package lnwallet import ( "bytes" "container/list" "crypto/sha256" "fmt" "reflect" "runtime" "testing" "github.com/btcsuite/btcd/blockchain" "github.com/btcsuite/btcd/btcec" "github.com/btcsuite/btcd/txscript" "github.com/btcsuite/btcd/wire" "github.com/btcsuite/btcutil" "github.com/davecgh/go-spew/spew" "github.com/lightningnetwork/lnd/chainntnfs" "github.com/lightningnetwork/lnd/channeldb" "github.com/lightningnetwork/lnd/input" "github.com/lightningnetwork/lnd/lntypes" "github.com/lightningnetwork/lnd/lnwallet/chainfee" "github.com/lightningnetwork/lnd/lnwire" "github.com/stretchr/testify/require" ) // createHTLC is a utility function for generating an HTLC with a given // preimage and a given amount. func createHTLC(id int, amount lnwire.MilliSatoshi) (*lnwire.UpdateAddHTLC, [32]byte) { preimage := bytes.Repeat([]byte{byte(id)}, 32) paymentHash := sha256.Sum256(preimage) var returnPreimage [32]byte copy(returnPreimage[:], preimage) return &lnwire.UpdateAddHTLC{ ID: uint64(id), PaymentHash: paymentHash, Amount: amount, Expiry: uint32(5), }, returnPreimage } func assertOutputExistsByValue(t *testing.T, commitTx *wire.MsgTx, value btcutil.Amount) { for _, txOut := range commitTx.TxOut { if txOut.Value == int64(value) { return } } t.Fatalf("unable to find output of value %v within tx %v", value, spew.Sdump(commitTx)) } // testAddSettleWorkflow tests a simple channel scenario where Alice and Bob // add, the settle an HTLC between themselves. func testAddSettleWorkflow(t *testing.T, tweakless bool) { // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. chanType := channeldb.SingleFunderTweaklessBit if !tweakless { chanType = channeldb.SingleFunderBit } aliceChannel, bobChannel, cleanUp, err := CreateTestChannels(chanType) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() paymentPreimage := bytes.Repeat([]byte{1}, 32) paymentHash := sha256.Sum256(paymentPreimage) htlcAmt := lnwire.NewMSatFromSatoshis(btcutil.SatoshiPerBitcoin) htlc := &lnwire.UpdateAddHTLC{ PaymentHash: paymentHash, Amount: htlcAmt, Expiry: uint32(5), } // First Alice adds the outgoing HTLC to her local channel's state // update log. Then Alice sends this wire message over to Bob who adds // this htlc to his remote state update log. aliceHtlcIndex, err := aliceChannel.AddHTLC(htlc, nil) if err != nil { t.Fatalf("unable to add htlc: %v", err) } bobHtlcIndex, err := bobChannel.ReceiveHTLC(htlc) if err != nil { t.Fatalf("unable to recv htlc: %v", err) } // Next alice commits this change by sending a signature message. Since // we expect the messages to be ordered, Bob will receive the HTLC we // just sent before he receives this signature, so the signature will // cover the HTLC. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("alice unable to sign commitment: %v", err) } // Bob receives this signature message, and checks that this covers the // state he has in his remote log. This includes the HTLC just sent // from Alice. err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("bob unable to process alice's new commitment: %v", err) } // Bob revokes his prior commitment given to him by Alice, since he now // has a valid signature for a newer commitment. bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to generate bob revocation: %v", err) } // Bob finally send a signature for Alice's commitment transaction. // This signature will cover the HTLC, since Bob will first send the // revocation just created. The revocation also acks every received // HTLC up to the point where Alice sent here signature. bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("bob unable to sign alice's commitment: %v", err) } // Alice then processes this revocation, sending her own revocation for // her prior commitment transaction. Alice shouldn't have any HTLCs to // forward since she's sending an outgoing HTLC. fwdPkg, _, _, _, err := aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatalf("alice unable to process bob's revocation: %v", err) } if len(fwdPkg.Adds) != 0 { t.Fatalf("alice forwards %v add htlcs, should forward none", len(fwdPkg.Adds)) } if len(fwdPkg.SettleFails) != 0 { t.Fatalf("alice forwards %v settle/fail htlcs, "+ "should forward none", len(fwdPkg.SettleFails)) } // Alice then processes bob's signature, and since she just received // the revocation, she expect this signature to cover everything up to // the point where she sent her signature, including the HTLC. err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("alice unable to process bob's new commitment: %v", err) } // Alice then generates a revocation for bob. aliceRevocation, _, err := aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke alice channel: %v", err) } // Finally Bob processes Alice's revocation, at this point the new HTLC // is fully locked in within both commitment transactions. Bob should // also be able to forward an HTLC now that the HTLC has been locked // into both commitment transactions. fwdPkg, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatalf("bob unable to process alice's revocation: %v", err) } if len(fwdPkg.Adds) != 1 { t.Fatalf("bob forwards %v add htlcs, should only forward one", len(fwdPkg.Adds)) } if len(fwdPkg.SettleFails) != 0 { t.Fatalf("bob forwards %v settle/fail htlcs, "+ "should forward none", len(fwdPkg.SettleFails)) } // At this point, both sides should have the proper number of satoshis // sent, and commitment height updated within their local channel // state. aliceSent := lnwire.MilliSatoshi(0) bobSent := lnwire.MilliSatoshi(0) if aliceChannel.channelState.TotalMSatSent != aliceSent { t.Fatalf("alice has incorrect milli-satoshis sent: %v vs %v", aliceChannel.channelState.TotalMSatSent, aliceSent) } if aliceChannel.channelState.TotalMSatReceived != bobSent { t.Fatalf("alice has incorrect milli-satoshis received %v vs %v", aliceChannel.channelState.TotalMSatReceived, bobSent) } if bobChannel.channelState.TotalMSatSent != bobSent { t.Fatalf("bob has incorrect milli-satoshis sent %v vs %v", bobChannel.channelState.TotalMSatSent, bobSent) } if bobChannel.channelState.TotalMSatReceived != aliceSent { t.Fatalf("bob has incorrect milli-satoshis received %v vs %v", bobChannel.channelState.TotalMSatReceived, aliceSent) } if bobChannel.currentHeight != 1 { t.Fatalf("bob has incorrect commitment height, %v vs %v", bobChannel.currentHeight, 1) } if aliceChannel.currentHeight != 1 { t.Fatalf("alice has incorrect commitment height, %v vs %v", aliceChannel.currentHeight, 1) } // Both commitment transactions should have three outputs, and one of // them should be exactly the amount of the HTLC. if len(aliceChannel.channelState.LocalCommitment.CommitTx.TxOut) != 3 { t.Fatalf("alice should have three commitment outputs, instead "+ "have %v", len(aliceChannel.channelState.LocalCommitment.CommitTx.TxOut)) } if len(bobChannel.channelState.LocalCommitment.CommitTx.TxOut) != 3 { t.Fatalf("bob should have three commitment outputs, instead "+ "have %v", len(bobChannel.channelState.LocalCommitment.CommitTx.TxOut)) } assertOutputExistsByValue(t, aliceChannel.channelState.LocalCommitment.CommitTx, htlcAmt.ToSatoshis()) assertOutputExistsByValue(t, bobChannel.channelState.LocalCommitment.CommitTx, htlcAmt.ToSatoshis()) // Now we'll repeat a similar exchange, this time with Bob settling the // HTLC once he learns of the preimage. var preimage [32]byte copy(preimage[:], paymentPreimage) err = bobChannel.SettleHTLC(preimage, bobHtlcIndex, nil, nil, nil) if err != nil { t.Fatalf("bob unable to settle inbound htlc: %v", err) } err = aliceChannel.ReceiveHTLCSettle(preimage, aliceHtlcIndex) if err != nil { t.Fatalf("alice unable to accept settle of outbound htlc: %v", err) } bobSig2, bobHtlcSigs2, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("bob unable to sign settle commitment: %v", err) } err = aliceChannel.ReceiveNewCommitment(bobSig2, bobHtlcSigs2) if err != nil { t.Fatalf("alice unable to process bob's new commitment: %v", err) } aliceRevocation2, _, err := aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("alice unable to generate revocation: %v", err) } aliceSig2, aliceHtlcSigs2, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("alice unable to sign new commitment: %v", err) } fwdPkg, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation2) if err != nil { t.Fatalf("bob unable to process alice's revocation: %v", err) } if len(fwdPkg.Adds) != 0 { t.Fatalf("bob forwards %v add htlcs, should forward none", len(fwdPkg.Adds)) } if len(fwdPkg.SettleFails) != 0 { t.Fatalf("bob forwards %v settle/fail htlcs, "+ "should forward none", len(fwdPkg.SettleFails)) } err = bobChannel.ReceiveNewCommitment(aliceSig2, aliceHtlcSigs2) if err != nil { t.Fatalf("bob unable to process alice's new commitment: %v", err) } bobRevocation2, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("bob unable to revoke commitment: %v", err) } fwdPkg, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation2) if err != nil { t.Fatalf("alice unable to process bob's revocation: %v", err) } if len(fwdPkg.Adds) != 0 { // Alice should now be able to forward the settlement HTLC to // any down stream peers. t.Fatalf("alice should be forwarding an add HTLC, "+ "instead forwarding %v: %v", len(fwdPkg.Adds), spew.Sdump(fwdPkg.Adds)) } if len(fwdPkg.SettleFails) != 1 { t.Fatalf("alice should be forwarding one settle/fails HTLC, "+ "instead forwarding: %v", len(fwdPkg.SettleFails)) } // At this point, Bob should have 6 BTC settled, with Alice still // having 4 BTC. Alice's channel should show 1 BTC sent and Bob's // channel should show 1 BTC received. They should also be at // commitment height two, with the revocation window extended by 1 (5). mSatTransferred := lnwire.NewMSatFromSatoshis(btcutil.SatoshiPerBitcoin) if aliceChannel.channelState.TotalMSatSent != mSatTransferred { t.Fatalf("alice satoshis sent incorrect %v vs %v expected", aliceChannel.channelState.TotalMSatSent, mSatTransferred) } if aliceChannel.channelState.TotalMSatReceived != 0 { t.Fatalf("alice satoshis received incorrect %v vs %v expected", aliceChannel.channelState.TotalMSatReceived, 0) } if bobChannel.channelState.TotalMSatReceived != mSatTransferred { t.Fatalf("bob satoshis received incorrect %v vs %v expected", bobChannel.channelState.TotalMSatReceived, mSatTransferred) } if bobChannel.channelState.TotalMSatSent != 0 { t.Fatalf("bob satoshis sent incorrect %v vs %v expected", bobChannel.channelState.TotalMSatSent, 0) } if bobChannel.currentHeight != 2 { t.Fatalf("bob has incorrect commitment height, %v vs %v", bobChannel.currentHeight, 2) } if aliceChannel.currentHeight != 2 { t.Fatalf("alice has incorrect commitment height, %v vs %v", aliceChannel.currentHeight, 2) } // The logs of both sides should now be cleared since the entry adding // the HTLC should have been removed once both sides receive the // revocation. if aliceChannel.localUpdateLog.Len() != 0 { t.Fatalf("alice's local not updated, should be empty, has %v "+ "entries instead", aliceChannel.localUpdateLog.Len()) } if aliceChannel.remoteUpdateLog.Len() != 0 { t.Fatalf("alice's remote not updated, should be empty, has %v "+ "entries instead", aliceChannel.remoteUpdateLog.Len()) } if len(aliceChannel.localUpdateLog.updateIndex) != 0 { t.Fatalf("alice's local log index not cleared, should be empty but "+ "has %v entries", len(aliceChannel.localUpdateLog.updateIndex)) } if len(aliceChannel.remoteUpdateLog.updateIndex) != 0 { t.Fatalf("alice's remote log index not cleared, should be empty but "+ "has %v entries", len(aliceChannel.remoteUpdateLog.updateIndex)) } } // TestSimpleAddSettleWorkflow tests a simple channel scenario wherein the // local node (Alice in this case) creates a new outgoing HTLC to bob, commits // this change, then bob immediately commits a settlement of the HTLC after the // initial add is fully committed in both commit chains. // // TODO(roasbeef): write higher level framework to exercise various states of // the state machine // * DSL language perhaps? // * constructed via input/output files func TestSimpleAddSettleWorkflow(t *testing.T) { t.Parallel() for _, tweakless := range []bool{true, false} { tweakless := tweakless t.Run(fmt.Sprintf("tweakless=%v", tweakless), func(t *testing.T) { testAddSettleWorkflow(t, tweakless) }) } } // TestChannelZeroAddLocalHeight tests that we properly set the addCommitHeightLocal // field during state log restoration. // // The full state transition of this test is: // // Alice Bob // -----add------> // -----sig------> // <----rev------- // <----sig------- // -----rev------> // <---settle----- // <----sig------- // -----rev------> // *alice dies* // <----add------- // x----sig------- // // The last sig will be rejected if addCommitHeightLocal is not set for the // initial add that Alice sent. This test checks that this behavior does // not occur and that we properly set the addCommitHeightLocal field. func TestChannelZeroAddLocalHeight(t *testing.T) { t.Parallel() // Create a test channel so that we can test the buggy behavior. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) require.NoError(t, err) defer cleanUp() // First we create an HTLC that Alice sends to Bob. htlc, _ := createHTLC(0, lnwire.MilliSatoshi(500000)) // -----add-----> _, err = aliceChannel.AddHTLC(htlc, nil) require.NoError(t, err) _, err = bobChannel.ReceiveHTLC(htlc) require.NoError(t, err) // Force a state transition to lock in this add on both commitments. // -----sig-----> // <----rev------ // <----sig------ // -----rev-----> err = ForceStateTransition(aliceChannel, bobChannel) require.NoError(t, err) // Now Bob should fail the htlc back to Alice. // <----fail----- err = bobChannel.FailHTLC(0, []byte("failreason"), nil, nil, nil) require.NoError(t, err) err = aliceChannel.ReceiveFailHTLC(0, []byte("bad")) require.NoError(t, err) // Bob should send a commitment signature to Alice. // <----sig------ bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() require.NoError(t, err) err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) require.NoError(t, err) // Alice should reply with a revocation. // -----rev-----> aliceRevocation, _, err := aliceChannel.RevokeCurrentCommitment() require.NoError(t, err) _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) require.NoError(t, err) // We now restore Alice's channel as this was the point at which // the addCommitHeightLocal field wouldn't be set, causing a force // close. newAliceChannel, err := NewLightningChannel( aliceChannel.Signer, aliceChannel.channelState, aliceChannel.sigPool, ) require.NoError(t, err) // Bob now sends an htlc to Alice htlc2, _ := createHTLC(0, lnwire.MilliSatoshi(500000)) // <----add----- _, err = bobChannel.AddHTLC(htlc2, nil) require.NoError(t, err) _, err = newAliceChannel.ReceiveHTLC(htlc2) require.NoError(t, err) // Bob should now send a commitment signature to Alice. // <----sig----- bobSig, bobHtlcSigs, _, err = bobChannel.SignNextCommitment() require.NoError(t, err) // Alice should accept the commitment. Previously she would // force close here. err = newAliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) require.NoError(t, err) } // TestCheckCommitTxSize checks that estimation size of commitment // transaction with some degree of error corresponds to the actual size. func TestCheckCommitTxSize(t *testing.T) { t.Parallel() checkSize := func(channel *LightningChannel, count int) { // Due to variable size of the signatures (70-73) in // witness script actual size of commitment transaction might // be lower on 6 weight. BaseCommitmentTxSizeEstimationError := 6 commitTx, err := channel.getSignedCommitTx() if err != nil { t.Fatalf("unable to initiate alice force close: %v", err) } actualCost := blockchain.GetTransactionWeight(btcutil.NewTx(commitTx)) estimatedCost := input.EstimateCommitTxWeight(count, false) diff := int(estimatedCost - actualCost) if 0 > diff || BaseCommitmentTxSizeEstimationError < diff { t.Fatalf("estimation is wrong, diff: %v", diff) } } // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // Check that weight estimation of the commitment transaction without // HTLCs is right. checkSize(aliceChannel, 0) checkSize(bobChannel, 0) // Adding HTLCs and check that size stays in allowable estimation // error window. for i := 0; i <= 10; i++ { htlc, _ := createHTLC(i, lnwire.MilliSatoshi(1e7)) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("alice unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("bob unable to receive htlc: %v", err) } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete state update: %v", err) } checkSize(aliceChannel, i+1) checkSize(bobChannel, i+1) } // Settle HTLCs and check that estimation is counting cost of settle // HTLCs properly. for i := 10; i >= 0; i-- { _, preimage := createHTLC(i, lnwire.MilliSatoshi(1e7)) err := bobChannel.SettleHTLC(preimage, uint64(i), nil, nil, nil) if err != nil { t.Fatalf("bob unable to settle inbound htlc: %v", err) } err = aliceChannel.ReceiveHTLCSettle(preimage, uint64(i)) if err != nil { t.Fatalf("alice unable to accept settle of outbound htlc: %v", err) } if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("unable to complete state update: %v", err) } checkSize(aliceChannel, i) checkSize(bobChannel, i) } } // TestCommitHTLCSigTieBreak asserts that HTLC signatures are sent the proper // BIP69+CLTV sorting expected by BOLT 3 when multiple HTLCs have identical // payment hashes and amounts, but differing CLTVs. This is exercised by adding // the HTLCs in the descending order of their CLTVs, and asserting that their // order is reversed when signing. func TestCommitHTLCSigTieBreak(t *testing.T) { t.Run("no restart", func(t *testing.T) { testCommitHTLCSigTieBreak(t, false) }) t.Run("restart", func(t *testing.T) { testCommitHTLCSigTieBreak(t, true) }) } func testCommitHTLCSigTieBreak(t *testing.T, restart bool) { aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels; %v", err) } defer cleanUp() const ( htlcAmt = lnwire.MilliSatoshi(20000000) numHtlcs = 2 ) // Add HTLCs with identical payment hashes and amounts, but descending // CLTV values. We will expect the signatures to appear in the reverse // order that the HTLCs are added due to the commitment sorting. for i := 0; i < numHtlcs; i++ { var ( preimage lntypes.Preimage hash = preimage.Hash() ) htlc := &lnwire.UpdateAddHTLC{ ID: uint64(i), PaymentHash: hash, Amount: htlcAmt, Expiry: uint32(numHtlcs - i), } if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("alice unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("bob unable to receive htlc: %v", err) } } // Have Alice initiate the first half of the commitment dance. The // tie-breaking for commitment sorting won't affect the commitment // signed by Alice because received HTLC scripts commit to the CLTV // directly, so the outputs will have different scriptPubkeys. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign alice's commitment: %v", err) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("unable to receive alice's commitment: %v", err) } bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke bob's commitment: %v", err) } _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatalf("unable to receive bob's revocation: %v", err) } // Now have Bob initiate the second half of the commitment dance. Here // the offered HTLC scripts he adds for Alice will need to have the // tie-breaking applied because the CLTV is not committed, but instead // implicit via the construction of the second-level transactions. bobSig, bobHtlcSigs, bobHtlcs, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign bob's commitment: %v", err) } if len(bobHtlcs) != numHtlcs { t.Fatalf("expected %d htlcs, got: %v", numHtlcs, len(bobHtlcs)) } // Ensure that our HTLCs appear in the reverse order from which they // were added by inspecting each's outpoint index. We expect the output // indexes to be in descending order, i.e. the first HTLC added had the // highest CLTV and should end up last. lastIndex := bobHtlcs[0].OutputIndex for i, htlc := range bobHtlcs[1:] { if htlc.OutputIndex >= lastIndex { t.Fatalf("htlc %d output index %d is not descending", i, htlc.OutputIndex) } lastIndex = htlc.OutputIndex } // If requsted, restart Alice so that we can test that the necessary // indexes can be reconstructed before needing to validate the // signatures from Bob. if restart { aliceState := aliceChannel.channelState aliceChannels, err := aliceState.Db.FetchOpenChannels( aliceState.IdentityPub, ) if err != nil { t.Fatalf("unable to fetch channel: %v", err) } aliceChannelNew, err := NewLightningChannel( aliceChannel.Signer, aliceChannels[0], aliceChannel.sigPool, ) if err != nil { t.Fatalf("unable to create new channel: %v", err) } aliceChannel = aliceChannelNew } // Finally, have Alice validate the signatures to ensure that she is // expecting the signatures in the proper order. err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("unable to receive bob's commitment: %v", err) } } // TestCooperativeChannelClosure checks that the coop close process finishes // with an agreement from both parties, and that the final balances of the // close tx check out. func TestCooperativeChannelClosure(t *testing.T) { t.Run("tweakless", func(t *testing.T) { testCoopClose(t, &coopCloseTestCase{ chanType: channeldb.SingleFunderTweaklessBit, }) }) t.Run("anchors", func(t *testing.T) { testCoopClose(t, &coopCloseTestCase{ chanType: channeldb.SingleFunderTweaklessBit | channeldb.AnchorOutputsBit, anchorAmt: anchorSize * 2, }) }) } type coopCloseTestCase struct { chanType channeldb.ChannelType anchorAmt btcutil.Amount } func testCoopClose(t *testing.T, testCase *coopCloseTestCase) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( testCase.chanType, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() aliceDeliveryScript := bobsPrivKey[:] bobDeliveryScript := testHdSeed[:] aliceFeeRate := chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) bobFeeRate := chainfee.SatPerKWeight( bobChannel.channelState.LocalCommitment.FeePerKw, ) // We'll start with both Alice and Bob creating a new close proposal // with the same fee. aliceFee := aliceChannel.CalcFee(aliceFeeRate) aliceSig, _, _, err := aliceChannel.CreateCloseProposal( aliceFee, aliceDeliveryScript, bobDeliveryScript, ) if err != nil { t.Fatalf("unable to create alice coop close proposal: %v", err) } bobFee := bobChannel.CalcFee(bobFeeRate) bobSig, _, _, err := bobChannel.CreateCloseProposal( bobFee, bobDeliveryScript, aliceDeliveryScript, ) if err != nil { t.Fatalf("unable to create bob coop close proposal: %v", err) } // With the proposals created, both sides should be able to properly // process the other party's signature. This indicates that the // transaction is well formed, and the signatures verify. aliceCloseTx, bobTxBalance, err := bobChannel.CompleteCooperativeClose( bobSig, aliceSig, bobDeliveryScript, aliceDeliveryScript, bobFee, ) if err != nil { t.Fatalf("unable to complete alice cooperative close: %v", err) } bobCloseSha := aliceCloseTx.TxHash() bobCloseTx, aliceTxBalance, err := aliceChannel.CompleteCooperativeClose( aliceSig, bobSig, aliceDeliveryScript, bobDeliveryScript, aliceFee, ) if err != nil { t.Fatalf("unable to complete bob cooperative close: %v", err) } aliceCloseSha := bobCloseTx.TxHash() if bobCloseSha != aliceCloseSha { t.Fatalf("alice and bob close transactions don't match: %v", err) } // Finally, make sure the final balances are correct from both's // perspective. aliceBalance := aliceChannel.channelState.LocalCommitment. LocalBalance.ToSatoshis() // The commit balance have had the initiator's (Alice) commitfee and // any anchors subtracted, so add that back to the final expected // balance. Alice also pays the coop close fee, so that must be // subtracted. commitFee := aliceChannel.channelState.LocalCommitment.CommitFee expBalanceAlice := aliceBalance + commitFee + testCase.anchorAmt - bobFee if aliceTxBalance != expBalanceAlice { t.Fatalf("expected balance %v got %v", expBalanceAlice, aliceTxBalance) } // Bob is not the initiator, so his final balance should simply be // equal to the latest commitment balance. expBalanceBob := bobChannel.channelState.LocalCommitment. LocalBalance.ToSatoshis() if bobTxBalance != expBalanceBob { t.Fatalf("expected bob's balance to be %v got %v", expBalanceBob, bobTxBalance) } } // TestForceClose checks that the resulting ForceCloseSummary is correct when a // peer is ForceClosing the channel. Will check outputs both above and below // the dust limit. Additionally, we'll ensure that the node which executed the // force close generates HTLC resolutions that are capable of sweeping both // incoming and outgoing HTLC's. func TestForceClose(t *testing.T) { t.Run("tweakless", func(t *testing.T) { testForceClose(t, &forceCloseTestCase{ chanType: channeldb.SingleFunderTweaklessBit, expectedCommitWeight: input.CommitWeight, }) }) t.Run("anchors", func(t *testing.T) { testForceClose(t, &forceCloseTestCase{ chanType: channeldb.SingleFunderTweaklessBit | channeldb.AnchorOutputsBit, expectedCommitWeight: input.AnchorCommitWeight, anchorAmt: anchorSize * 2, }) }) } type forceCloseTestCase struct { chanType channeldb.ChannelType expectedCommitWeight int64 anchorAmt btcutil.Amount } func testForceClose(t *testing.T, testCase *forceCloseTestCase) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( testCase.chanType, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() bobAmount := bobChannel.channelState.LocalCommitment.LocalBalance // First, we'll add an outgoing HTLC from Alice to Bob, such that it // will still be present within the broadcast commitment transaction. // We'll ensure that the HTLC amount is above Alice's dust limit. htlcAmount := lnwire.NewMSatFromSatoshis(20000) htlcAlice, _ := createHTLC(0, htlcAmount) if _, err := aliceChannel.AddHTLC(htlcAlice, nil); err != nil { t.Fatalf("alice unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlcAlice); err != nil { t.Fatalf("bob unable to recv add htlc: %v", err) } // We'll also a distinct HTLC from Bob -> Alice. This way, Alice will // have both an incoming and outgoing HTLC on her commitment // transaction. htlcBob, preimageBob := createHTLC(0, htlcAmount) if _, err := bobChannel.AddHTLC(htlcBob, nil); err != nil { t.Fatalf("alice unable to add htlc: %v", err) } if _, err := aliceChannel.ReceiveHTLC(htlcBob); err != nil { t.Fatalf("bob unable to recv add htlc: %v", err) } // Next, we'll perform two state transitions to ensure that both HTLC's // get fully locked-in. if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("Can't update the channel state: %v", err) } if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("Can't update the channel state: %v", err) } // With the cache populated, we'll now attempt the force close // initiated by Alice. closeSummary, err := aliceChannel.ForceClose() if err != nil { t.Fatalf("unable to force close channel: %v", err) } // Alice should detect that she can sweep the outgoing HTLC after a // timeout, but also that she's able to sweep in incoming HTLC Bob sent // her. if len(closeSummary.HtlcResolutions.OutgoingHTLCs) != 1 { t.Fatalf("alice out htlc resolutions not populated: expected %v "+ "htlcs, got %v htlcs", 1, len(closeSummary.HtlcResolutions.OutgoingHTLCs)) } if len(closeSummary.HtlcResolutions.IncomingHTLCs) != 1 { t.Fatalf("alice in htlc resolutions not populated: expected %v "+ "htlcs, got %v htlcs", 1, len(closeSummary.HtlcResolutions.IncomingHTLCs)) } // Verify the anchor resolutions for the anchor commitment format. if testCase.chanType.HasAnchors() { // Check the close summary resolution. anchorRes := closeSummary.AnchorResolution if anchorRes == nil { t.Fatal("expected anchor resolution") } if anchorRes.CommitAnchor.Hash != closeSummary.CloseTx.TxHash() { t.Fatal("commit tx not referenced by anchor res") } if anchorRes.AnchorSignDescriptor.Output.Value != int64(anchorSize) { t.Fatal("unexpected anchor size") } if anchorRes.AnchorSignDescriptor.WitnessScript == nil { t.Fatal("expected anchor witness script") } // Check the pre-confirmation resolutions. resList, err := aliceChannel.NewAnchorResolutions() if err != nil { t.Fatalf("pre-confirmation resolution error: %v", err) } if len(resList) != 2 { t.Fatal("expected two resolutions") } } // The SelfOutputSignDesc should be non-nil since the output to-self is // non-dust. aliceCommitResolution := closeSummary.CommitResolution if aliceCommitResolution == nil { t.Fatalf("alice fails to include to-self output in " + "ForceCloseSummary") } // The rest of the close summary should have been populated properly. aliceDelayPoint := aliceChannel.channelState.LocalChanCfg.DelayBasePoint if !aliceCommitResolution.SelfOutputSignDesc.KeyDesc.PubKey.IsEqual( aliceDelayPoint.PubKey, ) { t.Fatalf("alice incorrect pubkey in SelfOutputSignDesc") } // Factoring in the fee rate, Alice's amount should properly reflect // that we've added two additional HTLC to the commitment transaction. totalCommitWeight := testCase.expectedCommitWeight + (input.HTLCWeight * 2) feePerKw := chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) commitFee := feePerKw.FeeForWeight(totalCommitWeight) expectedAmount := (aliceChannel.Capacity / 2) - htlcAmount.ToSatoshis() - commitFee - testCase.anchorAmt if aliceCommitResolution.SelfOutputSignDesc.Output.Value != int64(expectedAmount) { t.Fatalf("alice incorrect