lnd.xprv/channeldb/graph.go

3491 lines
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package channeldb
import (
"bytes"
"crypto/sha256"
"encoding/binary"
"errors"
"fmt"
"image/color"
"io"
"math"
"net"
"time"
"github.com/btcsuite/btcd/btcec"
"github.com/btcsuite/btcd/chaincfg/chainhash"
"github.com/btcsuite/btcd/txscript"
"github.com/btcsuite/btcd/wire"
"github.com/btcsuite/btcutil"
"github.com/coreos/bbolt"
"github.com/lightningnetwork/lnd/lnwire"
)
var (
// nodeBucket is a bucket which houses all the vertices or nodes within
// the channel graph. This bucket has a single-sub bucket which adds an
// additional index from pubkey -> alias. Within the top-level of this
// bucket, the key space maps a node's compressed public key to the
// serialized information for that node. Additionally, there's a
// special key "source" which stores the pubkey of the source node. The
// source node is used as the starting point for all graph/queries and
// traversals. The graph is formed as a star-graph with the source node
// at the center.
//
// maps: pubKey -> nodeInfo
// maps: source -> selfPubKey
nodeBucket = []byte("graph-node")
// nodeUpdateIndexBucket is a sub-bucket of the nodeBucket. This bucket
// will be used to quickly look up the "freshness" of a node's last
// update to the network. The bucket only contains keys, and no values,
// it's mapping:
//
// maps: updateTime || nodeID -> nil
nodeUpdateIndexBucket = []byte("graph-node-update-index")
// sourceKey is a special key that resides within the nodeBucket. The
// sourceKey maps a key to the public key of the "self node".
sourceKey = []byte("source")
// aliasIndexBucket is a sub-bucket that's nested within the main
// nodeBucket. This bucket maps the public key of a node to its
// current alias. This bucket is provided as it can be used within a
// future UI layer to add an additional degree of confirmation.
aliasIndexBucket = []byte("alias")
// edgeBucket is a bucket which houses all of the edge or channel
// information within the channel graph. This bucket essentially acts
// as an adjacency list, which in conjunction with a range scan, can be
// used to iterate over all the incoming and outgoing edges for a
// particular node. Key in the bucket use a prefix scheme which leads
// with the node's public key and sends with the compact edge ID.
// For each chanID, there will be two entries within the bucket, as the
// graph is directed: nodes may have different policies w.r.t to fees
// for their respective directions.
//
// maps: pubKey || chanID -> channel edge policy for node
edgeBucket = []byte("graph-edge")
// unknownPolicy is represented as an empty slice. It is
// used as the value in edgeBucket for unknown channel edge policies.
// Unknown policies are still stored in the database to enable efficient
// lookup of incoming channel edges.
unknownPolicy = []byte{}
// chanStart is an array of all zero bytes which is used to perform
// range scans within the edgeBucket to obtain all of the outgoing
// edges for a particular node.
chanStart [8]byte
// edgeIndexBucket is an index which can be used to iterate all edges
// in the bucket, grouping them according to their in/out nodes.
// Additionally, the items in this bucket also contain the complete
// edge information for a channel. The edge information includes the
2018-04-18 05:02:04 +03:00
// capacity of the channel, the nodes that made the channel, etc. This
// bucket resides within the edgeBucket above. Creation of an edge
// proceeds in two phases: first the edge is added to the edge index,
// afterwards the edgeBucket can be updated with the latest details of
// the edge as they are announced on the network.
//
// maps: chanID -> pubKey1 || pubKey2 || restofEdgeInfo
edgeIndexBucket = []byte("edge-index")
// edgeUpdateIndexBucket is a sub-bucket of the main edgeBucket. This
// bucket contains an index which allows us to gauge the "freshness" of
// a channel's last updates.
//
// maps: updateTime || chanID -> nil
edgeUpdateIndexBucket = []byte("edge-update-index")
// channelPointBucket maps a channel's full outpoint (txid:index) to
// its short 8-byte channel ID. This bucket resides within the
// edgeBucket above, and can be used to quickly remove an edge due to
// the outpoint being spent, or to query for existence of a channel.
//
// maps: outPoint -> chanID
channelPointBucket = []byte("chan-index")
// graphMetaBucket is a top-level bucket which stores various meta-deta
// related to the on-disk channel graph. Data stored in this bucket
// includes the block to which the graph has been synced to, the total
// number of channels, etc.
graphMetaBucket = []byte("graph-meta")
// pruneLogBucket is a bucket within the graphMetaBucket that stores
// a mapping from the block height to the hash for the blocks used to
// prune the graph.
// Once a new block is discovered, any channels that have been closed
// (by spending the outpoint) can safely be removed from the graph, and
// the block is added to the prune log. We need to keep such a log for
// the case where a reorg happens, and we must "rewind" the state of the
// graph by removing channels that were previously confirmed. In such a
// case we'll remove all entries from the prune log with a block height
// that no longer exists.
pruneLogBucket = []byte("prune-log")
edgeBloomKey = []byte("edge-bloom")
nodeBloomKey = []byte("node-bloom")
)
const (
// MaxAllowedExtraOpaqueBytes is the largest amount of opaque bytes that
// we'll permit to be written to disk. We limit this as otherwise, it
// would be possible for a node to create a ton of updates and slowly
// fill our disk, and also waste bandwidth due to relaying.
MaxAllowedExtraOpaqueBytes = 10000
)
// ChannelGraph is a persistent, on-disk graph representation of the Lightning
// Network. This struct can be used to implement path finding algorithms on top
// of, and also to update a node's view based on information received from the
// p2p network. Internally, the graph is stored using a modified adjacency list
// representation with some added object interaction possible with each
// serialized edge/node. The graph is stored is directed, meaning that are two
// edges stored for each channel: an inbound/outbound edge for each node pair.
// Nodes, edges, and edge information can all be added to the graph
// independently. Edge removal results in the deletion of all edge information
// for that edge.
type ChannelGraph struct {
db *DB
// TODO(roasbeef): store and update bloom filter to reduce disk access
// due to current gossip model
// * LRU cache for edges?
}
// Database returns a pointer to the underlying database.
func (c *ChannelGraph) Database() *DB {
return c.db
}
// ForEachChannel iterates through all the channel edges stored within the
// graph and invokes the passed callback for each edge. The callback takes two
// edges as since this is a directed graph, both the in/out edges are visited.
// If the callback returns an error, then the transaction is aborted and the
// iteration stops early.
//
// NOTE: If an edge can't be found, or wasn't advertised, then a nil pointer
// for that particular channel edge routing policy will be passed into the
// callback.
func (c *ChannelGraph) ForEachChannel(cb func(*ChannelEdgeInfo, *ChannelEdgePolicy, *ChannelEdgePolicy) error) error {
// TODO(roasbeef): ptr map to reduce # of allocs? no duplicates
return c.db.View(func(tx *bbolt.Tx) error {
// First, grab the node bucket. This will be used to populate
// the Node pointers in each edge read from disk.
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNotFound
}
// Next, grab the edge bucket which stores the edges, and also
// the index itself so we can group the directed edges together
// logically.
edges := tx.Bucket(edgeBucket)
if edges == nil {
return ErrGraphNoEdgesFound
}
edgeIndex := edges.Bucket(edgeIndexBucket)
if edgeIndex == nil {
return ErrGraphNoEdgesFound
}
// For each edge pair within the edge index, we fetch each edge
// itself and also the node information in order to fully
// populated the object.
return edgeIndex.ForEach(func(chanID, edgeInfoBytes []byte) error {
infoReader := bytes.NewReader(edgeInfoBytes)
edgeInfo, err := deserializeChanEdgeInfo(infoReader)
if err != nil {
return err
}
edgeInfo.db = c.db
edge1, edge2, err := fetchChanEdgePolicies(
edgeIndex, edges, nodes, chanID, c.db,
)
if err != nil {
return err
}
// With both edges read, execute the call back. IF this
// function returns an error then the transaction will
// be aborted.
return cb(&edgeInfo, edge1, edge2)
})
})
}
// ForEachNode iterates through all the stored vertices/nodes in the graph,
// executing the passed callback with each node encountered. If the callback
// returns an error, then the transaction is aborted and the iteration stops
// early.
//
// If the caller wishes to re-use an existing boltdb transaction, then it
// should be passed as the first argument. Otherwise the first argument should
// be nil and a fresh transaction will be created to execute the graph
// traversal
//
// TODO(roasbeef): add iterator interface to allow for memory efficient graph
// traversal when graph gets mega
func (c *ChannelGraph) ForEachNode(tx *bbolt.Tx, cb func(*bbolt.Tx, *LightningNode) error) error {
traversal := func(tx *bbolt.Tx) error {
// First grab the nodes bucket which stores the mapping from
// pubKey to node information.
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNotFound
}
return nodes.ForEach(func(pubKey, nodeBytes []byte) error {
// If this is the source key, then we skip this
// iteration as the value for this key is a pubKey
// rather than raw node information.
if bytes.Equal(pubKey, sourceKey) || len(pubKey) != 33 {
return nil
}
nodeReader := bytes.NewReader(nodeBytes)
node, err := deserializeLightningNode(nodeReader)
if err != nil {
return err
}
node.db = c.db
// Execute the callback, the transaction will abort if
// this returns an error.
return cb(tx, &node)
})
}
// If no transaction was provided, then we'll create a new transaction
// to execute the transaction within.
if tx == nil {
return c.db.View(traversal)
}
// Otherwise, we re-use the existing transaction to execute the graph
// traversal.
return traversal(tx)
}
// SourceNode returns the source node of the graph. The source node is treated
// as the center node within a star-graph. This method may be used to kick off
// a path finding algorithm in order to explore the reachability of another
// node based off the source node.
func (c *ChannelGraph) SourceNode() (*LightningNode, error) {
var source *LightningNode
err := c.db.View(func(tx *bbolt.Tx) error {
// First grab the nodes bucket which stores the mapping from
// pubKey to node information.
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNotFound
}
node, err := c.sourceNode(nodes)
if err != nil {
return err
}
source = node
return nil
})
if err != nil {
return nil, err
}
return source, nil
}
// sourceNode uses an existing database transaction and returns the source node
// of the graph. The source node is treated as the center node within a
// star-graph. This method may be used to kick off a path finding algorithm in
// order to explore the reachability of another node based off the source node.
func (c *ChannelGraph) sourceNode(nodes *bbolt.Bucket) (*LightningNode, error) {
selfPub := nodes.Get(sourceKey)
if selfPub == nil {
return nil, ErrSourceNodeNotSet
}
// With the pubKey of the source node retrieved, we're able to
// fetch the full node information.
node, err := fetchLightningNode(nodes, selfPub)
if err != nil {
return nil, err
}
node.db = c.db
return &node, nil
}
// SetSourceNode sets the source node within the graph database. The source
// node is to be used as the center of a star-graph within path finding
// algorithms.
func (c *ChannelGraph) SetSourceNode(node *LightningNode) error {
nodePubBytes := node.PubKeyBytes[:]
return c.db.Update(func(tx *bbolt.Tx) error {
// First grab the nodes bucket which stores the mapping from
// pubKey to node information.
nodes, err := tx.CreateBucketIfNotExists(nodeBucket)
if err != nil {
return err
}
// Next we create the mapping from source to the targeted
// public key.
if err := nodes.Put(sourceKey, nodePubBytes); err != nil {
return err
}
// Finally, we commit the information of the lightning node
// itself.
return addLightningNode(tx, node)
})
}
// AddLightningNode adds a vertex/node to the graph database. If the node is not
// in the database from before, this will add a new, unconnected one to the
// graph. If it is present from before, this will update that node's
// information. Note that this method is expected to only be called to update
// an already present node from a node announcement, or to insert a node found
// in a channel update.
//
// TODO(roasbeef): also need sig of announcement
func (c *ChannelGraph) AddLightningNode(node *LightningNode) error {
return c.db.Update(func(tx *bbolt.Tx) error {
return addLightningNode(tx, node)
})
}
func addLightningNode(tx *bbolt.Tx, node *LightningNode) error {
nodes, err := tx.CreateBucketIfNotExists(nodeBucket)
if err != nil {
return err
}
aliases, err := nodes.CreateBucketIfNotExists(aliasIndexBucket)
if err != nil {
return err
}
updateIndex, err := nodes.CreateBucketIfNotExists(
nodeUpdateIndexBucket,
)
if err != nil {
return err
}
return putLightningNode(nodes, aliases, updateIndex, node)
}
// LookupAlias attempts to return the alias as advertised by the target node.
