wayland: add TTY and DRM master management through weston-launch

To run mutter as a display server, one needs to acquire and
release the DRM master, which is only possible for root, so
we take advantage of weston-launch, a small setuid helper binary
written for the weston project. We import our own slightly
modified copy of it, because weston-launch only launches weston,
for security reasons.

https://bugzilla.gnome.org/show_bug.cgi?id=705861
This commit is contained in:
Giovanni Campagna 2013-07-15 18:07:01 +02:00
parent 5f4121830c
commit a83049c103
10 changed files with 1557 additions and 3 deletions

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@ -138,6 +138,7 @@ AM_GLIB_GNU_GETTEXT
## here we get the flags we'll actually use
# GRegex requires Glib-2.14.0
PKG_CHECK_MODULES(ALL, glib-2.0 >= 2.14.0)
PKG_CHECK_MODULES(MUTTER_LAUNCH, libdrm libsystemd-login)
# Unconditionally use this dir to avoid a circular dep with gnomecc
GNOME_KEYBINDINGS_KEYSDIR="${datadir}/gnome-control-center/keybindings"
@ -232,7 +233,7 @@ if test x$enable_wayland = "xyes"; then
AC_SUBST(XWAYLAND_PATH)
MUTTER_PC_MODULES="$MUTTER_PC_MODULES wayland-server"
MUTTER_PC_MODULES="$MUTTER_PC_MODULES wayland-server libdrm"
AC_DEFINE(HAVE_WAYLAND, , [Building with Wayland support])
have_wayland=yes
fi

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@ -173,6 +173,8 @@ libmutter_la_SOURCES = \
if HAVE_WAYLAND
libmutter_la_SOURCES += \
wayland/meta-tty.c \
wayland/meta-tty.h \
wayland/meta-wayland.c \
wayland/meta-wayland-private.h \
wayland/meta-xwayland-private.h \
@ -186,7 +188,9 @@ libmutter_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
endif
libmutter_la_LDFLAGS = -no-undefined
@ -237,6 +241,19 @@ bin_PROGRAMS=mutter
mutter_SOURCES = core/mutter.c
mutter_LDADD = $(MUTTER_LIBS) libmutter.la
if HAVE_WAYLAND
bin_PROGRAMS+=mutter-launch
mutter_launch_SOURCES = wayland/weston-launch.c wayland/weston-launch.h
mutter_launch_CFLAGS = $(MUTTER_LAUNCH_CFLAGS)
mutter_launch_LDFLAGS = $(MUTTER_LAUNCH_LIBS) -lpam
install-exec-hook:
-chown root $(DESTDIR)$(bindir)/mutter-launch
-chmod u+s $(DESTDIR)$(bindir)/mutter-launch
endif
if HAVE_INTROSPECTION
include $(INTROSPECTION_MAKEFILE)

399
src/wayland/meta-tty.c Normal file
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@ -0,0 +1,399 @@
/*
* Copyright © 2010 Intel Corporation
* 2013 Red Hat, Inc.
*
* Permission to use, copy, modify, distribute, and sell this software and
* its documentation for any purpose is hereby granted without fee, provided
* that the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the name of the copyright holders not be used in
* advertising or publicity pertaining to distribution of the software
* without specific, written prior permission. The copyright holders make
* no representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
* SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
* RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
* CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "config.h"
#include <termios.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <signal.h>
#include <linux/kd.h>
#include <linux/vt.h>
#include <linux/major.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "meta-tty.h"
#include <gio/gio.h>
#include <glib-unix.h>
/* Introduced in 2.6.38 */
#ifndef K_OFF
#define K_OFF 0x04
#endif
struct _MetaTTYClass
{
GObjectClass parent_class;
};
struct _MetaTTY
{
GObject parent;
int fd;
struct termios terminal_attributes;
int input_source, vt_source;
int vt, starting_vt;
gboolean has_vt;
int kb_mode;
};
enum {
SIGNAL_ENTER,
SIGNAL_LEAVE,
SIGNAL_LAST
};
static int signals[SIGNAL_LAST];
static void meta_tty_initable_iface_init (GInitableIface *);
G_DEFINE_TYPE_WITH_CODE (MetaTTY, meta_tty, G_TYPE_OBJECT,
G_IMPLEMENT_INTERFACE (G_TYPE_INITABLE,
meta_tty_initable_iface_init));
static int
vt_handler (gpointer user_data)
{
MetaTTY *tty = user_data;
if (tty->has_vt)
{
tty->has_vt = FALSE;
g_signal_emit (tty, signals[SIGNAL_LEAVE], 0);
ioctl (tty->fd, VT_RELDISP, 1);
}
else
{
