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, 17 insertions, 5 deletions

diff --git a/sys/sys/random.h b/sys/sys/random.h
index 2714625..920d36b 100644
--- a/sys/sys/random.h
+++ b/sys/sys/random.h
@@ -31,7 +31,7 @@
 
 #ifdef _KERNEL
 
-int read_random(void *, int);
+u_int read_random(void *, u_int);
 
 /*
  * Note: if you add or remove members of random_entropy_source, remember to also update the
@@ -53,9 +53,10 @@ enum random_entropy_source {
 	RANDOM_NET_NG,
 	RANDOM_INTERRUPT,
 	RANDOM_SWI,
-	RANDOM_UMA_ALLOC,
-	RANDOM_ENVIRONMENTAL_END, /* This one is wasted */
-	/* High-quality HW RNGs from here on. */
+	RANDOM_FS_ATIME,
+	RANDOM_FAST,	/* Special!! Miscellaneous high performance stuff, like UMA/SLAB Allocator */
+	RANDOM_ENVIRONMENTAL_END = RANDOM_FAST,
+	/* Fast hardware random-number sources from here on. */
 	RANDOM_PURE_OCTEON,
 	RANDOM_PURE_SAFE,
 	RANDOM_PURE_GLXSB,
@@ -67,7 +68,18 @@ enum random_entropy_source {
 	RANDOM_PURE_VIRTIO,
 	ENTROPYSOURCE
 };
-void random_harvest(const void *, u_int, u_int, enum random_entropy_source);
+
+#define RANDOM_HARVEST_EVERYTHING_MASK ((1 << (RANDOM_ENVIRONMENTAL_END + 1)) - 1)
+
+#if defined(RANDOM_DUMMY)
+#define random_harvest_queue(a, b, c, d) do {} while (0)
+#define random_harvest_fast(a, b, c, d) do {} while (0)
+#define random_harvest_direct(a, b, c, d) do {} while (0)
+#else /* !defined(RANDOM_DUMMY) */
+void random_harvest_queue(const void *, u_int, u_int, enum random_entropy_source);
+void random_harvest_fast(const void *, u_int, u_int, enum random_entropy_source);
+void random_harvest_direct(const void *, u_int, u_int, enum random_entropy_source);
+#endif /* defined(RANDOM_DUMMY) */
 
 #endif /* _KERNEL */