// TODO(roasbeef): currently assumes that aliases are unique...
func (c *ChannelGraph) LookupAlias(pub *btcec.PublicKey) (string, error) {
var alias string
err := c.db.View(func(tx *bbolt.Tx) error {
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNodesNotFound
}
aliases := nodes.Bucket(aliasIndexBucket)
if aliases == nil {
return ErrGraphNodesNotFound
}
nodePub := pub.SerializeCompressed()
a := aliases.Get(nodePub)
if a == nil {
return ErrNodeAliasNotFound
}
// TODO(roasbeef): should actually be using the utf-8
// package...
alias = string(a)
return nil
})
if err != nil {
return "", err
}
return alias, nil
}
// DeleteLightningNode starts a new database transaction to remove a vertex/node
// from the database according to the node's public key.
func (c *ChannelGraph) DeleteLightningNode(nodePub *btcec.PublicKey) error {
// TODO(roasbeef): ensure dangling edges are removed...
return c.db.Update(func(tx *bbolt.Tx) error {
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNodeNotFound
}
return c.deleteLightningNode(
nodes, nodePub.SerializeCompressed(),
)
})
}
// deleteLightningNode uses an existing database transaction to remove a
// vertex/node from the database according to the node's public key.
func (c *ChannelGraph) deleteLightningNode(nodes *bbolt.Bucket,
compressedPubKey []byte) error {
aliases := nodes.Bucket(aliasIndexBucket)
if aliases == nil {
return ErrGraphNodesNotFound
}
if err := aliases.Delete(compressedPubKey); err != nil {
return err
}
// Before we delete the node, we'll fetch its current state so we can
// determine when its last update was to clear out the node update
// index.
node, err := fetchLightningNode(nodes, compressedPubKey)
if err != nil {
return err
}
if err := nodes.Delete(compressedPubKey); err != nil {
return err
}
// Finally, we'll delete the index entry for the node within the
// nodeUpdateIndexBucket as this node is no longer active, so we don't
// need to track its last update.
nodeUpdateIndex := nodes.Bucket(nodeUpdateIndexBucket)
if nodeUpdateIndex == nil {
return ErrGraphNodesNotFound
}
// In order to delete the entry, we'll need to reconstruct the key for
// its last update.
updateUnix := uint64(node.LastUpdate.Unix())
var indexKey [8 + 33]byte
byteOrder.PutUint64(indexKey[:8], updateUnix)
copy(indexKey[8:], compressedPubKey)
return nodeUpdateIndex.Delete(indexKey[:])
}
// AddChannelEdge adds a new (undirected, blank) edge to the graph database. An
// undirected edge from the two target nodes are created. The information
// stored denotes the static attributes of the channel, such as the channelID,
// the keys involved in creation of the channel, and the set of features that
// the channel supports. The chanPoint and chanID are used to uniquely identify
// the edge globally within the database.
func (c *ChannelGraph) AddChannelEdge(edge *ChannelEdgeInfo) error {
return c.db.Update(func(tx *bbolt.Tx) error {
return c.addChannelEdge(tx, edge)
})
}
// addChannelEdge is the private form of AddChannelEdge that allows callers to
// utilize an existing db transaction.
func (c *ChannelGraph) addChannelEdge(tx *bbolt.Tx, edge *ChannelEdgeInfo) error {
// Construct the channel's primary key which is the 8-byte channel ID.
var chanKey [8]byte
binary.BigEndian.PutUint64(chanKey[:], edge.ChannelID)
nodes, err := tx.CreateBucketIfNotExists(nodeBucket)
if err != nil {
return err
}
edges, err := tx.CreateBucketIfNotExists(edgeBucket)
if err != nil {
return err
}
edgeIndex, err := edges.CreateBucketIfNotExists(edgeIndexBucket)
if err != nil {
return err
}
chanIndex, err := edges.CreateBucketIfNotExists(channelPointBucket)
if err != nil {
return err
}
// First, attempt to check if this edge has already been created. If
// so, then we can exit early as this method is meant to be idempotent.
if edgeInfo := edgeIndex.Get(chanKey[:]); edgeInfo != nil {
return ErrEdgeAlreadyExist
}
// Before we insert the channel into the database, we'll ensure that
// both nodes already exist in the channel graph. If either node
// doesn't, then we'll insert a "shell" node that just includes its
// public key, so subsequent validation and queries can work properly.
_, node1Err := fetchLightningNode(nodes, edge.NodeKey1Bytes[:])
switch {
case node1Err == ErrGraphNodeNotFound:
node1Shell := LightningNode{
PubKeyBytes: edge.NodeKey1Bytes,
HaveNodeAnnouncement: false,
}
err := addLightningNode(tx, &node1Shell)
if err != nil {
return fmt.Errorf("unable to create shell node "+
"for: %x", edge.NodeKey1Bytes)
}
case node1Err != nil:
return err
}
_, node2Err := fetchLightningNode(nodes, edge.NodeKey2Bytes[:])
switch {
case node2Err == ErrGraphNodeNotFound:
node2Shell := LightningNode{
PubKeyBytes: edge.NodeKey2Bytes,
HaveNodeAnnouncement: false,
}
err := addLightningNode(tx, &node2Shell)
if err != nil {
return fmt.Errorf("unable to create shell node "+
"for: %x", edge.NodeKey2Bytes)
}
case node2Err != nil:
return err
}
// If the edge hasn't been created yet, then we'll first add it to the
// edge index in order to associate the edge between two nodes and also
// store the static components of the channel.
if err := putChanEdgeInfo(edgeIndex, edge, chanKey); err != nil {
return err
}
// Mark edge policies for both sides as unknown. This is to enable
// efficient incoming channel lookup for a node.
for _, key := range []*[33]byte{&edge.NodeKey1Bytes,
&edge.NodeKey2Bytes} {
err := putChanEdgePolicyUnknown(edges, edge.ChannelID,
key[:])
if err != nil {
return err
}
}
// Finally we add it to the channel index which maps channel points
// (outpoints) to the shorter channel ID's.
var b bytes.Buffer
if err := writeOutpoint(&b, &edge.ChannelPoint); err != nil {
return err
}
return chanIndex.Put(b.Bytes(), chanKey[:])
}
// HasChannelEdge returns true if the database knows of a channel edge with the
// passed channel ID, and false otherwise. If an edge with that ID is found
// within the graph, then two time stamps representing the last time the edge
// was updated for both directed edges are returned along with the boolean.
func (c *ChannelGraph) HasChannelEdge(chanID uint64) (time.Time, time.Time, bool, error) {
// TODO(roasbeef): check internal bloom filter first
var (
node1UpdateTime time.Time
node2UpdateTime time.Time
exists bool
)
if err := c.db.View(func(tx *bbolt.Tx) error {
edges := tx.Bucket(edgeBucket)
if edges == nil {
return ErrGraphNoEdgesFound
}
edgeIndex := edges.Bucket(edgeIndexBucket)
if edgeIndex == nil {
return ErrGraphNoEdgesFound
}
var channelID [8]byte
byteOrder.PutUint64(channelID[:], chanID)
if edgeIndex.Get(channelID[:]) == nil {
exists = false
return nil
}
exists = true
// If the channel has been found in the graph, then retrieve
// the edges itself so we can return the last updated
// timestamps.
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNodeNotFound
}
e1, e2, err := fetchChanEdgePolicies(edgeIndex, edges, nodes,
channelID[:], c.db)
if err != nil {
return err
}
// As we may have only one of the edges populated, only set the
// update time if the edge was found in the database.
if e1 != nil {
node1UpdateTime = e1.LastUpdate
}
if e2 != nil {
node2UpdateTime = e2.LastUpdate
}
return nil
}); err != nil {
return time.Time{}, time.Time{}, exists, err
}
return node1UpdateTime, node2UpdateTime, exists, nil
}
// UpdateChannelEdge retrieves and update edge of the graph database. Method
// only reserved for updating an edge info after its already been created.
// In order to maintain this constraints, we return an error in the scenario
// that an edge info hasn't yet been created yet, but someone attempts to update
// it.
func (c *ChannelGraph) UpdateChannelEdge(edge *ChannelEdgeInfo) error {
// Construct the channel's primary key which is the 8-byte channel ID.
var chanKey [8]byte
binary.BigEndian.PutUint64(chanKey[:], edge.ChannelID)
return c.db.Update(func(tx *bbolt.Tx) error {
edges := tx.Bucket(edgeBucket)
if edge == nil {
return ErrEdgeNotFound
}
edgeIndex := edges.Bucket(edgeIndexBucket)
if edgeIndex == nil {
return ErrEdgeNotFound
}
if edgeInfo := edgeIndex.Get(chanKey[:]); edgeInfo == nil {
return ErrEdgeNotFound
}
return putChanEdgeInfo(edgeIndex, edge, chanKey)
})
}
const (
// pruneTipBytes is the total size of the value which stores a prune
// entry of the graph in the prune log. The "prune tip" is the last
// entry in the prune log, and indicates if the channel graph is in
// sync with the current UTXO state. The structure of the value
// is: blockHash, taking 32 bytes total.
pruneTipBytes = 32
)
// PruneGraph prunes newly closed channels from the channel graph in response
// to a new block being solved on the network. Any transactions which spend the
// funding output of any known channels within he graph will be deleted.
// Additionally, the "prune tip", or the last block which has been used to
// prune the graph is stored so callers can ensure the graph is fully in sync
// with the current UTXO state. A slice of channels that have been closed by
// the target block are returned if the function succeeds without error.
func (c *ChannelGraph) PruneGraph(spentOutputs []*wire.OutPoint,
blockHash *chainhash.Hash, blockHeight uint32) ([]*ChannelEdgeInfo, error) {
var chansClosed []*ChannelEdgeInfo
err := c.db.Update(func(tx *bbolt.Tx) error {
// First grab the edges bucket which houses the information
// we'd like to delete
edges, err := tx.CreateBucketIfNotExists(edgeBucket)
if err != nil {
return err
}
// Next grab the two edge indexes which will also need to be updated.
edgeIndex, err := edges.CreateBucketIfNotExists(edgeIndexBucket)
if err != nil {
return err
}
chanIndex, err := edges.CreateBucketIfNotExists(channelPointBucket)
if err != nil {
return err
}
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrSourceNodeNotSet
}
// For each of the outpoints that have been spent within the
// block, we attempt to delete them from the graph as if that
// outpoint was a channel, then it has now been closed.
for _, chanPoint := range spentOutputs {
// TODO(roasbeef): load channel bloom filter, continue
// if NOT if filter
var opBytes bytes.Buffer
if err := writeOutpoint(&opBytes, chanPoint); err != nil {
return nil
}
// First attempt to see if the channel exists within
// the database, if not, then we can exit early.
chanID := chanIndex.Get(opBytes.Bytes())
if chanID == nil {
continue
}
// However, if it does, then we'll read out the full
// version so we can add it to the set of deleted
// channels.
edgeInfo, err := fetchChanEdgeInfo(edgeIndex, chanID)
if err != nil {
return err
}
// Attempt to delete the channel, an ErrEdgeNotFound
// will be returned if that outpoint isn't known to be
// a channel. If no error is returned, then a channel
// was successfully pruned.
err = delChannelByEdge(
edges, edgeIndex, chanIndex, nodes, chanPoint,
)
if err != nil && err != ErrEdgeNotFound {
return err
}
chansClosed = append(chansClosed, &edgeInfo)
}
metaBucket, err := tx.CreateBucketIfNotExists(graphMetaBucket)
if err != nil {
return err
}
pruneBucket, err := metaBucket.CreateBucketIfNotExists(pruneLogBucket)
if err != nil {
return err
}
// With the graph pruned, add a new entry to the prune log,
// which can be used to check if the graph is fully synced with
// the current UTXO state.
var blockHeightBytes [4]byte
byteOrder.PutUint32(blockHeightBytes[:], blockHeight)
var newTip [pruneTipBytes]byte
copy(newTip[:], blockHash[:])
err = pruneBucket.Put(blockHeightBytes[:], newTip[:])
if err != nil {
return err
}
// Now that the graph has been pruned, we'll also attempt to
// prune any nodes that have had a channel closed within the
// latest block.
return c.pruneGraphNodes(nodes, edgeIndex)
})
if err != nil {
return nil, err
}
return chansClosed, nil
}
// PruneGraphNodes is a garbage collection method which attempts to prune out
// any nodes from the channel graph that are currently unconnected. This ensure
// that we only maintain a graph of reachable nodes. In the event that a pruned
// node gains more channels, it will be re-added back to the graph.
func (c *ChannelGraph) PruneGraphNodes() error {
return c.db.Update(func(tx *bbolt.Tx) error {
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNodesNotFound
}
edges := tx.Bucket(edgeBucket)
if edges == nil {
return ErrGraphNotFound
}
edgeIndex := edges.Bucket(edgeIndexBucket)
if edgeIndex == nil {
return ErrGraphNoEdgesFound
}
return c.pruneGraphNodes(nodes, edgeIndex)
})
}
// pruneGraphNodes attempts to remove any nodes from the graph who have had a
// channel closed within the current block. If the node still has existing
// channels in the graph, this will act as a no-op.
func (c *ChannelGraph) pruneGraphNodes(nodes *bbolt.Bucket,
edgeIndex *bbolt.Bucket) error {
log.Trace("Pruning nodes from graph with no open channels")
// We'll retrieve the graph's source node to ensure we don't remove it
// even if it no longer has any open channels.
sourceNode, err := c.sourceNode(nodes)
if err != nil {
return err
}
// We'll use this map to keep count the number of references to a node
// in the graph. A node should only be removed once it has no more
// references in the graph.
nodeRefCounts := make(map[[33]byte]int)
err = nodes.ForEach(func(pubKey, nodeBytes []byte) error {
// If this is the source key, then we skip this
// iteration as the value for this key is a pubKey
// rather than raw node information.
if bytes.Equal(pubKey, sourceKey) || len(pubKey) != 33 {
return nil
}
var nodePub [33]byte
copy(nodePub[:], pubKey)
nodeRefCounts[nodePub] = 0
return nil
})
if err != nil {
return err
}
// To ensure we never delete the source node, we'll start off by
// bumping its ref count to 1.
nodeRefCounts[sourceNode.PubKeyBytes] = 1
// Next, we'll run through the edgeIndex which maps a channel ID to the
// edge info. We'll use this scan to populate our reference count map
// above.
err = edgeIndex.ForEach(func(chanID, edgeInfoBytes []byte) error {
// The first 66 bytes of the edge info contain the pubkeys of
// the nodes that this edge attaches. We'll extract them, and
// add them to the ref count map.
var node1, node2 [33]byte
copy(node1[:], edgeInfoBytes[:33])
copy(node2[:], edgeInfoBytes[33:])
// With the nodes extracted, we'll increase the ref count of
// each of the nodes.
