lnd.xprv/channeldb/channel.go
Johan T. Halseth 743ea7be74
contractcourt/chain_watcher: handleKnownRemoteState
Similar to what we did for the local state handling, we extract handling
all known remote states we can act on (breach, current, pending state)
into its own method.

Since we want to handle the case where we lost state (both in case of
local and remote close) last, we don't rely on the remote state number
to check which commit we are looking at, but match on TXIDs directly.
2020-12-03 08:01:08 +01:00

3504 lines
110 KiB
Go

package channeldb
import (
"bytes"
"crypto/sha256"
"encoding/binary"
"errors"
"fmt"
"io"
"net"
"strconv"
"strings"
"sync"
"github.com/btcsuite/btcd/btcec"
"github.com/btcsuite/btcd/chaincfg/chainhash"
"github.com/btcsuite/btcd/wire"
"github.com/btcsuite/btcutil"
"github.com/lightningnetwork/lnd/channeldb/kvdb"
"github.com/lightningnetwork/lnd/input"
"github.com/lightningnetwork/lnd/keychain"
"github.com/lightningnetwork/lnd/lnwire"
"github.com/lightningnetwork/lnd/shachain"
)
const (
// AbsoluteThawHeightThreshold is the threshold at which a thaw height
// begins to be interpreted as an absolute block height, rather than a
// relative one.
AbsoluteThawHeightThreshold uint32 = 500000
)
var (
// closedChannelBucket stores summarization information concerning
// previously open, but now closed channels.
closedChannelBucket = []byte("closed-chan-bucket")
// openChanBucket stores all the currently open channels. This bucket
// has a second, nested bucket which is keyed by a node's ID. Within
// that node ID bucket, all attributes required to track, update, and
// close a channel are stored.
//
// openChan -> nodeID -> chanPoint
//
// TODO(roasbeef): flesh out comment
openChannelBucket = []byte("open-chan-bucket")
// historicalChannelBucket stores all channels that have seen their
// commitment tx confirm. All information from their previous open state
// is retained.
historicalChannelBucket = []byte("historical-chan-bucket")
// chanInfoKey can be accessed within the bucket for a channel
// (identified by its chanPoint). This key stores all the static
// information for a channel which is decided at the end of the
// funding flow.
chanInfoKey = []byte("chan-info-key")
// localUpfrontShutdownKey can be accessed within the bucket for a channel
// (identified by its chanPoint). This key stores an optional upfront
// shutdown script for the local peer.
localUpfrontShutdownKey = []byte("local-upfront-shutdown-key")
// remoteUpfrontShutdownKey can be accessed within the bucket for a channel
// (identified by its chanPoint). This key stores an optional upfront
// shutdown script for the remote peer.
remoteUpfrontShutdownKey = []byte("remote-upfront-shutdown-key")
// chanCommitmentKey can be accessed within the sub-bucket for a
// particular channel. This key stores the up to date commitment state
// for a particular channel party. Appending a 0 to the end of this key
// indicates it's the commitment for the local party, and appending a 1
// to the end of this key indicates it's the commitment for the remote
// party.
chanCommitmentKey = []byte("chan-commitment-key")
// unsignedAckedUpdatesKey is an entry in the channel bucket that
// contains the remote updates that we have acked, but not yet signed
// for in one of our remote commits.
unsignedAckedUpdatesKey = []byte("unsigned-acked-updates-key")
// remoteUnsignedLocalUpdatesKey is an entry in the channel bucket that
// contains the local updates that the remote party has acked, but
// has not yet signed for in one of their local commits.
remoteUnsignedLocalUpdatesKey = []byte("remote-unsigned-local-updates-key")
// revocationStateKey stores their current revocation hash, our
// preimage producer and their preimage store.
revocationStateKey = []byte("revocation-state-key")
// dataLossCommitPointKey stores the commitment point received from the
// remote peer during a channel sync in case we have lost channel state.
dataLossCommitPointKey = []byte("data-loss-commit-point-key")
// forceCloseTxKey points to a the unilateral closing tx that we
// broadcasted when moving the channel to state CommitBroadcasted.
forceCloseTxKey = []byte("closing-tx-key")
// coopCloseTxKey points to a the cooperative closing tx that we
// broadcasted when moving the channel to state CoopBroadcasted.
coopCloseTxKey = []byte("coop-closing-tx-key")
// commitDiffKey stores the current pending commitment state we've
// extended to the remote party (if any). Each time we propose a new
// state, we store the information necessary to reconstruct this state
// from the prior commitment. This allows us to resync the remote party
// to their expected state in the case of message loss.
//
// TODO(roasbeef): rename to commit chain?
commitDiffKey = []byte("commit-diff-key")
// revocationLogBucket is dedicated for storing the necessary delta
// state between channel updates required to re-construct a past state
// in order to punish a counterparty attempting a non-cooperative
// channel closure. This key should be accessed from within the
// sub-bucket of a target channel, identified by its channel point.
revocationLogBucket = []byte("revocation-log-key")
// frozenChanKey is the key where we store the information for any
// active "frozen" channels. This key is present only in the leaf
// bucket for a given channel.
frozenChanKey = []byte("frozen-chans")
)
var (
// ErrNoCommitmentsFound is returned when a channel has not set
// commitment states.
ErrNoCommitmentsFound = fmt.Errorf("no commitments found")
// ErrNoChanInfoFound is returned when a particular channel does not
// have any channels state.
ErrNoChanInfoFound = fmt.Errorf("no chan info found")
// ErrNoRevocationsFound is returned when revocation state for a
// particular channel cannot be found.
ErrNoRevocationsFound = fmt.Errorf("no revocations found")
// ErrNoPendingCommit is returned when there is not a pending
// commitment for a remote party. A new commitment is written to disk
// each time we write a new state in order to be properly fault
// tolerant.
ErrNoPendingCommit = fmt.Errorf("no pending commits found")
// ErrInvalidCircuitKeyLen signals that a circuit key could not be
// decoded because the byte slice is of an invalid length.
ErrInvalidCircuitKeyLen = fmt.Errorf(
"length of serialized circuit key must be 16 bytes")
// ErrNoCommitPoint is returned when no data loss commit point is found
// in the database.
ErrNoCommitPoint = fmt.Errorf("no commit point found")
// ErrNoCloseTx is returned when no closing tx is found for a channel
// in the state CommitBroadcasted.
ErrNoCloseTx = fmt.Errorf("no closing tx found")
// ErrNoRestoredChannelMutation is returned when a caller attempts to
// mutate a channel that's been recovered.
ErrNoRestoredChannelMutation = fmt.Errorf("cannot mutate restored " +
"channel state")
// ErrChanBorked is returned when a caller attempts to mutate a borked
// channel.
ErrChanBorked = fmt.Errorf("cannot mutate borked channel")
// ErrLogEntryNotFound is returned when we cannot find a log entry at
// the height requested in the revocation log.
ErrLogEntryNotFound = fmt.Errorf("log entry not found")
// errHeightNotFound is returned when a query for channel balances at
// a height that we have not reached yet is made.
errHeightNotReached = fmt.Errorf("height requested greater than " +
"current commit height")
)
// ChannelType is an enum-like type that describes one of several possible
// channel types. Each open channel is associated with a particular type as the
// channel type may determine how higher level operations are conducted such as
// fee negotiation, channel closing, the format of HTLCs, etc. Structure-wise,
// a ChannelType is a bit field, with each bit denoting a modification from the
// base channel type of single funder.
type ChannelType uint8
const (
// NOTE: iota isn't used here for this enum needs to be stable
// long-term as it will be persisted to the database.
// SingleFunderBit represents a channel wherein one party solely funds
// the entire capacity of the channel.
SingleFunderBit ChannelType = 0
// DualFunderBit represents a channel wherein both parties contribute
// funds towards the total capacity of the channel. The channel may be
// funded symmetrically or asymmetrically.
DualFunderBit ChannelType = 1 << 0
// SingleFunderTweakless is similar to the basic SingleFunder channel
// type, but it omits the tweak for one's key in the commitment
// transaction of the remote party.
SingleFunderTweaklessBit ChannelType = 1 << 1
// NoFundingTxBit denotes if we have the funding transaction locally on
// disk. This bit may be on if the funding transaction was crafted by a
// wallet external to the primary daemon.
NoFundingTxBit ChannelType = 1 << 2
// AnchorOutputsBit indicates that the channel makes use of anchor
// outputs to bump the commitment transaction's effective feerate. This
// channel type also uses a delayed to_remote output script.
AnchorOutputsBit ChannelType = 1 << 3
// FrozenBit indicates that the channel is a frozen channel, meaning
// that only the responder can decide to cooperatively close the
// channel.
FrozenBit ChannelType = 1 << 4
)
// IsSingleFunder returns true if the channel type if one of the known single
// funder variants.
func (c ChannelType) IsSingleFunder() bool {
return c&DualFunderBit == 0
}
// IsDualFunder returns true if the ChannelType has the DualFunderBit set.
func (c ChannelType) IsDualFunder() bool {
return c&DualFunderBit == DualFunderBit
}
// IsTweakless returns true if the target channel uses a commitment that
// doesn't tweak the key for the remote party.
func (c ChannelType) IsTweakless() bool {
return c&SingleFunderTweaklessBit == SingleFunderTweaklessBit
}
// HasFundingTx returns true if this channel type is one that has a funding
// transaction stored locally.
func (c ChannelType) HasFundingTx() bool {
return c&NoFundingTxBit == 0
}
// HasAnchors returns true if this channel type has anchor ouputs on its
// commitment.
func (c ChannelType) HasAnchors() bool {
return c&AnchorOutputsBit == AnchorOutputsBit
}
// IsFrozen returns true if the channel is considered to be "frozen". A frozen
// channel means that only the responder can initiate a cooperative channel
// closure.
func (c ChannelType) IsFrozen() bool {
return c&FrozenBit == FrozenBit
}
// ChannelConstraints represents a set of constraints meant to allow a node to
// limit their exposure, enact flow control and ensure that all HTLCs are
// economically relevant. This struct will be mirrored for both sides of the
// channel, as each side will enforce various constraints that MUST be adhered
// to for the life time of the channel. The parameters for each of these
// constraints are static for the duration of the channel, meaning the channel
// must be torn down for them to change.
type ChannelConstraints struct {
// DustLimit is the threshold (in satoshis) below which any outputs
// should be trimmed. When an output is trimmed, it isn't materialized
// as an actual output, but is instead burned to miner's fees.
DustLimit btcutil.Amount
// ChanReserve is an absolute reservation on the channel for the
// owner of this set of constraints. This means that the current
// settled balance for this node CANNOT dip below the reservation
// amount. This acts as a defense against costless attacks when
// either side no longer has any skin in the game.
ChanReserve btcutil.Amount
// MaxPendingAmount is the maximum pending HTLC value that the
// owner of these constraints can offer the remote node at a
// particular time.
MaxPendingAmount lnwire.MilliSatoshi
// MinHTLC is the minimum HTLC value that the owner of these
// constraints can offer the remote node. If any HTLCs below this
// amount are offered, then the HTLC will be rejected. This, in
// tandem with the dust limit allows a node to regulate the
// smallest HTLC that it deems economically relevant.
MinHTLC lnwire.MilliSatoshi
// MaxAcceptedHtlcs is the maximum number of HTLCs that the owner of
// this set of constraints can offer the remote node. This allows each
// node to limit their over all exposure to HTLCs that may need to be
// acted upon in the case of a unilateral channel closure or a contract
// breach.
MaxAcceptedHtlcs uint16
// CsvDelay is the relative time lock delay expressed in blocks. Any
// settled outputs that pay to the owner of this channel configuration
// MUST ensure that the delay branch uses this value as the relative
// time lock. Similarly, any HTLC's offered by this node should use
// this value as well.
CsvDelay uint16
}
// ChannelConfig is a struct that houses the various configuration opens for
// channels. Each side maintains an instance of this configuration file as it
// governs: how the funding and commitment transaction to be created, the
// nature of HTLC's allotted, the keys to be used for delivery, and relative
// time lock parameters.
type ChannelConfig struct {
// ChannelConstraints is the set of constraints that must be upheld for
// the duration of the channel for the owner of this channel
// configuration. Constraints govern a number of flow control related
// parameters, also including the smallest HTLC that will be accepted
// by a participant.
ChannelConstraints
// MultiSigKey is the key to be used within the 2-of-2 output script
// for the owner of this channel config.
MultiSigKey keychain.KeyDescriptor
// RevocationBasePoint is the base public key to be used when deriving
// revocation keys for the remote node's commitment transaction. This
// will be combined along with a per commitment secret to derive a
// unique revocation key for each state.
RevocationBasePoint keychain.KeyDescriptor
// PaymentBasePoint is the base public key to be used when deriving
// the key used within the non-delayed pay-to-self output on the
// commitment transaction for a node. This will be combined with a
// tweak derived from the per-commitment point to ensure unique keys
// for each commitment transaction.
PaymentBasePoint keychain.KeyDescriptor
// DelayBasePoint is the base public key to be used when deriving the
// key used within the delayed pay-to-self output on the commitment
// transaction for a node. This will be combined with a tweak derived
// from the per-commitment point to ensure unique keys for each
// commitment transaction.
DelayBasePoint keychain.KeyDescriptor
// HtlcBasePoint is the base public key to be used when deriving the
// local HTLC key. The derived key (combined with the tweak derived
// from the per-commitment point) is used within the "to self" clause
// within any HTLC output scripts.