output value in SelfOutputSignDesc, "+ "expected %v, got %v", int64(expectedAmount), aliceCommitResolution.SelfOutputSignDesc.Output.Value) } // Alice's listed CSV delay should also match the delay that was // pre-committed to at channel opening. if aliceCommitResolution.MaturityDelay != uint32(aliceChannel.channelState.LocalChanCfg.CsvDelay) { t.Fatalf("alice: incorrect local CSV delay in ForceCloseSummary, "+ "expected %v, got %v", aliceChannel.channelState.LocalChanCfg.CsvDelay, aliceCommitResolution.MaturityDelay) } // Next, we'll ensure that the second level HTLC transaction it itself // spendable, and also that the delivery output (with delay) itself has // a valid sign descriptor. htlcResolution := closeSummary.HtlcResolutions.OutgoingHTLCs[0] outHtlcIndex := htlcResolution.SignedTimeoutTx.TxIn[0].PreviousOutPoint.Index senderHtlcPkScript := closeSummary.CloseTx.TxOut[outHtlcIndex].PkScript // First, verify that the second level transaction can properly spend // the multi-sig clause within the output on the commitment transaction // that produces this HTLC. timeoutTx := htlcResolution.SignedTimeoutTx vm, err := txscript.NewEngine(senderHtlcPkScript, timeoutTx, 0, txscript.StandardVerifyFlags, nil, nil, int64(htlcAmount.ToSatoshis())) if err != nil { t.Fatalf("unable to create engine: %v", err) } if err := vm.Execute(); err != nil { t.Fatalf("htlc timeout spend is invalid: %v", err) } // Next, we'll ensure that we can spend the output of the second level // transaction given a properly crafted sweep transaction. sweepTx := wire.NewMsgTx(2) sweepTx.AddTxIn(&wire.TxIn{ PreviousOutPoint: wire.OutPoint{ Hash: htlcResolution.SignedTimeoutTx.TxHash(), Index: 0, }, }) sweepTx.AddTxOut(&wire.TxOut{ PkScript: senderHtlcPkScript, Value: htlcResolution.SweepSignDesc.Output.Value, }) htlcResolution.SweepSignDesc.InputIndex = 0 sweepTx.TxIn[0].Witness, err = input.HtlcSpendSuccess(aliceChannel.Signer, &htlcResolution.SweepSignDesc, sweepTx, uint32(aliceChannel.channelState.LocalChanCfg.CsvDelay)) if err != nil { t.Fatalf("unable to gen witness for timeout output: %v", err) } // With the witness fully populated for the success spend from the // second-level transaction, we ensure that the scripts properly // validate given the information within the htlc resolution struct. vm, err = txscript.NewEngine( htlcResolution.SweepSignDesc.Output.PkScript, sweepTx, 0, txscript.StandardVerifyFlags, nil, nil, htlcResolution.SweepSignDesc.Output.Value, ) if err != nil { t.Fatalf("unable to create engine: %v", err) } if err := vm.Execute(); err != nil { t.Fatalf("htlc timeout spend is invalid: %v", err) } // Finally, the txid of the commitment transaction and the one returned // as the closing transaction should also match. closeTxHash := closeSummary.CloseTx.TxHash() commitTxHash := aliceChannel.channelState.LocalCommitment.CommitTx.TxHash() if !bytes.Equal(closeTxHash[:], commitTxHash[:]) { t.Fatalf("alice: incorrect close transaction txid") } // We'll now perform similar set of checks to ensure that Alice is able // to sweep the output that Bob sent to her on-chain with knowledge of // the preimage. inHtlcResolution := closeSummary.HtlcResolutions.IncomingHTLCs[0] inHtlcIndex := inHtlcResolution.SignedSuccessTx.TxIn[0].PreviousOutPoint.Index receiverHtlcScript := closeSummary.CloseTx.TxOut[inHtlcIndex].PkScript // With the original pkscript located, we'll now verify that the second // level transaction can spend from the multi-sig out. Supply the // preimage manually. This is usually done by the contract resolver // before publication. successTx := inHtlcResolution.SignedSuccessTx successTx.TxIn[0].Witness[3] = preimageBob[:] vm, err = txscript.NewEngine(receiverHtlcScript, successTx, 0, txscript.StandardVerifyFlags, nil, nil, int64(htlcAmount.ToSatoshis())) if err != nil { t.Fatalf("unable to create engine: %v", err) } if err := vm.Execute(); err != nil { t.Fatalf("htlc success spend is invalid: %v", err) } // Finally, we'll construct a transaction to spend the produced // second-level output with the attached SignDescriptor. sweepTx = wire.NewMsgTx(2) sweepTx.AddTxIn(&wire.TxIn{ PreviousOutPoint: inHtlcResolution.ClaimOutpoint, }) sweepTx.AddTxOut(&wire.TxOut{ PkScript: receiverHtlcScript, Value: inHtlcResolution.SweepSignDesc.Output.Value, }) inHtlcResolution.SweepSignDesc.InputIndex = 0 sweepTx.TxIn[0].Witness, err = input.HtlcSpendSuccess(aliceChannel.Signer, &inHtlcResolution.SweepSignDesc, sweepTx, uint32(aliceChannel.channelState.LocalChanCfg.CsvDelay)) if err != nil { t.Fatalf("unable to gen witness for timeout output: %v", err) } // The spend we create above spending the second level HTLC output // should validate without any issues. vm, err = txscript.NewEngine( inHtlcResolution.SweepSignDesc.Output.PkScript, sweepTx, 0, txscript.StandardVerifyFlags, nil, nil, inHtlcResolution.SweepSignDesc.Output.Value, ) if err != nil { t.Fatalf("unable to create engine: %v", err) } if err := vm.Execute(); err != nil { t.Fatalf("htlc timeout spend is invalid: %v", err) } // Check the same for Bob's ForceCloseSummary. closeSummary, err = bobChannel.ForceClose() if err != nil { t.Fatalf("unable to force close channel: %v", err) } bobCommitResolution := closeSummary.CommitResolution if bobCommitResolution == nil { t.Fatalf("bob fails to include to-self output in ForceCloseSummary") } bobDelayPoint := bobChannel.channelState.LocalChanCfg.DelayBasePoint if !bobCommitResolution.SelfOutputSignDesc.KeyDesc.PubKey.IsEqual(bobDelayPoint.PubKey) { t.Fatalf("bob incorrect pubkey in SelfOutputSignDesc") } if bobCommitResolution.SelfOutputSignDesc.Output.Value != int64(bobAmount.ToSatoshis()-htlcAmount.ToSatoshis()) { t.Fatalf("bob incorrect output value in SelfOutputSignDesc, "+ "expected %v, got %v", bobAmount.ToSatoshis(), int64(bobCommitResolution.SelfOutputSignDesc.Output.Value)) } if bobCommitResolution.MaturityDelay != uint32(bobChannel.channelState.LocalChanCfg.CsvDelay) { t.Fatalf("bob: incorrect local CSV delay in ForceCloseSummary, "+ "expected %v, got %v", bobChannel.channelState.LocalChanCfg.CsvDelay, bobCommitResolution.MaturityDelay) } closeTxHash = closeSummary.CloseTx.TxHash() commitTxHash = bobChannel.channelState.LocalCommitment.CommitTx.TxHash() if !bytes.Equal(closeTxHash[:], commitTxHash[:]) { t.Fatalf("bob: incorrect close transaction txid") } // As we didn't add the preimage of Alice's HTLC to bob's preimage // cache, he should only detect that he can sweep only his outgoing // HTLC upon force close. if len(closeSummary.HtlcResolutions.OutgoingHTLCs) != 1 { t.Fatalf("alice out htlc resolutions not populated: expected %v "+ "htlcs, got %v htlcs", 1, len(closeSummary.HtlcResolutions.OutgoingHTLCs)) } // Bob should recognize that the incoming HTLC is there, but the // preimage should be empty as he doesn't have the knowledge required // to sweep it. if len(closeSummary.HtlcResolutions.IncomingHTLCs) != 1 { t.Fatalf("bob in htlc resolutions not populated: expected %v "+ "htlcs, got %v htlcs", 1, len(closeSummary.HtlcResolutions.IncomingHTLCs)) } } // TestForceCloseDustOutput tests that if either side force closes with an // active dust output (for only a single party due to asymmetric dust values), // then the force close summary is well crafted. func TestForceCloseDustOutput(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // We set both node's channel reserves to 0, to make sure // they can create small dust ouputs without going under // their channel reserves. aliceChannel.channelState.LocalChanCfg.ChanReserve = 0 bobChannel.channelState.LocalChanCfg.ChanReserve = 0 aliceChannel.channelState.RemoteChanCfg.ChanReserve = 0 bobChannel.channelState.RemoteChanCfg.ChanReserve = 0 htlcAmount := lnwire.NewMSatFromSatoshis(500) aliceAmount := aliceChannel.channelState.LocalCommitment.LocalBalance bobAmount := bobChannel.channelState.LocalCommitment.LocalBalance // Have Bobs' to-self output be below her dust limit and check // ForceCloseSummary again on both peers. htlc, preimage := createHTLC(0, bobAmount-htlcAmount) bobHtlcIndex, err := bobChannel.AddHTLC(htlc, nil) if err != nil { t.Fatalf("alice unable to add htlc: %v", err) } aliceHtlcIndex, err := aliceChannel.ReceiveHTLC(htlc) if err != nil { t.Fatalf("bob unable to receive htlc: %v", err) } if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("Can't update the channel state: %v", err) } // Settle HTLC and sign new commitment. err = aliceChannel.SettleHTLC(preimage, aliceHtlcIndex, nil, nil, nil) if err != nil { t.Fatalf("bob unable to settle inbound htlc: %v", err) } err = bobChannel.ReceiveHTLCSettle(preimage, bobHtlcIndex) if err != nil { t.Fatalf("alice unable to accept settle of outbound htlc: %v", err) } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("Can't update the channel state: %v", err) } aliceAmount = aliceChannel.channelState.LocalCommitment.LocalBalance bobAmount = bobChannel.channelState.LocalCommitment.RemoteBalance closeSummary, err := aliceChannel.ForceClose() if err != nil { t.Fatalf("unable to force close channel: %v", err) } // Alice's to-self output should still be in the commitment // transaction. commitResolution := closeSummary.CommitResolution if commitResolution == nil { t.Fatalf("alice fails to include to-self output in " + "ForceCloseSummary") } if !commitResolution.SelfOutputSignDesc.KeyDesc.PubKey.IsEqual( aliceChannel.channelState.LocalChanCfg.DelayBasePoint.PubKey, ) { t.Fatalf("alice incorrect pubkey in SelfOutputSignDesc") } if commitResolution.SelfOutputSignDesc.Output.Value != int64(aliceAmount.ToSatoshis()) { t.Fatalf("alice incorrect output value in SelfOutputSignDesc, "+ "expected %v, got %v", aliceChannel.channelState.LocalCommitment.LocalBalance.ToSatoshis(), commitResolution.SelfOutputSignDesc.Output.Value) } if commitResolution.MaturityDelay != uint32(aliceChannel.channelState.LocalChanCfg.CsvDelay) { t.Fatalf("alice: incorrect local CSV delay in ForceCloseSummary, "+ "expected %v, got %v", aliceChannel.channelState.LocalChanCfg.CsvDelay, commitResolution.MaturityDelay) } closeTxHash := closeSummary.CloseTx.TxHash() commitTxHash := aliceChannel.channelState.LocalCommitment.CommitTx.TxHash() if !bytes.Equal(closeTxHash[:], commitTxHash[:]) { t.Fatalf("alice: incorrect close transaction txid") } closeSummary, err = bobChannel.ForceClose() if err != nil { t.Fatalf("unable to force close channel: %v", err) } // Bob's to-self output is below Bob's dust value and should be // reflected in the ForceCloseSummary. commitResolution = closeSummary.CommitResolution if commitResolution != nil { t.Fatalf("bob incorrectly includes to-self output in " + "ForceCloseSummary") } closeTxHash = closeSummary.CloseTx.TxHash() commitTxHash = bobChannel.channelState.LocalCommitment.CommitTx.TxHash() if !bytes.Equal(closeTxHash[:], commitTxHash[:]) { t.Fatalf("bob: incorrect close transaction txid") } } // TestDustHTLCFees checks that fees are calculated correctly when HTLCs fall // below the nodes' dust limit. In these cases, the amount of the dust HTLCs // should be applied to the commitment transaction fee. func TestDustHTLCFees(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() aliceStartingBalance := aliceChannel.channelState.LocalCommitment.LocalBalance // This HTLC amount should be lower than the dust limits of both nodes. htlcAmount := lnwire.NewMSatFromSatoshis(100) htlc, _ := createHTLC(0, htlcAmount) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("alice unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("bob unable to receive htlc: %v", err) } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("Can't update the channel state: %v", err) } // After the transition, we'll ensure that we performed fee accounting // properly. Namely, the local+remote+commitfee values should add up to // the total capacity of the channel. This same should hold for both // sides. totalSatoshisAlice := (aliceChannel.channelState.LocalCommitment.LocalBalance + aliceChannel.channelState.LocalCommitment.RemoteBalance + lnwire.NewMSatFromSatoshis(aliceChannel.channelState.LocalCommitment.CommitFee)) if totalSatoshisAlice+htlcAmount != lnwire.NewMSatFromSatoshis(aliceChannel.Capacity) { t.Fatalf("alice's funds leaked: total satoshis are %v, but channel "+ "capacity is %v", int64(totalSatoshisAlice), int64(aliceChannel.Capacity)) } totalSatoshisBob := (bobChannel.channelState.LocalCommitment.LocalBalance + bobChannel.channelState.LocalCommitment.RemoteBalance + lnwire.NewMSatFromSatoshis(bobChannel.channelState.LocalCommitment.CommitFee)) if totalSatoshisBob+htlcAmount != lnwire.NewMSatFromSatoshis(bobChannel.Capacity) { t.Fatalf("bob's funds leaked: total satoshis are %v, but channel "+ "capacity is %v", int64(totalSatoshisBob), int64(bobChannel.Capacity)) } // The commitment fee paid should be the same, as there have been no // new material outputs added. defaultFee := calcStaticFee(channeldb.SingleFunderTweaklessBit, 0) if aliceChannel.channelState.LocalCommitment.CommitFee != defaultFee { t.Fatalf("dust htlc amounts not subtracted from commitment fee "+ "expected %v, got %v", defaultFee, aliceChannel.channelState.LocalCommitment.CommitFee) } if bobChannel.channelState.LocalCommitment.CommitFee != defaultFee { t.Fatalf("dust htlc amounts not subtracted from commitment fee "+ "expected %v, got %v", defaultFee, bobChannel.channelState.LocalCommitment.CommitFee) } // Alice's final balance should reflect the HTLC deficit even though // the HTLC was paid to fees as it was trimmed. aliceEndBalance := aliceChannel.channelState.LocalCommitment.LocalBalance aliceExpectedBalance := aliceStartingBalance - htlcAmount if aliceEndBalance != aliceExpectedBalance { t.Fatalf("alice not credited for dust: expected %v, got %v", aliceExpectedBalance, aliceEndBalance) } } // TestHTLCDustLimit checks the situation in which an HTLC is larger than one // channel participant's dust limit, but smaller than the other participant's // dust limit. In this case, the participants' commitment chains will diverge. // In one commitment chain, the HTLC will be added as normal, in the other // chain, the amount of the HTLC will contribute to the fees to be paid. func TestHTLCDustLimit(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // The amount of the HTLC should be above Alice's dust limit and below // Bob's dust limit. htlcSat := (btcutil.Amount(500) + HtlcTimeoutFee( aliceChannel.channelState.ChanType, chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ), )) htlcAmount := lnwire.NewMSatFromSatoshis(htlcSat) htlc, preimage := createHTLC(0, htlcAmount) aliceHtlcIndex, err := aliceChannel.AddHTLC(htlc, nil) if err != nil { t.Fatalf("alice unable to add htlc: %v", err) } bobHtlcIndex, err := bobChannel.ReceiveHTLC(htlc) if err != nil { t.Fatalf("bob unable to receive htlc: %v", err) } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("Can't update the channel state: %v", err) } // At this point, Alice's commitment transaction should have an HTLC, // while Bob's should not, because the value falls beneath his dust // limit. The amount of the HTLC should be applied to fees in Bob's // commitment transaction. aliceCommitment := aliceChannel.localCommitChain.tip() if len(aliceCommitment.txn.TxOut) != 3 { t.Fatalf("incorrect # of outputs: expected %v, got %v", 3, len(aliceCommitment.txn.TxOut)) } bobCommitment := bobChannel.localCommitChain.tip() if len(bobCommitment.txn.TxOut) != 2 { t.Fatalf("incorrect # of outputs: expected %v, got %v", 2, len(bobCommitment.txn.TxOut)) } defaultFee := calcStaticFee(channeldb.SingleFunderTweaklessBit, 0) if bobChannel.channelState.LocalCommitment.CommitFee != defaultFee { t.Fatalf("dust htlc amount was subtracted from commitment fee "+ "expected %v, got %v", defaultFee, bobChannel.channelState.LocalCommitment.CommitFee) } // Settle HTLC and create a new commitment state. err = bobChannel.SettleHTLC(preimage, bobHtlcIndex, nil, nil, nil) if err != nil { t.Fatalf("bob unable to settle inbound htlc: %v", err) } err = aliceChannel.ReceiveHTLCSettle(preimage, aliceHtlcIndex) if err != nil { t.Fatalf("alice unable to accept settle of outbound htlc: %v", err) } if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("state transition error: %v", err) } // At this point, for Alice's commitment chains, the value of the HTLC // should have been added to Alice's balance and TotalSatoshisSent. commitment := aliceChannel.localCommitChain.tip() if len(commitment.txn.TxOut) != 2 { t.Fatalf("incorrect # of outputs: expected %v, got %v", 2, len(commitment.txn.TxOut)) } if aliceChannel.channelState.TotalMSatSent != htlcAmount { t.Fatalf("alice satoshis sent incorrect: expected %v, got %v", htlcAmount, aliceChannel.channelState.TotalMSatSent) } } // TestHTLCSigNumber tests that a received commitment is only accepted if it // comes with the exact number of valid HTLC signatures. func TestHTLCSigNumber(t *testing.T) { t.Parallel() // createChanWithHTLC is a helper method that sets ut two channels, and // adds HTLCs with the passed values to the channels. createChanWithHTLC := func(htlcValues ...btcutil.Amount) ( *LightningChannel, *LightningChannel, func()) { // Create a test channel funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. Alice's dustlimit is 200 sat, while // Bob has 1300 sat. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } for i, htlcSat := range htlcValues { htlcMsat := lnwire.NewMSatFromSatoshis(htlcSat) htlc, _ := createHTLC(i, htlcMsat) _, err := aliceChannel.AddHTLC(htlc, nil) if err != nil { t.Fatalf("alice unable to add htlc: %v", err) } _, err = bobChannel.ReceiveHTLC(htlc) if err != nil { t.Fatalf("bob unable to receive htlc: %v", err) } } return aliceChannel, bobChannel, cleanUp } // Calculate two values that will be below and above Bob's dust limit. estimator := chainfee.NewStaticEstimator(6000, 0) feePerKw, err := estimator.EstimateFeePerKW(1) if err != nil { t.Fatalf("unable to get fee: %v", err) } belowDust := btcutil.Amount(500) + HtlcTimeoutFee( channeldb.SingleFunderTweaklessBit, feePerKw, ) aboveDust := btcutil.Amount(1400) + HtlcSuccessFee( channeldb.SingleFunderTweaklessBit, feePerKw, ) // =================================================================== // Test that Bob will reject a commitment if Alice doesn't send enough // HTLC signatures. // =================================================================== aliceChannel, bobChannel, cleanUp := createChanWithHTLC(aboveDust, aboveDust) defer cleanUp() aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("Error signing next commitment: %v", err) } if len(aliceHtlcSigs) != 2 { t.Fatalf("expected 2 htlc sig, instead got %v", len(aliceHtlcSigs)) } // Now discard one signature from the htlcSig slice. Bob should reject // the commitment because of this. err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs[1:]) if err == nil { t.Fatalf("Expected Bob to reject signatures") } // =================================================================== // Test that Bob will reject a commitment if Alice doesn't send any // HTLC signatures. // =================================================================== aliceChannel, bobChannel, cleanUp = createChanWithHTLC(aboveDust) defer cleanUp() aliceSig, aliceHtlcSigs, _, err = aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("Error signing next commitment: %v", err) } if len(aliceHtlcSigs) != 1 { t.Fatalf("expected 1 htlc sig, instead got %v", len(aliceHtlcSigs)) } // Now just give Bob an empty htlcSig slice. He should reject the // commitment because of this. err = bobChannel.ReceiveNewCommitment(aliceSig, []lnwire.Sig{}) if err == nil { t.Fatalf("Expected Bob to reject signatures") } // ============================================================== // Test that sigs are not returned for HTLCs below dust limit. // ============================================================== aliceChannel, bobChannel, cleanUp = createChanWithHTLC(belowDust) defer cleanUp() aliceSig, aliceHtlcSigs, _, err = aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("Error signing next commitment: %v", err) } // Since the HTLC is below Bob's dust limit, Alice won't need to send // any signatures for this HTLC. if len(aliceHtlcSigs) != 0 { t.Fatalf("expected no htlc sigs, instead got %v", len(aliceHtlcSigs)) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("Bob failed receiving commitment: %v", err) } // ================================================================ // Test that sigs are correctly returned for HTLCs above dust limit. // ================================================================ aliceChannel, bobChannel, cleanUp = createChanWithHTLC(aboveDust) defer cleanUp() aliceSig, aliceHtlcSigs, _, err = aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("Error signing next commitment: %v", err) } // Since the HTLC is above Bob's dust limit, Alice should send a // signature for this HTLC. if len(aliceHtlcSigs) != 1 { t.Fatalf("expected 1 htlc sig, instead got %v", len(aliceHtlcSigs)) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("Bob failed receiving commitment: %v", err) } // ==================================================================== // Test that Bob will not validate a received commitment if Alice sends // signatures for HTLCs below the dust limit. // ==================================================================== aliceChannel, bobChannel, cleanUp = createChanWithHTLC(belowDust, aboveDust) defer cleanUp() // Alice should produce only one signature, since one HTLC is below // dust. aliceSig, aliceHtlcSigs, _, err = aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("Error signing next commitment: %v", err) } if len(aliceHtlcSigs) != 1 { t.Fatalf("expected 1 htlc sig, instead got %v", len(aliceHtlcSigs)) } // Add an extra signature. aliceHtlcSigs = append(aliceHtlcSigs, aliceHtlcSigs[0]) // Bob should reject these signatures since they don't match the number // of HTLCs above dust. err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err == nil { t.Fatalf("Expected Bob to reject signatures") } } // TestChannelBalanceDustLimit tests the condition when the remaining balance // for one of the channel participants is so small as to be considered dust. In // this case, the output for that participant is removed and all funds (minus // fees) in the commitment transaction are allocated to the remaining channel // participant. // // TODO(roasbeef): test needs to be fixed after reserve limits are done func TestChannelBalanceDustLimit(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // To allow Alice's balance to get beneath her dust limit, set the // channel reserve to be 0. aliceChannel.channelState.LocalChanCfg.ChanReserve = 0 bobChannel.channelState.RemoteChanCfg.ChanReserve = 0 // This amount should leave an amount larger than Alice's dust limit // once fees have been subtracted, but smaller than Bob's dust limit. // We account in fees for the HTLC we will be adding. defaultFee := calcStaticFee(channeldb.SingleFunderTweaklessBit, 1) aliceBalance := aliceChannel.channelState.LocalCommitment.LocalBalance.ToSatoshis() htlcSat := aliceBalance - defaultFee htlcSat += HtlcSuccessFee( aliceChannel.channelState.ChanType, chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ), ) htlcAmount := lnwire.NewMSatFromSatoshis(htlcSat) htlc, preimage := createHTLC(0, htlcAmount) aliceHtlcIndex, err := aliceChannel.AddHTLC(htlc, nil) if err != nil { t.Fatalf("alice unable to add htlc: %v", err) } bobHtlcIndex, err := bobChannel.ReceiveHTLC(htlc) if err != nil { t.Fatalf("bob unable to receive htlc: %v", err) } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("state transition error: %v", err) } err = bobChannel.SettleHTLC(preimage, bobHtlcIndex, nil, nil, nil) if err != nil { t.Fatalf("bob unable to settle inbound htlc: %v", err) } err = aliceChannel.ReceiveHTLCSettle(preimage, aliceHtlcIndex) if err != nil { t.Fatalf("alice unable to accept settle of outbound htlc: %v", err) } if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("state transition error: %v", err) } // At the conclusion of this test, in Bob's commitment chains, the // output for Alice's balance should have been removed as dust, leaving // only a single output that will send the remaining funds in the // channel to Bob. commitment := bobChannel.localCommitChain.tip() if len(commitment.txn.TxOut) != 1 { t.Fatalf("incorrect # of outputs: expected %v, got %v", 1, len(commitment.txn.TxOut)) } if aliceChannel.channelState.TotalMSatSent != htlcAmount { t.Fatalf("alice satoshis sent incorrect: expected %v, got %v", htlcAmount, aliceChannel.channelState.TotalMSatSent) } } func TestStateUpdatePersistence(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() htlcAmt := lnwire.NewMSatFromSatoshis(5000) var fakeOnionBlob [lnwire.OnionPacketSize]byte copy(fakeOnionBlob[:], bytes.Repeat([]byte{0x05}, lnwire.OnionPacketSize)) // Alice adds 3 HTLCs to the update log, while Bob adds a single HTLC. var alicePreimage [32]byte copy(alicePreimage[:], bytes.Repeat([]byte{0xaa}, 32)) var bobPreimage [32]byte copy(bobPreimage[:], bytes.Repeat([]byte{0xbb}, 32)) for i := 0; i < 3; i++ { rHash := sha256.Sum256(alicePreimage[:]) h := &lnwire.UpdateAddHTLC{ ID: uint64(i), PaymentHash: rHash, Amount: htlcAmt, Expiry: uint32(10), OnionBlob: fakeOnionBlob, } if _, err := aliceChannel.AddHTLC(h, nil); err != nil { t.Fatalf("unable to add alice's htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(h); err != nil { t.Fatalf("unable to recv alice's htlc: %v", err) } } rHash := sha256.Sum256(bobPreimage[:]) bobh := &lnwire.UpdateAddHTLC{ PaymentHash: rHash, Amount: htlcAmt, Expiry: uint32(10), OnionBlob: fakeOnionBlob, } if _, err := bobChannel.AddHTLC(bobh, nil); err != nil { t.Fatalf("unable to add bob's htlc: %v", err) } if _, err := aliceChannel.ReceiveHTLC(bobh); err != nil { t.Fatalf("unable to recv bob's htlc: %v", err) } // Also add a fee update to the update logs. fee := chainfee.SatPerKWeight(333) if err := aliceChannel.UpdateFee(fee); err != nil { t.Fatalf("unable to send fee update") } if err := bobChannel.ReceiveUpdateFee(fee); err != nil { t.Fatalf("unable to receive fee update") } // Helper method that asserts the expected number of updates are found // in the update logs. assertNumLogUpdates := func(numAliceUpdates, numBobUpdates int) { if aliceChannel.localUpdateLog.Len() != numAliceUpdates { t.Fatalf("expected %d local updates, found %d", numAliceUpdates, aliceChannel.localUpdateLog.Len()) } if aliceChannel.remoteUpdateLog.Len() != numBobUpdates { t.Fatalf("expected %d remote updates, found %d", numBobUpdates, aliceChannel.remoteUpdateLog.Len()) } if bobChannel.localUpdateLog.Len() != numBobUpdates { t.Fatalf("expected %d local updates, found %d", numBobUpdates, bobChannel.localUpdateLog.Len()) } if bobChannel.remoteUpdateLog.Len() != numAliceUpdates { t.Fatalf("expected %d remote updates, found %d", numAliceUpdates, bobChannel.remoteUpdateLog.Len()) } } // Both nodes should now have Alice's 3 Adds and 1 FeeUpdate in the // log, and Bob's 1 Add. assertNumLogUpdates(4, 1) // Next, Alice initiates a state transition to include the HTLC's she // added above in a new commitment state. if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete alice's state transition: %v", err) } // Since the HTLC Bob sent wasn't included in Bob's version of the // commitment transaction (but it was in Alice's, as he ACK'd her // changes before creating a new state), Bob needs to trigger another // state update in order to re-sync their states. if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("unable to complete bob's state transition: %v", err) } // After the state transition the fee update is fully locked in, and // should've been removed from both channels' update logs. if aliceChannel.localCommitChain.tail().feePerKw != fee { t.Fatalf("fee not locked in") } if bobChannel.localCommitChain.tail().feePerKw != fee { t.Fatalf("fee not locked in") } assertNumLogUpdates(3, 1) // The latest commitment from both sides should have all the HTLCs. numAliceOutgoing := aliceChannel.localCommitChain.tail().outgoingHTLCs numAliceIncoming := aliceChannel.localCommitChain.tail().incomingHTLCs if len(numAliceOutgoing) != 3 { t.Fatalf("expected %v htlcs, instead got %v", 3, numAliceOutgoing) } if len(numAliceIncoming) != 1 { t.Fatalf("expected %v htlcs, instead got %v", 1, numAliceIncoming) } numBobOutgoing := bobChannel.localCommitChain.tail().outgoingHTLCs numBobIncoming := bobChannel.localCommitChain.tail().incomingHTLCs if len(numBobOutgoing) != 1 { t.Fatalf("expected %v htlcs, instead got %v", 1, numBobOutgoing) } if len(numBobIncoming) != 3 { t.Fatalf("expected %v htlcs, instead got %v", 3, numBobIncoming) } // TODO(roasbeef): also ensure signatures were stored // * ensure expiry matches // Now fetch both of the channels created above from disk to simulate a // node restart with persistence. alicePub := aliceChannel.channelState.IdentityPub aliceChannels, err := aliceChannel.channelState.Db.FetchOpenChannels( alicePub, ) if err != nil { t.Fatalf("unable to fetch channel: %v", err) } bobPub := bobChannel.channelState.IdentityPub bobChannels, err := bobChannel.channelState.Db.FetchOpenChannels(bobPub) if err != nil { t.Fatalf("unable to fetch channel: %v", err) } aliceChannelNew, err := NewLightningChannel( aliceChannel.Signer, aliceChannels[0], aliceChannel.sigPool, ) if err != nil { t.Fatalf("unable to create new channel: %v", err) } bobChannelNew, err := NewLightningChannel( bobChannel.Signer, bobChannels[0], bobChannel.sigPool, ) if err != nil { t.Fatalf("unable to create new channel: %v", err) } // The state update logs of the new channels and the old channels // should now be identical other than the height the HTLCs were added. if aliceChannel.localUpdateLog.logIndex != aliceChannelNew.localUpdateLog.logIndex { t.Fatalf("alice log counter: expected %v, got %v", aliceChannel.localUpdateLog.logIndex, aliceChannelNew.localUpdateLog.logIndex) } if aliceChannel.remoteUpdateLog.logIndex != aliceChannelNew.remoteUpdateLog.logIndex { t.Fatalf("alice log counter: expected %v, got %v", aliceChannel.remoteUpdateLog.logIndex, aliceChannelNew.remoteUpdateLog.logIndex) } if aliceChannel.localUpdateLog.Len() != aliceChannelNew.localUpdateLog.Len() { t.Fatalf("alice log len: expected %v, got %v", aliceChannel.localUpdateLog.Len(), aliceChannelNew.localUpdateLog.Len()) } if aliceChannel.remoteUpdateLog.Len() != aliceChannelNew.remoteUpdateLog.Len() { t.Fatalf("alice log len: expected %v, got %v", aliceChannel.remoteUpdateLog.Len(), aliceChannelNew.remoteUpdateLog.Len()) } if bobChannel.localUpdateLog.logIndex != bobChannelNew.localUpdateLog.logIndex { t.Fatalf("bob log counter: expected %v, got %v", bobChannel.localUpdateLog.logIndex, bobChannelNew.localUpdateLog.logIndex) } if bobChannel.remoteUpdateLog.logIndex != bobChannelNew.remoteUpdateLog.logIndex { t.Fatalf("bob log counter: expected %v, got %v", bobChannel.remoteUpdateLog.logIndex, bobChannelNew.remoteUpdateLog.logIndex) } if bobChannel.localUpdateLog.Len() != bobChannelNew.localUpdateLog.Len() { t.Fatalf("bob log len: expected %v, got %v", bobChannel.localUpdateLog.Len(), bobChannelNew.localUpdateLog.Len()) } if bobChannel.remoteUpdateLog.Len() != bobChannelNew.remoteUpdateLog.Len() { t.Fatalf("bob log len: expected %v, got %v", bobChannel.remoteUpdateLog.Len(), bobChannelNew.remoteUpdateLog.Len()) } // TODO(roasbeef): expand test to also ensure state revocation log has // proper pk scripts // Newly generated pkScripts for HTLCs should be the same as in the old channel. for _, entry := range aliceChannel.localUpdateLog.htlcIndex { htlc := entry.Value.