path: root/xdmcp_plugin.c

/*
 * Remmina - The GTK Remote Desktop Client
 * Copyright (C) 2010 Vic Lee
 * Copyright (C) 2014-2015 Antenore Gatta, Fabio Castelli, Giovanni Panozzo
 * Copyright (C) 2016-2021 Antenore Gatta, Giovanni Panozzo
 *
 * 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.
 *
 *  In addition, as a special exception, the copyright holders give
 *  permission to link the code of portions of this program with the
 *  OpenSSL library under certain conditions as described in each
 *  individual source file, and distribute linked combinations
 *  including the two.
 *  You must obey the GNU General Public License in all respects
 *  for all of the code used other than OpenSSL. *  If you modify
 *  file(s) with this exception, you may extend this exception to your
 *  version of the file(s), but you are not obligated to do so. *  If you
 *  do not wish to do so, delete this exception statement from your
 *  version. *  If you delete this exception statement from all source
 *  files in the program, then also delete it here.
 *
 */

#include "common/remmina_plugin.h"
#include <gtk/gtkx.h>

INCLUDE_GET_AVAILABLE_XDISPLAY

#define REMMINA_PLUGIN_XDMCP_FEATURE_TOOL_SENDCTRLALTDEL 1
#define REMMINA_PLUGIN_XDMCP_FEATURE_GTKSOCKET 1

#define GET_PLUGIN_DATA(gp) (RemminaPluginXdmcpData*)g_object_get_data(G_OBJECT(gp), "plugin-data");

/* Forward declaration */
static RemminaProtocolPlugin remmina_plugin_xdmcp;

typedef struct _RemminaPluginXdmcpData {
	GtkWidget *socket;
	gint socket_id;
	GPid pid;
	gint output_fd;
	gint error_fd;
	gint display;
	gboolean ready;

	pthread_t thread;

} RemminaPluginXdmcpData;

static RemminaPluginService *remmina_plugin_service = NULL;


static void remmina_plugin_xdmcp_on_plug_added(GtkSocket *socket, RemminaProtocolWidget *gp)
{
	TRACE_CALL(__func__);
	RemminaPluginXdmcpData *gpdata = GET_PLUGIN_DATA(gp);

	remmina_plugin_service->protocol_plugin_signal_connection_opened(gp);
	gpdata->ready = TRUE;
}

static void remmina_plugin_xdmcp_on_plug_removed(GtkSocket *socket, RemminaProtocolWidget *gp)
{
	TRACE_CALL(__func__);
	remmina_plugin_service->protocol_plugin_signal_connection_closed(gp);
}

static gboolean remmina_plugin_xdmcp_start_xephyr(RemminaProtocolWidget *gp)
{
	TRACE_CALL(__func__);
	RemminaPluginXdmcpData *gpdata = GET_PLUGIN_DATA(gp);
	RemminaFile *remminafile;
	gchar *argv[50];
	gint argc;
	gchar *host;
	gint i;
	GError *error = NULL;
	gboolean ret;

	remminafile = remmina_plugin_service->protocol_plugin_get_file(gp);

	gpdata->display = remmina_get_available_xdisplay();
	if (gpdata->display == 0) {
		remmina_plugin_service->protocol_plugin_set_error(gp, _("Ran out of available local X display numbers."));
		return FALSE;
	}

	argc = 0;
	argv[argc++] = g_strdup("Xephyr");

	argv[argc++] = g_strdup_printf(":%i", gpdata->display);

	argv[argc++] = g_strdup("-parent");
	argv[argc++] = g_strdup_printf("%i", gpdata->socket_id);

	/* All Xephyr version between 1.5.0 and 1.6.4 will break when "-screen" argument is specified with "-parent".
	 * It’s not possible to support colour depth if you have those Xephyr version. Please see this bug
	 * http://bugs.freedesktop.org/show_bug.cgi?id=24144
	 * As a workaround, a "Default" colour depth will not add the "-screen" argument.
	 */
	i = remmina_plugin_service->file_get_int(remminafile, "colordepth", 8);
	if (i >= 8) {
		argv[argc++] = g_strdup("-screen");
		argv[argc++] = g_strdup_printf("%ix%ix%i",
			remmina_plugin_service->get_profile_remote_width(gp),
			remmina_plugin_service->get_profile_remote_height(gp), i);
	}

