Decouple yarrow from random(4) device.

* Make Yarrow an optional kernel component -- enabled by "YARROW_RNG" option.
  The files sha2.c, hash.c, randomdev_soft.c and yarrow.c comprise yarrow.

* random(4) device doesn't really depend on rijndael-*.  Yarrow, however, does.

* Add random_adaptors.[ch] which is basically a store of random_adaptor's.
  random_adaptor is basically an adapter that plugs in to random(4).
  random_adaptor can only be plugged in to random(4) very early in bootup.
  Unplugging random_adaptor from random(4) is not supported, and is probably a
  bad idea anyway, due to potential loss of entropy pools.
  We currently have 3 random_adaptors:
  + yarrow
  + rdrand (ivy.c)
  + nehemeiah

* Remove platform dependent logic from probe.c, and move it into
  corresponding registration routines of each random_adaptor provider.
  probe.c doesn't do anything other than picking a specific random_adaptor
  from a list of registered ones.

* If the kernel doesn't have any random_adaptor adapters present then the
  creation of /dev/random is postponed until next random_adaptor is kldload'ed.

* Fix randomdev_soft.c to refer to its own random_adaptor, instead of a
  system wide one.

Submitted by: arthurmesh@gmail.com, obrien
Obtained from: Juniper Networks
Reviewed by: obrien

2 files changed, 15 insertions, 4 deletions

diff --git a/tools/tools/sysdoc/sysdoc.sh b/tools/tools/sysdoc/sysdoc.sh
index c428174..b07c53d 100644
--- a/tools/tools/sysdoc/sysdoc.sh
+++ b/tools/tools/sysdoc/sysdoc.sh
@@ -88,7 +88,7 @@ EOF
 # tunables in our tunables.mdoc file and generate
 # the final 'inner circle' of our manual page.
 markup_create() {
-	sort  < _names |		\
+	sort -u  < _names |		\
 	xargs -n 1 /bin/sh ./sysctl.sh  \
 		> markup.file		\
 		2> tunables.TODO
@@ -238,9 +238,13 @@ if [ -z "$LOCATION" ] ;
     && for x in `find $LOCATION -name '*.kld'`  \
 	$LOCATION/kernel;			\
 	do nm $x |				\
-	grep ' sysctl___' | uniq |		\
-	sed 's/sysctl___//g' | sed 's/_/./g' |	\
-	awk {'print $3'} > _names;
+	sed -n '/sysctl___/ {
+		's/[\.a-z_]*sysctl___//g'
+		's/_/./g'
+		p
+	}' |					\
+	awk {'print $3'} |			\
+	sort -u > _names;
 	done;
 	markup_create
 	page_create
diff --git a/tools/tools/sysdoc/tunables.mdoc b/tools/tools/sysdoc/tunables.mdoc
index 8b426e6..4702ea3 100644
--- a/tools/tools/sysdoc/tunables.mdoc
+++ b/tools/tools/sysdoc/tunables.mdoc
@@ -1093,6 +1093,13 @@ line programs.
 kern.quantum
 
 ---
+kern.random.adaptors
+str
+
+Displays registered PRNG adaptors (sources).
+This is a read-only variable.
+
+---
 kern.random.sys.burst
 
 ---