fix: Enforce limits when joining rooms

Also, don't take read receipts into consideration for lazy loading.
Synapse doesn't do this and they're making initial syncs very large.

.forgejo/actions/upload-docker-artifacts/action.yml

@@ -54,7 +54,7 @@ runs:
       run: mv /tmp/binaries/sbin/conduwuit /tmp/binaries/conduwuit${{ inputs.cpu_suffix }}-${{ inputs.slug }}${{ inputs.artifact_suffix }}
 
     - name: Upload binary artifact
-      uses: forgejo/upload-artifact@v4
+      uses: forgejo/upload-artifact@v3
       with:
         name: conduwuit${{ inputs.cpu_suffix }}-${{ inputs.slug }}${{ inputs.artifact_suffix }}
         path: /tmp/binaries/conduwuit${{ inputs.cpu_suffix }}-${{ inputs.slug }}${{ inputs.artifact_suffix }}
@@ -62,7 +62,7 @@ runs:
 
     - name: Upload digest
       if: ${{ env.BUILTIN_REGISTRY_ENABLED == 'true' }}
-      uses: forgejo/upload-artifact@v4
+      uses: forgejo/upload-artifact@v3
       with:
         name: digests${{ inputs.digest_suffix }}-${{ inputs.slug }}${{ inputs.cpu_suffix }}
         path: /tmp/digests/*

.forgejo/workflows/build-debian.yml

@@ -126,7 +126,7 @@ jobs:
           [ -f /etc/conduwuit/conduwuit.toml ] && echo "✅ Config file installed"
 
       - name: Upload deb artifact
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v3
         with:
           name: continuwuity-${{ steps.debian-version.outputs.distribution }}
           path: ${{ steps.cargo-deb.outputs.path }}

.forgejo/workflows/build-fedora.yml

@@ -238,13 +238,13 @@ jobs:
           cp $BIN_RPM upload-bin/
 
       - name: Upload binary RPM
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v3
         with:
           name: continuwuity
           path: upload-bin/
 
       - name: Upload debug RPM artifact
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v3
         with:
           name: continuwuity-debug
           path: artifacts/*debuginfo*.rpm

.forgejo/workflows/element.yml

@@ -109,7 +109,7 @@ jobs:
           cat ./element-web/webapp/config.json
 
       - name: 📤 Upload Artifact
-        uses: forgejo/upload-artifact@v4
+        uses: forgejo/upload-artifact@v3
         with:
           name: element-web
           path: ./element-web/webapp/

docs/public/.well-known/matrix/client

@@ -1 +1 @@
-{"m.homeserver":{"base_url": "https://matrix.continuwuity.org"},"org.matrix.msc3575.proxy":{"url": "https://matrix.continuwuity.org"}}
+{"m.homeserver":{"base_url": "https://matrix.continuwuity.org"},"org.matrix.msc3575.proxy":{"url": "https://matrix.continuwuity.org"},"org.matrix.msc4143.rtc_foci":[{"type":"livekit","livekit_service_url":"https://livekit.ellis.link"}]}

src/api/client/membership/join.rs

@@ -44,6 +44,7 @@
 	rooms::{
 		state::RoomMutexGuard,
 		state_compressor::{CompressedState, HashSetCompressStateEvent},
+		timeline::pdu_fits,
 	},
 };
 
@@ -573,6 +574,13 @@ async fn join_room_by_id_helper_remote(
 					return state;
 				},
 			};
+			if !pdu_fits(&mut value.clone()) {
+				warn!(
+					"dropping incoming PDU {event_id} in room {room_id} from room join because \
+					 it exceeds 65535 bytes or is otherwise too large."
+				);
+				return state;
+			}
 			services.rooms.outlier.add_pdu_outlier(&event_id, &value);
 			if let Some(state_key) = &pdu.state_key {
 				let shortstatekey = services

src/api/client/message.rs

@@ -1,4 +1,5 @@
 use axum::extract::State;
+use axum_client_ip::InsecureClientIp;
 use conduwuit::{
 	Err, Result, at,
 	matrix::{
@@ -70,6 +71,7 @@
 ///   where the user was joined, depending on `history_visibility`)
 pub(crate) async fn get_message_events_route(
 	State(services): State<crate::State>,
+	InsecureClientIp(client_ip): InsecureClientIp,
 	body: Ruma<get_message_events::v3::Request>,
 ) -> Result<get_message_events::v3::Response> {
 	debug_assert!(IGNORED_MESSAGE_TYPES.is_sorted(), "IGNORED_MESSAGE_TYPES is not sorted");
@@ -78,6 +80,11 @@ pub(crate) async fn get_message_events_route(
 	let room_id = &body.room_id;
 	let filter = &body.filter;
 
