lnd: modifying comments in chancloser.go
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nsa
parent
ec2d999371
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8528ec4568
463
chancloser.go
463
chancloser.go
@ -14,24 +14,24 @@ import (
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)
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var (
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// ErrChanAlreadyClosing is returned when a channel shutdown is
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// attempted more than once.
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// ErrChanAlreadyClosing is returned when a channel shutdown is attempted
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// more than once.
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ErrChanAlreadyClosing = fmt.Errorf("channel shutdown already initiated")
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// ErrChanCloseNotFinished is returned when a caller attempts to access
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// a field or function that is contingent on the channel closure
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// negotiation already being completed.
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// a field or function that is contingent on the channel closure negotiation
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// already being completed.
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ErrChanCloseNotFinished = fmt.Errorf("close negotiation not finished")
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// ErrInvalidState is returned when the closing state machine receives
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// a message while it is in an unknown state.
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// ErrInvalidState is returned when the closing state machine receives a
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// message while it is in an unknown state.
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ErrInvalidState = fmt.Errorf("invalid state")
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// ErrUpfrontShutdownScriptMismatch is returned when a peer or end user
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// provides a script to cooperatively close out to which does not match
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// the upfront shutdown script previously set for that party.
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ErrUpfrontShutdownScriptMismatch = fmt.Errorf("shutdown " +
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"script does not match upfront shutdown script")
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// provides a cooperative close script which does not match the upfront
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// shutdown script previously set for that party.
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ErrUpfrontShutdownScriptMismatch = fmt.Errorf("shutdown script does not " +
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"match upfront shutdown script")
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)
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// closeState represents all the possible states the channel closer state
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@ -43,43 +43,42 @@ type closeState uint8
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const (
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// closeIdle is the initial starting state. In this state, the state
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// machine has been instantiated, but no state transitions have been
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// attempted. If a state machine receives a message while in this
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// state, then it is the responder to an initiated cooperative channel
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// closure.
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// attempted. If a state machine receives a message while in this state,
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// then it is the responder to an initiated cooperative channel closure.
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closeIdle closeState = iota
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// closeShutdownInitiated is the state that's transitioned to once the
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// initiator of a closing workflow sends the shutdown message. At this
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// point, they're waiting for the remote party to respond with their
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// own shutdown message. After which, they'll both enter the fee
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// negotiation phase.
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// point, they're waiting for the remote party to respond with their own
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// shutdown message. After which, they'll both enter the fee negotiation
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// phase.
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closeShutdownInitiated
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// closeFeeNegotiation is the third, and most persistent state. Both
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// parties enter this state after they've sent and received a shutdown
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// message. During this phase, both sides will send monotonically
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// increasing fee requests until one side accepts the last fee rate
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// offered by the other party. In this case, the party will broadcast
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// the closing transaction, and send the accepted fee to the remote
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// party. This then causes a shift into the closeFinished state.
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// increasing fee requests until one side accepts the last fee rate offered
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// by the other party. In this case, the party will broadcast the closing
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// transaction, and send the accepted fee to the remote party. This then
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// causes a shift into the closeFinished state.
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closeFeeNegotiation
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// closeFinished is the final state of the state machine. In this,
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// state a side has accepted a fee offer and has broadcast the valid
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// closing transaction to the network. During this phase, the closing
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// transaction becomes available for examination.
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// closeFinished is the final state of the state machine. In this state, a
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// side has accepted a fee offer and has broadcast the valid closing
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// transaction to the network. During this phase, the closing transaction
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// becomes available for examination.
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closeFinished
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)
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// ChanCloseCfg holds all the items that a channelCloser requires to carry out
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// its duties.
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// ChanCloseCfg holds all the items that a channelCloser requires to carry out its
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// duties.
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type ChanCloseCfg struct {
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// Channel is the channel that should be closed.
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Channel *lnwallet.LightningChannel
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// UnregisterChannel is a function closure that allows the
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// channelCloser to re-register a channel. Once this has been done, no
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// further HTLC's should be routed through the channel.
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// UnregisterChannel is a function closure that allows the channelCloser to
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// unregister a channel. Once this has been done, no further HTLC's should
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// be routed through the channel.
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UnregisterChannel func(lnwire.ChannelID)
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// BroadcastTx broadcasts the passed transaction to the network.
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@ -97,10 +96,10 @@ type ChanCloseCfg struct {
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Quit chan struct{}
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}
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// channelCloser is a state machine that handles the cooperative channel
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// closure procedure. This includes shutting down a channel, marking it
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// ineligible for routing HTLC's, negotiating fees with the remote party, and
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// finally broadcasting the fully signed closure transaction to the network.
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// channelCloser is a state machine that handles the cooperative channel closure
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// procedure. This includes shutting down a channel, marking it ineligible for
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// routing HTLC's, negotiating fees with the remote party, and finally
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// broadcasting the fully signed closure transaction to the network.
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type channelCloser struct {
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// state is the current state of the state machine.
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state closeState
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@ -117,71 +116,69 @@ type channelCloser struct {
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// negotiationHeight is the height that the fee negotiation begun at.
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negotiationHeight uint32
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// closingTx is the final, fully signed closing transaction. This will
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// only be populated once the state machine shifts to the closeFinished
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// state.