(*PaymentDescriptor) restoredHtlc := aliceChannelNew.localUpdateLog.lookupHtlc(htlc.HtlcIndex) if !bytes.Equal(htlc.ourPkScript, restoredHtlc.ourPkScript) { t.Fatalf("alice ourPkScript in ourLog: expected %X, got %X", htlc.ourPkScript[:5], restoredHtlc.ourPkScript[:5]) } if !bytes.Equal(htlc.theirPkScript, restoredHtlc.theirPkScript) { t.Fatalf("alice theirPkScript in ourLog: expected %X, got %X", htlc.theirPkScript[:5], restoredHtlc.theirPkScript[:5]) } } for _, entry := range aliceChannel.remoteUpdateLog.htlcIndex { htlc := entry.Value.(*PaymentDescriptor) restoredHtlc := aliceChannelNew.remoteUpdateLog.lookupHtlc(htlc.HtlcIndex) if !bytes.Equal(htlc.ourPkScript, restoredHtlc.ourPkScript) { t.Fatalf("alice ourPkScript in theirLog: expected %X, got %X", htlc.ourPkScript[:5], restoredHtlc.ourPkScript[:5]) } if !bytes.Equal(htlc.theirPkScript, restoredHtlc.theirPkScript) { t.Fatalf("alice theirPkScript in theirLog: expected %X, got %X", htlc.theirPkScript[:5], restoredHtlc.theirPkScript[:5]) } } for _, entry := range bobChannel.localUpdateLog.htlcIndex { htlc := entry.Value.(*PaymentDescriptor) restoredHtlc := bobChannelNew.localUpdateLog.lookupHtlc(htlc.HtlcIndex) if !bytes.Equal(htlc.ourPkScript, restoredHtlc.ourPkScript) { t.Fatalf("bob ourPkScript in ourLog: expected %X, got %X", htlc.ourPkScript[:5], restoredHtlc.ourPkScript[:5]) } if !bytes.Equal(htlc.theirPkScript, restoredHtlc.theirPkScript) { t.Fatalf("bob theirPkScript in ourLog: expected %X, got %X", htlc.theirPkScript[:5], restoredHtlc.theirPkScript[:5]) } } for _, entry := range bobChannel.remoteUpdateLog.htlcIndex { htlc := entry.Value.(*PaymentDescriptor) restoredHtlc := bobChannelNew.remoteUpdateLog.lookupHtlc(htlc.HtlcIndex) if !bytes.Equal(htlc.ourPkScript, restoredHtlc.ourPkScript) { t.Fatalf("bob ourPkScript in theirLog: expected %X, got %X", htlc.ourPkScript[:5], restoredHtlc.ourPkScript[:5]) } if !bytes.Equal(htlc.theirPkScript, restoredHtlc.theirPkScript) { t.Fatalf("bob theirPkScript in theirLog: expected %X, got %X", htlc.theirPkScript[:5], restoredHtlc.theirPkScript[:5]) } } // Now settle all the HTLCs, then force a state update. The state // update should succeed as both sides have identical. for i := 0; i < 3; i++ { err := bobChannelNew.SettleHTLC(alicePreimage, uint64(i), nil, nil, nil) if err != nil { t.Fatalf("unable to settle htlc #%v: %v", i, err) } err = aliceChannelNew.ReceiveHTLCSettle(alicePreimage, uint64(i)) if err != nil { t.Fatalf("unable to settle htlc#%v: %v", i, err) } } err = aliceChannelNew.SettleHTLC(bobPreimage, 0, nil, nil, nil) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } err = bobChannelNew.ReceiveHTLCSettle(bobPreimage, 0) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } // Similar to the two transitions above, as both Bob and Alice added // entries to the update log before a state transition was initiated by // either side, both sides are required to trigger an update in order // to lock in their changes. if err := ForceStateTransition(aliceChannelNew, bobChannelNew); err != nil { t.Fatalf("unable to update commitments: %v", err) } if err := ForceStateTransition(bobChannelNew, aliceChannelNew); err != nil { t.Fatalf("unable to update commitments: %v", err) } // The amounts transferred should been updated as per the amounts in // the HTLCs if aliceChannelNew.channelState.TotalMSatSent != htlcAmt*3 { t.Fatalf("expected %v alice satoshis sent, got %v", htlcAmt*3, aliceChannelNew.channelState.TotalMSatSent) } if aliceChannelNew.channelState.TotalMSatReceived != htlcAmt { t.Fatalf("expected %v alice satoshis received, got %v", htlcAmt, aliceChannelNew.channelState.TotalMSatReceived) } if bobChannelNew.channelState.TotalMSatSent != htlcAmt { t.Fatalf("expected %v bob satoshis sent, got %v", htlcAmt, bobChannel.channelState.TotalMSatSent) } if bobChannelNew.channelState.TotalMSatReceived != htlcAmt*3 { t.Fatalf("expected %v bob satoshis sent, got %v", htlcAmt*3, bobChannel.channelState.TotalMSatReceived) } // As a final test, we'll ensure that the HTLC counters for both sides // has been persisted properly. If we instruct Alice to add a new HTLC, // it should have an index of 3. If we instruct Bob to do the // same, it should have an index of 1. aliceHtlcIndex, err := aliceChannel.AddHTLC(bobh, nil) if err != nil { t.Fatalf("unable to add htlc: %v", err) } if aliceHtlcIndex != 3 { t.Fatalf("wrong htlc index: expected %v, got %v", 3, aliceHtlcIndex) } bobHtlcIndex, err := bobChannel.AddHTLC(bobh, nil) if err != nil { t.Fatalf("unable to add htlc: %v", err) } if bobHtlcIndex != 1 { t.Fatalf("wrong htlc index: expected %v, got %v", 1, aliceHtlcIndex) } } func TestCancelHTLC(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // Add a new HTLC from Alice to Bob, then trigger a new state // transition in order to include it in the latest state. htlcAmt := lnwire.NewMSatFromSatoshis(btcutil.SatoshiPerBitcoin) var preImage [32]byte copy(preImage[:], bytes.Repeat([]byte{0xaa}, 32)) htlc := &lnwire.UpdateAddHTLC{ PaymentHash: sha256.Sum256(preImage[:]), Amount: htlcAmt, Expiry: 10, } aliceHtlcIndex, err := aliceChannel.AddHTLC(htlc, nil) if err != nil { t.Fatalf("unable to add alice htlc: %v", err) } bobHtlcIndex, err := bobChannel.ReceiveHTLC(htlc) if err != nil { t.Fatalf("unable to add bob htlc: %v", err) } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to create new commitment state: %v", err) } // With the HTLC committed, Alice's balance should reflect the clearing // of the new HTLC. aliceExpectedBalance := btcutil.Amount(btcutil.SatoshiPerBitcoin*4) - calcStaticFee(channeldb.SingleFunderTweaklessBit, 1) if aliceChannel.channelState.LocalCommitment.LocalBalance.ToSatoshis() != aliceExpectedBalance { t.Fatalf("Alice's balance is wrong: expected %v, got %v", aliceExpectedBalance, aliceChannel.channelState.LocalCommitment.LocalBalance.ToSatoshis()) } // Now, with the HTLC committed on both sides, trigger a cancellation // from Bob to Alice, removing the HTLC. err = bobChannel.FailHTLC(bobHtlcIndex, []byte("failreason"), nil, nil, nil) if err != nil { t.Fatalf("unable to cancel HTLC: %v", err) } err = aliceChannel.ReceiveFailHTLC(aliceHtlcIndex, []byte("bad")) if err != nil { t.Fatalf("unable to recv htlc cancel: %v", err) } // Now trigger another state transition, the HTLC should now be removed // from both sides, with balances reflected. if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("unable to create new commitment: %v", err) } // Now HTLCs should be present on the commitment transaction for either // side. if len(aliceChannel.localCommitChain.tip().outgoingHTLCs) != 0 || len(aliceChannel.remoteCommitChain.tip().outgoingHTLCs) != 0 { t.Fatalf("htlc's still active from alice's POV") } if len(aliceChannel.localCommitChain.tip().incomingHTLCs) != 0 || len(aliceChannel.remoteCommitChain.tip().incomingHTLCs) != 0 { t.Fatalf("htlc's still active from alice's POV") } if len(bobChannel.localCommitChain.tip().outgoingHTLCs) != 0 || len(bobChannel.remoteCommitChain.tip().outgoingHTLCs) != 0 { t.Fatalf("htlc's still active from bob's POV") } if len(bobChannel.localCommitChain.tip().incomingHTLCs) != 0 || len(bobChannel.remoteCommitChain.tip().incomingHTLCs) != 0 { t.Fatalf("htlc's still active from bob's POV") } expectedBalance := btcutil.Amount(btcutil.SatoshiPerBitcoin * 5) staticFee := calcStaticFee(channeldb.SingleFunderTweaklessBit, 0) if aliceChannel.channelState.LocalCommitment.LocalBalance.ToSatoshis() != expectedBalance-staticFee { t.Fatalf("balance is wrong: expected %v, got %v", aliceChannel.channelState.LocalCommitment.LocalBalance.ToSatoshis(), expectedBalance-staticFee) } if aliceChannel.channelState.LocalCommitment.RemoteBalance.ToSatoshis() != expectedBalance { t.Fatalf("balance is wrong: expected %v, got %v", aliceChannel.channelState.LocalCommitment.RemoteBalance.ToSatoshis(), expectedBalance) } if bobChannel.channelState.LocalCommitment.LocalBalance.ToSatoshis() != expectedBalance { t.Fatalf("balance is wrong: expected %v, got %v", bobChannel.channelState.LocalCommitment.LocalBalance.ToSatoshis(), expectedBalance) } if bobChannel.channelState.LocalCommitment.RemoteBalance.ToSatoshis() != expectedBalance-staticFee { t.Fatalf("balance is wrong: expected %v, got %v", bobChannel.channelState.LocalCommitment.RemoteBalance.ToSatoshis(), expectedBalance-staticFee) } } func TestCooperativeCloseDustAdherence(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() aliceFeeRate := chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) bobFeeRate := chainfee.SatPerKWeight( bobChannel.channelState.LocalCommitment.FeePerKw, ) setDustLimit := func(dustVal btcutil.Amount) { aliceChannel.channelState.LocalChanCfg.DustLimit = dustVal aliceChannel.channelState.RemoteChanCfg.DustLimit = dustVal bobChannel.channelState.LocalChanCfg.DustLimit = dustVal bobChannel.channelState.RemoteChanCfg.DustLimit = dustVal } resetChannelState := func() { aliceChannel.status = channelOpen bobChannel.status = channelOpen } setBalances := func(aliceBalance, bobBalance lnwire.MilliSatoshi) { aliceChannel.channelState.LocalCommitment.LocalBalance = aliceBalance aliceChannel.channelState.LocalCommitment.RemoteBalance = bobBalance bobChannel.channelState.LocalCommitment.LocalBalance = bobBalance bobChannel.channelState.LocalCommitment.RemoteBalance = aliceBalance } aliceDeliveryScript := bobsPrivKey[:] bobDeliveryScript := testHdSeed[:] // We'll start be initializing the limit of both Alice and Bob to 10k // satoshis. dustLimit := btcutil.Amount(10000) setDustLimit(dustLimit) // Both sides currently have over 1 BTC settled as part of their // balances. As a result, performing a cooperative closure now result // in both sides having an output within the closure transaction. aliceFee := btcutil.Amount(aliceChannel.CalcFee(aliceFeeRate)) + 1000 aliceSig, _, _, err := aliceChannel.CreateCloseProposal( aliceFee, aliceDeliveryScript, bobDeliveryScript, ) if err != nil { t.Fatalf("unable to close channel: %v", err) } bobFee := btcutil.Amount(bobChannel.CalcFee(bobFeeRate)) + 1000 bobSig, _, _, err := bobChannel.CreateCloseProposal( bobFee, bobDeliveryScript, aliceDeliveryScript, ) if err != nil { t.Fatalf("unable to close channel: %v", err) } closeTx, _, err := bobChannel.CompleteCooperativeClose( bobSig, aliceSig, bobDeliveryScript, aliceDeliveryScript, bobFee, ) if err != nil { t.Fatalf("unable to accept channel close: %v", err) } // The closure transaction should have exactly two outputs. if len(closeTx.TxOut) != 2 { t.Fatalf("close tx has wrong number of outputs: expected %v "+ "got %v", 2, len(closeTx.TxOut)) } // We'll reset the channel states before proceeding to our next test. resetChannelState() // Next we'll modify the current balances and dust limits such that // Bob's current balance is _below_ his dust limit. aliceBal := lnwire.NewMSatFromSatoshis(btcutil.SatoshiPerBitcoin) bobBal := lnwire.NewMSatFromSatoshis(250) setBalances(aliceBal, bobBal) // Attempt another cooperative channel closure. It should succeed // without any issues. aliceSig, _, _, err = aliceChannel.CreateCloseProposal( aliceFee, aliceDeliveryScript, bobDeliveryScript, ) if err != nil { t.Fatalf("unable to close channel: %v", err) } bobSig, _, _, err = bobChannel.CreateCloseProposal( bobFee, bobDeliveryScript, aliceDeliveryScript, ) if err != nil { t.Fatalf("unable to close channel: %v", err) } closeTx, _, err = bobChannel.CompleteCooperativeClose( bobSig, aliceSig, bobDeliveryScript, aliceDeliveryScript, bobFee, ) if err != nil { t.Fatalf("unable to accept channel close: %v", err) } // The closure transaction should only have a single output, and that // output should be Alice's balance. if len(closeTx.TxOut) != 1 { t.Fatalf("close tx has wrong number of outputs: expected %v "+ "got %v", 1, len(closeTx.TxOut)) } commitFee := aliceChannel.channelState.LocalCommitment.CommitFee aliceExpectedBalance := aliceBal.ToSatoshis() - aliceFee + commitFee if closeTx.TxOut[0].Value != int64(aliceExpectedBalance) { t.Fatalf("alice's balance is incorrect: expected %v, got %v", aliceExpectedBalance, int64(closeTx.TxOut[0].Value)) } // We'll modify the current balances and dust limits such that // Alice's current balance is too low to pay the proposed fee. setBalances(bobBal, aliceBal) resetChannelState() // Attempting to close with this fee now should fail, since Alice // cannot afford it. _, _, _, err = aliceChannel.CreateCloseProposal( aliceFee, aliceDeliveryScript, bobDeliveryScript, ) if err == nil { t.Fatalf("expected error") } // Finally, we'll modify the current balances and dust limits such that // Alice's balance after paying the coop fee is _below_ her dust limit. lowBalance := lnwire.NewMSatFromSatoshis(aliceFee) + 1000 setBalances(lowBalance, aliceBal) resetChannelState() // Our final attempt at another cooperative channel closure. It should // succeed without any issues. aliceSig, _, _, err = aliceChannel.CreateCloseProposal( aliceFee, aliceDeliveryScript, bobDeliveryScript, ) if err != nil { t.Fatalf("unable to close channel: %v", err) } bobSig, _, _, err = bobChannel.CreateCloseProposal( bobFee, bobDeliveryScript, aliceDeliveryScript, ) if err != nil { t.Fatalf("unable to close channel: %v", err) } closeTx, _, err = bobChannel.CompleteCooperativeClose( bobSig, aliceSig, bobDeliveryScript, aliceDeliveryScript, bobFee, ) if err != nil { t.Fatalf("unable to accept channel close: %v", err) } // The closure transaction should only have a single output, and that // output should be Bob's balance. if len(closeTx.TxOut) != 1 { t.Fatalf("close tx has wrong number of outputs: expected %v "+ "got %v", 1, len(closeTx.TxOut)) } if closeTx.TxOut[0].Value != int64(aliceBal.ToSatoshis()) { t.Fatalf("bob's balance is incorrect: expected %v, got %v", aliceBal.ToSatoshis(), closeTx.TxOut[0].Value) } } // TestUpdateFeeAdjustments tests that the state machine is able to properly // accept valid fee changes, as well as reject any invalid fee updates. func TestUpdateFeeAdjustments(t *testing.T) { t.Parallel() aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // First, we'll grab the current base fee rate as we'll be using this // to make relative adjustments int he fee rate. baseFeeRate := aliceChannel.channelState.LocalCommitment.FeePerKw // We'll first try to increase the fee rate 5x, this should be able to // be committed without any issue. newFee := chainfee.SatPerKWeight(baseFeeRate * 5) if err := aliceChannel.UpdateFee(newFee); err != nil { t.Fatalf("unable to alice update fee: %v", err) } if err := bobChannel.ReceiveUpdateFee(newFee); err != nil { t.Fatalf("unable to bob update fee: %v", err) } // With the fee updates applied, we'll now initiate a state transition // to ensure the fee update is locked in. if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to create new commitment: %v", err) } // We'll now attempt to increase the fee rate 1,000,000x of the base // fee. This should result in an error as Alice won't be able to pay // this new fee rate. newFee = chainfee.SatPerKWeight(baseFeeRate * 1000000) if err := aliceChannel.UpdateFee(newFee); err == nil { t.Fatalf("alice should reject the fee rate") } // Finally, we'll attempt to adjust the fee down and use a fee which is // smaller than the initial base fee rate. The fee application and // state transition should proceed without issue. newFee = chainfee.SatPerKWeight(baseFeeRate / 10) if err := aliceChannel.UpdateFee(newFee); err != nil { t.Fatalf("unable to alice update fee: %v", err) } if err := bobChannel.ReceiveUpdateFee(newFee); err != nil { t.Fatalf("unable to bob update fee: %v", err) } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to create new commitment: %v", err) } } // TestUpdateFeeFail tests that the signature verification will fail if they // fee updates are out of sync. func TestUpdateFeeFail(t *testing.T) { t.Parallel() aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // Bob receives the update, that will apply to his commitment // transaction. if err := bobChannel.ReceiveUpdateFee(333); err != nil { t.Fatalf("unable to apply fee update: %v", err) } // Alice sends signature for commitment that does not cover any fee // update. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("alice unable to sign commitment: %v", err) } // Bob verifies this commit, meaning that he checks that it is // consistent everything he has received. This should fail, since he got // the fee update, but Alice never sent it. err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err == nil { t.Fatalf("expected bob to fail receiving alice's signature") } } // TestUpdateFeeConcurrentSig tests that the channel can properly handle a fee // update that it receives concurrently with signing its next commitment. func TestUpdateFeeConcurrentSig(t *testing.T) { t.Parallel() aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() paymentPreimage := bytes.Repeat([]byte{1}, 32) paymentHash := sha256.Sum256(paymentPreimage) htlc := &lnwire.UpdateAddHTLC{ PaymentHash: paymentHash, Amount: btcutil.SatoshiPerBitcoin, Expiry: uint32(5), } // First Alice adds the outgoing HTLC to her local channel's state // update log. Then Alice sends this wire message over to Bob who // adds this htlc to his remote state update log. if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } // Simulate Alice sending update fee message to bob. fee := chainfee.SatPerKWeight(333) if err := aliceChannel.UpdateFee(fee); err != nil { t.Fatalf("unable to send fee update") } // Alice signs a commitment, and sends this to bob. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("alice unable to sign commitment: %v", err) } // At the same time, Bob signs a commitment. bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("bob unable to sign alice's commitment: %v", err) } // ...that Alice receives. err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("alice unable to process bob's new commitment: %v", err) } // Now let Bob receive the fee update + commitment that Alice sent. if err := bobChannel.ReceiveUpdateFee(fee); err != nil { t.Fatalf("unable to receive fee update") } // Bob receives this signature message, and verifies that it is // consistent with the state he had for Alice, including the received // HTLC and fee update. err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("bob unable to process alice's new commitment: %v", err) } if chainfee.SatPerKWeight(bobChannel.channelState.LocalCommitment.FeePerKw) == fee { t.Fatalf("bob's feePerKw was unexpectedly locked in") } // Bob can revoke the prior commitment he had. This should lock in the // fee update for him. _, _, err = bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to generate bob revocation: %v", err) } if chainfee.SatPerKWeight(bobChannel.channelState.LocalCommitment.FeePerKw) != fee { t.Fatalf("bob's feePerKw was not locked in") } } // TestUpdateFeeSenderCommits verifies that the state machine progresses as // expected if we send a fee update, and then the sender of the fee update // sends a commitment signature. func TestUpdateFeeSenderCommits(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() paymentPreimage := bytes.Repeat([]byte{1}, 32) paymentHash := sha256.Sum256(paymentPreimage) htlc := &lnwire.UpdateAddHTLC{ PaymentHash: paymentHash, Amount: btcutil.SatoshiPerBitcoin, Expiry: uint32(5), } // First Alice adds the outgoing HTLC to her local channel's state // update log. Then Alice sends this wire message over to Bob who // adds this htlc to his remote state update log. if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } // Simulate Alice sending update fee message to bob. fee := chainfee.SatPerKWeight(333) aliceChannel.UpdateFee(fee) bobChannel.ReceiveUpdateFee(fee) // Alice signs a commitment, which will cover everything sent to Bob // (the HTLC and the fee update), and everything acked by Bob (nothing // so far). aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("alice unable to sign commitment: %v", err) } // Bob receives this signature message, and verifies that it is // consistent with the state he had for Alice, including the received // HTLC and fee update. err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("bob unable to process alice's new commitment: %v", err) } if chainfee.SatPerKWeight( bobChannel.channelState.LocalCommitment.FeePerKw, ) == fee { t.Fatalf("bob's feePerKw was unexpectedly locked in") } // Bob can revoke the prior commitment he had. This should lock in the // fee update for him. bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to generate bob revocation: %v", err) } if chainfee.SatPerKWeight( bobChannel.channelState.LocalCommitment.FeePerKw, ) != fee { t.Fatalf("bob's feePerKw was not locked in") } // Bob commits to all updates he has received from Alice. This includes // the HTLC he received, and the fee update. bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("bob unable to sign alice's commitment: %v", err) } // Alice receives the revocation of the old one, and can now assume // that Bob's received everything up to the signature she sent, // including the HTLC and fee update. _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatalf("alice unable to process bob's revocation: %v", err) } // Alice receives new signature from Bob, and assumes this covers the // changes. err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("alice unable to process bob's new commitment: %v", err) } if chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) == fee { t.Fatalf("alice's feePerKw was unexpectedly locked in") } // Alice can revoke the old commitment, which will lock in the fee // update. aliceRevocation, _, err := aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke alice channel: %v", err) } if chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) != fee { t.Fatalf("alice's feePerKw was not locked in") } // Bob receives revocation from Alice. _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatalf("bob unable to process alice's revocation: %v", err) } } // TestUpdateFeeReceiverCommits tests that the state machine progresses as // expected if we send a fee update, and then the receiver of the fee update // sends a commitment signature. func TestUpdateFeeReceiverCommits(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() paymentPreimage := bytes.Repeat([]byte{1}, 32) paymentHash := sha256.Sum256(paymentPreimage) htlc := &lnwire.UpdateAddHTLC{ PaymentHash: paymentHash, Amount: btcutil.SatoshiPerBitcoin, Expiry: uint32(5), } // First Alice adds the outgoing HTLC to her local channel's state // update log. Then Alice sends this wire message over to Bob who // adds this htlc to his remote state update log. if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } // Simulate Alice sending update fee message to bob fee := chainfee.SatPerKWeight(333) aliceChannel.UpdateFee(fee) bobChannel.ReceiveUpdateFee(fee) // Bob commits to every change he has sent since last time (none). He // does not commit to the received HTLC and fee update, since Alice // cannot know if he has received them. bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("alice unable to sign commitment: %v", err) } // Alice receives this signature message, and verifies that it is // consistent with the remote state, not including any of the updates. err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("bob unable to process alice's new commitment: %v", err) } // Alice can revoke the prior commitment she had, this will ack // everything received before last commitment signature, but in this // case that is nothing. aliceRevocation, _, err := aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to generate bob revocation: %v", err) } // Bob receives the revocation of the old commitment _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatalf("alice unable to process bob's revocation: %v", err) } // Alice will sign next commitment. Since she sent the revocation, she // also ack'ed everything received, but in this case this is nothing. // Since she sent the two updates, this signature will cover those two. