Implement support for running on Wayland through Weston

This implements rudimentary support for running Anaconda on Wayland
using the Weston compositor through XWayland. This support also
includes simple auth-less VNC remote access, though authenticated
VNC support requires extra effort since Weston's authenticated
VNC support uses TLS certificates and we do not have a good way
to plumb that through right now (more info in weston-vnc(7)).

anaconda.py

@@ -144,10 +144,22 @@ def setup_environment():
     if "LD_PRELOAD" in os.environ:
         del os.environ["LD_PRELOAD"]
 
+    # Required for Wayland compositors
+    if os.path.isdir("/tmp/anaconda-xdgrundir"):
+        os.environ["XDG_RUNTIME_DIR"] = "/tmp/anaconda-xdgrundir"
+
+    # Go ahead and set $WAYLAND_DISPLAY whether we're going to use X or not
+    if "WAYLAND_DISPLAY" in os.environ:
+        flags.preexisting_wayland = True
+    else:
+        os.environ["WAYLAND_DISPLAY"] = constants.WAYLAND_SOCKET_NAME
+
     # Go ahead and set $DISPLAY whether we're going to use X or not
+    # only if X11 is being used
+    from pyanaconda.core.kernel import kernel_arguments
     if "DISPLAY" in os.environ:
         flags.preexisting_x11 = True
-    else:
+    elif "x11" in kernel_arguments and os.path.isfile("/usr/bin/Xorg"):
         os.environ["DISPLAY"] = ":%s" % constants.X_DISPLAY_NUMBER
 
     # We mostly don't run from bash, so it won't load the file for us, and libreport will then
@@ -296,10 +308,11 @@ def setup_environment():
     except pid.PidFileError as e:
         log.error("Unable to create %s, exiting", pidfile.filename)
 
-        # If we had a $DISPLAY at start and zenity is available, we may be
-        # running in a live environment and we can display an error dialog.
+        # If we had a Wayland/X11 display at start and zenity is available,
+        # we may be running in a live environment and we can display an error dialog.
         # Otherwise just print an error.
-        if flags.preexisting_x11 and os.access("/usr/bin/zenity", os.X_OK):
+        preexisting_graphics = flags.preexisting_wayland or flags.preexisting_x11
+        if preexisting_graphics and os.access("/usr/bin/zenity", os.X_OK):
             # The module-level _() calls are ok here because the language may
             # be set from the live environment in this case, and anaconda's
             # language setup hasn't happened yet.

anaconda.spec.in

@@ -248,15 +248,20 @@ Requires: zram-generator
 # needed for proper driver disk support - if RPMs must be installed, a repo is needed
 Requires: createrepo_c
 # Display stuff moved from lorax templates
+## For Wayland
+Requires: weston
+Requires: xorg-x11-server-Xwayland
+## For X11
 Requires: xorg-x11-drivers
 Requires: xorg-x11-server-Xorg
 Requires: xrandr
+Requires: gnome-kiosk
+## Common stuff
 Requires: xrdb
 Requires: dbus-x11
 Requires: gsettings-desktop-schemas
 Requires: nm-connection-editor
 Requires: librsvg2
-Requires: gnome-kiosk
 Requires: brltty
 # dependencies for rpm-ostree payload module
 Requires: rpm-ostree >= %{rpmostreever}
@@ -394,6 +399,7 @@ rm -rf \
 %{_sbindir}/anaconda
 %{_sbindir}/handle-sshpw
 %{_datadir}/anaconda
+%{_sysconfdir}/pam.d/anaconda
 %{_prefix}/libexec/anaconda
 %exclude %{_datadir}/anaconda/gnome
 %exclude %{_datadir}/anaconda/pixmaps

configure.ac

@@ -111,6 +111,7 @@ AC_CONFIG_FILES([Makefile
                  data/liveinst/gnome/Makefile
                  data/systemd/Makefile
                  data/dbus/Makefile
+                 data/pam/Makefile
                  data/window-manager/Makefile
                  data/window-manager/config/Makefile
                  po/Makefile

data/Makefile.am

@@ -15,7 +15,7 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-SUBDIRS = command-stubs liveinst systemd pixmaps window-manager dbus conf.d profile.d
+SUBDIRS = command-stubs liveinst systemd pixmaps window-manager dbus conf.d profile.d pam
 
