q-dev: usb device full identity

qubesusbproxy/core3ext.py

@@ -5,6 +5,8 @@
 #
 # Copyright (C) 2016  Marek Marczykowski-Górecki
 #                                   <[email protected]>
+# Copyright (C) 2024  Piotr Bartman-Szwarc
+#                                   <[email protected]>
 #
 # 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
@@ -19,21 +21,18 @@
 # 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.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
-#
+
 import asyncio
-import base64
 import collections
 import fcntl
 import grp
-import itertools
 import os
 import re
 import string
 import subprocess
 import sys
 
 import tempfile
-from enum import Enum
 from typing import List, Optional, Dict, Tuple
 
 import qubes.devices
@@ -152,13 +151,6 @@ def parent_device(self) -> Optional[qubes.devices.DeviceInfo]:
         """
         return None
 
-    # @property
-    # def port_id(self) -> str:
-    #     """
-    #     Which port the device is connected to.
-    #     """
-    #     return self.ident.split("-")[1]
-
     def _load_interfaces_from_qubesdb(self) \
             -> List[qubes.devices.DeviceInterface]:
         result = [qubes.devices.DeviceInterface.unknown()]
@@ -256,8 +248,8 @@ def frontend_domain(self):
                 untrusted_connected_to]
         except KeyError:
             self.backend_domain.log.warning(
-                'Device {} has invalid VM name in connected-to '
-                'property: '.format(self.ident, untrusted_connected_to))
+                f'Device {self.ident} has invalid VM name in connected-to '
+                f'property: {untrusted_connected_to}')
             return None
         return connected_to
 
@@ -327,6 +319,10 @@ class QubesUSBException(qubes.exc.QubesException):
     pass
 
 
+class UnrecognizedDevice(QubesUSBException):
+    pass
+
+
 def modify_qrexec_policy(service, line, add):
     """
     Add/remove *line* to qrexec policy of a *service*.
@@ -407,11 +403,13 @@ def on_domain_init_load(self, vm, event):
 
     async def _attach_and_notify(self, vm, device, options):
         # bypass DeviceCollection logic preventing double attach
-        await self.on_device_attach_usb(vm,
-            'device-pre-attach:usb', device, options)
-        await vm.fire_event_async('device-attach:usb',
-                device=device,
-                options=options)
+        try:
+            await self.on_device_attach_usb(
+                vm, 'device-pre-attach:usb', device, options)
+        except UnrecognizedDevice:
+            return
+        await vm.fire_event_async(
+            'device-attach:usb', device=device, options=options)
 
     @qubes.ext.handler('domain-qdb-change:/qubes-usb-devices')
     def on_qdb_change(self, vm, event, path):
@@ -469,7 +467,9 @@ def on_qdb_change(self, vm, event, path):
         for dev_ident, front_vm in attached.items():
             dev = USBDevice(vm, dev_ident)
             asyncio.ensure_future(front_vm.fire_event_async(
-                'device-attach:usb', device=dev, options={}))
+                'device-attach:usb', device=dev,
+                options={'identity': dev.full_identity})
+            )
 
         self.devices_cache[vm.name] = current_devices
 
@@ -536,29 +536,46 @@ def on_device_list_attached(self, vm, event, **kwargs):
 
         for dev in self.get_all_devices(vm.app):
             if dev.frontend_domain == vm:
-                yield (dev, {})
+                yield (dev, {'identity': dev.full_identity})
 
     @qubes.ext.handler('device-pre-attach:usb')
     async def on_device_attach_usb(self, vm, event, device, options):
         # pylint: disable=unused-argument
+
+        if options:
+            if list(options.keys()) != ['identity']:
+                raise qubes.exc.QubesException(
+                    'USB device attach do not support user options')
+            identity = options['identity']
+            if device.full_identity != identity:
+                print(f"Unrecognized identity, skipping attachment of {device}",
+                      file=sys.stderr)
+                raise UnrecognizedDevice(
+                    "Device presented identity "
+                    f"{device.full_identity} "
+                    f"does not match expected {identity}"
+                )
+
         if not vm.is_running() or vm.qid == 0:
+            # print(f"Qube is not running, skipping attachment of {device}",
+            #       file=sys.stderr)
             return
 
         if not isinstance(device, USBDevice):
+            # print("The device is not recognized as usb device, "
+            #       f"skipping attachment of {device}",
+            #       file=sys.stderr)
             return
 
-        if options:
-            raise qubes.exc.QubesException(
-                'USB device attach do not support options')
-
         if device.frontend_domain:
             raise qubes.devices.DeviceAlreadyAttached(
-                'Device {!s} already attached to {!s}'.format(device,
-                    device.frontend_domain)
+                'Device {!s} already attached to {!s}'.format(
+                    device, device.frontend_domain)
             )
 
-        stubdom_qrexec = (vm.virt_mode == 'hvm' and \
-            vm.features.check_with_template('stubdom-qrexec', False))
+        stubdom_qrexec = (
+                vm.virt_mode == 'hvm'
+                and vm.features.check_with_template('stubdom-qrexec', False))
 
         name = vm.name + '-dm' if stubdom_qrexec else vm.name