wayland: add TTY and DRM master management

Now that we have a setuid launcher binary, we can make use of
using a private protocol through the socket we're passed at startup.

We also use the new hook in clutter-evdev to ask mutter-launch for
the FDs of the input devices we need, and we emulate the old X
DRM lock with a nested GMainContext without sources.

In the future, mutter-launch will be replaced with the new logind
API currently in development.

https://bugzilla.gnome.org/show_bug.cgi?id=705861

configure.ac

@@ -232,7 +232,7 @@ AS_IF([test "x$WAYLAND_SCANNER" = "xno"],
 AC_SUBST([WAYLAND_SCANNER])
 AC_SUBST(XWAYLAND_PATH)
 
-MUTTER_PC_MODULES="$MUTTER_PC_MODULES wayland-server"
+MUTTER_PC_MODULES="$MUTTER_PC_MODULES wayland-server libdrm"
 PKG_CHECK_MODULES(MUTTER, $MUTTER_PC_MODULES)
 
 PKG_CHECK_EXISTS([xi >= 1.6.99.1],

src/Makefile.am

@@ -195,7 +195,9 @@ libmutter_wayland_la_SOURCES +=			\
 	wayland/meta-wayland-seat.c		\
 	wayland/meta-wayland-seat.h		\
 	wayland/meta-wayland-stage.h		\
-	wayland/meta-wayland-stage.c
+	wayland/meta-wayland-stage.c		\
+	wayland/meta-weston-launch.c		\
+	wayland/meta-weston-launch.h
 
 libmutter_wayland_la_LDFLAGS = -no-undefined
 libmutter_wayland_la_LIBADD  = $(MUTTER_LIBS)

src/core/main.c

@@ -58,6 +58,7 @@
 #include "meta-wayland-private.h"
 
 #include <glib-object.h>
+#include <glib-unix.h>
 #include <gdk/gdkx.h>
 
 #include <stdlib.h>
@@ -352,59 +353,12 @@ meta_finalize (void)
     meta_wayland_finalize ();
 }
 
-static int signal_pipe_fds[2] = { -1, -1 };
-
-static void
-signal_handler (int signum)
-{
-  if (signal_pipe_fds[1] >= 0)
-    {
-      switch (signum)
-        {
-        case SIGTERM:
-          write (signal_pipe_fds[1], "T", 1);
-          break;
-        default:
-          break;
-        }
-    }
-}
-
 static gboolean
-on_signal (GIOChannel *source,
+on_sigterm (gpointer user_data)
-           GIOCondition condition,
-           void *data)
 {
-  char signal;
+  meta_quit (EXIT_SUCCESS);
-  int count;
 
-  for (;;)
+  return G_SOURCE_REMOVE;
-    {
-      count = read (signal_pipe_fds[0], &signal, 1);
-      if (count == EINTR)
-        continue;
-      if (count < 0)
-        {
-          const char *msg = strerror (errno);
-          g_warning ("Error handling signal: %s", msg);
-        }
-      if (count != 1)
-        {
-          g_warning ("Unexpectedly failed to read byte from signal pipe\n");
-          return TRUE;
-        }
-      break;
-    }
-  switch (signal)
-    {
-    case 'T': /* SIGTERM */
-      meta_quit (META_EXIT_SUCCESS);
-      break;
-    default:
-      g_warning ("Spurious character '%c' read from signal pipe", signal);
-    }
-
-  return TRUE;
 }
 
 /**
@@ -418,7 +372,6 @@ meta_init (void)
 {
   struct sigaction act;
   sigset_t empty_mask;
-  GIOChannel *channel;
   
   sigemptyset (&empty_mask);
   act.sa_handler = SIG_IGN;
@@ -433,20 +386,7 @@ meta_init (void)
                 g_strerror (errno));
 #endif
 