	if (i == 2) {
		argv[argc++] = g_strdup("-grayscale");
	}

	if (remmina_plugin_service->file_get_int(remminafile, "showcursor", FALSE)) {
		argv[argc++] = g_strdup("-host-cursor");
	}
	if (remmina_plugin_service->file_get_int(remminafile, "once", FALSE)) {
		argv[argc++] = g_strdup("-once");
	}
	/* Listen on TCP protocol */
	if (remmina_plugin_service->file_get_int(remminafile, "listen_on_tcp", FALSE)) {
		argv[argc++] = g_strdup("-listen");
		argv[argc++] = g_strdup("tcp");
	}

	if (!remmina_plugin_service->file_get_int(remminafile, "ssh_tunnel_enabled", FALSE)) {
		remmina_plugin_service->get_server_port(remmina_plugin_service->file_get_string(remminafile, "server"), 0,
			&host, &i);

		argv[argc++] = g_strdup("-query");
		argv[argc++] = host;

		if (i) {
			argv[argc++] = g_strdup("-port");
			argv[argc++] = g_strdup_printf("%i", i);
		}
	}else  {
		/* When the connection is through an SSH tunnel, it connects back to local Unix socket,
		 * so for security we can disable TCP listening */
		argv[argc++] = g_strdup("-nolisten");
		argv[argc++] = g_strdup("tcp");

		/* FIXME: It’s better to get the magic cookie back from xqproxy, then call xauth,
		 * instead of disable access control */
		argv[argc++] = g_strdup("-ac");
	}

	argv[argc++] = NULL;

	ret = g_spawn_async(NULL, argv, NULL, G_SPAWN_SEARCH_PATH, NULL, NULL, &gpdata->pid, &error);
	for (i = 0; i < argc; i++)
		g_free(argv[i]);

	if (!ret) {
		remmina_plugin_service->protocol_plugin_set_error(gp, "%s", error->message);
		return FALSE;
	}

	return TRUE;
}

static gboolean remmina_plugin_xdmcp_tunnel_init_callback(RemminaProtocolWidget *gp, gint remotedisplay, const gchar *server,
							  gint port)
{
	TRACE_CALL(__func__);
	RemminaPluginXdmcpData *gpdata = GET_PLUGIN_DATA(gp);
	RemminaFile *remminafile;

	remminafile = remmina_plugin_service->protocol_plugin_get_file(gp);

	if (!remmina_plugin_xdmcp_start_xephyr(gp))
		return FALSE;
	while (!gpdata->ready)
		sleep(1);

	remmina_plugin_service->protocol_plugin_set_display(gp, gpdata->display);

	if (remmina_plugin_service->file_get_string(remminafile, "exec")) {
		return remmina_plugin_service->protocol_plugin_ssh_exec(gp, FALSE, "DISPLAY=localhost:%i.0 %s", remotedisplay,
			remmina_plugin_service->file_get_string(remminafile, "exec"));
	}else  {
		return remmina_plugin_service->protocol_plugin_ssh_exec(gp, TRUE,
			"xqproxy -display %i -host %s -port %i -query -manage", remotedisplay, server, port);
	}
}

static gboolean remmina_plugin_xdmcp_main(RemminaProtocolWidget *gp)
{
	TRACE_CALL(__func__);
	RemminaPluginXdmcpData *gpdata = GET_PLUGIN_DATA(gp);
	RemminaFile *remminafile;

	remminafile = remmina_plugin_service->protocol_plugin_get_file(gp);

	if (remmina_plugin_service->file_get_int(remminafile, "ssh_tunnel_enabled", FALSE)) {
		if (!remmina_plugin_service->protocol_plugin_start_xport_tunnel(gp, remmina_plugin_xdmcp_tunnel_init_callback)) {
			gpdata->thread = 0;
			return FALSE;
		}
	}else  {
		if (!remmina_plugin_xdmcp_start_xephyr(gp)) {
			gpdata->thread = 0;
			return FALSE;
		}
	}

	gpdata->thread = 0;
	return TRUE;
}

static gpointer
remmina_plugin_xdmcp_main_thread(gpointer data)
{
	TRACE_CALL(__func__);
	pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);

