fix: Actually flush destinations before selecting new events

Fixes !admin media delete --mxc <url> responding with an error message
when the media was deleted successfully.

Cargo.lock

@@ -1222,7 +1222,7 @@ dependencies = [
 [[package]]
 name = "continuwuity-admin-api"
 version = "0.1.0"
-source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=e087ff15888156942ca2ffe6097d1b4c3fd27628#e087ff15888156942ca2ffe6097d1b4c3fd27628"
+source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf#a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf"
 dependencies = [
  "ruma-common",
  "serde",
@@ -1601,7 +1601,7 @@ dependencies = [
 [[package]]
 name = "draupnir-antispam"
 version = "0.1.0"
-source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=e087ff15888156942ca2ffe6097d1b4c3fd27628#e087ff15888156942ca2ffe6097d1b4c3fd27628"
+source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf#a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf"
 dependencies = [
  "ruma-common",
  "serde",
@@ -3003,7 +3003,7 @@ checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
 [[package]]
 name = "meowlnir-antispam"
 version = "0.1.0"
-source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=e087ff15888156942ca2ffe6097d1b4c3fd27628#e087ff15888156942ca2ffe6097d1b4c3fd27628"
+source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf#a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf"
 dependencies = [
  "ruma-common",
  "serde",
@@ -4095,7 +4095,7 @@ dependencies = [
 [[package]]
 name = "ruma"
 version = "0.10.1"
-source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=e087ff15888156942ca2ffe6097d1b4c3fd27628#e087ff15888156942ca2ffe6097d1b4c3fd27628"
+source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf#a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf"
 dependencies = [
  "assign",
  "continuwuity-admin-api",
@@ -4118,7 +4118,7 @@ dependencies = [
 [[package]]
 name = "ruma-appservice-api"
 version = "0.10.0"
-source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=e087ff15888156942ca2ffe6097d1b4c3fd27628#e087ff15888156942ca2ffe6097d1b4c3fd27628"
+source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf#a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf"
 dependencies = [
  "js_int",
  "ruma-common",
@@ -4130,7 +4130,7 @@ dependencies = [
 [[package]]
 name = "ruma-client-api"
 version = "0.18.0"
-source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=e087ff15888156942ca2ffe6097d1b4c3fd27628#e087ff15888156942ca2ffe6097d1b4c3fd27628"
+source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf#a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf"
 dependencies = [
  "as_variant",
  "assign",
@@ -4153,7 +4153,7 @@ dependencies = [
 [[package]]
 name = "ruma-common"
 version = "0.13.0"
-source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=e087ff15888156942ca2ffe6097d1b4c3fd27628#e087ff15888156942ca2ffe6097d1b4c3fd27628"
+source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf#a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf"
 dependencies = [
  "as_variant",
  "base64 0.22.1",
@@ -4185,7 +4185,7 @@ dependencies = [
 [[package]]
 name = "ruma-events"
 version = "0.28.1"
-source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=e087ff15888156942ca2ffe6097d1b4c3fd27628#e087ff15888156942ca2ffe6097d1b4c3fd27628"
+source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf#a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf"
 dependencies = [
  "as_variant",
  "indexmap",
@@ -4210,7 +4210,7 @@ dependencies = [
 [[package]]
 name = "ruma-federation-api"
 version = "0.9.0"
-source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=e087ff15888156942ca2ffe6097d1b4c3fd27628#e087ff15888156942ca2ffe6097d1b4c3fd27628"
+source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf#a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf"
 dependencies = [
  "bytes",
  "headers",
@@ -4232,7 +4232,7 @@ dependencies = [
 [[package]]
 name = "ruma-identifiers-validation"
 version = "0.9.5"
-source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=e087ff15888156942ca2ffe6097d1b4c3fd27628#e087ff15888156942ca2ffe6097d1b4c3fd27628"
+source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf#a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf"
 dependencies = [
  "js_int",
  "thiserror 2.0.18",
@@ -4241,7 +4241,7 @@ dependencies = [
 [[package]]
 name = "ruma-identity-service-api"
 version = "0.9.0"
-source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=e087ff15888156942ca2ffe6097d1b4c3fd27628#e087ff15888156942ca2ffe6097d1b4c3fd27628"
+source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf#a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf"
 dependencies = [
  "js_int",
  "ruma-common",
@@ -4251,7 +4251,7 @@ dependencies = [
 [[package]]
 name = "ruma-macros"
 version = "0.13.0"
-source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=e087ff15888156942ca2ffe6097d1b4c3fd27628#e087ff15888156942ca2ffe6097d1b4c3fd27628"
+source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf#a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf"
 dependencies = [
  "cfg-if",
  "proc-macro-crate",
@@ -4266,7 +4266,7 @@ dependencies = [
 [[package]]
 name = "ruma-push-gateway-api"
 version = "0.9.0"
-source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=e087ff15888156942ca2ffe6097d1b4c3fd27628#e087ff15888156942ca2ffe6097d1b4c3fd27628"
+source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf#a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf"
 dependencies = [
  "js_int",
  "ruma-common",
@@ -4278,7 +4278,7 @@ dependencies = [
 [[package]]
 name = "ruma-signatures"
 version = "0.15.0"
-source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=e087ff15888156942ca2ffe6097d1b4c3fd27628#e087ff15888156942ca2ffe6097d1b4c3fd27628"
+source = "git+https://forgejo.ellis.link/continuwuation/ruwuma?rev=a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf#a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf"
 dependencies = [
  "base64 0.22.1",
  "ed25519-dalek",