ioctl (tty->fd, VT_RELDISP, VT_ACKACQ);
tty->has_vt = 1;
g_signal_emit (tty, signals[SIGNAL_ENTER], 0);
}
return 1;
}
static int
on_tty_input (int fd,
GIOCondition mask,
gpointer user_data)
{
MetaTTY *tty = user_data;
/* Ignore input to tty. We get keyboard events from evdev */
tcflush(tty->fd, TCIFLUSH);
return 1;
}
static int
try_open_vt (MetaTTY *tty,
GError **error)
{
int tty0, fd;
char filename[16];
tty0 = open ("/dev/tty0", O_WRONLY | O_CLOEXEC);
if (tty0 < 0)
{
g_set_error (error, G_IO_ERROR,
g_io_error_from_errno (errno),
"Could not open tty0: %s", strerror (errno));
return -1;
}
if (ioctl (tty0, VT_OPENQRY, &tty->vt) < 0 || tty->vt == -1) {
g_set_error (error, G_IO_ERROR,
g_io_error_from_errno (errno),
"Could not open tty0: %s", strerror (errno));
close (tty0);
return -1;
}
close (tty0);
snprintf (filename, sizeof filename, "/dev/tty%d", tty->vt);
g_debug("compositor: using new vt %s\n", filename);
fd = open (filename, O_RDWR | O_NOCTTY | O_CLOEXEC);
return fd;
}
/* FIXME? */
static int
tty_activate_vt (MetaTTY *tty,
int vt)
{
return ioctl(tty->fd, VT_ACTIVATE, vt);
}
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 (env, NULL, 10);
}
static gboolean
meta_tty_initable_init(GInitable *initable,
GCancellable *cancellable,
GError **error)
{
MetaTTY *tty = META_TTY (initable);
struct termios raw_attributes;
struct vt_mode mode = { 0 };
int ret;
struct stat buf;
struct vt_stat vts;
tty->fd = env_get_fd ("WESTON_TTY_FD");
if (tty->fd < 0)
tty->fd = STDIN_FILENO;
if (fstat(tty->fd, &buf) == 0 &&
major(buf.st_rdev) == TTY_MAJOR &&
minor(buf.st_rdev) > 0)
{
if (tty->fd == STDIN_FILENO)
tty->fd = fcntl(STDIN_FILENO, F_DUPFD_CLOEXEC, 0);
tty->vt = minor(buf.st_rdev);
}
else
{
/* Fall back to try opening a new VT. This typically
* requires root. */
tty->fd = try_open_vt(tty, error);
}
if (tty->fd <= 0 && (!error || !*error))
{
g_set_error (error, G_IO_ERROR,
g_io_error_from_errno (errno),
"Could not open tty0: %s", strerror (errno));
return FALSE;
}
if (ioctl(tty->fd, VT_GETSTATE, &vts) == 0)
tty->starting_vt = vts.v_active;
else
tty->starting_vt = tty->vt;
if (tty->starting_vt != tty->vt)
{
if (ioctl(tty->fd, VT_ACTIVATE, tty->vt) < 0 ||
ioctl(tty->fd, VT_WAITACTIVE, tty->vt) < 0)
{
g_set_error (error, G_IO_ERROR,
g_io_error_from_errno (errno),
"Failed to switch to new vt: %s", strerror (errno));
goto err;
}
}
if (tcgetattr(tty->fd, &tty->terminal_attributes) < 0)
{
g_set_error (error, G_IO_ERROR,
g_io_error_from_errno (errno),
"Could not get terminal attributes: %s", strerror (errno));
goto err;
}
/* Ignore control characters and disable echo */
raw_attributes = tty->terminal_attributes;
cfmakeraw(&raw_attributes);
/* Fix up line endings to be normal (cfmakeraw hoses them) */
raw_attributes.c_oflag |= OPOST | OCRNL;
/* Don't generate ttou signals */
raw_attributes.c_oflag &= ~TOSTOP;
if (tcsetattr(tty->fd, TCSANOW, &raw_attributes) < 0)
g_warning("Could not put terminal into raw mode: %s", strerror (errno));
ioctl(tty->fd, KDGKBMODE, &tty->kb_mode);
ret = ioctl(tty->fd, KDSKBMODE, K_OFF);
if (ret)
{
ret = ioctl(tty->fd, KDSKBMODE, K_RAW);
if (ret)
{
g_set_error (error, G_IO_ERROR,
g_io_error_from_errno (errno),
"Failed to set keyboard mode: %s", strerror (errno));
goto err_attr;
}
tty->input_source = g_unix_fd_add (tty->fd,
G_IO_IN,
on_tty_input, tty);
}
ret = ioctl(tty->fd, KDSETMODE, KD_GRAPHICS);
if (ret)
{
g_set_error (error, G_IO_ERROR,
g_io_error_from_errno (errno),
"Failed to set KD_GRAPHICS mode: %s", strerror (errno));
goto err_kdkbmode;
}
tty->has_vt = 1;
mode.mode = VT_PROCESS;
mode.relsig = SIGUSR1;
mode.acqsig = SIGUSR1;
if (ioctl(tty->fd, VT_SETMODE, &mode) < 0)
{
g_set_error (error, G_IO_ERROR,
g_io_error_from_errno (errno),
"Failed to take control of vt handling: %s", strerror (errno));
goto err_kdmode;
}
tty->vt_source = g_unix_signal_add (SIGUSR1, vt_handler, tty);
return TRUE;
err_kdmode:
ioctl (tty->fd, KDSETMODE, KD_TEXT);
err_kdkbmode:
if (tty->input_source)
g_source_remove (tty->input_source);
ioctl (tty->fd, KDSKBMODE, tty->kb_mode);
err_attr:
tcsetattr (tty->fd, TCSANOW, &tty->terminal_attributes);
err:
close (tty->fd);
return FALSE;
}
static void
tty_reset (MetaTTY *tty)
{
struct vt_mode mode = { 0 };
if (ioctl (tty->fd, KDSKBMODE, tty->kb_mode))
g_warning ("failed to restore keyboard mode: %s", strerror (errno));
if (ioctl (tty->fd, KDSETMODE, KD_TEXT))
g_warning ("failed to set KD_TEXT mode on tty: %s", strerror (errno));
if (tcsetattr (tty->fd, TCSANOW, &tty->terminal_attributes) < 0)
g_warning ("could not restore terminal to canonical mode");
mode.mode = VT_AUTO;
if (ioctl (tty->fd, VT_SETMODE, &mode) < 0)
g_warning ("could not reset vt handling\n");
if (tty->has_vt && tty->vt != tty->starting_vt)
{
ioctl(tty->fd, VT_ACTIVATE, tty->starting_vt);
ioctl(tty->fd, VT_WAITACTIVE, tty->starting_vt);
}
}
static void
meta_tty_finalize (GObject *object)
{
MetaTTY *tty = META_TTY (object);
if (tty->input_source)
g_source_remove (tty->input_source);
g_source_remove (tty->vt_source);
tty_reset (tty);
close (tty->fd);
G_OBJECT_CLASS (meta_tty_parent_class)->finalize (object);
}
static void
meta_tty_init (MetaTTY *self)
{
}
static void
meta_tty_class_init (MetaTTYClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->finalize = meta_tty_finalize;
signals[SIGNAL_ENTER] = g_signal_new ("enter",
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST,
0, /* class offset */
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,
0, /* class offset */
NULL, NULL, /* accumulator */
g_cclosure_marshal_VOID__VOID,
G_TYPE_NONE, 0);
}
static void
meta_tty_initable_iface_init (GInitableIface *iface)
{
iface->init = meta_tty_initable_init;
}
MetaTTY *
meta_tty_new (void)
{
GError *error;
MetaTTY *tty;
error = NULL;
tty = g_initable_new (META_TYPE_TTY, NULL, &error, NULL);
if (tty == NULL)
{
g_warning ("Failed to initalize TTY handling: %s", error->message);
g_error_free (error);
}
return tty;
}

43
src/wayland/meta-tty.h Normal file
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@ -0,0 +1,43 @@
/*
* 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_TTY_H
#define META_TTY_H
#include <glib-object.h>
G_BEGIN_DECLS
#define META_TYPE_TTY (meta_tty_get_type())
#define META_TTY(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), META_TYPE_TTY, MetaTTY))
#define META_TTY_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), META_TYPE_TTY, MetaTTYClass))
#define META_IS_TTY(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), META_TYPE_TTY))
#define META_IS_TTY_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), META_TYPE_TTY))
#define META_TTY_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), META_TTY, MetaTTYClass))
typedef struct _MetaTTY MetaTTY;
typedef struct _MetaTTYClass MetaTTYClass;
GType meta_tty_get_type (void) G_GNUC_CONST;
MetaTTY *meta_tty_new (void);
G_END_DECLS
#endif /* META_TTY_H */

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@ -28,6 +28,7 @@
#include <cairo.h>
#include "window-private.h"
#include "meta-tty.h"
typedef struct _MetaWaylandCompositor MetaWaylandCompositor;
@ -165,6 +166,10 @@ struct _MetaWaylandCompositor
struct wl_client *xwayland_client;
struct wl_resource *xserver_resource;
MetaTTY *tty;
int drm_fd;
GSocket *weston_launch;
MetaWaylandSeat *seat;
/* This surface is only used to keep drag of the implicit grab when

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@ -48,6 +48,7 @@
#include <meta/types.h>
#include <meta/main.h>
#include "frame.h"
#include "meta-weston-launch.h"
static MetaWaylandCompositor _meta_wayland_compositor;
@ -1379,11 +1380,59 @@ event_emission_hook_cb (GSignalInvocationHint *ihint,
return TRUE /* stay connected */;
}
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 (env, NULL, 10);
}
static void
on_our_vt_enter (MetaTTY *tty,
MetaWaylandCompositor *compositor)
{
GError *error;
error = NULL;
if (!meta_weston_launch_set_master (compositor->weston_launch,
compositor->drm_fd, TRUE, &error))
{
g_warning ("Failed to become DRM master: %s", error->message);
g_error_free (error);
}
}
static void
on_our_vt_leave (MetaTTY *tty,
MetaWaylandCompositor *compositor)
{
GError *error;
