From 7b73571dabd30c70f860239d1163ada43dc7e242 Mon Sep 17 00:00:00 2001
From: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Fri, 24 Apr 2020 13:36:28 +0100
Subject: [PATCH] Prevent roomserver query API from trying to handle requests
 for stub rooms

---
 roomserver/query/query.go              | 24 ++++++++++++++++++++++++
 roomserver/storage/interface.go        |  1 +
 roomserver/storage/postgres/storage.go | 10 ++++++++++
 roomserver/storage/sqlite3/storage.go  | 10 ++++++++++
 4 files changed, 45 insertions(+)

diff --git a/roomserver/query/query.go b/roomserver/query/query.go
index e9286b4e6..6489a30fd 100644
--- a/roomserver/query/query.go
+++ b/roomserver/query/query.go
@@ -61,6 +61,14 @@ func (r *RoomserverQueryAPI) QueryLatestEventsAndState(
 	if roomNID == 0 {
 		return nil
 	}
+	isStub, err := r.DB.IsRoomStub(ctx, roomNID)
+	if err != nil {
+		return err
+	}
+	if isStub {
+		response.RoomExists = false
+		return nil
+	}
 	response.RoomExists = true
 	response.RoomVersion = roomVersion
 
@@ -121,6 +129,14 @@ func (r *RoomserverQueryAPI) QueryStateAfterEvents(
 	if roomNID == 0 {
 		return nil
 	}
+	isStub, err := r.DB.IsRoomStub(ctx, roomNID)
+	if err != nil {
+		return err
+	}
+	if isStub {
+		response.RoomExists = false
+		return nil
+	}
 	response.RoomExists = true
 	response.RoomVersion = roomVersion
 
@@ -656,6 +672,14 @@ func (r *RoomserverQueryAPI) QueryStateAndAuthChain(
 	if roomNID == 0 {
 		return nil
 	}
+	isStub, err := r.DB.IsRoomStub(ctx, roomNID)
+	if err != nil {
+		return err
+	}
+	if isStub {
+		response.RoomExists = false
+		return nil
+	}
 	response.RoomExists = true
 
 	roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, request.RoomID)
diff --git a/roomserver/storage/interface.go b/roomserver/storage/interface.go
index 0235e51ed..d5ac143bf 100644
--- a/roomserver/storage/interface.go
+++ b/roomserver/storage/interface.go
@@ -83,4 +83,5 @@ type Database interface {
 	GetMembershipEventNIDsForRoom(ctx context.Context, roomNID types.RoomNID, joinOnly bool) ([]types.EventNID, error)
 	EventsFromIDs(ctx context.Context, eventIDs []string) ([]types.Event, error)
 	GetRoomVersionForRoom(ctx context.Context, roomID string) (gomatrixserverlib.RoomVersion, error)
+	IsRoomStub(ctx context.Context, roomNID types.RoomNID) (bool, error)
 }
diff --git a/roomserver/storage/postgres/storage.go b/roomserver/storage/postgres/storage.go
index 6f2b96610..bb06db963 100644
--- a/roomserver/storage/postgres/storage.go
+++ b/roomserver/storage/postgres/storage.go
@@ -772,6 +772,16 @@ func (d *Database) GetRoomVersionForRoomNID(
 	)
 }
 
+func (d *Database) IsRoomStub(
+	ctx context.Context, roomNID types.RoomNID,
+) (bool, error) {
+	nids, _, err := d.statements.selectLatestEventNIDs(ctx, roomNID)
+	if err != nil {
+		return false, err
+	}
+	return len(nids) == 0, nil
+}
+
 type transaction struct {
 	ctx context.Context
 	txn *sql.Tx
diff --git a/roomserver/storage/sqlite3/storage.go b/roomserver/storage/sqlite3/storage.go
index 444a8fdd5..b9b37cbbe 100644
--- a/roomserver/storage/sqlite3/storage.go
+++ b/roomserver/storage/sqlite3/storage.go
@@ -926,6 +926,16 @@ func (d *Database) GetRoomVersionForRoomNID(
 	)
 }
 
+func (d *Database) IsRoomStub(
+	ctx context.Context, roomNID types.RoomNID,
+) (bool, error) {
+	nids, _, err := d.statements.selectLatestEventNIDs(ctx, nil, roomNID)
+	if err != nil {
+		return false, err
+	}
+	return len(nids) == 0, nil
+}
+
 type transaction struct {
 	ctx context.Context
 	txn *sql.Tx