split s2s into units

Signed-off-by: Jason Volk <jason@zemos.net>

src/api/server/event_auth.rs

@@ -0,0 +1,59 @@
+use std::sync::Arc;
+
+use ruma::{
+	api::{client::error::ErrorKind, federation::authorization::get_event_authorization},
+	RoomId,
+};
+
+use crate::{services, Error, PduEvent, Result, Ruma};
+
+/// # `GET /_matrix/federation/v1/event_auth/{roomId}/{eventId}`
+///
+/// Retrieves the auth chain for a given event.
+///
+/// - This does not include the event itself
+pub(crate) async fn get_event_authorization_route(
+	body: Ruma<get_event_authorization::v1::Request>,
+) -> Result<get_event_authorization::v1::Response> {
+	let origin = body.origin.as_ref().expect("server is authenticated");
+
+	if !services()
+		.rooms
+		.state_cache
+		.server_in_room(origin, &body.room_id)?
+	{
+		return Err(Error::BadRequest(ErrorKind::forbidden(), "Server is not in room."));
+	}
+
+	services()
+		.rooms
+		.event_handler
+		.acl_check(origin, &body.room_id)?;
+
+	let event = services()
+		.rooms
+		.timeline
+		.get_pdu_json(&body.event_id)?
+		.ok_or_else(|| Error::BadRequest(ErrorKind::NotFound, "Event not found."))?;
+
+	let room_id_str = event
+		.get("room_id")
+		.and_then(|val| val.as_str())
+		.ok_or_else(|| Error::bad_database("Invalid event in database."))?;
+
+	let room_id =
+		<&RoomId>::try_from(room_id_str).map_err(|_| Error::bad_database("Invalid room_id in event in database."))?;
+
+	let auth_chain_ids = services()
+		.rooms
+		.auth_chain
+		.event_ids_iter(room_id, vec![Arc::from(&*body.event_id)])
+		.await?;
+
+	Ok(get_event_authorization::v1::Response {
+		auth_chain: auth_chain_ids
+			.filter_map(|id| services().rooms.timeline.get_pdu_json(&id).ok()?)
+			.map(PduEvent::convert_to_outgoing_federation_event)
+			.collect(),
+	})
+}