error = NULL;
if (!meta_weston_launch_set_master (compositor->weston_launch,
compositor->drm_fd, FALSE, &error))
{
g_warning ("Failed to release DRM master: %s", error->message);
g_error_free (error);
}
/* FIXME: we must release input devices as well! */
}
void
meta_wayland_init (void)
{
MetaWaylandCompositor *compositor = &_meta_wayland_compositor;
guint event_signal;
ClutterBackend *backend;
CoglContext *cogl_context;
CoglRenderer *cogl_renderer;
memset (compositor, 0, sizeof (MetaWaylandCompositor));
@ -1423,6 +1472,34 @@ meta_wayland_init (void)
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)
{
/* Running on bare metal, let's initalize DRM master and VT handling */
int weston_launch_fd;
weston_launch_fd = env_get_fd ("WESTON_LAUNCHER_SOCK");
if (weston_launch_fd >= 0)
compositor->weston_launch = g_socket_new_from_fd (weston_launch_fd, NULL);
compositor->tty = meta_tty_new ();
if (compositor->tty)
{
g_signal_connect (compositor->tty, "enter", G_CALLBACK (on_our_vt_enter), compositor);
g_signal_connect (compositor->tty, "leave", G_CALLBACK (on_our_vt_leave), compositor);
}
on_our_vt_enter (compositor->tty, compositor);
}
compositor->stage = meta_wayland_stage_new ();
clutter_stage_set_user_resizable (CLUTTER_STAGE (compositor->stage), FALSE);
g_signal_connect_after (compositor->stage, "paint",
@ -1480,5 +1557,10 @@ 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->tty);
}

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@ -0,0 +1,202 @@
/*
* 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 <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"
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[i]; i++)
g_object_unref (in_all_cmsg[i]);
g_free (in_all_cmsg);
return FALSE;
}
if (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_weston_launch_set_master (GSocket *weston_launch,
int drm_fd,
gboolean master,
GError **error)
{
if (weston_launch)
{
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),
drm_fd, error) == FALSE)
{
g_object_unref (cmsg);
return FALSE;
}
ok = send_message_to_wl (weston_launch, &message, sizeof message, cmsg, NULL, error);
g_object_unref (cmsg);
return ok;
}
else
{
int ret;
if (master)
ret = drmSetMaster (drm_fd);
else
ret = drmDropMaster (drm_fd);
if (ret < 0)
{
g_set_error (error, G_IO_ERROR, g_io_error_from_errno (-ret),
"Failed to set DRM master directly: %s", strerror (-ret));
return FALSE;
}
else
return TRUE;
}
}
int
meta_weston_launch_open_input_device (GSocket *weston_launch,
const char *name,
int flags,
GError **error)
{
if (weston_launch)
{
struct weston_launcher_open *message;
GSocketControlMessage *cmsg;
gboolean ok;
int *fds, n_fd;
int ret;
message = g_malloc (sizeof (struct weston_launcher_open) +
strlen (name));
message->header.opcode = WESTON_LAUNCHER_OPEN;
message->flags = flags;
strcpy (message->path, name);
ok = send_message_to_wl (weston_launch, message,
sizeof (struct weston_launcher_open) + strlen (name),
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);
}
else
ret = -1;
g_free (message);
g_object_unref (cmsg);
return ret;
}
else
{
int ret;
ret = open (name, flags, 0);
if (ret < 0)
g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errno),
"Failed to open input device directly: %s", strerror (errno));
return ret;
}
}

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@ -0,0 +1,56 @@
/*
* 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>
/* Keep this in sync with weston-launch */
enum weston_launcher_opcode {
WESTON_LAUNCHER_OPEN,
WESTON_LAUNCHER_DRM_SET_MASTER
};
struct weston_launcher_message {
int opcode;
};
struct weston_launcher_open {
struct weston_launcher_message header;
int flags;
char path[0];
};
struct weston_launcher_set_master {
struct weston_launcher_message header;
int set_master;
};
gboolean meta_weston_launch_set_master (GSocket *weston_launch,
int drm_fd,
gboolean master,
GError **error);
int meta_weston_launch_open_input_device (GSocket *weston_launch,
const char *name,
int flags,
GError **error);
#endif

703
src/wayland/weston-launch.c Normal file
