Add dm-tool command add-nested-seat

1 files changed, 100 insertions, 1 deletions

diff --git a/utils/dm-tool.c b/utils/dm-tool.c
index a5b174b5..bf7b82f3 100644
--- a/utils/dm-tool.c
+++ b/utils/dm-tool.c
@@ -16,6 +16,11 @@
 #include <glib/gi18n.h>
 #include <gio/gio.h>
 
+static GDBusProxy *dm_proxy, *seat_proxy;
+
+static gint xephyr_display_number;
+static GPid xephyr_pid;
+
 static void
 usage ()
 {
@@ -24,13 +29,58 @@ usage ()
     g_printerr ("\n");
 }
 
+static void
+xephyr_setup_cb (gpointer user_data)
+{
+    signal (SIGUSR1, SIG_IGN);
+}
+
+static void
+xephyr_signal_cb (int signum)
+{
+    gchar *display_number_string, *path;
+    GVariantBuilder *properties;
+    GVariant *result;
+    GError *error = NULL;
+
+    properties = g_variant_builder_new (G_VARIANT_TYPE ("a(ss)"));
+    display_number_string = g_strdup_printf ("%d", xephyr_display_number);
+    g_variant_builder_add_value (properties, g_variant_new ("(ss)", "xserver-display-number", display_number_string));
+    g_free (display_number_string);
+
+    result = g_dbus_proxy_call_sync (dm_proxy,
+                                     "AddSeat",
+                                     g_variant_new ("(sa(ss))", "xremote", properties),
+                                     G_DBUS_CALL_FLAGS_NONE,
+                                     -1,
+                                     NULL,
+                                     &error);
+    g_variant_builder_unref (properties);
+    if (!result)
+    {
+        g_printerr ("Unable to add seat: %s\n", error->message);
+        kill (xephyr_pid, SIGQUIT);
+        exit (EXIT_FAILURE);
+    }
+
+    if (!g_variant_is_of_type (result, G_VARIANT_TYPE ("(o)")))
+    {
+        g_printerr ("Unexpected response to AddSeat: %s\n", g_variant_get_type_string (result));
+        exit (EXIT_FAILURE);
+    }
+
+    g_variant_get (result, "(&o)", &path);
+    g_print ("%s\n", path);
+
+    exit (EXIT_SUCCESS);
+}
+
 int
 main (int argc, char **argv)
 {
     gchar *command;
     gint n_options;
     gchar **options;
-    GDBusProxy *dm_proxy, *seat_proxy;
     GError *error = NULL;
     gint arg_index;
     GBusType bus_type = G_BUS_TYPE_SYSTEM;
@@ -58,6 +108,7 @@ main (int argc, char **argv)
                         "  switch-to-greeter                   Switch to the greeter\n"
                         "  switch-to-user USERNAME [SESSION]   Switch to a user session\n"
                         "  switch-to-guest [SESSION]           Switch to a guest session\n"
+                        "  add-nested-seat                     Start a nested display\n"
                         "  add-seat TYPE [NAME=VALUE...]       Add a dynamic seat\n");
             return EXIT_SUCCESS;
         }
@@ -195,6 +246,54 @@ main (int argc, char **argv)
         }
         return EXIT_SUCCESS;
     }
+    else if (strcmp (command, "add-nested-seat") == 0)
+    {
+        gchar *path, *xephyr_command, **xephyr_argv;
+        GMainLoop *loop;
+
+        path = g_find_program_in_path ("Xephyr");
+        if (!path)
+        {
+            g_printerr ("Unable to find Xephry, please install it\n");
+            return EXIT_FAILURE;
+        }
+
+        /* Get a unique display number.  It's racy, but the only reliable method to get one */
+        xephyr_display_number = 0;
+        while (TRUE)
+        {
+            gchar *lock_name;
+            gboolean has_lock;
+
+            lock_name = g_strdup_printf ("/tmp/.X%d-lock", xephyr_display_number);
+            has_lock = g_file_test (lock_name, G_FILE_TEST_EXISTS);
+            g_free (lock_name);
+          
+            if (has_lock)
+                xephyr_display_number++;
+            else
+                break;
+        }
+
+        /* Wait for signal from Xephyr is ready */
+        signal (SIGUSR1, xephyr_signal_cb);
+
+        xephyr_command = g_strdup_printf ("Xephyr :%d", xephyr_display_number);
+        if (!g_shell_parse_argv (xephyr_command, NULL, &xephyr_argv, &error) ||
+            !g_spawn_async (NULL, xephyr_argv, NULL,
+                            G_SPAWN_DO_NOT_REAP_CHILD | G_SPAWN_SEARCH_PATH | G_SPAWN_STDOUT_TO_DEV_NULL | G_SPAWN_STDERR_TO_DEV_NULL,
+                            xephyr_setup_cb, NULL,
+                            &xephyr_pid, &error))
+        {
+            g_printerr ("Error running Xephyr: %s\n", error->message);
+            exit (EXIT_FAILURE);
+        }
+        g_clear_error (&error);
+
+        /* Block until ready */
+        loop = g_main_loop_new (NULL, FALSE);
+        g_main_loop_run (loop);
+    }
     else if (strcmp (command, "add-seat") == 0)
     {
         GVariant *result;