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// closingTx is the final, fully signed closing transaction. This will only
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// be populated once the state machine shifts to the closeFinished state.
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closingTx *wire.MsgTx
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// idealFeeSat is the ideal fee that the state machine should initially
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// offer when starting negotiation. This will be used as a baseline.
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idealFeeSat btcutil.Amount
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// lastFeeProposal is the last fee that we proposed to the remote
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// party. We'll use this as a pivot point to rachet our next offer up,
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// or down, or simply accept the remote party's prior offer.
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// lastFeeProposal is the last fee that we proposed to the remote party.
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// We'll use this as a pivot point to ratchet our next offer up, down, or
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// simply accept the remote party's prior offer.
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lastFeeProposal btcutil.Amount
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// priorFeeOffers is a map that keeps track of all the proposed fees
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// that we've offered during the fee negotiation. We use this map to
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// cut the negotiation early if the remote party ever sends an offer
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// that we've sent in the past. Once negotiation terminates, we can
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// extract the prior signature of our accepted offer from this map.
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// priorFeeOffers is a map that keeps track of all the proposed fees that
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// we've offered during the fee negotiation. We use this map to cut the
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// negotiation early if the remote party ever sends an offer that we've
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// sent in the past. Once negotiation terminates, we can extract the prior
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// signature of our accepted offer from this map.
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//
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// TODO(roasbeef): need to ensure if they broadcast w/ any of our prior
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// sigs, we are aware of
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priorFeeOffers map[btcutil.Amount]*lnwire.ClosingSigned
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// closeReq is the initial closing request. This will only be populated
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// if we're the initiator of this closing negotiation.
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// closeReq is the initial closing request. This will only be populated if
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// we're the initiator of this closing negotiation.
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//
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// TODO(roasbeef): abstract away
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closeReq *htlcswitch.ChanClose
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// localDeliveryScript is the script that we'll send our settled
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// channel funds to.
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// localDeliveryScript is the script that we'll send our settled channel
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// funds to.
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localDeliveryScript []byte
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// remoteDeliveryScript is the script that we'll send the remote
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// party's settled channel funds to.
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// remoteDeliveryScript is the script that we'll send the remote party's
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// settled channel funds to.
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remoteDeliveryScript []byte
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// locallyInitiated is true if we initiated the channel close.
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locallyInitiated bool
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}
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// NewChanCloser creates a new instance of the channel closure given the
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// passed configuration, and delivery+fee preference. The final argument should
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// only be populated iff, we're the initiator of this closing request.
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// NewChanCloser creates a new instance of the channel closure given the passed
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// configuration, and delivery+fee preference. The final argument should only
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// be populated iff, we're the initiator of this closing request.
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func NewChanCloser(cfg ChanCloseCfg, deliveryScript []byte,
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idealFeePerKw chainfee.SatPerKWeight, negotiationHeight uint32,
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closeReq *htlcswitch.ChanClose, locallyInitiated bool) *channelCloser {
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// Given the target fee-per-kw, we'll compute what our ideal _total_
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// fee will be starting at for this fee negotiation.
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// Given the target fee-per-kw, we'll compute what our ideal _total_ fee
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// will be starting at for this fee negotiation.
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//
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// TODO(roasbeef): should factor in minimal commit
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idealFeeSat := cfg.Channel.CalcFee(idealFeePerKw)
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// If this fee is greater than the fee currently present within the
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// commitment transaction, then we'll clamp it down to be within the
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// proper range.
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// commitment transaction, then we'll clamp it down to be within the proper
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// range.
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//
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// TODO(roasbeef): clamp fee func?
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channelCommitFee := cfg.Channel.StateSnapshot().CommitFee
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if idealFeeSat > channelCommitFee {
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peerLog.Infof("Ideal starting fee of %v is greater than "+
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"commit fee of %v, clamping", int64(idealFeeSat),
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int64(channelCommitFee))
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peerLog.Infof("Ideal starting fee of %v is greater than commit "+
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"fee of %v, clamping", int64(idealFeeSat), int64(channelCommitFee))
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idealFeeSat = channelCommitFee
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}
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@ -207,30 +204,30 @@ func NewChanCloser(cfg ChanCloseCfg, deliveryScript []byte,
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// initChanShutdown begins the shutdown process by un-registering the channel,
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// and creating a valid shutdown message to our target delivery address.
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func (c *channelCloser) initChanShutdown() (*lnwire.Shutdown, error) {
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// With both items constructed we'll now send the shutdown message for
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// this particular channel, advertising a shutdown request to our
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// desired closing script.
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// With both items constructed we'll now send the shutdown message for this
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// particular channel, advertising a shutdown request to our desired
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// closing script.
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shutdown := lnwire.NewShutdown(c.cid, c.localDeliveryScript)
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// TODO(roasbeef): err if channel has htlc's?
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// Before closing, we'll attempt to send a disable update for the
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// channel. We do so before closing the channel as otherwise the current
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// edge policy won't be retrievable from the graph.
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// Before closing, we'll attempt to send a disable update for the channel.
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// We do so before closing the channel as otherwise the current edge policy
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// won't be retrievable from the graph.
