//! Various user-configurable channel limits and settings which ChannelManager
//! applies for you.
-use ln::channelmanager::{BREAKDOWN_TIMEOUT, MAX_LOCAL_BREAKDOWN_TIMEOUT};
+use crate::ln::channel::MAX_FUNDING_SATOSHIS_NO_WUMBO;
+use crate::ln::channelmanager::{BREAKDOWN_TIMEOUT, MAX_LOCAL_BREAKDOWN_TIMEOUT};
/// Configuration we set when applicable.
///
/// Applied only for inbound channels (see ChannelHandshakeLimits::max_minimum_depth for the
/// equivalent limit applied to outbound channels).
///
+ /// A lower-bound of 1 is applied, requiring all channels to have a confirmed commitment
+ /// transaction before operation. If you wish to accept channels with zero confirmations, see
+ /// [`UserConfig::manually_accept_inbound_channels`] and
+ /// [`ChannelManager::accept_inbound_channel_from_trusted_peer_0conf`].
+ ///
/// Default value: 6.
+ ///
+ /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
+ /// [`ChannelManager::accept_inbound_channel_from_trusted_peer_0conf`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel_from_trusted_peer_0conf
pub minimum_depth: u32,
/// 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
/// Default value: 1. If the value is less than 1, it is ignored and set to 1, as is required
/// by the protocol.
pub our_htlc_minimum_msat: u64,
+ /// Sets the percentage of the channel value we will cap the total value of outstanding inbound
+ /// HTLCs to.
+ ///
+ /// This can be set to a value between 1-100, where the value corresponds to the percent of the
+ /// channel value in whole percentages.
+ ///
+ /// Note that:
+ /// * If configured to another value than the default value 10, any new channels created with
+ /// the non default value will cause versions of LDK prior to 0.0.104 to refuse to read the
+ /// `ChannelManager`.
+ ///
+ /// * This caps the total value for inbound HTLCs in-flight only, and there's currently
+ /// no way to configure the cap for the total value of outbound HTLCs in-flight.
+ ///
+ /// * The requirements for your node being online to ensure the safety of HTLC-encumbered funds
+ /// are different from the non-HTLC-encumbered funds. This makes this an important knob to
+ /// restrict exposure to loss due to being offline for too long.
+ /// See [`ChannelHandshakeConfig::our_to_self_delay`] and [`ChannelConfig::cltv_expiry_delta`]
+ /// for more information.
+ ///
+ /// Default value: 10.
+ /// Minimum value: 1, any values less than 1 will be treated as 1 instead.
+ /// Maximum value: 100, any values larger than 100 will be treated as 100 instead.
+ pub max_inbound_htlc_value_in_flight_percent_of_channel: u8,
+ /// If set, we attempt to negotiate the `scid_privacy` (referred to as `scid_alias` in the
+ /// BOLTs) option for outbound private channels. This provides better privacy by not including
+ /// our real on-chain channel UTXO in each invoice and requiring that our counterparty only
+ /// relay HTLCs to us using the channel's SCID alias.
+ ///
+ /// If this option is set, channels may be created that will not be readable by LDK versions
+ /// prior to 0.0.106, causing [`ChannelManager`]'s read method to return a
+ /// [`DecodeError::InvalidValue`].
+ ///
+ /// Note that setting this to true does *not* prevent us from opening channels with
+ /// counterparties that do not support the `scid_alias` option; we will simply fall back to a
+ /// private channel without that option.
+ ///
+ /// Ignored if the channel is negotiated to be announced, see
+ /// [`ChannelHandshakeConfig::announced_channel`] and
+ /// [`ChannelHandshakeLimits::force_announced_channel_preference`] for more.
+ ///
+ /// Default value: false. This value is likely to change to true in the future.
+ ///
+ /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+ /// [`DecodeError::InvalidValue`]: crate::ln::msgs::DecodeError::InvalidValue
+ pub negotiate_scid_privacy: bool,
+ /// Set to announce the channel publicly and notify all nodes that they can route via this
+ /// channel.
+ ///
+ /// This should only be set to true for nodes which expect to be online reliably.
