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Diffstat (limited to 'xorg-server/config/dbus-core.c')
-rw-r--r--xorg-server/config/dbus-core.c248
1 files changed, 248 insertions, 0 deletions
diff --git a/xorg-server/config/dbus-core.c b/xorg-server/config/dbus-core.c
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index 000000000..b349c6e3c
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+++ b/xorg-server/config/dbus-core.c
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+/*
+ * Copyright © 2006-2007 Daniel Stone
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Author: Daniel Stone <daniel@fooishbar.org>
+ */
+
+#ifdef HAVE_DIX_CONFIG_H
+#include <dix-config.h>
+#endif
+
+#define DBUS_API_SUBJECT_TO_CHANGE
+#include <dbus/dbus.h>
+#include <sys/select.h>
+
+#include "config-backends.h"
+#include "dix.h"
+#include "os.h"
+
+/* How often to attempt reconnecting when we get booted off the bus. */
+#define RECONNECT_DELAY (10 * 1000) /* in ms */
+
+struct dbus_core_info {
+ int fd;
+ DBusConnection *connection;
+ OsTimerPtr timer;
+ struct config_dbus_core_hook *hooks;
+};
+static struct dbus_core_info bus_info;
+
+static CARD32 reconnect_timer(OsTimerPtr timer, CARD32 time, pointer arg);
+
+static void
+wakeup_handler(pointer data, int err, pointer read_mask)
+{
+ struct dbus_core_info *info = data;
+
+ if (info->connection && FD_ISSET(info->fd, (fd_set *) read_mask)) {
+ do {
+ dbus_connection_read_write_dispatch(info->connection, 0);
+ } while (info->connection &&
+ dbus_connection_get_is_connected(info->connection) &&
+ dbus_connection_get_dispatch_status(info->connection) == DBUS_DISPATCH_DATA_REMAINS);
+ }
+}
+
+static void
+block_handler(pointer data, struct timeval **tv, pointer read_mask)
+{
+}
+
+/**
+ * Disconnect (if we haven't already been forcefully disconnected), clean up
+ * after ourselves, and call all registered disconnect hooks.
+ */
+static void
+teardown(void)
+{
+ struct config_dbus_core_hook *hook;
+
+ if (bus_info.timer) {
+ TimerFree(bus_info.timer);
+ bus_info.timer = NULL;
+ }
+
+ /* We should really have pre-disconnect hooks and run them here, for
+ * completeness. But then it gets awkward, given that you can't
+ * guarantee that they'll be called ... */
+ if (bus_info.connection)
+ dbus_connection_unref(bus_info.connection);
+
+ RemoveBlockAndWakeupHandlers(block_handler, wakeup_handler, &bus_info);
+ if (bus_info.fd != -1)
+ RemoveGeneralSocket(bus_info.fd);
+ bus_info.fd = -1;
+ bus_info.connection = NULL;
+
+ for (hook = bus_info.hooks; hook; hook = hook->next) {
+ if (hook->disconnect)
+ hook->disconnect(hook->data);
+ }
+}
+
+/**
+ * This is a filter, which only handles the disconnected signal, which
+ * doesn't go to the normal message handling function. This takes
+ * precedence over the message handling function, so have have to be
+ * careful to ignore anything we don't want to deal with here.
+ */
+static DBusHandlerResult
+message_filter(DBusConnection *connection, DBusMessage *message, void *data)
+{
+ /* If we get disconnected, then take everything down, and attempt to
+ * reconnect immediately (assuming it's just a restart). The
+ * connection isn't valid at this point, so throw it out immediately. */
+ if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL,
+ "Disconnected")) {
+ DebugF("[config/dbus-core] disconnected from bus\n");
+ bus_info.connection = NULL;
+ teardown();
+
+ if (bus_info.timer)
+ TimerFree(bus_info.timer);
+ bus_info.timer = TimerSet(NULL, 0, 1, reconnect_timer, NULL);
+
+ return DBUS_HANDLER_RESULT_HANDLED;
+ }
+
+ return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+}
+
+/**
+ * Attempt to connect to the system bus, and set a filter to deal with
+ * disconnection (see message_filter above).
+ *
+ * @return 1 on success, 0 on failure.
+ */
+static int
+connect_to_bus(void)
+{
+ DBusError error;
+ struct config_dbus_core_hook *hook;
+
+ dbus_error_init(&error);
+ bus_info.connection = dbus_bus_get(DBUS_BUS_SYSTEM, &error);
+ if (!bus_info.connection || dbus_error_is_set(&error)) {
+ DebugF("[config/dbus-core] error connecting to system bus: %s (%s)\n",
+ error.name, error.message);
+ goto err_begin;
+ }
+
+ /* Thankyou. Really, thankyou. */
+ dbus_connection_set_exit_on_disconnect(bus_info.connection, FALSE);
+
+ if (!dbus_connection_get_unix_fd(bus_info.connection, &bus_info.fd)) {
+ ErrorF("[config/dbus-core] couldn't get fd for system bus\n");
+ goto err_unref;
+ }
+
+ if (!dbus_connection_add_filter(bus_info.connection, message_filter,
+ &bus_info, NULL)) {
+ ErrorF("[config/dbus-core] couldn't add filter: %s (%s)\n", error.name,
+ error.message);
+ goto err_fd;
+ }
+
+ dbus_error_free(&error);
+ AddGeneralSocket(bus_info.fd);
+
+ RegisterBlockAndWakeupHandlers(block_handler, wakeup_handler, &bus_info);
+
+ for (hook = bus_info.hooks; hook; hook = hook->next) {
+ if (hook->connect)
+ hook->connect(bus_info.connection, hook->data);
+ }
+
+ return 1;
+
+err_fd:
+ bus_info.fd = -1;
+err_unref:
+ dbus_connection_unref(bus_info.connection);
+ bus_info.connection = NULL;
+err_begin:
+ dbus_error_free(&error);
+
+ return 0;
+}
+
+static CARD32
+reconnect_timer(OsTimerPtr timer, CARD32 time, pointer arg)
+{
+ if (connect_to_bus()) {
+ TimerFree(bus_info.timer);
+ bus_info.timer = NULL;
+ return 0;
+ }
+ else {
+ return RECONNECT_DELAY;
+ }
+}
+
+int
+config_dbus_core_add_hook(struct config_dbus_core_hook *hook)
+{
+ struct config_dbus_core_hook **prev;
+
+ for (prev = &bus_info.hooks; *prev; prev = &(*prev)->next)
+ ;
+
+ hook->next = NULL;
+ *prev = hook;
+
+ /* If we're already connected, call the connect hook. */
+ if (bus_info.connection)
+ hook->connect(bus_info.connection, hook->data);
+
+ return 1;
+}
+
+void
+config_dbus_core_remove_hook(struct config_dbus_core_hook *hook)
+{
+ struct config_dbus_core_hook **prev;
+
+ for (prev = &bus_info.hooks; *prev; prev = &(*prev)->next) {
+ if (*prev == hook) {
+ *prev = hook->next;
+ break;
+ }
+ }
+}
+
+int
+config_dbus_core_init(void)
+{
+ memset(&bus_info, 0, sizeof(bus_info));
+ bus_info.fd = -1;
+ bus_info.hooks = NULL;
+ bus_info.connection = NULL;
+ bus_info.timer = TimerSet(NULL, 0, 1, reconnect_timer, NULL);
+
+ return 1;
+}
+
+void
+config_dbus_core_fini(void)
+{
+ teardown();
+}