lnd.xprv/peer.go
Olaoluwa Osuntokun 1e39cfc65f
Merge pull request #1364 from halseth/data-loss-protect
Data loss protection
2018-07-31 20:53:42 -07:00

2086 lines
62 KiB
Go

package main
import (
"bytes"
"container/list"
"fmt"
"net"
"sync"
"sync/atomic"
"time"
"github.com/btcsuite/btcd/btcec"
"github.com/btcsuite/btcd/chaincfg/chainhash"
"github.com/btcsuite/btcd/connmgr"
"github.com/btcsuite/btcd/txscript"
"github.com/btcsuite/btcd/wire"
"github.com/davecgh/go-spew/spew"
"github.com/go-errors/errors"
"github.com/lightningnetwork/lnd/brontide"
"github.com/lightningnetwork/lnd/chainntnfs"
"github.com/lightningnetwork/lnd/channeldb"
"github.com/lightningnetwork/lnd/contractcourt"
"github.com/lightningnetwork/lnd/htlcswitch"
"github.com/lightningnetwork/lnd/lnpeer"
"github.com/lightningnetwork/lnd/lnrpc"
"github.com/lightningnetwork/lnd/lnwallet"
"github.com/lightningnetwork/lnd/lnwire"
)
var (
numNodes int32
// ErrPeerExiting signals that the peer received a disconnect request.
ErrPeerExiting = errors.Errorf("peer exiting")
)
const (
// pingInterval is the interval at which ping messages are sent.
pingInterval = 1 * time.Minute
// idleTimeout is the duration of inactivity before we time out a peer.
idleTimeout = 5 * time.Minute
// writeMessageTimeout is the timeout used when writing a message to peer.
writeMessageTimeout = 10 * time.Second
// outgoingQueueLen is the buffer size of the channel which houses
// messages to be sent across the wire, requested by objects outside
// this struct.
outgoingQueueLen = 50
)
// outgoingMsg packages an lnwire.Message to be sent out on the wire, along with
// a buffered channel which will be sent upon once the write is complete. This
// buffered channel acts as a semaphore to be used for synchronization purposes.
type outgoingMsg struct {
msg lnwire.Message
errChan chan error // MUST be buffered.
}
// newChannelMsg packages an lnwallet.LightningChannel with a channel that
// allows the receiver of the request to report when the funding transaction
// has been confirmed and the channel creation process completed.
type newChannelMsg struct {
channel *lnwallet.LightningChannel
done chan struct{}
}
// closeMsgs is a wrapper struct around any wire messages that deal with the
// cooperative channel closure negotiation process. This struct includes the
// raw channel ID targeted along with the original message.
type closeMsg struct {
cid lnwire.ChannelID
msg lnwire.Message
}
// chanSnapshotReq is a message sent by outside subsystems to a peer in order
// to gain a snapshot of the peer's currently active channels.
type chanSnapshotReq struct {
resp chan []*channeldb.ChannelSnapshot
}
// peer is an active peer on the Lightning Network. This struct is responsible
// for managing any channel state related to this peer. To do so, it has
// several helper goroutines to handle events such as HTLC timeouts, new
// funding workflow, and detecting an uncooperative closure of any active
// channels.
// TODO(roasbeef): proper reconnection logic
type peer struct {
// MUST be used atomically.
started int32
disconnect int32
// The following fields are only meant to be used *atomically*
bytesReceived uint64
bytesSent uint64
// pingTime is a rough estimate of the RTT (round-trip-time) between us
// and the connected peer. This time is expressed in micro seconds.
// To be used atomically.
// TODO(roasbeef): also use a WMA or EMA?
pingTime int64
// pingLastSend is the Unix time expressed in nanoseconds when we sent
// our last ping message. To be used atomically.
pingLastSend int64
connReq *connmgr.ConnReq
conn net.Conn
addr *lnwire.NetAddress
pubKeyBytes [33]byte
inbound bool
// This mutex protects all the stats below it.
sync.RWMutex
timeConnected time.Time
lastSend time.Time
lastRecv time.Time
// sendQueue is the channel which is used to queue outgoing to be
// written onto the wire. Note that this channel is unbuffered.
sendQueue chan outgoingMsg
// outgoingQueue is a buffered channel which allows second/third party
// objects to queue messages to be sent out on the wire.
outgoingQueue chan outgoingMsg
// activeChannels is a map which stores the state machines of all
// active channels. Channels are indexed into the map by the txid of
// the funding transaction which opened the channel.
activeChanMtx sync.RWMutex
activeChannels map[lnwire.ChannelID]*lnwallet.LightningChannel
// newChannels is used by the fundingManager to send fully opened
// channels to the source peer which handled the funding workflow.
newChannels chan *newChannelMsg
// activeChanCloses is a map that keep track of all the active
// cooperative channel closures that are active. Any channel closing
// messages are directed to one of these active state machines. Once
// the channel has been closed, the state machine will be delete from
// the map.
activeChanCloses map[lnwire.ChannelID]*channelCloser
// localCloseChanReqs is a channel in which any local requests to close
// a particular channel are sent over.
localCloseChanReqs chan *htlcswitch.ChanClose
// chanCloseMsgs is a channel that any message related to channel
// closures are sent over. This includes lnwire.Shutdown message as
// well as lnwire.ClosingSigned messages.
chanCloseMsgs chan *closeMsg
server *server
// localFeatures is the set of local features that we advertised to the
// remote node.
localFeatures *lnwire.RawFeatureVector
// remoteLocalFeatures is the local feature vector received from the
// peer during the connection handshake.
remoteLocalFeatures *lnwire.FeatureVector
// remoteGlobalFeatures is the global feature vector received from the
// peer during the connection handshake.
remoteGlobalFeatures *lnwire.FeatureVector
// failedChannels is a set that tracks channels we consider `failed`.
// This is a temporary measure until we have implemented real failure
// handling at the link level, to handle the case where we reconnect to
// a peer and try to re-sync a failed channel, triggering a disconnect
// loop.
// TODO(halseth): remove when link failure is properly handled.
failedChannels map[lnwire.ChannelID]struct{}
// writeBuf is a buffer that we'll re-use in order to encode wire
// messages to write out directly on the socket. By re-using this
// buffer, we avoid needing to allocate more memory each time a new
// message is to be sent to a peer.
writeBuf [lnwire.MaxMessagePayload]byte
queueQuit chan struct{}
quit chan struct{}
wg sync.WaitGroup
}
// A compile-time check to ensure that peer satisfies the lnpeer.Peer interface.
var _ lnpeer.Peer = (*peer)(nil)
// newPeer creates a new peer from an establish connection object, and a
// pointer to the main server.
func newPeer(conn net.Conn, connReq *connmgr.ConnReq, server *server,
addr *lnwire.NetAddress, inbound bool,
localFeatures *lnwire.RawFeatureVector) (*peer, error) {
nodePub := addr.IdentityKey
p := &peer{
conn: conn,
addr: addr,
inbound: inbound,
connReq: connReq,
server: server,
localFeatures: localFeatures,
sendQueue: make(chan outgoingMsg),
outgoingQueue: make(chan outgoingMsg),
activeChannels: make(map[lnwire.ChannelID]*lnwallet.LightningChannel),
newChannels: make(chan *newChannelMsg, 1),
activeChanCloses: make(map[lnwire.ChannelID]*channelCloser),
localCloseChanReqs: make(chan *htlcswitch.ChanClose),
chanCloseMsgs: make(chan *closeMsg),
failedChannels: make(map[lnwire.ChannelID]struct{}),
queueQuit: make(chan struct{}),
quit: make(chan struct{}),
}
copy(p.pubKeyBytes[:], nodePub.SerializeCompressed())
return p, nil
}
// Start starts all helper goroutines the peer needs for normal operations. In
// the case this peer has already been started, then this function is a loop.
func (p *peer) Start() error {
if atomic.AddInt32(&p.started, 1) != 1 {
return nil
}
peerLog.Tracef("peer %v starting", p)
// Exchange local and global features, the init message should be very
// first between two nodes.
if err := p.sendInitMsg(); err != nil {
return fmt.Errorf("unable to send init msg: %v", err)
}
// Before we launch any of the helper goroutines off the peer struct,
// we'll first ensure proper adherence to the p2p protocol. The init
// message MUST be sent before any other message.
