fix: Only sync LDAP admin status when admin_filter is configured

Closes #1307

changelog.d/1307.bugfix.md

@@ -0,0 +1 @@
+LDAP-enabled servers will no longer have all admins demoted when LDAP-controlled admins are not configured. Contributed by @Jade

changelog.d/1308.feature.md

@@ -0,0 +1,2 @@
+Added unstable support for [MSC4406: `M_SENDER_IGNORED`](https://github.com/matrix-org/matrix-spec-proposals/pull/4406).
+Contributed by @nex

changelog.d/1368.feature

@@ -0,0 +1 @@
+Improved the handling of restricted join rules and improved the performance of local-first joins. Contributed by @nex.

changelog.d/1372.feature.md

@@ -0,0 +1 @@
+You can now set a custom User Agent for URL previews; the default one has been modified to be less likely to be rejected. Contributed by @trashpanda

conduwuit-example.toml

@@ -1474,6 +1474,10 @@
 #
 #url_preview_check_root_domain = false
 
+# User agent that is used specifically when fetching url previews.
+#
+#url_preview_user_agent = "continuwuity/<version> (bot; +https://continuwuity.org)"
+
 # List of forbidden room aliases and room IDs as strings of regex
 # patterns.
 #

src/admin/user/commands.rs

@@ -140,7 +140,6 @@ pub(super) async fn create_user(&self, username: String, password: Option<String
 						self.services.globals.server_name().to_owned(),
 						room_server_name.to_owned(),
 					],
-					None,
 					&None,
 				)
 				.await
@@ -549,7 +548,6 @@ pub(super) async fn force_join_list_of_local_users(
 			&room_id,
 			Some(String::from(BULK_JOIN_REASON)),
 			&servers,
-			None,
 			&None,
 		)
 		.await
@@ -635,7 +633,6 @@ pub(super) async fn force_join_all_local_users(
 			&room_id,
 			Some(String::from(BULK_JOIN_REASON)),
 			&servers,
-			None,
 			&None,
 		)
 		.await
@@ -675,8 +672,7 @@ pub(super) async fn force_join_room(
 		self.services.globals.user_is_local(&user_id),
 		"Parsed user_id must be a local user"
 	);
-	join_room_by_id_helper(self.services, &user_id, &room_id, None, &servers, None, &None)
-		.await?;
+	join_room_by_id_helper(self.services, &user_id, &room_id, None, &servers, &None).await?;
 
 	self.write_str(&format!("{user_id} has been joined to {room_id}.",))
 		.await

src/api/client/account.rs

@@ -583,7 +583,6 @@ pub(crate) async fn register_route(
 					&room_id,
 					Some("Automatically joining this room upon registration".to_owned()),
 					&[services.globals.server_name().to_owned(), room_server_name.to_owned()],
-					None,
 					&body.appservice_info,
 				)
 				.boxed()

src/api/client/context.rs

@@ -16,7 +16,10 @@ use ruma::{OwnedEventId, UserId, api::client::context::get_context, events::Stat
 
 use crate::{
 	Ruma,
-	client::message::{event_filter, ignored_filter, lazy_loading_witness, visibility_filter},
+	client::{
+		is_ignored_pdu,
+		message::{event_filter, ignored_filter, lazy_loading_witness, visibility_filter},
+	},
 };
 
 const LIMIT_MAX: usize = 100;
@@ -78,6 +81,9 @@ pub(crate) async fn get_context_route(
 		return Err!(Request(NotFound("Event not found.")));
 	}
 
+	// Return M_SENDER_IGNORED if the sender of base_event is ignored (MSC4406)
+	is_ignored_pdu(&services, &base_pdu, sender_user).await?;
+
 	let base_count = base_id.pdu_count();
 
 	let base_event = ignored_filter(&services, (base_count, base_pdu), sender_user);

src/api/client/membership/join.rs

@@ -3,7 +3,7 @@ use std::{borrow::Borrow, collections::HashMap, iter::once, sync::Arc};
 use axum::extract::State;
 use axum_client_ip::InsecureClientIp;
 use conduwuit::{
-	Err, Result, debug, debug_info, debug_warn, err, error, info,
+	Err, Result, debug, debug_info, debug_warn, err, error, info, is_true,
 	matrix::{
 		StateKey,
 		event::{gen_event_id, gen_event_id_canonical_json},
@@ -26,7 +26,7 @@ use ruma::{
 	api::{
 		client::{
 			error::ErrorKind,
-			membership::{ThirdPartySigned, join_room_by_id, join_room_by_id_or_alias},
+			membership::{join_room_by_id, join_room_by_id_or_alias},
 		},
 		federation::{self},
 	},
@@ -34,7 +34,7 @@ use ruma::{
 	events::{
 		StateEventType,
 		room::{
-			join_rules::{AllowRule, JoinRule},
+			join_rules::JoinRule,
 			member::{MembershipState, RoomMemberEventContent},
 		},
 	},
@@ -48,9 +48,13 @@ use service::{
 		timeline::pdu_fits,
 	},
 };
+use tokio::join;
 
 use super::{banned_room_check, validate_remote_member_event_stub};
-use crate::Ruma;
+use crate::{
+	Ruma,
+	server::{select_authorising_user, user_can_perform_restricted_join},
+};
 
