use ln::features::{ChannelFeatures, InitFeatures};
use ln::msgs;
use ln::msgs::{DecodeError, OptionalField, DataLossProtect};
-use ln::script::ShutdownScript;
-use ln::channelmanager::{PendingHTLCStatus, HTLCSource, HTLCFailReason, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, 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, build_closing_transaction};
+use ln::script::{self, ShutdownScript};
+use ln::channelmanager::{CounterpartyForwardingInfo, PendingHTLCStatus, HTLCSource, HTLCFailReason, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, 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, ClosingTransaction};
use ln::chan_utils;
use chain::BestBlock;
use chain::chaininterface::{FeeEstimator,ConfirmationTarget};
use io;
use prelude::*;
use core::{cmp,mem,fmt};
-use core::convert::TryFrom;
use core::ops::Deref;
#[cfg(any(test, feature = "fuzztarget", debug_assertions))]
use sync::Mutex;
}
}
-/// Information needed for constructing an invoice route hint for this channel.
-#[derive(Clone, Debug, PartialEq)]
-pub struct CounterpartyForwardingInfo {
- /// Base routing fee in millisatoshis.
- pub fee_base_msat: u32,
- /// Amount in millionths of a satoshi the channel will charge per transferred satoshi.
- pub fee_proportional_millionths: u32,
- /// The minimum difference in cltv_expiry between an ingoing HTLC and its outgoing counterpart,
- /// such that the outgoing HTLC is forwardable to this counterparty. See `msgs::ChannelUpdate`'s
- /// `cltv_expiry_delta` for more details.
- pub cltv_expiry_delta: u16,
-}
-
/// A return value enum for get_update_fulfill_htlc. See UpdateFulfillCommitFetch variants for
/// description
enum UpdateFulfillFetch {
monitor_pending_forwards: Vec<(PendingHTLCInfo, u64)>,
monitor_pending_failures: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>,
- // pending_update_fee is filled when sending and receiving update_fee
- // For outbound channel, feerate_per_kw is updated with the value from
- // pending_update_fee when revoke_and_ack is received
+ // pending_update_fee is filled when sending and receiving update_fee.
//
- // For inbound channel, feerate_per_kw is updated when it receives
- // commitment_signed and revoke_and_ack is generated
- // The pending value is kept when another pair of update_fee and commitment_signed
- // is received during AwaitingRemoteRevoke and relieved when the expected
- // revoke_and_ack is received and new commitment_signed is generated to be
- // sent to the funder. Otherwise, the pending value is removed when receiving
- // commitment_signed.
+ // Because it follows the same commitment flow as HTLCs, `FeeUpdateState` is either `Outbound`
+ // or matches a subset of the `InboundHTLCOutput` variants. It is then updated/used when
+ // generating new commitment transactions with exactly the same criteria as inbound/outbound
+ // HTLCs with similar state.
pending_update_fee: Option<(u32, FeeUpdateState)>,
- // update_fee() during ChannelState::AwaitingRemoteRevoke is hold in
- // holdina_cell_update_fee then moved to pending_udpate_fee when revoke_and_ack
- // is received. holding_cell_update_fee is updated when there are additional
- // update_fee() during ChannelState::AwaitingRemoteRevoke.
+ // If a `send_update_fee()` call is made with ChannelState::AwaitingRemoteRevoke set, we place
+ // it here instead of `pending_update_fee` in the same way as we place outbound HTLC updates in
+ // `holding_cell_htlc_updates` instead of `pending_outbound_htlcs`. It is released into
+ // `pending_update_fee` with the same criteria as outbound HTLC updates but can be updated by
+ // further `send_update_fee` calls, dropping the previous holding cell update entirely.
holding_cell_update_fee: Option<u32>,
next_holder_htlc_id: u64,
next_counterparty_htlc_id: u64,
/// closing_signed message and handling it in `maybe_propose_closing_signed`.
pending_counterparty_closing_signed: Option<msgs::ClosingSigned>,
- /// The minimum and maximum absolute fee we are willing to place on the closing transaction.
- /// These are set once we reach `closing_negotiation_ready`.
+ /// The minimum and maximum absolute fee, in satoshis, we are willing to place on the closing
+ /// transaction. These are set once we reach `closing_negotiation_ready`.