+	services
+		.users
+		.update_device_last_seen(sender_user, sender_device, client_ip)
+		.await;
+
 	if !services.rooms.metadata.exists(room_id).await {
 		return Err!(Request(Forbidden("Room does not exist to this server")));
 	}

src/api/client/read_marker.rs

@@ -1,6 +1,7 @@
 use std::collections::BTreeMap;
 
 use axum::extract::State;
+use axum_client_ip::InsecureClientIp;
 use conduwuit::{Err, PduCount, Result, err};
 use ruma::{
 	MilliSecondsSinceUnixEpoch,
@@ -118,9 +119,14 @@ pub(crate) async fn set_read_marker_route(
 /// Sets private read marker and public read receipt EDU.
 pub(crate) async fn create_receipt_route(
 	State(services): State<crate::State>,
+	InsecureClientIp(client_ip): InsecureClientIp,
 	body: Ruma<create_receipt::v3::Request>,
 ) -> Result<create_receipt::v3::Response> {
 	let sender_user = body.sender_user();
+	services
+		.users
+		.update_device_last_seen(sender_user, body.sender_device.as_deref(), client_ip)
+		.await;
 
 	if matches!(
 		&body.receipt_type,

src/api/client/redact.rs

@@ -1,4 +1,5 @@
 use axum::extract::State;
+use axum_client_ip::InsecureClientIp;
 use conduwuit::{Err, Result, matrix::pdu::PduBuilder};
 use ruma::{
 	api::client::redact::redact_event, events::room::redaction::RoomRedactionEventContent,
@@ -13,9 +14,14 @@
 /// - TODO: Handle txn id
 pub(crate) async fn redact_event_route(
 	State(services): State<crate::State>,
+	InsecureClientIp(client_ip): InsecureClientIp,
 	body: Ruma<redact_event::v3::Request>,
 ) -> Result<redact_event::v3::Response> {
 	let sender_user = body.sender_user();
+	services
+		.users
+		.update_device_last_seen(sender_user, body.sender_device.as_deref(), client_ip)
+		.await;
 	let body = &body.body;
 	if services.users.is_suspended(sender_user).await? {
 		// TODO: Users can redact their own messages while suspended

src/api/client/send.rs

@@ -1,6 +1,7 @@
 use std::collections::BTreeMap;
 
 use axum::extract::State;
+use axum_client_ip::InsecureClientIp;
 use conduwuit::{Err, Result, err, matrix::pdu::PduBuilder, utils};
 use ruma::{api::client::message::send_message_event, events::MessageLikeEventType};
 use serde_json::from_str;
@@ -18,6 +19,7 @@
 ///   allowed
 pub(crate) async fn send_message_event_route(
 	State(services): State<crate::State>,
+	InsecureClientIp(client_ip): InsecureClientIp,
 	body: Ruma<send_message_event::v3::Request>,
 ) -> Result<send_message_event::v3::Response> {
 	let sender_user = body.sender_user();
@@ -27,6 +29,11 @@ pub(crate) async fn send_message_event_route(
 		return Err!(Request(UserSuspended("You cannot perform this action while suspended.")));
 	}
 
+	services
+		.users
+		.update_device_last_seen(sender_user, body.sender_device.as_deref(), client_ip)
+		.await;
+
 	// Forbid m.room.encrypted if encryption is disabled
 	if MessageLikeEventType::RoomEncrypted == body.event_type && !services.config.allow_encryption
 	{

src/api/client/state.rs

@@ -1,4 +1,5 @@
 use axum::extract::State;
+use axum_client_ip::InsecureClientIp;
 use conduwuit::{
 	Err, Result, err,
 	matrix::{Event, pdu::PduBuilder},
@@ -7,7 +8,7 @@
 use conduwuit_service::Services;
 use futures::{FutureExt, TryStreamExt};
 use ruma::{
-	OwnedEventId, RoomId, UserId,
+	MilliSecondsSinceUnixEpoch, OwnedEventId, RoomId, UserId,
 	api::client::state::{get_state_events, get_state_events_for_key, send_state_event},
 	events::{
 		AnyStateEventContent, StateEventType,
@@ -30,9 +31,14 @@
 /// Sends a state event into the room.
 pub(crate) async fn send_state_event_for_key_route(
 	State(services): State<crate::State>,
+	InsecureClientIp(ip): InsecureClientIp,
 	body: Ruma<send_state_event::v3::Request>,
 ) -> Result<send_state_event::v3::Response> {
 	let sender_user = body.sender_user();
+	services
+		.users
+		.update_device_last_seen(sender_user, body.sender_device.as_deref(), ip)
+		.await;
 