2018-07-31 11:29:12 +03:00
nodeRefCounts[node1]++
nodeRefCounts[node2]++
return nil
})
if err != nil {
return err
}
// Finally, we'll make a second pass over the set of nodes, and delete
// any nodes that have a ref count of zero.
var numNodesPruned int
for nodePubKey, refCount := range nodeRefCounts {
// If the ref count of the node isn't zero, then we can safely
// skip it as it still has edges to or from it within the
// graph.
if refCount != 0 {
continue
}
// If we reach this point, then there are no longer any edges
// that connect this node, so we can delete it.
if err := c.deleteLightningNode(nodes, nodePubKey[:]); err != nil {
log.Warnf("Unable to prune node %x from the "+
"graph: %v", nodePubKey, err)
continue
}
log.Infof("Pruned unconnected node %x from channel graph",
nodePubKey[:])
numNodesPruned++
}
if numNodesPruned > 0 {
log.Infof("Pruned %v unconnected nodes from the channel graph",
numNodesPruned)
}
return nil
}
// DisconnectBlockAtHeight is used to indicate that the block specified
// by the passed height has been disconnected from the main chain. This
// will "rewind" the graph back to the height below, deleting channels
// that are no longer confirmed from the graph. The prune log will be
// set to the last prune height valid for the remaining chain.
// Channels that were removed from the graph resulting from the
// disconnected block are returned.
func (c *ChannelGraph) DisconnectBlockAtHeight(height uint32) ([]*ChannelEdgeInfo,
error) {
// Every channel having a ShortChannelID starting at 'height'
// will no longer be confirmed.
startShortChanID := lnwire.ShortChannelID{
BlockHeight: height,
}
// Delete everything after this height from the db.
endShortChanID := lnwire.ShortChannelID{
BlockHeight: math.MaxUint32 & 0x00ffffff,
TxIndex: math.MaxUint32 & 0x00ffffff,
TxPosition: math.MaxUint16,
}
// The block height will be the 3 first bytes of the channel IDs.
var chanIDStart [8]byte
byteOrder.PutUint64(chanIDStart[:], startShortChanID.ToUint64())
var chanIDEnd [8]byte
byteOrder.PutUint64(chanIDEnd[:], endShortChanID.ToUint64())
// Keep track of the channels that are removed from the graph.
var removedChans []*ChannelEdgeInfo
if err := c.db.Update(func(tx *bbolt.Tx) error {
edges, err := tx.CreateBucketIfNotExists(edgeBucket)
if err != nil {
return err
}
edgeIndex, err := edges.CreateBucketIfNotExists(edgeIndexBucket)
if err != nil {
return err
}
chanIndex, err := edges.CreateBucketIfNotExists(channelPointBucket)
if err != nil {
return err
}
nodes, err := tx.CreateBucketIfNotExists(nodeBucket)
if err != nil {
return err
}
// Scan from chanIDStart to chanIDEnd, deleting every
// found edge.
cursor := edgeIndex.Cursor()
for k, v := cursor.Seek(chanIDStart[:]); k != nil &&
bytes.Compare(k, chanIDEnd[:]) <= 0; k, v = cursor.Next() {
edgeInfoReader := bytes.NewReader(v)
edgeInfo, err := deserializeChanEdgeInfo(edgeInfoReader)
if err != nil {
return err
}
err = delChannelByEdge(
edges, edgeIndex, chanIndex, nodes, &edgeInfo.ChannelPoint,
)
if err != nil && err != ErrEdgeNotFound {
return err
}
removedChans = append(removedChans, &edgeInfo)
}
// Delete all the entries in the prune log having a height
// greater or equal to the block disconnected.
metaBucket, err := tx.CreateBucketIfNotExists(graphMetaBucket)
if err != nil {
return err
}
pruneBucket, err := metaBucket.CreateBucketIfNotExists(pruneLogBucket)
if err != nil {
return err
}
var pruneKeyStart [4]byte
byteOrder.PutUint32(pruneKeyStart[:], height)
var pruneKeyEnd [4]byte
byteOrder.PutUint32(pruneKeyEnd[:], math.MaxUint32)
pruneCursor := pruneBucket.Cursor()
for k, _ := pruneCursor.Seek(pruneKeyStart[:]); k != nil &&
bytes.Compare(k, pruneKeyEnd[:]) <= 0; k, _ = pruneCursor.Next() {
if err := pruneCursor.Delete(); err != nil {
return err
}
}
return nil
}); err != nil {
return nil, err
}
return removedChans, nil
}
// PruneTip returns the block height and hash of the latest block that has been
// used to prune channels in the graph. Knowing the "prune tip" allows callers
// to tell if the graph is currently in sync with the current best known UTXO
// state.
func (c *ChannelGraph) PruneTip() (*chainhash.Hash, uint32, error) {
var (
tipHash chainhash.Hash
tipHeight uint32
)
err := c.db.View(func(tx *bbolt.Tx) error {
graphMeta := tx.Bucket(graphMetaBucket)
if graphMeta == nil {
return ErrGraphNotFound
}
pruneBucket := graphMeta.Bucket(pruneLogBucket)
if pruneBucket == nil {
return ErrGraphNeverPruned
}
pruneCursor := pruneBucket.Cursor()
// The prune key with the largest block height will be our
// prune tip.
k, v := pruneCursor.Last()
if k == nil {
return ErrGraphNeverPruned
}
// Once we have the prune tip, the value will be the block hash,
// and the key the block height.
copy(tipHash[:], v[:])
tipHeight = byteOrder.Uint32(k[:])
return nil
})
if err != nil {
return nil, 0, err
}
return &tipHash, tipHeight, nil
}
// DeleteChannelEdge removes an edge from the database as identified by its
// funding outpoint. If the edge does not exist within the database, then
// ErrEdgeNotFound will be returned.
func (c *ChannelGraph) DeleteChannelEdge(chanPoint *wire.OutPoint) error {
// TODO(roasbeef): possibly delete from node bucket if node has no more
// channels
// TODO(roasbeef): don't delete both edges?
return c.db.Update(func(tx *bbolt.Tx) error {
// First grab the edges bucket which houses the information
// we'd like to delete
edges := tx.Bucket(edgeBucket)
if edges == nil {
return ErrEdgeNotFound
}
// Next grab the two edge indexes which will also need to be
// updated.
edgeIndex := edges.Bucket(edgeIndexBucket)
if edgeIndex == nil {
return ErrEdgeNotFound
}
chanIndex := edges.Bucket(channelPointBucket)
if chanIndex == nil {
return ErrEdgeNotFound
}
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNodeNotFound
}
return delChannelByEdge(
edges, edgeIndex, chanIndex, nodes, chanPoint,
)
})
}
// ChannelID attempt to lookup the 8-byte compact channel ID which maps to the
// passed channel point (outpoint). If the passed channel doesn't exist within
// the database, then ErrEdgeNotFound is returned.
func (c *ChannelGraph) ChannelID(chanPoint *wire.OutPoint) (uint64, error) {
var chanID uint64
var b bytes.Buffer
if err := writeOutpoint(&b, chanPoint); err != nil {
return 0, nil
}
if err := c.db.View(func(tx *bbolt.Tx) error {
edges := tx.Bucket(edgeBucket)
if edges == nil {
return ErrGraphNoEdgesFound
}
chanIndex := edges.Bucket(channelPointBucket)
if chanIndex == nil {
return ErrGraphNoEdgesFound
}
chanIDBytes := chanIndex.Get(b.Bytes())
if chanIDBytes == nil {
return ErrEdgeNotFound
}
chanID = byteOrder.Uint64(chanIDBytes)
return nil
}); err != nil {
return 0, err
}
return chanID, nil
}
// TODO(roasbeef): allow updates to use Batch?
// HighestChanID returns the "highest" known channel ID in the channel graph.
// This represents the "newest" channel from the PoV of the chain. This method
// can be used by peers to quickly determine if they're graphs are in sync.
func (c *ChannelGraph) HighestChanID() (uint64, error) {
var cid uint64
err := c.db.View(func(tx *bbolt.Tx) error {
edges := tx.Bucket(edgeBucket)
if edges == nil {
return ErrGraphNoEdgesFound
}
edgeIndex := edges.Bucket(edgeIndexBucket)
if edgeIndex == nil {
return ErrGraphNoEdgesFound
}
// In order to find the highest chan ID, we'll fetch a cursor
// and use that to seek to the "end" of our known rage.
cidCursor := edgeIndex.Cursor()
lastChanID, _ := cidCursor.Last()
// If there's no key, then this means that we don't actually
// know of any channels, so we'll return a predicable error.
if lastChanID == nil {
return ErrGraphNoEdgesFound
}
// Otherwise, we'll de serialize the channel ID and return it
// to the caller.
cid = byteOrder.Uint64(lastChanID)
return nil
})
if err != nil && err != ErrGraphNoEdgesFound {
return 0, err
}
return cid, nil
}
// ChannelEdge represents the complete set of information for a channel edge in
// the known channel graph. This struct couples the core information of the
// edge as well as each of the known advertised edge policies.
type ChannelEdge struct {
// Info contains all the static information describing the channel.
Info *ChannelEdgeInfo
// Policy1 points to the "first" edge policy of the channel containing
// the dynamic information required to properly route through the edge.
Policy1 *ChannelEdgePolicy
// Policy2 points to the "second" edge policy of the channel containing
// the dynamic information required to properly route through the edge.
Policy2 *ChannelEdgePolicy
}
// ChanUpdatesInHorizon returns all the known channel edges which have at least
// one edge that has an update timestamp within the specified horizon.
func (c *ChannelGraph) ChanUpdatesInHorizon(startTime, endTime time.Time) ([]ChannelEdge, error) {
// To ensure we don't return duplicate ChannelEdges, we'll use an
// additional map to keep track of the edges already seen to prevent
// re-adding it.
edgesSeen := make(map[uint64]struct{})
var edgesInHorizon []ChannelEdge
err := c.db.View(func(tx *bbolt.Tx) error {
edges := tx.Bucket(edgeBucket)
if edges == nil {
return ErrGraphNoEdgesFound
}
edgeIndex := edges.Bucket(edgeIndexBucket)
if edgeIndex == nil {
return ErrGraphNoEdgesFound
}
edgeUpdateIndex := edges.Bucket(edgeUpdateIndexBucket)
if edgeUpdateIndex == nil {
return ErrGraphNoEdgesFound
}
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNodesNotFound
}
// We'll now obtain a cursor to perform a range query within
// the index to find all channels within the horizon.
updateCursor := edgeUpdateIndex.Cursor()
var startTimeBytes, endTimeBytes [8 + 8]byte
byteOrder.PutUint64(
startTimeBytes[:8], uint64(startTime.Unix()),
)
byteOrder.PutUint64(
endTimeBytes[:8], uint64(endTime.Unix()),
)
// With our start and end times constructed, we'll step through
// the index collecting the info and policy of each update of
// each channel that has a last update within the time range.
for indexKey, _ := updateCursor.Seek(startTimeBytes[:]); indexKey != nil &&
bytes.Compare(indexKey, endTimeBytes[:]) <= 0; indexKey, _ = updateCursor.Next() {
// We have a new eligible entry, so we'll slice of the
// chan ID so we can query it in the DB.
chanID := indexKey[8:]
// If we've already retrieved the info and policies for
// this edge, then we can skip it as we don't need to do
// so again.
chanIDInt := byteOrder.Uint64(chanID)
if _, ok := edgesSeen[chanIDInt]; ok {
continue
}
// First, we'll fetch the static edge information.
edgeInfo, err := fetchChanEdgeInfo(edgeIndex, chanID)
if err != nil {
chanID := byteOrder.Uint64(chanID)
return fmt.Errorf("unable to fetch info for "+
"edge with chan_id=%v: %v", chanID, err)
}
edgeInfo.db = c.db
// With the static information obtained, we'll now
// fetch the dynamic policy info.
edge1, edge2, err := fetchChanEdgePolicies(
edgeIndex, edges, nodes, chanID, c.db,
)
if err != nil {
chanID := byteOrder.Uint64(chanID)
return fmt.Errorf("unable to fetch policies "+
"for edge with chan_id=%v: %v", chanID,
err)
}
// Finally, we'll collate this edge with the rest of
// edges to be returned.
edgesSeen[chanIDInt] = struct{}{}
edgesInHorizon = append(edgesInHorizon, ChannelEdge{
Info: &edgeInfo,
Policy1: edge1,
Policy2: edge2,
})
}
return nil
})
switch {
case err == ErrGraphNoEdgesFound:
fallthrough
case err == ErrGraphNodesNotFound:
break
case err != nil:
return nil, err
}
return edgesInHorizon, nil
}
// NodeUpdatesInHorizon returns all the known lightning node which have an
// update timestamp within the passed range. This method can be used by two
// nodes to quickly determine if they have the same set of up to date node
// announcements.
