Update storage code to allow plugins

Add naive plugin support to the storage code, it will
load plugins from $(libdir)/fprintd/modules, given the configuration
from /etc/fprintd.conf.

TODO

@@ -11,13 +11,6 @@ Enforce command sequences:
  etc
 
 
-- Make storage handling a GObject interface, would make plugging in new
-  backends easier, even handling plugins?
-- Make storage per-manager
-- Move storage setting to a configuration file
-- Kill FromStorage variants, we should always load/read from our custom storage
-
-- Handle the client disconnecting without releasing the device
 - Check whether we actually want claim to open the device, or allow
   some operations to not require claiming the device
 

configure.ac

@@ -17,17 +17,13 @@ PKG_CHECK_MODULES(FPRINT, [libfprint > 0.1.0])
 AC_SUBST(FPRINT_LIBS)
 AC_SUBST(FPRINT_CFLAGS)
 
-PKG_CHECK_MODULES(GLIB, "glib-2.0")
+PKG_CHECK_MODULES(GLIB, glib-2.0 dbus-glib-1)
 AC_SUBST(GLIB_CFLAGS)
 AC_SUBST(GLIB_LIBS)
 
-PKG_CHECK_MODULES(DBUS_GLIB, "dbus-glib-1")
-AC_SUBST(DBUS_GLIB_LIBS)
-AC_SUBST(DBUS_GLIB_CFLAGS)
-
-PKG_CHECK_MODULES(POLKIT, polkit >= 0.8 polkit-dbus)
-AC_SUBST(POLKIT_LIBS)
-AC_SUBST(POLKIT_CFLAGS)
+PKG_CHECK_MODULES(DAEMON, glib-2.0 dbus-glib-1 gmodule-2.0 polkit >= 0.8 polkit-dbus)
+AC_SUBST(DAEMON_LIBS)
+AC_SUBST(DAEMON_CFLAGS)
 
 AC_CHECK_PROG([POLKIT_POLICY_FILE_VALIDATE],
 	      [polkit-policy-file-validate], [polkit-policy-file-validate])
@@ -38,6 +34,8 @@ DBUS_SERVICES_DIR="$DATADIR/dbus-1/services"
 AC_SUBST(DBUS_SERVICES_DIR)
 AC_DEFINE_UNQUOTED(DBUS_SERVICES_DIR, "$DBUS_SERVICES_DIR", [Where services dir for DBUS is])
 
+AC_DEFINE_UNQUOTED(SYSCONFDIR, "$sysconfdir", [Where the configuration file will be located])
+
 # Restore gnu89 inline semantics on gcc 4.3 and newer
 saved_cflags="$CFLAGS"
 CFLAGS="$CFLAGS -fgnu89-inline"

src/Makefile.am

@@ -7,8 +7,8 @@ EXTRA_DIST = fprintd.xml
 libexec_PROGRAMS = fprintd
 
 fprintd_SOURCES = main.c manager.c device.c file_storage.c
-fprintd_LDADD = $(DBUS_GLIB_LIBS) $(FPRINT_LIBS) $(POLKIT_LIBS)
-fprintd_CFLAGS = $(AM_CFLAGS) $(DBUS_GLIB_CFLAGS) $(FPRINT_CFLAGS) $(POLKIT_CFLAGS) -DLOCALEDIR=\""$(datadir)/locale"\"
+fprintd_LDADD = $(FPRINT_LIBS) $(DAEMON_LIBS)
+fprintd_CFLAGS = $(AM_CFLAGS) $(FPRINT_CFLAGS) $(DAEMON_CFLAGS) -DLOCALEDIR=\""$(datadir)/locale"\" -DPLUGINDIR=\""$(libdir)/fprintd/modules"\"
 
 manager-dbus-glue.h: manager.xml
 	dbus-binding-tool --prefix=fprint_manager --mode=glib-server $< --output=$@

src/device.c

@@ -49,8 +49,6 @@ static void fprint_device_enroll_start(FprintDevice *rdev,
 	guint32 finger_num, DBusGMethodInvocation *context);
 static void fprint_device_enroll_stop(FprintDevice *rdev,
 	DBusGMethodInvocation *context);
-static gboolean fprint_device_set_storage_type(FprintDevice *rdev,
-	gint type);
 static void fprint_device_list_enrolled_fingers(FprintDevice *rdev, 
 	DBusGMethodInvocation *context);
 static void fprint_device_delete_enrolled_fingers(FprintDevice *rdev,
@@ -197,8 +195,6 @@ static void fprint_device_init(FprintDevice *device)
 {
 	FprintDevicePrivate *priv = DEVICE_GET_PRIVATE(device);
 	priv->id = ++last_id;
-	priv->storage_type = FP_FILE_STORAGE;
-	storages[priv->storage_type].init();
 
