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htlcswitch: add additional comments and logging

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This commit is contained in:
Olaoluwa Osuntokun 2018-03-12 18:52:52 -07:00
parent c285bb5814
commit 1af8fa9367
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GPG Key ID: 964EA263DD637C21
5 changed files with 247 additions and 155 deletions
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100
htlcswitch/circuit_map.go
View File

@ -6,6 +6,7 @@ import (
"sync"
"github.com/coreos/bbolt"
"github.com/davecgh/go-spew/spew"
"github.com/go-errors/errors"
"github.com/lightningnetwork/lnd/channeldb"
"github.com/lightningnetwork/lnd/lnwire"
@ -47,7 +48,8 @@ var (
type CircuitModifier interface {
// OpenCircuits preemptively records a batch keystones that will mark
// currently pending circuits as open. These changes can be rolled back
// on restart if the outgoing Adds do not make it into a commitment txn.
// on restart if the outgoing Adds do not make it into a commitment
// txn.
OpenCircuits(...Keystone) error
// TrimOpenCircuits removes a channel's open channels with htlc indexes
@ -60,11 +62,11 @@ type CircuitModifier interface {
DeleteCircuits(inKeys ...CircuitKey) error
}
// CircuitFwdActions represents the forwarding decision made by the circuit map,
// and is returned from CommitCircuits. The sequence of circuits provided to
// CommitCircuits is split into three subsequences, allowing the caller to do an
// in-order scan, comparing the head of each subsequence, to determine the
// decision made by the circuit map.
// CircuitFwdActions represents the forwarding decision made by the circuit
// map, and is returned from CommitCircuits. The sequence of circuits provided
// to CommitCircuits is split into three sub-sequences, allowing the caller to
// do an in-order scan, comparing the head of each subsequence, to determine
// the decision made by the circuit map.
type CircuitFwdActions struct {
// Adds is the subsequence of circuits that were successfully committed
// in the circuit map.
@ -85,10 +87,10 @@ type CircuitMap interface {
CircuitModifier
// CommitCircuits attempts to add the given circuits to the circuit
// map. The list of circuits is split into three distinct subsequences,
// corresponding to adds, drops, and fails. Adds should be forwarded to
// the switch, while fails should be failed back locally within the
// calling link.
// map. The list of circuits is split into three distinct
// sub-sequences, corresponding to adds, drops, and fails. Adds should
// be forwarded to the switch, while fails should be failed back
// locally within the calling link.
CommitCircuits(circuit ...*PaymentCircuit) (*CircuitFwdActions, error)
// CloseCircuit marks the circuit identified by `outKey` as closing
@ -105,8 +107,8 @@ type CircuitMap interface {
// inKey.
LookupCircuit(inKey CircuitKey) *PaymentCircuit
// LookupOpenCircuit queries the circuit map for a circuit identified by
// its outgoing circuit key.
// LookupOpenCircuit queries the circuit map for a circuit identified
// by its outgoing circuit key.
LookupOpenCircuit(outKey CircuitKey) *PaymentCircuit
// LookupByPaymentHash queries the circuit map and returns all open
@ -124,15 +126,15 @@ type CircuitMap interface {
var (
// circuitAddKey is the key used to retrieve the bucket containing
// payment circuits. A circuit records information about how to return a
// packet to the source link, potentially including an error encrypter
// for applying this hop's encryption to the payload in the reverse
// direction.
// payment circuits. A circuit records information about how to return
// a packet to the source link, potentially including an error
// encrypter for applying this hop's encryption to the payload in the
// reverse direction.
circuitAddKey = []byte("circuit-adds")
// circuitKeystoneKey is used to retrieve the bucket containing circuit
// keystones, which are set in place once a forwarded packet is assigned
// an index on an outgoing commitment txn.
// keystones, which are set in place once a forwarded packet is
// assigned an index on an outgoing commitment txn.
circuitKeystoneKey = []byte("circuit-keystones")
)
@ -143,18 +145,19 @@ var (
// outgoing CircuitKey if the circuit is fully-opened.
type circuitMap struct {
// db provides the persistent storage engine for the circuit map.
//
// TODO(conner): create abstraction to allow for the substitution of
// other persistence engines.
db *channeldb.DB
mtx sync.RWMutex
// pending is an in-memory mapping of all half payment circuits, and
// is kept in sync with the on-disk contents of the circuit map.
// pending is an in-memory mapping of all half payment circuits, and is
// kept in sync with the on-disk contents of the circuit map.
pending map[CircuitKey]*PaymentCircuit
// opened is an in-memory mapping of all full payment circuits, which is
// also synchronized with the persistent state of the circuit map.
// opened is an in-memory mapping of all full payment circuits, which
// is also synchronized with the persistent state of the circuit map.
opened map[CircuitKey]*PaymentCircuit
// closed is an in-memory set of circuits for which the switch has
@ -211,11 +214,12 @@ func (cm *circuitMap) initBuckets() error {
})
}
// restoreMemState loads the contents of the half circuit and full circuit buckets
// from disk and reconstructs the in-memory representation of the circuit map.
