[mutter] remote-access-controller: Allow inhibiting remote access

[Jonas Ådahl <jadahl src gnome org>]

commit 4300f1f91d726051893146d7b294d8852782f137
Author: Jonas Ådahl <jadahl gmail com>
Date:   Tue Apr 21 15:44:32 2020 +0200

    remote-access-controller: Allow inhibiting remote access
    
    Inhibiting remote access means any current remote access session is
    terminated, and no new ones can be created, until remote access is
    uninhibited. The inhibitation is ref counted, meaning there can be more
    than one inhibitor.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1212

 src/backends/meta-backend-types.h                  |  1 +
 src/backends/meta-backend.c                        |  4 +-
 .../meta-remote-access-controller-private.h        |  4 ++
 src/backends/meta-remote-access-controller.c       | 49 ++++++++++++++++++++++
 src/backends/meta-remote-desktop.c                 | 39 +++++++++++++++++
 src/backends/meta-remote-desktop.h                 |  4 ++
 src/backends/meta-screen-cast.c                    | 34 +++++++++++++++
 src/backends/meta-screen-cast.h                    |  4 ++
 src/meta/meta-remote-access-controller.h           |  6 +++
 9 files changed, 143 insertions(+), 2 deletions(-)
---
diff --git a/src/backends/meta-backend-types.h b/src/backends/meta-backend-types.h
index eb982d73e..98cac8b9e 100644
--- a/src/backends/meta-backend-types.h
+++ b/src/backends/meta-backend-types.h
@@ -49,6 +49,7 @@ typedef struct _MetaTileInfo MetaTileInfo;
 typedef struct _MetaRenderer MetaRenderer;
 typedef struct _MetaRendererView MetaRendererView;
 
+typedef struct _MetaRemoteDesktop MetaRemoteDesktop;
 typedef struct _MetaScreenCast MetaScreenCast;
 typedef struct _MetaScreenCastSession MetaScreenCastSession;
 typedef struct _MetaScreenCastStream MetaScreenCastStream;
diff --git a/src/backends/meta-backend.c b/src/backends/meta-backend.c
index 6c5f61336..1c6a6783a 100644
--- a/src/backends/meta-backend.c
+++ b/src/backends/meta-backend.c
@@ -552,12 +552,12 @@ meta_backend_real_post_init (MetaBackend *backend)
     }
 
 #ifdef HAVE_REMOTE_DESKTOP
-  priv->remote_access_controller =
-    g_object_new (META_TYPE_REMOTE_ACCESS_CONTROLLER, NULL);
   priv->dbus_session_watcher = g_object_new (META_TYPE_DBUS_SESSION_WATCHER, NULL);
   priv->screen_cast = meta_screen_cast_new (backend,
                                             priv->dbus_session_watcher);
   priv->remote_desktop = meta_remote_desktop_new (priv->dbus_session_watcher);
+  priv->remote_access_controller =
+    meta_remote_access_controller_new (priv->remote_desktop, priv->screen_cast);
 #endif /* HAVE_REMOTE_DESKTOP */
 
   if (!meta_monitor_manager_is_headless (priv->monitor_manager))
diff --git a/src/backends/meta-remote-access-controller-private.h 
b/src/backends/meta-remote-access-controller-private.h
index 81477057c..8c8a319c4 100644
--- a/src/backends/meta-remote-access-controller-private.h
+++ b/src/backends/meta-remote-access-controller-private.h
@@ -21,8 +21,12 @@
 #ifndef META_REMOTE_ACCESS_CONTROLLER_PRIVATE_H
 #define META_REMOTE_ACCESS_CONTROLLER_PRIVATE_H
 
+#include "backends/meta-backend-types.h"
 #include "meta/meta-remote-access-controller.h"
 
+MetaRemoteAccessController * meta_remote_access_controller_new (MetaRemoteDesktop *remote_desktop,
+                                                                MetaScreenCast    *screen_cast);
+
 void meta_remote_access_controller_notify_new_handle (MetaRemoteAccessController *controller,
                                                       MetaRemoteAccessHandle     *handle);
 
diff --git a/src/backends/meta-remote-access-controller.c b/src/backends/meta-remote-access-controller.c
index e9b2a70f6..71b7f1f7b 100644
--- a/src/backends/meta-remote-access-controller.c
+++ b/src/backends/meta-remote-access-controller.c
@@ -22,6 +22,9 @@
 
 #include "backends/meta-remote-access-controller-private.h"
 
