Cppcheck report - cafe-screensaver (cppcheck 2.14.0-1+b1): src/cafe-screensaver-command.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
 *
 * Copyright (C) 2004-2006 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 St, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 * Authors: William Jon McCann <mccann@jhu.edu>
 *
 */

#include "config.h"

#include <stdlib.h>
#include <locale.h>
#include <glib.h>
#include <glib/gi18n.h>

#define DBUS_API_SUBJECT_TO_CHANGE
#include <dbus/dbus.h>
#include <dbus/dbus-glib.h>
#include <dbus/dbus-glib-lowlevel.h>

#define GS_SERVICE   "org.cafe.ScreenSaver"
#define GS_PATH      "/org/cafe/ScreenSaver"
#define GS_INTERFACE "org.cafe.ScreenSaver"

static gboolean do_quit       = FALSE;
static gboolean do_lock       = FALSE;
static gboolean do_unlock     = FALSE;
static gboolean do_cycle      = FALSE;
static gboolean do_activate   = FALSE;
static gboolean do_deactivate = FALSE;
static gboolean do_version    = FALSE;
static gboolean do_poke       = FALSE;
static gboolean do_inhibit    = FALSE;

static gboolean do_query      = FALSE;
static gboolean do_time       = FALSE;

static char    *inhibit_reason      = NULL;
static char    *inhibit_application = NULL;

static GOptionEntry entries [] =
{
	{
		"exit", 0, 0, G_OPTION_ARG_NONE, &do_quit,
		N_("Causes the screensaver to exit gracefully"), NULL
	},
	{
		"query", 'q', 0, G_OPTION_ARG_NONE, &do_query,
		N_("Query the state of the screensaver"), NULL
	},
	{
		"time", 't', 0, G_OPTION_ARG_NONE, &do_time,
		N_("Query the length of time the screensaver has been active"), NULL
	},
	{
		"lock", 'l', 0, G_OPTION_ARG_NONE, &do_lock,
		N_("Tells the running screensaver process to lock the screen immediately"), NULL
	},
	{
		"unlock", 'u', 0, G_OPTION_ARG_NONE, &do_unlock,
		N_("Tells the running screensaver process to unlock the screen immediately"), NULL
	},
	{
		"cycle", 'c', 0, G_OPTION_ARG_NONE, &do_cycle,
		N_("If the screensaver is active then switch to another graphics demo"), NULL
	},
	{
		"activate", 'a', 0, G_OPTION_ARG_NONE, &do_activate,
		N_("Turn the screensaver on (blank the screen)"), NULL
	},
	{
		"deactivate", 'd', 0, G_OPTION_ARG_NONE, &do_deactivate,
		N_("If the screensaver is active then deactivate it (un-blank the screen)"), NULL
	},
	{
		"poke", 'p', 0, G_OPTION_ARG_NONE, &do_poke,
		N_("Poke the running screensaver to simulate user activity"), NULL
	},
	{
		"inhibit", 'i', 0, G_OPTION_ARG_NONE, &do_inhibit,
		N_("Inhibit the screensaver from activating.  Command blocks while inhibit is active."), NULL
	},
	{
		"application-name", 'n', 0, G_OPTION_ARG_STRING, &inhibit_application,
		N_("The calling application that is inhibiting the screensaver"), NULL
	},
	{
		"reason", 'r', 0, G_OPTION_ARG_STRING, &inhibit_reason,
		N_("The reason for inhibiting the screensaver"), NULL
	},
	{
		"version", 'V', 0, G_OPTION_ARG_NONE, &do_version,
		N_("Version of this application"), NULL
	},
	{ NULL }
};

static GMainLoop *loop = NULL;

static gboolean
screensaver_is_running (DBusConnection *connection)
{
	DBusError               error;
	gboolean                exists;

	g_return_val_if_fail (connection != NULL, FALSE);

	dbus_error_init (&error);
	exists = dbus_bus_name_has_owner (connection, GS_SERVICE, &error);
	if (dbus_error_is_set (&error))
		dbus_error_free (&error);

	return exists;
}

static DBusMessage *
screensaver_send_message_inhibit (DBusConnection *connection,
                                  const char     *application,
                                  const char     *reason)
{
	DBusMessage    *message;
	DBusMessage    *reply;
	DBusError       error;
	DBusMessageIter iter;

	g_return_val_if_fail (connection != NULL, NULL);

	dbus_error_init (&error);

	message = dbus_message_new_method_call (GS_SERVICE, GS_PATH, GS_INTERFACE, "Inhibit");
	if (message == NULL)
	{
		g_warning ("Couldn't allocate the dbus message");
		return NULL;
	}

	dbus_message_iter_init_append (message, &iter);
	dbus_message_iter_append_basic (&iter, DBUS_TYPE_STRING, &application);
	dbus_message_iter_append_basic (&iter, DBUS_TYPE_STRING, &reason);

