package lnwire import ( "fmt" "io" "github.com/roasbeef/btcd/wire" ) // HTLCSettleRequest is sent by Alice to Bob when she wishes to settle a // particular HTLC referenced by its HTLCKey within a specific active channel // referenced by ChannelPoint. The message allows multiple hash preimages to be // presented in order to support N-of-M HTLC contracts. A subsequent // CommitSignature message will be sent by Alice to "lock-in" the removal of the // specified HTLC, possible containing a batch signature covering several settled // HTLC's. type HTLCSettleRequest struct { // ChannelPoint references an active channel which holds the HTLC to be // settled. ChannelPoint *wire.OutPoint // HTLCKey denotes the exact HTLC stage within the receiving node's // commitment transaction to be removed. // TODO(roasbeef): rename to LogIndex HTLCKey HTLCKey // RedemptionProofs are the R-value preimages required to fully settle // an HTLC. The number of preimages in the slice will depend on the // specific ContractType of the referenced HTLC. RedemptionProofs [][32]byte } // NewHTLCSettleRequest returns a new empty HTLCSettleRequest. func NewHTLCSettleRequest(chanPoint *wire.OutPoint, key HTLCKey, redemptionProofs [][32]byte) *HTLCSettleRequest { return &HTLCSettleRequest{ ChannelPoint: chanPoint, HTLCKey: key, RedemptionProofs: redemptionProofs, } } // A compile time check to ensure HTLCSettleRequest implements the lnwire.Message // interface. var _ Message = (*HTLCSettleRequest)(nil) // Decode deserializes a serialized HTLCSettleRequest message stored in the passed // io.Reader observing the specified protocol version. // // This is part of the lnwire.Message interface. func (c *HTLCSettleRequest) Decode(r io.Reader, pver uint32) error { // ChannelPoint(8) // HTLCKey(8) // RedemptionProofs(N*32) err := readElements(r, &c.ChannelPoint, &c.HTLCKey, &c.RedemptionProofs, ) if err != nil { return err } return nil } // Encode serializes the target HTLCSettleRequest into the passed io.Writer // observing the protocol version specified. // // This is part of the lnwire.Message interface. func (c *HTLCSettleRequest) Encode(w io.Writer, pver uint32) error { err := writeElements(w, c.ChannelPoint, c.HTLCKey, c.RedemptionProofs, ) if err != nil { return err } return nil } // Command returns the integer uniquely identifying this message type on the // wire. // // This is part of the lnwire.Message interface. func (c *HTLCSettleRequest) Command() uint32 { return CmdHTLCSettleRequest } // MaxPayloadLength returns the maximum allowed payload size for a HTLCSettleRequest // complete message observing the specified protocol version. // // This is part of the lnwire.Message interface. func (c *HTLCSettleRequest) MaxPayloadLength(uint32) uint32 { // 36 + 8 + (32 * 15) return 524 } // Validate performs any necessary sanity checks to ensure all fields present // on the HTLCSettleRequest are valid. // // This is part of the lnwire.Message interface. func (c *HTLCSettleRequest) Validate() error { // We're good! return nil } // String returns the string representation of the target HTLCSettleRequest. // // This is part of the lnwire.Message interface. func (c *HTLCSettleRequest) String() string { var redemptionProofs string for i, rh := range c.RedemptionProofs { redemptionProofs += fmt.Sprintf("\n\tSlice\t%d\n", i) redemptionProofs += fmt.Sprintf("\t\tRedemption Proof: %x\n", rh) } return fmt.Sprintf("\n--- Begin HTLCSettleRequest ---\n") + fmt.Sprintf("ChannelPoint:\t%d\n", c.ChannelPoint) + fmt.Sprintf("HTLCKey:\t%d\n", c.HTLCKey) + fmt.Sprintf("RedemptionHashes:") + redemptionProofs + fmt.Sprintf("--- End HTLCSettleRequest ---\n") }