Add free-form text to qube for notes, comments, ...

Core and API part of adding free-form text to each qube for comments,
notes, descriptions, remarks, reminders, etc.

fixes: QubesOS/qubes-issues#899

Author: alimirjamali

Makefile

@@ -109,6 +109,8 @@ ADMIN_API_METHODS_SIMPLE = \
 	admin.vm.firewall.GetPolicy \
 	admin.vm.firewall.SetPolicy \
 	admin.vm.firewall.Reload \
+	admin.vm.notes.Get \
+	admin.vm.notes.Set \
 	admin.vm.property.Get \
 	admin.vm.property.GetAll \
 	admin.vm.property.GetDefault \

qubes/api/admin.py

@@ -2038,3 +2038,23 @@ async def vm_current_state(self):
             "power_state": self.dest.get_power_state(),
         }
         return " ".join("{}={}".format(k, v) for k, v in state.items())
+
+    @qubes.api.method(
+        "admin.vm.notes.Get", no_payload=True, scope="local", read=True
+    )
+    async def vm_notes_get(self):
+        """Get qube notes"""
+        self.enforce(self.dest.name != "dom0")
+        self.fire_event_for_permission()
+        return self.dest.get_notes()
+
+    @qubes.api.method("admin.vm.notes.Set", scope="local", write=True)
+    async def vm_notes_set(self, untrusted_payload):
+        """Set qube notes"""
+        allowed_chars = string.printable + " \t\n"
+        self.enforce(self.dest.name != "dom0")
+        self.enforce(all(c in allowed_chars for c in self.arg))
+        self.fire_event_for_permission()
+        notes = "".join([c if c in allowed_chars else '_' for \
+            c in untrusted_payload.decode("ascii")])
+        self.dest.set_notes(notes)

qubes/vm/qubesvm.py

@@ -2585,6 +2585,43 @@ def kernelopts_common(self):
         else:
             return base_kernelopts + qubes.config.defaults["kernelopts_common"]
 
+    #
+    # free-form text for descriptions, notes, comments, remarks, etc.
+    #
+
+    @property
+    def notes_file(self) -> str:
+        """Notes file name within /var/lib/qubes (per each qube sub-dir)"""
+        return "notes.txt"
+
+    def has_notes(self) -> bool:
+        """Return `True` if there is a qube notes file present"""
+        return os.path.exists(os.path.join(self.dir_path, self.notes_file))
+
+    def get_notes(self) -> str:
+        """Read the notes file and return its content"""
+        try:
+            with open(os.path.join(self.dir_path, self.notes_file), \
+                    encoding="ascii") as fd:
+                return fd.read()
+        except EnvironmentError:  # pylint: disable=broad-except
+            # problem accessing file, like ENOTFOUND, EPERM or sth
+            return ""
+
+    def set_notes(self, notes: str) -> bool:
+        """Write to notes file"""
+        try:
+            with open(
+                os.path.join(self.dir_path, self.notes_file),
+                'w',
+                encoding="ascii",
+            ) as fd:
+                fd.write(notes)
+                fd.close()
+        except EnvironmentError:  # pylint: disable=broad-except
+            return False
+        return True
+
     #
     # helper methods
     #

rpm_spec/core-dom0.spec.in

@@ -286,6 +286,8 @@ admin.vm.feature.Set
 admin.vm.firewall.Get
 admin.vm.firewall.Reload
 admin.vm.firewall.Set
+admin.vm.notes.Get
+admin.vm.notes.Set
 admin.vm.property.Get
 admin.vm.property.GetAll
 admin.vm.property.GetDefault