readErr := make(chan error, 1)
msgChan := make(chan lnwire.Message, 1)
p.wg.Add(1)
go func() {
defer p.wg.Done()
msg, err := p.readNextMessage()
if err != nil {
readErr <- err
msgChan <- nil
return
}
readErr <- nil
msgChan <- msg
}()
select {
// In order to avoid blocking indefinitely, we'll give the other peer
// an upper timeout of 15 seconds to respond before we bail out early.
case <-time.After(time.Second * 15):
return fmt.Errorf("peer did not complete handshake within 5 " +
"seconds")
case err := <-readErr:
if err != nil {
return fmt.Errorf("unable to read init msg: %v", err)
}
}
// Once the init message arrives, we can parse it so we can figure out
// the negotiation of features for this session.
msg := <-msgChan
if msg, ok := msg.(*lnwire.Init); ok {
if err := p.handleInitMsg(msg); err != nil {
return err
}
} else {
return errors.New("very first message between nodes " +
"must be init message")
}
// Fetch and then load all the active channels we have with this remote
// peer from the database.
activeChans, err := p.server.chanDB.FetchOpenChannels(p.addr.IdentityKey)
if err != nil {
peerLog.Errorf("unable to fetch active chans "+
"for peer %v: %v", p, err)
return err
}
// Next, load all the active channels we have with this peer,
// registering them with the switch and launching the necessary
// goroutines required to operate them.
peerLog.Debugf("Loaded %v active channels from database with "+
"NodeKey(%x)", len(activeChans), p.PubKey())
if err := p.loadActiveChannels(activeChans); err != nil {
return fmt.Errorf("unable to load channels: %v", err)
}
p.wg.Add(5)
go p.queueHandler()
go p.writeHandler()
go p.readHandler()
go p.channelManager()
go p.pingHandler()
return nil
}
// loadActiveChannels creates indexes within the peer for tracking all active
// channels returned by the database.
func (p *peer) loadActiveChannels(chans []*channeldb.OpenChannel) error {
for _, dbChan := range chans {
lnChan, err := lnwallet.NewLightningChannel(
p.server.cc.signer, p.server.witnessBeacon, dbChan,
)
if err != nil {
return err
}
chanPoint := &dbChan.FundingOutpoint
chanID := lnwire.NewChanIDFromOutPoint(chanPoint)
peerLog.Infof("NodeKey(%x) loading ChannelPoint(%v)",
p.PubKey(), chanPoint)
// Skip adding any permanently irreconcilable channels to the
// htlcswitch.
if dbChan.ChanStatus() != channeldb.Default {
peerLog.Warnf("ChannelPoint(%v) has status %v, won't "+
"start.", chanPoint, dbChan.ChanStatus)
lnChan.Stop()
continue
}
// Also skip adding any channel marked as `failed` for this
// session.
if _, ok := p.failedChannels[chanID]; ok {
peerLog.Warnf("ChannelPoint(%v) is failed, won't "+
"start.", chanPoint)
lnChan.Stop()
continue
}
_, currentHeight, err := p.server.cc.chainIO.GetBestBlock()
if err != nil {
lnChan.Stop()
return err
}
// Before we register this new link with the HTLC Switch, we'll
// need to fetch its current link-layer forwarding policy from
// the database.
graph := p.server.chanDB.ChannelGraph()
info, p1, p2, err := graph.FetchChannelEdgesByOutpoint(chanPoint)
if err != nil && err != channeldb.ErrEdgeNotFound {
lnChan.Stop()
return err
}
// We'll filter out our policy from the directional channel
// edges based whom the edge connects to. If it doesn't connect
// to us, then we know that we were the one that advertised the
// policy.
//
// TODO(roasbeef): can add helper method to get policy for
// particular channel.
var selfPolicy *channeldb.ChannelEdgePolicy
if info != nil && bytes.Equal(info.NodeKey1Bytes[:],
p.server.identityPriv.PubKey().SerializeCompressed()) {
selfPolicy = p1
} else {
selfPolicy = p2
}
// If we don't yet have an advertised routing policy, then
// we'll use the current default, otherwise we'll translate the
// routing policy into a forwarding policy.
var forwardingPolicy *htlcswitch.ForwardingPolicy
if selfPolicy != nil {
forwardingPolicy = &htlcswitch.ForwardingPolicy{
MinHTLC: selfPolicy.MinHTLC,
BaseFee: selfPolicy.FeeBaseMSat,
FeeRate: selfPolicy.FeeProportionalMillionths,
TimeLockDelta: uint32(selfPolicy.TimeLockDelta),
}
} else {
forwardingPolicy = &p.server.cc.routingPolicy
}
peerLog.Tracef("Using link policy of: %v", spew.Sdump(forwardingPolicy))
// Register this new channel link with the HTLC Switch. This is
// necessary to properly route multi-hop payments, and forward
// new payments triggered by RPC clients.
chainEvents, err := p.server.chainArb.SubscribeChannelEvents(
*chanPoint,
)
if err != nil {
lnChan.Stop()
return err
}
// Create the link and add it to the switch.
err = p.addLink(
chanPoint, lnChan, forwardingPolicy, chainEvents,
currentHeight, true,
)
if err != nil {
lnChan.Stop()
return err
}
p.activeChanMtx.Lock()
p.activeChannels[chanID] = lnChan
p.activeChanMtx.Unlock()
}
return nil
}
// addLink creates and adds a new link from the specified channel.
func (p *peer) addLink(chanPoint *wire.OutPoint,
lnChan *lnwallet.LightningChannel,
forwardingPolicy *htlcswitch.ForwardingPolicy,
chainEvents *contractcourt.ChainEventSubscription,
currentHeight int32, syncStates bool) error {
// onChannelFailure will be called by the link in case the channel
// fails for some reason.
onChannelFailure := func(chanID lnwire.ChannelID,
shortChanID lnwire.ShortChannelID,
linkErr htlcswitch.LinkFailureError) {
select {
// If the server is already exiting, then none of the actions
// below can finish exiting, so we'll exit early as well.
case <-p.server.quit:
return
default:
}
// The link has notified us about a failure. We launch a go
// routine to stop the link, disconnect the peer and optionally
// force close the channel. We must launch a goroutine since we
// must let OnChannelFailure return in order for the link to
// completely stop in the call to RemoveLink.
p.server.wg.Add(1)
go func() {
defer p.server.wg.Done()
// We begin by removing the link from the switch, such
// that it won't be attempted used for any more
// updates.
// TODO(halseth): should introduce a way to atomically
// stop/pause the link and cancel back any adds in its
// mailboxes such that we can safely force close
// without the link being added again and updates being
// applied.
err := p.server.htlcSwitch.RemoveLink(chanID)
if err != nil {
peerLog.Errorf("unable to stop link(%v): %v",
shortChanID, err)
}
// If the error encountered was severe enough, we'll
// now force close the channel.
if linkErr.ForceClose {
peerLog.Warnf("Force closing link(%v)",
shortChanID)
closeTx, err := p.server.chainArb.ForceCloseContract(*chanPoint)
if err != nil {
peerLog.Errorf("unable to force close "+
"link(%v): %v", shortChanID,
err)
} else {
peerLog.Infof("channel(%v) force "+
"closed with txid %v",
shortChanID, closeTx.TxHash())
}
}
// Send an error to the peer, why we failed the
// channel.
if linkErr.ShouldSendToPeer() {
// If SendData is set, send it to the peer. If
// not, we'll use the standard error messages
// in the payload. We only include sendData in
// the cases where the error data does not
// contain sensitive information.
data := []byte(linkErr.Error())
if linkErr.SendData != nil {
data = linkErr.SendData
}
err := p.SendMessage(true, &lnwire.Error{
ChanID: chanID,
Data: data,
})
if err != nil {
peerLog.Errorf("unable to send msg to "+
"remote peer: %v", err)
}
}
// Initiate disconnection.
