lnd.xprv/channeldb/graph.go

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package channeldb
import (
"bytes"
"encoding/binary"
"fmt"
"image/color"
"io"
"math"
"net"
"time"
"github.com/boltdb/bolt"
"github.com/lightningnetwork/lnd/lnwire"
"github.com/roasbeef/btcd/btcec"
"github.com/roasbeef/btcd/chaincfg/chainhash"
"github.com/roasbeef/btcd/wire"
"github.com/roasbeef/btcutil"
)
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 -> nofInfo
// maps: source -> selfPubKey
nodeBucket = []byte("graph-node")
// 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 _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 edgeID,
// 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 || edgeID -> edge policy for node
edgeBucket = []byte("graph-edge")
// 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
// capacity of the channel, the nodes that made the channel, etc. This
// bucket resides within the edgeBucket above. Creation of a 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")
// 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")
)
// 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 *bolt.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
}
// The first node is contained within the first half of
// the edge information.
node1Pub := edgeInfoBytes[:33]
edge1, err := fetchChanEdgePolicy(edges, chanID, node1Pub, nodes)
if err != nil && err != ErrEdgeNotFound &&
err != ErrGraphNodeNotFound {
return err
}
// The targeted edge may have not been advertised
// within the network, so we ensure it's non-nil before
// dereferencing its attributes.
if edge1 != nil {
edge1.db = c.db
if edge1.Node != nil {
edge1.Node.db = c.db
}
}
// Similarly, the second node is contained within the
// latter half of the edge information.
node2Pub := edgeInfoBytes[33:]
edge2, err := fetchChanEdgePolicy(edges, chanID, node2Pub, nodes)
if err != nil && err != ErrEdgeNotFound &&
err != ErrGraphNodeNotFound {
return err
}
// The targeted edge may have not been advertised
// within the network, so we ensure it's non-nil before
// dereferencing its attributes.
if edge2 != nil {
edge2.db = c.db
if edge2.Node != nil {
edge2.Node.db = c.db
}
}
// 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 *bolt.Tx, cb func(*bolt.Tx, *LightningNode) error) error {
traversal := func(tx *bolt.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 *bolt.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
}
selfPub := nodes.Get(sourceKey)
if selfPub == nil {
return 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 err
}
source = node
source.db = c.db
return nil
})
if err != nil {
return nil, err
}
return source, 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 *bolt.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 *bolt.Tx) error {
return addLightningNode(tx, node)
})
}
func addLightningNode(tx *bolt.Tx, node *LightningNode) error {
nodes, err := tx.CreateBucketIfNotExists(nodeBucket)
if err != nil {
return err
}
aliases, err := nodes.CreateBucketIfNotExists(aliasIndexBucket)
if err != nil {
return err
}
return putLightningNode(nodes, aliases, 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 *bolt.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 removes a vertex/node from the database according to the
// node's public key.
func (c *ChannelGraph) DeleteLightningNode(nodePub *btcec.PublicKey) error {
pub := nodePub.SerializeCompressed()
// TODO(roasbeef): ensure dangling edges are removed...
return c.db.Update(func(tx *bolt.Tx) error {
nodes, err := tx.CreateBucketIfNotExists(nodeBucket)
if err != nil {
return err
}
aliases, err := tx.CreateBucketIfNotExists(aliasIndexBucket)
if err != nil {
return err
}
if err := aliases.Delete(pub); err != nil {
return err
}
return nodes.Delete(pub)
})
}
// 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 {
// 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 *bolt.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
}
// 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.
