12986279612

Committed 27 Jan 2025 09:51AM UTC coverage: 57.652% (-1.1%) from 58.788%

Build # 12986279612

Build Type

Pull #9447

github

Committed by

yyforyongyu

Commit Message

sweep: rename methods for clarity

We now rename "third party" to "unknown" as the inputs can be spent via
an older sweeping tx, a third party (anchor), or a remote party (pin).
In fee bumper we don't have the info to distinguish the above cases, and
leave them to be further handled by the sweeper as it has more context.

Pull Request Pull Request #9447: sweep: start tracking input spending status in the fee bumper

Run Details

83 of 87 new or added lines in 2 files covered. (95.4%)

19578 existing lines in 256 files now uncovered.

103448 of 179434 relevant lines covered (57.65%)

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68.27

/aliasmgr/aliasmgr.go

package aliasmgr

import (
        "encoding/binary"
        "fmt"
        "sync"

        "github.com/lightningnetwork/lnd/fn/v2"
        "github.com/lightningnetwork/lnd/htlcswitch/hop"
        "github.com/lightningnetwork/lnd/kvdb"
        "github.com/lightningnetwork/lnd/lnwire"
        "golang.org/x/exp/maps"
)

// UpdateLinkAliases is a function type for a function that locates the active
// link that matches the given shortID and triggers an update based on the
// latest values of the alias manager.
type UpdateLinkAliases func(shortID lnwire.ShortChannelID) error

// ScidAliasMap is a map from a base short channel ID to a set of alias short
// channel IDs.
type ScidAliasMap map[lnwire.ShortChannelID][]lnwire.ShortChannelID

var (
        // aliasBucket stores aliases as keys and their base SCIDs as values.
        // This is used to populate the maps that the Manager uses. The keys
        // are alias SCIDs and the values are their respective base SCIDs. This
        // is used instead of the other way around (base -> alias...) because
        // updating an alias would require fetching all the existing aliases,
        // adding another one, and then flushing the write to disk. This is
        // inefficient compared to N 1:1 mappings at the cost of marginally
        // more disk space.
        aliasBucket = []byte("alias-bucket")

        // confirmedBucket stores whether or not a given base SCID should no
        // longer have entries in the ToBase maps. The key is the SCID that is
        // confirmed with 6 confirmations and is public, and the value is
        // empty.
        confirmedBucket = []byte("base-bucket")

        // aliasAllocBucket is a root-level bucket that stores the last alias
        // that was allocated. It is used to allocate a new alias when
        // requested.
        aliasAllocBucket = []byte("alias-alloc-bucket")

        // lastAliasKey is a key in the aliasAllocBucket whose value is the
        // last allocated alias ShortChannelID. This will be updated upon calls
        // to RequestAlias.
        lastAliasKey = []byte("last-alias-key")

        // invoiceAliasBucket is a root-level bucket that stores the alias
        // SCIDs that our peers send us in the channel_ready TLV. The keys are
        // the ChannelID generated from the FundingOutpoint and the values are
        // the remote peer's alias SCID.
        invoiceAliasBucket = []byte("invoice-alias-bucket")

        // byteOrder denotes the byte order of database (de)-serialization
        // operations.
        byteOrder = binary.BigEndian

        // AliasStartBlockHeight is the starting block height of the alias
        // range.
        AliasStartBlockHeight uint32 = 16_000_000

        // AliasEndBlockHeight is the ending block height of the alias range.
        AliasEndBlockHeight uint32 = 16_250_000

        // StartingAlias is the first alias ShortChannelID that will get
        // assigned by RequestAlias. The starting BlockHeight is chosen so that
        // legitimate SCIDs in integration tests aren't mistaken for an alias.
        StartingAlias = lnwire.ShortChannelID{
                BlockHeight: AliasStartBlockHeight,
                TxIndex:     0,
                TxPosition:  0,
        }

        // errNoBase is returned when a base SCID isn't found.
        errNoBase = fmt.Errorf("no base found")

