From b2b57314facd0111c17f4b74459d81013680a651 Mon Sep 17 00:00:00 2001 From: Olaoluwa Osuntokun Date: Sun, 9 Dec 2018 19:37:47 -0800 Subject: [PATCH] channeldb: add new RestoreChannelShells method In this commit, we add a new type (ChannelShell) along with a new method, RestoreChannelShells which allows a caller to insert a series of channel shells into the database. These channel shells will allow a restored node to initiate the DLP protocol and recover their set of existing channels. When we insert a channel shell, we re-create the original link node, and also add the outgoing edge to the channel graph. This way we can be sure that upon start up, we attempt to connect to the remote peers, and that the normal graph query commands will operate as expected. --- channeldb/db.go | 107 ++++++++++++++++++++++++++ channeldb/db_test.go | 177 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 284 insertions(+) diff --git a/channeldb/db.go b/channeldb/db.go index 8e27b021..c4262ffa 100644 --- a/channeldb/db.go +++ b/channeldb/db.go @@ -8,6 +8,7 @@ import ( "os" "path/filepath" "sync" + "time" "github.com/btcsuite/btcd/btcec" "github.com/btcsuite/btcd/wire" @@ -869,6 +870,112 @@ func (d *DB) PruneLinkNodes() error { }) } +// ChannelShell is a shell of a channel that is meant to be used for channel +// recovery purposes. It contains a minimal OpenChannel instance along with +// addresses for that target node. +type ChannelShell struct { + // NodeAddrs the set of addresses that this node has known to be + // reachable at in the past. + NodeAddrs []net.Addr + + // Chan is a shell of an OpenChannel, it contains only the items + // required to restore the channel on disk. + Chan *OpenChannel +} + +// RestoreChannelShells is a method that allows the caller to reconstruct the +// state of an OpenChannel from the ChannelShell. We'll attempt to write the +// new channel to disk, create a LinkNode instance with the passed node +// addresses, and finally create an edge within the graph for the channel as +// well. This method is idempotent, so repeated calls with the same set of +// channel shells won't modify the database after the initial call. +func (d *DB) RestoreChannelShells(channelShells ...*ChannelShell) error { + chanGraph := ChannelGraph{d} + + return d.Update(func(tx *bbolt.Tx) error { + for _, channelShell := range channelShells { + channel := channelShell.Chan + + // First, we'll attempt to create a new open channel + // and link node for this channel. If the channel + // already exists, then in order to ensure this method + // is idempotent, we'll continue to the next step. + channel.Db = d + err := syncNewChannel( + tx, channel, channelShell.NodeAddrs, + ) + if err != nil { + return err + } + + // Next, we'll create an active edge in the graph + // database for this channel in order to restore our + // partial view of the network. + // + // TODO(roasbeef): if we restore *after* the channel + // has been closed on chain, then need to inform the + // router that it should try and prune these values as + // we can detect them + edgeInfo := ChannelEdgeInfo{ + ChannelID: channel.ShortChannelID.ToUint64(), + ChainHash: channel.ChainHash, + ChannelPoint: channel.FundingOutpoint, + } + + nodes := tx.Bucket(nodeBucket) + if nodes == nil { + return ErrGraphNotFound + } + selfNode, err := chanGraph.sourceNode(nodes) + if err != nil { + return err + } + + // Depending on which pub key is smaller, we'll assign + // our roles as "node1" and "node2". + chanPeer := channel.IdentityPub.SerializeCompressed() + selfIsSmaller := bytes.Compare( + selfNode.PubKeyBytes[:], chanPeer, + ) == -1 + if selfIsSmaller { + copy(edgeInfo.NodeKey1Bytes[:], selfNode.PubKeyBytes[:]) + copy(edgeInfo.NodeKey2Bytes[:], chanPeer) + } else { + copy(edgeInfo.NodeKey1Bytes[:], chanPeer) + copy(edgeInfo.NodeKey2Bytes[:], selfNode.PubKeyBytes[:]) + } + + // With the edge info shell constructed, we'll now add + // it to the graph. + err = chanGraph.addChannelEdge(tx, &edgeInfo) + if err != nil { + return err + } + + // Similarly, we'll construct a channel edge shell and + // add that itself to the graph. + chanEdge := ChannelEdgePolicy{ + ChannelID: edgeInfo.ChannelID, + LastUpdate: time.Now(), + } + + // If their pubkey is larger, then we'll flip the + // direction bit to indicate that us, the "second" node + // is updating their policy. + if !selfIsSmaller { + chanEdge.ChannelFlags |= lnwire.ChanUpdateDirection + } + + err = updateEdgePolicy(tx, &chanEdge) + if err != nil { + return err + } + } + + return nil + }) +} + // AddrsForNode consults the graph and channel database for all addresses known // to the passed node public key. func (d *DB) AddrsForNode(nodePub *btcec.PublicKey) ([]net.Addr, error) { diff --git a/channeldb/db_test.go b/channeldb/db_test.go index 17018333..261e0b36 100644 --- a/channeldb/db_test.go +++ b/channeldb/db_test.go @@ -2,16 +2,22 @@ package channeldb import ( "io/ioutil" + "math" + "math/rand" "net" "os" "path/filepath" "reflect" "testing" + "github.com/btcsuite/btcd/btcec" + "github.com/btcsuite/btcd/chaincfg/chainhash" "github.com/btcsuite/btcd/wire" "github.com/btcsuite/btcutil" "github.com/davecgh/go-spew/spew" + "github.com/lightningnetwork/lnd/keychain" "github.com/lightningnetwork/lnd/lnwire" + "github.com/lightningnetwork/lnd/shachain" ) func