HtlcBasePoint keychain.KeyDescriptor
}
// ChannelCommitment is a snapshot of the commitment state at a particular
// point in the commitment chain. With each state transition, a snapshot of the
// current state along with all non-settled HTLCs are recorded. These snapshots
// detail the state of the _remote_ party's commitment at a particular state
// number. For ourselves (the local node) we ONLY store our most recent
// (unrevoked) state for safety purposes.
type ChannelCommitment struct {
// CommitHeight is the update number that this ChannelDelta represents
// the total number of commitment updates to this point. This can be
// viewed as sort of a "commitment height" as this number is
// monotonically increasing.
CommitHeight uint64
// LocalLogIndex is the cumulative log index index of the local node at
// this point in the commitment chain. This value will be incremented
// for each _update_ added to the local update log.
LocalLogIndex uint64
// LocalHtlcIndex is the current local running HTLC index. This value
// will be incremented for each outgoing HTLC the local node offers.
LocalHtlcIndex uint64
// RemoteLogIndex is the cumulative log index index of the remote node
// at this point in the commitment chain. This value will be
// incremented for each _update_ added to the remote update log.
RemoteLogIndex uint64
// RemoteHtlcIndex is the current remote running HTLC index. This value
// will be incremented for each outgoing HTLC the remote node offers.
RemoteHtlcIndex uint64
// LocalBalance is the current available settled balance within the
// channel directly spendable by us.
//
// NOTE: This is the balance *after* subtracting any commitment fee,
// AND anchor output values.
LocalBalance lnwire.MilliSatoshi
// RemoteBalance is the current available settled balance within the
// channel directly spendable by the remote node.
//
// NOTE: This is the balance *after* subtracting any commitment fee,
// AND anchor output values.
RemoteBalance lnwire.MilliSatoshi
// CommitFee is the amount calculated to be paid in fees for the
// current set of commitment transactions. The fee amount is persisted
// with the channel in order to allow the fee amount to be removed and
// recalculated with each channel state update, including updates that
// happen after a system restart.
CommitFee btcutil.Amount
// FeePerKw is the min satoshis/kilo-weight that should be paid within
// the commitment transaction for the entire duration of the channel's
// lifetime. This field may be updated during normal operation of the
// channel as on-chain conditions change.
//
// TODO(halseth): make this SatPerKWeight. Cannot be done atm because
// this will cause the import cycle lnwallet<->channeldb. Fee
// estimation stuff should be in its own package.
FeePerKw btcutil.Amount
// CommitTx is the latest version of the commitment state, broadcast
// able by us.
CommitTx *wire.MsgTx
// CommitSig is one half of the signature required to fully complete
// the script for the commitment transaction above. This is the
// signature signed by the remote party for our version of the
// commitment transactions.
CommitSig []byte
// Htlcs is the set of HTLC's that are pending at this particular
// commitment height.
Htlcs []HTLC
// TODO(roasbeef): pending commit pointer?
// * lets just walk through
}
// ChannelStatus is a bit vector used to indicate whether an OpenChannel is in
// the default usable state, or a state where it shouldn't be used.
type ChannelStatus uint8
var (
// ChanStatusDefault is the normal state of an open channel.
ChanStatusDefault ChannelStatus
// ChanStatusBorked indicates that the channel has entered an
// irreconcilable state, triggered by a state desynchronization or
// channel breach. Channels in this state should never be added to the
// htlc switch.
ChanStatusBorked ChannelStatus = 1
// ChanStatusCommitBroadcasted indicates that a commitment for this
// channel has been broadcasted.
ChanStatusCommitBroadcasted ChannelStatus = 1 << 1
// ChanStatusLocalDataLoss indicates that we have lost channel state
// for this channel, and broadcasting our latest commitment might be
// considered a breach.
//
// TODO(halseh): actually enforce that we are not force closing such a
// channel.
ChanStatusLocalDataLoss ChannelStatus = 1 << 2
// ChanStatusRestored is a status flag that signals that the channel
// has been restored, and doesn't have all the fields a typical channel
// will have.
ChanStatusRestored ChannelStatus = 1 << 3
// ChanStatusCoopBroadcasted indicates that a cooperative close for
// this channel has been broadcasted. Older cooperatively closed
// channels will only have this status set. Newer ones will also have
// close initiator information stored using the local/remote initiator
// status. This status is set in conjunction with the initiator status
// so that we do not need to check multiple channel statues for
// cooperative closes.
ChanStatusCoopBroadcasted ChannelStatus = 1 << 4
// ChanStatusLocalCloseInitiator indicates that we initiated closing
// the channel.
ChanStatusLocalCloseInitiator ChannelStatus = 1 << 5
// ChanStatusRemoteCloseInitiator indicates that the remote node
// initiated closing the channel.
ChanStatusRemoteCloseInitiator ChannelStatus = 1 << 6
)
// chanStatusStrings maps a ChannelStatus to a human friendly string that
// describes that status.
var chanStatusStrings = map[ChannelStatus]string{
ChanStatusDefault: "ChanStatusDefault",
ChanStatusBorked: "ChanStatusBorked",
ChanStatusCommitBroadcasted: "ChanStatusCommitBroadcasted",
ChanStatusLocalDataLoss: "ChanStatusLocalDataLoss",
ChanStatusRestored: "ChanStatusRestored",
ChanStatusCoopBroadcasted: "ChanStatusCoopBroadcasted",
ChanStatusLocalCloseInitiator: "ChanStatusLocalCloseInitiator",
ChanStatusRemoteCloseInitiator: "ChanStatusRemoteCloseInitiator",
}
// orderedChanStatusFlags is an in-order list of all that channel status flags.
var orderedChanStatusFlags = []ChannelStatus{
ChanStatusBorked,
ChanStatusCommitBroadcasted,
ChanStatusLocalDataLoss,
ChanStatusRestored,
ChanStatusCoopBroadcasted,
ChanStatusLocalCloseInitiator,
ChanStatusRemoteCloseInitiator,
}
// String returns a human-readable representation of the ChannelStatus.
func (c ChannelStatus) String() string {
// If no flags are set, then this is the default case.
if c == ChanStatusDefault {
return chanStatusStrings[ChanStatusDefault]
}
// Add individual bit flags.
statusStr := ""
for _, flag := range orderedChanStatusFlags {
if c&flag == flag {
statusStr += chanStatusStrings[flag] + "|"
c -= flag
}
}
// Remove anything to the right of the final bar, including it as well.
statusStr = strings.TrimRight(statusStr, "|")
// Add any remaining flags which aren't accounted for as hex.
if c != 0 {
statusStr += "|0x" + strconv.FormatUint(uint64(c), 16)
}
// If this was purely an unknown flag, then remove the extra bar at the
// start of the string.
statusStr = strings.TrimLeft(statusStr, "|")
return statusStr
}
// OpenChannel encapsulates the persistent and dynamic state of an open channel
// with a remote node. An open channel supports several options for on-disk
// serialization depending on the exact context. Full (upon channel creation)
// state commitments, and partial (due to a commitment update) writes are
// supported. Each partial write due to a state update appends the new update
// to an on-disk log, which can then subsequently be queried in order to
// "time-travel" to a prior state.
type OpenChannel struct {
// ChanType denotes which type of channel this is.
ChanType ChannelType
// ChainHash is a hash which represents the blockchain that this
// channel will be opened within. This value is typically the genesis
// hash. In the case that the original chain went through a contentious
// hard-fork, then this value will be tweaked using the unique fork
// point on each branch.
ChainHash chainhash.Hash
// FundingOutpoint is the outpoint of the final funding transaction.
// This value uniquely and globally identifies the channel within the
// target blockchain as specified by the chain hash parameter.
FundingOutpoint wire.OutPoint
// ShortChannelID encodes the exact location in the chain in which the
// channel was initially confirmed. This includes: the block height,
// transaction index, and the output within the target transaction.
ShortChannelID lnwire.ShortChannelID
// IsPending indicates whether a channel's funding transaction has been
// confirmed.
IsPending bool
// IsInitiator is a bool which indicates if we were the original
// initiator for the channel. This value may affect how higher levels
// negotiate fees, or close the channel.
IsInitiator bool
// chanStatus is the current status of this channel. If it is not in
// the state Default, it should not be used for forwarding payments.
chanStatus ChannelStatus
// FundingBroadcastHeight is the height in which the funding
// transaction was broadcast. This value can be used by higher level
// sub-systems to determine if a channel is stale and/or should have
// been confirmed before a certain height.
FundingBroadcastHeight uint32
// NumConfsRequired is the number of confirmations a channel's funding
// transaction must have received in order to be considered available
// for normal transactional use.
NumConfsRequired uint16
// ChannelFlags holds the flags that were sent as part of the
// open_channel message.
ChannelFlags lnwire.FundingFlag
// IdentityPub is the identity public key of the remote node this
// channel has been established with.
IdentityPub *btcec.PublicKey
// Capacity is the total capacity of this channel.
Capacity btcutil.Amount
// TotalMSatSent is the total number of milli-satoshis we've sent
// within this channel.
TotalMSatSent lnwire.MilliSatoshi
// TotalMSatReceived is the total number of milli-satoshis we've
// received within this channel.
TotalMSatReceived lnwire.MilliSatoshi
// LocalChanCfg is the channel configuration for the local node.
LocalChanCfg ChannelConfig
// RemoteChanCfg is the channel configuration for the remote node.
RemoteChanCfg ChannelConfig
// LocalCommitment is the current local commitment state for the local
// party. This is stored distinct from the state of the remote party
// as there are certain asymmetric parameters which affect the
// structure of each commitment.
LocalCommitment ChannelCommitment
// RemoteCommitment is the current remote commitment state for the
// remote party. This is stored distinct from the state of the local
// party as there are certain asymmetric parameters which affect the
// structure of each commitment.
RemoteCommitment ChannelCommitment
// RemoteCurrentRevocation is the current revocation for their
// commitment transaction. However, since this the derived public key,
// we don't yet have the private key so we aren't yet able to verify
// that it's actually in the hash chain.
RemoteCurrentRevocation *btcec.PublicKey
// RemoteNextRevocation is the revocation key to be used for the *next*
// commitment transaction we create for the local node. Within the
// specification, this value is referred to as the
// per-commitment-point.
RemoteNextRevocation *btcec.PublicKey
// RevocationProducer is used to generate the revocation in such a way
// that remote side might store it efficiently and have the ability to
// restore the revocation by index if needed. Current implementation of
// secret producer is shachain producer.
RevocationProducer shachain.Producer
// RevocationStore is used to efficiently store the revocations for
// previous channels states sent to us by remote side. Current
// implementation of secret store is shachain store.
RevocationStore shachain.Store
// Packager is used to create and update forwarding packages for this
// channel, which encodes all necessary information to recover from
// failures and reforward HTLCs that were not fully processed.
Packager FwdPackager
// FundingTxn is the transaction containing this channel's funding
// outpoint. Upon restarts, this txn will be rebroadcast if the channel
// is found to be pending.
//
// NOTE: This value will only be populated for single-funder channels
// for which we are the initiator, and that we also have the funding
// transaction for. One can check this by using the HasFundingTx()
// method on the ChanType field.
FundingTxn *wire.MsgTx
// LocalShutdownScript is set to a pre-set script if the channel was opened
// by the local node with option_upfront_shutdown_script set. If the option
// was not set, the field is empty.
LocalShutdownScript lnwire.DeliveryAddress
// RemoteShutdownScript is set to a pre-set script if the channel was opened
// by the remote node with option_upfront_shutdown_script set. If the option
// was not set, the field is empty.
RemoteShutdownScript lnwire.DeliveryAddress
// ThawHeight is the height when a frozen channel once again becomes a
// normal channel. If this is zero, then there're no restrictions on
// this channel. If the value is lower than 500,000, then it's
// interpreted as a relative height, or an absolute height otherwise.
ThawHeight uint32
// TODO(roasbeef): eww
Db *DB
// TODO(roasbeef): just need to store local and remote HTLC's?
sync.RWMutex
}
// ShortChanID returns the current ShortChannelID of this channel.
func (c *OpenChannel) ShortChanID() lnwire.ShortChannelID {
c.RLock()
defer c.RUnlock()
return c.ShortChannelID
}
// ChanStatus returns the current ChannelStatus of this channel.
func (c *OpenChannel) ChanStatus() ChannelStatus {
c.RLock()
defer c.RUnlock()
return c.chanStatus
}
// ApplyChanStatus allows the caller to modify the internal channel state in a
// thead-safe manner.
func (c *OpenChannel) ApplyChanStatus(status ChannelStatus) error {
c.Lock()
defer c.Unlock()
return c.putChanStatus(status)
}
// ClearChanStatus allows the caller to clear a particular channel status from
// the primary channel status bit field. After this method returns, a call to
// HasChanStatus(status) should return false.
func (c *OpenChannel) ClearChanStatus(status ChannelStatus) error {
c.Lock()
defer c.Unlock()
return c.clearChanStatus(status)
}
// HasChanStatus returns true if the internal bitfield channel status of the
// target channel has the specified status bit set.
func (c *OpenChannel) HasChanStatus(status ChannelStatus) bool {
c.RLock()
defer c.RUnlock()
return c.hasChanStatus(status)
}
func (c *OpenChannel) hasChanStatus(status ChannelStatus) bool {
// Special case ChanStatusDefualt since it isn't actually flag, but a
// particular combination (or lack-there-of) of flags.
if status == ChanStatusDefault {
return c.chanStatus == ChanStatusDefault
}
return c.chanStatus&status == status
}
// RefreshShortChanID updates the in-memory channel state using the latest
// value observed on disk.
//
// TODO: the name of this function should be changed to reflect the fact that
// it is not only refreshing the short channel id but all the channel state.
