a8d667ba35
This commit also adds a BreachConfig to abstract the instantiation of the breach arbiter, as well as various formatting improvements.
1423 lines
47 KiB
Go
1423 lines
47 KiB
Go
package main
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import (
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"bytes"
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"encoding/binary"
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"errors"
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"io"
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"sync"
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"sync/atomic"
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"github.com/boltdb/bolt"
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"github.com/davecgh/go-spew/spew"
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"github.com/lightningnetwork/lnd/chainntnfs"
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"github.com/lightningnetwork/lnd/channeldb"
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"github.com/lightningnetwork/lnd/htlcswitch"
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"github.com/lightningnetwork/lnd/lnwallet"
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"github.com/roasbeef/btcd/blockchain"
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"github.com/roasbeef/btcd/btcec"
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"github.com/roasbeef/btcd/chaincfg/chainhash"
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"github.com/roasbeef/btcd/txscript"
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"github.com/roasbeef/btcd/wire"
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"github.com/roasbeef/btcutil"
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)
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// retributionBucket stores retribution state on disk between detecting a
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// contract breach, broadcasting a justice transaction that sweeps the channel,
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// and finally witnessing the justice transaction confirm on the blockchain. It
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// is critical that such state is persisted on disk, so that if our node
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// restarts at any point during the retribution procedure, we can recover and
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// continue from the persisted state.
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var retributionBucket = []byte("retribution")
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// BreachConfig bundles the required subsystems used by the breach arbiter. An
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// instance of BreachConfig is passed to newBreachArbiter during instantiation.
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type BreachConfig struct {
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// Signer is used by the breach arbiter to generate sweep transactions,
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// which move coins from previously open channels back to the user's
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// wallet.
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Signer lnwallet.Signer
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// DB provides access to the user's channels, allowing the breach
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// arbiter to determine the current state of a user's channels, and how
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// it should respond to channel closure.
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DB *channeldb.DB
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// PublishTransaction facilitates the process of broadcasting a
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// transaction to the network.
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PublishTransaction func(*wire.MsgTx) error
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// Notifier provides a publish/subscribe interface for event driven
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// notifications regarding the confirmation of txids.
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Notifier chainntnfs.ChainNotifier
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// ChainIO is used by the breach arbiter to determine the current height
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// of the blockchain, which is required to subscribe for spend
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// notifications from Notifier.
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ChainIO lnwallet.BlockChainIO
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// Estimator is used by the breach arbiter to determine an appropriate
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// fee level when generating, signing, and broadcasting sweep
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// transactions.
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Estimator lnwallet.FeeEstimator
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// CloseLink allows the breach arbiter to shutdown any channel links for
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// which it detects a breach, ensuring now further activity will
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// continue across the link. The method accepts link's channel point and a
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// close type to be included in the channel close summary.
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CloseLink func(*wire.OutPoint, htlcswitch.ChannelCloseType)
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// Store is a persistent resource that maintains information regarding
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// breached channels. This is used in conjunction with DB to recover
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// from crashes, restarts, or other failures.
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Store RetributionStore
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// GenSweepScript generates the receiving scripts for swept outputs.
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GenSweepScript func() ([]byte, error)
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}
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// breachArbiter is a special subsystem which is responsible for watching and
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// acting on the detection of any attempted uncooperative channel breaches by
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// channel counterparties. This file essentially acts as deterrence code for
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// those attempting to launch attacks against the daemon. In practice it's
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// expected that the logic in this file never gets executed, but it is
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// important to have it in place just in case we encounter cheating channel
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// counterparties.
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// TODO(roasbeef): closures in config for subsystem pointers to decouple?
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type breachArbiter struct {
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cfg *BreachConfig
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// breachObservers is a map which tracks all the active breach
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// observers we're currently managing. The key of the map is the
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// funding outpoint of the channel, and the value is a channel which
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// will be closed once we detect that the channel has been
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// cooperatively closed, thereby killing the goroutine and freeing up
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// resources.
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breachObservers map[wire.OutPoint]chan struct{}
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// breachedContracts is a channel which is used internally within the
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// struct to send the necessary information required to punish a
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// counterparty once a channel breach is detected. Breach observers
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// use this to communicate with the main contractObserver goroutine.
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breachedContracts chan *retributionInfo
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// newContracts is a channel which is used by outside subsystems to
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// notify the breachArbiter of a new contract (a channel) that should
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// be watched.
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newContracts chan *lnwallet.LightningChannel
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// settledContracts is a channel by outside subsystems to notify
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// the breachArbiter that a channel has peacefully been closed. Once a
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// channel has been closed the arbiter no longer needs to watch for
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// breach closes.
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settledContracts chan *wire.OutPoint
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started uint32
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stopped uint32
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quit chan struct{}
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wg sync.WaitGroup
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}
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// newBreachArbiter creates a new instance of a breachArbiter initialized with
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// its dependent objects.
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func newBreachArbiter(cfg *BreachConfig) *breachArbiter {
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return &breachArbiter{
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cfg: cfg,
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breachObservers: make(map[wire.OutPoint]chan struct{}),
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breachedContracts: make(chan *retributionInfo),
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newContracts: make(chan *lnwallet.LightningChannel),
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settledContracts: make(chan *wire.OutPoint),
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quit: make(chan struct{}),
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}
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}
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// Start is an idempotent method that officially starts the breachArbiter along
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// with all other goroutines it needs to perform its functions.
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func (b *breachArbiter) Start() error {
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if !atomic.CompareAndSwapUint32(&b.started, 0, 1) {
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return nil
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}
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brarLog.Tracef("Starting breach arbiter")
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// We load all pending retributions from the database and
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// deterministically reconstruct a channel close summary for each. In
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// the event that a channel is still open after being breached, we can
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// use the close summary to reinitiate a channel close so that the
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// breach is reflected in channeldb.
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breachRetInfos := make(map[wire.OutPoint]retributionInfo)
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closeSummaries := make(map[wire.OutPoint]channeldb.ChannelCloseSummary)
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err := b.cfg.Store.ForAll(func(ret *retributionInfo) error {
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// Extract emitted retribution information.
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breachRetInfos[ret.chanPoint] = *ret
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// Deterministically reconstruct channel close summary from
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// persisted retribution information and record in breach close
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// summaries map under the corresponding channel point.
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closeSummary := channeldb.ChannelCloseSummary{
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ChanPoint: ret.chanPoint,
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ClosingTXID: ret.commitHash,
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RemotePub: ret.remoteIdentity,
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Capacity: ret.capacity,
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SettledBalance: ret.settledBalance,
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CloseType: channeldb.BreachClose,
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IsPending: true,
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}
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closeSummaries[ret.chanPoint] = closeSummary
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return nil
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})
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if err != nil {
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return err
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}
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// We need to query that database state for all currently active
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// channels, each of these channels will need a goroutine assigned to
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// it to watch for channel breaches.
