Add support for MSC4155 (#1013)

[rendered msc here](https://github.com/Johennes/matrix-spec-proposals/blob/johannes/invite-filtering/proposals/4155-invite-filtering.md). Closes #836.

Co-authored-by: nexy7574 <git@nexy7574.co.uk>
Reviewed-on: https://forgejo.ellis.link/continuwuation/continuwuity/pulls/1013
Reviewed-by: nex <nex@noreply.forgejo.ellis.link>
Co-authored-by: Ginger <ginger@gingershaped.computer>
Co-committed-by: Ginger <ginger@gingershaped.computer>

Cargo.toml

@@ -381,6 +381,7 @@ features = [
     "unstable-msc4095",
     "unstable-msc4121",
     "unstable-msc4125",
+	"unstable-msc4155",
     "unstable-msc4186",
     "unstable-msc4203", # sending to-device events to appservices
     "unstable-msc4210", # remove legacy mentions

src/api/client/membership/invite.rs

@@ -4,11 +4,14 @@ use conduwuit::{
 	Err, Result, debug_error, err, info,
 	matrix::{event::gen_event_id_canonical_json, pdu::PduBuilder},
 };
-use futures::{FutureExt, join};
+use futures::FutureExt;
 use ruma::{
 	OwnedServerName, RoomId, UserId,
 	api::{client::membership::invite_user, federation::membership::create_invite},
-	events::room::member::{MembershipState, RoomMemberEventContent},
+	events::{
+		invite_permission_config::FilterLevel,
+		room::member::{MembershipState, RoomMemberEventContent},
+	},
 };
 use service::Services;
 
@@ -47,22 +50,21 @@ pub(crate) async fn invite_user_route(
 	.await?;
 
 	match &body.recipient {
-		| invite_user::v3::InvitationRecipient::UserId { user_id } => {
-			let sender_ignored_recipient = services.users.user_is_ignored(sender_user, user_id);
-			let recipient_ignored_by_sender =
-				services.users.user_is_ignored(user_id, sender_user);
+		| invite_user::v3::InvitationRecipient::UserId { user_id: recipient_user } => {
+			let sender_filter_level = services
+				.users
+				.invite_filter_level(recipient_user, sender_user)
+				.await;
 
-			let (sender_ignored_recipient, recipient_ignored_by_sender) =
-				join!(sender_ignored_recipient, recipient_ignored_by_sender);
-
-			if sender_ignored_recipient {
+			if !matches!(sender_filter_level, FilterLevel::Allow) {
+				// drop invites if the sender has the recipient filtered
 				return Ok(invite_user::v3::Response {});
 			}
 
 			if let Ok(target_user_membership) = services
 				.rooms
 				.state_accessor
-				.get_member(&body.room_id, user_id)
+				.get_member(&body.room_id, recipient_user)
 				.await
 			{
 				if target_user_membership.membership == MembershipState::Ban {
@@ -70,16 +72,27 @@ pub(crate) async fn invite_user_route(
 				}
 			}
 
-			if recipient_ignored_by_sender {
-				// silently drop the invite to the recipient if they've been ignored by the
-				// sender, pretend it worked
-				return Ok(invite_user::v3::Response {});
+			// check for blocked invites if the recipient is a local user.
+			if services.globals.user_is_local(recipient_user) {
+				let recipient_filter_level = services
+					.users
+					.invite_filter_level(sender_user, recipient_user)
+					.await;
+
+				// ignored invites aren't handled here
+				// since the recipient's membership should still be changed to `invite`.
+				// they're filtered out in the individual /sync handlers.
+				if matches!(recipient_filter_level, FilterLevel::Block) {
+					return Err!(Request(InviteBlocked(
+						"{recipient_user} has blocked invites from you."
+					)));
+				}
 			}
 
 			invite_helper(
 				&services,
 				sender_user,
-				user_id,
+				recipient_user,
 				&body.room_id,
 				body.reason.clone(),
 				false,
@@ -98,7 +111,7 @@ pub(crate) async fn invite_user_route(
 pub(crate) async fn invite_helper(
 	services: &Services,
 	sender_user: &UserId,
-	user_id: &UserId,
+	recipient_user: &UserId,
 	room_id: &RoomId,
 	reason: Option<String>,
 	is_direct: bool,
@@ -111,12 +124,12 @@ pub(crate) async fn invite_helper(
 		return Err!(Request(Forbidden("Invites are not allowed on this server.")));
 	}
 