 /// # `POST /_matrix/client/r0/rooms/{roomId}/join`
 ///
@@ -116,7 +120,6 @@ pub(crate) async fn join_room_by_id_route(
 		&body.room_id,
 		body.reason.clone(),
 		&servers,
-		body.third_party_signed.as_ref(),
 		&body.appservice_info,
 	)
 	.boxed()
@@ -248,7 +251,6 @@ pub(crate) async fn join_room_by_id_or_alias_route(
 		&room_id,
 		body.reason.clone(),
 		&servers,
-		body.third_party_signed.as_ref(),
 		appservice_info,
 	)
 	.boxed()
@@ -263,7 +265,6 @@ pub async fn join_room_by_id_helper(
 	room_id: &RoomId,
 	reason: Option<String>,
 	servers: &[OwnedServerName],
-	third_party_signed: Option<&ThirdPartySigned>,
 	appservice_info: &Option<RegistrationInfo>,
 ) -> Result<join_room_by_id::v3::Response> {
 	let state_lock = services.rooms.state.mutex.lock(room_id).await;
@@ -351,17 +352,9 @@ pub async fn join_room_by_id_helper(
 	}
 
 	if server_in_room {
-		join_room_by_id_helper_local(
-			services,
-			sender_user,
-			room_id,
-			reason,
-			servers,
-			third_party_signed,
-			state_lock,
-		)
-		.boxed()
-		.await?;
+		join_room_by_id_helper_local(services, sender_user, room_id, reason, servers, state_lock)
+			.boxed()
+			.await?;
 	} else {
 		// Ask a remote server if we are not participating in this room
 		join_room_by_id_helper_remote(
@@ -370,7 +363,6 @@ pub async fn join_room_by_id_helper(
 			room_id,
 			reason,
 			servers,
-			third_party_signed,
 			state_lock,
 		)
 		.boxed()
@@ -386,7 +378,6 @@ async fn join_room_by_id_helper_remote(
 	room_id: &RoomId,
 	reason: Option<String>,
 	servers: &[OwnedServerName],
-	_third_party_signed: Option<&ThirdPartySigned>,
 	state_lock: RoomMutexGuard,
 ) -> Result {
 	info!("Joining {room_id} over federation.");
@@ -396,11 +387,10 @@ async fn join_room_by_id_helper_remote(
 
 	info!("make_join finished");
 
-	let Some(room_version_id) = make_join_response.room_version else {
-		return Err!(BadServerResponse("Remote room version is not supported by conduwuit"));
-	};
+	let room_version_id = make_join_response.room_version.unwrap_or(RoomVersionId::V1);
 
 	if !services.server.supported_room_version(&room_version_id) {
+		// How did we get here?
 		return Err!(BadServerResponse(
 			"Remote room version {room_version_id} is not supported by conduwuit"
 		));
@@ -429,10 +419,6 @@ async fn join_room_by_id_helper_remote(
 		}
 	};
 
-	join_event_stub.insert(
-		"origin".to_owned(),
-		CanonicalJsonValue::String(services.globals.server_name().as_str().to_owned()),
-	);
 	join_event_stub.insert(
 		"origin_server_ts".to_owned(),
 		CanonicalJsonValue::Integer(
@@ -744,87 +730,45 @@ async fn join_room_by_id_helper_local(
 	room_id: &RoomId,
 	reason: Option<String>,
 	servers: &[OwnedServerName],
-	_third_party_signed: Option<&ThirdPartySigned>,
 	state_lock: RoomMutexGuard,
 ) -> Result {
-	debug_info!("We can join locally");
-	let join_rules = services.rooms.state_accessor.get_join_rules(room_id).await;
+	info!("Joining room locally");
 
-	let mut restricted_join_authorized = None;
-	match join_rules {
-		| JoinRule::Restricted(restricted) | JoinRule::KnockRestricted(restricted) => {
-			for restriction in restricted.allow {
-				match restriction {
-					| AllowRule::RoomMembership(membership) => {
-						if services
-							.rooms
-							.state_cache
-							.is_joined(sender_user, &membership.room_id)
-							.await
-						{
-							restricted_join_authorized = Some(true);
-							break;
-						}
-					},
-					| AllowRule::UnstableSpamChecker => {
-						match services
-							.antispam
-							.meowlnir_accept_make_join(room_id.to_owned(), sender_user.to_owned())
-							.await
-						{
-							| Ok(()) => {
-								restricted_join_authorized = Some(true);
-								break;
-							},
-							| Err(_) =>
-								return Err!(Request(Forbidden(
-									"Antispam rejected join request."
-								))),
-						}
-					},
-					| _ => {},
-				}
+	let (room_version, join_rules, is_invited) = join!(
+		services.rooms.state.get_room_version(room_id),
+		services.rooms.state_accessor.get_join_rules(room_id),
+		services.rooms.state_cache.is_invited(sender_user, room_id)
+	);
+
+	let room_version = room_version?;
+	let mut auth_user: Option<OwnedUserId> = None;
+	if !is_invited && matches!(join_rules, JoinRule::Restricted(_) | JoinRule::KnockRestricted(_))
+	{
+		use RoomVersionId::*;
+		if !matches!(room_version, V1 | V2 | V3 | V4 | V5 | V6 | V7) {
+			// This is a restricted room, check if we can complete the join requirements
+			// locally.
+			let needs_auth_user =
+				user_can_perform_restricted_join(services, sender_user, room_id, &room_version)
+					.await;
+			if needs_auth_user.is_ok_and(is_true!()) {
+				// If there was an error or the value is false, we'll try joining over
+				// federation. Since it's Ok(true), we can authorise this locally.
+				// If we can't select a local user, this will remain None, the join will fail,
+				// and we'll fall back to federation.
+				auth_user = select_authorising_user(services, room_id, sender_user, &state_lock)
+					.await
+					.ok();
 			}
-		},
-		| _ => {},
-	}
-	let join_authorized_via_users_server = if restricted_join_authorized.is_none() {
-		None
-	} else {
-		match restricted_join_authorized.unwrap() {
-			| true => services
-				.rooms
-				.state_cache
-				.local_users_in_room(room_id)
-				.filter(|user| {
-					trace!("Checking if {user} can invite {sender_user} to {room_id}");
-					services.rooms.state_accessor.user_can_invite(
-						room_id,
-						user,
-						sender_user,
-						&state_lock,
-					)
-				})
-				.boxed()
-				.next()
-				.await
-				.map(ToOwned::to_owned),
-			| false => {
-				warn!(
-					"Join authorization failed for restricted join in room {room_id} for user \
-					 {sender_user}"
-				);
-				return Err!(Request(Forbidden("You are not authorized to join this room.")));
-			},
 		}
-	};
+	}
 
 	let content = RoomMemberEventContent {
 		displayname: services.users.displayname(sender_user).await.ok(),
 		avatar_url: services.users.avatar_url(sender_user).await.ok(),
 		blurhash: services.users.blurhash(sender_user).await.ok(),
 		reason: reason.clone(),
-		join_authorized_via_users_server,
+		join_authorized_via_users_server: auth_user,
 		..RoomMemberEventContent::new(MembershipState::Join)
 	};
 