func (c *ChannelGraph) NodeUpdatesInHorizon(startTime, endTime time.Time) ([]LightningNode, error) {
var nodesInHorizon []LightningNode
err := c.db.View(func(tx *bbolt.Tx) error {
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNodesNotFound
}
nodeUpdateIndex := nodes.Bucket(nodeUpdateIndexBucket)
if nodeUpdateIndex == nil {
return ErrGraphNodesNotFound
}
// We'll now obtain a cursor to perform a range query within
// the index to find all node announcements within the horizon.
updateCursor := nodeUpdateIndex.Cursor()
var startTimeBytes, endTimeBytes [8 + 33]byte
byteOrder.PutUint64(
startTimeBytes[:8], uint64(startTime.Unix()),
)
byteOrder.PutUint64(
endTimeBytes[:8], uint64(endTime.Unix()),
)
// With our start and end times constructed, we'll step through
// the index collecting info for each node within the time
// range.
for indexKey, _ := updateCursor.Seek(startTimeBytes[:]); indexKey != nil &&
bytes.Compare(indexKey, endTimeBytes[:]) <= 0; indexKey, _ = updateCursor.Next() {
nodePub := indexKey[8:]
node, err := fetchLightningNode(nodes, nodePub)
if err != nil {
return err
}
node.db = c.db
nodesInHorizon = append(nodesInHorizon, node)
}
return nil
})
switch {
case err == ErrGraphNoEdgesFound:
fallthrough
case err == ErrGraphNodesNotFound:
break
case err != nil:
return nil, err
}
return nodesInHorizon, nil
}
// FilterKnownChanIDs takes a set of channel IDs and return the subset of chan
// ID's that we don't know of in the passed set. In other words, we perform a
// set difference of our set of chan ID's and the ones passed in. This method
// can be used by callers to determine the set of channels ta peer knows of
// that we don't.
func (c *ChannelGraph) FilterKnownChanIDs(chanIDs []uint64) ([]uint64, error) {
var newChanIDs []uint64
err := c.db.View(func(tx *bbolt.Tx) error {
edges := tx.Bucket(edgeBucket)
if edges == nil {
return ErrGraphNoEdgesFound
}
edgeIndex := edges.Bucket(edgeIndexBucket)
if edgeIndex == nil {
return ErrGraphNoEdgesFound
}
// We'll run through the set of chanIDs and collate only the
// set of channel that are unable to be found within our db.
var cidBytes [8]byte
for _, cid := range chanIDs {
byteOrder.PutUint64(cidBytes[:], cid)
if v := edgeIndex.Get(cidBytes[:]); v == nil {
newChanIDs = append(newChanIDs, cid)
}
}
return nil
})
switch {
// If we don't know of any edges yet, then we'll return the entire set
// of chan IDs specified.
case err == ErrGraphNoEdgesFound:
return chanIDs, nil
case err != nil:
return nil, err
}
return newChanIDs, nil
}
// FilterChannelRange returns the channel ID's of all known channels which were
// mined in a block height within the passed range. This method can be used to
// quickly share with a peer the set of channels we know of within a particular
// range to catch them up after a period of time offline.
func (c *ChannelGraph) FilterChannelRange(startHeight, endHeight uint32) ([]uint64, error) {
var chanIDs []uint64
startChanID := &lnwire.ShortChannelID{
BlockHeight: startHeight,
}
endChanID := lnwire.ShortChannelID{
BlockHeight: endHeight,
TxIndex: math.MaxUint32 & 0x00ffffff,
TxPosition: math.MaxUint16,
}
// As we need to perform a range scan, we'll convert the starting and
// ending height to their corresponding values when encoded using short
// channel ID's.
var chanIDStart, chanIDEnd [8]byte
byteOrder.PutUint64(chanIDStart[:], startChanID.ToUint64())
byteOrder.PutUint64(chanIDEnd[:], endChanID.ToUint64())
err := c.db.View(func(tx *bbolt.Tx) error {
edges := tx.Bucket(edgeBucket)
if edges == nil {
return ErrGraphNoEdgesFound
}
edgeIndex := edges.Bucket(edgeIndexBucket)
if edgeIndex == nil {
return ErrGraphNoEdgesFound
}
cursor := edgeIndex.Cursor()
// We'll now iterate through the database, and find each
// channel ID that resides within the specified range.
var cid uint64
for k, _ := cursor.Seek(chanIDStart[:]); k != nil &&
bytes.Compare(k, chanIDEnd[:]) <= 0; k, _ = cursor.Next() {
// This channel ID rests within the target range, so
// we'll convert it into an integer and add it to our
// returned set.
cid = byteOrder.Uint64(k)
chanIDs = append(chanIDs, cid)
}
return nil
})
switch {
// If we don't know of any channels yet, then there's nothing to
// filter, so we'll return an empty slice.
case err == ErrGraphNoEdgesFound:
return chanIDs, nil
case err != nil:
return nil, err
}
return chanIDs, nil
}
// FetchChanInfos returns the set of channel edges that correspond to the
// passed channel ID's. This can be used to respond to peer queries that are
// seeking to fill in gaps in their view of the channel graph.
func (c *ChannelGraph) FetchChanInfos(chanIDs []uint64) ([]ChannelEdge, error) {
// TODO(roasbeef): sort cids?
var (
chanEdges []ChannelEdge
cidBytes [8]byte
)
err := c.db.View(func(tx *bbolt.Tx) error {
edges := tx.Bucket(edgeBucket)
if edges == nil {
return ErrGraphNoEdgesFound
}
edgeIndex := edges.Bucket(edgeIndexBucket)
if edgeIndex == nil {
return ErrGraphNoEdgesFound
}
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNotFound
}
for _, cid := range chanIDs {
byteOrder.PutUint64(cidBytes[:], cid)
// First, we'll fetch the static edge information.
edgeInfo, err := fetchChanEdgeInfo(
edgeIndex, cidBytes[:],
)
if err != nil {
return err
}
edgeInfo.db = c.db
// With the static information obtained, we'll now
// fetch the dynamic policy info.
edge1, edge2, err := fetchChanEdgePolicies(
edgeIndex, edges, nodes, cidBytes[:], c.db,
)
if err != nil {
return err
}
chanEdges = append(chanEdges, ChannelEdge{
Info: &edgeInfo,
Policy1: edge1,
Policy2: edge2,
})
}
return nil
})
if err != nil {
return nil, err
}
return chanEdges, nil
}
func delEdgeUpdateIndexEntry(edgesBucket *bbolt.Bucket, chanID uint64,
edge1, edge2 *ChannelEdgePolicy) error {
// First, we'll fetch the edge update index bucket which currently
// stores an entry for the channel we're about to delete.
updateIndex := edgesBucket.Bucket(edgeUpdateIndexBucket)
if updateIndex == nil {
// No edges in bucket, return early.
return nil
}
// Now that we have the bucket, we'll attempt to construct a template
// for the index key: updateTime || chanid.
var indexKey [8 + 8]byte
byteOrder.PutUint64(indexKey[8:], chanID)
// With the template constructed, we'll attempt to delete an entry that
// would have been created by both edges: we'll alternate the update
// times, as one may had overridden the other.
if edge1 != nil {
byteOrder.PutUint64(indexKey[:8], uint64(edge1.LastUpdate.Unix()))
if err := updateIndex.Delete(indexKey[:]); err != nil {
return err
}
}
// We'll also attempt to delete the entry that may have been created by
// the second edge.
if edge2 != nil {
byteOrder.PutUint64(indexKey[:8], uint64(edge2.LastUpdate.Unix()))
if err := updateIndex.Delete(indexKey[:]); err != nil {
return err
}
}
return nil
}
func delChannelByEdge(edges *bbolt.Bucket, edgeIndex *bbolt.Bucket,
chanIndex *bbolt.Bucket, nodes *bbolt.Bucket, chanPoint *wire.OutPoint) error {
var b bytes.Buffer
if err := writeOutpoint(&b, chanPoint); err != nil {
return err
}
// If the channel's outpoint doesn't exist within the outpoint index,
// then the edge does not exist.
chanID := chanIndex.Get(b.Bytes())
if chanID == nil {
return ErrEdgeNotFound
}
// Otherwise we obtain the two public keys from the mapping: chanID ->
// pubKey1 || pubKey2. With this, we can construct the keys which house
// both of the directed edges for this channel.
nodeKeys := edgeIndex.Get(chanID)
if nodeKeys == nil {
return fmt.Errorf("could not find nodekeys for chanID %v",
chanID)
}
// We'll also remove the entry in the edge update index bucket before
// we delete the edges themselves so we can access their last update
// times.
cid := byteOrder.Uint64(chanID)
edge1, edge2, err := fetchChanEdgePolicies(
edgeIndex, edges, nodes, chanID, nil,
)
if err != nil {
return err
}
err = delEdgeUpdateIndexEntry(edges, cid, edge1, edge2)
if err != nil {
return err
}
// The edge key is of the format pubKey || chanID. First we construct
// the latter half, populating the channel ID.
var edgeKey [33 + 8]byte
copy(edgeKey[33:], chanID)
// With the latter half constructed, copy over the first public key to
// delete the edge in this direction, then the second to delete the
// edge in the opposite direction.
copy(edgeKey[:33], nodeKeys[:33])
if edges.Get(edgeKey[:]) != nil {
if err := edges.Delete(edgeKey[:]); err != nil {
return err
}
}
copy(edgeKey[:33], nodeKeys[33:])
if edges.Get(edgeKey[:]) != nil {
if err := edges.Delete(edgeKey[:]); err != nil {
return err
}
}
// Finally, with the edge data deleted, we can purge the information
// from the two edge indexes.
if err := edgeIndex.Delete(chanID); err != nil {
return err
}
return chanIndex.Delete(b.Bytes())
}
// UpdateEdgePolicy updates the edge routing policy for a single directed edge
// within the database for the referenced channel. The `flags` attribute within
// the ChannelEdgePolicy determines which of the directed edges are being
// updated. If the flag is 1, then the first node's information is being
// updated, otherwise it's the second node's information. The node ordering is
// determined by the lexicographical ordering of the identity public keys of
// the nodes on either side of the channel.
func (c *ChannelGraph) UpdateEdgePolicy(edge *ChannelEdgePolicy) error {
return c.db.Update(func(tx *bbolt.Tx) error {
return updateEdgePolicy(tx, edge)
})
}
// updateEdgePolicy attempts to update an edge's policy within the relevant
// buckets using an existing database transaction.
func updateEdgePolicy(tx *bbolt.Tx, edge *ChannelEdgePolicy) error {
edges := tx.Bucket(edgeBucket)
if edges == nil {
return ErrEdgeNotFound
}
edgeIndex := edges.Bucket(edgeIndexBucket)
if edgeIndex == nil {
return ErrEdgeNotFound
}
nodes, err := tx.CreateBucketIfNotExists(nodeBucket)
if err != nil {
return err
}
// Create the channelID key be converting the channel ID
// integer into a byte slice.
var chanID [8]byte
byteOrder.PutUint64(chanID[:], edge.ChannelID)
// With the channel ID, we then fetch the value storing the two
// nodes which connect this channel edge.
nodeInfo := edgeIndex.Get(chanID[:])
if nodeInfo == nil {
return ErrEdgeNotFound
}
// Depending on the flags value passed above, either the first
// or second edge policy is being updated.
var fromNode, toNode []byte
if edge.ChannelFlags&lnwire.ChanUpdateDirection == 0 {
fromNode = nodeInfo[:33]
toNode = nodeInfo[33:66]
} else {
fromNode = nodeInfo[33:66]
toNode = nodeInfo[:33]
}
// Finally, with the direction of the edge being updated
// identified, we update the on-disk edge representation.
return putChanEdgePolicy(edges, nodes, edge, fromNode, toNode)
}
// LightningNode represents an individual vertex/node within the channel graph.
// A node is connected to other nodes by one or more channel edges emanating
// from it. As the graph is directed, a node will also have an incoming edge
// attached to it for each outgoing edge.
type LightningNode struct {
// PubKeyBytes is the raw bytes of the public key of the target node.
PubKeyBytes [33]byte
pubKey *btcec.PublicKey
// HaveNodeAnnouncement indicates whether we received a node
// announcement for this particular node. If true, the remaining fields
// will be set, if false only the PubKey is known for this node.
HaveNodeAnnouncement bool
// LastUpdate is the last time the vertex information for this node has
// been updated.
LastUpdate time.Time
// Address is the TCP address this node is reachable over.
Addresses []net.Addr
// Color is the selected color for the node.
Color color.RGBA
// Alias is a nick-name for the node. The alias can be used to confirm
// a node's identity or to serve as a short ID for an address book.
Alias string
// AuthSigBytes is the raw signature under the advertised public key
// which serves to authenticate the attributes announced by this node.
AuthSigBytes []byte
// Features is the list of protocol features supported by this node.
Features *lnwire.FeatureVector
// ExtraOpaqueData is the set of data that was appended to this
// message, some of which we may not actually know how to iterate or
// parse. By holding onto this data, we ensure that we're able to
// properly validate the set of signatures that cover these new fields,
// and ensure we're able to make upgrades to the network in a forwards
// compatible manner.
ExtraOpaqueData []byte
db *DB
// TODO(roasbeef): discovery will need storage to keep it's last IP
// address and re-announce if interface changes?
// TODO(roasbeef): add update method and fetch?
}
// PubKey is the node's long-term identity public key. This key will be used to
// authenticated any advertisements/updates sent by the node.
//
// NOTE: By having this method to access an attribute, we ensure we only need
// to fully deserialize the pubkey if absolutely necessary.