// Afterwards, the state of the hash index is reconstructed using the recovered
// set of full circuits.
// restoreMemState loads the contents of the half circuit and full circuit
// buckets from disk and reconstructs the in-memory representation of the
// circuit map. Afterwards, the state of the hash index is reconstructed using
// the recovered set of full circuits.
func (cm *circuitMap) restoreMemState() error {
log.Infof("Restoring in-memory circuit state from disk")
var (
opened = make(map[CircuitKey]*PaymentCircuit)
@ -286,6 +290,9 @@ func (cm *circuitMap) restoreMemState() error {
cm.opened = opened
cm.closed = make(map[CircuitKey]struct{})
log.Infof("Payment circuits loaded: num_pending=%v, num_open=%v",
len(pending), len(opened))
// Finally, reconstruct the hash index by running through our set of
// open circuits.
cm.hashIndex = make(map[[32]byte]map[CircuitKey]struct{})
@ -339,18 +346,22 @@ func (cm *circuitMap) trimAllOpenCircuits() error {
}
// TrimOpenCircuits removes a channel's keystones above the short chan id's
// highest committed htlc index. This has the effect of returning those circuits
// to a half-open state. Since opening of circuits is done in advance of
// actually committing the Add htlcs into a commitment txn, this allows circuits
// to be opened preemetively, since we can roll them back after any failures.
// highest committed htlc index. This has the effect of returning those
// circuits to a half-open state. Since opening of circuits is done in advance
// of actually committing the Add htlcs into a commitment txn, this allows
// circuits to be opened preemptively, since we can roll them back after any
// failures.
func (cm *circuitMap) TrimOpenCircuits(chanID lnwire.ShortChannelID,
start uint64) error {
log.Infof("Trimming open circuits for chan_id=%v, start_htlc_id=%v",
chanID, start)
var trimmedOutKeys []CircuitKey
// Scan forward from the last unacked htlc id, stopping as soon as we
// don't find any more. Outgoing htlc id's must be assigned in order, so
// there should never be disjoint segments of keystones to trim.
// don't find any more. Outgoing htlc id's must be assigned in order,
// so there should never be disjoint segments of keystones to trim.
cm.mtx.Lock()
for i := start; ; i++ {
outKey := CircuitKey{
@ -440,6 +451,10 @@ func (cm *circuitMap) LookupByPaymentHash(hash [32]byte) []*PaymentCircuit {
func (cm *circuitMap) CommitCircuits(circuits ...*PaymentCircuit) (
*CircuitFwdActions, error) {
log.Tracef("Committing fresh circuits: %v", newLogClosure(func() string {
return spew.Sdump(circuits)
}))
actions := &CircuitFwdActions{}
// If an empty list was passed, return early to avoid grabbing the lock.
@ -563,7 +578,8 @@ func (cm *circuitMap) CommitCircuits(circuits ...*PaymentCircuit) (
// Keystone is a tuple binding an incoming and outgoing CircuitKey. Keystones
// are preemptively written by an outgoing link before signing a new commitment
// state, and cements which HTLCs we are awaiting a response from a remote peer.
// state, and cements which HTLCs we are awaiting a response from a remote
// peer.
type Keystone struct {
InKey CircuitKey
OutKey CircuitKey
@ -583,6 +599,10 @@ func (cm *circuitMap) OpenCircuits(keystones ...Keystone) error {
return nil
}
log.Tracef("Opening finalized circuits: %v", newLogClosure(func() string {
return spew.Sdump(keystones)
}))
// Check that all keystones correspond to committed-but-unopened
// circuits.
cm.mtx.RLock()
@ -658,8 +678,7 @@ func (cm *circuitMap) addCircuitToHashIndex(c *PaymentCircuit) {
// FailCircuit marks the circuit identified by `inKey` as closing in-memory,
// which prevents duplicate settles/fails from completing an open circuit twice.
func (cm *circuitMap) FailCircuit(
inKey CircuitKey) (*PaymentCircuit, error) {
func (cm *circuitMap) FailCircuit(inKey CircuitKey) (*PaymentCircuit, error) {
cm.mtx.Lock()
defer cm.mtx.Unlock()
@ -679,11 +698,10 @@ func (cm *circuitMap) FailCircuit(
return circuit, nil
}
// CloseCircuit marks the circuit identified by `outKey` as closing
// in-memory, which prevents duplicate settles/fails from completing an open
// CloseCircuit marks the circuit identified by `outKey` as closing in-memory,
// which prevents duplicate settles/fails from completing an open
// circuit twice.
func (cm *circuitMap) CloseCircuit(
outKey CircuitKey) (*PaymentCircuit, error) {
func (cm *circuitMap) CloseCircuit(outKey CircuitKey) (*PaymentCircuit, error) {
cm.mtx.Lock()
defer cm.mtx.Unlock()
@ -709,6 +727,10 @@ func (cm *circuitMap) CloseCircuit(
// circuit key.
func (cm *circuitMap) DeleteCircuits(inKeys ...CircuitKey) error {
log.Tracef("Deleting resolved circuits: %v", newLogClosure(func() string {
return spew.Sdump(inKeys)
}))
var (
closingCircuits = make(map[CircuitKey]struct{})
removedCircuits = make(map[CircuitKey]*PaymentCircuit)

205
htlcswitch/link.go
View File

@ -9,6 +9,7 @@ import (
"crypto/sha256"
"github.com/davecgh/go-spew/spew"
"github.com/go-errors/errors"
"github.com/lightningnetwork/lnd/chainntnfs"
"github.com/lightningnetwork/lnd/channeldb"
@ -140,8 +141,9 @@ type ChannelLinkConfig struct {
// DecodeHopIterators facilitates batched decoding of HTLC Sphinx onion
// blobs, which are then used to inform how to forward an HTLC.
