admin cmd to force download and use a server's room state

Signed-off-by: strawberry <strawberry@puppygock.gay>

src/admin/debug/debug_commands.rs

@@ -1,9 +1,15 @@
-use std::{collections::BTreeMap, sync::Arc, time::Instant};
+use std::{
+	collections::{BTreeMap, HashMap},
+	sync::Arc,
+	time::Instant,
+};
 
+use api::client::validate_and_add_event_id;
 use conduit::{utils::HtmlEscape, Error, Result};
 use ruma::{
-	api::client::error::ErrorKind, events::room::message::RoomMessageEventContent, CanonicalJsonObject, EventId,
-	RoomId, RoomVersionId, ServerName,
+	api::{client::error::ErrorKind, federation::event::get_room_state},
+	events::room::message::RoomMessageEventContent,
+	CanonicalJsonObject, EventId, RoomId, RoomVersionId, ServerName,
 };
 use service::{rooms::event_handler::parse_incoming_pdu, sending::resolve::resolve_actual_dest, services, PduEvent};
 use tokio::sync::RwLock;
@@ -472,6 +478,147 @@ pub(crate) async fn latest_pdu_in_room(_body: Vec<&str>, room_id: Box<RoomId>) -
 	Ok(RoomMessageEventContent::text_plain(format!("{latest_pdu:?}")))
 }
 
+#[tracing::instrument(skip(_body))]
+pub(crate) async fn force_set_room_state_from_server(
+	_body: Vec<&str>, server_name: Box<ServerName>, room_id: Box<RoomId>,
+) -> Result<RoomMessageEventContent> {
+	if !services()
+		.rooms
+		.state_cache
+		.server_in_room(&services().globals.config.server_name, &room_id)?
+	{
+		return Ok(RoomMessageEventContent::text_plain(
+			"We are not participating in the room / we don't know about the room ID.",
+		));
+	}
+
+	let first_pdu = services()
+		.rooms
+		.timeline
+		.latest_pdu_in_room(&room_id)?
+		.ok_or_else(|| Error::bad_database("Failed to find the latest PDU in database"))?;
+
+	let room_version = services().rooms.state.get_room_version(&room_id)?;
+
+	let mut state: HashMap<u64, Arc<EventId>> = HashMap::new();
+	let pub_key_map = RwLock::new(BTreeMap::new());
+
+	let remote_state_response = services()
+		.sending
+		.send_federation_request(
+			&server_name,
+			get_room_state::v1::Request {
+				room_id: room_id.clone().into(),
+				event_id: first_pdu.event_id.clone().into(),
+			},
+		)
+		.await?;
+
+	let mut events = Vec::with_capacity(remote_state_response.pdus.len());
+
+	for pdu in remote_state_response.pdus.clone() {
+		events.push(match parse_incoming_pdu(&pdu) {
+			Ok(t) => t,
+			Err(e) => {
+				warn!("Could not parse PDU, ignoring: {e}");
+				continue;
+			},
+		});
+	}
+
+	info!("Fetching required signing keys for all the state events we got");
+	services()
+		.rooms
+		.event_handler
+		.fetch_required_signing_keys(events.iter().map(|(_event_id, event, _room_id)| event), &pub_key_map)
+		.await?;
+
+	info!("Going through room_state response PDUs");
+	for result in remote_state_response
+		.pdus
+		.iter()
+		.map(|pdu| validate_and_add_event_id(pdu, &room_version, &pub_key_map))
+	{
+		let Ok((event_id, value)) = result.await else {
+			continue;
+		};
+
+		let pdu = PduEvent::from_id_val(&event_id, value.clone()).map_err(|e| {
+			warn!("Invalid PDU in fetching remote room state PDUs response: {} {:?}", e, value);
+			Error::BadServerResponse("Invalid PDU in send_join response.")
+		})?;
+
+		services()
+			.rooms
+			.outlier
+			.add_pdu_outlier(&event_id, &value)?;
+		if let Some(state_key) = &pdu.state_key {
+			let shortstatekey = services()
+				.rooms
+				.short
+				.get_or_create_shortstatekey(&pdu.kind.to_string().into(), state_key)?;
+			state.insert(shortstatekey, pdu.event_id.clone());
+		}
+	}
+
+	info!("Going through auth_chain response");
+	for result in remote_state_response
+		.auth_chain
+		.iter()
+		.map(|pdu| validate_and_add_event_id(pdu, &room_version, &pub_key_map))
+	{
+		let Ok((event_id, value)) = result.await else {
+			continue;
+		};
+
+		services()
+			.rooms
+			.outlier
+			.add_pdu_outlier(&event_id, &value)?;
+	}
+
+	let new_room_state = services()
+		.rooms
+		.event_handler
+		.resolve_state(room_id.clone().as_ref(), &room_version, state)
+		.await?;
+
+	info!("Forcing new room state");
+	let (short_state_hash, new, removed) = services()
+		.rooms
+		.state_compressor
+		.save_state(room_id.clone().as_ref(), new_room_state)?;
+
+	let mutex_state = Arc::clone(
+		services()
+			.globals
+			.roomid_mutex_state
+			.write()
+			.await
+			.entry(room_id.clone().into())
+			.or_default(),
+	);
+	let state_lock = mutex_state.lock().await;
+
+	services()
+		.rooms
+		.state
+		.force_state(room_id.clone().as_ref(), short_state_hash, new, removed, &state_lock)
+		.await?;
+
+	info!(
+		"Updating joined counts for room just in case (e.g. we may have found a difference in the room's \
+		 m.room.member state"
+	);
+	services().rooms.state_cache.update_joined_count(&room_id)?;
+
+	drop(state_lock);
+
+	Ok(RoomMessageEventContent::text_plain(
+		"Successfully forced the room state from the requested remote server.",
+	))
+}
+
 pub(crate) async fn resolve_true_destination(
 	_body: Vec<&str>, server_name: Box<ServerName>, no_cache: bool,
 ) -> Result<RoomMessageEventContent> {

