From 7a42c5f5a4939470a5ea94ed89954c94e0ca2e4d Mon Sep 17 00:00:00 2001
From: Neil Horman <nhorman@tuxdriver.com>
Date: Fri, 27 Oct 2017 15:23:50 -0400
Subject: [PATCH] Resolves: bz 1490632

---
 check-rng-entropy             | 10 ++++++++++
 entropy-check.service         | 17 +++++++++++++++++
 rng-tools.spec                | 13 +++++++++++--
 rngd-exit-code-for-list.patch | 21 +++++++++++++++++++++
 rngd.service                  |  1 -
 5 files changed, 59 insertions(+), 3 deletions(-)
 create mode 100755 check-rng-entropy
 create mode 100644 entropy-check.service
 create mode 100644 rngd-exit-code-for-list.patch

diff --git a/check-rng-entropy b/check-rng-entropy
new file mode 100755
index 0000000..3c29b8b
--- /dev/null
+++ b/check-rng-entropy
@@ -0,0 +1,10 @@
+#!/bin/sh
+rngd --list > /dev/null 2>&1
+
+if [ $? -eq 0 ]
+then
+	systemctl enable rngd.service
+	systemctl start rngd.service
+fi
+
+exit 0
diff --git a/entropy-check.service b/entropy-check.service
new file mode 100644
index 0000000..0d38976
--- /dev/null
+++ b/entropy-check.service
@@ -0,0 +1,17 @@
+[Unit]
+Description=Checker to look for entropy sources and enable rngd
+DefaultDependencies=no
+Conflicts=shutdown.target
+After=systemd-remount-fs.service
+Before=systemd-sysusers.service sysinit.target shutdown.target
+ConditionFirstBoot=yes
+
+[Service]
+Type=oneshot
+ExecStart=/usr/bin/check-rng-entropy
+StandardOutput=null
+StandardError=null
+
+[Install]
+WantedBy=sysinit.target
+
diff --git a/rng-tools.spec b/rng-tools.spec
index 52d25ee..8542fe5 100644
--- a/rng-tools.spec
+++ b/rng-tools.spec
@@ -4,12 +4,14 @@
 Summary:        Random number generator related utilities
 Name:           rng-tools
 Version:        6.1
-Release:        1%{?dist}
+Release:        2%{?dist}
 Group:          System Environment/Base
 License:        GPLv2+
 URL:            https://github.com/nhorman/rng-tools
 Source0:        https://github.com/nhorman/rng-tools/archive/rng-tools-%{version}.tar.gz
 Source1:        rngd.service
+Source2:	check-rng-entropy
+Source3:	entropy-check.service
 
 # https://sourceforge.net/p/gkernel/patches/111/
 
@@ -42,15 +44,19 @@ Hardware random number generation tools.
 
 # install systemd unit file
 install -Dt %{buildroot}%{_unitdir} -m0644 %{SOURCE1}
-
+install -Dt %{buildroot}%{_unitdir} -m0644 %{SOURCE2}
+install -Dt %{buildroot}%{_bindir} -m0755 %{SOURCE3}
 %post
 %systemd_post rngd.service
+%systemd_post entropy-check.service
 
 %preun
 %systemd_preun rngd.service
+%systemd_preun entropy-check.service
 
 %postun
 %systemd_postun_with_restart rngd.service
+%systemd_postun_with_restart entropy-check.service
 
 %files
 %{!?_licensedir:%global license %%doc}
@@ -63,6 +69,9 @@ install -Dt %{buildroot}%{_unitdir} -m0644 %{SOURCE1}
 %attr(0644,root,root)   %{_unitdir}/rngd.service
 
 %changelog
+* Fri Oct 26 2017 Neil Horman <nhorman@redhat.com> - 6.1-2
+- Conditionally enable rngd on entropy src availability (bz 1490632)
+
 * Tue Oct 10 2017 Neil Horman <nhorman@redhat.com> - 6.1-1
 - update to latest upstream
 
diff --git a/rngd-exit-code-for-list.patch b/rngd-exit-code-for-list.patch
new file mode 100644
index 0000000..a79ec91
--- /dev/null
+++ b/rngd-exit-code-for-list.patch
@@ -0,0 +1,21 @@
+diff -up ./rngd.c.orig ./rngd.c
+--- ./rngd.c.orig	2017-10-27 14:18:52.617286574 -0400
++++ ./rngd.c	2017-10-27 14:19:34.189456107 -0400
+@@ -423,12 +423,15 @@ int main(int argc, char **argv)
+ 	}
+ 
+ 	if (arguments->list) {
++		int rc = 1;
+ 		msg_squash = false;
+ 		printf("Available entropy sources:\n");
+ 		for (i=0; i < ENT_MAX; i++) 
+-			if (entropy_sources[i].init && entropy_sources[i].disabled == false)
++			if (entropy_sources[i].init && entropy_sources[i].disabled == false) {
++				rc = 0;
+ 				printf("%d: %s\n", i, entropy_sources[i].rng_name);
+-		return 1;
++			}
++		return rc;
+ 	}
+ 
+ 	if (!ent_sources) {
diff --git a/rngd.service b/rngd.service
index 33829f6..3d9dcb5 100644
--- a/rngd.service
+++ b/rngd.service
@@ -3,7 +3,6 @@ Description=Hardware RNG Entropy Gatherer Daemon
 
 [Service]
 ExecStart=/sbin/rngd -f
-SuccessExitStatus=66
 
 [Install]
 WantedBy=multi-user.target