// NOTE: This function assumes the same set of readers and preimages are
// always presented for the same identifier.
//
// NOTE: This function assumes the same set of readers and preimages
// are always presented for the same identifier.
DecodeHopIterators func([]byte, []DecodeHopIteratorRequest) (
[]DecodeHopIteratorResponse, error)
@ -210,14 +212,15 @@ type ChannelLinkConfig struct {
// BatchTicker is the ticker that determines the interval that we'll
// use to check the batch to see if there're any updates we should
// flush out. By batching updates into a single commit, we attempt
// to increase throughput by maximizing the number of updates
// coalesced into a single commit.
// flush out. By batching updates into a single commit, we attempt to
// increase throughput by maximizing the number of updates coalesced
// into a single commit.
BatchTicker Ticker
// FwdPkgGCTicker is the ticker determining the frequency at which
// garbage collection of forwarding packages occurs. We use a time-based
// approach, as opposed to block epochs, as to not hinder syncing.
// garbage collection of forwarding packages occurs. We use a
// time-based approach, as opposed to block epochs, as to not hinder
// syncing.
FwdPkgGCTicker Ticker
// BatchSize is the max size of a batch of updates done to the link
@ -232,8 +235,8 @@ type ChannelLinkConfig struct {
}
// channelLink is the service which drives a channel's commitment update
// state-machine. In the event that an htlc needs to be propagated to another
// link, the forward handler from config is used which sends htlc to the
// state-machine. In the event that an HTLC needs to be propagated to another
// link, the forward handler from config is used which sends HTLC to the
// switch. Additionally, the link encapsulate logic of commitment protocol
// message ordering and updates.
type channelLink struct {
@ -246,8 +249,8 @@ type channelLink struct {
// current number of settles that have been sent, but not yet committed
// to the commitment.
//
// TODO(andrew.shvv) remove after we add additional
// BatchNumber() method in state machine.
// TODO(andrew.shvv) remove after we add additional BatchNumber()
// method in state machine.
batchCounter uint32
// bestHeight is the best known height of the main chain. The link will
@ -255,10 +258,22 @@ type channelLink struct {
bestHeight uint32
// keystoneBatch represents a volatile list of keystones that must be
// written before attempting to sign the next commitment txn.
// written before attempting to sign the next commitment txn. These
// represent all the HTLC's forwarded to the link from the switch. Once
// we lock them into our outgoing commitment, then the circuit has a
// keystone, and is fully opened.
keystoneBatch []Keystone
// openedCircuits is the set of all payment circuits that will be open
// once we make our next commitment. After making the commitment we'll
// ACK all these from our mailbox to ensure that they don't get
// re-delivered if we reconnect.
openedCircuits []CircuitKey
// closedCircuits is the set of all payment circuits that will be
// closed once we make our next commitment. After taking the commitment
// we'll ACK all these to ensure that they don't get re-delivered if we
// reconnect.
closedCircuits []CircuitKey
// channel is a lightning network channel to which we apply htlc
@ -526,9 +541,9 @@ func (l *channelLink) syncChanStates() error {
closedCircuits []CircuitKey
)
// We've just received a ChnSync message from the remote party,
// so we'll process the message in order to determine if we
// need to re-transmit any messages to the remote party.
// We've just received a ChanSync message from the remote
// party, so we'll process the message in order to determine
// if we need to re-transmit any messages to the remote party.
msgsToReSend, openedCircuits, closedCircuits, err =
l.channel.ProcessChanSyncMsg(remoteChanSyncMsg)
if err != nil {
@ -539,7 +554,8 @@ func (l *channelLink) syncChanStates() error {
}
// Repopulate any identifiers for circuits that may have been
// opened or unclosed.
// opened or unclosed. This may happen if we needed to
// retransmit a commitment signature message.
l.openedCircuits = openedCircuits
l.closedCircuits = closedCircuits
@ -574,10 +590,10 @@ func (l *channelLink) syncChanStates() error {
}
// resolveFwdPkgs loads any forwarding packages for this link from disk, and
// reprocesses them in order. The primary goal is to make sure that any HTLCs we
// previously received are reinstated in memory, and forwarded to the switch if
// necessary. After a restart, this will also delete any previously completed
// packages.
