package channeldb import ( "bytes" "io" "net" "time" "github.com/btcsuite/btcd/btcec" "github.com/btcsuite/btcd/wire" "github.com/lightningnetwork/lnd/kvdb" ) var ( // nodeInfoBucket stores metadata pertaining to nodes that we've had // direct channel-based correspondence with. This bucket allows one to // query for all open channels pertaining to the node by exploring each // node's sub-bucket within the openChanBucket. nodeInfoBucket = []byte("nib") ) // LinkNode stores metadata related to node's that we have/had a direct // channel open with. Information such as the Bitcoin network the node // advertised, and its identity public key are also stored. Additionally, this // struct and the bucket its stored within have store data similar to that of // Bitcoin's addrmanager. The TCP address information stored within the struct // can be used to establish persistent connections will all channel // counterparties on daemon startup. // // TODO(roasbeef): also add current OnionKey plus rotation schedule? // TODO(roasbeef): add bitfield for supported services // * possibly add a wire.NetAddress type, type type LinkNode struct { // Network indicates the Bitcoin network that the LinkNode advertises // for incoming channel creation. Network wire.BitcoinNet // IdentityPub is the node's current identity public key. Any // channel/topology related information received by this node MUST be // signed by this public key. IdentityPub *btcec.PublicKey // LastSeen tracks the last time this node was seen within the network. // A node should be marked as seen if the daemon either is able to // establish an outgoing connection to the node or receives a new // incoming connection from the node. This timestamp (stored in unix // epoch) may be used within a heuristic which aims to determine when a // channel should be unilaterally closed due to inactivity. // // TODO(roasbeef): replace with block hash/height? // * possibly add a time-value metric into the heuristic? LastSeen time.Time // Addresses is a list of IP address in which either we were able to // reach the node over in the past, OR we received an incoming // authenticated connection for the stored identity public key. Addresses []net.Addr db *DB } // NewLinkNode creates a new LinkNode from the provided parameters, which is // backed by an instance of channeldb. func (db *DB) NewLinkNode(bitNet wire.BitcoinNet, pub *btcec.PublicKey, addrs ...net.Addr) *LinkNode { return &LinkNode{ Network: bitNet, IdentityPub: pub, LastSeen: time.Now(), Addresses: addrs, db: db, } } // UpdateLastSeen updates the last time this node was directly encountered on // the Lightning Network. func (l *LinkNode) UpdateLastSeen(lastSeen time.Time) error { l.LastSeen = lastSeen return l.Sync() } // AddAddress appends the specified TCP address to the list of known addresses // this node is/was known to be reachable at. func (l *LinkNode) AddAddress(addr net.Addr) error { for _, a := range l.Addresses { if a.String() == addr.String() { return nil } } l.Addresses = append(l.Addresses, addr) return l.Sync() } // Sync performs a full database sync which writes the current up-to-date data // within the struct to the database. func (l *LinkNode) Sync() error { // Finally update the database by storing the link node and updating // any relevant indexes. return kvdb.Update(l.db, func(tx kvdb.RwTx) error { nodeMetaBucket := tx.ReadWriteBucket(nodeInfoBucket) if nodeMetaBucket == nil { return ErrLinkNodesNotFound } return putLinkNode(nodeMetaBucket, l) }, func() {}) } // putLinkNode serializes then writes the encoded version of the passed link // node into the nodeMetaBucket. This function is provided in order to allow // the ability to re-use a database transaction across many operations. func putLinkNode(nodeMetaBucket kvdb.RwBucket, l *LinkNode) error { // First serialize the LinkNode into its raw-bytes encoding. var b bytes.Buffer if err := serializeLinkNode(&b, l); err != nil { return err } // Finally insert the link-node into the node metadata bucket keyed // according to the its pubkey serialized in compressed form. nodePub := l.IdentityPub.SerializeCompressed() return nodeMetaBucket.Put(nodePub, b.Bytes()) } // DeleteLinkNode removes the link node with the given identity from the // database. func (db *DB) DeleteLinkNode(identity *btcec.PublicKey) error { return kvdb.Update(db, func(tx kvdb.RwTx) error { return db.deleteLinkNode(tx, identity) }, func() {}) } func (db *DB) deleteLinkNode(tx kvdb.RwTx, identity *btcec.PublicKey) error { nodeMetaBucket := tx.ReadWriteBucket(nodeInfoBucket) if nodeMetaBucket == nil { return ErrLinkNodesNotFound } pubKey := identity.SerializeCompressed() return nodeMetaBucket.Delete(pubKey) } // FetchLinkNode attempts to lookup the data for a LinkNode based on a target // identity public key. If a particular LinkNode for the passed identity public // key cannot be found, then ErrNodeNotFound if returned. func (db *DB) FetchLinkNode(identity *btcec.PublicKey) (*LinkNode, error) { var linkNode *LinkNode err := kvdb.View(db, func(tx kvdb.RTx) error { node, err := fetchLinkNode(tx, identity) if err != nil { return err } linkNode = node return nil }, func() { linkNode = nil }) return linkNode, err } func fetchLinkNode(tx kvdb.RTx, targetPub *btcec.PublicKey) (*LinkNode, error) { // First fetch the bucket for storing node metadata, bailing out early // if it hasn't been created yet. nodeMetaBucket := tx.ReadBucket(nodeInfoBucket) if nodeMetaBucket == nil { return nil, ErrLinkNodesNotFound } // If a link node for that particular public key cannot be located, // then exit early with an ErrNodeNotFound. pubKey := targetPub.SerializeCompressed() nodeBytes := nodeMetaBucket.Get(pubKey) if nodeBytes == nil { return nil, ErrNodeNotFound } // Finally, decode and allocate a fresh LinkNode object to be returned // to the caller. nodeReader := bytes.NewReader(nodeBytes) return deserializeLinkNode(nodeReader) } // TODO(roasbeef): update link node addrs in server upon connection // FetchAllLinkNodes starts a new database transaction to fetch all nodes with // whom we have active channels with. func (db *DB) FetchAllLinkNodes() ([]*LinkNode, error) { var linkNodes []*LinkNode err := kvdb.View(db, func(tx kvdb.RTx) error { nodes, err := db.fetchAllLinkNodes(tx) if err != nil { return err } linkNodes = nodes return nil }, func() { linkNodes = nil }) if err != nil { return nil, err } return linkNodes, nil } // fetchAllLinkNodes uses an existing database transaction to fetch all nodes // with whom we have active channels with. func (db *DB) fetchAllLinkNodes(tx kvdb.RTx) ([]*LinkNode, error) { nodeMetaBucket := tx.ReadBucket(nodeInfoBucket) if nodeMetaBucket == nil { return nil, ErrLinkNodesNotFound } var linkNodes []*LinkNode err := nodeMetaBucket.ForEach(func(k, v []byte) error { if v == nil { return nil } nodeReader := bytes.NewReader(v) linkNode, err := deserializeLinkNode(nodeReader) if err != nil { return err } linkNodes = append(linkNodes, linkNode) return nil }) if err != nil { return nil, err } return linkNodes, nil } func serializeLinkNode(w io.Writer, l *LinkNode) error { var buf [8]byte byteOrder.PutUint32(buf[:4], uint32(l.Network)) if _, err := w.Write(buf[:4]); err != nil { return err } serializedID := l.IdentityPub.SerializeCompressed() if _, err := w.Write(serializedID); err != nil { return err } seenUnix := uint64(l.LastSeen.Unix()) byteOrder.PutUint64(buf[:], seenUnix) if _, err := w.Write(buf[:]); err != nil { return err } numAddrs := uint32(len(l.Addresses)) byteOrder.PutUint32(buf[:4], numAddrs) if _, err := w.Write(buf[:4]); err != nil { return err } for _, addr := range l.Addresses { if err := serializeAddr(w, addr); err != nil { return err } } return nil } func deserializeLinkNode(r io.Reader) (*LinkNode, error) { var ( err error buf [8]byte ) node := &LinkNode{} if _, err := io.ReadFull(r, buf[:4]); err != nil { return nil, err } node.Network = wire.BitcoinNet(byteOrder.Uint32(buf[:4])) var pub [33]byte if _, err := io.ReadFull(r, pub[:]); err != nil { return nil, err } node.IdentityPub, err = btcec.ParsePubKey(pub[:], btcec.S256()) if err != nil { return nil, err } if _, err := io.ReadFull(r, buf[:]); err != nil { return nil, err } node.LastSeen = time.Unix(int64(byteOrder.Uint64(buf[:])), 0) if _, err := io.ReadFull(r, buf[:4]); err != nil { return nil, err } numAddrs := byteOrder.Uint32(buf[:4]) node.Addresses = make([]net.Addr, numAddrs) for i := uint32(0); i < numAddrs; i++ { addr, err := deserializeAddr(r) if err != nil { return nil, err } node.Addresses[i] = addr } return node, nil }