#[cfg(test)]
pub(crate) closing_fee_limits: Option<(u64, u64)>,
#[cfg(not(test))]
/// it's 2^24.
pub const MAX_FUNDING_SATOSHIS: u64 = 1 << 24;
-/// Maximum counterparty `dust_limit_satoshis` allowed. 2 * standard dust threshold on p2wsh output
-/// Scales up on Bitcoin Core's proceeding policy with dust outputs. A typical p2wsh output is 43
-/// bytes to which Core's `GetDustThreshold()` sums up a minimal spend of 67 bytes (even if
-/// a p2wsh witnessScript might be *effectively* smaller), `dustRelayFee` is set to 3000sat/kb, thus
-/// 110 * 3000 / 1000 = 330. Per-protocol rules, all time-sensitive outputs are p2wsh, a value of
-/// 330 sats is the lower bound desired to ensure good propagation of transactions. We give a bit
-/// of margin to our counterparty and pick up 660 satoshis as an accepted `dust_limit_satoshis`
-/// upper bound to avoid negotiation conflicts with other implementations.
-pub const MAX_DUST_LIMIT_SATOSHIS: u64 = 2 * 330;
-
-/// A typical p2wsh output is 43 bytes to which Core's `GetDustThreshold()` sums up a minimal
-/// spend of 67 bytes (even if a p2wsh witnessScript might be *effectively* smaller), `dustRelayFee`
-/// is set to 3000sat/kb, thus 110 * 3000 / 1000 = 330. Per-protocol rules, all time-sensitive outputs
-/// are p2wsh, a value of 330 sats is the lower bound desired to ensure good propagation of transactions.
-pub const MIN_DUST_LIMIT_SATOSHIS: u64 = 330;
+/// The maximum network dust limit for standard script formats. This currently represents the
+/// minimum output value for a P2SH output before Bitcoin Core 22 considers the entire
+/// transaction non-standard and thus refuses to relay it.
+/// We also use this as the maximum counterparty `dust_limit_satoshis` allowed, given many
+/// implementations use this value for their dust limit today.
+pub const MAX_STD_OUTPUT_DUST_LIMIT_SATOSHIS: u64 = 546;
+
+/// The maximum channel dust limit we will accept from our counterparty.
+pub const MAX_CHAN_DUST_LIMIT_SATOSHIS: u64 = MAX_STD_OUTPUT_DUST_LIMIT_SATOSHIS;
+
+/// The dust limit is used for both the commitment transaction outputs as well as the closing
+/// transactions. For cooperative closing transactions, we require segwit outputs, though accept
+/// *any* segwit scripts, which are allowed to be up to 42 bytes in length.
+/// In order to avoid having to concern ourselves with standardness during the closing process, we
+/// simply require our counterparty to use a dust limit which will leave any segwit output
+/// standard.
+/// See https://github.com/lightningnetwork/lightning-rfc/issues/905 for more details.
+pub const MIN_DUST_LIMIT_SATOSHIS: u64 = 354;
/// Used to return a simple Error back to ChannelManager. Will get converted to a
/// msgs::ErrorAction::SendErrorMessage or msgs::ErrorAction::IgnoreError as appropriate with our
if msg.dust_limit_satoshis < MIN_DUST_LIMIT_SATOSHIS {
return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the implementation limit ({})", msg.dust_limit_satoshis, MIN_DUST_LIMIT_SATOSHIS)));
}
- if msg.dust_limit_satoshis > MAX_DUST_LIMIT_SATOSHIS {
- return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the implementation limit ({})", msg.dust_limit_satoshis, MAX_DUST_LIMIT_SATOSHIS)));
+ if msg.dust_limit_satoshis > MAX_CHAN_DUST_LIMIT_SATOSHIS {
+ return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the implementation limit ({})", msg.dust_limit_satoshis, MAX_CHAN_DUST_LIMIT_SATOSHIS)));
}
// Convert things into internal flags and prep our state:
if script.len() == 0 {
None
} else {
- match ShutdownScript::try_from((script.clone(), their_features)) {
- Ok(shutdown_script) => Some(shutdown_script.into_inner()),
- Err(_) => return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided an unacceptable scriptpubkey format: {}", script))),