-	if !services.globals.user_is_local(user_id) {
+	if !services.globals.user_is_local(recipient_user) {
 		let (pdu, pdu_json, invite_room_state) = {
 			let state_lock = services.rooms.state.mutex.lock(room_id).await;
 
 			let content = RoomMemberEventContent {
-				avatar_url: services.users.avatar_url(user_id).await.ok(),
+				avatar_url: services.users.avatar_url(recipient_user).await.ok(),
 				is_direct: Some(is_direct),
 				reason,
 				..RoomMemberEventContent::new(MembershipState::Invite)
@@ -126,7 +139,7 @@ pub(crate) async fn invite_helper(
 				.rooms
 				.timeline
 				.create_hash_and_sign_event(
-					PduBuilder::state(user_id.to_string(), &content),
+					PduBuilder::state(recipient_user.to_string(), &content),
 					sender_user,
 					Some(room_id),
 					&state_lock,
@@ -144,7 +157,7 @@ pub(crate) async fn invite_helper(
 
 		let response = services
 			.sending
-			.send_federation_request(user_id.server_name(), create_invite::v2::Request {
+			.send_federation_request(recipient_user.server_name(), create_invite::v2::Request {
 				room_id: room_id.to_owned(),
 				event_id: (*pdu.event_id).to_owned(),
 				room_version: room_version_id.clone(),
@@ -173,7 +186,7 @@ pub(crate) async fn invite_helper(
 			return Err!(Request(BadJson(warn!(
 				%pdu.event_id, %event_id,
 				"Server {} sent event with wrong event ID",
-				user_id.server_name()
+				recipient_user.server_name()
 			))));
 		}
 
@@ -213,9 +226,9 @@ pub(crate) async fn invite_helper(
 	let state_lock = services.rooms.state.mutex.lock(room_id).await;
 
 	let content = RoomMemberEventContent {
-		displayname: services.users.displayname(user_id).await.ok(),
-		avatar_url: services.users.avatar_url(user_id).await.ok(),
-		blurhash: services.users.blurhash(user_id).await.ok(),
+		displayname: services.users.displayname(recipient_user).await.ok(),
+		avatar_url: services.users.avatar_url(recipient_user).await.ok(),
+		blurhash: services.users.blurhash(recipient_user).await.ok(),
 		is_direct: Some(is_direct),
 		reason,
 		..RoomMemberEventContent::new(MembershipState::Invite)
@@ -225,7 +238,7 @@ pub(crate) async fn invite_helper(
 		.rooms
 		.timeline
 		.build_and_append_pdu(
-			PduBuilder::state(user_id.to_string(), &content),
+			PduBuilder::state(recipient_user.to_string(), &content),
 			sender_user,
 			Some(room_id),
 			&state_lock,

src/api/client/message.rs

@@ -30,6 +30,7 @@ use ruma::{
 	events::{
 		AnyStateEvent, StateEventType,
 		TimelineEventType::{self, *},
+		invite_permission_config::FilterLevel,
 	},
 	serde::Raw,
 };
@@ -267,7 +268,7 @@ pub(crate) async fn ignored_filter(
 pub(crate) async fn is_ignored_pdu<Pdu>(
 	services: &Services,
 	event: &Pdu,
-	user_id: &UserId,
+	recipient_user: &UserId,
 ) -> bool
 where
 	Pdu: Event + Send + Sync,
@@ -278,20 +279,28 @@ where
 		return true;
 	}
 
-	let ignored_type = IGNORED_MESSAGE_TYPES.binary_search(event.kind()).is_ok();
+	if IGNORED_MESSAGE_TYPES.binary_search(event.kind()).is_ok() {
+		// this PDU is a non-state event which it is safe to ignore
+		return true;
+	}
 