// maybe Refresh/Reload?
func (c *OpenChannel) RefreshShortChanID() error {
c.Lock()
defer c.Unlock()
err := kvdb.View(c.Db, func(tx kvdb.RTx) error {
chanBucket, err := fetchChanBucket(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
if err != nil {
return err
}
// We'll re-populating the in-memory channel with the info
// fetched from disk.
if err := fetchChanInfo(chanBucket, c); err != nil {
return fmt.Errorf("unable to fetch chan info: %v", err)
}
return nil
}, func() {})
if err != nil {
return err
}
return nil
}
// fetchChanBucket is a helper function that returns the bucket where a
// channel's data resides in given: the public key for the node, the outpoint,
// and the chainhash that the channel resides on.
func fetchChanBucket(tx kvdb.RTx, nodeKey *btcec.PublicKey,
outPoint *wire.OutPoint, chainHash chainhash.Hash) (kvdb.RBucket, error) {
// First fetch the top level bucket which stores all data related to
// current, active channels.
openChanBucket := tx.ReadBucket(openChannelBucket)
if openChanBucket == nil {
return nil, ErrNoChanDBExists
}
// TODO(roasbeef): CreateTopLevelBucket on the interface isn't like
// CreateIfNotExists, will return error
// Within this top level bucket, fetch the bucket dedicated to storing
// open channel data specific to the remote node.
nodePub := nodeKey.SerializeCompressed()
nodeChanBucket := openChanBucket.NestedReadBucket(nodePub)
if nodeChanBucket == nil {
return nil, ErrNoActiveChannels
}
// We'll then recurse down an additional layer in order to fetch the
// bucket for this particular chain.
chainBucket := nodeChanBucket.NestedReadBucket(chainHash[:])
if chainBucket == nil {
return nil, ErrNoActiveChannels
}
// With the bucket for the node and chain fetched, we can now go down
// another level, for this channel itself.
var chanPointBuf bytes.Buffer
if err := writeOutpoint(&chanPointBuf, outPoint); err != nil {
return nil, err
}
chanBucket := chainBucket.NestedReadBucket(chanPointBuf.Bytes())
if chanBucket == nil {
return nil, ErrChannelNotFound
}
return chanBucket, nil
}
// fetchChanBucketRw is a helper function that returns the bucket where a
// channel's data resides in given: the public key for the node, the outpoint,
// and the chainhash that the channel resides on. This differs from
// fetchChanBucket in that it returns a writeable bucket.
func fetchChanBucketRw(tx kvdb.RwTx, nodeKey *btcec.PublicKey, // nolint:interfacer
outPoint *wire.OutPoint, chainHash chainhash.Hash) (kvdb.RwBucket, error) {
readBucket, err := fetchChanBucket(tx, nodeKey, outPoint, chainHash)
if err != nil {
return nil, err
}
return readBucket.(kvdb.RwBucket), nil
}
// fullSync syncs the contents of an OpenChannel while re-using an existing
// database transaction.
func (c *OpenChannel) fullSync(tx kvdb.RwTx) error {
// First fetch the top level bucket which stores all data related to
// current, active channels.
openChanBucket, err := tx.CreateTopLevelBucket(openChannelBucket)
if err != nil {
return err
}
// Within this top level bucket, fetch the bucket dedicated to storing
// open channel data specific to the remote node.
nodePub := c.IdentityPub.SerializeCompressed()
nodeChanBucket, err := openChanBucket.CreateBucketIfNotExists(nodePub)
if err != nil {
return err
}
// We'll then recurse down an additional layer in order to fetch the
// bucket for this particular chain.
chainBucket, err := nodeChanBucket.CreateBucketIfNotExists(c.ChainHash[:])
if err != nil {
return err
}
// With the bucket for the node fetched, we can now go down another
// level, creating the bucket for this channel itself.
var chanPointBuf bytes.Buffer
if err := writeOutpoint(&chanPointBuf, &c.FundingOutpoint); err != nil {
return err
}
chanBucket, err := chainBucket.CreateBucket(
chanPointBuf.Bytes(),
)
switch {
case err == kvdb.ErrBucketExists:
// If this channel already exists, then in order to avoid
// overriding it, we'll return an error back up to the caller.
return ErrChanAlreadyExists
case err != nil:
return err
}
return putOpenChannel(chanBucket, c)
}
// MarkAsOpen marks a channel as fully open given a locator that uniquely
// describes its location within the chain.
func (c *OpenChannel) MarkAsOpen(openLoc lnwire.ShortChannelID) error {
c.Lock()
defer c.Unlock()
if err := kvdb.Update(c.Db, func(tx kvdb.RwTx) error {
chanBucket, err := fetchChanBucket(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
if err != nil {
return err
}
channel, err := fetchOpenChannel(chanBucket, &c.FundingOutpoint)
if err != nil {
return err
}
channel.IsPending = false
channel.ShortChannelID = openLoc
return putOpenChannel(chanBucket.(kvdb.RwBucket), channel)
}, func() {}); err != nil {
return err
}
c.IsPending = false
c.ShortChannelID = openLoc
c.Packager = NewChannelPackager(openLoc)
return nil
}
// MarkDataLoss marks sets the channel status to LocalDataLoss and stores the
// passed commitPoint for use to retrieve funds in case the remote force closes
// the channel.
func (c *OpenChannel) MarkDataLoss(commitPoint *btcec.PublicKey) error {
c.Lock()
defer c.Unlock()
var b bytes.Buffer
if err := WriteElement(&b, commitPoint); err != nil {
return err
}
putCommitPoint := func(chanBucket kvdb.RwBucket) error {
return chanBucket.Put(dataLossCommitPointKey, b.Bytes())
}
return c.putChanStatus(ChanStatusLocalDataLoss, putCommitPoint)
}
// DataLossCommitPoint retrieves the stored commit point set during
// MarkDataLoss. If not found ErrNoCommitPoint is returned.
func (c *OpenChannel) DataLossCommitPoint() (*btcec.PublicKey, error) {
var commitPoint *btcec.PublicKey
err := kvdb.View(c.Db, func(tx kvdb.RTx) error {
chanBucket, err := fetchChanBucket(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
switch err {
case nil:
case ErrNoChanDBExists, ErrNoActiveChannels, ErrChannelNotFound:
return ErrNoCommitPoint
default:
return err
}
bs := chanBucket.Get(dataLossCommitPointKey)
if bs == nil {
return ErrNoCommitPoint
}
r := bytes.NewReader(bs)
if err := ReadElements(r, &commitPoint); err != nil {
return err
}
return nil
}, func() {
commitPoint = nil
})
if err != nil {
return nil, err
}
return commitPoint, nil
}
// MarkBorked marks the event when the channel as reached an irreconcilable
// state, such as a channel breach or state desynchronization. Borked channels
// should never be added to the switch.
func (c *OpenChannel) MarkBorked() error {
c.Lock()
defer c.Unlock()
return c.putChanStatus(ChanStatusBorked)
}
// ChanSyncMsg returns the ChannelReestablish message that should be sent upon
// reconnection with the remote peer that we're maintaining this channel with.
// The information contained within this message is necessary to re-sync our
// commitment chains in the case of a last or only partially processed message.
// When the remote party receiver this message one of three things may happen:
//
// 1. We're fully synced and no messages need to be sent.
// 2. We didn't get the last CommitSig message they sent, to they'll re-send
// it.
// 3. We didn't get the last RevokeAndAck message they sent, so they'll
// re-send it.
//
// If this is a restored channel, having status ChanStatusRestored, then we'll
// modify our typical chan sync message to ensure they force close even if
// we're on the very first state.
func (c *OpenChannel) ChanSyncMsg() (*lnwire.ChannelReestablish, error) {
c.Lock()
defer c.Unlock()
// The remote commitment height that we'll send in the
// ChannelReestablish message is our current commitment height plus
// one. If the receiver thinks that our commitment height is actually
// *equal* to this value, then they'll re-send the last commitment that
// they sent but we never fully processed.
localHeight := c.LocalCommitment.CommitHeight
nextLocalCommitHeight := localHeight + 1
// The second value we'll send is the height of the remote commitment
// from our PoV. If the receiver thinks that their height is actually
// *one plus* this value, then they'll re-send their last revocation.
remoteChainTipHeight := c.RemoteCommitment.CommitHeight
// If this channel has undergone a commitment update, then in order to
// prove to the remote party our knowledge of their prior commitment
// state, we'll also send over the last commitment secret that the
// remote party sent.
var lastCommitSecret [32]byte
if remoteChainTipHeight != 0 {
remoteSecret, err := c.RevocationStore.LookUp(
remoteChainTipHeight - 1,
)
if err != nil {
return nil, err
}
lastCommitSecret = [32]byte(*remoteSecret)
}
// Additionally, we'll send over the current unrevoked commitment on
// our local commitment transaction.
currentCommitSecret, err := c.RevocationProducer.AtIndex(
localHeight,
)
if err != nil {
return nil, err
}
// If we've restored this channel, then we'll purposefully give them an
// invalid LocalUnrevokedCommitPoint so they'll force close the channel
// allowing us to sweep our funds.
if c.hasChanStatus(ChanStatusRestored) {
currentCommitSecret[0] ^= 1
// If this is a tweakless channel, then we'll purposefully send
// a next local height taht's invalid to trigger a force close
// on their end. We do this as tweakless channels don't require
// that the commitment point is valid, only that it's present.
if c.ChanType.IsTweakless() {
nextLocalCommitHeight = 0
}
}
return &lnwire.ChannelReestablish{
ChanID: lnwire.NewChanIDFromOutPoint(
&c.FundingOutpoint,
),
NextLocalCommitHeight: nextLocalCommitHeight,
RemoteCommitTailHeight: remoteChainTipHeight,
LastRemoteCommitSecret: lastCommitSecret,
LocalUnrevokedCommitPoint: input.ComputeCommitmentPoint(
currentCommitSecret[:],
),
}, nil
}
// isBorked returns true if the channel has been marked as borked in the
// database. This requires an existing database transaction to already be
// active.
//
// NOTE: The primary mutex should already be held before this method is called.
func (c *OpenChannel) isBorked(chanBucket kvdb.RBucket) (bool, error) {
channel, err := fetchOpenChannel(chanBucket, &c.FundingOutpoint)
if err != nil {
return false, err
}
return channel.chanStatus != ChanStatusDefault, nil
}
// MarkCommitmentBroadcasted marks the channel as a commitment transaction has
// been broadcast, either our own or the remote, and we should watch the chain
// for it to confirm before taking any further action. It takes as argument the
// closing tx _we believe_ will appear in the chain. This is only used to
// republish this tx at startup to ensure propagation, and we should still
// handle the case where a different tx actually hits the chain.
func (c *OpenChannel) MarkCommitmentBroadcasted(closeTx *wire.MsgTx,
locallyInitiated bool) error {
return c.markBroadcasted(
ChanStatusCommitBroadcasted, forceCloseTxKey, closeTx,
locallyInitiated,
)
}
// MarkCoopBroadcasted marks the channel to indicate that a cooperative close
// transaction has been broadcast, either our own or the remote, and that we
// should watch the chain for it to confirm before taking further action. It
// takes as argument a cooperative close tx that could appear on chain, and
// should be rebroadcast upon startup. This is only used to republish and
// ensure propagation, and we should still handle the case where a different tx
// actually hits the chain.
func (c *OpenChannel) MarkCoopBroadcasted(closeTx *wire.MsgTx,
locallyInitiated bool) error {
return c.markBroadcasted(
ChanStatusCoopBroadcasted, coopCloseTxKey, closeTx,
locallyInitiated,
)
}
// markBroadcasted is a helper function which modifies the channel status of the
// receiving channel and inserts a close transaction under the requested key,
// which should specify either a coop or force close. It adds a status which
// indicates the party that initiated the channel close.
func (c *OpenChannel) markBroadcasted(status ChannelStatus, key []byte,
closeTx *wire.MsgTx, locallyInitiated bool) error {
c.Lock()
defer c.Unlock()
// If a closing tx is provided, we'll generate a closure to write the
// transaction in the appropriate bucket under the given key.
var putClosingTx func(kvdb.RwBucket) error
if closeTx != nil {
var b bytes.Buffer
if err := WriteElement(&b, closeTx); err != nil {
return err
}
putClosingTx = func(chanBucket kvdb.RwBucket) error {
return chanBucket.Put(key, b.Bytes())
}
}
// Add the initiator status to the status provided. These statuses are
// set in addition to the broadcast status so that we do not need to
// migrate the original logic which does not store initiator.
if locallyInitiated {
status |= ChanStatusLocalCloseInitiator
} else {
status |= ChanStatusRemoteCloseInitiator
}
return c.putChanStatus(status, putClosingTx)
}
// BroadcastedCommitment retrieves the stored unilateral closing tx set during
// MarkCommitmentBroadcasted. If not found ErrNoCloseTx is returned.
func (c *OpenChannel) BroadcastedCommitment() (*wire.MsgTx, error) {
return c.getClosingTx(forceCloseTxKey)
}
// BroadcastedCooperative retrieves the stored cooperative closing tx set during
// MarkCoopBroadcasted. If not found ErrNoCloseTx is returned.
func (c *OpenChannel) BroadcastedCooperative() (*wire.MsgTx, error) {
return c.getClosingTx(coopCloseTxKey)
}
// getClosingTx is a helper method which returns the stored closing transaction
// for key. The caller should use either the force or coop closing keys.
func (c *OpenChannel) getClosingTx(key []byte) (*wire.MsgTx, error) {
var closeTx *wire.MsgTx
err := kvdb.View(c.Db, func(tx kvdb.RTx) error {
chanBucket, err := fetchChanBucket(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
switch err {
case nil:
case ErrNoChanDBExists, ErrNoActiveChannels, ErrChannelNotFound:
return ErrNoCloseTx
default:
return err
}
bs := chanBucket.Get(key)
if bs == nil {
return ErrNoCloseTx
}
r := bytes.NewReader(bs)
return ReadElement(r, &closeTx)
}, func() {
closeTx = nil
})
if err != nil {
return nil, err
}
return closeTx, nil
}
// putChanStatus appends the given status to the channel. fs is an optional
// list of closures that are given the chanBucket in order to atomically add
// extra information together with the new status.
