chore(emergency kit): Add option to rollback channel to last stable state

Author: holzeis

coordinator/src/admin.rs

@@ -447,6 +447,50 @@ pub async fn delete_dlc_channel(
     Ok(())
 }
 
+/// This function attempts to roll back a DLC channel to the last stable state!
+/// The action is irreversible, only use if you know what you are doing!
+#[instrument(skip_all, err(Debug))]
+pub async fn roll_back_dlc_channel(
+    Path(channel_id_string): Path<String>,
+    State(state): State<Arc<AppState>>,
+    Query(params): Query<Confirmation>,
+) -> Result<(), AppError> {
+    if !params.i_know_what_i_am_doing.unwrap_or_default() {
+        let error_message =
+            "Looks like you don't know what you are doing! Go and ask your supervisor for help!";
+        tracing::warn!(error_message);
+        return Err(AppError::BadRequest(error_message.to_string()));
+    }
+
+    let channel_id = parse_dlc_channel_id(&channel_id_string)
+        .map_err(|_| AppError::BadRequest("Provided channel ID was invalid".to_string()))?;
+
+    tracing::info!(channel_id = %channel_id_string, "Attempting to roll back dlc channel to last stable state");
+
+    let channel = state
+        .node
+        .inner
+        .get_dlc_channel_by_id(&channel_id)
+        .map_err(|e| AppError::BadRequest(format!("Couldn't find channel. {e:#}")))?;
+    if let Channel::Signed(signed_channel) = channel {
+        state
+            .node
+            .inner
+            .roll_back_channel(&signed_channel)
+            .map_err(|e| {
+                AppError::InternalServerError(format!("Failed to roll back channel. {e:#}"))
+            })?
+    } else {
+        return Err(AppError::BadRequest(
+            "It's only possible to rollback a channel in state signed".to_string(),
+        ));
+    }
+
+    tracing::info!(channel_id = %channel_id_string, "Rolled back dlc channel");
+
+    Ok(())
+}
+
 #[instrument(skip_all, err(Debug))]
 pub async fn sign_message(
     Path(msg): Path<String>,

coordinator/src/routes.rs

@@ -9,6 +9,7 @@ use crate::admin::is_connected;
 use crate::admin::list_dlc_channels;
 use crate::admin::list_on_chain_transactions;
 use crate::admin::list_peers;
+use crate::admin::roll_back_dlc_channel;
 use crate::admin::sign_message;
 use crate::backup::SledBackup;
 use crate::campaign::post_push_campaign;
@@ -172,6 +173,10 @@ pub fn router(
             "/api/admin/dlc_channels/:channel_id",
             delete(delete_dlc_channel),
         )
+        .route(
+            "/api/admin/dlc_channels/rollback/:channel_id",
+            post(roll_back_dlc_channel),
+        )
         .route("/api/admin/transactions", get(list_on_chain_transactions))
         .route("/api/admin/sign/:msg", get(sign_message))
         .route("/api/admin/connect", post(connect_to_peer))

mobile/lib/common/settings/emergency_kit_screen.dart

@@ -181,6 +181,25 @@ class _EmergencyKitScreenState extends State<EmergencyKitScreen> {
                           goRouter.pop();
                         }),
                     const SizedBox(height: 30),
+                    EmergencyKitButton(
+                        icon: const Icon(FontAwesomeIcons.backwardStep),
+                        title: "Rollback channel state",
+                        onPressed: () async {
+                          final messenger = ScaffoldMessenger.of(context);
+                          final orderChangeNotifier = context.read<OrderChangeNotifier>();
+                          final goRouter = GoRouter.of(context);
+
+                          try {
+                            await rust.api.rollBackChannelState();
+                            await orderChangeNotifier.initialize();
+                            showSnackBar(messenger, "Successfully rolled back channel state");
+                          } catch (e) {
+                            showSnackBar(messenger, "Failed to rollback channel state. Error: $e");
+                          }
+
+                          goRouter.pop();
+                        }),
+                    const SizedBox(height: 30),
                     Visibility(
                         visible: config.network == "regtest",
                         child: EmergencyKitButton(

mobile/native/src/api.rs

@@ -819,3 +819,10 @@ pub fn get_new_random_name() -> SyncReturn<String> {
 pub async fn update_nickname(nickname: String) -> Result<()> {
     users::update_username(nickname).await
 }
+
+pub fn roll_back_channel_state() -> Result<()> {
+    tracing::warn!(
+        "Executing emergency kit! Attempting to rollback channel state to last stable state"
+    );
+    ln_dlc::roll_back_channel_state()
+}

mobile/native/src/ln_dlc/mod.rs

@@ -1057,3 +1057,14 @@ fn confirmation_status_to_status_and_timestamp(
 
     (status, timestamp.unix_timestamp() as u64)
 }
+
+pub fn roll_back_channel_state() -> Result<()> {
+    let node = state::get_node();
+
+    let counterparty_pubkey = config::get_coordinator_info().pubkey;
+    let signed_channel = node
+        .inner
+        .get_signed_channel_by_trader_id(counterparty_pubkey)?;
+
+    node.inner.roll_back_channel(&signed_channel)
+}