        // errNoPeerAlias is returned when the peer's alias for a given
        // channel is not found.
        errNoPeerAlias = fmt.Errorf("no peer alias found")

        // ErrAliasNotFound is returned when the alias is not found and can't
        // be mapped to a base SCID.
        ErrAliasNotFound = fmt.Errorf("alias not found")
)

// Manager is a struct that handles aliases for LND. It has an underlying
// database that can allocate aliases for channels, stores the peer's last
// alias for use in our hop hints, and contains mappings that both the Switch
// and Gossiper use.
type Manager struct {
        backend kvdb.Backend

        // linkAliasUpdater is a function used by the alias manager to
        // facilitate live update of aliases in other subsystems.
        linkAliasUpdater UpdateLinkAliases

        // baseToSet is a mapping from the "base" SCID to the set of aliases
        // for this channel. This mapping includes all channels that
        // negotiated the option-scid-alias feature bit.
        baseToSet ScidAliasMap

        // aliasToBase is a mapping that maps all aliases for a given channel
        // to its base SCID. This is only used for channels that have
        // negotiated option-scid-alias feature bit.
        aliasToBase map[lnwire.ShortChannelID]lnwire.ShortChannelID

        // peerAlias is a cache for the alias SCIDs that our peers send us in
        // the channel_ready TLV. The keys are the ChannelID generated from
        // the FundingOutpoint and the values are the remote peer's alias SCID.
        // The values should match the ones stored in the "invoice-alias-bucket"
        // bucket.
        peerAlias map[lnwire.ChannelID]lnwire.ShortChannelID

        sync.RWMutex
}

// NewManager initializes an alias Manager from the passed database backend.
func NewManager(db kvdb.Backend, linkAliasUpdater UpdateLinkAliases) (*Manager,
        error) {

        m := &Manager{
                backend:          db,
                baseToSet:        make(ScidAliasMap),
                linkAliasUpdater: linkAliasUpdater,
        }

        m.aliasToBase = make(map[lnwire.ShortChannelID]lnwire.ShortChannelID)
        m.peerAlias = make(map[lnwire.ChannelID]lnwire.ShortChannelID)

        err := m.populateMaps()
        return m, err
}

// populateMaps reads the database state and populates the maps.
func (m *Manager) populateMaps() error {
        // This map tracks the base SCIDs that are confirmed and don't need to
        // have entries in the *ToBase mappings as they won't be used in the
        // gossiper.
        baseConfMap := make(map[lnwire.ShortChannelID]struct{})

        // This map caches what is found in the database and is used to
        // populate the Manager's actual maps.
        aliasMap := make(map[lnwire.ShortChannelID]lnwire.ShortChannelID)

        // This map caches the ChannelID/alias SCIDs stored in the database and
        // is used to populate the Manager's cache.
        peerAliasMap := make(map[lnwire.ChannelID]lnwire.ShortChannelID)

        err := kvdb.Update(m.backend, func(tx kvdb.RwTx) error {
                baseConfBucket, err := tx.CreateTopLevelBucket(confirmedBucket)
                if err != nil {
                        return err
                }

                err = baseConfBucket.ForEach(func(k, v []byte) error {
                        // The key will the base SCID and the value will be
                        // empty. Existence in the bucket means the SCID is
                        // confirmed.
                        baseScid := lnwire.NewShortChanIDFromInt(
                                byteOrder.Uint64(k),
                        )
                        baseConfMap[baseScid] = struct{}{}
                        return nil
                })
                if err != nil {
                        return err
                }

                aliasToBaseBucket, err := tx.CreateTopLevelBucket(aliasBucket)
                if err != nil {
                        return err
                }

                err = aliasToBaseBucket.ForEach(func(k, v []byte) error {
                        // The key will be the alias SCID and the value will be
                        // the base SCID.
                        aliasScid := lnwire.NewShortChanIDFromInt(
                                byteOrder.Uint64(k),
                        )
                        baseScid := lnwire.NewShortChanIDFromInt(
                                byteOrder.Uint64(v),
                        )
                        aliasMap[aliasScid] = baseScid
                        return nil
                })
                if err != nil {
                        return err
                }

                invAliasBucket, err := tx.CreateTopLevelBucket(
                        invoiceAliasBucket,
                )
                if err != nil {
                        return err
                }

                err = invAliasBucket.ForEach(func(k, v []byte) error {
                        var chanID lnwire.ChannelID
                        copy(chanID[:], k)
                        alias := lnwire.NewShortChanIDFromInt(
                                byteOrder.Uint64(v),
                        )