func (c *OpenChannel) putChanStatus(status ChannelStatus,
fs ...func(kvdb.RwBucket) error) error {
if err := kvdb.Update(c.Db, func(tx kvdb.RwTx) error {
chanBucket, err := fetchChanBucketRw(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
if err != nil {
return err
}
channel, err := fetchOpenChannel(chanBucket, &c.FundingOutpoint)
if err != nil {
return err
}
// Add this status to the existing bitvector found in the DB.
status = channel.chanStatus | status
channel.chanStatus = status
if err := putOpenChannel(chanBucket, channel); err != nil {
return err
}
for _, f := range fs {
// Skip execution of nil closures.
if f == nil {
continue
}
if err := f(chanBucket); err != nil {
return err
}
}
return nil
}, func() {}); err != nil {
return err
}
// Update the in-memory representation to keep it in sync with the DB.
c.chanStatus = status
return nil
}
func (c *OpenChannel) clearChanStatus(status ChannelStatus) error {
if err := kvdb.Update(c.Db, func(tx kvdb.RwTx) error {
chanBucket, err := fetchChanBucketRw(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
if err != nil {
return err
}
channel, err := fetchOpenChannel(chanBucket, &c.FundingOutpoint)
if err != nil {
return err
}
// Unset this bit in the bitvector on disk.
status = channel.chanStatus & ^status
channel.chanStatus = status
return putOpenChannel(chanBucket, channel)
}, func() {}); err != nil {
return err
}
// Update the in-memory representation to keep it in sync with the DB.
c.chanStatus = status
return nil
}
// putChannel serializes, and stores the current state of the channel in its
// entirety.
func putOpenChannel(chanBucket kvdb.RwBucket, channel *OpenChannel) error {
// First, we'll write out all the relatively static fields, that are
// decided upon initial channel creation.
if err := putChanInfo(chanBucket, channel); err != nil {
return fmt.Errorf("unable to store chan info: %v", err)
}
// With the static channel info written out, we'll now write out the
// current commitment state for both parties.
if err := putChanCommitments(chanBucket, channel); err != nil {
return fmt.Errorf("unable to store chan commitments: %v", err)
}
// Next, if this is a frozen channel, we'll add in the axillary
// information we need to store.
if channel.ChanType.IsFrozen() {
err := storeThawHeight(
chanBucket, channel.ThawHeight,
)
if err != nil {
return fmt.Errorf("unable to store thaw height: %v", err)
}
}
// Finally, we'll write out the revocation state for both parties
// within a distinct key space.
if err := putChanRevocationState(chanBucket, channel); err != nil {
return fmt.Errorf("unable to store chan revocations: %v", err)
}
return nil
}
// fetchOpenChannel retrieves, and deserializes (including decrypting
// sensitive) the complete channel currently active with the passed nodeID.
func fetchOpenChannel(chanBucket kvdb.RBucket,
chanPoint *wire.OutPoint) (*OpenChannel, error) {
channel := &OpenChannel{
FundingOutpoint: *chanPoint,
}
// First, we'll read all the static information that changes less
// frequently from disk.
if err := fetchChanInfo(chanBucket, channel); err != nil {
return nil, fmt.Errorf("unable to fetch chan info: %v", err)
}
// With the static information read, we'll now read the current
// commitment state for both sides of the channel.
if err := fetchChanCommitments(chanBucket, channel); err != nil {
return nil, fmt.Errorf("unable to fetch chan commitments: %v", err)
}
// Next, if this is a frozen channel, we'll add in the axillary
// information we need to store.
if channel.ChanType.IsFrozen() {
thawHeight, err := fetchThawHeight(chanBucket)
if err != nil {
return nil, fmt.Errorf("unable to store thaw "+
"height: %v", err)
}
channel.ThawHeight = thawHeight
}
// Finally, we'll retrieve the current revocation state so we can
// properly
if err := fetchChanRevocationState(chanBucket, channel); err != nil {
return nil, fmt.Errorf("unable to fetch chan revocations: %v", err)
}
channel.Packager = NewChannelPackager(channel.ShortChannelID)
return channel, nil
}
// SyncPending writes the contents of the channel to the database while it's in
// the pending (waiting for funding confirmation) state. The IsPending flag
// will be set to true. When the channel's funding transaction is confirmed,
// the channel should be marked as "open" and the IsPending flag set to false.
// Note that this function also creates a LinkNode relationship between this
// newly created channel and a new LinkNode instance. This allows listing all
// channels in the database globally, or according to the LinkNode they were
// created with.
//
// TODO(roasbeef): addr param should eventually be an lnwire.NetAddress type
// that includes service bits.
func (c *OpenChannel) SyncPending(addr net.Addr, pendingHeight uint32) error {
c.Lock()
defer c.Unlock()
c.FundingBroadcastHeight = pendingHeight
return kvdb.Update(c.Db, func(tx kvdb.RwTx) error {
return syncNewChannel(tx, c, []net.Addr{addr})
}, func() {})
}
// syncNewChannel will write the passed channel to disk, and also create a
// LinkNode (if needed) for the channel peer.
func syncNewChannel(tx kvdb.RwTx, c *OpenChannel, addrs []net.Addr) error {
// First, sync all the persistent channel state to disk.
if err := c.fullSync(tx); err != nil {
return err
}
nodeInfoBucket, err := tx.CreateTopLevelBucket(nodeInfoBucket)
if err != nil {
return err
}
// If a LinkNode for this identity public key already exists,
// then we can exit early.
nodePub := c.IdentityPub.SerializeCompressed()
if nodeInfoBucket.Get(nodePub) != nil {
return nil
}
// Next, we need to establish a (possibly) new LinkNode relationship
// for this channel. The LinkNode metadata contains reachability,
// up-time, and service bits related information.
linkNode := c.Db.NewLinkNode(wire.MainNet, c.IdentityPub, addrs...)
// TODO(roasbeef): do away with link node all together?
return putLinkNode(nodeInfoBucket, linkNode)
}
// UpdateCommitment updates the local commitment state. It locks in the pending
// local updates that were received by us from the remote party. The commitment
// state completely describes the balance state at this point in the commitment
// chain. In addition to that, it persists all the remote log updates that we
// have acked, but not signed a remote commitment for yet. These need to be
// persisted to be able to produce a valid commit signature if a restart would
// occur. This method its to be called when we revoke our prior commitment
// state.
func (c *OpenChannel) UpdateCommitment(newCommitment *ChannelCommitment,
unsignedAckedUpdates []LogUpdate) error {
c.Lock()
defer c.Unlock()
// If this is a restored channel, then we want to avoid mutating the
// state as all, as it's impossible to do so in a protocol compliant
// manner.
if c.hasChanStatus(ChanStatusRestored) {
return ErrNoRestoredChannelMutation
}
err := kvdb.Update(c.Db, func(tx kvdb.RwTx) error {
chanBucket, err := fetchChanBucketRw(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
if err != nil {
return err
}
// If the channel is marked as borked, then for safety reasons,
// we shouldn't attempt any further updates.
isBorked, err := c.isBorked(chanBucket)
if err != nil {
return err
}
if isBorked {
return ErrChanBorked
}
if err = putChanInfo(chanBucket, c); err != nil {
return fmt.Errorf("unable to store chan info: %v", err)
}
// With the proper bucket fetched, we'll now write the latest
// commitment state to disk for the target party.
err = putChanCommitment(
chanBucket, newCommitment, true,
)
if err != nil {
return fmt.Errorf("unable to store chan "+
"revocations: %v", err)
}
// Persist unsigned but acked remote updates that need to be
// restored after a restart.
var b bytes.Buffer
err = serializeLogUpdates(&b, unsignedAckedUpdates)
if err != nil {
return err
}
err = chanBucket.Put(unsignedAckedUpdatesKey, b.Bytes())
if err != nil {
return fmt.Errorf("unable to store dangline remote "+
"updates: %v", err)
}
// Persist the remote unsigned local updates that are not included
// in our new commitment.
updateBytes := chanBucket.Get(remoteUnsignedLocalUpdatesKey)
if updateBytes == nil {
return nil
}
r := bytes.NewReader(updateBytes)
updates, err := deserializeLogUpdates(r)
if err != nil {
return err
}
var validUpdates []LogUpdate
for _, upd := range updates {
// Filter for updates that are not on our local
// commitment.
if upd.LogIndex >= newCommitment.LocalLogIndex {
validUpdates = append(validUpdates, upd)
}
}
var b2 bytes.Buffer
err = serializeLogUpdates(&b2, validUpdates)
if err != nil {
return fmt.Errorf("unable to serialize log updates: %v", err)
}
err = chanBucket.Put(remoteUnsignedLocalUpdatesKey, b2.Bytes())
if err != nil {
return fmt.Errorf("unable to restore chanbucket: %v", err)
}
return nil
}, func() {})
if err != nil {
return err
}
c.LocalCommitment = *newCommitment
return nil
}
// BalancesAtHeight returns the local and remote balances on our commitment
// transactions as of a given height.
//
// NOTE: these are our balances *after* subtracting the commitment fee and
// anchor outputs.
func (c *OpenChannel) BalancesAtHeight(height uint64) (lnwire.MilliSatoshi,
lnwire.MilliSatoshi, error) {
if height > c.LocalCommitment.CommitHeight &&
height > c.RemoteCommitment.CommitHeight {
return 0, 0, errHeightNotReached
}
// If our current commit is as the desired height, we can return our
// current balances.
if c.LocalCommitment.CommitHeight == height {
return c.LocalCommitment.LocalBalance,
c.LocalCommitment.RemoteBalance, nil
}
// If our current remote commit is at the desired height, we can return
// the current balances.
if c.RemoteCommitment.CommitHeight == height {
return c.RemoteCommitment.LocalBalance,
c.RemoteCommitment.RemoteBalance, nil
}
// If we are not currently on the height requested, we need to look up
// the previous height to obtain our balances at the given height.
commit, err := c.FindPreviousState(height)
if err != nil {
return 0, 0, err
}
return commit.LocalBalance, commit.RemoteBalance, nil
}
// ActiveHtlcs returns a slice of HTLC's which are currently active on *both*
// commitment transactions.
func (c *OpenChannel) ActiveHtlcs() []HTLC {
c.RLock()
defer c.RUnlock()
// We'll only return HTLC's that are locked into *both* commitment
// transactions. So we'll iterate through their set of HTLC's to note
// which ones are present on their commitment.
remoteHtlcs := make(map[[32]byte]struct{})
for _, htlc := range c.RemoteCommitment.Htlcs {
onionHash := sha256.Sum256(htlc.OnionBlob)
remoteHtlcs[onionHash] = struct{}{}
}
// Now that we know which HTLC's they have, we'll only mark the HTLC's
// as active if *we* know them as well.
activeHtlcs := make([]HTLC, 0, len(remoteHtlcs))
for _, htlc := range c.LocalCommitment.Htlcs {
onionHash := sha256.Sum256(htlc.OnionBlob)
if _, ok := remoteHtlcs[onionHash]; !ok {
continue
}
activeHtlcs = append(activeHtlcs, htlc)
}
return activeHtlcs
}
// HTLC is the on-disk representation of a hash time-locked contract. HTLCs are
// contained within ChannelDeltas which encode the current state of the
// commitment between state updates.
//
// TODO(roasbeef): save space by using smaller ints at tail end?
type HTLC struct {
// Signature is the signature for the second level covenant transaction
// for this HTLC. The second level transaction is a timeout tx in the
// case that this is an outgoing HTLC, and a success tx in the case
// that this is an incoming HTLC.
//
// TODO(roasbeef): make [64]byte instead?
Signature []byte
// RHash is the payment hash of the HTLC.
RHash [32]byte
// Amt is the amount of milli-satoshis this HTLC escrows.
Amt lnwire.MilliSatoshi
// RefundTimeout is the absolute timeout on the HTLC that the sender
// must wait before reclaiming the funds in limbo.
RefundTimeout uint32
// OutputIndex is the output index for this particular HTLC output
// within the commitment transaction.
OutputIndex int32
// Incoming denotes whether we're the receiver or the sender of this
// HTLC.
Incoming bool
// OnionBlob is an opaque blob which is used to complete multi-hop
// routing.
OnionBlob []byte
// HtlcIndex is the HTLC counter index of this active, outstanding
// HTLC. This differs from the LogIndex, as the HtlcIndex is only
// incremented for each offered HTLC, while they LogIndex is
// incremented for each update (includes settle+fail).
HtlcIndex uint64
// LogIndex is the cumulative log index of this HTLC. This differs
// from the HtlcIndex as this will be incremented for each new log
// update added.
LogIndex uint64
}
// SerializeHtlcs writes out the passed set of HTLC's into the passed writer
// using the current default on-disk serialization format.
//
// NOTE: This API is NOT stable, the on-disk format will likely change in the
// future.
func SerializeHtlcs(b io.Writer, htlcs ...HTLC) error {
numHtlcs := uint16(len(htlcs))
if err := WriteElement(b, numHtlcs); err != nil {
return err
}
for _, htlc := range htlcs {
if err := WriteElements(b,
htlc.Signature, htlc.RHash, htlc.Amt, htlc.RefundTimeout,
htlc.OutputIndex, htlc.Incoming, htlc.OnionBlob[:],
htlc.HtlcIndex, htlc.LogIndex,
); err != nil {
return err
}
}
return nil
}
// DeserializeHtlcs attempts to read out a slice of HTLC's from the passed
// io.Reader. The bytes within the passed reader MUST have been previously
// written to using the SerializeHtlcs function.