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("bob unable to sign alice's commitment: %v", err) } // Bob gets the signature for the new commitment from Alice. He assumes // this covers everything received from alice, including the two updates. err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("alice unable to process bob's new commitment: %v", err) } if chainfee.SatPerKWeight( bobChannel.channelState.LocalCommitment.FeePerKw, ) == fee { t.Fatalf("bob's feePerKw was unexpectedly locked in") } // Bob can revoke the old commitment. This will ack what he has // received, including the HTLC and fee update. This will lock in the // fee update for bob. bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke alice channel: %v", err) } if chainfee.SatPerKWeight( bobChannel.channelState.LocalCommitment.FeePerKw, ) != fee { t.Fatalf("bob's feePerKw was not locked in") } // Bob will send a new signature, which will cover what he just acked: // the HTLC and fee update. bobSig, bobHtlcSigs, _, err = bobChannel.SignNextCommitment() if err != nil { t.Fatalf("alice unable to sign commitment: %v", err) } // Alice receives revocation from Bob, and can now be sure that Bob // received the two updates, and they are considered locked in. _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatalf("bob unable to process alice's revocation: %v", err) } // Alice will receive the signature from Bob, which will cover what was // just acked by his revocation. err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("alice unable to process bob's new commitment: %v", err) } if chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) == fee { t.Fatalf("alice's feePerKw was unexpectedly locked in") } // After Alice now revokes her old commitment, the fee update should // lock in. aliceRevocation, _, err = aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to generate bob revocation: %v", err) } if chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) != fee { t.Fatalf("Alice's feePerKw was not locked in") } // Bob receives revocation from Alice. _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatalf("bob unable to process alice's revocation: %v", err) } } // TestUpdateFeeReceiverSendsUpdate tests that receiving a fee update as channel // initiator fails, and that trying to initiate fee update as non-initiation // fails. func TestUpdateFeeReceiverSendsUpdate(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // Since Alice is the channel initiator, she should fail when receiving // fee update fee := chainfee.SatPerKWeight(333) err = aliceChannel.ReceiveUpdateFee(fee) if err == nil { t.Fatalf("expected alice to fail receiving fee update") } // Similarly, initiating fee update should fail for Bob. err = bobChannel.UpdateFee(fee) if err == nil { t.Fatalf("expected bob to fail initiating fee update") } } // Test that if multiple update fee messages are sent consecutively, then the // last one is the one that is being committed to. func TestUpdateFeeMultipleUpdates(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // Simulate Alice sending update fee message to bob. fee1 := chainfee.SatPerKWeight(333) fee2 := chainfee.SatPerKWeight(333) fee := chainfee.SatPerKWeight(333) aliceChannel.UpdateFee(fee1) aliceChannel.UpdateFee(fee2) aliceChannel.UpdateFee(fee) // Alice signs a commitment, which will cover everything sent to Bob // (the HTLC and the fee update), and everything acked by Bob (nothing // so far). aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("alice unable to sign commitment: %v", err) } bobChannel.ReceiveUpdateFee(fee1) bobChannel.ReceiveUpdateFee(fee2) bobChannel.ReceiveUpdateFee(fee) // Bob receives this signature message, and verifies that it is // consistent with the state he had for Alice, including the received // HTLC and fee update. err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("bob unable to process alice's new commitment: %v", err) } if chainfee.SatPerKWeight( bobChannel.channelState.LocalCommitment.FeePerKw, ) == fee { t.Fatalf("bob's feePerKw was unexpectedly locked in") } // Alice sending more fee updates now should not mess up the old fee // they both committed to. fee3 := chainfee.SatPerKWeight(444) fee4 := chainfee.SatPerKWeight(555) fee5 := chainfee.SatPerKWeight(666) aliceChannel.UpdateFee(fee3) aliceChannel.UpdateFee(fee4) aliceChannel.UpdateFee(fee5) bobChannel.ReceiveUpdateFee(fee3) bobChannel.ReceiveUpdateFee(fee4) bobChannel.ReceiveUpdateFee(fee5) // Bob can revoke the prior commitment he had. This should lock in the // fee update for him. bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to generate bob revocation: %v", err) } if chainfee.SatPerKWeight( bobChannel.channelState.LocalCommitment.FeePerKw, ) != fee { t.Fatalf("bob's feePerKw was not locked in") } // Bob commits to all updates he has received from Alice. This includes // the HTLC he received, and the fee update. bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("bob unable to sign alice's commitment: %v", err) } // Alice receives the revocation of the old one, and can now assume that // Bob's received everything up to the signature she sent, including the // HTLC and fee update. _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatalf("alice unable to process bob's revocation: %v", err) } // Alice receives new signature from Bob, and assumes this covers the // changes. if err := aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs); err != nil { t.Fatalf("alice unable to process bob's new commitment: %v", err) } if chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) == fee { t.Fatalf("alice's feePerKw was unexpectedly locked in") } // Alice can revoke the old commitment, which will lock in the fee // update. aliceRevocation, _, err := aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke alice channel: %v", err) } if chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) != fee { t.Fatalf("alice's feePerKw was not locked in") } // Bob receives revocation from Alice. _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatalf("bob unable to process alice's revocation: %v", err) } } // TestAddHTLCNegativeBalance tests that if enough HTLC's are added to the // state machine to drive the balance to zero, then the next HTLC attempted to // be added will result in an error being returned. func TestAddHTLCNegativeBalance(t *testing.T) { t.Parallel() // We'll kick off the test by creating our channels which both are // loaded with 5 BTC each. aliceChannel, _, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // We set the channel reserve to 0, such that we can add HTLCs all the // way to a negative balance. aliceChannel.channelState.LocalChanCfg.ChanReserve = 0 // First, we'll add 3 HTLCs of 1 BTC each to Alice's commitment. const numHTLCs = 3 htlcAmt := lnwire.NewMSatFromSatoshis(btcutil.SatoshiPerBitcoin) for i := 0; i < numHTLCs; i++ { htlc, _ := createHTLC(i, htlcAmt) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } } // Alice now has an available balance of 2 BTC. We'll add a new HTLC of // value 2 BTC, which should make Alice's balance negative (since she // has to pay a commitment fee). htlcAmt = lnwire.NewMSatFromSatoshis(2 * btcutil.SatoshiPerBitcoin) htlc, _ := createHTLC(numHTLCs+1, htlcAmt) _, err = aliceChannel.AddHTLC(htlc, nil) if err != ErrBelowChanReserve { t.Fatalf("expected balance below channel reserve, instead "+ "got: %v", err) } } // assertNoChanSyncNeeded is a helper function that asserts that upon restart, // two channels conclude that they're fully synchronized and don't need to // retransmit any new messages. func assertNoChanSyncNeeded(t *testing.T, aliceChannel *LightningChannel, bobChannel *LightningChannel) { _, _, line, _ := runtime.Caller(1) aliceChanSyncMsg, err := aliceChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("line #%v: unable to produce chan sync msg: %v", line, err) } bobMsgsToSend, _, _, err := bobChannel.ProcessChanSyncMsg(aliceChanSyncMsg) if err != nil { t.Fatalf("line #%v: unable to process ChannelReestablish "+ "msg: %v", line, err) } if len(bobMsgsToSend) != 0 { t.Fatalf("line #%v: bob shouldn't have to send any messages, "+ "instead wants to send: %v", line, spew.Sdump(bobMsgsToSend)) } bobChanSyncMsg, err := bobChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("line #%v: unable to produce chan sync msg: %v", line, err) } aliceMsgsToSend, _, _, err := aliceChannel.ProcessChanSyncMsg(bobChanSyncMsg) if err != nil { t.Fatalf("line #%v: unable to process ChannelReestablish "+ "msg: %v", line, err) } if len(bobMsgsToSend) != 0 { t.Fatalf("line #%v: alice shouldn't have to send any "+ "messages, instead wants to send: %v", line, spew.Sdump(aliceMsgsToSend)) } } // TestChanSyncFullySynced tests that after a successful commitment exchange, // and a forced restart, both nodes conclude that they're fully synchronized // and don't need to retransmit any messages. func TestChanSyncFullySynced(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // If we exchange channel sync messages from the get-go , then both // sides should conclude that no further synchronization is needed. assertNoChanSyncNeeded(t, aliceChannel, bobChannel) // Next, we'll create an HTLC for Alice to extend to Bob. var paymentPreimage [32]byte copy(paymentPreimage[:], bytes.Repeat([]byte{1}, 32)) paymentHash := sha256.Sum256(paymentPreimage[:]) htlcAmt := lnwire.NewMSatFromSatoshis(btcutil.SatoshiPerBitcoin) htlc := &lnwire.UpdateAddHTLC{ PaymentHash: paymentHash, Amount: htlcAmt, Expiry: uint32(5), } aliceHtlcIndex, err := aliceChannel.AddHTLC(htlc, nil) if err != nil { t.Fatalf("unable to add htlc: %v", err) } bobHtlcIndex, err := bobChannel.ReceiveHTLC(htlc) if err != nil { t.Fatalf("unable to recv htlc: %v", err) } // Then we'll initiate a state transition to lock in this new HTLC. if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete alice's state transition: %v", err) } // At this point, if both sides generate a ChannelReestablish message, // they should both conclude that they're fully in sync. assertNoChanSyncNeeded(t, aliceChannel, bobChannel) // If bob settles the HTLC, and then initiates a state transition, they // should both still think that they're in sync. err = bobChannel.SettleHTLC(paymentPreimage, bobHtlcIndex, nil, nil, nil) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } err = aliceChannel.ReceiveHTLCSettle(paymentPreimage, aliceHtlcIndex) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } // Next, we'll complete Bob's state transition, and assert again that // they think they're fully synced. if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("unable to complete bob's state transition: %v", err) } assertNoChanSyncNeeded(t, aliceChannel, bobChannel) // Finally, if we simulate a restart on both sides, then both should // still conclude that they don't need to synchronize their state. alicePub := aliceChannel.channelState.IdentityPub aliceChannels, err := aliceChannel.channelState.Db.FetchOpenChannels( alicePub, ) if err != nil { t.Fatalf("unable to fetch channel: %v", err) } bobPub := bobChannel.channelState.IdentityPub bobChannels, err := bobChannel.channelState.Db.FetchOpenChannels(bobPub) if err != nil { t.Fatalf("unable to fetch channel: %v", err) } aliceChannelNew, err := NewLightningChannel( aliceChannel.Signer, aliceChannels[0], aliceChannel.sigPool, ) if err != nil { t.Fatalf("unable to create new channel: %v", err) } bobChannelNew, err := NewLightningChannel( bobChannel.Signer, bobChannels[0], bobChannel.sigPool, ) if err != nil { t.Fatalf("unable to create new channel: %v", err) } assertNoChanSyncNeeded(t, aliceChannelNew, bobChannelNew) } // restartChannel reads the passed channel from disk, and returns a newly // initialized instance. This simulates one party restarting and losing their // in memory state. func restartChannel(channelOld *LightningChannel) (*LightningChannel, error) { nodePub := channelOld.channelState.IdentityPub nodeChannels, err := channelOld.channelState.Db.FetchOpenChannels( nodePub, ) if err != nil { return nil, err } channelNew, err := NewLightningChannel( channelOld.Signer, nodeChannels[0], channelOld.sigPool, ) if err != nil { return nil, err } return channelNew, nil } // TestChanSyncOweCommitment tests that if Bob restarts (and then Alice) before // he receives Alice's CommitSig message, then Alice concludes that she needs // to re-send the CommitDiff. After the diff has been sent, both nodes should // resynchronize and be able to complete the dangling commit. func TestChanSyncOweCommitment(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() var fakeOnionBlob [lnwire.OnionPacketSize]byte copy(fakeOnionBlob[:], bytes.Repeat([]byte{0x05}, lnwire.OnionPacketSize)) // We'll start off the scenario with Bob sending 3 HTLC's to Alice in a // single state update. htlcAmt := lnwire.NewMSatFromSatoshis(20000) const numBobHtlcs = 3 var bobPreimage [32]byte copy(bobPreimage[:], bytes.Repeat([]byte{0xbb}, 32)) for i := 0; i < 3; i++ { rHash := sha256.Sum256(bobPreimage[:]) h := &lnwire.UpdateAddHTLC{ PaymentHash: rHash, Amount: htlcAmt, Expiry: uint32(10), OnionBlob: fakeOnionBlob, } htlcIndex, err := bobChannel.AddHTLC(h, nil) if err != nil { t.Fatalf("unable to add bob's htlc: %v", err) } h.ID = htlcIndex if _, err := aliceChannel.ReceiveHTLC(h); err != nil { t.Fatalf("unable to recv bob's htlc: %v", err) } } chanID := lnwire.NewChanIDFromOutPoint( &aliceChannel.channelState.FundingOutpoint, ) // With the HTLC's applied to both update logs, we'll initiate a state // transition from Bob. if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("unable to complete bob's state transition: %v", err) } // Next, Alice's settles all 3 HTLC's from Bob, and also adds a new // HTLC of her own. for i := 0; i < 3; i++ { err := aliceChannel.SettleHTLC(bobPreimage, uint64(i), nil, nil, nil) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } err = bobChannel.ReceiveHTLCSettle(bobPreimage, uint64(i)) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } } var alicePreimage [32]byte copy(alicePreimage[:], bytes.Repeat([]byte{0xaa}, 32)) rHash := sha256.Sum256(alicePreimage[:]) aliceHtlc := &lnwire.UpdateAddHTLC{ ChanID: chanID, PaymentHash: rHash, Amount: htlcAmt, Expiry: uint32(10), OnionBlob: fakeOnionBlob, } aliceHtlcIndex, err := aliceChannel.AddHTLC(aliceHtlc, nil) if err != nil { t.Fatalf("unable to add alice's htlc: %v", err) } bobHtlcIndex, err := bobChannel.ReceiveHTLC(aliceHtlc) if err != nil { t.Fatalf("unable to recv alice's htlc: %v", err) } // Now we'll begin the core of the test itself. Alice will extend a new // commitment to Bob, but the connection drops before Bob can process // it. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } // Bob doesn't get this message so upon reconnection, they need to // synchronize. Alice should conclude that she owes Bob a commitment, // while Bob should think he's properly synchronized. aliceSyncMsg, err := aliceChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } bobSyncMsg, err := bobChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } // This is a helper function that asserts Alice concludes that she // needs to retransmit the exact commitment that we failed to send // above. assertAliceCommitRetransmit := func() { aliceMsgsToSend, _, _, err := aliceChannel.ProcessChanSyncMsg( bobSyncMsg, ) if err != nil { t.Fatalf("unable to process chan sync msg: %v", err) } if len(aliceMsgsToSend) != 5 { t.Fatalf("expected alice to send %v messages instead "+ "will send %v: %v", 5, len(aliceMsgsToSend), spew.Sdump(aliceMsgsToSend)) } // Each of the settle messages that Alice sent should match her // original intent. for i := 0; i < 3; i++ { settleMsg, ok := aliceMsgsToSend[i].(*lnwire.UpdateFulfillHTLC) if !ok { t.Fatalf("expected an HTLC settle message, "+ "instead have %v", spew.Sdump(settleMsg)) } if settleMsg.ID != uint64(i) { t.Fatalf("wrong ID in settle msg: expected %v, "+ "got %v", i, settleMsg.ID) } if settleMsg.ChanID != chanID { t.Fatalf("incorrect chan id: expected %v, got %v", chanID, settleMsg.ChanID) } if settleMsg.PaymentPreimage != bobPreimage { t.Fatalf("wrong pre-image: expected %v, got %v", alicePreimage, settleMsg.PaymentPreimage) } } // The HTLC add message should be identical. if _, ok := aliceMsgsToSend[3].(*lnwire.UpdateAddHTLC); !ok { t.Fatalf("expected an HTLC add message, instead have %v", spew.Sdump(aliceMsgsToSend[3])) } if !reflect.DeepEqual(aliceHtlc, aliceMsgsToSend[3]) { t.Fatalf("htlc msg doesn't match exactly: "+ "expected %v got %v", spew.Sdump(aliceHtlc), spew.Sdump(aliceMsgsToSend[3])) } // Next, we'll ensure that the CommitSig message exactly // matches what Alice originally intended to send. commitSigMsg, ok := aliceMsgsToSend[4].(*lnwire.CommitSig) if !ok { t.Fatalf("expected a CommitSig message, instead have %v", spew.Sdump(aliceMsgsToSend[4])) } if commitSigMsg.CommitSig != aliceSig { t.Fatalf("commit sig msgs don't match: expected %x got %x", aliceSig, commitSigMsg.CommitSig) } if len(commitSigMsg.HtlcSigs) != len(aliceHtlcSigs) { t.Fatalf("wrong number of htlc sigs: expected %v, got %v", len(aliceHtlcSigs), len(commitSigMsg.HtlcSigs)) } for i, htlcSig := range commitSigMsg.HtlcSigs { if htlcSig != aliceHtlcSigs[i] { t.Fatalf("htlc sig msgs don't match: "+ "expected %x got %x", aliceHtlcSigs[i], htlcSig) } } } // Alice should detect that she needs to re-send 5 messages: the 3 // settles, her HTLC add, and finally her commit sig message. assertAliceCommitRetransmit() // From Bob's Pov he has nothing else to send, so he should conclude he // has no further action remaining. bobMsgsToSend, _, _, err := bobChannel.ProcessChanSyncMsg(aliceSyncMsg) if err != nil { t.Fatalf("unable to process chan sync msg: %v", err) } if len(bobMsgsToSend) != 0 { t.Fatalf("expected bob to send %v messages instead will "+ "send %v: %v", 5, len(bobMsgsToSend), spew.Sdump(bobMsgsToSend)) } // If we restart Alice, she should still conclude that she needs to // send the exact same set of messages. aliceChannel, err = restartChannel(aliceChannel) if err != nil { t.Fatalf("unable to restart alice: %v", err) } assertAliceCommitRetransmit() // TODO(roasbeef): restart bob as well??? // At this point, we should be able to resume the prior state update // without any issues, resulting in Alice settling the 3 htlc's, and // adding one of her own. err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("bob unable to process alice's commitment: %v", err) } bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke bob commitment: %v", err) } bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("bob unable to sign commitment: %v", err) } _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatalf("alice unable to recv revocation: %v", err) } err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("alice unable to rev bob's commitment: %v", err) } aliceRevocation, _, err := aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("alice unable to revoke commitment: %v", err) } _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatalf("bob unable to recv revocation: %v", err) } // At this point, we'll now assert that their log states are what we // expect. // // Alice's local log counter should be 4 and her HTLC index 3. She // should detect Bob's remote log counter as being 3 and his HTLC index // 3 as well. if aliceChannel.localUpdateLog.logIndex != 4 { t.Fatalf("incorrect log index: expected %v, got %v", 4, aliceChannel.localUpdateLog.logIndex) } if aliceChannel.localUpdateLog.htlcCounter != 1 { t.Fatalf("incorrect htlc index: expected %v, got %v", 1, aliceChannel.localUpdateLog.htlcCounter) } if aliceChannel.remoteUpdateLog.logIndex != 3 { t.Fatalf("incorrect log index: expected %v, got %v", 3, aliceChannel.localUpdateLog.logIndex) } if aliceChannel.remoteUpdateLog.htlcCounter != 3 { t.Fatalf("incorrect htlc index: expected %v, got %v", 3, aliceChannel.localUpdateLog.htlcCounter) } // Bob should also have the same state, but mirrored. if bobChannel.localUpdateLog.logIndex != 3 { t.Fatalf("incorrect log index: expected %v, got %v", 3, bobChannel.localUpdateLog.logIndex) } if bobChannel.localUpdateLog.htlcCounter != 3 { t.Fatalf("incorrect htlc index: expected %v, got %v", 3, bobChannel.localUpdateLog.htlcCounter) } if bobChannel.remoteUpdateLog.logIndex != 4 { t.Fatalf("incorrect log index: expected %v, got %v", 4, bobChannel.localUpdateLog.logIndex) } if bobChannel.remoteUpdateLog.htlcCounter != 1 { t.Fatalf("incorrect htlc index: expected %v, got %v", 1, bobChannel.localUpdateLog.htlcCounter) } // We'll conclude the test by having Bob settle Alice's HTLC, then // initiate a state transition. err = bobChannel.SettleHTLC(alicePreimage, bobHtlcIndex, nil, nil, nil) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } err = aliceChannel.ReceiveHTLCSettle(alicePreimage, aliceHtlcIndex) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("unable to complete bob's state transition: %v", err) } // At this point, the final balances of both parties should properly // reflect the amount of HTLC's sent. bobMsatSent := numBobHtlcs * htlcAmt if aliceChannel.channelState.TotalMSatSent != htlcAmt { t.Fatalf("wrong value for msat sent: expected %v, got %v", htlcAmt, aliceChannel.channelState.TotalMSatSent) } if aliceChannel.channelState.TotalMSatReceived != bobMsatSent { t.Fatalf("wrong value for msat recv: expected %v, got %v", bobMsatSent, aliceChannel.channelState.TotalMSatReceived) } if bobChannel.channelState.TotalMSatSent != bobMsatSent { t.Fatalf("wrong value for msat sent: expected %v, got %v", bobMsatSent, bobChannel.channelState.TotalMSatSent) } if bobChannel.channelState.TotalMSatReceived != htlcAmt { t.Fatalf("wrong value for msat recv: expected %v, got %v", htlcAmt, bobChannel.channelState.TotalMSatReceived) } } // TestChanSyncOweCommitmentPendingRemote asserts that local updates are applied // to the remote commit across restarts. func TestChanSyncOweCommitmentPendingRemote(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() var fakeOnionBlob [lnwire.OnionPacketSize]byte copy(fakeOnionBlob[:], bytes.Repeat([]byte{0x05}, lnwire.OnionPacketSize)) // We'll start off the scenario where Bob send two htlcs to Alice in a // single state update. var preimages []lntypes.Preimage const numHtlcs = 2 for id := byte(0); id < numHtlcs; id++ { htlcAmt := lnwire.NewMSatFromSatoshis(20000) var bobPreimage [32]byte copy(bobPreimage[:], bytes.Repeat([]byte{id}, 32)) rHash := sha256.Sum256(bobPreimage[:]) h := &lnwire.UpdateAddHTLC{ PaymentHash: rHash, Amount: htlcAmt, Expiry: uint32(10), OnionBlob: fakeOnionBlob, } htlcIndex, err := bobChannel.AddHTLC(h, nil) if err != nil { t.Fatalf("unable to add bob's htlc: %v", err) } h.ID = htlcIndex if _, err := aliceChannel.ReceiveHTLC(h); err != nil { t.Fatalf("unable to recv bob's htlc: %v", err) } preimages = append(preimages, bobPreimage) } // With the HTLCs applied to both update logs, we'll initiate a state // transition from Bob. if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("unable to complete bob's state transition: %v", err) } // Next, Alice settles the HTLCs from Bob in distinct state updates. for i := 0; i < numHtlcs; i++ { err = aliceChannel.SettleHTLC(preimages[i], uint64(i), nil, nil, nil) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } err = bobChannel.ReceiveHTLCSettle(preimages[i], uint64(i)) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("unable to receive commitment: %v", err) } // Bob revokes his current commitment. After this call // completes, the htlc is settled on the local commitment // transaction. Bob still owes Alice a signature to also settle // the htlc on her local commitment transaction. bobRevoke, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke commitment: %v", err) } _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevoke) if err != nil { t.Fatalf("unable to revoke commitment: %v", err) } } // We restart Bob. This should have no impact on further message that // are generated. bobChannel, err = restartChannel(bobChannel) if err != nil { t.Fatalf("unable to restart bob: %v", err) } // Bob signs the commitment he owes. bobCommit, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } // This commitment is expected to contain no htlcs anymore. if len(bobHtlcSigs) != 0 { t.Fatalf("no htlcs expected, but got %v", len(bobHtlcSigs)) } // Get Alice to revoke and trigger Bob to compact his logs. err = aliceChannel.ReceiveNewCommitment(bobCommit, bobHtlcSigs) if err != nil { t.Fatal(err) } aliceRevoke, _, err := aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatal(err) } _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevoke) if err != nil { t.Fatal(err) } } // TestChanSyncOweRevocation tests that if Bob restarts (and then Alice) before // he receiver's Alice's RevokeAndAck message, then Alice concludes that she // needs to re-send the RevokeAndAck. After the revocation has been sent, both // nodes should be able to successfully complete another state transition. func TestChanSyncOweRevocation(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() chanID := lnwire.NewChanIDFromOutPoint( &aliceChannel.channelState.FundingOutpoint, ) // We'll start the test with Bob extending a single HTLC to Alice, and // then initiating a state transition. htlcAmt := lnwire.NewMSatFromSatoshis(20000) var bobPreimage [32]byte copy(bobPreimage[:], bytes.Repeat([]byte{0xaa}, 32)) rHash := sha256.Sum256(bobPreimage[:]) bobHtlc := &lnwire.UpdateAddHTLC{ ChanID: chanID, PaymentHash: rHash, Amount: htlcAmt, Expiry: uint32(10), } bobHtlcIndex, err := bobChannel.AddHTLC(bobHtlc, nil) if err != nil { t.Fatalf("unable to add bob's htlc: %v", err) } aliceHtlcIndex, err := aliceChannel.ReceiveHTLC(bobHtlc) if err != nil { t.Fatalf("unable to recv bob's htlc: %v", err) } if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("unable to complete bob's state transition: %v", err) } // Next, Alice will settle that single HTLC, the _begin_ the start of a // state transition. err = aliceChannel.SettleHTLC(bobPreimage, aliceHtlcIndex, nil, nil, nil) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } err = bobChannel.ReceiveHTLCSettle(bobPreimage, bobHtlcIndex) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } // We'll model the state transition right up until Alice needs to send // her revocation message to complete the state transition. // // Alice signs the next state, then Bob receives and sends his // revocation message. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("bob unable to process alice's commitment: %v", err) } bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke bob commitment: %v", err) } bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("bob unable to sign commitment: %v", err) } _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatalf("alice unable to recv revocation: %v", err) } err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("alice unable to rev bob's commitment: %v", err) } // At this point, we'll simulate the connection breaking down by Bob's // lack of knowledge of the revocation message that Alice just sent. aliceRevocation, _, err := aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("alice unable to revoke commitment: %v", err) } // If we fetch the channel sync messages at this state, then Alice // should report that she owes Bob a revocation message, while Bob // thinks they're fully in sync. aliceSyncMsg, err := aliceChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } bobSyncMsg, err := bobChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } assertAliceOwesRevoke := func() { aliceMsgsToSend, _, _, err := aliceChannel.ProcessChanSyncMsg(bobSyncMsg) if err != nil { t.Fatalf("unable to process chan sync msg: %v", err) } if len(aliceMsgsToSend) != 1 { t.Fatalf("expected single message retransmission from Alice, "+ "instead got %v", spew.Sdump(aliceMsgsToSend)) } aliceReRevoke, ok := aliceMsgsToSend[0].(*lnwire.RevokeAndAck) if !ok { t.Fatalf("expected to retransmit revocation msg, instead "+ "have: %v", spew.Sdump(aliceMsgsToSend[0])) } // Alice should re-send the revocation message for her prior // state. expectedRevocation, err := aliceChannel.generateRevocation( aliceChannel.currentHeight - 1, ) if err != nil { t.Fatalf("unable to regenerate revocation: %v", err) } if !reflect.DeepEqual(expectedRevocation, aliceReRevoke) { t.Fatalf("wrong re-revocation: expected %v, got %v", expectedRevocation, aliceReRevoke) } } // From Bob's PoV he shouldn't think that he owes Alice any messages. bobMsgsToSend, _, _, err := bobChannel.ProcessChanSyncMsg(aliceSyncMsg) if err != nil { t.Fatalf("unable to process chan sync msg: %v", err) } if len(bobMsgsToSend) != 0 { t.Fatalf("expected bob to not retransmit, instead has: %v", spew.Sdump(bobMsgsToSend)) } // Alice should detect that she owes Bob a revocation message, and only // that single message. assertAliceOwesRevoke() // If we restart Alice, then she should still decide that she owes a // revocation message to Bob. aliceChannel, err = restartChannel(aliceChannel) if err != nil { t.Fatalf("unable to restart alice: %v", err) } assertAliceOwesRevoke() // TODO(roasbeef): restart bob too??? // We'll continue by then allowing bob to process Alice's revocation message. _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatalf("bob unable to recv revocation: %v", err) } // Finally, Alice will add an HTLC over her own such that we assert the // channel can continue to receive updates. var alicePreimage [32]byte copy(bobPreimage[:], bytes.Repeat([]byte{0xaa}, 32)) rHash = sha256.Sum256(alicePreimage[:]) aliceHtlc := &lnwire.UpdateAddHTLC{ ChanID: chanID, PaymentHash: rHash, Amount: htlcAmt, Expiry: uint32(10), } if _, err := aliceChannel.AddHTLC(aliceHtlc, nil); err != nil { t.Fatalf("unable to add alice's htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(aliceHtlc); err != nil { t.Fatalf("unable to recv alice's htlc: %v", err) } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete alice's state transition: %v", err) } // At this point, both sides should detect that they're fully synced. assertNoChanSyncNeeded(t, aliceChannel, bobChannel) } // TestChanSyncOweRevocationAndCommit tests that if Alice initiates a state // transition with Bob and Bob sends both a RevokeAndAck and CommitSig message // but Alice doesn't receive them before the connection dies, then he'll // retransmit them both. func TestChanSyncOweRevocationAndCommit(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() htlcAmt := lnwire.NewMSatFromSatoshis(20000) // We'll kick off the test by having Bob send Alice an HTLC, then lock // it in with a state transition. var bobPreimage [32]byte copy(bobPreimage[:], bytes.Repeat([]byte{0xaa}, 32)) rHash := sha256.Sum256(bobPreimage[:]) bobHtlc := &lnwire.UpdateAddHTLC{ PaymentHash: rHash, Amount: htlcAmt, Expiry: uint32(10), } bobHtlcIndex, err := bobChannel.AddHTLC(bobHtlc, nil) if err != nil { t.Fatalf("unable to add bob's htlc: %v", err) } aliceHtlcIndex, err := aliceChannel.ReceiveHTLC(bobHtlc) if err != nil { t.Fatalf("unable to recv bob's htlc: %v", err) } if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("unable to complete bob's state transition: %v", err) } // Next, Alice will settle that incoming HTLC, then we'll start the // core of the test itself. err = aliceChannel.SettleHTLC(bobPreimage, aliceHtlcIndex, nil, nil, nil) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } err = bobChannel.ReceiveHTLCSettle(bobPreimage, bobHtlcIndex) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } // Progressing the exchange: Alice will send her signature, Bob will // receive, send a revocation and also a signature for Alice's state. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("bob unable to process alice's commitment: %v", err) } // Bob generates the revoke and sig message, but the messages don't // reach Alice before the connection dies. bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke bob commitment: %v", err) } bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("bob unable to sign commitment: %v", err) } // If we now attempt to resync, then Alice should conclude that she // doesn't need any further updates, while Bob concludes that he needs // to re-send both his revocation and commit sig message. aliceSyncMsg, err := aliceChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } bobSyncMsg, err := bobChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } aliceMsgsToSend, _, _, err := aliceChannel.ProcessChanSyncMsg(bobSyncMsg) if err != nil { t.Fatalf("unable to process chan sync msg: %v", err) } if len(aliceMsgsToSend) != 0 { t.Fatalf("expected alice to not retransmit, instead she's "+ "sending: %v", spew.Sdump(aliceMsgsToSend)) } assertBobSendsRevokeAndCommit := func() { bobMsgsToSend, _, _, err := bobChannel.ProcessChanSyncMsg(aliceSyncMsg) if err != nil { t.Fatalf("unable to process chan sync msg: %v", err) } if len(bobMsgsToSend) != 2 { t.Fatalf("expected bob to send %v messages, instead "+ "sends: %v", 2, spew.Sdump(bobMsgsToSend)) } bobReRevoke, ok := bobMsgsToSend[0].(*lnwire.RevokeAndAck) if !ok { t.Fatalf("expected bob to re-send revoke, instead sending: %v", spew.Sdump(bobMsgsToSend[0])) } if !reflect.DeepEqual(bobReRevoke, bobRevocation) { t.Fatalf("revocation msgs don't match: expected %v, got %v", bobRevocation, bobReRevoke) } bobReCommitSigMsg, ok := bobMsgsToSend[1].(*lnwire.CommitSig) if !ok { t.Fatalf("expected bob to re-send commit sig, instead sending: %v", spew.Sdump(bobMsgsToSend[1])) } if bobReCommitSigMsg.CommitSig != bobSig { t.Fatalf("commit sig msgs don't match: expected %x got %x", bobSig, bobReCommitSigMsg.CommitSig) } if len(bobReCommitSigMsg.HtlcSigs) != len(bobHtlcSigs) { t.Fatalf("wrong number of htlc sigs: expected %v, got %v", len(bobHtlcSigs), len(bobReCommitSigMsg.HtlcSigs)) } for i, htlcSig := range bobReCommitSigMsg.HtlcSigs { if htlcSig != aliceHtlcSigs[i] { t.Fatalf("htlc sig msgs don't match: "+ "expected %x got %x", bobHtlcSigs[i], htlcSig) } } } // We expect Bob to send exactly two messages: first his revocation // message to Alice, and second his original commit sig message. assertBobSendsRevokeAndCommit() // At this point we simulate the connection failing with a restart from // Bob. He should still re-send the exact same set of messages. bobChannel, err = restartChannel(bobChannel) if err != nil { t.Fatalf("unable to restart channel: %v", err) } assertBobSendsRevokeAndCommit() // We'll now finish the state transition by having Alice process both // messages, and send her final revocation. _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatalf("alice unable to recv revocation: %v", err) } err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("alice unable to rev bob's commitment: %v", err) } aliceRevocation, _, err := aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("alice unable to revoke commitment: %v", err) } _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatalf("bob unable to recv revocation: %v", err) } } // TestChanSyncOweRevocationAndCommitForceTransition tests that if Alice // initiates a state transition with Bob, but Alice fails to receive his // RevokeAndAck and the connection dies before Bob sends his CommitSig message, // then Bob will re-send her RevokeAndAck message. Bob will also send and // _identical_ CommitSig as he detects his commitment chain is ahead of // Alice's. func TestChanSyncOweRevocationAndCommitForceTransition(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() htlcAmt := lnwire.NewMSatFromSatoshis(20000) // We'll kick off the test by having Bob send Alice an HTLC, then lock // it in with a state transition. var bobPreimage [32]byte copy(bobPreimage[:], bytes.Repeat([]byte{0xaa}, 32)) rHash := sha256.Sum256(bobPreimage[:]) var bobHtlc [2]*lnwire.UpdateAddHTLC bobHtlc[0] = &lnwire.UpdateAddHTLC{ PaymentHash: rHash, Amount: htlcAmt, Expiry: uint32(10), } bobHtlcIndex, err := bobChannel.AddHTLC(bobHtlc[0], nil) if err != nil { t.Fatalf("unable to add bob's htlc: %v", err) } aliceHtlcIndex, err := aliceChannel.ReceiveHTLC(bobHtlc[0]) if err != nil { t.Fatalf("unable to recv bob's htlc: %v", err) } if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("unable to complete bob's state transition: %v", err) } // To ensure the channel sync logic handles the case where the two // commit chains are at different heights, we'll add another HTLC from // Bob to Alice, but let Alice skip the commitment for this state // update. rHash = sha256.Sum256(bytes.Repeat([]byte{0xbb}, 32)) bobHtlc[1] = &lnwire.UpdateAddHTLC{ PaymentHash: rHash, Amount: htlcAmt, Expiry: uint32(10), ID: 1, } _, err = bobChannel.AddHTLC(bobHtlc[1], nil) if err != nil { t.Fatalf("unable to add bob's htlc: %v", err) } _, err = aliceChannel.ReceiveHTLC(bobHtlc[1]) if err != nil { t.Fatalf("unable to recv bob's htlc: %v", err) } // Bob signs the new state update, and sends the signature to Alice. bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("bob unable to sign commitment: %v", err) } err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("alice unable to rev bob's commitment: %v", err) } // Alice revokes her current state, but doesn't immediately send a // signature for Bob's updated state. Instead she will issue a new // update before sending a new CommitSig. This will lead to Alice's // local commit chain getting height > remote commit chain. aliceRevocation, _, err := aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("alice unable to revoke commitment: %v", err) } _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatalf("bob unable to recv revocation: %v", err) } // Next, Alice will settle that incoming HTLC, then we'll start the // core of the test itself. err = aliceChannel.SettleHTLC(bobPreimage, aliceHtlcIndex, nil, nil, nil) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } err = bobChannel.ReceiveHTLCSettle(bobPreimage, bobHtlcIndex) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } // Progressing the exchange: Alice will send her signature, with Bob // processing the new state locally. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("bob unable to process alice's commitment: %v", err) } // Bob then sends his revocation message, but before Alice can process // it (and before he scan send his CommitSig message), then connection // dies. bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke bob commitment: %v", err) } // Now if we attempt to synchronize states at this point, Alice should // detect that she owes nothing, while Bob should re-send both his // RevokeAndAck as well as his commitment message. aliceSyncMsg, err := aliceChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } bobSyncMsg, err := bobChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } aliceMsgsToSend, _, _, err := aliceChannel.ProcessChanSyncMsg(bobSyncMsg) if err != nil { t.Fatalf("unable to process chan sync msg: %v", err) } if len(aliceMsgsToSend) != 0 { t.Fatalf("expected alice to not retransmit, instead she's "+ "sending: %v", spew.Sdump(aliceMsgsToSend)) } // If we process Alice's sync message from Bob's PoV, then he should // send his RevokeAndAck message again. Additionally, the CommitSig // message that he sends should be sufficient to finalize the state // transition. bobMsgsToSend, _, _, err := bobChannel.ProcessChanSyncMsg(aliceSyncMsg) if err != nil { t.Fatalf("unable to process chan sync msg: %v", err) } if len(bobMsgsToSend) != 2 { t.Fatalf("expected bob to send %v messages, instead "+ "sends: %v", 2, spew.Sdump(bobMsgsToSend)) } bobReRevoke, ok := bobMsgsToSend[0].(*lnwire.RevokeAndAck) if !ok { t.Fatalf("expected bob to re-send revoke, instead sending: %v", spew.Sdump(bobMsgsToSend[0])) } if !reflect.DeepEqual(bobReRevoke, bobRevocation) { t.Fatalf("revocation msgs don't match: expected %v, got %v", bobRevocation, bobReRevoke) } // The second message should be his CommitSig message that he never // sent, but will send in order to force both states to synchronize. bobReCommitSigMsg, ok := bobMsgsToSend[1].(*lnwire.CommitSig) if !ok { t.Fatalf("expected bob to re-send commit sig, instead sending: %v", spew.Sdump(bobMsgsToSend[1])) } // At this point we simulate the connection failing with a restart from // Bob. He should still re-send the exact same set of messages. bobChannel, err = restartChannel(bobChannel) if err != nil { t.Fatalf("unable to restart channel: %v", err) } if len(bobMsgsToSend) != 2 { t.Fatalf("expected bob to send %v messages, instead "+ "sends: %v", 2, spew.Sdump(bobMsgsToSend)) } bobReRevoke, ok = bobMsgsToSend[0].(*lnwire.RevokeAndAck) if !ok { t.Fatalf("expected bob to re-send revoke, instead sending: %v", spew.Sdump(bobMsgsToSend[0])) } bobSigMsg, ok := bobMsgsToSend[1].(*lnwire.CommitSig) if !ok { t.Fatalf("expected bob to re-send commit sig, instead sending: %v", spew.Sdump(bobMsgsToSend[1])) } if !reflect.DeepEqual(bobReRevoke, bobRevocation) { t.Fatalf("revocation msgs don't match: expected %v, got %v", bobRevocation, bobReRevoke) } if bobReCommitSigMsg.CommitSig != bobSigMsg.CommitSig { t.Fatalf("commit sig msgs don't match: expected %x got %x", bobSigMsg.CommitSig, bobReCommitSigMsg.CommitSig) } if len(bobReCommitSigMsg.HtlcSigs) != len(bobSigMsg.HtlcSigs) { t.Fatalf("wrong number of htlc sigs: expected %v, got %v", len(bobSigMsg.HtlcSigs), len(bobReCommitSigMsg.HtlcSigs)) } for i, htlcSig := range bobReCommitSigMsg.HtlcSigs { if htlcSig != bobSigMsg.HtlcSigs[i] { t.Fatalf("htlc sig msgs don't match: "+ "expected %x got %x", bobSigMsg.HtlcSigs[i], htlcSig) } } // Now, we'll continue the exchange, sending Bob's revocation and // signature message to Alice, ending with Alice sending her revocation // message to Bob. _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatalf("alice unable to recv revocation: %v", err) } err = aliceChannel.ReceiveNewCommitment( bobSigMsg.CommitSig, bobSigMsg.HtlcSigs, ) if err != nil { t.Fatalf("alice unable to rev bob's commitment: %v", err) } aliceRevocation, _, err = aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("alice unable to revoke commitment: %v", err) } _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatalf("bob unable to recv revocation: %v", err) } } // TestChanSyncFailure tests the various scenarios during channel sync where we // should be able to detect that the channels cannot be synced because of // invalid state. func TestChanSyncFailure(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() htlcAmt := lnwire.NewMSatFromSatoshis(20000) index := byte(0) // advanceState is a helper method to fully advance the channel state // by one. advanceState := func() { t.Helper() // We'll kick off the test by having Bob send Alice an HTLC, // then lock it in with a state transition. var bobPreimage [32]byte copy(bobPreimage[:], bytes.Repeat([]byte{0xaa - index}, 32)) rHash := sha256.Sum256(bobPreimage[:]) bobHtlc := &lnwire.UpdateAddHTLC{ PaymentHash: rHash, Amount: htlcAmt, Expiry: uint32(10), ID: uint64(index), } index++ _, err := bobChannel.AddHTLC(bobHtlc, nil) if err != nil { t.Fatalf("unable to add bob's htlc: %v", err) } _, err = aliceChannel.ReceiveHTLC(bobHtlc) if err != nil { t.Fatalf("unable to recv bob's htlc: %v", err) } err = ForceStateTransition(bobChannel, aliceChannel) if err != nil { t.Fatalf("unable to complete bob's state "+ "transition: %v", err) } } // halfAdvance is a helper method that sends a new commitment signature // from Alice to Bob, but doesn't make Bob revoke his current state. halfAdvance := func() { t.Helper() // We'll kick off the test by having Bob send Alice an HTLC, // then lock it in with a state transition. var bobPreimage [32]byte copy(bobPreimage[:], bytes.Repeat([]byte{0xaa - index}, 32)) rHash := sha256.Sum256(bobPreimage[:]) bobHtlc := &lnwire.UpdateAddHTLC{ PaymentHash: rHash, Amount: htlcAmt, Expiry: uint32(10), ID: uint64(index), } index++ _, err := bobChannel.AddHTLC(bobHtlc, nil) if err != nil { t.Fatalf("unable to add bob's htlc: %v", err) } _, err = aliceChannel.ReceiveHTLC(bobHtlc) if err != nil { t.Fatalf("unable to recv bob's htlc: %v", err) } aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign next commit: %v", err) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("unable to receive commit sig: %v", err) } } // assertLocalDataLoss checks that aliceOld and bobChannel detects that // Alice has lost state during sync. assertLocalDataLoss := func(aliceOld *LightningChannel) { t.Helper() aliceSyncMsg, err := aliceOld.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } bobSyncMsg, err := bobChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } // Alice should detect from Bob's message that she lost state. _, _, _, err = aliceOld.ProcessChanSyncMsg(bobSyncMsg) if _, ok := err.(*ErrCommitSyncLocalDataLoss); !ok { t.Fatalf("wrong error, expected "+ "ErrCommitSyncLocalDataLoss instead got: %v", err) } // Bob should detect that Alice probably lost state. _, _, _, err = bobChannel.ProcessChanSyncMsg(aliceSyncMsg) if err != ErrCommitSyncRemoteDataLoss { t.Fatalf("wrong error, expected "+ "ErrCommitSyncRemoteDataLoss instead got: %v", err) } } // clearBorkedState is a method that allows us to clear the borked // state that will arise after the first chan message sync. We need to // do this in order to be able to continue to update the commitment // state for our test scenarios. clearBorkedState := func() { err = aliceChannel.channelState.ClearChanStatus( channeldb.ChanStatusLocalDataLoss | channeldb.ChanStatusBorked, ) if err != nil { t.Fatalf("unable to update channel state: %v", err) } err = bobChannel.channelState.ClearChanStatus( channeldb.ChanStatusLocalDataLoss | channeldb.ChanStatusBorked, ) if err != nil { t.Fatalf("unable to update channel state: %v", err) } } // Start by advancing the state. advanceState() // They should be in sync. assertNoChanSyncNeeded(t, aliceChannel, bobChannel) // Make a copy of Alice's state from the database at this point. aliceOld, err := restartChannel(aliceChannel) if err != nil { t.Fatalf("unable to restart channel: %v", err) } // Advance the states. advanceState() // Trying to sync up the old version of Alice's channel should detect // that we are out of sync. assertLocalDataLoss(aliceOld) // Make sure the up-to-date channels still are in sync. assertNoChanSyncNeeded(t, aliceChannel, bobChannel) // Clear the borked state before we attempt to advance. clearBorkedState() // Advance the state again, and do the same check. advanceState() assertNoChanSyncNeeded(t, aliceChannel, bobChannel) assertLocalDataLoss(aliceOld) // If we remove the recovery options from Bob's message, Alice cannot // tell if she lost state, since Bob might be lying. She still should // be able to detect that chains cannot be synced. bobSyncMsg, err := bobChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } bobSyncMsg.LocalUnrevokedCommitPoint = nil _, _, _, err = aliceOld.ProcessChanSyncMsg(bobSyncMsg) if err != ErrCannotSyncCommitChains { t.Fatalf("wrong error, expected ErrCannotSyncCommitChains "+ "instead got: %v", err) } // If Bob lies about the NextLocalCommitHeight, making it greater than // what Alice expect, she cannot tell for sure whether she lost state, // but should detect the desync. bobSyncMsg, err = bobChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } bobSyncMsg.NextLocalCommitHeight++ _, _, _, err = aliceChannel.ProcessChanSyncMsg(bobSyncMsg) if err != ErrCannotSyncCommitChains { t.Fatalf("wrong error, expected ErrCannotSyncCommitChains "+ "instead got: %v", err) } // If Bob's NextLocalCommitHeight is lower than what Alice expects, Bob // probably lost state. bobSyncMsg, err = bobChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } bobSyncMsg.NextLocalCommitHeight-- _, _, _, err = aliceChannel.ProcessChanSyncMsg(bobSyncMsg) if err != ErrCommitSyncRemoteDataLoss { t.Fatalf("wrong error, expected ErrCommitSyncRemoteDataLoss "+ "instead got: %v", err) } // If Alice and Bob's states are in sync, but Bob is sending the wrong // LocalUnrevokedCommitPoint, Alice should detect this. bobSyncMsg, err = bobChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } p := bobSyncMsg.LocalUnrevokedCommitPoint.SerializeCompressed() p[4] ^= 0x01 modCommitPoint, err := btcec.ParsePubKey(p, btcec.S256()) if err != nil { t.Fatalf("unable to parse pubkey: %v", err) } bobSyncMsg.LocalUnrevokedCommitPoint = modCommitPoint _, _, _, err = aliceChannel.ProcessChanSyncMsg(bobSyncMsg) if err != ErrInvalidLocalUnrevokedCommitPoint { t.Fatalf("wrong error, expected "+ "ErrInvalidLocalUnrevokedCommitPoint instead got: %v", err) } // Make sure the up-to-date channels still are good. assertNoChanSyncNeeded(t, aliceChannel, bobChannel) // Clear the borked state before we attempt to advance. clearBorkedState() // Finally check that Alice is also able to detect a wrong commit point // when there's a pending remote commit. halfAdvance() bobSyncMsg, err = bobChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } bobSyncMsg.LocalUnrevokedCommitPoint = modCommitPoint _, _, _, err = aliceChannel.ProcessChanSyncMsg(bobSyncMsg) if err != ErrInvalidLocalUnrevokedCommitPoint { t.Fatalf("wrong error, expected "+ "ErrInvalidLocalUnrevokedCommitPoint instead got: %v", err) } } // TestFeeUpdateRejectInsaneFee tests that if the initiator tries to attach a // fee that would put them below their current reserve, then it's rejected by // the state machine. func TestFeeUpdateRejectInsaneFee(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, _, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // Next, we'll try to add a fee rate to Alice which is 1,000,000x her // starting fee rate. startingFeeRate := chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) newFeeRate := startingFeeRate * 1000000 // Both Alice and Bob should reject this new fee rate as it is far too // large. if err := aliceChannel.UpdateFee(newFeeRate); err == nil { t.Fatalf("alice should have rejected fee update") } } // TestChannelRetransmissionFeeUpdate tests that the initiator will include any // pending fee updates if it needs to retransmit signatures. func TestChannelRetransmissionFeeUpdate(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // First, we'll fetch the current fee rate present within the // commitment transactions. startingFeeRate := chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) // Next, we'll start a commitment update, with Alice sending a new // update to double the fee rate of the commitment. newFeeRate := startingFeeRate * 2 if err := aliceChannel.UpdateFee(newFeeRate); err != nil { t.Fatalf("unable to update fee for Alice's channel: %v", err) } if err := bobChannel.ReceiveUpdateFee(newFeeRate); err != nil { t.Fatalf("unable to update fee for Bob's channel: %v", err) } // Now, Alice will send a new commitment to Bob, but we'll simulate a // connection failure, so Bob doesn't get her signature. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } // Restart both channels to simulate a connection restart. aliceChannel, err = restartChannel(aliceChannel) if err != nil { t.Fatalf("unable to restart alice: %v", err) } bobChannel, err = restartChannel(bobChannel) if err != nil { t.Fatalf("unable to restart channel: %v", err) } // Bob doesn't get this message so upon reconnection, they need to // synchronize. Alice should conclude that she owes Bob a commitment, // while Bob should think he's properly synchronized. aliceSyncMsg, err := aliceChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } bobSyncMsg, err := bobChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to produce chan sync msg: %v", err) } // Bob should detect that he doesn't need to send anything to Alice. bobMsgsToSend, _, _, err := bobChannel.ProcessChanSyncMsg(aliceSyncMsg) if err != nil { t.Fatalf("unable to process chan sync msg: %v", err) } if len(bobMsgsToSend) != 0 { t.Fatalf("expected bob to send %v messages instead "+ "will send %v: %v", 0, len(bobMsgsToSend), spew.Sdump(bobMsgsToSend)) } // When Alice processes Bob's chan sync message, she should realize // that she needs to first send a new UpdateFee message, and also a // CommitSig. aliceMsgsToSend, _, _, err := aliceChannel.ProcessChanSyncMsg( bobSyncMsg, ) if err != nil { t.Fatalf("unable to process chan sync msg: %v", err) } if len(aliceMsgsToSend) != 2 { t.Fatalf("expected alice to send %v messages instead "+ "will send %v: %v", 2, len(aliceMsgsToSend), spew.Sdump(aliceMsgsToSend)) } // The first message should be an UpdateFee message. retransFeeMsg, ok := aliceMsgsToSend[0].(*lnwire.UpdateFee) if !ok { t.Fatalf("expected UpdateFee message, instead have: %v", spew.Sdump(aliceMsgsToSend[0])) } // The fee should match exactly the new fee update we applied above. if retransFeeMsg.FeePerKw != uint32(newFeeRate) { t.Fatalf("fee update doesn't match: expected %v, got %v", uint32(newFeeRate), retransFeeMsg) } // The second, should be a CommitSig message, and be identical to the // sig message she sent prior. commitSigMsg, ok := aliceMsgsToSend[1].(*lnwire.CommitSig) if !ok { t.Fatalf("expected a CommitSig message, instead have %v", spew.Sdump(aliceMsgsToSend[1])) } if commitSigMsg.CommitSig != aliceSig { t.Fatalf("commit sig msgs don't match: expected %x got %x", aliceSig, commitSigMsg.CommitSig) } if len(commitSigMsg.HtlcSigs) != len(aliceHtlcSigs) { t.Fatalf("wrong number of htlc sigs: expected %v, got %v", len(aliceHtlcSigs), len(commitSigMsg.HtlcSigs)) } for i, htlcSig := range commitSigMsg.HtlcSigs { if htlcSig != aliceHtlcSigs[i] { t.Fatalf("htlc sig msgs don't match: "+ "expected %x got %x", aliceHtlcSigs[i], htlcSig) } } // Now, we if re-apply the updates to Bob, we should be able to resume // the commitment update as normal. if err := bobChannel.ReceiveUpdateFee(newFeeRate); err != nil { t.Fatalf("unable to update fee for Bob's channel: %v", err) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("bob unable to process alice's commitment: %v", err) } bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke bob commitment: %v", err) } bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("bob unable to sign commitment: %v", err) } _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatalf("alice unable to recv revocation: %v", err) } err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("alice unable to rev bob's commitment: %v", err) } aliceRevocation, _, err := aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("alice unable to revoke commitment: %v", err) } _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatalf("bob unable to recv revocation: %v", err) } // Both parties should now have the latest fee rate locked-in. if chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) != newFeeRate { t.Fatalf("alice's feePerKw was not locked in") } if chainfee.SatPerKWeight( bobChannel.channelState.LocalCommitment.FeePerKw, ) != newFeeRate { t.Fatalf("bob's feePerKw was not locked in") } // Finally, we'll add with adding a new HTLC, then forcing a state // transition. This should also proceed as normal. var bobPreimage [32]byte copy(bobPreimage[:], bytes.Repeat([]byte{0xaa}, 32)) rHash := sha256.Sum256(bobPreimage[:]) bobHtlc := &lnwire.UpdateAddHTLC{ PaymentHash: rHash, Amount: lnwire.NewMSatFromSatoshis(20000), Expiry: uint32(10), } if _, err := bobChannel.AddHTLC(bobHtlc, nil); err != nil { t.Fatalf("unable to add bob's htlc: %v", err) } if _, err := aliceChannel.ReceiveHTLC(bobHtlc); err != nil { t.Fatalf("unable to recv bob's htlc: %v", err) } if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("unable to complete bob's state transition: %v", err) } } // TestFeeUpdateOldDiskFormat tests that we properly recover FeeUpdates written // to disk using the old format, where the logIndex was not written. func TestFeeUpdateOldDiskFormat(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // helper that counts the number of updates, and number of fee updates // in the given log. countLog := func(log *updateLog) (int, int) { var numUpdates, numFee int for e := log.Front(); e != nil; e = e.Next() { htlc := e.Value.(*PaymentDescriptor) if htlc.EntryType == FeeUpdate { numFee++ } numUpdates++ } return numUpdates, numFee } // helper that asserts that Alice's local log and Bob's remote log // contains the expected number of fee updates and adds. assertLogItems := func(expFee, expAdd int) { t.Helper() expUpd := expFee + expAdd upd, fees := countLog(aliceChannel.localUpdateLog) if upd != expUpd { t.Fatalf("expected %d updates, found %d in Alice's "+ "log", expUpd, upd) } if fees != expFee { t.Fatalf("expected %d fee updates, found %d in "+ "Alice's log", expFee, fees) } upd, fees = countLog(bobChannel.remoteUpdateLog) if upd != expUpd { t.Fatalf("expected %d updates, found %d in Bob's log", expUpd, upd) } if fees != expFee { t.Fatalf("expected %d fee updates, found %d in Bob's "+ "log", expFee, fees) } } // First, we'll fetch the current fee rate present within the // commitment transactions. startingFeeRate := chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) newFeeRate := startingFeeRate // We will send a few HTLCs and a fee update. htlcAmt := lnwire.NewMSatFromSatoshis(0.1 * btcutil.SatoshiPerBitcoin) const numHTLCs = 30 var htlcs []*lnwire.UpdateAddHTLC for i := 0; i < numHTLCs; i++ { htlc, _ := createHTLC(i, htlcAmt) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } htlcs = append(htlcs, htlc) if i%5 != 0 { continue } // After every 5th HTLC, we'll also include a fee update. newFeeRate += startingFeeRate if err := aliceChannel.UpdateFee(newFeeRate); err != nil { t.Fatalf("unable to update fee for Alice's channel: %v", err) } if err := bobChannel.ReceiveUpdateFee(newFeeRate); err != nil { t.Fatalf("unable to update fee for Bob's channel: %v", err) } } // Check that the expected number of items is found in the logs. expFee := numHTLCs / 5 assertLogItems(expFee, numHTLCs) // Now, Alice will send a new commitment to Bob, but we'll simulate a // connection failure, so Bob doesn't get the signature. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } // Before restarting Alice, to mimic the old format, we fetch the // pending remote commit from disk, set the UpdateFee message's // logIndex to 0, and re-write it. pendingRemoteCommitDiff, err := aliceChannel.channelState.RemoteCommitChainTip() if err != nil { t.Fatal(err) } for i, u := range pendingRemoteCommitDiff.LogUpdates { switch u.UpdateMsg.(type) { case *lnwire.UpdateFee: pendingRemoteCommitDiff.LogUpdates[i].LogIndex = 0 } } err = aliceChannel.channelState.AppendRemoteCommitChain( pendingRemoteCommitDiff, ) if err != nil { t.Fatal(err) } // Restart both channels to simulate a connection restart. This will // trigger a update logs restoration. aliceChannel, err = restartChannel(aliceChannel) if err != nil { t.Fatalf("unable to restart alice: %v", err) } bobChannel, err = restartChannel(bobChannel) if err != nil { t.Fatalf("unable to restart channel: %v", err) } // After a reconnection, Alice will resend the pending updates, that // was not ACKed by Bob, so we re-send the HTLCs and fee updates. newFeeRate = startingFeeRate for i := 0; i < numHTLCs; i++ { htlc := htlcs[i] if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } if i%5 != 0 { continue } newFeeRate += startingFeeRate if err := bobChannel.ReceiveUpdateFee(newFeeRate); err != nil { t.Fatalf("unable to update fee for Bob's channel: %v", err) } } assertLogItems(expFee, numHTLCs) // We send Alice's commitment signatures, and finish the state // transition. err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("bob unable to process alice's commitment: %v", err) } bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke bob commitment: %v", err) } bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("bob unable to sign commitment: %v", err) } _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatalf("alice unable to recv revocation: %v", err) } err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("alice unable to rev bob's commitment: %v", err) } aliceRevocation, _, err := aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("alice unable to revoke commitment: %v", err) } _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatalf("bob unable to recv revocation: %v", err) } // Both parties should now have the latest fee rate locked-in. if chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) != newFeeRate { t.Fatalf("alice's feePerKw was not locked in") } if chainfee.SatPerKWeight( bobChannel.channelState.LocalCommitment.FeePerKw, ) != newFeeRate { t.Fatalf("bob's feePerKw was not locked in") } // Finally, to trigger a compactLogs execution, we'll add a new HTLC, // then force a state transition. htlc, _ := createHTLC(numHTLCs, htlcAmt) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete bob's state transition: %v", err) } // Finally, check the logs to make sure all fee updates have been // removed... assertLogItems(0, numHTLCs+1) // ...and the final fee rate locked in. if chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) != newFeeRate { t.Fatalf("alice's feePerKw was not locked in") } if chainfee.SatPerKWeight( bobChannel.channelState.LocalCommitment.FeePerKw, ) != newFeeRate { t.Fatalf("bob's feePerKw was not locked in") } } // TestChanSyncUnableToSync tests that if Alice or Bob receive an invalid // ChannelReestablish messages,then they reject the message and declare the // channel un-continuable by returning ErrCannotSyncCommitChains. func TestChanSyncUnableToSync(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // If we immediately send both sides a "bogus" ChanSync message, then // they both should conclude that they're unable to synchronize the // state. badChanSync := &lnwire.ChannelReestablish{ ChanID: lnwire.NewChanIDFromOutPoint( &aliceChannel.channelState.FundingOutpoint, ), NextLocalCommitHeight: 1000, RemoteCommitTailHeight: 9000, } _, _, _, err = bobChannel.ProcessChanSyncMsg(badChanSync) if err != ErrCannotSyncCommitChains { t.Fatalf("expected error instead have: %v", err) } _, _, _, err = aliceChannel.ProcessChanSyncMsg(badChanSync) if err != ErrCannotSyncCommitChains { t.Fatalf("expected error instead have: %v", err) } } // TestChanSyncInvalidLastSecret ensures that if Alice and Bob have completed // state transitions in an existing channel, and then send a ChannelReestablish // message after a restart, the following holds: if Alice has lost data, so she // sends an invalid commit secret then both parties recognize this as possible // data loss. func TestChanSyncInvalidLastSecret(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // We'll create a new instances of Alice before doing any state updates // such that we have the initial in memory state at the start of the // channel. aliceOld, err := restartChannel(aliceChannel) if err != nil { t.Fatalf("unable to restart alice") } // First, we'll add an HTLC, and then initiate a state transition // between the two parties such that we actually have a prior // revocation to send. var paymentPreimage [32]byte copy(paymentPreimage[:], bytes.Repeat([]byte{1}, 32)) paymentHash := sha256.Sum256(paymentPreimage[:]) htlcAmt := lnwire.NewMSatFromSatoshis(btcutil.SatoshiPerBitcoin) htlc := &lnwire.UpdateAddHTLC{ PaymentHash: paymentHash, Amount: htlcAmt, Expiry: uint32(5), } if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } // Then we'll initiate a state transition to lock in this new HTLC. if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete alice's state transition: %v", err) } // Next, we'll restart both parties in order to simulate a connection // re-establishment. aliceChannel, err = restartChannel(aliceChannel) if err != nil { t.Fatalf("unable to restart alice: %v", err) } bobChannel, err = restartChannel(bobChannel) if err != nil { t.Fatalf("unable to restart bob: %v", err) } // Next, we'll produce the ChanSync messages for both parties. aliceChanSync, err := aliceChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to generate chan sync msg: %v", err) } bobChanSync, err := bobChannel.channelState.ChanSyncMsg() if err != nil { t.Fatalf("unable to generate chan sync msg: %v", err) } // We'll modify Alice's sync message to have an invalid commitment // secret. aliceChanSync.LastRemoteCommitSecret[4] ^= 0x01 // Alice's former self should conclude that she possibly lost data as // Bob is sending a valid commit secret for the latest state. _, _, _, err = aliceOld.ProcessChanSyncMsg(bobChanSync) if _, ok := err.