2017-01-10 06:02:34 +03:00
if edgeInfo := edgeIndex.Get(chanKey[:]); edgeInfo != nil {
return ErrEdgeAlreadyExist
}
// 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
}
// 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 the 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 *bolt.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 *bolt.Tx) error {
edges, err := tx.CreateBucketIfNotExists(edgeBucket)
if err != nil {
return err
}
edgeIndex, err := edges.CreateBucketIfNotExists(edgeIndexBucket)
if err != nil {
return err
}
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 *bolt.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
}
// 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
}
chansClosed = append(chansClosed, edgeInfo)
// 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,
chanPoint)
if err != nil && err != ErrEdgeNotFound {
return err
}
}
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[:])
return pruneBucket.Put(blockHeightBytes[:], newTip[:])
})
if err != nil {
return nil, err
}
return chansClosed, 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 *bolt.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
}
// 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,
&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 *bolt.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 *bolt.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
}
return delChannelByEdge(edges, edgeIndex, chanIndex, 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 *bolt.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
}
func delChannelByEdge(edges *bolt.Bucket, edgeIndex *bolt.Bucket,
chanIndex *bolt.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)
}
// 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 *bolt.Tx) error {
edges, err := tx.CreateBucketIfNotExists(edgeBucket)
if err != nil {
return err
}
edgeIndex, err := edges.CreateBucketIfNotExists(edgeIndexBucket)
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.Flags&lnwire.ChanUpdateDirection == 0 {
fromNode = nodeInfo[:33]
toNode = nodeInfo[33:67]
} else {
fromNode = nodeInfo[33:67]
toNode = nodeInfo[:33]
}
// Finally, with the direction of the edge being updated
// identified, we update the on-disk edge representation.
return putChanEdgePolicy(edges, 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
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.
func (c *LightningNode) PubKey() (*btcec.PublicKey, error) {
if c.pubKey != nil {
return c.pubKey, nil
}
key, err := btcec.ParsePubKey(c.PubKeyBytes[:], btcec.S256())
if err != nil {
return nil, err
}
c.pubKey = key
c.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.
func (c *LightningNode) AuthSig() (*btcec.Signature, error) {
return btcec.ParseSignature(c.AuthSigBytes, btcec.S256())
}
// AddPubKey is a setter-link method that can be used to swap out the public
// key for a node.
func (c *LightningNode) AddPubKey(key *btcec.PublicKey) {
c.pubKey = key
copy(c.PubKeyBytes[:], key.SerializeCompressed())
}
// 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 *bolt.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 *bolt.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 the outgoing channel edges from this
// node, executing the passed callback with each edge as its sole argument. The
// first edge policy is the outgoing edge *to* 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.
//
// 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 *bolt.Tx,
cb func(*bolt.Tx, *ChannelEdgeInfo, *ChannelEdgePolicy, *ChannelEdgePolicy) error) error {
pub, err := l.PubKey()
if err != nil {
return err
}
nodePub := pub.SerializeCompressed()
traversal := func(tx *bolt.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, edgeInfo := edgeCursor.Seek(nodeStart[:]); bytes.HasPrefix(nodeEdge, nodePub); nodeEdge, edgeInfo = edgeCursor.Next() {
// If the prefix still matches, then the value is the
// raw edge information. So we can now serialize the
// edge info and fetch the outgoing node in order to
// retrieve the full channel edge.
edgeReader := bytes.NewReader(edgeInfo)
toEdgePolicy, err := deserializeChanEdgePolicy(edgeReader, nodes)
if err != nil {
return err
}
toEdgePolicy.db = l.db
toEdgePolicy.Node.db = l.db
chanID := nodeEdge[33:]
edgeInfo, err := fetchChanEdgeInfo(edgeIndex, chanID)
if err != nil {
return err
}
// We'll also fetch the incoming edge so this
// information can be available to the caller.
incomingNodeKey, err := toEdgePolicy.Node.PubKey()
if err != nil {
return err
}
incomingNode := incomingNodeKey.SerializeCompressed()
fromEdgePolicy, err := fetchChanEdgePolicy(
edges, chanID, incomingNode, nodes,
)
if err != nil && err != ErrEdgeNotFound &&
err != ErrGraphNodeNotFound {
return err
}
if fromEdgePolicy != nil {
fromEdgePolicy.db = l.db
if fromEdgePolicy.Node != nil {
fromEdgePolicy.Node.db = l.db
}
}
// Finally, we execute the callback.
err = cb(tx, edgeInfo, toEdgePolicy, fromEdgePolicy)
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
// processed on the network, then a 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
}
// 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
}
// ChannelAuthProof is the authentication proof (the signature portion) for a
// channel. Using the four signatures contained in the struct, and some
// auxillary 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
}
// NodeSig1 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
}
// NodeSig2 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.
func (p *ChannelAuthProof) IsEmpty() bool {
return len(p.NodeSig1Bytes) == 0 ||
len(p.NodeSig2Bytes) == 0 ||
len(p.BitcoinSig1Bytes) == 0 ||
len(p.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
// Flags is a bitfield which signals the capabilities of the channel as
// well as the directed edge this update applies to.