// reprocesses them in order. The primary goal is to make sure that any HTLCs
// we previously received are reinstated in memory, and forwarded to the switch
// if necessary. After a restart, this will also delete any previously
// completed packages.
func (l *channelLink) resolveFwdPkgs() error {
fwdPkgs, err := l.channel.LoadFwdPkgs()
if err != nil {
@ -623,10 +639,10 @@ func (l *channelLink) resolveFwdPkg(fwdPkg *channeldb.FwdPkg) (bool, error) {
}
// Otherwise this is either a new package or one has gone through
// processing, but contains htlcs that need to be restored in memory. We
// replay this forwarding package to make sure our local mem state is
// resurrected, we mimic any original responses back to the remote
// party, and reforward the relevant HTLCs to the switch.
// processing, but contains htlcs that need to be restored in memory.
// We replay this forwarding package to make sure our local mem state
// is resurrected, we mimic any original responses back to the remote
// party, and re-forward the relevant HTLCs to the switch.
// If the package is fully acked but not completed, it must still have
// settles and fails to propagate.
@ -637,10 +653,10 @@ func (l *channelLink) resolveFwdPkg(fwdPkg *channeldb.FwdPkg) (bool, error) {
l.processRemoteSettleFails(fwdPkg, settleFails)
}
// Finally, replay *ALL ADDS* in this forwarding package. The downstream
// logic is able to filter out any duplicates, but we must shove the
// entire, original set of adds down the pipeline so that the batch of
// adds presented to the sphinx router does not ever change.
// Finally, replay *ALL ADDS* in this forwarding package. The
// downstream logic is able to filter out any duplicates, but we must
// shove the entire, original set of adds down the pipeline so that the
// batch of adds presented to the sphinx router does not ever change.
var needUpdate bool
if !fwdPkg.AckFilter.IsFull() {
adds := lnwallet.PayDescsFromRemoteLogUpdates(
@ -717,10 +733,10 @@ func (l *channelLink) htlcManager() {
// commitment txn. We use the next local htlc index as the cut off
// point, since all indexes below that are committed.
//
// NOTE: This is automatically done by the switch when it starts up, but
// is necessary to prevent inconsistencies in the case that the link
// flaps. This is a result of a link's life-cycle being shorter than
// that of the switch.
// NOTE: This is automatically done by the switch when it starts up,
// but is necessary to prevent inconsistencies in the case that the
// link flaps. This is a result of a link's life-cycle being shorter
// than that of the switch.
localHtlcIndex := l.channel.LocalHtlcIndex()
err := l.cfg.Circuits.TrimOpenCircuits(l.ShortChanID(), localHtlcIndex)
if err != nil {
@ -737,7 +753,6 @@ func (l *channelLink) htlcManager() {
// re-synchronize state with the remote peer. settledHtlcs is a map of
// HTLC's that we re-settled as part of the channel state sync.
if l.cfg.SyncStates {
// TODO(roasbeef): need to ensure haven't already settled?
if err := l.syncChanStates(); err != nil {
l.errorf("unable to synchronize channel states: %v", err)
l.fail(err.Error())
@ -745,9 +760,9 @@ func (l *channelLink) htlcManager() {
}
}
// With the channel states synced, we now reset the mailbox to ensure we
// start processing all unacked packets in order. This is done here to
// ensure that all acknowledgments that occur during channel
// With the channel states synced, we now reset the mailbox to ensure
// we start processing all unacked packets in order. This is done here
// to ensure that all acknowledgments that occur during channel
// resynchronization have taken affect, causing us only to pull unacked
// packets after starting to read from the downstream mailbox.
l.mailBox.ResetPackets()
@ -827,7 +842,8 @@ out:
// TODO(roasbeef): remove all together
go func() {
chanPoint := l.channel.ChannelPoint()
if err := l.cfg.Peer.WipeChannel(chanPoint); err != nil {
err := l.cfg.Peer.WipeChannel(chanPoint)
if err != nil {
log.Errorf("unable to wipe channel %v", err)
}
}()
@ -895,6 +911,7 @@ out:
l.overflowQueue.AddPkt(pkt)
continue
}
l.handleDownStreamPkt(pkt, false)
// A message from the connected peer was just received. This
@ -956,7 +973,7 @@ func (l *channelLink) handleDownStreamPkt(pkt *htlcPacket, isReProcess bool) {
// The channels spare bandwidth is fully allocated, so
// we'll put this HTLC into the overflow queue.
case lnwallet.ErrMaxHTLCNumber:
log.Infof("Downstream htlc add update with "+
l.infof("Downstream htlc add update with "+
"payment hash(%x) have been added to "+
"reprocessing queue, batch: %v",
htlc.PaymentHash[:],
@ -969,7 +986,7 @@ func (l *channelLink) handleDownStreamPkt(pkt *htlcPacket, isReProcess bool) {
// machine, as a result, we'll signal the switch to
// cancel the pending payment.
