lnd.xprv/contractcourt/briefcase.go

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package contractcourt
import (
"bytes"
"encoding/binary"
"fmt"
"io"
"github.com/btcsuite/btcd/btcec"
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"github.com/btcsuite/btcd/chaincfg/chainhash"
"github.com/btcsuite/btcd/txscript"
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"github.com/btcsuite/btcd/wire"
"github.com/lightningnetwork/lnd/channeldb"
"github.com/lightningnetwork/lnd/channeldb/kvdb"
"github.com/lightningnetwork/lnd/input"
"github.com/lightningnetwork/lnd/lnwallet"
)
// ContractResolutions is a wrapper struct around the two forms of resolutions
// we may need to carry out once a contract is closing: resolving the
// commitment output, and resolving any incoming+outgoing HTLC's still present
// in the commitment.
type ContractResolutions struct {
// CommitHash is the txid of the commitment transaction.
CommitHash chainhash.Hash
// CommitResolution contains all data required to fully resolve a
// commitment output.
CommitResolution *lnwallet.CommitOutputResolution
// HtlcResolutions contains all data required to fully resolve any
// incoming+outgoing HTLC's present within the commitment transaction.
HtlcResolutions lnwallet.HtlcResolutions
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// AnchorResolution contains the data required to sweep the anchor
// output. If the channel type doesn't include anchors, the value of
// this field will be nil.
AnchorResolution *lnwallet.AnchorResolution
}
// IsEmpty returns true if the set of resolutions is "empty". A resolution is
// empty if: our commitment output has been trimmed, and we don't have any
// incoming or outgoing HTLC's active.
func (c *ContractResolutions) IsEmpty() bool {
return c.CommitResolution == nil &&
len(c.HtlcResolutions.IncomingHTLCs) == 0 &&
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len(c.HtlcResolutions.OutgoingHTLCs) == 0 &&
c.AnchorResolution == nil
}
// ArbitratorLog is the primary source of persistent storage for the
// ChannelArbitrator. The log stores the current state of the
// ChannelArbitrator's internal state machine, any items that are required to
// properly make a state transition, and any unresolved contracts.
type ArbitratorLog interface {
// TODO(roasbeef): document on interface the errors expected to be
// returned
// CurrentState returns the current state of the ChannelArbitrator. It
// takes an optional database transaction, which will be used if it is
// non-nil, otherwise the lookup will be done in its own transaction.
CurrentState(tx kvdb.RTx) (ArbitratorState, error)
// CommitState persists, the current state of the chain attendant.
CommitState(ArbitratorState) error
// InsertUnresolvedContracts inserts a set of unresolved contracts into
// the log. The log will then persistently store each contract until
// they've been swapped out, or resolved. It takes a set of report which
// should be written to disk if as well if it is non-nil.
InsertUnresolvedContracts(reports []*channeldb.ResolverReport,
resolvers ...ContractResolver) error
// FetchUnresolvedContracts returns all unresolved contracts that have
// been previously written to the log.
FetchUnresolvedContracts() ([]ContractResolver, error)
// SwapContract performs an atomic swap of the old contract for the new
// contract. This method is used when after a contract has been fully
// resolved, it produces another contract that needs to be resolved.
SwapContract(old ContractResolver, new ContractResolver) error
// ResolveContract marks a contract as fully resolved. Once a contract
// has been fully resolved, it is deleted from persistent storage.
ResolveContract(ContractResolver) error
// LogContractResolutions stores a complete contract resolution for the
// contract under watch. This method will be called once the
// ChannelArbitrator either force closes a channel, or detects that the
// remote party has broadcast their commitment on chain.
LogContractResolutions(*ContractResolutions) error
// FetchContractResolutions fetches the set of previously stored
// contract resolutions from persistent storage.
FetchContractResolutions() (*ContractResolutions, error)
// InsertConfirmedCommitSet stores the known set of active HTLCs at the
// time channel closure. We'll use this to reconstruct our set of chain
// actions anew based on the confirmed and pending commitment state.
InsertConfirmedCommitSet(c *CommitSet) error
// FetchConfirmedCommitSet fetches the known confirmed active HTLC set
// from the database. It takes an optional database transaction, which
// will be used if it is non-nil, otherwise the lookup will be done in
// its own transaction.
FetchConfirmedCommitSet(tx kvdb.RTx) (*CommitSet, error)
// FetchChainActions attempts to fetch the set of previously stored
// chain actions. We'll use this upon restart to properly advance our
// state machine forward.
//
// NOTE: This method only exists in order to be able to serve nodes had
// channels in the process of closing before the CommitSet struct was
// introduced.
FetchChainActions() (ChainActionMap, error)
// WipeHistory is to be called ONLY once *all* contracts have been
// fully resolved, and the channel closure if finalized. This method
// will delete all on-disk state within the persistent log.
WipeHistory() error
}
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// ArbitratorState is an enum that details the current state of the
// ChannelArbitrator's state machine.
type ArbitratorState uint8
const (
// StateDefault is the default state. In this state, no major actions
// need to be executed.
