Introduce LegacyChannelConfig to remain backwards compatible
[rust-lightning] / lightning / src / util / config.rs
index c2c73d8cb6c8bffb589a23e7c8e55d8725696922..570e570a893e9583e4bb57ca18d4cb7c515a581c 100644 (file)
@@ -291,30 +291,6 @@ pub struct ChannelConfig {
        ///
        /// [`MIN_CLTV_EXPIRY_DELTA`]: crate::ln::channelmanager::MIN_CLTV_EXPIRY_DELTA
        pub cltv_expiry_delta: u16,
-       /// Set to announce the channel publicly and notify all nodes that they can route via this
-       /// channel.
-       ///
-       /// This should only be set to true for nodes which expect to be online reliably.
-       ///
-       /// As the node which funds a channel picks this value this will only apply for new outbound
-       /// channels unless [`ChannelHandshakeLimits::force_announced_channel_preference`] is set.
-       ///
-       /// This cannot be changed after the initial channel handshake.
-       ///
-       /// Default value: false.
-       pub announced_channel: bool,
-       /// When set, we commit to an upfront shutdown_pubkey at channel open. If our counterparty
-       /// supports it, they will then enforce the mutual-close output to us matches what we provided
-       /// at intialization, preventing us from closing to an alternate pubkey.
-       ///
-       /// This is set to true by default to provide a slight increase in security, though ultimately
-       /// any attacker who is able to take control of a channel can just as easily send the funds via
-       /// lightning payments, so we never require that our counterparties support this option.
-       ///
-       /// This cannot be changed after a channel has been initialized.
-       ///
-       /// Default value: true.
-       pub commit_upfront_shutdown_pubkey: bool,
        /// Limit our total exposure to in-flight HTLCs which are burned to fees as they are too
        /// small to claim on-chain.
        ///
@@ -363,23 +339,83 @@ impl Default for ChannelConfig {
                        forwarding_fee_proportional_millionths: 0,
                        forwarding_fee_base_msat: 1000,
                        cltv_expiry_delta: 6 * 12, // 6 blocks/hour * 12 hours
-                       announced_channel: false,
-                       commit_upfront_shutdown_pubkey: true,
                        max_dust_htlc_exposure_msat: 5_000_000,
                        force_close_avoidance_max_fee_satoshis: 1000,
                }
        }
 }
 
-impl_writeable_tlv_based!(ChannelConfig, {
-       (0, forwarding_fee_proportional_millionths, required),
-       (1, max_dust_htlc_exposure_msat, (default_value, 5_000_000)),
-       (2, cltv_expiry_delta, required),
-       (3, force_close_avoidance_max_fee_satoshis, (default_value, 1000)),
-       (4, announced_channel, required),
-       (6, commit_upfront_shutdown_pubkey, required),
-       (8, forwarding_fee_base_msat, required),
-});
+/// Legacy version of [`ChannelConfig`] that stored the static
+/// [`ChannelHandshakeConfig::announced_channel`] and
+/// [`ChannelHandshakeConfig::commit_upfront_shutdown_pubkey`] fields.
+#[derive(Copy, Clone, Debug)]
+pub(crate) struct LegacyChannelConfig {
+       pub(crate) mutable: ChannelConfig,
+       /// Deprecated but may still be read from. See [`ChannelHandshakeConfig::announced_channel`] to
+       /// set this when opening/accepting a channel.
+       pub(crate) announced_channel: bool,
+       /// Deprecated but may still be read from. See
+       /// [`ChannelHandshakeConfig::commit_upfront_shutdown_pubkey`] to set this when
+       /// opening/accepting a channel.
+       pub(crate) commit_upfront_shutdown_pubkey: bool,
+}
+
+impl Default for LegacyChannelConfig {
+       fn default() -> Self {
+               Self {
+                       mutable: ChannelConfig::default(),
+                       announced_channel: false,
+                       commit_upfront_shutdown_pubkey: true,
+               }
+       }
+}
+
+impl ::util::ser::Writeable for LegacyChannelConfig {
+       fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), ::io::Error> {
+               write_tlv_fields!(writer, {
+                       (0, self.mutable.forwarding_fee_proportional_millionths, required),
+                       (1, self.mutable.max_dust_htlc_exposure_msat, (default_value, 5_000_000)),
+                       (2, self.mutable.cltv_expiry_delta, required),
+                       (3, self.mutable.force_close_avoidance_max_fee_satoshis, (default_value, 1000)),
+                       (4, self.announced_channel, required),
+                       (6, self.commit_upfront_shutdown_pubkey, required),
+                       (8, self.mutable.forwarding_fee_base_msat, required),
+               });
+               Ok(())
+       }
+}
+
+impl ::util::ser::Readable for LegacyChannelConfig {
+       fn read<R: ::io::Read>(reader: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {
+               let mut forwarding_fee_proportional_millionths = 0;
+               let mut max_dust_htlc_exposure_msat = 5_000_000;
+               let mut cltv_expiry_delta = 0;
+               let mut force_close_avoidance_max_fee_satoshis = 1000;
+               let mut announced_channel = false;
+               let mut commit_upfront_shutdown_pubkey = false;
+               let mut forwarding_fee_base_msat = 0;
+               read_tlv_fields!(reader, {
+                       (0, forwarding_fee_proportional_millionths, required),
+                       (1, max_dust_htlc_exposure_msat, (default_value, 5_000_000)),
+                       (2, cltv_expiry_delta, required),
+                       (3, force_close_avoidance_max_fee_satoshis, (default_value, 1000)),
+                       (4, announced_channel, required),
+                       (6, commit_upfront_shutdown_pubkey, required),
+                       (8, forwarding_fee_base_msat, required),
+               });
+               Ok(Self {
+                       mutable: ChannelConfig {
+                               forwarding_fee_proportional_millionths,
+                               max_dust_htlc_exposure_msat,
+                               cltv_expiry_delta,
+                               force_close_avoidance_max_fee_satoshis,
+                               forwarding_fee_base_msat,
+                       },
+                       announced_channel,
+                       commit_upfront_shutdown_pubkey,
+               })
+       }
+}
 
 /// Top-level config which holds ChannelHandshakeLimits and ChannelConfig.
 ///