default:
log.Warnf("Unable to handle downstream add HTLC: %v", err)
l.warnf("Unable to handle downstream add HTLC: %v", err)
var (
localFailure = false
@ -984,7 +1001,7 @@ func (l *channelLink) handleDownStreamPkt(pkt *htlcPacket, isReProcess bool) {
var b bytes.Buffer
err := lnwire.EncodeFailure(&b, failure, 0)
if err != nil {
log.Errorf("unable to encode failure: %v", err)
l.errorf("unable to encode failure: %v", err)
return
}
reason = lnwire.OpaqueReason(b.Bytes())
@ -993,7 +1010,7 @@ func (l *channelLink) handleDownStreamPkt(pkt *htlcPacket, isReProcess bool) {
var err error
reason, err = pkt.obfuscator.EncryptFirstHop(failure)
if err != nil {
log.Errorf("unable to obfuscate error: %v", err)
l.errorf("unable to obfuscate error: %v", err)
return
}
}
@ -1027,7 +1044,7 @@ func (l *channelLink) handleDownStreamPkt(pkt *htlcPacket, isReProcess bool) {
}
}
log.Tracef("Received downstream htlc: payment_hash=%x, "+
l.tracef("Received downstream htlc: payment_hash=%x, "+
"local_log_index=%v, batch_size=%v",
htlc.PaymentHash[:], index, l.batchCounter+1)
@ -1047,7 +1064,6 @@ func (l *channelLink) handleDownStreamPkt(pkt *htlcPacket, isReProcess bool) {
// An HTLC we forward to the switch has just settled somewhere
// upstream. Therefore we settle the HTLC within the our local
// state machine.
closedCircuitRef := pkt.inKey()
if err := l.channel.SettleHTLC(
htlc.PaymentPreimage,
@ -1138,7 +1154,7 @@ func (l *channelLink) handleUpstreamMsg(msg lnwire.Message) {
return
}
log.Tracef("Receive upstream htlc with payment hash(%x), "+
l.tracef("Receive upstream htlc with payment hash(%x), "+
"assigning index: %v", msg.PaymentHash[:], index)
case *lnwire.UpdateFulfillHTLC:
@ -1159,7 +1175,7 @@ func (l *channelLink) handleUpstreamMsg(msg lnwire.Message) {
go func() {
err := l.cfg.PreimageCache.AddPreimage(pre[:])
if err != nil {
log.Errorf("unable to add preimage=%x to "+
l.errorf("unable to add preimage=%x to "+
"cache", pre[:])
}
}()
@ -1191,7 +1207,7 @@ func (l *channelLink) handleUpstreamMsg(msg lnwire.Message) {
// form.
var b bytes.Buffer
if err := lnwire.EncodeFailure(&b, failure, 0); err != nil {
log.Errorf("unable to encode malformed error: %v", err)
l.errorf("unable to encode malformed error: %v", err)
return
}
@ -1330,12 +1346,12 @@ func (l *channelLink) handleUpstreamMsg(msg lnwire.Message) {
}
// ackDownStreamPackets is responsible for removing htlcs from a link's
// mailbox for packets delivered from server, and cleaning up any circuits
// closed by signing a previous commitment txn. This method ensures that the
// circuits are removed from the circuit map before removing them from the
// link's mailbox, otherwise it could be possible for some circuit to be missed
// if this link flaps.
// ackDownStreamPackets is responsible for removing htlcs from a link's mailbox
// for packets delivered from server, and cleaning up any circuits closed by
// signing a previous commitment txn. This method ensures that the circuits are
// removed from the circuit map before removing them from the link's mailbox,
// otherwise it could be possible for some circuit to be missed if this link
// flaps.
//
// The `forgive` flag allows this method to tolerate restarts, and ignores
// errors that could be caused by a previous circuit deletion. Under normal
@ -1346,15 +1362,15 @@ func (l *channelLink) ackDownStreamPackets(forgive bool) error {
// previous commitment signature. This will prevent the Adds from being
// replayed if this link disconnects.
for _, inKey := range l.openedCircuits {
// In order to test the sphinx replay logic of the remote party,
// unsafe replay does not acknowledge the packets from the
// mailbox. We can then force a replay of any Add packets held
// in memory by disconnecting and reconnecting the link.
// In order to test the sphinx replay logic of the remote
// party, unsafe replay does not acknowledge the packets from
// the mailbox. We can then force a replay of any Add packets
// held in memory by disconnecting and reconnecting the link.
if l.cfg.UnsafeReplay {
continue
}
l.debugf("Removing Add packet %s from mailbox", inKey)
l.debugf("removing Add packet %s from mailbox", inKey)
l.mailBox.AckPacket(inKey)
}
@ -1370,11 +1386,11 @@ func (l *channelLink) ackDownStreamPackets(forgive bool) error {
case ErrUnknownCircuit:
if forgive {
// After a restart, we may have already removed this
// circuit. Since it shouldn't be possible for a circuit
// to be closed by different htlcs, we assume this error
// signals that the whole batch was successfully
// removed.
l.warnf("Forgiving unknown circuit error after " +
// circuit. Since it shouldn't be possible for a
// circuit to be closed by different htlcs, we assume
// this error signals that the whole batch was
// successfully removed.
l.warnf("forgiving unknown circuit error after " +
"attempting deletion, circuit was probably " +
"removed before shutting down.")
break
@ -1392,9 +1408,9 @@ func (l *channelLink) ackDownStreamPackets(forgive bool) error {
// Settle/Fails in the mailbox to ensure they do not get redelivered
// after startup. If forgive is enabled and we've reached this point,
// the circuits must have been removed at some point, so it is now safe
// to unqueue the corresponding Settle/Fails.
