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, 26 insertions, 7 deletions

diff --git a/sys/dev/random/unit_test.h b/sys/dev/random/unit_test.h
index 9fc0931..648d294 100644
--- a/sys/dev/random/unit_test.h
+++ b/sys/dev/random/unit_test.h
@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 2013 Mark R V Murray
+ * Copyright (c) 2013-2015 Mark R V Murray
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -28,20 +28,39 @@
 
 
 #ifndef UNIT_TEST_H_INCLUDED
-#define UNIT_TEST_H_INCLUDED
+#define	UNIT_TEST_H_INCLUDED
+
+#ifdef _KERNEL
+#error "Random unit tests cannot be compiled into the kernel."
+#endif
 
 void random_adaptor_unblock(void);
 
+#if defined(clang) && __has_builtin(__builtin_readcyclecounter)
+#define	rdtsc __builtin_readcyclecounter
+#else /* !clang */
+#if defined(__amd64__) || defined(__i386__)
+static __inline uint64_t
+rdtsc(void)
+{
+	uint32_t low, high;
+
+	__asm __volatile("rdtsc" : "=a" (low), "=d" (high));
+	return (low | ((uint64_t)high << 32));
+}
+#else /* __amd64__ || __i386__ */
+#error "No rdtsc() implementation available."
+#endif /* __amd64__ || __i386__ */
+#endif /* !clang */
+
 static __inline uint64_t
 get_cyclecount(void)
 {
 
-	/* Shaddup! */
-	return (4ULL);
+	return (rdtsc());
 }
 
-// #define PAGE_SIZE	4096
-#define HARVESTSIZE	16
+#define	HARVESTSIZE	2
 
 enum random_entropy_source {
 	RANDOM_START = 0,
@@ -51,7 +70,7 @@ enum random_entropy_source {
 
 struct harvest_event {
 	uintmax_t			he_somecounter;		/* fast counter for clock jitter */
-	uint8_t				he_entropy[HARVESTSIZE];/* some harvested entropy */
+	uint32_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 */