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func (l *LightningNode) PubKey() (*btcec.PublicKey, error) {
if l.pubKey != nil {
return l.pubKey, nil
}
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key, err := btcec.ParsePubKey(l.PubKeyBytes[:], btcec.S256())
if err != nil {
return nil, err
}
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l.pubKey = key
l.pubKey.Curve = nil
return key, nil
}
// AuthSig is a signature under the advertised public key which serves to
// authenticate the attributes announced by this node.
//
// NOTE: By having this method to access an attribute, we ensure we only need
// to fully deserialize the signature if absolutely necessary.
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func (l *LightningNode) AuthSig() (*btcec.Signature, error) {
return btcec.ParseSignature(l.AuthSigBytes, btcec.S256())
}
// AddPubKey is a setter-link method that can be used to swap out the public
// key for a node.
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func (l *LightningNode) AddPubKey(key *btcec.PublicKey) {
l.pubKey = key
copy(l.PubKeyBytes[:], key.SerializeCompressed())
}
// NodeAnnouncement retrieves the latest node announcement of the node.
func (l *LightningNode) NodeAnnouncement(signed bool) (*lnwire.NodeAnnouncement,
error) {
if !l.HaveNodeAnnouncement {
return nil, fmt.Errorf("node does not have node announcement")
}
alias, err := lnwire.NewNodeAlias(l.Alias)
if err != nil {
return nil, err
}
nodeAnn := &lnwire.NodeAnnouncement{
Features: l.Features.RawFeatureVector,
NodeID: l.PubKeyBytes,
RGBColor: l.Color,
Alias: alias,
Addresses: l.Addresses,
Timestamp: uint32(l.LastUpdate.Unix()),
ExtraOpaqueData: l.ExtraOpaqueData,
}
if !signed {
return nodeAnn, nil
}
sig, err := lnwire.NewSigFromRawSignature(l.AuthSigBytes)
if err != nil {
return nil, err
}
nodeAnn.Signature = sig
return nodeAnn, nil
}
// isPublic determines whether the node is seen as public within the graph from
// the source node's point of view. An existing database transaction can also be
// specified.
func (l *LightningNode) isPublic(tx *bbolt.Tx, sourcePubKey []byte) (bool, error) {
// In order to determine whether this node is publicly advertised within
// the graph, we'll need to look at all of its edges and check whether
// they extend to any other node than the source node. errDone will be
// used to terminate the check early.
nodeIsPublic := false
errDone := errors.New("done")
err := l.ForEachChannel(tx, func(_ *bbolt.Tx, info *ChannelEdgeInfo,
_, _ *ChannelEdgePolicy) error {
// If this edge doesn't extend to the source node, we'll
// terminate our search as we can now conclude that the node is
// publicly advertised within the graph due to the local node
// knowing of the current edge.
if !bytes.Equal(info.NodeKey1Bytes[:], sourcePubKey) &&
!bytes.Equal(info.NodeKey2Bytes[:], sourcePubKey) {
nodeIsPublic = true
return errDone
}
// Since the edge _does_ extend to the source node, we'll also
// need to ensure that this is a public edge.
if info.AuthProof != nil {
nodeIsPublic = true
return errDone
}
// Otherwise, we'll continue our search.
return nil
})
if err != nil && err != errDone {
return false, err
}
return nodeIsPublic, nil
}
// FetchLightningNode attempts to look up a target node by its identity public
// key. If the node isn't found in the database, then ErrGraphNodeNotFound is
// returned.
func (c *ChannelGraph) FetchLightningNode(pub *btcec.PublicKey) (*LightningNode, error) {
var node *LightningNode
nodePub := pub.SerializeCompressed()
err := c.db.View(func(tx *bbolt.Tx) error {
// First grab the nodes bucket which stores the mapping from
// pubKey to node information.
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNotFound
}
// If a key for this serialized public key isn't found, then
// the target node doesn't exist within the database.
nodeBytes := nodes.Get(nodePub)
if nodeBytes == nil {
return ErrGraphNodeNotFound
}
// If the node is found, then we can de deserialize the node
// information to return to the user.
nodeReader := bytes.NewReader(nodeBytes)
n, err := deserializeLightningNode(nodeReader)
if err != nil {
return err
}
n.db = c.db
node = &n
return nil
})
if err != nil {
return nil, err
}
return node, nil
}
// HasLightningNode determines if the graph has a vertex identified by the
// target node identity public key. If the node exists in the database, a
// timestamp of when the data for the node was lasted updated is returned along
// with a true boolean. Otherwise, an empty time.Time is returned with a false
// boolean.
func (c *ChannelGraph) HasLightningNode(nodePub [33]byte) (time.Time, bool, error) {
var (
updateTime time.Time
exists bool
)
err := c.db.View(func(tx *bbolt.Tx) error {
// First grab the nodes bucket which stores the mapping from
// pubKey to node information.
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNotFound
}
// If a key for this serialized public key isn't found, we can
// exit early.
nodeBytes := nodes.Get(nodePub[:])
if nodeBytes == nil {
exists = false
return nil
}
// Otherwise we continue on to obtain the time stamp
// representing the last time the data for this node was
// updated.
nodeReader := bytes.NewReader(nodeBytes)
node, err := deserializeLightningNode(nodeReader)
if err != nil {
return err
}
exists = true
updateTime = node.LastUpdate
return nil
})
if err != nil {
return time.Time{}, exists, nil
}
return updateTime, exists, nil
}
// ForEachChannel iterates through all channels of this node, executing the
// passed callback with an edge info structure and the policies of each end
// of the channel. The first edge policy is the outgoing edge *to* the
// the connecting node, while the second is the incoming edge *from* the
// connecting node. If the callback returns an error, then the iteration is
// halted with the error propagated back up to the caller.
//
// Unknown policies are passed into the callback as nil values.
//
// If the caller wishes to re-use an existing boltdb transaction, then it
// should be passed as the first argument. Otherwise the first argument should
// be nil and a fresh transaction will be created to execute the graph
// traversal.
func (l *LightningNode) ForEachChannel(tx *bbolt.Tx,
cb func(*bbolt.Tx, *ChannelEdgeInfo, *ChannelEdgePolicy, *ChannelEdgePolicy) error) error {
nodePub := l.PubKeyBytes[:]
traversal := func(tx *bbolt.Tx) error {
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNotFound
}
edges := tx.Bucket(edgeBucket)
if edges == nil {
return ErrGraphNotFound
}
edgeIndex := edges.Bucket(edgeIndexBucket)
if edgeIndex == nil {
return ErrGraphNoEdgesFound
}
// In order to reach all the edges for this node, we take
// advantage of the construction of the key-space within the
// edge bucket. The keys are stored in the form: pubKey ||
// chanID. Therefore, starting from a chanID of zero, we can
// scan forward in the bucket, grabbing all the edges for the
// node. Once the prefix no longer matches, then we know we're
// done.
var nodeStart [33 + 8]byte
copy(nodeStart[:], nodePub)
copy(nodeStart[33:], chanStart[:])
// Starting from the key pubKey || 0, we seek forward in the
// bucket until the retrieved key no longer has the public key
// as its prefix. This indicates that we've stepped over into
// another node's edges, so we can terminate our scan.
edgeCursor := edges.Cursor()
for nodeEdge, _ := edgeCursor.Seek(nodeStart[:]); bytes.HasPrefix(nodeEdge, nodePub); nodeEdge, _ = edgeCursor.Next() {
// If the prefix still matches, the channel id is
// returned in nodeEdge. Channel id is used to lookup
// the node at the other end of the channel and both
// edge policies.
chanID := nodeEdge[33:]
edgeInfo, err := fetchChanEdgeInfo(edgeIndex, chanID)
if err != nil {
return err
}
edgeInfo.db = l.db
outgoingPolicy, err := fetchChanEdgePolicy(
edges, chanID, nodePub, nodes,
)
if err != nil {
return err
}
otherNode, err := edgeInfo.OtherNodeKeyBytes(nodePub)
if err != nil {
return err
}
incomingPolicy, err := fetchChanEdgePolicy(
edges, chanID, otherNode, nodes,
)
if err != nil {
return err
}
// Finally, we execute the callback.
err = cb(tx, &edgeInfo, outgoingPolicy, incomingPolicy)
if err != nil {
return err
}
}
return nil
}
// If no transaction was provided, then we'll create a new transaction
// to execute the transaction within.
if tx == nil {
return l.db.View(traversal)
}
// Otherwise, we re-use the existing transaction to execute the graph
// traversal.
return traversal(tx)
}
// ChannelEdgeInfo represents a fully authenticated channel along with all its
// unique attributes. Once an authenticated channel announcement has been
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// processed on the network, then an instance of ChannelEdgeInfo encapsulating
// the channels attributes is stored. The other portions relevant to routing
// policy of a channel are stored within a ChannelEdgePolicy for each direction
// of the channel.
type ChannelEdgeInfo struct {
// ChannelID is the unique channel ID for the channel. The first 3
// bytes are the block height, the next 3 the index within the block,
// and the last 2 bytes are the output index for the channel.
ChannelID uint64
// ChainHash is the hash that uniquely identifies the chain that this
// channel was opened within.
//
// TODO(roasbeef): need to modify db keying for multi-chain
// * must add chain hash to prefix as well
ChainHash chainhash.Hash
// NodeKey1Bytes is the raw public key of the first node.
NodeKey1Bytes [33]byte
nodeKey1 *btcec.PublicKey
// NodeKey2Bytes is the raw public key of the first node.
NodeKey2Bytes [33]byte
nodeKey2 *btcec.PublicKey
// BitcoinKey1Bytes is the raw public key of the first node.
BitcoinKey1Bytes [33]byte
bitcoinKey1 *btcec.PublicKey
// BitcoinKey2Bytes is the raw public key of the first node.
BitcoinKey2Bytes [33]byte
bitcoinKey2 *btcec.PublicKey
// Features is an opaque byte slice that encodes the set of channel
// specific features that this channel edge supports.
Features []byte
// AuthProof is the authentication proof for this channel. This proof
// contains a set of signatures binding four identities, which attests
// to the legitimacy of the advertised channel.
AuthProof *ChannelAuthProof
// ChannelPoint is the funding outpoint of the channel. This can be
// used to uniquely identify the channel within the channel graph.
ChannelPoint wire.OutPoint
// Capacity is the total capacity of the channel, this is determined by
// the value output in the outpoint that created this channel.
Capacity btcutil.Amount
// ExtraOpaqueData is the set of data that was appended to this
// message, some of which we may not actually know how to iterate or
// parse. By holding onto this data, we ensure that we're able to
// properly validate the set of signatures that cover these new fields,
// and ensure we're able to make upgrades to the network in a forwards
// compatible manner.
ExtraOpaqueData []byte
db *DB
}
// AddNodeKeys is a setter-like method that can be used to replace the set of
// keys for the target ChannelEdgeInfo.
func (c *ChannelEdgeInfo) AddNodeKeys(nodeKey1, nodeKey2, bitcoinKey1,
bitcoinKey2 *btcec.PublicKey) {
c.nodeKey1 = nodeKey1
copy(c.NodeKey1Bytes[:], c.nodeKey1.SerializeCompressed())
c.nodeKey2 = nodeKey2
copy(c.NodeKey2Bytes[:], nodeKey2.SerializeCompressed())
c.bitcoinKey1 = bitcoinKey1
copy(c.BitcoinKey1Bytes[:], c.bitcoinKey1.SerializeCompressed())
c.bitcoinKey2 = bitcoinKey2
copy(c.BitcoinKey2Bytes[:], bitcoinKey2.SerializeCompressed())
}
// NodeKey1 is the identity public key of the "first" node that was involved in
// the creation of this channel. A node is considered "first" if the
// lexicographical ordering the its serialized public key is "smaller" than
// that of the other node involved in channel creation.
//
// NOTE: By having this method to access an attribute, we ensure we only need
// to fully deserialize the pubkey if absolutely necessary.
func (c *ChannelEdgeInfo) NodeKey1() (*btcec.PublicKey, error) {
if c.nodeKey1 != nil {
return c.nodeKey1, nil
}
key, err := btcec.ParsePubKey(c.NodeKey1Bytes[:], btcec.S256())
if err != nil {
return nil, err
}
c.nodeKey1 = key
return key, nil
}
// NodeKey2 is the identity public key of the "second" node that was
// involved in the creation of this channel. A node is considered
// "second" if the lexicographical ordering the its serialized public
// key is "larger" than that of the other node involved in channel
// creation.
//
// NOTE: By having this method to access an attribute, we ensure we only need
// to fully deserialize the pubkey if absolutely necessary.
func (c *ChannelEdgeInfo) NodeKey2() (*btcec.PublicKey, error) {
if c.nodeKey2 != nil {
return c.nodeKey2, nil
}
key, err := btcec.ParsePubKey(c.NodeKey2Bytes[:], btcec.S256())
if err != nil {
return nil, err
}
c.nodeKey2 = key
return key, nil
}
// BitcoinKey1 is the Bitcoin multi-sig key belonging to the first
// node, that was involved in the funding transaction that originally
// created the channel that this struct represents.
//
// NOTE: By having this method to access an attribute, we ensure we only need
// to fully deserialize the pubkey if absolutely necessary.
func (c *ChannelEdgeInfo) BitcoinKey1() (*btcec.PublicKey, error) {
if c.bitcoinKey1 != nil {
return c.bitcoinKey1, nil
}
key, err := btcec.ParsePubKey(c.BitcoinKey1Bytes[:], btcec.S256())
if err != nil {
return nil, err
}
c.bitcoinKey1 = key
return key, nil
}
// BitcoinKey2 is the Bitcoin multi-sig key belonging to the second
// node, that was involved in the funding transaction that originally
// created the channel that this struct represents.