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if err := c.cfg.DisableChannel(c.chanPoint); err != nil {
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peerLog.Warnf("Unable to disable channel %v on "+
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"close: %v", c.chanPoint, err)
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peerLog.Warnf("Unable to disable channel %v on close: %v",
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c.chanPoint, err)
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}
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// Before returning the shutdown message, we'll unregister the channel
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// to ensure that it isn't seen as usable within the system.
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// Before returning the shutdown message, we'll unregister the channel to
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// ensure that it isn't seen as usable within the system.
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c.cfg.UnregisterChannel(c.cid)
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// Before continuing, mark the channel as cooperatively closed with a
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// nil txn. Even though we haven't negotiated the final txn, this
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// guarantees that our listchannels rpc will be externally consistent,
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// and reflect that the channel is being shutdown by the time the
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// closing request returns.
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// Before continuing, mark the channel as cooperatively closed with a nil
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// txn. Even though we haven't negotiated the final txn, this guarantees
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// that our listchannels rpc will be externally consistent, and reflect
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// that the channel is being shutdown by the time the closing request
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// returns.
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err := c.cfg.Channel.MarkCoopBroadcasted(nil, c.locallyInitiated)
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if err != nil {
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return nil, err
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@ -246,13 +243,13 @@ func (c *channelCloser) initChanShutdown() (*lnwire.Shutdown, error) {
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// send to the remote party. Upon completion, we enter the
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// closeShutdownInitiated phase as we await a response.
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func (c *channelCloser) ShutdownChan() (*lnwire.Shutdown, error) {
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// If we attempt to shutdown the channel for the first time, and we're
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// not in the closeIdle state, then the caller made an error.
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// If we attempt to shutdown the channel for the first time, and we're not
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// in the closeIdle state, then the caller made an error.
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if c.state != closeIdle {
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return nil, ErrChanAlreadyClosing
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}
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peerLog.Infof("ChannelPoint(%v): initiating shutdown of", c.chanPoint)
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peerLog.Infof("ChannelPoint(%v): initiating shutdown", c.chanPoint)
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shutdownMsg, err := c.initChanShutdown()
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if err != nil {
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@ -260,12 +257,12 @@ func (c *channelCloser) ShutdownChan() (*lnwire.Shutdown, error) {
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}
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// With the opening steps complete, we'll transition into the
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// closeShutdownInitiated state. In this state, we'll wait until the
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// other party sends their version of the shutdown message.
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// closeShutdownInitiated state. In this state, we'll wait until the other
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// party sends their version of the shutdown message.
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c.state = closeShutdownInitiated
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// Finally, we'll return the shutdown message to the caller so it can
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// send it to the remote peer.
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// Finally, we'll return the shutdown message to the caller so it can send
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// it to the remote peer.
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return shutdownMsg, nil
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}
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@ -274,7 +271,7 @@ func (c *channelCloser) ShutdownChan() (*lnwire.Shutdown, error) {
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// NOTE: This transaction is only available if the state machine is in the
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// closeFinished state.
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func (c *channelCloser) ClosingTx() (*wire.MsgTx, error) {
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// If the state machine hasn't finished closing the channel then we'll
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// If the state machine hasn't finished closing the channel, then we'll
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// return an error as we haven't yet computed the closing tx.
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if c.state != closeFinished {
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return nil, ErrChanCloseNotFinished
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@ -303,14 +300,13 @@ func (c *channelCloser) NegotiationHeight() uint32 {
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}
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// maybeMatchScript attempts to match the script provided in our peer's
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// shutdown message with the upfront shutdown script we have on record.
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// If no upfront shutdown script was set, we do not need to enforce option
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// upfront shutdown, so the function returns early. If an upfront script is
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// set, we check whether it matches the script provided by our peer. If they
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// do not match, we use the disconnect function provided to disconnect from
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// the peer.
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func maybeMatchScript(disconnect func() error,
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upfrontScript, peerScript lnwire.DeliveryAddress) error {
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// shutdown message with the upfront shutdown script we have on record. If no
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// upfront shutdown script was set, we do not need to enforce option upfront
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// shutdown, so the function returns early. If an upfront script is set, we
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// check whether it matches the script provided by our peer. If they do not
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// match, we use the disconnect function provided to disconnect from the peer.
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func maybeMatchScript(disconnect func() error, upfrontScript,
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peerScript lnwire.DeliveryAddress) error {
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// If no upfront shutdown script was set, return early because we do not
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// need to enforce closure to a specific script.
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@ -341,41 +337,43 @@ func maybeMatchScript(disconnect func() error,
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// the next set of messages to be sent, and a bool indicating if the fee
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// negotiation process has completed. If the second value is true, then this
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// means the channelCloser can be garbage collected.
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func (c *channelCloser) ProcessCloseMsg(msg lnwire.Message) ([]lnwire.Message, bool, error) {
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func (c *channelCloser) ProcessCloseMsg(msg lnwire.Message) ([]lnwire.Message,
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bool, error) {
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switch c.state {
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// If we're in the close idle state, and we're receiving a channel
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// closure related message, then this indicates that we're on the
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// receiving side of an initiated channel closure.
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// If we're in the close idle state, and we're receiving a channel closure
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// related message, then this indicates that we're on the receiving side of
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// an initiated channel closure.