-  if (pipe (signal_pipe_fds) != 0)
+  g_unix_signal_add (SIGTERM, on_sigterm, NULL);
-    g_printerr ("Failed to create signal pipe: %s\n",
-                g_strerror (errno));
-
-  channel = g_io_channel_unix_new (signal_pipe_fds[0]);
-  g_io_channel_set_flags (channel, G_IO_FLAG_NONBLOCK, NULL);
-  g_io_add_watch (channel, G_IO_IN, (GIOFunc) on_signal, NULL);
-  g_io_channel_set_close_on_unref (channel, TRUE);
-  g_io_channel_unref (channel);
-
-  act.sa_handler = &signal_handler;
-  if (sigaction (SIGTERM, &act, NULL) < 0)
-    g_printerr ("Failed to register SIGTERM handler: %s\n",
-		g_strerror (errno));
 
   if (g_getenv ("MUTTER_VERBOSE"))
     meta_set_verbose (TRUE);

src/wayland/meta-wayland-private.h

@@ -28,6 +28,7 @@
 #include <cairo.h>
 
 #include "window-private.h"
+#include "meta-weston-launch.h"
 #include <meta/meta-cursor-tracker.h>
 
 typedef struct _MetaWaylandCompositor MetaWaylandCompositor;
@@ -148,6 +149,9 @@ struct _MetaWaylandCompositor
   struct wl_client *xwayland_client;
   struct wl_resource *xserver_resource;
 
+  MetaLauncher *launcher;
+  int drm_fd;
+
   MetaWaylandSeat *seat;
 
   /* This surface is only used to keep drag of the implicit grab when
@@ -338,6 +342,8 @@ void                    meta_wayland_compositor_repick          (MetaWaylandComp
 void                    meta_wayland_compositor_set_input_focus (MetaWaylandCompositor *compositor,
                                                                  MetaWindow            *window);
 
+MetaLauncher           *meta_wayland_compositor_get_launcher    (MetaWaylandCompositor *compositor);
+
 void                    meta_wayland_surface_free               (MetaWaylandSurface    *surface);
 
 #endif /* META_WAYLAND_PRIVATE_H */

src/wayland/meta-wayland.c

@@ -50,6 +50,7 @@
 #include <meta/main.h>
 #include "frame.h"
 #include "meta-idle-monitor-private.h"
+#include "meta-weston-launch.h"
 #include "monitor-private.h"
 
 static MetaWaylandCompositor _meta_wayland_compositor;
@@ -1529,6 +1530,9 @@ meta_wayland_init (void)
   MetaWaylandCompositor *compositor = &_meta_wayland_compositor;
   guint event_signal;
   MetaMonitorManager *monitors;
+  ClutterBackend *backend;
+  CoglContext *cogl_context;
+  CoglRenderer *cogl_renderer;
 
   memset (compositor, 0, sizeof (MetaWaylandCompositor));
 
@@ -1565,9 +1569,35 @@ meta_wayland_init (void)
 
   clutter_wayland_set_compositor_display (compositor->wayland_display);
 
+  if (getenv ("WESTON_LAUNCHER_SOCK"))
+      compositor->launcher = meta_launcher_new ();
+
   if (clutter_init (NULL, NULL) != CLUTTER_INIT_SUCCESS)
     g_error ("Failed to initialize Clutter");
 