Cargo.toml

@@ -343,7 +343,7 @@ version = "0.1.2"
 [workspace.dependencies.ruma]
 git = "https://forgejo.ellis.link/continuwuation/ruwuma"
 #branch = "conduwuit-changes"
-rev = "e087ff15888156942ca2ffe6097d1b4c3fd27628"
+rev = "a4b5e89f4951c87e903ef224c2d1c2c4ef1ebeaf"
 features = [
     "compat",
     "rand",

changelog.d/1441.bugfix

@@ -0,0 +1 @@
+Removed the `allow_public_room_directory_without_auth` config option. Contributed by @0xnim.

changelog.d/1442.feature

@@ -0,0 +1 @@
+Implement MSC4143 MatrixRTC transport discovery endpoint. Move RTC foci configuration from `[global.well_known]` to a new `[global.matrix_rtc]` section with a `foci` field. Contributed by @0xnim

changelog.d/1445.bugfix

@@ -0,0 +1 @@
+Fixed sliding sync v5 list ranges always starting from 0, causing extra rooms to be unnecessarily processed and returned. Contributed by @0xnim

complement/complement.config.toml

@@ -9,7 +9,6 @@ address = "0.0.0.0"
 allow_device_name_federation = true
 allow_guest_registration = true
 allow_public_room_directory_over_federation = true
-allow_public_room_directory_without_auth = true
 allow_registration = true
 database_path = "/database"
 log = "trace,h2=debug,hyper=debug"

conduwuit-example.toml

@@ -546,12 +546,6 @@
 #
 #allow_public_room_directory_over_federation = false
 
-# Set this to true to allow your server's public room directory to be
-# queried without client authentication (access token) through the Client
-# APIs. Set this to false to protect against /publicRooms spiders.
-#
-#allow_public_room_directory_without_auth = false
-
 # Allow guests/unauthenticated users to access TURN credentials.
 #
 # This is the equivalent of Synapse's `turn_allow_guests` config option.
@@ -1850,14 +1844,13 @@
 #
 #support_mxid =
 
-# A list of MatrixRTC foci URLs which will be served as part of the
+# **DEPRECATED**: Use `[global.matrix_rtc].foci` instead.
-# MSC4143 client endpoint at /.well-known/matrix/client.  If you're
-# setting up livekit, you'd want something like:
-# rtc_focus_server_urls = [
-#     { type = "livekit", livekit_service_url = "https://livekit.example.com" },
-# ]
 #
-# To disable, set this to be an empty vector (`[]`).
+# A list of MatrixRTC foci URLs which will be served as part of the
+# MSC4143 client endpoint at /.well-known/matrix/client.
+#
+# This option is deprecated and will be removed in a future release.
+# Please migrate to the new `[global.matrix_rtc]` config section.
 #
 #rtc_focus_server_urls = []
 
