Add DEV_RANDOM pseudo-option and use it to "include out" random(4)

if desired.

Retire randomdev_none.c and introduce random_infra.c for resident
infrastructure. Completely stub out random(4) calls in the "without
DEV_RANDOM" case.

Add RANDOM_LOADABLE option to allow loadable Yarrow/Fortuna/LocallyWritten
algorithm.  Add a skeleton "other" algorithm framework for folks
to add their own processing code. NIST, anyone?

Retire the RANDOM_DUMMY option.

Build modules for Yarrow, Fortuna and "other".

Use atomics for the live entropy rate-tracking.

Convert ints to bools for the 'seeded' logic.

Move _write() function from the algorithm-specific areas to randomdev.c

Get rid of reseed() function - it is unused.

Tidy up the opt_*.h includes.

Update documentation for random(4) modules.

Fix test program (reviewers, please leave this).

Differential Revision:    https://reviews.freebsd.org/D3354
Reviewed by:              wblock,delphij,jmg,bjk
Approved by:              so (/dev/random blanket)

1 files changed, 25 insertions, 6 deletions

diff --git a/sys/sys/random.h b/sys/sys/random.h
index 78a9955..92eb80f 100644
--- a/sys/sys/random.h
+++ b/sys/sys/random.h
@@ -33,10 +33,29 @@
 
 #include <sys/types.h>
 
+#include "opt_random.h"
+
+#if defined(RANDOM_LOADABLE) && defined(RANDOM_YARROW)
+#error "Cannot define both RANDOM_LOADABLE and RANDOM_YARROW"
+#endif
+
 struct uio;
 
+#if defined(DEV_RANDOM)
 u_int read_random(void *, u_int);
 int read_random_uio(struct uio *, bool);
+#else
+static __inline int
+read_random_uio(void *a __unused, u_int b __unused)
+{
+	return (0);
+}
+static __inline u_int
+read_random(void *a __unused, u_int b __unused)
+{
+	return (0);
+}
+#endif
 
 /*
  * Note: if you add or remove members of random_entropy_source, remember to also update the
@@ -76,15 +95,15 @@ 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) */
+#if defined(DEV_RANDOM)
 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) */
+#else
+#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)
+#endif
 
 #endif /* _KERNEL */