 	if services.users.is_suspended(sender_user).await? {
 		return Err!(Request(UserSuspended("You cannot perform this action while suspended.")));
@@ -61,9 +67,10 @@ pub(crate) async fn send_state_event_for_key_route(
 /// Sends a state event into the room.
 pub(crate) async fn send_state_event_for_empty_key_route(
 	State(services): State<crate::State>,
+	InsecureClientIp(ip): InsecureClientIp,
 	body: Ruma<send_state_event::v3::Request>,
 ) -> Result<RumaResponse<send_state_event::v3::Response>> {
-	send_state_event_for_key_route(State(services), body)
+	send_state_event_for_key_route(State(services), InsecureClientIp(ip), body)
 		.boxed()
 		.await
 		.map(RumaResponse)
@@ -185,7 +192,7 @@ async fn send_state_event_for_key_helper(
 	event_type: &StateEventType,
 	json: &Raw<AnyStateEventContent>,
 	state_key: &str,
-	timestamp: Option<ruma::MilliSecondsSinceUnixEpoch>,
+	timestamp: Option<MilliSecondsSinceUnixEpoch>,
 ) -> Result<OwnedEventId> {
 	allowed_to_send_state_event(services, room_id, event_type, state_key, json).await?;
 	let state_lock = services.rooms.state.mutex.lock(room_id).await;

src/api/client/sync/v3/mod.rs

@@ -9,6 +9,7 @@
 };
 
 use axum::extract::State;
+use axum_client_ip::InsecureClientIp;
 use conduwuit::{
 	Result, extract_variant,
 	utils::{
@@ -180,6 +181,7 @@ fn lazy_loading_enabled(&self) -> bool {
 )]
 pub(crate) async fn sync_events_route(
 	State(services): State<crate::State>,
+	InsecureClientIp(client_ip): InsecureClientIp,
 	body: Ruma<sync_events::v3::Request>,
 ) -> Result<sync_events::v3::Response, RumaResponse<UiaaResponse>> {
 	let (sender_user, sender_device) = body.sender();
@@ -192,6 +194,12 @@ pub(crate) async fn sync_events_route(
 			.await?;
 	}
 
+	// Increment the "device last active" metadata
+	services
+		.users
+		.update_device_last_seen(sender_user, Some(sender_device), client_ip)
+		.await;
+
 	// Setup watchers, so if there's no response, we can wait for them
 	let watcher = services.sync.watch(sender_user, sender_device);
 

src/api/client/sync/v5.rs

@@ -6,6 +6,7 @@
 };
 
 use axum::extract::State;
+use axum_client_ip::InsecureClientIp;
 use conduwuit::{
 	Err, Error, Result, at, error, extract_variant, is_equal_to,
 	matrix::{Event, TypeStateKey, pdu::PduCount},
@@ -61,11 +62,18 @@
 /// [MSC4186]: https://github.com/matrix-org/matrix-spec-proposals/pull/4186
 pub(crate) async fn sync_events_v5_route(
 	State(ref services): State<crate::State>,
+	InsecureClientIp(client_ip): InsecureClientIp,
 	body: Ruma<sync_events::v5::Request>,
 ) -> Result<sync_events::v5::Response> {
 	debug_assert!(DEFAULT_BUMP_TYPES.is_sorted(), "DEFAULT_BUMP_TYPES is not sorted");
 	let sender_user = body.sender_user.as_ref().expect("user is authenticated");
 	let sender_device = body.sender_device.as_ref().expect("user is authenticated");
+
+	services
+		.users
+		.update_device_last_seen(sender_user, Some(sender_device), client_ip)
+		.await;
+
 	let mut body = body.body;
 
 	// Setup watchers, so if there's no response, we can wait for them

src/api/client/typing.rs

@@ -1,4 +1,5 @@
 use axum::extract::State;
+use axum_client_ip::InsecureClientIp;
 use conduwuit::{Err, Result, utils, utils::math::Tried};
 use ruma::api::client::typing::create_typing_event;
 
