra->rra_ra->ra_priority); - - error = sbuf_finish(&sbuf); - sbuf_delete(&sbuf); - sx_sunlock(&random_adaptors_lock); - - return (error); -} - -static int -random_sysctl_active_adaptor_handler(SYSCTL_HANDLER_ARGS) -{ - struct random_adaptors *rra; - struct sbuf sbuf; - int error; - - sx_slock(&random_adaptors_lock); - KASSERT(random_adaptor != NULL, ("No active random adaptor in %s", __func__)); - - sbuf_new_for_sysctl(&sbuf, NULL, 16, req); - LIST_FOREACH(rra, &random_adaptors_list, rra_entries) - if (rra->rra_ra == random_adaptor) { - sbuf_cat(&sbuf, rra->rra_name); - break; - } - error = sbuf_finish(&sbuf); - sbuf_delete(&sbuf); - sx_sunlock(&random_adaptors_lock); - - return (error); -} - -void -random_adaptors_init(void) -{ - -#ifdef RANDOM_DEBUG - printf("random: %s\n", __func__); -#endif - - SYSCTL_PROC(_kern_random, OID_AUTO, adaptors, - CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, - NULL, 0, random_sysctl_adaptors_handler, "A", - "Random Number Generator adaptors"); - - SYSCTL_PROC(_kern_random, OID_AUTO, active_adaptor, - CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, - NULL, 0, random_sysctl_active_adaptor_handler, "A", - "Active Random Number Generator Adaptor"); - - sx_init(&random_adaptors_lock, "random_adaptors"); - - mtx_init(&random_read_rate_mtx, "read rate mutex", NULL, MTX_DEF); - - /* The dummy adaptor is not a module by itself, but part of the - * randomdev module. - */ - random_adaptor_register("dummy", &randomdev_dummy); - - live_entropy_sources_init(); -} - -void -random_adaptors_deinit(void) -{ - -#ifdef RANDOM_DEBUG - printf("random: %s\n", __func__); -#endif - - live_entropy_sources_deinit(); - - /* Don't do this! Panic will surely follow! */ - /* random_adaptor_deregister("dummy"); */ - - mtx_destroy(&random_read_rate_mtx); - - sx_destroy(&random_adaptors_lock); -} - -/* - * Reseed the active adaptor shortly before starting init(8). - */ -/* ARGSUSED */ -static void -random_adaptors_seed(void *unused __unused) -{ - - sx_slock(&random_adaptors_lock); - KASSERT(random_adaptor != NULL, ("No active random adaptor in %s", __func__)); - - random_adaptor->ra_reseed(); - sx_sunlock(&random_adaptors_lock); - - arc4rand(NULL, 0, 1); -} -SYSINIT(random_seed, SI_SUB_KTHREAD_INIT, SI_ORDER_FIRST, - random_adaptors_seed, NULL); |