@@ -840,6 +784,7 @@ async fn join_room_by_id_helper_local(
 		)
 		.await
 	else {
+		info!("Joined room locally");
 		return Ok(());
 	};
 
@@ -847,138 +792,13 @@ async fn join_room_by_id_helper_local(
 		return Err(error);
 	}
 
-	warn!(
+	info!(
 		?error,
-		servers = %servers.len(),
-		"Could not join restricted room locally, attempting remote join",
+		remote_servers = %servers.len(),
+		"Could not join room locally, attempting remote join",
 	);
-	let Ok((make_join_response, remote_server)) =
-		make_join_request(services, sender_user, room_id, servers).await
-	else {
-		return Err(error);
-	};
-
-	let Some(room_version_id) = make_join_response.room_version else {
-		return Err!(BadServerResponse("Remote room version is not supported by conduwuit"));
-	};
-
-	if !services.server.supported_room_version(&room_version_id) {
-		return Err!(BadServerResponse(
-			"Remote room version {room_version_id} is not supported by conduwuit"
-		));
-	}
-
-	let mut join_event_stub: CanonicalJsonObject =
-		serde_json::from_str(make_join_response.event.get()).map_err(|e| {
-			err!(BadServerResponse("Invalid make_join event json received from server: {e:?}"))
-		})?;
-
-	validate_remote_member_event_stub(
-		&MembershipState::Join,
-		sender_user,
-		room_id,
-		&join_event_stub,
-	)?;
-
-	let join_authorized_via_users_server = join_event_stub
-		.get("content")
-		.map(|s| {
-			s.as_object()?
-				.get("join_authorised_via_users_server")?
-				.as_str()
-		})
-		.and_then(|s| OwnedUserId::try_from(s.unwrap_or_default()).ok());
-
-	join_event_stub.insert(
-		"origin".to_owned(),
-		CanonicalJsonValue::String(services.globals.server_name().as_str().to_owned()),
-	);
-	join_event_stub.insert(
-		"origin_server_ts".to_owned(),
-		CanonicalJsonValue::Integer(
-			utils::millis_since_unix_epoch()
-				.try_into()
-				.expect("Timestamp is valid js_int value"),
-		),
-	);
-	join_event_stub.insert(
-		"content".to_owned(),
-		to_canonical_value(RoomMemberEventContent {
-			displayname: services.users.displayname(sender_user).await.ok(),
-			avatar_url: services.users.avatar_url(sender_user).await.ok(),
-			blurhash: services.users.blurhash(sender_user).await.ok(),
-			reason,
-			join_authorized_via_users_server,
-			..RoomMemberEventContent::new(MembershipState::Join)
-		})
-		.expect("event is valid, we just created it"),
-	);
-
-	// We keep the "event_id" in the pdu only in v1 or
-	// v2 rooms
-	match room_version_id {
-		| RoomVersionId::V1 | RoomVersionId::V2 => {},
-		| _ => {
-			join_event_stub.remove("event_id");
-		},
-	}
-
-	// In order to create a compatible ref hash (EventID) the `hashes` field needs
-	// to be present
-	services
-		.server_keys
-		.hash_and_sign_event(&mut join_event_stub, &room_version_id)?;
-
-	// Generate event id
-	let event_id = gen_event_id(&join_event_stub, &room_version_id)?;
-
-	// Add event_id back
-	join_event_stub
-		.insert("event_id".to_owned(), CanonicalJsonValue::String(event_id.clone().into()));
-
-	// It has enough fields to be called a proper event now
-	let join_event = join_event_stub;
-
-	let send_join_response = services
-		.sending
-		.send_synapse_request(
-			&remote_server,
-			federation::membership::create_join_event::v2::Request {
-				room_id: room_id.to_owned(),
-				event_id: event_id.clone(),
-				omit_members: false,
-				pdu: services
-					.sending
-					.convert_to_outgoing_federation_event(join_event.clone())
-					.await,
-			},
-		)
-		.await?;
-
-	if let Some(signed_raw) = send_join_response.room_state.event {
-		let (signed_event_id, signed_value) =
-			gen_event_id_canonical_json(&signed_raw, &room_version_id).map_err(|e| {
-				err!(Request(BadJson(warn!("Could not convert event to canonical JSON: {e}"))))
-			})?;
-
-		if signed_event_id != event_id {
-			return Err!(Request(BadJson(
-				warn!(%signed_event_id, %event_id, "Server {remote_server} sent event with wrong event ID")
-			)));
-		}
-
-		drop(state_lock);
-		services
-			.rooms
-			.event_handler
-			.handle_incoming_pdu(&remote_server, room_id, &signed_event_id, signed_value, true)
-			.boxed()
-			.await?;
-	} else {
-		return Err(error);
-	}
-
-	Ok(())
+	join_room_by_id_helper_remote(services, sender_user, room_id, reason, servers, state_lock)
+		.await
 }
 
 async fn make_join_request(
@@ -987,17 +807,16 @@ async fn make_join_request(
 	room_id: &RoomId,
 	servers: &[OwnedServerName],
 ) -> Result<(federation::membership::prepare_join_event::v1::Response, OwnedServerName)> {
-	let mut make_join_response_and_server =
-		Err!(BadServerResponse("No server available to assist in joining."));
-
-	let mut make_join_counter: usize = 0;
-	let mut incompatible_room_version_count: usize = 0;
+	let mut make_join_counter: usize = 1;
 
