dbus-service.c

Linux的蓝牙操作工具。配合bluez-lib使用

/*
 *
 *  BlueZ - Bluetooth protocol stack for Linux
 *
 *  Copyright (C) 2006-2007  Nokia Corporation
 *  Copyright (C) 2004-2007  Marcel Holtmann <[e-mail]>
 *
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <dirent.h>
#include <signal.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/wait.h>

#include <bluetooth/sdp.h>

#include <glib.h>

#include <dbus/dbus.h>

#include "dbus.h"
#include "dbus-helper.h"
#include "hcid.h"
#include "notify.h"
#include "server.h"
#include "dbus-common.h"
#include "dbus-error.h"
#include "error.h"
#include "manager.h"
#include "adapter.h"
#include "dbus-service.h"
#include "dbus-hci.h"

#define SERVICE_INTERFACE "org.bluez.Service"

#define STARTUP_TIMEOUT (10 * 1000) /* 10 seconds */
#define SHUTDOWN_TIMEOUT (2 * 1000) /* 2 seconds */

#define SERVICE_SUFFIX ".service"
#define SERVICE_GROUP "Bluetooth Service"

#define NAME_MATCH "interface=" DBUS_INTERFACE_DBUS ",member=NameOwnerChanged"

static GSList *services = NULL;
static GSList *removed = NULL;

static void service_free(struct service *service)
{
	if (!service)
		return;

	if (service->action)
		dbus_message_unref(service->action);

	g_free(service->bus_name);
	g_free(service->filename);
	g_free(service->object_path);
	g_free(service->name);
	g_free(service->descr);
	g_free(service->ident);

	g_free(service);
}

static void service_exit(const char *name, struct service *service)
{
	DBusConnection *conn = get_dbus_connection();

	debug("Service owner exited: %s", name);

	dbus_connection_emit_signal(conn, service->object_path,
					SERVICE_INTERFACE, "Stopped",
					DBUS_TYPE_INVALID);

	if (service->action) {
		DBusMessage *reply;
		reply = dbus_message_new_method_return(service->action);
		send_message_and_unref(conn, reply);
		dbus_message_unref(service->action);
		service->action = NULL;
	}

	g_free(service->bus_name);
	service->bus_name = NULL;
}

static DBusHandlerResult get_info(DBusConnection *conn,
					DBusMessage *msg, void *data)
{
	struct service *service = data;
	DBusMessage *reply;
	DBusMessageIter iter;
	DBusMessageIter dict;
	dbus_bool_t running;

	reply = dbus_message_new_method_return(msg);
	if (!reply)
		return DBUS_HANDLER_RESULT_NEED_MEMORY;

	dbus_message_iter_init_append(reply, &iter);

	dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY,
			DBUS_DICT_ENTRY_BEGIN_CHAR_AS_STRING
			DBUS_TYPE_STRING_AS_STRING DBUS_TYPE_VARIANT_AS_STRING
			DBUS_DICT_ENTRY_END_CHAR_AS_STRING, &dict);

	dbus_message_iter_append_dict_entry(&dict, "identifier",
			DBUS_TYPE_STRING, &service->ident);

	dbus_message_iter_append_dict_entry(&dict, "name",
			DBUS_TYPE_STRING, &service->name);

	dbus_message_iter_append_dict_entry(&dict, "description",
			DBUS_TYPE_STRING, &service->descr);

	running = (service->external || service->bus_name) ? TRUE : FALSE;

	dbus_message_iter_append_dict_entry(&dict, "running",
			DBUS_TYPE_BOOLEAN, &running);

	dbus_message_iter_close_container(&iter, &dict);

	return send_message_and_unref(conn, reply);
}

static DBusHandlerResult get_identifier(DBusConnection *conn,
					DBusMessage *msg, void *data)
{

	struct service *service = data;
	DBusMessage *reply;
	const char *identifier = "";

	reply = dbus_message_new_method_return(msg);
	if (!reply)
		return DBUS_HANDLER_RESULT_NEED_MEMORY;

	if (service->ident)
		identifier = service->ident;

	dbus_message_append_args(reply,
			DBUS_TYPE_STRING, &identifier,
			DBUS_TYPE_INVALID);

	return send_message_and_unref(conn, reply);
}

static DBusHandlerResult get_name(DBusConnection *conn,
					DBusMessage *msg, void *data)
{

	struct service *service = data;
	DBusMessage *reply;
	const char *name = "";

	reply = dbus_message_new_method_return(msg);
	if (!reply)
		return DBUS_HANDLER_RESULT_NEED_MEMORY;

	if (service->name)
		name = service->name;

	dbus_message_append_args(reply,
			DBUS_TYPE_STRING, &name,
			DBUS_TYPE_INVALID);

	return send_message_and_unref(conn, reply);
}

static DBusHandlerResult get_description(DBusConnection *conn,
						DBusMessage *msg, void *data)
{
	struct service *service = data;
	DBusMessage *reply;
	const char *description = "";

	reply = dbus_message_new_method_return(msg);
	if (!reply)
		return DBUS_HANDLER_RESULT_NEED_MEMORY;