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case closeIdle:
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// First, we'll assert that we have a channel shutdown message,
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// otherwise, this is an attempted invalid state transition.
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shutDownMsg, ok := msg.(*lnwire.Shutdown)
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// as otherwise, this is an attempted invalid state transition.
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shutdownMsg, ok := msg.(*lnwire.Shutdown)
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if !ok {
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return nil, false, fmt.Errorf("expected lnwire.Shutdown, "+
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"instead have %v", spew.Sdump(msg))
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return nil, false, fmt.Errorf("expected lnwire.Shutdown, instead "+
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"have %v", spew.Sdump(msg))
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}
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// As we're the responder to this shutdown (the other party
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// wants to close), we'll check if this is a frozen channel or
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// not. If the channel is frozen as we were also the initiator
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// of the channel opening, then we'll deny their close attempt.
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// As we're the responder to this shutdown (the other party wants to
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// close), we'll check if this is a frozen channel or not. If the
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// channel is frozen and we were not also the initiator of the channel
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// opening, then we'll deny their close attempt.
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chanInitiator := c.cfg.Channel.IsInitiator()
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if !chanInitiator && c.cfg.Channel.State().ChanType.IsFrozen() &&
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c.negotiationHeight < c.cfg.Channel.State().ThawHeight {
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chanState := c.cfg.Channel.State()
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if !chanInitiator && chanState.ChanType.IsFrozen() &&
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c.negotiationHeight < chanState.ThawHeight {
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return nil, false, fmt.Errorf("initiator attempting "+
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"to co-op close frozen ChannelPoint(%v) "+
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"(current_height=%v, thaw_height=%v)",
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c.chanPoint, c.negotiationHeight,
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c.cfg.Channel.State().ThawHeight)
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return nil, false, fmt.Errorf("initiator attempting to co-op "+
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"close frozen ChannelPoint(%v) (current_height=%v, "+
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"thaw_height=%v)", c.chanPoint, c.negotiationHeight,
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chanState.ThawHeight)
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}
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// If the remote node opened the channel with option upfront shutdown
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// script, check that the script they provided matches.
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if err := maybeMatchScript(
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c.cfg.Disconnect, c.cfg.Channel.RemoteUpfrontShutdownScript(),
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shutDownMsg.Address,
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shutdownMsg.Address,
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); err != nil {
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return nil, false, err
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}
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@ -383,29 +381,29 @@ func (c *channelCloser) ProcessCloseMsg(msg lnwire.Message) ([]lnwire.Message, b
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// Once we have checked that the other party has not violated option
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// upfront shutdown we set their preference for delivery address. We'll
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// use this when we craft the closure transaction.
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c.remoteDeliveryScript = shutDownMsg.Address
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c.remoteDeliveryScript = shutdownMsg.Address
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// We'll generate a shutdown message of our own to send across
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// the wire.
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// We'll generate a shutdown message of our own to send across the
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// wire.
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localShutdown, err := c.initChanShutdown()
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if err != nil {
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return nil, false, err
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}
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peerLog.Infof("ChannelPoint(%v): Responding to shutdown",
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peerLog.Infof("ChannelPoint(%v): responding to shutdown",
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c.chanPoint)
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msgsToSend := make([]lnwire.Message, 0, 2)
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msgsToSend = append(msgsToSend, localShutdown)
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// After the other party receives this message, we'll actually
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||||
// start the final stage of the closure process: fee
|
||||
// negotiation. So we'll update our internal state to reflect
|
||||
// this, so we can handle the next message sent.
|
||||
// After the other party receives this message, we'll actually start
|
||||
// the final stage of the closure process: fee negotiation. So we'll
|
||||
// update our internal state to reflect this, so we can handle the next
|
||||
// message sent.
|
||||
c.state = closeFeeNegotiation
|
||||
|
||||
// We'll also craft our initial close proposal in order to keep
|
||||
// the negotiation moving, but only if we're the negotiator.
|
||||
// We'll also craft our initial close proposal in order to keep the
|
||||
// negotiation moving, but only if we're the negotiator.
|
||||
if chanInitiator {
|
||||
closeSigned, err := c.proposeCloseSigned(c.idealFeeSat)
|
||||
if err != nil {
|
||||
@ -414,47 +412,45 @@ func (c *channelCloser) ProcessCloseMsg(msg lnwire.Message) ([]lnwire.Message, b
|
||||
msgsToSend = append(msgsToSend, closeSigned)
|
||||
}
|
||||
|
||||
// We'll return both sets of messages to send to the remote
|
||||
// party to kick off the fee negotiation process.
|
||||
// We'll return both sets of messages to send to the remote party to
|
||||
// kick off the fee negotiation process.
|
||||
return msgsToSend, false, nil
|
||||
|
||||
// If we just initiated a channel shutdown, and we receive a new
|
||||
// message, then this indicates the other party is ready to shutdown as
|
||||
// well. In this state we'll send our first signature.
|
||||
// If we just initiated a channel shutdown, and we receive a new message,
|
||||
// then this indicates the other party is ready to shutdown as well. In
|
||||
// this state we'll send our first signature.
|
||||
case closeShutdownInitiated:
|
||||
// First, we'll assert that we have a channel shutdown message,
|
||||
// otherwise, this is an attempted invalid state transition.