+ ///
+ /// As the node which funds a channel picks this value this will only apply for new outbound
+ /// channels unless [`ChannelHandshakeLimits::force_announced_channel_preference`] is set.
+ ///
+ /// Default value: false.
+ pub announced_channel: bool,
+ /// When set, we commit to an upfront shutdown_pubkey at channel open. If our counterparty
+ /// supports it, they will then enforce the mutual-close output to us matches what we provided
+ /// at intialization, preventing us from closing to an alternate pubkey.
+ ///
+ /// This is set to true by default to provide a slight increase in security, though ultimately
+ /// any attacker who is able to take control of a channel can just as easily send the funds via
+ /// lightning payments, so we never require that our counterparties support this option.
+ ///
+ /// The upfront key committed is provided from [`SignerProvider::get_shutdown_scriptpubkey`].
+ ///
+ /// Default value: true.
+ ///
+ /// [`SignerProvider::get_shutdown_scriptpubkey`]: crate::chain::keysinterface::SignerProvider::get_shutdown_scriptpubkey
+ pub commit_upfront_shutdown_pubkey: bool,
+
+ /// The Proportion of the channel value to configure as counterparty's channel reserve,
+ /// i.e., `their_channel_reserve_satoshis` for both outbound and inbound channels.
+ ///
+ /// `their_channel_reserve_satoshis` is the minimum balance that the other node has to maintain
+ /// on their side, at all times.
+ /// This ensures that if our counterparty broadcasts a revoked state, we can punish them by
+ /// claiming at least this value on chain.
+ ///
+ /// Channel reserve values greater than 30% could be considered highly unreasonable, since that
+ /// amount can never be used for payments.
+ /// Also, if our selected channel reserve for counterparty and counterparty's selected
+ /// channel reserve for us sum up to equal or greater than channel value, channel negotiations
+ /// will fail.
+ ///
+ /// Note: Versions of LDK earlier than v0.0.104 will fail to read channels with any channel reserve
+ /// other than the default value.
+ ///
+ /// Default value: 1% of channel value, i.e., configured as 10,000 millionths.
+ /// Minimum value: If the calculated proportional value is less than 1000 sats, it will be treated
+ /// as 1000 sats instead, which is a safe implementation-specific lower bound.
+ /// Maximum value: 1,000,000, any values larger than 1 Million will be treated as 1 Million (or 100%)
+ /// instead, although channel negotiations will fail in that case.
+ pub their_channel_reserve_proportional_millionths: u32
}
impl Default for ChannelHandshakeConfig {
minimum_depth: 6,
our_to_self_delay: BREAKDOWN_TIMEOUT,
our_htlc_minimum_msat: 1,
+ max_inbound_htlc_value_in_flight_percent_of_channel: 10,
+ negotiate_scid_privacy: false,
+ announced_channel: false,
+ commit_upfront_shutdown_pubkey: true,
+ their_channel_reserve_proportional_millionths: 10_000,
}
}
}
///
/// These limits are only applied to our counterparty's limits, not our own.
///
-/// Use 0/<type>::max_value() as appropriate to skip checking.
+/// Use 0/`<type>::max_value()` as appropriate to skip checking.
///
/// Provides sane defaults for most configurations.
///
/// are applied mostly only to incoming channels that's not much of a problem.
#[derive(Copy, Clone, Debug)]
pub struct ChannelHandshakeLimits {
- /// Minimum allowed satoshis when a channel is funded, this is supplied by the sender and so
+ /// Minimum allowed satoshis when a channel is funded. This is supplied by the sender and so
/// only applies to inbound channels.
///
/// Default value: 0.
pub min_funding_satoshis: u64,
+ /// Maximum allowed satoshis when a channel is funded. This is supplied by the sender and so
+ /// only applies to inbound channels.
+ ///
+ /// Default value: 2^24 - 1.
+ pub max_funding_satoshis: u64,
/// The remote node sets a limit on the minimum size of HTLCs we can send to them. This allows
/// you to limit the maximum minimum-size they can require.
///
///
/// Default value: 144, or roughly one day and only applies to outbound channels.
pub max_minimum_depth: u32,
+ /// Whether we implicitly trust funding transactions generated by us for our own outbound
+ /// channels to not be double-spent.