 	for remote_server in servers {
 		if services.globals.server_is_ours(remote_server) {
 			continue;
 		}
-		info!("Asking {remote_server} for make_join ({make_join_counter})");
+		info!(
+			"Asking {remote_server} for make_join (attempt {make_join_counter}/{})",
+			servers.len()
+		);
 		let make_join_response = services
 			.sending
 			.send_federation_request(
@@ -1025,47 +844,44 @@ async fn make_join_request(
 					warn!("make_join response from {remote_server} failed validation: {e}");
 					continue;
 				}
-				make_join_response_and_server = Ok((response, remote_server.clone()));
-				break;
+				return Ok((response, remote_server.clone()));
 			},
-			| Err(e) => {
-				info!("make_join request to {remote_server} failed: {e}");
-				if matches!(
-					e.kind(),
-					ErrorKind::IncompatibleRoomVersion { .. } | ErrorKind::UnsupportedRoomVersion
-				) {
-					incompatible_room_version_count =
-						incompatible_room_version_count.saturating_add(1);
-				}
-
-				if incompatible_room_version_count > 15 {
+			| Err(e) => match e.kind() {
+				| ErrorKind::UnableToAuthorizeJoin => {
 					info!(
-						"15 servers have responded with M_INCOMPATIBLE_ROOM_VERSION or \
-						 M_UNSUPPORTED_ROOM_VERSION, assuming that conduwuit does not support \
-						 the room version {room_id}: {e}"
+						"{remote_server} was unable to verify the joining user satisfied \
+						 restricted join requirements: {e}. Will continue trying."
 					);
-					make_join_response_and_server =
-						Err!(BadServerResponse("Room version is not supported by Conduwuit"));
-					return make_join_response_and_server;
-				}
-
-				if make_join_counter > 40 {
+				},
+				| ErrorKind::UnableToGrantJoin => {
+					info!(
+						"{remote_server} believes the joining user satisfies restricted join \
+						 rules, but is unable to authorise a join for us. Will continue trying."
+					);
+				},
+				| ErrorKind::IncompatibleRoomVersion { room_version } => {
 					warn!(
-						"40 servers failed to provide valid make_join response, assuming no \
-						 server can assist in joining."
+						"{remote_server} reports the room we are trying to join is \
+						 v{room_version}, which we do not support."
 					);
-					make_join_response_and_server =
-						Err!(BadServerResponse("No server available to assist in joining."));
-
-					return make_join_response_and_server;
-				}
+					return Err(e);
+				},
+				| ErrorKind::Forbidden { .. } => {
+					warn!("{remote_server} refuses to let us join: {e}.");
+					return Err(e);
+				},
+				| ErrorKind::NotFound => {
+					info!(
+						"{remote_server} does not know about {room_id}: {e}. Will continue \
+						 trying."
+					);
+				},
+				| _ => {
+					info!("{remote_server} failed to make_join: {e}. Will continue trying.");
+				},
 			},
 		}
-
-		if make_join_response_and_server.is_ok() {
-			break;
-		}
 	}
-
-	make_join_response_and_server
+	info!("All {} servers were unable to assist in joining {room_id} :(", servers.len());
+	Err!(BadServerResponse("No server available to assist in joining."))
 }

src/api/client/membership/knock.rs

@@ -253,7 +253,6 @@ async fn knock_room_by_id_helper(
 				room_id,
 				reason.clone(),
 				servers,
-				None,
 				&None,
 			)
 			.await

src/api/client/message.rs

@@ -1,7 +1,7 @@
 use axum::extract::State;
 use axum_client_ip::InsecureClientIp;
 use conduwuit::{
-	Err, Result, at, debug_warn,
+	Err, Error, Result, at, debug_warn,
 	matrix::{
 		event::{Event, Matches},
 		pdu::PduCount,
@@ -26,7 +26,7 @@ use ruma::{
 	DeviceId, RoomId, UserId,
 	api::{
 		Direction,
-		client::{filter::RoomEventFilter, message::get_message_events},
+		client::{error::ErrorKind, filter::RoomEventFilter, message::get_message_events},
 	},
 	events::{
 		AnyStateEvent, StateEventType,
@@ -279,23 +279,30 @@ pub(crate) async fn ignored_filter(
 
 	is_ignored_pdu(services, pdu, user_id)
 		.await
+		.unwrap_or(true)
 		.eq(&false)
 		.then_some(item)
 }
 
+/// Determine whether a PDU should be ignored for a given recipient user.
+/// Returns True if this PDU should be ignored, returns False otherwise.
+///
+/// The error SenderIgnored is returned if the sender or the sender's server is
+/// ignored by the relevant user. If the error cannot be returned to the user,
+/// it should equate to a true value (i.e. ignored).
 #[inline]
 pub(crate) async fn is_ignored_pdu<Pdu>(
 	services: &Services,
 	event: &Pdu,
 	recipient_user: &UserId,
-) -> bool
+) -> Result<bool>
 where
 	Pdu: Event + Send + Sync,
 {
 	// exclude Synapse's dummy events from bloating up response bodies. clients
 	// don't need to see this.
 	if event.kind().to_cow_str() == "org.matrix.dummy_event" {
-		return true;
+		return Ok(true);
 	}
 
 	let sender_user = event.sender();
@@ -310,21 +317,27 @@ where
 
 	if !type_ignored {
 		// We cannot safely ignore this type
-		return false;
+		return Ok(false);
 	}
 
 	if server_ignored {
 		// the sender's server is ignored, so ignore this event
-		return true;
+		return Err(Error::BadRequest(
+			ErrorKind::SenderIgnored { sender: None },
+			"The sender's server is ignored by this server.",
+		));
 	}
 
 	if user_ignored && !services.config.send_messages_from_ignored_users_to_client {
 		// the recipient of this PDU has the sender ignored, and we're not
 		// configured to send ignored messages to clients
-		return true;
+		return Err(Error::BadRequest(
+			ErrorKind::SenderIgnored { sender: Some(event.sender().to_owned()) },
+			"You have ignored this sender.",
+		));
 	}
 
-	false
+	Ok(false)
 }
 
 #[inline]

src/api/client/relations.rs

@@ -1,6 +1,6 @@
 use axum::extract::State;
 use conduwuit::{
-	Err, Result, at, debug_warn,
+	Err, Result, at, debug_warn, err,
 	matrix::{Event, event::RelationTypeEqual, pdu::PduCount},
 	utils::{IterStream, ReadyExt, result::FlatOk, stream::WidebandExt},
 };
@@ -18,7 +18,7 @@ use ruma::{
 	events::{TimelineEventType, relation::RelationType},
 };
 
-use crate::Ruma;
+use crate::{Ruma, client::is_ignored_pdu};
 
