Add ability to limit amount uploaded by a user (#18527)

You can now configure how much media can be uploaded by a user in a
given time period.

Note the first commit here is a refactor of create/upload content
function

Author: erikjohnston

changelog.d/18527.feature

@@ -0,0 +1 @@
+Add ability to limit amount uploaded by a user in a given time period.

docs/usage/configuration/config_documentation.md

@@ -2086,6 +2086,23 @@ Example configuration:
 max_upload_size: 60M
 ```
 ---
+### `media_upload_limits`
+
+*(array)* A list of media upload limits defining how much data a given user can upload in a given time period.
+
+An empty list means no limits are applied.
+
+Defaults to `[]`.
+
+Example configuration:
+```yaml
+media_upload_limits:
+- time_period: 1h
+  max_size: 100M
+- time_period: 1w
+  max_size: 500M
+```
+---
 ### `max_image_pixels`
 
 *(byte size)* Maximum number of pixels that will be thumbnailed. Defaults to `"32M"`.

schema/synapse-config.schema.yaml

@@ -2335,6 +2335,30 @@ properties:
     default: 50M
     examples:
       - 60M
+  media_upload_limits:
+    type: array
+    description: >-
+      A list of media upload limits defining how much data a given user can
+      upload in a given time period.
+
+
+      An empty list means no limits are applied.
+    default: []
+    items:
+      time_period:
+        type: "#/$defs/duration"
+        description: >-
+          The time period over which the limit applies. Required.
+      max_size:
+        type: "#/$defs/bytes"
+        description: >-
+          Amount of data that can be uploaded in the time period by the user.
+          Required.
+    examples:
+      - - time_period: 1h
+          max_size: 100M
+        - time_period: 1w
+          max_size: 500M
   max_image_pixels:
     $ref: "#/$defs/bytes"
     description: Maximum number of pixels that will be thumbnailed.

synapse/config/repository.py

@@ -119,6 +119,15 @@ def parse_thumbnail_requirements(
     }
 
 
+@attr.s(auto_attribs=True, slots=True, frozen=True)
+class MediaUploadLimit:
+    """A limit on the amount of data a user can upload in a given time
+    period."""
+
+    max_bytes: int
+    time_period_ms: int
+
+
 class ContentRepositoryConfig(Config):
     section = "media"
 
@@ -274,6 +283,13 @@ def read_config(self, config: JsonDict, **kwargs: Any) -> None:
 
         self.enable_authenticated_media = config.get("enable_authenticated_media", True)
 
+        self.media_upload_limits: List[MediaUploadLimit] = []
+        for limit_config in config.get("media_upload_limits", []):
+            time_period_ms = self.parse_duration(limit_config["time_period"])
+            max_bytes = self.parse_size(limit_config["max_size"])
+
+            self.media_upload_limits.append(MediaUploadLimit(max_bytes, time_period_ms))
+
     def generate_config_section(self, data_dir_path: str, **kwargs: Any) -> str:
         assert data_dir_path is not None
         media_store = os.path.join(data_dir_path, "media_store")

synapse/handlers/sso.py

@@ -824,7 +824,7 @@ def is_allowed_mime_type(content_type: str) -> bool:
                         return True
 
             # store it in media repository
-            avatar_mxc_url = await self._media_repo.create_content(
+            avatar_mxc_url = await self._media_repo.create_or_update_content(
                 media_type=headers[b"Content-Type"][0].decode("utf-8"),
                 upload_name=upload_name,
                 content=picture,

synapse/media/media_repository.py

@@ -177,6 +177,13 @@ def __init__(self, hs: "HomeServer"):
         else:
             self.url_previewer = None
 
+        # We get the media upload limits and sort them in descending order of
+        # time period, so that we can apply some optimizations.
+        self.media_upload_limits = hs.config.media.media_upload_limits
+        self.media_upload_limits.sort(
+            key=lambda limit: limit.time_period_ms, reverse=True
+        )
+
     def _start_update_recently_accessed(self) -> Deferred:
         return run_as_background_process(
             "update_recently_accessed_media", self._update_recently_accessed
@@ -285,80 +292,37 @@ async def verify_can_upload(self, media_id: str, auth_user: UserID) -> None:
             raise NotFoundError("Media ID has expired")
 
     @trace
-    async def update_content(
-        self,
-        media_id: str,
-        media_type: str,
-        upload_name: Optional[str],
-        content: IO,
-        content_length: int,
-        auth_user: UserID,
-    ) -> None:
-        """Update the content of the given media ID.
-
-        Args:
-            media_id: The media ID to replace.
-            media_type: The content type of the file.
-            upload_name: The name of the file, if provided.
-            content: A file like object that is the content to store
-            content_length: The length of the content
-            auth_user: The user_id of the uploader
-        """
-        file_info = FileInfo(server_name=None, file_id=media_id)
-        sha256reader = SHA256TransparentIOReader(content)
-        # This implements all of IO as it has a passthrough
