package htlcswitch import ( "github.com/lightningnetwork/lnd/channeldb" "github.com/lightningnetwork/lnd/lnwire" ) // htlcPacket is a wrapper around htlc lnwire update, which adds additional // information which is needed by this package. type htlcPacket struct { // destNode is the first-hop destination of a local created HTLC add // message. destNode [33]byte // incomingChanID is the ID of the channel that we have received an incoming // HTLC on. incomingChanID lnwire.ShortChannelID // outgoingChanID is the ID of the channel that we have offered or will // offer an outgoing HTLC on. outgoingChanID lnwire.ShortChannelID // incomingHTLCID is the ID of the HTLC that we have received from the peer // on the incoming channel. incomingHTLCID uint64 // incomingHtlcAmt is the value of the *incoming* HTLC. This will be // set by the link when it receives an incoming HTLC to be forwarded // through the switch. Then the outgoing link will use this once it // creates a full circuit add. This allows us to properly populate the // forwarding event for this circuit/packet in the case the payment // circuit is successful. incomingHtlcAmt lnwire.MilliSatoshi // outgoingHTLCID is the ID of the HTLC that we offered to the peer on the // outgoing channel. outgoingHTLCID uint64 // sourceRef is used by forwarded htlcPackets to locate incoming Add // entry in a fwdpkg owned by the incoming link. This value can be nil // if there is no such entry, e.g. switch initiated payments. sourceRef *channeldb.AddRef // destRef is used to locate a settle/fail entry in the outgoing link's // fwdpkg. If sourceRef is non-nil, this reference should be to a // settle/fail in response to the sourceRef. destRef *channeldb.SettleFailRef // incomingAmount is the value in milli-satoshis that arrived on an // incoming link. incomingAmount lnwire.MilliSatoshi // amount is the value of the HTLC that is being created or modified. amount lnwire.MilliSatoshi // htlc lnwire message type of which depends on switch request type. htlc lnwire.Message // obfuscator contains the necessary state to allow the switch to wrap // any forwarded errors in an additional layer of encryption. obfuscator ErrorEncrypter // localFailure is set to true if an HTLC fails for a local payment before // the first hop. In this case, the failure reason is simply encoded, not // encrypted with any shared secret. localFailure bool // hasSource is set to true if the incomingChanID and incomingHTLCID // fields of a forwarded fail packet are already set and do not need to // be looked up in the circuit map. hasSource bool // isResolution is set to true if this packet was actually an incoming // resolution message from an outside sub-system. We'll treat these as // if they emanated directly from the switch. As a result, we'll // encrypt all errors related to this packet as if we were the first // hop. isResolution bool // circuit holds a reference to an Add's circuit which is persisted in // the switch during successful forwarding. circuit *PaymentCircuit // incomingTimeout is the timeout that the incoming HTLC carried. This // is the timeout of the HTLC applied to the incoming link. incomingTimeout uint32 // outgoingTimeout is the timeout of the proposed outgoing HTLC. This // will be extraced from the hop payload recevived by the incoming // link. outgoingTimeout uint32 } // inKey returns the circuit key used to identify the incoming htlc. func (p *htlcPacket) inKey() CircuitKey { return CircuitKey{ ChanID: p.incomingChanID, HtlcID: p.incomingHTLCID, } } // outKey returns the circuit key used to identify the outgoing, forwarded htlc. func (p *htlcPacket) outKey() CircuitKey { return CircuitKey{ ChanID: p.outgoingChanID, HtlcID: p.outgoingHTLCID, } } // keystone returns a tuple containing the incoming and outgoing circuit keys. func (p *htlcPacket) keystone() Keystone { return Keystone{ InKey: p.inKey(), OutKey: p.outKey(), } }