Merge pull request #1898 from Roasbeef/always-funding-import

tapchannel: address fault tolerance gap for initiator during channel funding

Author: jtobin

tapchannel/aux_sweeper.go

@@ -1415,7 +1415,26 @@ func importOutputProofs(scid lnwire.ShortChannelID,
 // the funding outputs we need.
 //
 // TODO(roasbeef): assume single asset for now, also additional inputs
+ctxb := context.Background()
 for _, proofToImport := range outputProofs {
+// Check if the proof is already imported to avoid redundant
+// work.
+fundingLocator := proof.Locator{
+AssetID: fn.Ptr(proofToImport.Asset.ID()),
+ScriptKey: *proofToImport.Asset.ScriptKey.PubKey,
+OutPoint: fn.Ptr(proofToImport.OutPoint()),
+}
+proofExists, err := proofArchive.HasProof(ctxb, fundingLocator)
+if err != nil {
+return fmt.Errorf("unable to check if proof "+
+"exists: %w", err)
+}
+if proofExists {
+log.Infof("Proof already imported for %v, skipping",
+limitSpewer.Sdump(fundingLocator))
+continue
+}
+
 proofPrevID, err := proofToImport.Asset.PrimaryPrevID()
 if err != nil {
 return fmt.Errorf("unable to get primary prev "+
@@ -1443,7 +1462,6 @@ func importOutputProofs(scid lnwire.ShortChannelID,
 
 // First, we'll make a courier to use in fetching the proofs we
 // need.
-ctxb := context.Background()
 proofFetcher, err := proofDispatch.NewCourier(
 ctxb, courierAddr, true,
 )
@@ -1505,18 +1523,10 @@ func importOutputProofs(scid lnwire.ShortChannelID,
 return fmt.Errorf("unable to encode proof: %w", err)
 }
 
-fundingUTXO := proofToImport.Asset
 err = proofArchive.ImportProofs(
 ctxb, vCtx, false, &proof.AnnotatedProof{
-//nolint:lll
-Locator: proof.Locator{
-AssetID: fn.Ptr(fundingUTXO.ID()),
-ScriptKey: *fundingUTXO.ScriptKey.PubKey,
-OutPoint: fn.Ptr(
-proofToImport.OutPoint(),
-),
-},
-Blob: finalProofBuf.Bytes(),
+Locator: fundingLocator,
+Blob: finalProofBuf.Bytes(),
 },
 )
 if err != nil {
@@ -1576,26 +1586,24 @@ func (a *AuxSweeper) importCommitTx(req lnwallet.ResolutionReq,
 fundingInputProofs[inputProof.Asset.ID()] = inputProof
 }
 
-// If we're the responder, then we'll also fetch+complete the proofs
-// for the funding transaction here so we can properly recognize the
-// spent input below.
-if !req.Initiator {
-vCtx := proof.VerifierCtx{
-HeaderVerifier: a.cfg.HeaderVerifier,
-MerkleVerifier: proof.DefaultMerkleVerifier,
-GroupVerifier: a.cfg.GroupVerifier,
-ChainLookupGen: a.cfg.ChainBridge,
-IgnoreChecker: a.cfg.IgnoreChecker,
-}
-err := importOutputProofs(
-req.ShortChanID, maps.Values(fundingInputProofs),
-a.cfg.DefaultCourierAddr, a.cfg.ProofFetcher,
-a.cfg.ChainBridge, vCtx, a.cfg.ProofArchive,
-)
-if err != nil {
-return fmt.Errorf("unable to import output "+
-"proofs: %w", err)
-}
+// We'll always attempt to import the proof for the funding outputs.
+// It's possible that the initiator failed to do so after the funding
+// transaction confirmed.
+vCtx := proof.VerifierCtx{
+HeaderVerifier: a.cfg.HeaderVerifier,
+MerkleVerifier: proof.DefaultMerkleVerifier,
+GroupVerifier: a.cfg.GroupVerifier,
+ChainLookupGen: a.cfg.ChainBridge,
+IgnoreChecker: a.cfg.IgnoreChecker,
+}
+err = importOutputProofs(
+req.ShortChanID, maps.Values(fundingInputProofs),
+a.cfg.DefaultCourierAddr, a.cfg.ProofFetcher,
+a.cfg.ChainBridge, vCtx, a.cfg.ProofArchive,
+)
+if err != nil {
+return fmt.Errorf("unable to import output "+
+"proofs: %w", err)
 }
 
 err = updateProofsFromShortChanID(