classes-dbus: Create a default dbus config file

Create a default dbus configuration file when one doesn't exist in
${FILESPATH}.

The default configuration allows the configured user to own the
service name and allows send_destination="*".

Change-Id: If309d2aed02f6326201ce156be3133f05c720b9c
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-phosphor/classes/obmc-phosphor-dbus-service.bbclass b/meta-phosphor/classes/obmc-phosphor-dbus-service.bbclass
index 3277cdb..e7f6340 100644
--- a/meta-phosphor/classes/obmc-phosphor-dbus-service.bbclass
+++ b/meta-phosphor/classes/obmc-phosphor-dbus-service.bbclass
@@ -4,9 +4,12 @@
 #    The list of packages to which files should be added.
 #
 #  DBUS_SERVICE_${PN} += "org.openbmc.Foo"
-#    A list of dbus service names.  The class will look for a dbus
-#    configuration file with the same name with .conf appended.
-#
+#    A list of dbus service names.  The class will look for a
+#    dbus configuration file with the same name with .conf
+#    appended.  If one is found, it is added to the package
+#    and used verbatim.  If it is not found, a default one
+#    (with very open permissions) is generated and used.
+
 inherit dbus-dir
 inherit obmc-phosphor-utils
 
@@ -14,16 +17,42 @@
 DBUS_PACKAGES ?= "${PN}"
 
 _INSTALL_DBUS_CONFIGS=""
+_DEFAULT_DBUS_CONFIGS=""
+
+
+python dbus_do_postinst() {
+    def make_default_dbus_config(d, service):
+        path = d.getVar('D', True)
+        path += d.getVar('dbus_system_confdir', True)
+        with open('%s/%s.conf' % (path, service), 'w+') as fd:
+            fd.write('<!DOCTYPE busconfig PUBLIC "-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"\n')
+            fd.write('        "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">\n')
+            fd.write('<busconfig>\n')
+            fd.write('        <policy user="root">\n')
+            fd.write('                <allow own="%s"/>\n' % service)
+            fd.write('                <allow send_destination="%s"/>\n' % service)
+            fd.write('        </policy>\n')
+            fd.write('</busconfig>\n')
+            fd.close()
+
+
+    for service in listvar_to_list(d, '_DEFAULT_DBUS_CONFIGS'):
+        make_default_dbus_config(d, service)
+}
 
 
 python() {
     searchpaths = d.getVar('FILESPATH', True)
 
     def add_dbus_config(d, service, pkg):
-        set_append(d, 'SRC_URI', 'file://%s.conf' % service)
+        path = bb.utils.which(searchpaths, '%s.conf' % service)
+        if not os.path.isfile(path):
+            set_append(d, '_DEFAULT_DBUS_CONFIGS', service)
+        else:
+            set_append(d, 'SRC_URI', 'file://%s.conf' % service)
+            set_append(d, '_INSTALL_DBUS_CONFIGS', '%s.conf' % service)
         set_append(d, 'FILES_%s' % pkg, '%s%s.conf' \
             % (d.getVar('dbus_system_confdir', True), service))
-        set_append(d, '_INSTALL_DBUS_CONFIGS', '%s.conf' % service)
 
 
     for pkg in listvar_to_list(d, 'DBUS_PACKAGES'):
@@ -36,10 +65,13 @@
 
 do_install_append() {
         # install the dbus configuration files
-        [ -z "${_INSTALL_DBUS_CONFIGS}" ] || \
+        [ -z "${_INSTALL_DBUS_CONFIGS}" ] && \
+                [ -z "${_DEFAULT_DBUS_CONFIGS}" ] || \
                 install -d ${D}${dbus_system_confdir}
         for c in ${_INSTALL_DBUS_CONFIGS}; do
                 install -m 0644 ${WORKDIR}/$c \
                         ${D}${dbus_system_confdir}$c
         done
 }
+
+do_install[postfuncs] += "dbus_do_postinst"