|
||||
shutDownMsg, ok := msg.(*lnwire.Shutdown)
|
||||
// First, we'll assert that we have a channel shutdown message.
|
||||
// Otherwise, this is an attempted invalid state transition.
|
||||
shutdownMsg, ok := msg.(*lnwire.Shutdown)
|
||||
if !ok {
|
||||
return nil, false, fmt.Errorf("expected lnwire.Shutdown, "+
|
||||
"instead have %v", spew.Sdump(msg))
|
||||
return nil, false, fmt.Errorf("expected lnwire.Shutdown, instead "+
|
||||
"have %v", spew.Sdump(msg))
|
||||
}
|
||||
|
||||
// If the remote node opened the channel with option upfront shutdown
|
||||
// script, check that the script they provided matches.
|
||||
if err := maybeMatchScript(
|
||||
c.cfg.Disconnect, c.cfg.Channel.RemoteUpfrontShutdownScript(),
|
||||
shutDownMsg.Address,
|
||||
if err := maybeMatchScript(c.cfg.Disconnect,
|
||||
c.cfg.Channel.RemoteUpfrontShutdownScript(), shutdownMsg.Address,
|
||||
); err != nil {
|
||||
return nil, false, err
|
||||
}
|
||||
|
||||
// Now that we know this is a valid shutdown message and address, we'll
|
||||
// record their preferred delivery closing script.
|
||||
c.remoteDeliveryScript = shutDownMsg.Address
|
||||
c.remoteDeliveryScript = shutdownMsg.Address
|
||||
|
||||
// At this point, we can now start the fee negotiation state,
|
||||
// by constructing and sending our initial signature for what
|
||||
// we think the closing transaction should look like.
|
||||
// At this point, we can now start the fee negotiation state, by
|
||||
// constructing and sending our initial signature for what we think the
|
||||
// closing transaction should look like.
|
||||
c.state = closeFeeNegotiation
|
||||
|
||||
peerLog.Infof("ChannelPoint(%v): shutdown response received, "+
|
||||
"entering fee negotiation", c.chanPoint)
|
||||
|
||||
// Starting with our ideal fee rate, we'll create an initial
|
||||
// closing proposal, but only if we're the initiator, as
|
||||
// otherwise, the other party will send their first proposal
|
||||
// first.
|
||||
// Starting with our ideal fee rate, we'll create an initial closing
|
||||
// proposal, but only if we're the initiator, as otherwise, the other
|
||||
// party will send their initial proposal first.
|
||||
if c.cfg.Channel.IsInitiator() {
|
||||
closeSigned, err := c.proposeCloseSigned(c.idealFeeSat)
|
||||
if err != nil {
|
||||
@ -466,48 +462,45 @@ func (c *channelCloser) ProcessCloseMsg(msg lnwire.Message) ([]lnwire.Message, b
|
||||
|
||||
return nil, false, nil
|
||||
|
||||
// If we're receiving a message while we're in the fee negotiation
|
||||
// phase, then this indicates the remote party is responding to a closed
|
||||
// signed message we sent, or kicking off the process with their own.
|
||||
// If we're receiving a message while we're in the fee negotiation phase,
|
||||
// then this indicates the remote party is responding to a close signed
|
||||
// message we sent, or kicking off the process with their own.
|
||||
case closeFeeNegotiation:
|
||||
// First, we'll assert that we're actually getting a
|
||||
// CloseSigned message, otherwise an invalid state transition
|
||||
// was attempted.
|
||||
// First, we'll assert that we're actually getting a ClosingSigned
|
||||
// message, otherwise an invalid state transition was attempted.
|
||||
closeSignedMsg, ok := msg.(*lnwire.ClosingSigned)
|
||||
if !ok {
|
||||
return nil, false, fmt.Errorf("expected lnwire.ClosingSigned, "+
|
||||
"instead have %v", spew.Sdump(msg))
|
||||
}
|
||||
|
||||
// We'll compare the proposed total fee, to what we've proposed
|
||||
// during the negotiations, if it doesn't match any of our
|
||||
// prior offers, then we'll attempt to rachet the fee closer to
|
||||
// We'll compare the proposed total fee, to what we've proposed during
|
||||
// the negotiations. If it doesn't match any of our prior offers, then
|
||||
// we'll attempt to ratchet the fee closer to
|
||||
remoteProposedFee := closeSignedMsg.FeeSatoshis
|
||||
if _, ok := c.priorFeeOffers[remoteProposedFee]; !ok {
|
||||
// We'll now attempt to rachet towards a fee deemed
|
||||
// acceptable by both parties, factoring in our ideal
|
||||
// fee rate, and the last proposed fee by both sides.
|
||||
// We'll now attempt to ratchet towards a fee deemed acceptable by
|
||||
// both parties, factoring in our ideal fee rate, and the last
|
||||
// proposed fee by both sides.
|
||||
feeProposal := calcCompromiseFee(c.chanPoint,
|
||||
c.idealFeeSat, c.lastFeeProposal,
|
||||
remoteProposedFee,
|
||||
)
|
||||
|
||||
// With our new fee proposal calculated, we'll craft a
|
||||
// new close signed signature to send to the other
|
||||
// party so we can continue the fee negotiation
|
||||
// process.