+ ///
+ /// If this is set, we assume that our own funding transactions are *never* double-spent, and
+ /// thus we can trust them without any confirmations. This is generally a reasonable
+ /// assumption, given we're the only ones who could ever double-spend it (assuming we have sole
+ /// control of the signing keys).
+ ///
+ /// You may wish to un-set this if you allow the user to (or do in an automated fashion)
+ /// double-spend the funding transaction to RBF with an alternative channel open.
+ ///
+ /// This only applies if our counterparty set their confirmations-required value to 0, and we
+ /// always trust our own funding transaction at 1 confirmation irrespective of this value.
+ /// Thus, this effectively acts as a `min_minimum_depth`, with the only possible values being
+ /// `true` (0) and `false` (1).
+ ///
+ /// Default value: true
+ pub trust_own_funding_0conf: bool,
/// Set to force an incoming channel to match our announced channel preference in
- /// [`ChannelConfig::announced_channel`].
+ /// [`ChannelHandshakeConfig::announced_channel`].
///
/// For a node which is not online reliably, this should be set to true and
- /// [`ChannelConfig::announced_channel`] set to false, ensuring that no announced (aka public)
+ /// [`ChannelHandshakeConfig::announced_channel`] set to false, ensuring that no announced (aka public)
/// channels will ever be opened.
///
/// Default value: true.
fn default() -> Self {
ChannelHandshakeLimits {
min_funding_satoshis: 0,
+ max_funding_satoshis: MAX_FUNDING_SATOSHIS_NO_WUMBO,
max_htlc_minimum_msat: <u64>::max_value(),
min_max_htlc_value_in_flight_msat: 0,
max_channel_reserve_satoshis: <u64>::max_value(),
min_max_accepted_htlcs: 0,
+ trust_own_funding_0conf: true,
max_minimum_depth: 144,
force_announced_channel_preference: true,
their_to_self_delay: MAX_LOCAL_BREAKDOWN_TIMEOUT,
/// Options which apply on a per-channel basis and may change at runtime or based on negotiation
/// with our counterparty.
-#[derive(Copy, Clone, Debug)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub struct ChannelConfig {
/// Amount (in millionths of a satoshi) charged per satoshi for payments forwarded outbound
/// over the channel.
///
/// [`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.
- ///
- /// This should only be set to true for nodes which expect to be online reliably.
- ///
- /// As the node which funds a channel picks this value this will only apply for new outbound
- /// channels unless [`ChannelHandshakeLimits::force_announced_channel_preference`] is set.
- ///
- /// This cannot be changed after the initial channel handshake.
- ///
- /// Default value: false.
- pub announced_channel: bool,
- /// When set, we commit to an upfront shutdown_pubkey at channel open. If our counterparty
- /// supports it, they will then enforce the mutual-close output to us matches what we provided
- /// at intialization, preventing us from closing to an alternate pubkey.
- ///
- /// This is set to true by default to provide a slight increase in security, though ultimately
- /// any attacker who is able to take control of a channel can just as easily send the funds via
- /// lightning payments, so we never require that our counterparties support this option.
- ///
- /// This cannot be changed after a channel has been initialized.
- ///
- /// Default value: true.
- pub commit_upfront_shutdown_pubkey: bool,
/// Limit our total exposure to in-flight HTLCs which are burned to fees as they are too
/// small to claim on-chain.
///
/// to such payments may be sustantial if there are many dust HTLCs present when the
/// channel is force-closed.
///
+ /// The dust threshold for each HTLC is based on the `dust_limit_satoshis` for each party in a
+ /// channel negotiated throughout the channel open process, along with the fees required to have
+ /// a broadcastable HTLC spending transaction. When a channel supports anchor outputs
+ /// (specifically the zero fee HTLC transaction variant), this threshold no longer takes into
+ /// account the HTLC transaction fee as it is zero.