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@ -0,0 +1,703 @@
/*
* Copyright © 2012 Benjamin Franzke
*
* Permission to use, copy, modify, distribute, and sell this software and
* its documentation for any purpose is hereby granted without fee, provided
* that the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the name of the copyright holders not be used in
* advertising or publicity pertaining to distribution of the software
* without specific, written prior permission. The copyright holders make
* no representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
* SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
* RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
* CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <poll.h>
#include <errno.h>
#include <error.h>
#include <getopt.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <sys/signalfd.h>
#include <signal.h>
#include <unistd.h>
#include <fcntl.h>
#include <limits.h>
#include <termios.h>
#include <linux/vt.h>
#include <linux/major.h>
#include <pwd.h>
#include <grp.h>
#include <security/pam_appl.h>
#include <xf86drm.h>
#ifdef HAVE_SYSTEMD_LOGIN
#include <systemd/sd-login.h>
#endif
#include "weston-launch.h"
#define MAX_ARGV_SIZE 256
struct weston_launch {
struct pam_conv pc;
pam_handle_t *ph;
int tty;
int ttynr;
int sock[2];
struct passwd *pw;
int signalfd;
pid_t child;
int verbose;
char *new_user;
};
union cmsg_data { unsigned char b[4]; int fd; };
static gid_t *
read_groups(void)
{
int n;
gid_t *groups;
n = getgroups(0, NULL);
if (n < 0) {
fprintf(stderr, "Unable to retrieve groups: %m\n");
return NULL;
}
groups = malloc(n * sizeof(gid_t));
if (!groups)
return NULL;
if (getgroups(n, groups) < 0) {
fprintf(stderr, "Unable to retrieve groups: %m\n");
free(groups);
return NULL;
}
return groups;
}
static int
weston_launch_allowed(struct weston_launch *wl)
{
struct group *gr;
gid_t *groups;
int i;
#ifdef HAVE_SYSTEMD_LOGIN
char *session, *seat;
int err;
#endif
if (getuid() == 0)
return 1;
gr = getgrnam("weston-launch");
if (gr) {
groups = read_groups();
if (groups) {
for (i = 0; groups[i]; ++i) {
if (groups[i] == gr->gr_gid) {
free(groups);
return 1;
}
}
free(groups);
}
}
#ifdef HAVE_SYSTEMD_LOGIN
err = sd_pid_get_session(getpid(), &session);
if (err == 0 && session) {
if (sd_session_is_active(session) &&
sd_session_get_seat(session, &seat) == 0) {
free(seat);
free(session);
return 1;
}
free(session);
}
#endif
return 0;
}
static int
pam_conversation_fn(int msg_count,
const struct pam_message **messages,
struct pam_response **responses,
void *user_data)
{
return PAM_SUCCESS;
}
static int
setup_pam(struct weston_launch *wl)
{
int err;
wl->pc.conv = pam_conversation_fn;
wl->pc.appdata_ptr = wl;
err = pam_start("login", wl->pw->pw_name, &wl->pc, &wl->ph);
if (err != PAM_SUCCESS) {
fprintf(stderr, "failed to start pam transaction: %d: %s\n",
err, pam_strerror(wl->ph, err));
return -1;
}
err = pam_set_item(wl->ph, PAM_TTY, ttyname(wl->tty));
if (err != PAM_SUCCESS) {
fprintf(stderr, "failed to set PAM_TTY item: %d: %s\n",
err, pam_strerror(wl->ph, err));
return -1;
}
err = pam_open_session(wl->ph, 0);
if (err != PAM_SUCCESS) {
fprintf(stderr, "failed to open pam session: %d: %s\n",
err, pam_strerror(wl->ph, err));
return -1;
}
return 0;
}
static int
setup_launcher_socket(struct weston_launch *wl)
{
if (socketpair(AF_LOCAL, SOCK_DGRAM, 0, wl->sock) < 0)
error(1, errno, "socketpair failed");
fcntl(wl->sock[0], F_SETFD, O_CLOEXEC);
return 0;
}
static int
setup_signals(struct weston_launch *wl)
{
int ret;
sigset_t mask;
struct sigaction sa;
memset(&sa, 0, sizeof sa);
sa.sa_handler = SIG_DFL;
sa.sa_flags = SA_NOCLDSTOP | SA_RESTART;
ret = sigaction(SIGCHLD, &sa, NULL);
assert(ret == 0);
sa.sa_handler = SIG_IGN;
sa.sa_flags = 0;
sigaction(SIGHUP, &sa, NULL);
ret = sigemptyset(&mask);
assert(ret == 0);
sigaddset(&mask, SIGCHLD);
sigaddset(&mask, SIGINT);
sigaddset(&mask, SIGTERM);
ret = sigprocmask(SIG_BLOCK, &mask, NULL);
assert(ret == 0);
wl->signalfd = signalfd(-1, &mask, SFD_NONBLOCK | SFD_CLOEXEC);
if (wl->signalfd < 0)
return -errno;
