refactor: Centralize server forbidden checks into moderation module

This moves all checks related to `forbidden_remote_server_names`,
`forbidden_remote_room_directory_server_names` and
`prevent_media_downloads_from` to a new `moderation` module.
This is useful for implementing more complicated logic globally.
Mostly the changes from #673, but is also relevant for #750

src/api/client/directory.rs

@@ -52,13 +52,8 @@ pub(crate) async fn get_public_rooms_filtered_route(
 ) -> Result<get_public_rooms_filtered::v3::Response> {
 	if let Some(server) = &body.server {
 		if services
-			.config
-			.forbidden_remote_room_directory_server_names
-			.is_match(server.host())
-			|| services
-				.config
-				.forbidden_remote_server_names
-				.is_match(server.host())
+			.moderation
+			.is_remote_server_room_directory_forbidden(server)
 		{
 			return Err!(Request(Forbidden("Server is banned on this homeserver.")));
 		}
@@ -92,15 +87,7 @@ pub(crate) async fn get_public_rooms_route(
 	body: Ruma<get_public_rooms::v3::Request>,
 ) -> Result<get_public_rooms::v3::Response> {
 	if let Some(server) = &body.server {
-		if services
-			.config
-			.forbidden_remote_room_directory_server_names
-			.is_match(server.host())
-			|| services
-				.config
-				.forbidden_remote_server_names
-				.is_match(server.host())
-		{
+		if services.moderation.is_remote_server_forbidden(server) {
 			return Err!(Request(Forbidden("Server is banned on this homeserver.")));
 		}
 	}

src/api/client/membership.rs

@@ -83,9 +83,8 @@ async fn banned_room_check(
 	if let Some(room_id) = room_id {
 		if services.rooms.metadata.is_banned(room_id).await
 			|| services
-				.config
-				.forbidden_remote_server_names
-				.is_match(room_id.server_name().expect("legacy room mxid").host())
+				.moderation
+				.is_remote_server_forbidden(room_id.server_name().expect("legacy room mxid"))
 		{
 			warn!(
 				"User {user_id} who is not an admin attempted to send an invite for or \

src/api/client/message.rs

@@ -274,9 +274,8 @@ pub(crate) async fn is_ignored_pdu(
 	let ignored_type = IGNORED_MESSAGE_TYPES.binary_search(&pdu.kind).is_ok();
 
 	let ignored_server = services
-		.config
-		.forbidden_remote_server_names
-		.is_match(pdu.sender().server_name().host());
+		.moderation
+		.is_remote_server_forbidden(pdu.sender().server_name());
 
 	if ignored_type
 		&& (ignored_server || services.users.user_is_ignored(&pdu.sender, user_id).await)

src/api/router/auth.rs

@@ -306,7 +306,7 @@ async fn auth_server(
 }
 
 fn auth_server_checks(services: &Services, x_matrix: &XMatrix) -> Result<()> {
-	if !services.server.config.allow_federation {
+	if !services.config.allow_federation {
 		return Err!(Config("allow_federation", "Federation is disabled."));
 	}
 
@@ -316,11 +316,7 @@ fn auth_server_checks(services: &Services, x_matrix: &XMatrix) -> Result<()> {
 	}
 
 	let origin = &x_matrix.origin;
-	if services
-		.config
-		.forbidden_remote_server_names
-		.is_match(origin.host())
-	{
+	if services.moderation.is_remote_server_forbidden(origin) {
 		return Err!(Request(Forbidden(debug_warn!(
 			"Federation requests from {origin} denied."
 		))));

src/api/server/invite.rs

@@ -37,19 +37,14 @@ pub(crate) async fn create_invite_route(
 	}
 
 	if let Some(server) = body.room_id.server_name() {
-		if services
-			.config
-			.forbidden_remote_server_names
-			.is_match(server.host())
-		{
+		if services.moderation.is_remote_server_forbidden(server) {
 			return Err!(Request(Forbidden("Server is banned on this homeserver.")));
 		}
 	}
 
 	if services
-		.config
-		.forbidden_remote_server_names
-		.is_match(body.origin().host())
+		.moderation
+		.is_remote_server_forbidden(body.origin())
 	{
 		warn!(
 			"Received federated/remote invite from banned server {} for room ID {}. Rejecting.",

src/api/server/make_join.rs

@@ -42,9 +42,8 @@ pub(crate) async fn create_join_event_template_route(
 		.await?;
 
