Fix serialization expected lengths and check them in test/fuzzing

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

diff --git a/lightning/src/util/config.rs b/lightning/src/util/config.rs
index f43423d7c0c0af923a4ac8f08a562aea474f946c..de83f227b2365af938539a62c5688d25d7d7be37 100644 (file)
--- a/lightning/src/util/config.rs
+++ b/lightning/src/util/config.rs
@@ -23,18 +23,21 @@ pub struct ChannelHandshakeConfig {
        ///
        /// Default value: 6.
        pub minimum_depth: u32,
-       /// Set to the amount of time we require our counterparty to wait to claim their money.
+       /// Set to the number of blocks we require our counterparty to wait to claim their money (ie
+       /// the number of blocks we have to punish our counterparty if they broadcast a revoked
+       /// transaction).
        ///
-       /// It's one of the main parameter of our security model. We (or one of our watchtowers) MUST
-       /// be online to check for peer having broadcast a revoked transaction to steal our funds
-       /// at least once every our_to_self_delay blocks.
+       /// This is one of the main parameters of our security model. We (or one of our watchtowers) MUST
+       /// be online to check for revoked transactions on-chain at least once every our_to_self_delay
+       /// blocks (minus some margin to allow us enough time to broadcast and confirm a transaction,
+       /// possibly with time in between to RBF the spending transaction).
        ///
        /// Meanwhile, asking for a too high delay, we bother peer to freeze funds for nothing in
        /// case of an honest unilateral channel close, which implicitly decrease the economic value of
        /// our channel.
        ///
-       /// Default value: BREAKDOWN_TIMEOUT (currently 144), we enforce it as a minimum at channel
-       /// opening so you can tweak config to ask for more security, not less.
+       /// Default value: [`BREAKDOWN_TIMEOUT`], we enforce it as a minimum at channel opening so you
+       /// can tweak config to ask for more security, not less.
        pub our_to_self_delay: u16,
        /// Set to the smallest value HTLC we will accept to process.
        ///
@@ -129,8 +132,8 @@ pub struct ChannelHandshakeLimits {
        /// Not checking this value would be a security issue, as our peer would be able to set it to
        /// max relative lock-time (a year) and we would "lose" money as it would be locked for a long time.
        ///
-       /// Default value: MAX_LOCAL_BREAKDOWN_TIMEOUT (1008), which we also enforce as a maximum value
-       /// so you can tweak config to reduce the loss of having useless locked funds (if your peer accepts)
+       /// Default value: 2016, which we also enforce as a maximum value so you can tweak config to
+       /// reduce the loss of having useless locked funds (if your peer accepts)
        pub their_to_self_delay: u16
 }
 
@@ -161,6 +164,26 @@ pub struct ChannelConfig {
        ///
        /// Default value: 0.
        pub fee_proportional_millionths: u32,
+       /// The difference in the CLTV value between incoming HTLCs and an outbound HTLC forwarded over
+       /// the channel this config applies to.
+       ///
+       /// This is analogous to [`ChannelHandshakeConfig::our_to_self_delay`] but applies to in-flight
+       /// HTLC balance when a channel appears on-chain whereas
+       /// [`ChannelHandshakeConfig::our_to_self_delay`] applies to the remaining
+       /// (non-HTLC-encumbered) balance.
+       ///
+       /// Thus, for HTLC-encumbered balances to be enforced on-chain when a channel is force-closed,
+       /// we (or one of our watchtowers) MUST be online to check for broadcast of the current
+       /// commitment transaction at least once per this many blocks (minus some margin to allow us
+       /// enough time to broadcast and confirm a transaction, possibly with time in between to RBF
+       /// the spending transaction).
+       ///
+       /// Default value: 72 (12 hours at an average of 6 blocks/hour).
+       /// Minimum value: [`MIN_CLTV_EXPIRY_DELTA`], any values less than this will be treated as
+       ///                [`MIN_CLTV_EXPIRY_DELTA`] instead.
+       ///
+       /// [`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.
        ///
@@ -192,6 +215,7 @@ impl Default for ChannelConfig {
        fn default() -> Self {
                ChannelConfig {
                        fee_proportional_millionths: 0,
+                       cltv_expiry_delta: 6 * 12, // 6 blocks/hour * 12 hours
                        announced_channel: false,
                        commit_upfront_shutdown_pubkey: true,
                }
@@ -199,8 +223,9 @@ impl Default for ChannelConfig {
 }
 
 //Add write and readable traits to channelconfig
-impl_writeable!(ChannelConfig, 8+1+1, {
+impl_writeable!(ChannelConfig, 4+2+1+1, {
        fee_proportional_millionths,
+       cltv_expiry_delta,
        announced_channel,
        commit_upfront_shutdown_pubkey
 });