return 0;
}
static void
setenv_fd(const char *env, int fd)
{
char buf[32];
snprintf(buf, sizeof buf, "%d", fd);
setenv(env, buf, 1);
}
static int
handle_setmaster(struct weston_launch *wl, struct msghdr *msg, ssize_t len)
{
int ret = -1;
struct cmsghdr *cmsg;
struct weston_launcher_set_master *message;
union cmsg_data *data;
if (len != sizeof(*message)) {
error(0, 0, "missing value in setmaster request");
goto out;
}
message = msg->msg_iov->iov_base;
cmsg = CMSG_FIRSTHDR(msg);
if (!cmsg ||
cmsg->cmsg_level != SOL_SOCKET ||
cmsg->cmsg_type != SCM_RIGHTS) {
error(0, 0, "invalid control message");
goto out;
}
data = (union cmsg_data *) CMSG_DATA(cmsg);
if (data->fd == -1) {
error(0, 0, "missing drm fd in socket request");
goto out;
}
if (message->set_master)
ret = drmSetMaster(data->fd);
else
ret = drmDropMaster(data->fd);
close(data->fd);
if (wl->verbose)
fprintf(stderr, "weston-launch: %sMaster, ret: %d, fd: %d\n",
message->set_master ? "set" : "drop", ret, data->fd);
out:
do {
len = send(wl->sock[0], &ret, sizeof ret, 0);
} while (len < 0 && errno == EINTR);
if (len < 0)
return -1;
return 0;
}
static int
handle_open(struct weston_launch *wl, struct msghdr *msg, ssize_t len)
{
int fd = -1, ret = -1;
char control[CMSG_SPACE(sizeof(fd))];
struct cmsghdr *cmsg;
struct stat s;
struct msghdr nmsg;
struct iovec iov;
struct weston_launcher_open *message;
union cmsg_data *data;
message = msg->msg_iov->iov_base;
if ((size_t)len < sizeof(*message))
goto err0;
/* Ensure path is null-terminated */
((char *) message)[len-1] = '\0';
if (stat(message->path, &s) < 0)
goto err0;
fd = open(message->path, message->flags);
if (fd < 0) {
fprintf(stderr, "Error opening device %s: %m\n",
message->path);
goto err0;
}
if (major(s.st_rdev) != INPUT_MAJOR) {
close(fd);
fd = -1;
fprintf(stderr, "Device %s is not an input device\n",
message->path);
goto err0;
}
err0:
memset(&nmsg, 0, sizeof nmsg);
nmsg.msg_iov = &iov;
nmsg.msg_iovlen = 1;
if (fd != -1) {
nmsg.msg_control = control;
nmsg.msg_controllen = sizeof control;
cmsg = CMSG_FIRSTHDR(&nmsg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
data = (union cmsg_data *) CMSG_DATA(cmsg);
data->fd = fd;
nmsg.msg_controllen = cmsg->cmsg_len;
ret = 0;
}
iov.iov_base = &ret;
iov.iov_len = sizeof ret;
if (wl->verbose)
fprintf(stderr, "weston-launch: opened %s: ret: %d, fd: %d\n",
message->path, ret, fd);
do {
len = sendmsg(wl->sock[0], &nmsg, 0);
} while (len < 0 && errno == EINTR);
close(fd);
if (len < 0)
return -1;
return 0;
}
static int
handle_socket_msg(struct weston_launch *wl)
{
char control[CMSG_SPACE(sizeof(int))];
char buf[BUFSIZ];
struct msghdr msg;
struct iovec iov;
int ret = -1;
ssize_t len;
struct weston_launcher_message *message;
memset(&msg, 0, sizeof(msg));
iov.iov_base = buf;
iov.iov_len = sizeof buf;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = control;
msg.msg_controllen = sizeof control;
do {
len = recvmsg(wl->sock[0], &msg, 0);
} while (len < 0 && errno == EINTR);
if (len < 1)
return -1;
message = (void *) buf;
switch (message->opcode) {
case WESTON_LAUNCHER_OPEN:
ret = handle_open(wl, &msg, len);
break;
case WESTON_LAUNCHER_DRM_SET_MASTER:
ret = handle_setmaster(wl, &msg, len);
break;
}
return ret;
}
static void
quit(struct weston_launch *wl, int status)
{
int err;
close(wl->signalfd);
close(wl->sock[0]);
if (wl->new_user) {
err = pam_close_session(wl->ph, 0);
if (err)
fprintf(stderr, "pam_close_session failed: %d: %s\n",
err, pam_strerror(wl->ph, err));
pam_end(wl->ph, err);
}
exit(status);
}
static int
handle_signal(struct weston_launch *wl)
{
struct signalfd_siginfo sig;
int pid, status, ret;
if (read(wl->signalfd, &sig, sizeof sig) != sizeof sig) {
error(0, errno, "reading signalfd failed");
return -1;
}
switch (sig.ssi_signo) {
case SIGCHLD:
pid = waitpid(-1, &status, 0);
if (pid == wl->child) {
wl->child = 0;
if (WIFEXITED(status))
ret = WEXITSTATUS(status);
else if (WIFSIGNALED(status))
/*
* If weston dies because of signal N, we
* return 10+N. This is distinct from
* weston-launch dying because of a signal
* (128+N).
