package loop import ( "time" "github.com/btcsuite/btcd/btcutil" "github.com/lightninglabs/loop/loopdb" "github.com/lightninglabs/loop/swap" "github.com/lightningnetwork/lnd/lntypes" "github.com/lightningnetwork/lnd/routing/route" "github.com/lightningnetwork/lnd/zpay32" ) // OutRequest contains the required parameters for a loop out swap. type OutRequest struct { // Amount specifies the requested swap amount in sat. This does not // include the swap and miner fee. Amount btcutil.Amount // Destination address for the swap. DestAddr btcutil.Address // MaxSwapRoutingFee is the maximum off-chain fee in msat that may be // paid for payment to the server. This limit is applied during path // finding. Typically this value is taken from the response of the // LoopOutQuote call. MaxSwapRoutingFee btcutil.Amount // MaxPrepayRoutingFee is the maximum off-chain fee in msat that may be // paid for payment to the server. This limit is applied during path // finding. Typically this value is taken from the response of the // LoopOutQuote call. MaxPrepayRoutingFee btcutil.Amount // MaxSwapFee is the maximum we are willing to pay the server for the // swap. This value is not disclosed in the swap initiation call, but // if the server asks for a higher fee, we abort the swap. Typically // this value is taken from the response of the LoopOutQuote call. It // includes the prepay amount. MaxSwapFee btcutil.Amount // MaxPrepayAmount is the maximum amount of the swap fee that may be // charged as a prepayment. MaxPrepayAmount btcutil.Amount // MaxMinerFee is the maximum in on-chain fees that we are willing to // spent. If we want to sweep the on-chain htlc and the fee estimate // turns out higher than this value, we cancel the swap. If the fee // estimate is lower, we publish the sweep tx. // // If the sweep tx isn't confirmed, we are forced to ratchet up fees // until it is swept. Possibly even exceeding MaxMinerFee if we get // close to the htlc timeout. Because the initial publication revealed // the preimage, we have no other choice. The server may already have // pulled the off-chain htlc. Only when the fee becomes higher than the // swap amount, we can only wait for fees to come down and hope - if we // are past the timeout - that the server isn't publishing the // revocation. // // MaxMinerFee is typically taken from the response of the // LoopOutQuote call. MaxMinerFee btcutil.Amount // SweepConfTarget specifies the targeted confirmation target for the // client sweep tx. SweepConfTarget int32 // HtlcConfirmations specifies the number of confirmations we require // for on chain loop out htlcs. HtlcConfirmations int32 // OutgoingChanSet optionally specifies the short channel ids of the // channels that may be used to loop out. OutgoingChanSet loopdb.ChannelSet // SwapPublicationDeadline can be set by the client to allow the server // delaying publication of the swap HTLC to save on chain fees. SwapPublicationDeadline time.Time // Expiry is the absolute expiry height of the on-chain htlc. Expiry int32 // Label contains an optional label for the swap. Label string // Initiator is an optional string that identifies what software // initiated the swap (loop CLI, autolooper, LiT UI and so on) and is // appended to the user agent string. Initiator string } // Out contains the full details of a loop out request. This includes things // like the payment hash, the total value, and the final CTLV delay of the // swap. We'll use this to track an active swap throughout that various swap // stages. type Out struct { // LoopOutContract describes the details of this loop.Out. Using these // details,the full swap can be executed. loopdb.LoopOutContract // State is the current state of the target swap. State loopdb.SwapState // SwapInfoKit contains shared data amongst all swap types. SwapInfoKit } // LoopOutQuoteRequest specifies the swap parameters for which a quote is // requested. type LoopOutQuoteRequest struct { // Amount specifies the requested swap amount in sat. This does not // include the swap and miner fee. Amount btcutil.Amount // SweepConfTarget specifies the targeted confirmation target for the // client sweep tx. SweepConfTarget int32 // SwapPublicationDeadline can be set by the client to allow the server // delaying publication of the swap HTLC to save on chain fees. SwapPublicationDeadline time.Time // TODO: Add argument to specify confirmation target for server // publishing htlc. This may influence the swap fee quote, because the // server needs to pay more for faster confirmations. // // TODO: Add arguments to specify maximum total time locks for the // off-chain swap payment and prepayment. This may influence the // available routes and off-chain fee estimates. To apply these maximum // values properly, the server needs to be queried for its required // final cltv delta values for the off-chain payments. } // LoopOutTerms are the server terms on which it executes swaps. type LoopOutTerms struct { // MinSwapAmount is the minimum amount that the server requires for a // swap. MinSwapAmount btcutil.Amount // MaxSwapAmount is the maximum amount that the server accepts for a // swap. MaxSwapAmount btcutil.Amount // MinCltvDelta is the minimum expiry delta for loop out swaps. MinCltvDelta int32 // MaxCltvDelta is the maximum expiry delta for loop out swaps. MaxCltvDelta int32 } // LoopOutQuote contains estimates for the fees making up the total swap cost // for the client. type LoopOutQuote struct { // SwapFee is the fee that the swap server is charging for the swap. SwapFee btcutil.Amount // PrepayAmount is the part of the swap fee that is requested as a // prepayment. PrepayAmount btcutil.Amount // MinerFee is an estimate of the on-chain fee that needs to be paid to // sweep the htlc. MinerFee btcutil.Amount // SwapPaymentDest is the node pubkey where to swap payment needs to be // sent to. SwapPaymentDest [33]byte } // LoopInRequest contains the required parameters for the swap. type LoopInRequest struct { // Amount specifies the requested swap amount in sat. This does not // include the swap and miner fee. Amount btcutil.Amount // MaxSwapFee is the maximum we are willing to pay the server for the // swap. This value is