path: root/daemon/gdm-simple-slave.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
 *
 * Copyright (C) 2007 William Jon McCann <mccann@jhu.edu>
 *
 * 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 Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>

#ifdef  HAVE_LOGINDEVPERM
#include <libdevinfo.h>
#endif  /* HAVE_LOGINDEVPERM */

#include <glib.h>
#include <glib/gi18n.h>
#include <glib/gstdio.h>
#include <glib-object.h>

#include <X11/Xlib.h> /* for Display */

#include <act/act-user-manager.h>

#include "gdm-common.h"

#include "gdm-settings-keys.h"

#include "gdm-simple-slave.h"

#include "gdm-server.h"
#include "gdm-session.h"
#include "gdm-session-glue.h"
#include "gdm-launch-environment.h"
#include "gdm-settings-direct.h"
#include "gdm-settings-keys.h"

#define GDM_SIMPLE_SLAVE_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), GDM_TYPE_SIMPLE_SLAVE, GdmSimpleSlavePrivate))

#define MAX_CONNECT_ATTEMPTS  10
#define DEFAULT_PING_INTERVAL 15

#define INITIAL_SETUP_USERNAME "gnome-initial-setup"
#define GNOME_SESSION_SESSIONS_PATH DATADIR "/gnome-session/sessions"

struct GdmSimpleSlavePrivate
{
        GPid               pid;
        char              *username;
        gint               greeter_reset_id;

        int                ping_interval;

        GPid               server_pid;
        guint              connection_attempts;

        GdmServer         *server;

#ifdef  HAVE_LOGINDEVPERM
        gboolean           use_logindevperm;
#endif
};

enum {
        PROP_0,
};

static void     gdm_simple_slave_class_init     (GdmSimpleSlaveClass *klass);
static void     gdm_simple_slave_init           (GdmSimpleSlave      *simple_slave);
static void     gdm_simple_slave_finalize       (GObject             *object);

G_DEFINE_TYPE (GdmSimpleSlave, gdm_simple_slave, GDM_TYPE_SLAVE)

#ifdef  HAVE_LOGINDEVPERM
static void
gdm_simple_slave_grant_console_permissions (GdmSimpleSlave *slave)
{
        const char *username;
        const char *display_device;
        struct passwd *passwd_entry;

        username = gdm_session_get_username (slave->priv->session);
        display_device = gdm_session_get_display_device (slave->priv->session);

        if (username != NULL) {
                gdm_get_pwent_for_name (username, &passwd_entry);

                /*
                 * Only do logindevperm processing if /dev/console or
                 * a device associated with a VT
                 */
                if (display_device != NULL &&
                   (strncmp (display_device, "/dev/vt/", strlen ("/dev/vt/")) == 0 ||
                    strcmp  (display_device, "/dev/console") == 0)) {
                        g_debug ("Logindevperm login for user %s, device %s",
                                 username, display_device);
                        (void) di_devperm_login (display_device,
                                                 passwd_entry->pw_uid,
                                                 passwd_entry->pw_gid,
                                                 NULL);
                        slave->priv->use_logindevperm = TRUE;
                }
        }

        if (!slave->priv->use_logindevperm) {
                g_debug ("Not calling di_devperm_login login for user %s, device %s",
                         username, display_device);
        }
}

static void
gdm_simple_slave_revoke_console_permissions (GdmSimpleSlave *slave)
{
        const char *username;
        const char *display_device;

        username = gdm_session_get_username (slave->priv->session);
        display_device = gdm_session_get_display_device (slave->priv->session);

        /*
         * Only do logindevperm processing if /dev/console or a device
         * associated with a VT.  Do this after processing the PostSession
         * script so that permissions for devices are not returned to root
         * before running the script.
         */
        if (slave->priv->use_logindevperm == TRUE &&
            display_device != NULL &&
           (strncmp (display_device, "/dev/vt/", strlen ("/dev/vt/")) == 0 ||
            strcmp  (display_device, "/dev/console") == 0)) {
                g_debug ("di_devperm_logout for user %s, device %s",
                         username, display_device);
                (void) di_devperm_logout (display_device);
                slave->priv->use_logindevperm = FALSE;
        } else {
                g_debug ("Not calling di_devperm_logout logout for user %s, device %s",
                         username, display_device);
        }
}
#endif  /* HAVE_LOGINDEVPERM */

static void
setup_server (GdmSimpleSlave *slave)
{
}

static gboolean
idle_connect_to_display (GdmSimpleSlave *slave)
{
        gboolean res;

        slave->priv->connection_attempts++;

        res = gdm_slave_connect_to_x11_display (GDM_SLAVE (slave));
        if (res) {
                setup_server (slave);
        } else {
                if (slave->priv->connection_attempts >= MAX_CONNECT_ATTEMPTS) {
                        g_warning ("Unable to connect to display after %d tries - bailing out", slave->priv->connection_attempts);
                        exit (1);
                }
                return TRUE;
        }