//
// NOTE: This API is NOT stable, the on-disk format will likely change in the
// future.
func DeserializeHtlcs(r io.Reader) ([]HTLC, error) {
var numHtlcs uint16
if err := ReadElement(r, &numHtlcs); err != nil {
return nil, err
}
var htlcs []HTLC
if numHtlcs == 0 {
return htlcs, nil
}
htlcs = make([]HTLC, numHtlcs)
for i := uint16(0); i < numHtlcs; i++ {
if err := ReadElements(r,
&htlcs[i].Signature, &htlcs[i].RHash, &htlcs[i].Amt,
&htlcs[i].RefundTimeout, &htlcs[i].OutputIndex,
&htlcs[i].Incoming, &htlcs[i].OnionBlob,
&htlcs[i].HtlcIndex, &htlcs[i].LogIndex,
); err != nil {
return htlcs, err
}
}
return htlcs, nil
}
// Copy returns a full copy of the target HTLC.
func (h *HTLC) Copy() HTLC {
clone := HTLC{
Incoming: h.Incoming,
Amt: h.Amt,
RefundTimeout: h.RefundTimeout,
OutputIndex: h.OutputIndex,
}
copy(clone.Signature[:], h.Signature)
copy(clone.RHash[:], h.RHash[:])
return clone
}
// LogUpdate represents a pending update to the remote commitment chain. The
// log update may be an add, fail, or settle entry. We maintain this data in
// order to be able to properly retransmit our proposed
// state if necessary.
type LogUpdate struct {
// LogIndex is the log index of this proposed commitment update entry.
LogIndex uint64
// UpdateMsg is the update message that was included within the our
// local update log. The LogIndex value denotes the log index of this
// update which will be used when restoring our local update log if
// we're left with a dangling update on restart.
UpdateMsg lnwire.Message
}
// Encode writes a log update to the provided io.Writer.
func (l *LogUpdate) Encode(w io.Writer) error {
return WriteElements(w, l.LogIndex, l.UpdateMsg)
}
// Decode reads a log update from the provided io.Reader.
func (l *LogUpdate) Decode(r io.Reader) error {
return ReadElements(r, &l.LogIndex, &l.UpdateMsg)
}
// CircuitKey is used by a channel to uniquely identify the HTLCs it receives
// from the switch, and is used to purge our in-memory state of HTLCs that have
// already been processed by a link. Two list of CircuitKeys are included in
// each CommitDiff to allow a link to determine which in-memory htlcs directed
// the opening and closing of circuits in the switch's circuit map.
type CircuitKey struct {
// ChanID is the short chanid indicating the HTLC's origin.
//
// NOTE: It is fine for this value to be blank, as this indicates a
// locally-sourced payment.
ChanID lnwire.ShortChannelID
// HtlcID is the unique htlc index predominately assigned by links,
// though can also be assigned by switch in the case of locally-sourced
// payments.
HtlcID uint64
}
// SetBytes deserializes the given bytes into this CircuitKey.
func (k *CircuitKey) SetBytes(bs []byte) error {
if len(bs) != 16 {
return ErrInvalidCircuitKeyLen
}
k.ChanID = lnwire.NewShortChanIDFromInt(
binary.BigEndian.Uint64(bs[:8]))
k.HtlcID = binary.BigEndian.Uint64(bs[8:])
return nil
}
// Bytes returns the serialized bytes for this circuit key.
func (k CircuitKey) Bytes() []byte {
var bs = make([]byte, 16)
binary.BigEndian.PutUint64(bs[:8], k.ChanID.ToUint64())
binary.BigEndian.PutUint64(bs[8:], k.HtlcID)
return bs
}
// Encode writes a CircuitKey to the provided io.Writer.
func (k *CircuitKey) Encode(w io.Writer) error {
var scratch [16]byte
binary.BigEndian.PutUint64(scratch[:8], k.ChanID.ToUint64())
binary.BigEndian.PutUint64(scratch[8:], k.HtlcID)
_, err := w.Write(scratch[:])
return err
}
// Decode reads a CircuitKey from the provided io.Reader.
func (k *CircuitKey) Decode(r io.Reader) error {
var scratch [16]byte
if _, err := io.ReadFull(r, scratch[:]); err != nil {
return err
}
k.ChanID = lnwire.NewShortChanIDFromInt(
binary.BigEndian.Uint64(scratch[:8]))
k.HtlcID = binary.BigEndian.Uint64(scratch[8:])
return nil
}
// String returns a string representation of the CircuitKey.
func (k CircuitKey) String() string {
return fmt.Sprintf("(Chan ID=%s, HTLC ID=%d)", k.ChanID, k.HtlcID)
}
// CommitDiff represents the delta needed to apply the state transition between
// two subsequent commitment states. Given state N and state N+1, one is able
// to apply the set of messages contained within the CommitDiff to N to arrive
// at state N+1. Each time a new commitment is extended, we'll write a new
// commitment (along with the full commitment state) to disk so we can
// re-transmit the state in the case of a connection loss or message drop.
type CommitDiff struct {
// ChannelCommitment is the full commitment state that one would arrive
// at by applying the set of messages contained in the UpdateDiff to
// the prior accepted commitment.
Commitment ChannelCommitment
// LogUpdates is the set of messages sent prior to the commitment state
// transition in question. Upon reconnection, if we detect that they
// don't have the commitment, then we re-send this along with the
// proper signature.
LogUpdates []LogUpdate
// CommitSig is the exact CommitSig message that should be sent after
// the set of LogUpdates above has been retransmitted. The signatures
// within this message should properly cover the new commitment state
// and also the HTLC's within the new commitment state.
CommitSig *lnwire.CommitSig
// OpenedCircuitKeys is a set of unique identifiers for any downstream
// Add packets included in this commitment txn. After a restart, this
// set of htlcs is acked from the link's incoming mailbox to ensure
// there isn't an attempt to re-add them to this commitment txn.
OpenedCircuitKeys []CircuitKey
// ClosedCircuitKeys records the unique identifiers for any settle/fail
// packets that were resolved by this commitment txn. After a restart,
// this is used to ensure those circuits are removed from the circuit
// map, and the downstream packets in the link's mailbox are removed.
ClosedCircuitKeys []CircuitKey
// AddAcks specifies the locations (commit height, pkg index) of any
// Adds that were failed/settled in this commit diff. This will ack
// entries in *this* channel's forwarding packages.
//
// NOTE: This value is not serialized, it is used to atomically mark the
// resolution of adds, such that they will not be reprocessed after a
// restart.
AddAcks []AddRef
// SettleFailAcks specifies the locations (chan id, commit height, pkg
// index) of any Settles or Fails that were locked into this commit
// diff, and originate from *another* channel, i.e. the outgoing link.
//
// NOTE: This value is not serialized, it is used to atomically acks
// settles and fails from the forwarding packages of other channels,
// such that they will not be reforwarded internally after a restart.
SettleFailAcks []SettleFailRef
}
// serializeLogUpdates serializes provided list of updates to a stream.
func serializeLogUpdates(w io.Writer, logUpdates []LogUpdate) error {
numUpdates := uint16(len(logUpdates))
if err := binary.Write(w, byteOrder, numUpdates); err != nil {
return err
}
for _, diff := range logUpdates {
err := WriteElements(w, diff.LogIndex, diff.UpdateMsg)
if err != nil {
return err
}
}
return nil
}
// deserializeLogUpdates deserializes a list of updates from a stream.
func deserializeLogUpdates(r io.Reader) ([]LogUpdate, error) {
var numUpdates uint16
if err := binary.Read(r, byteOrder, &numUpdates); err != nil {
return nil, err
}
logUpdates := make([]LogUpdate, numUpdates)
for i := 0; i < int(numUpdates); i++ {
err := ReadElements(r,
&logUpdates[i].LogIndex, &logUpdates[i].UpdateMsg,
)
if err != nil {
return nil, err
}
}
return logUpdates, nil
}
func serializeCommitDiff(w io.Writer, diff *CommitDiff) error {
if err := serializeChanCommit(w, &diff.Commitment); err != nil {
return err
}
if err := diff.CommitSig.Encode(w, 0); err != nil {
return err
}
if err := serializeLogUpdates(w, diff.LogUpdates); err != nil {
return err
}
numOpenRefs := uint16(len(diff.OpenedCircuitKeys))
if err := binary.Write(w, byteOrder, numOpenRefs); err != nil {
return err
}
for _, openRef := range diff.OpenedCircuitKeys {
err := WriteElements(w, openRef.ChanID, openRef.HtlcID)
if err != nil {
return err
}
}
numClosedRefs := uint16(len(diff.ClosedCircuitKeys))
if err := binary.Write(w, byteOrder, numClosedRefs); err != nil {
return err
}
for _, closedRef := range diff.ClosedCircuitKeys {
err := WriteElements(w, closedRef.ChanID, closedRef.HtlcID)
if err != nil {
return err
}
}
return nil
}
func deserializeCommitDiff(r io.Reader) (*CommitDiff, error) {
var (
d CommitDiff
err error
)
d.Commitment, err = deserializeChanCommit(r)
if err != nil {
return nil, err
}
d.CommitSig = &lnwire.CommitSig{}
if err := d.CommitSig.Decode(r, 0); err != nil {
return nil, err
}
d.LogUpdates, err = deserializeLogUpdates(r)
if err != nil {
return nil, err
}
var numOpenRefs uint16
if err := binary.Read(r, byteOrder, &numOpenRefs); err != nil {
return nil, err
}
d.OpenedCircuitKeys = make([]CircuitKey, numOpenRefs)
for i := 0; i < int(numOpenRefs); i++ {
err := ReadElements(r,
&d.OpenedCircuitKeys[i].ChanID,
&d.OpenedCircuitKeys[i].HtlcID)
if err != nil {
return nil, err
}
}
var numClosedRefs uint16
if err := binary.Read(r, byteOrder, &numClosedRefs); err != nil {
return nil, err
}
d.ClosedCircuitKeys = make([]CircuitKey, numClosedRefs)
for i := 0; i < int(numClosedRefs); i++ {
err := ReadElements(r,
&d.ClosedCircuitKeys[i].ChanID,
&d.ClosedCircuitKeys[i].HtlcID)
if err != nil {
return nil, err
}
}
return &d, nil
}
// AppendRemoteCommitChain appends a new CommitDiff to the end of the
// commitment chain for the remote party. This method is to be used once we
// have prepared a new commitment state for the remote party, but before we
// transmit it to the remote party. The contents of the argument should be
// sufficient to retransmit the updates and signature needed to reconstruct the
// state in full, in the case that we need to retransmit.
func (c *OpenChannel) AppendRemoteCommitChain(diff *CommitDiff) error {
c.Lock()
defer c.Unlock()
// If this is a restored channel, then we want to avoid mutating the
// state at all, as it's impossible to do so in a protocol compliant
// manner.
if c.hasChanStatus(ChanStatusRestored) {
return ErrNoRestoredChannelMutation
}
return kvdb.Update(c.Db, func(tx kvdb.RwTx) error {
// First, we'll grab the writable bucket where this channel's
// data resides.
chanBucket, err := fetchChanBucketRw(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
if err != nil {
return err
}
// If the channel is marked as borked, then for safety reasons,
// we shouldn't attempt any further updates.
isBorked, err := c.isBorked(chanBucket)
if err != nil {
return err
}
if isBorked {
return ErrChanBorked
}
// Any outgoing settles and fails necessarily have a
// corresponding adds in this channel's forwarding packages.
// Mark all of these as being fully processed in our forwarding
// package, which prevents us from reprocessing them after
// startup.
err = c.Packager.AckAddHtlcs(tx, diff.AddAcks...)
if err != nil {
return err
}
// Additionally, we ack from any fails or settles that are
// persisted in another channel's forwarding package. This
// prevents the same fails and settles from being retransmitted
// after restarts. The actual fail or settle we need to
// propagate to the remote party is now in the commit diff.
err = c.Packager.AckSettleFails(tx, diff.SettleFailAcks...)
if err != nil {
return err
}
// TODO(roasbeef): use seqno to derive key for later LCP
// With the bucket retrieved, we'll now serialize the commit
// diff itself, and write it to disk.
var b bytes.Buffer
if err := serializeCommitDiff(&b, diff); err != nil {
return err
}
return chanBucket.Put(commitDiffKey, b.Bytes())
}, func() {})
}
// RemoteCommitChainTip returns the "tip" of the current remote commitment
// chain. This value will be non-nil iff, we've created a new commitment for
// the remote party that they haven't yet ACK'd. In this case, their commitment
// chain will have a length of two: their current unrevoked commitment, and
// this new pending commitment. Once they revoked their prior state, we'll swap
// these pointers, causing the tip and the tail to point to the same entry.
func (c *OpenChannel) RemoteCommitChainTip() (*CommitDiff, error) {
var cd *CommitDiff
err := kvdb.View(c.Db, func(tx kvdb.RTx) error {
chanBucket, err := fetchChanBucket(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
switch err {
case nil:
case ErrNoChanDBExists, ErrNoActiveChannels, ErrChannelNotFound:
return ErrNoPendingCommit
default:
return err
}
tipBytes := chanBucket.Get(commitDiffKey)
if tipBytes == nil {
return ErrNoPendingCommit
}
tipReader := bytes.NewReader(tipBytes)
dcd, err := deserializeCommitDiff(tipReader)
if err != nil {
return err
}
cd = dcd
return nil
}, func() {
cd = nil
})
if err != nil {
return nil, err
}
return cd, err
}
// UnsignedAckedUpdates retrieves the persisted unsigned acked remote log
// updates that still need to be signed for.
func (c *OpenChannel) UnsignedAckedUpdates() ([]LogUpdate, error) {
var updates []LogUpdate
err := kvdb.View(c.Db, func(tx kvdb.RTx) error {
chanBucket, err := fetchChanBucket(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
switch err {
case nil:
case ErrNoChanDBExists, ErrNoActiveChannels, ErrChannelNotFound:
return nil
default:
return err
}
updateBytes := chanBucket.Get(unsignedAckedUpdatesKey)
if updateBytes == nil {
return nil
}
r := bytes.NewReader(updateBytes)
updates, err = deserializeLogUpdates(r)
return err
}, func() {
updates = nil
})
if err != nil {
return nil, err
}
return updates, nil
}
// RemoteUnsignedLocalUpdates retrieves the persisted, unsigned local log
// updates that the remote still needs to sign for.
func (c *OpenChannel) RemoteUnsignedLocalUpdates() ([]LogUpdate, error) {
var updates []LogUpdate
err := kvdb.View(c.Db, func(tx kvdb.RTx) error {
chanBucket, err := fetchChanBucket(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
switch err {
case nil:
break
case ErrNoChanDBExists, ErrNoActiveChannels, ErrChannelNotFound:
return nil
default:
return err
}
updateBytes := chanBucket.Get(remoteUnsignedLocalUpdatesKey)
if updateBytes == nil {
return nil
}
r := bytes.NewReader(updateBytes)
updates, err = deserializeLogUpdates(r)
return err
}, func() {
updates = nil
})
if err != nil {
return nil, err
}
return updates, nil
}
// InsertNextRevocation inserts the _next_ commitment point (revocation) into
// the database, and also modifies the internal RemoteNextRevocation attribute
// to point to the passed key. This method is to be using during final channel
// set up, _after_ the channel has been fully confirmed.