 /// # `GET /_matrix/client/r0/rooms/{roomId}/relations/{eventId}/{relType}/{eventType}`
 pub(crate) async fn get_relating_events_with_rel_type_and_event_type_route(
@@ -118,6 +118,14 @@ async fn paginate_relations_with_filter(
 		debug_warn!(req_evt = %target, %room_id, "Event relations requested by {sender_user} but is not allowed to see it, returning 404");
 		return Err!(Request(NotFound("Event not found.")));
 	}
+	let target_pdu = services
+		.rooms
+		.timeline
+		.get_pdu(target)
+		.await
+		.map_err(|_| err!(Request(NotFound("Event not found."))))?;
+	// Return M_SENDER_IGNORED if the sender of base_event is ignored (MSC4406)
+	is_ignored_pdu(services, &target_pdu, sender_user).await?;
 
 	let start: PduCount = from
 		.map(str::parse)
@@ -159,6 +167,7 @@ async fn paginate_relations_with_filter(
 		.ready_take_while(|(count, _)| Some(*count) != to)
 		.take(limit)
 		.wide_filter_map(|item| visibility_filter(services, sender_user, item))
+		.wide_filter_map(|item| ignored_filter(services, item, sender_user))
 		.then(async |mut pdu| {
 			if let Err(e) = services
 				.rooms
@@ -214,3 +223,17 @@ async fn visibility_filter<Pdu: Event + Send + Sync>(
 		.await
 		.then_some(item)
 }
+
+async fn ignored_filter<Pdu: Event + Send + Sync>(
+	services: &Services,
+	item: (PduCount, Pdu),
+	sender_user: &UserId,
+) -> Option<(PduCount, Pdu)> {
+	let (_, pdu) = &item;
+
+	if is_ignored_pdu(services, pdu, sender_user).await.ok()? {
+		None
+	} else {
+		Some(item)
+	}
+}

src/api/client/room/event.rs

@@ -29,7 +29,7 @@ pub(crate) async fn get_room_event_route(
 
 	let (mut event, visible) = try_join(event, visible).await?;
 
-	if !visible || is_ignored_pdu(services, &event, body.sender_user()).await {
+	if !visible || is_ignored_pdu(services, &event, body.sender_user()).await? {
 		return Err!(Request(Forbidden("You don't have permission to view this event.")));
 	}
 

src/api/client/session.rs

@@ -107,7 +107,7 @@ pub(super) async fn ldap_login(
 ) -> Result<OwnedUserId> {
 	let (user_dn, is_ldap_admin) = match services.config.ldap.bind_dn.as_ref() {
 		| Some(bind_dn) if bind_dn.contains("{username}") =>
-			(bind_dn.replace("{username}", lowercased_user_id.localpart()), false),
+			(bind_dn.replace("{username}", lowercased_user_id.localpart()), None),
 		| _ => {
 			debug!("Searching user in LDAP");
 
@@ -144,12 +144,16 @@ pub(super) async fn ldap_login(
 			.await?;
 	}
 
-	let is_conduwuit_admin = services.admin.user_is_admin(lowercased_user_id).await;
+	// Only sync admin status if LDAP can actually determine it.
+	// None means LDAP cannot determine admin status (manual config required).
+	if let Some(is_ldap_admin) = is_ldap_admin {
+		let is_conduwuit_admin = services.admin.user_is_admin(lowercased_user_id).await;
 
-	if is_ldap_admin && !is_conduwuit_admin {
-		Box::pin(services.admin.make_user_admin(lowercased_user_id)).await?;
-	} else if !is_ldap_admin && is_conduwuit_admin {
-		Box::pin(services.admin.revoke_admin(lowercased_user_id)).await?;
+		if is_ldap_admin && !is_conduwuit_admin {
+			Box::pin(services.admin.make_user_admin(lowercased_user_id)).await?;
+		} else if !is_ldap_admin && is_conduwuit_admin {
+			Box::pin(services.admin.revoke_admin(lowercased_user_id)).await?;
+		}
 	}
 
 	Ok(user_id)

src/api/client/sync/v5.rs

@@ -685,8 +685,15 @@ async fn collect_required_state(
 	required_state_request: &BTreeSet<TypeStateKey>,
 ) -> Vec<Raw<AnySyncStateEvent>> {
 	let mut required_state = Vec::new();
+	let mut wildcard_types: HashSet<&StateEventType> = HashSet::new();
+
 	for (event_type, state_key) in required_state_request {
+		if wildcard_types.contains(event_type) {
+			continue;
+		}
+
 		if state_key.as_str() == "*" {
+			wildcard_types.insert(event_type);
 			if let Ok(keys) = services
 				.rooms
 				.state_accessor
@@ -703,7 +710,6 @@ async fn collect_required_state(
 						required_state.push(Event::into_format(event));
 					}
 				}
-				break;
 			}
 		} else if let Ok(event) = services
 			.rooms

src/api/server/make_join.rs

@@ -16,6 +16,8 @@ use ruma::{
 	},
 };
 use serde_json::value::to_raw_value;
+use service::rooms::state::RoomMutexGuard;
+use tokio::join;
 
 use crate::Ruma;
 