 	/* Setup PolicyKit */
 	priv->pol_ctx = polkit_context_new ();
@@ -514,8 +510,8 @@ static void fprint_device_verify_start(FprintDevice *rdev,
 
 	g_message("start verification device %d finger %d", priv->id, finger_num);
 
-	r = storages[priv->storage_type].print_data_load(priv->dev, (enum fp_finger)finger_num, 
-							 &data, priv->username);
+	r = store.print_data_load(priv->dev, (enum fp_finger)finger_num, 
+				  &data, priv->username);
 
 	if (r < 0 || !data) {
 		g_set_error(&error, FPRINT_ERROR, FPRINT_ERROR_NO_SUCH_LOADED_PRINT,
@@ -577,7 +573,7 @@ static void enroll_stage_cb(struct fp_dev *dev, int result,
 
 	g_message("enroll_stage_cb: result %d", result);
 	if (result == FP_ENROLL_COMPLETE) {
-		r = storages[priv->storage_type].print_data_save(print, session->enroll_finger, priv->username);
+		r = store.print_data_save(print, session->enroll_finger, priv->username);
 		if (r < 0)
 			result = FP_ENROLL_FAIL;
 	}
@@ -650,20 +646,6 @@ static void fprint_device_enroll_stop(FprintDevice *rdev,
 	}
 }
 
-static gboolean fprint_device_set_storage_type(FprintDevice *rdev,
-	gint type)
-{
-	FprintDevicePrivate *priv = DEVICE_GET_PRIVATE(rdev);
-
-	if (type >= FP_STORAGES_COUNT) return FALSE;
-
-	storages[priv->storage_type].deinit();
-	priv->storage_type = type;
-	storages[priv->storage_type].init();
-
-	return TRUE;
-}
-
 static void fprint_device_list_enrolled_fingers(FprintDevice *rdev,
 	DBusGMethodInvocation *context)
 {
@@ -683,7 +665,7 @@ static void fprint_device_list_enrolled_fingers(FprintDevice *rdev,
 		return;
 	}
 
-	prints = storages[priv->storage_type].discover_prints(priv->dev, priv->username);
+	prints = store.discover_prints(priv->dev, priv->username);
 	if (!prints) {
 		g_set_error(&error, FPRINT_ERROR, FPRINT_ERROR_DISCOVER_PRINTS,
 			"Failed to discover prints");
@@ -720,7 +702,7 @@ static void fprint_device_delete_enrolled_fingers(FprintDevice *rdev,
 	}
 
 	for (i = LEFT_THUMB; i <= RIGHT_LITTLE; i++) {
-		storages[priv->storage_type].print_data_delete(priv->dev, i, priv->username);
+		store.print_data_delete(priv->dev, i, priv->username);
 	}
 
 	dbus_g_method_return(context);

src/device.xml

@@ -47,11 +47,6 @@
 			<arg type="i" name="result" />
 		</signal>
 
-		<method name="SetStorageType">
-			<arg type="u" name="storage_id" direction="in" />
-			<annotation name="org.freedesktop.DBus.GLib.Async" value="" />
-		</method>
-
 		<method name="SetUsername">
 			<arg type="s" name="username" direction="in" />
 			<annotation name="org.freedesktop.DBus.GLib.Async" value="" />

src/main.c

@@ -27,8 +27,11 @@
 #include <glib/gi18n.h>
 #include <libfprint/fprint.h>
 #include <glib-object.h>
+#include <gmodule.h>
 
 #include "fprintd.h"
+#include "storage.h"
+#include "file_storage.h"
 
 DBusGConnection *fprintd_dbus_conn = NULL;
 static gboolean g_fatal_warnings = FALSE;
@@ -200,6 +203,88 @@ static int setup_pollfds(void)
 	return 0;
 }
 