        return FALSE;
}

static void
on_server_ready (GdmServer      *server,
                 GdmSimpleSlave *slave)
{
        g_idle_add ((GSourceFunc)idle_connect_to_display, slave);
}

static void
on_server_exited (GdmServer      *server,
                  int             exit_code,
                  GdmSimpleSlave *slave)
{
        g_debug ("GdmSimpleSlave: server exited with code %d\n", exit_code);

        gdm_slave_stop (GDM_SLAVE (slave));
}

static void
on_server_died (GdmServer      *server,
                int             signal_number,
                GdmSimpleSlave *slave)
{
        g_debug ("GdmSimpleSlave: server died with signal %d, (%s)",
                 signal_number,
                 g_strsignal (signal_number));

        gdm_slave_stop (GDM_SLAVE (slave));
}

static gboolean
gdm_simple_slave_run (GdmSimpleSlave *slave)
{
        char    *display_name;
        char    *auth_file;
        char    *seat_id;
        gboolean display_is_local;
        gboolean display_is_initial;

        g_object_get (slave,
                      "display-is-local", &display_is_local,
                      "display-name", &display_name,
                      "display-seat-id", &seat_id,
                      "display-x11-authority-file", &auth_file,
                      "display-is-initial", &display_is_initial,
                      NULL);

        /* if this is local display start a server if one doesn't
         * exist */
        if (display_is_local) {
                gboolean res;
                gboolean disable_tcp;

                slave->priv->server = gdm_server_new (display_name, seat_id, auth_file, display_is_initial);

                disable_tcp = TRUE;
                if (gdm_settings_direct_get_boolean (GDM_KEY_DISALLOW_TCP, &disable_tcp)) {
                        g_object_set (slave->priv->server,
                                      "disable-tcp", disable_tcp,
                                      NULL);
                }

                g_signal_connect (slave->priv->server,
                                  "exited",
                                  G_CALLBACK (on_server_exited),
                                  slave);
                g_signal_connect (slave->priv->server,
                                  "died",
                                  G_CALLBACK (on_server_died),
                                  slave);
                g_signal_connect (slave->priv->server,
                                  "ready",
                                  G_CALLBACK (on_server_ready),
                                  slave);

                res = gdm_server_start (slave->priv->server);
                if (! res) {
                        g_warning (_("Could not start the X "
                                     "server (your graphical environment) "
                                     "due to an internal error. "
                                     "Please contact your system administrator "
                                     "or check your syslog to diagnose. "
                                     "In the meantime this display will be "
                                     "disabled.  Please restart GDM when "
                                     "the problem is corrected."));
                        exit (1);
                }

                g_debug ("GdmSimpleSlave: Started X server");
        } else {
                g_timeout_add (500, (GSourceFunc)idle_connect_to_display, slave);
        }

        g_free (display_name);
        g_free (auth_file);

        return TRUE;
}

static gboolean
gdm_simple_slave_start (GdmSlave *slave)
{
        GDM_SLAVE_CLASS (gdm_simple_slave_parent_class)->start (slave);

        gdm_simple_slave_run (GDM_SIMPLE_SLAVE (slave));

        return TRUE;
}

static gboolean
gdm_simple_slave_stop (GdmSlave *slave)
{
        GdmSimpleSlave *self = GDM_SIMPLE_SLAVE (slave);

        g_debug ("GdmSimpleSlave: Stopping simple_slave");

        GDM_SLAVE_CLASS (gdm_simple_slave_parent_class)->stop (slave);

        if (self->priv->server != NULL) {
                gdm_server_stop (self->priv->server);
                g_clear_object (&self->priv->server);
        }

        return TRUE;
}

static void
gdm_simple_slave_class_init (GdmSimpleSlaveClass *klass)
{
        GObjectClass  *object_class = G_OBJECT_CLASS (klass);
        GdmSlaveClass *slave_class = GDM_SLAVE_CLASS (klass);

        object_class->finalize = gdm_simple_slave_finalize;

        slave_class->start = gdm_simple_slave_start;
        slave_class->stop = gdm_simple_slave_stop;

        g_type_class_add_private (klass, sizeof (GdmSimpleSlavePrivate));
}

static void
gdm_simple_slave_init (GdmSimpleSlave *slave)
{
        slave->priv = GDM_SIMPLE_SLAVE_GET_PRIVATE (slave);
#ifdef  HAVE_LOGINDEVPERM
        slave->priv->use_logindevperm = FALSE;
#endif
}

static void
gdm_simple_slave_finalize (GObject *object)
{
        GdmSimpleSlave *slave;

        g_return_if_fail (object != NULL);
        g_return_if_fail (GDM_IS_SIMPLE_SLAVE (object));

        slave = GDM_SIMPLE_SLAVE (object);

        g_return_if_fail (slave->priv != NULL);

        if (slave->priv->greeter_reset_id > 0) {
                g_source_remove (slave->priv->greeter_reset_id);
                slave->priv->greeter_reset_id = 0;
        }

        G_OBJECT_CLASS (gdm_simple_slave_parent_class)->finalize (object);
}