// to un-queue the corresponding Settle/Fails.
for _, inKey := range l.closedCircuits {
l.debugf("Removing Fail/Settle packet %s from mailbox", inKey)
l.debugf("removing Fail/Settle packet %s from mailbox", inKey)
l.mailBox.AckPacket(inKey)
}
@ -1526,24 +1542,29 @@ type getBandwidthCmd struct {
func (l *channelLink) Bandwidth() lnwire.MilliSatoshi {
channelBandwidth := l.channel.AvailableBalance()
overflowBandwidth := l.overflowQueue.TotalHtlcAmount()
linkBandwidth := channelBandwidth - overflowBandwidth
reserve := lnwire.NewMSatFromSatoshis(l.channel.LocalChanReserve())
// If the channel reserve is greater than the total available
// balance of the link, just return 0.
// To compute the total bandwidth, we'll take the current available
// bandwidth, then subtract the overflow bandwidth as we'll eventually
// also need to evaluate those HTLC's once space on the commitment
// transaction is free.
linkBandwidth := channelBandwidth - overflowBandwidth
// If the channel reserve is greater than the total available balance
// of the link, just return 0.
reserve := lnwire.NewMSatFromSatoshis(l.channel.LocalChanReserve())
if linkBandwidth < reserve {
return 0
}
// Else the amount that is available to flow through the link at
// this point is the available balance minus the reserve amount
// we are required to keep as collateral.
// Else the amount that is available to flow through the link at this
// point is the available balance minus the reserve amount we are
// required to keep as collateral.
return linkBandwidth - reserve
}
// AttachMailBox updates the current mailbox used by this link, and hooks up the
// mailbox's message and packet outboxes to the link's upstream and downstream
// chans, respectively.
// AttachMailBox updates the current mailbox used by this link, and hooks up
// the mailbox's message and packet outboxes to the link's upstream and
// downstream chans, respectively.
func (l *channelLink) AttachMailBox(mailbox MailBox) {
l.Lock()
l.mailBox = mailbox
@ -1611,6 +1632,7 @@ func (l *channelLink) String() string {
func (l *channelLink) HandleSwitchPacket(pkt *htlcPacket) error {
l.tracef("received switch packet inkey=%v, outkey=%v",
pkt.inKey(), pkt.outKey())
l.mailBox.AddPacket(pkt)
return nil
}
@ -1669,12 +1691,16 @@ func (l *channelLink) processRemoteSettleFails(fwdPkg *channeldb.FwdPkg,
var switchPackets []*htlcPacket
for i, pd := range settleFails {
// Skip any settles or fails that have already been acknowledged
// by the incoming link that originated the forwarded Add.
// Skip any settles or fails that have already been
// acknowledged by the incoming link that originated the
// forwarded Add.
if fwdPkg.SettleFailFilter.Contains(uint16(i)) {
continue
}
// TODO(roasbeef): rework log entries to a shared
// interface.
switch pd.EntryType {
// A settle for an HTLC we previously forwarded HTLC has been
@ -1759,8 +1785,8 @@ func (l *channelLink) processRemoteAdds(fwdPkg *channeldb.FwdPkg,
// Atomically decode the incoming htlcs, simultaneously checking for
// replay attempts. A particular index in the returned, spare list of
// channel iterators should only be used if the failure code at the same
// index is lnwire.FailCodeNone.
// channel iterators should only be used if the failure code at the
// same index is lnwire.FailCodeNone.
decodeResps, sphinxErr := l.cfg.DecodeHopIterators(
fwdPkg.ID(), decodeReqs,
)
@ -1781,11 +1807,11 @@ func (l *channelLink) processRemoteAdds(fwdPkg *channeldb.FwdPkg,
if fwdPkg.State == channeldb.FwdStateProcessed &&
fwdPkg.AckFilter.Contains(idx) {
// If this index is already found in the ack filter, the
// response to this forwarding decision has already been
// committed by one of our commitment txns. ADDs in this
// state are waiting for the rest of the fwding package
// to get acked before being garbage collected.
// If this index is already found in the ack filter,
// the response to this forwarding decision has already
// been committed by one of our commitment txns. ADDs
// in this state are waiting for the rest of the fwding
// package to get acked before being garbage collected.
continue
}
@ -2313,14 +2339,14 @@ func (l *channelLink) forwardBatch(packets ...*htlcPacket) {
l.handleBatchFwdErrs(errChan)
}
// handleBatchFwdErrs waits on the given errChan until it is closed, logging the
// errors returned from any unsuccessful forwarding attempts.
// handleBatchFwdErrs waits on the given errChan until it is closed, logging
// the errors returned from any unsuccessful forwarding attempts.
func (l *channelLink) handleBatchFwdErrs(errChan chan error) {
for {
err, ok := <-errChan
if !ok {
// Err chan has been drained or switch is shutting down.
