--- /dev/null
+//! Various user-configurable channel limits and settings which ChannelManager
+//! applies for you.
+
+use ln::channelmanager::{BREAKDOWN_TIMEOUT, MAX_LOCAL_BREAKDOWN_TIMEOUT};
+
+/// Top-level config which holds ChannelHandshakeLimits and ChannelConfig.
+#[derive(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 config which affects behavior during channel lifetime.
+ pub channel_options: ChannelConfig,
+}
+
+impl UserConfig {
+ /// Provides sane defaults for most configurations (but with 0 relay fees!)
+ pub fn new() -> Self{
+ UserConfig {
+ own_channel_config: ChannelHandshakeConfig::new(),
+ peer_channel_config_limits: ChannelHandshakeLimits::new(),
+ channel_options: ChannelConfig::new(),
+ }
+ }
+}
+
+/// Configuration we set when applicable.
+#[derive(Clone, Debug)]
+pub struct ChannelHandshakeConfig {
+ /// Confirmations we will wait for before considering the channel locked in.
+ /// Applied only for inbound channels (see ChannelHandshakeLimits::max_minimum_depth for the
+ /// equivalent limit applied to outbound channels).
+ pub minimum_depth: u32,
+ /// Set to the amount of time we require our counterparty to wait to claim their money.
+ ///
+ /// It's one of the main parameter of our security model. We (or one of our watchtowers) MUST
+ /// be online to check for peer having broadcast a revoked transaction to steal our funds
+ /// at least once every our_to_self_delay blocks.
+ /// Default is BREAKDOWN_TIMEOUT, we enforce it as a minimum at channel opening so you can
+ /// tweak config to ask for more security, not less.
+ ///
+ /// Meanwhile, asking for a too high delay, we bother peer to freeze funds for nothing in
+ /// case of an honest unilateral channel close, which implicitly decrease the economic value of
+ /// our channel.
+ pub our_to_self_delay: u16,
+}
+
+impl ChannelHandshakeConfig {
+ /// Provides sane defaults for `ChannelHandshakeConfig`
+ pub fn new() -> ChannelHandshakeConfig {
+ ChannelHandshakeConfig {
+ minimum_depth: 6,
+ our_to_self_delay: BREAKDOWN_TIMEOUT,
+ }
+ }
+}
+
+/// Optional channel limits which are applied during channel creation.
+///
+/// These limits are only applied to our counterparty's limits, not our own.
+///
+/// Use 0/<type>::max_value() as appropriate to skip checking.
+#[derive(Copy, Clone, Debug)]
+pub struct ChannelHandshakeLimits {
+ /// Minimum allowed satoshis when a channel is funded, this is supplied by the sender and so
+ /// only applies to inbound channels.
+ pub min_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.
+ pub max_htlc_minimum_msat: u64,
+ /// The remote node sets a limit on the maximum value of pending HTLCs to them at any given
+ /// time to limit their funds exposure to HTLCs. This allows you to set a minimum such value.
+ pub min_max_htlc_value_in_flight_msat: u64,
+ /// The remote node will require we keep a certain amount in direct payment to ourselves at all
+ /// time, ensuring that we are able to be punished if we broadcast an old state. This allows to
+ /// you limit the amount which we will have to keep to ourselves (and cannot use for HTLCs).
+ pub max_channel_reserve_satoshis: u64,
+ /// The remote node sets a limit on the maximum number of pending HTLCs to them at any given
+ /// time. This allows you to set a minimum such value.
+ pub min_max_accepted_htlcs: u16,
+ /// Outputs below a certain value will not be added to on-chain transactions. The dust value is
+ /// required to always be higher than this value so this only applies to HTLC outputs (and
+ /// potentially to-self outputs before any payments have been made).
+ /// Thus, HTLCs below this amount plus HTLC transaction fees are not enforceable on-chain.
+ /// This setting allows you to set a minimum dust limit for their commitment transactions,
+ /// reflecting the reality that tiny outputs are not considered standard transactions and will
+ /// not propagate through the Bitcoin network.
+ /// Defaults to 546, or the current dust limit on the Bitcoin network.
+ pub min_dust_limit_satoshis: u64,
+ /// Maximum allowed threshold above which outputs will not be generated in their commitment
+ /// transactions.
+ /// HTLCs below this amount plus HTLC transaction fees are not enforceable on-chain.
+ pub max_dust_limit_satoshis: u64,
+ /// Before a channel is usable the funding transaction will need to be confirmed by at least a
+ /// certain number of blocks, specified by the node which is not the funder (as the funder can
+ /// assume they aren't going to double-spend themselves).
+ /// This config allows you to set a limit on the maximum amount of time to wait. Defaults to
+ /// 144 blocks or roughly one day and only applies to outbound channels.
+ pub max_minimum_depth: u32,
+ /// Set to force the incoming channel to match our announced channel preference in
+ /// ChannelConfig.
+ /// Defaults to true to make the default that no announced channels are possible (which is
+ /// appropriate for any nodes which are not online very reliably).
+ pub force_announced_channel_preference: bool,
+ /// Set to the amount of time we're willing to wait to claim money back to us.
+ ///
+ /// Not checking this value would be a security issue, as our peer would be able to set it to
+ /// max relative lock-time (a year) and we would "lose" money as it would be locked for a long time.
+ /// Default is MAX_LOCAL_BREAKDOWN_TIMEOUT, which we also enforce as a maximum value
+ /// so you can tweak config to reduce the loss of having useless locked funds (if your peer accepts)
+ pub their_to_self_delay: u16
+}
+
+impl ChannelHandshakeLimits {
+ /// Provides sane defaults for most configurations.
+ ///
+ /// Most additional limits are disabled except those with which specify a default in individual
+ /// field documentation. Note that this may result in barely-usable channels, but since they
+ /// are applied mostly only to incoming channels that's not much of a problem.
+ pub fn new() -> Self {
+ ChannelHandshakeLimits {
+ min_funding_satoshis: 0,
+ 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,
+ min_dust_limit_satoshis: 546,
+ max_dust_limit_satoshis: <u64>::max_value(),
+ 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)]
+pub struct ChannelConfig {
+ /// Amount (in millionths of a satoshi) the channel will charge per transferred satoshi.
+ /// This may be allowed to change at runtime in a later update, however doing so must result in
+ /// update messages sent to notify all nodes of our updated relay fee.
+ pub fee_proportional_millionths: u32,
+ /// 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_preferences is set.
+ ///
+ /// This cannot be changed after the initial channel handshake.
+ 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.
+ pub commit_upfront_shutdown_pubkey: bool
+}
+
+impl ChannelConfig {
+ /// Provides sane defaults for most configurations (but with zero relay fees!).
+ pub fn new() -> Self {
+ ChannelConfig {
+ fee_proportional_millionths: 0,
+ announced_channel: false,
+ commit_upfront_shutdown_pubkey: true,
+ }
+ }
+}
+
+//Add write and readable traits to channelconfig
+impl_writeable!(ChannelConfig, 8+1+1, {
+ fee_proportional_millionths,
+ announced_channel,
+ commit_upfront_shutdown_pubkey
+});
projects / rust-lightning / blobdiff