From 9d3c6f1849120e732a9230959cb302575765ea8c Mon Sep 17 00:00:00 2001 From: ThibG Date: Thu, 28 Feb 2019 15:22:21 +0100 Subject: Improved remote thread fetching (#10106) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit * Fetch up to 5 replies when discovering a new remote status This is used for resolving threads downwards. The originating server must add a “replies” attributes with such replies for it to be useful. * Add some tests for ActivityPub::FetchRepliesWorker * Add specs for ActivityPub::FetchRepliesService * Serialize up to 5 public self-replies for ActivityPub notes * Add specs for ActivityPub::NoteSerializer * Move exponential backoff logic to a worker concern * Fetch first page of paginated collections when fetching thread replies * Add specs for paginated collections in replies * Move Note replies serialization to a first CollectionPage The collection isn't actually paginable yet as it has no id nor a `next` field. This may come in another PR. * Use pluck(:uri) instead of map(&:uri) to improve performances * Fix fetching replies when they are in a CollectionPage --- app/services/activitypub/fetch_replies_service.rb | 60 +++++++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100644 app/services/activitypub/fetch_replies_service.rb (limited to 'app/services') diff --git a/app/services/activitypub/fetch_replies_service.rb b/app/services/activitypub/fetch_replies_service.rb new file mode 100644 index 000000000..95c486a43 --- /dev/null +++ b/app/services/activitypub/fetch_replies_service.rb @@ -0,0 +1,60 @@ +# frozen_string_literal: true + +class ActivityPub::FetchRepliesService < BaseService + include JsonLdHelper + + def call(parent_status, collection_or_uri, allow_synchronous_requests = true) + @account = parent_status.account + @allow_synchronous_requests = allow_synchronous_requests + + @items = collection_items(collection_or_uri) + return if @items.nil? + + FetchReplyWorker.push_bulk(filtered_replies) + + @items + end + + private + + def collection_items(collection_or_uri) + collection = fetch_collection(collection_or_uri) + return unless collection.is_a?(Hash) + + collection = fetch_collection(collection['first']) if collection['first'].present? + return unless collection.is_a?(Hash) + + case collection['type'] + when 'Collection', 'CollectionPage' + collection['items'] + when 'OrderedCollection', 'OrderedCollectionPage' + collection['orderedItems'] + end + end + + def fetch_collection(collection_or_uri) + return collection_or_uri if collection_or_uri.is_a?(Hash) + return unless @allow_synchronous_requests + return if invalid_origin?(collection_or_uri) + collection = fetch_resource_without_id_validation(collection_or_uri) + raise Mastodon::UnexpectedResponseError if collection.nil? + collection + end + + def filtered_replies + # Only fetch replies to the same server as the original status to avoid + # amplification attacks. + + # Also limit to 5 fetched replies to limit potential for DoS. + @items.map { |item| value_or_id(item) }.reject { |uri| invalid_origin?(uri) }.take(5) + end + + def invalid_origin?(url) + return true if unsupported_uri_scheme?(url) + + needle = Addressable::URI.parse(url).host + haystack = Addressable::URI.parse(@account.uri).host + + !haystack.casecmp(needle).zero? + end +end -- cgit