+  backend = clutter_get_default_backend ();
+  cogl_context = clutter_backend_get_cogl_context (backend);
+  cogl_renderer = cogl_display_get_renderer (cogl_context_get_display (cogl_context));
+
+  if (cogl_renderer_get_winsys_id (cogl_renderer) == COGL_WINSYS_ID_EGL_KMS)
+    compositor->drm_fd = cogl_kms_renderer_get_kms_fd (cogl_renderer);
+  else
+    compositor->drm_fd = -1;
+
+  if (compositor->drm_fd >= 0)
+    {
+      GError *error;
+
+      meta_launcher_set_drm_fd (compositor->launcher, compositor->drm_fd);
+
+      error = NULL;
+      if (!meta_launcher_set_master (compositor->launcher, TRUE, &error))
+	{
+	  g_error ("Failed to become DRM master: %s", error->message);
+	  g_error_free (error);
+	}
+    }
+
   meta_monitor_manager_initialize ();
   monitors = meta_monitor_manager_get ();
   g_signal_connect (monitors, "monitors-changed",
@@ -1630,5 +1660,16 @@ meta_wayland_init (void)
 void
 meta_wayland_finalize (void)
 {
-  meta_xwayland_stop (meta_wayland_compositor_get_default ());
+  MetaWaylandCompositor *compositor;
+
+  compositor = meta_wayland_compositor_get_default ();
+
+  meta_xwayland_stop (compositor);
+  g_clear_object (&compositor->launcher);
+}
+
+MetaLauncher *
+meta_wayland_compositor_get_launcher (MetaWaylandCompositor *compositor)
+{
+  return compositor->launcher;
 }

