Band-aid diskless booting by running a new preseedrandom script before

initdiskless.  The output of several commands and if available the
contents of /entropy are feed into /dev/random to kickstart the PRNG.
/etc/rc.d/initrandom is left alone to maintain the previous behavior as
much as possiable.

Further work in this area is probably needed.

Discussed with:	markm

3 files changed, 49 insertions, 0 deletions

diff --git a/etc/rc.d/initdiskless b/etc/rc.d/initdiskless
index b84dab9..47ab3ec 100644
--- a/etc/rc.d/initdiskless
+++ b/etc/rc.d/initdiskless
@@ -26,6 +26,7 @@
 #
 # $FreeBSD$
 #
+# REQUIRE: preseedrandom
 # PROVIDE: initdiskless
 # KEYWORD: FreeBSD nojail
 
diff --git a/etc/rc.d/preseedrandom b/etc/rc.d/preseedrandom
new file mode 100644
index 0000000..ecbfc3c
--- /dev/null
+++ b/etc/rc.d/preseedrandom
@@ -0,0 +1,47 @@
+#!/bin/sh
+#
+# $FreeBSD$
+#
+
+# PROVIDE: preseedrandom
+# KEYWORD: FreeBSD nojail
+
+feed_dev_random()
+{
+	if [ -f "${1}" -a -r "${1}" -a -s "${1}" ]; then
+		cat "${1}" | dd of=/dev/random bs=8k 2>/dev/null
+	fi
+}
+
+entropy_file="/entropy"
+
+soft_random_generator=`sysctl kern.random 2>/dev/null`
+
+if [ -n "${soft_random_generator}" ] ; then
+
+	echo -n 'Pre-seeding PRNG:'
+
+	# XXX temporary until we can improve the entropy
+	# harvesting rate.
+	# Entropy below is not great, but better than nothing.
+	# This unblocks the generator at startup
+	( ps -fauxww; sysctl -a; date; df -ib; dmesg; ps -fauxww; ) \
+	    | dd of=/dev/random bs=8k 2>/dev/null
+	cat /bin/ls | dd of=/dev/random bs=8k 2>/dev/null
+
+	# First pass at reseeding /dev/random.
+	#
+	case ${entropy_file} in
+	[Nn][Oo] | '')
+		;;
+	*)
+		if [ -w /dev/random ]; then
+			feed_dev_random "${entropy_file}"
+		fi
+		;;
+	esac
+
+	echo -n ' kickstart'
+
+	echo '.'
+fi
diff --git a/etc/rc.initdiskless b/etc/rc.initdiskless
index b84dab9..47ab3ec 100644
--- a/etc/rc.initdiskless
+++ b/etc/rc.initdiskless
@@ -26,6 +26,7 @@
 #
 # $FreeBSD$
 #
+# REQUIRE: preseedrandom
 # PROVIDE: initdiskless
 # KEYWORD: FreeBSD nojail