@@ -85,16 +87,24 @@ pub(crate) async fn create_join_event_template_route(
 	}
 
 	let state_lock = services.rooms.state.mutex.lock(&body.room_id).await;
-	let is_invited = services
-		.rooms
-		.state_cache
-		.is_invited(&body.user_id, &body.room_id)
-		.await;
+	let (is_invited, is_joined) = join!(
+		services
+			.rooms
+			.state_cache
+			.is_invited(&body.user_id, &body.room_id),
+		services
+			.rooms
+			.state_cache
+			.is_joined(&body.user_id, &body.room_id)
+	);
 	let join_authorized_via_users_server: Option<OwnedUserId> = {
 		use RoomVersionId::*;
-		if matches!(room_version_id, V1 | V2 | V3 | V4 | V5 | V6 | V7) || is_invited {
-			// room version does not support restricted join rules, or the user is currently
-			// already invited
+		if is_joined || is_invited {
+			// User is already joined or invited and consequently does not need an
+			// authorising user
+			None
+		} else if matches!(room_version_id, V1 | V2 | V3 | V4 | V5 | V6 | V7) {
+			// room version does not support restricted join rules
 			None
 		} else if user_can_perform_restricted_join(
 			&services,
@@ -104,32 +114,10 @@ pub(crate) async fn create_join_event_template_route(
 		)
 		.await?
 		{
-			let Some(auth_user) = services
-				.rooms
-				.state_cache
-				.local_users_in_room(&body.room_id)
-				.filter(|user| {
-					services.rooms.state_accessor.user_can_invite(
-						&body.room_id,
-						user,
-						&body.user_id,
-						&state_lock,
-					)
-				})
-				.boxed()
-				.next()
-				.await
-				.map(ToOwned::to_owned)
-			else {
-				info!(
-					"No local user is able to authorize the join of {} into {}",
-					&body.user_id, &body.room_id
-				);
-				return Err!(Request(UnableToGrantJoin(
-					"No user on this server is able to assist in joining."
-				)));
-			};
-			Some(auth_user)
+			Some(
+				select_authorising_user(&services, &body.room_id, &body.user_id, &state_lock)
+					.await?,
+			)
 		} else {
 			None
 		}
@@ -159,9 +147,7 @@ pub(crate) async fn create_join_event_template_route(
 		)
 		.await?;
 	drop(state_lock);
-
-	// room v3 and above removed the "event_id" field from remote PDU format
-	maybe_strip_event_id(&mut pdu_json, &room_version_id)?;
+	pdu_json.remove("event_id");
 
 	Ok(prepare_join_event::v1::Response {
 		room_version: Some(room_version_id),
@@ -169,6 +155,38 @@ pub(crate) async fn create_join_event_template_route(
 	})
 }
 
+/// Attempts to find a user who is able to issue an invite in the target room.
+pub(crate) async fn select_authorising_user(
+	services: &Services,
+	room_id: &RoomId,
+	user_id: &UserId,
+	state_lock: &RoomMutexGuard,
+) -> Result<OwnedUserId> {
+	let auth_user = services
+		.rooms
+		.state_cache
+		.local_users_in_room(room_id)
+		.filter(|user| {
+			services
+				.rooms
+				.state_accessor
+				.user_can_invite(room_id, user, user_id, state_lock)
+		})
+		.boxed()
+		.next()
+		.await
+		.map(ToOwned::to_owned);
+
+	match auth_user {
+		| Some(auth_user) => Ok(auth_user),
+		| None => {
+			Err!(Request(UnableToGrantJoin(
+				"No user on this server is able to assist in joining."
+			)))
+		},
+	}
+}
+
 /// Checks whether the given user can join the given room via a restricted join.
 pub(crate) async fn user_can_perform_restricted_join(
 	services: &Services,
@@ -180,12 +198,9 @@ pub(crate) async fn user_can_perform_restricted_join(
 
 	// restricted rooms are not supported on <=v7
 	if matches!(room_version_id, V1 | V2 | V3 | V4 | V5 | V6 | V7) {
-		return Ok(false);
-	}
-
-	if services.rooms.state_cache.is_joined(user_id, room_id).await {
-		// joining user is already joined, there is nothing we need to do
-		return Ok(false);
+		// This should be impossible as it was checked earlier on, but retain this check
+		// for safety.
+		unreachable!("user_can_perform_restricted_join got incompatible room version");
 	}
 
 	let Ok(join_rules_event_content) = services
@@ -205,17 +220,31 @@ pub(crate) async fn user_can_perform_restricted_join(
 	let (JoinRule::Restricted(r) | JoinRule::KnockRestricted(r)) =
 		join_rules_event_content.join_rule
 	else {
+		// This is not a restricted room
 		return Ok(false);
 	};
 
 	if r.allow.is_empty() {
-		debug_info!("{room_id} is restricted but the allow key is empty");
-		return Ok(false);
+		// This will never be authorisable, return forbidden.
+		return Err!(Request(Forbidden("You are not invited to this room.")));
 	}
 
+	let mut could_satisfy = true;
 	for allow_rule in &r.allow {
 		match allow_rule {
 			| AllowRule::RoomMembership(membership) => {
+				if !services
+					.rooms
+					.state_cache
+					.server_in_room(services.globals.server_name(), &membership.room_id)
+					.await
+				{
+					// Since we can't check this room, mark could_satisfy as false
+					// so that we can return M_UNABLE_TO_AUTHORIZE_JOIN later.
+					could_satisfy = false;
+					continue;
+				}
+
 				if services
 					.rooms
 					.state_cache
@@ -239,6 +268,8 @@ pub(crate) async fn user_can_perform_restricted_join(
 					| Err(_) => Err!(Request(Forbidden("Antispam rejected join request."))),
 				},
 			| _ => {
+				// We don't recognise this join rule, so we cannot satisfy the request.
+				could_satisfy = false;
 				debug_info!(
 					"Unsupported allow rule in restricted join for room {}: {:?}",
 					room_id,
@@ -248,9 +279,23 @@ pub(crate) async fn user_can_perform_restricted_join(
 		}
 	}
 
-	Err!(Request(UnableToAuthorizeJoin(
-		"Joining user is not known to be in any required room."
-	)))
+	if could_satisfy {
+		// We were able to check all the restrictions and can be certain that the
+		// prospective member is not permitted to join.
+		Err!(Request(Forbidden(
+			"You do not belong to any of the rooms or spaces required to join this room."
+		)))
+	} else {
+		// We were unable to check all the restrictions. This usually means we aren't in
+		// one of the rooms this one is restricted to, ergo can't check its state for
+		// the user's membership, and consequently the user *might* be able to join if
+		// they ask another server.
+		Err!(Request(UnableToAuthorizeJoin(
+			"You do not belong to any of the recognised rooms or spaces required to join this \
+			 room, but this server is unable to verify every requirement. You may be able to \
+			 join via another server."
+		)))
+	}
 }
 
 pub(crate) fn maybe_strip_event_id(

src/core/config/mod.rs

@@ -1696,6 +1696,11 @@ pub struct Config {
 	#[serde(default)]
 	pub url_preview_check_root_domain: bool,
 