@@ -9,10 +10,15 @@
 /// Sets the typing state of the sender user.
 pub(crate) async fn create_typing_event_route(
 	State(services): State<crate::State>,
+	InsecureClientIp(ip): InsecureClientIp,
 	body: Ruma<create_typing_event::v3::Request>,
 ) -> Result<create_typing_event::v3::Response> {
 	use create_typing_event::v3::Typing;
 	let sender_user = body.sender_user();
+	services
+		.users
+		.update_device_last_seen(sender_user, body.sender_device.as_deref(), ip)
+		.await;
 
 	if sender_user != body.user_id && body.appservice_info.is_none() {
 		return Err!(Request(Forbidden("You cannot update typing status of other users.")));

src/core/matrix/state_res/event_auth.rs

@@ -177,11 +177,6 @@ pub async fn auth_check<E, F, Fut>(
 
 	// [synapse] do_sig_check check the event has valid signatures for member events
 
-	// TODO do_size_check is false when called by `iterative_auth_check`
-	// do_size_check is also mostly accomplished by ruma with the exception of
-	// checking event_type, state_key, and json are below a certain size (255 and
-	// 65_536 respectively)
-
 	let sender = incoming_event.sender();
 
 	// Implementation of https://spec.matrix.org/latest/rooms/v1/#authorization-rules

src/service/globals/mod.rs

@@ -31,12 +31,13 @@ fn build(args: crate::Args<'_>) -> Result<Arc<Self>> {
 
 		let turn_secret = config.turn_secret_file.as_ref().map_or_else(
 			|| config.turn_secret.clone(),
-			|path| {
-				std::fs::read_to_string(path).unwrap_or_else(|e| {
+			|path| match std::fs::read_to_string(path) {
+				| Ok(secret) => secret.trim().to_owned(),
+				| Err(e) => {
 					error!("Failed to read the TURN secret file: {e}");
 
 					config.turn_secret.clone()
-				})
+				},
 			},
 		);
 
@@ -49,7 +50,7 @@ fn build(args: crate::Args<'_>) -> Result<Arc<Self>> {
 					return config.registration_token.clone();
 				};
 
-				Some(token)
+				Some(token.trim().to_owned())
 			},
 		);
 

src/service/migrations.rs

@@ -590,6 +590,10 @@ async fn fix_readreceiptid_readreceipt_duplicates(services: &Services) -> Result
 
 const FIXED_CORRUPT_MSC4133_FIELDS_MARKER: &[u8] = b"fix_corrupt_msc4133_fields";
 async fn fix_corrupt_msc4133_fields(services: &Services) -> Result {
+	// Due to an old bug, some conduwuit databases have `us.cloke.msc4175.tz` user
+	// profile fields with raw strings instead of quoted JSON ones.
+	// This migration fixes that.
+
 	use serde_json::{Value, from_slice};
 	type KeyVal<'a> = ((OwnedUserId, String), &'a [u8]);
 
@@ -606,24 +610,28 @@ async fn fix_corrupt_msc4133_fields(services: &Services) -> Result {
 			async |(mut total, mut fixed),
 			       ((user, key), value): KeyVal<'_>|
 			       -> Result<(usize, usize)> {
-				if let Err(error) = from_slice::<Value>(value) {
-					// Due to an old bug, some conduwuit databases have `us.cloke.msc4175.tz` user
-					// profile fields with raw strings instead of quoted JSON ones.
-					// This migration fixes that.
-					let new_value = if key == "us.cloke.msc4175.tz" {
-						Value::String(String::from_utf8(value.to_vec())?)
-					} else {
-						return Err!(
-							"failed to deserialize msc4133 key {} of user {}: {}",
-							key,
-							user,
-							error
+				match from_slice::<Value>(value) {
+					// corrupted timezone field
+					| Err(_) if key == "us.cloke.msc4175.tz" => {
+						let new_value = Value::String(String::from_utf8(value.to_vec())?);
+						useridprofilekey_value.put((user, key), Json(new_value));
+						fixed = fixed.saturating_add(1);
+					},
+					// corrupted value for some other key
+					| Err(error) => {
+						warn!(
+							"deleting MSC4133 key {} for user {} due to deserialization \
+							 failure: {}",
+							key, user, error
 						);
-					};
-
-					useridprofilekey_value.put((user, key), Json(new_value));
-					fixed = fixed.saturating_add(1);
+						useridprofilekey_value.del((user, key));
+					},
+					// other key with no issues
+					| Ok(_) => {
+						// do nothing
+					},
 				}
+
 				total = total.saturating_add(1);
 
