Implement room v12 (#943)

**Does not yet work!** Currently, state resolution does not correctly resolve conflicting states. Everything else appears to work as expected, so stateres will be fixed soon, then we should be clear for takeoff.

Also: a lot of things currently accept a nullable room ID that really just don't need to. This will need tidying up before merge. Some authentication checks have also been disabled temporarily but nothing important.

A lot of things are tagged with `TODO(hydra)`, those need resolving before merge. External contributors should PR to the `hydra/public` branch, *not* ` main`.

---

This PR should be squash merged.

Reviewed-on: https://forgejo.ellis.link/continuwuation/continuwuity/pulls/943
Co-authored-by: nexy7574 <git@nexy7574.co.uk>
Co-committed-by: nexy7574 <git@nexy7574.co.uk>

src/service/rooms/event_handler/handle_outlier_pdu.rs

@@ -139,6 +139,7 @@ where
 		&pdu_event,
 		None, // TODO: third party invite
 		state_fetch,
+		create_event.as_pdu(),
 	)
 	.await
 	.map_err(|e| err!(Request(Forbidden("Auth check failed: {e:?}"))))?;

src/service/rooms/event_handler/mod.rs

@@ -99,7 +99,10 @@ impl Service {
 }
 
 fn check_room_id<Pdu: Event>(room_id: &RoomId, pdu: &Pdu) -> Result {
-	if pdu.room_id() != room_id {
+	if pdu
+		.room_id()
+		.is_some_and(|claimed_room_id| claimed_room_id != room_id)
+	{
 		return Err!(Request(InvalidParam(error!(
 			pdu_event_id = ?pdu.event_id(),
 			pdu_room_id = ?pdu.room_id(),

src/service/rooms/event_handler/parse_incoming_pdu.rs

@@ -1,7 +1,8 @@
 use conduwuit::{
-	Result, err, implement, matrix::event::gen_event_id_canonical_json, result::FlatOk,
+	Result, RoomVersion, err, implement, matrix::event::gen_event_id_canonical_json,
+	result::FlatOk,
 };
-use ruma::{CanonicalJsonObject, CanonicalJsonValue, OwnedEventId, OwnedRoomId};
+use ruma::{CanonicalJsonObject, CanonicalJsonValue, OwnedEventId, OwnedRoomId, RoomVersionId};
 use serde_json::value::RawValue as RawJsonValue;
 
 type Parsed = (OwnedRoomId, OwnedEventId, CanonicalJsonObject);
@@ -11,12 +12,44 @@ pub async fn parse_incoming_pdu(&self, pdu: &RawJsonValue) -> Result<Parsed> {
 	let value = serde_json::from_str::<CanonicalJsonObject>(pdu.get()).map_err(|e| {
 		err!(BadServerResponse(debug_warn!("Error parsing incoming event {e:?}")))
 	})?;
-
-	let room_id: OwnedRoomId = value
-		.get("room_id")
+	let event_type = value
+		.get("type")
 		.and_then(CanonicalJsonValue::as_str)
-		.map(OwnedRoomId::parse)
-		.flat_ok_or(err!(Request(InvalidParam("Invalid room_id in pdu"))))?;
+		.ok_or_else(|| err!(Request(InvalidParam("Missing or invalid type in pdu"))))?;
+
+	let room_id: OwnedRoomId = if event_type != "m.room.create" {
+		value
+			.get("room_id")
+			.and_then(CanonicalJsonValue::as_str)
+			.map(OwnedRoomId::parse)
+			.flat_ok_or(err!(Request(InvalidParam("Invalid room_id in pdu"))))?
+	} else {
+		// v12 rooms might have no room_id in the create event. We'll need to check the
+		// content.room_version
+		let content = value
+			.get("content")
+			.and_then(CanonicalJsonValue::as_object)
+			.ok_or_else(|| err!(Request(InvalidParam("Missing or invalid content in pdu"))))?;
+		let room_version = content
+			.get("room_version")
+			.and_then(CanonicalJsonValue::as_str)
+			.unwrap_or("1");
+		let vi = RoomVersionId::try_from(room_version).unwrap_or(RoomVersionId::V1);
+		let vf = RoomVersion::new(&vi).expect("supported room version");
+		if vf.room_ids_as_hashes {
+			let (event_id, _) = gen_event_id_canonical_json(pdu, &vi).map_err(|e| {
+				err!(Request(InvalidParam("Could not convert event to canonical json: {e}")))
+			})?;
+			OwnedRoomId::parse(event_id.as_str().replace('$', "!")).expect("valid room ID")
+		} else {
+			// V11 or below room, room_id must be present
+			value
+				.get("room_id")
+				.and_then(CanonicalJsonValue::as_str)
+				.map(OwnedRoomId::parse)
+				.flat_ok_or(err!(Request(InvalidParam("Invalid or missing room_id in pdu"))))?
+		}
+	};
 