// TODO(halseth): consider not disconnecting the peer,
// as we might still have other active channels with
// the same peer.
p.Disconnect(linkErr)
}()
}
linkCfg := htlcswitch.ChannelLinkConfig{
Peer: p,
DecodeHopIterators: p.server.sphinx.DecodeHopIterators,
ExtractErrorEncrypter: p.server.sphinx.ExtractErrorEncrypter,
FetchLastChannelUpdate: fetchLastChanUpdate(
p.server, p.PubKey(),
),
DebugHTLC: cfg.DebugHTLC,
HodlMask: cfg.Hodl.Mask(),
Registry: p.server.invoices,
Switch: p.server.htlcSwitch,
Circuits: p.server.htlcSwitch.CircuitModifier(),
ForwardPackets: p.server.htlcSwitch.ForwardPackets,
FwrdingPolicy: *forwardingPolicy,
FeeEstimator: p.server.cc.feeEstimator,
PreimageCache: p.server.witnessBeacon,
ChainEvents: chainEvents,
UpdateContractSignals: func(signals *contractcourt.ContractSignals) error {
return p.server.chainArb.UpdateContractSignals(
*chanPoint, signals,
)
},
OnChannelFailure: onChannelFailure,
SyncStates: syncStates,
BatchTicker: htlcswitch.NewBatchTicker(50 * time.Millisecond),
FwdPkgGCTicker: htlcswitch.NewBatchTicker(time.Minute),
BatchSize: 10,
UnsafeReplay: cfg.UnsafeReplay,
MinFeeUpdateTimeout: htlcswitch.DefaultMinLinkFeeUpdateTimeout,
MaxFeeUpdateTimeout: htlcswitch.DefaultMaxLinkFeeUpdateTimeout,
}
link := htlcswitch.NewChannelLink(linkCfg, lnChan)
// With the channel link created, we'll now notify the htlc switch so
// this channel can be used to dispatch local payments and also
// passively forward payments.
return p.server.htlcSwitch.AddLink(link)
}
// WaitForDisconnect waits until the peer has disconnected. A peer may be
// disconnected if the local or remote side terminating the connection, or an
// irrecoverable protocol error has been encountered.
func (p *peer) WaitForDisconnect() {
p.wg.Wait()
}
// Disconnect terminates the connection with the remote peer. Additionally, a
// signal is sent to the server and htlcSwitch indicating the resources
// allocated to the peer can now be cleaned up.
func (p *peer) Disconnect(reason error) {
if !atomic.CompareAndSwapInt32(&p.disconnect, 0, 1) {
return
}
peerLog.Tracef("Disconnecting %s, reason: %v", p, reason)
// Ensure that the TCP connection is properly closed before continuing.
p.conn.Close()
close(p.quit)
}
// String returns the string representation of this peer.
func (p *peer) String() string {
return p.conn.RemoteAddr().String()
}
// readNextMessage reads, and returns the next message on the wire along with
// any additional raw payload.
func (p *peer) readNextMessage() (lnwire.Message, error) {
noiseConn, ok := p.conn.(*brontide.Conn)
if !ok {
return nil, fmt.Errorf("brontide.Conn required to read messages")
}
// First we'll read the next _full_ message. We do this rather than
// reading incrementally from the stream as the Lightning wire protocol
// is message oriented and allows nodes to pad on additional data to
// the message stream.
rawMsg, err := noiseConn.ReadNextMessage()
atomic.AddUint64(&p.bytesReceived, uint64(len(rawMsg)))
if err != nil {
return nil, err
}
// Next, create a new io.Reader implementation from the raw message,
// and use this to decode the message directly from.
msgReader := bytes.NewReader(rawMsg)
nextMsg, err := lnwire.ReadMessage(msgReader, 0)
if err != nil {
return nil, err
}
p.logWireMessage(nextMsg, true)
return nextMsg, nil
}
// msgStream implements a goroutine-safe, in-order stream of messages to be
// delivered via closure to a receiver. These messages MUST be in order due to
// the nature of the lightning channel commitment and gossiper state machines.
// TODO(conner): use stream handler interface to abstract out stream
// state/logging
type msgStream struct {
streamShutdown int32 // To be used atomically.
peer *peer
apply func(lnwire.Message)
startMsg string
stopMsg string
msgCond *sync.Cond
msgs []lnwire.Message
mtx sync.Mutex
bufSize uint32
producerSema chan struct{}
wg sync.WaitGroup
quit chan struct{}
}
// newMsgStream creates a new instance of a chanMsgStream for a particular
// channel identified by its channel ID. bufSize is the max number of messages
// that should be buffered in the internal queue. Callers should set this to a
// sane value that avoids blocking unnecessarily, but doesn't allow an
// unbounded amount of memory to be allocated to buffer incoming messages.
func newMsgStream(p *peer, startMsg, stopMsg string, bufSize uint32,
apply func(lnwire.Message)) *msgStream {
stream := &msgStream{
peer: p,
apply: apply,
startMsg: startMsg,
stopMsg: stopMsg,
producerSema: make(chan struct{}, bufSize),
quit: make(chan struct{}),
}
stream.msgCond = sync.NewCond(&stream.mtx)
// Before we return the active stream, we'll populate the producer's
// semaphore channel. We'll use this to ensure that the producer won't
// attempt to allocate memory in the queue for an item until it has
// sufficient extra space.
for i := uint32(0); i < bufSize; i++ {
stream.producerSema <- struct{}{}
}
return stream
}
// Start starts the chanMsgStream.
func (ms *msgStream) Start() {
ms.wg.Add(1)
go ms.msgConsumer()
}
// Stop stops the chanMsgStream.
func (ms *msgStream) Stop() {
// TODO(roasbeef): signal too?
close(ms.quit)
// Now that we've closed the channel, we'll repeatedly signal the msg
// consumer until we've detected that it has exited.
for atomic.LoadInt32(&ms.streamShutdown) == 0 {
ms.msgCond.Signal()
time.Sleep(time.Millisecond * 100)
}
ms.wg.Wait()
}
// msgConsumer is the main goroutine that streams messages from the peer's
// readHandler directly to the target channel.
func (ms *msgStream) msgConsumer() {
defer ms.wg.Done()
defer peerLog.Tracef(ms.stopMsg)
peerLog.Tracef(ms.startMsg)
for {
// First, we'll check our condition. If the queue of messages
// is empty, then we'll wait until a new item is added.
ms.msgCond.L.Lock()
for len(ms.msgs) == 0 {
ms.msgCond.Wait()
// If we woke up in order to exit, then we'll do so.
// Otherwise, we'll check the message queue for any new
// items.
select {
case <-ms.quit:
ms.msgCond.L.Unlock()
atomic.StoreInt32(&ms.streamShutdown, 1)
return
default:
}
}
// Grab the message off the front of the queue, shifting the
// slice's reference down one in order to remove the message
// from the queue.
msg := ms.msgs[0]
ms.msgs[0] = nil // Set to nil to prevent GC leak.
ms.msgs = ms.msgs[1:]
ms.msgCond.L.Unlock()
ms.apply(msg)
// We've just successfully processed an item, so we'll signal
// to the producer that a new slot in the buffer. We'll use
// this to bound the size of the buffer to avoid allowing it to
// grow indefinitely.
select {
case ms.producerSema <- struct{}{}:
case <-ms.quit:
atomic.StoreInt32(&ms.streamShutdown, 1)
return
}
}
}
// AddMsg adds a new message to the msgStream. This function is safe for
// concurrent access.
func (ms *msgStream) AddMsg(msg lnwire.Message) {
// First, we'll attempt to receive from the producerSema struct. This
// acts as a sempahore to prevent us from indefinitely buffering
// incoming items from the wire. Either the msg queue isn't full, and
// we'll not block, or the queue is full, and we'll block until either
// we're signalled to quit, or a slot is freed up.
select {
case <-ms.producerSema:
case <-ms.quit:
return
}
// Next, we'll lock the condition, and add the message to the end of
// the message queue.
ms.msgCond.L.Lock()
ms.msgs = append(ms.msgs, msg)
ms.msgCond.L.Unlock()
// With the message added, we signal to the msgConsumer that there are
// additional messages to consume.
ms.msgCond.Signal()
}
// newChanMsgStream is used to create a msgStream between the peer and
// particular channel link in the htlcswitch. We utilize additional
// synchronization with the fundingManager to ensure we don't attempt to
// dispatch a message to a channel before it is fully active. A reference to the
// channel this stream forwards to his held in scope to prevent unnecessary
// lookups.