|
||||
// With our new fee proposal calculated, we'll craft a new close
|
||||
// signed signature to send to the other party so we can continue
|
||||
// the fee negotiation process.
|
||||
closeSigned, err := c.proposeCloseSigned(feeProposal)
|
||||
if err != nil {
|
||||
return nil, false, err
|
||||
}
|
||||
|
||||
// If the compromise fee doesn't match what the peer
|
||||
// proposed, then we'll return this latest close signed
|
||||
// message so we continue negotiation.
|
||||
// If the compromise fee doesn't match what the peer proposed, then
|
||||
// we'll return this latest close signed message so we can continue
|
||||
// negotiation.
|
||||
if feeProposal != remoteProposedFee {
|
||||
peerLog.Debugf("ChannelPoint(%v): close tx "+
|
||||
"fee disagreement, continuing negotiation",
|
||||
c.chanPoint)
|
||||
peerLog.Debugf("ChannelPoint(%v): close tx fee "+
|
||||
"disagreement, continuing negotiation", c.chanPoint)
|
||||
return []lnwire.Message{closeSigned}, false, nil
|
||||
}
|
||||
}
|
||||
@ -515,9 +508,9 @@ func (c *channelCloser) ProcessCloseMsg(msg lnwire.Message) ([]lnwire.Message, b
|
||||
peerLog.Infof("ChannelPoint(%v) fee of %v accepted, ending "+
|
||||
"negotiation", c.chanPoint, remoteProposedFee)
|
||||
|
||||
// Otherwise, we've agreed on a fee for the closing
|
||||
// transaction! We'll craft the final closing transaction so
|
||||
// we can broadcast it to the network.
|
||||
// Otherwise, we've agreed on a fee for the closing transaction! We'll
|
||||
// craft the final closing transaction so we can broadcast it to the
|
||||
// network.
|
||||
matchingSig := c.priorFeeOffers[remoteProposedFee].Signature
|
||||
localSig, err := matchingSig.ToSignature()
|
||||
if err != nil {
|
||||
@ -530,56 +523,51 @@ func (c *channelCloser) ProcessCloseMsg(msg lnwire.Message) ([]lnwire.Message, b
|
||||
}
|
||||
|
||||
closeTx, _, err := c.cfg.Channel.CompleteCooperativeClose(
|
||||
localSig, remoteSig, c.localDeliveryScript,
|
||||
c.remoteDeliveryScript, remoteProposedFee,
|
||||
localSig, remoteSig, c.localDeliveryScript, c.remoteDeliveryScript,
|
||||
remoteProposedFee,
|
||||
)
|
||||
if err != nil {
|
||||
return nil, false, err
|
||||
}
|
||||
c.closingTx = closeTx
|
||||
|
||||
// Before publishing the closing tx, we persist it to the
|
||||
// database, such that it can be republished if something goes
|
||||
// wrong.
|
||||
err = c.cfg.Channel.MarkCoopBroadcasted(
|
||||
closeTx, c.locallyInitiated,
|
||||
)
|
||||
// Before publishing the closing tx, we persist it to the database,
|
||||
// such that it can be republished if something goes wrong.
|
||||
err = c.cfg.Channel.MarkCoopBroadcasted(closeTx, c.locallyInitiated)
|
||||
if err != nil {
|
||||
return nil, false, err
|
||||
}
|
||||
|
||||
// With the closing transaction crafted, we'll now broadcast it
|
||||
// to the network.
|
||||
// With the closing transaction crafted, we'll now broadcast it to the
|
||||
// network.
|
||||
peerLog.Infof("Broadcasting cooperative close tx: %v",
|
||||
newLogClosure(func() string {
|
||||
return spew.Sdump(closeTx)
|
||||
}))
|
||||
err = c.cfg.BroadcastTx(closeTx, "")
|
||||
if err != nil {
|
||||
}),
|
||||
)
|
||||
if err := c.cfg.BroadcastTx(closeTx, ""); err != nil {
|
||||
return nil, false, err
|
||||
}
|
||||
|
||||
// Finally, we'll transition to the closeFinished state, and
|
||||
// also return the final close signed message we sent.
|
||||
// Additionally, we return true for the second argument to
|
||||
// indicate we're finished with the channel closing
|
||||
// negotiation.
|
||||
// Finally, we'll transition to the closeFinished state, and also
|
||||
// return the final close signed message we sent. Additionally, we
|
||||
// return true for the second argument to indicate we're finished with
|
||||
// the channel closing negotiation.
|
||||
c.state = closeFinished
|
||||
matchingOffer := c.priorFeeOffers[remoteProposedFee]
|
||||
return []lnwire.Message{matchingOffer}, true, nil
|
||||
|
||||
// If we receive a message while in the closeFinished state, then this
|
||||
// should only be the remote party echoing the last ClosingSigned
|
||||
// message that we agreed on.
|
||||
// If we received a message while in the closeFinished state, then this
|
||||
// should only be the remote party echoing the last ClosingSigned message
|
||||
// that we agreed on.