+static void
+set_storage_file (void)
+{
+	store.init = &file_storage_init;
+	store.deinit = &file_storage_deinit;
+	store.print_data_save = &file_storage_print_data_save;
+	store.print_data_load = &file_storage_print_data_load;
+	store.print_data_delete = &file_storage_print_data_delete;
+	store.discover_prints = &file_storage_discover_prints;
+}
+
+static gboolean
+load_storage_module (const char *module_name)
+{
+	GModule *module;
+	char *filename;
+
+	filename = g_module_build_path (PLUGINDIR, module_name);
+	module = g_module_open (filename, 0);
+	g_free (filename);
+	if (module == NULL)
+		return FALSE;
+
+	if (!g_module_symbol (module, "init", (gpointer *) &store.init) ||
+	    !g_module_symbol (module, "deinit", (gpointer *) &store.deinit) ||
+	    !g_module_symbol (module, "print_data_save", (gpointer *) &store.print_data_save) ||
+	    !g_module_symbol (module, "print_data_load", (gpointer *) &store.print_data_load) ||
+	    !g_module_symbol (module, "print_data_delete", (gpointer *) &store.print_data_delete) ||
+	    !g_module_symbol (module, "discover_prints", (gpointer *) &store.discover_prints)) {
+	    	g_module_close (module);
+	    	return FALSE;
+	}
+
+	g_module_make_resident (module);
+
+	return TRUE;
+}
+
+static gboolean
+load_conf (void)
+{
+	GKeyFile *file;
+	char *filename;
+	char *module_name;
+	GError *error = NULL;
+	gboolean ret;
+
+	filename = g_build_filename (SYSCONFDIR, "fprintd.conf", NULL);
+	file = g_key_file_new ();
+	if (!g_key_file_load_from_file (file, filename, G_KEY_FILE_NONE, &error)) {
+		g_print ("Could not open fprintd.conf: %s\n", error->message);
+		goto bail;
+	}
+
+	g_free (filename);
+	filename = NULL;
+
+	module_name = g_key_file_get_string (file, "storage", "type", &error);
+	if (module_name == NULL)
+		goto bail;
+
+	g_key_file_free (file);
+
+	if (g_str_equal (module_name, "file")) {
+		g_free (module_name);
+		set_storage_file ();
+		return TRUE;
+	}
+
+	ret = load_storage_module (module_name);
+	g_free (module_name);
+
+	return ret;
+
+bail:
+	g_key_file_free (file);
+	g_free (filename);
+	g_error_free (error);
+
+	return FALSE;
+}
+
 static const GOptionEntry entries[] = {
 	{"g-fatal-warnings", 0, 0, G_OPTION_ARG_NONE, &g_fatal_warnings, "Make all warnings fatal", NULL},
 	{ NULL }
@@ -237,6 +322,12 @@ int main(int argc, char **argv)
 		g_log_set_always_fatal (fatal_mask);
 	}
 
+	/* Load the configuration file,
+	 * and the default storage plugin */
+	if (!load_conf())
+		set_storage_file ();
+	store.init ();
+
 	r = fp_init();
 	if (r < 0) {
 		g_error("fprint init failed with error %d\n", r);

src/storage.h

@@ -22,8 +22,6 @@
 
 #define STORAGE_H
 
-#include "file_storage.h"
-
 typedef int (*storage_print_data_save)(struct fp_print_data *data,
 	enum fp_finger finger, const char *username);
 typedef int (*storage_print_data_load)(struct fp_dev *dev,
@@ -45,26 +43,8 @@ struct storage {
 
 typedef struct storage fp_storage;
 
-enum storage_type {
-	FP_FILE_STORAGE = 0,
-
-	FP_STORAGES_COUNT,
-};
-
-typedef enum storage_type fp_storage_type;
-
-fp_storage storages[FP_STORAGES_COUNT] = {
-	{
-		.init = &file_storage_init,
-		.deinit = &file_storage_deinit,
-		.print_data_save = &file_storage_print_data_save,
-		.print_data_load = &file_storage_print_data_load,
-		.print_data_delete = &file_storage_print_data_delete,
-		.discover_prints = &file_storage_discover_prints,
-	},
-
-};
-
+/* The currently setup store */
+fp_storage store;
 
 #endif
 

tests/Makefile.am

@@ -5,12 +5,12 @@ CLEANFILES = $(BUILT_SOURCES)
 bin_PROGRAMS = verify enroll
 
 verify_SOURCES = verify.c
-verify_CFLAGS = $(AM_CFLAGS) $(DBUS_GLIB_CFLAGS)
-verify_LDADD = $(DBUS_GLIB_LIBS)
+verify_CFLAGS = $(AM_CFLAGS) $(GLIB_CFLAGS)
+verify_LDADD = $(GLIB_LIBS)
 
 enroll_SOURCES = enroll.c
-enroll_CFLAGS = $(AM_CFLAGS) $(DBUS_GLIB_CFLAGS)
-enroll_LDADD = $(DBUS_GLIB_LIBS)
+enroll_CFLAGS = $(AM_CFLAGS) $(GLIB_CFLAGS)
+enroll_LDADD = $(GLIB_LIBS)
 
 manager-dbus-glue.h: ../src/manager.xml
 	dbus-binding-tool --prefix=fprint_manager --mode=glib-client $< --output=$@