From ba19d407d0024d4194eb6cb8c6d90da68ba47b5a Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Tue, 9 Sep 2025 04:44:02 +0000
Subject: [PATCH] Add config to control `m.federate` in room create events.
 (fixes #151)

Signed-off-by: Jason Volk <jason@zemos.net>
---
 src/api/client/room/create.rs | 20 ++++++++++++++++++++
 src/core/config/mod.rs        | 13 ++++++++++++-
 tuwunel-example.toml          | 13 ++++++++++++-
 3 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/src/api/client/room/create.rs b/src/api/client/room/create.rs
index 752917c3..ea634e50 100644
--- a/src/api/client/room/create.rs
+++ b/src/api/client/room/create.rs
@@ -413,6 +413,12 @@ async fn create_create_event(
 					))))
 				})?;
 
+			if !services.config.federate_created_rooms {
+				if !services.config.allow_federation || !content.contains_key("m.federate") {
+					content.insert("m.federate".into(), json!(false).try_into()?);
+				}
+			}
+
 			content.insert(
 				"room_version".into(),
 				json!(room_version.as_str())
@@ -428,6 +434,10 @@ async fn create_create_event(
 			let mut content =
 				serde_json::from_str::<CanonicalJsonObject>(to_raw_value(&content)?.get())?;
 
+			if !services.config.federate_created_rooms {
+				content.insert("m.federate".into(), json!(false).try_into()?);
+			}
+
 			content.insert("room_version".into(), json!(room_version.as_str()).try_into()?);
 			content
 		},
@@ -535,6 +545,12 @@ async fn create_create_event_legacy(
 				},
 			}
 
+			if !services.config.federate_created_rooms {
+				if !services.config.allow_federation || !content.contains_key("m.federate") {
+					content.insert("m.federate".into(), json!(false).try_into()?);
+				}
+			}
+
 			content.insert(
 				"room_version".into(),
 				json!(room_version.as_str())
@@ -556,6 +572,10 @@ async fn create_create_event_legacy(
 			let mut content =
 				serde_json::from_str::<CanonicalJsonObject>(to_raw_value(&content)?.get())?;
 
+			if !services.config.federate_created_rooms {
+				content.insert("m.federate".into(), json!(false).try_into()?);
+			}
+
 			content.insert("room_version".into(), json!(room_version.as_str()).try_into()?);
 			content
 		},
diff --git a/src/core/config/mod.rs b/src/core/config/mod.rs
index 1a1035d9..b565d786 100644
--- a/src/core/config/mod.rs
+++ b/src/core/config/mod.rs
@@ -560,10 +560,21 @@ pub struct Config {
 	pub allow_encryption: bool,
 
 	/// Controls whether federation is allowed or not. It is not recommended to
-	/// disable this after the fact due to potential federation breakage.
+	/// disable this after installation due to potential federation breakage but
+	/// this is technically not a permanent setting.
 	#[serde(default = "true_fn")]
 	pub allow_federation: bool,
 
+	/// Sets the default `m.federate` property for newly created rooms when the
+	/// client does not request one. If `allow_federation` is set to false at
+	/// the same this value is set to false it then always overrides the client
+	/// requested `m.federate` value to false.
+	///
+	/// Rooms are fixed to the setting at the time of their creation and can
+	/// never be changed; changing this value only affects new rooms.
+	#[serde(default = "true_fn")]
+	pub federate_created_rooms: bool,
+
 	/// Allows federation requests to be made to itself
 	///
 	/// This isn't intended and is very likely a bug if federation requests are
diff --git a/tuwunel-example.toml b/tuwunel-example.toml
index 6c709665..56129211 100644
--- a/tuwunel-example.toml
+++ b/tuwunel-example.toml
@@ -435,10 +435,21 @@
 #allow_encryption = true
 
 # Controls whether federation is allowed or not. It is not recommended to
-# disable this after the fact due to potential federation breakage.
+# disable this after installation due to potential federation breakage but
+# this is technically not a permanent setting.
 #
 #allow_federation = true
 
+# Sets the default `m.federate` property for newly created rooms when the
+# client does not request one. If `allow_federation` is set to false at
+# the same this value is set to false it then always overrides the client
+# requested `m.federate` value to false.
+#
+# Rooms are fixed to the setting at the time of their creation and can
+# never be changed; changing this value only affects new rooms.
+#
+#federate_created_rooms = true
+
 # Allows federation requests to be made to itself
 #
 # This isn't intended and is very likely a bug if federation requests are