Add RouteBlinding feature flag

The RouteBlinding feature flag is signals support for relaying payments
over blinded paths. It is used for paying BOLT 12 invoices, which are
required to included at least one blinded path.

diff --git a/lightning/src/ln/features.rs b/lightning/src/ln/features.rs
index 08df63e7033b03f92c88aeb8b133a47b6cb8ef2e..df5c0abf25f2a27f8d81589447435b61a15589ef 100644 (file)
--- a/lightning/src/ln/features.rs
+++ b/lightning/src/ln/features.rs
@@ -45,6 +45,8 @@
 //!     and HTLC transactions are pre-signed with zero fee (see
 //!     [BOLT-3](https://github.com/lightning/bolts/blob/master/03-transactions.md) for more
 //!     information).
+//! - `RouteBlinding` - requires/supports that a node can relay payments over blinded paths
+//!     (see [BOLT-4](https://github.com/lightning/bolts/blob/master/04-onion-routing.md#route-blinding) for more information).
 //! - `ShutdownAnySegwit` - requires/supports that future segwit versions are allowed in `shutdown`
 //!     (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md) for more information).
 //! - `OnionMessages` - requires/supports forwarding onion messages
@@ -143,7 +145,7 @@ mod sealed {
                // Byte 2
                BasicMPP | Wumbo | AnchorsNonzeroFeeHtlcTx | AnchorsZeroFeeHtlcTx,
                // Byte 3
-               ShutdownAnySegwit | Taproot,
+               RouteBlinding | ShutdownAnySegwit | Taproot,
                // Byte 4
                OnionMessages,
                // Byte 5
@@ -159,7 +161,7 @@ mod sealed {
                // Byte 2
                BasicMPP | Wumbo | AnchorsNonzeroFeeHtlcTx | AnchorsZeroFeeHtlcTx,
                // Byte 3
-               ShutdownAnySegwit | Taproot,
+               RouteBlinding | ShutdownAnySegwit | Taproot,
                // Byte 4
                OnionMessages,
                // Byte 5
@@ -391,6 +393,9 @@ mod sealed {
        define_feature!(23, AnchorsZeroFeeHtlcTx, [InitContext, NodeContext, ChannelTypeContext],
                "Feature flags for `option_anchors_zero_fee_htlc_tx`.", set_anchors_zero_fee_htlc_tx_optional,
                set_anchors_zero_fee_htlc_tx_required, supports_anchors_zero_fee_htlc_tx, requires_anchors_zero_fee_htlc_tx);
+       define_feature!(25, RouteBlinding, [InitContext, NodeContext],
+               "Feature flags for `option_route_blinding`.", set_route_blinding_optional,
+               set_route_blinding_required, supports_route_blinding, requires_route_blinding);
        define_feature!(27, ShutdownAnySegwit, [InitContext, NodeContext],
                "Feature flags for `opt_shutdown_anysegwit`.", set_shutdown_any_segwit_optional,
                set_shutdown_any_segwit_required, supports_shutdown_anysegwit, requires_shutdown_anysegwit);
@@ -1053,6 +1058,7 @@ mod tests {
                init_features.set_basic_mpp_optional();
                init_features.set_wumbo_optional();
                init_features.set_anchors_zero_fee_htlc_tx_optional();
+               init_features.set_route_blinding_optional();
                init_features.set_shutdown_any_segwit_optional();
                init_features.set_onion_messages_optional();
                init_features.set_channel_type_optional();
@@ -1069,7 +1075,7 @@ mod tests {
                        // - option_data_loss_protect (req)
                        // - var_onion_optin (req) | static_remote_key (req) | payment_secret(req)
                        // - basic_mpp | wumbo | option_anchors_zero_fee_htlc_tx
-                       // - opt_shutdown_anysegwit
+                       // - option_route_blinding | opt_shutdown_anysegwit
                        // - onion_messages
                        // - option_channel_type | option_scid_alias
                        // - option_zeroconf
@@ -1077,7 +1083,7 @@ mod tests {
                        assert_eq!(node_features.flags[0], 0b00000001);
                        assert_eq!(node_features.flags[1], 0b01010001);
                        assert_eq!(node_features.flags[2], 0b10001010);
-                       assert_eq!(node_features.flags[3], 0b00001000);
+                       assert_eq!(node_features.flags[3], 0b00001010);
                        assert_eq!(node_features.flags[4], 0b10000000);
                        assert_eq!(node_features.flags[5], 0b10100000);
                        assert_eq!(node_features.flags[6], 0b00001000);