//
// NOTE: By having this method to access an attribute, we ensure we only need
// to fully deserialize the pubkey if absolutely necessary.
func (c *ChannelEdgeInfo) BitcoinKey2() (*btcec.PublicKey, error) {
if c.bitcoinKey2 != nil {
return c.bitcoinKey2, nil
}
key, err := btcec.ParsePubKey(c.BitcoinKey2Bytes[:], btcec.S256())
if err != nil {
return nil, err
}
c.bitcoinKey2 = key
return key, nil
}
// OtherNodeKeyBytes returns the node key bytes of the other end of
// the channel.
func (c *ChannelEdgeInfo) OtherNodeKeyBytes(thisNodeKey []byte) (
[]byte, error) {
switch {
case bytes.Equal(c.NodeKey1Bytes[:], thisNodeKey):
return c.NodeKey2Bytes[:], nil
case bytes.Equal(c.NodeKey2Bytes[:], thisNodeKey):
return c.NodeKey1Bytes[:], nil
default:
return nil, fmt.Errorf("node not participating in this channel")
}
}
// FetchOtherNode attempts to fetch the full LightningNode that's opposite of
// the target node in the channel. This is useful when one knows the pubkey of
// one of the nodes, and wishes to obtain the full LightningNode for the other
// end of the channel.
func (c *ChannelEdgeInfo) FetchOtherNode(tx *bbolt.Tx, thisNodeKey []byte) (*LightningNode, error) {
// Ensure that the node passed in is actually a member of the channel.
var targetNodeBytes [33]byte
switch {
case bytes.Equal(c.NodeKey1Bytes[:], thisNodeKey):
targetNodeBytes = c.NodeKey2Bytes
case bytes.Equal(c.NodeKey2Bytes[:], thisNodeKey):
targetNodeBytes = c.NodeKey1Bytes
default:
return nil, fmt.Errorf("node not participating in this channel")
}
var targetNode *LightningNode
fetchNodeFunc := func(tx *bbolt.Tx) error {
// First grab the nodes bucket which stores the mapping from
// pubKey to node information.
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNotFound
}
node, err := fetchLightningNode(nodes, targetNodeBytes[:])
if err != nil {
return err
}
node.db = c.db
targetNode = &node
return nil
}
// If the transaction is nil, then we'll need to create a new one,
// otherwise we can use the existing db transaction.
var err error
if tx == nil {
err = c.db.View(fetchNodeFunc)
} else {
err = fetchNodeFunc(tx)
}
return targetNode, err
}
// ChannelAuthProof is the authentication proof (the signature portion) for a
// channel. Using the four signatures contained in the struct, and some
// auxiliary knowledge (the funding script, node identities, and outpoint) nodes
// on the network are able to validate the authenticity and existence of a
// channel. Each of these signatures signs the following digest: chanID ||
// nodeID1 || nodeID2 || bitcoinKey1|| bitcoinKey2 || 2-byte-feature-len ||
// features.
type ChannelAuthProof struct {
// nodeSig1 is a cached instance of the first node signature.
nodeSig1 *btcec.Signature
// NodeSig1Bytes are the raw bytes of the first node signature encoded
// in DER format.
NodeSig1Bytes []byte
// nodeSig2 is a cached instance of the second node signature.
nodeSig2 *btcec.Signature
// NodeSig2Bytes are the raw bytes of the second node signature
// encoded in DER format.
NodeSig2Bytes []byte
// bitcoinSig1 is a cached instance of the first bitcoin signature.
bitcoinSig1 *btcec.Signature
// BitcoinSig1Bytes are the raw bytes of the first bitcoin signature
// encoded in DER format.
BitcoinSig1Bytes []byte
// bitcoinSig2 is a cached instance of the second bitcoin signature.
bitcoinSig2 *btcec.Signature
// BitcoinSig2Bytes are the raw bytes of the second bitcoin signature
// encoded in DER format.
BitcoinSig2Bytes []byte
}
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// Node1Sig is the signature using the identity key of the node that is first
// in a lexicographical ordering of the serialized public keys of the two nodes
// that created the channel.
//
// NOTE: By having this method to access an attribute, we ensure we only need
// to fully deserialize the signature if absolutely necessary.
func (c *ChannelAuthProof) Node1Sig() (*btcec.Signature, error) {
if c.nodeSig1 != nil {
return c.nodeSig1, nil
}
sig, err := btcec.ParseSignature(c.NodeSig1Bytes, btcec.S256())
if err != nil {
return nil, err
}
c.nodeSig1 = sig
return sig, nil
}
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// Node2Sig is the signature using the identity key of the node that is second
// in a lexicographical ordering of the serialized public keys of the two nodes
// that created the channel.
//
// NOTE: By having this method to access an attribute, we ensure we only need
// to fully deserialize the signature if absolutely necessary.
func (c *ChannelAuthProof) Node2Sig() (*btcec.Signature, error) {
if c.nodeSig2 != nil {
return c.nodeSig2, nil
}
sig, err := btcec.ParseSignature(c.NodeSig2Bytes, btcec.S256())
if err != nil {
return nil, err
}
c.nodeSig2 = sig
return sig, nil
}
// BitcoinSig1 is the signature using the public key of the first node that was
// used in the channel's multi-sig output.
//
// NOTE: By having this method to access an attribute, we ensure we only need
// to fully deserialize the signature if absolutely necessary.
func (c *ChannelAuthProof) BitcoinSig1() (*btcec.Signature, error) {
if c.bitcoinSig1 != nil {
return c.bitcoinSig1, nil
}
sig, err := btcec.ParseSignature(c.BitcoinSig1Bytes, btcec.S256())
if err != nil {
return nil, err
}
c.bitcoinSig1 = sig
return sig, nil
}
// BitcoinSig2 is the signature using the public key of the second node that
// was used in the channel's multi-sig output.
//
// NOTE: By having this method to access an attribute, we ensure we only need
// to fully deserialize the signature if absolutely necessary.
func (c *ChannelAuthProof) BitcoinSig2() (*btcec.Signature, error) {
if c.bitcoinSig2 != nil {
return c.bitcoinSig2, nil
}
sig, err := btcec.ParseSignature(c.BitcoinSig2Bytes, btcec.S256())
if err != nil {
return nil, err
}
c.bitcoinSig2 = sig
return sig, nil
}
// IsEmpty check is the authentication proof is empty Proof is empty if at
// least one of the signatures are equal to nil.
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func (c *ChannelAuthProof) IsEmpty() bool {
return len(c.NodeSig1Bytes) == 0 ||
len(c.NodeSig2Bytes) == 0 ||
len(c.BitcoinSig1Bytes) == 0 ||
len(c.BitcoinSig2Bytes) == 0
}
// ChannelEdgePolicy represents a *directed* edge within the channel graph. For
// each channel in the database, there are two distinct edges: one for each
// possible direction of travel along the channel. The edges themselves hold
// information concerning fees, and minimum time-lock information which is
// utilized during path finding.
type ChannelEdgePolicy struct {
// SigBytes is the raw bytes of the signature of the channel edge
// policy. We'll only parse these if the caller needs to access the
// signature for validation purposes.
SigBytes []byte
// sig is a cached fully parsed signature.
sig *btcec.Signature
// ChannelID is the unique channel ID for the channel. The first 3
// bytes are the block height, the next 3 the index within the block,
// and the last 2 bytes are the output index for the channel.
ChannelID uint64
// LastUpdate is the last time an authenticated edge for this channel
// was received.
LastUpdate time.Time
// MessageFlags is a bitfield which indicates the presence of optional
// fields (like max_htlc) in the policy.
MessageFlags lnwire.ChanUpdateMsgFlags
// ChannelFlags is a bitfield which signals the capabilities of the
// channel as well as the directed edge this update applies to.
ChannelFlags lnwire.ChanUpdateChanFlags
// TimeLockDelta is the number of blocks this node will subtract from
// the expiry of an incoming HTLC. This value expresses the time buffer
// the node would like to HTLC exchanges.
TimeLockDelta uint16
// MinHTLC is the smallest value HTLC this node will accept, expressed
// in millisatoshi.
MinHTLC lnwire.MilliSatoshi
// MaxHTLC is the largest value HTLC this node will accept, expressed
// in millisatoshi.
MaxHTLC lnwire.MilliSatoshi
// FeeBaseMSat is the base HTLC fee that will be charged for forwarding
// ANY HTLC, expressed in mSAT's.
FeeBaseMSat lnwire.MilliSatoshi
// FeeProportionalMillionths is the rate that the node will charge for
// HTLCs for each millionth of a satoshi forwarded.
FeeProportionalMillionths lnwire.MilliSatoshi
// Node is the LightningNode that this directed edge leads to. Using
// this pointer the channel graph can further be traversed.
Node *LightningNode
// ExtraOpaqueData is the set of data that was appended to this
// message, some of which we may not actually know how to iterate or
// parse. By holding onto this data, we ensure that we're able to
// properly validate the set of signatures that cover these new fields,
// and ensure we're able to make upgrades to the network in a forwards
// compatible manner.
ExtraOpaqueData []byte
db *DB
}
// Signature is a channel announcement signature, which is needed for proper
// edge policy announcement.
//
// NOTE: By having this method to access an attribute, we ensure we only need
// to fully deserialize the signature if absolutely necessary.
func (c *ChannelEdgePolicy) Signature() (*btcec.Signature, error) {
if c.sig != nil {
return c.sig, nil
}
sig, err := btcec.ParseSignature(c.SigBytes, btcec.S256())
if err != nil {
return nil, err
}
c.sig = sig
return sig, nil
}
// FetchChannelEdgesByOutpoint attempts to lookup the two directed edges for
// the channel identified by the funding outpoint. If the channel can't be
// found, then ErrEdgeNotFound is returned. A struct which houses the general
// information for the channel itself is returned as well as two structs that
// contain the routing policies for the channel in either direction.
func (c *ChannelGraph) FetchChannelEdgesByOutpoint(op *wire.OutPoint) (*ChannelEdgeInfo, *ChannelEdgePolicy, *ChannelEdgePolicy, error) {
var (
edgeInfo *ChannelEdgeInfo
policy1 *ChannelEdgePolicy
policy2 *ChannelEdgePolicy
)
err := c.db.View(func(tx *bbolt.Tx) error {
// First, grab the node bucket. This will be used to populate
// the Node pointers in each edge read from disk.
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNotFound
}
// Next, grab the edge bucket which stores the edges, and also
// the index itself so we can group the directed edges together
// logically.
edges := tx.Bucket(edgeBucket)
if edges == nil {
return ErrGraphNoEdgesFound
}
edgeIndex := edges.Bucket(edgeIndexBucket)
if edgeIndex == nil {
return ErrGraphNoEdgesFound
}
// If the channel's outpoint doesn't exist within the outpoint
// index, then the edge does not exist.
chanIndex := edges.Bucket(channelPointBucket)
if chanIndex == nil {
return ErrGraphNoEdgesFound
}
var b bytes.Buffer
if err := writeOutpoint(&b, op); err != nil {
return err
}
chanID := chanIndex.Get(b.Bytes())
if chanID == nil {
return ErrEdgeNotFound
}
// If the channel is found to exists, then we'll first retrieve
// the general information for the channel.
edge, err := fetchChanEdgeInfo(edgeIndex, chanID)
if err != nil {
return err
}
edgeInfo = &edge
edgeInfo.db = c.db
// Once we have the information about the channels' parameters,
// we'll fetch the routing policies for each for the directed
// edges.
e1, e2, err := fetchChanEdgePolicies(
edgeIndex, edges, nodes, chanID, c.db,
)
if err != nil {
return err
}
policy1 = e1
policy2 = e2
return nil
})
if err != nil {
return nil, nil, nil, err
}
return edgeInfo, policy1, policy2, nil
}
// FetchChannelEdgesByID attempts to lookup the two directed edges for the
// channel identified by the channel ID. If the channel can't be found, then
// ErrEdgeNotFound is returned. A struct which houses the general information
// for the channel itself is returned as well as two structs that contain the
// routing policies for the channel in either direction.
func (c *ChannelGraph) FetchChannelEdgesByID(chanID uint64) (*ChannelEdgeInfo, *ChannelEdgePolicy, *ChannelEdgePolicy, error) {
var (
edgeInfo *ChannelEdgeInfo
policy1 *ChannelEdgePolicy
policy2 *ChannelEdgePolicy
channelID [8]byte
)
err := c.db.View(func(tx *bbolt.Tx) error {
// First, grab the node bucket. This will be used to populate
// the Node pointers in each edge read from disk.