StateDefault ArbitratorState = 0
// StateBroadcastCommit is a state that indicates that the attendant
// has decided to broadcast the commitment transaction, but hasn't done
// so yet.
StateBroadcastCommit ArbitratorState = 1
// StateCommitmentBroadcasted is a state that indicates that the
// attendant has broadcasted the commitment transaction, and is now
// waiting for it to confirm.
StateCommitmentBroadcasted ArbitratorState = 6
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// StateContractClosed is a state that indicates the contract has
// already been "closed", meaning the commitment is confirmed on chain.
// At this point, we can now examine our active contracts, in order to
// create the proper resolver for each one.
StateContractClosed ArbitratorState = 2
// StateWaitingFullResolution is a state that indicates that the
// commitment transaction has been confirmed, and the attendant is now
// waiting for all unresolved contracts to be fully resolved.
StateWaitingFullResolution ArbitratorState = 3
// StateFullyResolved is the final state of the attendant. In this
// state, all related contracts have been resolved, and the attendant
// can now be garbage collected.
StateFullyResolved ArbitratorState = 4
// StateError is the only error state of the resolver. If we enter this
// state, then we cannot proceed with manual intervention as a state
// transition failed.
StateError ArbitratorState = 5
)
// String returns a human readable string describing the ArbitratorState.
func (a ArbitratorState) String() string {
switch a {
case StateDefault:
return "StateDefault"
case StateBroadcastCommit:
return "StateBroadcastCommit"
case StateCommitmentBroadcasted:
return "StateCommitmentBroadcasted"
case StateContractClosed:
return "StateContractClosed"
case StateWaitingFullResolution:
return "StateWaitingFullResolution"
case StateFullyResolved:
return "StateFullyResolved"
case StateError:
return "StateError"
default:
return "unknown state"
}
}
// resolverType is an enum that enumerates the various types of resolvers. When
// writing resolvers to disk, we prepend this to the raw bytes stored. This
// allows us to properly decode the resolver into the proper type.
type resolverType uint8
const (
// resolverTimeout is the type of a resolver that's tasked with
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// resolving an outgoing HTLC that is very close to timing out.
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resolverTimeout resolverType = 0
// resolverSuccess is the type of a resolver that's tasked with
// resolving an incoming HTLC that we already know the preimage of.
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resolverSuccess resolverType = 1
// resolverOutgoingContest is the type of a resolver that's tasked with
// resolving an outgoing HTLC that hasn't yet timed out.
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resolverOutgoingContest resolverType = 2
// resolverIncomingContest is the type of a resolver that's tasked with
// resolving an incoming HTLC that we don't yet know the preimage to.
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resolverIncomingContest resolverType = 3
// resolverUnilateralSweep is the type of resolver that's tasked with
// sweeping out direct commitment output form the remote party's
// commitment transaction.
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resolverUnilateralSweep resolverType = 4
)
// resolverIDLen is the size of the resolver ID key. This is 36 bytes as we get
// 32 bytes from the hash of the prev tx, and 4 bytes for the output index.
const resolverIDLen = 36
// resolverID is a key that uniquely identifies a resolver within a particular
// chain. For this value we use the full outpoint of the resolver.
type resolverID [resolverIDLen]byte
// newResolverID returns a resolverID given the outpoint of a contract.
func newResolverID(op wire.OutPoint) resolverID {
var r resolverID
copy(r[:], op.Hash[:])
endian.PutUint32(r[32:], op.Index)
return r
}
// logScope is a key that we use to scope the storage of a ChannelArbitrator
// within the global log. We use this key to create a unique bucket within the
// database and ensure that we don't have any key collisions. The log's scope
// is define as: chainHash || chanPoint, where chanPoint is the chan point of
// the original channel.
type logScope [32 + 36]byte
// newLogScope creates a new logScope key from the passed chainhash and
// chanPoint.
func newLogScope(chain chainhash.Hash, op wire.OutPoint) (*logScope, error) {
var l logScope
b := bytes.NewBuffer(l[0:0])
if _, err := b.Write(chain[:]); err != nil {
return nil, err
}
if _, err := b.Write(op.Hash[:]); err != nil {
return nil, err
}
if err := binary.Write(b, endian, op.Index); err != nil {
return nil, err
}
return &l, nil
}
var (
// stateKey is the key that we use to store the current state of the
// arbitrator.
stateKey = []byte("state")
// contractsBucketKey is the bucket within the logScope that will store
// all the active unresolved contracts.
contractsBucketKey = []byte("contractkey")
// resolutionsKey is the key under the logScope that we'll use to store
// the full set of resolutions for a channel.
resolutionsKey = []byte("resolutions")
// resolutionsSignDetailsKey is the key under the logScope where we
// will store input.SignDetails for each HTLC resolution. If this is
// not found under the logScope, it means it was written before
// SignDetails was introduced, and should be set nil for each HTLC
// resolution.
resolutionsSignDetailsKey = []byte("resolutions-sign-details")
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// anchorResolutionKey is the key under the logScope that we'll use to
// store the anchor resolution, if any.
