Enhancement to NetBSD /etc/rc.d/entropy

entropy.diff

diff -r 093934994b6c etc/rc.d/entropy
--- a/etc/rc.d/entropy	Wed Feb 08 18:28:10 2023 +0000
+++ b/etc/rc.d/entropy	Fri Mar 03 08:39:40 2023 +1300
@@ -16,7 +16,11 @@
 entropy_start()
 {
 	case ${entropy-} in
-	'')	;;
+	'')	if [ $(sysctl -n kern.entropy.needed) -gt 0 ]
+		then
+			err 1 "not enough entropy available, see entropy(7)"
+		fi
+		;;
 	check)	echo -n "Checking for entropy..."
 		# dd will print an error message `Resource temporarily
 		# unavailable' to stderr, which is a little annoying,
diff -r 093934994b6c share/man/man7/entropy.7
--- a/share/man/man7/entropy.7	Wed Feb 08 18:28:10 2023 +0000
+++ b/share/man/man7/entropy.7	Fri Mar 03 08:39:40 2023 +1300
@@ -135,6 +135,16 @@
 .Nx
 will wait for entropy before booting to multiuser (with the caveat that
 it may cause boot to hang forever).
+.It
+If
+.Sq Li entropy
+is not set in
+.Xr rc.conf 5
+and the system doesn't have enough entropy, then
+.Pa /etc/rc.d/entropy
+will exit with an error message on the console and in
+.Pa /var/run/rc.log
+without interrupting multiuser boot.
 .El
 .Pp
 Since it is difficult to confidently model the unpredictability of most