path: root/src/ephy-dbus.c

/*
 *  Copyright (C) 2004, 2005 Jean-François Rameau
 *  Copyright (C) 2006 Christian Persch
 *
 *  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, 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 *  $Id$
 */

#include "config.h"

#include "ephy-dbus.h"
#include "ephy-type-builtins.h"
#include "ephy-marshal.h"
#include "ephy-debug.h"
#include "ephy-activation.h"
#include "ephy-dbus-server-bindings.h"

#include <string.h>
#include <dbus/dbus-glib-bindings.h>

/* dbus 0.6 API change */
#ifndef DBUS_NAME_FLAG_PROHIBIT_REPLACEMENT
#define DBUS_NAME_FLAG_PROHIBIT_REPLACEMENT 0
#endif

/* dbus < 0.6 compat */
#ifndef DBUS_NAME_FLAG_DO_NOT_QUEUE
#define DBUS_NAME_FLAG_DO_NOT_QUEUE 0
#endif

#define RECONNECT_DELAY 3000

#define EPHY_DBUS_GET_PRIVATE(object)(G_TYPE_INSTANCE_GET_PRIVATE ((object), EPHY_TYPE_DBUS, EphyDbusPrivate))

struct _EphyDbusPrivate
{
    DBusGConnection *session_bus;
    DBusGConnection *system_bus;
    guint session_reconnect_timeout_id;
    guint system_reconnect_timeout_id;
    guint is_session_service_owner : 1;
};

enum
{
    CONNECTED,
    DISCONNECTED,
    LAST_SIGNAL
};

static EphyDbus *ephy_dbus_instance;

static guint signals[LAST_SIGNAL];
static GObjectClass *parent_class;
GQuark ephy_dbus_error_quark;

/* Filter signals form session bus */
static DBusHandlerResult session_filter_func (DBusConnection *connection,
                              DBusMessage *message,
                              void *user_data);
/* Filter signals from system bus */
static DBusHandlerResult system_filter_func (DBusConnection *connection,
                             DBusMessage *message,
                             void *user_data);

/* Both  connect to their respective bus */
static gboolean ephy_dbus_connect_to_session_bus (EphyDbus*, GError**);
static gboolean ephy_dbus_connect_to_system_bus  (EphyDbus*, GError**);

/* implementation of the DBUS helpers */

static gboolean
ephy_dbus_connect_to_session_bus_cb (gpointer user_data)
{
    EphyDbus *dbus = EPHY_DBUS (user_data);

    if (!ephy_dbus_connect_to_session_bus (dbus, NULL))
    {
        /* try again */
        return TRUE;
    }

    dbus->priv->session_reconnect_timeout_id = 0;

    /* we're done */
    return FALSE;
}

static gboolean
ephy_dbus_connect_to_system_bus_cb (gpointer user_data)
{
    EphyDbus *dbus = EPHY_DBUS (user_data);

    if (!ephy_dbus_connect_to_system_bus (dbus, NULL))
    {
        /* try again */
        return TRUE;
    }

    dbus->priv->system_reconnect_timeout_id = 0;

    /* we're done */
    return FALSE;
}

static DBusHandlerResult
session_filter_func (DBusConnection *connection,
                 DBusMessage *message,
                 void *user_data)
{
    EphyDbus *ephy_dbus = EPHY_DBUS (user_data);
    EphyDbusPrivate *priv = ephy_dbus->priv;

    if (dbus_message_is_signal (message,
                    DBUS_INTERFACE_LOCAL,
                    "Disconnected"))
    {
        LOG ("EphyDbus disconnected from session bus");

        dbus_g_connection_unref (priv->session_bus);
        priv->session_bus = NULL;

        g_signal_emit (ephy_dbus, signals[DISCONNECTED], 0, EPHY_DBUS_SESSION);

        /* try to reconnect later ... */
        priv->session_reconnect_timeout_id =
            g_timeout_add (RECONNECT_DELAY,
                       (GSourceFunc) ephy_dbus_connect_to_session_bus_cb,
                       ephy_dbus);

        return DBUS_HANDLER_RESULT_HANDLED;
    }

    return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}

static DBusHandlerResult
system_filter_func (DBusConnection *connection,
                DBusMessage *message,
                void *user_data)
{
    EphyDbus *ephy_dbus = EPHY_DBUS (user_data);
    EphyDbusPrivate *priv = ephy_dbus->priv;

    LOG ("EphyDbus filtering message from system bus");

    if (dbus_message_is_signal (message,
                    DBUS_INTERFACE_LOCAL,
                    "Disconnected"))
    {
        LOG ("EphyDbus disconnected from system bus");

        dbus_g_connection_unref (priv->system_bus);
        priv->system_bus = NULL;

        g_signal_emit (ephy_dbus, signals[DISCONNECTED], 0, EPHY_DBUS_SYSTEM);