anchorResolutionKey = []byte("anchor-resolution")
// actionsBucketKey is the key under the logScope that we'll use to
// store all chain actions once they're determined.
actionsBucketKey = []byte("chain-actions")
// commitSetKey is the primary key under the logScope that we'll use to
// store the confirmed active HTLC sets once we learn that a channel
// has closed out on chain.
commitSetKey = []byte("commit-set")
)
var (
// errScopeBucketNoExist is returned when we can't find the proper
// bucket for an arbitrator's scope.
errScopeBucketNoExist = fmt.Errorf("scope bucket not found")
// errNoContracts is returned when no contracts are found within the
// log.
errNoContracts = fmt.Errorf("no stored contracts")
// errNoResolutions is returned when the log doesn't contain any active
// chain resolutions.
errNoResolutions = fmt.Errorf("no contract resolutions exist")
// errNoActions is retuned when the log doesn't contain any stored
// chain actions.
errNoActions = fmt.Errorf("no chain actions exist")
// errNoCommitSet is return when the log doesn't contained a CommitSet.
// This can happen if the channel hasn't closed yet, or a client is
// running an older version that didn't yet write this state.
errNoCommitSet = fmt.Errorf("no commit set exists")
)
// boltArbitratorLog is an implementation of the ArbitratorLog interface backed
// by a bolt DB instance.
type boltArbitratorLog struct {
db kvdb.Backend
cfg ChannelArbitratorConfig
scopeKey logScope
}
// newBoltArbitratorLog returns a new instance of the boltArbitratorLog given
// an arbitrator config, and the items needed to create its log scope.
func newBoltArbitratorLog(db kvdb.Backend, cfg ChannelArbitratorConfig,
chainHash chainhash.Hash, chanPoint wire.OutPoint) (*boltArbitratorLog, error) {
scope, err := newLogScope(chainHash, chanPoint)
if err != nil {
return nil, err
}
return &boltArbitratorLog{
db: db,
cfg: cfg,
scopeKey: *scope,
}, nil
}
// A compile time check to ensure boltArbitratorLog meets the ArbitratorLog
// interface.
var _ ArbitratorLog = (*boltArbitratorLog)(nil)
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func fetchContractReadBucket(tx kvdb.RTx, scopeKey []byte) (kvdb.RBucket, error) {
scopeBucket := tx.ReadBucket(scopeKey)
if scopeBucket == nil {
return nil, errScopeBucketNoExist
}
contractBucket := scopeBucket.NestedReadBucket(contractsBucketKey)
if contractBucket == nil {
return nil, errNoContracts
}
return contractBucket, nil
}
func fetchContractWriteBucket(tx kvdb.RwTx, scopeKey []byte) (kvdb.RwBucket, error) {
scopeBucket, err := tx.CreateTopLevelBucket(scopeKey)
if err != nil {
return nil, err
}
contractBucket, err := scopeBucket.CreateBucketIfNotExists(
contractsBucketKey,
)
if err != nil {
return nil, err
}
return contractBucket, nil
}
// writeResolver is a helper method that writes a contract resolver and stores
// it it within the passed contractBucket using its unique resolutionsKey key.
func (b *boltArbitratorLog) writeResolver(contractBucket kvdb.RwBucket,
res ContractResolver) error {
// Only persist resolvers that are stateful. Stateless resolvers don't
// expose a resolver key.
resKey := res.ResolverKey()
if resKey == nil {
return nil
}
// First, we'll write to the buffer the type of this resolver. Using
// this byte, we can later properly deserialize the resolver properly.
var (
buf bytes.Buffer
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rType resolverType
)
switch res.(type) {
case *htlcTimeoutResolver:
rType = resolverTimeout
case *htlcSuccessResolver:
rType = resolverSuccess
case *htlcOutgoingContestResolver:
rType = resolverOutgoingContest
case *htlcIncomingContestResolver:
rType = resolverIncomingContest
case *commitSweepResolver:
rType = resolverUnilateralSweep
}
if _, err := buf.Write([]byte{byte(rType)}); err != nil {
return err
}
// With the type of the resolver written, we can then write out the raw
// bytes of the resolver itself.
if err := res.Encode(&buf); err != nil {
return err
}
return contractBucket.Put(resKey, buf.Bytes())
}
// CurrentState returns the current state of the ChannelArbitrator. It takes an
// optional database transaction, which will be used if it is non-nil, otherwise
// the lookup will be done in its own transaction.
//
// NOTE: Part of the ContractResolver interface.
func (b *boltArbitratorLog) CurrentState(tx kvdb.RTx) (ArbitratorState, error) {
var (
s ArbitratorState
err error
)
if tx != nil {
s, err = b.currentState(tx)
} else {
err = kvdb.View(b.db, func(tx kvdb.RTx) error {
s, err = b.currentState(tx)
return err
}, func() {
s = 0
})
}
if err != nil && err != errScopeBucketNoExist {
return s, err
}
return s, nil
}
func (b *boltArbitratorLog) currentState(tx kvdb.RTx) (ArbitratorState, error) {
scopeBucket := tx.ReadBucket(b.scopeKey[:])
if scopeBucket == nil {
return 0, errScopeBucketNoExist
}
stateBytes := scopeBucket.Get(stateKey)
if stateBytes == nil {
return 0, nil
}
return ArbitratorState(stateBytes[0]), nil
}
// CommitState persists, the current state of the chain attendant.