// Either way, return.
// Err chan has been drained or switch is shutting
// down. Either way, return.
return
}
@ -2335,9 +2361,8 @@ func (l *channelLink) handleBatchFwdErrs(errChan chan error) {
// sendHTLCError functions cancels HTLC and send cancel message back to the
// peer from which HTLC was received.
func (l *channelLink) sendHTLCError(htlcIndex uint64,
failure lnwire.FailureMessage, e ErrorEncrypter,
sourceRef *channeldb.AddRef) {
func (l *channelLink) sendHTLCError(htlcIndex uint64, failure lnwire.FailureMessage,
e ErrorEncrypter, sourceRef *channeldb.AddRef) {
reason, err := e.EncryptFirstHop(failure)
if err != nil {

16
htlcswitch/log.go
View File

@ -24,3 +24,19 @@ func DisableLog() {
func UseLogger(logger btclog.Logger) {
log = logger
}
// logClosure is used to provide a closure over expensive logging operations so
// don't have to be performed when the logging level doesn't warrant it.
type logClosure func() string
// String invokes the underlying function and returns the result.
func (c logClosure) String() string {
return c()
}
// newLogClosure returns a new closure over a function that returns a string
// which itself provides a Stringer interface so that it can be used with the
// logging system.
func newLogClosure(c func() string) logClosure {
return logClosure(c)
}

20
htlcswitch/mailbox.go
View File

@ -247,6 +247,7 @@ func (m *memoryMailBox) mailCourier(cType courierType) {
select {
case msgDone := <-m.msgReset:
m.wireMessages.Init()
close(msgDone)
case <-m.quit:
m.wireCond.L.Unlock()
@ -261,8 +262,13 @@ func (m *memoryMailBox) mailCourier(cType courierType) {
m.pktCond.Wait()
select {
// Resetting the packet queue means just moving
// our pointer to the front. This ensures that
// any un-ACK'd messages are re-delivered upon
// reconnect.
case pktDone := <-m.pktReset:
m.pktHead = m.htlcPkts.Front()
close(pktDone)
case <-m.quit:
m.pktCond.L.Unlock()
@ -272,17 +278,22 @@ func (m *memoryMailBox) mailCourier(cType courierType) {
}
}
// Grab the datum off the front of the queue, shifting the
// slice's reference down one in order to remove the datum from
// the queue.
var (
nextPkt *htlcPacket
nextMsg lnwire.Message
)
switch cType {
// Grab the datum off the front of the queue, shifting the
// slice's reference down one in order to remove the datum from
// the queue.
case wireCourier:
entry := m.wireMessages.Front()
nextMsg = m.wireMessages.Remove(entry).(lnwire.Message)
// For packets, we actually never remove an item until it has
// been ACK'd by the link. This ensures that if a read packet
// doesn't make it into a commitment, then it'll be
// re-delivered once the link comes back online.
case pktCourier:
nextPkt = m.pktHead.Value.(*htlcPacket)
m.pktHead = m.pktHead.Next()
@ -297,6 +308,7 @@ func (m *memoryMailBox) mailCourier(cType courierType) {
m.pktCond.L.Unlock()
}
// With the next message obtained, we'll now select to attempt
// to deliver the message. If we receive a kill signal, then
// we'll bail out.
switch cType {
@ -307,6 +319,7 @@ func (m *memoryMailBox) mailCourier(cType courierType) {
m.wireCond.L.Lock()
m.wireMessages.Init()
m.wireCond.L.Unlock()
close(msgDone)
case <-m.quit:
return
@ -319,6 +332,7 @@ func (m *memoryMailBox) mailCourier(cType courierType) {
m.pktCond.L.Lock()
m.pktHead = m.htlcPkts.Front()
m.pktCond.L.Unlock()
close(pktDone)
case <-m.quit:
return

61
htlcswitch/switch.go
View File

@ -346,8 +346,8 @@ func (s *Switch) SendHTLC(nextNode [33]byte, htlc *lnwire.UpdateAddHTLC,
"while waiting for payment result")
}
// Remove circuit since we are about to complete an
// add/fail of this HTLC.
// Remove circuit since we are about to complete an add/fail of this
// HTLC.
if teardownErr := s.teardownCircuit(response); teardownErr != nil {
log.Warnf("unable to teardown circuit %s: %v",
response.inKey(), teardownErr)
@ -409,7 +409,7 @@ type updatePoliciesCmd struct {
// updateLinkPolicies attempts to update the forwarding policies for the set of
// passed links identified by their channel points. If a nil set of channel
// points is passed, then the forwarding policies for all active links will be
// updated.k
// updated.
func (s *Switch) updateLinkPolicies(c *updatePoliciesCmd) error {
log.Debugf("Updating link policies: %v", spew.Sdump(c))
@ -440,9 +440,9 @@ func (s *Switch) updateLinkPolicies(c *updatePoliciesCmd) error {
return nil
}
// forward is used in order to find next channel link and apply htlc
// update. Also this function is used by channel links itself in order to
// forward the update after it has been included in the channel.