+#include "backends/meta-remote-desktop.h"
+#include "backends/meta-screen-cast.h"
+
 enum
 {
   HANDLE_STOPPED,
@@ -54,6 +57,9 @@ G_DEFINE_TYPE_WITH_PRIVATE (MetaRemoteAccessHandle,
 struct _MetaRemoteAccessController
 {
   GObject parent;
+
+  MetaRemoteDesktop *remote_desktop;
+  MetaScreenCast *screen_cast;
 };
 
 G_DEFINE_TYPE (MetaRemoteAccessController,
@@ -122,6 +128,49 @@ meta_remote_access_controller_notify_new_handle (MetaRemoteAccessController *con
                  handle);
 }
 
+/**
+ * meta_remote_access_controller_inhibit_remote_access:
+ * @controller: a #MetaRemoteAccessController
+ *
+ * Inhibits remote access sessions from being created and running. Any active
+ * remote access session will be terminated.
+ */
+void
+meta_remote_access_controller_inhibit_remote_access (MetaRemoteAccessController *controller)
+{
+  meta_remote_desktop_inhibit (controller->remote_desktop);
+  meta_screen_cast_inhibit (controller->screen_cast);
+}
+
+/**
+ * meta_remote_access_controller_uninhibit_remote_access:
+ * @controller: a #MetaRemoteAccessController
+ *
+ * Uninhibits remote access sessions from being created and running. If this was
+ * the last inhibitation that was inhibited, new remote access sessions can now
+ * be created.
+ */
+void
+meta_remote_access_controller_uninhibit_remote_access (MetaRemoteAccessController *controller)
+{
+  meta_screen_cast_uninhibit (controller->screen_cast);
+  meta_remote_desktop_uninhibit (controller->remote_desktop);
+}
+
+MetaRemoteAccessController *
+meta_remote_access_controller_new (MetaRemoteDesktop *remote_desktop,
+                                   MetaScreenCast    *screen_cast)
+{
+  MetaRemoteAccessController *remote_access_controller;
+
+  remote_access_controller = g_object_new (META_TYPE_REMOTE_ACCESS_CONTROLLER,
+                                           NULL);
+  remote_access_controller->remote_desktop = remote_desktop;
+  remote_access_controller->screen_cast = screen_cast;
+
+  return remote_access_controller;
+}
+
 static void
 meta_remote_access_handle_init (MetaRemoteAccessHandle *handle)
 {
diff --git a/src/backends/meta-remote-desktop.c b/src/backends/meta-remote-desktop.c
index b94055885..95dd95e7e 100644
--- a/src/backends/meta-remote-desktop.c
+++ b/src/backends/meta-remote-desktop.c
@@ -56,6 +56,8 @@ struct _MetaRemoteDesktop
 
   int dbus_name_id;
 
+  int inhibit_count;
+
   GHashTable *sessions;
 
   MetaDbusSessionWatcher *session_watcher;
@@ -70,6 +72,34 @@ G_DEFINE_TYPE_WITH_CODE (MetaRemoteDesktop,
                          G_IMPLEMENT_INTERFACE (META_DBUS_TYPE_REMOTE_DESKTOP,
                                                 meta_remote_desktop_init_iface));
 
+void
+meta_remote_desktop_inhibit (MetaRemoteDesktop *remote_desktop)
+{
+  remote_desktop->inhibit_count++;
+  if (remote_desktop->inhibit_count == 1)
+    {
+      GHashTableIter iter;
+      gpointer key, value;
+
+      g_hash_table_iter_init (&iter, remote_desktop->sessions);
+      while (g_hash_table_iter_next (&iter, &key, &value))
+        {
+          MetaRemoteDesktopSession *session = value;
+
+          g_hash_table_iter_steal (&iter);
+          meta_remote_desktop_session_close (session);
+        }
+    }
+}
+
+void
+meta_remote_desktop_uninhibit (MetaRemoteDesktop *remote_desktop)
+{
+  g_return_if_fail (remote_desktop->inhibit_count > 0);
+
+  remote_desktop->inhibit_count--;
+}
+
 GDBusConnection *
 meta_remote_desktop_get_connection (MetaRemoteDesktop *remote_desktop)
 {
@@ -108,6 +138,15 @@ handle_create_session (MetaDBusRemoteDesktop *skeleton,
   char *session_path;
   const char *client_dbus_name;
 