-	let ignored_server = services
+	let sender_user = event.sender();
+
+	if services
 		.moderation
-		.is_remote_server_ignored(event.sender().server_name());
-
-	if ignored_type
-		&& (ignored_server
-			|| (!services.config.send_messages_from_ignored_users_to_client
-				&& services
-					.users
-					.user_is_ignored(event.sender(), user_id)
-					.await))
+		.is_remote_server_ignored(sender_user.server_name())
 	{
+		// this PDU was sent by a remote server which we are ignoring
+		return true;
+	}
+
+	if services
+		.users
+		.user_is_ignored(sender_user, recipient_user)
+		.await && !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;
 	}
 
@@ -320,6 +329,29 @@ pub(crate) fn event_filter(item: PdusIterItem, filter: &RoomEventFilter) -> Opti
 	filter.matches(pdu).then_some(item)
 }
 
+#[inline]
+pub(crate) async fn is_ignored_invite(
+	services: &Services,
+	recipient_user: &UserId,
+	room_id: &RoomId,
+) -> bool {
+	let Ok(sender_user) = services
+		.rooms
+		.state_cache
+		.invite_sender(recipient_user, room_id)
+		.await
+	else {
+		// the invite may have been sent before the invite_sender table existed.
+		// assume it's not ignored
+		return false;
+	};
+
+	services
+		.users
+		.invite_filter_level(&sender_user, recipient_user)
+		.await == FilterLevel::Ignore
+}
+
 #[cfg_attr(debug_assertions, ctor::ctor)]
 fn _is_sorted() {
 	debug_assert!(

src/api/client/room/create.rs

@@ -1,4 +1,4 @@
-use std::collections::BTreeMap;
+use std::collections::{BTreeMap, BTreeSet};
 
 use axum::extract::State;
 use conduwuit::{
@@ -13,6 +13,7 @@ use ruma::{
 	api::client::room::{self, create_room},
 	events::{
 		TimelineEventType,
+		invite_permission_config::FilterLevel,
 		room::{
 			canonical_alias::RoomCanonicalAliasEventContent,
 			create::RoomCreateEventContent,
@@ -121,6 +122,40 @@ pub(crate) async fn create_room_route(
 		return Err!(Request(Forbidden("Publishing rooms to the room directory is not allowed")));
 	}
 
+	let mut invitees = BTreeSet::new();
+
+	for recipient_user in &body.invite {
+		if !matches!(
+			services
+				.users
+				.invite_filter_level(recipient_user, sender_user)
+				.await,
+			FilterLevel::Allow
+		) {
+			// drop invites if the creator has them blocked
+			continue;
+		}
+
+		// if the recipient of the invite is local and has the sender blocked, error
+		// out. if the recipient is remote we can't tell yet, and if they're local and
+		// have the sender _ignored_ their invite will be filtered out in
+		// the handlers for the individual /sync endpoints
+		if services.globals.user_is_local(recipient_user)
+			&& matches!(
+				services
+					.users
+					.invite_filter_level(sender_user, recipient_user)
+					.await,
+				FilterLevel::Block
+			) {
+			return Err!(Request(InviteBlocked(
+				"{recipient_user} has blocked invites from you."
+			)));
+		}
+
+		invitees.insert(recipient_user.clone());
+	}
+
 	let alias: Option<OwnedRoomAliasId> = match body.room_alias_name.as_ref() {
 		| Some(alias) =>
 			Some(room_alias_check(&services, alias, body.appservice_info.as_ref()).await?),
@@ -252,19 +287,11 @@ pub(crate) async fn create_room_route(
 		| _ => RoomPreset::PrivateChat, // Room visibility should not be custom
 	});
 
-	let mut users = BTreeMap::from_iter([(sender_user.to_owned(), int!(100))]);
+	let mut power_levels_to_grant = BTreeMap::from_iter([(sender_user.to_owned(), int!(100))]);
 
 	if preset == RoomPreset::TrustedPrivateChat {
-		for invite in &body.invite {
-			if services.users.user_is_ignored(sender_user, invite).await {
-				continue;
-			} else if services.users.user_is_ignored(invite, sender_user).await {
-				// silently drop the invite to the recipient if they've been ignored by the
-				// sender, pretend it worked
-				continue;
-			}
-
-			users.insert(invite.clone(), int!(100));
+		for recipient_user in &invitees {
+			power_levels_to_grant.insert(recipient_user.clone(), int!(100));
 		}
 	}
 
