mirror of
https://github.com/lightningnetwork/lnd.git
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1348c6b35b
In this commit, we introduce a series of interfaces and methods that will allow external callers to backup either all channels, or a specific channel identified by its channel point. In order to abstract away the details w.r.t _how_ we obtain the set of open channels, or their storage mechanisms, we introduce a new LiveChannelSource interfaces. This interfaces allows us to fetch all channels, a channel by its channel point, and also all the known addresses for a node as we'll need this in order to connect out to the node in the case of a recovery attempt.
100 lines
3.3 KiB
Go
100 lines
3.3 KiB
Go
package chanbackup
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import (
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"fmt"
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"net"
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"github.com/btcsuite/btcd/btcec"
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"github.com/btcsuite/btcd/wire"
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"github.com/lightningnetwork/lnd/channeldb"
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)
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// LiveChannelSource is an interface that allows us to query for the set of
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// live channels. A live channel is one that is open, and has not had a
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// commitment transaction broadcast.
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type LiveChannelSource interface {
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// FetchAllChannels returns all known live channels.
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FetchAllChannels() ([]*channeldb.OpenChannel, error)
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// FetchChannel attempts to locate a live channel identified by the
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// passed chanPoint.
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FetchChannel(chanPoint wire.OutPoint) (*channeldb.OpenChannel, error)
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// AddrsForNode returns all known addresses for the target node public
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// key.
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AddrsForNode(nodePub *btcec.PublicKey) ([]net.Addr, error)
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}
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// assembleChanBackup attempts to assemble a static channel backup for the
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// passed open channel. The backup includes all information required to restore
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// the channel, as well as addressing information so we can find the peer and
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// reconnect to them to initiate the protocol.
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func assembleChanBackup(chanSource LiveChannelSource,
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openChan *channeldb.OpenChannel) (*Single, error) {
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log.Debugf("Crafting backup for ChannelPoint(%v)",
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openChan.FundingOutpoint)
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// First, we'll query the channel source to obtain all the addresses
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// that are are associated with the peer for this channel.
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nodeAddrs, err := chanSource.AddrsForNode(openChan.IdentityPub)
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if err != nil {
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return nil, err
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}
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single := NewSingle(openChan, nodeAddrs)
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return &single, nil
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}
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// FetchBackupForChan attempts to create a plaintext static channel backup for
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// the target channel identified by its channel point. If we're unable to find
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// the target channel, then an error will be returned.
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func FetchBackupForChan(chanPoint wire.OutPoint,
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chanSource LiveChannelSource) (*Single, error) {
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// First, we'll query the channel source to see if the channel is known
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// and open within the database.
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targetChan, err := chanSource.FetchChannel(chanPoint)
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if err != nil {
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// If we can't find the channel, then we return with an error,
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// as we have nothing to backup.
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return nil, fmt.Errorf("unable to find target channel")
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}
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// Once we have the target channel, we can assemble the backup using
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// the source to obtain any extra information that we may need.
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staticChanBackup, err := assembleChanBackup(chanSource, targetChan)
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if err != nil {
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return nil, fmt.Errorf("unable to create chan backup: %v", err)
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}
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return staticChanBackup, nil
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}
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// FetchStaticChanBackups will return a plaintext static channel back up for
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// all known active/open channels within the passed channel source.
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func FetchStaticChanBackups(chanSource LiveChannelSource) ([]Single, error) {
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// First, we'll query the backup source for information concerning all
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// currently open and available channels.
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openChans, err := chanSource.FetchAllChannels()
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if err != nil {
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return nil, err
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}
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// Now that we have all the channels, we'll use the chanSource to
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// obtain any auxiliary information we need to craft a backup for each
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// channel.
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staticChanBackups := make([]Single, len(openChans))
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for i, openChan := range openChans {
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chanBackup, err := assembleChanBackup(chanSource, openChan)
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if err != nil {
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return nil, err
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}
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staticChanBackups[i] = *chanBackup
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}
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return staticChanBackups, nil
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}
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