func newChanMsgStream(p *peer, cid lnwire.ChannelID) *msgStream {
var chanLink htlcswitch.ChannelLink
return newMsgStream(p,
fmt.Sprintf("Update stream for ChannelID(%x) created", cid[:]),
fmt.Sprintf("Update stream for ChannelID(%x) exiting", cid[:]),
1000,
func(msg lnwire.Message) {
_, isChanSycMsg := msg.(*lnwire.ChannelReestablish)
// If this is the chanSync message, then we'll deliver
// it immediately to the active link.
if !isChanSycMsg {
// We'll send a message to the funding manager
// and wait iff an active funding process for
// this channel hasn't yet completed. We do
// this in order to account for the following
// scenario: we send the funding locked message
// to the other side, they immediately send a
// channel update message, but we haven't yet
// sent the channel to the channelManager.
p.server.fundingMgr.waitUntilChannelOpen(cid)
}
// TODO(roasbeef): only wait if not chan sync
// Dispatch the commitment update message to the proper active
// goroutine dedicated to this channel.
if chanLink == nil {
link, err := p.server.htlcSwitch.GetLink(cid)
if err != nil {
peerLog.Errorf("recv'd update for unknown "+
"channel %v from %v", cid, p)
return
}
chanLink = link
}
chanLink.HandleChannelUpdate(msg)
},
)
}
// newDiscMsgStream is used to setup a msgStream between the peer and the
// authenticated gossiper. This stream should be used to forward all remote
// channel announcements.
func newDiscMsgStream(p *peer) *msgStream {
return newMsgStream(p,
"Update stream for gossiper created",
"Update stream for gossiper exited",
1000,
func(msg lnwire.Message) {
p.server.authGossiper.ProcessRemoteAnnouncement(msg, p)
},
)
}
// readHandler is responsible for reading messages off the wire in series, then
// properly dispatching the handling of the message to the proper subsystem.
//
// NOTE: This method MUST be run as a goroutine.
func (p *peer) readHandler() {
// We'll stop the timer after a new messages is received, and also
// reset it after we process the next message.
idleTimer := time.AfterFunc(idleTimeout, func() {
err := fmt.Errorf("Peer %s no answer for %s -- disconnecting",
p, idleTimeout)
p.Disconnect(err)
})
discStream := newDiscMsgStream(p)
discStream.Start()
defer discStream.Stop()
chanMsgStreams := make(map[lnwire.ChannelID]*msgStream)
out:
for atomic.LoadInt32(&p.disconnect) == 0 {
nextMsg, err := p.readNextMessage()
idleTimer.Stop()
if err != nil {
peerLog.Infof("unable to read message from %v: %v",
p, err)
switch err.(type) {
// If this is just a message we don't yet recognize,
// we'll continue processing as normal as this allows
// us to introduce new messages in a forwards
// compatible manner.
case *lnwire.UnknownMessage:
idleTimer.Reset(idleTimeout)
continue
// If they sent us an address type that we don't yet
// know of, then this isn't a dire error, so we'll
// simply continue parsing the remainder of their
// messages.
case *lnwire.ErrUnknownAddrType:
idleTimer.Reset(idleTimeout)
continue
// If the error we encountered wasn't just a message we
// didn't recognize, then we'll stop all processing s
// this is a fatal error.
default:
break out
}
}
var (
isChanUpdate bool
targetChan lnwire.ChannelID
)
switch msg := nextMsg.(type) {
case *lnwire.Pong:
// When we receive a Pong message in response to our
// last ping message, we'll use the time in which we
// sent the ping message to measure a rough estimate of
// round trip time.
pingSendTime := atomic.LoadInt64(&p.pingLastSend)
delay := (time.Now().UnixNano() - pingSendTime) / 1000
atomic.StoreInt64(&p.pingTime, delay)
case *lnwire.Ping:
pongBytes := make([]byte, msg.NumPongBytes)
p.queueMsg(lnwire.NewPong(pongBytes), nil)
case *lnwire.OpenChannel:
p.server.fundingMgr.processFundingOpen(msg, p)
case *lnwire.AcceptChannel:
p.server.fundingMgr.processFundingAccept(msg, p)
case *lnwire.FundingCreated:
p.server.fundingMgr.processFundingCreated(msg, p)
case *lnwire.FundingSigned:
p.server.fundingMgr.processFundingSigned(msg, p)
case *lnwire.FundingLocked:
p.server.fundingMgr.processFundingLocked(msg, p)
case *lnwire.Shutdown:
select {
case p.chanCloseMsgs <- &closeMsg{msg.ChannelID, msg}:
case <-p.quit:
break out
}
case *lnwire.ClosingSigned:
select {
case p.chanCloseMsgs <- &closeMsg{msg.ChannelID, msg}:
case <-p.quit:
break out
}
case *lnwire.Error:
key := p.addr.IdentityKey
switch {
// In the case of an all-zero channel ID we want to
// forward the error to all channels with this peer.
case msg.ChanID == lnwire.ConnectionWideID:
for chanID, chanStream := range chanMsgStreams {
chanStream.AddMsg(nextMsg)
// Also marked this channel as failed,
// so we won't try to restart it on
// reconnect with this peer.
p.failedChannels[chanID] = struct{}{}
}
// If the channel ID for the error message corresponds
// to a pending channel, then the funding manager will
// handle the error.
case p.server.fundingMgr.IsPendingChannel(msg.ChanID, key):
p.server.fundingMgr.processFundingError(msg, key)
// If not we hand the error to the channel link for
// this channel.
default:
isChanUpdate = true
targetChan = msg.ChanID
// Also marked this channel as failed, so we
// won't try to restart it on reconnect with
// this peer.
p.failedChannels[targetChan] = struct{}{}
}
// TODO(roasbeef): create ChanUpdater interface for the below
case *lnwire.UpdateAddHTLC:
isChanUpdate = true
targetChan = msg.ChanID
case *lnwire.UpdateFulfillHTLC:
isChanUpdate = true
targetChan = msg.ChanID
case *lnwire.UpdateFailMalformedHTLC:
isChanUpdate = true
targetChan = msg.ChanID
case *lnwire.UpdateFailHTLC:
isChanUpdate = true
targetChan = msg.ChanID
case *lnwire.RevokeAndAck:
isChanUpdate = true
targetChan = msg.ChanID
case *lnwire.CommitSig:
isChanUpdate = true
targetChan = msg.ChanID
case *lnwire.UpdateFee:
isChanUpdate = true
targetChan = msg.ChanID
case *lnwire.ChannelReestablish:
isChanUpdate = true
targetChan = msg.ChanID
case *lnwire.ChannelUpdate,
*lnwire.ChannelAnnouncement,
*lnwire.NodeAnnouncement,
*lnwire.AnnounceSignatures,
*lnwire.GossipTimestampRange,
*lnwire.QueryShortChanIDs,
*lnwire.QueryChannelRange,
*lnwire.ReplyChannelRange,
*lnwire.ReplyShortChanIDsEnd:
discStream.AddMsg(msg)
default:
peerLog.Errorf("unknown message %v received from peer "+
"%v", uint16(msg.MsgType()), p)
}
if isChanUpdate {
// If this is a channel update, then we need to feed it
// into the channel's in-order message stream.
chanStream, ok := chanMsgStreams[targetChan]
if !ok {
// If a stream hasn't yet been created, then
// we'll do so, add it to the map, and finally
// start it.
chanStream = newChanMsgStream(p, targetChan)
chanMsgStreams[targetChan] = chanStream
chanStream.Start()
}
// With the stream obtained, add the message to the
// stream so we can continue processing message.
chanStream.AddMsg(nextMsg)
}
idleTimer.Reset(idleTimeout)
}
p.wg.Done()
p.Disconnect(errors.New("read handler closed"))
for cid, chanStream := range chanMsgStreams {
chanStream.Stop()
delete(chanMsgStreams, cid)
}
peerLog.Tracef("readHandler for peer %v done", p)
}
// messageSummary returns a human-readable string that summarizes a
// incoming/outgoing message. Not all messages will have a summary, only those
// which have additional data that can be informative at a glance.