//
// NOTE: If this method isn't called, then the target channel won't be able to
// propose new states for the commitment state of the remote party.
func (c *OpenChannel) InsertNextRevocation(revKey *btcec.PublicKey) error {
c.Lock()
defer c.Unlock()
c.RemoteNextRevocation = revKey
err := kvdb.Update(c.Db, func(tx kvdb.RwTx) error {
chanBucket, err := fetchChanBucketRw(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
if err != nil {
return err
}
return putChanRevocationState(chanBucket, c)
}, func() {})
if err != nil {
return err
}
return nil
}
// AdvanceCommitChainTail records the new state transition within an on-disk
// append-only log which records all state transitions by the remote peer. In
// the case of an uncooperative broadcast of a prior state by the remote peer,
// this log can be consulted in order to reconstruct the state needed to
// rectify the situation. This method will add the current commitment for the
// remote party to the revocation log, and promote the current pending
// commitment to the current remote commitment. The updates parameter is the
// set of local updates that the peer still needs to send us a signature for.
// We store this set of updates in case we go down.
func (c *OpenChannel) AdvanceCommitChainTail(fwdPkg *FwdPkg,
updates []LogUpdate) error {
c.Lock()
defer c.Unlock()
// If this is a restored channel, then we want to avoid mutating the
// state at all, as it's impossible to do so in a protocol compliant
// manner.
if c.hasChanStatus(ChanStatusRestored) {
return ErrNoRestoredChannelMutation
}
var newRemoteCommit *ChannelCommitment
err := kvdb.Update(c.Db, func(tx kvdb.RwTx) error {
chanBucket, err := fetchChanBucketRw(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
if err != nil {
return err
}
// If the channel is marked as borked, then for safety reasons,
// we shouldn't attempt any further updates.
isBorked, err := c.isBorked(chanBucket)
if err != nil {
return err
}
if isBorked {
return ErrChanBorked
}
// Persist the latest preimage state to disk as the remote peer
// has just added to our local preimage store, and given us a
// new pending revocation key.
if err := putChanRevocationState(chanBucket, c); err != nil {
return err
}
// With the current preimage producer/store state updated,
// append a new log entry recording this the delta of this
// state transition.
//
// TODO(roasbeef): could make the deltas relative, would save
// space, but then tradeoff for more disk-seeks to recover the
// full state.
logKey := revocationLogBucket
logBucket, err := chanBucket.CreateBucketIfNotExists(logKey)
if err != nil {
return err
}
// Before we append this revoked state to the revocation log,
// we'll swap out what's currently the tail of the commit tip,
// with the current locked-in commitment for the remote party.
tipBytes := chanBucket.Get(commitDiffKey)
tipReader := bytes.NewReader(tipBytes)
newCommit, err := deserializeCommitDiff(tipReader)
if err != nil {
return err
}
err = putChanCommitment(
chanBucket, &newCommit.Commitment, false,
)
if err != nil {
return err
}
if err := chanBucket.Delete(commitDiffKey); err != nil {
return err
}
// With the commitment pointer swapped, we can now add the
// revoked (prior) state to the revocation log.
//
// TODO(roasbeef): store less
err = appendChannelLogEntry(logBucket, &c.RemoteCommitment)
if err != nil {
return err
}
// Lastly, we write the forwarding package to disk so that we
// can properly recover from failures and reforward HTLCs that
// have not received a corresponding settle/fail.
if err := c.Packager.AddFwdPkg(tx, fwdPkg); err != nil {
return err
}
// Persist the unsigned acked updates that are not included
// in their new commitment.
updateBytes := chanBucket.Get(unsignedAckedUpdatesKey)
if updateBytes == nil {
// If there are no updates to sign, we don't need to
// filter out any updates.
newRemoteCommit = &newCommit.Commitment
return nil
}
r := bytes.NewReader(updateBytes)
unsignedUpdates, err := deserializeLogUpdates(r)
if err != nil {
return err
}
var validUpdates []LogUpdate
for _, upd := range unsignedUpdates {
lIdx := upd.LogIndex
// Filter for updates that are not on the remote
// commitment.
if lIdx >= newCommit.Commitment.RemoteLogIndex {
validUpdates = append(validUpdates, upd)
}
}
var b bytes.Buffer
err = serializeLogUpdates(&b, validUpdates)
if err != nil {
return fmt.Errorf("unable to serialize log updates: %v", err)
}
err = chanBucket.Put(unsignedAckedUpdatesKey, b.Bytes())
if err != nil {
return fmt.Errorf("unable to store under unsignedAckedUpdatesKey: %v", err)
}
// Persist the local updates the peer hasn't yet signed so they
// can be restored after restart.
var b2 bytes.Buffer
err = serializeLogUpdates(&b2, updates)
if err != nil {
return err
}
err = chanBucket.Put(remoteUnsignedLocalUpdatesKey, b2.Bytes())
if err != nil {
return fmt.Errorf("unable to restore remote unsigned "+
"local updates: %v", err)
}
newRemoteCommit = &newCommit.Commitment
return nil
}, func() {
newRemoteCommit = nil
})
if err != nil {
return err
}
// With the db transaction complete, we'll swap over the in-memory
// pointer of the new remote commitment, which was previously the tip
// of the commit chain.
c.RemoteCommitment = *newRemoteCommit
return nil
}
// NextLocalHtlcIndex returns the next unallocated local htlc index. To ensure
// this always returns the next index that has been not been allocated, this
// will first try to examine any pending commitments, before falling back to the
// last locked-in remote commitment.
func (c *OpenChannel) NextLocalHtlcIndex() (uint64, error) {
// First, load the most recent commit diff that we initiated for the
// remote party. If no pending commit is found, this is not treated as
// a critical error, since we can always fall back.
pendingRemoteCommit, err := c.RemoteCommitChainTip()
if err != nil && err != ErrNoPendingCommit {
return 0, err
}
// If a pending commit was found, its local htlc index will be at least
// as large as the one on our local commitment.
if pendingRemoteCommit != nil {
return pendingRemoteCommit.Commitment.LocalHtlcIndex, nil
}
// Otherwise, fallback to using the local htlc index of their commitment.
return c.RemoteCommitment.LocalHtlcIndex, nil
}
// LoadFwdPkgs scans the forwarding log for any packages that haven't been
// processed, and returns their deserialized log updates in map indexed by the
// remote commitment height at which the updates were locked in.
func (c *OpenChannel) LoadFwdPkgs() ([]*FwdPkg, error) {
c.RLock()
defer c.RUnlock()
var fwdPkgs []*FwdPkg
if err := kvdb.View(c.Db, func(tx kvdb.RTx) error {
var err error
fwdPkgs, err = c.Packager.LoadFwdPkgs(tx)
return err
}, func() {
fwdPkgs = nil
}); err != nil {
return nil, err
}
return fwdPkgs, nil
}
// AckAddHtlcs updates the AckAddFilter containing any of the provided AddRefs
// indicating that a response to this Add has been committed to the remote party.
// Doing so will prevent these Add HTLCs from being reforwarded internally.
func (c *OpenChannel) AckAddHtlcs(addRefs ...AddRef) error {
c.Lock()
defer c.Unlock()
return kvdb.Update(c.Db, func(tx kvdb.RwTx) error {
return c.Packager.AckAddHtlcs(tx, addRefs...)
}, func() {})
}
// AckSettleFails updates the SettleFailFilter containing any of the provided
// SettleFailRefs, indicating that the response has been delivered to the
// incoming link, corresponding to a particular AddRef. Doing so will prevent
// the responses from being retransmitted internally.
func (c *OpenChannel) AckSettleFails(settleFailRefs ...SettleFailRef) error {
c.Lock()
defer c.Unlock()
return kvdb.Update(c.Db, func(tx kvdb.RwTx) error {
return c.Packager.AckSettleFails(tx, settleFailRefs...)
}, func() {})
}
// SetFwdFilter atomically sets the forwarding filter for the forwarding package
// identified by `height`.
func (c *OpenChannel) SetFwdFilter(height uint64, fwdFilter *PkgFilter) error {
c.Lock()
defer c.Unlock()
return kvdb.Update(c.Db, func(tx kvdb.RwTx) error {
return c.Packager.SetFwdFilter(tx, height, fwdFilter)
}, func() {})
}
// RemoveFwdPkgs atomically removes forwarding packages specified by the remote
// commitment heights. If one of the intermediate RemovePkg calls fails, then the
// later packages won't be removed.
//
// NOTE: This method should only be called on packages marked FwdStateCompleted.
func (c *OpenChannel) RemoveFwdPkgs(heights ...uint64) error {
c.Lock()
defer c.Unlock()
return kvdb.Update(c.Db, func(tx kvdb.RwTx) error {
for _, height := range heights {
err := c.Packager.RemovePkg(tx, height)
if err != nil {
return err
}
}
return nil
}, func() {})
}
// RevocationLogTail returns the "tail", or the end of the current revocation
// log. This entry represents the last previous state for the remote node's
// commitment chain. The ChannelDelta returned by this method will always lag
// one state behind the most current (unrevoked) state of the remote node's
// commitment chain.
func (c *OpenChannel) RevocationLogTail() (*ChannelCommitment, error) {
c.RLock()
defer c.RUnlock()
// If we haven't created any state updates yet, then we'll exit early as
// there's nothing to be found on disk in the revocation bucket.
if c.RemoteCommitment.CommitHeight == 0 {
return nil, nil
}
var commit ChannelCommitment
if err := kvdb.View(c.Db, func(tx kvdb.RTx) error {
chanBucket, err := fetchChanBucket(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
if err != nil {
return err
}
logBucket := chanBucket.NestedReadBucket(revocationLogBucket)
if logBucket == nil {
return ErrNoPastDeltas
}
// Once we have the bucket that stores the revocation log from
// this channel, we'll jump to the _last_ key in bucket. As we
// store the update number on disk in a big-endian format,
// this will retrieve the latest entry.
cursor := logBucket.ReadCursor()
_, tailLogEntry := cursor.Last()
logEntryReader := bytes.NewReader(tailLogEntry)
// Once we have the entry, we'll decode it into the channel
// delta pointer we created above.
var dbErr error
commit, dbErr = deserializeChanCommit(logEntryReader)
if dbErr != nil {
return dbErr
}
return nil
}, func() {}); err != nil {
return nil, err
}
return &commit, nil
}
// CommitmentHeight returns the current commitment height. The commitment
// height represents the number of updates to the commitment state to date.
// This value is always monotonically increasing. This method is provided in
// order to allow multiple instances of a particular open channel to obtain a
// consistent view of the number of channel updates to date.
func (c *OpenChannel) CommitmentHeight() (uint64, error) {
c.RLock()
defer c.RUnlock()
var height uint64
err := kvdb.View(c.Db, func(tx kvdb.RTx) error {
// Get the bucket dedicated to storing the metadata for open
// channels.
chanBucket, err := fetchChanBucket(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
if err != nil {
return err
}
commit, err := fetchChanCommitment(chanBucket, true)
if err != nil {
return err
}
height = commit.CommitHeight
return nil
}, func() {
height = 0
})
if err != nil {
return 0, err
}
return height, nil
}
// FindPreviousState scans through the append-only log in an attempt to recover
// the previous channel state indicated by the update number. This method is
// intended to be used for obtaining the relevant data needed to claim all
// funds rightfully spendable in the case of an on-chain broadcast of the
// commitment transaction.
func (c *OpenChannel) FindPreviousState(updateNum uint64) (*ChannelCommitment, error) {
c.RLock()
defer c.RUnlock()
var commit ChannelCommitment
err := kvdb.View(c.Db, func(tx kvdb.RTx) error {
chanBucket, err := fetchChanBucket(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
if err != nil {
return err
}
logBucket := chanBucket.NestedReadBucket(revocationLogBucket)
if logBucket == nil {
return ErrNoPastDeltas
}
c, err := fetchChannelLogEntry(logBucket, updateNum)
if err != nil {
return err
}
commit = c
return nil
}, func() {})
if err != nil {
return nil, err
}
return &commit, nil
}
// ClosureType is an enum like structure that details exactly _how_ a channel
// was closed. Three closure types are currently possible: none, cooperative,
// local force close, remote force close, and (remote) breach.
type ClosureType uint8
const (
// CooperativeClose indicates that a channel has been closed
// cooperatively. This means that both channel peers were online and
// signed a new transaction paying out the settled balance of the
// contract.
