Do a factory reset when there's no policy.kern file in a store

With rpm-ostree, /var/ directory doesn't contain any file, just
directories. It means that SELinux policy can't be managed or rebuilt
and users have to use only the default policy.

This update adds /usr/share/selinux/POLICYTYPE/default directory and
selinux-factory-reset service.

/var/lib/selinux/POLICYTYPE/active

selinux-reset-policy

selinux-factory-reset

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+if [ ! -f /etc/selinux/config ]; then
+    SELINUXTYPE=none
+else
+    source /etc/selinux/config
+fi
+
+cp -R --preserve=mode,ownership,timestamps,links /usr/share/selinux/$1/default/* /var/lib/selinux/$1
+
+if selinuxenabled; then
+    semodule -B -n
+
+    if [ "$1" = "$SELINUXTYPE" ]; then
+        reboot
+    fi
+fi

selinux-factory-reset@.service

@@ -0,0 +1,17 @@
+[Unit]
+Description=Reset SELinux policy to factory default
+DefaultDependencies=no
+Requires=local-fs.target
+Conflicts=shutdown.target
+After=local-fs.target
+Before=sysinit.target shutdown.target
+ConditionSecurity=selinux
+ConditionKernelCommandLine=|selinux-factory-reset
+ConditionPathExists=|!/var/lib/selinux/%I/active/policy.kern
+
+[Service]
+ExecStart=/usr/libexec/selinux/selinux-factory-reset %I
+Type=oneshot
+TimeoutSec=0
+RemainAfterExit=yes
+StandardInput=tty

selinux-policy.spec

@@ -56,6 +56,12 @@ Source29: serefpolicy-contrib-%{version}.tgz
 Source30: booleans.subs_dist
 
 Source35: docker-selinux.tgz
+
+# Do a factory reset when there's no policy.kern file in a store
+# http://bugzilla.redhat.com/1290659
+Source100: selinux-factory-reset
+Source101: selinux-factory-reset@.service
+
 Url: http://github.com/TresysTechnology/refpolicy/wiki
 BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 BuildArch: noarch
@@ -253,6 +259,10 @@ rm -rf %{buildroot}%{_sysconfdir}/selinux/%1/modules/active/policy.kern \
 %{_sharedstatedir}/selinux/%1/active/seusers \
 %{_sharedstatedir}/selinux/%1/active/file_contexts \
 %{_sharedstatedir}/selinux/%1/active/policy.kern \
+%{_datadir}/selinux/%1 \
+%{_libexecdir}/selinux/selinux-factory-reset \
+%{_unitdir}/selinux-factory-reset@.service \
+%{_unitdir}/basic.target.wants/selinux-factory-reset@%1.service \
 %nil
 
 %define relabel() \
@@ -312,7 +322,18 @@ for i in $contrib_modules $base_modules; do \
     if [ $i != "sandbox" ];then \
         echo "%verify(not md5 size mtime) %{_sharedstatedir}/selinux/%1/active/modules/100/$i" >> %{buildroot}/%{_usr}/share/selinux/%1/nonbasemodules.lst \
     fi; \
-done
+done;
+
+%define installFactoryResetFiles() \
+mkdir -p %{buildroot}%{_datadir}/selinux/%1/default \
+cp -R --preserve=mode,ownership,timestamps,links %{buildroot}%{_sharedstatedir}/selinux/%1/active %{buildroot}%{_datadir}/selinux/%1/default/ \
+find %{buildroot}%{_datadir}/selinux/%1/default/ -name hll | xargs rm \
+find %{buildroot}%{_datadir}/selinux/%1/default/ -name lang_ext | xargs sed -i 's/pp/cil/' \
+mkdir -p %{buildroot}/%{_libexecdir}/selinux/ \
+install -p %{SOURCE100} %{buildroot}/%{_libexecdir}/selinux/ \
+mkdir   -m 755 -p %{buildroot}/%{_unitdir}/basic.target.wants/ \
+install -m 644 -p %{SOURCE101} %{buildroot}/%{_unitdir}/ \
+ln -s ../selinux-factory-reset@.service %{buildroot}/%{_unitdir}/basic.target.wants/selinux-factory-reset@%1.service
 
 %build
 
@@ -367,6 +388,7 @@ make UNK_PERMS=%4 NAME=%1 TYPE=%2 DISTRO=%{distro} UBAC=n DIRECT_INITRC=%3 MONOL
 mv sandbox.pp %{buildroot}/usr/share/selinux/packages/sandbox.pp
 %modulesList targeted
 %nonBaseModulesList targeted
+%installFactoryResetFiles targeted
 %endif
 
 %if %{BUILD_MINIMUM}
@@ -380,6 +402,7 @@ rm -f %{buildroot}/%{_sysconfdir}/selinux/minimum/modules/active/modules/sandbox
 rm -rf %{buildroot}%{_sharedstatedir}/selinux/minimum/active/modules/100/sandbox
 %modulesList minimum
 %nonBaseModulesList minimum
+%installFactoryResetFiles minimum
 %endif
 
 %if %{BUILD_MLS}
@@ -389,6 +412,7 @@ rm -rf %{buildroot}%{_sharedstatedir}/selinux/minimum/active/modules/100/sandbox
 %installCmds mls mls n deny
 %modulesList mls
 %nonBaseModulesList mls
+%installFactoryResetFiles mls
 %endif
 
 mkdir -p %{buildroot}%{_mandir}