func messageSummary(msg lnwire.Message) string {
switch msg := msg.(type) {
case *lnwire.Init:
// No summary.
return ""
case *lnwire.OpenChannel:
return fmt.Sprintf("temp_chan_id=%x, chain=%v, csv=%v, amt=%v, "+
"push_amt=%v, reserve=%v, flags=%v",
msg.PendingChannelID[:], msg.ChainHash,
msg.CsvDelay, msg.FundingAmount, msg.PushAmount,
msg.ChannelReserve, msg.ChannelFlags)
case *lnwire.AcceptChannel:
return fmt.Sprintf("temp_chan_id=%x, reserve=%v, csv=%v, num_confs=%v",
msg.PendingChannelID[:], msg.ChannelReserve, msg.CsvDelay,
msg.MinAcceptDepth)
case *lnwire.FundingCreated:
return fmt.Sprintf("temp_chan_id=%x, chan_point=%v",
msg.PendingChannelID[:], msg.FundingPoint)
case *lnwire.FundingSigned:
return fmt.Sprintf("chan_id=%v", msg.ChanID)
case *lnwire.FundingLocked:
return fmt.Sprintf("chan_id=%v, next_point=%x",
msg.ChanID, msg.NextPerCommitmentPoint.SerializeCompressed())
case *lnwire.Shutdown:
return fmt.Sprintf("chan_id=%v, script=%x", msg.ChannelID,
msg.Address[:])
case *lnwire.ClosingSigned:
return fmt.Sprintf("chan_id=%v, fee_sat=%v", msg.ChannelID,
msg.FeeSatoshis)
case *lnwire.UpdateAddHTLC:
return fmt.Sprintf("chan_id=%v, id=%v, amt=%v, expiry=%v, hash=%x",
msg.ChanID, msg.ID, msg.Amount, msg.Expiry, msg.PaymentHash[:])
case *lnwire.UpdateFailHTLC:
return fmt.Sprintf("chan_id=%v, id=%v, reason=%x", msg.ChanID,
msg.ID, msg.Reason)
case *lnwire.UpdateFulfillHTLC:
return fmt.Sprintf("chan_id=%v, id=%v, pre_image=%x",
msg.ChanID, msg.ID, msg.PaymentPreimage[:])
case *lnwire.CommitSig:
return fmt.Sprintf("chan_id=%v, num_htlcs=%v", msg.ChanID,
len(msg.HtlcSigs))
case *lnwire.RevokeAndAck:
return fmt.Sprintf("chan_id=%v, rev=%x, next_point=%x",
msg.ChanID, msg.Revocation[:],
msg.NextRevocationKey.SerializeCompressed())
case *lnwire.UpdateFailMalformedHTLC:
return fmt.Sprintf("chan_id=%v, id=%v, fail_code=%v",
msg.ChanID, msg.ID, msg.FailureCode)
case *lnwire.Error:
return fmt.Sprintf("chan_id=%v, err=%v", msg.ChanID, string(msg.Data))
case *lnwire.AnnounceSignatures:
return fmt.Sprintf("chan_id=%v, short_chan_id=%v", msg.ChannelID,
msg.ShortChannelID.ToUint64())
case *lnwire.ChannelAnnouncement:
return fmt.Sprintf("chain_hash=%v, short_chan_id=%v",
msg.ChainHash, msg.ShortChannelID.ToUint64())
case *lnwire.ChannelUpdate:
return fmt.Sprintf("chain_hash=%v, short_chan_id=%v, flag=%v, "+
"update_time=%v", msg.ChainHash,
msg.ShortChannelID.ToUint64(), msg.Flags,
time.Unix(int64(msg.Timestamp), 0))
case *lnwire.NodeAnnouncement:
return fmt.Sprintf("node=%x, update_time=%v",
msg.NodeID, time.Unix(int64(msg.Timestamp), 0))
case *lnwire.Ping:
// No summary.
return ""
case *lnwire.Pong:
// No summary.
return ""
case *lnwire.UpdateFee:
return fmt.Sprintf("chan_id=%v, fee_update_sat=%v",
msg.ChanID, int64(msg.FeePerKw))
case *lnwire.ChannelReestablish:
return fmt.Sprintf("next_local_height=%v, remote_tail_height=%v",
msg.NextLocalCommitHeight, msg.RemoteCommitTailHeight)
case *lnwire.ReplyShortChanIDsEnd:
return fmt.Sprintf("chain_hash=%v, complete=%v", msg.ChainHash,
msg.Complete)
case *lnwire.ReplyChannelRange:
return fmt.Sprintf("complete=%v, encoding=%v, num_chans=%v",
msg.Complete, msg.EncodingType, len(msg.ShortChanIDs))
case *lnwire.QueryShortChanIDs:
return fmt.Sprintf("chain_hash=%v, encoding=%v, num_chans=%v",
msg.ChainHash, msg.EncodingType, len(msg.ShortChanIDs))
case *lnwire.QueryChannelRange:
return fmt.Sprintf("chain_hash=%v, start_height=%v, "+
"num_blocks=%v", msg.ChainHash, msg.FirstBlockHeight,
msg.NumBlocks)
case *lnwire.GossipTimestampRange:
return fmt.Sprintf("chain_hash=%v, first_stamp=%v, "+
"stamp_range=%v", msg.ChainHash,
time.Unix(int64(msg.FirstTimestamp), 0),
msg.TimestampRange)
}
return ""
}
// logWireMessage logs the receipt or sending of particular wire message. This
// function is used rather than just logging the message in order to produce
// less spammy log messages in trace mode by setting the 'Curve" parameter to
// nil. Doing this avoids printing out each of the field elements in the curve
// parameters for secp256k1.
func (p *peer) logWireMessage(msg lnwire.Message, read bool) {
summaryPrefix := "Received"
if !read {
summaryPrefix = "Sending"
}
peerLog.Debugf("%v", newLogClosure(func() string {
// Debug summary of message.
summary := messageSummary(msg)
if len(summary) > 0 {
summary = "(" + summary + ")"
}
preposition := "to"
if read {
preposition = "from"
}
return fmt.Sprintf("%v %v%s %v %s", summaryPrefix,
msg.MsgType(), summary, preposition, p)
}))
switch m := msg.(type) {
case *lnwire.ChannelReestablish:
if m.LocalUnrevokedCommitPoint != nil {
m.LocalUnrevokedCommitPoint.Curve = nil
}
case *lnwire.RevokeAndAck:
m.NextRevocationKey.Curve = nil
case *lnwire.AcceptChannel:
m.FundingKey.Curve = nil
m.RevocationPoint.Curve = nil
m.PaymentPoint.Curve = nil
m.DelayedPaymentPoint.Curve = nil
m.HtlcPoint.Curve = nil
m.FirstCommitmentPoint.Curve = nil
case *lnwire.OpenChannel:
m.FundingKey.Curve = nil
m.RevocationPoint.Curve = nil
m.PaymentPoint.Curve = nil
m.DelayedPaymentPoint.Curve = nil
m.HtlcPoint.Curve = nil
m.FirstCommitmentPoint.Curve = nil
case *lnwire.FundingLocked:
m.NextPerCommitmentPoint.Curve = nil
}
prefix := "readMessage from"
if !read {
prefix = "writeMessage to"
}
peerLog.Tracef(prefix+" %v: %v", p, newLogClosure(func() string {
return spew.Sdump(msg)
}))
}
// writeMessage writes the target lnwire.Message to the remote peer.
func (p *peer) writeMessage(msg lnwire.Message) error {
// Simply exit if we're shutting down.
if atomic.LoadInt32(&p.disconnect) != 0 {
return ErrPeerExiting
}
p.logWireMessage(msg, false)
// We'll re-slice of static write buffer to allow this new message to
// utilize all available space. We also ensure we cap the capacity of
// this new buffer to the static buffer which is sized for the largest
// possible protocol message.
b := bytes.NewBuffer(p.writeBuf[0:0:len(p.writeBuf)])
// With the temp buffer created and sliced properly (length zero, full
// capacity), we'll now encode the message directly into this buffer.
n, err := lnwire.WriteMessage(b, msg, 0)
atomic.AddUint64(&p.bytesSent, uint64(n))
p.conn.SetWriteDeadline(time.Now().Add(writeMessageTimeout))
// Finally, write the message itself in a single swoop.
