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, 66 insertions, 20 deletions

diff --git a/sys/dev/random/randomdev.h b/sys/dev/random/randomdev.h
index 4ca88ff..0af741f 100644
--- a/sys/dev/random/randomdev.h
+++ b/sys/dev/random/randomdev.h
@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 2000-2013 Mark R V Murray
+ * Copyright (c) 2000-2015 Mark R V Murray
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -27,41 +27,87 @@
  */
 
 #ifndef SYS_DEV_RANDOM_RANDOMDEV_H_INCLUDED
-#define SYS_DEV_RANDOM_RANDOMDEV_H_INCLUDED
+#define	SYS_DEV_RANDOM_RANDOMDEV_H_INCLUDED
 
 /* This header contains only those definitions that are global
  * and non algorithm-specific for the entropy processor
  */
 
-typedef void random_init_func_t(void);
-typedef void random_deinit_func_t(void);
-
-void randomdev_init_harvester(void (*)(const void *, u_int, u_int, enum random_entropy_source));
-void randomdev_init_reader(void (*)(uint8_t *, u_int));
-void randomdev_deinit_harvester(void);
-void randomdev_deinit_reader(void);
-
-/* Stub/fake routines for when no entropy processor is loaded */
-extern void dummy_random_read_phony(uint8_t *, u_int);
-
-/* kern.random sysctls */
 #ifdef SYSCTL_DECL	/* from sysctl.h */
 SYSCTL_DECL(_kern_random);
 
-/* If this was C++, the macro below would be a template */
-#define RANDOM_CHECK_UINT(name, min, max)				\
+#define	RANDOM_CHECK_UINT(name, min, max)				\
 static int								\
 random_check_uint_##name(SYSCTL_HANDLER_ARGS)				\
 {									\
 	if (oidp->oid_arg1 != NULL) {					\
-		 if (*(u_int *)(oidp->oid_arg1) <= (min))		\
+		if (*(u_int *)(oidp->oid_arg1) <= (min))		\
 			*(u_int *)(oidp->oid_arg1) = (min);		\
-		 else if (*(u_int *)(oidp->oid_arg1) > (max))		\
+		else if (*(u_int *)(oidp->oid_arg1) > (max))		\
 			*(u_int *)(oidp->oid_arg1) = (max);		\
 	}								\
-        return (sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2,	\
+	return (sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2,	\
 		req));							\
 }
 #endif /* SYSCTL_DECL */
 
-#endif
+MALLOC_DECLARE(M_ENTROPY);
+
+#define	RANDOM_ALG_READ_RATE_MINIMUM	32
+
+struct harvest_event;
+
+typedef void random_alg_pre_read_t(void);
+typedef void random_alg_read_t(uint8_t *, u_int);
+typedef void random_alg_post_read_t(void);
+typedef void random_alg_write_t(uint8_t *, u_int);
+typedef int random_alg_seeded_t(void);
+typedef void random_alg_reseed_t(void);
+typedef void random_alg_eventprocessor_t(struct harvest_event *);
+
+typedef u_int random_source_read_t(void *, u_int);
+
+/*
+ * Random Algorithm is a processor of randomness for the kernel
+ * and for userland.
+ */
+struct random_algorithm {
+	const char			*ra_ident;
+	u_int				 ra_poolcount;
+	random_alg_pre_read_t		*ra_pre_read;
+	random_alg_read_t		*ra_read;
+	random_alg_post_read_t		*ra_post_read;
+	random_alg_write_t		*ra_write;
+	random_alg_reseed_t		*ra_reseed;
+	random_alg_seeded_t		*ra_seeded;
+	random_alg_eventprocessor_t	*ra_event_processor;
+};
+
+extern struct random_algorithm random_alg_context;
+
+/*
+ * Random Source is a source of entropy that can provide
+ * specified or approximate amount of entropy immediately
+ * upon request.
+ */
+struct random_source {
+	const char				*rs_ident;
+	enum random_entropy_source		 rs_source;
+	random_source_read_t			*rs_read;
+};
+
+#if !defined(RANDOM_DUMMY)
+struct random_sources {
+	LIST_ENTRY(random_sources)		 rrs_entries;
+	struct random_source			*rrs_source;
+};
+#endif /* !defined(RANDOM_DUMMY) */
+
+void random_source_register(struct random_source *);
+void random_source_deregister(struct random_source *);
+
+void random_sources_feed(void);
+
+void randomdev_unblock(void);
+
+#endif /* SYS_DEV_RANDOM_RANDOMDEV_H_INCLUDED */