package migration_01_to_11 import ( "bytes" "encoding/binary" "fmt" "image/color" "io" "net" "time" "github.com/btcsuite/btcd/btcec" "github.com/btcsuite/btcd/chaincfg/chainhash" "github.com/btcsuite/btcd/wire" "github.com/btcsuite/btcutil" "github.com/lightningnetwork/lnd/channeldb/kvdb" "github.com/lightningnetwork/lnd/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{} // 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 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") // zombieBucket is a sub-bucket of the main edgeBucket bucket // responsible for maintaining an index of zombie channels. Each entry // exists within the bucket as follows: // // maps: chanID -> pubKey1 || pubKey2 // // The chanID represents the channel ID of the edge that is marked as a // zombie and is used as the key, which maps to the public keys of the // edge's participants. zombieBucket = []byte("zombie-index") // disabledEdgePolicyBucket is a sub-bucket of the main edgeBucket bucket // responsible for maintaining an index of disabled edge policies. Each // entry exists within the bucket as follows: // // maps: -> []byte{} // // The chanID represents the channel ID of the edge and the direction is // one byte representing the direction of the edge. The main purpose of // this index is to allow pruning disabled channels in a fast way without // the need to iterate all over the graph. disabledEdgePolicyBucket = []byte("disabled-edge-policy-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") ) 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 } // newChannelGraph allocates a new ChannelGraph backed by a DB instance. The // returned instance has its own unique reject cache and channel cache. func newChannelGraph(db *DB, rejectCacheSize, chanCacheSize int) *ChannelGraph { return &ChannelGraph{ db: db, } } // 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 := kvdb.View(c.db, func(tx kvdb.RTx) error { // First grab the nodes bucket which stores the mapping from // pubKey to node information. nodes := tx.ReadBucket(nodeBucket) if nodes == nil { return ErrGraphNotFound } node, err := c.sourceNode(nodes) if err != nil { return err } source = node return nil }, func() { source = 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 kvdb.RBucket) (*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 kvdb.Update(c.db, func(tx kvdb.RwTx) error { // First grab the nodes bucket which stores the mapping from // pubKey to node information. nodes, err := tx.CreateTopLevelBucket(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) }, func() {}) } func addLightningNode(tx kvdb.RwTx, node *LightningNode) error { nodes, err := tx.CreateTopLevelBucket(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) } // updateEdgePolicy attempts to update an edge's policy within the relevant // buckets using an existing database transaction. The returned boolean will be // true if the updated policy belongs to node1, and false if the policy belonged // to node2. func updateEdgePolicy(tx kvdb.RwTx, edge *ChannelEdgePolicy) (bool, error) { edges, err := tx.CreateTopLevelBucket(edgeBucket) if err != nil { return false, ErrEdgeNotFound } edgeIndex := edges.NestedReadWriteBucket(edgeIndexBucket) if edgeIndex == nil { return false, ErrEdgeNotFound } nodes, err := tx.CreateTopLevelBucket(nodeBucket) if err != nil { return false, 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 false, ErrEdgeNotFound } // Depending on the flags value passed above, either the first // or second edge policy is being updated. var fromNode, toNode []byte var isUpdate1 bool if edge.ChannelFlags&lnwire.ChanUpdateDirection == 0 { fromNode = nodeInfo[:33] toNode = nodeInfo[33:66] isUpdate1 = true } else { fromNode = nodeInfo[33:66] toNode = nodeInfo[:33] isUpdate1 = false } // Finally, with the direction of the edge being updated // identified, we update the on-disk edge representation. err = putChanEdgePolicy(edges, nodes, edge, fromNode, toNode) if err != nil { return false, err } return isUpdate1, nil } // 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. func (l *LightningNode) PubKey() (*btcec.PublicKey, error) { if l.pubKey != nil { return l.pubKey, nil } key, err := btcec.ParsePubKey(l.PubKeyBytes[:], btcec.S256()) if err != nil { return nil, err } l.pubKey = key return key, nil } // ChannelEdgeInfo represents a fully authenticated channel along with all its // unique attributes. Once an authenticated channel announcement has been // 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 // NodeKey2Bytes is the raw public key of the first node. NodeKey2Bytes [33]byte // BitcoinKey1Bytes is the raw public key of the first node. BitcoinKey1Bytes [33]byte // BitcoinKey2Bytes is the raw public key of the first node. BitcoinKey2Bytes [33]byte // 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 } // 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 { // NodeSig1Bytes are the raw bytes of the first node signature encoded // in DER format. NodeSig1Bytes []byte // NodeSig2Bytes are the raw bytes of the second node signature // encoded in DER format. NodeSig2Bytes []byte // BitcoinSig1Bytes are the raw bytes of the first bitcoin signature // encoded in DER format. BitcoinSig1Bytes []byte // BitcoinSig2Bytes are the raw bytes of the second bitcoin signature // encoded in DER format. BitcoinSig2Bytes []byte } // IsEmpty check is the authentication proof is empty Proof is empty if at // least one of the signatures are equal to nil. 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. Do not set SigBytes directly, but // use SetSigBytes instead to make sure that the cache is invalidated. SigBytes []byte // 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 } // IsDisabled determines whether the edge has the disabled bit set. func (c *ChannelEdgePolicy) IsDisabled() bool { return c.ChannelFlags&lnwire.ChanUpdateDisabled == lnwire.ChanUpdateDisabled } func putLightningNode(nodeBucket kvdb.RwBucket, aliasBucket kvdb.RwBucket, updateIndex kvdb.RwBucket, 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 kvdb.RBucket, 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, nil) 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 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 kvdb.RwBucket, 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 } updateEdgePolicyDisabledIndex( edges, edge.ChannelID, edge.ChannelFlags&lnwire.ChanUpdateDirection > 0, edge.IsDisabled(), ) return edges.Put(edgeKey[:], b.Bytes()[:]) } // updateEdgePolicyDisabledIndex is used to update the disabledEdgePolicyIndex // bucket by either add a new disabled ChannelEdgePolicy or remove an existing // one. // The direction represents the direction of the edge and disabled is used for // deciding whether to remove or add an entry to the bucket. // In general a channel is disabled if two entries for the same chanID exist // in this bucket. // Maintaining the bucket this way allows a fast retrieval of disabled // channels, for example when prune is needed. func updateEdgePolicyDisabledIndex(edges kvdb.RwBucket, chanID uint64, direction bool, disabled bool) error { var disabledEdgeKey [8 + 1]byte byteOrder.PutUint64(disabledEdgeKey[0:], chanID) if direction { disabledEdgeKey[8] = 1 } disabledEdgePolicyIndex, err := edges.CreateBucketIfNotExists( disabledEdgePolicyBucket, ) if err != nil { return err } if disabled { return disabledEdgePolicyIndex.Put(disabledEdgeKey[:], []byte{}) } return disabledEdgePolicyIndex.Delete(disabledEdgeKey[:]) } // putChanEdgePolicyUnknown marks the edge policy as unknown // in the edges bucket. func putChanEdgePolicyUnknown(edges kvdb.RwBucket, 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 kvdb.RBucket, chanID []byte, nodePub []byte, nodes kvdb.RBucket) (*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 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 kvdb.RBucket) (*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 }