src/wayland/meta-weston-launch.c

@@ -0,0 +1,432 @@
+/*
+ * Copyright (C) 2013 Red Hat, Inc.
+ *
+ * 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., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+#include <config.h>
+
+#include <gio/gio.h>
+#include <gio/gunixfdmessage.h>
+
+#include <clutter/clutter.h>
+#include <clutter/evdev/clutter-evdev.h>
+
+#include <glib.h>
+#include <sys/time.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+
+#include <drm.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+
+#include "meta-weston-launch.h"
+
+struct _MetaLauncherClass
+{
+  GObjectClass parent_class;
+
+  void (*enter) (MetaLauncher *);
+  void (*leave) (MetaLauncher *);
+};
+
+struct _MetaLauncher
+{
+  GObject parent;
+
+  GSocket *weston_launch;
+  int drm_fd;
+
+  gboolean vt_switched;
+
+  GMainContext *nested_context;
+  GMainLoop *nested_loop;
+
+  GSource *inner_source;
+  GSource *outer_source;
+};
+
+enum {
+  SIGNAL_ENTER,
+  SIGNAL_LEAVE,
+  SIGNAL_LAST
+};
+
+static int signals[SIGNAL_LAST];
+
+G_DEFINE_TYPE (MetaLauncher, meta_launcher, G_TYPE_OBJECT);
+
+static gboolean
+send_message_to_wl (GSocket                *weston_launch,
+		    void                   *message,
+		    gsize                   size,
+		    GSocketControlMessage  *out_cmsg,
+		    GSocketControlMessage **in_cmsg,
+		    GError                **error)
+{
+  int ok;
+  GInputVector in_iov = { &ok, sizeof (int) };
+  GOutputVector out_iov = { message, size };
+  GSocketControlMessage *out_all_cmsg[2];
+  GSocketControlMessage **in_all_cmsg;
+  int flags = 0;
+  int i;
+
+  out_all_cmsg[0] = out_cmsg;
+  out_all_cmsg[1] = NULL;
+  if (g_socket_send_message (weston_launch, NULL,
+			     &out_iov, 1,
+			     out_all_cmsg, -1,
+			     flags, NULL, error) != (gssize)size)
+    return FALSE;
+
+  if (g_socket_receive_message (weston_launch, NULL,
+				&in_iov, 1,
+				&in_all_cmsg, NULL,
+				&flags, NULL, error) != sizeof (int))
+    return FALSE;
+
+  if (ok != 0)
+    {
+      if (ok == -1)
+	g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+		     "Got failure from weston-launch");
+      else
+	g_set_error (error, G_IO_ERROR, g_io_error_from_errno (-ok),
+		     "Got failure from weston-launch: %s", strerror (-ok));
+
+      for (i = 0; in_all_cmsg && in_all_cmsg[i]; i++)
+	g_object_unref (in_all_cmsg[i]);
+      g_free (in_all_cmsg);
+
+      return FALSE;
+    }
+
+  if (in_all_cmsg && in_all_cmsg[0])
+    {
+      for (i = 1; in_all_cmsg[i]; i++)
+	g_object_unref (in_all_cmsg[i]);
+      *in_cmsg = in_all_cmsg[0];
+    }
+
+  g_free (in_all_cmsg);
+  return TRUE;
+}	    
+
+gboolean
+meta_launcher_set_master (MetaLauncher  *self,
+			  gboolean       master,
+			  GError       **error)
+{
+  struct weston_launcher_set_master message;
+  GSocketControlMessage *cmsg;
+  gboolean ok;
+
+  message.header.opcode = WESTON_LAUNCHER_DRM_SET_MASTER;
+  message.set_master = master;
+
+  cmsg = g_unix_fd_message_new ();
+  if (g_unix_fd_message_append_fd (G_UNIX_FD_MESSAGE (cmsg),
+				   self->drm_fd, error) == FALSE)
+    {
+      g_object_unref (cmsg);
+      return FALSE;
+    }
+
+  ok = send_message_to_wl (self->weston_launch, &message,
+			   sizeof message, cmsg, NULL, error);
+
+  g_object_unref (cmsg);
+  return ok;
+}
+
+int
+meta_launcher_open_input_device (MetaLauncher  *self,
+				 const char    *name,
+				 int            flags,
+				 GError       **error)
+{
+  struct weston_launcher_open *message;
+  GSocketControlMessage *cmsg;
+  gboolean ok;
+  gsize size;
+  int *fds, n_fd;
+  int ret;
+
+  size = sizeof (struct weston_launcher_open) + strlen (name) + 1;
+  message = g_malloc (size);
+  message->header.opcode = WESTON_LAUNCHER_OPEN;
+  message->flags = flags;
+  strcpy (message->path, name);
+  message->path[strlen(name)] = 0;
+
+  ok = send_message_to_wl (self->weston_launch, message, size,
+			   NULL, &cmsg, error);
+
+  if (ok)
+    {
+      g_assert (G_IS_UNIX_FD_MESSAGE (cmsg));
+
+      fds = g_unix_fd_message_steal_fds (G_UNIX_FD_MESSAGE (cmsg), &n_fd);
+      g_assert (n_fd == 1);
+
+      ret = fds[0];
+      g_free (fds);
+      g_object_unref (cmsg);
+    }
+  else
+    ret = -1;
+
+  g_free (message);
+  return ret;
+}
+
+static void
+meta_launcher_finalize (GObject *object)
+{
+  MetaLauncher *launcher = META_LAUNCHER (object);
+
+  g_source_destroy (launcher->outer_source);
+  g_source_destroy (launcher->inner_source);
+
+  g_main_loop_unref (launcher->nested_loop);
+  g_main_context_unref (launcher->nested_context);
+
+  g_object_unref (launcher->weston_launch);
+
+  G_OBJECT_CLASS (meta_launcher_parent_class)->finalize (object);
+}
+
+static void
+meta_launcher_enter (MetaLauncher *launcher)
+{
+  GError *error;
+
+  error = NULL;
+  if (!meta_launcher_set_master (launcher, TRUE, &error))
+    {
+      g_critical ("Failed to become DRM master: %s", error->message);
+      g_error_free (error);
+    }
+
+  clutter_evdev_reclaim_devices ();
+}
+
+static void
+meta_launcher_leave (MetaLauncher *launcher)