-        fname = await self.media_storage.store_file(sha256reader.wrap(), file_info)
-        sha256 = sha256reader.hexdigest()
-        should_quarantine = await self.store.get_is_hash_quarantined(sha256)
-        logger.info("Stored local media in file %r", fname)
-
-        if should_quarantine:
-            logger.warning(
-                "Media has been automatically quarantined as it matched existing quarantined media"
-            )
-
-        await self.store.update_local_media(
-            media_id=media_id,
-            media_type=media_type,
-            upload_name=upload_name,
-            media_length=content_length,
-            user_id=auth_user,
-            sha256=sha256,
-            quarantined_by="system" if should_quarantine else None,
-        )
-
-        try:
-            await self._generate_thumbnails(None, media_id, media_id, media_type)
-        except Exception as e:
-            logger.info("Failed to generate thumbnails: %s", e)
-
-    @trace
-    async def create_content(
+    async def create_or_update_content(
         self,
         media_type: str,
         upload_name: Optional[str],
         content: IO,
         content_length: int,
         auth_user: UserID,
+        media_id: Optional[str] = None,
     ) -> MXCUri:
-        """Store uploaded content for a local user and return the mxc URL
+        """Create or update the content of the given media ID.
 
         Args:
             media_type: The content type of the file.
             upload_name: The name of the file, if provided.
             content: A file like object that is the content to store
             content_length: The length of the content
             auth_user: The user_id of the uploader
+            media_id: The media ID to update if provided, otherwise creates
+                new media ID.
 
         Returns:
             The mxc url of the stored content
         """
 
-        media_id = random_string(24)
+        is_new_media = media_id is None
+        if media_id is None:
+            media_id = random_string(24)
 
         file_info = FileInfo(server_name=None, file_id=media_id)
-        # This implements all of IO as it has a passthrough
         sha256reader = SHA256TransparentIOReader(content)
+        # This implements all of IO as it has a passthrough
         fname = await self.media_storage.store_file(sha256reader.wrap(), file_info)
         sha256 = sha256reader.hexdigest()
         should_quarantine = await self.store.get_is_hash_quarantined(sha256)
@@ -370,16 +334,56 @@ async def create_content(
                 "Media has been automatically quarantined as it matched existing quarantined media"
             )
 
-        await self.store.store_local_media(
-            media_id=media_id,
-            media_type=media_type,
-            time_now_ms=self.clock.time_msec(),
-            upload_name=upload_name,
-            media_length=content_length,
-            user_id=auth_user,
-            sha256=sha256,
-            quarantined_by="system" if should_quarantine else None,
-        )
+        # Check that the user has not exceeded any of the media upload limits.
+
+        # This is the total size of media uploaded by the user in the last
+        # `time_period_ms` milliseconds, or None if we haven't checked yet.
+        uploaded_media_size: Optional[int] = None
+
+        # Note: the media upload limits are sorted so larger time periods are
+        # first.
+        for limit in self.media_upload_limits:
+            # We only need to check the amount of media uploaded by the user in
+            # this latest (smaller) time period if the amount of media uploaded
+            # in a previous (larger) time period is above the limit.
+            #
+            # This optimization means that in the common case where the user
+            # hasn't uploaded much media, we only need to query the database
+            # once.
+            if (
+                uploaded_media_size is None
+                or uploaded_media_size + content_length > limit.max_bytes
+            ):
+                uploaded_media_size = await self.store.get_media_uploaded_size_for_user(
+                    user_id=auth_user.to_string(), time_period_ms=limit.time_period_ms
+                )
+
+            if uploaded_media_size + content_length > limit.max_bytes:
+                raise SynapseError(
+                    400, "Media upload limit exceeded", Codes.RESOURCE_LIMIT_EXCEEDED
+                )
+
+        if is_new_media:
+            await self.store.store_local_media(
+                media_id=media_id,
+                media_type=media_type,
+                time_now_ms=self.clock.time_msec(),
+                upload_name=upload_name,
+                media_length=content_length,
+                user_id=auth_user,
+                sha256=sha256,
+                quarantined_by="system" if should_quarantine else None,
+            )
+        else:
+            await self.store.update_local_media(
+                media_id=media_id,
+                media_type=media_type,
+                upload_name=upload_name,
+                media_length=content_length,