+ if !script::is_bolt2_compliant(&script, their_features) {
+ return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided an unacceptable scriptpubkey format: {}", script)))
}
+ Some(script.clone())
}
},
// Peer is signaling upfront shutdown but don't opt-out with correct mechanism (a.k.a 0-length script). Peer looks buggy, we fail the channel
}
#[inline]
- fn build_closing_transaction(&self, proposed_total_fee_satoshis: u64, skip_remote_output: bool) -> (Transaction, u64) {
+ fn build_closing_transaction(&self, proposed_total_fee_satoshis: u64, skip_remote_output: bool) -> (ClosingTransaction, u64) {
assert!(self.pending_inbound_htlcs.is_empty());
assert!(self.pending_outbound_htlcs.is_empty());
assert!(self.pending_update_fee.is_none());
let counterparty_shutdown_script = self.counterparty_shutdown_scriptpubkey.clone().unwrap();
let funding_outpoint = self.funding_outpoint().into_bitcoin_outpoint();
- (build_closing_transaction(value_to_holder as u64, value_to_counterparty as u64, holder_shutdown_script, counterparty_shutdown_script, funding_outpoint), total_fee_satoshis)
+ let closing_transaction = ClosingTransaction::new(value_to_holder as u64, value_to_counterparty as u64, holder_shutdown_script, counterparty_shutdown_script, funding_outpoint);
+ (closing_transaction, total_fee_satoshis)
}
fn funding_outpoint(&self) -> OutPoint {
if msg.dust_limit_satoshis < MIN_DUST_LIMIT_SATOSHIS {
return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the implementation limit ({})", msg.dust_limit_satoshis, MIN_DUST_LIMIT_SATOSHIS)));
}
- if msg.dust_limit_satoshis > MAX_DUST_LIMIT_SATOSHIS {
- return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the implementation limit ({})", msg.dust_limit_satoshis, MAX_DUST_LIMIT_SATOSHIS)));
+ if msg.dust_limit_satoshis > MAX_CHAN_DUST_LIMIT_SATOSHIS {
+ return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the implementation limit ({})", msg.dust_limit_satoshis, MAX_CHAN_DUST_LIMIT_SATOSHIS)));
}
if msg.minimum_depth > config.peer_channel_config_limits.max_minimum_depth {
return Err(ChannelError::Close(format!("We consider the minimum depth to be unreasonably large. Expected minimum: ({}). Actual: ({})", config.peer_channel_config_limits.max_minimum_depth, msg.minimum_depth)));
if script.len() == 0 {
None
} else {
- match ShutdownScript::try_from((script.clone(), their_features)) {
- Ok(shutdown_script) => Some(shutdown_script.into_inner()),
- Err(_) => return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided an unacceptable scriptpubkey format: {}", script))),
+ if !script::is_bolt2_compliant(&script, their_features) {
+ return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided an unacceptable scriptpubkey format: {}", script)));
}
+ Some(script.clone())
}
},
// Peer is signaling upfront shutdown but don't opt-out with correct mechanism (a.k.a 0-length script). Peer looks buggy, we fail the channel
// We can't accept HTLCs sent after we've sent a shutdown.
let local_sent_shutdown = (self.channel_state & (ChannelState::ChannelFunded as u32 | ChannelState::LocalShutdownSent as u32)) != (ChannelState::ChannelFunded as u32);
if local_sent_shutdown {
- pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x1000|20);
+ pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x4000|8);
}
// If the remote has sent a shutdown prior to adding this HTLC, then they are in violation of the spec.
let remote_sent_shutdown = (self.channel_state & (ChannelState::ChannelFunded as u32 | ChannelState::RemoteShutdownSent as u32)) != (ChannelState::ChannelFunded as u32);
/// monitor update failure must *not* have been sent to the remote end, and must instead
/// have been dropped. They will be regenerated when monitor_updating_restored is called.
