freebsd-nq/sys/dev/random/random_adaptors.h
David E. O'Brien 5711939b63 * Add random_adaptors.[ch] which is basically a store of random_adaptor's.
random_adaptor is basically an adapter that plugs in to random(4).
  random_adaptor can only be plugged in to random(4) very early in bootup.
  Unplugging random_adaptor from random(4) is not supported, and is probably a
  bad idea anyway, due to potential loss of entropy pools.
  We currently have 3 random_adaptors:
  + yarrow
  + rdrand (ivy.c)
  + nehemeiah

* Remove platform dependent logic from probe.c, and move it into
  corresponding registration routines of each random_adaptor provider.
  probe.c doesn't do anything other than picking a specific random_adaptor
  from a list of registered ones.

* If the kernel doesn't have any random_adaptor adapters present then the
  creation of /dev/random is postponed until next random_adaptor is kldload'ed.

* Fix randomdev_soft.c to refer to its own random_adaptor, instead of a
  system wide one.

Submitted by: arthurmesh@gmail.com, obrien
Obtained from: Juniper Networks
Reviewed by: so (des)
2013-08-09 15:31:50 +00:00

67 lines
2.5 KiB
C

/*-
* Copyright (c) 2013 Arthur Mesh <arthurmesh@gmail.com>
* 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.
*
* $FreeBSD$
*/
#ifndef __RANDOM_ADAPTORS_H__
#define __RANDOM_ADAPTORS_H__
#include <sys/eventhandler.h>
struct random_adaptors {
LIST_ENTRY(random_adaptors) entries; /* list of providers */
const char *name; /* name of random adaptor */
struct random_adaptor *rsp;
};
struct random_adaptor *random_adaptor_get(const char *);
int random_adaptor_register(const char *, struct random_adaptor *);
/*
* random_adaptor's should be registered prior to
* random module (SI_SUB_DRIVERS/SI_ORDER_MIDDLE)
*/
#define RANDOM_ADAPTOR_MODULE(name, modevent, ver) \
static moduledata_t name##_mod = { \
#name, \
modevent, \
0 \
}; \
DECLARE_MODULE(name, name##_mod, SI_SUB_DRIVERS, \
SI_ORDER_SECOND); \
MODULE_VERSION(name, ver); \
MODULE_DEPEND(name, random, 1, 1, 1);
typedef void (*random_adaptor_attach_hook)(void *, struct random_adaptor *);
EVENTHANDLER_DECLARE(random_adaptor_attach, random_adaptor_attach_hook);
/* kern.random sysctls */
#ifdef SYSCTL_DECL /* from sysctl.h */
SYSCTL_DECL(_kern_random);
#endif /* SYSCTL_DECL */
#endif /* __RANDOM_ADAPTORS_H__ */