	CANCEL_ASYNC
	if (!remmina_plugin_xdmcp_main((RemminaProtocolWidget*)data)) {
		IDLE_ADD((GSourceFunc)remmina_plugin_service->protocol_plugin_signal_connection_closed, data);
	}
	return NULL;
}

static void remmina_plugin_xdmcp_init(RemminaProtocolWidget *gp)
{
	TRACE_CALL(__func__);
	RemminaPluginXdmcpData *gpdata;

	gpdata = g_new0(RemminaPluginXdmcpData, 1);
	g_object_set_data_full(G_OBJECT(gp), "plugin-data", gpdata, g_free);

	gpdata->socket = gtk_socket_new();
	remmina_plugin_service->protocol_plugin_register_hostkey(gp, gpdata->socket);
	gtk_widget_show(gpdata->socket);
	g_signal_connect(G_OBJECT(gpdata->socket), "plug-added", G_CALLBACK(remmina_plugin_xdmcp_on_plug_added), gp);
	g_signal_connect(G_OBJECT(gpdata->socket), "plug-removed", G_CALLBACK(remmina_plugin_xdmcp_on_plug_removed), gp);
	gtk_container_add(GTK_CONTAINER(gp), gpdata->socket);

}



static gboolean remmina_plugin_xdmcp_open_connection(RemminaProtocolWidget *gp)
{
	TRACE_CALL(__func__);
	RemminaPluginXdmcpData *gpdata = GET_PLUGIN_DATA(gp);
	RemminaFile *remminafile;
	gint width, height;

	if (!remmina_plugin_service->gtksocket_available()) {
		remmina_plugin_service->protocol_plugin_set_error(gp,
			_("The protocol “%s” is unavailable because GtkSocket only works under X.Org."),
			remmina_plugin_xdmcp.name);
		return FALSE;
	}

	remminafile = remmina_plugin_service->protocol_plugin_get_file(gp);

	width = remmina_plugin_service->get_profile_remote_width(gp);
	height = remmina_plugin_service->get_profile_remote_height(gp);
	remmina_plugin_service->protocol_plugin_set_width(gp, width);
	remmina_plugin_service->protocol_plugin_set_height(gp, height);
	gtk_widget_set_size_request(GTK_WIDGET(gp), width, height);
	gpdata->socket_id = gtk_socket_get_id(GTK_SOCKET(gpdata->socket));


	if (remmina_plugin_service->file_get_int(remminafile, "ssh_tunnel_enabled", FALSE)) {
		if (pthread_create(&gpdata->thread, NULL, remmina_plugin_xdmcp_main_thread, gp)) {
			remmina_plugin_service->protocol_plugin_set_error(gp,
				"Could not start pthread. Using non-threaded mode instead…");
			gpdata->thread = 0;
			return FALSE;
		}else  {
			return TRUE;
		}
	}else  {
		return remmina_plugin_xdmcp_main(gp);
	}

}

static gboolean remmina_plugin_xdmcp_close_connection(RemminaProtocolWidget *gp)
{
	TRACE_CALL(__func__);
	RemminaPluginXdmcpData *gpdata = GET_PLUGIN_DATA(gp);

	if (gpdata->thread) {
		pthread_cancel(gpdata->thread);
		if (gpdata->thread) pthread_join(gpdata->thread, NULL);
	}

	if (gpdata->pid) {
		kill(gpdata->pid, SIGTERM);
		g_spawn_close_pid(gpdata->pid);
		gpdata->pid = 0;
	}

	remmina_plugin_service->protocol_plugin_signal_connection_closed(gp);

	return FALSE;
}

/* Send Ctrl+Alt+Del keystrokes to the plugin socket widget */
static void remmina_plugin_xdmcp_send_ctrlaltdel(RemminaProtocolWidget *gp)
{
	TRACE_CALL(__func__);
	guint keys[] = { GDK_KEY_Control_L, GDK_KEY_Alt_L, GDK_KEY_Delete };
	RemminaPluginXdmcpData *gpdata = GET_PLUGIN_DATA(gp);

	remmina_plugin_service->protocol_plugin_send_keys_signals(gpdata->socket,
		keys, G_N_ELEMENTS(keys), GDK_KEY_PRESS | GDK_KEY_RELEASE);
}

static gboolean remmina_plugin_xdmcp_query_feature(RemminaProtocolWidget *gp, const RemminaProtocolFeature *feature)
{
	TRACE_CALL(__func__);
	return TRUE;
}

static void remmina_plugin_xdmcp_call_feature(RemminaProtocolWidget *gp, const RemminaProtocolFeature *feature)
{
	TRACE_CALL(__func__);

	switch (feature->id) {
	case REMMINA_PLUGIN_XDMCP_FEATURE_TOOL_SENDCTRLALTDEL:
		remmina_plugin_xdmcp_send_ctrlaltdel(gp);
		break;
	default:
		break;
	}
}

/* Array of key/value pairs for colour depths */
static gpointer colordepth_list[] =
{
	"0",  N_("Default"),
	"2",  N_("Grayscale"),
	"8",  N_("256 colours"),
	"16", N_("High colour (16 bit)"),
	"24", N_("True colour (24 bit)"),
	NULL
};