|
||||
case closeFinished:
|
||||
if _, ok := msg.(*lnwire.ClosingSigned); !ok {
|
||||
return nil, false, fmt.Errorf("expected "+
|
||||
"lnwire.ClosingSigned, instead have %v",
|
||||
spew.Sdump(msg))
|
||||
return nil, false, fmt.Errorf("expected lnwire.ClosingSigned, "+
|
||||
"instead have %v", spew.Sdump(msg))
|
||||
}
|
||||
|
||||
// There's no more to do as both sides should have already
|
||||
// broadcast the closing transaction at this state.
|
||||
// There's no more to do as both sides should have already broadcast
|
||||
// the closing transaction at this state.
|
||||
return nil, true, nil
|
||||
|
||||
// Otherwise, we're in an unknown state, and can't proceed.
|
||||
@ -589,8 +577,8 @@ func (c *channelCloser) ProcessCloseMsg(msg lnwire.Message) ([]lnwire.Message, b
|
||||
}
|
||||
|
||||
// proposeCloseSigned attempts to propose a new signature for the closing
|
||||
// transaction for a channel based on the prior fee negotiations and our
|
||||
// current compromise fee.
|
||||
// transaction for a channel based on the prior fee negotiations and our current
|
||||
// compromise fee.
|
||||
func (c *channelCloser) proposeCloseSigned(fee btcutil.Amount) (*lnwire.ClosingSigned, error) {
|
||||
rawSig, _, _, err := c.cfg.Channel.CreateCloseProposal(
|
||||
fee, c.localDeliveryScript, c.remoteDeliveryScript,
|
||||
@ -599,9 +587,8 @@ func (c *channelCloser) proposeCloseSigned(fee btcutil.Amount) (*lnwire.ClosingS
|
||||
return nil, err
|
||||
}
|
||||
|
||||
// We'll note our last signature and proposed fee so when the remote
|
||||
// party responds we'll be able to decide if we've agreed on fees or
|
||||
// not.
|
||||
// We'll note our last signature and proposed fee so when the remote party
|
||||
// responds we'll be able to decide if we've agreed on fees or not.
|
||||
c.lastFeeProposal = fee
|
||||
parsedSig, err := lnwire.NewSigFromSignature(rawSig)
|
||||
if err != nil {
|
||||
@ -611,9 +598,9 @@ func (c *channelCloser) proposeCloseSigned(fee btcutil.Amount) (*lnwire.ClosingS
|
||||
peerLog.Infof("ChannelPoint(%v): proposing fee of %v sat to close "+
|
||||
"chan", c.chanPoint, int64(fee))
|
||||
|
||||
// We'll assemble a ClosingSigned message using this information and
|
||||
// return it to the caller so we can kick off the final stage of the
|
||||
// channel closure project.
|
||||
// We'll assemble a ClosingSigned message using this information and return
|
||||
// it to the caller so we can kick off the final stage of the channel
|
||||
// closure process.
|
||||
closeSignedMsg := lnwire.NewClosingSigned(c.cid, fee, parsedSig)
|
||||
|
||||
// We'll also save this close signed, in the case that the remote party
|
||||
@ -628,26 +615,25 @@ func (c *channelCloser) proposeCloseSigned(fee btcutil.Amount) (*lnwire.ClosingS
|
||||
// compromise and to ensure that the fee negotiation has a stopping point. We
|
||||
// consider their fee acceptable if it's within 30% of our fee.
|
||||
func feeInAcceptableRange(localFee, remoteFee btcutil.Amount) bool {
|
||||
// If our offer is lower than theirs, then we'll accept their
|
||||
// offer if it's no more than 30% *greater* than our current
|
||||
// offer.
|
||||
// If our offer is lower than theirs, then we'll accept their offer if it's
|
||||
// no more than 30% *greater* than our current offer.
|
||||
if localFee < remoteFee {
|
||||
acceptableRange := localFee + ((localFee * 3) / 10)
|
||||
return remoteFee <= acceptableRange
|
||||
}
|
||||
|
||||
// If our offer is greater than theirs, then we'll accept their offer
|
||||
// if it's no more than 30% *less* than our current offer.
|
||||
// If our offer is greater than theirs, then we'll accept their offer if
|
||||
// it's no more than 30% *less* than our current offer.
|
||||
acceptableRange := localFee - ((localFee * 3) / 10)
|
||||
return remoteFee >= acceptableRange
|
||||
}
|
||||
|
||||
// rachetFee is our step function used to inch our fee closer to something that
|
||||
// both sides can agree on. If up is true, then we'll attempt to increase our
|
||||
// offered fee. Otherwise, if up is false, then we'll attempt to decrease our
|
||||
// offered fee.
|
||||
func rachetFee(fee btcutil.Amount, up bool) btcutil.Amount {
|
||||
// If we need to rachet up, then we'll increase our fee by 10%.
|
||||
// ratchetFee is our step function used to inch our fee closer to something
|
||||
// that both sides can agree on. If up is true, then we'll attempt to increase
|
||||
// our offered fee. Otherwise, if up is false, then we'll attempt to decrease
|
||||
// our offered fee.
|
||||
func ratchetFee(fee btcutil.Amount, up bool) btcutil.Amount {
|
||||
// If we need to ratchet up, then we'll increase our fee by 10%.