@@ -1879,6 +1872,23 @@
 #
 #blurhash_max_raw_size = 33554432
 
+[global.matrix_rtc]
+
+# A list of MatrixRTC foci (transports) which will be served via the
+# MSC4143 RTC transports endpoint at
+# `/_matrix/client/v1/rtc/transports`. If you're setting up livekit,
+# you'd want something like:
+# ```toml
+# [global.matrix_rtc]
+# foci = [
+#     { type = "livekit", livekit_service_url = "https://livekit.example.com" },
+# ]
+# ```
+#
+# To disable, set this to an empty list (`[]`).
+#
+#foci = []
+
 [global.ldap]
 
 # Whether to enable LDAP login.

docs/calls/livekit.mdx

@@ -78,47 +78,19 @@ You will need to allow ports `7881/tcp` and `50100:50200/udp` through your firew
 
 ### 3. Telling clients where to find LiveKit
 
-To tell clients where to find LiveKit, you need to add the address of your `lk-jwt-service` to your client .well-known file. To do so, in the config section `global.well-known`, add (or modify) the option `rtc_focus_server_urls`.
+To tell clients where to find LiveKit, you need to add the address of your `lk-jwt-service` to the `[global.matrix_rtc]` config section using the `foci` option.
 
-The variable should be a list of servers serving as MatrixRTC endpoints to serve in the well-known file to the client.
+The variable should be a list of servers serving as MatrixRTC endpoints. Clients discover these via the `/_matrix/client/v1/rtc/transports` endpoint (MSC4143).
 
 ```toml
-rtc_focus_server_urls = [
+[global.matrix_rtc]
+foci = [
     { type = "livekit", livekit_service_url = "https://livekit.example.com" },
 ]
 ```
 
 Remember to replace the URL with the address you are deploying your instance of lk-jwt-service to.
 
-#### Serving .well-known manually
-
-If you don't let Continuwuity serve your `.well-known` files, you need to add the following lines to your `.well-known/matrix/client` file, remembering to replace the URL with your own `lk-jwt-service` deployment:
-
-```json
-  "org.matrix.msc4143.rtc_foci": [
-    {
-      "type": "livekit",
-      "livekit_service_url": "https://livekit.example.com"
-    }
-  ]
-```
-
-The final file should look something like this:
-
-```json
-{
-  "m.homeserver": {
-    "base_url":"https://matrix.example.com"
-  },
-  "org.matrix.msc4143.rtc_foci": [
-    {
-      "type": "livekit",
-      "livekit_service_url": "https://livekit.example.com"
-    }
-  ]
-}
-```
-
 ### 4. Configure your Reverse Proxy
 
 Reverse proxies can be configured in many different ways - so we can't provide a step by step for this.

src/admin/media/commands.rs

@@ -29,7 +29,9 @@ pub(super) async fn delete(
 			.delete(&mxc.as_str().try_into()?)
 			.await?;
 
-		return Err!("Deleted the MXC from our database and on our filesystem.",);
+		return self
+			.write_str("Deleted the MXC from our database and on our filesystem.")
+			.await;
 	}
 
 	if let Some(event_id) = event_id {

src/api/client/sync/v5.rs

@@ -336,7 +336,9 @@ where
 		let ranges = list.ranges.clone();
 
 		for mut range in ranges {
-			range.0 = uint!(0);
+			range.0 = range
+				.0
+				.min(UInt::try_from(active_rooms.len()).unwrap_or(UInt::MAX));
 			range.1 = range.1.checked_add(uint!(1)).unwrap_or(range.1);
 			range.1 = range
 				.1

src/api/client/well_known.rs

@@ -27,10 +27,32 @@ pub(crate) async fn well_known_client(
 		identity_server: None,
 		sliding_sync_proxy: Some(SlidingSyncProxyInfo { url: client_url }),
 		tile_server: None,
-		rtc_foci: services.config.well_known.rtc_focus_server_urls.clone(),
+		rtc_foci: services
+			.config
+			.matrix_rtc
+			.effective_foci(&services.config.well_known.rtc_focus_server_urls)
+			.to_vec(),
 	})
 }
 
+/// # `GET /_matrix/client/v1/rtc/transports`
+/// # `GET /_matrix/client/unstable/org.matrix.msc4143/rtc/transports`
+///
+/// Returns the list of MatrixRTC foci (transports) configured for this
+/// homeserver, implementing MSC4143.
+pub(crate) async fn get_rtc_transports(
+	State(services): State<crate::State>,
+	_body: Ruma<ruma::api::client::discovery::get_rtc_transports::Request>,
+) -> Result<ruma::api::client::discovery::get_rtc_transports::Response> {
+	Ok(ruma::api::client::discovery::get_rtc_transports::Response::new(
+		services
+			.config
+			.matrix_rtc
+			.effective_foci(&services.config.well_known.rtc_focus_server_urls)
+			.to_vec(),
+	))
+}
+
 /// # `GET /.well-known/matrix/support`
 ///
 /// Server support contact and support page of a homeserver's domain.

