+ // First check the channel type is known, failing before we do anything else if we don't
+ // support this channel type.
+ let channel_type = if let Some(channel_type) = &msg.channel_type {
+ if channel_type.supports_any_optional_bits() {
+ return Err(ChannelError::Close("Channel Type field contained optional bits - this is not allowed".to_owned()));
+ }
+ if *channel_type != ChannelTypeFeatures::only_static_remote_key() {
+ return Err(ChannelError::Close("Channel Type was not understood".to_owned()));
+ }
+ channel_type.clone()
+ } else {
+ ChannelTypeFeatures::from_counterparty_init(&their_features)
+ };
+ if !channel_type.supports_static_remote_key() {
+ return Err(ChannelError::Close("Channel Type was not understood - we require static remote key".to_owned()));
+ }
+