+	/// User agent that is used specifically when fetching url previews.
+	///
+	/// default: "continuwuity/<version> (bot; +https://continuwuity.org)"
+	pub url_preview_user_agent: Option<String>,
+
 	/// List of forbidden room aliases and room IDs as strings of regex
 	/// patterns.
 	///

src/core/error/response.rs

@@ -85,7 +85,8 @@ pub(super) fn bad_request_code(kind: &ErrorKind) -> StatusCode {
 		| Unrecognized => StatusCode::METHOD_NOT_ALLOWED,
 
 		// 404
-		| NotFound | NotImplemented | FeatureDisabled => StatusCode::NOT_FOUND,
+		| NotFound | NotImplemented | FeatureDisabled | SenderIgnored { .. } =>
+			StatusCode::NOT_FOUND,
 
 		// 403
 		| GuestAccessForbidden

src/core/info/version.rs

@@ -8,9 +8,11 @@
 use std::sync::OnceLock;
 
 static BRANDING: &str = "continuwuity";
+static WEBSITE: &str = "https://continuwuity.org";
 static SEMANTIC: &str = env!("CARGO_PKG_VERSION");
 
 static VERSION: OnceLock<String> = OnceLock::new();
+static VERSION_UA: OnceLock<String> = OnceLock::new();
 static USER_AGENT: OnceLock<String> = OnceLock::new();
 
 #[inline]
@@ -19,11 +21,18 @@ pub fn name() -> &'static str { BRANDING }
 
 #[inline]
 pub fn version() -> &'static str { VERSION.get_or_init(init_version) }
+#[inline]
+pub fn version_ua() -> &'static str { VERSION_UA.get_or_init(init_version_ua) }
 
 #[inline]
 pub fn user_agent() -> &'static str { USER_AGENT.get_or_init(init_user_agent) }
 
-fn init_user_agent() -> String { format!("{}/{}", name(), version()) }
+fn init_user_agent() -> String { format!("{}/{} (bot; +{WEBSITE})", name(), version_ua()) }
+
+fn init_version_ua() -> String {
+	conduwuit_build_metadata::version_tag()
+		.map_or_else(|| SEMANTIC.to_owned(), |extra| format!("{SEMANTIC}+{extra}"))
+}
 
 fn init_version() -> String {
 	conduwuit_build_metadata::version_tag()

src/service/client/mod.rs

@@ -36,6 +36,11 @@ impl crate::Service for Service {
 			.clone()
 			.and_then(Either::right);
 
+		let url_preview_user_agent = config
+			.url_preview_user_agent
+			.clone()
+			.unwrap_or_else(|| conduwuit::version::user_agent().to_owned());
+
 		Ok(Arc::new(Self {
 			default: base(config)?
 				.dns_resolver(resolver.resolver.clone())
@@ -49,6 +54,7 @@ impl crate::Service for Service {
 				.dns_resolver(resolver.resolver.clone())
 				.timeout(Duration::from_secs(config.url_preview_timeout))
 				.redirect(redirect::Policy::limited(3))
+				.user_agent(url_preview_user_agent)
 				.build()?,
 
 			extern_media: base(config)?

src/service/rooms/event_handler/handle_incoming_pdu.rs

@@ -4,18 +4,83 @@ use std::{
 };
 
 use conduwuit::{
-	Err, Event, Result, debug::INFO_SPAN_LEVEL, defer, err, implement, info,
-	utils::stream::IterStream, warn,
+	Err, Event, PduEvent, Result, debug::INFO_SPAN_LEVEL, debug_error, debug_info, defer, err,
+	implement, info, trace, utils::stream::IterStream, warn,
 };
 use futures::{
 	FutureExt, TryFutureExt, TryStreamExt,
-	future::{OptionFuture, try_join5},
+	future::{OptionFuture, try_join4},
+};
+use ruma::{
+	CanonicalJsonValue, EventId, OwnedUserId, RoomId, ServerName, UserId,
+	events::{
+		StateEventType, TimelineEventType,
+		room::member::{MembershipState, RoomMemberEventContent},
+	},
 };
-use ruma::{CanonicalJsonValue, EventId, RoomId, ServerName, UserId, events::StateEventType};
 use tracing::debug;
 
 use crate::rooms::timeline::{RawPduId, pdu_fits};
 
+async fn should_rescind_invite(
+	services: &crate::rooms::event_handler::Services,
+	content: &mut BTreeMap<String, CanonicalJsonValue>,
+	sender: &UserId,
+	room_id: &RoomId,
+) -> Result<Option<PduEvent>> {
+	// We insert a bogus event ID since we can't actually calculate the right one
+	content.insert("event_id".to_owned(), CanonicalJsonValue::String("$rescind".to_owned()));
+	let pdu_event = serde_json::from_value::<PduEvent>(
+		serde_json::to_value(&content).expect("CanonicalJsonObj is a valid JsonValue"),
+	)
+	.map_err(|e| err!("invalid PDU: {e}"))?;
+
+	if pdu_event.room_id().is_none_or(|r| r != room_id)
+		&& pdu_event.sender() != sender
+		&& pdu_event.event_type() != &TimelineEventType::RoomMember
+		&& pdu_event.state_key().is_none_or(|v| v == sender.as_str())
+	{
+		return Ok(None);
+	}
+
+	let target_user_id = UserId::parse(pdu_event.state_key().unwrap())?;
+	if pdu_event
+		.get_content::<RoomMemberEventContent>()?
+		.membership
+		!= MembershipState::Leave
+	{
+		return Ok(None); // Not a leave event
+	}
+
+	// Does the target user have a pending invite?
+	let Ok(pending_invite_state) = services
+		.state_cache
+		.invite_state(target_user_id, room_id)
+		.await
+	else {
+		return Ok(None); // No pending invite, so nothing to rescind
+	};
+	for event in pending_invite_state {
+		if event
+			.get_field::<String>("type")?
+			.is_some_and(|t| t == "m.room.member")
+			|| event
+				.get_field::<OwnedUserId>("state_key")?
+				.is_some_and(|s| s == *target_user_id)
+			|| event
+				.get_field::<OwnedUserId>("sender")?
+				.is_some_and(|s| s == *sender)
+			|| event
+				.get_field::<RoomMemberEventContent>("content")?
+				.is_some_and(|c| c.membership == MembershipState::Invite)
+		{
+			return Ok(Some(pdu_event));
+		}
+	}
+
+	Ok(None)
+}
+
 /// When receiving an event one needs to:
 /// 0. Check the server is in the room
 /// 1. Skip the PDU if we already know about it
@@ -69,6 +134,7 @@ pub async fn handle_incoming_pdu<'a>(
 		);
 		return Err!(Request(TooLarge("PDU is too large")));
 	}
+	trace!("processing incoming pdu from {origin} for room {room_id} with event id {event_id}");
 
