Changed feature keyboard_layout to a property

Purpose: make it easier to implement more robust keyboard layout tools and
propagation.

references QubesOS/qubes-issues#1396
references QubesOS/qubes-issues#4294

qubes/ext/gui.py

@@ -93,10 +93,8 @@ def on_domain_qdb_create(self, vm, event):
                 vm.untrusted_qdb.write('/qubes-gui-domain-xid',
                                        str(vm.guivm.xid))
 
-            # Add keyboard layout from that of GuiVM
-            kbd_layout = vm.guivm.features.get('keyboard-layout', None)
-            if kbd_layout:
-                vm.untrusted_qdb.write('/keyboard-layout', kbd_layout)
+        # Add keyboard layout
+        vm.untrusted_qdb.write('/keyboard-layout', vm.keyboard_layout)
 
         # Set GuiVM prefix
         guivm_windows_prefix = vm.features.get('guivm-windows-prefix', 'GuiVM')
@@ -121,22 +119,16 @@ def on_domain_start(self, vm, event, **kwargs):
             attached_vm.untrusted_qdb.write('/qubes-gui-domain-xid',
                                             str(vm.xid))
 
-    @qubes.ext.handler('domain-feature-pre-set:keyboard-layout')
-    def on_feature_pre_set(self, subject, event, feature, value, oldvalue=None):
-        untrusted_xkb_layout = value.split('+')
-        if len(untrusted_xkb_layout) != 3:
-            raise qubes.exc.QubesValueError("Invalid number of parameters")
-
-        untrusted_layout = untrusted_xkb_layout[0]
-        untrusted_variant = untrusted_xkb_layout[1]
-        untrusted_options = untrusted_xkb_layout[2]
-
-        re_variant = r'^[a-zA-Z0-9-_]*$'
-        re_options = r'^[a-zA-Z0-9-_:,]*$'
-
-        if not untrusted_layout.isalpha():
-            raise qubes.exc.QubesValueError("Invalid layout provided")
-        if not re.match(re_variant, untrusted_variant):
-            raise qubes.exc.QubesValueError("Invalid variant provided")
-        if not re.match(re_options, untrusted_options):
-            raise qubes.exc.QubesValueError("Invalid options provided")
+    @qubes.ext.handler('property-reset:keyboard_layout')
+    def on_keyboard_reset(self, subject, event, name, oldvalue=None):
+        if getattr(subject, 'guivm'):
+            kbd_layout = subject.guivm.keyboard_layout
+        else:
+            kbd_layout = 'us++'
+
+        subject.untrusted_qdb.write('/keyboard-layout', kbd_layout)
+
+    @qubes.ext.handler('property-set:keyboard_layout')
+    def on_keyboard_set(self, subject, event, name, newvalue, oldvalue=None):
+        subject.untrusted_qdb.write('/keyboard-layout', newvalue)
+

qubes/vm/adminvm.py

@@ -28,6 +28,7 @@
 import qubes
 import qubes.exc
 import qubes.vm
+from qubes.vm.qubesvm import _setter_kbd_layout
 
 
 class AdminVM(qubes.vm.BaseVM):
@@ -61,6 +62,13 @@ class AdminVM(qubes.vm.BaseVM):
         setter=qubes.property.forbidden,
         doc='True if this machine may be updated on its own.')
 
+    # for changes in keyboard_layout, see also the same property in QubesVM
+    keyboard_layout = qubes.property(
+        'keyboard_layout',
+        type=str,
+        setter=_setter_kbd_layout,
+        doc='Keyboard layout for this VM')
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
 

qubes/vm/qubesvm.py

@@ -23,6 +23,7 @@
 import asyncio
 import base64
 import grp
+import re
 import os
 import os.path
 import shutil
@@ -115,6 +116,30 @@ def _setter_virt_mode(self, prop, value):
     return value
 
 
+def _setter_kbd_layout(self, prop, value):
+    untrusted_xkb_layout = value.split('+')
+    if len(untrusted_xkb_layout) != 3:
+        raise qubes.exc.QubesPropertyValueError(
+            self, prop, value, "invalid number of keyboard layout parameters")
+
+    untrusted_layout = untrusted_xkb_layout[0]
+    untrusted_variant = untrusted_xkb_layout[1]
+    untrusted_options = untrusted_xkb_layout[2]
+
+    re_variant = r'^[a-zA-Z0-9-_]*$'
+    re_options = r'^[a-zA-Z0-9-_:,]*$'
+
+    if not untrusted_layout.isalpha():
+        raise qubes.exc.QubesPropertyValueError(
+            self, prop, value, "Invalid keyboard layout provided")
+    if not re.match(re_variant, untrusted_variant):
+        raise qubes.exc.QubesPropertyValueError(
+            self, prop, value, "Invalid laoyout variant provided")
+    if not re.match(re_options, untrusted_options):
+        raise qubes.exc.QubesPropertyValueError(
+            self, prop, value, "Invalid layout options provided")
+
+
 def _default_virt_mode(self):
     if self.devices['pci'].persistent():
         return 'hvm'
@@ -690,6 +715,14 @@ class QubesVM(qubes.vm.mix.net.NetVMMixin, qubes.vm.BaseVM):
         setter=qubes.property.forbidden,
         doc='True if this machine may be updated on its own.')
 
+    # for changes in keyboard_layout, see also the same property in AdminVM
+    keyboard_layout = qubes.property(
+        'keyboard_layout',
+        default=(lambda self: self.guivm.keyboard_layout),
+        type=str,
+        setter=_setter_kbd_layout,
+        doc='Keyboard layout for this VM')
+
     #
     # static, class-wide properties
     #