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activeChannels, err := b.cfg.DB.FetchAllChannels()
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if err != nil && err != channeldb.ErrNoActiveChannels {
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brarLog.Errorf("unable to fetch active channels: %v", err)
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return err
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}
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nActive := len(activeChannels)
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if nActive > 0 {
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brarLog.Infof("Retrieved %v channels from database, watching "+
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"with vigilance!", nActive)
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}
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// Here we will determine a set of channels that will need to be managed
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// by the contractObserver. For each of the open channels read from
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// disk, we will create a channel state machine that can be used to
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// watch for any potential channel closures. We must first exclude any
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// channel whose retribution process has been initiated, and proceed to
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// mark them as closed. The state machines generated for these filtered
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// channels can be discarded, as their fate will be placed in the hands
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// of an exactRetribution task spawned later.
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//
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// NOTE: Spawning of the exactRetribution task is intentionally
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// postponed until after this step in order to ensure that the all
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// breached channels are reflected as closed in channeldb and consistent
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// with what is checkpointed by the breach arbiter. Instead of treating
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// the breached-and-closed and breached-but-still-active channels as
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// separate sets of channels, we first ensure that all
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// breached-but-still-active channels are promoted to
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// breached-and-closed during restart, allowing us to treat them as a
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// single set from here on out. This approach also has the added benefit
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// of minimizing the likelihood that the wrong number of tasks are
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// spawned per breached channel, and prevents us from being in a
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// position where retribution has completed but the channel is still
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// marked as open in channeldb.
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channelsToWatch := make([]*lnwallet.LightningChannel, 0, nActive)
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for _, chanState := range activeChannels {
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// Initialize active channel from persisted channel state.
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channel, err := lnwallet.NewLightningChannel(
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nil, b.cfg.Notifier, b.cfg.Estimator, chanState,
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)
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if err != nil {
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brarLog.Errorf("unable to load channel from "+
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"disk: %v", err)
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return err
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}
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// Before marking this as an active channel that the breach
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// arbiter should watch, check to see if this channel was
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// previously breached. If so, we attempt to reflect this in the
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// channeldb by closing the channel. Upon success, we continue
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// because the channel is no longer open, and thus does not need
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// to be managed by the contractObserver.
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chanPoint := chanState.FundingOutpoint
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if closeSummary, ok := closeSummaries[chanPoint]; ok {
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// Since this channel should not be open, we immediately
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// notify the HTLC switch that this link should be
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// closed, and that all activity on the link should
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// cease.
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b.cfg.CloseLink(&chanState.FundingOutpoint,
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htlcswitch.CloseBreach)
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// Ensure channeldb is consistent with the persisted
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// breach.
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err := channel.DeleteState(&closeSummary)
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if err != nil {
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brarLog.Errorf("unable to delete channel "+
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"state: %v", err)
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return err
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}
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// Now that this channel is both breached _and_ closed,
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// we can skip adding it to the `channelsToWatch` since
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// we can begin the retribution process immediately.
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continue
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}
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// Finally, add this channel to breach arbiter's list of
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// channels to watch.
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channelsToWatch = append(channelsToWatch, channel)
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}
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// TODO(roasbeef): instead use closure height of channel
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_, currentHeight, err := b.cfg.ChainIO.GetBestBlock()
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if err != nil {
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return err
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}
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// Additionally, we'll also want to watch any pending close or force
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// close transactions to we can properly mark them as resolved in the
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// database.
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if err := b.watchForPendingCloseConfs(currentHeight); err != nil {
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return err
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}
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// Spawn the exactRetribution tasks to monitor and resolve any breaches
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// that were loaded from the retribution store.
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for chanPoint, closeSummary := range closeSummaries {
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// Register for a notification when the breach transaction is
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// confirmed on chain.
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breachTXID := closeSummary.ClosingTXID
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confChan, err := b.cfg.Notifier.RegisterConfirmationsNtfn(
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&breachTXID, 1, uint32(currentHeight))
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if err != nil {
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brarLog.Errorf("unable to register for conf updates "+
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"for txid: %v, err: %v", breachTXID, err)
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return err
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}
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// Launch a new goroutine which to finalize the channel
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// retribution after the breach transaction confirms.
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retInfo := breachRetInfos[chanPoint]
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b.wg.Add(1)
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go b.exactRetribution(confChan, &retInfo)
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}
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// Start watching the remaining active channels!
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b.wg.Add(1)
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go b.contractObserver(channelsToWatch)
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return nil
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}
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// watchForPendingCloseConfs dispatches confirmation notification subscribers
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// that mark any pending channels as fully closed when signaled.
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func (b *breachArbiter) watchForPendingCloseConfs(currentHeight int32) error {
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pendingCloseChans, err := b.cfg.DB.FetchClosedChannels(true)
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if err != nil {
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brarLog.Errorf("unable to fetch closing channels: %v", err)
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return err
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}
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for _, pendingClose := range pendingCloseChans {
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// If this channel was force closed, and we have a non-zero
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// time-locked balance, then the utxoNursery is currently
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// watching over it. As a result we don't need to watch over
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// it.
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if pendingClose.CloseType == channeldb.ForceClose &&
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pendingClose.TimeLockedBalance != 0 {
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continue
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}
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brarLog.Infof("Watching for the closure of ChannelPoint(%v)",
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pendingClose.ChanPoint)
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closeTXID := pendingClose.ClosingTXID
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confNtfn, err := b.cfg.Notifier.RegisterConfirmationsNtfn(
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&closeTXID, 1, uint32(currentHeight),
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)
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if err != nil {
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return err
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}
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b.wg.Add(1)
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go func(chanPoint wire.OutPoint) {
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defer b.wg.Done()
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// In the case that the ChainNotifier is shutting down,
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// all subscriber notification channels will be closed,
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// generating a nil receive.
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select {
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case confInfo, ok := <-confNtfn.Confirmed:
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if !ok {
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return
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}
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brarLog.Infof("ChannelPoint(%v) is "+
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"fully closed, at height: %v",
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chanPoint, confInfo.BlockHeight)
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// TODO(roasbeef): need to store
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// UnilateralCloseSummary on disk so can
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// possibly sweep output here
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err := b.cfg.DB.MarkChanFullyClosed(&chanPoint)
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if err != nil {
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brarLog.Errorf("unable to mark channel"+
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" as closed: %v", err)
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}
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case <-b.quit:
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return
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}
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}(pendingClose.ChanPoint)
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}
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return nil
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}
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// Stop is an idempotent method that signals the breachArbiter to execute a
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// graceful shutdown. This function will block until all goroutines spawned by
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// the breachArbiter have gracefully exited.
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func (b *breachArbiter) Stop() error {
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if !atomic.CompareAndSwapUint32(&b.stopped, 0, 1) {
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return nil
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}
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brarLog.Infof("Breach arbiter shutting down")
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close(b.quit)
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b.wg.Wait()
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return nil
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}
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// contractObserver is the primary goroutine for the breachArbiter. This
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// goroutine is responsible for managing goroutines that watch for breaches for
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// all current active and newly created channels. If a channel breach is
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// detected by a spawned child goroutine, then the contractObserver will
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// execute the retribution logic required to sweep ALL outputs from a contested
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// channel into the daemon's wallet.
