From 1d7e42af0ae7440137acad0feff71a93cb7da216 Mon Sep 17 00:00:00 2001 From: Olaoluwa Osuntokun Date: Sun, 9 Dec 2018 20:12:24 -0800 Subject: [PATCH] rpc: implement new SCB related RPC calls --- rpcserver.go | 280 ++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 255 insertions(+), 25 deletions(-) diff --git a/rpcserver.go b/rpcserver.go index 6007e91c..12aeefba 100644 --- a/rpcserver.go +++ b/rpcserver.go @@ -31,6 +31,7 @@ import ( proxy "github.com/grpc-ecosystem/grpc-gateway/runtime" "github.com/lightningnetwork/lnd/autopilot" "github.com/lightningnetwork/lnd/build" + "github.com/lightningnetwork/lnd/chanbackup" "github.com/lightningnetwork/lnd/channeldb" "github.com/lightningnetwork/lnd/channelnotifier" "github.com/lightningnetwork/lnd/htlcswitch" @@ -357,6 +358,22 @@ var ( Entity: "offchain", Action: "read", }}, + "/lnrpc.Lightning/RestoreChannelBackups": {{ + Entity: "offchain", + Action: "write", + }}, + "/lnrpc.Lightning/ExportChannelBackup": {{ + Entity: "offchain", + Action: "read", + }}, + "/lnrpc.Lightning/ExportAllChannelBackups": {{ + Entity: "offchain", + Action: "read", + }}, + "/lnrpc.Lightning/SubscribeChannelBackups": {{ + Entity: "offchain", + Action: "read", + }}, } ) @@ -1415,17 +1432,12 @@ out: switch update := fundingUpdate.Update.(type) { case *lnrpc.OpenStatusUpdate_ChanOpen: chanPoint := update.ChanOpen.ChannelPoint - txidHash, err := getChanPointFundingTxid(chanPoint) - if err != nil { - return err - } - - h, err := chainhash.NewHash(txidHash) + txid, err := getChanPointFundingTxid(chanPoint) if err != nil { return err } outpoint = wire.OutPoint{ - Hash: *h, + Hash: *txid, Index: chanPoint.OutputIndex, } @@ -1573,7 +1585,7 @@ func (r *rpcServer) OpenChannelSync(ctx context.Context, // getChanPointFundingTxid returns the given channel point's funding txid in // raw bytes. -func getChanPointFundingTxid(chanPoint *lnrpc.ChannelPoint) ([]byte, error) { +func getChanPointFundingTxid(chanPoint *lnrpc.ChannelPoint) (*chainhash.Hash, error) { var txid []byte // A channel point's funding txid can be get/set as a byte slice or a @@ -1591,7 +1603,7 @@ func getChanPointFundingTxid(chanPoint *lnrpc.ChannelPoint) ([]byte, error) { txid = h[:] } - return txid, nil + return chainhash.NewHash(txid) } // CloseChannel attempts to close an active channel identified by its channel @@ -1608,16 +1620,11 @@ func (r *rpcServer) CloseChannel(in *lnrpc.CloseChannelRequest, force := in.Force index := in.ChannelPoint.OutputIndex - txidHash, err := getChanPointFundingTxid(in.GetChannelPoint()) + txid, err := getChanPointFundingTxid(in.GetChannelPoint()) if err != nil { rpcsLog.Errorf("[closechannel] unable to get funding txid: %v", err) return err } - txid, err := chainhash.NewHash(txidHash) - if err != nil { - rpcsLog.Errorf("[closechannel] invalid txid: %v", err) - return err - } chanPoint := wire.NewOutPoint(txid, index) rpcsLog.Tracef("[closechannel] request for ChannelPoint(%v), force=%v", @@ -1821,11 +1828,7 @@ func (r *rpcServer) AbandonChannel(ctx context.Context, // We'll parse out the arguments to we can obtain the chanPoint of the // target channel. - txidHash, err := getChanPointFundingTxid(in.GetChannelPoint()) - if err != nil { - return nil, err - } - txid, err := chainhash.NewHash(txidHash) + txid, err := getChanPointFundingTxid(in.GetChannelPoint()) if err != nil { return nil, err } @@ -2433,6 +2436,8 @@ func (r *rpcServer) ListChannels(ctx context.Context, resp := &lnrpc.ListChannelsResponse{} + // TODO(roasbeef): expose chan status flags as well + graph := r.server.chanDB.ChannelGraph() dbChannels, err := r.server.chanDB.FetchAllOpenChannels() @@ -2540,6 +2545,7 @@ func createRPCOpenChannel(r *rpcServer, graph *channeldb.ChannelGraph, PendingHtlcs: make([]*lnrpc.HTLC, len(localCommit.Htlcs)), CsvDelay: uint32(dbChannel.LocalChanCfg.CsvDelay), Initiator: dbChannel.IsInitiator, + ChanStatusFlags: dbChannel.ChanStatus().String(), } for i, htlc := range localCommit.Htlcs { @@ -4503,11 +4509,7 @@ func (r *rpcServer) UpdateChannelPolicy(ctx context.Context, // Otherwise, we're targeting an individual channel by its channel // point. case *lnrpc.PolicyUpdateRequest_ChanPoint: - txidHash, err := getChanPointFundingTxid(scope.ChanPoint) - if err != nil { - return nil, err - } - txid, err := chainhash.NewHash(txidHash) + txid, err := getChanPointFundingTxid(scope.ChanPoint) if err != nil { return nil, err } @@ -4676,3 +4678,231 @@ func (r *rpcServer) ForwardingHistory(ctx context.Context, return resp, nil } + +// ExportChannelBackup attempts to return an encrypted static channel backup +// for the target channel identified by it channel point. The backup is +// encrypted with a key generated from the aezeed seed of the user. The +// returned backup can either be restored using the RestoreChannelBackup method +// once lnd is running, or via the InitWallet and UnlockWallet methods from the +// WalletUnlocker service. +func (r *rpcServer) ExportChannelBackup(ctx context.Context, + in *lnrpc.ChannelPoint) (*lnrpc.ChannelBackup, error) { + + // First, we'll convert the lnrpc channel point into a wire.OutPoint + // that we can manipulate. + txid, err := getChanPointFundingTxid(in) + if err != nil { + return nil, err + } + chanPoint := wire.OutPoint{ + Hash: *txid, + Index: in.OutputIndex, + } + + // Next, we'll attempt to fetch a channel backup for this channel from + // the database. If this channel has been closed, or the outpoint is + // unknown, then we'll return an error + unpackedBackup, err := chanbackup.FetchBackupForChan( + chanPoint, r.server.chanDB, + ) + if err != nil { + return nil, err + } + + // At this point, we have an unpacked backup (plaintext) so we'll now + // attempt to serialize and encrypt it in order to create a packed + // backup. + packedBackups, err := chanbackup.PackStaticChanBackups( + []chanbackup.Single{*unpackedBackup}, + r.server.cc.keyRing, + ) + if err != nil { + return nil, fmt.Errorf("packing of back ups failed: %v", err) + } + + // Before we proceed, we'll ensure that we received a backup for this + // channel, otherwise, we'll bail out. + packedBackup, ok := packedBackups[chanPoint] + if !ok { + return nil, fmt.Errorf("expected single backup for "+ + "ChannelPoint(%v), got %v", chanPoint, + len(packedBackup)) + } + + return &lnrpc.ChannelBackup{ + ChanPoint: in, + ChanBackup: packedBackup, + }, nil +} + +// createBackupSnapshot converts the passed Single backup into a snapshot which +// contains individual packed single backups, as well as a single packed multi +// backup. +func (r *rpcServer) createBackupSnapshot(backups []chanbackup.Single) ( + *lnrpc.ChanBackupSnapshot, error) { + + // Once we have the set of back ups, we'll attempt to pack them all + // into a series of single channel backups. + singleChanPackedBackups, err := chanbackup.PackStaticChanBackups( + backups, r.server.cc.keyRing, + ) + if err != nil { + return nil, fmt.Errorf("unable to pack set of chan "+ + "backups: %v", err) + } + + // Now that we have our set of single packed backups, we'll morph that + // into a form that the proto response requires. + numBackups := len(singleChanPackedBackups) + singleBackupResp := &lnrpc.ChannelBackups{ + ChanBackups: make([]*lnrpc.ChannelBackup, 0, numBackups), + } + for chanPoint, singlePackedBackup := range singleChanPackedBackups { + txid := chanPoint.Hash + rpcChanPoint := &lnrpc.ChannelPoint{ + FundingTxid: &lnrpc.ChannelPoint_FundingTxidBytes{ + FundingTxidBytes: txid[:], + }, + OutputIndex: chanPoint.Index, + } + + singleBackupResp.ChanBackups = append( + singleBackupResp.ChanBackups, + &lnrpc.ChannelBackup{ + ChanPoint: rpcChanPoint, + ChanBackup: singlePackedBackup, + }, + ) + } + + // In addition, to the set of single chan backups, we'll also create a + // single multi-channel backup which can be serialized into a single + // file for safe storage. + var b bytes.Buffer + unpackedMultiBackup := chanbackup.Multi{ + StaticBackups: backups, + } + err = unpackedMultiBackup.PackToWriter(&b, r.server.cc.keyRing) + if err != nil { + return nil, fmt.Errorf("unable to multi-pack backups: %v", err) + } + + multiBackupResp := &lnrpc.MultiChanBackup{ + MultiChanBackup: b.Bytes(), + } + for _, singleBackup := range singleBackupResp.ChanBackups { + multiBackupResp.ChanPoints = append( + multiBackupResp.ChanPoints, singleBackup.ChanPoint, + ) + } + + return &lnrpc.ChanBackupSnapshot{ + SingleChanBackups: singleBackupResp, + MultiChanBackup: multiBackupResp, + }, nil +} + +// ExportAllChannelBackups returns static channel backups for all existing +// channels known to lnd. A set of regular singular static channel backups for +// each channel are returned. Additionally, a multi-channel backup is returned +// as well, which contains a single encrypted blob containing the backups of +// each channel. +func (r *rpcServer) ExportAllChannelBackups(ctx context.Context, + in *lnrpc.ChanBackupExportRequest) (*lnrpc.ChanBackupSnapshot, error) { + + // First, we'll attempt to read back ups for ALL currently opened + // channels from disk. + allUnpackedBackups, err := chanbackup.FetchStaticChanBackups( + r.server.chanDB, + ) + if err != nil { + return nil, fmt.Errorf("unable to fetch all static chan "+ + "backups: %v", err) + } + + // With the backups assembled, we'll create a full snapshot. + return r.createBackupSnapshot(allUnpackedBackups) +} + +// RestoreChannelBackups accepts a set of singular channel backups, or a single +// encrypted multi-chan backup and attempts to recover any funds remaining +// within the channel. If we're able to unpack the backup, then the new channel +// will be shown under listchannels, as well as pending channels. +func (r *rpcServer) RestoreChannelBackups(ctx context.Context, + in *lnrpc.RestoreChanBackupRequest) (*lnrpc.RestoreBackupResponse, error) { + + // First, we'll make our implementation of the + // chanbackup.ChannelRestorer interface which we'll use to properly + // restore either a set of chanbackup.Single or chanbackup.Multi + // backups. + chanRestorer := &chanDBRestorer{ + db: r.server.chanDB, + secretKeys: r.server.cc.keyRing, + chainArb: r.server.chainArb, + } + + // We'll accept either a list of Single backups, or a single Multi + // backup which contains several single backups. + switch { + case in.GetChanBackups() != nil: + chanBackupsProtos := in.GetChanBackups() + + // Now that we know what type of backup we're working with, + // we'll parse them all out into a more suitable format. + packedBackups := make([][]byte, 0, len(chanBackupsProtos.ChanBackups)) + for _, chanBackup := range chanBackupsProtos.ChanBackups { + packedBackups = append( + packedBackups, chanBackup.ChanBackup, + ) + } + + // With our backups obtained, we'll now restore them which will + // write the new backups to disk, and then attempt to connect + // out to any peers that we know of which were our prior + // channel peers. + err := chanbackup.UnpackAndRecoverSingles( + chanbackup.PackedSingles(packedBackups), + r.server.cc.keyRing, chanRestorer, r.server, + ) + if err != nil { + return nil, fmt.Errorf("unable to unpack single "+ + "backups: %v", err) + } + + case in.GetMultiChanBackup() != nil: + packedMultiBackup := in.GetMultiChanBackup() + + // With our backups obtained, we'll now restore them which will + // write the new backups to disk, and then attempt to connect + // out to any peers that we know of which were our prior + // channel peers. + packedMulti := chanbackup.PackedMulti(packedMultiBackup) + err := chanbackup.UnpackAndRecoverMulti( + packedMulti, r.server.cc.keyRing, chanRestorer, + r.server, + ) + if err != nil { + return nil, fmt.Errorf("unable to unpack chan "+ + "backup: %v", err) + } + } + + return &lnrpc.RestoreBackupResponse{}, nil +} + +// SubscribeChannelBackups allows a client to sub-subscribe to the most up to +// date information concerning the state of all channel back ups. Each time a +// new channel is added, we return the new set of channels, along with a +// multi-chan backup containing the backup info for all channels. Each time a +// channel is closed, we send a new update, which contains new new chan back +// ups, but the updated set of encrypted multi-chan backups with the closed +// channel(s) removed. +func (r *rpcServer) SubscribeChannelBackups(req *lnrpc.ChannelBackupSubscription, + updateStream lnrpc.Lightning_SubscribeChannelBackupsServer) error { + + // TODO(roasbeef): hook up to chan notifier + + // TODO(roasbeef): make chanbackup.SubSwapper + + return nil +}