src/admin/debug/mod.rs

@@ -1,5 +1,5 @@
 use clap::Subcommand;
-use debug_commands::{first_pdu_in_room, latest_pdu_in_room};
+use debug_commands::{first_pdu_in_room, force_set_room_state_from_server, latest_pdu_in_room};
 use ruma::{events::room::message::RoomMessageEventContent, EventId, RoomId, ServerName};
 
 use self::debug_commands::{
@@ -123,6 +123,27 @@ pub(crate) enum DebugCommand {
 		room_id: Box<RoomId>,
 	},
 
+	/// - Forcefully replaces the room state of our local copy of the specified
+	///   room, with the copy (auth chain and room state events) the specified
+	///   remote server says.
+	///
+	/// A common desire for room deletion is to simply "reset" our copy of the
+	/// room. While this admin command is not a replacement for that, if you
+	/// know you have split/broken room state and you know another server in the
+	/// room that has the best/working room state, this command can let you use
+	/// their room state. Such example is your server saying users are in a
+	/// room, but other servers are saying they're not in the room in question.
+	///
+	/// This command will get the latest PDU in the room we know about, and
+	/// request the room state at that point in time via
+	/// `/_matrix/federation/v1/state/{roomId}`.
+	ForceSetRoomStateFromServer {
+		/// The impacted room ID
+		room_id: Box<RoomId>,
+		/// The server we will use to query the room state for
+		server_name: Box<ServerName>,
+	},
+
 	/// - Runs a server name through conduwuit's true destination resolution
 	///   process
 	///
@@ -174,6 +195,10 @@ pub(crate) async fn process(command: DebugCommand, body: Vec<&str>) -> Result<Ro
 			server,
 			force,
 		} => get_remote_pdu_list(body, server, force).await?,
+		DebugCommand::ForceSetRoomStateFromServer {
+			room_id,
+			server_name,
+		} => force_set_room_state_from_server(body, server_name, room_id).await?,
 		DebugCommand::ResolveTrueDestination {
 			server_name,
 			no_cache,