 				Ok((total, fixed))

src/service/rooms/event_handler/handle_incoming_pdu.rs

@@ -14,7 +14,7 @@
 use ruma::{CanonicalJsonValue, EventId, RoomId, ServerName, UserId, events::StateEventType};
 use tracing::debug;
 
-use crate::rooms::timeline::RawPduId;
+use crate::rooms::timeline::{RawPduId, pdu_fits};
 
 /// When receiving an event one needs to:
 /// 0. Check the server is in the room
@@ -62,6 +62,13 @@ pub async fn handle_incoming_pdu<'a>(
 	if let Ok(pdu_id) = self.services.timeline.get_pdu_id(event_id).await {
 		return Ok(Some(pdu_id));
 	}
+	if !pdu_fits(&mut value.clone()) {
+		warn!(
+			"dropping incoming PDU {event_id} in room {room_id} from {origin} because it \
+			 exceeds 65535 bytes or is otherwise too large."
+		);
+		return Err!(Request(TooLarge("PDU is too large")));
+	}
 
 	// 1.1 Check the server is in the room
 	let meta_exists = self.services.metadata.exists(room_id).map(Ok);

src/service/rooms/event_handler/handle_outlier_pdu.rs

@@ -1,7 +1,8 @@
 use std::collections::{BTreeMap, HashMap, hash_map};
 
 use conduwuit::{
-	Err, Event, PduEvent, Result, debug, debug_info, debug_warn, err, implement, state_res, trace,
+	Err, Event, PduEvent, Result, debug, debug_info, debug_warn, err, implement, state_res,
+	trace, warn,
 };
 use futures::future::ready;
 use ruma::{
@@ -10,6 +11,7 @@
 };
 
 use super::{check_room_id, get_room_version_id, to_room_version};
+use crate::rooms::timeline::pdu_fits;
 
 #[implement(super::Service)]
 #[allow(clippy::too_many_arguments)]
@@ -25,6 +27,13 @@ pub(super) async fn handle_outlier_pdu<'a, Pdu>(
 where
 	Pdu: Event + Send + Sync,
 {
+	if !pdu_fits(&mut value.clone()) {
+		warn!(
+			"dropping incoming PDU {event_id} in room {room_id} from {origin} because it \
+			 exceeds 65535 bytes or is otherwise too large."
+		);
+		return Err!(Request(TooLarge("PDU is too large")));
+	}
 	// 1. Remove unsigned field
 	value.remove("unsigned");
 

src/service/rooms/timeline/create.rs

@@ -23,6 +23,40 @@
 
 use super::RoomMutexGuard;
 
+pub fn pdu_fits(owned_obj: &mut CanonicalJsonObject) -> bool {
+	// room IDs, event IDs, senders, types, and state keys must all be <= 255 bytes
+	if let Some(CanonicalJsonValue::String(room_id)) = owned_obj.get("room_id") {
+		if room_id.len() > 255 {
+			return false;
+		}
+	}
+	if let Some(CanonicalJsonValue::String(event_id)) = owned_obj.get("event_id") {
+		if event_id.len() > 255 {
+			return false;
+		}
+	}
+	if let Some(CanonicalJsonValue::String(sender)) = owned_obj.get("sender") {
+		if sender.len() > 255 {
+			return false;
+		}
+	}
+	if let Some(CanonicalJsonValue::String(kind)) = owned_obj.get("type") {
+		if kind.len() > 255 {
+			return false;
+		}
+	}
+	if let Some(CanonicalJsonValue::String(state_key)) = owned_obj.get("state_key") {
+		if state_key.len() > 255 {
+			return false;
+		}
+	}
+	// Now check the full PDU size
+	match serde_json::to_string(owned_obj) {
+		| Ok(s) => s.len() <= 65535,
+		| Err(_) => false,
+	}
+}
+
 #[implement(super::Service)]
 pub async fn create_hash_and_sign_event(
 	&self,
@@ -148,19 +182,6 @@ fn from_evt(
 		}
 	}
 
