/// design of LN state machines, allowing asynchronous updates.
pub(crate) const CONCURRENT_INBOUND_HTLC_FEE_BUFFER: u32 = 2;
+/// When a channel is opened, we check that the funding amount is enough to pay for relevant
+/// commitment transaction fees, with at least this many HTLCs present on the commitment
+/// transaction (not counting the value of the HTLCs themselves).
+pub(crate) const MIN_AFFORDABLE_HTLC_COUNT: usize = 4;
+
// TODO: We should refactor this to be an Inbound/OutboundChannel until initial setup handshaking
// has been completed, and then turn into a Channel to get compiler-time enforcement of things like
// calling channel_id() before we're set up or things like get_outbound_funding_signed on an
holding_cell_update_fee: Option<u32>,
next_holder_htlc_id: u64,
next_counterparty_htlc_id: u64,
- update_time_counter: u32,
feerate_per_kw: u32,
+ /// The timestamp set on our latest `channel_update` message for this channel. It is updated
+ /// when the channel is updated in ways which may impact the `channel_update` message or when a
+ /// new block is received, ensuring it's always at least moderately close to the current real
+ /// time.
+ update_time_counter: u32,
+
#[cfg(debug_assertions)]
/// Max to_local and to_remote outputs in a locally-generated commitment transaction
holder_max_commitment_tx_output: Mutex<(u64, u64)>,
cmp::min(channel_value_satoshis, cmp::max(q, 1000)) //TODO
}
+ pub(crate) fn opt_anchors(&self) -> bool {
+ self.channel_transaction_parameters.opt_anchors.is_some()
+ }
+
// Constructors:
pub fn new_outbound<K: Deref, F: Deref>(
fee_estimator: &F, keys_provider: &K, counterparty_node_id: PublicKey, their_features: &InitFeatures,
let feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
+ let value_to_self_msat = channel_value_satoshis * 1000 - push_msat;
+ let commitment_tx_fee = Self::commit_tx_fee_msat(feerate, MIN_AFFORDABLE_HTLC_COUNT);
+ if value_to_self_msat < commitment_tx_fee {
+ return Err(APIError::APIMisuseError{ err: format!("Funding amount ({}) can't even pay fee for initial commitment transaction fee of {}.", value_to_self_msat / 1000, commitment_tx_fee / 1000) });
+ }
+
let mut secp_ctx = Secp256k1::new();
secp_ctx.seeded_randomize(&keys_provider.get_secure_random_bytes());
cur_holder_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
cur_counterparty_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
- value_to_self_msat: channel_value_satoshis * 1000 - push_msat,
+ value_to_self_msat,
pending_inbound_htlcs: Vec::new(),
pending_outbound_htlcs: Vec::new(),
holder_selected_contest_delay: config.own_channel_config.our_to_self_delay,
is_outbound_from_holder: true,
counterparty_parameters: None,
- funding_outpoint: None
+ funding_outpoint: None,
+ opt_anchors: None,
},
funding_transaction: None,
// we either accept their preference or the preferences match
local_config.announced_channel = announce;
- let background_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
-
let holder_selected_channel_reserve_satoshis = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(msg.funding_satoshis);
if holder_selected_channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
return Err(ChannelError::Close(format!("Suitable channel reserve not found. remote_channel_reserve was ({}). dust_limit_satoshis is ({}).", holder_selected_channel_reserve_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS)));
}
// check if the funder's amount for the initial commitment tx is sufficient
- // for full fee payment
+ // for full fee payment plus a few HTLCs to ensure the channel will be useful.
let funders_amount_msat = msg.funding_satoshis * 1000 - msg.push_msat;
- let lower_limit = background_feerate as u64 * COMMITMENT_TX_BASE_WEIGHT;
- if funders_amount_msat < lower_limit {
- return Err(ChannelError::Close(format!("Insufficient funding amount ({}) for initial commitment. Must be at least {}", funders_amount_msat, lower_limit)));
+ let commitment_tx_fee = Self::commit_tx_fee_msat(msg.feerate_per_kw, MIN_AFFORDABLE_HTLC_COUNT) / 1000;
+ if funders_amount_msat / 1000 < commitment_tx_fee {
+ return Err(ChannelError::Close(format!("Funding amount ({} sats) can't even pay fee for initial commitment transaction fee of {} sats.", funders_amount_msat / 1000, commitment_tx_fee)));
}
- let to_local_msat = msg.push_msat;
- let to_remote_msat = funders_amount_msat - background_feerate as u64 * COMMITMENT_TX_BASE_WEIGHT;
- if to_local_msat <= msg.channel_reserve_satoshis * 1000 && to_remote_msat <= holder_selected_channel_reserve_satoshis * 1000 {
- return Err(ChannelError::Close("Insufficient funding amount for initial commitment".to_owned()));
+ let to_remote_satoshis = funders_amount_msat / 1000 - commitment_tx_fee;
+ // While it's reasonable for us to not meet the channel reserve initially (if they don't
+ // want to push much to us), our counterparty should always have more than our reserve.