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//
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// NOTE: This MUST be run as a goroutine.
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func (b *breachArbiter) contractObserver(
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activeChannels []*lnwallet.LightningChannel) {
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defer b.wg.Done()
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// For each active channel found within the database, we launch a
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// detected breachObserver goroutine for that channel and also track
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// the new goroutine within the breachObservers map so we can cancel it
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// later if necessary.
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for _, channel := range activeChannels {
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settleSignal := make(chan struct{})
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chanPoint := channel.ChannelPoint()
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b.breachObservers[*chanPoint] = settleSignal
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b.wg.Add(1)
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go b.breachObserver(channel, settleSignal)
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}
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// TODO(roasbeef): need to ensure currentHeight passed in doesn't
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// result in lost notification
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out:
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for {
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select {
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case breachInfo := <-b.breachedContracts:
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_, currentHeight, err := b.cfg.ChainIO.GetBestBlock()
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if err != nil {
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brarLog.Errorf("unable to get best height: %v",
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err)
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}
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// A new channel contract has just been breached! We
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// first register for a notification to be dispatched
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// once the breach transaction (the revoked commitment
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// transaction) has been confirmed in the chain to
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// ensure we're not dealing with a moving target.
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breachTXID := &breachInfo.commitHash
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cfChan, err := b.cfg.Notifier.RegisterConfirmationsNtfn(
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breachTXID, 1, uint32(currentHeight),
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)
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if err != nil {
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brarLog.Errorf("unable to register for conf "+
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"updates for txid: %v, err: %v",
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breachTXID, err)
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continue
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}
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brarLog.Warnf("A channel has been breached with "+
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"txid: %v. Waiting for confirmation, then "+
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"justice will be served!", breachTXID)
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// With the retribution state persisted, channel close
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// persisted, and notification registered, we launch a
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// new goroutine which will finalize the channel
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// retribution after the breach transaction has been
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// confirmed.
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b.wg.Add(1)
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go b.exactRetribution(cfChan, breachInfo)
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delete(b.breachObservers, breachInfo.chanPoint)
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case contract := <-b.newContracts:
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// A new channel has just been opened within the
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// daemon, so we launch a new breachObserver to handle
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// the detection of attempted contract breaches.
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settleSignal := make(chan struct{})
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chanPoint := contract.ChannelPoint()
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// If the contract is already being watched, then an
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// additional send indicates we have a stale version of
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// the contract. So we'll cancel active watcher
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// goroutine to create a new instance with the latest
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// contract reference.
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if oldSignal, ok := b.breachObservers[*chanPoint]; ok {
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brarLog.Infof("ChannelPoint(%v) is now live, "+
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"abandoning state contract for live "+
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"version", chanPoint)
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close(oldSignal)
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}
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b.breachObservers[*chanPoint] = settleSignal
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brarLog.Debugf("New contract detected, launching " +
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"breachObserver")
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b.wg.Add(1)
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go b.breachObserver(contract, settleSignal)
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// TODO(roasbeef): add doneChan to signal to peer
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// continue * peer send over to us on
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// loadActiveChanenls, sync until we're aware so no
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// state transitions
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case chanPoint := <-b.settledContracts:
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// A new channel has been closed either unilaterally or
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// cooperatively, as a result we no longer need a
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// breachObserver detected to the channel.
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killSignal, ok := b.breachObservers[*chanPoint]
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if !ok {
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brarLog.Errorf("Unable to find contract: %v",
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chanPoint)
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continue
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}
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brarLog.Debugf("ChannelPoint(%v) has been settled, "+
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"cancelling breachObserver", chanPoint)
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// If we had a breachObserver active, then we signal it
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// for exit and also delete its state from our tracking
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// map.
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close(killSignal)
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delete(b.breachObservers, *chanPoint)
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case <-b.quit:
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break out
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}
|
|
}
|
|
|
|
return
|
|
}
|
|
|
|
// exactRetribution is a goroutine which is executed once a contract breach has
|
|
// been detected by a breachObserver. This function is responsible for
|
|
// punishing a counterparty for violating the channel contract by sweeping ALL
|
|
// the lingering funds within the channel into the daemon's wallet.
|
|
//
|
|
// NOTE: This MUST be run as a goroutine.
|
|
func (b *breachArbiter) exactRetribution(
|
|
confChan *chainntnfs.ConfirmationEvent,
|
|
breachInfo *retributionInfo) {
|
|
|
|
defer b.wg.Done()
|
|
|
|
// TODO(roasbeef): state needs to be checkpointed here
|
|
|
|
select {
|
|
case _, ok := <-confChan.Confirmed:
|
|
// If the second value is !ok, then the channel has been closed
|
|
// signifying a daemon shutdown, so we exit.
|
|
if !ok {
|
|
return
|
|
}
|
|
|
|
// Otherwise, if this is a real confirmation notification, then
|
|
// we fall through to complete our duty.
|
|
case <-b.quit:
|
|
return
|
|
}
|
|
|
|
brarLog.Debugf("Breach transaction %v has been confirmed, sweeping "+
|
|
"revoked funds", breachInfo.commitHash)
|
|
|
|
// With the breach transaction confirmed, we now create the justice tx
|
|
// which will claim ALL the funds within the channel.
|
|
justiceTx, err := b.createJusticeTx(breachInfo)
|
|
if err != nil {
|
|
brarLog.Errorf("unable to create justice tx: %v", err)
|
|
return
|
|
}
|
|
|
|
brarLog.Debugf("Broadcasting justice tx: %v",
|
|
newLogClosure(func() string {
|
|
return spew.Sdump(justiceTx)
|
|
}))
|
|
|
|
_, currentHeight, err := b.cfg.ChainIO.GetBestBlock()
|
|
if err != nil {
|
|
brarLog.Errorf("unable to get current height: %v", err)
|
|
return
|
|
}
|
|
|
|
// Finally, broadcast the transaction, finalizing the channels'
|
|
// retribution against the cheating counterparty.
|
|
if err := b.cfg.PublishTransaction(justiceTx); err != nil {
|
|
brarLog.Errorf("unable to broadcast "+
|
|
"justice tx: %v", err)
|
|
return
|
|
}
|
|
|
|
// As a conclusionary step, we register for a notification to be
|
|
// dispatched once the justice tx is confirmed. After confirmation we
|
|
// notify the caller that initiated the retribution workflow that the
|
|
// deed has been done.
