Huge cleanup of random(4) code.

* GENERAL
- Update copyright.
- Make kernel options for RANDOM_YARROW and RANDOM_DUMMY. Set
  neither to ON, which means we want Fortuna
- If there is no 'device random' in the kernel, there will be NO
  random(4) device in the kernel, and the KERN_ARND sysctl will
  return nothing. With RANDOM_DUMMY there will be a random(4) that
  always blocks.
- Repair kern.arandom (KERN_ARND sysctl). The old version went
  through arc4random(9) and was a bit weird.
- Adjust arc4random stirring a bit - the existing code looks a little
  suspect.
- Fix the nasty pre- and post-read overloading by providing explictit
  functions to do these tasks.
- Redo read_random(9) so as to duplicate random(4)'s read internals.
  This makes it a first-class citizen rather than a hack.
- Move stuff out of locked regions when it does not need to be
  there.
- Trim RANDOM_DEBUG printfs. Some are excess to requirement, some
  behind boot verbose.
- Use SYSINIT to sequence the startup.
- Fix init/deinit sysctl stuff.
- Make relevant sysctls also tunables.
- Add different harvesting "styles" to allow for different requirements
  (direct, queue, fast).
- Add harvesting of FFS atime events. This needs to be checked for
  weighing down the FS code.
- Add harvesting of slab allocator events. This needs to be checked for
  weighing down the allocator code.
- Fix the random(9) manpage.
- Loadable modules are not present for now. These will be re-engineered
  when the dust settles.
- Use macros for locks.
- Fix comments.

* src/share/man/...
- Update the man pages.

* src/etc/...
- The startup/shutdown work is done in D2924.

* src/UPDATING
- Add UPDATING announcement.

* src/sys/dev/random/build.sh
- Add copyright.
- Add libz for unit tests.

* src/sys/dev/random/dummy.c
- Remove; no longer needed. Functionality incorporated into randomdev.*.

* live_entropy_sources.c live_entropy_sources.h
- Remove; content moved.
- move content to randomdev.[ch] and optimise.

* src/sys/dev/random/random_adaptors.c src/sys/dev/random/random_adaptors.h
- Remove; plugability is no longer used. Compile-time algorithm
  selection is the way to go.

* src/sys/dev/random/random_harvestq.c src/sys/dev/random/random_harvestq.h
- Add early (re)boot-time randomness caching.

* src/sys/dev/random/randomdev_soft.c src/sys/dev/random/randomdev_soft.h
- Remove; no longer needed.

* src/sys/dev/random/uint128.h
- Provide a fake uint128_t; if a real one ever arrived, we can use
  that instead. All that is needed here is N=0, N++, N==0, and some
  localised trickery is used to manufacture a 128-bit 0ULLL.

* src/sys/dev/random/unit_test.c src/sys/dev/random/unit_test.h
- Improve unit tests; previously the testing human needed clairvoyance;
  now the test will do a basic check of compressibility. Clairvoyant
  talent is still a good idea.
- This is still a long way off a proper unit test.

* src/sys/dev/random/fortuna.c src/sys/dev/random/fortuna.h
- Improve messy union to just uint128_t.
- Remove unneeded 'static struct fortuna_start_cache'.
- Tighten up up arithmetic.
- Provide a method to allow eternal junk to be introduced; harden
  it against blatant by compress/hashing.
- Assert that locks are held correctly.
- Fix the nasty pre- and post-read overloading by providing explictit
  functions to do these tasks.
- Turn into self-sufficient module (no longer requires randomdev_soft.[ch])

* src/sys/dev/random/yarrow.c src/sys/dev/random/yarrow.h
- Improve messy union to just uint128_t.
- Remove unneeded 'staic struct start_cache'.
- Tighten up up arithmetic.
- Provide a method to allow eternal junk to be introduced; harden
  it against blatant by compress/hashing.
- Assert that locks are held correctly.
- Fix the nasty pre- and post-read overloading by providing explictit
  functions to do these tasks.
- Turn into self-sufficient module (no longer requires randomdev_soft.[ch])
- Fix some magic numbers elsewhere used as FAST and SLOW.