Flags lnwire.ChanUpdateFlag
// 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
// 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
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 *bolt.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
// 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 *bolt.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
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
}
// ChannelView returns the verifiable edge information for each active channel
// within the known channel graph. The set of UTXO's returned are the ones that
// need to be watched on chain to detect channel closes on the resident
// blockchain.
func (c *ChannelGraph) ChannelView() ([]wire.OutPoint, error) {
var chanPoints []wire.OutPoint
if err := c.db.View(func(tx *bolt.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
}
// 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, _ []byte) error {
chanPointReader := bytes.NewReader(chanPointBytes)
var chanPoint wire.OutPoint
err := readOutpoint(chanPointReader, &chanPoint)
if err != nil {
return err
}
chanPoints = append(chanPoints, chanPoint)
return nil
})
}); err != nil {
return nil, err
}
return chanPoints, nil
}
// NewChannelEdgePolicy returns a new blank ChannelEdgePolicy.
func (c *ChannelGraph) NewChannelEdgePolicy() *ChannelEdgePolicy {
return &ChannelEdgePolicy{db: c.db}
}
func putLightningNode(nodeBucket *bolt.Bucket, aliasBucket *bolt.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
}
}
err = wire.WriteVarBytes(&b, 0, node.AuthSigBytes)
if err != nil {
return err
}
if err := aliasBucket.Put(nodePub, []byte(node.Alias)); err != nil {
return err
}
return nodeBucket.Put(nodePub, b.Bytes())
}
func fetchLightningNode(nodeBucket *bolt.Bucket,
nodePub []byte) (*LightningNode, error) {
nodeBytes := nodeBucket.Get(nodePub)
if nodeBytes == nil {
return nil, ErrGraphNodeNotFound
}
nodeReader := bytes.NewReader(nodeBytes)
return deserializeLightningNode(nodeReader)
}
func deserializeLightningNode(r io.Reader) (*LightningNode, error) {
var (
scratch [8]byte
err error
)
node := &LightningNode{}
if _, err := r.Read(scratch[:]); err != nil {
return nil, err
}
unix := int64(byteOrder.Uint64(scratch[:]))
node.LastUpdate = time.Unix(unix, 0)
if _, err := io.ReadFull(r, node.PubKeyBytes[:]); err != nil {
return nil, err
}
if _, err := r.Read(scratch[:2]); err != nil {
return nil, 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 nil, err
}
if err := binary.Read(r, byteOrder, &node.Color.G); err != nil {
return nil, err
}
if err := binary.Read(r, byteOrder, &node.Color.B); err != nil {
return nil, err
}
node.Alias, err = wire.ReadVarString(r, 0)
if err != nil {
return nil, err
}
fv := lnwire.NewFeatureVector(nil, lnwire.GlobalFeatures)
err = fv.Decode(r)
if err != nil {
return nil, err
}
node.Features = fv
if _, err := r.Read(scratch[:2]); err != nil {
return nil, 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 nil, err
}
addresses = append(addresses, address)
}
node.Addresses = addresses
node.AuthSigBytes, err = wire.ReadVarBytes(r, 0, 80, "sig")
if err != nil {
return nil, err
}
return node, nil
}
func putChanEdgeInfo(edgeIndex *bolt.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
}
return edgeIndex.Put(chanID[:], b.Bytes())
}
func fetchChanEdgeInfo(edgeIndex *bolt.Bucket,
chanID []byte) (*ChannelEdgeInfo, error) {