                        peerAliasMap[chanID] = alias

                        return nil
                })

                return err
        }, func() {
                baseConfMap = make(map[lnwire.ShortChannelID]struct{})
                aliasMap = make(map[lnwire.ShortChannelID]lnwire.ShortChannelID)
                peerAliasMap = make(map[lnwire.ChannelID]lnwire.ShortChannelID)
        })
        if err != nil {
                return err
        }

        // Populate the baseToSet map regardless if the baseSCID is marked as
        // public with 6 confirmations.
        for aliasSCID, baseSCID := range aliasMap {
                m.baseToSet[baseSCID] = append(m.baseToSet[baseSCID], aliasSCID)

                // Skip if baseSCID is in the baseConfMap.
                if _, ok := baseConfMap[baseSCID]; ok {
                        continue
                }

                m.aliasToBase[aliasSCID] = baseSCID
        }

        // Populate the peer alias cache.
        m.peerAlias = peerAliasMap

        return nil
}

// AddLocalAlias adds a database mapping from the passed alias to the passed
// base SCID. The gossip boolean marks whether or not to create a mapping
// that the gossiper will use. It is set to false for the upgrade path where
// the feature-bit is toggled on and there are existing channels. The linkUpdate
// flag is used to signal whether this function should also trigger an update
// on the htlcswitch scid alias maps.
func (m *Manager) AddLocalAlias(alias, baseScid lnwire.ShortChannelID,
        gossip, linkUpdate bool) error {

        // We need to lock the manager for the whole duration of this method,
        // except for the very last part where we call the link updater. In
        // order for us to safely use a defer _and_ still be able to manually
        // unlock, we use a sync.Once.
        m.Lock()
        unlockOnce := sync.Once{}
        unlock := func() {
                unlockOnce.Do(m.Unlock)
        }
        defer unlock()

        err := kvdb.Update(m.backend, func(tx kvdb.RwTx) error {
                // If the caller does not want to allow the alias to be used
                // for a channel update, we'll mark it in the baseConfBucket.
                if !gossip {
                        var baseGossipBytes [8]byte
                        byteOrder.PutUint64(
                                baseGossipBytes[:], baseScid.ToUint64(),
                        )

                        confBucket, err := tx.CreateTopLevelBucket(
                                confirmedBucket,
                        )
                        if err != nil {
                                return err
                        }

                        err = confBucket.Put(baseGossipBytes[:], []byte{})
                        if err != nil {
                                return err
                        }
                }

                aliasToBaseBucket, err := tx.CreateTopLevelBucket(aliasBucket)
                if err != nil {
                        return err
                }

                var (
                        aliasBytes [8]byte
                        baseBytes  [8]byte
                )

                byteOrder.PutUint64(aliasBytes[:], alias.ToUint64())
                byteOrder.PutUint64(baseBytes[:], baseScid.ToUint64())
                return aliasToBaseBucket.Put(aliasBytes[:], baseBytes[:])
        }, func() {})
        if err != nil {
                return err
        }

        // Update the aliasToBase and baseToSet maps.
        m.baseToSet[baseScid] = append(m.baseToSet[baseScid], alias)

        // Only store the gossiper map if gossip is true.
        if gossip {
                m.aliasToBase[alias] = baseScid
        }

        // We definitely need to unlock the Manager before calling the link
        // updater. If we don't, we'll deadlock. We use a sync.Once to ensure
        // that we only unlock once.
        unlock()

