pub const OUR_MAX_HTLCS: u16 = 50; //TODO
const SPENDING_INPUT_FOR_A_OUTPUT_WEIGHT: u64 = 79; // prevout: 36, nSequence: 4, script len: 1, witness lengths: (3+1)/4, sig: 73/4, if-selector: 1, redeemScript: (6 ops + 2*33 pubkeys + 1*2 delay)/4
-const B_OUTPUT_PLUS_SPENDING_INPUT_WEIGHT: u64 = 104; // prevout: 40, nSequence: 4, script len: 1, witness lengths: 3/4, sig: 73/4, pubkey: 33/4, output: 31 (TODO: Wrong? Useless?)
#[cfg(not(test))]
const COMMITMENT_TX_BASE_WEIGHT: u64 = 724;
/// 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;
+
/// 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
/// channel_id in ChannelManager.
cmp::min(channel_value_satoshis, cmp::max(q, 1000)) //TODO
}
- fn derive_holder_dust_limit_satoshis(at_open_background_feerate: u32) -> u64 {
- cmp::max(at_open_background_feerate as u64 * B_OUTPUT_PLUS_SPENDING_INPUT_WEIGHT / 1000, 546) //TODO
- }
-
// Constructors:
pub fn new_outbound<K: Deref, F: Deref>(fee_estimator: &F, keys_provider: &K, counterparty_node_id: PublicKey, channel_value_satoshis: u64, push_msat: u64, user_id: u64, config: &UserConfig) -> Result<Channel<Signer>, APIError>
where K::Target: KeysInterface<Signer = Signer>,
if holder_selected_contest_delay < BREAKDOWN_TIMEOUT {
return Err(APIError::APIMisuseError {err: format!("Configured with an unreasonable our_to_self_delay ({}) putting user funds at risks", holder_selected_contest_delay)});
}
- let background_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
- if Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(channel_value_satoshis) < Channel::<Signer>::derive_holder_dust_limit_satoshis(background_feerate) {
- return Err(APIError::FeeRateTooHigh{err: format!("Not enough reserve above dust limit can be found at current fee rate({})", background_feerate), feerate: background_feerate});
+ let holder_selected_channel_reserve_satoshis = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(channel_value_satoshis);
+ if holder_selected_channel_reserve_satoshis < MIN_DUST_LIMIT_SATOSHIS {
+ return Err(APIError::APIMisuseError { err: format!("Holder selected channel reserve below implemention limit dust_limit_satoshis {}", holder_selected_channel_reserve_satoshis) });
}
let feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
feerate_per_kw: feerate,
counterparty_dust_limit_satoshis: 0,
- holder_dust_limit_satoshis: Channel::<Signer>::derive_holder_dust_limit_satoshis(background_feerate),
+ holder_dust_limit_satoshis: MIN_DUST_LIMIT_SATOSHIS,
counterparty_max_htlc_value_in_flight_msat: 0,
counterparty_selected_channel_reserve_satoshis: 0,
counterparty_htlc_minimum_msat: 0,
if msg.max_accepted_htlcs < config.peer_channel_config_limits.min_max_accepted_htlcs {
return Err(ChannelError::Close(format!("max_accepted_htlcs ({}) is less than the user specified limit ({})", msg.max_accepted_htlcs, config.peer_channel_config_limits.min_max_accepted_htlcs)));
}
- if msg.dust_limit_satoshis < config.peer_channel_config_limits.min_dust_limit_satoshis {
- return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the user specified limit ({})", msg.dust_limit_satoshis, config.peer_channel_config_limits.min_dust_limit_satoshis)));
+ 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 > config.peer_channel_config_limits.max_dust_limit_satoshis {
- return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the user specified limit ({})", msg.dust_limit_satoshis, config.peer_channel_config_limits.max_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)));
}
// Convert things into internal flags and prep our state:
let background_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
- let holder_dust_limit_satoshis = Channel::<Signer>::derive_holder_dust_limit_satoshis(background_feerate);
let holder_selected_channel_reserve_satoshis = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(msg.funding_satoshis);
- if holder_selected_channel_reserve_satoshis < holder_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, holder_dust_limit_satoshis)));
+ if holder_selected_channel_reserve_satoshis < MIN_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_DUST_LIMIT_SATOSHIS)));
}
- if msg.channel_reserve_satoshis < holder_dust_limit_satoshis {
- return Err(ChannelError::Close(format!("channel_reserve_satoshis ({}) is smaller than our dust limit ({})", msg.channel_reserve_satoshis, holder_dust_limit_satoshis)));
+ if msg.channel_reserve_satoshis < MIN_DUST_LIMIT_SATOSHIS {
+ return Err(ChannelError::Close(format!("channel_reserve_satoshis ({}) is smaller than our dust limit ({})", msg.channel_reserve_satoshis, MIN_DUST_LIMIT_SATOSHIS)));
}
if holder_selected_channel_reserve_satoshis < msg.dust_limit_satoshis {
return Err(ChannelError::Close(format!("Dust limit ({}) too high for the channel reserve we require the remote to keep ({})", msg.dust_limit_satoshis, holder_selected_channel_reserve_satoshis)));
feerate_per_kw: msg.feerate_per_kw,
channel_value_satoshis: msg.funding_satoshis,
counterparty_dust_limit_satoshis: msg.dust_limit_satoshis,
- holder_dust_limit_satoshis,
+ holder_dust_limit_satoshis: MIN_DUST_LIMIT_SATOSHIS,
counterparty_max_htlc_value_in_flight_msat: cmp::min(msg.max_htlc_value_in_flight_msat, msg.funding_satoshis * 1000),
counterparty_selected_channel_reserve_satoshis: msg.channel_reserve_satoshis,
counterparty_htlc_minimum_msat: msg.htlc_minimum_msat,
if msg.max_accepted_htlcs < config.peer_channel_config_limits.min_max_accepted_htlcs {
return Err(ChannelError::Close(format!("max_accepted_htlcs ({}) is less than the user specified limit ({})", msg.max_accepted_htlcs, config.peer_channel_config_limits.min_max_accepted_htlcs)));
}
- if msg.dust_limit_satoshis < config.peer_channel_config_limits.min_dust_limit_satoshis {
- return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the user specified limit ({})", msg.dust_limit_satoshis, config.peer_channel_config_limits.min_dust_limit_satoshis)));
+ 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 > config.peer_channel_config_limits.max_dust_limit_satoshis {
- return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the user specified limit ({})", msg.dust_limit_satoshis, config.peer_channel_config_limits.max_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.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)));
// Create Node B's channel by receiving Node A's open_channel message
// Make sure A's dust limit is as we expect.
let open_channel_msg = node_a_chan.get_open_channel(genesis_block(network).header.block_hash());
- assert_eq!(open_channel_msg.dust_limit_satoshis, 1560);
let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap());
let node_b_chan = Channel::<EnforcingSigner>::new_from_req(&&feeest, &&keys_provider, node_b_node_id, InitFeatures::known(), &open_channel_msg, 7, &config).unwrap();
let mut accept_channel_msg = node_b_chan.get_accept_channel();
accept_channel_msg.dust_limit_satoshis = 546;
node_a_chan.accept_channel(&accept_channel_msg, &config, InitFeatures::known()).unwrap();
+ node_a_chan.holder_dust_limit_satoshis = 1560;
// Put some inbound and outbound HTLCs in A's channel.
let htlc_amount_msat = 11_092_000; // put an amount below A's effective dust limit but above B's.