X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Futil%2Fconfig.rs;h=f3fd0ce70793451fbe6e58ce3e2efc81ca84b3b5;hb=c620944f16e63448c9c4c541c1390e498888b7df;hp=0b61a5699ea853489d1a59901584784edcba7c0f;hpb=88fef649b15fa030cb91de76d58346a0bc408834;p=rust-lightning diff --git a/lightning/src/util/config.rs b/lightning/src/util/config.rs index 0b61a569..f3fd0ce7 100644 --- a/lightning/src/util/config.rs +++ b/lightning/src/util/config.rs @@ -1,57 +1,60 @@ +// This file is Copyright its original authors, visible in version control +// history. +// +// This file is licensed under the Apache License, Version 2.0 or the MIT license +// , at your option. +// You may not use this file except in accordance with one or both of these +// licenses. + //! 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)] +/// +/// Default::default() provides sane defaults. +#[derive(Copy, 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). + /// + /// Default value: 6. pub minimum_depth: u32, - /// Set to the amount of time we require our counterparty to wait to claim their money. + /// 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 + /// transaction). /// - /// 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. + /// This is one of the main parameters of our security model. We (or one of our watchtowers) MUST + /// be online to check for revoked transactions on-chain at least once every our_to_self_delay + /// blocks (minus some margin to allow us enough time to broadcast and confirm a transaction, + /// possibly with time in between to RBF the spending transaction). /// /// 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. + /// + /// Default value: [`BREAKDOWN_TIMEOUT`], we enforce it as a minimum at channel opening so you + /// can tweak config to ask for more security, not less. pub our_to_self_delay: u16, + /// Set to the smallest value HTLC we will accept to process. + /// + /// This value is sent to our counterparty on channel-open and we close the channel any time + /// our counterparty misbehaves by sending us an HTLC with a value smaller than this. + /// + /// 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, } -impl ChannelHandshakeConfig { - /// Provides sane defaults for `ChannelHandshakeConfig` - pub fn new() -> ChannelHandshakeConfig { +impl Default for ChannelHandshakeConfig { + fn default() -> ChannelHandshakeConfig { ChannelHandshakeConfig { minimum_depth: 6, our_to_self_delay: BREAKDOWN_TIMEOUT, + our_htlc_minimum_msat: 1, } } } @@ -61,72 +64,71 @@ impl ChannelHandshakeConfig { /// These limits are only applied to our counterparty's limits, not our own. /// /// Use 0/::max_value() as appropriate to skip checking. +/// +/// 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. #[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. + /// + /// Default value: 0. 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. + /// + /// Default value: u64::max_value. 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. + /// + /// Default value: 0. 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). + /// + /// Default value: u64::max_value. 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. + /// + /// Default value: 0. 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. + /// This config allows you to set a limit on the maximum amount of time to wait. + /// + /// Default value: 144, 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 + /// + /// Default value: 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) + /// + /// Default value: 2016, 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 { +impl Default for ChannelHandshakeLimits { + fn default() -> Self { ChannelHandshakeLimits { min_funding_satoshis: 0, max_htlc_minimum_msat: ::max_value(), min_max_htlc_value_in_flight_msat: 0, max_channel_reserve_satoshis: ::max_value(), min_max_accepted_htlcs: 0, - min_dust_limit_satoshis: 546, - max_dust_limit_satoshis: ::max_value(), max_minimum_depth: 144, force_announced_channel_preference: true, their_to_self_delay: MAX_LOCAL_BREAKDOWN_TIMEOUT, @@ -138,10 +140,46 @@ impl ChannelHandshakeLimits { /// with our counterparty. #[derive(Copy, Clone, Debug)] pub struct ChannelConfig { - /// Amount (in millionths of a satoshi) the channel will charge per transferred satoshi. + /// Amount (in millionths of a satoshi) charged per satoshi for payments forwarded outbound + /// over the channel. + /// 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. + /// + /// Default value: 0. + pub forwarding_fee_proportional_millionths: u32, + /// Amount (in milli-satoshi) charged for payments forwarded outbound over the channel, in + /// excess of [`forwarding_fee_proportional_millionths`]. /// 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, + /// + /// The default value of a single satoshi roughly matches the market rate on many routing nodes + /// as of July 2021. Adjusting it upwards or downwards may change whether nodes route through + /// this node. + /// + /// Default value: 1000. + /// + /// [`forwarding_fee_proportional_millionths`]: ChannelConfig::forwarding_fee_proportional_millionths + pub forwarding_fee_base_msat: u32, + /// The difference in the CLTV value between incoming HTLCs and an outbound HTLC forwarded over + /// the channel this config applies to. + /// + /// This is analogous to [`ChannelHandshakeConfig::our_to_self_delay`] but applies to in-flight + /// HTLC balance when a channel appears on-chain whereas + /// [`ChannelHandshakeConfig::our_to_self_delay`] applies to the remaining + /// (non-HTLC-encumbered) balance. + /// + /// Thus, for HTLC-encumbered balances to be enforced on-chain when a channel is force-closed, + /// we (or one of our watchtowers) MUST be online to check for broadcast of the current + /// commitment transaction at least once per this many blocks (minus some margin to allow us + /// enough time to broadcast and confirm a transaction, possibly with time in between to RBF + /// the spending transaction). + /// + /// Default value: 72 (12 hours at an average of 6 blocks/hour). + /// Minimum value: [`MIN_CLTV_EXPIRY_DELTA`], any values less than this will be treated as + /// [`MIN_CLTV_EXPIRY_DELTA`] instead. + /// + /// [`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. /// @@ -151,6 +189,8 @@ pub struct ChannelConfig { /// channels unless ChannelHandshakeLimits::force_announced_channel_preferences 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 @@ -161,23 +201,52 @@ pub struct ChannelConfig { /// 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 } -impl ChannelConfig { +impl Default for ChannelConfig { /// Provides sane defaults for most configurations (but with zero relay fees!). - pub fn new() -> Self { + fn default() -> Self { ChannelConfig { - fee_proportional_millionths: 0, + 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, } } } -//Add write and readable traits to channelconfig -impl_writeable!(ChannelConfig, 8+1+1, { - fee_proportional_millionths, - announced_channel, - commit_upfront_shutdown_pubkey +impl_writeable_tlv_based!(ChannelConfig, { + (0, forwarding_fee_proportional_millionths, required), + (2, cltv_expiry_delta, required), + (4, announced_channel, required), + (6, commit_upfront_shutdown_pubkey, required), + (8, forwarding_fee_base_msat, required), }); + +/// 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 config which affects behavior during channel lifetime. + pub channel_options: ChannelConfig, +} + +impl Default for UserConfig { + fn default() -> Self { + UserConfig { + own_channel_config: ChannelHandshakeConfig::default(), + peer_channel_config_limits: ChannelHandshakeLimits::default(), + channel_options: ChannelConfig::default(), + } + } +}