	reply = dbus_connection_send_with_reply_and_block (connection,
	        message,
	        -1, &error);
	if (dbus_error_is_set (&error))
	{
		g_warning ("%s raised:\n %s\n\n", error.name, error.message);
		reply = NULL;
	}

	dbus_connection_flush (connection);

	dbus_message_unref (message);
	dbus_error_free (&error);

	return reply;
}

static DBusMessage *
screensaver_send_message_bool (DBusConnection *connection,
                               const char     *name,
                               gboolean        value)
{
	DBusMessage    *message;
	DBusMessage    *reply;
	DBusError       error;
	DBusMessageIter iter;

	g_return_val_if_fail (connection != NULL, NULL);
	g_return_val_if_fail (name != NULL, NULL);

	dbus_error_init (&error);

	message = dbus_message_new_method_call (GS_SERVICE, GS_PATH, GS_INTERFACE, name);
	if (message == NULL)
	{
		g_warning ("Couldn't allocate the dbus message");
		return NULL;
	}

	dbus_message_iter_init_append (message, &iter);
	dbus_message_iter_append_basic (&iter, DBUS_TYPE_BOOLEAN, &value);

	reply = dbus_connection_send_with_reply_and_block (connection,
	        message,
	        -1, &error);
	if (dbus_error_is_set (&error))
	{
		g_warning ("%s raised:\n %s\n\n", error.name, error.message);
		reply = NULL;
	}

	dbus_connection_flush (connection);

	dbus_message_unref (message);
	dbus_error_free (&error);

	return reply;
}

static DBusMessage *
screensaver_send_message_void (DBusConnection *connection,
                               const char     *name,
                               gboolean        expect_reply)
{
	DBusMessage *message;
	DBusMessage *reply;
	DBusError    error;

	g_return_val_if_fail (connection != NULL, NULL);
	g_return_val_if_fail (name != NULL, NULL);

	dbus_error_init (&error);

	message = dbus_message_new_method_call (GS_SERVICE, GS_PATH, GS_INTERFACE, name);
	if (message == NULL)
	{
		g_warning ("Couldn't allocate the dbus message");
		return NULL;
	}

	if (! expect_reply)
	{
		if (!dbus_connection_send (connection, message, NULL))
			g_warning ("could not send message");
		reply = NULL;
	}
	else
	{
		reply = dbus_connection_send_with_reply_and_block (connection,
		        message,
		        -1, &error);
		if (dbus_error_is_set (&error))
		{
			g_warning ("%s raised:\n %s\n\n", error.name, error.message);
			reply = NULL;
		}
	}
	dbus_connection_flush (connection);

	dbus_message_unref (message);
	dbus_error_free (&error);

	return reply;
}

static char **
get_string_from_iter (DBusMessageIter *iter,
                      int             *num_elements)
{
	int    count;
	char **buffer;

	if (num_elements != NULL)
	{
		*num_elements = 0;
	}

	count = 0;
	buffer = (char **)malloc (sizeof (char *) * 8);

	if (buffer == NULL)
	{
		goto oom;
	}

	buffer[0] = NULL;
	while (dbus_message_iter_get_arg_type (iter) == DBUS_TYPE_STRING)
	{
		const char *value;
		char       *str;

		if ((count % 8) == 0 && count != 0)
		{
			buffer = realloc (buffer, sizeof (char *) * (count + 8));<--- Common realloc mistake: 'buffer' nulled but not freed upon failure
			if (buffer == NULL)
			{
				goto oom;
			}
		}

		dbus_message_iter_get_basic (iter, &value);
		str = strdup (value);
		if (str == NULL)
		{
			goto oom;
		}

		buffer[count] = str;

		dbus_message_iter_next (iter);
		count++;
	}

	if ((count % 8) == 0)
	{
		buffer = realloc (buffer, sizeof (char *) * (count + 1));<--- Common realloc mistake: 'buffer' nulled but not freed upon failure
		if (buffer == NULL)
		{
			goto oom;
		}
	}

	buffer[count] = NULL;
	if (num_elements != NULL)
	{
		*num_elements = count;
	}
	return buffer;

oom:
	g_debug ("%s %d : error allocating memory\n", __FILE__, __LINE__);
	return NULL;

}

static gboolean
do_command (DBusConnection *connection)
{
	DBusMessage *reply;

	if (do_quit)
	{
		reply = screensaver_send_message_void (connection, "Quit", FALSE);
		goto done;
	}

	if (do_query)
	{
		DBusMessageIter iter;
		DBusMessageIter array;
		dbus_bool_t     v;

		reply = screensaver_send_message_void (connection, "GetActive", TRUE);
		if (! reply)
		{
			g_message ("Did not receive a reply from the screensaver.");
			goto done;
		}

		dbus_message_iter_init (reply, &iter);
		dbus_message_iter_get_basic (&iter, &v);
		g_print (_("The screensaver is %s\n"), v ? _("active") : _("inactive"));

		dbus_message_unref (reply);

		reply = screensaver_send_message_void (connection, "GetInhibitors", TRUE);
		if (! reply)
		{
			g_message ("Did not receive a reply from screensaver.");
			goto done;
		}