	if (service->descr)
		description = service->descr;

	dbus_message_append_args(reply,
			DBUS_TYPE_STRING, &description,
			DBUS_TYPE_INVALID);

	return send_message_and_unref(conn, reply);
}

static DBusHandlerResult get_bus_name(DBusConnection *conn,
						DBusMessage *msg, void *data)
{
	struct service *service = data;
	DBusMessage *reply;

	if (!service->bus_name)
		return error_not_available(conn, msg);

	reply = dbus_message_new_method_return(msg);
	if (!reply)
		return DBUS_HANDLER_RESULT_NEED_MEMORY;

	dbus_message_append_args(reply,
			DBUS_TYPE_STRING, &service->bus_name,
			DBUS_TYPE_INVALID);

	return send_message_and_unref(conn, reply);
}

static void service_setup(gpointer data)
{
	/* struct service *service = data; */
}

static DBusHandlerResult service_filter(DBusConnection *conn,
					DBusMessage *msg, void *data)
{
	DBusError err;
	struct service *service = data;
	const char *name, *old, *new;
	unsigned long pid;

	if (!dbus_message_is_signal(msg, DBUS_INTERFACE_DBUS, "NameOwnerChanged"))
		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;

	if (!dbus_message_get_args(msg, NULL,
			DBUS_TYPE_STRING, &name, DBUS_TYPE_STRING, &old,
				DBUS_TYPE_STRING, &new, DBUS_TYPE_INVALID)) {
		error("Invalid arguments for NameOwnerChanged signal");
		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
	}

	if (*new == '\0' || *old != '\0' || *new != ':')
		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;

	if (!dbus_bus_get_unix_process_id(conn, new, &pid)) {
		error("Could not get PID of %s", new);
		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
	}

	if ((GPid) pid != service->pid)
		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;

	debug("Child PID %d got the unique bus name %s", service->pid, new);

	service->bus_name = g_strdup(new);

	dbus_error_init(&err);
	dbus_bus_remove_match(conn, NAME_MATCH, &err);
	if (dbus_error_is_set(&err)) {
		error("Remove match \"%s\" failed: %s" NAME_MATCH, err.message);
		dbus_error_free(&err);
	}
	dbus_connection_remove_filter(conn, service_filter, service);

	if (service->action) {
		msg = dbus_message_new_method_return(service->action);
		if (msg) {
			if (dbus_message_is_method_call(service->action, MANAGER_INTERFACE,
							"ActivateService"))
				dbus_message_append_args(msg, DBUS_TYPE_STRING, &new,
							DBUS_TYPE_INVALID);
			send_message_and_unref(conn, msg);
		}

		dbus_message_unref(service->action);
		service->action = NULL;
	}

	if (service->startup_timer) {
		g_source_remove(service->startup_timer);
		service->startup_timer = 0;
	} else
		debug("service_filter: timeout was already removed!");

	name_listener_add(conn, new, (name_cb_t) service_exit, service);

	dbus_connection_emit_signal(conn, service->object_path,
					SERVICE_INTERFACE, "Started",
					DBUS_TYPE_INVALID);

	return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}

static void abort_startup(struct service *service, DBusConnection *conn, int ecode)
{
	DBusError err;

	if (conn) {
		dbus_error_init(&err);
		dbus_bus_remove_match(conn, NAME_MATCH, &err);
		if (dbus_error_is_set(&err)) {
			error("Remove match \"%s\" failed: %s" NAME_MATCH, err.message);
		dbus_error_free(&err);
		}

		dbus_connection_remove_filter(conn, service_filter, service);
	}

	g_source_remove(service->startup_timer);
	service->startup_timer = 0;

	if (service->action) {
		if (conn)
			error_failed_errno(conn, service->action, ecode);
		dbus_message_unref(service->action);
		service->action = NULL;
	}

	if (service->pid > 0 && kill(service->pid, SIGKILL) < 0)
		error("kill(%d, SIGKILL): %s (%d)", service->pid,
				strerror(errno), errno);
}

static void service_died(GPid pid, gint status, gpointer data)
{
	struct service *service = data;

	if (WIFEXITED(status))
		debug("%s (%s) exited with status %d", service->name,
				service->ident, WEXITSTATUS(status));
	else
		debug("%s (%s) was killed by signal %d", service->name,
				service->ident, WTERMSIG(status));

	g_spawn_close_pid(pid);
	service->pid = 0;

	if (service->startup_timer)
		abort_startup(service, get_dbus_connection(), ECANCELED);

	if (service->shutdown_timer) {
		g_source_remove(service->shutdown_timer);
		service->shutdown_timer = 0;
	}

	if (g_slist_find(removed, service)) {
		removed = g_slist_remove(removed, service);
		service_free(service);
	}
}

static gboolean service_shutdown_timeout(gpointer data)
{
	struct service *service = data;

	if (service->pid > 0) {
		debug("SIGKILL for \"%s\" (PID %d) since it didn't exit yet",
			service->name, service->pid);

