fedora: Refresh SELinux labels in scriptlets, require -selinux package

Instead of:
  https://fedoraproject.org/wiki/SELinux_Policy_Modules_Packaging_Draft

follow this:
  https://fedoraproject.org/wiki/PackagingDrafts/SELinux_Independent_Policy

which seems to make more sense and fixes the issue that, on a fresh
install, without a reboot, the file contexts for the binaries are not
actually updated.

In detail:

- labels are refreshed using the selinux_relabel_pre and
  selinux_relabel_post on install, upgrade, and uninstall

- use the selinux_modules_install and selinux_modules_uninstall
  macros, instead of calling 'semodule' directly (no functional
  changes in our case)

- require the -selinux package on SELinux-enabled environments and if
  the current system policy is "targeted"

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

contrib/fedora/passt.spec

@@ -8,6 +8,7 @@
 # Author: Stefano Brivio <sbrivio@redhat.com>
 
 %global git_hash {{{ git_head }}}
+%global selinuxtype targeted
 
 Name:		passt
 Version:	{{{ git_version }}}
@@ -19,6 +20,7 @@ URL:		https://passt.top/
 Source:		https://passt.top/passt/snapshot/passt-%{git_hash}.tar.xz
 
 BuildRequires:	gcc, make, checkpolicy, selinux-policy-devel
+Requires:	(%{name}-selinux = %{version}-%{release} if selinux-policy-%{selinuxtype})
 
 %description
 passt implements a translation layer between a Layer-2 network interface and
@@ -66,13 +68,21 @@ install -p -m 644 -D pasta.pp %{buildroot}%{_datadir}/selinux/packages/%{name}/p
 install -p -m 644 -D pasta.if %{buildroot}%{_datadir}/selinux/devel/include/contrib/pasta.if
 popd
 
-%post selinux
-semodule -i %{_datadir}/selinux/packages/%{name}/passt.pp 2>/dev/null || :
-semodule -i %{_datadir}/selinux/packages/%{name}/pasta.pp 2>/dev/null || :
+%pre selinux
+%selinux_relabel_pre -s %{selinuxtype}
 
-%preun selinux
-semodule -r passt 2>/dev/null || :
-semodule -r pasta 2>/dev/null || :
+%post selinux
+%selinux_modules_install -s %{selinuxtype} %{_datadir}/selinux/packages/%{name}/passt.pp
+%selinux_modules_install -s %{selinuxtype} %{_datadir}/selinux/packages/%{name}/pasta.pp
+
+%postun selinux
+if [ $1 -eq 0 ]; then
+	%selinux_modules_uninstall -s %{selinuxtype} passt
+	%selinux_modules_uninstall -s %{selinuxtype} pasta
+fi
+
+%posttrans selinux
+%selinux_relabel_post -s %{selinuxtype}
 
 %files
 %license LICENSES/{AGPL-3.0-or-later.txt,BSD-3-Clause.txt}