CooperativeClose ClosureType = 0
// LocalForceClose indicates that we have unilaterally broadcast our
// current commitment state on-chain.
LocalForceClose ClosureType = 1
// RemoteForceClose indicates that the remote peer has unilaterally
// broadcast their current commitment state on-chain.
RemoteForceClose ClosureType = 4
// BreachClose indicates that the remote peer attempted to broadcast a
// prior _revoked_ channel state.
BreachClose ClosureType = 2
// FundingCanceled indicates that the channel never was fully opened
// before it was marked as closed in the database. This can happen if
// we or the remote fail at some point during the opening workflow, or
// we timeout waiting for the funding transaction to be confirmed.
FundingCanceled ClosureType = 3
// Abandoned indicates that the channel state was removed without
// any further actions. This is intended to clean up unusable
// channels during development.
Abandoned ClosureType = 5
)
// ChannelCloseSummary contains the final state of a channel at the point it
// was closed. Once a channel is closed, all the information pertaining to that
// channel within the openChannelBucket is deleted, and a compact summary is
// put in place instead.
type ChannelCloseSummary struct {
// ChanPoint is the outpoint for this channel's funding transaction,
// and is used as a unique identifier for the channel.
ChanPoint wire.OutPoint
// ShortChanID encodes the exact location in the chain in which the
// channel was initially confirmed. This includes: the block height,
// transaction index, and the output within the target transaction.
ShortChanID lnwire.ShortChannelID
// ChainHash is the hash of the genesis block that this channel resides
// within.
ChainHash chainhash.Hash
// ClosingTXID is the txid of the transaction which ultimately closed
// this channel.
ClosingTXID chainhash.Hash
// RemotePub is the public key of the remote peer that we formerly had
// a channel with.
RemotePub *btcec.PublicKey
// Capacity was the total capacity of the channel.
Capacity btcutil.Amount
// CloseHeight is the height at which the funding transaction was
// spent.
CloseHeight uint32
// SettledBalance is our total balance settled balance at the time of
// channel closure. This _does not_ include the sum of any outputs that
// have been time-locked as a result of the unilateral channel closure.
SettledBalance btcutil.Amount
// TimeLockedBalance is the sum of all the time-locked outputs at the
// time of channel closure. If we triggered the force closure of this
// channel, then this value will be non-zero if our settled output is
// above the dust limit. If we were on the receiving side of a channel
// force closure, then this value will be non-zero if we had any
// outstanding outgoing HTLC's at the time of channel closure.
TimeLockedBalance btcutil.Amount
// CloseType details exactly _how_ the channel was closed. Five closure
// types are possible: cooperative, local force, remote force, breach
// and funding canceled.
CloseType ClosureType
// IsPending indicates whether this channel is in the 'pending close'
// state, which means the channel closing transaction has been
// confirmed, but not yet been fully resolved. In the case of a channel
// that has been cooperatively closed, it will go straight into the
// fully resolved state as soon as the closing transaction has been
// confirmed. However, for channels that have been force closed, they'll
// stay marked as "pending" until _all_ the pending funds have been
// swept.
IsPending bool
// RemoteCurrentRevocation is the current revocation for their
// commitment transaction. However, since this is the derived public key,
// we don't yet have the private key so we aren't yet able to verify
// that it's actually in the hash chain.
RemoteCurrentRevocation *btcec.PublicKey
// RemoteNextRevocation is the revocation key to be used for the *next*
// commitment transaction we create for the local node. Within the
// specification, this value is referred to as the
// per-commitment-point.
RemoteNextRevocation *btcec.PublicKey
// LocalChanCfg is the channel configuration for the local node.
LocalChanConfig ChannelConfig
// LastChanSyncMsg is the ChannelReestablish message for this channel
// for the state at the point where it was closed.
LastChanSyncMsg *lnwire.ChannelReestablish
}
// CloseChannel closes a previously active Lightning channel. Closing a channel
// entails deleting all saved state within the database concerning this
// channel. This method also takes a struct that summarizes the state of the
// channel at closing, this compact representation will be the only component
// of a channel left over after a full closing. It takes an optional set of
// channel statuses which will be written to the historical channel bucket.
// These statuses are used to record close initiators.
func (c *OpenChannel) CloseChannel(summary *ChannelCloseSummary,
statuses ...ChannelStatus) error {
c.Lock()
defer c.Unlock()
return kvdb.Update(c.Db, func(tx kvdb.RwTx) error {
openChanBucket := tx.ReadWriteBucket(openChannelBucket)
if openChanBucket == nil {
return ErrNoChanDBExists
}
nodePub := c.IdentityPub.SerializeCompressed()
nodeChanBucket := openChanBucket.NestedReadWriteBucket(nodePub)
if nodeChanBucket == nil {
return ErrNoActiveChannels
}
chainBucket := nodeChanBucket.NestedReadWriteBucket(c.ChainHash[:])
if chainBucket == nil {
return ErrNoActiveChannels
}
var chanPointBuf bytes.Buffer
err := writeOutpoint(&chanPointBuf, &c.FundingOutpoint)
if err != nil {
return err
}
chanKey := chanPointBuf.Bytes()
chanBucket := chainBucket.NestedReadWriteBucket(
chanKey,
)
if chanBucket == nil {
return ErrNoActiveChannels
}
// Before we delete the channel state, we'll read out the full
// details, as we'll also store portions of this information
// for record keeping.
chanState, err := fetchOpenChannel(
chanBucket, &c.FundingOutpoint,
)
if err != nil {
return err
}
// Now that the index to this channel has been deleted, purge
// the remaining channel metadata from the database.
err = deleteOpenChannel(chanBucket)
if err != nil {
return err
}
// We'll also remove the channel from the frozen channel bucket
// if we need to.
if c.ChanType.IsFrozen() {
err := deleteThawHeight(chanBucket)
if err != nil {
return err
}
}
// With the base channel data deleted, attempt to delete the
// information stored within the revocation log.
logBucket := chanBucket.NestedReadWriteBucket(revocationLogBucket)
if logBucket != nil {
err = chanBucket.DeleteNestedBucket(revocationLogBucket)
if err != nil {
return err
}
}
err = chainBucket.DeleteNestedBucket(chanPointBuf.Bytes())
if err != nil {
return err
}
// Add channel state to the historical channel bucket.
historicalBucket, err := tx.CreateTopLevelBucket(
historicalChannelBucket,
)
if err != nil {
return err
}
historicalChanBucket, err :=
historicalBucket.CreateBucketIfNotExists(chanKey)
if err != nil {
return err
}
// Apply any additional statuses to the channel state.
for _, status := range statuses {
chanState.chanStatus |= status
}
err = putOpenChannel(historicalChanBucket, chanState)
if err != nil {
return err
}
// Finally, create a summary of this channel in the closed
// channel bucket for this node.
return putChannelCloseSummary(
tx, chanPointBuf.Bytes(), summary, chanState,
)
}, func() {})
}
// ChannelSnapshot is a frozen snapshot of the current channel state. A
// snapshot is detached from the original channel that generated it, providing
// read-only access to the current or prior state of an active channel.
//
// TODO(roasbeef): remove all together? pretty much just commitment
type ChannelSnapshot struct {
// RemoteIdentity is the identity public key of the remote node that we
// are maintaining the open channel with.
RemoteIdentity btcec.PublicKey
// ChanPoint is the outpoint that created the channel. This output is
// found within the funding transaction and uniquely identified the
// channel on the resident chain.
ChannelPoint wire.OutPoint
// ChainHash is the genesis hash of the chain that the channel resides
// within.
ChainHash chainhash.Hash
// Capacity is the total capacity of the channel.
Capacity btcutil.Amount
// TotalMSatSent is the total number of milli-satoshis we've sent
// within this channel.
TotalMSatSent lnwire.MilliSatoshi
// TotalMSatReceived is the total number of milli-satoshis we've
// received within this channel.
TotalMSatReceived lnwire.MilliSatoshi
// ChannelCommitment is the current up-to-date commitment for the
// target channel.
ChannelCommitment
}
// Snapshot returns a read-only snapshot of the current channel state. This
// snapshot includes information concerning the current settled balance within
// the channel, metadata detailing total flows, and any outstanding HTLCs.
func (c *OpenChannel) Snapshot() *ChannelSnapshot {
c.RLock()
defer c.RUnlock()
localCommit := c.LocalCommitment
snapshot := &ChannelSnapshot{
RemoteIdentity: *c.IdentityPub,
ChannelPoint: c.FundingOutpoint,
Capacity: c.Capacity,
TotalMSatSent: c.TotalMSatSent,
TotalMSatReceived: c.TotalMSatReceived,
ChainHash: c.ChainHash,
ChannelCommitment: ChannelCommitment{
LocalBalance: localCommit.LocalBalance,
RemoteBalance: localCommit.RemoteBalance,
CommitHeight: localCommit.CommitHeight,
CommitFee: localCommit.CommitFee,
},
}
// Copy over the current set of HTLCs to ensure the caller can't mutate
// our internal state.
snapshot.Htlcs = make([]HTLC, len(localCommit.Htlcs))
for i, h := range localCommit.Htlcs {
snapshot.Htlcs[i] = h.Copy()
}
return snapshot
}
// LatestCommitments returns the two latest commitments for both the local and
// remote party. These commitments are read from disk to ensure that only the
// latest fully committed state is returned. The first commitment returned is
// the local commitment, and the second returned is the remote commitment.
func (c *OpenChannel) LatestCommitments() (*ChannelCommitment, *ChannelCommitment, error) {
err := kvdb.View(c.Db, func(tx kvdb.RTx) error {
chanBucket, err := fetchChanBucket(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
if err != nil {
return err
}
return fetchChanCommitments(chanBucket, c)
}, func() {})
if err != nil {
return nil, nil, err
}
return &c.LocalCommitment, &c.RemoteCommitment, nil
}
// RemoteRevocationStore returns the most up to date commitment version of the
// revocation storage tree for the remote party. This method can be used when
// acting on a possible contract breach to ensure, that the caller has the most
// up to date information required to deliver justice.
func (c *OpenChannel) RemoteRevocationStore() (shachain.Store, error) {
err := kvdb.View(c.Db, func(tx kvdb.RTx) error {
chanBucket, err := fetchChanBucket(
tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
)
if err != nil {
return err
}
return fetchChanRevocationState(chanBucket, c)
}, func() {})
if err != nil {
return nil, err
}
return c.RevocationStore, nil
}
// AbsoluteThawHeight determines a frozen channel's absolute thaw height. If the
// channel is not frozen, then 0 is returned.
func (c *OpenChannel) AbsoluteThawHeight() (uint32, error) {
// Only frozen channels have a thaw height.
if !c.ChanType.IsFrozen() {
return 0, nil
}
// If the channel's thaw height is below the absolute threshold, then
// it's interpreted as a relative height to the chain's current height.
if c.ThawHeight < AbsoluteThawHeightThreshold {
// We'll only known of the channel's short ID once it's
// confirmed.
if c.IsPending {
return 0, errors.New("cannot use relative thaw " +
"height for unconfirmed channel")
}
return c.ShortChannelID.BlockHeight + c.ThawHeight, nil
}
return c.ThawHeight, nil
}
func putChannelCloseSummary(tx kvdb.RwTx, chanID []byte,
summary *ChannelCloseSummary, lastChanState *OpenChannel) error {
closedChanBucket, err := tx.CreateTopLevelBucket(closedChannelBucket)
if err != nil {
return err
}
summary.RemoteCurrentRevocation = lastChanState.RemoteCurrentRevocation
summary.RemoteNextRevocation = lastChanState.RemoteNextRevocation
summary.LocalChanConfig = lastChanState.LocalChanCfg
var b bytes.Buffer
if err := serializeChannelCloseSummary(&b, summary); err != nil {
return err
}
return closedChanBucket.Put(chanID, b.Bytes())
}
func serializeChannelCloseSummary(w io.Writer, cs *ChannelCloseSummary) error {
err := WriteElements(w,
cs.ChanPoint, cs.ShortChanID, cs.ChainHash, cs.ClosingTXID,
cs.CloseHeight, cs.RemotePub, cs.Capacity, cs.SettledBalance,
cs.TimeLockedBalance, cs.CloseType, cs.IsPending,
)
if err != nil {
return err
}
// If this is a close channel summary created before the addition of
// the new fields, then we can exit here.
if cs.RemoteCurrentRevocation == nil {
return WriteElements(w, false)
}
// If fields are present, write boolean to indicate this, and continue.
if err := WriteElements(w, true); err != nil {
return err
}
if err := WriteElements(w, cs.RemoteCurrentRevocation); err != nil {
return err
}
if err := writeChanConfig(w, &cs.LocalChanConfig); err != nil {
return err
}
// The RemoteNextRevocation field is optional, as it's possible for a
// channel to be closed before we learn of the next unrevoked
// revocation point for the remote party. Write a boolen indicating
// whether this field is present or not.
if err := WriteElements(w, cs.RemoteNextRevocation != nil); err != nil {
return err
}
// Write the field, if present.
if cs.RemoteNextRevocation != nil {
if err = WriteElements(w, cs.RemoteNextRevocation); err != nil {
return err
}
}
// Write whether the channel sync message is present.
if err := WriteElements(w, cs.LastChanSyncMsg != nil); err != nil {
return err
}
// Write the channel sync message, if present.