// forward is used in order to find next channel link and apply htlc update.
// Also this function is used by channel links itself in order to forward the
// update after it has been included in the channel.
func (s *Switch) forward(packet *htlcPacket) error {
switch htlc := packet.htlc.(type) {
case *lnwire.UpdateAddHTLC:
@ -475,10 +475,11 @@ func (s *Switch) forward(packet *htlcPacket) error {
return s.route(packet)
}
// ForwardPackets adds a list of packets to the switch for processing. Fails and
// settles are added on a first past, simultaneously constructing circuits for
// any adds. After persisting the circuits, another pass of the adds is given to
// forward them through the router.
// ForwardPackets adds a list of packets to the switch for processing. Fails
// and settles are added on a first past, simultaneously constructing circuits
// for any adds. After persisting the circuits, another pass of the adds is
// given to forward them through the router.
//
// NOTE: This method guarantees that the returned err chan will eventually be
// closed. The receiver should read on the channel until receiving such a
// signal.
@ -911,7 +912,6 @@ func (s *Switch) handlePacketForward(packet *htlcPacket) error {
return destination.HandleSwitchPacket(packet)
case *lnwire.UpdateFailHTLC, *lnwire.UpdateFulfillHTLC:
// If the source of this packet has not been set, use the
// circuit map to lookup the origin.
circuit, err := s.closeCircuit(packet)
@ -1032,10 +1032,9 @@ func (s *Switch) failAddPacket(packet *htlcPacket,
// set the incoming chan and htlc ID of the given packet if the source was
// found, and will properly [re]encrypt any failure messages.
func (s *Switch) closeCircuit(pkt *htlcPacket) (*PaymentCircuit, error) {
// If the packet has its source, that means it was failed locally by the
// outgoing link. We fail it here to make sure only one response makes
// it through the switch.
// If the packet has its source, that means it was failed locally by
// the outgoing link. We fail it here to make sure only one response
// makes it through the switch.
if pkt.hasSource {
circuit, err := s.circuits.FailCircuit(pkt.inKey())
switch err {
@ -1044,15 +1043,16 @@ func (s *Switch) closeCircuit(pkt *htlcPacket) (*PaymentCircuit, error) {
case nil:
return circuit, nil
// Circuit was previously closed, but has not been deleted. We'll just
// drop this response until the circuit has been fully removed.
// Circuit was previously closed, but has not been deleted.
// We'll just drop this response until the circuit has been
// fully removed.
case ErrCircuitClosing:
return nil, err
// Failed to close circuit because it does not exist. This is likely
// because the circuit was already successfully closed. Since
// this packet failed locally, there is no forwarding package
// entry to acknowledge.
// Failed to close circuit because it does not exist. This is
// likely because the circuit was already successfully closed.
// Since this packet failed locally, there is no forwarding
// package entry to acknowledge.
case ErrUnknownCircuit:
return nil, err
@ -1062,8 +1062,8 @@ func (s *Switch) closeCircuit(pkt *htlcPacket) (*PaymentCircuit, error) {
}
}
// Otherwise, this is packet was received from the remote party.
// Use circuit map to find the incoming link to receive the settle/fail.
// Otherwise, this is packet was received from the remote party. Use
// circuit map to find the incoming link to receive the settle/fail.
circuit, err := s.circuits.CloseCircuit(pkt.outKey())
switch err {
@ -1074,6 +1074,16 @@ func (s *Switch) closeCircuit(pkt *htlcPacket) (*PaymentCircuit, error) {
pkt.circuit = circuit
pkt.sourceRef = &circuit.AddRef
pktType := "SETTLE"
if _, ok := pkt.htlc.(*lnwire.UpdateFailHTLC); ok {
pktType = "FAIL"
}
log.Debugf("Closed completed %s circuit for %x: "+
"(%s, %d) <-> (%s, %d)", pktType, pkt.circuit.PaymentHash,
pkt.incomingChanID, pkt.incomingHTLCID,
pkt.outgoingChanID, pkt.outgoingHTLCID)
return circuit, nil
// Circuit was previously closed, but has not been deleted. We'll just
@ -1105,6 +1115,10 @@ func (s *Switch) closeCircuit(pkt *htlcPacket) (*PaymentCircuit, error) {
}
}
// ackSettleFail is used by the switch to ACK any settle/fail entries in the
// forwarding package of the outgoing link for a payment circuit. We do this if
// we're the originator of the payment, so the link stops attempting to
// re-broadcast.
func (s *Switch) ackSettleFail(settleFailRef channeldb.SettleFailRef) error {
return s.cfg.DB.Update(func(tx *bolt.Tx) error {
return s.cfg.SwitchPackager.AckSettleFails(tx, settleFailRef)
@ -1149,6 +1163,7 @@ func (s *Switch) teardownCircuit(pkt *htlcPacket) error {
default:
log.Debugf("Tearing down incomplete circuit with %s for inkey=%v",
pktType, pkt.inKey())
err := s.circuits.DeleteCircuits(pkt.inKey())
if err != nil {
log.Warnf("Failed to tear down pending %s circuit for %x: "+