*/
ret = 10 + WTERMSIG(status);
else
ret = 0;
quit(wl, ret);
}
break;
case SIGTERM:
case SIGINT:
if (wl->child)
kill(wl->child, sig.ssi_signo);
break;
default:
return -1;
}
return 0;
}
static int
setup_tty(struct weston_launch *wl, const char *tty)
{
struct stat buf;
char *t;
if (!wl->new_user) {
wl->tty = STDIN_FILENO;
} else if (tty) {
t = ttyname(STDIN_FILENO);
if (t && strcmp(t, tty) == 0)
wl->tty = STDIN_FILENO;
else
wl->tty = open(tty, O_RDWR | O_NOCTTY);
} else {
int tty0 = open("/dev/tty0", O_WRONLY | O_CLOEXEC);
char filename[16];
if (tty0 < 0)
error(1, errno, "could not open tty0");
if (ioctl(tty0, VT_OPENQRY, &wl->ttynr) < 0 || wl->ttynr == -1)
error(1, errno, "failed to find non-opened console");
snprintf(filename, sizeof filename, "/dev/tty%d", wl->ttynr);
wl->tty = open(filename, O_RDWR | O_NOCTTY);
close(tty0);
}
if (wl->tty < 0)
error(1, errno, "failed to open tty");
if (tty) {
if (fstat(wl->tty, &buf) < 0)
error(1, errno, "stat %s failed", tty);
if (major(buf.st_rdev) != TTY_MAJOR)
error(1, 0, "invalid tty device: %s", tty);
wl->ttynr = minor(buf.st_rdev);
}
return 0;
}
static void
setup_session(struct weston_launch *wl)
{
char **env;
char *term;
int i;
if (wl->tty != STDIN_FILENO) {
if (setsid() < 0)
error(1, errno, "setsid failed");
if (ioctl(wl->tty, TIOCSCTTY, 0) < 0)
error(1, errno, "TIOCSCTTY failed - tty is in use");
}
if (setgid(wl->pw->pw_gid) < 0 ||
#ifdef HAVE_INITGROUPS
initgroups(wl->pw->pw_name, wl->pw->pw_gid) < 0 ||
#endif
setuid(wl->pw->pw_uid) < 0)
error(1, errno, "dropping privileges failed");
term = getenv("TERM");
clearenv();
setenv("TERM", term, 1);
setenv("USER", wl->pw->pw_name, 1);
setenv("LOGNAME", wl->pw->pw_name, 1);
setenv("HOME", wl->pw->pw_dir, 1);
setenv("SHELL", wl->pw->pw_shell, 1);
env = pam_getenvlist(wl->ph);
if (env) {
for (i = 0; env[i]; ++i) {
if (putenv(env[i]) < 0)
error(0, 0, "putenv %s failed", env[i]);
}
free(env);
}
}
static void
launch_compositor(struct weston_launch *wl, int argc, char *argv[])
{
char command[PATH_MAX];
char *child_argv[MAX_ARGV_SIZE];
sigset_t mask;
int i;
if (wl->verbose)
printf("weston-launch: spawned weston with pid: %d\n", getpid());
if (wl->new_user)
setup_session(wl);
if (wl->tty != STDIN_FILENO)
setenv_fd("WESTON_TTY_FD", wl->tty);
setenv_fd("WESTON_LAUNCHER_SOCK", wl->sock[1]);
unsetenv("DISPLAY");
/* Do not give our signal mask to the new process. */
sigemptyset(&mask);
sigaddset(&mask, SIGTERM);
sigaddset(&mask, SIGCHLD);
sigaddset(&mask, SIGINT);
sigprocmask(SIG_UNBLOCK, &mask, NULL);
snprintf (command, PATH_MAX, "%s \"$@\"", argv[0]);
child_argv[0] = wl->pw->pw_shell;
child_argv[1] = "-l";
child_argv[2] = "-c";
child_argv[3] = command;
for (i = 0; i < argc; ++i)
child_argv[4 + i] = argv[i];
child_argv[4 + i] = NULL;
execv(child_argv[0], child_argv);
error(1, errno, "exec failed");
}
static void
help(const char *name)
{
fprintf(stderr, "Usage: %s [args...] [-- [weston args..]]\n", name);
fprintf(stderr, " -u, --user Start session as specified username\n");
fprintf(stderr, " -t, --tty Start session on alternative tty\n");
fprintf(stderr, " -v, --verbose Be verbose\n");
fprintf(stderr, " -h, --help Display this help message\n");
}
int
main(int argc, char *argv[])
{