        // Finally, we trigger a htlcswitch update if the flag is set, in order
        // for any future htlc that references the added alias to be properly
        // routed.
        if linkUpdate {
                return m.linkAliasUpdater(baseScid)
        }

        return nil
}

// GetAliases fetches the set of aliases stored under a given base SCID from
// write-through caches.
func (m *Manager) GetAliases(
        base lnwire.ShortChannelID) []lnwire.ShortChannelID {

        m.RLock()
        defer m.RUnlock()

        aliasSet, ok := m.baseToSet[base]
        if ok {
                // Copy the found alias slice.
                setCopy := make([]lnwire.ShortChannelID, len(aliasSet))
                copy(setCopy, aliasSet)
                return setCopy
        }

        return nil
}

// FindBaseSCID finds the base SCID for a given alias. This is used in the
// gossiper to find the correct SCID to lookup in the graph database.
func (m *Manager) FindBaseSCID(
        alias lnwire.ShortChannelID) (lnwire.ShortChannelID, error) {

        m.RLock()
        defer m.RUnlock()

        base, ok := m.aliasToBase[alias]
        if ok {
                return base, nil
        }

        return lnwire.ShortChannelID{}, errNoBase
}

// DeleteSixConfs removes a mapping for the gossiper once six confirmations
// have been reached and the channel is public. At this point, only the
// confirmed SCID should be used.
func (m *Manager) DeleteSixConfs(baseScid lnwire.ShortChannelID) error {
        m.Lock()
        defer m.Unlock()

        err := kvdb.Update(m.backend, func(tx kvdb.RwTx) error {
                baseConfBucket, err := tx.CreateTopLevelBucket(confirmedBucket)
                if err != nil {
                        return err
                }

                var baseBytes [8]byte
                byteOrder.PutUint64(baseBytes[:], baseScid.ToUint64())
                return baseConfBucket.Put(baseBytes[:], []byte{})
        }, func() {})
        if err != nil {
                return err
        }

        // Now that the database state has been updated, we'll delete all of
        // the aliasToBase mappings for this SCID.
        for alias, base := range m.aliasToBase {
                if base.ToUint64() == baseScid.ToUint64() {
                        delete(m.aliasToBase, alias)
                }
        }

        return nil
}

// DeleteLocalAlias removes a mapping from the database and the Manager's maps.
func (m *Manager) DeleteLocalAlias(alias,
        baseScid lnwire.ShortChannelID) error {

        // We need to lock the manager for the whole duration of this method,
        // except for the very last part where we call the link updater. In
        // order for us to safely use a defer _and_ still be able to manually
        // unlock, we use a sync.Once.
        m.Lock()
        unlockOnce := sync.Once{}
        unlock := func() {
                unlockOnce.Do(m.Unlock)
        }
        defer unlock()

        err := kvdb.Update(m.backend, func(tx kvdb.RwTx) error {
                aliasToBaseBucket, err := tx.CreateTopLevelBucket(aliasBucket)
                if err != nil {
                        return err
                }

                var aliasBytes [8]byte
                byteOrder.PutUint64(aliasBytes[:], alias.ToUint64())

                // If the user attempts to delete an alias that doesn't exist,
                // we'll want to inform them about it and not just do nothing.
                if aliasToBaseBucket.Get(aliasBytes[:]) == nil {
                        return ErrAliasNotFound
                }

                return aliasToBaseBucket.Delete(aliasBytes[:])
        }, func() {})
        if err != nil {
                return err
        }

        // Now that the database state has been updated, we'll delete the
        // mapping from the Manager's maps.
        aliasSet, ok := m.baseToSet[baseScid]
        if !ok {
                return ErrAliasNotFound
        }

        // We'll filter the alias set and remove the alias from it.
        aliasSet = fn.Filter(aliasSet, func(a lnwire.ShortChannelID) bool {
                return a.ToUint64() != alias.ToUint64()
        })

        // If the alias set is empty, we'll delete the base SCID from the
        // baseToSet map.
        if len(aliasSet) == 0 {
                delete(m.baseToSet, baseScid)
        } else {
                m.baseToSet[baseScid] = aliasSet
        }

