use ln::features::{ChannelFeatures, InitFeatures};
use ln::msgs;
use ln::msgs::{DecodeError, OptionalField, DataLossProtect};
-use ln::channelmanager::{PendingHTLCStatus, HTLCSource, HTLCFailReason, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, PaymentPreimage, PaymentHash, BREAKDOWN_TIMEOUT, MAX_LOCAL_BREAKDOWN_TIMEOUT};
+use ln::channelmanager::{PendingHTLCStatus, HTLCSource, HTLCFailReason, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, PaymentPreimage, PaymentHash, BREAKDOWN_TIMEOUT, MIN_CLTV_EXPIRY_DELTA, MAX_LOCAL_BREAKDOWN_TIMEOUT};
use ln::chan_utils::{CounterpartyCommitmentSecrets, TxCreationKeys, HTLCOutputInCommitment, HTLC_SUCCESS_TX_WEIGHT, HTLC_TIMEOUT_TX_WEIGHT, make_funding_redeemscript, ChannelPublicKeys, CommitmentTransaction, HolderCommitmentTransaction, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, MAX_HTLCS, get_commitment_transaction_number_obscure_factor};
use ln::chan_utils;
use chain::chaininterface::{FeeEstimator,ConfirmationTarget};
self.config.fee_proportional_millionths
}
+ pub fn get_cltv_expiry_delta(&self) -> u16 {
+ cmp::max(self.config.cltv_expiry_delta, MIN_CLTV_EXPIRY_DELTA)
+ }
+
#[cfg(test)]
pub fn get_feerate(&self) -> u32 {
self.feerate_per_kw
pub(crate) const MAX_LOCAL_BREAKDOWN_TIMEOUT: u16 = 2 * 6 * 24 * 7;
/// The minimum number of blocks between an inbound HTLC's CLTV and the corresponding outbound
-/// HTLC's CLTV. This should always be a few blocks greater than channelmonitor::CLTV_CLAIM_BUFFER,
-/// ie the node we forwarded the payment on to should always have enough room to reliably time out
-/// the HTLC via a full update_fail_htlc/commitment_signed dance before we hit the
-/// CLTV_CLAIM_BUFFER point (we static assert that it's at least 3 blocks more).
-const CLTV_EXPIRY_DELTA: u16 = 6 * 12; //TODO?
+/// HTLC's CLTV. The current default represents roughly six hours of blocks at six blocks/hour.
+///
+/// This can be increased (but not decreased) through [`ChannelConfig::cltv_expiry_delta`]
+///
+/// [`ChannelConfig::cltv_expiry_delta`]: crate::util::config::ChannelConfig::cltv_expiry_delta
+// This should always be a few blocks greater than channelmonitor::CLTV_CLAIM_BUFFER,
+// i.e. the node we forwarded the payment on to should always have enough room to reliably time out
+// the HTLC via a full update_fail_htlc/commitment_signed dance before we hit the
+// CLTV_CLAIM_BUFFER point (we static assert that it's at least 3 blocks more).
+pub const MIN_CLTV_EXPIRY_DELTA: u16 = 6 * 6;
pub(super) const CLTV_FAR_FAR_AWAY: u32 = 6 * 24 * 7; //TODO?
// Check that our CLTV_EXPIRY is at least CLTV_CLAIM_BUFFER + ANTI_REORG_DELAY + LATENCY_GRACE_PERIOD_BLOCKS,
// LATENCY_GRACE_PERIOD_BLOCKS.
#[deny(const_err)]
#[allow(dead_code)]
-const CHECK_CLTV_EXPIRY_SANITY: u32 = CLTV_EXPIRY_DELTA as u32 - LATENCY_GRACE_PERIOD_BLOCKS - CLTV_CLAIM_BUFFER - ANTI_REORG_DELAY - LATENCY_GRACE_PERIOD_BLOCKS;
+const CHECK_CLTV_EXPIRY_SANITY: u32 = MIN_CLTV_EXPIRY_DELTA as u32 - LATENCY_GRACE_PERIOD_BLOCKS - CLTV_CLAIM_BUFFER - ANTI_REORG_DELAY - LATENCY_GRACE_PERIOD_BLOCKS;
// Check for ability of an attacker to make us fail on-chain by delaying inbound claim. See
// ChannelMontior::would_broadcast_at_height for a description of why this is needed.
#[deny(const_err)]
#[allow(dead_code)]
-const CHECK_CLTV_EXPIRY_SANITY_2: u32 = CLTV_EXPIRY_DELTA as u32 - LATENCY_GRACE_PERIOD_BLOCKS - 2*CLTV_CLAIM_BUFFER;
+const CHECK_CLTV_EXPIRY_SANITY_2: u32 = MIN_CLTV_EXPIRY_DELTA as u32 - LATENCY_GRACE_PERIOD_BLOCKS - 2*CLTV_CLAIM_BUFFER;
/// Details of a channel, as returned by ChannelManager::list_channels and ChannelManager::list_usable_channels
#[derive(Clone)]
if fee.is_none() || msg.amount_msat < fee.unwrap() || (msg.amount_msat - fee.unwrap()) < *amt_to_forward { // fee_insufficient
break Some(("Prior hop has deviated from specified fees parameters or origin node has obsolete ones", 0x1000 | 12, Some(self.get_channel_update(chan).unwrap())));
}
- if (msg.cltv_expiry as u64) < (*outgoing_cltv_value) as u64 + CLTV_EXPIRY_DELTA as u64 { // incorrect_cltv_expiry
+ if (msg.cltv_expiry as u64) < (*outgoing_cltv_value) as u64 + chan.get_cltv_expiry_delta() as u64 { // incorrect_cltv_expiry
break Some(("Forwarding node has tampered with the intended HTLC values or origin node has an obsolete cltv_expiry_delta", 0x1000 | 13, Some(self.get_channel_update(chan).unwrap())));
}
let cur_height = self.latest_block_height.load(Ordering::Acquire) as u32 + 1;
short_channel_id,
timestamp: chan.get_update_time_counter(),
flags: (!were_node_one) as u8 | ((!chan.is_live() as u8) << 1),
- cltv_expiry_delta: CLTV_EXPIRY_DELTA,
+ cltv_expiry_delta: chan.get_cltv_expiry_delta(),
htlc_minimum_msat: chan.get_counterparty_htlc_minimum_msat(),
htlc_maximum_msat: OptionalField::Present(chan.get_announced_htlc_max_msat()),
fee_base_msat: chan.get_holder_fee_base_msat(&self.fee_estimator),
///
/// 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.
///
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,
}
}
//Add write and readable traits to channelconfig
-impl_writeable!(ChannelConfig, 8+1+1, {
+impl_writeable!(ChannelConfig, 8+2+1+1, {
fee_proportional_millionths,
+ cltv_expiry_delta,
announced_channel,
commit_upfront_shutdown_pubkey
});