Differential Revision: https://reviews.freebsd.org/D2025
Reviewed by: vsevolod,delphij,rwatson,trasz,jmg
Approved by: so (delphij)

1 files changed, 16 insertions, 34 deletions

diff --git a/sys/dev/random/random_harvestq.h b/sys/dev/random/random_harvestq.h
index ab09a3f..f1de86f 100644
--- a/sys/dev/random/random_harvestq.h
+++ b/sys/dev/random/random_harvestq.h
@@ -1,6 +1,5 @@
 /*-
- * Copyright (c) 2013-2014 Mark R V Murray
- * Copyright (c) 2013 Arthur Mesh <arthurmesh@gmail.com>
+ * Copyright (c) 2013-2015 Mark R V Murray
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -28,43 +27,26 @@
  */
 
 #ifndef SYS_DEV_RANDOM_RANDOM_HARVESTQ_H_INCLUDED
-#define SYS_DEV_RANDOM_RANDOM_HARVESTQ_H_INCLUDED
+#define	SYS_DEV_RANDOM_RANDOM_HARVESTQ_H_INCLUDED
 
-#define HARVESTSIZE	16	/* max size of each harvested entropy unit */
+#define	HARVESTSIZE	2	/* Max length in words of each harvested entropy unit */
 
 /* These are used to queue harvested packets of entropy. The entropy
  * buffer size is pretty arbitrary.
  */
 struct harvest_event {
-	uintmax_t			he_somecounter;		/* fast counter for clock jitter */
-	uint8_t				he_entropy[HARVESTSIZE];/* some harvested entropy */
-	u_int				he_size;		/* harvested entropy byte count */
-	u_int				he_bits;		/* stats about the entropy */
-	u_int				he_destination;		/* destination pool of this entropy */
-	enum random_entropy_source	he_source;		/* origin of the entropy */
-};
-
-void random_harvestq_init(void (*)(struct harvest_event *), int);
-void random_harvestq_deinit(void);
-void random_harvestq_internal(const void *, u_int, u_int, enum random_entropy_source);
-
-/* Pool count is used by anything needing to know how many entropy
- * pools are currently being maintained.
- * This is of use to (e.g.) the live source feed where we need to give
- * all the pools a top-up.
- */
-extern int harvest_pool_count;
-
-/* This is in randomdev.c as it needs to be permanently in the kernel */
-void randomdev_set_wakeup_exit(void *);
-
-/* Force all currently pending queue contents to clear, and kick the software processor */
-void random_harvestq_flush(void);
-
-/* Function called to process one harvested stochastic event */
-extern void (*harvest_process_event)(struct harvest_event *);
-
-/* Round-robin destination cache. */
-extern u_int harvest_destination[ENTROPYSOURCE];
+	uint32_t	he_somecounter;		/* fast counter for clock jitter */
+	uint32_t	he_entropy[HARVESTSIZE];/* some harvested entropy */
+	uint8_t		he_size;		/* harvested entropy byte count */
+	uint8_t		he_bits;		/* stats about the entropy */
+	uint8_t		he_destination;		/* destination pool of this entropy */
+	uint8_t		he_source;		/* origin of the entropy */
+} __packed;
+
+#define	RANDOM_HARVESTQ_BOOT_ENTROPY_FILE	"/boot/entropy"
+
+#define	RANDOM_HARVEST_INIT_LOCK(x)	mtx_init(&harvest_context.hc_mtx, "entropy harvest mutex", NULL, MTX_SPIN)
+#define	RANDOM_HARVEST_LOCK(x)		mtx_lock_spin(&harvest_context.hc_mtx)
+#define	RANDOM_HARVEST_UNLOCK(x)	mtx_unlock_spin(&harvest_context.hc_mtx)
 
 #endif /* SYS_DEV_RANDOM_RANDOM_HARVESTQ_H_INCLUDED */