|
|
justiceTXID := justiceTx.TxHash()
|
|
confChan, err = b.cfg.Notifier.RegisterConfirmationsNtfn(
|
|
&justiceTXID, 1, uint32(currentHeight))
|
|
if err != nil {
|
|
brarLog.Errorf("unable to register for conf for txid: %v",
|
|
justiceTXID)
|
|
return
|
|
}
|
|
|
|
select {
|
|
case _, ok := <-confChan.Confirmed:
|
|
if !ok {
|
|
return
|
|
}
|
|
|
|
// TODO(roasbeef): factor in HTLCs
|
|
revokedFunds := breachInfo.revokedOutput.amt
|
|
totalFunds := revokedFunds + breachInfo.selfOutput.amt
|
|
|
|
brarLog.Infof("Justice for ChannelPoint(%v) has "+
|
|
"been served, %v revoked funds (%v total) "+
|
|
"have been claimed", breachInfo.chanPoint,
|
|
revokedFunds, totalFunds)
|
|
|
|
// With the channel closed, mark it in the database as such.
|
|
err := b.cfg.DB.MarkChanFullyClosed(&breachInfo.chanPoint)
|
|
if err != nil {
|
|
brarLog.Errorf("unable to mark chan as closed: %v", err)
|
|
}
|
|
|
|
// Justice has been carried out; we can safely delete the
|
|
// retribution info from the database.
|
|
err = b.cfg.Store.Remove(&breachInfo.chanPoint)
|
|
if err != nil {
|
|
brarLog.Errorf("unable to remove retribution "+
|
|
"from the db: %v", err)
|
|
}
|
|
|
|
// TODO(roasbeef): add peer to blacklist?
|
|
|
|
// TODO(roasbeef): close other active channels with offending
|
|
// peer
|
|
|
|
return
|
|
case <-b.quit:
|
|
return
|
|
}
|
|
}
|
|
|
|
// breachObserver notifies the breachArbiter contract observer goroutine that a
|
|
// channel's contract has been breached by the prior counterparty. Once
|
|
// notified the breachArbiter will attempt to sweep ALL funds within the
|
|
// channel using the information provided within the BreachRetribution
|
|
// generated due to the breach of channel contract. The funds will be swept
|
|
// only after the breaching transaction receives a necessary number of
|
|
// confirmations.
|
|
func (b *breachArbiter) breachObserver(contract *lnwallet.LightningChannel,
|
|
settleSignal chan struct{}) {
|
|
|
|
defer b.wg.Done()
|
|
|
|
chanPoint := contract.ChannelPoint()
|
|
|
|
brarLog.Debugf("Breach observer for ChannelPoint(%v) started",
|
|
chanPoint)
|
|
|
|
select {
|
|
// A read from this channel indicates that the contract has been
|
|
// settled cooperatively so we exit as our duties are no longer needed.
|
|
case <-settleSignal:
|
|
contract.Stop()
|
|
return
|
|
|
|
// The channel has been closed by a normal means: force closing with
|
|
// the latest commitment transaction.
|
|
case closeInfo := <-contract.UnilateralClose:
|
|
// Launch a goroutine to cancel out this contract within the
|
|
// breachArbiter's main goroutine.
|
|
b.wg.Add(1)
|
|
go func() {
|
|
defer b.wg.Done()
|
|
|
|
select {
|
|
case b.settledContracts <- chanPoint:
|
|
case <-b.quit:
|
|
}
|
|
}()
|
|
|
|
// Next, we'll launch a goroutine to wait until the closing
|
|
// transaction has been confirmed so we can mark the contract
|
|
// as resolved in the database. This go routine is _not_ tracked
|
|
// by the breach arbiter's wait group since the callback may not
|
|
// be executed before shutdown, potentially leading to a
|
|
// deadlocks as the arbiter may not be able to finish shutting
|
|
// down.
|
|
//
|
|
// TODO(roasbeef): also notify utxoNursery, might've had
|
|
// outbound HTLC's in flight
|
|
go waitForChanToClose(uint32(closeInfo.SpendingHeight),
|
|
b.cfg.Notifier, nil, chanPoint, closeInfo.SpenderTxHash,
|
|
func() {
|
|
// As we just detected a channel was closed via
|
|
// a unilateral commitment broadcast by the
|
|
// remote party, we'll need to sweep our main
|
|
// commitment output, and any outstanding
|
|
// outgoing HTLC we had as well.
|
|
//
|
|
// TODO(roasbeef): actually sweep HTLC's *
|
|
// ensure reliable confirmation
|
|
if closeInfo.SelfOutPoint != nil {
|
|
sweepTx, err := b.craftCommitSweepTx(
|
|
closeInfo,
|
|
)
|
|
if err != nil {
|
|
brarLog.Errorf("unable to "+
|
|
"generate sweep tx: %v",
|
|
err)
|
|
goto close
|
|
}
|
|
|
|
brarLog.Infof("Sweeping breached "+
|
|
"outputs with: %v",
|
|
spew.Sdump(sweepTx))
|
|
|
|
err = b.cfg.PublishTransaction(sweepTx)
|
|
if err != nil {
|
|
brarLog.Errorf("unable to "+
|
|
"broadcast tx: %v", err)
|
|
}
|
|
}
|
|
|
|
close:
|
|
brarLog.Infof("Force closed ChannelPoint(%v) "+
|
|
"is fully closed, updating DB",
|
|
chanPoint)
|
|
|
|
err := b.cfg.DB.MarkChanFullyClosed(chanPoint)
|
|
if err != nil {
|
|
brarLog.Errorf("unable to mark chan "+
|
|
"as closed: %v", err)
|
|
}
|
|
})
|
|
|
|
// A read from this channel indicates that a channel breach has been
|
|
// detected! So we notify the main coordination goroutine with the
|
|
// information needed to bring the counterparty to justice.
|
|
case breachInfo := <-contract.ContractBreach:
|
|
brarLog.Warnf("REVOKED STATE #%v FOR ChannelPoint(%v) "+
|
|
"broadcast, REMOTE PEER IS DOING SOMETHING "+
|
|
"SKETCHY!!!", breachInfo.RevokedStateNum,
|
|
chanPoint)
|
|
|
|
// Immediately notify the HTLC switch that this link has been
|
|
// breached in order to ensure any incoming or outgoing
|
|
// multi-hop HTLCs aren't sent over this link, nor any other
|
|
// links associated with this peer.
|
|
b.cfg.CloseLink(chanPoint, htlcswitch.CloseBreach)
|
|
|
|
// TODO(roasbeef): need to handle case of remote broadcast
|
|
// mid-local initiated state-transition, possible
|
|
// false-positive?
|
|
|
|
// Obtain a snapshot of the final channel state, which can be
|
|
// used to reclose a breached channel in the event of a failure.
|
|
chanInfo := contract.StateSnapshot()
|
|
|
|
// Using the breach information provided by the wallet and the
|
|
// channel snapshot, construct the retribution information that
|
|
// will be persisted to disk.
|
|
retInfo := newRetributionInfo(chanPoint, breachInfo, chanInfo)
|
|
|
|
// Persist the pending retribution state to disk.
|
|
if err := b.cfg.Store.Add(retInfo); err != nil {
|
|
brarLog.Errorf("unable to persist retribution info "+
|
|
"to db: %v", err)
|
|
}
|
|
|
|
// TODO(conner): move responsibility of channel closure into
|
|
// lnwallet. Have breach arbiter ACK after writing to disk, then
|
|
// have wallet mark channel as closed. This allows the wallet to
|
|
// attempt to retransmit the breach info if the either arbiter
|
|
// or the wallet goes down before completing the hand off.