+                user_id=auth_user,
+                sha256=sha256,
+                quarantined_by="system" if should_quarantine else None,
+            )
 
         try:
             await self._generate_thumbnails(None, media_id, media_id, media_type)

synapse/rest/media/upload_resource.py

@@ -120,7 +120,7 @@ async def on_POST(self, request: SynapseRequest) -> None:
 
         try:
             content: IO = request.content  # type: ignore
-            content_uri = await self.media_repo.create_content(
+            content_uri = await self.media_repo.create_or_update_content(
                 media_type, upload_name, content, content_length, requester.user
             )
         except SpamMediaException:
@@ -170,13 +170,13 @@ async def on_PUT(
 
             try:
                 content: IO = request.content  # type: ignore
-                await self.media_repo.update_content(
-                    media_id,
+                await self.media_repo.create_or_update_content(
                     media_type,
                     upload_name,
                     content,
                     content_length,
                     requester.user,
+                    media_id=media_id,
                 )
             except SpamMediaException:
                 # For uploading of media we want to respond with a 400, instead of

synapse/storage/databases/main/media_repository.py

@@ -1034,3 +1034,39 @@ def get_matching_media_txn(
             "local_media_repository",
             sha256,
         )
+
+    async def get_media_uploaded_size_for_user(
+        self, user_id: str, time_period_ms: int
+    ) -> int:
+        """Get the total size of media uploaded by a user in the last
+        time_period_ms milliseconds.
+
+        Args:
+            user_id: The user ID to check.
+            time_period_ms: The time period in milliseconds to consider.
+
+        Returns:
+            The total size of media uploaded by the user in bytes.
+        """
+
+        sql = """
+            SELECT COALESCE(SUM(media_length), 0)
+            FROM local_media_repository
+            WHERE user_id = ? AND created_ts > ?
+        """
+
+        def _get_media_uploaded_size_for_user_txn(
+            txn: LoggingTransaction,
+        ) -> int:
+            # Calculate the timestamp for the start of the time period
+            start_ts = self._clock.time_msec() - time_period_ms
+            txn.execute(sql, (user_id, start_ts))
+            row = txn.fetchone()
+            if row is None:
+                return 0
+            return row[0]
+
+        return await self.db_pool.runInteraction(
+            "get_media_uploaded_size_for_user",
+            _get_media_uploaded_size_for_user_txn,
+        )

tests/federation/test_federation_media.py

@@ -67,7 +67,7 @@ def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
     def test_file_download(self) -> None:
         content = io.BytesIO(b"file_to_stream")
         content_uri = self.get_success(
-            self.media_repo.create_content(
+            self.media_repo.create_or_update_content(
                 "text/plain",
                 "test_upload",
                 content,
@@ -110,7 +110,7 @@ def test_file_download(self) -> None:
 
         content = io.BytesIO(SMALL_PNG)
         content_uri = self.get_success(
-            self.media_repo.create_content(
+            self.media_repo.create_or_update_content(
                 "image/png",
                 "test_png_upload",
                 content,
@@ -152,7 +152,7 @@ def test_federation_etag(self) -> None:
 
         content = io.BytesIO(b"file_to_stream")
         content_uri = self.get_success(
-            self.media_repo.create_content(
+            self.media_repo.create_or_update_content(
                 "text/plain",
                 "test_upload",
                 content,
@@ -215,7 +215,7 @@ def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
     def test_thumbnail_download_scaled(self) -> None:
         content = io.BytesIO(small_png.data)
         content_uri = self.get_success(
-            self.media_repo.create_content(
+            self.media_repo.create_or_update_content(
                 "image/png",
                 "test_png_thumbnail",
                 content,
@@ -255,7 +255,7 @@ def test_thumbnail_download_scaled(self) -> None:
     def test_thumbnail_download_cropped(self) -> None:
         content = io.BytesIO(small_png.data)
         content_uri = self.get_success(
-            self.media_repo.create_content(
+            self.media_repo.create_or_update_content(
                 "image/png",
                 "test_png_thumbnail",
                 content,

tests/media/test_media_retention.py

@@ -78,7 +78,7 @@ def _create_media_and_set_attributes(
             # If the meda
             random_content = bytes(random_string(24), "utf-8")
             mxc_uri: MXCUri = self.get_success(
-                media_repository.create_content(
+                media_repository.create_or_update_content(
                     media_type="text/plain",
                     upload_name=None,
                     content=io.BytesIO(random_content),