if cs.LastChanSyncMsg != nil {
if err := WriteElements(w, cs.LastChanSyncMsg); err != nil {
return err
}
}
return nil
}
func deserializeCloseChannelSummary(r io.Reader) (*ChannelCloseSummary, error) {
c := &ChannelCloseSummary{}
err := ReadElements(r,
&c.ChanPoint, &c.ShortChanID, &c.ChainHash, &c.ClosingTXID,
&c.CloseHeight, &c.RemotePub, &c.Capacity, &c.SettledBalance,
&c.TimeLockedBalance, &c.CloseType, &c.IsPending,
)
if err != nil {
return nil, err
}
// We'll now check to see if the channel close summary was encoded with
// any of the additional optional fields.
var hasNewFields bool
err = ReadElements(r, &hasNewFields)
if err != nil {
return nil, err
}
// If fields are not present, we can return.
if !hasNewFields {
return c, nil
}
// Otherwise read the new fields.
if err := ReadElements(r, &c.RemoteCurrentRevocation); err != nil {
return nil, err
}
if err := readChanConfig(r, &c.LocalChanConfig); err != nil {
return nil, err
}
// Finally, we'll attempt to read the next unrevoked commitment point
// for the remote party. If we closed the channel before receiving a
// funding locked message then this might not be present. A boolean
// indicating whether the field is present will come first.
var hasRemoteNextRevocation bool
err = ReadElements(r, &hasRemoteNextRevocation)
if err != nil {
return nil, err
}
// If this field was written, read it.
if hasRemoteNextRevocation {
err = ReadElements(r, &c.RemoteNextRevocation)
if err != nil {
return nil, err
}
}
// Check if we have a channel sync message to read.
var hasChanSyncMsg bool
err = ReadElements(r, &hasChanSyncMsg)
if err == io.EOF {
return c, nil
} else if err != nil {
return nil, err
}
// If a chan sync message is present, read it.
if hasChanSyncMsg {
// We must pass in reference to a lnwire.Message for the codec
// to support it.
var msg lnwire.Message
if err := ReadElements(r, &msg); err != nil {
return nil, err
}
chanSync, ok := msg.(*lnwire.ChannelReestablish)
if !ok {
return nil, errors.New("unable cast db Message to " +
"ChannelReestablish")
}
c.LastChanSyncMsg = chanSync
}
return c, nil
}
func writeChanConfig(b io.Writer, c *ChannelConfig) error {
return WriteElements(b,
c.DustLimit, c.MaxPendingAmount, c.ChanReserve, c.MinHTLC,
c.MaxAcceptedHtlcs, c.CsvDelay, c.MultiSigKey,
c.RevocationBasePoint, c.PaymentBasePoint, c.DelayBasePoint,
c.HtlcBasePoint,
)
}
// fundingTxPresent returns true if expect the funding transcation to be found
// on disk or already populated within the passed oen chanel struct.
func fundingTxPresent(channel *OpenChannel) bool {
chanType := channel.ChanType
return chanType.IsSingleFunder() && chanType.HasFundingTx() &&
channel.IsInitiator &&
!channel.hasChanStatus(ChanStatusRestored)
}
func putChanInfo(chanBucket kvdb.RwBucket, channel *OpenChannel) error {
var w bytes.Buffer
if err := WriteElements(&w,
channel.ChanType, channel.ChainHash, channel.FundingOutpoint,
channel.ShortChannelID, channel.IsPending, channel.IsInitiator,
channel.chanStatus, channel.FundingBroadcastHeight,
channel.NumConfsRequired, channel.ChannelFlags,
channel.IdentityPub, channel.Capacity, channel.TotalMSatSent,
channel.TotalMSatReceived,
); err != nil {
return err
}
// For single funder channels that we initiated, and we have the
// funding transaction, then write the funding txn.
if fundingTxPresent(channel) {
if err := WriteElement(&w, channel.FundingTxn); err != nil {
return err
}
}
if err := writeChanConfig(&w, &channel.LocalChanCfg); err != nil {
return err
}
if err := writeChanConfig(&w, &channel.RemoteChanCfg); err != nil {
return err
}
if err := chanBucket.Put(chanInfoKey, w.Bytes()); err != nil {
return err
}
// Finally, add optional shutdown scripts for the local and remote peer if
// they are present.
if err := putOptionalUpfrontShutdownScript(
chanBucket, localUpfrontShutdownKey, channel.LocalShutdownScript,
); err != nil {
return err
}
return putOptionalUpfrontShutdownScript(
chanBucket, remoteUpfrontShutdownKey, channel.RemoteShutdownScript,
)
}
// putOptionalUpfrontShutdownScript adds a shutdown script under the key
// provided if it has a non-zero length.
func putOptionalUpfrontShutdownScript(chanBucket kvdb.RwBucket, key []byte,
script []byte) error {
// If the script is empty, we do not need to add anything.
if len(script) == 0 {
return nil
}
var w bytes.Buffer
if err := WriteElement(&w, script); err != nil {
return err
}
return chanBucket.Put(key, w.Bytes())
}
// getOptionalUpfrontShutdownScript reads the shutdown script stored under the
// key provided if it is present. Upfront shutdown scripts are optional, so the
// function returns with no error if the key is not present.
func getOptionalUpfrontShutdownScript(chanBucket kvdb.RBucket, key []byte,
script *lnwire.DeliveryAddress) error {
// Return early if the bucket does not exit, a shutdown script was not set.
bs := chanBucket.Get(key)
if bs == nil {
return nil
}
var tempScript []byte
r := bytes.NewReader(bs)
if err := ReadElement(r, &tempScript); err != nil {
return err
}
*script = tempScript
return nil
}
func serializeChanCommit(w io.Writer, c *ChannelCommitment) error {
if err := WriteElements(w,
c.CommitHeight, c.LocalLogIndex, c.LocalHtlcIndex,
c.RemoteLogIndex, c.RemoteHtlcIndex, c.LocalBalance,
c.RemoteBalance, c.CommitFee, c.FeePerKw, c.CommitTx,
c.CommitSig,
); err != nil {
return err
}
return SerializeHtlcs(w, c.Htlcs...)
}
func putChanCommitment(chanBucket kvdb.RwBucket, c *ChannelCommitment,
local bool) error {
var commitKey []byte
if local {
commitKey = append(chanCommitmentKey, byte(0x00))
} else {
commitKey = append(chanCommitmentKey, byte(0x01))
}
var b bytes.Buffer
if err := serializeChanCommit(&b, c); err != nil {
return err
}
return chanBucket.Put(commitKey, b.Bytes())
}
func putChanCommitments(chanBucket kvdb.RwBucket, channel *OpenChannel) error {
// If this is a restored channel, then we don't have any commitments to
// write.
if channel.hasChanStatus(ChanStatusRestored) {
return nil
}
err := putChanCommitment(
chanBucket, &channel.LocalCommitment, true,
)
if err != nil {
return err
}
return putChanCommitment(
chanBucket, &channel.RemoteCommitment, false,
)
}
func putChanRevocationState(chanBucket kvdb.RwBucket, channel *OpenChannel) error {
var b bytes.Buffer
err := WriteElements(
&b, channel.RemoteCurrentRevocation, channel.RevocationProducer,
channel.RevocationStore,
)
if err != nil {
return err
}
// TODO(roasbeef): don't keep producer on disk
// If the next revocation is present, which is only the case after the
// FundingLocked message has been sent, then we'll write it to disk.
if channel.RemoteNextRevocation != nil {
err = WriteElements(&b, channel.RemoteNextRevocation)
if err != nil {
return err
}
}
return chanBucket.Put(revocationStateKey, b.Bytes())
}
func readChanConfig(b io.Reader, c *ChannelConfig) error {
return ReadElements(b,
&c.DustLimit, &c.MaxPendingAmount, &c.ChanReserve,
&c.MinHTLC, &c.MaxAcceptedHtlcs, &c.CsvDelay,
&c.MultiSigKey, &c.RevocationBasePoint,
&c.PaymentBasePoint, &c.DelayBasePoint,
&c.HtlcBasePoint,
)
}
func fetchChanInfo(chanBucket kvdb.RBucket, channel *OpenChannel) error {
infoBytes := chanBucket.Get(chanInfoKey)
if infoBytes == nil {
return ErrNoChanInfoFound
}
r := bytes.NewReader(infoBytes)
if err := ReadElements(r,
&channel.ChanType, &channel.ChainHash, &channel.FundingOutpoint,
&channel.ShortChannelID, &channel.IsPending, &channel.IsInitiator,
&channel.chanStatus, &channel.FundingBroadcastHeight,
&channel.NumConfsRequired, &channel.ChannelFlags,
&channel.IdentityPub, &channel.Capacity, &channel.TotalMSatSent,
&channel.TotalMSatReceived,
); err != nil {
return err
}
// For single funder channels that we initiated and have the funding
// transaction to, read the funding txn.
if fundingTxPresent(channel) {
if err := ReadElement(r, &channel.FundingTxn); err != nil {
return err
}
}
if err := readChanConfig(r, &channel.LocalChanCfg); err != nil {
return err
}
if err := readChanConfig(r, &channel.RemoteChanCfg); err != nil {
return err
}
channel.Packager = NewChannelPackager(channel.ShortChannelID)
// Finally, read the optional shutdown scripts.
if err := getOptionalUpfrontShutdownScript(
chanBucket, localUpfrontShutdownKey, &channel.LocalShutdownScript,
); err != nil {
return err
}
return getOptionalUpfrontShutdownScript(
chanBucket, remoteUpfrontShutdownKey, &channel.RemoteShutdownScript,
)
}
func deserializeChanCommit(r io.Reader) (ChannelCommitment, error) {
var c ChannelCommitment
err := ReadElements(r,
&c.CommitHeight, &c.LocalLogIndex, &c.LocalHtlcIndex, &c.RemoteLogIndex,
&c.RemoteHtlcIndex, &c.LocalBalance, &c.RemoteBalance,
&c.CommitFee, &c.FeePerKw, &c.CommitTx, &c.CommitSig,
)
if err != nil {
return c, err
}
c.Htlcs, err = DeserializeHtlcs(r)
if err != nil {
return c, err
}
return c, nil
}
func fetchChanCommitment(chanBucket kvdb.RBucket, local bool) (ChannelCommitment, error) {
var commitKey []byte
if local {
commitKey = append(chanCommitmentKey, byte(0x00))
} else {
commitKey = append(chanCommitmentKey, byte(0x01))
}
commitBytes := chanBucket.Get(commitKey)
if commitBytes == nil {
return ChannelCommitment{}, ErrNoCommitmentsFound
}
r := bytes.NewReader(commitBytes)
return deserializeChanCommit(r)
}
func fetchChanCommitments(chanBucket kvdb.RBucket, channel *OpenChannel) error {
var err error
// If this is a restored channel, then we don't have any commitments to
// read.
if channel.hasChanStatus(ChanStatusRestored) {
return nil
}
channel.LocalCommitment, err = fetchChanCommitment(chanBucket, true)
if err != nil {
return err
}
channel.RemoteCommitment, err = fetchChanCommitment(chanBucket, false)
if err != nil {
return err
}
return nil
}
func fetchChanRevocationState(chanBucket kvdb.RBucket, channel *OpenChannel) error {
revBytes := chanBucket.Get(revocationStateKey)
if revBytes == nil {
return ErrNoRevocationsFound
}
r := bytes.NewReader(revBytes)
err := ReadElements(
r, &channel.RemoteCurrentRevocation, &channel.RevocationProducer,
&channel.RevocationStore,
)
if err != nil {
return err
}
// If there aren't any bytes left in the buffer, then we don't yet have
// the next remote revocation, so we can exit early here.
if r.Len() == 0 {
return nil
}
// Otherwise we'll read the next revocation for the remote party which
// is always the last item within the buffer.
return ReadElements(r, &channel.RemoteNextRevocation)
}
func deleteOpenChannel(chanBucket kvdb.RwBucket) error {
if err := chanBucket.Delete(chanInfoKey); err != nil {
return err
}
err := chanBucket.Delete(append(chanCommitmentKey, byte(0x00)))
if err != nil {
return err
}
err = chanBucket.Delete(append(chanCommitmentKey, byte(0x01)))
if err != nil {
return err
}
if err := chanBucket.Delete(revocationStateKey); err != nil {
return err
}
if diff := chanBucket.Get(commitDiffKey); diff != nil {
return chanBucket.Delete(commitDiffKey)
}
return nil
}
// makeLogKey converts a uint64 into an 8 byte array.
func makeLogKey(updateNum uint64) [8]byte {
var key [8]byte
byteOrder.PutUint64(key[:], updateNum)
return key
}
func appendChannelLogEntry(log kvdb.RwBucket,
commit *ChannelCommitment) error {
var b bytes.Buffer
if err := serializeChanCommit(&b, commit); err != nil {
return err
}
logEntrykey := makeLogKey(commit.CommitHeight)
return log.Put(logEntrykey[:], b.Bytes())
}
func fetchChannelLogEntry(log kvdb.RBucket,
updateNum uint64) (ChannelCommitment, error) {
logEntrykey := makeLogKey(updateNum)
commitBytes := log.Get(logEntrykey[:])
if commitBytes == nil {
return ChannelCommitment{}, ErrLogEntryNotFound
}
commitReader := bytes.NewReader(commitBytes)
return deserializeChanCommit(commitReader)
}
func fetchThawHeight(chanBucket kvdb.RBucket) (uint32, error) {
var height uint32
heightBytes := chanBucket.Get(frozenChanKey)
heightReader := bytes.NewReader(heightBytes)
if err := ReadElements(heightReader, &height); err != nil {
return 0, err
}
return height, nil
}
func storeThawHeight(chanBucket kvdb.RwBucket, height uint32) error {
var heightBuf bytes.Buffer
if err := WriteElements(&heightBuf, height); err != nil {
return err
}
return chanBucket.Put(frozenChanKey, heightBuf.Bytes())
}
func deleteThawHeight(chanBucket kvdb.RwBucket) error {
return chanBucket.Delete(frozenChanKey)
}