//
// NOTE: Part of the ContractResolver interface.
func (b *boltArbitratorLog) CommitState(s ArbitratorState) error {
return kvdb.Batch(b.db, func(tx kvdb.RwTx) error {
scopeBucket, err := tx.CreateTopLevelBucket(b.scopeKey[:])
if err != nil {
return err
}
return scopeBucket.Put(stateKey[:], []byte{uint8(s)})
})
}
// FetchUnresolvedContracts returns all unresolved contracts that have been
// previously written to the log.
//
// NOTE: Part of the ContractResolver interface.
func (b *boltArbitratorLog) FetchUnresolvedContracts() ([]ContractResolver, error) {
resolverCfg := ResolverConfig{
ChannelArbitratorConfig: b.cfg,
Checkpoint: b.checkpointContract,
}
var contracts []ContractResolver
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err := kvdb.View(b.db, func(tx kvdb.RTx) error {
contractBucket, err := fetchContractReadBucket(tx, b.scopeKey[:])
if err != nil {
return err
}
return contractBucket.ForEach(func(resKey, resBytes []byte) error {
if len(resKey) != resolverIDLen {
return nil
}
var res ContractResolver
// We'll snip off the first byte of the raw resolver
// bytes in order to extract what type of resolver
// we're about to encode.
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resType := resolverType(resBytes[0])
// Then we'll create a reader using the remaining
// bytes.
resReader := bytes.NewReader(resBytes[1:])
switch resType {
case resolverTimeout:
res, err = newTimeoutResolverFromReader(
resReader, resolverCfg,
)
case resolverSuccess:
res, err = newSuccessResolverFromReader(
resReader, resolverCfg,
)
case resolverOutgoingContest:
res, err = newOutgoingContestResolverFromReader(
resReader, resolverCfg,
)
case resolverIncomingContest:
res, err = newIncomingContestResolverFromReader(
resReader, resolverCfg,
)
case resolverUnilateralSweep:
res, err = newCommitSweepResolverFromReader(
resReader, resolverCfg,
)
default:
return fmt.Errorf("unknown resolver type: %v", resType)
}
if err != nil {
return err
}
contracts = append(contracts, res)
return nil
})
}, func() {
contracts = nil
})
if err != nil && err != errScopeBucketNoExist && err != errNoContracts {
return nil, err
}
return contracts, nil
}
// InsertUnresolvedContracts inserts a set of unresolved contracts into the
// log. The log will then persistently store each contract until they've been
// swapped out, or resolved.
//
// NOTE: Part of the ContractResolver interface.
func (b *boltArbitratorLog) InsertUnresolvedContracts(reports []*channeldb.ResolverReport,
resolvers ...ContractResolver) error {
return kvdb.Batch(b.db, func(tx kvdb.RwTx) error {
contractBucket, err := fetchContractWriteBucket(tx, b.scopeKey[:])
if err != nil {
return err
}
for _, resolver := range resolvers {
err = b.writeResolver(contractBucket, resolver)
if err != nil {
return err
}
}
// Persist any reports that are present.
for _, report := range reports {
err := b.cfg.PutResolverReport(tx, report)
if err != nil {
return err
}
}
return nil
})
}
// SwapContract performs an atomic swap of the old contract for the new
// contract. This method is used when after a contract has been fully resolved,
// it produces another contract that needs to be resolved.
//
// NOTE: Part of the ContractResolver interface.
func (b *boltArbitratorLog) SwapContract(oldContract, newContract ContractResolver) error {
return kvdb.Batch(b.db, func(tx kvdb.RwTx) error {
contractBucket, err := fetchContractWriteBucket(tx, b.scopeKey[:])
if err != nil {
return err
}
oldContractkey := oldContract.ResolverKey()
if err := contractBucket.Delete(oldContractkey); err != nil {
return err
}
return b.writeResolver(contractBucket, newContract)
})
}
// ResolveContract marks a contract as fully resolved. Once a contract has been
// fully resolved, it is deleted from persistent storage.
//
// NOTE: Part of the ContractResolver interface.
func (b *boltArbitratorLog) ResolveContract(res ContractResolver) error {
return kvdb.Batch(b.db, func(tx kvdb.RwTx) error {
contractBucket, err := fetchContractWriteBucket(tx, b.scopeKey[:])
if err != nil {
return err
}
resKey := res.ResolverKey()
return contractBucket.Delete(resKey)
})
}
// LogContractResolutions stores a set of chain actions which are derived from
// our set of active contracts, and the on-chain state. We'll write this et of
// cations when: we decide to go on-chain to resolve a contract, or we detect
// that the remote party has gone on-chain.