+ ///
/// This limit is applied for sent, forwarded, and received HTLCs and limits the total
/// exposure across all three types per-channel. Setting this too low may prevent the
/// sending or receipt of low-value HTLCs on high-traffic nodes, and this limit is very
forwarding_fee_proportional_millionths: 0,
forwarding_fee_base_msat: 1000,
cltv_expiry_delta: 6 * 12, // 6 blocks/hour * 12 hours
- announced_channel: false,
- commit_upfront_shutdown_pubkey: true,
max_dust_htlc_exposure_msat: 5_000_000,
force_close_avoidance_max_fee_satoshis: 1000,
}
impl_writeable_tlv_based!(ChannelConfig, {
(0, forwarding_fee_proportional_millionths, required),
- (1, max_dust_htlc_exposure_msat, (default_value, 5_000_000)),
- (2, cltv_expiry_delta, required),
- (3, force_close_avoidance_max_fee_satoshis, (default_value, 1000)),
- (4, announced_channel, required),
- (6, commit_upfront_shutdown_pubkey, required),
- (8, forwarding_fee_base_msat, required),
+ (2, forwarding_fee_base_msat, required),
+ (4, cltv_expiry_delta, required),
+ (6, max_dust_htlc_exposure_msat, required),
+ // ChannelConfig serialized this field with a required type of 8 prior to the introduction of
+ // LegacyChannelConfig. To make sure that serialization is not compatible with this one, we use
+ // the next required type of 10, which if seen by the old serialization will always fail.
+ (10, force_close_avoidance_max_fee_satoshis, required),
});
+/// Legacy version of [`ChannelConfig`] that stored the static
+/// [`ChannelHandshakeConfig::announced_channel`] and
+/// [`ChannelHandshakeConfig::commit_upfront_shutdown_pubkey`] fields.
+#[derive(Copy, Clone, Debug)]
+pub(crate) struct LegacyChannelConfig {
+ pub(crate) options: ChannelConfig,
+ /// Deprecated but may still be read from. See [`ChannelHandshakeConfig::announced_channel`] to
+ /// set this when opening/accepting a channel.
+ pub(crate) announced_channel: bool,
+ /// Deprecated but may still be read from. See
+ /// [`ChannelHandshakeConfig::commit_upfront_shutdown_pubkey`] to set this when
+ /// opening/accepting a channel.
+ pub(crate) commit_upfront_shutdown_pubkey: bool,
+}
+
+impl Default for LegacyChannelConfig {
+ fn default() -> Self {
+ Self {
+ options: ChannelConfig::default(),
+ announced_channel: false,
+ commit_upfront_shutdown_pubkey: true,
+ }
+ }
+}
+
+impl crate::util::ser::Writeable for LegacyChannelConfig {
+ fn write<W: crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), crate::io::Error> {
+ write_tlv_fields!(writer, {
+ (0, self.options.forwarding_fee_proportional_millionths, required),
+ (1, self.options.max_dust_htlc_exposure_msat, (default_value, 5_000_000)),
+ (2, self.options.cltv_expiry_delta, required),
+ (3, self.options.force_close_avoidance_max_fee_satoshis, (default_value, 1000)),
+ (4, self.announced_channel, required),
+ (6, self.commit_upfront_shutdown_pubkey, required),
+ (8, self.options.forwarding_fee_base_msat, required),
+ });
+ Ok(())
+ }
+}
+
+impl crate::util::ser::Readable for LegacyChannelConfig {
+ fn read<R: crate::io::Read>(reader: &mut R) -> Result<Self, crate::ln::msgs::DecodeError> {
+ let mut forwarding_fee_proportional_millionths = 0;
+ let mut max_dust_htlc_exposure_msat = 5_000_000;
+ let mut cltv_expiry_delta = 0;
+ let mut force_close_avoidance_max_fee_satoshis = 1000;
+ let mut announced_channel = false;
+ let mut commit_upfront_shutdown_pubkey = false;
+ let mut forwarding_fee_base_msat = 0;
+ read_tlv_fields!(reader, {
+ (0, forwarding_fee_proportional_millionths, required),
+ (1, max_dust_htlc_exposure_msat, (default_value, 5_000_000u64)),
+ (2, cltv_expiry_delta, required),
+ (3, force_close_avoidance_max_fee_satoshis, (default_value, 1000u64)),
+ (4, announced_channel, required),
+ (6, commit_upfront_shutdown_pubkey, required),
+ (8, forwarding_fee_base_msat, required),
+ });
+ Ok(Self {
+ options: ChannelConfig {
+ forwarding_fee_proportional_millionths,
+ max_dust_htlc_exposure_msat,
+ cltv_expiry_delta,
+ force_close_avoidance_max_fee_satoshis,
+ forwarding_fee_base_msat,
+ },
+ announced_channel,
+ commit_upfront_shutdown_pubkey,
+ })
+ }
+}
+
/// Top-level config which holds ChannelHandshakeLimits and ChannelConfig.
