1 //! Various user-configurable channel limits and settings which ChannelManager
4 /// Top-level config which holds ChannelHandshakeLimits and ChannelConfig.
5 #[derive(Clone, Debug)]
6 pub struct UserConfig {
7 /// Channel config that we propose to our counterparty.
8 pub own_channel_config: ChannelHandshakeConfig,
9 /// Limits applied to our counterparty's proposed channel config settings.
10 pub peer_channel_config_limits: ChannelHandshakeLimits,
11 /// Channel config which affects behavior during channel lifetime.
12 pub channel_options: ChannelConfig,
16 /// Provides sane defaults for most configurations (but with 0 relay fees!)
19 own_channel_config: ChannelHandshakeConfig::new(),
20 peer_channel_config_limits: ChannelHandshakeLimits::new(),
21 channel_options: ChannelConfig::new(),
26 /// Configuration we set when applicable.
27 #[derive(Clone, Debug)]
28 pub struct ChannelHandshakeConfig {
29 /// Confirmations we will wait for before considering the channel locked in.
30 /// Applied only for inbound channels (see ChannelHandshakeLimits::max_minimum_depth for the
31 /// equivalent limit applied to outbound channels).
32 pub minimum_depth: u32,
35 impl ChannelHandshakeConfig {
36 /// Provides sane defaults for `ChannelHandshakeConfig`
37 pub fn new() -> ChannelHandshakeConfig {
38 ChannelHandshakeConfig {
44 /// Optional channel limits which are applied during channel creation.
46 /// These limits are only applied to our counterparty's limits, not our own.
48 /// Use 0/<type>::max_value() as appropriate to skip checking.
49 #[derive(Copy, Clone, Debug)]
50 pub struct ChannelHandshakeLimits {
51 /// Minimum allowed satoshis when a channel is funded, this is supplied by the sender and so
52 /// only applies to inbound channels.
53 pub min_funding_satoshis: u64,
54 /// The remote node sets a limit on the minimum size of HTLCs we can send to them. This allows
55 /// you to limit the maximum minimum-size they can require.
56 pub max_htlc_minimum_msat: u64,
57 /// The remote node sets a limit on the maximum value of pending HTLCs to them at any given
58 /// time to limit their funds exposure to HTLCs. This allows you to set a minimum such value.
59 pub min_max_htlc_value_in_flight_msat: u64,
60 /// The remote node will require we keep a certain amount in direct payment to ourselves at all
61 /// time, ensuring that we are able to be punished if we broadcast an old state. This allows to
62 /// you limit the amount which we will have to keep to ourselves (and cannot use for HTLCs).
63 pub max_channel_reserve_satoshis: u64,
64 /// The remote node sets a limit on the maximum number of pending HTLCs to them at any given
65 /// time. This allows you to set a minimum such value.
66 pub min_max_accepted_htlcs: u16,
67 /// Outputs below a certain value will not be added to on-chain transactions. The dust value is
68 /// required to always be higher than this value so this only applies to HTLC outputs (and
69 /// potentially to-self outputs before any payments have been made).
70 /// Thus, HTLCs below this amount plus HTLC transaction fees are not enforceable on-chain.
71 /// This setting allows you to set a minimum dust limit for their commitment transactions,
72 /// reflecting the reality that tiny outputs are not considered standard transactions and will
73 /// not propagate through the Bitcoin network.
74 /// Defaults to 546, or the current dust limit on the Bitcoin network.
75 pub min_dust_limit_satoshis: u64,
76 /// Maximum allowed threshold above which outputs will not be generated in their commitment
78 /// HTLCs below this amount plus HTLC transaction fees are not enforceable on-chain.
79 pub max_dust_limit_satoshis: u64,
80 /// Before a channel is usable the funding transaction will need to be confirmed by at least a
81 /// certain number of blocks, specified by the node which is not the funder (as the funder can
82 /// assume they aren't going to double-spend themselves).
83 /// This config allows you to set a limit on the maximum amount of time to wait. Defaults to
84 /// 144 blocks or roughly one day and only applies to outbound channels.
85 pub max_minimum_depth: u32,
86 /// Set to force the incoming channel to match our announced channel preference in
88 /// Defaults to true to make the default that no announced channels are possible (which is
89 /// appropriate for any nodes which are not online very reliably).
90 pub force_announced_channel_preference: bool,
93 impl ChannelHandshakeLimits {
94 /// Provides sane defaults for most configurations.
96 /// Most additional limits are disabled except those with which specify a default in individual
97 /// field documentation. Note that this may result in barely-usable channels, but since they
98 /// are applied mostly only to incoming channels that's not much of a problem.
99 pub fn new() -> Self {
100 ChannelHandshakeLimits {
101 min_funding_satoshis: 0,
102 max_htlc_minimum_msat: <u64>::max_value(),
103 min_max_htlc_value_in_flight_msat: 0,
104 max_channel_reserve_satoshis: <u64>::max_value(),
105 min_max_accepted_htlcs: 0,
106 min_dust_limit_satoshis: 546,
107 max_dust_limit_satoshis: <u64>::max_value(),
108 max_minimum_depth: 144,
109 force_announced_channel_preference: true,
114 /// Options which apply on a per-channel basis and may change at runtime or based on negotiation
115 /// with our counterparty.
116 #[derive(Copy, Clone, Debug)]
117 pub struct ChannelConfig {
118 /// Amount (in millionths of a satoshi) the channel will charge per transferred satoshi.
119 /// This may be allowed to change at runtime in a later update, however doing so must result in
120 /// update messages sent to notify all nodes of our updated relay fee.
121 pub fee_proportional_millionths: u32,
122 /// Set to announce the channel publicly and notify all nodes that they can route via this
125 /// This should only be set to true for nodes which expect to be online reliably.
127 /// As the node which funds a channel picks this value this will only apply for new outbound
128 /// channels unless ChannelHandshakeLimits::force_announced_channel_preferences is set.
130 /// This cannot be changed after the initial channel handshake.
131 pub announced_channel: bool,
135 /// Provides sane defaults for most configurations (but with zero relay fees!).
136 pub fn new() -> Self {
138 fee_proportional_millionths: 0,
139 announced_channel: false,
144 //Add write and readable traits to channelconfig
145 impl_writeable!(ChannelConfig, 8+1, {
146 fee_proportional_millionths,