|
||||
if up {
|
||||
return fee + ((fee * 1) / 10)
|
||||
}
|
||||
@ -659,62 +645,59 @@ func rachetFee(fee btcutil.Amount, up bool) btcutil.Amount {
|
||||
// calcCompromiseFee performs the current fee negotiation algorithm, taking
|
||||
// into consideration our ideal fee based on current fee environment, the fee
|
||||
// we last proposed (if any), and the fee proposed by the peer.
|
||||
func calcCompromiseFee(chanPoint wire.OutPoint,
|
||||
ourIdealFee, lastSentFee, remoteFee btcutil.Amount) btcutil.Amount {
|
||||
func calcCompromiseFee(chanPoint wire.OutPoint, ourIdealFee, lastSentFee,
|
||||
remoteFee btcutil.Amount) btcutil.Amount {
|
||||
|
||||
// TODO(roasbeef): take in number of rounds as well?
|
||||
|
||||
peerLog.Infof("ChannelPoint(%v): computing fee compromise, ideal=%v, "+
|
||||
"last_sent=%v, remote_offer=%v", chanPoint, int64(ourIdealFee),
|
||||
peerLog.Infof("ChannelPoint(%v): computing fee compromise, ideal="+
|
||||
"%v, last_sent=%v, remote_offer=%v", chanPoint, int64(ourIdealFee),
|
||||
int64(lastSentFee), int64(remoteFee))
|
||||
|
||||
// Otherwise, we'll need to attempt to make a fee compromise if this is
|
||||
// the second round, and neither side has agreed on fees.
|
||||
// Otherwise, we'll need to attempt to make a fee compromise if this is the
|
||||
// second round, and neither side has agreed on fees.
|
||||
switch {
|
||||
|
||||
// If their proposed fee is identical to our ideal fee, then we'll go
|
||||
// with that as we can short circuit the fee negotiation. Similarly, if
|
||||
// we haven't sent an offer yet, we'll default to our ideal fee.
|
||||
// If their proposed fee is identical to our ideal fee, then we'll go with
|
||||
// that as we can short circuit the fee negotiation. Similarly, if we
|
||||
// haven't sent an offer yet, we'll default to our ideal fee.
|
||||
case ourIdealFee == remoteFee || lastSentFee == 0:
|
||||
return ourIdealFee
|
||||
|
||||
// If the last fee we sent, is equal to the fee the remote party is
|
||||
// offering, then we can simply return this fee as the negotiation is
|
||||
// over.
|
||||
// offering, then we can simply return this fee as the negotiation is over.
|
||||
case remoteFee == lastSentFee:
|
||||
return lastSentFee
|
||||
|
||||
// If the fee the remote party is offering is less than the last one we
|
||||
// sent, then we'll need to rachet down in order to move our offer
|
||||
// closer to theirs.
|
||||
// sent, then we'll need to ratchet down in order to move our offer closer
|
||||
// to theirs.
|
||||
case remoteFee < lastSentFee:
|
||||
// If the fee is lower, but still acceptable, then we'll just
|
||||
// return this fee and end the negotiation.
|
||||
// If the fee is lower, but still acceptable, then we'll just return
|
||||
// this fee and end the negotiation.
|
||||
if feeInAcceptableRange(lastSentFee, remoteFee) {
|
||||
peerLog.Infof("ChannelPoint(%v): proposed remote fee "+
|
||||
"is close enough, capitulating", chanPoint)
|
||||
peerLog.Infof("ChannelPoint(%v): proposed remote fee is "+
|
||||
"close enough, capitulating", chanPoint)
|
||||
return remoteFee
|
||||
}
|
||||
|
||||
// Otherwise, we'll rachet the fee *down* using our current
|
||||
// algorithm.
|
||||
return rachetFee(lastSentFee, false)
|
||||
// Otherwise, we'll ratchet the fee *down* using our current algorithm.
|
||||
return ratchetFee(lastSentFee, false)
|
||||
|
||||
// If the fee the remote party is offering is greater than the last one
|
||||
// we sent, then we'll rachet up in order to ensure we terminate
|
||||
// eventually.
|
||||
// If the fee the remote party is offering is greater than the last one we
|
||||
// sent, then we'll ratchet up in order to ensure we terminate eventually.
|
||||
case remoteFee > lastSentFee:
|
||||
// If the fee is greater, but still acceptable, then we'll just
|
||||
// return this fee in order to put an end to the negotiation.
|
||||
// If the fee is greater, but still acceptable, then we'll just return
|
||||
// this fee in order to put an end to the negotiation.
|
||||
if feeInAcceptableRange(lastSentFee, remoteFee) {
|
||||
peerLog.Infof("ChannelPoint(%v): proposed remote fee "+
|
||||
"is close enough, capitulating", chanPoint)
|
||||
peerLog.Infof("ChannelPoint(%v): proposed remote fee is "+
|
||||
"close enough, capitulating", chanPoint)
|
||||
return remoteFee
|
||||
}
|
||||
|
||||
// Otherwise, we'll rachet the fee up using our current
|
||||
// algorithm.
|
||||
return rachetFee(lastSentFee, true)
|
||||
return ratchetFee(lastSentFee, true)
|
||||
|
||||
default:
|
||||
// TODO(roasbeef): fail if their fee isn't in expected range
|
||||
|
||||
Loading…
Reference in New Issue
Block a user