src/api/router.rs

@@ -184,6 +184,7 @@ pub fn build(router: Router<State>, server: &Server) -> Router<State> {
 		.ruma_route(&client::put_suspended_status)
 		.ruma_route(&client::well_known_support)
 		.ruma_route(&client::well_known_client)
+		.ruma_route(&client::get_rtc_transports)
 		.route("/_conduwuit/server_version", get(client::conduwuit_server_version))
 		.route("/_continuwuity/server_version", get(client::conduwuit_server_version))
 		.ruma_route(&client::room_initial_sync_route)

src/api/router/auth.rs

@@ -4,7 +4,7 @@ use axum_extra::{
 	headers::{Authorization, authorization::Bearer},
 	typed_header::TypedHeaderRejectionReason,
 };
-use conduwuit::{Err, Error, Result, debug_error, err, warn};
+use conduwuit::{Err, Error, Result, debug_error, debug_info, err, warn};
 use futures::{
 	TryFutureExt,
 	future::{
@@ -67,23 +67,17 @@ pub(super) async fn auth(
 	if metadata.authentication == AuthScheme::None {
 		match metadata {
 			| &get_public_rooms::v3::Request::METADATA => {
-				if !services
+				match token {
-					.server
+					| Token::Appservice(_) | Token::User(_) => {
-					.config
+						// we should have validated the token above
-					.allow_public_room_directory_without_auth
+						// already
-				{
+					},
-					match token {
+					| Token::None | Token::Invalid => {
-						| Token::Appservice(_) | Token::User(_) => {
+						return Err(Error::BadRequest(
-							// we should have validated the token above
+							ErrorKind::MissingToken,
-							// already
+							"Missing or invalid access token.",
-						},
+						));
-						| Token::None | Token::Invalid => {
+					},
-							return Err(Error::BadRequest(
-								ErrorKind::MissingToken,
-								"Missing or invalid access token.",
-							));
-						},
-					}
 				}
 			},
 			| &get_profile::v3::Request::METADATA
@@ -335,6 +329,14 @@ async fn auth_server(
 		return Err!(Request(Forbidden("Failed to verify X-Matrix signatures.")));
 	}
 
+	if services.sending.server_is_offline(destination).await {
+		debug_info!(?destination, "server returned from being offline");
+		services
+			.sending
+			.mark_server_online(destination, false)
+			.await;
+	}
+
 	Ok(Auth {
 		origin: origin.to_owned().into(),
 		sender_user: None,

src/core/config/mod.rs

@@ -678,12 +678,6 @@ pub struct Config {
 	#[serde(default)]
 	pub allow_public_room_directory_over_federation: bool,
 
-	/// Set this to true to allow your server's public room directory to be
-	/// queried without client authentication (access token) through the Client
-	/// APIs. Set this to false to protect against /publicRooms spiders.
-	#[serde(default)]
-	pub allow_public_room_directory_without_auth: bool,
-
 	/// Allow guests/unauthenticated users to access TURN credentials.
 	///
 	/// This is the equivalent of Synapse's `turn_allow_guests` config option.
@@ -2086,6 +2080,12 @@ pub struct Config {
 	/// display: nested
 	#[serde(default)]
 	pub blurhashing: BlurhashConfig,
+
+	/// Configuration for MatrixRTC (MSC4143) transport discovery.
+	/// display: nested
+	#[serde(default)]
+	pub matrix_rtc: MatrixRtcConfig,
+
 	#[serde(flatten)]
 	#[allow(clippy::zero_sized_map_values)]
 	// this is a catchall, the map shouldn't be zero at runtime
@@ -2151,17 +2151,16 @@ pub struct WellKnownConfig {
 	/// listed.
 	pub support_mxid: Option<OwnedUserId>,
 