@@ -289,7 +316,7 @@ pub(crate) async fn create_room_route(
 			}
 		}
 	} else {
-		users.insert(sender_user.to_owned(), int!(100));
+		power_levels_to_grant.insert(sender_user.to_owned(), int!(100));
 		creators.clear(); // If this vec is not empty, default_power_levels_content will
 		// treat this as a v12 room
 	}
@@ -297,7 +324,7 @@ pub(crate) async fn create_room_route(
 	let power_levels_content = default_power_levels_content(
 		body.power_level_content_override.as_ref(),
 		&body.visibility,
-		users,
+		power_levels_to_grant,
 		creators,
 	)?;
 
@@ -459,17 +486,9 @@ pub(crate) async fn create_room_route(
 
 	// 8. Events implied by invite (and TODO: invite_3pid)
 	drop(state_lock);
-	for user_id in &body.invite {
-		if services.users.user_is_ignored(sender_user, user_id).await {
-			continue;
-		} else if services.users.user_is_ignored(user_id, sender_user).await {
-			// silently drop the invite to the recipient if they've been ignored by the
-			// sender, pretend it worked
-			continue;
-		}
-
+	for recipient_user in &invitees {
 		if let Err(e) =
-			invite_helper(&services, sender_user, user_id, &room_id, None, body.is_direct)
+			invite_helper(&services, sender_user, recipient_user, &room_id, None, body.is_direct)
 				.boxed()
 				.await
 		{

src/api/client/sync/v3.rs

@@ -60,7 +60,10 @@ use ruma::{
 use service::rooms::short::{ShortEventId, ShortStateKey};
 
 use super::{load_timeline, share_encrypted_room};
-use crate::{Ruma, RumaResponse, client::ignored_filter};
+use crate::{
+	Ruma, RumaResponse,
+	client::{ignored_filter, is_ignored_invite},
+};
 
 #[derive(Default)]
 struct StateChanges {
@@ -238,6 +241,13 @@ pub(crate) async fn build_sync_events(
 		.rooms
 		.state_cache
 		.rooms_invited(sender_user)
+		.wide_filter_map(async |(room_id, invite_state)| {
+			if is_ignored_invite(services, sender_user, &room_id).await {
+				None
+			} else {
+				Some((room_id, invite_state))
+			}
+		})
 		.fold_default(|mut invited_rooms: BTreeMap<_, _>, (room_id, invite_state)| async move {
 			let invite_count = services
 				.rooms

src/api/client/sync/v4.rs

@@ -11,6 +11,7 @@ use conduwuit::{
 	utils::{
 		BoolExt, IterStream, ReadyExt, TryFutureExtExt,
 		math::{ruma_from_usize, usize_from_ruma, usize_from_u64_truncated},
+		stream::WidebandExt,
 	},
 	warn,
 };
@@ -39,7 +40,7 @@ use ruma::{
 use super::{load_timeline, share_encrypted_room};
 use crate::{
 	Ruma,
-	client::{DEFAULT_BUMP_TYPES, ignored_filter},
+	client::{DEFAULT_BUMP_TYPES, ignored_filter, is_ignored_invite},
 };
 
 type TodoRooms = BTreeMap<OwnedRoomId, (BTreeSet<TypeStateKey>, usize, u64)>;
@@ -102,6 +103,13 @@ pub(crate) async fn sync_events_v4_route(
 		.rooms
 		.state_cache
 		.rooms_invited(sender_user)
+		.wide_filter_map(async |(room_id, invite_state)| {
+			if is_ignored_invite(&services, sender_user, &room_id).await {
+				None
+			} else {
+				Some((room_id, invite_state))
+			}
+		})
 		.map(|r| r.0)
 		.collect()
 		.await;