|
|
|
|
// Now that the breach arbiter has persisted the information,
|
|
// we can go ahead and mark the channel as closed in the
|
|
// channeldb. This step is done after persisting the
|
|
// retribution information so that a failure between these steps
|
|
// will cause an attempt to monitor the still-open channel.
|
|
// However, since the retribution information was persisted
|
|
// before, the arbiter will recognize that the channel should be
|
|
// closed, and proceed to mark it as such after a restart, and
|
|
// forgo monitoring it for breaches.
|
|
|
|
// Construct the breached channel's close summary marking the
|
|
// channel using the snapshot from before, and marking this as a
|
|
// BreachClose.
|
|
closeInfo := &channeldb.ChannelCloseSummary{
|
|
ChanPoint: *chanPoint,
|
|
ClosingTXID: breachInfo.BreachTransaction.TxHash(),
|
|
RemotePub: &chanInfo.RemoteIdentity,
|
|
Capacity: chanInfo.Capacity,
|
|
SettledBalance: chanInfo.LocalBalance.ToSatoshis(),
|
|
CloseType: channeldb.BreachClose,
|
|
IsPending: true,
|
|
}
|
|
|
|
// Next, persist the channel close to disk. Upon restart, the
|
|
// arbiter will recognize that this channel has been breached
|
|
// and marked close, and fast track its path to justice.
|
|
if err := contract.DeleteState(closeInfo); err != nil {
|
|
brarLog.Errorf("unable to delete channel state: %v",
|
|
err)
|
|
}
|
|
|
|
// Finally, we send the retribution information into the
|
|
// breachArbiter event loop to deal swift justice.
|
|
select {
|
|
case b.breachedContracts <- retInfo:
|
|
case <-b.quit:
|
|
}
|
|
|
|
case <-b.quit:
|
|
return
|
|
}
|
|
}
|
|
|
|
// SpendableOutput an interface which can be used by the breach arbiter to
|
|
// construct a transaction spending from outputs we control.
|
|
type SpendableOutput interface {
|
|
// Amount returns the number of satoshis contained within the output.
|
|
Amount() btcutil.Amount
|
|
|
|
// Outpoint returns the reference to the output being spent, used to
|
|
// construct the corresponding transaction input.
|
|
OutPoint() *wire.OutPoint
|
|
|
|
// BuildWitness returns a valid witness allowing this output to be
|
|
// spent, the witness should be attached to the transaction at the
|
|
// location determined by the given `txinIdx`.
|
|
BuildWitness(signer lnwallet.Signer,
|
|
txn *wire.MsgTx,
|
|
hashCache *txscript.TxSigHashes,
|
|
txinIdx int) ([][]byte, error)
|
|
}
|
|
|
|
// breachedOutput contains all the information needed to sweep a breached
|
|
// output. A breached output is an output that we are now entitled to due to a
|
|
// revoked commitment transaction being broadcast.
|
|
type breachedOutput struct {
|
|
amt btcutil.Amount
|
|
outpoint wire.OutPoint
|
|
witnessType lnwallet.WitnessType
|
|
signDesc lnwallet.SignDescriptor
|
|
|
|
witnessFunc lnwallet.WitnessGenerator
|
|
}
|
|
|
|
// newBreachedOutput assembles a new breachedOutput that can be used by the
|
|
// breach arbiter to construct a justice or sweep transaction.
|
|
func newBreachedOutput(outpoint *wire.OutPoint,
|
|
witnessType lnwallet.WitnessType,
|
|
signDescriptor *lnwallet.SignDescriptor) *breachedOutput {
|
|
|
|
amount := signDescriptor.Output.Value
|
|
|
|
return &breachedOutput{
|
|
amt: btcutil.Amount(amount),
|
|
outpoint: *outpoint,
|
|
witnessType: witnessType,
|
|
signDesc: *signDescriptor,
|
|
}
|
|
}
|
|
|
|
// Amount returns the number of satoshis contained in the breached output.
|
|
func (bo *breachedOutput) Amount() btcutil.Amount {
|
|
return bo.amt
|
|
}
|
|
|
|
// OutPoint returns the breached outputs identifier that is to be included as a
|
|
// transaction input.
|
|
func (bo *breachedOutput) OutPoint() *wire.OutPoint {
|
|
return &bo.outpoint
|
|
}
|
|
|
|
// BuildWitness computes a valid witness that allows us to spend from the
|
|
// breached output. It does so by first generating and memoizing the witness
|
|
// generation function, which parameterized primarily by the witness type and
|
|
// sign descriptor. The method then returns the witness computed by invoking
|
|
// this function on the first and subsequent calls.
|
|
func (bo *breachedOutput) BuildWitness(signer lnwallet.Signer,
|
|
txn *wire.MsgTx,
|
|
hashCache *txscript.TxSigHashes,
|
|
txinIdx int) ([][]byte, error) {
|
|
|
|
// First, we ensure that the witness generation function has
|
|
// been initialized for this breached output.
|
|
if bo.witnessFunc == nil {
|
|
bo.witnessFunc = bo.witnessType.GenWitnessFunc(
|
|
signer, &bo.signDesc,
|
|
)
|
|
}
|
|
|
|
// Now that we have ensured that the witness generation function has
|
|
// been initialized, we can proceed to execute it and generate the
|
|
// witness for this particular breached output.
|
|
return bo.witnessFunc(txn, hashCache, txinIdx)
|
|
}
|
|
|
|
// Add compile-time constraint ensuring breachedOutput implements
|
|
// SpendableOutput.
|
|
var _ SpendableOutput = (*breachedOutput)(nil)
|
|
|
|
// retributionInfo encapsulates all the data needed to sweep all the contested
|
|
// funds within a channel whose contract has been breached by the prior
|
|
// counterparty. This struct is used to create the justice transaction which
|
|
// spends all outputs of the commitment transaction into an output controlled
|
|
// by the wallet.
|
|
type retributionInfo struct {
|
|
commitHash chainhash.Hash
|
|
chanPoint wire.OutPoint
|
|
|
|
// TODO(conner): remove the following group of fields after decoupling
|
|
// the breach arbiter from the wallet.
|
|
|
|
// Fields copied from channel snapshot when a breach is detected. This
|
|
// is necessary for deterministically constructing the channel close
|
|
// summary in the event that the breach arbiter crashes before closing
|
|
// the channel.
|
|
remoteIdentity *btcec.PublicKey
|
|
capacity btcutil.Amount
|
|
settledBalance btcutil.Amount
|
|
|
|
selfOutput *breachedOutput
|
|
|
|
revokedOutput *breachedOutput
|
|
|
|
htlcOutputs []*breachedOutput
|
|
|
|
doneChan chan struct{}
|
|
}
|
|
|
|
// newRetributionInfo constructs a retributionInfo containing all the
|
|
// information required by the breach arbiter to recover funds from breached
|
|
// channels. The information is primarily populated using the BreachRetribution
|
|
// delivered by the wallet when it detects a channel breach.