-	/// A list of MatrixRTC foci URLs which will be served as part of the
+	/// **DEPRECATED**: Use `[global.matrix_rtc].foci` instead.
-	/// MSC4143 client endpoint at /.well-known/matrix/client.  If you're
-	/// setting up livekit, you'd want something like:
-	/// rtc_focus_server_urls = [
-	///     { type = "livekit", livekit_service_url = "https://livekit.example.com" },
-	/// ]
 	///
-	/// To disable, set this to be an empty vector (`[]`).
+	/// A list of MatrixRTC foci URLs which will be served as part of the
+	/// MSC4143 client endpoint at /.well-known/matrix/client.
+	///
+	/// This option is deprecated and will be removed in a future release.
+	/// Please migrate to the new `[global.matrix_rtc]` config section.
 	///
 	/// default: []
-	#[serde(default = "default_rtc_focus_urls")]
+	#[serde(default)]
 	pub rtc_focus_server_urls: Vec<RtcFocusInfo>,
 }
 
@@ -2190,6 +2189,43 @@ pub struct BlurhashConfig {
 	pub blurhash_max_raw_size: u64,
 }
 
+#[derive(Clone, Debug, Deserialize, Default)]
+#[config_example_generator(filename = "conduwuit-example.toml", section = "global.matrix_rtc")]
+pub struct MatrixRtcConfig {
+	/// A list of MatrixRTC foci (transports) which will be served via the
+	/// MSC4143 RTC transports endpoint at
+	/// `/_matrix/client/v1/rtc/transports`. If you're setting up livekit,
+	/// you'd want something like:
+	/// ```toml
+	/// [global.matrix_rtc]
+	/// foci = [
+	///     { type = "livekit", livekit_service_url = "https://livekit.example.com" },
+	/// ]
+	/// ```
+	///
+	/// To disable, set this to an empty list (`[]`).
+	///
+	/// default: []
+	#[serde(default)]
+	pub foci: Vec<RtcFocusInfo>,
+}
+
+impl MatrixRtcConfig {
+	/// Returns the effective foci, falling back to the deprecated
+	/// `rtc_focus_server_urls` if the new config is empty.
+	#[must_use]
+	pub fn effective_foci<'a>(
+		&'a self,
+		deprecated_foci: &'a [RtcFocusInfo],
+	) -> &'a [RtcFocusInfo] {
+		if !self.foci.is_empty() {
+			&self.foci
+		} else {
+			deprecated_foci
+		}
+	}
+}
+
 #[derive(Clone, Debug, Default, Deserialize)]
 #[config_example_generator(filename = "conduwuit-example.toml", section = "global.ldap")]
 pub struct LdapConfig {
@@ -2383,6 +2419,7 @@ const DEPRECATED_KEYS: &[&str] = &[
 	"well_known_support_email",
 	"well_known_support_mxid",
 	"registration_token_file",
+	"well_known.rtc_focus_server_urls",
 ];
 
 impl Config {
@@ -2666,9 +2703,6 @@ fn default_rocksdb_stats_level() -> u8 { 1 }
 #[inline]
 pub fn default_default_room_version() -> RoomVersionId { RoomVersionId::V11 }
 
-#[must_use]
-pub fn default_rtc_focus_urls() -> Vec<RtcFocusInfo> { vec![] }
-
 fn default_ip_range_denylist() -> Vec<String> {
 	vec![
 		"127.0.0.0/8".to_owned(),

src/service/sending/mod.rs

@@ -5,6 +5,7 @@ mod dest;
 mod sender;
 
 use std::{
+	collections::HashSet,
 	fmt::Debug,
 	hash::{DefaultHasher, Hash, Hasher},
 	iter::once,
@@ -19,8 +20,8 @@ use conduwuit::{
 	warn,
 };
 use futures::{FutureExt, Stream, StreamExt};
-use ruma::{RoomId, ServerName, UserId, api::OutgoingRequest};
+use ruma::{OwnedServerName, RoomId, ServerName, UserId, api::OutgoingRequest};
-use tokio::{task, task::JoinSet};
+use tokio::{sync::RwLock, task, task::JoinSet};
 
 use self::data::Data;
 pub use self::{
@@ -37,6 +38,7 @@ pub struct Service {
 	server: Arc<Server>,
 	services: Services,
 	channels: Vec<(loole::Sender<Msg>, loole::Receiver<Msg>)>,
+	pub offline_servers: RwLock<HashSet<OwnedServerName>>,
 }
 
 struct Services {
@@ -52,6 +54,7 @@ struct Services {
 	account_data: Dep<account_data::Service>,
 	appservice: Dep<crate::appservice::Service>,
 	pusher: Dep<pusher::Service>,
+	resolver: Dep<crate::resolver::Service>,
 	federation: Dep<federation::Service>,
 }
 