struct weston_launch wl;
int i, c;
char *tty = NULL;
struct option opts[] = {
{ "user", required_argument, NULL, 'u' },
{ "tty", required_argument, NULL, 't' },
{ "verbose", no_argument, NULL, 'v' },
{ "help", no_argument, NULL, 'h' },
{ 0, 0, NULL, 0 }
};
memset(&wl, 0, sizeof wl);
while ((c = getopt_long(argc, argv, "u:t::vh", opts, &i)) != -1) {
switch (c) {
case 'u':
wl.new_user = optarg;
if (getuid() != 0)
error(1, 0, "Permission denied. -u allowed for root only");
break;
case 't':
tty = optarg;
break;
case 'v':
wl.verbose = 1;
break;
case 'h':
help("weston-launch");
exit(EXIT_FAILURE);
}
}
if ((argc - optind) > (MAX_ARGV_SIZE - 6))
error(1, E2BIG, "Too many arguments to pass to weston");
if (strcmp (argv[optind], "mutter") &&
strcmp (argv[optind], "gnome-shell") &&
strcmp (argv[optind], "gnome-shell-real"))
error(1, 0, "mutter-launch can only be used to launch mutter or gnome-shell");
if (wl.new_user)
wl.pw = getpwnam(wl.new_user);
else
wl.pw = getpwuid(getuid());
if (wl.pw == NULL)
error(1, errno, "failed to get username");
if (!weston_launch_allowed(&wl))
error(1, 0, "Permission denied. You should either:\n"
#ifdef HAVE_SYSTEMD_LOGIN
" - run from an active and local (systemd) session.\n"
#else
" - enable systemd session support for weston-launch.\n"
#endif
" - or add yourself to the 'weston-launch' group.");
if (setup_tty(&wl, tty) < 0)
exit(EXIT_FAILURE);
if (wl.new_user && setup_pam(&wl) < 0)
exit(EXIT_FAILURE);
if (setup_launcher_socket(&wl) < 0)
exit(EXIT_FAILURE);
if (setup_signals(&wl) < 0)
exit(EXIT_FAILURE);
wl.child = fork();
if (wl.child == -1) {
error(1, errno, "fork failed");
exit(EXIT_FAILURE);
}
if (wl.child == 0)
launch_compositor(&wl, argc - optind, argv + optind);
close(wl.sock[1]);
if (wl.tty != STDIN_FILENO)
close(wl.tty);
while (1) {
struct pollfd fds[2];
int n;
fds[0].fd = wl.sock[0];
fds[0].events = POLLIN;
fds[1].fd = wl.signalfd;
fds[1].events = POLLIN;
n = poll(fds, 2, -1);
if (n < 0)
error(0, errno, "poll failed");
if (fds[0].revents & POLLIN)
handle_socket_msg(&wl);
if (fds[1].revents)
handle_signal(&wl);
}
return 0;
}

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@ -0,0 +1,46 @@
/*
* Copyright © 2012 Benjamin Franzke
*
* Permission to use, copy, modify, distribute, and sell this software and
* its documentation for any purpose is hereby granted without fee, provided
* that the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the name of the copyright holders not be used in
* advertising or publicity pertaining to distribution of the software
* without specific, written prior permission. The copyright holders make
* no representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
* SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
* RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
* CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef _WESTON_LAUNCH_H_
#define _WESTON_LAUNCH_H_
enum weston_launcher_opcode {
WESTON_LAUNCHER_OPEN,
WESTON_LAUNCHER_DRM_SET_MASTER
};
struct weston_launcher_message {
int opcode;
};
struct weston_launcher_open {
struct weston_launcher_message header;
int flags;
char path[0];
};
struct weston_launcher_set_master {
struct weston_launcher_message header;
int set_master;
};
#endif