+{
+  GError *error;
+
+  error = NULL;
+  if (!meta_launcher_set_master (launcher, FALSE, &error))
+    {
+      g_critical ("Failed to release DRM master: %s", error->message);
+      g_error_free (error);
+    }
+
+  clutter_evdev_release_devices ();
+}
+
+
+static int
+on_evdev_device_open (const char  *path,
+		      int          flags,
+		      gpointer     user_data,
+		      GError     **error)
+{
+  MetaLauncher *launcher = user_data;
+
+  return meta_launcher_open_input_device (launcher, path, flags, error);
+}
+
+static void
+handle_vt_enter (MetaLauncher *launcher)
+{
+  g_assert (launcher->vt_switched);
+
+  g_main_loop_quit (launcher->nested_loop);
+}
+
+static void
+handle_request_vt_switch (MetaLauncher *launcher)
+{
+  struct weston_launcher_message message;
+  GError *error;
+  gboolean ok;
+
+  g_signal_emit (launcher, signals[SIGNAL_LEAVE], 0);
+
+  message.opcode = WESTON_LAUNCHER_CONFIRM_VT_SWITCH;
+
+  error = NULL;
+  ok = send_message_to_wl (launcher->weston_launch, &message,
+			   sizeof (message), NULL, NULL, &error);
+  if (!ok) {
+    g_warning ("Failed to acknowledge VT switch: %s", error->message);
+    g_error_free (error);
+
+    return;
+  }
+
+  g_assert (!launcher->vt_switched);
+  launcher->vt_switched = TRUE;
+
+  /* We can't do anything at this point, because we don't
+     have input devices and we don't have the DRM master,
+     so let's run a nested busy loop until the VT is reentered */
+  g_main_loop_run (launcher->nested_loop);
+
+  g_assert (launcher->vt_switched);
+  launcher->vt_switched = FALSE;
+
+  g_signal_emit (launcher, signals[SIGNAL_ENTER], 0);
+}
+
+static void
+on_socket_readable (GSocket      *socket,
+		    GIOCondition  condition,
+		    gpointer      user_data)
+{
+  MetaLauncher *launcher = user_data;
+  struct weston_launcher_message header;
+  gssize read;
+  GError *error;
+
+  if ((condition & G_IO_IN) == 0)
+    return;
+
+  error = NULL;
+  read = g_socket_receive (socket, (char*)&header, sizeof(header), NULL, &error);
+  if (read < (gssize)sizeof(header))
+    {
+      g_warning ("Error reading from weston-launcher socket: %s", error->message);
+      g_error_free (error);
+      return;
+    }
+
+  switch (header.opcode)
+    {
+    case WESTON_LAUNCHER_SERVER_REQUEST_VT_SWITCH:
+      handle_request_vt_switch (launcher);
+      break;
+
+    case WESTON_LAUNCHER_SERVER_VT_ENTER:
+      handle_vt_enter (launcher);
+      break;
+    }
+}
+
+static int
+env_get_fd (const char *env)
+{
+  const char *value;
+
+  value = g_getenv (env);
+
+  if (value == NULL)
+    return -1;
+  else
+    return g_ascii_strtoll (value, NULL, 10);
+}
+
+static void
+meta_launcher_init (MetaLauncher *self)
+{
+  int launch_fd;
+
+  launch_fd = env_get_fd ("WESTON_LAUNCHER_SOCK");
+  if (launch_fd < 0)
+    g_error ("Invalid mutter-launch socket");
+
+  self->weston_launch = g_socket_new_from_fd (launch_fd, NULL);
+
+  clutter_evdev_set_open_callback (on_evdev_device_open, self);
+
+  self->nested_context = g_main_context_new ();
+  self->nested_loop = g_main_loop_new (self->nested_context, FALSE);
+
+  self->outer_source = g_socket_create_source (self->weston_launch, G_IO_IN, NULL);
+  g_source_set_callback (self->outer_source, (GSourceFunc)on_socket_readable, self, NULL);
+  g_source_attach (self->outer_source, NULL);
+  g_source_unref (self->outer_source);
+
+  self->inner_source = g_socket_create_source (self->weston_launch, G_IO_IN, NULL);
+  g_source_set_callback (self->inner_source, (GSourceFunc)on_socket_readable, self, NULL);
+  g_source_attach (self->inner_source, self->nested_context);
+  g_source_unref (self->inner_source);
+}
+
+static void
+meta_launcher_class_init (MetaLauncherClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->finalize = meta_launcher_finalize;
+
+  klass->enter = meta_launcher_enter;
+  klass->leave = meta_launcher_leave;
+
+  signals[SIGNAL_ENTER] = g_signal_new ("enter",
+					G_TYPE_FROM_CLASS (klass),
+					G_SIGNAL_RUN_FIRST,
+					G_STRUCT_OFFSET (MetaLauncherClass, enter),
+					NULL, NULL, /* accumulator */
+					g_cclosure_marshal_VOID__VOID,
+					G_TYPE_NONE, 0);
+
+  signals[SIGNAL_LEAVE] = g_signal_new ("leave",
+					G_TYPE_FROM_CLASS (klass),
+					G_SIGNAL_RUN_FIRST,
+					G_STRUCT_OFFSET (MetaLauncherClass, leave),
+					NULL, NULL, /* accumulator */
+					g_cclosure_marshal_VOID__VOID,
+					G_TYPE_NONE, 0);
+}
+
+MetaLauncher *
+meta_launcher_new (void)
+{
+  return g_object_new (META_TYPE_LAUNCHER, NULL);
+}
+
+gboolean
+meta_launcher_activate_vt (MetaLauncher  *launcher,
+			   int            vt,
+			   GError       **error)
+{
+  struct weston_launcher_activate_vt message;
+
+  message.header.opcode = WESTON_LAUNCHER_ACTIVATE_VT;
+  message.vt = vt;
+
+  return send_message_to_wl (launcher->weston_launch, &message,
+			     sizeof (message), NULL, NULL, error);
+}
+
+void
+meta_launcher_set_drm_fd (MetaLauncher *launcher,
+			  int           drm_fd)
+{
+  launcher->drm_fd = drm_fd;
+}