///
/// Default::default() provides sane defaults for most configurations
/// (but currently with 0 relay fees!)
#[derive(Copy, Clone, Debug)]
pub struct UserConfig {
- /// Channel config that we propose to our counterparty.
- pub own_channel_config: ChannelHandshakeConfig,
- /// Limits applied to our counterparty's proposed channel config settings.
- pub peer_channel_config_limits: ChannelHandshakeLimits,
+ /// Channel handshake config that we propose to our counterparty.
+ pub channel_handshake_config: ChannelHandshakeConfig,
+ /// Limits applied to our counterparty's proposed channel handshake config settings.
+ pub channel_handshake_limits: ChannelHandshakeLimits,
/// Channel config which affects behavior during channel lifetime.
- pub channel_options: ChannelConfig,
+ pub channel_config: ChannelConfig,
/// If this is set to false, we will reject any HTLCs which were to be forwarded over private
/// channels. This prevents us from taking on HTLC-forwarding risk when we intend to run as a
/// node which is not online reliably.
///
/// For nodes which are not online reliably, you should set all channels to *not* be announced
- /// (using [`ChannelConfig::announced_channel`] and
+ /// (using [`ChannelHandshakeConfig::announced_channel`] and
/// [`ChannelHandshakeLimits::force_announced_channel_preference`]) and set this to false to
/// ensure you are not exposed to any forwarding risk.
///
/// If this is set to false, we do not accept inbound requests to open a new channel.
/// Default value: true.
pub accept_inbound_channels: bool,
+ /// If this is set to true, the user needs to manually accept inbound requests to open a new
+ /// channel.
+ ///
+ /// When set to true, [`Event::OpenChannelRequest`] will be triggered once a request to open a
+ /// new inbound channel is received through a [`msgs::OpenChannel`] message. In that case, a
+ /// [`msgs::AcceptChannel`] message will not be sent back to the counterparty node unless the
+ /// user explicitly chooses to accept the request.
+ ///
+ /// Default value: false.
+ ///
+ /// [`Event::OpenChannelRequest`]: crate::util::events::Event::OpenChannelRequest
+ /// [`msgs::OpenChannel`]: crate::ln::msgs::OpenChannel
+ /// [`msgs::AcceptChannel`]: crate::ln::msgs::AcceptChannel
+ pub manually_accept_inbound_channels: bool,
+ /// If this is set to true, LDK will intercept HTLCs that are attempting to be forwarded over
+ /// fake short channel ids generated via [`ChannelManager::get_intercept_scid`]. Upon HTLC
+ /// intercept, LDK will generate an [`Event::HTLCIntercepted`] which MUST be handled by the user.
+ ///
+ /// Setting this to true may break backwards compatibility with LDK versions < 0.0.113.
+ ///
+ /// Default value: false.
+ ///
+ /// [`ChannelManager::get_intercept_scid`]: crate::ln::channelmanager::ChannelManager::get_intercept_scid
+ /// [`Event::HTLCIntercepted`]: crate::util::events::Event::HTLCIntercepted
+ pub accept_intercept_htlcs: bool,
}
impl Default for UserConfig {
fn default() -> Self {
UserConfig {
- own_channel_config: ChannelHandshakeConfig::default(),
- peer_channel_config_limits: ChannelHandshakeLimits::default(),
- channel_options: ChannelConfig::default(),
+ channel_handshake_config: ChannelHandshakeConfig::default(),
+ channel_handshake_limits: ChannelHandshakeLimits::default(),
+ channel_config: ChannelConfig::default(),
accept_forwards_to_priv_channels: false,
accept_inbound_channels: true,
+ manually_accept_inbound_channels: false,
+ accept_intercept_htlcs: false,
}
}
}
projects / rust-lightning / blobdiff