 CLEANFILES = *~
 

data/pam/Makefile.am

@@ -0,0 +1,21 @@
+# Copyright (C) 2024  Neal Gompa.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published
+# by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+CLEANFILES = *~
+
+pamdir           = $(sysconfdir)/pam.d
+dist_pam_DATA    = anaconda
+
+MAINTAINERCLEANFILES = Makefile.in

data/pam/anaconda

@@ -0,0 +1,8 @@
+#%PAM-1.0
+auth       sufficient  pam_permit.so
+account    sufficient  pam_permit.so
+password   sufficient  pam_permit.so
+session    required    pam_loginuid.so
+-session   optional    pam_keyinit.so revoke
+-session   optional    pam_limits.so
+session    required    pam_systemd.so

data/systemd/anaconda.service

@@ -5,6 +5,15 @@ Wants=anaconda-noshell.service
 
 [Service]
 Type=forking
-Environment=HOME=/root MALLOC_CHECK_=2 MALLOC_PERTURB_=204 PATH=/usr/bin:/bin:/sbin:/usr/sbin:/mnt/sysimage/bin:/mnt/sysimage/usr/bin:/mnt/sysimage/usr/sbin:/mnt/sysimage/sbin LANG=en_US.UTF-8 GDK_BACKEND=x11 XDG_RUNTIME_DIR=/tmp GIO_USE_VFS=local
+Environment=HOME=/root MALLOC_CHECK_=2 MALLOC_PERTURB_=204 PATH=/usr/bin:/bin:/sbin:/usr/sbin:/mnt/sysimage/bin:/mnt/sysimage/usr/bin:/mnt/sysimage/usr/sbin:/mnt/sysimage/sbin LANG=en_US.UTF-8 GDK_BACKEND=x11 XDG_RUNTIME_DIR=/tmp/anaconda-xdgrundir GIO_USE_VFS=local
 WorkingDirectory=/root
+User=root
+Group=root
+ExecStartPre=/usr/bin/mkdir -p /tmp/anaconda-xdgrundir
+ExecStartPre=/usr/bin/chmod 700 /tmp/anaconda-xdgrundir
 ExecStart=/usr/bin/tmux -u -f /usr/share/anaconda/tmux.conf start
+PAMName=anaconda
+TTYPath=/dev/tty6
+TTYReset=yes
+TTYVHangup=yes
+TTYVTDisallocate=yes

pyanaconda/core/constants.py

@@ -261,6 +261,9 @@ class SecretStatus(Enum):
 IPMI_ABORTED = 0x9          # installation finished unsuccessfully, due to some non-exn error
 IPMI_FAILED = 0xA           # installation hit an exception
 
+# Wayland socket name to use
+WAYLAND_SOCKET_NAME = "wl-sysinstall-0"
+
 # X display number to use
 X_DISPLAY_NUMBER = 1
 
@@ -315,13 +318,27 @@ class DisplayModes(Enum):
     False: "noninteractive"
 }
 
+# Weston configuration
+WESTON_CONFIG = {
+  "core": {
+    "shell": "kiosk",
+    "xwayland": "true"
+  }
+}
+
 # Loggers
 LOGGER_ANACONDA_ROOT = "anaconda"
 LOGGER_MAIN = "anaconda.main"
 LOGGER_STDOUT = "anaconda.stdout"
 LOGGER_PROGRAM = "program"
 LOGGER_SIMPLELINE = "simpleline"
 
+# Wayland display vars file
+WAYLAND_DISPLAY_VARS_FILE = "/tmp/anaconda-wayland-display-vars"
+
+# Timeout for starting Wayland
+WAYLAND_TIMEOUT = 60
+
 # Timeout for starting X
 X_TIMEOUT = 60
 

pyanaconda/core/util.py

@@ -18,13 +18,17 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
+import configparser
 import os
 import os.path
+import pathlib
 import subprocess
 # Used for ascii_lowercase, ascii_uppercase constants
 import tempfile
+import time
 import re
 import signal
+import stat
 import sys
 import types
 import inspect
@@ -39,8 +43,9 @@
 from pyanaconda.core.configuration.anaconda import conf
 from pyanaconda.core.path import make_directories, open_with_perm, join_paths
 from pyanaconda.core.process_watchers import WatchProcesses
-from pyanaconda.core.constants import DRACUT_SHUTDOWN_EJECT, \
-    IPMI_ABORTED, X_TIMEOUT, PACKAGES_LIST_FILE
+from pyanaconda.core.constants import DRACUT_SHUTDOWN_EJECT, IPMI_ABORTED, \
+    WAYLAND_SOCKET_NAME, WAYLAND_DISPLAY_VARS_FILE, WAYLAND_TIMEOUT, \
+    WESTON_CONFIG, X_TIMEOUT, PACKAGES_LIST_FILE
 from pyanaconda.core.live_user import get_live_user
 from pyanaconda.errors import RemovedModuleError
 