-	// if event_type != TimelineEventType::RoomCreate && prev_events.is_empty() {
-	// 	return Err!(Request(Unknown("Event incorrectly had zero prev_events.")));
-	// }
-	// if state_key.is_none() && depth.lt(&uint!(2)) {
-	// 	// The first two events in a room are always m.room.create and
-	// m.room.member, 	// so any other events with that same depth are illegal.
-	// 	warn!(
-	// 		"Had unsafe depth {depth} when creating non-state event in {}. Cowardly
-	// aborting", 		room_id.expect("room_id is Some here").as_str()
-	// 	);
-	// 	return Err!(Request(Unknown("Unsafe depth for non-state event.")));
-	// }
-
 	let mut pdu = PduEvent {
 		event_id: ruma::event_id!("$thiswillbefilledinlater").into(),
 		room_id: room_id.map(ToOwned::to_owned),
@@ -269,8 +290,16 @@ fn from_evt(
 	}
 	// Generate event id
 	pdu.event_id = gen_event_id(&pdu_json, &room_version_id)?;
-	// Check with the policy server
 	pdu_json.insert("event_id".into(), CanonicalJsonValue::String(pdu.event_id.clone().into()));
+	// Verify that the *full* PDU isn't over 64KiB.
+	// Ruma only validates that it's under 64KiB before signing and hashing.
+	// Has to be cloned to prevent mutating pdu_json itself :(
+	if !pdu_fits(&mut pdu_json.clone()) {
+		// feckin huge PDU mate
+		return Err!(Request(TooLarge("Message/PDU is too long (exceeds 65535 bytes)")));
+	}
+
+	// Check with the policy server
 	if room_id.is_some() {
 		trace!(
 			"Checking event in room {} with policy server",

src/service/rooms/timeline/mod.rs

@@ -26,7 +26,7 @@
 use serde::Deserialize;
 
 use self::data::Data;
-pub use self::data::PdusIterItem;
+pub use self::{create::pdu_fits, data::PdusIterItem};
 use crate::{
 	Dep, account_data, admin, appservice, globals, pusher, rooms, sending, server_keys, users,
 };

src/service/users/mod.rs

@@ -1,6 +1,6 @@
 #[cfg(feature = "ldap")]
 use std::collections::HashMap;
-use std::{collections::BTreeMap, mem, sync::Arc};
+use std::{collections::BTreeMap, mem, net::IpAddr, sync::Arc};
 
 #[cfg(feature = "ldap")]
 use conduwuit::result::LogErr;
@@ -25,6 +25,7 @@
 		invite_permission_config::{FilterLevel, InvitePermissionConfigEvent},
 	},
 	serde::Raw,
+	uint,
 };
 use serde::{Deserialize, Serialize};
 use serde_json::json;
@@ -980,6 +981,7 @@ pub async fn remove_to_device_events<Until>(
 			.await;
 	}
 
+	/// Updates device metadata and increments the device list version.
 	pub async fn update_device_metadata(
 		&self,
 		user_id: &UserId,
@@ -987,13 +989,51 @@ pub async fn update_device_metadata(
 		device: &Device,
 	) -> Result<()> {
 		increment(&self.db.userid_devicelistversion, user_id.as_bytes());
+		self.update_device_metadata_no_increment(user_id, device_id, device)
+			.await
+	}
 
+	// Updates device metadata without incrementing the device list version.
+	// This is namely used for updating the last_seen_ip and last_seen_ts values,
+	// as those do not need a device list version bump due to them not being
+	// relevant to other consumers.
+	pub async fn update_device_metadata_no_increment(
+		&self,
+		user_id: &UserId,
+		device_id: &DeviceId,
+		device: &Device,
+	) -> Result<()> {
 		let key = (user_id, device_id);
 		self.db.userdeviceid_metadata.put(key, Json(device));
 
 		Ok(())
 	}
 
+	pub async fn update_device_last_seen(
+		&self,
+		user_id: &UserId,
+		device_id: Option<&DeviceId>,
+		ip: IpAddr,
+	) {
+		let now = MilliSecondsSinceUnixEpoch::now();
+		if let Some(device_id) = device_id {
+			if let Ok(mut device) = self.get_device_metadata(user_id, device_id).await {
+				device.last_seen_ip = Some(ip.to_string());
+				// If the last update was less than 10 seconds ago, don't update the timestamp
+				if let Some(prev) = device.last_seen_ts {
+					if now.get().saturating_sub(prev.get()) < uint!(10_000) {
+						return;
+					}
+				}
+				device.last_seen_ts = Some(now);
+
+				self.update_device_metadata_no_increment(user_id, device_id, &device)
+					.await
+					.ok();
+			}
+		}
+	}
+
 	/// Get device metadata.
 	pub async fn get_device_metadata(
 		&self,