backups: Use new utility for handling file uploads

- Use dedicated directory for uploads

- Uploaded backup archives are owned by root and read-only (0o600)

Signed-off-by: Joseph Nuthalapati <njoseph@riseup.net>
[sunil: Fix checking the relativeness of file path before removing]
[sunil: Create backups upload path recursively]
Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: Sunil Mohan Adapa <sunil@medhas.org>

plinth/modules/backups/decorators.py

@@ -4,9 +4,8 @@ Decorators for the backup views.
 """
 
 import functools
-import os
 
-from . import SESSION_PATH_VARIABLE
+from . import privileged, SESSION_PATH_VARIABLE
 
 
 def delete_tmp_backup_file(function):
@@ -15,12 +14,12 @@ def delete_tmp_backup_file(function):
     XXX: Implement a better way to delete uploaded files.
 
     """
+
     @functools.wraps(function)
     def wrapper(request, *args, **kwargs):
         path = request.session.get(SESSION_PATH_VARIABLE, None)
         if path:
-            if os.path.isfile(path):
-                os.remove(path)
+            privileged.remove_uploaded_archive(path)
             del request.session[SESSION_PATH_VARIABLE]
         return function(request, *args, **kwargs)
 

plinth/modules/backups/privileged.py

@@ -8,11 +8,13 @@ import re
 import subprocess
 import tarfile
 
+from plinth import action_utils
 from plinth.actions import privileged, secret_str
 from plinth.utils import Version
 
 TIMEOUT = 30
 BACKUPS_DATA_PATH = pathlib.Path('/var/lib/plinth/backups-data/')
+BACKUPS_UPLOAD_PATH = pathlib.Path('/var/lib/freedombox/backups-upload/')
 MANIFESTS_FOLDER = '/var/lib/plinth/backups-manifests/'
 
 
@@ -143,6 +145,24 @@ def list_repo(path: str,
     return json.loads(process.stdout.decode())
 
 
+@privileged
+def add_uploaded_archive(file_name: str, temporary_file_path: str):
+    """Store an archive uploaded by the user."""
+    BACKUPS_UPLOAD_PATH.mkdir(parents=True, exist_ok=True)
+    action_utils.move_uploaded_file(temporary_file_path, BACKUPS_UPLOAD_PATH,
+                                    file_name, allow_overwrite=True,
+                                    permissions=0o600)
+
+
+@privileged
+def remove_uploaded_archive(file_path: str):
+    """Delete the archive uploaded by the user."""
+    resolved_file_path = pathlib.Path(file_path).resolve()
+    if (resolved_file_path.is_relative_to(BACKUPS_UPLOAD_PATH)
+            and resolved_file_path.is_file()):
+        resolved_file_path.unlink()
+
+
 def _get_borg_version():
     """Return the version of borgbackup."""
     process = _run(['borg', '--version'], stdout=subprocess.PIPE)

plinth/modules/backups/views.py

@@ -5,7 +5,6 @@ Views for the backups app.
 
 import logging
 import os
-import tempfile
 from datetime import datetime
 from urllib.parse import unquote
 
@@ -190,11 +189,13 @@ class UploadArchiveView(SuccessMessageMixin, FormView):
         return context
 
     def form_valid(self, form):
-        """store uploaded file."""
-        with tempfile.NamedTemporaryFile(delete=False) as tmp_file:
-            self.request.session[SESSION_PATH_VARIABLE] = tmp_file.name
-            for chunk in self.request.FILES['backups-file'].chunks():
-                tmp_file.write(chunk)
+        """Store uploaded file."""
+        uploaded_file = self.request.FILES['backups-file']
+        # Hold on to Django's uploaded file. It will be used by other views.
+        privileged.add_uploaded_archive(uploaded_file.name,
+                                        uploaded_file.temporary_file_path())
+        self.request.session[SESSION_PATH_VARIABLE] = str(
+            privileged.BACKUPS_UPLOAD_PATH / uploaded_file.name)
         return super().form_valid(form)