|
|
func newRetributionInfo(chanPoint *wire.OutPoint,
|
|
breachInfo *lnwallet.BreachRetribution,
|
|
chanInfo *channeldb.ChannelSnapshot) *retributionInfo {
|
|
|
|
// First, record the breach information and witness type for the local
|
|
// channel point. This will allow us to completely generate a valid
|
|
// witness in the event of failures, as it will be persisted in the
|
|
// retribution store. Here we use CommitmentNoDelay since this output
|
|
// belongs to us and has no time-based constraints on spending.
|
|
selfOutput := newBreachedOutput(
|
|
&breachInfo.LocalOutpoint,
|
|
lnwallet.CommitmentNoDelay,
|
|
&breachInfo.LocalOutputSignDesc,
|
|
)
|
|
|
|
// Second, record the same information and witness type regarding the
|
|
// remote outpoint, which belongs to the party who tried to steal our
|
|
// money! Here we set witnessType of the breachedOutput to
|
|
// CommitmentRevoke, since we will be using a revoke key, withdrawing
|
|
// the funds from the commitment transaction immediately.
|
|
revokedOutput := newBreachedOutput(
|
|
&breachInfo.RemoteOutpoint,
|
|
lnwallet.CommitmentRevoke,
|
|
&breachInfo.RemoteOutputSignDesc,
|
|
)
|
|
|
|
// Determine the number of second layer HTLCs we will attempt to sweep.
|
|
nHtlcs := len(breachInfo.HtlcRetributions)
|
|
|
|
// Lastly, for each of the breached HTLC outputs, assemble the
|
|
// information we will persist to disk, such that we will be able to
|
|
// deterministically generate a valid witness for each output. This will
|
|
// allow the breach arbiter to recover from failures, in the event that
|
|
// it must sign and broadcast the justice transaction.
|
|
htlcOutputs := make([]*breachedOutput, nHtlcs)
|
|
for i, breachedHtlc := range breachInfo.HtlcRetributions {
|
|
// Using the breachedHtlc's incoming flag, determine the
|
|
// appropriate witness type that needs to be generated in order
|
|
// to sweep the HTLC output.
|
|
var htlcWitnessType lnwallet.WitnessType
|
|
if breachedHtlc.IsIncoming {
|
|
htlcWitnessType = lnwallet.HtlcAcceptedRevoke
|
|
} else {
|
|
htlcWitnessType = lnwallet.HtlcOfferedRevoke
|
|
}
|
|
|
|
htlcOutputs[i] = newBreachedOutput(
|
|
&breachInfo.HtlcRetributions[i].OutPoint, htlcWitnessType,
|
|
&breachInfo.HtlcRetributions[i].SignDesc)
|
|
}
|
|
|
|
// TODO(conner): remove dependency on channel snapshot after decoupling
|
|
// channel closure from the breach arbiter.
|
|
|
|
return &retributionInfo{
|
|
commitHash: breachInfo.BreachTransaction.TxHash(),
|
|
chanPoint: *chanPoint,
|
|
remoteIdentity: &chanInfo.RemoteIdentity,
|
|
capacity: chanInfo.Capacity,
|
|
settledBalance: chanInfo.LocalBalance.ToSatoshis(),
|
|
selfOutput: selfOutput,
|
|
revokedOutput: revokedOutput,
|
|
htlcOutputs: htlcOutputs,
|
|
}
|
|
}
|
|
|
|
// createJusticeTx creates a transaction which exacts "justice" by sweeping ALL
|
|
// the funds within the channel which we are now entitled to due to a breach of
|
|
// the channel's contract by the counterparty. This function returns a *fully*
|
|
// signed transaction with the witness for each input fully in place.
|
|
func (b *breachArbiter) createJusticeTx(
|
|
r *retributionInfo) (*wire.MsgTx, error) {
|
|
|
|
// Determine the number of HTLCs to be swept by the justice txn.
|
|
nHtlcs := len(r.htlcOutputs)
|
|
|
|
// Assemble the breached outputs into a slice of spendable outputs,
|
|
// starting with the self and revoked outputs, then adding any htlc
|
|
// outputs.
|
|
breachedOutputs := make([]SpendableOutput, 2+nHtlcs)
|
|
breachedOutputs[0] = r.selfOutput
|
|
breachedOutputs[1] = r.revokedOutput
|
|
for i, htlcOutput := range r.htlcOutputs {
|
|
breachedOutputs[2+i] = htlcOutput
|
|
}
|
|
|
|
// Compute the transaction weight of the justice transaction, which
|
|
// includes 2 + nHtlcs inputs and one output.
|
|
var txWeight uint64
|
|
// Begin with a base txn weight, e.g. version, nLockTime, etc.
|
|
txWeight += 4*lnwallet.BaseSweepTxSize + lnwallet.WitnessHeaderSize
|
|
// Add to_local revoke script and tx input.
|
|
txWeight += 4*lnwallet.InputSize + lnwallet.ToLocalPenaltyWitnessSize
|
|
// Add to_remote p2wpkh witness and tx input.
|
|
txWeight += 4*lnwallet.InputSize + lnwallet.P2WKHWitnessSize
|
|
|
|
// Compute the appropriate weight contributed by each revoked accepted
|
|
// or offered HTLC witnesses and tx inputs.
|
|
for _, htlcOutput := range r.htlcOutputs {
|
|
switch htlcOutput.witnessType {
|
|
case lnwallet.HtlcOfferedRevoke:
|
|
txWeight += 4*lnwallet.InputSize +
|
|
lnwallet.OfferedHtlcPenaltyWitnessSize
|
|
case lnwallet.HtlcAcceptedRevoke:
|
|
txWeight += 4*lnwallet.InputSize +
|
|
lnwallet.AcceptedHtlcPenaltyWitnessSize
|
|
}
|
|
}
|
|
|
|
return b.sweepSpendableOutputsTxn(txWeight, breachedOutputs...)
|
|
}
|
|
|
|
// craftCommitmentSweepTx creates a transaction to sweep the non-delayed output
|
|
// within the commitment transaction that pays to us. We must manually sweep
|
|
// this output as it uses a tweaked public key in its pkScript, so the wallet
|
|
// won't immediacy be aware of it.
|
|
//
|
|
// TODO(roasbeef): alternative options
|
|
// * leave the output in the chain, use as input to future funding tx
|
|
// * leave output in the chain, extend wallet to add knowledge of how to claim
|
|
func (b *breachArbiter) craftCommitSweepTx(
|
|
closeInfo *lnwallet.UnilateralCloseSummary) (*wire.MsgTx, error) {
|
|
|
|
selfOutput := newBreachedOutput(
|
|
closeInfo.SelfOutPoint,
|
|
lnwallet.CommitmentNoDelay,
|
|
closeInfo.SelfOutputSignDesc,
|
|
)
|
|
|
|
// Compute the transaction weight of the commit sweep transaction, which
|
|
// includes a single input and output.