+  if (remote_desktop->inhibit_count > 0)
+    {
+      g_dbus_method_invocation_return_error (invocation, G_DBUS_ERROR,
+                                             G_DBUS_ERROR_ACCESS_DENIED,
+                                             "Session creation inhibited");
+
+      return TRUE;
+    }
+
   peer_name = g_dbus_method_invocation_get_sender (invocation);
   session = meta_remote_desktop_session_new (remote_desktop,
                                              peer_name,
diff --git a/src/backends/meta-remote-desktop.h b/src/backends/meta-remote-desktop.h
index 3eebc13d5..210a84a04 100644
--- a/src/backends/meta-remote-desktop.h
+++ b/src/backends/meta-remote-desktop.h
@@ -36,6 +36,10 @@ G_DECLARE_FINAL_TYPE (MetaRemoteDesktop, meta_remote_desktop,
                       META, REMOTE_DESKTOP,
                       MetaDBusRemoteDesktopSkeleton)
 
+void meta_remote_desktop_inhibit (MetaRemoteDesktop *remote_desktop);
+
+void meta_remote_desktop_uninhibit (MetaRemoteDesktop *remote_desktop);
+
 MetaRemoteDesktopSession * meta_remote_desktop_get_session (MetaRemoteDesktop *remote_desktop,
                                                             const char        *session_id);
 
diff --git a/src/backends/meta-screen-cast.c b/src/backends/meta-screen-cast.c
index b473aa8eb..fddaf4fca 100644
--- a/src/backends/meta-screen-cast.c
+++ b/src/backends/meta-screen-cast.c
@@ -40,6 +40,8 @@ struct _MetaScreenCast
 
   int dbus_name_id;
 
+  int inhibit_count;
+
   GList *sessions;
 
   MetaDbusSessionWatcher *session_watcher;
@@ -54,6 +56,29 @@ G_DEFINE_TYPE_WITH_CODE (MetaScreenCast, meta_screen_cast,
                          G_IMPLEMENT_INTERFACE (META_DBUS_TYPE_SCREEN_CAST,
                                                 meta_screen_cast_init_iface))
 
+void
+meta_screen_cast_inhibit (MetaScreenCast *screen_cast)
+{
+  screen_cast->inhibit_count++;
+  if (screen_cast->inhibit_count == 1)
+    {
+      while (screen_cast->sessions)
+        {
+          MetaScreenCastSession *session = screen_cast->sessions->data;
+
+          meta_screen_cast_session_close (session);
+        }
+    }
+}
+
+void
+meta_screen_cast_uninhibit (MetaScreenCast *screen_cast)
+{
+  g_return_if_fail (screen_cast->inhibit_count > 0);
+
+  screen_cast->inhibit_count--;
+}
+
 GDBusConnection *
 meta_screen_cast_get_connection (MetaScreenCast *screen_cast)
 {
@@ -119,6 +144,15 @@ handle_create_session (MetaDBusScreenCast    *skeleton,
   gboolean disable_animations;
   MetaScreenCastSessionType session_type;
 
+  if (screen_cast->inhibit_count > 0)
+    {
+      g_dbus_method_invocation_return_error (invocation, G_DBUS_ERROR,
+                                             G_DBUS_ERROR_ACCESS_DENIED,
+                                             "Session creation inhibited");
+
+      return TRUE;
+    }
+
   g_variant_lookup (properties, "remote-desktop-session-id", "s",
                     &remote_desktop_session_id);
 
diff --git a/src/backends/meta-screen-cast.h b/src/backends/meta-screen-cast.h
index 994c40c53..a3b650cd8 100644
--- a/src/backends/meta-screen-cast.h
+++ b/src/backends/meta-screen-cast.h
@@ -42,6 +42,10 @@ G_DECLARE_FINAL_TYPE (MetaScreenCast, meta_screen_cast,
                       META, SCREEN_CAST,
                       MetaDBusScreenCastSkeleton)
 
+void meta_screen_cast_inhibit (MetaScreenCast *screen_cast);
+
+void meta_screen_cast_uninhibit (MetaScreenCast *screen_cast);
+
 GDBusConnection * meta_screen_cast_get_connection (MetaScreenCast *screen_cast);
 
 MetaBackend * meta_screen_cast_get_backend (MetaScreenCast *screen_cast);
diff --git a/src/meta/meta-remote-access-controller.h b/src/meta/meta-remote-access-controller.h
index 939566a36..81b717eac 100644
--- a/src/meta/meta-remote-access-controller.h
+++ b/src/meta/meta-remote-access-controller.h
@@ -54,4 +54,10 @@ G_DECLARE_FINAL_TYPE (MetaRemoteAccessController,
                       META, REMOTE_ACCESS_CONTROLLER,
                       GObject)
 
+META_EXPORT
+void meta_remote_access_controller_inhibit_remote_access (MetaRemoteAccessController *controller);
+
+META_EXPORT
+void meta_remote_access_controller_uninhibit_remote_access (MetaRemoteAccessController *controller);
+
 #endif /* META_REMOTE_ACCESS_CONTROLLER_H */