edgeInfoBytes := edgeIndex.Get(chanID)
if edgeInfoBytes == nil {
return nil, 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 nil, err
}
if _, err := io.ReadFull(r, edgeInfo.NodeKey2Bytes[:]); err != nil {
return nil, err
}
if _, err := io.ReadFull(r, edgeInfo.BitcoinKey1Bytes[:]); err != nil {
return nil, err
}
if _, err := io.ReadFull(r, edgeInfo.BitcoinKey2Bytes[:]); err != nil {
return nil, err
}
edgeInfo.Features, err = wire.ReadVarBytes(r, 0, 900, "features")
if err != nil {
return nil, err
}
proof := &ChannelAuthProof{}
readSig := func() ([]byte, error) {
return wire.ReadVarBytes(r, 0, 80, "sigs")
}
proof.NodeSig1Bytes, err = readSig()
if err != nil {
return nil, err
}
proof.NodeSig2Bytes, err = readSig()
if err != nil {
return nil, err
}
proof.BitcoinSig1Bytes, err = readSig()
if err != nil {
return nil, err
}
proof.BitcoinSig2Bytes, err = readSig()
if err != nil {
return nil, err
}
if !proof.IsEmpty() {
edgeInfo.AuthProof = proof
}
edgeInfo.ChannelPoint = wire.OutPoint{}
if err := readOutpoint(r, &edgeInfo.ChannelPoint); err != nil {
return nil, err
}
if err := binary.Read(r, byteOrder, &edgeInfo.Capacity); err != nil {
return nil, err
}
if err := binary.Read(r, byteOrder, &edgeInfo.ChannelID); err != nil {
return nil, err
}
if _, err := io.ReadFull(r, edgeInfo.ChainHash[:]); err != nil {
return nil, err
}
return edgeInfo, nil
}
func putChanEdgePolicy(edges *bolt.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
err := wire.WriteVarBytes(&b, 0, edge.SigBytes)
if err != nil {
return err
}
if err := binary.Write(&b, byteOrder, edge.ChannelID); err != nil {
return err
}
var scratch [8]byte
updateUnix := uint64(edge.LastUpdate.Unix())
byteOrder.PutUint64(scratch[:], updateUnix)
if _, err := b.Write(scratch[:]); err != nil {
return err
}
if err := binary.Write(&b, byteOrder, edge.Flags); err != nil {
return err
}
if err := binary.Write(&b, byteOrder, edge.TimeLockDelta); err != nil {
return err
}
if err := binary.Write(&b, byteOrder, uint64(edge.MinHTLC)); err != nil {
return err
}
if err := binary.Write(&b, byteOrder, uint64(edge.FeeBaseMSat)); err != nil {
return err
}
if err := binary.Write(&b, byteOrder, uint64(edge.FeeProportionalMillionths)); err != nil {
return err
}
if _, err := b.Write(to); err != nil {
return err
}
return edges.Put(edgeKey[:], b.Bytes()[:])
}
func fetchChanEdgePolicy(edges *bolt.Bucket, chanID []byte,
nodePub []byte, nodes *bolt.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
}
edgeReader := bytes.NewReader(edgeBytes)
return deserializeChanEdgePolicy(edgeReader, nodes)
}
func fetchChanEdgePolicies(edgeIndex *bolt.Bucket, edges *bolt.Bucket,
nodes *bolt.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 && err != ErrEdgeNotFound {
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[33:67]
edge2, err := fetchChanEdgePolicy(edges, chanID, node2Pub, nodes)
if err != nil && err != ErrEdgeNotFound {
return nil, nil, err
}
if edge2 != nil {
edge2.db = db
edge2.Node.db = db
}
return edge1, edge2, nil
}
func deserializeChanEdgePolicy(r io.Reader,
nodes *bolt.Bucket) (*ChannelEdgePolicy, error) {
edge := &ChannelEdgePolicy{}
sigBytes, err := wire.ReadVarBytes(r, 0, 80, "sig")
if err != nil {
return nil, err
}
edge.SigBytes = sigBytes
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.Flags); 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, err
}
edge.Node = node
return edge, nil
}