/* Array of RemminaProtocolSetting for basic settings.
 * Each item is composed by:
 * a) RemminaProtocolSettingType for setting type
 * b) Setting name
 * c) Setting description
 * d) Compact disposition
 * e) Values for REMMINA_PROTOCOL_SETTING_TYPE_SELECT or REMMINA_PROTOCOL_SETTING_TYPE_COMBO
 * f) Setting tooltip
 */
static const RemminaProtocolSetting remmina_plugin_xdmcp_basic_settings[] =
{
	{ REMMINA_PROTOCOL_SETTING_TYPE_SERVER,	    "server",	     NULL,					 FALSE, NULL,		 NULL },
	{ REMMINA_PROTOCOL_SETTING_TYPE_RESOLUTION, "resolution",	     NULL,					 FALSE, NULL,		 NULL },
	{ REMMINA_PROTOCOL_SETTING_TYPE_SELECT,	    "colordepth",    N_("Colour depth"),				 FALSE, colordepth_list, NULL },
	{ REMMINA_PROTOCOL_SETTING_TYPE_TEXT,	    "exec",	     N_("Start-up program"),			 FALSE, NULL,		 NULL },
	{ REMMINA_PROTOCOL_SETTING_TYPE_CHECK,	    "showcursor",    N_("Use local cursor"),			 FALSE, NULL,		 NULL },
	{ REMMINA_PROTOCOL_SETTING_TYPE_CHECK,	    "once",	     N_("Disconnect after first session"),	 FALSE, NULL,		 NULL },
	{ REMMINA_PROTOCOL_SETTING_TYPE_CHECK,	    "listen_on_tcp", N_("Listen for TCP connections"), FALSE, NULL,		 NULL },
	{ REMMINA_PROTOCOL_SETTING_TYPE_END,	    NULL,	     NULL,					 FALSE, NULL,		 NULL }
};

/* Array for available features.
 * The last element of the array must be REMMINA_PROTOCOL_FEATURE_TYPE_END. */
static const RemminaProtocolFeature remmina_plugin_xdmcp_features[] =
{
	{ REMMINA_PROTOCOL_FEATURE_TYPE_TOOL, REMMINA_PLUGIN_XDMCP_FEATURE_TOOL_SENDCTRLALTDEL, N_("Send Ctrl+Alt+Delete"), NULL, NULL },
	{ REMMINA_PROTOCOL_FEATURE_TYPE_GTKSOCKET, REMMINA_PLUGIN_XDMCP_FEATURE_GTKSOCKET,	    NULL,	   NULL,	NULL},
	{ REMMINA_PROTOCOL_FEATURE_TYPE_END,  0,						NULL,			    NULL, NULL }
};

/* Protocol plugin definition and features */
static RemminaProtocolPlugin remmina_plugin_xdmcp =
{
	REMMINA_PLUGIN_TYPE_PROTOCOL,                   // Type
	"XDMCP",                                        // Name
	N_("XDMCP - X Remote Session"),                 // Description
	GETTEXT_PACKAGE,                                // Translation domain
	VERSION,                                        // Version number
	"remmina-xdmcp-symbolic",                       // Icon for normal connection
	"remmina-xdmcp-ssh-symbolic",                   // Icon for SSH connection
	remmina_plugin_xdmcp_basic_settings,            // Array for basic settings
	NULL,                                           // Array for advanced settings
	REMMINA_PROTOCOL_SSH_SETTING_TUNNEL,            // SSH settings type
	remmina_plugin_xdmcp_features,                  // Array for available features
	remmina_plugin_xdmcp_init,                      // Plugin initialization
	remmina_plugin_xdmcp_open_connection,           // Plugin open connection
	remmina_plugin_xdmcp_close_connection,          // Plugin close connection
	remmina_plugin_xdmcp_query_feature,             // Query for available features
	remmina_plugin_xdmcp_call_feature,              // Call a feature
	NULL,                                           // Send a keystroke
	NULL                                            // No screenshot support available
};

G_MODULE_EXPORT gboolean
remmina_plugin_entry(RemminaPluginService *service)
{
	TRACE_CALL(__func__);
	remmina_plugin_service = service;

	bindtextdomain(GETTEXT_PACKAGE, REMMINA_RUNTIME_LOCALEDIR);
	bind_textdomain_codeset(GETTEXT_PACKAGE, "UTF-8");

	if (!service->register_plugin((RemminaPlugin*)&remmina_plugin_xdmcp)) {
		return FALSE;
	}

	return TRUE;
}