//
// NOTE: Part of the ContractResolver interface.
func (b *boltArbitratorLog) LogContractResolutions(c *ContractResolutions) error {
return kvdb.Batch(b.db, func(tx kvdb.RwTx) error {
scopeBucket, err := tx.CreateTopLevelBucket(b.scopeKey[:])
if err != nil {
return err
}
var b bytes.Buffer
if _, err := b.Write(c.CommitHash[:]); err != nil {
return err
}
// First, we'll write out the commit output's resolution.
if c.CommitResolution == nil {
if err := binary.Write(&b, endian, false); err != nil {
return err
}
} else {
if err := binary.Write(&b, endian, true); err != nil {
return err
}
err = encodeCommitResolution(&b, c.CommitResolution)
if err != nil {
return err
}
}
// As we write the HTLC resolutions, we'll serialize the sign
// details for each, to store under a new key.
var signDetailsBuf bytes.Buffer
// With the output for the commitment transaction written, we
// can now write out the resolutions for the incoming and
// outgoing HTLC's.
numIncoming := uint32(len(c.HtlcResolutions.IncomingHTLCs))
if err := binary.Write(&b, endian, numIncoming); err != nil {
return err
}
for _, htlc := range c.HtlcResolutions.IncomingHTLCs {
err := encodeIncomingResolution(&b, &htlc)
if err != nil {
return err
}
err = encodeSignDetails(&signDetailsBuf, htlc.SignDetails)
if err != nil {
return err
}
}
numOutgoing := uint32(len(c.HtlcResolutions.OutgoingHTLCs))
if err := binary.Write(&b, endian, numOutgoing); err != nil {
return err
}
for _, htlc := range c.HtlcResolutions.OutgoingHTLCs {
err := encodeOutgoingResolution(&b, &htlc)
if err != nil {
return err
}
err = encodeSignDetails(&signDetailsBuf, htlc.SignDetails)
if err != nil {
return err
}
}
// Put the resolutions under the resolutionsKey.
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err = scopeBucket.Put(resolutionsKey, b.Bytes())
if err != nil {
return err
}
// We'll put the serialized sign details under its own key to
// stay backwards compatible.
err = scopeBucket.Put(
resolutionsSignDetailsKey, signDetailsBuf.Bytes(),
)
if err != nil {
return err
}
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// Write out the anchor resolution if present.
if c.AnchorResolution != nil {
var b bytes.Buffer
err := encodeAnchorResolution(&b, c.AnchorResolution)
if err != nil {
return err
}
err = scopeBucket.Put(anchorResolutionKey, b.Bytes())
if err != nil {
return err
}
}
return nil
})
}
// FetchContractResolutions fetches the set of previously stored contract
// resolutions from persistent storage.
//
// NOTE: Part of the ContractResolver interface.
func (b *boltArbitratorLog) FetchContractResolutions() (*ContractResolutions, error) {
var c *ContractResolutions
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err := kvdb.View(b.db, func(tx kvdb.RTx) error {
scopeBucket := tx.ReadBucket(b.scopeKey[:])
if scopeBucket == nil {
return errScopeBucketNoExist
}
resolutionBytes := scopeBucket.Get(resolutionsKey)
if resolutionBytes == nil {
return errNoResolutions
}
resReader := bytes.NewReader(resolutionBytes)
_, err := io.ReadFull(resReader, c.CommitHash[:])
if err != nil {
return err
}
// First, we'll attempt to read out the commit resolution (if
// it exists).
var haveCommitRes bool
err = binary.Read(resReader, endian, &haveCommitRes)
if err != nil {
return err
}
if haveCommitRes {
c.CommitResolution = &lnwallet.CommitOutputResolution{}
err = decodeCommitResolution(
resReader, c.CommitResolution,
)
if err != nil {
return err
}
}
var (
numIncoming uint32
numOutgoing uint32
)
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// Next, we'll read out the incoming and outgoing HTLC
// resolutions.
err = binary.Read(resReader, endian, &numIncoming)
if err != nil {
return err
}
c.HtlcResolutions.IncomingHTLCs = make([]lnwallet.IncomingHtlcResolution, numIncoming)
for i := uint32(0); i < numIncoming; i++ {
err := decodeIncomingResolution(
resReader, &c.HtlcResolutions.IncomingHTLCs[i],
)
if err != nil {
return err
}
}
err = binary.Read(resReader, endian, &numOutgoing)
if err != nil {
return err
}
c.HtlcResolutions.OutgoingHTLCs = make([]lnwallet.OutgoingHtlcResolution, numOutgoing)
for i := uint32(0); i < numOutgoing; i++ {
err := decodeOutgoingResolution(
resReader, &c.HtlcResolutions.OutgoingHTLCs[i],
)
if err != nil {
return err
}
}
// Now we attempt to get the sign details for our HTLC
// resolutions. If not present the channel is of a type that
// doesn't need them. If present there will be SignDetails
// encoded for each HTLC resolution.
signDetailsBytes := scopeBucket.Get(resolutionsSignDetailsKey)
if signDetailsBytes != nil {
r := bytes.NewReader(signDetailsBytes)
// They will be encoded in the same order as the
// resolutions: firs incoming HTLCs, then outgoing.