 	let room_version_id = self
 		.services
@@ -24,10 +57,8 @@ pub async fn parse_incoming_pdu(&self, pdu: &RawJsonValue) -> Result<Parsed> {
 		.get_room_version(&room_id)
 		.await
 		.map_err(|_| err!("Server is not in room {room_id}"))?;
-
 	let (event_id, value) = gen_event_id_canonical_json(pdu, &room_version_id).map_err(|e| {
 		err!(Request(InvalidParam("Could not convert event to canonical json: {e}")))
 	})?;
-
 	Ok((room_id, event_id, value))
 }

src/service/rooms/event_handler/upgrade_outlier_pdu.rs

@@ -102,6 +102,7 @@ where
 		&incoming_pdu,
 		None, // TODO: third party invite
 		|ty, sk| state_fetch(ty.clone(), sk.into()),
+		create_event.as_pdu(),
 	)
 	.await
 	.map_err(|e| err!(Request(Forbidden("Auth check failed: {e:?}"))))?;
@@ -123,6 +124,7 @@ where
 			incoming_pdu.sender(),
 			incoming_pdu.state_key(),
 			incoming_pdu.content(),
+			&room_version,
 		)
 		.await?;
 
@@ -140,6 +142,7 @@ where
 		&incoming_pdu,
 		None, // third-party invite
 		state_fetch,
+		create_event.as_pdu(),
 	)
 	.await
 	.map_err(|e| err!(Request(Forbidden("Auth check failed: {e:?}"))))?;
@@ -156,7 +159,7 @@ where
 			!self
 				.services
 				.state_accessor
-				.user_can_redact(&redact_id, incoming_pdu.sender(), incoming_pdu.room_id(), true)
+				.user_can_redact(&redact_id, incoming_pdu.sender(), room_id, true)
 				.await?,
 	};
 
@@ -172,7 +175,7 @@ where
 	// Now we calculate the set of extremities this room has after the incoming
 	// event has been applied. We start with the previous extremities (aka leaves)
 	trace!("Calculating extremities");
-	let extremities: Vec<_> = self
+	let mut extremities: Vec<_> = self
 		.services
 		.state
 		.get_forward_extremities(room_id)
@@ -192,6 +195,7 @@ where
 		})
 		.collect()
 		.await;
+	extremities.push(incoming_pdu.event_id().to_owned());
 
 	debug!(
 		"Retained {} extremities checked against {} prev_events",
@@ -303,6 +307,7 @@ where
 		);
 		// assert!(extremities.is_empty(), "soft_fail extremities empty");
 		let extremities = extremities.iter().map(Borrow::borrow);
+		debug_assert!(extremities.clone().count() > 0, "extremities not empty");
 
 		self.services
 			.timeline
@@ -313,6 +318,7 @@ where
 				state_ids_compressed,
 				soft_fail,
 				&state_lock,
+				room_id,
 			)
 			.await?;
 
@@ -336,6 +342,7 @@ where
 		.iter()
 		.map(Borrow::borrow)
 		.chain(once(incoming_pdu.event_id()));
+	debug_assert!(extremities.clone().count() > 0, "extremities not empty");
 
 	let pdu_id = self
 		.services
@@ -347,6 +354,7 @@ where
 			state_ids_compressed,
 			soft_fail,
 			&state_lock,
+			room_id,
 		)
 		.await?;