Negotiate `scid_alias` for private channels based on a new config

[rust-lightning] / lightning / src / util / config.rs

diff --git a/lightning/src/util/config.rs b/lightning/src/util/config.rs
index 55d506e79f145a386919ecce11f54ea7adbb432f..bd8b40b66567e8a5346e8e551568aaf1d539eae5 100644 (file)
--- a/lightning/src/util/config.rs
+++ b/lightning/src/util/config.rs
@@ -47,6 +47,28 @@ pub struct ChannelHandshakeConfig {
        /// Default value: 1. If the value is less than 1, it is ignored and set to 1, as is required
        /// by the protocol.
        pub our_htlc_minimum_msat: u64,
+       /// If set, we attempt to negotiate the `scid_privacy` (referred to as `scid_alias` in the
+       /// BOLTs) option for outbound private channels. This provides better privacy by not including
+       /// our real on-chain channel UTXO in each invoice and requiring that our counterparty only
+       /// relay HTLCs to us using the channel's SCID alias.
+       ///
+       /// If this option is set, channels may be created that will not be readable by LDK versions
+       /// prior to 0.0.106, causing [`ChannelManager`]'s read method to return a
+       /// [`DecodeError:InvalidValue`].
+       ///
+       /// Note that setting this to true does *not* prevent us from opening channels with
+       /// counterparties that do not support the `scid_alias` option; we will simply fall back to a
+       /// private channel without that option.
+       ///
+       /// Ignored if the channel is negotiated to be announced, see
+       /// [`ChannelConfig::announced_channel`] and
+       /// [`ChannelHandshakeLimits::force_announced_channel_preference`] for more.
+       ///
+       /// Default value: false. This value is likely to change to true in the future.
+       ///
+       /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+       /// [`DecodeError:InvalidValue`]: crate::ln::msgs::DecodeError::InvalidValue
+       pub negotiate_scid_privacy: bool,
 }
 
 impl Default for ChannelHandshakeConfig {
@@ -55,6 +77,7 @@ impl Default for ChannelHandshakeConfig {
                        minimum_depth: 6,
                        our_to_self_delay: BREAKDOWN_TIMEOUT,
                        our_htlc_minimum_msat: 1,
+                       negotiate_scid_privacy: false,
                }
        }
 }