pub fn monitor_update_failed(&mut self, resend_raa: bool, resend_commitment: bool, mut pending_forwards: Vec<(PendingHTLCInfo, u64)>, mut pending_fails: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>) {
- assert_eq!(self.channel_state & ChannelState::MonitorUpdateFailed as u32, 0);
- self.monitor_pending_revoke_and_ack = resend_raa;
- self.monitor_pending_commitment_signed = resend_commitment;
- assert!(self.monitor_pending_forwards.is_empty());
- mem::swap(&mut pending_forwards, &mut self.monitor_pending_forwards);
- assert!(self.monitor_pending_failures.is_empty());
- mem::swap(&mut pending_fails, &mut self.monitor_pending_failures);
+ self.monitor_pending_revoke_and_ack |= resend_raa;
+ self.monitor_pending_commitment_signed |= resend_commitment;
+ self.monitor_pending_forwards.append(&mut pending_forwards);
+ self.monitor_pending_failures.append(&mut pending_fails);
self.channel_state |= ChannelState::MonitorUpdateFailed as u32;
}
cmp::max(normal_feerate as u64 * tx_weight / 1000 + self.config.force_close_avoidance_max_fee_satoshis,
proposed_max_feerate as u64 * tx_weight / 1000)
} else {
- u64::max_value()
+ self.channel_value_satoshis - (self.value_to_self_msat + 999) / 1000
};
self.closing_fee_limits = Some((proposed_total_fee_satoshis, proposed_max_total_fee_satoshis));
}
assert_eq!(self.channel_state & ChannelState::ShutdownComplete as u32, 0);
- let shutdown_scriptpubkey = match ShutdownScript::try_from((msg.scriptpubkey.clone(), their_features)) {
- Ok(script) => script.into_inner(),
- Err(_) => return Err(ChannelError::Close(format!("Got a nonstandard scriptpubkey ({}) from remote peer", msg.scriptpubkey.to_bytes().to_hex()))),
- };
+ if !script::is_bolt2_compliant(&msg.scriptpubkey, their_features) {
+ return Err(ChannelError::Close(format!("Got a nonstandard scriptpubkey ({}) from remote peer", msg.scriptpubkey.to_bytes().to_hex())));
+ }
if self.counterparty_shutdown_scriptpubkey.is_some() {
- if Some(&shutdown_scriptpubkey) != self.counterparty_shutdown_scriptpubkey.as_ref() {
- return Err(ChannelError::Close(format!("Got shutdown request with a scriptpubkey ({}) which did not match their previous scriptpubkey.", shutdown_scriptpubkey.to_bytes().to_hex())));
+ if Some(&msg.scriptpubkey) != self.counterparty_shutdown_scriptpubkey.as_ref() {
+ return Err(ChannelError::Close(format!("Got shutdown request with a scriptpubkey ({}) which did not match their previous scriptpubkey.", msg.scriptpubkey.to_bytes().to_hex())));
}
} else {
- self.counterparty_shutdown_scriptpubkey = Some(shutdown_scriptpubkey);
+ self.counterparty_shutdown_scriptpubkey = Some(msg.scriptpubkey.clone());
}
// If we have any LocalAnnounced updates we'll probably just get back an update_fail_htlc
Ok((shutdown, monitor_update, dropped_outbound_htlcs))
}
- fn build_signed_closing_transaction(&self, tx: &mut Transaction, counterparty_sig: &Signature, sig: &Signature) {
- if tx.input.len() != 1 { panic!("Tried to sign closing transaction that had input count != 1!"); }
- if tx.input[0].witness.len() != 0 { panic!("Tried to re-sign closing transaction"); }
- if tx.output.len() > 2 { panic!("Tried to sign bogus closing transaction"); }
+ fn build_signed_closing_transaction(&self, closing_tx: &ClosingTransaction, counterparty_sig: &Signature, sig: &Signature) -> Transaction {
+ let mut tx = closing_tx.trust().built_transaction().clone();
tx.input[0].witness.push(Vec::new()); // First is the multisig dummy
tx.input[0].witness[2].push(SigHashType::All as u8);
tx.input[0].witness.push(self.get_funding_redeemscript().into_bytes());
+ tx
}
pub fn closing_signed<F: Deref>(&mut self, fee_estimator: &F, msg: &msgs::ClosingSigned) -> Result<(Option<msgs::ClosingSigned>, Option<Transaction>), ChannelError>
if used_total_fee != msg.fee_satoshis {
return Err(ChannelError::Close(format!("Remote sent us a closing_signed with a fee other than the value they can claim. Fee in message: {}. Actual closing tx fee: {}", msg.fee_satoshis, used_total_fee)));
}
- let mut sighash = hash_to_message!(&bip143::SigHashCache::new(&closing_tx).signature_hash(0, &funding_redeemscript, self.channel_value_satoshis, SigHashType::All)[..]);
+ let sighash = closing_tx.trust().get_sighash_all(&funding_redeemscript, self.channel_value_satoshis);
match self.secp_ctx.verify(&sighash, &msg.signature, &self.get_counterparty_pubkeys().funding_pubkey) {
Ok(_) => {},
// The remote end may have decided to revoke their output due to inconsistent dust
// limits, so check for that case by re-checking the signature here.