src/wayland/meta-weston-launch.h

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2013 Red Hat, Inc.
+ *
+ * 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., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+#ifndef META_WESTON_LAUNCH_H
+#define META_WESTON_LAUNCH_H
+
+#include <glib-object.h>
+#include "weston-launch.h"
+
+#define META_TYPE_LAUNCHER              (meta_launcher_get_type())
+#define META_LAUNCHER(obj)              (G_TYPE_CHECK_INSTANCE_CAST ((obj), META_TYPE_LAUNCHER, MetaLauncher))
+#define META_LAUNCHER_CLASS(klass)      (G_TYPE_CHECK_CLASS_CAST ((klass), META_TYPE_LAUNCHER, MetaLauncherClass))
+#define META_IS_LAUNCHER(obj)           (G_TYPE_CHECK_INSTANCE_TYPE ((obj), META_TYPE_LAUNCHER))
+#define META_IS_LAUNCHER_CLASS(klass)   (G_TYPE_CHECK_CLASS_TYPE ((klass), META_TYPE_LAUNCHER))
+#define META_LAUNCHER_GET_CLASS(obj)    (G_TYPE_INSTANCE_GET_CLASS ((obj), META_LAUNCHER, MetaLauncherClass))
+
+typedef struct _MetaLauncher      MetaLauncher;
+typedef struct _MetaLauncherClass MetaLauncherClass;
+
+GType             meta_launcher_get_type                (void) G_GNUC_CONST;
+
+MetaLauncher     *meta_launcher_new                     (void);
+
+gboolean          meta_launcher_activate_vt             (MetaLauncher  *self,
+							 int            number,
+							 GError       **error);
+
+void              meta_launcher_set_drm_fd              (MetaLauncher  *self,
+							 int            drm_fd);
+gboolean          meta_launcher_set_master              (MetaLauncher  *self,
+							 gboolean       master,
+							 GError       **error);
+int               meta_launcher_open_input_device       (MetaLauncher  *self,
+							 const char    *name,
+							 int            flags,
+							 GError       **error);
+
+#endif