_, err = p.conn.Write(b.Bytes())
return err
}
// writeHandler is a goroutine dedicated to reading messages off of an incoming
// queue, and writing them out to the wire. This goroutine coordinates with the
// queueHandler in order to ensure the incoming message queue is quickly
// drained.
//
// NOTE: This method MUST be run as a goroutine.
func (p *peer) writeHandler() {
var exitErr error
out:
for {
select {
case outMsg := <-p.sendQueue:
switch outMsg.msg.(type) {
// If we're about to send a ping message, then log the
// exact time in which we send the message so we can
// use the delay as a rough estimate of latency to the
// remote peer.
case *lnwire.Ping:
// TODO(roasbeef): do this before the write?
// possibly account for processing within func?
now := time.Now().UnixNano()
atomic.StoreInt64(&p.pingLastSend, now)
}
// Write out the message to the socket, responding with
// error if `errChan` is non-nil. The `errChan` allows
// callers to optionally synchronize sends with the
// writeHandler.
err := p.writeMessage(outMsg.msg)
if outMsg.errChan != nil {
outMsg.errChan <- err
}
if err != nil {
exitErr = errors.Errorf("unable to write message: %v", err)
break out
}
case <-p.quit:
exitErr = ErrPeerExiting
break out
}
}
p.wg.Done()
p.Disconnect(exitErr)
peerLog.Tracef("writeHandler for peer %v done", p)
}
// queueHandler is responsible for accepting messages from outside subsystems
// to be eventually sent out on the wire by the writeHandler.
//
// NOTE: This method MUST be run as a goroutine.
func (p *peer) queueHandler() {
defer p.wg.Done()
// pendingMsgs will hold all messages waiting to be added
// to the sendQueue.
pendingMsgs := list.New()
for {
// Examine the front of the queue.
elem := pendingMsgs.Front()
if elem != nil {
// There's an element on the queue, try adding
// it to the sendQueue. We also watch for
// messages on the outgoingQueue, in case the
// writeHandler cannot accept messages on the
// sendQueue.
select {
case p.sendQueue <- elem.Value.(outgoingMsg):
pendingMsgs.Remove(elem)
case msg := <-p.outgoingQueue:
pendingMsgs.PushBack(msg)
case <-p.quit:
return
}
} else {
// If there weren't any messages to send to the
// writeHandler, then we'll accept a new message
// into the queue from outside sub-systems.
select {
case msg := <-p.outgoingQueue:
pendingMsgs.PushBack(msg)
case <-p.quit:
return
}
}
}
}
// pingHandler is responsible for periodically sending ping messages to the
// remote peer in order to keep the connection alive and/or determine if the
// connection is still active.
//
// NOTE: This method MUST be run as a goroutine.
func (p *peer) pingHandler() {
defer p.wg.Done()
pingTicker := time.NewTicker(pingInterval)
defer pingTicker.Stop()
// TODO(roasbeef): make dynamic in order to create fake cover traffic
const numPingBytes = 16
out:
for {
select {
case <-pingTicker.C:
p.queueMsg(lnwire.NewPing(numPingBytes), nil)
case <-p.quit:
break out
}
}
}
// PingTime returns the estimated ping time to the peer in microseconds.
func (p *peer) PingTime() int64 {
return atomic.LoadInt64(&p.pingTime)
}
// queueMsg queues a new lnwire.Message to be eventually sent out on the
// wire. It returns an error if we failed to queue the message. An error
// is sent on errChan if the message fails being sent to the peer, or
// nil otherwise.
func (p *peer) queueMsg(msg lnwire.Message, errChan chan error) {
select {
case p.outgoingQueue <- outgoingMsg{msg, errChan}:
case <-p.quit:
peerLog.Tracef("Peer shutting down, could not enqueue msg.")
if errChan != nil {
errChan <- ErrPeerExiting
}
}
}
// ChannelSnapshots returns a slice of channel snapshots detailing all
// currently active channels maintained with the remote peer.
func (p *peer) ChannelSnapshots() []*channeldb.ChannelSnapshot {
p.activeChanMtx.RLock()
defer p.activeChanMtx.RUnlock()
snapshots := make([]*channeldb.ChannelSnapshot, 0, len(p.activeChannels))
for _, activeChan := range p.activeChannels {
// We'll only return a snapshot for channels that are
// *immedately* available for routing payments over.
if activeChan.RemoteNextRevocation() == nil {
continue
}
snapshot := activeChan.StateSnapshot()
snapshots = append(snapshots, snapshot)
}
return snapshots
}
// genDeliveryScript returns a new script to be used to send our funds to in
// the case of a cooperative channel close negotiation.
func (p *peer) genDeliveryScript() ([]byte, error) {
deliveryAddr, err := p.server.cc.wallet.NewAddress(
lnwallet.WitnessPubKey, false,
)
if err != nil {
return nil, err
}
peerLog.Infof("Delivery addr for channel close: %v",
deliveryAddr)
return txscript.PayToAddrScript(deliveryAddr)
}
// channelManager is goroutine dedicated to handling all requests/signals
// pertaining to the opening, cooperative closing, and force closing of all
// channels maintained with the remote peer.
//
// NOTE: This method MUST be run as a goroutine.
func (p *peer) channelManager() {
defer p.wg.Done()
out:
for {
select {
// A new channel has arrived which means we've just completed a
// funding workflow. We'll initialize the necessary local
// state, and notify the htlc switch of a new link.
case newChanReq := <-p.newChannels:
chanPoint := newChanReq.channel.ChannelPoint()
chanID := lnwire.NewChanIDFromOutPoint(chanPoint)
newChan := newChanReq.channel
// Make sure this channel is not already active.
p.activeChanMtx.Lock()
if currentChan, ok := p.activeChannels[chanID]; ok {
peerLog.Infof("Already have ChannelPoint(%v), "+
"ignoring.", chanPoint)
p.activeChanMtx.Unlock()
close(newChanReq.done)
newChanReq.channel.Stop()
// If we're being sent a new channel, and our
// existing channel doesn't have the next
// revocation, then we need to update the
// current existing channel.
if currentChan.RemoteNextRevocation() != nil {
continue
}
peerLog.Infof("Processing retransmitted "+
"FundingLocked for ChannelPoint(%v)",
chanPoint)
nextRevoke := newChan.RemoteNextRevocation()
err := currentChan.InitNextRevocation(nextRevoke)
if err != nil {
peerLog.Errorf("unable to init chan "+
"revocation: %v", err)
continue
}
continue
}
// If not already active, we'll add this channel to the
// set of active channels, so we can look it up later
// easily according to its channel ID.
p.activeChannels[chanID] = newChan
p.activeChanMtx.Unlock()
peerLog.Infof("New channel active ChannelPoint(%v) "+
"with NodeKey(%x)", chanPoint, p.PubKey())
// Next, we'll assemble a ChannelLink along with the
// necessary items it needs to function.
//
// TODO(roasbeef): panic on below?