@@ -96,9 +99,11 @@ impl crate::Service for Service {
 				account_data: args.depend::<account_data::Service>("account_data"),
 				appservice: args.depend::<crate::appservice::Service>("appservice"),
 				pusher: args.depend::<pusher::Service>("pusher"),
+				resolver: args.depend::<crate::resolver::Service>("resolver"),
 				federation: args.depend::<federation::Service>("federation"),
 			},
 			channels: (0..num_senders).map(|_| loole::unbounded()).collect(),
+			offline_servers: RwLock::new(HashSet::new()),
 		}))
 	}
 
@@ -146,6 +151,8 @@ impl crate::Service for Service {
 	fn name(&self) -> &str { crate::service::make_name(std::module_path!()) }
 
 	fn unconstrained(&self) -> bool { true }
+
+	async fn clear_cache(&self) { self.offline_servers.write().await.clear(); }
 }
 
 impl Service {
@@ -379,6 +386,39 @@ impl Service {
 		let chans = self.channels.len().max(1);
 		hash.overflowing_rem(chans).0
 	}
+
+	/// Marks a server as offline
+	pub async fn mark_server_offline(&self, server: OwnedServerName) {
+		self.offline_servers.write().await.insert(server);
+	}
+
+	/// Marks a server as online again and flushes the senders if it was
+	/// previously marked as offline
+	pub async fn mark_server_online(&self, server: &ServerName, skip_flush: bool) {
+		if self.offline_servers.write().await.remove(server) && !skip_flush {
+			// Flush the senders if this server was previously offline
+			self.services.resolver.cache.del_destination(server);
+			self.services.resolver.cache.del_override(server);
+			self.dispatch(Msg {
+				dest: Destination::Federation(server.to_owned()),
+				event: SendingEvent::Flush,
+				queue_id: Vec::<u8>::new(),
+			})
+			.inspect_err(|e| {
+				error!(
+					?server,
+					?e,
+					"failed to dispatch flush message for server coming back online"
+				);
+			})
+			.ok();
+		}
+	}
+
+	/// Checks if a server is currently marked as offline
+	pub async fn server_is_offline(&self, server: &ServerName) -> bool {
+		self.offline_servers.read().await.contains(server)
+	}
 }
 
 fn num_senders(args: &crate::Args<'_>) -> usize {

src/service/sending/sender.rs

@@ -9,6 +9,7 @@ use std::{
 };
 
 use base64::{Engine as _, engine::general_purpose::URL_SAFE_NO_PAD};
+use conduwuit::debug_warn;
 use conduwuit_core::{
 	Error, Event, Result, debug, err, error,
 	result::LogErr,
@@ -135,7 +136,13 @@ impl Service {
 	) {
 		match response {
 			| Ok(dest) => self.handle_response_ok(&dest, futures, statuses).await,
-			| Err((dest, e)) => Self::handle_response_err(dest, statuses, &e),
+			| Err((dest, e)) => {
+				Self::handle_response_err(dest.clone(), statuses, &e);
+				if let Destination::Federation(server_name) = dest {
+					debug_warn!(?server_name, "marking server offline due to error: {e:?}");
+					self.mark_server_offline(server_name).await;
+				}
+			},
 		}
 	}
 
@@ -180,6 +187,12 @@ impl Service {
 		} else {
 			statuses.remove(dest);
 		}
+		if let Destination::Federation(server_name) = dest {
+			self.mark_server_online(server_name, true).await;
+			// We skip the flush here because we were already able to contact
+			// the server, and have queued any pending events, and the
+			// resolver cache will be fine.
+		}
 	}
 
 	#[allow(clippy::needless_pass_by_ref_mut)]
@@ -190,6 +203,9 @@ impl Service {
 		futures: &mut SendingFutures<'a>,
 		statuses: &mut CurTransactionStatus,
 	) {
+		if msg.event == SendingEvent::Flush {
+			statuses.remove(&msg.dest);
+		}
 		let iv = vec![(msg.queue_id, msg.event)];
 		if let Ok(Some(events)) = self.select_events(&msg.dest, iv, statuses).await {
 			if !events.is_empty() {