for i := uint32(0); i < numIncoming; i++ {
htlc := &c.HtlcResolutions.IncomingHTLCs[i]
htlc.SignDetails, err = decodeSignDetails(r)
if err != nil {
return err
}
}
for i := uint32(0); i < numOutgoing; i++ {
htlc := &c.HtlcResolutions.OutgoingHTLCs[i]
htlc.SignDetails, err = decodeSignDetails(r)
if err != nil {
return err
}
}
}
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anchorResBytes := scopeBucket.Get(anchorResolutionKey)
if anchorResBytes != nil {
c.AnchorResolution = &lnwallet.AnchorResolution{}
resReader := bytes.NewReader(anchorResBytes)
err := decodeAnchorResolution(
resReader, c.AnchorResolution,
)
if err != nil {
return err
}
}
return nil
}, func() {
c = &ContractResolutions{}
})
if err != nil {
return nil, err
}
return c, err
}
// FetchChainActions attempts to fetch the set of previously stored chain
// actions. We'll use this upon restart to properly advance our state machine
// forward.
//
// NOTE: Part of the ContractResolver interface.
func (b *boltArbitratorLog) FetchChainActions() (ChainActionMap, error) {
var actionsMap ChainActionMap
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err := kvdb.View(b.db, func(tx kvdb.RTx) error {
scopeBucket := tx.ReadBucket(b.scopeKey[:])
if scopeBucket == nil {
return errScopeBucketNoExist
}
actionsBucket := scopeBucket.NestedReadBucket(actionsBucketKey)
if actionsBucket == nil {
return errNoActions
}
return actionsBucket.ForEach(func(action, htlcBytes []byte) error {
if htlcBytes == nil {
return nil
}
chainAction := ChainAction(action[0])
htlcReader := bytes.NewReader(htlcBytes)
htlcs, err := channeldb.DeserializeHtlcs(htlcReader)
if err != nil {
return err
}
actionsMap[chainAction] = htlcs
return nil
})
}, func() {
actionsMap = make(ChainActionMap)
})
if err != nil {
return nil, err
}
return actionsMap, nil
}
// InsertConfirmedCommitSet stores the known set of active HTLCs at the time
// channel closure. We'll use this to reconstruct our set of chain actions anew
// based on the confirmed and pending commitment state.
//
// NOTE: Part of the ContractResolver interface.
func (b *boltArbitratorLog) InsertConfirmedCommitSet(c *CommitSet) error {
return kvdb.Batch(b.db, func(tx kvdb.RwTx) error {
scopeBucket, err := tx.CreateTopLevelBucket(b.scopeKey[:])
if err != nil {
return err
}
var b bytes.Buffer
if err := encodeCommitSet(&b, c); err != nil {
return err
}
return scopeBucket.Put(commitSetKey, b.Bytes())
})
}
// FetchConfirmedCommitSet fetches the known confirmed active HTLC set from the
// database. It takes an optional database transaction, which will be used if it
// is non-nil, otherwise the lookup will be done in its own transaction.
//
// NOTE: Part of the ContractResolver interface.
func (b *boltArbitratorLog) FetchConfirmedCommitSet(tx kvdb.RTx) (*CommitSet, error) {
if tx != nil {
return b.fetchConfirmedCommitSet(tx)
}
var c *CommitSet
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err := kvdb.View(b.db, func(tx kvdb.RTx) error {
var err error
c, err = b.fetchConfirmedCommitSet(tx)
return err
}, func() {
c = nil
})
if err != nil {
return nil, err
}
return c, nil
}
func (b *boltArbitratorLog) fetchConfirmedCommitSet(tx kvdb.RTx) (*CommitSet,
error) {
scopeBucket := tx.ReadBucket(b.scopeKey[:])
if scopeBucket == nil {
return nil, errScopeBucketNoExist
}
commitSetBytes := scopeBucket.Get(commitSetKey)
if commitSetBytes == nil {
return nil, errNoCommitSet
}
return decodeCommitSet(bytes.NewReader(commitSetBytes))
}
// WipeHistory is to be called ONLY once *all* contracts have been fully
// resolved, and the channel closure if finalized. This method will delete all
// on-disk state within the persistent log.
//
// NOTE: Part of the ContractResolver interface.
func (b *boltArbitratorLog) WipeHistory() error {
return kvdb.Update(b.db, func(tx kvdb.RwTx) error {
scopeBucket, err := tx.CreateTopLevelBucket(b.scopeKey[:])
if err != nil {
return err
}
// Once we have the main top-level bucket, we'll delete the key
// that stores the state of the arbitrator.
if err := scopeBucket.Delete(stateKey[:]); err != nil {
return err
}
// Next, we'll delete any lingering contract state within the
// contracts bucket by removing the bucket itself.
err = scopeBucket.DeleteNestedBucket(contractsBucketKey)
if err != nil && err != kvdb.ErrBucketNotFound {
return err
}
// Next, we'll delete storage of any lingering contract
// resolutions.