src/api/client/sync/v5.rs

@@ -14,6 +14,7 @@ use conduwuit::{
 		BoolExt, FutureBoolExt, IterStream, ReadyExt, TryFutureExtExt,
 		future::ReadyEqExt,
 		math::{ruma_from_usize, usize_from_ruma},
+		stream::WidebandExt,
 	},
 	warn,
 };
@@ -38,7 +39,7 @@ use ruma::{
 use super::share_encrypted_room;
 use crate::{
 	Ruma,
-	client::{DEFAULT_BUMP_TYPES, ignored_filter, sync::load_timeline},
+	client::{DEFAULT_BUMP_TYPES, ignored_filter, is_ignored_invite, sync::load_timeline},
 };
 
 type SyncInfo<'a> = (&'a UserId, &'a DeviceId, u64, &'a sync_events::v5::Request);
@@ -106,6 +107,13 @@ pub(crate) async fn sync_events_v5_route(
 		.rooms
 		.state_cache
 		.rooms_invited(sender_user)
+		.wide_filter_map(async |(room_id, invite_state)| {
+			if is_ignored_invite(services, sender_user, &room_id).await {
+				None
+			} else {
+				Some((room_id, invite_state))
+			}
+		})
 		.map(|r| r.0)
 		.collect::<Vec<OwnedRoomId>>();
 

src/api/server/invite.rs

@@ -61,13 +61,16 @@ pub(crate) async fn create_invite_route(
 	let mut signed_event = utils::to_canonical_object(&body.event)
 		.map_err(|_| err!(Request(InvalidParam("Invite event is invalid."))))?;
 
-	let invited_user: OwnedUserId = signed_event
+	let recipient_user: OwnedUserId = signed_event
 		.get("state_key")
 		.try_into()
 		.map(UserId::to_owned)
 		.map_err(|e| err!(Request(InvalidParam("Invalid state_key property: {e}"))))?;
 
-	if !services.globals.server_is_ours(invited_user.server_name()) {
+	if !services
+		.globals
+		.server_is_ours(recipient_user.server_name())
+	{
 		return Err!(Request(InvalidParam("User does not belong to this homeserver.")));
 	}
 
@@ -75,7 +78,7 @@ pub(crate) async fn create_invite_route(
 	services
 		.rooms
 		.event_handler
-		.acl_check(invited_user.server_name(), &body.room_id)
+		.acl_check(recipient_user.server_name(), &body.room_id)
 		.await?;
 
 	services
@@ -89,18 +92,19 @@ pub(crate) async fn create_invite_route(
 	// Add event_id back
 	signed_event.insert("event_id".to_owned(), CanonicalJsonValue::String(event_id.to_string()));
 
-	let sender: &UserId = signed_event
+	let sender_user: &UserId = signed_event
 		.get("sender")
 		.try_into()
 		.map_err(|e| err!(Request(InvalidParam("Invalid sender property: {e}"))))?;
 
 	if services.rooms.metadata.is_banned(&body.room_id).await
-		&& !services.users.is_admin(&invited_user).await
+		&& !services.users.is_admin(&recipient_user).await
 	{
 		return Err!(Request(Forbidden("This room is banned on this homeserver.")));
 	}
 
-	if services.config.block_non_admin_invites && !services.users.is_admin(&invited_user).await {
+	if services.config.block_non_admin_invites && !services.users.is_admin(&recipient_user).await
+	{
 		return Err!(Request(Forbidden("This server does not allow room invites.")));
 	}
 
@@ -131,9 +135,9 @@ pub(crate) async fn create_invite_route(
 			.state_cache
 			.update_membership(
 				&body.room_id,
-				&invited_user,
+				&recipient_user,
 				RoomMemberEventContent::new(MembershipState::Invite),
-				sender,
+				sender_user,
 				Some(invite_state),
 				body.via.clone(),
 				true,
@@ -141,7 +145,7 @@ pub(crate) async fn create_invite_route(
 			.await?;
 
 		for appservice in services.appservice.read().await.values() {
-			if appservice.is_user_match(&invited_user) {
+			if appservice.is_user_match(&recipient_user) {
 				services
 					.sending
 					.send_appservice_request(

