package discovery import ( "github.com/go-errors/errors" "github.com/lightningnetwork/lnd/channeldb" "github.com/lightningnetwork/lnd/lnwallet" "github.com/lightningnetwork/lnd/lnwire" "github.com/roasbeef/btcd/btcec" ) // createChanAnnouncement is a helper function which creates all channel // announcements given the necessary channel related database items. This // function is used to transform out databse structs into the coresponding wire // sturcts for announcing new channels to other peers, or simply syncing up a // peer's initial routing table upon connect. func createChanAnnouncement(chanProof *channeldb.ChannelAuthProof, chanInfo *channeldb.ChannelEdgeInfo, e1, e2 *channeldb.ChannelEdgePolicy) (*lnwire.ChannelAnnouncement, *lnwire.ChannelUpdate, *lnwire.ChannelUpdate) { // First, using the parameters of the channel, along with the channel // authentication chanProof, we'll create re-create the original // authenticated channel announcement. chanID := lnwire.NewShortChanIDFromInt(chanInfo.ChannelID) chanAnn := &lnwire.ChannelAnnouncement{ NodeSig1: chanProof.NodeSig1, NodeSig2: chanProof.NodeSig2, ShortChannelID: chanID, BitcoinSig1: chanProof.BitcoinSig1, BitcoinSig2: chanProof.BitcoinSig2, NodeID1: chanInfo.NodeKey1, NodeID2: chanInfo.NodeKey2, BitcoinKey1: chanInfo.BitcoinKey1, BitcoinKey2: chanInfo.BitcoinKey2, } // We'll unconditionally queue the channel's existence chanProof as it // will need to be processed before either of the channel update // networkMsgs. // Since it's up to a node's policy as to whether they advertise the // edge in dire direction, we don't create an advertisement if the edge // is nil. var edge1Ann, edge2Ann *lnwire.ChannelUpdate if e1 != nil { edge1Ann = &lnwire.ChannelUpdate{ Signature: e1.Signature, ShortChannelID: chanID, Timestamp: uint32(e1.LastUpdate.Unix()), Flags: 0, TimeLockDelta: e1.TimeLockDelta, HtlcMinimumMsat: uint32(e1.MinHTLC), FeeBaseMsat: uint32(e1.FeeBaseMSat), FeeProportionalMillionths: uint32(e1.FeeProportionalMillionths), } } if e2 != nil { edge2Ann = &lnwire.ChannelUpdate{ Signature: e2.Signature, ShortChannelID: chanID, Timestamp: uint32(e2.LastUpdate.Unix()), Flags: 1, TimeLockDelta: e2.TimeLockDelta, HtlcMinimumMsat: uint32(e2.MinHTLC), FeeBaseMsat: uint32(e2.FeeBaseMSat), FeeProportionalMillionths: uint32(e2.FeeProportionalMillionths), } } return chanAnn, edge1Ann, edge2Ann } // copyPubKey performs a copy of the target public key, setting a fresh curve // parameter during the process. func copyPubKey(pub *btcec.PublicKey) *btcec.PublicKey { return &btcec.PublicKey{ Curve: btcec.S256(), X: pub.X, Y: pub.Y, } } // SignAnnouncement is a helper function which is used to sign any outgoing // channel node node announcement messages. func SignAnnouncement(signer lnwallet.MessageSigner, pubKey *btcec.PublicKey, msg lnwire.Message) (*btcec.Signature, error) { var ( data []byte err error ) switch m := msg.(type) { case *lnwire.ChannelAnnouncement: data, err = m.DataToSign() case *lnwire.ChannelUpdate: data, err = m.DataToSign() case *lnwire.NodeAnnouncement: data, err = m.DataToSign() default: return nil, errors.New("can't sign message " + "of this format") } if err != nil { return nil, errors.Errorf("unable to get data to sign: %v", err) } return signer.SignMessage(pubKey, data) }