+ if to_remote_satoshis < holder_selected_channel_reserve_satoshis {
+ return Err(ChannelError::Close("Insufficient funding amount for initial reserve".to_owned()));
}
let counterparty_shutdown_scriptpubkey = if their_features.supports_upfront_shutdown_script() {
selected_contest_delay: msg.to_self_delay,
pubkeys: counterparty_pubkeys,
}),
- funding_outpoint: None
+ funding_outpoint: None,
+ opt_anchors: None
},
funding_transaction: None,
let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(commitment_number,
value_to_a as u64,
value_to_b as u64,
- false,
+ self.channel_transaction_parameters.opt_anchors.is_some(),
funding_pubkey_a,
funding_pubkey_b,
keys.clone(),
for (idx, (htlc, source)) in htlcs_cloned.drain(..).enumerate() {
if let Some(_) = htlc.transaction_output_index {
let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_stats.feerate_per_kw,
- self.get_counterparty_selected_contest_delay().unwrap(), &htlc,
+ self.get_counterparty_selected_contest_delay().unwrap(), &htlc, self.opt_anchors(),
&keys.broadcaster_delayed_payment_key, &keys.revocation_key);
- let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys);
+ let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, self.opt_anchors(), &keys);
let htlc_sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, SigHashType::All)[..]);
log_trace!(logger, "Checking HTLC tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} in channel {}.",
log_bytes!(msg.htlc_signatures[idx].serialize_compact()[..]), log_bytes!(keys.countersignatory_htlc_key.serialize()),
}
pub fn set_channel_update_status(&mut self, status: ChannelUpdateStatus) {
+ self.update_time_counter += 1;
self.channel_update_status = status;
}
for (ref htlc_sig, ref htlc) in htlc_signatures.iter().zip(htlcs) {
log_trace!(logger, "Signed remote HTLC tx {} with redeemscript {} with pubkey {} -> {} in channel {}",
- encode::serialize_hex(&chan_utils::build_htlc_transaction(&counterparty_commitment_txid, commitment_stats.feerate_per_kw, self.get_holder_selected_contest_delay(), htlc, &counterparty_keys.broadcaster_delayed_payment_key, &counterparty_keys.revocation_key)),
- encode::serialize_hex(&chan_utils::get_htlc_redeemscript(&htlc, &counterparty_keys)),
+ encode::serialize_hex(&chan_utils::build_htlc_transaction(&counterparty_commitment_txid, commitment_stats.feerate_per_kw, self.get_holder_selected_contest_delay(), htlc, self.opt_anchors(), &counterparty_keys.broadcaster_delayed_payment_key, &counterparty_keys.revocation_key)),
+ encode::serialize_hex(&chan_utils::get_htlc_redeemscript(&htlc, self.opt_anchors(), &counterparty_keys)),
log_bytes!(counterparty_keys.broadcaster_htlc_key.serialize()),
log_bytes!(htlc_sig.serialize_compact()[..]), log_bytes!(self.channel_id()));
}
return Err(DecodeError::UnknownRequiredFeature);
}
+ if channel_parameters.opt_anchors.is_some() {
+ // Relax this check when ChannelTypeFeatures supports anchors.
+ return Err(DecodeError::InvalidValue);
+ }
+
let mut secp_ctx = Secp256k1::new();
secp_ctx.seeded_randomize(&keys_source.get_secure_random_bytes());
let remote_signature = Signature::from_der(&hex::decode($counterparty_htlc_sig_hex).unwrap()[..]).unwrap();
let ref htlc = htlcs[$htlc_idx];
+ let opt_anchors = false;
let htlc_tx = chan_utils::build_htlc_transaction(&unsigned_tx.txid, chan.feerate_per_kw,
chan.get_counterparty_selected_contest_delay().unwrap(),
- &htlc, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
- let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys);
+ &htlc, opt_anchors, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
+ let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, opt_anchors, &keys);
let htlc_sighash = Message::from_slice(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, SigHashType::All)[..]).unwrap();
secp_ctx.verify(&htlc_sighash, &remote_signature, &keys.countersignatory_htlc_key).unwrap();
projects / rust-lightning / blobdiff