src/core/error/response.rs

@@ -73,6 +73,7 @@ pub(super) fn bad_request_code(kind: &ErrorKind) -> StatusCode {
 		| ThreepidAuthFailed
 		| UserDeactivated
 		| ThreepidDenied
+		| InviteBlocked
 		| WrongRoomKeysVersion { .. }
 		| Forbidden { .. } => StatusCode::FORBIDDEN,
 

src/database/maps.rs

@@ -434,4 +434,8 @@ pub(super) static MAPS: &[Descriptor] = &[
 		name: "userroomid_notificationcount",
 		..descriptor::RANDOM
 	},
+	Descriptor {
+		name: "userroomid_invitesender",
+		..descriptor::RANDOM_SMALL
+	},
 ];

src/service/rooms/state_cache/mod.rs

@@ -12,7 +12,7 @@ use conduwuit::{
 use database::{Deserialized, Ignore, Interfix, Map};
 use futures::{Stream, StreamExt, future::join5, pin_mut};
 use ruma::{
-	OwnedRoomId, RoomId, ServerName, UserId,
+	OwnedRoomId, OwnedUserId, RoomId, ServerName, UserId,
 	events::{AnyStrippedStateEvent, AnySyncStateEvent, room::member::MembershipState},
 	serde::Raw,
 };
@@ -49,6 +49,7 @@ struct Data {
 	userroomid_joined: Arc<Map>,
 	userroomid_leftstate: Arc<Map>,
 	userroomid_knockedstate: Arc<Map>,
+	userroomid_invitesender: Arc<Map>,
 }
 
 type AppServiceInRoomCache = SyncRwLock<HashMap<OwnedRoomId, HashMap<String, bool>>>;
@@ -83,6 +84,7 @@ impl crate::Service for Service {
 				userroomid_joined: args.db["userroomid_joined"].clone(),
 				userroomid_leftstate: args.db["userroomid_leftstate"].clone(),
 				userroomid_knockedstate: args.db["userroomid_knockedstate"].clone(),
+				userroomid_invitesender: args.db["userroomid_invitesender"].clone(),
 			},
 		}))
 	}
@@ -523,3 +525,14 @@ pub async fn is_left(&self, user_id: &UserId, room_id: &RoomId) -> bool {
 	let key = (user_id, room_id);
 	self.db.userroomid_leftstate.qry(&key).await.is_ok()
 }
+
+#[implement(Service)]
+#[tracing::instrument(skip(self), level = "trace")]
+pub async fn invite_sender(&self, user_id: &UserId, room_id: &RoomId) -> Result<OwnedUserId> {
+	let key = (user_id, room_id);
+	self.db
+		.userroomid_invitesender
+		.qry(&key)
+		.await
+		.deserialized()
+}

src/service/rooms/state_cache/update.rs

@@ -1,6 +1,6 @@
 use std::collections::HashSet;
 
-use conduwuit::{Result, implement, is_not_empty, utils::ReadyExt, warn};
+use conduwuit::{Err, Result, implement, is_not_empty, utils::ReadyExt, warn};
 use database::{Json, serialize_key};
 use futures::StreamExt;
 use ruma::{
@@ -9,6 +9,7 @@ use ruma::{
 		AnyStrippedStateEvent, AnySyncStateEvent, GlobalAccountDataEventType,
 		RoomAccountDataEventType, StateEventType,
 		direct::DirectEvent,
+		invite_permission_config::FilterLevel,
 		room::{
 			create::RoomCreateEventContent,
 			member::{MembershipState, RoomMemberEventContent},
@@ -121,12 +122,21 @@ pub async fn update_membership(
 			self.mark_as_joined(user_id, room_id);
 		},
 		| MembershipState::Invite => {
-			// We want to know if the sender is ignored by the receiver
-			if self.services.users.user_is_ignored(sender, user_id).await {
-				return Ok(());
+			// return an error for blocked invites. ignored invites aren't handled here
+			// since the recipient's membership should still be changed to `invite`.
+			// they're filtered out in the individual /sync handlers
+			if matches!(
+				self.services
+					.users
+					.invite_filter_level(sender, user_id)
+					.await,
+				FilterLevel::Block
+			) {
+				return Err!(Request(InviteBlocked(
+					"{user_id} has blocked invites from {sender}."
+				)));
 			}
-
-			self.mark_as_invited(user_id, room_id, last_state, invite_via)
+			self.mark_as_invited(user_id, room_id, sender, last_state, invite_via)
 				.await;
 		},
 		| MembershipState::Leave | MembershipState::Ban => {
@@ -231,6 +241,7 @@ pub fn mark_as_joined(&self, user_id: &UserId, room_id: &RoomId) {
 
