iptables: Split the iptables modules into separate packages

By splitting the iptables modules into separate packages it is
possible to pick and choose the modules to install and thereby reduce
the total size of the installed modules.

Backwards compatibility is maintained by adding a recommendation of
iptables-modules, which is a meta package that depends on all the
generated packages.

(From OE-Core rev: 2e99caca64704d1ec51f4f65048d945e5ff1384f)

Signed-off-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-extended/iptables/iptables_1.6.2.bb

@@ -7,17 +7,6 @@ LICENSE = "GPLv2+"
 LIC_FILES_CHKSUM = "file://COPYING;md5=b234ee4d69f5fce4486a80fdaf4a4263\
                     file://iptables/iptables.c;beginline=13;endline=25;md5=c5cffd09974558cf27d0f763df2a12dc"
 
-RRECOMMENDS_${PN} = "kernel-module-x-tables \
-                     kernel-module-ip-tables \
-                     kernel-module-iptable-filter \
-                     kernel-module-iptable-nat \
-                     kernel-module-nf-defrag-ipv4 \
-                     kernel-module-nf-conntrack \
-                     kernel-module-nf-conntrack-ipv4 \
-                     kernel-module-nf-nat \
-                     kernel-module-ipt-masquerade"
-FILES_${PN} =+ "${libdir}/xtables/ ${datadir}/xtables"
-
 SRC_URI = "http://netfilter.org/projects/iptables/files/iptables-${PV}.tar.bz2 \
            file://0001-configure-Add-option-to-enable-disable-libnfnetlink.patch \
            file://0002-configure.ac-only-check-conntrack-when-libnfnetlink-enabled.patch \
@@ -28,8 +17,8 @@ SRC_URI[sha256sum] = "55d02dfa46263343a401f297d44190f2a3e5113c8933946f094ed40237
 
 inherit autotools pkgconfig
 
-EXTRA_OECONF = "--with-kernel=${STAGING_INCDIR} \
-               "
+EXTRA_OECONF = "--with-kernel=${STAGING_INCDIR}"
+
 PACKAGECONFIG ?= "${@bb.utils.filter('DISTRO_FEATURES', 'ipv6', d)}"
 
 PACKAGECONFIG[ipv6] = "--enable-ipv6,--disable-ipv6,"
@@ -45,3 +34,31 @@ do_configure_prepend() {
 	# Keep ax_check_linker_flags.m4 which belongs to autoconf-archive.
 	rm -f libtool.m4 lt~obsolete.m4 ltoptions.m4 ltsugar.m4 ltversion.m4
 }
+
+PACKAGES += "${PN}-modules"
+PACKAGES_DYNAMIC += "^${PN}-module-.*"
+
+python populate_packages_prepend() {
+    modules = do_split_packages(d, '${libdir}/xtables', 'lib(.*)\.so$', '${PN}-module-%s', '${PN} module %s', extra_depends='')
+    if modules:
+        metapkg = d.getVar('PN') + '-modules'
+        d.appendVar('RDEPENDS_' + metapkg, ' ' + ' '.join(modules))
+}
+
+FILES_${PN} += "${datadir}/xtables"
+
+ALLOW_EMPTY_${PN}-modules = "1"
+
+RDEPENDS_${PN} = "${PN}-module-xt-standard"
+RRECOMMENDS_${PN} = " \
+    ${PN}-modules \
+    kernel-module-x-tables \
+    kernel-module-ip-tables \
+    kernel-module-iptable-filter \
+    kernel-module-iptable-nat \
+    kernel-module-nf-defrag-ipv4 \
+    kernel-module-nf-conntrack \
+    kernel-module-nf-conntrack-ipv4 \
+    kernel-module-nf-nat \
+    kernel-module-ipt-masquerade \
+"