if err := scopeBucket.Delete(resolutionsKey); err != nil {
return err
}
err = scopeBucket.Delete(resolutionsSignDetailsKey)
if err != nil {
return err
}
// We'll delete any chain actions that are still stored by
// removing the enclosing bucket.
err = scopeBucket.DeleteNestedBucket(actionsBucketKey)
if err != nil && err != kvdb.ErrBucketNotFound {
return err
}
// Finally, we'll delete the enclosing bucket itself.
return tx.DeleteTopLevelBucket(b.scopeKey[:])
}, func() {})
}
// checkpointContract is a private method that will be fed into
// ContractResolver instances to checkpoint their state once they reach
// milestones during contract resolution. If the report provided is non-nil,
// it should also be recorded.
func (b *boltArbitratorLog) checkpointContract(c ContractResolver,
reports ...*channeldb.ResolverReport) error {
return kvdb.Update(b.db, func(tx kvdb.RwTx) error {
contractBucket, err := fetchContractWriteBucket(tx, b.scopeKey[:])
if err != nil {
return err
}
if err := b.writeResolver(contractBucket, c); err != nil {
return err
}
for _, report := range reports {
if err := b.cfg.PutResolverReport(tx, report); err != nil {
return err
}
}
return nil
}, func() {})
}
// encodeSignDetails encodes the gived SignDetails struct to the writer.
// SignDetails is allowed to be nil, in which we will encode that it is not
// present.
func encodeSignDetails(w io.Writer, s *input.SignDetails) error {
// If we don't have sign details, write false and return.
if s == nil {
return binary.Write(w, endian, false)
}
// Otherwise write true, and the contents of the SignDetails.
if err := binary.Write(w, endian, true); err != nil {
return err
}
err := input.WriteSignDescriptor(w, &s.SignDesc)
if err != nil {
return err
}
err = binary.Write(w, endian, uint32(s.SigHashType))
if err != nil {
return err
}
// Write the DER-encoded signature.
b := s.PeerSig.Serialize()
if err := wire.WriteVarBytes(w, 0, b); err != nil {
return err
}
return nil
}
// decodeSignDetails extracts a single SignDetails from the reader. It is
// allowed to return nil in case the SignDetails were empty.
func decodeSignDetails(r io.Reader) (*input.SignDetails, error) {
var present bool
if err := binary.Read(r, endian, &present); err != nil {
return nil, err
}
// Simply return nil if the next SignDetails was not present.
if !present {
return nil, nil
}
// Otherwise decode the elements of the SignDetails.
s := input.SignDetails{}
err := input.ReadSignDescriptor(r, &s.SignDesc)
if err != nil {
return nil, err
}
var sigHash uint32
err = binary.Read(r, endian, &sigHash)
if err != nil {
return nil, err
}
s.SigHashType = txscript.SigHashType(sigHash)
// Read DER-encoded signature.
rawSig, err := wire.ReadVarBytes(r, 0, 200, "signature")
if err != nil {
return nil, err
}
sig, err := btcec.ParseDERSignature(rawSig, btcec.S256())
if err != nil {
return nil, err
}
s.PeerSig = sig
return &s, nil
}
func encodeIncomingResolution(w io.Writer, i *lnwallet.IncomingHtlcResolution) error {
if _, err := w.Write(i.Preimage[:]); err != nil {
return err
}
if i.SignedSuccessTx == nil {
if err := binary.Write(w, endian, false); err != nil {
return err
}
} else {
if err := binary.Write(w, endian, true); err != nil {
return err
}
if err := i.SignedSuccessTx.Serialize(w); err != nil {
return err
}
}
if err := binary.Write(w, endian, i.CsvDelay); err != nil {
return err
}
if _, err := w.Write(i.ClaimOutpoint.Hash[:]); err != nil {
return err
}
if err := binary.Write(w, endian, i.ClaimOutpoint.Index); err != nil {
return err
}
err := input.WriteSignDescriptor(w, &i.SweepSignDesc)
if err != nil {
return err
}
return nil
}
func decodeIncomingResolution(r io.Reader, h *lnwallet.IncomingHtlcResolution) error {
if _, err := io.ReadFull(r, h.Preimage[:]); err != nil {
return err
}
var txPresent bool
if err := binary.Read(r, endian, &txPresent); err != nil {
return err
}
if txPresent {
h.SignedSuccessTx = &wire.MsgTx{}
if err := h.SignedSuccessTx.Deserialize(r); err != nil {
return err
}
}
err := binary.Read(r, endian, &h.CsvDelay)
if err != nil {
return err
}
_, err = io.ReadFull(r, h.ClaimOutpoint.Hash[:])
if err != nil {
return err
}
err = binary.Read(r, endian, &h.ClaimOutpoint.Index)
if err != nil {
return err
}
return input.ReadSignDescriptor(r, &h.SweepSignDesc)