		if (kill(service->pid, SIGKILL) < 0)
			error("kill(%d, SIGKILL): %s (%d)", service->pid,
						strerror(errno), errno);
	}

	service->shutdown_timer = 0;

	return FALSE;
}

static void stop_service(struct service *service, gboolean remove)
{
	if (service->pid > 0 && kill(service->pid, SIGTERM) < 0)
		error("kill(%d, SIGTERM): %s (%d)", service->pid,
				strerror(errno), errno);

	service->shutdown_timer = g_timeout_add(SHUTDOWN_TIMEOUT,
						service_shutdown_timeout,
						service);

	if (remove) {
		services = g_slist_remove(services, service);
		removed = g_slist_append(removed, service);
	}
}

static gboolean service_startup_timeout(gpointer data)
{
	struct service *service = data;

	debug("Killing \"%s\" (PID %d) because it did not connect to D-Bus in time",
			service->name, service->pid);

	abort_startup(service, get_dbus_connection(), ETIME);

	return FALSE;
}

int service_start(struct service *service, DBusConnection *conn)
{
	DBusError derr;
	char *addr, *argv[2], *envp[2], command[PATH_MAX], address[256];

	if (!dbus_connection_add_filter(conn, service_filter, service, NULL)) {
		error("Unable to add signal filter");
		return -1;
	}

	dbus_error_init(&derr);
	dbus_bus_add_match(conn, NAME_MATCH, &derr);
	if (dbus_error_is_set(&derr)) {
		error("Add match \"%s\" failed: %s", derr.message);
		dbus_error_free(&derr);
		dbus_connection_remove_filter(conn, service_filter, service);
		return -1;
	}

	snprintf(command, sizeof(command) - 1, "%s/bluetoothd-service-%s",
						SERVICEDIR, service->ident);
	argv[0] = command;
	argv[1] = NULL;

	addr = get_local_server_address();

	snprintf(address, sizeof(address) - 1, "BLUETOOTHD_ADDRESS=%s", addr);
	envp[0] = address;
	envp[1] = NULL;

	dbus_free(addr);

	if (!g_spawn_async(SERVICEDIR, argv, envp, G_SPAWN_DO_NOT_REAP_CHILD,
				service_setup, service, &service->pid, NULL)) {
		error("Unable to execute %s", argv[0]);
		dbus_connection_remove_filter(conn, service_filter, service);
		dbus_bus_remove_match(conn, NAME_MATCH, NULL);
		return -1;
	}

	g_child_watch_add(service->pid, service_died, service);

	debug("%s executed with PID %d", argv[0], service->pid);

	service->startup_timer = g_timeout_add(STARTUP_TIMEOUT,
						service_startup_timeout,
						service);

	return 0;
}

static DBusHandlerResult start(DBusConnection *conn,
				DBusMessage *msg, void *data)
{
	struct service *service = data;

	if (service->external || service->pid)
		return error_failed_errno(conn, msg, EALREADY);

	if (service_start(service, conn) < 0)
		return error_failed_errno(conn, msg, ENOEXEC);

	service->action = dbus_message_ref(msg);

	return DBUS_HANDLER_RESULT_HANDLED;
}

static DBusHandlerResult stop(DBusConnection *conn,
				DBusMessage *msg, void *data)
{
	struct service *service  = data;

	if (service->external || !service->bus_name)
		return error_failed_errno(conn, msg, EPERM);

	stop_service(service, FALSE);

	service->action = dbus_message_ref(msg);

	return DBUS_HANDLER_RESULT_HANDLED;
}

static DBusHandlerResult is_running(DBusConnection *conn,
					DBusMessage *msg, void *data)
{
	struct service *service = data;
	DBusMessage *reply;
	dbus_bool_t running;

	reply = dbus_message_new_method_return(msg);
	if (!reply)
		return DBUS_HANDLER_RESULT_NEED_MEMORY;

	running = (service->external || service->bus_name) ? TRUE : FALSE;

	dbus_message_append_args(reply,
			DBUS_TYPE_BOOLEAN, &running,
			DBUS_TYPE_INVALID);

	return send_message_and_unref(conn, reply);
}

static DBusHandlerResult is_external(DBusConnection *conn,
					DBusMessage *msg, void *data)
{
	struct service *service = data;
	DBusMessage *reply;

	reply = dbus_message_new_method_return(msg);
	if (!reply)
		return DBUS_HANDLER_RESULT_NEED_MEMORY;

	dbus_message_append_args(reply,
			DBUS_TYPE_BOOLEAN, &service->external,
			DBUS_TYPE_INVALID);

	return send_message_and_unref(conn, reply);
}

static DBusHandlerResult set_trusted(DBusConnection *conn,
					DBusMessage *msg, void *data)
{
	struct service *service = data;
	DBusMessage *reply;
	const char *address;

	if (!dbus_message_get_args(msg, NULL,
			DBUS_TYPE_STRING, &address,
			DBUS_TYPE_INVALID))
		return error_invalid_arguments(conn, msg, NULL);

	if (check_address(address) < 0)
		return error_invalid_arguments(conn, msg, NULL);

	reply = dbus_message_new_method_return(msg);