        // Finally, we'll delete the aliasToBase mapping from the Manager's
        // cache (but this is only set if we gossip the alias).
        delete(m.aliasToBase, alias)

        // We definitely need to unlock the Manager before calling the link
        // updater. If we don't, we'll deadlock. We use a sync.Once to ensure
        // that we only unlock once.
        unlock()

        return m.linkAliasUpdater(baseScid)
}

// PutPeerAlias stores the peer's alias SCID once we learn of it in the
// channel_ready message.
func (m *Manager) PutPeerAlias(chanID lnwire.ChannelID,
        alias lnwire.ShortChannelID) error {

        m.Lock()
        defer m.Unlock()

        err := kvdb.Update(m.backend, func(tx kvdb.RwTx) error {
                bucket, err := tx.CreateTopLevelBucket(invoiceAliasBucket)
                if err != nil {
                        return err
                }

                var scratch [8]byte
                byteOrder.PutUint64(scratch[:], alias.ToUint64())
                return bucket.Put(chanID[:], scratch[:])
        }, func() {})
        if err != nil {
                return err
        }

        // Now that the database state has been updated, we can update it in
        // our cache.
        m.peerAlias[chanID] = alias

        return nil
}

// GetPeerAlias retrieves a peer's alias SCID by the channel's ChanID.
func (m *Manager) GetPeerAlias(chanID lnwire.ChannelID) (lnwire.ShortChannelID,
        error) {

        m.RLock()
        defer m.RUnlock()

        alias, ok := m.peerAlias[chanID]
        if !ok || alias == hop.Source {
                return lnwire.ShortChannelID{}, errNoPeerAlias
        }

        return alias, nil
}

// RequestAlias returns a new ALIAS ShortChannelID to the caller by allocating
// the next un-allocated ShortChannelID. The starting ShortChannelID is
// 16000000:0:0 and the ending ShortChannelID is 16250000:16777215:65535. This
// gives roughly 2^58 possible ALIAS ShortChannelIDs which ensures this space
// won't get exhausted.
func (m *Manager) RequestAlias() (lnwire.ShortChannelID, error) {
        var nextAlias lnwire.ShortChannelID

        m.RLock()
        defer m.RUnlock()

        // haveAlias returns true if the passed alias is already assigned to a
        // channel in the baseToSet map.
        haveAlias := func(maybeNextAlias lnwire.ShortChannelID) bool {
                return fn.Any(
                        maps.Values(m.baseToSet),
                        func(aliasList []lnwire.ShortChannelID) bool {
                                return fn.Any(
                                        aliasList,
                                        func(alias lnwire.ShortChannelID) bool {
                                                return alias == maybeNextAlias
                                        },
                                )
                        },
                )
        }

        err := kvdb.Update(m.backend, func(tx kvdb.RwTx) error {
                bucket, err := tx.CreateTopLevelBucket(aliasAllocBucket)
                if err != nil {
                        return err
                }

                lastBytes := bucket.Get(lastAliasKey)
                if lastBytes == nil {
                        // If the key does not exist, then we can write the
                        // StartingAlias to it.
                        nextAlias = StartingAlias

                        // If the very first alias is already assigned, we'll
                        // keep incrementing until we find an unassigned alias.
                        // This is to avoid collision with custom added SCID
                        // aliases that fall into the same range as the ones we
                        // generate here monotonically. Those custom SCIDs are
                        // stored in a different bucket, but we can just check
                        // the in-memory map for simplicity.
                        for {
                                if !haveAlias(nextAlias) {
                                        break
                                }

                                nextAlias = getNextScid(nextAlias)

                                // Abort if we've reached the end of the range.
                                if nextAlias.BlockHeight >=
                                        AliasEndBlockHeight {

                                        return fmt.Errorf("range for custom " +
                                                "aliases exhausted")
                                }
                        }