|
|
var txWeight uint64
|
|
// Begin with a base txn weight, e.g. version, nLockTime, etc.
|
|
txWeight += 4*lnwallet.BaseSweepTxSize + lnwallet.WitnessHeaderSize
|
|
// Add to_local p2wpkh witness and tx input.
|
|
txWeight += 4*lnwallet.InputSize + lnwallet.P2WKHWitnessSize
|
|
|
|
return b.sweepSpendableOutputsTxn(txWeight, selfOutput)
|
|
}
|
|
|
|
// sweepSpendableOutputsTxn creates a signed transaction from a sequence of
|
|
// spendable outputs by sweeping the funds into a single p2wkh output.
|
|
func (b *breachArbiter) sweepSpendableOutputsTxn(txWeight uint64,
|
|
inputs ...SpendableOutput) (*wire.MsgTx, error) {
|
|
|
|
// First, we obtain a new public key script from the wallet which we'll
|
|
// sweep the funds to.
|
|
// TODO(roasbeef): possibly create many outputs to minimize change in
|
|
// the future?
|
|
pkScript, err := b.cfg.GenSweepScript()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Compute the total amount contained in the inputs.
|
|
var totalAmt btcutil.Amount
|
|
for _, input := range inputs {
|
|
totalAmt += input.Amount()
|
|
}
|
|
|
|
feePerWeight := b.cfg.Estimator.EstimateFeePerWeight(1)
|
|
txFee := btcutil.Amount(txWeight * feePerWeight)
|
|
|
|
sweepAmt := int64(totalAmt - txFee)
|
|
|
|
// With the fee calculated, we can now create the transaction using the
|
|
// information gathered above and the provided retribution information.
|
|
txn := wire.NewMsgTx(2)
|
|
|
|
// We begin by adding the output to which our funds will be deposited.
|
|
txn.AddTxOut(&wire.TxOut{
|
|
PkScript: pkScript,
|
|
Value: sweepAmt,
|
|
})
|
|
|
|
// Next, we add all of the spendable outputs as inputs to the
|
|
// transaction.
|
|
for _, input := range inputs {
|
|
txn.AddTxIn(&wire.TxIn{
|
|
PreviousOutPoint: *input.OutPoint(),
|
|
})
|
|
}
|
|
|
|
// Before signing the transaction, check to ensure that it meets some
|
|
// basic validity requirements.
|
|
btx := btcutil.NewTx(txn)
|
|
if err := blockchain.CheckTransactionSanity(btx); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Create a sighash cache to improve the performance of hashing and
|
|
// signing SigHashAll inputs.
|
|
hashCache := txscript.NewTxSigHashes(txn)
|
|
|
|
// Create a closure that encapsulates the process of initializing a
|
|
// particular output's witness generation function, computing the
|
|
// witness, and attaching it to the transaction. This function accepts
|
|
// an integer index representing the intended txin index, and the
|
|
// breached output from which it will spend.
|
|
addWitness := func(idx int, so SpendableOutput) error {
|
|
// First, we construct a valid witness for this outpoint and
|
|
// transaction using the SpendableOutput's witness generation
|
|
// function.
|
|
witness, err := so.BuildWitness(
|
|
b.cfg.Signer, txn, hashCache, idx,
|
|
)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
// Then, we add the witness to the transaction at the
|
|
// appropriate txin index.
|
|
txn.TxIn[idx].Witness = witness
|
|
|
|
return nil
|
|
}
|
|
|
|
// Finally, generate a witness for each output and attach it to the
|
|
// transaction.
|
|
for i, input := range inputs {
|
|
if err := addWitness(i, input); err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
|
|
return txn, nil
|
|
}
|
|
|
|
// RetributionStore provides an interface for managing a persistent map from
|
|
// wire.OutPoint -> retributionInfo. Upon learning of a breach, a BreachArbiter
|
|
// should record the retributionInfo for the breached channel, which serves a
|
|
// checkpoint in the event that retribution needs to be resumed after failure.
|
|
// A RetributionStore provides an interface for managing the persisted set, as
|
|
// well as mapping user defined functions over the entire on-disk contents.
|
|
//
|
|
// Calls to RetributionStore may occur concurrently. A concrete instance of
|
|
// RetributionStore should use appropriate synchronization primitives, or
|
|
// be otherwise safe for concurrent access.
|
|
type RetributionStore interface {
|
|
// Add persists the retributionInfo to disk, using the information's
|
|
// chanPoint as the key. This method should overwrite any existing
|
|
// entires found under the same key, and an error should be raised if
|
|
// the addition fails.
|
|
Add(retInfo *retributionInfo) error
|
|
|
|
// Remove deletes the retributionInfo from disk, if any exists, under
|
|
// the given key. An error should be re raised if the removal fails.
|
|
Remove(key *wire.OutPoint) error
|
|
|
|
// ForAll iterates over the existing on-disk contents and applies a
|
|
// chosen, read-only callback to each. This method should ensure that it
|
|
// immediately propagate any errors generated by the callback.
|
|
ForAll(cb func(*retributionInfo) error) error
|
|
}
|
|
|
|
// retributionStore handles persistence of retribution states to disk and is
|
|
// backed by a boltdb bucket. The primary responsibility of the retribution
|
|
// store is to ensure that we can recover from a restart in the middle of a
|
|
// breached contract retribution.
|
|
type retributionStore struct {
|
|
db *channeldb.DB
|
|
}
|
|
|
|
// newRetributionStore creates a new instance of a retributionStore.
|
|
func newRetributionStore(db *channeldb.DB) *retributionStore {
|
|
return &retributionStore{
|
|
db: db,
|
|
}
|
|
}
|
|
|
|
// Add adds a retribution state to the retributionStore, which is then persisted
|
|
// to disk.
|
|
func (rs *retributionStore) Add(ret *retributionInfo) error {
|
|
return rs.db.Update(func(tx *bolt.Tx) error {
|
|
// If this is our first contract breach, the retributionBucket
|
|
// won't exist, in which case, we just create a new bucket.
|
|
retBucket, err := tx.CreateBucketIfNotExists(retributionBucket)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
var outBuf bytes.Buffer
|
|
if err := writeOutpoint(&outBuf, &ret.chanPoint); err != nil {
|
|
return err
|
|
}
|
|
|
|
var retBuf bytes.Buffer
|
|
if err := ret.Encode(&retBuf); err != nil {
|
|
return err
|
|
}
|
|
|
|
return retBucket.Put(outBuf.Bytes(), retBuf.Bytes())
|
|
})
|
|
}
|
|
|
|
// Remove removes a retribution state from the retributionStore database.
|
|
func (rs *retributionStore) Remove(key *wire.OutPoint) error {
|
|
return rs.db.Update(func(tx *bolt.Tx) error {
|
|
retBucket := tx.Bucket(retributionBucket)
|
|
|
|
// We return an error if the bucket is not already created,
|
|
// since normal operation of the breach arbiter should never try
|
|
// to remove a finalized retribution state that is not already
|
|
// stored in the db.