closing_tx = self.build_closing_transaction(msg.fee_satoshis, true).0;
- sighash = hash_to_message!(&bip143::SigHashCache::new(&closing_tx).signature_hash(0, &funding_redeemscript, self.channel_value_satoshis, SigHashType::All)[..]);
+ let sighash = closing_tx.trust().get_sighash_all(&funding_redeemscript, self.channel_value_satoshis);
secp_check!(self.secp_ctx.verify(&sighash, &msg.signature, self.counterparty_funding_pubkey()), "Invalid closing tx signature from peer".to_owned());
},
};
assert!(self.shutdown_scriptpubkey.is_some());
if let Some((last_fee, sig)) = self.last_sent_closing_fee {
if last_fee == msg.fee_satoshis {
- self.build_signed_closing_transaction(&mut closing_tx, &msg.signature, &sig);
+ let tx = self.build_signed_closing_transaction(&mut closing_tx, &msg.signature, &sig);
self.channel_state = ChannelState::ShutdownComplete as u32;
self.update_time_counter += 1;
- return Ok((None, Some(closing_tx)));
+ return Ok((None, Some(tx)));
}
}
macro_rules! propose_fee {
($new_fee: expr) => {
- let (mut tx, used_fee) = if $new_fee == msg.fee_satoshis {
+ let (closing_tx, used_fee) = if $new_fee == msg.fee_satoshis {
(closing_tx, $new_fee)
} else {
self.build_closing_transaction($new_fee, false)
};
let sig = self.holder_signer
- .sign_closing_transaction(&tx, &self.secp_ctx)
+ .sign_closing_transaction(&closing_tx, &self.secp_ctx)
.map_err(|_| ChannelError::Close("External signer refused to sign closing transaction".to_owned()))?;
let signed_tx = if $new_fee == msg.fee_satoshis {
self.channel_state = ChannelState::ShutdownComplete as u32;
self.update_time_counter += 1;
- self.build_signed_closing_transaction(&mut tx, &msg.signature, &sig);
+ let tx = self.build_signed_closing_transaction(&closing_tx, &msg.signature, &sig);
Some(tx)
} else { None };
if !self.is_outbound() {
// They have to pay, so pick the highest fee in the overlapping range.
- debug_assert_eq!(our_max_fee, u64::max_value()); // We should never set an upper bound
+ // We should never set an upper bound aside from their full balance
+ debug_assert_eq!(our_max_fee, self.channel_value_satoshis - (self.value_to_self_msat + 999) / 1000);
propose_fee!(cmp::min(max_fee_satoshis, our_max_fee));
} else {
if msg.fee_satoshis < our_min_fee || msg.fee_satoshis > our_max_fee {
// more dust balance if the feerate increases when we have several HTLCs pending
// which are near the dust limit.
let mut feerate_per_kw = self.feerate_per_kw;
+ // If there's a pending update fee, use it to ensure we aren't under-estimating
+ // potential feerate updates coming soon.
if let Some((feerate, _)) = self.pending_update_fee {
feerate_per_kw = cmp::max(feerate_per_kw, feerate);
}
if self.is_outbound() {
self.pending_update_fee.map(|(a, _)| a).write(writer)?;
} else if let Some((feerate, FeeUpdateState::AwaitingRemoteRevokeToAnnounce)) = self.pending_update_fee {
- // As for inbound HTLCs, if the update was only announced and never committed, drop it.
Some(feerate).write(writer)?;
} else {
+ // As for inbound HTLCs, if the update was only announced and never committed in a
+ // commitment_signed, drop it.
None::<u32>.write(writer)?;
}
self.holding_cell_update_fee.write(writer)?;