 	if services
-		.config
-		.forbidden_remote_server_names
-		.is_match(body.origin().host())
+		.moderation
+		.is_remote_server_forbidden(body.origin())
 	{
 		warn!(
 			"Server {} for remote user {} tried joining room ID {} which has a server name that \
@@ -57,11 +56,7 @@ pub(crate) async fn create_join_event_template_route(
 	}
 
 	if let Some(server) = body.room_id.server_name() {
-		if services
-			.config
-			.forbidden_remote_server_names
-			.is_match(server.host())
-		{
+		if services.moderation.is_remote_server_forbidden(server) {
 			return Err!(Request(Forbidden(warn!(
 				"Room ID server name {server} is banned on this homeserver."
 			))));

src/api/server/make_knock.rs

@@ -33,9 +33,8 @@ pub(crate) async fn create_knock_event_template_route(
 		.await?;
 
 	if services
-		.config
-		.forbidden_remote_server_names
-		.is_match(body.origin().host())
+		.moderation
+		.is_remote_server_forbidden(body.origin())
 	{
 		warn!(
 			"Server {} for remote user {} tried knocking room ID {} which has a server name \
@@ -48,11 +47,7 @@ pub(crate) async fn create_knock_event_template_route(
 	}
 
 	if let Some(server) = body.room_id.server_name() {
-		if services
-			.config
-			.forbidden_remote_server_names
-			.is_match(server.host())
-		{
+		if services.moderation.is_remote_server_forbidden(server) {
 			return Err!(Request(Forbidden("Server is banned on this homeserver.")));
 		}
 	}

src/api/server/send_join.rs

@@ -268,9 +268,8 @@ pub(crate) async fn create_join_event_v1_route(
 	body: Ruma<create_join_event::v1::Request>,
 ) -> Result<create_join_event::v1::Response> {
 	if services
-		.config
-		.forbidden_remote_server_names
-		.is_match(body.origin().host())
+		.moderation
+		.is_remote_server_forbidden(body.origin())
 	{
 		warn!(
 			"Server {} tried joining room ID {} through us who has a server name that is \
@@ -282,11 +281,7 @@ pub(crate) async fn create_join_event_v1_route(
 	}
 
 	if let Some(server) = body.room_id.server_name() {
-		if services
-			.config
-			.forbidden_remote_server_names
-			.is_match(server.host())
-		{
+		if services.moderation.is_remote_server_forbidden(server) {
 			warn!(
 				"Server {} tried joining room ID {} through us which has a server name that is \
 				 globally forbidden. Rejecting.",
@@ -314,19 +309,14 @@ pub(crate) async fn create_join_event_v2_route(
 	body: Ruma<create_join_event::v2::Request>,
 ) -> Result<create_join_event::v2::Response> {
 	if services
-		.config
-		.forbidden_remote_server_names
-		.is_match(body.origin().host())
+		.moderation
+		.is_remote_server_forbidden(body.origin())
 	{
 		return Err!(Request(Forbidden("Server is banned on this homeserver.")));
 	}
 
 	if let Some(server) = body.room_id.server_name() {
-		if services
-			.config
-			.forbidden_remote_server_names
-			.is_match(server.host())
-		{
+		if services.moderation.is_remote_server_forbidden(server) {
 			warn!(
 				"Server {} tried joining room ID {} through us which has a server name that is \
 				 globally forbidden. Rejecting.",

src/api/server/send_knock.rs

@@ -26,9 +26,8 @@ pub(crate) async fn create_knock_event_v1_route(
 	body: Ruma<send_knock::v1::Request>,
 ) -> Result<send_knock::v1::Response> {
 	if services
-		.config
-		.forbidden_remote_server_names
-		.is_match(body.origin().host())
+		.moderation
+		.is_remote_server_forbidden(body.origin())
 	{
 		warn!(
 			"Server {} tried knocking room ID {} who has a server name that is globally \
@@ -40,11 +39,7 @@ pub(crate) async fn create_knock_event_v1_route(
 	}
 
 	if let Some(server) = body.room_id.server_name() {
-		if services
-			.config
-			.forbidden_remote_server_names
-			.is_match(server.host())
-		{
+		if services.moderation.is_remote_server_forbidden(server) {
 			warn!(
 				"Server {} tried knocking room ID {} which has a server name that is globally \
 				 forbidden. Rejecting.",