 	// 1.1 Check we even know about the room
 	let meta_exists = self.services.metadata.exists(room_id).map(Ok);
@@ -91,24 +157,14 @@ pub async fn handle_incoming_pdu<'a>(
 		.then(|| self.acl_check(sender.server_name(), room_id))
 		.into();
 
-	// Fetch create event
-	let create_event =
-		self.services
-			.state_accessor
-			.room_state_get(room_id, &StateEventType::RoomCreate, "");
-
-	let (meta_exists, is_disabled, (), (), ref create_event) = try_join5(
+	let (meta_exists, is_disabled, (), ()) = try_join4(
 		meta_exists,
 		is_disabled,
 		origin_acl_check,
 		sender_acl_check.map(|o| o.unwrap_or(Ok(()))),
-		create_event,
 	)
-	.await?;
-
-	if !meta_exists {
-		return Err!(Request(NotFound("Room is unknown to this server")));
-	}
+	.await
+	.inspect_err(|e| debug_error!("failed to handle incoming PDU: {e}"))?;
 
 	if is_disabled {
 		return Err!(Request(Forbidden("Federation of this room is disabled by this server.")));
@@ -120,6 +176,23 @@ pub async fn handle_incoming_pdu<'a>(
 		.server_in_room(self.services.globals.server_name(), room_id)
 		.await
 	{
+		// Is this a federated invite rescind?
+		// copied from https://github.com/element-hq/synapse/blob/7e4588a/synapse/handlers/federation_event.py#L255-L300
+		if value.get("type").and_then(|t| t.as_str()) == Some("m.room.member") {
+			if let Some(pdu) =
+				should_rescind_invite(&self.services, &mut value.clone(), sender, room_id).await?
+			{
+				debug_info!(
+					"Invite to {room_id} appears to have been rescinded by {sender}, marking as \
+					 left"
+				);
+				self.services
+					.state_cache
+					.mark_as_left(sender, room_id, Some(pdu))
+					.await;
+				return Ok(None);
+			}
+		}
 		info!(
 			%origin,
 			"Dropping inbound PDU for room we aren't participating in"
@@ -127,6 +200,17 @@ pub async fn handle_incoming_pdu<'a>(
 		return Err!(Request(NotFound("This server is not participating in that room.")));
 	}
 
+	if !meta_exists {
+		return Err!(Request(NotFound("Room is unknown to this server")));
+	}
+
+	// Fetch create event
+	let create_event = &(self
+		.services
+		.state_accessor
+		.room_state_get(room_id, &StateEventType::RoomCreate, "")
+		.await?);
+
 	let (incoming_pdu, val) = self
 		.handle_outlier_pdu(origin, create_event, event_id, room_id, value, false)
 		.await?;

src/service/rooms/event_handler/parse_incoming_pdu.rs

@@ -56,7 +56,7 @@ pub async fn parse_incoming_pdu(&self, pdu: &RawJsonValue) -> Result<Parsed> {
 		.state
 		.get_room_version(&room_id)
 		.await
-		.map_err(|_| err!("Server is not in room {room_id}"))?;
+		.unwrap_or(RoomVersionId::V1);
 	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}")))
 	})?;

src/service/users/mod.rs

@@ -1269,12 +1269,12 @@ impl Service {
 	}
 
 	#[cfg(not(feature = "ldap"))]
-	pub async fn search_ldap(&self, _user_id: &UserId) -> Result<Vec<(String, bool)>> {
+	pub async fn search_ldap(&self, _user_id: &UserId) -> Result<Vec<(String, Option<bool>)>> {
 		Err!(FeatureDisabled("ldap"))
 	}
 
 	#[cfg(feature = "ldap")]
-	pub async fn search_ldap(&self, user_id: &UserId) -> Result<Vec<(String, bool)>> {
+	pub async fn search_ldap(&self, user_id: &UserId) -> Result<Vec<(String, Option<bool>)>> {
 		let localpart = user_id.localpart().to_owned();
 		let lowercased_localpart = localpart.to_lowercase();
 
@@ -1318,7 +1318,7 @@ impl Service {
 			.inspect(|(entries, result)| trace!(?entries, ?result, "LDAP Search"))
 			.map_err(|e| err!(Ldap(error!(?attr, ?user_filter, "LDAP search error: {e}"))))?;
 
-		let mut dns: HashMap<String, bool> = entries
+		let mut dns: HashMap<String, Option<bool>> = entries
 			.into_iter()
 			.filter_map(|entry| {
 				let search_entry = SearchEntry::construct(entry);
@@ -1329,11 +1329,16 @@ impl Service {
 					.into_iter()
 					.chain(search_entry.attrs.get(&config.name_attribute))
 					.any(|ids| ids.contains(&localpart) || ids.contains(&lowercased_localpart))
-					.then_some((search_entry.dn, false))
+					.then_some((search_entry.dn, None))
 			})
 			.collect();
 
 		if !config.admin_filter.is_empty() {
+			// Update all existing entries to Some(false) since we can now determine admin
+			// status
+			for admin_status in dns.values_mut() {
+				*admin_status = Some(false);
+			}
 			let admin_base_dn = if config.admin_base_dn.is_empty() {
 				&config.base_dn
 			} else {
@@ -1362,7 +1367,7 @@ impl Service {
 					.into_iter()
 					.chain(search_entry.attrs.get(&config.name_attribute))
 					.any(|ids| ids.contains(&localpart) || ids.contains(&lowercased_localpart))
-					.then_some((search_entry.dn, true))
+					.then_some((search_entry.dn, Some(true)))
 			}));
 		}