UBUNTU: [Packaging] wireguard -- add support for building signed .ko

BugLink: https://bugs.launchpad.net/bugs/1861284

Add support for building, signing, and shipping the wireguard.ko from
the wireguard-dkms package.  Drop this into the linux-modules package.
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com
Signed-off-by: Ian May <ian.may@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

debian/dkms-versions

+wireguard-linux-compat 0

debian/rules

@@ -43,6 +43,7 @@ ifneq ($(DEB_HOST_ARCH),$(DEB_BUILD_ARCH))
 	do_tools=false
 	disable_d_i=true
 	do_zfs=false
+	do_dkms_wireguard=false
 endif
 
 # Are any of the kernel signing options enabled.
@@ -74,6 +75,7 @@ ifeq ($(do_mainline_build),true)
 	do_tools=false
 	no_dumpfile=1
 	do_zfs=false
+	do_dkms_wireguard=false
 	skipabi=true
 	skipmodule=true
 	skipretpoline=true
@@ -101,6 +103,9 @@ flavours := $(firstword $(flavours))
 disable_d_i=true
 endif
 
+# Versions of dkms packages.
+dkms_wireguard_version=$(shell gawk '/^wireguard-linux-compat / { print $$2; }' debian/dkms-versions)
+
 # Debian Build System targets
 binary: binary-indep binary-arch
 

debian/rules.d/2-binary-arch.mk

@@ -428,6 +428,8 @@ endif
 	install -d $(dkms_dir) $(dkms_dir)/headers $(dkms_dir)/build $(dkms_dir)/source
 	cp -rp "$(hdrdir)" "$(indep_hdrdir)" "$(dkms_dir)/headers"
 
+	$(if $(filter true,$(do_dkms_wireguard)),$(call build_dkms, $(mods_pkg_name)-$*, $(pkgdir)/lib/modules/$(abi_release)-$*/kernel, wireguard, pool/universe/w/wireguard-linux-compat/wireguard-dkms_$(dkms_wireguard_version)_all.deb))
+
 	# Build the final ABI information.
 	install -d $(abidir)
 	sed -e 's/^\(.\+\)[[:space:]]\+\(.\+\)[[:space:]]\(.\+\)$$/\3 \2 \1/'	\