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNotFound
}
// Next, grab the edge bucket which stores the edges, and also
// the index itself so we can group the directed edges together
// logically.
edges := tx.Bucket(edgeBucket)
if edges == nil {
return ErrGraphNoEdgesFound
}
edgeIndex := edges.Bucket(edgeIndexBucket)
if edgeIndex == nil {
return ErrGraphNoEdgesFound
}
byteOrder.PutUint64(channelID[:], chanID)
edge, err := fetchChanEdgeInfo(edgeIndex, channelID[:])
if err != nil {
return err
}
edgeInfo = &edge
edgeInfo.db = c.db
e1, e2, err := fetchChanEdgePolicies(
edgeIndex, edges, nodes, channelID[:], c.db,
)
if err != nil {
return err
}
policy1 = e1
policy2 = e2
return nil
})
if err != nil {
return nil, nil, nil, err
}
return edgeInfo, policy1, policy2, nil
}
// IsPublicNode is a helper method that determines whether the node with the
// given public key is seen as a public node in the graph from the graph's
// source node's point of view.
func (c *ChannelGraph) IsPublicNode(pubKey [33]byte) (bool, error) {
var nodeIsPublic bool
err := c.db.View(func(tx *bbolt.Tx) error {
nodes := tx.Bucket(nodeBucket)
if nodes == nil {
return ErrGraphNodesNotFound
}
ourPubKey := nodes.Get(sourceKey)
if ourPubKey == nil {
return ErrSourceNodeNotSet
}
node, err := fetchLightningNode(nodes, pubKey[:])
if err != nil {
return err
}
nodeIsPublic, err = node.isPublic(tx, ourPubKey)
return err
})
if err != nil {
return false, err
}
return nodeIsPublic, nil
}
// genMultiSigP2WSH generates the p2wsh'd multisig script for 2 of 2 pubkeys.
func genMultiSigP2WSH(aPub, bPub []byte) ([]byte, error) {
if len(aPub) != 33 || len(bPub) != 33 {
return nil, fmt.Errorf("Pubkey size error. Compressed " +
"pubkeys only")
}
// Swap to sort pubkeys if needed. Keys are sorted in lexicographical
// order. The signatures within the scriptSig must also adhere to the
// order, ensuring that the signatures for each public key appears in
// the proper order on the stack.
if bytes.Compare(aPub, bPub) == 1 {
aPub, bPub = bPub, aPub
}
// First, we'll generate the witness script for the multi-sig.
bldr := txscript.NewScriptBuilder()
bldr.AddOp(txscript.OP_2)
bldr.AddData(aPub) // Add both pubkeys (sorted).
bldr.AddData(bPub)
bldr.AddOp(txscript.OP_2)
bldr.AddOp(txscript.OP_CHECKMULTISIG)
witnessScript, err := bldr.Script()
if err != nil {
return nil, err
}
// With the witness script generated, we'll now turn it into a p2sh
// script:
// * OP_0 <sha256(script)>
bldr = txscript.NewScriptBuilder()
bldr.AddOp(txscript.OP_0)
scriptHash := sha256.Sum256(witnessScript)
bldr.AddData(scriptHash[:])
return bldr.Script()
}
// EdgePoint couples the outpoint of a channel with the funding script that it
// creates. The FilteredChainView will use this to watch for spends of this
// edge point on chain. We require both of these values as depending on the
// concrete implementation, either the pkScript, or the out point will be used.
type EdgePoint struct {
// FundingPkScript is the p2wsh multi-sig script of the target channel.
FundingPkScript []byte
// OutPoint is the outpoint of the target channel.
OutPoint wire.OutPoint
}
// String returns a human readable version of the target EdgePoint. We return
// the outpoint directly as it is enough to uniquely identify the edge point.
func (e *EdgePoint) String() string {
return e.OutPoint.String()
}
// ChannelView returns the verifiable edge information for each active channel
// within the known channel graph. The set of UTXO's (along with their scripts)
// returned are the ones that need to be watched on chain to detect channel
// closes on the resident blockchain.
func (c *ChannelGraph) ChannelView() ([]EdgePoint, error) {
var edgePoints []EdgePoint
if err := c.db.View(func(tx *bbolt.Tx) error {
// We're going to iterate over the entire channel index, so
// we'll need to fetch the edgeBucket to get to the index as
// it's a sub-bucket.
edges := tx.Bucket(edgeBucket)
if edges == nil {
return ErrGraphNoEdgesFound
}
chanIndex := edges.Bucket(channelPointBucket)
if chanIndex == nil {
return ErrGraphNoEdgesFound
}
edgeIndex := edges.Bucket(edgeIndexBucket)
if edgeIndex == nil {
return ErrGraphNoEdgesFound
}
// Once we have the proper bucket, we'll range over each key
// (which is the channel point for the channel) and decode it,
// accumulating each entry.
return chanIndex.ForEach(func(chanPointBytes, chanID []byte) error {
chanPointReader := bytes.NewReader(chanPointBytes)
var chanPoint wire.OutPoint
err := readOutpoint(chanPointReader, &chanPoint)
if err != nil {
return err
}
edgeInfo, err := fetchChanEdgeInfo(
edgeIndex, chanID,
)
if err != nil {
return err
}
pkScript, err := genMultiSigP2WSH(
edgeInfo.BitcoinKey1Bytes[:],
edgeInfo.BitcoinKey2Bytes[:],
)
if err != nil {
return err
}
edgePoints = append(edgePoints, EdgePoint{
FundingPkScript: pkScript,
OutPoint: chanPoint,
})
return nil
})
}); err != nil {
return nil, err
}
return edgePoints, nil
}
// NewChannelEdgePolicy returns a new blank ChannelEdgePolicy.
func (c *ChannelGraph) NewChannelEdgePolicy() *ChannelEdgePolicy {
return &ChannelEdgePolicy{db: c.db}
}
func putLightningNode(nodeBucket *bbolt.Bucket, aliasBucket *bbolt.Bucket,
updateIndex *bbolt.Bucket, node *LightningNode) error {
var (
scratch [16]byte
b bytes.Buffer
)
pub, err := node.PubKey()
if err != nil {
return err
}
nodePub := pub.SerializeCompressed()
// If the node has the update time set, write it, else write 0.
updateUnix := uint64(0)
if node.LastUpdate.Unix() > 0 {
updateUnix = uint64(node.LastUpdate.Unix())
}
byteOrder.PutUint64(scratch[:8], updateUnix)
if _, err := b.Write(scratch[:8]); err != nil {
return err
}
if _, err := b.Write(nodePub); err != nil {
return err
}
// If we got a node announcement for this node, we will have the rest
// of the data available. If not we don't have more data to write.
if !node.HaveNodeAnnouncement {
// Write HaveNodeAnnouncement=0.
byteOrder.PutUint16(scratch[:2], 0)
if _, err := b.Write(scratch[:2]); err != nil {
return err
}
return nodeBucket.Put(nodePub, b.Bytes())
}
// Write HaveNodeAnnouncement=1.
byteOrder.PutUint16(scratch[:2], 1)
if _, err := b.Write(scratch[:2]); err != nil {
return err
}
if err := binary.Write(&b, byteOrder, node.Color.R); err != nil {
return err
}
if err := binary.Write(&b, byteOrder, node.Color.G); err != nil {
return err
}
if err := binary.Write(&b, byteOrder, node.Color.B); err != nil {
return err
}
if err := wire.WriteVarString(&b, 0, node.Alias); err != nil {
return err
}
if err := node.Features.Encode(&b); err != nil {
return err
}
numAddresses := uint16(len(node.Addresses))
byteOrder.PutUint16(scratch[:2], numAddresses)
if _, err := b.Write(scratch[:2]); err != nil {
return err
}
for _, address := range node.Addresses {
if err := serializeAddr(&b, address); err != nil {
return err
}
}
sigLen := len(node.AuthSigBytes)
if sigLen > 80 {
return fmt.Errorf("max sig len allowed is 80, had %v",
sigLen)
}
err = wire.WriteVarBytes(&b, 0, node.AuthSigBytes)
if err != nil {
return err
}
if len(node.ExtraOpaqueData) > MaxAllowedExtraOpaqueBytes {
return ErrTooManyExtraOpaqueBytes(len(node.ExtraOpaqueData))
}
err = wire.WriteVarBytes(&b, 0, node.ExtraOpaqueData)
if err != nil {
return err
}
if err := aliasBucket.Put(nodePub, []byte(node.Alias)); err != nil {
return err
}
// With the alias bucket updated, we'll now update the index that
// tracks the time series of node updates.
var indexKey [8 + 33]byte
byteOrder.PutUint64(indexKey[:8], updateUnix)
copy(indexKey[8:], nodePub)
// If there was already an old index entry for this node, then we'll
// delete the old one before we write the new entry.
if nodeBytes := nodeBucket.Get(nodePub); nodeBytes != nil {
// Extract out the old update time to we can reconstruct the
// prior index key to delete it from the index.
oldUpdateTime := nodeBytes[:8]
var oldIndexKey [8 + 33]byte
copy(oldIndexKey[:8], oldUpdateTime)
copy(oldIndexKey[8:], nodePub)
if err := updateIndex.Delete(oldIndexKey[:]); err != nil {
return err
}
}
if err := updateIndex.Put(indexKey[:], nil); err != nil {
return err
}
return nodeBucket.Put(nodePub, b.Bytes())
}
func fetchLightningNode(nodeBucket *bbolt.Bucket,
nodePub []byte) (LightningNode, error) {
nodeBytes := nodeBucket.Get(nodePub)
if nodeBytes == nil {
return LightningNode{}, ErrGraphNodeNotFound
}
nodeReader := bytes.NewReader(nodeBytes)
return deserializeLightningNode(nodeReader)
}
func deserializeLightningNode(r io.Reader) (LightningNode, error) {
var (
node LightningNode
scratch [8]byte
err error
)
if _, err := r.Read(scratch[:]); err != nil {
return LightningNode{}, err
}
unix := int64(byteOrder.Uint64(scratch[:]))
node.LastUpdate = time.Unix(unix, 0)
if _, err := io.ReadFull(r, node.PubKeyBytes[:]); err != nil {
return LightningNode{}, err
}
if _, err := r.Read(scratch[:2]); err != nil {
return LightningNode{}, err
}
hasNodeAnn := byteOrder.Uint16(scratch[:2])
if hasNodeAnn == 1 {
node.HaveNodeAnnouncement = true
} else {
node.HaveNodeAnnouncement = false
}
// The rest of the data is optional, and will only be there if we got a node
// announcement for this node.
if !node.HaveNodeAnnouncement {
return node, nil
}
// We did get a node announcement for this node, so we'll have the rest
// of the data available.
if err := binary.Read(r, byteOrder, &node.Color.R); err != nil {
return LightningNode{}, err
}
if err := binary.Read(r, byteOrder, &node.Color.G); err != nil {
return LightningNode{}, err
}
if err := binary.Read(r, byteOrder, &node.Color.B); err != nil {
return LightningNode{}, err
}
node.Alias, err = wire.ReadVarString(r, 0)
if err != nil {
return LightningNode{}, err
}
fv := lnwire.NewFeatureVector(nil, lnwire.GlobalFeatures)
err = fv.Decode(r)
if err != nil {
return LightningNode{}, err
}
node.Features = fv
if _, err := r.Read(scratch[:2]); err != nil {
return LightningNode{}, err
}
numAddresses := int(byteOrder.Uint16(scratch[:2]))
var addresses []net.Addr
for i := 0; i < numAddresses; i++ {
address, err := deserializeAddr(r)
if err != nil {
return LightningNode{}, err
}
addresses = append(addresses, address)
}
node.Addresses = addresses
node.AuthSigBytes, err = wire.ReadVarBytes(r, 0, 80, "sig")
if err != nil {
return LightningNode{}, err
}
// We'll try and see if there are any opaque bytes left, if not, then
// we'll ignore the EOF error and return the node as is.