_, currentHeight, err := p.server.cc.chainIO.GetBestBlock()
if err != nil {
peerLog.Errorf("unable to get best block: %v", err)
continue
}
chainEvents, err := p.server.chainArb.SubscribeChannelEvents(
*chanPoint,
)
if err != nil {
peerLog.Errorf("unable to subscribe to chain "+
"events: %v", err)
continue
}
// Create the link and add it to the switch.
err = p.addLink(
chanPoint, newChan, &p.server.cc.routingPolicy,
chainEvents, currentHeight, false,
)
if err != nil {
peerLog.Errorf("can't register new channel "+
"link(%v) with NodeKey(%x): %v", chanPoint,
p.PubKey(), err)
}
close(newChanReq.done)
// We've just received a local request to close an active
// channel. If will either kick of a cooperative channel
// closure negotiation, or be a notification of a breached
// contract that should be abandoned.
case req := <-p.localCloseChanReqs:
p.handleLocalCloseReq(req)
// We've received a new cooperative channel closure related
// message from the remote peer, we'll use this message to
// advance the chan closer state machine.
case closeMsg := <-p.chanCloseMsgs:
// We'll now fetch the matching closing state machine
// in order to continue, or finalize the channel
// closure process.
chanCloser, err := p.fetchActiveChanCloser(closeMsg.cid)
if err != nil {
// If the channel is not known to us, we'll
// simply ignore this message.
if err == ErrChannelNotFound {
continue
}
peerLog.Errorf("Unable to respond to remote "+
"close msg: %v", err)
errMsg := &lnwire.Error{
ChanID: closeMsg.cid,
Data: lnwire.ErrorData(err.Error()),
}
p.queueMsg(errMsg, nil)
continue
}
// Next, we'll process the next message using the
// target state machine. We'll either continue
// negotiation, or halt.
msgs, closeFin, err := chanCloser.ProcessCloseMsg(
closeMsg.msg,
)
if err != nil {
err := fmt.Errorf("unable to process close "+
"msg: %v", err)
peerLog.Error(err)
// As the negotiations failed, we'll reset the
// channel state to ensure we act to on-chain
// events as normal.
chanCloser.cfg.channel.ResetState()
if chanCloser.CloseRequest() != nil {
chanCloser.CloseRequest().Err <- err
}
delete(p.activeChanCloses, closeMsg.cid)
continue
}
// Queue any messages to the remote peer that need to
// be sent as a part of this latest round of
// negotiations.
for _, msg := range msgs {
p.queueMsg(msg, nil)
}
// If we haven't finished close negotiations, then
// we'll continue as we can't yet finalize the closure.
if !closeFin {
continue
}
// Otherwise, we've agreed on a closing fee! In this
// case, we'll wrap up the channel closure by notifying
// relevant sub-systems and launching a goroutine to
// wait for close tx conf.
p.finalizeChanClosure(chanCloser)
case <-p.quit:
// As, we've been signalled to exit, we'll reset all
// our active channel back to their default state.
p.activeChanMtx.Lock()
for _, channel := range p.activeChannels {
channel.ResetState()
}
p.activeChanMtx.Unlock()
break out
}
}
}
// fetchActiveChanCloser attempts to fetch the active chan closer state machine
// for the target channel ID. If the channel isn't active an error is returned.
// Otherwise, either an existing state machine will be returned, or a new one
// will be created.
func (p *peer) fetchActiveChanCloser(chanID lnwire.ChannelID) (*channelCloser, error) {
// First, we'll ensure that we actually know of the target channel. If
// not, we'll ignore this message.
p.activeChanMtx.RLock()
channel, ok := p.activeChannels[chanID]
p.activeChanMtx.RUnlock()
if !ok {
return nil, ErrChannelNotFound
}
// We'll attempt to look up the matching state machine, if we can't
// find one then this means that the remote party is initiating a
// cooperative channel closure.
chanCloser, ok := p.activeChanCloses[chanID]
if !ok {
// If we need to create a chan closer for the first time, then
// we'll check to ensure that the channel is even in the proper
// state to allow a co-op channel closure.
if len(channel.ActiveHtlcs()) != 0 {
return nil, fmt.Errorf("cannot co-op close " +
"channel w/ active htlcs")
}
// We'll create a valid closing state machine in order to
// respond to the initiated cooperative channel closure.
deliveryAddr, err := p.genDeliveryScript()
if err != nil {
peerLog.Errorf("unable to gen delivery script: %v", err)
return nil, fmt.Errorf("close addr unavailable")
}
// In order to begin fee negotiations, we'll first compute our
// target ideal fee-per-kw. We'll set this to a lax value, as
// we weren't the ones that initiated the channel closure.
feePerVSize, err := p.server.cc.feeEstimator.EstimateFeePerVSize(6)
if err != nil {
peerLog.Errorf("unable to query fee estimator: %v", err)
return nil, fmt.Errorf("unable to estimate fee")
}
// We'll then convert the sat per weight to sat per k/w as this
// is the native unit used within the protocol when dealing
// with fees.
targetFeePerKw := feePerVSize.FeePerKWeight()
_, startingHeight, err := p.server.cc.chainIO.GetBestBlock()
if err != nil {
peerLog.Errorf("unable to obtain best block: %v", err)
return nil, fmt.Errorf("cannot obtain best block")
}
chanCloser = newChannelCloser(
chanCloseCfg{
channel: channel,
unregisterChannel: p.server.htlcSwitch.RemoveLink,
broadcastTx: p.server.cc.wallet.PublishTransaction,
disableChannel: p.server.disableChannel,
quit: p.quit,
},
deliveryAddr,
targetFeePerKw,
uint32(startingHeight),
nil,
)
p.activeChanCloses[chanID] = chanCloser
}
return chanCloser, nil
}
// handleLocalCloseReq kicks-off the workflow to execute a cooperative or
// forced unilateral closure of the channel initiated by a local subsystem.
func (p *peer) handleLocalCloseReq(req *htlcswitch.ChanClose) {
chanID := lnwire.NewChanIDFromOutPoint(req.ChanPoint)
p.activeChanMtx.RLock()
channel, ok := p.activeChannels[chanID]
p.activeChanMtx.RUnlock()
if !ok {
err := fmt.Errorf("unable to close channel, ChannelID(%v) is "+
"unknown", chanID)
peerLog.Errorf(err.Error())
req.Err <- err
return
}
switch req.CloseType {
// A type of CloseRegular indicates that the user has opted to close
// out this channel on-chain, so we execute the cooperative channel
// closure workflow.
case htlcswitch.CloseRegular:
// First, we'll fetch a fresh delivery address that we'll use
// to send the funds to in the case of a successful
// negotiation.
deliveryAddr, err := p.genDeliveryScript()
if err != nil {
peerLog.Errorf(err.Error())
req.Err <- err
return
}
// Next, we'll create a new channel closer state machine to
// handle the close negotiation.
_, startingHeight, err := p.server.cc.chainIO.GetBestBlock()
if err != nil {
peerLog.Errorf(err.Error())
req.Err <- err
return
}
chanCloser := newChannelCloser(
chanCloseCfg{
channel: channel,
unregisterChannel: p.server.htlcSwitch.RemoveLink,
broadcastTx: p.server.cc.wallet.PublishTransaction,
disableChannel: p.server.disableChannel,
quit: p.quit,
},
deliveryAddr,
req.TargetFeePerKw,
uint32(startingHeight),
req,
)
p.activeChanCloses[chanID] = chanCloser
// Finally, we'll initiate the channel shutdown within the
// chanCloser, and send the shutdown message to the remote
// party to kick things off.
shutdownMsg, err := chanCloser.ShutdownChan()
if err != nil {
peerLog.Errorf(err.Error())
req.Err <- err
delete(p.activeChanCloses, chanID)
// As we were unable to shutdown the channel, we'll
// return it back to its normal state.
channel.ResetState()
return
}
p.queueMsg(shutdownMsg, nil)
// A type of CloseBreach indicates that the counterparty has breached
// the channel therefore we need to clean up our local state.
case htlcswitch.CloseBreach:
// TODO(roasbeef): no longer need with newer beach logic?
peerLog.Infof("ChannelPoint(%v) has been breached, wiping "+
"channel", req.ChanPoint)
if err := p.WipeChannel(req.ChanPoint); err != nil {
peerLog.Infof("Unable to wipe channel after detected "+
"breach: %v", err)
req.Err <- err
return
}
return
}
}
// finalizeChanClosure performs the final clean up steps once the cooperative
// closure transaction has been fully broadcast. The finalized closing state
// machine should be passed in. Once the transaction has been sufficiently
// confirmed, the channel will be marked as fully closed within the database,
// and any clients will be notified of updates to the closing state.
func (p *peer) finalizeChanClosure(chanCloser *channelCloser) {
closeReq := chanCloser.CloseRequest()
// First, we'll clear all indexes related to the channel in question.
chanPoint := chanCloser.cfg.channel.ChannelPoint()
if err := p.WipeChannel(chanPoint); err != nil {
if closeReq != nil {
closeReq.Err <- err
}
}
chanCloser.cfg.channel.Stop()
// Next, we'll launch a goroutine which will request to be notified by
// the ChainNotifier once the closure transaction obtains a single
// confirmation.