@@ -165,6 +170,92 @@ def preexec():
     return partsubp(preexec_fn=preexec)
 
 
+class WaylandStatus:
+    """Status of Wayland launch.
+
+    Values of an instance can be modified from the handler functions.
+    """
+    def __init__(self):
+        self.started = False
+        self.timed_out = False
+
+    def needs_waiting(self):
+        return not (self.started or self.timed_out)
+
+
+def startWl(weston_config=WESTON_CONFIG, output_redirect=None, timeout=WAYLAND_TIMEOUT):
+    """ Start Weston for Wayland and return once Weston is ready to accept connections.
+
+        We can identify whether Weston is ready by testing if
+        the Wayland socket is open yet. Once it is, we can return success.
+
+        :param weston_config: The weston.ini(5) configuration to use, as a dictionary
+        :param output_redirect: file or file descriptor to redirect stdout and stderr to
+        :param timeout: Number of seconds to timing out.
+    """
+    wl_status = WaylandStatus()
+
+    # Create the wayland vars getenv script file for Weston
+    wl_getenv_script_file = tempfile.NamedTemporaryFile(mode="w",
+                                                        suffix="-wl-weston-getenv-sh",
+                                                        delete=False)
+    wl_getenv_script = f"""#!/bin/sh
+    rm -f {WAYLAND_DISPLAY_VARS_FILE}
+    echo "[wayland_vars]" >> {WAYLAND_DISPLAY_VARS_FILE}
+    echo "WAYLAND_DISPLAY=$WAYLAND_DISPLAY" >> {WAYLAND_DISPLAY_VARS_FILE}
+    echo "DISPLAY=$DISPLAY" >> {WAYLAND_DISPLAY_VARS_FILE}
+    exit 0
+    """
+    wl_getenv_script_file.write(wl_getenv_script)
+    wl_getenv_script_file.close()
+
+    weston_autolaunch_config = {"autolaunch":{"path":wl_getenv_script_file.name}}
+
+    os.chmod(wl_getenv_script_file.name,
+             os.stat(wl_getenv_script_file.name).st_mode | stat.S_IEXEC)
+
+    # Create the config file for Weston
+    weston_config_file = tempfile.NamedTemporaryFile(mode="w",
+                                                     suffix="-wl-weston-sysinstall-ini",
+                                                     delete=False)
+    weston_config_ini = configparser.ConfigParser()
+    for section, options in (weston_config | weston_autolaunch_config).items():
+        weston_config_ini.add_section(section)
+        for key, value in options.items():
+            weston_config_ini.set(section, key, str(value))
+    weston_config_ini.write(weston_config_file, space_around_delimiters=False)
+    weston_config_file.close()
+
+    # Determine whether to use drm or vnc backend
+    weston_backend = "drm"
+    if "vnc" in weston_config:
+        weston_backend = "vnc"
+
+    log.debug("Starting Weston.")
+    argv = ["weston", f"--backend={weston_backend}",
+            f"--config={weston_config_file.name}", "--log=/tmp/weston.log",
+            f"--socket={WAYLAND_SOCKET_NAME}"]
+
+    childproc = startProgram(argv, stdout=output_redirect, stderr=output_redirect)
+    WatchProcesses.watch_process(childproc, argv[0])
+
+    for _ in range(0, timeout):
+        try:
+            xdg_runtime_dir = os.getenv("XDG_RUNTIME_DIR")
+            pathlib.Path(xdg_runtime_dir, WAYLAND_SOCKET_NAME).resolve(strict=True)
+            wl_status.started = True
+            return wl_status.started
+        except Exception:
+            if wl_status.needs_waiting():
+                time.sleep(1)
+    wl_status.timed_out = True
+    WatchProcesses.unwatch_process(childproc)
+    childproc.terminate()
+    log.debug("Exception handler test suspended to prevent accidental activation by "
+              "delayed Weston start.")
+    raise TimeoutError("Timeout trying to start %s" % argv[0])
+
+
 class X11Status:
     """Status of Xorg launch.