TestOpenWithCreate(t *testing.T) { @@ -271,3 +277,174 @@ func TestFetchChannel(t *testing.T) { t.Fatalf("expected query to fail") } } + +func genRandomChannelShell() (*ChannelShell, error) { + var testPriv [32]byte + if _, err := rand.Read(testPriv[:]); err != nil { + return nil, err + } + + _, pub := btcec.PrivKeyFromBytes(btcec.S256(), testPriv[:]) + + var chanPoint wire.OutPoint + if _, err := rand.Read(chanPoint.Hash[:]); err != nil { + return nil, err + } + + pub.Curve = nil + + chanPoint.Index = uint32(rand.Intn(math.MaxUint16)) + + chanStatus := ChanStatusDefault | ChanStatusRestored + + var shaChainPriv [32]byte + if _, err := rand.Read(testPriv[:]); err != nil { + return nil, err + } + revRoot, err := chainhash.NewHash(shaChainPriv[:]) + if err != nil { + return nil, err + } + shaChainProducer := shachain.NewRevocationProducer(*revRoot) + + return &ChannelShell{ + NodeAddrs: []net.Addr{&net.TCPAddr{ + IP: net.ParseIP("127.0.0.1"), + Port: 18555, + }}, + Chan: &OpenChannel{ + chanStatus: chanStatus, + ChainHash: rev, + FundingOutpoint: chanPoint, + ShortChannelID: lnwire.NewShortChanIDFromInt( + uint64(rand.Int63()), + ), + IdentityPub: pub, + LocalChanCfg: ChannelConfig{ + ChannelConstraints: ChannelConstraints{ + CsvDelay: uint16(rand.Int63()), + }, + PaymentBasePoint: keychain.KeyDescriptor{ + KeyLocator: keychain.KeyLocator{ + Family: keychain.KeyFamily(rand.Int63()), + Index: uint32(rand.Int63()), + }, + }, + }, + RemoteCurrentRevocation: pub, + IsPending: false, + RevocationStore: shachain.NewRevocationStore(), + RevocationProducer: shaChainProducer, + }, + }, nil +} + +// TestRestoreChannelShells tests that we're able to insert a partially channel +// populated to disk. This is useful for channel recovery purposes. We should +// find the new channel shell on disk, and also the db should be populated with +// an edge for that channel. +func TestRestoreChannelShells(t *testing.T) { + t.Parallel() + + cdb, cleanUp, err := makeTestDB() + if err != nil { + t.Fatalf("unable to make test database: %v", err) + } + defer cleanUp() + + // First, we'll make our channel shell, it will only have the minimal + // amount of information required for us to initiate the data loss + // protection feature. + channelShell, err := genRandomChannelShell() + if err != nil { + t.Fatalf("unable to gen channel shell: %v", err) + } + + graph := cdb.ChannelGraph() + + // Before we can restore the channel, we'll need to make a source node + // in the graph as the channel edge we create will need to have a + // origin. + testNode, err := createTestVertex(cdb) + if err != nil { + t.Fatalf("unable to create test node: %v", err) + } + if err := graph.SetSourceNode(testNode); err != nil { + t.Fatalf("unable to set source node: %v", err) + } + + // With the channel shell constructed, we'll now insert it into the + // database with the restoration method. + if err := cdb.RestoreChannelShells(channelShell); err != nil { + t.Fatalf("unable to restore channel shell: %v", err) + } + + // Now that the channel has been inserted, we'll attempt to query for + // it to ensure we can properly locate it via various means. + // + // First, we'll attempt to query for all channels that we have with the + // node public key that was restored. + nodeChans, err := cdb.FetchOpenChannels(channelShell.Chan.IdentityPub) + if err != nil { + t.Fatalf("unable find channel: %v", err) + } + + // We should now find a single channel from the database. + if len(nodeChans) != 1 { + t.Fatalf("unable to find restored channel by node "+ + "pubkey: %v", err) + } + + // That single channel should have the proper channel point, and also + // the expected set of flags to indicate that it was a restored + // channel. + if nodeChans[0].FundingOutpoint != channelShell.Chan.FundingOutpoint { + t.Fatalf("wrong funding outpoint: expected %v, got %v", + nodeChans[0].FundingOutpoint, + channelShell.Chan.FundingOutpoint) + } + if !nodeChans[0].HasChanStatus(ChanStatusRestored) { + t.Fatalf("node has wrong status flags: %v", + nodeChans[0].chanStatus) + } + + // We should also be able to find the channel if we query for it + // directly. + _, err = cdb.FetchChannel(channelShell.Chan.FundingOutpoint) + if err != nil { + t.Fatalf("unable to fetch channel: %v", err) + } + + // We should also be able to find the link node that was inserted by + // its public key. + linkNode, err := cdb.FetchLinkNode(channelShell.Chan.IdentityPub) + if err != nil { + t.Fatalf("unable to fetch link node: %v", err) + } + + // The node should have the same address, as specified in the channel + // shell. + if reflect.DeepEqual(linkNode.Addresses, channelShell.NodeAddrs) { + t.Fatalf("addr mismach: expected %v, got %v", + linkNode.Addresses, channelShell.NodeAddrs) + } + + // Finally, we'll ensure that the edge for the channel was properly + // inserted. + chanInfos, err := graph.FetchChanInfos( + []uint64{channelShell.Chan.ShortChannelID.ToUint64()}, + ) + if err != nil { + t.Fatalf("unable to find edges: %v", err) + } + + if len(chanInfos) != 1 { + t.Fatalf("wrong amount of chan infos: expected %v got %v", + len(chanInfos), 1) + } + + // We should only find a single edge. + if chanInfos[0].Policy1 != nil && chanInfos[0].Policy2 != nil { + t.Fatalf("only a single edge should be inserted: %v", err) + } +}