notifier := p.server.cc.chainNotifier
// If any error happens during waitForChanToClose, forward it to
// closeReq. If this channel closure is not locally initiated, closeReq
// will be nil, so just ignore the error.
errChan := make(chan error, 1)
if closeReq != nil {
errChan = closeReq.Err
}
closingTx, err := chanCloser.ClosingTx()
if err != nil {
if closeReq != nil {
peerLog.Error(err)
closeReq.Err <- err
}
}
closingTxid := closingTx.TxHash()
// If this is a locally requested shutdown, update the caller with a
// new event detailing the current pending state of this request.
if closeReq != nil {
closeReq.Updates <- &lnrpc.CloseStatusUpdate{
Update: &lnrpc.CloseStatusUpdate_ClosePending{
ClosePending: &lnrpc.PendingUpdate{
Txid: closingTxid[:],
},
},
}
}
go waitForChanToClose(chanCloser.negotiationHeight, notifier, errChan,
chanPoint, &closingTxid, func() {
// Respond to the local subsystem which requested the
// channel closure.
if closeReq != nil {
closeReq.Updates <- &lnrpc.CloseStatusUpdate{
Update: &lnrpc.CloseStatusUpdate_ChanClose{
ChanClose: &lnrpc.ChannelCloseUpdate{
ClosingTxid: closingTxid[:],
Success: true,
},
},
}
}
// Remove the persistent connection to this peer if we
// no longer have open channels with them.
p.activeChanMtx.Lock()
numActiveChans := len(p.activeChannels)
p.activeChanMtx.Unlock()
if numActiveChans == 0 {
p.server.prunePersistentPeerConnection(
p.pubKeyBytes,
)
}
})
}
// waitForChanToClose uses the passed notifier to wait until the channel has
// been detected as closed on chain and then concludes by executing the
// following actions: the channel point will be sent over the settleChan, and
// finally the callback will be executed. If any error is encountered within
// the function, then it will be sent over the errChan.
func waitForChanToClose(bestHeight uint32, notifier chainntnfs.ChainNotifier,
errChan chan error, chanPoint *wire.OutPoint,
closingTxID *chainhash.Hash, cb func()) {
peerLog.Infof("Waiting for confirmation of cooperative close of "+
"ChannelPoint(%v) with txid: %v", chanPoint,
closingTxID)
// TODO(roasbeef): add param for num needed confs
confNtfn, err := notifier.RegisterConfirmationsNtfn(closingTxID, 1,
bestHeight)
if err != nil {
if errChan != nil {
errChan <- err
}
return
}
// In the case that the ChainNotifier is shutting down, all subscriber
// notification channels will be closed, generating a nil receive.
height, ok := <-confNtfn.Confirmed
if !ok {
return
}
// The channel has been closed, remove it from any active indexes, and
// the database state.
peerLog.Infof("ChannelPoint(%v) is now closed at "+
"height %v", chanPoint, height.BlockHeight)
// Finally, execute the closure call back to mark the confirmation of
// the transaction closing the contract.
cb()
}
// WipeChannel removes the passed channel point from all indexes associated
// with the peer, and the switch.
func (p *peer) WipeChannel(chanPoint *wire.OutPoint) error {
chanID := lnwire.NewChanIDFromOutPoint(chanPoint)
p.activeChanMtx.Lock()
if channel, ok := p.activeChannels[chanID]; ok {
channel.Stop()
delete(p.activeChannels, chanID)
if len(p.activeChannels) == 0 {
p.server.prunePersistentPeerConnection(p.pubKeyBytes)
}
}
p.activeChanMtx.Unlock()
// Instruct the HtlcSwitch to close this link as the channel is no
// longer active.
if err := p.server.htlcSwitch.RemoveLink(chanID); err != nil {
if err == htlcswitch.ErrChannelLinkNotFound {
peerLog.Warnf("unable remove channel link with "+
"ChannelPoint(%v): %v", chanID, err)
return nil
}
return err
}
return nil
}
// handleInitMsg handles the incoming init message which contains global and
// local features vectors. If feature vectors are incompatible then disconnect.
func (p *peer) handleInitMsg(msg *lnwire.Init) error {
p.remoteLocalFeatures = lnwire.NewFeatureVector(msg.LocalFeatures,
lnwire.LocalFeatures)
p.remoteGlobalFeatures = lnwire.NewFeatureVector(msg.GlobalFeatures,
lnwire.GlobalFeatures)
unknownLocalFeatures := p.remoteLocalFeatures.UnknownRequiredFeatures()
if len(unknownLocalFeatures) > 0 {
err := errors.Errorf("Peer set unknown local feature bits: %v",
unknownLocalFeatures)
peerLog.Error(err)
return err
}
unknownGlobalFeatures := p.remoteGlobalFeatures.UnknownRequiredFeatures()
if len(unknownGlobalFeatures) > 0 {
err := errors.Errorf("Peer set unknown global feature bits: %v",
unknownGlobalFeatures)
peerLog.Error(err)
return err
}
return nil
}
// sendInitMsg sends init message to remote peer which contains our currently
// supported local and global features.
func (p *peer) sendInitMsg() error {
msg := lnwire.NewInitMessage(
p.server.globalFeatures.RawFeatureVector,
p.localFeatures,
)
return p.writeMessage(msg)
}
// SendMessage sends a variadic number of message to remote peer. The first
// argument denotes if the method should block until the message has been sent
// to the remote peer.
func (p *peer) SendMessage(sync bool, msgs ...lnwire.Message) error {
// Add all incoming messages to the outgoing queue. A list of error
// chans is populated for each message if the caller requested a sync
// send.
var errChans []chan error
for _, msg := range msgs {
// If a sync send was requested, create an error chan to listen
// for an ack from the writeHandler.
var errChan chan error
if sync {
errChan = make(chan error, 1)
errChans = append(errChans, errChan)
}
p.queueMsg(msg, errChan)
}
// Wait for all replies from the writeHandler. For async sends, this
// will be a NOP as the list of error chans is nil.
for _, errChan := range errChans {
select {
case err := <-errChan:
return err
case <-p.quit:
return ErrPeerExiting
}
}
return nil
}
// PubKey returns the pubkey of the peer in compressed serialized format.
func (p *peer) PubKey() [33]byte {
return p.pubKeyBytes
}
// IdentityKey returns the public key of the remote peer.
func (p *peer) IdentityKey() *btcec.PublicKey {
return p.addr.IdentityKey
}
// Address returns the network address of the remote peer.
func (p *peer) Address() net.Addr {
return p.addr.Address
}
// AddNewChannel adds a new channel to the peer. The channel should fail to be
// added if the cancel channel is closed.
func (p *peer) AddNewChannel(channel *lnwallet.LightningChannel,
cancel <-chan struct{}) error {
newChanDone := make(chan struct{})
newChanMsg := &newChannelMsg{
channel: channel,
done: newChanDone,
}
select {
case p.newChannels <- newChanMsg:
case <-cancel:
return errors.New("canceled adding new channel")
case <-p.quit:
return ErrPeerExiting
}
// We pause here to wait for the peer to recognize the new channel
// before we close the channel barrier corresponding to the channel.
select {
case <-newChanDone:
case <-p.quit:
return ErrPeerExiting
}
return nil
}
// TODO(roasbeef): make all start/stop mutexes a CAS
// fetchLastChanUpdate returns a function which is able to retrieve the last
// channel update for a target channel.
func fetchLastChanUpdate(s *server,
pubKey [33]byte) func(lnwire.ShortChannelID) (*lnwire.ChannelUpdate, error) {
return func(cid lnwire.ShortChannelID) (*lnwire.ChannelUpdate, error) {
info, edge1, edge2, err := s.chanRouter.GetChannelByID(cid)
if err != nil {
return nil, err
}
if edge1 == nil || edge2 == nil {
return nil, fmt.Errorf("unable to find channel by "+
"ShortChannelID(%v)", cid)
}
// If we're the outgoing node on the first edge, then that
// means the second edge is our policy. Otherwise, the first
// edge is our policy.
var local *channeldb.ChannelEdgePolicy
if bytes.Equal(edge1.Node.PubKeyBytes[:], pubKey[:]) {
local = edge2
} else {
local = edge1
}
return extractChannelUpdate(info, local)
}
}