libfido2-initial: new recipe

Use this recipe to break a circular dependency between libfido2 and
systemd when systemd's fido PACKAGECONFIG is enabled. systemd depends
on libfido2, and libfido2 depends on udev provided by systemd. However,
systemd only depends on the headers provided by libfido2 and its pkgconf
data. systemd uses only the datatypes provided, and opportunistically
enables fido support if libfido2 is found.

This recipe provides only the headers and pkgconf data. This is
sufficient to allow systemd to build support for libfido2.

It only works with a related change I've submitted to openembedded core.

Signed-off-by: Dan McGregor <danmcgr@protonmail.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-support/libfido2/libfido2-initial_1.16.0.bb

@@ -0,0 +1,40 @@
+SUMMARY = "FIDO 2.0 support library"
+DESCRIPTION = "libfido2 provides library functionality and command-line tools to \
+communicate with a FIDO device over USB, and to verify attestation and \
+assertion signatures."
+HOMEPAGE = "https://developers.yubico.com/libfido2"
+LICENSE = "BSD-2-Clause"
+SECTION = "libs/network"
+
+LIC_FILES_CHKSUM = "file://LICENSE;md5=20be19aaa222f71738712b26f7f8717b"
+
+SRC_URI = "https://developers.yubico.com/${BPN}/Releases/${BPN}-${PV}.tar.gz"
+SRC_URI[sha256sum] = "8c2b6fb279b5b42e9ac92ade71832e485852647b53607c43baaafbbcecea04e4"
+
+inherit nopackages
+
+PACKAGES = ""
+
+# The purpose of this recipe is to break a circular dependency between libfido2 and
+# systemd. libfido2 depends on udev (provided by systemd) to build, while systemd
+# depends on libfido2 if the fido feature is enabled. However, systemd doesn't
+# actually link against libfido2. It only needs the headers in place and a dummy
+# shared library. It opportunistically dlopens libfido2 if it's present, but
+# for that to work it needs the headers in place.
+# Just fake enough to make systemd happy, and have it RRECOMMEND the real libfido2.
+do_install() {
+    mkdir -p ${D}${includedir}/libfido2-initial/fido
+    mkdir -p ${D}${datadir}/pkgconfig
+
+    install -m 644 ${S}/src/fido.h ${D}${includedir}/libfido2-initial
+    install -m 644 ${S}/src/fido/* ${D}${includedir}/libfido2-initial/fido/
+
+    # Real libfido2 installs its pkg conf file in ${libdir}.
+    sed -e 's,@CMAKE_INSTALL_PREFIX@,${exec_prefix},' \
+        -e 's,@CMAKE_INSTALL_LIBDIR@,${baselib}/libfido2-initial,' \
+        -e 's,@FIDO_VERSION@,${PV},' \
+        -e 's,@PROJECT_NAME@,${BPN},' \
+        -e '/^Cflags/s,$,/libfido2-initial,' \
+        ${S}/src/libfido2.pc.in > ${D}${datadir}/pkgconfig/libfido2.pc
+
+}