 	self.db.userroomid_invitestate.remove(&userroom_id);
 	self.db.roomuserid_invitecount.remove(&roomuser_id);
+	self.db.userroomid_invitesender.remove(&userroom_id);
 
 	self.db.userroomid_leftstate.remove(&userroom_id);
 	self.db.roomuserid_leftcount.remove(&roomuser_id);
@@ -268,6 +279,7 @@ pub fn mark_as_left(&self, user_id: &UserId, room_id: &RoomId) {
 
 	self.db.userroomid_invitestate.remove(&userroom_id);
 	self.db.roomuserid_invitecount.remove(&roomuser_id);
+	self.db.userroomid_invitesender.remove(&userroom_id);
 
 	self.db.userroomid_knockedstate.remove(&userroom_id);
 	self.db.roomuserid_knockedcount.remove(&roomuser_id);
@@ -304,6 +316,7 @@ pub fn mark_as_knocked(
 
 	self.db.userroomid_invitestate.remove(&userroom_id);
 	self.db.roomuserid_invitecount.remove(&roomuser_id);
+	self.db.userroomid_invitesender.remove(&userroom_id);
 
 	self.db.userroomid_leftstate.remove(&userroom_id);
 	self.db.roomuserid_leftcount.remove(&roomuser_id);
@@ -335,6 +348,7 @@ pub async fn mark_as_invited(
 	&self,
 	user_id: &UserId,
 	room_id: &RoomId,
+	sender_user: &UserId,
 	last_state: Option<Vec<Raw<AnyStrippedStateEvent>>>,
 	invite_via: Option<Vec<OwnedServerName>>,
 ) {
@@ -350,6 +364,9 @@ pub async fn mark_as_invited(
 	self.db
 		.roomuserid_invitecount
 		.raw_aput::<8, _, _>(&roomuser_id, self.services.globals.next_count().unwrap());
+	self.db
+		.userroomid_invitesender
+		.raw_put(&userroom_id, sender_user);
 
 	self.db.userroomid_joined.remove(&userroom_id);
 	self.db.roomuserid_joined.remove(&roomuser_id);

src/service/users/mod.rs

@@ -20,7 +20,9 @@ use ruma::{
 	api::client::{device::Device, error::ErrorKind, filter::FilterDefinition},
 	encryption::{CrossSigningKey, DeviceKeys, OneTimeKey},
 	events::{
-		AnyToDeviceEvent, GlobalAccountDataEventType, ignored_user_list::IgnoredUserListEvent,
+		AnyToDeviceEvent, GlobalAccountDataEventType,
+		ignored_user_list::IgnoredUserListEvent,
+		invite_permission_config::{FilterLevel, InvitePermissionConfigEvent},
 	},
 	serde::Raw,
 };
@@ -139,6 +141,26 @@ impl Service {
 			})
 	}
 
+	/// Returns the recipient's filter level for an invite from the sender.
+	pub async fn invite_filter_level(
+		&self,
+		sender_user: &UserId,
+		recipient_user: &UserId,
+	) -> FilterLevel {
+		if self.user_is_ignored(sender_user, recipient_user).await {
+			FilterLevel::Ignore
+		} else {
+			self.services
+				.account_data
+				.get_global(recipient_user, GlobalAccountDataEventType::InvitePermissionConfig)
+				.await
+				.map(|config: InvitePermissionConfigEvent| {
+					config.content.user_filter_level(sender_user)
+				})
+				.unwrap_or(FilterLevel::Allow)
+		}
+	}
+
 	/// Check if a user is an admin
 	#[inline]
 	pub async fn is_admin(&self, user_id: &UserId) -> bool {