not disclosed in the swap initiation call, but if // the server asks for a higher fee, we abort the swap. Typically this // value is taken from the response of the LoopInQuote call. It // includes the prepay amount. MaxSwapFee btcutil.Amount // MaxMinerFee is the maximum in on-chain fees that we are willing to // spent. If we publish the on-chain htlc and the fee estimate turns out // higher than this value, we cancel the swap. // // MaxMinerFee is typically taken from the response of the LoopInQuote // call. MaxMinerFee btcutil.Amount // HtlcConfTarget specifies the targeted confirmation target for the // client htlc tx. HtlcConfTarget int32 // LastHop optionally specifies the last hop to use for the loop in // payment. LastHop *route.Vertex // ExternalHtlc specifies whether the htlc is published by an external // source. ExternalHtlc bool // Label contains an optional label for the swap. Label string // Initiator is an optional string that identifies what software // initiated the swap (loop CLI, autolooper, LiT UI and so on) and is // appended to the user agent string. Initiator string // Private indicates whether the destination node should be considered // private. In which case, loop will generate hophints to assist with // probing and payment. Private bool // RouteHints are optional route hints to reach the destination through // private channels. RouteHints [][]zpay32.HopHint } // LoopInTerms are the server terms on which it executes loop in swaps. type LoopInTerms struct { // MinSwapAmount is the minimum amount that the server requires for a // swap. MinSwapAmount btcutil.Amount // MaxSwapAmount is the maximum amount that the server accepts for a // swap. MaxSwapAmount btcutil.Amount } // In contains status information for a loop in swap. type In struct { loopdb.LoopInContract SwapInfoKit // State where the swap is in. State loopdb.SwapState } // LoopInQuoteRequest specifies the swap parameters for which a quote is // requested. type LoopInQuoteRequest struct { // Amount specifies the requested swap amount in sat. This does not // include the swap and miner fee. Amount btcutil.Amount // HtlcConfTarget specifies the targeted confirmation target for the // client sweep tx. HtlcConfTarget int32 // ExternalHtlc specifies whether the htlc is published by an external // source. ExternalHtlc bool // LastHop is an optional last hop to use. This last hop is used when // the client has already requested a server probe for more accurate // routing fee estimation. LastHop *route.Vertex // RouteHints are optional route hints to reach the destination through // private channels. RouteHints [][]zpay32.HopHint // Private indicates whether the destination node should be considered // private. In which case, loop will generate hophints to assist with // probing and payment. Private bool } // LoopInQuote contains estimates for the fees making up the total swap cost // for the client. type LoopInQuote struct { // SwapFee is the fee that the swap server is charging for the swap. SwapFee btcutil.Amount // MinerFee is an estimate of the on-chain fee that needs to be paid to // sweep the htlc. MinerFee btcutil.Amount // Time lock delta relative to current block height that swap server // will accept on the swap initiation call. CltvDelta int32 } // LoopInSwapInfo contains essential information of a loop-in swap after the // swap is initiated. type LoopInSwapInfo struct { // nolint // SwapHash contains the sha256 hash of the swap preimage. SwapHash lntypes.Hash // HtlcAddressP2WSH contains the native segwit swap htlc address, // where the loop-in funds may be paid. HtlcAddressP2WSH btcutil.Address // HtlcAddressNP2WSH contains the nested segwit swap htlc address, // where the loop-in funds may be paid. HtlcAddressNP2WSH btcutil.Address // ServerMessages is the human-readable message received from the loop // server. ServerMessage string } // LoopOutSwapInfo contains essential information of a loop-out swap after the // swap is initiated. type LoopOutSwapInfo struct { // nolint:revive // SwapHash contains the sha256 hash of the swap preimage. SwapHash lntypes.Hash // HtlcAddressP2WSH contains the native segwit swap htlc address that // the server will publish to. HtlcAddressP2WSH btcutil.Address // ServerMessages is the human-readable message received from the loop // server. ServerMessage string } // SwapInfoKit contains common swap info fields. type SwapInfoKit struct { // Hash is the sha256 hash of the preimage that unlocks the htlcs. It // is used to uniquely identify this swap. Hash lntypes.Hash // LastUpdateTime is the time of the last update of this swap. LastUpdateTime time.Time } // SwapInfo exposes common info fields for loop in and loop out swaps. type SwapInfo struct { loopdb.SwapStateData loopdb.SwapContract // LastUpdateTime is the time of the last state change. LastUpdate time.Time // SwapHash stores the swap preimage hash. SwapHash lntypes.Hash // SwapType describes whether this is a loop in or loop out swap. SwapType swap.Type // HtlcAddressP2WSH stores the address of the P2WSH (native segwit) // swap htlc. This is used for both loop-in and loop-out. HtlcAddressP2WSH btcutil.Address // HtlcAddressNP2WSH stores the address of the NP2WSH (nested segwit) // swap htlc. This is only used for external loop-in. HtlcAddressNP2WSH btcutil.Address // ExternalHtlc is set to true for external loop-in swaps. ExternalHtlc bool // LastHop optionally specifies the last hop to use for the loop in // payment. On a loop out this field is nil. LastHop *route.Vertex // OutgoingChanSet optionally specifies the short channel ids of the // channels that may be used to loop out. On a loop in this field // is nil. OutgoingChanSet loopdb.ChannelSet } // LastUpdate returns the last update time of the swap func (s *In) LastUpdate() time.Time { return s.LastUpdateTime } // SwapHash returns the swap hash. func (s *In) SwapHash() lntypes.Hash { return s.Hash } // ProbeRequest specifies probe parameters for the server probe. type ProbeRequest struct { // Amount is the amount that will be probed. Amount btcutil.Amount // LastHop is the last hop along the route. LastHop *route.Vertex // Optional hop hints. RouteHints [][]zpay32.HopHint }