		dbus_message_iter_init (reply, &iter);
		dbus_message_iter_recurse (&iter, &array);

		if (dbus_message_iter_get_arg_type (&array) == DBUS_TYPE_INVALID)
		{
			g_print (_("The screensaver is not inhibited\n"));
		}
		else
		{
			char **inhibitors;
			int    i;
			int    num;

			g_print (_("The screensaver is being inhibited by:\n"));
			inhibitors = get_string_from_iter (&array, &num);
			for (i = 0; i < num; i++)
			{
				g_print ("\t%s\n", inhibitors[i]);
			}
			g_strfreev (inhibitors);
		}

		dbus_message_unref (reply);
	}

	if (do_time)
	{
		DBusMessageIter iter;
		dbus_bool_t     v;
		dbus_int32_t    t;

		reply = screensaver_send_message_void (connection, "GetActive", TRUE);
		if (! reply)
		{
			g_message ("Did not receive a reply from the screensaver.");
			goto done;
		}

		dbus_message_iter_init (reply, &iter);
		dbus_message_iter_get_basic (&iter, &v);
		dbus_message_unref (reply);

		if (v)
		{

			reply = screensaver_send_message_void (connection, "GetActiveTime", TRUE);
			dbus_message_iter_init (reply, &iter);
			dbus_message_iter_get_basic (&iter, &t);
			g_print (_("The screensaver has been active for %d seconds.\n"), t);

			dbus_message_unref (reply);
		}
		else
		{
			g_print (_("The screensaver is not currently active.\n"));
		}
	}

	if (do_lock)
	{
		reply = screensaver_send_message_void (connection, "Lock", FALSE);<--- Variable 'reply' is assigned a value that is never used.
	}

	if (do_unlock)
	{
		reply = screensaver_send_message_void (connection, "Unlock", FALSE);<--- Variable 'reply' is assigned a value that is never used.
	}

	if (do_cycle)
	{
		reply = screensaver_send_message_void (connection, "Cycle", FALSE);<--- Variable 'reply' is assigned a value that is never used.
	}

	if (do_poke)
	{
		reply = screensaver_send_message_void (connection, "SimulateUserActivity", FALSE);<--- Variable 'reply' is assigned a value that is never used.
	}

	if (do_activate)
	{
		reply = screensaver_send_message_bool (connection, "SetActive", TRUE);
		if (! reply)
		{
			g_message ("Did not receive a reply from the screensaver.");
			goto done;
		}
		dbus_message_unref (reply);
	}

	if (do_deactivate)
	{
		reply = screensaver_send_message_bool (connection, "SetActive", FALSE);
		if (! reply)
		{
			g_message ("Did not receive a reply from the screensaver.");
			goto done;
		}
		dbus_message_unref (reply);
	}

	if (do_inhibit)
	{
		reply = screensaver_send_message_inhibit (connection,
		        inhibit_application ? inhibit_application : "Unknown",
		        inhibit_reason ? inhibit_reason : "Unknown");
		if (! reply)
		{
			g_message ("Did not receive a reply from the screensaver.");
			goto done;
		}
		dbus_message_unref (reply);

		return FALSE;
	}

done:
	g_main_loop_quit (loop);

	return FALSE;
}

int
main (int    argc,
      char **argv)
{
	DBusConnection *connection;
	DBusError       dbus_error;
	GOptionContext *context;
	gboolean        retval;
	GError         *error = NULL;

#ifdef ENABLE_NLS
	bindtextdomain (GETTEXT_PACKAGE, CAFELOCALEDIR);
# ifdef HAVE_BIND_TEXTDOMAIN_CODESET
	bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
# endif
	textdomain (GETTEXT_PACKAGE);
#endif

	g_set_prgname (argv[0]);

	if (setlocale (LC_ALL, "") == NULL)
		g_warning ("Locale not understood by C library, internationalization will not work\n");

	context = g_option_context_new (NULL);
	g_option_context_add_main_entries (context, entries, NULL);
	retval = g_option_context_parse (context, &argc, &argv, &error);

	g_option_context_free (context);

	if (! retval)
	{
		g_warning ("%s", error->message);
		g_error_free (error);
		exit (1);
	}

	if (do_version)
	{
		g_print ("%s %s\n", argv [0], VERSION);
		exit (1);
	}

	dbus_error_init (&dbus_error);
	connection = dbus_bus_get (DBUS_BUS_SESSION, &dbus_error);
	if (! connection)
	{
		g_message ("Failed to connect to the D-BUS daemon: %s", dbus_error.message);
		dbus_error_free (&dbus_error);
		exit (1);
	}

	dbus_connection_setup_with_g_main (connection, NULL);

	if (! screensaver_is_running (connection))
	{
		g_message ("Screensaver is not running!");
		exit (1);
	}

	g_idle_add ((GSourceFunc)do_command, connection);

	loop = g_main_loop_new (NULL, FALSE);
	g_main_loop_run (loop);

	return 0;
}