        /* try to reconnect later ... */
        priv->system_reconnect_timeout_id =
            g_timeout_add (RECONNECT_DELAY,
                       (GSourceFunc) ephy_dbus_connect_to_system_bus_cb,
                       ephy_dbus);

        return DBUS_HANDLER_RESULT_HANDLED;
    }

    return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}

static gboolean
ephy_dbus_connect_to_system_bus (EphyDbus *ephy_dbus,
                 GError **error)
{
    EphyDbusPrivate *priv = ephy_dbus->priv;

    LOG ("EphyDbus connecting to system DBUS");

    priv->system_bus = dbus_g_bus_get (DBUS_BUS_SYSTEM, error);
    if (priv->system_bus == NULL)
    {
        g_warning ("Unable to connect to system bus: %s", error ? (*error)->message : "");
        return FALSE;
    }

    if (dbus_g_connection_get_connection (priv->system_bus) == NULL)
    {
        g_warning ("DBus connection is null");
        g_set_error (error,
                 EPHY_DBUS_ERROR_QUARK,
                 0,
                 "DBus connection is NULL");
        return FALSE;
    }

    dbus_connection_set_exit_on_disconnect 
        (dbus_g_connection_get_connection (priv->system_bus),
         FALSE);

    dbus_connection_add_filter
        (dbus_g_connection_get_connection (priv->system_bus),
         system_filter_func, ephy_dbus, NULL);

    g_signal_emit (ephy_dbus, signals[CONNECTED], 0, EPHY_DBUS_SYSTEM);

    return TRUE;
}

static gboolean
ephy_dbus_connect_to_session_bus (EphyDbus *ephy_dbus,
                  GError **error)
{
    EphyDbusPrivate *priv = ephy_dbus->priv;
    DBusGProxy *proxy;
    guint request_ret;
    
    LOG ("EphyDbus connecting to session DBUS");

    /* Init the DBus connection */
    priv->session_bus = dbus_g_bus_get (DBUS_BUS_SESSION, error);
    if (priv->session_bus == NULL)
    {
        g_warning("Unable to connect to session bus: %s", error ? (*error)->message : "");
        return FALSE;
    }

    dbus_connection_set_exit_on_disconnect 
        (dbus_g_connection_get_connection (priv->session_bus),
         FALSE);

    dbus_connection_add_filter
        (dbus_g_connection_get_connection (priv->session_bus),
         session_filter_func, ephy_dbus, NULL);
    
    dbus_g_object_type_install_info (EPHY_TYPE_DBUS,
                     &dbus_glib_ephy_activation_object_info);

    /* Register DBUS path */
    dbus_g_connection_register_g_object (priv->session_bus,
                         DBUS_EPHY_PATH,
                         G_OBJECT (ephy_dbus));

    /* Register the service name, the constant here are defined in dbus-glib-bindings.h */
    proxy = dbus_g_proxy_new_for_name (priv->session_bus,
                       DBUS_SERVICE_DBUS,
                       DBUS_PATH_DBUS,
                       DBUS_INTERFACE_DBUS);

    if (!org_freedesktop_DBus_request_name (proxy,
                        DBUS_EPHY_SERVICE,
                        DBUS_NAME_FLAG_PROHIBIT_REPLACEMENT |
                        DBUS_NAME_FLAG_DO_NOT_QUEUE,
                        &request_ret, error))
    {
        /* We have a BIG problem! */
        g_warning ("RequestName failed: %s\n", error ? (*error)->message : "");
        return FALSE;
    }

    if (request_ret == DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER ||
        request_ret == DBUS_REQUEST_NAME_REPLY_ALREADY_OWNER)
    {
        priv->is_session_service_owner = TRUE;
    }
    else if (request_ret == DBUS_REQUEST_NAME_REPLY_EXISTS ||
         request_ret == DBUS_REQUEST_NAME_REPLY_IN_QUEUE)
    {
        priv->is_session_service_owner = FALSE;
    }

    LOG ("Instance is %ssession bus owner.", priv->is_session_service_owner ? "" : "NOT ");

    g_object_unref (proxy);

    return TRUE;
}

static void
ephy_dbus_disconnect_bus (DBusGConnection *bus)
{
    if (bus != NULL) {
        dbus_connection_close
            (dbus_g_connection_get_connection (bus));
        dbus_g_connection_unref (bus);
    }
}

/* Public methods */

static void
ephy_dbus_shutdown (EphyDbus *dbus)
{
    EphyDbusPrivate *priv = dbus->priv;

    LOG ("EphyDbus shutdown");

    if (priv->session_reconnect_timeout_id != 0)
    {
        g_source_remove (priv->session_reconnect_timeout_id);
        priv->session_reconnect_timeout_id = 0;
    }

    if (priv->system_reconnect_timeout_id != 0)
    {
        g_source_remove (priv->system_reconnect_timeout_id);
        priv->system_reconnect_timeout_id = 0;
    }

    if (priv->session_bus)
    {
        dbus_connection_remove_filter
            (dbus_g_connection_get_connection (priv->session_bus),
             session_filter_func, dbus);
        ephy_dbus_disconnect_bus (priv->session_bus);
        priv->session_bus = NULL;
    }

        if (priv->system_bus)
    {
        dbus_connection_remove_filter
            (dbus_g_connection_get_connection (priv->system_bus),
             system_filter_func, dbus);
        ephy_dbus_disconnect_bus (priv->system_bus);
        priv->system_bus = NULL;
    }
}