node.ExtraOpaqueData, err = wire.ReadVarBytes(
r, 0, MaxAllowedExtraOpaqueBytes, "blob",
)
switch {
case err == io.ErrUnexpectedEOF:
case err == io.EOF:
case err != nil:
return LightningNode{}, err
}
return node, nil
}
func putChanEdgeInfo(edgeIndex *bbolt.Bucket, edgeInfo *ChannelEdgeInfo, chanID [8]byte) error {
var b bytes.Buffer
if _, err := b.Write(edgeInfo.NodeKey1Bytes[:]); err != nil {
return err
}
if _, err := b.Write(edgeInfo.NodeKey2Bytes[:]); err != nil {
return err
}
if _, err := b.Write(edgeInfo.BitcoinKey1Bytes[:]); err != nil {
return err
}
if _, err := b.Write(edgeInfo.BitcoinKey2Bytes[:]); err != nil {
return err
}
if err := wire.WriteVarBytes(&b, 0, edgeInfo.Features); err != nil {
return err
}
authProof := edgeInfo.AuthProof
var nodeSig1, nodeSig2, bitcoinSig1, bitcoinSig2 []byte
if authProof != nil {
nodeSig1 = authProof.NodeSig1Bytes
nodeSig2 = authProof.NodeSig2Bytes
bitcoinSig1 = authProof.BitcoinSig1Bytes
bitcoinSig2 = authProof.BitcoinSig2Bytes
}
if err := wire.WriteVarBytes(&b, 0, nodeSig1); err != nil {
return err
}
if err := wire.WriteVarBytes(&b, 0, nodeSig2); err != nil {
return err
}
if err := wire.WriteVarBytes(&b, 0, bitcoinSig1); err != nil {
return err
}
if err := wire.WriteVarBytes(&b, 0, bitcoinSig2); err != nil {
return err
}
if err := writeOutpoint(&b, &edgeInfo.ChannelPoint); err != nil {
return err
}
if err := binary.Write(&b, byteOrder, uint64(edgeInfo.Capacity)); err != nil {
return err
}
if _, err := b.Write(chanID[:]); err != nil {
return err
}
if _, err := b.Write(edgeInfo.ChainHash[:]); err != nil {
return err
}
if len(edgeInfo.ExtraOpaqueData) > MaxAllowedExtraOpaqueBytes {
return ErrTooManyExtraOpaqueBytes(len(edgeInfo.ExtraOpaqueData))
}
err := wire.WriteVarBytes(&b, 0, edgeInfo.ExtraOpaqueData)
if err != nil {
return err
}
return edgeIndex.Put(chanID[:], b.Bytes())
}
func fetchChanEdgeInfo(edgeIndex *bbolt.Bucket,
chanID []byte) (ChannelEdgeInfo, error) {
edgeInfoBytes := edgeIndex.Get(chanID)
if edgeInfoBytes == nil {
return ChannelEdgeInfo{}, ErrEdgeNotFound
}
edgeInfoReader := bytes.NewReader(edgeInfoBytes)
return deserializeChanEdgeInfo(edgeInfoReader)
}
func deserializeChanEdgeInfo(r io.Reader) (ChannelEdgeInfo, error) {
var (
err error
edgeInfo ChannelEdgeInfo
)
if _, err := io.ReadFull(r, edgeInfo.NodeKey1Bytes[:]); err != nil {
return ChannelEdgeInfo{}, err
}
if _, err := io.ReadFull(r, edgeInfo.NodeKey2Bytes[:]); err != nil {
return ChannelEdgeInfo{}, err
}
if _, err := io.ReadFull(r, edgeInfo.BitcoinKey1Bytes[:]); err != nil {
return ChannelEdgeInfo{}, err
}
if _, err := io.ReadFull(r, edgeInfo.BitcoinKey2Bytes[:]); err != nil {
return ChannelEdgeInfo{}, err
}
edgeInfo.Features, err = wire.ReadVarBytes(r, 0, 900, "features")
if err != nil {
return ChannelEdgeInfo{}, err
}
proof := &ChannelAuthProof{}
proof.NodeSig1Bytes, err = wire.ReadVarBytes(r, 0, 80, "sigs")
if err != nil {
return ChannelEdgeInfo{}, err
}
proof.NodeSig2Bytes, err = wire.ReadVarBytes(r, 0, 80, "sigs")
if err != nil {
return ChannelEdgeInfo{}, err
}
proof.BitcoinSig1Bytes, err = wire.ReadVarBytes(r, 0, 80, "sigs")
if err != nil {
return ChannelEdgeInfo{}, err
}
proof.BitcoinSig2Bytes, err = wire.ReadVarBytes(r, 0, 80, "sigs")
if err != nil {
return ChannelEdgeInfo{}, err
}
if !proof.IsEmpty() {
edgeInfo.AuthProof = proof
}
edgeInfo.ChannelPoint = wire.OutPoint{}
if err := readOutpoint(r, &edgeInfo.ChannelPoint); err != nil {
return ChannelEdgeInfo{}, err
}
if err := binary.Read(r, byteOrder, &edgeInfo.Capacity); err != nil {
return ChannelEdgeInfo{}, err
}
if err := binary.Read(r, byteOrder, &edgeInfo.ChannelID); err != nil {
return ChannelEdgeInfo{}, err
}
if _, err := io.ReadFull(r, edgeInfo.ChainHash[:]); err != nil {
return ChannelEdgeInfo{}, err
}
// We'll try and see if there are any opaque bytes left, if not, then
// we'll ignore the EOF error and return the edge as is.
edgeInfo.ExtraOpaqueData, err = wire.ReadVarBytes(
r, 0, MaxAllowedExtraOpaqueBytes, "blob",
)
switch {
case err == io.ErrUnexpectedEOF:
case err == io.EOF:
case err != nil:
return ChannelEdgeInfo{}, err
}
return edgeInfo, nil
}
func putChanEdgePolicy(edges, nodes *bbolt.Bucket, edge *ChannelEdgePolicy,
from, to []byte) error {
var edgeKey [33 + 8]byte
copy(edgeKey[:], from)
byteOrder.PutUint64(edgeKey[33:], edge.ChannelID)
var b bytes.Buffer
if err := serializeChanEdgePolicy(&b, edge, to); err != nil {
return err
}
// Before we write out the new edge, we'll create a new entry in the
// update index in order to keep it fresh.
updateUnix := uint64(edge.LastUpdate.Unix())
var indexKey [8 + 8]byte
byteOrder.PutUint64(indexKey[:8], updateUnix)
byteOrder.PutUint64(indexKey[8:], edge.ChannelID)
updateIndex, err := edges.CreateBucketIfNotExists(edgeUpdateIndexBucket)
if err != nil {
return err
}
// If there was already an entry for this edge, then we'll need to
// delete the old one to ensure we don't leave around any after-images.
// An unknown policy value does not have a update time recorded, so
// it also does not need to be removed.
if edgeBytes := edges.Get(edgeKey[:]); edgeBytes != nil &&
!bytes.Equal(edgeBytes[:], unknownPolicy) {
// In order to delete the old entry, we'll need to obtain the
// *prior* update time in order to delete it. To do this, we'll
// need to deserialize the existing policy within the database
// (now outdated by the new one), and delete its corresponding
// entry within the update index. We'll ignore any
// ErrEdgePolicyOptionalFieldNotFound error, as we only need
// the channel ID and update time to delete the entry.
// TODO(halseth): get rid of these invalid policies in a
// migration.
oldEdgePolicy, err := deserializeChanEdgePolicy(
bytes.NewReader(edgeBytes), nodes,
)
if err != nil && err != ErrEdgePolicyOptionalFieldNotFound {
return err
}
oldUpdateTime := uint64(oldEdgePolicy.LastUpdate.Unix())
var oldIndexKey [8 + 8]byte
byteOrder.PutUint64(oldIndexKey[:8], oldUpdateTime)
byteOrder.PutUint64(oldIndexKey[8:], edge.ChannelID)
if err := updateIndex.Delete(oldIndexKey[:]); err != nil {
return err
}
}
if err := updateIndex.Put(indexKey[:], nil); err != nil {
return err
}
return edges.Put(edgeKey[:], b.Bytes()[:])
}
// putChanEdgePolicyUnknown marks the edge policy as unknown
// in the edges bucket.
func putChanEdgePolicyUnknown(edges *bbolt.Bucket, channelID uint64,
from []byte) error {
var edgeKey [33 + 8]byte
copy(edgeKey[:], from)
byteOrder.PutUint64(edgeKey[33:], channelID)
if edges.Get(edgeKey[:]) != nil {
return fmt.Errorf("Cannot write unknown policy for channel %v "+
" when there is already a policy present", channelID)
}
return edges.Put(edgeKey[:], unknownPolicy)
}
func fetchChanEdgePolicy(edges *bbolt.Bucket, chanID []byte,
nodePub []byte, nodes *bbolt.Bucket) (*ChannelEdgePolicy, error) {
var edgeKey [33 + 8]byte
copy(edgeKey[:], nodePub)
copy(edgeKey[33:], chanID[:])
edgeBytes := edges.Get(edgeKey[:])
if edgeBytes == nil {
return nil, ErrEdgeNotFound
}
// No need to deserialize unknown policy.
if bytes.Equal(edgeBytes[:], unknownPolicy) {
return nil, nil
}
edgeReader := bytes.NewReader(edgeBytes)
ep, err := deserializeChanEdgePolicy(edgeReader, nodes)
switch {
// If the db policy was missing an expected optional field, we return
// nil as if the policy was unknown.
case err == ErrEdgePolicyOptionalFieldNotFound:
return nil, nil
case err != nil:
return nil, err
}
return ep, nil
}
func fetchChanEdgePolicies(edgeIndex *bbolt.Bucket, edges *bbolt.Bucket,
nodes *bbolt.Bucket, chanID []byte,
db *DB) (*ChannelEdgePolicy, *ChannelEdgePolicy, error) {
edgeInfo := edgeIndex.Get(chanID)
if edgeInfo == nil {
return nil, nil, ErrEdgeNotFound
}
// The first node is contained within the first half of the edge
// information. We only propagate the error here and below if it's
// something other than edge non-existence.
node1Pub := edgeInfo[:33]
edge1, err := fetchChanEdgePolicy(edges, chanID, node1Pub, nodes)
if err != nil {
return nil, nil, err
}
// As we may have a single direction of the edge but not the other,
// only fill in the database pointers if the edge is found.
if edge1 != nil {
edge1.db = db
edge1.Node.db = db
}
// Similarly, the second node is contained within the latter
// half of the edge information.
node2Pub := edgeInfo[33:66]
edge2, err := fetchChanEdgePolicy(edges, chanID, node2Pub, nodes)
if err != nil {
return nil, nil, err
}
if edge2 != nil {
edge2.db = db
edge2.Node.db = db
}
return edge1, edge2, nil
}
func serializeChanEdgePolicy(w io.Writer, edge *ChannelEdgePolicy,
to []byte) error {
err := wire.WriteVarBytes(w, 0, edge.SigBytes)
if err != nil {
return err
}
if err := binary.Write(w, byteOrder, edge.ChannelID); err != nil {
return err
}
var scratch [8]byte
updateUnix := uint64(edge.LastUpdate.Unix())
byteOrder.PutUint64(scratch[:], updateUnix)
if _, err := w.Write(scratch[:]); err != nil {
return err
}
if err := binary.Write(w, byteOrder, edge.MessageFlags); err != nil {
return err
}
if err := binary.Write(w, byteOrder, edge.ChannelFlags); err != nil {
return err
}
if err := binary.Write(w, byteOrder, edge.TimeLockDelta); err != nil {
return err
}
if err := binary.Write(w, byteOrder, uint64(edge.MinHTLC)); err != nil {
return err
}
if err := binary.Write(w, byteOrder, uint64(edge.FeeBaseMSat)); err != nil {
return err
}
if err := binary.Write(w, byteOrder, uint64(edge.FeeProportionalMillionths)); err != nil {
return err
}
if _, err := w.Write(to); err != nil {
return err
}
// If the max_htlc field is present, we write it. To be compatible with
// older versions that wasn't aware of this field, we write it as part
// of the opaque data.
// TODO(halseth): clean up when moving to TLV.
var opaqueBuf bytes.Buffer
if edge.MessageFlags.HasMaxHtlc() {
err := binary.Write(&opaqueBuf, byteOrder, uint64(edge.MaxHTLC))
if err != nil {
return err
}
}
if len(edge.ExtraOpaqueData) > MaxAllowedExtraOpaqueBytes {
return ErrTooManyExtraOpaqueBytes(len(edge.ExtraOpaqueData))
}
if _, err := opaqueBuf.Write(edge.ExtraOpaqueData); err != nil {
return err
}
if err := wire.WriteVarBytes(w, 0, opaqueBuf.Bytes()); err != nil {
return err
}
return nil
}
func deserializeChanEdgePolicy(r io.Reader,
nodes *bbolt.Bucket) (*ChannelEdgePolicy, error) {
edge := &ChannelEdgePolicy{}
var err error
edge.SigBytes, err = wire.ReadVarBytes(r, 0, 80, "sig")
if err != nil {
return nil, err
}
if err := binary.Read(r, byteOrder, &edge.ChannelID); err != nil {
return nil, err
}
var scratch [8]byte
if _, err := r.Read(scratch[:]); err != nil {
return nil, err
}
unix := int64(byteOrder.Uint64(scratch[:]))
edge.LastUpdate = time.Unix(unix, 0)
if err := binary.Read(r, byteOrder, &edge.MessageFlags); err != nil {
return nil, err
}
if err := binary.Read(r, byteOrder, &edge.ChannelFlags); err != nil {
return nil, err
}
if err := binary.Read(r, byteOrder, &edge.TimeLockDelta); err != nil {
return nil, err
}
var n uint64
if err := binary.Read(r, byteOrder, &n); err != nil {
return nil, err
}
edge.MinHTLC = lnwire.MilliSatoshi(n)
if err := binary.Read(r, byteOrder, &n); err != nil {
return nil, err
}
edge.FeeBaseMSat = lnwire.MilliSatoshi(n)
if err := binary.Read(r, byteOrder, &n); err != nil {
return nil, err
}
edge.FeeProportionalMillionths = lnwire.MilliSatoshi(n)
var pub [33]byte
if _, err := r.Read(pub[:]); err != nil {
return nil, err
}
node, err := fetchLightningNode(nodes, pub[:])
if err != nil {
return nil, fmt.Errorf("unable to fetch node: %x, %v",
pub[:], err)
}
edge.Node = &node
// We'll try and see if there are any opaque bytes left, if not, then
// we'll ignore the EOF error and return the edge as is.
edge.ExtraOpaqueData, err = wire.ReadVarBytes(
r, 0, MaxAllowedExtraOpaqueBytes, "blob",
)
switch {
case err == io.ErrUnexpectedEOF:
case err == io.EOF:
case err != nil:
return nil, err
}
// See if optional fields are present.
if edge.MessageFlags.HasMaxHtlc() {
// The max_htlc field should be at the beginning of the opaque
// bytes.
opq := edge.ExtraOpaqueData
// If the max_htlc field is not present, it might be old data
// stored before this field was validated. We'll return the
// edge along with an error.
if len(opq) < 8 {
return edge, ErrEdgePolicyOptionalFieldNotFound
}
maxHtlc := byteOrder.Uint64(opq[:8])
edge.MaxHTLC = lnwire.MilliSatoshi(maxHtlc)
// Exclude the parsed field from the rest of the opaque data.
edge.ExtraOpaqueData = opq[8:]
}
return edge, nil
}