}
func encodeOutgoingResolution(w io.Writer, o *lnwallet.OutgoingHtlcResolution) error {
if err := binary.Write(w, endian, o.Expiry); err != nil {
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return err
}
if o.SignedTimeoutTx == nil {
if err := binary.Write(w, endian, false); err != nil {
return err
}
} else {
if err := binary.Write(w, endian, true); err != nil {
return err
}
if err := o.SignedTimeoutTx.Serialize(w); err != nil {
return err
}
}
if err := binary.Write(w, endian, o.CsvDelay); err != nil {
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return err
}
if _, err := w.Write(o.ClaimOutpoint.Hash[:]); err != nil {
return err
}
if err := binary.Write(w, endian, o.ClaimOutpoint.Index); err != nil {
return err
}
return input.WriteSignDescriptor(w, &o.SweepSignDesc)
}
func decodeOutgoingResolution(r io.Reader, o *lnwallet.OutgoingHtlcResolution) error {
err := binary.Read(r, endian, &o.Expiry)
if err != nil {
return err
}
var txPresent bool
if err := binary.Read(r, endian, &txPresent); err != nil {
return err
}
if txPresent {
o.SignedTimeoutTx = &wire.MsgTx{}
if err := o.SignedTimeoutTx.Deserialize(r); err != nil {
return err
}
}
err = binary.Read(r, endian, &o.CsvDelay)
if err != nil {
return err
}
_, err = io.ReadFull(r, o.ClaimOutpoint.Hash[:])
if err != nil {
return err
}
err = binary.Read(r, endian, &o.ClaimOutpoint.Index)
if err != nil {
return err
}
return input.ReadSignDescriptor(r, &o.SweepSignDesc)
}
func encodeCommitResolution(w io.Writer,
c *lnwallet.CommitOutputResolution) error {
if _, err := w.Write(c.SelfOutPoint.Hash[:]); err != nil {
return err
}
err := binary.Write(w, endian, c.SelfOutPoint.Index)
if err != nil {
return err
}
err = input.WriteSignDescriptor(w, &c.SelfOutputSignDesc)
if err != nil {
return err
}
return binary.Write(w, endian, c.MaturityDelay)
}
func decodeCommitResolution(r io.Reader,
c *lnwallet.CommitOutputResolution) error {
_, err := io.ReadFull(r, c.SelfOutPoint.Hash[:])
if err != nil {
return err
}
err = binary.Read(r, endian, &c.SelfOutPoint.Index)
if err != nil {
return err
}
err = input.ReadSignDescriptor(r, &c.SelfOutputSignDesc)
if err != nil {
return err
}
return binary.Read(r, endian, &c.MaturityDelay)
}
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func encodeAnchorResolution(w io.Writer,
a *lnwallet.AnchorResolution) error {
if _, err := w.Write(a.CommitAnchor.Hash[:]); err != nil {
return err
}
err := binary.Write(w, endian, a.CommitAnchor.Index)
if err != nil {
return err
}
return input.WriteSignDescriptor(w, &a.AnchorSignDescriptor)
}
func decodeAnchorResolution(r io.Reader,
a *lnwallet.AnchorResolution) error {
_, err := io.ReadFull(r, a.CommitAnchor.Hash[:])
if err != nil {
return err
}
err = binary.Read(r, endian, &a.CommitAnchor.Index)
if err != nil {
return err
}
return input.ReadSignDescriptor(r, &a.AnchorSignDescriptor)
}
func encodeHtlcSetKey(w io.Writer, h *HtlcSetKey) error {
err := binary.Write(w, endian, h.IsRemote)
if err != nil {
return err
}
return binary.Write(w, endian, h.IsPending)
}
func encodeCommitSet(w io.Writer, c *CommitSet) error {
if err := encodeHtlcSetKey(w, c.ConfCommitKey); err != nil {
return err
}
numSets := uint8(len(c.HtlcSets))
if err := binary.Write(w, endian, numSets); err != nil {
return err
}
for htlcSetKey, htlcs := range c.HtlcSets {
htlcSetKey := htlcSetKey
if err := encodeHtlcSetKey(w, &htlcSetKey); err != nil {
return err
}
if err := channeldb.SerializeHtlcs(w, htlcs...); err != nil {
return err
}
}
return nil
}
func decodeHtlcSetKey(r io.Reader, h *HtlcSetKey) error {
err := binary.Read(r, endian, &h.IsRemote)
if err != nil {
return err
}
return binary.Read(r, endian, &h.IsPending)
}
func decodeCommitSet(r io.Reader) (*CommitSet, error) {
c := &CommitSet{
ConfCommitKey: &HtlcSetKey{},
HtlcSets: make(map[HtlcSetKey][]channeldb.HTLC),
}
if err := decodeHtlcSetKey(r, c.ConfCommitKey); err != nil {
return nil, err
}
var numSets uint8
if err := binary.Read(r, endian, &numSets); err != nil {
return nil, err
}
for i := uint8(0); i < numSets; i++ {
var htlcSetKey HtlcSetKey
if err := decodeHtlcSetKey(r, &htlcSetKey); err != nil {
return nil, err
}
htlcs, err := channeldb.DeserializeHtlcs(r)
if err != nil {
return nil, err
}
c.HtlcSets[htlcSetKey] = htlcs
}
return c, nil
}