|
|
if retBucket == nil {
|
|
return errors.New("unable to remove retribution " +
|
|
"because the db bucket doesn't exist.")
|
|
}
|
|
|
|
var outBuf bytes.Buffer
|
|
if err := writeOutpoint(&outBuf, key); err != nil {
|
|
return err
|
|
}
|
|
|
|
return retBucket.Delete(outBuf.Bytes())
|
|
})
|
|
}
|
|
|
|
// ForAll iterates through all stored retributions and executes the passed
|
|
// callback function on each retribution.
|
|
func (rs *retributionStore) ForAll(cb func(*retributionInfo) error) error {
|
|
return rs.db.View(func(tx *bolt.Tx) error {
|
|
// If the bucket does not exist, then there are no pending
|
|
// retributions.
|
|
retBucket := tx.Bucket(retributionBucket)
|
|
if retBucket == nil {
|
|
return nil
|
|
}
|
|
|
|
// Otherwise, we fetch each serialized retribution info,
|
|
// deserialize it, and execute the passed in callback function
|
|
// on it.
|
|
return retBucket.ForEach(func(outBytes, retBytes []byte) error {
|
|
ret := &retributionInfo{}
|
|
if err := ret.Decode(
|
|
bytes.NewBuffer(retBytes),
|
|
); err != nil {
|
|
return err
|
|
}
|
|
|
|
return cb(ret)
|
|
})
|
|
})
|
|
}
|
|
|
|
// Encode serializes the retribution into the passed byte stream.
|
|
func (ret *retributionInfo) Encode(w io.Writer) error {
|
|
var scratch [8]byte
|
|
|
|
if _, err := w.Write(ret.commitHash[:]); err != nil {
|
|
return err
|
|
}
|
|
|
|
if err := writeOutpoint(w, &ret.chanPoint); err != nil {
|
|
return err
|
|
}
|
|
|
|
if _, err := w.Write(
|
|
ret.remoteIdentity.SerializeCompressed()); err != nil {
|
|
return err
|
|
}
|
|
|
|
binary.BigEndian.PutUint64(scratch[:8], uint64(ret.capacity))
|
|
if _, err := w.Write(scratch[:8]); err != nil {
|
|
return err
|
|
}
|
|
|
|
binary.BigEndian.PutUint64(scratch[:8], uint64(ret.settledBalance))
|
|
if _, err := w.Write(scratch[:8]); err != nil {
|
|
return err
|
|
}
|
|
|
|
if err := ret.selfOutput.Encode(w); err != nil {
|
|
return err
|
|
}
|
|
|
|
if err := ret.revokedOutput.Encode(w); err != nil {
|
|
return err
|
|
}
|
|
|
|
numHtlcOutputs := len(ret.htlcOutputs)
|
|
if err := wire.WriteVarInt(w, 0, uint64(numHtlcOutputs)); err != nil {
|
|
return err
|
|
}
|
|
|
|
for i := 0; i < numHtlcOutputs; i++ {
|
|
if err := ret.htlcOutputs[i].Encode(w); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// Dencode deserializes a retribution from the passed byte stream.
|
|
func (ret *retributionInfo) Decode(r io.Reader) error {
|
|
var scratch [33]byte
|
|
|
|
if _, err := io.ReadFull(r, scratch[:32]); err != nil {
|
|
return err
|
|
}
|
|
hash, err := chainhash.NewHash(scratch[:32])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
ret.commitHash = *hash
|
|
|
|
if err := readOutpoint(r, &ret.chanPoint); err != nil {
|
|
return err
|
|
}
|
|
|
|
if _, err = io.ReadFull(r, scratch[:33]); err != nil {
|
|
return err
|
|
}
|
|
remoteIdentity, err := btcec.ParsePubKey(scratch[:33], btcec.S256())
|
|
if err != nil {
|
|
return err
|
|
}
|
|
ret.remoteIdentity = remoteIdentity
|
|
|
|
if _, err := io.ReadFull(r, scratch[:8]); err != nil {
|
|
return err
|
|
}
|
|
ret.capacity = btcutil.Amount(binary.BigEndian.Uint64(scratch[:8]))
|
|
|
|
if _, err := io.ReadFull(r, scratch[:8]); err != nil {
|
|
return err
|
|
}
|
|
ret.settledBalance = btcutil.Amount(
|
|
binary.BigEndian.Uint64(scratch[:8]))
|
|
|
|
ret.selfOutput = &breachedOutput{}
|
|
if err := ret.selfOutput.Decode(r); err != nil {
|
|
return err
|
|
}
|
|
|
|
ret.revokedOutput = &breachedOutput{}
|
|
if err := ret.revokedOutput.Decode(r); err != nil {
|
|
return err
|
|
}
|
|
|
|
numHtlcOutputsU64, err := wire.ReadVarInt(r, 0)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
numHtlcOutputs := int(numHtlcOutputsU64)
|
|
|
|
ret.htlcOutputs = make([]*breachedOutput, numHtlcOutputs)
|
|
for i := range ret.htlcOutputs {
|
|
ret.htlcOutputs[i] = &breachedOutput{}
|
|
if err := ret.htlcOutputs[i].Decode(r); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// Encode serializes a breachedOutput into the passed byte stream.
|
|
func (bo *breachedOutput) Encode(w io.Writer) error {
|
|
var scratch [8]byte
|
|
|
|
binary.BigEndian.PutUint64(scratch[:8], uint64(bo.amt))
|
|
if _, err := w.Write(scratch[:8]); err != nil {
|
|
return err
|
|
}
|
|
|
|
if err := writeOutpoint(w, &bo.outpoint); err != nil {
|
|
return err
|
|
}
|
|
|
|
if err := lnwallet.WriteSignDescriptor(w, &bo.signDesc); err != nil {
|
|
return err
|
|
}
|
|
|
|
binary.BigEndian.PutUint16(scratch[:2], uint16(bo.witnessType))
|
|
if _, err := w.Write(scratch[:2]); err != nil {
|
|
return err
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// Decode deserializes a breachedOutput from the passed byte stream.
|
|
func (bo *breachedOutput) Decode(r io.Reader) error {
|
|
var scratch [8]byte
|
|
|
|
if _, err := io.ReadFull(r, scratch[:8]); err != nil {
|
|
return err
|
|
}
|
|
bo.amt = btcutil.Amount(binary.BigEndian.Uint64(scratch[:8]))
|
|
|
|
if err := readOutpoint(r, &bo.outpoint); err != nil {
|
|
return err
|
|
}
|
|
|
|
if err := lnwallet.ReadSignDescriptor(r, &bo.signDesc); err != nil {
|
|
return err
|
|
}
|
|
|
|
if _, err := io.ReadFull(r, scratch[:2]); err != nil {
|
|
return err
|
|
}
|
|
bo.witnessType = lnwallet.WitnessType(
|
|
binary.BigEndian.Uint16(scratch[:2]))
|
|
|
|
return nil
|
|
}
|