                        var scratch [8]byte
                        byteOrder.PutUint64(scratch[:], nextAlias.ToUint64())
                        return bucket.Put(lastAliasKey, scratch[:])
                }

                // Otherwise the key does exist so we can convert the retrieved
                // lastAlias to a ShortChannelID and use it to assign the next
                // ShortChannelID. This next ShortChannelID will then be
                // persisted in the database.
                lastScid := lnwire.NewShortChanIDFromInt(
                        byteOrder.Uint64(lastBytes),
                )
                nextAlias = getNextScid(lastScid)

                // If the next alias is already assigned, we'll keep
                // incrementing until we find an unassigned alias. This is to
                // avoid collision with custom added SCID aliases that fall into
                // the same range as the ones we generate here monotonically.
                // Those custom SCIDs are stored in a different bucket, but we
                // can just check the in-memory map for simplicity.
                for {
                        if !haveAlias(nextAlias) {
                                break
                        }

                        nextAlias = getNextScid(nextAlias)

                        // Abort if we've reached the end of the range.
                        if nextAlias.BlockHeight >= AliasEndBlockHeight {
                                return fmt.Errorf("range for custom " +
                                        "aliases exhausted")
                        }
                }

                var scratch [8]byte
                byteOrder.PutUint64(scratch[:], nextAlias.ToUint64())
                return bucket.Put(lastAliasKey, scratch[:])
        }, func() {
                nextAlias = lnwire.ShortChannelID{}
        })
        if err != nil {
                return nextAlias, err
        }

        return nextAlias, nil
}

// ListAliases returns a carbon copy of baseToSet. This is used by the rpc
// layer.
func (m *Manager) ListAliases() ScidAliasMap {
        m.RLock()
        defer m.RUnlock()

        baseCopy := make(ScidAliasMap)

        for k, v := range m.baseToSet {
                setCopy := make([]lnwire.ShortChannelID, len(v))
                copy(setCopy, v)
                baseCopy[k] = setCopy
        }

        return baseCopy
}

// getNextScid is a utility function that returns the next SCID for a given
// alias SCID. The BlockHeight ranges from [16000000, 16250000], the TxIndex
// ranges from [1, 16777215], and the TxPosition ranges from [1, 65535].
func getNextScid(last lnwire.ShortChannelID) lnwire.ShortChannelID {
        var (
                next            lnwire.ShortChannelID
                incrementIdx    bool
                incrementHeight bool
        )

        // If the TxPosition is 65535, then it goes to 0 and we need to
        // increment the TxIndex.
        if last.TxPosition == 65535 {
                incrementIdx = true
        }

        // If the TxIndex is 16777215 and we need to increment it, then it goes
        // to 0 and we need to increment the BlockHeight.
        if last.TxIndex == 16777215 && incrementIdx {
                incrementIdx = false
                incrementHeight = true
        }

        switch {
        // If we increment the TxIndex, then TxPosition goes to 0.
        case incrementIdx:
                next.BlockHeight = last.BlockHeight
                next.TxIndex = last.TxIndex + 1
                next.TxPosition = 0

        // If we increment the BlockHeight, then the Tx fields go to 0.
        case incrementHeight:
                next.BlockHeight = last.BlockHeight + 1
                next.TxIndex = 0
                next.TxPosition = 0

        // Otherwise, we only need to increment the TxPosition.
        default:
                next.BlockHeight = last.BlockHeight
                next.TxIndex = last.TxIndex
                next.TxPosition = last.TxPosition + 1
        }

        return next
}

// IsAlias returns true if the passed SCID is an alias. The function determines
// this by looking at the BlockHeight. If the BlockHeight is greater than
// AliasStartBlockHeight and less than AliasEndBlockHeight, then it is an alias
// assigned by RequestAlias. These bounds only apply to aliases we generate.
// Our peers are free to use any range they choose.
func IsAlias(scid lnwire.ShortChannelID) bool {
        return scid.BlockHeight >= AliasStartBlockHeight &&
                scid.BlockHeight < AliasEndBlockHeight
}

lightningnetwork / lnd / 12986279612

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