/* Class implementation */

static void
ephy_dbus_init (EphyDbus *dbus)
{
    dbus->priv = EPHY_DBUS_GET_PRIVATE (dbus);

    LOG ("EphyDbus initialising");
}

static void
ephy_dbus_finalize (GObject *object)
{
    EphyDbus *dbus = EPHY_DBUS (object);

    /* Have to do this after the object's weak ref notifiers have
     * been called, see https://bugs.freedesktop.org/show_bug.cgi?id=5688
     */
    ephy_dbus_shutdown (dbus);

    LOG ("EphyDbus finalised");

    parent_class->finalize (object);
}

static void
ephy_dbus_class_init (EphyDbusClass *klass)
{
    GObjectClass *object_class = G_OBJECT_CLASS (klass);

    parent_class = g_type_class_peek_parent (klass);

    object_class->finalize = ephy_dbus_finalize;

    signals[CONNECTED] =
        g_signal_new ("connected",
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_FIRST,
                  G_STRUCT_OFFSET (EphyDbusClass, connected),
                  NULL, NULL,
                  ephy_marshal_VOID__ENUM,
                  G_TYPE_NONE,
                  1,
                  EPHY_TYPE_DBUS_BUS);

    signals[DISCONNECTED] =
        g_signal_new ("disconnected",
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_FIRST,
                  G_STRUCT_OFFSET (EphyDbusClass, disconnected),
                  NULL, NULL,
                  ephy_marshal_VOID__ENUM,
                  G_TYPE_NONE,
                  1,
                  EPHY_TYPE_DBUS_BUS);

    g_type_class_add_private (object_class, sizeof(EphyDbusPrivate));
}

GType
ephy_dbus_get_type (void)
{
    static GType type = 0;

    if (G_UNLIKELY (type == 0))
    {
        static const GTypeInfo our_info =
        {
            sizeof (EphyDbusClass),
            NULL, /* base_init */
            NULL, /* base_finalize */
            (GClassInitFunc) ephy_dbus_class_init,
            NULL,
            NULL, /* class_data */
            sizeof (EphyDbus),
            0, /* n_preallocs */
            (GInstanceInitFunc) ephy_dbus_init
        };

        type = g_type_register_static (G_TYPE_OBJECT,
                           "EphyDbus",
                           &our_info, 0);
    }

    return type;
}

EphyDbus *
ephy_dbus_get_default (void)
{
    g_assert (ephy_dbus_instance != NULL);

    return ephy_dbus_instance;
}

DBusGConnection *
ephy_dbus_get_bus (EphyDbus *dbus,
           EphyDbusBus kind)
{
    DBusGConnection *bus = NULL;

    g_return_val_if_fail (EPHY_IS_DBUS (dbus), NULL);

    if (kind == EPHY_DBUS_SYSTEM)
    {
        /* We connect lazily to the system bus */
        if (dbus->priv->system_bus == NULL)
        {
            ephy_dbus_connect_to_system_bus (dbus, NULL);
        }
        bus = dbus->priv->system_bus;
    }
    else if (kind == EPHY_DBUS_SESSION)
    {
        bus = dbus->priv->session_bus;
    }
    else
    {
        g_assert_not_reached ();
    }

    g_assert (bus != NULL);

    return bus;
}

DBusGProxy *
ephy_dbus_get_proxy (EphyDbus *dbus,
             EphyDbusBus kind)
{
    DBusGConnection *bus = NULL;

    g_return_val_if_fail (EPHY_IS_DBUS (dbus), NULL);
    
    bus = ephy_dbus_get_bus (dbus, kind);

    if (bus == NULL)
    {
        g_warning ("Unable to get proxy for the %s bus.\n",
               kind == EPHY_DBUS_SESSION ? "session" : "system");
        return NULL;
    }

    return dbus_g_proxy_new_for_name (bus,
                      DBUS_EPHY_SERVICE,
                      DBUS_EPHY_PATH,
                      DBUS_EPHY_INTERFACE);
}

/* private API */

gboolean
_ephy_dbus_startup (GError **error)
{
    g_assert (ephy_dbus_instance == NULL);

    ephy_dbus_error_quark = g_quark_from_static_string ("ephy-dbus-error");
        
    ephy_dbus_instance = g_object_new (EPHY_TYPE_DBUS, NULL);

    /* We only connect to the session bus on startup*/
    return ephy_dbus_connect_to_session_bus (ephy_dbus_instance, error);
}

void
_ephy_dbus_release (void)
{
    g_assert (ephy_dbus_instance != NULL);

    g_object_unref (ephy_dbus_instance);
    ephy_dbus_instance = NULL;
}

gboolean
_ephy_dbus_is_name_owner (void)
{
    g_assert (ephy_dbus_instance != NULL);

    return ephy_dbus_instance->priv->is_session_service_owner;
}