(*ErrCommitSyncLocalDataLoss); !ok { t.Fatalf("wrong error, expected ErrCommitSyncLocalDataLoss "+ "instead got: %v", err) } // Bob should conclude that he should force close the channel, as Alice // cannot continue operation. _, _, _, err = bobChannel.ProcessChanSyncMsg(aliceChanSync) if err != ErrInvalidLastCommitSecret { t.Fatalf("wrong error, expected ErrInvalidLastCommitSecret, "+ "instead got: %v", err) } } // TestChanAvailableBandwidth tests the accuracy of the AvailableBalance() // method. The value returned from this message should reflect the value // returned within the commitment state of a channel after the transition is // initiated. func TestChanAvailableBandwidth(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() aliceReserve := lnwire.NewMSatFromSatoshis( aliceChannel.channelState.LocalChanCfg.ChanReserve, ) feeRate := chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) htlcFee := lnwire.NewMSatFromSatoshis( feeRate.FeeForWeight(input.HTLCWeight), ) assertBandwidthEstimateCorrect := func(aliceInitiate bool) { // With the HTLC's added, we'll now query the AvailableBalance // method for the current available channel bandwidth from // Alice's PoV. aliceAvailableBalance := aliceChannel.AvailableBalance() // With this balance obtained, we'll now trigger a state update // to actually determine what the current up to date balance // is. if aliceInitiate { err := ForceStateTransition(aliceChannel, bobChannel) if err != nil { t.Fatalf("unable to complete alice's state "+ "transition: %v", err) } } else { err := ForceStateTransition(bobChannel, aliceChannel) if err != nil { t.Fatalf("unable to complete alice's state "+ "transition: %v", err) } } // Now, we'll obtain the current available bandwidth in Alice's // latest commitment and compare that to the prior estimate. aliceBalance := aliceChannel.channelState.LocalCommitment.LocalBalance // The balance we have available for new HTLCs should be the // current local commitment balance, minus the channel reserve // and the fee for adding an HTLC. expBalance := aliceBalance - aliceReserve - htlcFee if expBalance != aliceAvailableBalance { _, _, line, _ := runtime.Caller(1) t.Fatalf("line: %v, incorrect balance: expected %v, "+ "got %v", line, expBalance, aliceAvailableBalance) } } // First, we'll add 3 outgoing HTLC's from Alice to Bob. const numHtlcs = 3 var htlcAmt lnwire.MilliSatoshi = 100000 alicePreimages := make([][32]byte, numHtlcs) for i := 0; i < numHtlcs; i++ { htlc, preImage := createHTLC(i, htlcAmt) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } alicePreimages[i] = preImage } assertBandwidthEstimateCorrect(true) // We'll repeat the same exercise, but with non-dust HTLCs. So we'll // crank up the value of the HTLC's we're adding to the commitment // transaction. htlcAmt = lnwire.NewMSatFromSatoshis(30000) for i := 0; i < numHtlcs; i++ { htlc, preImage := createHTLC(numHtlcs+i, htlcAmt) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } alicePreimages = append(alicePreimages, preImage) } assertBandwidthEstimateCorrect(true) // Next, we'll have Bob 5 of Alice's HTLC's, and cancel one of them (in // the update log). for i := 0; i < (numHtlcs*2)-1; i++ { preImage := alicePreimages[i] err := bobChannel.SettleHTLC(preImage, uint64(i), nil, nil, nil) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } err = aliceChannel.ReceiveHTLCSettle(preImage, uint64(i)) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } } htlcIndex := uint64((numHtlcs * 2) - 1) err = bobChannel.FailHTLC(htlcIndex, []byte("f"), nil, nil, nil) if err != nil { t.Fatalf("unable to cancel HTLC: %v", err) } err = aliceChannel.ReceiveFailHTLC(htlcIndex, []byte("bad")) if err != nil { t.Fatalf("unable to recv htlc cancel: %v", err) } // We must do a state transition before the balance is available // for Alice. if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete alice's state "+ "transition: %v", err) } // With the HTLC's settled in the log, we'll now assert that if we // initiate a state transition, then our guess was correct. assertBandwidthEstimateCorrect(false) // TODO(roasbeef): additional tests from diff starting conditions } // TestChanAvailableBalanceNearHtlcFee checks that we get the expected reported // balance when it is close to the htlc fee. func TestChanAvailableBalanceNearHtlcFee(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // Alice and Bob start with half the channel capacity. aliceBalance := lnwire.NewMSatFromSatoshis(5 * btcutil.SatoshiPerBitcoin) bobBalance := lnwire.NewMSatFromSatoshis(5 * btcutil.SatoshiPerBitcoin) aliceReserve := lnwire.NewMSatFromSatoshis( aliceChannel.channelState.LocalChanCfg.ChanReserve, ) bobReserve := lnwire.NewMSatFromSatoshis( bobChannel.channelState.LocalChanCfg.ChanReserve, ) aliceDustlimit := lnwire.NewMSatFromSatoshis( aliceChannel.channelState.LocalChanCfg.DustLimit, ) feeRate := chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ) htlcFee := lnwire.NewMSatFromSatoshis( feeRate.FeeForWeight(input.HTLCWeight), ) commitFee := lnwire.NewMSatFromSatoshis( aliceChannel.channelState.LocalCommitment.CommitFee, ) htlcTimeoutFee := lnwire.NewMSatFromSatoshis( HtlcTimeoutFee(aliceChannel.channelState.ChanType, feeRate), ) htlcSuccessFee := lnwire.NewMSatFromSatoshis( HtlcSuccessFee(aliceChannel.channelState.ChanType, feeRate), ) // Helper method to check the current reported balance. checkBalance := func(t *testing.T, expBalanceAlice, expBalanceBob lnwire.MilliSatoshi) { t.Helper() aliceBalance := aliceChannel.AvailableBalance() if aliceBalance != expBalanceAlice { t.Fatalf("Expected alice balance %v, got %v", expBalanceAlice, aliceBalance) } bobBalance := bobChannel.AvailableBalance() if bobBalance != expBalanceBob { t.Fatalf("Expected bob balance %v, got %v", expBalanceBob, bobBalance) } } // Helper method to send an HTLC from Alice to Bob, decreasing Alice's // balance. htlcIndex := uint64(0) sendHtlc := func(htlcAmt lnwire.MilliSatoshi) { t.Helper() htlc, preImage := createHTLC(int(htlcIndex), htlcAmt) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete alice's state "+ "transition: %v", err) } err = bobChannel.SettleHTLC(preImage, htlcIndex, nil, nil, nil) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } err = aliceChannel.ReceiveHTLCSettle(preImage, htlcIndex) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete alice's state "+ "transition: %v", err) } htlcIndex++ aliceBalance -= htlcAmt bobBalance += htlcAmt } // Balance should start out equal to half the channel capacity minus // the commitment fee Alice must pay and the channel reserve. In // addition the HTLC fee will be subtracted fromt the balance to // reflect that this value must be reserved for any payment above the // dust limit. expAliceBalance := aliceBalance - commitFee - aliceReserve - htlcFee // Bob is not the initiator, so he will have all his balance available, // since Alice pays for fees. Bob only need to keep his balance above // the reserve. expBobBalance := bobBalance - bobReserve checkBalance(t, expAliceBalance, expBobBalance) // Find the minumim size of a non-dust HTLC. aliceNonDustHtlc := aliceDustlimit + htlcTimeoutFee // Send a HTLC leaving Alice's remaining balance just enough to have // nonDustHtlc left after paying the commit fee and htlc fee. htlcAmt := aliceBalance - (commitFee + aliceReserve + htlcFee + aliceNonDustHtlc) sendHtlc(htlcAmt) // Now the real balance left will be // nonDustHtlc+commitfee+aliceReserve+htlcfee. The available balance // reported will just be nonDustHtlc, since the rest of the balance is // reserved. expAliceBalance = aliceNonDustHtlc expBobBalance = bobBalance - bobReserve checkBalance(t, expAliceBalance, expBobBalance) // Send an HTLC using all but one msat of the reported balance. htlcAmt = aliceNonDustHtlc - 1 sendHtlc(htlcAmt) // 1 msat should be left. expAliceBalance = 1 // Bob should still have all his balance available, since even though // Alice cannot afford to add a non-dust HTLC, she can afford to add a // non-dust HTLC from Bob. expBobBalance = bobBalance - bobReserve checkBalance(t, expAliceBalance, expBobBalance) // Sendng the last msat. htlcAmt = 1 sendHtlc(htlcAmt) // No balance left. expAliceBalance = 0 // We try to always reserve enough for the non-iniitator to be able to // add an HTLC, hence Bob should still have all his non-reserved // balance available. expBobBalance = bobBalance - bobReserve checkBalance(t, expAliceBalance, expBobBalance) // Even though Alice has a reported balance of 0, this is because we // try to avoid getting into the position where she cannot pay the fee // for Bob adding another HTLC. This means she actually _has_ some // balance left, and we now force the channel into this situation by // sending yet another HTLC. In practice this can also happen if a fee // update eats into Alice's balance. htlcAmt = 1 sendHtlc(htlcAmt) // Now Alice balance is so low that she cannot even afford to add a new // HTLC from Bob to the commitment transaction. Bob's balance should // reflect this, by only reporting dust amount being available. Alice // should still report a zero balance. // Since the dustlimit is different for the two commitments, the // largest HTLC Bob can send that Alice can afford on both commitments // (remember she cannot afford to pay the HTLC fee) is the largest dust // HTLC on Alice's commitemnt, since her dust limit is lower. bobNonDustHtlc := aliceDustlimit + htlcSuccessFee expBobBalance = bobNonDustHtlc - 1 expAliceBalance = 0 checkBalance(t, expAliceBalance, expBobBalance) } // TestSignCommitmentFailNotLockedIn tests that a channel will not attempt to // create a new state if it doesn't yet know of the next revocation point for // the remote party. func TestSignCommitmentFailNotLockedIn(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, _, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // Next, we'll modify Alice's internal state to omit knowledge of Bob's // next revocation point. aliceChannel.channelState.RemoteNextRevocation = nil // If we now try to initiate a state update, then it should fail as // Alice is unable to actually create a new state. _, _, _, err = aliceChannel.SignNextCommitment() if err != ErrNoWindow { t.Fatalf("expected ErrNoWindow, instead have: %v", err) } } // TestLockedInHtlcForwardingSkipAfterRestart ensures that after a restart, a // state machine doesn't attempt to re-forward any HTLC's that were already // locked in, but in a prior state. func TestLockedInHtlcForwardingSkipAfterRestart(t *testing.T) { t.Parallel() // First, we'll make a channel between Alice and Bob. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // We'll now add two HTLC's from Alice to Bob, then Alice will initiate // a state transition. var htlcAmt lnwire.MilliSatoshi = 100000 htlc, _ := createHTLC(0, htlcAmt) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } htlc2, _ := createHTLC(1, htlcAmt) if _, err := aliceChannel.AddHTLC(htlc2, nil); err != nil { t.Fatalf("unable to add htlc2: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc2); err != nil { t.Fatalf("unable to recv htlc2: %v", err) } // We'll now manually initiate a state transition between Alice and // bob. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatal(err) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatal(err) } bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatal(err) } // Alice should detect that she doesn't need to forward any HTLC's. fwdPkg, _, _, _, err := aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatal(err) } if len(fwdPkg.Adds) != 0 { t.Fatalf("alice shouldn't forward any HTLC's, instead wants to "+ "forward %v htlcs", len(fwdPkg.Adds)) } if len(fwdPkg.SettleFails) != 0 { t.Fatalf("alice shouldn't forward any HTLC's, instead wants to "+ "forward %v htlcs", len(fwdPkg.SettleFails)) } // Now, have Bob initiate a transition to lock in the Adds sent by // Alice. bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatal(err) } err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatal(err) } aliceRevocation, _, err := aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatal(err) } // Bob should now detect that he now has 2 incoming HTLC's that he can // forward along. fwdPkg, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatal(err) } if len(fwdPkg.Adds) != 2 { t.Fatalf("bob should forward 2 hltcs, instead has %v", len(fwdPkg.Adds)) } if len(fwdPkg.SettleFails) != 0 { t.Fatalf("bob should forward 0 hltcs, instead has %v", len(fwdPkg.SettleFails)) } // We'll now restart both Alice and Bob. This emulates a reconnection // between the two peers. aliceChannel, err = restartChannel(aliceChannel) if err != nil { t.Fatalf("unable to restart alice: %v", err) } bobChannel, err = restartChannel(bobChannel) if err != nil { t.Fatalf("unable to restart bob: %v", err) } // With both nodes restarted, Bob will now attempt to cancel one of // Alice's HTLC's. err = bobChannel.FailHTLC(htlc.ID, []byte("failreason"), nil, nil, nil) if err != nil { t.Fatalf("unable to cancel HTLC: %v", err) } err = aliceChannel.ReceiveFailHTLC(htlc.ID, []byte("bad")) if err != nil { t.Fatalf("unable to recv htlc cancel: %v", err) } // We'll now initiate another state transition, but this time Bob will // lead. bobSig, bobHtlcSigs, _, err = bobChannel.SignNextCommitment() if err != nil { t.Fatal(err) } err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatal(err) } aliceRevocation, _, err = aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatal(err) } // At this point, Bob receives the revocation from Alice, which is now // his signal to examine all the HTLC's that have been locked in to // process. fwdPkg, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatal(err) } // Bob should detect that he doesn't need to forward *any* HTLC's, as // he was the one that initiated extending the commitment chain of // Alice. if len(fwdPkg.Adds) != 0 { t.Fatalf("alice shouldn't forward any HTLC's, instead wants to "+ "forward %v htlcs", len(fwdPkg.Adds)) } if len(fwdPkg.SettleFails) != 0 { t.Fatalf("alice shouldn't forward any HTLC's, instead wants to "+ "forward %v htlcs", len(fwdPkg.SettleFails)) } // Now, begin another state transition led by Alice, and fail the second // HTLC part-way through the dance. aliceSig, aliceHtlcSigs, _, err = aliceChannel.SignNextCommitment() if err != nil { t.Fatal(err) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatal(err) } // Failing the HTLC here will cause the update to be included in Alice's // remote log, but it should not be committed by this transition. err = bobChannel.FailHTLC(htlc2.ID, []byte("failreason"), nil, nil, nil) if err != nil { t.Fatalf("unable to cancel HTLC: %v", err) } err = aliceChannel.ReceiveFailHTLC(htlc2.ID, []byte("bad")) if err != nil { t.Fatalf("unable to recv htlc cancel: %v", err) } bobRevocation, _, err = bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatal(err) } // Alice should detect that she doesn't need to forward any Adds's, but // that the Fail has been locked in an can be forwarded. _, adds, settleFails, _, err := aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatal(err) } if len(adds) != 0 { t.Fatalf("alice shouldn't forward any HTLC's, instead wants to "+ "forward %v htlcs", len(adds)) } if len(settleFails) != 1 { t.Fatalf("alice should only forward %d HTLC's, instead wants to "+ "forward %v htlcs", 1, len(settleFails)) } if settleFails[0].ParentIndex != htlc.ID { t.Fatalf("alice should forward fail for htlcid=%d, instead "+ "forwarding id=%d", htlc.ID, settleFails[0].ParentIndex) } // We'll now restart both Alice and Bob. This emulates a reconnection // between the two peers. aliceChannel, err = restartChannel(aliceChannel) if err != nil { t.Fatalf("unable to restart alice: %v", err) } bobChannel, err = restartChannel(bobChannel) if err != nil { t.Fatalf("unable to restart bob: %v", err) } // Readd the Fail to both Alice and Bob's channels, as the non-committed // update will not have survived the restart. err = bobChannel.FailHTLC(htlc2.ID, []byte("failreason"), nil, nil, nil) if err != nil { t.Fatalf("unable to cancel HTLC: %v", err) } err = aliceChannel.ReceiveFailHTLC(htlc2.ID, []byte("bad")) if err != nil { t.Fatalf("unable to recv htlc cancel: %v", err) } // Have Alice initiate a state transition, which does not include the // HTLCs just readded to the channel state. aliceSig, aliceHtlcSigs, _, err = aliceChannel.SignNextCommitment() if err != nil { t.Fatal(err) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatal(err) } bobRevocation, _, err = bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatal(err) } // Alice should detect that she doesn't need to forward any HTLC's, as // the updates haven't been committed by Bob yet. fwdPkg, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatal(err) } if len(fwdPkg.Adds) != 0 { t.Fatalf("alice shouldn't forward any HTLC's, instead wants to "+ "forward %v htlcs", len(fwdPkg.Adds)) } if len(fwdPkg.SettleFails) != 0 { t.Fatalf("alice shouldn't forward any HTLC's, instead wants to "+ "forward %v htlcs", len(fwdPkg.SettleFails)) } // Now initiate a final update from Bob to lock in the final Fail. bobSig, bobHtlcSigs, _, err = bobChannel.SignNextCommitment() if err != nil { t.Fatal(err) } err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatal(err) } aliceRevocation, _, err = aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatal(err) } // Bob should detect that he has nothing to forward, as he hasn't // received any HTLCs. fwdPkg, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatal(err) } if len(fwdPkg.Adds) != 0 { t.Fatalf("bob should forward 4 hltcs, instead has %v", len(fwdPkg.Adds)) } if len(fwdPkg.SettleFails) != 0 { t.Fatalf("bob should forward 0 hltcs, instead has %v", len(fwdPkg.SettleFails)) } // Finally, have Bob initiate a state transition that locks in the Fail // added after the restart. aliceSig, aliceHtlcSigs, _, err = aliceChannel.SignNextCommitment() if err != nil { t.Fatal(err) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatal(err) } bobRevocation, _, err = bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatal(err) } // When Alice receives the revocation, she should detect that she // can now forward the freshly locked-in Fail. _, adds, settleFails, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatal(err) } if len(adds) != 0 { t.Fatalf("alice shouldn't forward any HTLC's, instead wants to "+ "forward %v htlcs", len(adds)) } if len(settleFails) != 1 { t.Fatalf("alice should only forward one HTLC, instead wants to "+ "forward %v htlcs", len(settleFails)) } if settleFails[0].ParentIndex != htlc2.ID { t.Fatalf("alice should forward fail for htlcid=%d, instead "+ "forwarding id=%d", htlc2.ID, settleFails[0].ParentIndex) } } // TestInvalidCommitSigError tests that if the remote party sends us an invalid // commitment signature, then we'll reject it and return a special error that // contains information to allow the remote party to debug their issues. func TestInvalidCommitSigError(t *testing.T) { t.Parallel() // First, we'll make a channel between Alice and Bob. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // With the channel established, we'll now send a single HTLC from // Alice to Bob. var htlcAmt lnwire.MilliSatoshi = 100000 htlc, _ := createHTLC(0, htlcAmt) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } // Alice will now attempt to initiate a state transition. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign new commit: %v", err) } // Before the signature gets to Bob, we'll mutate it, such that the // signature is now actually invalid. aliceSig[0] ^= 88 // Bob should reject this new state, and return the proper error. err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err == nil { t.Fatalf("bob accepted invalid state but shouldn't have") } if _, ok := err.(*InvalidCommitSigError); !ok { t.Fatalf("bob sent incorrect error, expected %T, got %T", &InvalidCommitSigError{}, err) } } // TestChannelUnilateralCloseHtlcResolution tests that in the case of a // unilateral channel closure, then the party that didn't broadcast the // commitment is able to properly sweep all relevant outputs. func TestChannelUnilateralCloseHtlcResolution(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // We'll start off the test by adding an HTLC in both directions, then // initiating enough state transitions to lock both of them in. htlcAmount := lnwire.NewMSatFromSatoshis(20000) htlcAlice, _ := createHTLC(0, htlcAmount) if _, err := aliceChannel.AddHTLC(htlcAlice, nil); err != nil { t.Fatalf("alice unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlcAlice); err != nil { t.Fatalf("bob unable to recv add htlc: %v", err) } htlcBob, preimageBob := createHTLC(0, htlcAmount) if _, err := bobChannel.AddHTLC(htlcBob, nil); err != nil { t.Fatalf("bob unable to add htlc: %v", err) } if _, err := aliceChannel.ReceiveHTLC(htlcBob); err != nil { t.Fatalf("alice unable to recv add htlc: %v", err) } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("Can't update the channel state: %v", err) } if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("Can't update the channel state: %v", err) } // With both HTLC's locked in, we'll now simulate Bob force closing the // transaction on Alice. bobForceClose, err := bobChannel.ForceClose() if err != nil { t.Fatalf("unable to close: %v", err) } // We'll then use Bob's transaction to trigger a spend notification for // Alice. closeTx := bobForceClose.CloseTx commitTxHash := closeTx.TxHash() spendDetail := &chainntnfs.SpendDetail{ SpendingTx: closeTx, SpenderTxHash: &commitTxHash, } aliceCloseSummary, err := NewUnilateralCloseSummary( aliceChannel.channelState, aliceChannel.Signer, spendDetail, aliceChannel.channelState.RemoteCommitment, aliceChannel.channelState.RemoteCurrentRevocation, ) if err != nil { t.Fatalf("unable to create alice close summary: %v", err) } // She should detect that she can sweep both the outgoing HTLC as well // as the incoming one from Bob. if len(aliceCloseSummary.HtlcResolutions.OutgoingHTLCs) != 1 { t.Fatalf("alice out htlc resolutions not populated: expected %v "+ "htlcs, got %v htlcs", 1, len(aliceCloseSummary.HtlcResolutions.OutgoingHTLCs)) } if len(aliceCloseSummary.HtlcResolutions.IncomingHTLCs) != 1 { t.Fatalf("alice in htlc resolutions not populated: expected %v "+ "htlcs, got %v htlcs", 1, len(aliceCloseSummary.HtlcResolutions.IncomingHTLCs)) } outHtlcResolution := aliceCloseSummary.HtlcResolutions.OutgoingHTLCs[0] inHtlcResolution := aliceCloseSummary.HtlcResolutions.IncomingHTLCs[0] // First, we'll ensure that Alice can directly spend the outgoing HTLC // given a transaction with the proper lock time set. receiverHtlcScript := closeTx.TxOut[outHtlcResolution.ClaimOutpoint.Index].PkScript sweepTx := wire.NewMsgTx(2) sweepTx.AddTxIn(&wire.TxIn{ PreviousOutPoint: outHtlcResolution.ClaimOutpoint, }) sweepTx.AddTxOut(&wire.TxOut{ PkScript: receiverHtlcScript, Value: outHtlcResolution.SweepSignDesc.Output.Value, }) outHtlcResolution.SweepSignDesc.InputIndex = 0 outHtlcResolution.SweepSignDesc.SigHashes = txscript.NewTxSigHashes( sweepTx, ) sweepTx.LockTime = outHtlcResolution.Expiry // With the transaction constructed, we'll generate a witness that // should be valid for it, and verify using an instance of Script. sweepTx.TxIn[0].Witness, err = input.ReceiverHtlcSpendTimeout( aliceChannel.Signer, &outHtlcResolution.SweepSignDesc, sweepTx, int32(outHtlcResolution.Expiry), ) if err != nil { t.Fatalf("unable to witness: %v", err) } vm, err := txscript.NewEngine( outHtlcResolution.SweepSignDesc.Output.PkScript, sweepTx, 0, txscript.StandardVerifyFlags, nil, nil, outHtlcResolution.SweepSignDesc.Output.Value, ) if err != nil { t.Fatalf("unable to create engine: %v", err) } if err := vm.Execute(); err != nil { t.Fatalf("htlc timeout spend is invalid: %v", err) } // Next, we'll ensure that we're able to sweep the incoming HTLC with a // similar sweep transaction, this time using the payment pre-image. senderHtlcScript := closeTx.TxOut[inHtlcResolution.ClaimOutpoint.Index].PkScript sweepTx = wire.NewMsgTx(2) sweepTx.AddTxIn(&wire.TxIn{ PreviousOutPoint: inHtlcResolution.ClaimOutpoint, }) sweepTx.AddTxOut(&wire.TxOut{ PkScript: senderHtlcScript, Value: inHtlcResolution.SweepSignDesc.Output.Value, }) inHtlcResolution.SweepSignDesc.InputIndex = 0 inHtlcResolution.SweepSignDesc.SigHashes = txscript.NewTxSigHashes( sweepTx, ) sweepTx.TxIn[0].Witness, err = input.SenderHtlcSpendRedeem( aliceChannel.Signer, &inHtlcResolution.SweepSignDesc, sweepTx, preimageBob[:], ) if err != nil { t.Fatalf("unable to generate witness for success "+ "output: %v", err) } // Finally, we'll verify the constructed witness to ensure that Alice // can properly sweep the output. vm, err = txscript.NewEngine( inHtlcResolution.SweepSignDesc.Output.PkScript, sweepTx, 0, txscript.StandardVerifyFlags, nil, nil, inHtlcResolution.SweepSignDesc.Output.Value, ) if err != nil { t.Fatalf("unable to create engine: %v", err) } if err := vm.Execute(); err != nil { t.Fatalf("htlc timeout spend is invalid: %v", err) } } // TestChannelUnilateralClosePendingCommit tests that if the remote party // broadcasts their pending commit (hasn't yet revoked the lower one), then // we'll create a proper unilateral channel clsoure that can sweep the created // outputs. func TestChannelUnilateralClosePendingCommit(t *testing.T) { t.Parallel() // Create a test channel which will be used for the duration of this // unittest. The channel will be funded evenly with Alice having 5 BTC, // and Bob having 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // First, we'll add an HTLC from Alice to Bob, just to be be able to // create a new state transition. htlcAmount := lnwire.NewMSatFromSatoshis(20000) htlcAlice, _ := createHTLC(0, htlcAmount) if _, err := aliceChannel.AddHTLC(htlcAlice, nil); err != nil { t.Fatalf("alice unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlcAlice); err != nil { t.Fatalf("bob unable to recv add htlc: %v", err) } // With the HTLC added, we'll now manually initiate a state transition // from Alice to Bob. _, _, _, err = aliceChannel.SignNextCommitment() if err != nil { t.Fatal(err) } // At this point, Alice's commitment chain should have a new pending // commit for Bob. We'll extract it so we can simulate Bob broadcasting // the commitment due to an issue. bobCommit := aliceChannel.remoteCommitChain.tip().txn bobTxHash := bobCommit.TxHash() spendDetail := &chainntnfs.SpendDetail{ SpenderTxHash: &bobTxHash, SpendingTx: bobCommit, } // At this point, if we attempt to create a unilateral close summary // using this commitment, but with the wrong state, we should find that // our output wasn't picked up. aliceWrongCloseSummary, err := NewUnilateralCloseSummary( aliceChannel.channelState, aliceChannel.Signer, spendDetail, aliceChannel.channelState.RemoteCommitment, aliceChannel.channelState.RemoteCurrentRevocation, ) if err != nil { t.Fatalf("unable to create alice close summary: %v", err) } if aliceWrongCloseSummary.CommitResolution != nil { t.Fatalf("alice shouldn't have found self output") } // If we create the close summary again, but this time use Alice's // pending commit to Bob, then the unilateral close summary should be // properly populated. aliceRemoteChainTip, err := aliceChannel.channelState.RemoteCommitChainTip() if err != nil { t.Fatalf("unable to fetch remote chain tip: %v", err) } aliceCloseSummary, err := NewUnilateralCloseSummary( aliceChannel.channelState, aliceChannel.Signer, spendDetail, aliceRemoteChainTip.Commitment, aliceChannel.channelState.RemoteNextRevocation, ) if err != nil { t.Fatalf("unable to create alice close summary: %v", err) } // With this proper version, Alice's commit resolution should have been // properly located. if aliceCloseSummary.CommitResolution == nil { t.Fatalf("unable to find alice's commit resolution") } // The proper short channel ID should also be set in Alice's close // channel summary. if aliceCloseSummary.ChannelCloseSummary.ShortChanID != aliceChannel.ShortChanID() { t.Fatalf("wrong short chan ID, expected %v got %v", aliceChannel.ShortChanID(), aliceCloseSummary.ChannelCloseSummary.ShortChanID) } aliceSignDesc := aliceCloseSummary.CommitResolution.SelfOutputSignDesc // Finally, we'll ensure that we're able to properly sweep our output // from using the materials within the unilateral close summary. sweepTx := wire.NewMsgTx(2) sweepTx.AddTxIn(&wire.TxIn{ PreviousOutPoint: aliceCloseSummary.CommitResolution.SelfOutPoint, }) sweepTx.AddTxOut(&wire.TxOut{ PkScript: testHdSeed[:], Value: aliceSignDesc.Output.Value, }) aliceSignDesc.SigHashes = txscript.NewTxSigHashes(sweepTx) sweepTx.TxIn[0].Witness, err = input.CommitSpendNoDelay( aliceChannel.Signer, &aliceSignDesc, sweepTx, false, ) if err != nil { t.Fatalf("unable to generate sweep witness: %v", err) } // If we validate the signature on the new sweep transaction, it should // be fully valid. vm, err := txscript.NewEngine( aliceSignDesc.Output.PkScript, sweepTx, 0, txscript.StandardVerifyFlags, nil, nil, aliceSignDesc.Output.Value, ) if err != nil { t.Fatalf("unable to create engine: %v", err) } if err := vm.Execute(); err != nil { t.Fatalf("htlc timeout spend is invalid: %v", err) } } // TestDesyncHTLCs checks that we cannot add HTLCs that would make the // balance negative, when the remote and local update logs are desynced. func TestDesyncHTLCs(t *testing.T) { t.Parallel() // We'll kick off the test by creating our channels which both are // loaded with 5 BTC each. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // First add one HTLC of value 4.1 BTC. htlcAmt := lnwire.NewMSatFromSatoshis(4.1 * btcutil.SatoshiPerBitcoin) htlc, _ := createHTLC(0, htlcAmt) aliceIndex, err := aliceChannel.AddHTLC(htlc, nil) if err != nil { t.Fatalf("unable to add htlc: %v", err) } bobIndex, err := bobChannel.ReceiveHTLC(htlc) if err != nil { t.Fatalf("unable to recv htlc: %v", err) } // Lock this HTLC in. if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete state update: %v", err) } // Now let Bob fail this HTLC. err = bobChannel.FailHTLC(bobIndex, []byte("failreason"), nil, nil, nil) if err != nil { t.Fatalf("unable to cancel HTLC: %v", err) } if err := aliceChannel.ReceiveFailHTLC(aliceIndex, []byte("bad")); err != nil { t.Fatalf("unable to recv htlc cancel: %v", err) } // Alice now has gotten all her original balance (5 BTC) back, however, // adding a new HTLC at this point SHOULD fail, since if she adds the // HTLC and signs the next state, Bob cannot assume she received the // FailHTLC, and must assume she doesn't have the necessary balance // available. // // We try adding an HTLC of value 1 BTC, which should fail because the // balance is unavailable. htlcAmt = lnwire.NewMSatFromSatoshis(1 * btcutil.SatoshiPerBitcoin) htlc, _ = createHTLC(1, htlcAmt) if _, err = aliceChannel.AddHTLC(htlc, nil); err != ErrBelowChanReserve { t.Fatalf("expected ErrInsufficientBalance, instead received: %v", err) } // Now do a state transition, which will ACK the FailHTLC, making Alice // able to add the new HTLC. if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete state update: %v", err) } if _, err = aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } } // TODO(roasbeef): testing.Quick test case for retrans!!! // TestMaxAcceptedHTLCs tests that the correct error message (ErrMaxHTLCNumber) // is thrown when a node tries to accept more than MaxAcceptedHTLCs in a // channel. func TestMaxAcceptedHTLCs(t *testing.T) { t.Parallel() // We'll kick off the test by creating our channels which both are // loaded with 5 BTC each. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // One over the maximum number of HTLCs that either can accept. const numHTLCs = 12 // Set the remote's required MaxAcceptedHtlcs. This means that Alice // can only offer the remote up to numHTLCs HTLCs. aliceChannel.channelState.LocalChanCfg.MaxAcceptedHtlcs = numHTLCs bobChannel.channelState.RemoteChanCfg.MaxAcceptedHtlcs = numHTLCs // Similarly, set the remote config's MaxAcceptedHtlcs. This means // that the remote will be aware that Bob will only accept up to // numHTLCs at a time. aliceChannel.channelState.RemoteChanCfg.MaxAcceptedHtlcs = numHTLCs bobChannel.channelState.LocalChanCfg.MaxAcceptedHtlcs = numHTLCs // Each HTLC amount is 0.1 BTC. htlcAmt := lnwire.NewMSatFromSatoshis(0.1 * btcutil.SatoshiPerBitcoin) // htlcID is used to keep track of the HTLC that Bob will fail back to // Alice. var htlcID uint64 // Send the maximum allowed number of HTLCs. for i := 0; i < numHTLCs; i++ { htlc, _ := createHTLC(i, htlcAmt) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } // Just assign htlcID to the last received HTLC. htlcID = htlc.ID } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to transition state: %v", err) } // The next HTLC should fail with ErrMaxHTLCNumber. htlc, _ := createHTLC(numHTLCs, htlcAmt) _, err = aliceChannel.AddHTLC(htlc, nil) if err != ErrMaxHTLCNumber { t.Fatalf("expected ErrMaxHTLCNumber, instead received: %v", err) } // Receiving the next HTLC should fail. if _, err := bobChannel.ReceiveHTLC(htlc); err != ErrMaxHTLCNumber { t.Fatalf("expected ErrMaxHTLCNumber, instead received: %v", err) } // Bob will fail the htlc specified by htlcID and then force a state // transition. err = bobChannel.FailHTLC(htlcID, []byte{}, nil, nil, nil) if err != nil { t.Fatalf("unable to fail htlc: %v", err) } if err := aliceChannel.ReceiveFailHTLC(htlcID, []byte{}); err != nil { t.Fatalf("unable to receive fail htlc: %v", err) } if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("unable to transition state: %v", err) } // Bob should succeed in adding a new HTLC since a previous HTLC was just // failed. We use numHTLCs here since the previous AddHTLC with this index // failed. htlc, _ = createHTLC(numHTLCs, htlcAmt) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } // Add a commitment to Bob's commitment chain. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign next commitment: %v", err) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("unable to recv new commitment: %v", err) } // The next HTLC should fail with ErrMaxHTLCNumber. The index is incremented // by one. htlc, _ = createHTLC(numHTLCs+1, htlcAmt) if _, err = aliceChannel.AddHTLC(htlc, nil); err != ErrMaxHTLCNumber { t.Fatalf("expected ErrMaxHTLCNumber, instead received: %v", err) } // Likewise, Bob should not be able to receive this HTLC if Alice can't // add it. if _, err := bobChannel.ReceiveHTLC(htlc); err != ErrMaxHTLCNumber { t.Fatalf("expected ErrMaxHTLCNumber, instead received: %v", err) } } // TestMaxAsynchronousHtlcs tests that Bob correctly receives (and does not // fail) an HTLC from Alice when exchanging asynchronous payments. We want to // mimic the following case where Bob's commitment transaction is full before // starting: // Alice Bob // 1. <---settle/fail--- // 2. <-------sig------- // 3. --------sig------> (covers an add sent before step 1) // 4. <-------rev------- // 5. --------rev------> // 6. --------add------> // 7. - - - - sig - - -> // This represents an asynchronous commitment dance in which both sides are // sending signatures at the same time. In step 3, the signature does not // cover the recent settle/fail that Bob sent in step 1. However, the add that // Alice sends to Bob in step 6 does not overflow Bob's commitment transaction. // This is because validateCommitmentSanity counts the HTLC's by ignoring // HTLC's which will be removed in the next signature that Alice sends. Thus, // the add won't overflow. This is because the signature received in step 7 // covers the settle/fail in step 1 and makes space for the add in step 6. func TestMaxAsynchronousHtlcs(t *testing.T) { t.Parallel() // We'll kick off the test by creating our channels which both are // loaded with 5 BTC each. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // One over the maximum number of HTLCs that either can accept. const numHTLCs = 12 // Set the remote's required MaxAcceptedHtlcs. This means that Alice // can only offer the remote up to numHTLCs HTLCs. aliceChannel.channelState.LocalChanCfg.MaxAcceptedHtlcs = numHTLCs bobChannel.channelState.RemoteChanCfg.MaxAcceptedHtlcs = numHTLCs // Similarly, set the remote config's MaxAcceptedHtlcs. This means // that the remote will be aware that Bob will only accept up to // numHTLCs at a time. aliceChannel.channelState.RemoteChanCfg.MaxAcceptedHtlcs = numHTLCs bobChannel.channelState.LocalChanCfg.MaxAcceptedHtlcs = numHTLCs // Each HTLC amount is 0.1 BTC. htlcAmt := lnwire.NewMSatFromSatoshis(0.1 * btcutil.SatoshiPerBitcoin) var htlcID uint64 // Send the maximum allowed number of HTLCs minus one. for i := 0; i < numHTLCs-1; i++ { htlc, _ := createHTLC(i, htlcAmt) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } // Just assign htlcID to the last received HTLC. htlcID = htlc.ID } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to transition state: %v", err) } // Send an HTLC to Bob so that Bob's commitment transaction is full. htlc, _ := createHTLC(numHTLCs-1, htlcAmt) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } // Fail back an HTLC and sign a commitment as in steps 1 & 2. err = bobChannel.FailHTLC(htlcID, []byte{}, nil, nil, nil) if err != nil { t.Fatalf("unable to fail htlc: %v", err) } if err := aliceChannel.ReceiveFailHTLC(htlcID, []byte{}); err != nil { t.Fatalf("unable to receive fail htlc: %v", err) } bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign next commitment: %v", err) } err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("unable to receive new commitment: %v", err) } // Cover the HTLC referenced with id equal to numHTLCs-1 with a new // signature (step 3). aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign next commitment: %v", err) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("unable to receive new commitment: %v", err) } // Both sides exchange revocations as in step 4 & 5. bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke revocation: %v", err) } _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatalf("unable to receive revocation: %v", err) } aliceRevocation, _, err := aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke revocation: %v", err) } _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatalf("unable to receive revocation: %v", err) } // Send the final Add which should succeed as in step 6. htlc, _ = createHTLC(numHTLCs, htlcAmt) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } // Receiving the commitment should succeed as in step 7 since space was // made. aliceSig, aliceHtlcSigs, _, err = aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign next commitment: %v", err) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("unable to receive new commitment: %v", err) } } // TestMaxPendingAmount tests that the maximum overall pending HTLC value is met // given several HTLCs that, combined, exceed this value. An ErrMaxPendingAmount // error should be returned. func TestMaxPendingAmount(t *testing.T) { t.Parallel() // We'll kick off the test by creating our channels which both are // loaded with 5 BTC each. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // We set the remote required MaxPendingAmount to 3 BTC. We will // attempt to overflow this value and see if it gives us the // ErrMaxPendingAmount error. maxPending := lnwire.NewMSatFromSatoshis(btcutil.SatoshiPerBitcoin * 3) // We set the max pending amount of Alice's config. This mean that she // cannot offer Bob HTLCs with a total value above this limit at a given // time. aliceChannel.channelState.LocalChanCfg.MaxPendingAmount = maxPending bobChannel.channelState.RemoteChanCfg.MaxPendingAmount = maxPending // First, we'll add 2 HTLCs of 1.5 BTC each to Alice's commitment. // This won't trigger Alice's ErrMaxPendingAmount error. const numHTLCs = 2 htlcAmt := lnwire.NewMSatFromSatoshis(1.5 * btcutil.SatoshiPerBitcoin) for i := 0; i < numHTLCs; i++ { htlc, _ := createHTLC(i, htlcAmt) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } } // We finally add one more HTLC of 0.1 BTC to Alice's commitment. This // SHOULD trigger Alice's ErrMaxPendingAmount error. htlcAmt = lnwire.NewMSatFromSatoshis(0.1 * btcutil.SatoshiPerBitcoin) htlc, _ := createHTLC(numHTLCs, htlcAmt) _, err = aliceChannel.AddHTLC(htlc, nil) if err != ErrMaxPendingAmount { t.Fatalf("expected ErrMaxPendingAmount, instead received: %v", err) } // And also Bob shouldn't be accepting this HTLC upon calling ReceiveHTLC. if _, err := bobChannel.ReceiveHTLC(htlc); err != ErrMaxPendingAmount { t.Fatalf("expected ErrMaxPendingAmount, instead received: %v", err) } } func assertChannelBalances(t *testing.T, alice, bob *LightningChannel, aliceBalance, bobBalance btcutil.Amount) { _, _, line, _ := runtime.Caller(1) aliceSelfBalance := alice.channelState.LocalCommitment.LocalBalance.ToSatoshis() aliceBobBalance := alice.channelState.LocalCommitment.RemoteBalance.ToSatoshis() if aliceSelfBalance != aliceBalance { t.Fatalf("line #%v: wrong alice self balance: expected %v, got %v", line, aliceBalance, aliceSelfBalance) } if aliceBobBalance != bobBalance { t.Fatalf("line #%v: wrong alice bob's balance: expected %v, got %v", line, bobBalance, aliceBobBalance) } bobSelfBalance := bob.channelState.LocalCommitment.LocalBalance.ToSatoshis() bobAliceBalance := bob.channelState.LocalCommitment.RemoteBalance.ToSatoshis() if bobSelfBalance != bobBalance { t.Fatalf("line #%v: wrong bob self balance: expected %v, got %v", line, bobBalance, bobSelfBalance) } if bobAliceBalance != aliceBalance { t.Fatalf("line #%v: wrong alice bob's balance: expected %v, got %v", line, aliceBalance, bobAliceBalance) } } // TestChanReserve tests that the ErrBelowChanReserve error is thrown when an // HTLC is added that causes a node's balance to dip below its channel reserve // limit. func TestChanReserve(t *testing.T) { t.Parallel() setupChannels := func() (*LightningChannel, *LightningChannel, func()) { // We'll kick off the test by creating our channels which both // are loaded with 5 BTC each. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } // We set the remote required ChanReserve to 0.5 BTC. We will // attempt to cause Alice's balance to dip below this amount // and test whether it triggers the ErrBelowChanReserve error. aliceMinReserve := btcutil.Amount(0.5 * btcutil.SatoshiPerBitcoin) // Alice will need to keep her reserve above aliceMinReserve, // so set this limit to here local config. aliceChannel.channelState.LocalChanCfg.ChanReserve = aliceMinReserve // During channel opening Bob will also get to know Alice's // minimum reserve, and this will be found in his remote // config. bobChannel.channelState.RemoteChanCfg.ChanReserve = aliceMinReserve // We set Bob's channel reserve to a value that is larger than // his current balance in the channel. This will ensure that // after a channel is first opened, Bob can still receive HTLCs // even though his balance is less than his channel reserve. bobMinReserve := btcutil.Amount(6 * btcutil.SatoshiPerBitcoin) bobChannel.channelState.LocalChanCfg.ChanReserve = bobMinReserve aliceChannel.channelState.RemoteChanCfg.ChanReserve = bobMinReserve return aliceChannel, bobChannel, cleanUp } aliceChannel, bobChannel, cleanUp := setupChannels() defer cleanUp() aliceIndex := 0 bobIndex := 0 // Add an HTLC that will increase Bob's balance. This should succeed, // since Alice stays above her channel reserve, and Bob increases his // balance (while still being below his channel reserve). // // Resulting balances: // Alice: 4.5 // Bob: 5.0 htlcAmt := lnwire.NewMSatFromSatoshis(0.5 * btcutil.SatoshiPerBitcoin) htlc, _ := createHTLC(aliceIndex, htlcAmt) aliceIndex++ if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } // Force a state transition, making sure this HTLC is considered valid // even though the channel reserves are not met. if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete state update: %v", err) } commitFee := aliceChannel.channelState.LocalCommitment.CommitFee assertChannelBalances( t, aliceChannel, bobChannel, btcutil.SatoshiPerBitcoin*4.5-commitFee, btcutil.SatoshiPerBitcoin*5, ) // Now let Bob try to add an HTLC. This should fail, since it will // decrease his balance, which is already below the channel reserve. // // Resulting balances: // Alice: 4.5 // Bob: 5.0 htlc, _ = createHTLC(bobIndex, htlcAmt) bobIndex++ _, err := bobChannel.AddHTLC(htlc, nil) if err != ErrBelowChanReserve { t.Fatalf("expected ErrBelowChanReserve, instead received: %v", err) } // Alice will reject this htlc upon receiving the htlc. if _, err := aliceChannel.ReceiveHTLC(htlc); err != ErrBelowChanReserve { t.Fatalf("expected ErrBelowChanReserve, instead received: %v", err) } // We must setup the channels again, since a violation of the channel // constraints leads to channel shutdown. aliceChannel, bobChannel, cleanUp = setupChannels() defer cleanUp() aliceIndex = 0 bobIndex = 0 // Now we'll add HTLC of 3.5 BTC to Alice's commitment, this should put // Alice's balance at 1.5 BTC. // // Resulting balances: // Alice: 1.5 // Bob: 9.5 htlcAmt = lnwire.NewMSatFromSatoshis(3.5 * btcutil.SatoshiPerBitcoin) // The first HTLC should successfully be sent. htlc, _ = createHTLC(aliceIndex, htlcAmt) aliceIndex++ if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } // Add a second HTLC of 1 BTC. This should fail because it will take // Alice's balance all the way down to her channel reserve, but since // she is the initiator the additional transaction fee makes her // balance dip below. htlcAmt = lnwire.NewMSatFromSatoshis(1 * btcutil.SatoshiPerBitcoin) htlc, _ = createHTLC(aliceIndex, htlcAmt) aliceIndex++ _, err = aliceChannel.AddHTLC(htlc, nil) if err != ErrBelowChanReserve { t.Fatalf("expected ErrBelowChanReserve, instead received: %v", err) } // Likewise, Bob will reject receiving the htlc because of the same reason. if _, err := bobChannel.ReceiveHTLC(htlc); err != ErrBelowChanReserve { t.Fatalf("expected ErrBelowChanReserve, instead received: %v", err) } // We must setup the channels again, since a violation of the channel // constraints leads to channel shutdown. aliceChannel, bobChannel, cleanUp = setupChannels() defer cleanUp() aliceIndex = 0 bobIndex = 0 // Add a HTLC of 2 BTC to Alice, and the settle it. // Resulting balances: // Alice: 3.0 // Bob: 7.0 htlcAmt = lnwire.NewMSatFromSatoshis(2 * btcutil.SatoshiPerBitcoin) htlc, preimage := createHTLC(aliceIndex, htlcAmt) aliceIndex++ aliceHtlcIndex, err := aliceChannel.AddHTLC(htlc, nil) if err != nil { t.Fatalf("unable to add htlc: %v", err) } bobHtlcIndex, err := bobChannel.ReceiveHTLC(htlc) if err != nil { t.Fatalf("unable to recv htlc: %v", err) } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete state update: %v", err) } commitFee = aliceChannel.channelState.LocalCommitment.CommitFee assertChannelBalances( t, aliceChannel, bobChannel, btcutil.SatoshiPerBitcoin*3-commitFee, btcutil.SatoshiPerBitcoin*5, ) if err := bobChannel.SettleHTLC(preimage, bobHtlcIndex, nil, nil, nil); err != nil { t.Fatalf("bob unable to settle inbound htlc: %v", err) } if err := aliceChannel.ReceiveHTLCSettle(preimage, aliceHtlcIndex); err != nil { t.Fatalf("alice unable to accept settle of outbound htlc: %v", err) } if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("unable to complete state update: %v", err) } commitFee = aliceChannel.channelState.LocalCommitment.CommitFee assertChannelBalances( t, aliceChannel, bobChannel, btcutil.SatoshiPerBitcoin*3-commitFee, btcutil.SatoshiPerBitcoin*7, ) // And now let Bob add an HTLC of 1 BTC. This will take Bob's balance // all the way down to his channel reserve, but since he is not paying // the fee this is okay. htlcAmt = lnwire.NewMSatFromSatoshis(1 * btcutil.SatoshiPerBitcoin) htlc, _ = createHTLC(bobIndex, htlcAmt) bobIndex++ if _, err := bobChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := aliceChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } // Do a last state transition, which should succeed. if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("unable to complete state update: %v", err) } commitFee = aliceChannel.channelState.LocalCommitment.CommitFee assertChannelBalances( t, aliceChannel, bobChannel, btcutil.SatoshiPerBitcoin*3-commitFee, btcutil.SatoshiPerBitcoin*6, ) } // TestChanReserveRemoteInitiator tests that the channel reserve of the // initiator is accounted for when adding HTLCs, whether the initiator is the // local or remote node. func TestChanReserveRemoteInitiator(t *testing.T) { t.Parallel() // We start out with a channel where both parties have 5 BTC. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatal(err) } defer cleanUp() // Set Alice's channel reserve to be 5 BTC-commitfee. This means she // has just enough balance to cover the comitment fee, but not enough // to add any more HTLCs to the commitment. Although a reserve this // high is unrealistic, a channel can easiliy get into a situation // where the initiator cannot pay for the fee of any more HTLCs. commitFee := aliceChannel.channelState.LocalCommitment.CommitFee aliceMinReserve := 5*btcutil.SatoshiPerBitcoin - commitFee aliceChannel.channelState.LocalChanCfg.ChanReserve = aliceMinReserve bobChannel.channelState.RemoteChanCfg.ChanReserve = aliceMinReserve // Now let Bob attempt to add an HTLC of 0.1 BTC. He has plenty of // money available to spend, but Alice, which is the initiator, cannot // afford any more HTLCs on the commitment transaction because that // would take here below her channel reserve.. htlcAmt := lnwire.NewMSatFromSatoshis(0.1 * btcutil.SatoshiPerBitcoin) htlc, _ := createHTLC(0, htlcAmt) // Bob should refuse to add this HTLC, since he realizes it will create // an invalid commitment. _, err = bobChannel.AddHTLC(htlc, nil) if err != ErrBelowChanReserve { t.Fatalf("expected ErrBelowChanReserve, instead received: %v", err) } // Of course Alice will also not have enough balance to add it herself. _, err = aliceChannel.AddHTLC(htlc, nil) if err != ErrBelowChanReserve { t.Fatalf("expected ErrBelowChanReserve, instead received: %v", err) } // Same for Alice, she should refuse to accept this second HTLC. if _, err := aliceChannel.ReceiveHTLC(htlc); err != ErrBelowChanReserve { t.Fatalf("expected ErrBelowChanReserve, instead received: %v", err) } } // TestChanReserveLocalInitiatorDustHtlc tests that fee the initiator must pay // when adding HTLCs is accounted for, even though the HTLC is considered dust // by the remote bode. func TestChanReserveLocalInitiatorDustHtlc(t *testing.T) { t.Parallel() aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatal(err) } defer cleanUp() // The amount of the HTLC should not be considered dust according to // Alice's dust limit (200 sat), but be dust according to Bob's dust // limit (1300 sat). It is considered dust if the amount remaining // after paying the HTLC fee is below the dustlimit, so we choose a // size of 500+htlcFee. htlcSat := btcutil.Amount(500) + HtlcTimeoutFee( aliceChannel.channelState.ChanType, chainfee.SatPerKWeight( aliceChannel.channelState.LocalCommitment.FeePerKw, ), ) // Set Alice's channel reserve to be low enough to carry the value of // the HTLC, but not low enough to allow the extra fee from adding the // HTLC to the commitment. commitFee := aliceChannel.channelState.LocalCommitment.CommitFee aliceMinReserve := 5*btcutil.SatoshiPerBitcoin - commitFee - htlcSat aliceChannel.channelState.LocalChanCfg.ChanReserve = aliceMinReserve bobChannel.channelState.RemoteChanCfg.ChanReserve = aliceMinReserve htlcDustAmt := lnwire.NewMSatFromSatoshis(htlcSat) htlc, _ := createHTLC(0, htlcDustAmt) // Alice should realize that the fee she must pay to add this HTLC to // the local commitment would take her below the channel reserve. _, err = aliceChannel.AddHTLC(htlc, nil) if err != ErrBelowChanReserve { t.Fatalf("expected ErrBelowChanReserve, instead received: %v", err) } } // TestMinHTLC tests that the ErrBelowMinHTLC error is thrown if an HTLC is added // that is below the minimm allowed value for HTLCs. func TestMinHTLC(t *testing.T) { t.Parallel() // We'll kick off the test by creating our channels which both are // loaded with 5 BTC each. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // We set Alice's MinHTLC to 0.1 BTC. We will attempt to send an // HTLC BELOW this value to trigger the ErrBelowMinHTLC error. minValue := lnwire.NewMSatFromSatoshis(0.1 * btcutil.SatoshiPerBitcoin) // Setting the min value in Alice's local config means that the // remote will not accept any HTLCs of value less than specified. aliceChannel.channelState.LocalChanCfg.MinHTLC = minValue bobChannel.channelState.RemoteChanCfg.MinHTLC = minValue // First, we will add an HTLC of 0.5 BTC. This will not trigger // ErrBelowMinHTLC. htlcAmt := lnwire.NewMSatFromSatoshis(0.5 * btcutil.SatoshiPerBitcoin) htlc, _ := createHTLC(0, htlcAmt) if _, err := aliceChannel.AddHTLC(htlc, nil); err != nil { t.Fatalf("unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlc); err != nil { t.Fatalf("unable to recv htlc: %v", err) } // We add an HTLC below the min value, this should result in // an ErrBelowMinHTLC error. amt := minValue - 100 htlc, _ = createHTLC(1, amt) _, err = aliceChannel.AddHTLC(htlc, nil) if err != ErrBelowMinHTLC { t.Fatalf("expected ErrBelowMinHTLC, instead received: %v", err) } // Bob will receive this HTLC, but reject the next received htlc, since // the htlc is too small. _, err = bobChannel.ReceiveHTLC(htlc) if err != ErrBelowMinHTLC { t.Fatalf("expected ErrBelowMinHTLC, instead received: %v", err) } } // TestInvalidHTLCAmt tests that ErrInvalidHTLCAmt is returned when trying to // add HTLCs that don't carry a positive value. func TestInvalidHTLCAmt(t *testing.T) { t.Parallel() // We'll kick off the test by creating our channels which both are // loaded with 5 BTC each. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // We'll set the min HTLC values for each party to zero, which // technically would permit zero-value HTLCs. aliceChannel.channelState.LocalChanCfg.MinHTLC = 0 bobChannel.channelState.RemoteChanCfg.MinHTLC = 0 // Create a zero-value HTLC. htlcAmt := lnwire.MilliSatoshi(0) htlc, _ := createHTLC(0, htlcAmt) // Sending or receiving the HTLC should fail with ErrInvalidHTLCAmt. _, err = aliceChannel.AddHTLC(htlc, nil) if err != ErrInvalidHTLCAmt { t.Fatalf("expected ErrInvalidHTLCAmt, got: %v", err) } _, err = bobChannel.ReceiveHTLC(htlc) if err != ErrInvalidHTLCAmt { t.Fatalf("expected ErrInvalidHTLCAmt, got: %v", err) } } // TestNewBreachRetributionSkipsDustHtlcs ensures that in the case of a // contract breach, all dust HTLCs are ignored and not reflected in the // produced BreachRetribution struct. We ignore these HTLCs as they aren't // actually manifested on the commitment transaction, as a result we can't // actually revoked them. func TestNewBreachRetributionSkipsDustHtlcs(t *testing.T) { t.Parallel() // We'll kick off the test by creating our channels which both are // loaded with 5 BTC each. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() var fakeOnionBlob [lnwire.OnionPacketSize]byte copy(fakeOnionBlob[:], bytes.Repeat([]byte{0x05}, lnwire.OnionPacketSize)) // We'll modify the dust settings on both channels to be a predictable // value for the prurpose of the test. dustValue := btcutil.Amount(200) aliceChannel.channelState.LocalChanCfg.DustLimit = dustValue aliceChannel.channelState.RemoteChanCfg.DustLimit = dustValue bobChannel.channelState.LocalChanCfg.DustLimit = dustValue bobChannel.channelState.RemoteChanCfg.DustLimit = dustValue // We'll now create a series of dust HTLC's, and send then from Alice // to Bob, finally locking both of them in. var bobPreimage [32]byte copy(bobPreimage[:], bytes.Repeat([]byte{0xbb}, 32)) for i := 0; i < 3; i++ { rHash := sha256.Sum256(bobPreimage[:]) h := &lnwire.UpdateAddHTLC{ PaymentHash: rHash, Amount: lnwire.NewMSatFromSatoshis(dustValue), Expiry: uint32(10), OnionBlob: fakeOnionBlob, } htlcIndex, err := aliceChannel.AddHTLC(h, nil) if err != nil { t.Fatalf("unable to add bob's htlc: %v", err) } h.ID = htlcIndex if _, err := bobChannel.ReceiveHTLC(h); err != nil { t.Fatalf("unable to recv bob's htlc: %v", err) } } // With the HTLC's applied to both update logs, we'll initiate a state // transition from Alice. if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete alice's state transition: %v", err) } // At this point, we'll capture the current state number, as well as // the current commitment. revokedStateNum := aliceChannel.channelState.LocalCommitment.CommitHeight // We'll now have Bob settle those HTLC's to Alice and then advance // forward to a new state. for i := 0; i < 3; i++ { err := bobChannel.SettleHTLC(bobPreimage, uint64(i), nil, nil, nil) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } err = aliceChannel.ReceiveHTLCSettle(bobPreimage, uint64(i)) if err != nil { t.Fatalf("unable to settle htlc: %v", err) } } if err := ForceStateTransition(bobChannel, aliceChannel); err != nil { t.Fatalf("unable to complete bob's state transition: %v", err) } // At this point, we'll now simulate a contract breach by Bob using the // NewBreachRetribution method. breachRet, err := NewBreachRetribution( aliceChannel.channelState, revokedStateNum, 100, ) if err != nil { t.Fatalf("unable to create breach retribution: %v", err) } // The retribution shouldn't have any HTLCs set as they were all below // dust for both parties. if len(breachRet.HtlcRetributions) != 0 { t.Fatalf("zero HTLC retributions should have been created, "+ "instead %v were", len(breachRet.HtlcRetributions)) } } // compareHtlcs compares two PaymentDescriptors. func compareHtlcs(htlc1, htlc2 *PaymentDescriptor) error { if htlc1.LogIndex != htlc2.LogIndex { return fmt.Errorf("htlc log index did not match") } if htlc1.HtlcIndex != htlc2.HtlcIndex { return fmt.Errorf("htlc index did not match") } if htlc1.ParentIndex != htlc2.ParentIndex { return fmt.Errorf("htlc parent index did not match") } if htlc1.RHash != htlc2.RHash { return fmt.Errorf("htlc rhash did not match") } return nil } // compareIndexes is a helper method to compare two index maps. func compareIndexes(a, b map[uint64]*list.Element) error { for k1, e1 := range a { e2, ok := b[k1] if !ok { return fmt.Errorf("element with key %d "+ "not found in b", k1) } htlc1, htlc2 := e1.Value.(*PaymentDescriptor), e2.Value.(*PaymentDescriptor) if err := compareHtlcs(htlc1, htlc2); err != nil { return err } } for k1, e1 := range b { e2, ok := a[k1] if !ok { return fmt.Errorf("element with key %d not "+ "found in a", k1) } htlc1, htlc2 := e1.Value.(*PaymentDescriptor), e2.Value.(*PaymentDescriptor) if err := compareHtlcs(htlc1, htlc2); err != nil { return err } } return nil } // compareLogs is a helper method to compare two updateLogs. func compareLogs(a, b *updateLog) error { if a.logIndex != b.logIndex { return fmt.Errorf("log indexes don't match: %d vs %d", a.logIndex, b.logIndex) } if a.htlcCounter != b.htlcCounter { return fmt.Errorf("htlc counters don't match: %d vs %d", a.htlcCounter, b.htlcCounter) } if err := compareIndexes(a.updateIndex, b.updateIndex); err != nil { return fmt.Errorf("update indexes don't match: %v", err) } if err := compareIndexes(a.htlcIndex, b.htlcIndex); err != nil { return fmt.Errorf("htlc indexes don't match: %v", err) } if a.Len() != b.Len() { return fmt.Errorf("list lengths not equal: %d vs %d", a.Len(), b.Len()) } e1, e2 := a.Front(), b.Front() for ; e1 != nil; e1, e2 = e1.Next(), e2.Next() { htlc1, htlc2 := e1.Value.(*PaymentDescriptor), e2.Value.(*PaymentDescriptor) if err := compareHtlcs(htlc1, htlc2); err != nil { return err } } return nil } // TestChannelRestoreUpdateLogs makes sure we are able to properly restore the // update logs in the case where a different number of HTLCs are locked in on // the local, remote and pending remote commitment. func TestChannelRestoreUpdateLogs(t *testing.T) { t.Parallel() aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // First, we'll add an HTLC from Alice to Bob, which we will lock in on // Bob's commit, but not on Alice's. htlcAmount := lnwire.NewMSatFromSatoshis(20000) htlcAlice, _ := createHTLC(0, htlcAmount) if _, err := aliceChannel.AddHTLC(htlcAlice, nil); err != nil { t.Fatalf("alice unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlcAlice); err != nil { t.Fatalf("bob unable to recv add htlc: %v", err) } // Let Alice sign a new state, which will include the HTLC just sent. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } // Bob receives this commitment signature, and revokes his old state. err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("unable to receive commitment: %v", err) } bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke commitment: %v", err) } // When Alice now receives this revocation, she will advance her remote // commitment chain to the commitment which includes the HTLC just // sent. However her local commitment chain still won't include the // state with the HTLC, since she hasn't received a new commitment // signature from Bob yet. _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatalf("unable to recive revocation: %v", err) } // Now make Alice send and sign an additional HTLC. We don't let Bob // receive it. We do this since we want to check that update logs are // restored properly below, and we'll only restore updates that have // been ACKed. htlcAlice, _ = createHTLC(1, htlcAmount) if _, err := aliceChannel.AddHTLC(htlcAlice, nil); err != nil { t.Fatalf("alice unable to add htlc: %v", err) } // Send the signature covering the HTLC. This is okay, since the local // and remote commit chains are updated in an async fashion. Since the // remote chain was updated with the latest state (since Bob sent the // revocation earlier) we can keep advancing the remote commit chain. aliceSig, aliceHtlcSigs, _, err = aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } // After Alice has signed this commitment, her local commitment will // contain no HTLCs, her remote commitment will contain an HTLC with // index 0, and the pending remote commitment (a signed remote // commitment which is not AKCed yet) will contain an additional HTLC // with index 1. // We now re-create the channels, mimicking a restart. This should sync // the update logs up to the correct state set up above. newAliceChannel, err := NewLightningChannel( aliceChannel.Signer, aliceChannel.channelState, aliceChannel.sigPool, ) if err != nil { t.Fatalf("unable to create new channel: %v", err) } newBobChannel, err := NewLightningChannel( bobChannel.Signer, bobChannel.channelState, bobChannel.sigPool, ) if err != nil { t.Fatalf("unable to create new channel: %v", err) } // compare all the logs between the old and new channels, to make sure // they all got restored properly. err = compareLogs(aliceChannel.localUpdateLog, newAliceChannel.localUpdateLog) if err != nil { t.Fatalf("alice local log not restored: %v", err) } err = compareLogs(aliceChannel.remoteUpdateLog, newAliceChannel.remoteUpdateLog) if err != nil { t.Fatalf("alice remote log not restored: %v", err) } err = compareLogs(bobChannel.localUpdateLog, newBobChannel.localUpdateLog) if err != nil { t.Fatalf("bob local log not restored: %v", err) } err = compareLogs(bobChannel.remoteUpdateLog, newBobChannel.remoteUpdateLog) if err != nil { t.Fatalf("bob remote log not restored: %v", err) } } // fetchNumUpdates counts the number of updateType in the log. func fetchNumUpdates(t updateType, log *updateLog) int { num := 0 for e := log.Front(); e != nil; e = e.Next() { htlc := e.Value.(*PaymentDescriptor) if htlc.EntryType == t { num++ } } return num } // assertInLog checks that the given log contains the expected number of Adds // and Fails. func assertInLog(t *testing.T, log *updateLog, numAdds, numFails int) { adds := fetchNumUpdates(Add, log) if adds != numAdds { t.Fatalf("expected %d adds, found %d", numAdds, adds) } fails := fetchNumUpdates(Fail, log) if fails != numFails { t.Fatalf("expected %d fails, found %d", numFails, fails) } } // assertInLogs asserts that the expected number of Adds and Fails occurs in // the local and remote update log of the given channel. func assertInLogs(t *testing.T, channel *LightningChannel, numAddsLocal, numFailsLocal, numAddsRemote, numFailsRemote int) { assertInLog(t, channel.localUpdateLog, numAddsLocal, numFailsLocal) assertInLog(t, channel.remoteUpdateLog, numAddsRemote, numFailsRemote) } // restoreAndAssert creates a new LightningChannel from the given channel's // state, and asserts that the new channel has had its logs restored to the // expected state. func restoreAndAssert(t *testing.T, channel *LightningChannel, numAddsLocal, numFailsLocal, numAddsRemote, numFailsRemote int) { newChannel, err := NewLightningChannel( channel.Signer, channel.channelState, channel.sigPool, ) if err != nil { t.Fatalf("unable to create new channel: %v", err) } assertInLog(t, newChannel.localUpdateLog, numAddsLocal, numFailsLocal) assertInLog(t, newChannel.remoteUpdateLog, numAddsRemote, numFailsRemote) } // TestChannelRestoreUpdateLogsFailedHTLC runs through a scenario where an // HTLC is added and failed, and asserts along the way that we would restore // the update logs of the channel to the expected state at any point. func TestChannelRestoreUpdateLogsFailedHTLC(t *testing.T) { t.Parallel() aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // First, we'll add an HTLC from Alice to Bob, and lock it in for both. htlcAmount := lnwire.NewMSatFromSatoshis(20000) htlcAlice, _ := createHTLC(0, htlcAmount) if _, err := aliceChannel.AddHTLC(htlcAlice, nil); err != nil { t.Fatalf("alice unable to add htlc: %v", err) } // The htlc Alice sent should be in her local update log. assertInLogs(t, aliceChannel, 1, 0, 0, 0) // A restore at this point should NOT restore this update, as it is not // locked in anywhere yet. restoreAndAssert(t, aliceChannel, 0, 0, 0, 0) if _, err := bobChannel.ReceiveHTLC(htlcAlice); err != nil { t.Fatalf("bob unable to recv add htlc: %v", err) } // Lock in the Add on both sides. if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete state update: %v", err) } // Since it is locked in, Alice should have the Add in the local log, // and it should be restored during restoration. assertInLogs(t, aliceChannel, 1, 0, 0, 0) restoreAndAssert(t, aliceChannel, 1, 0, 0, 0) // Now we make Bob fail this HTLC. err = bobChannel.FailHTLC(0, []byte("failreason"), nil, nil, nil) if err != nil { t.Fatalf("unable to cancel HTLC: %v", err) } err = aliceChannel.ReceiveFailHTLC(0, []byte("failreason")) if err != nil { t.Fatalf("unable to recv htlc cancel: %v", err) } // This Fail update should have been added to Alice's remote update log. assertInLogs(t, aliceChannel, 1, 0, 0, 1) // Restoring should restore the HTLC added to Alice's local log, but // NOT the Fail sent by Bob, since it is not locked in. restoreAndAssert(t, aliceChannel, 1, 0, 0, 0) // Bob sends a signature. bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("unable to receive commitment: %v", err) } // When Alice receives Bob's new commitment, the logs will stay the // same until she revokes her old state. The Fail will still not be // restored during a restoration. assertInLogs(t, aliceChannel, 1, 0, 0, 1) restoreAndAssert(t, aliceChannel, 1, 0, 0, 0) aliceRevocation, _, err := aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke commitment: %v", err) } _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatalf("bob unable to process alice's revocation: %v", err) } // At this point Alice has advanced her local commitment chain to a // commitment with no HTLCs left. The current state on her remote // commitment chain, however, still has the HTLC active, as she hasn't // sent a new signature yet. If we'd now restart and restore, the htlc // failure update should still be waiting for inclusion in Alice's next // signature. Otherwise the produced signature would be invalid. assertInLogs(t, aliceChannel, 1, 0, 0, 1) restoreAndAssert(t, aliceChannel, 1, 0, 0, 1) // Now send a signature from Alice. This will give Bob a new commitment // where the HTLC is removed. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("unable to receive commitment: %v", err) } // When sending a new commitment, Alice will add a pending commit to // her remote chain. Since the unsigned acked updates aren't deleted // until we receive a revocation, the fail should still be present. assertInLogs(t, aliceChannel, 1, 0, 0, 1) restoreAndAssert(t, aliceChannel, 1, 0, 0, 1) // When Alice receives Bob's revocation, the Fail is irrevocably locked // in on both sides. She should compact the logs, removing the HTLC and // the corresponding Fail from the local update log. bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke commitment: %v", err) } _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatalf("unable to receive revocation: %v", err) } assertInLogs(t, aliceChannel, 0, 0, 0, 0) restoreAndAssert(t, aliceChannel, 0, 0, 0, 0) } // TestDuplicateFailRejection tests that if either party attempts to fail an // HTLC twice, then we'll reject the second fail attempt. func TestDuplicateFailRejection(t *testing.T) { t.Parallel() aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // First, we'll add an HTLC from Alice to Bob, and lock it in for both // parties. htlcAmount := lnwire.NewMSatFromSatoshis(20000) htlcAlice, _ := createHTLC(0, htlcAmount) if _, err := aliceChannel.AddHTLC(htlcAlice, nil); err != nil { t.Fatalf("alice unable to add htlc: %v", err) } _, err = bobChannel.ReceiveHTLC(htlcAlice) if err != nil { t.Fatalf("unable to recv htlc: %v", err) } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete state update: %v", err) } // With the HTLC locked in, we'll now have Bob fail the HTLC back to // Alice. err = bobChannel.FailHTLC(0, []byte("failreason"), nil, nil, nil) if err != nil { t.Fatalf("unable to cancel HTLC: %v", err) } if err := aliceChannel.ReceiveFailHTLC(0, []byte("bad")); err != nil { t.Fatalf("unable to recv htlc cancel: %v", err) } // If we attempt to fail it AGAIN, then both sides should reject this // second failure attempt. err = bobChannel.FailHTLC(0, []byte("failreason"), nil, nil, nil) if err == nil { t.Fatalf("duplicate HTLC failure attempt should have failed") } if err := aliceChannel.ReceiveFailHTLC(0, []byte("bad")); err == nil { t.Fatalf("duplicate HTLC failure attempt should have failed") } // We'll now have Bob sign a new commitment to lock in the HTLC fail // for Alice. _, _, _, err = bobChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commit: %v", err) } // We'll now force a restart for Bob and Alice, so we can test the // persistence related portion of this assertion. bobChannel, err = restartChannel(bobChannel) if err != nil { t.Fatalf("unable to restart channel: %v", err) } aliceChannel, err = restartChannel(aliceChannel) if err != nil { t.Fatalf("unable to restart channel: %v", err) } // If we try to fail the same HTLC again, then we should get an error. err = bobChannel.FailHTLC(0, []byte("failreason"), nil, nil, nil) if err == nil { t.Fatalf("duplicate HTLC failure attempt should have failed") } // Alice on the other hand should accept the failure again, as she // dropped all items in the logs which weren't committed. if err := aliceChannel.ReceiveFailHTLC(0, []byte("bad")); err != nil { t.Fatalf("unable to recv htlc cancel: %v", err) } } // TestDuplicateSettleRejection tests that if either party attempts to settle // an HTLC twice, then we'll reject the second settle attempt. func TestDuplicateSettleRejection(t *testing.T) { t.Parallel() aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // First, we'll add an HTLC from Alice to Bob, and lock it in for both // parties. htlcAmount := lnwire.NewMSatFromSatoshis(20000) htlcAlice, alicePreimage := createHTLC(0, htlcAmount) if _, err := aliceChannel.AddHTLC(htlcAlice, nil); err != nil { t.Fatalf("alice unable to add htlc: %v", err) } _, err = bobChannel.ReceiveHTLC(htlcAlice) if err != nil { t.Fatalf("unable to recv htlc: %v", err) } if err := ForceStateTransition(aliceChannel, bobChannel); err != nil { t.Fatalf("unable to complete state update: %v", err) } // With the HTLC locked in, we'll now have Bob settle the HTLC back to // Alice. err = bobChannel.SettleHTLC(alicePreimage, uint64(0), nil, nil, nil) if err != nil { t.Fatalf("unable to cancel HTLC: %v", err) } err = aliceChannel.ReceiveHTLCSettle(alicePreimage, uint64(0)) if err != nil { t.Fatalf("unable to recv htlc cancel: %v", err) } // If we attempt to fail it AGAIN, then both sides should reject this // second failure attempt. err = bobChannel.SettleHTLC(alicePreimage, uint64(0), nil, nil, nil) if err == nil { t.Fatalf("duplicate HTLC failure attempt should have failed") } err = aliceChannel.ReceiveHTLCSettle(alicePreimage, uint64(0)) if err == nil { t.Fatalf("duplicate HTLC failure attempt should have failed") } // We'll now have Bob sign a new commitment to lock in the HTLC fail // for Alice. _, _, _, err = bobChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commit: %v", err) } // We'll now force a restart for Bob and Alice, so we can test the // persistence related portion of this assertion. bobChannel, err = restartChannel(bobChannel) if err != nil { t.Fatalf("unable to restart channel: %v", err) } aliceChannel, err = restartChannel(aliceChannel) if err != nil { t.Fatalf("unable to restart channel: %v", err) } // If we try to fail the same HTLC again, then we should get an error. err = bobChannel.SettleHTLC(alicePreimage, uint64(0), nil, nil, nil) if err == nil { t.Fatalf("duplicate HTLC failure attempt should have failed") } // Alice on the other hand should accept the failure again, as she // dropped all items in the logs which weren't committed. err = aliceChannel.ReceiveHTLCSettle(alicePreimage, uint64(0)) if err != nil { t.Fatalf("unable to recv htlc cancel: %v", err) } } // TestChannelRestoreCommitHeight tests that the local and remote commit // heights of HTLCs are set correctly across restores. func TestChannelRestoreCommitHeight(t *testing.T) { t.Parallel() aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // helper method to check add heights of the htlcs found in the given // log after a restore. restoreAndAssertCommitHeights := func(t *testing.T, channel *LightningChannel, remoteLog bool, htlcIndex uint64, expLocal, expRemote uint64) *LightningChannel { newChannel, err := NewLightningChannel( channel.Signer, channel.channelState, channel.sigPool, ) if err != nil { t.Fatalf("unable to create new channel: %v", err) } var pd *PaymentDescriptor if remoteLog { if newChannel.localUpdateLog.lookupHtlc(htlcIndex) != nil { t.Fatalf("htlc found in wrong log") } pd = newChannel.remoteUpdateLog.lookupHtlc(htlcIndex) } else { if newChannel.remoteUpdateLog.lookupHtlc(htlcIndex) != nil { t.Fatalf("htlc found in wrong log") } pd = newChannel.localUpdateLog.lookupHtlc(htlcIndex) } if pd == nil { t.Fatalf("htlc not found in log") } if pd.addCommitHeightLocal != expLocal { t.Fatalf("expected local add height to be %d, was %d", expLocal, pd.addCommitHeightLocal) } if pd.addCommitHeightRemote != expRemote { t.Fatalf("expected remote add height to be %d, was %d", expRemote, pd.addCommitHeightRemote) } return newChannel } // We'll send an HtLC from Alice to Bob. htlcAmount := lnwire.NewMSatFromSatoshis(100000000) htlcAlice, _ := createHTLC(0, htlcAmount) if _, err := aliceChannel.AddHTLC(htlcAlice, nil); err != nil { t.Fatalf("alice unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlcAlice); err != nil { t.Fatalf("bob unable to recv add htlc: %v", err) } // Let Alice sign a new state, which will include the HTLC just sent. aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } // The HTLC should only be on the pending remote commitment, so the // only the remote add height should be set during a restore. aliceChannel = restoreAndAssertCommitHeights( t, aliceChannel, false, 0, 0, 1, ) // Bob receives this commitment signature, and revokes his old state. err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("unable to receive commitment: %v", err) } bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke commitment: %v", err) } // Now the HTLC is locked into Bob's commitment, a restoration should // set only the local commit height, as it is not locked into Alice's // yet. bobChannel = restoreAndAssertCommitHeights(t, bobChannel, true, 0, 1, 0) // Alice receives the revocation, ACKing her pending commitment. _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatalf("unable to recive revocation: %v", err) } // However, the HTLC is still not locked into her local commitment, so // the local add height should still be 0 after a restoration. aliceChannel = restoreAndAssertCommitHeights( t, aliceChannel, false, 0, 0, 1, ) // Now let Bob send the commitment signature making the HTLC lock in on // Alice's commitment. bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } // At this stage Bob has a pending remote commitment. Make sure // restoring at this stage correcly restores the HTLC add commit // heights. bobChannel = restoreAndAssertCommitHeights(t, bobChannel, true, 0, 1, 1) err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("unable to receive commitment: %v", err) } aliceRevocation, _, err := aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke commitment: %v", err) } // Now both the local and remote add heights should be properly set. aliceChannel = restoreAndAssertCommitHeights( t, aliceChannel, false, 0, 1, 1, ) _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatalf("unable to recive revocation: %v", err) } // Alice ACKing Bob's pending commitment shouldn't change the heights // restored. bobChannel = restoreAndAssertCommitHeights(t, bobChannel, true, 0, 1, 1) // Send andother HTLC from Alice to Bob, to test whether already // existing HTLCs (the HTLC with index 0) keep getting the add heights // restored properly. htlcAlice, _ = createHTLC(1, htlcAmount) if _, err := aliceChannel.AddHTLC(htlcAlice, nil); err != nil { t.Fatalf("alice unable to add htlc: %v", err) } if _, err := bobChannel.ReceiveHTLC(htlcAlice); err != nil { t.Fatalf("bob unable to recv add htlc: %v", err) } // Send a new signature from Alice to Bob, making Alice have a pending // remote commitment. aliceSig, aliceHtlcSigs, _, err = aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } // A restoration should keep the add heights iof the first HTLC, and // the new HTLC should have a remote add height 2. aliceChannel = restoreAndAssertCommitHeights( t, aliceChannel, false, 0, 1, 1, ) aliceChannel = restoreAndAssertCommitHeights( t, aliceChannel, false, 1, 0, 2, ) err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) if err != nil { t.Fatalf("unable to receive commitment: %v", err) } bobRevocation, _, err = bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke commitment: %v", err) } // Since Bob just revoked another commitment, a restoration should // increase the add height of the firt HTLC to 2, as we only keep the // last unrevoked commitment. The new HTLC will also have a local add // height of 2. bobChannel = restoreAndAssertCommitHeights(t, bobChannel, true, 0, 2, 1) bobChannel = restoreAndAssertCommitHeights(t, bobChannel, true, 1, 2, 0) // Alice receives the revocation, ACKing her pending commitment for Bob. _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) if err != nil { t.Fatalf("unable to receive revocation: %v", err) } // Alice receiving Bob's revocation should bump both addCommitHeightRemote // heights to 2. aliceChannel = restoreAndAssertCommitHeights( t, aliceChannel, false, 0, 1, 2, ) aliceChannel = restoreAndAssertCommitHeights( t, aliceChannel, false, 1, 0, 2, ) // Sign a new state for Alice, making Bob have a pending remote // commitment. bobSig, bobHtlcSigs, _, err = bobChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } // The signing of a new commitment for Alice should have given the new // HTLC an add height. bobChannel = restoreAndAssertCommitHeights(t, bobChannel, true, 0, 2, 1) bobChannel = restoreAndAssertCommitHeights(t, bobChannel, true, 1, 2, 2) // Alice should receive the commitment and send over a revocation. err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("unable to receive commitment: %v", err) } aliceRevocation, _, err = aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke commitment: %v", err) } // Both heights should be 2 and they are on both commitments. aliceChannel = restoreAndAssertCommitHeights( t, aliceChannel, false, 0, 2, 2, ) aliceChannel = restoreAndAssertCommitHeights( t, aliceChannel, false, 1, 2, 2, ) // Bob receives the revocation, which should set both addCommitHeightRemote // fields to 2. _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) if err != nil { t.Fatalf("unable to receive revocation: %v", err) } bobChannel = restoreAndAssertCommitHeights(t, bobChannel, true, 0, 2, 2) bobChannel = restoreAndAssertCommitHeights(t, bobChannel, true, 1, 2, 2) // Bob now fails back the htlc that was just locked in. err = bobChannel.FailHTLC(0, []byte("failreason"), nil, nil, nil) if err != nil { t.Fatalf("unable to cancel HTLC: %v", err) } err = aliceChannel.ReceiveFailHTLC(0, []byte("bad")) if err != nil { t.Fatalf("unable to recv htlc cancel: %v", err) } // Now Bob signs for the fail update. bobSig, bobHtlcSigs, _, err = bobChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commitment: %v", err) } // Bob has a pending commitment for Alice, it shouldn't affect the add // commit heights though. bobChannel = restoreAndAssertCommitHeights(t, bobChannel, true, 0, 2, 2) _ = restoreAndAssertCommitHeights(t, bobChannel, true, 1, 2, 2) // Alice receives commitment, sends revocation. err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) if err != nil { t.Fatalf("unable to receive commitment: %v", err) } _, _, err = aliceChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke commitment: %v", err) } aliceChannel = restoreAndAssertCommitHeights( t, aliceChannel, false, 0, 3, 2, ) _ = restoreAndAssertCommitHeights(t, aliceChannel, false, 1, 3, 2) } // TestForceCloseFailLocalDataLoss tests that we don't allow a force close of a // channel that's in a non-default state. func TestForceCloseFailLocalDataLoss(t *testing.T) { t.Parallel() aliceChannel, _, cleanUp, err := CreateTestChannels( channeldb.SingleFunderBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // Now that we have our set of channels, we'll modify the channel state // to have a non-default channel flag. err = aliceChannel.channelState.ApplyChanStatus( channeldb.ChanStatusLocalDataLoss, ) if err != nil { t.Fatalf("unable to apply channel state: %v", err) } // Due to the change above, if we attempt to force close this // channel, we should fail as it isn't safe to force close a // channel that isn't in the pure default state. _, err = aliceChannel.ForceClose() if err == nil { t.Fatalf("expected force close to fail due to non-default " + "chan state") } } // TestForceCloseBorkedState tests that once we force close a channel, it's // marked as borked in the database. Additionally, all calls to mutate channel // state should also fail. func TestForceCloseBorkedState(t *testing.T) { t.Parallel() aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // Do the commitment dance until Bob sends a revocation so Alice is // able to receive the revocation, and then also make a new state // herself. aliceSigs, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commit: %v", err) } err = bobChannel.ReceiveNewCommitment(aliceSigs, aliceHtlcSigs) if err != nil { t.Fatalf("unable to receive commitment: %v", err) } revokeMsg, _, err := bobChannel.RevokeCurrentCommitment() if err != nil { t.Fatalf("unable to revoke bob commitment: %v", err) } bobSigs, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() if err != nil { t.Fatalf("unable to sign commit: %v", err) } err = aliceChannel.ReceiveNewCommitment(bobSigs, bobHtlcSigs) if err != nil { t.Fatalf("unable to receive commitment: %v", err) } // Now that we have a new Alice channel, we'll force close once to // trigger the update on disk to mark the channel as borked. if _, err := aliceChannel.ForceClose(); err != nil { t.Fatalf("unable to force close channel: %v", err) } // Next we'll mark the channel as borked before we proceed. err = aliceChannel.channelState.ApplyChanStatus( channeldb.ChanStatusBorked, ) if err != nil { t.Fatalf("unable to apply chan status: %v", err) } // The on-disk state should indicate that the channel is now borked. if !aliceChannel.channelState.HasChanStatus( channeldb.ChanStatusBorked, ) { t.Fatalf("chan status not updated as borked") } // At this point, all channel mutating methods should now fail as they // shouldn't be able to proceed if the channel is borked. _, _, _, _, err = aliceChannel.ReceiveRevocation(revokeMsg) if err != channeldb.ErrChanBorked { t.Fatalf("advance commitment tail should have failed") } // We manually advance the commitment tail here since the above // ReceiveRevocation call will fail before it's actually advanced. aliceChannel.remoteCommitChain.advanceTail() _, _, _, err = aliceChannel.SignNextCommitment() if err != channeldb.ErrChanBorked { t.Fatalf("sign commitment should have failed: %v", err) } _, _, err = aliceChannel.RevokeCurrentCommitment() if err != channeldb.ErrChanBorked { t.Fatalf("append remove chain tail should have failed") } } // TestChannelMaxFeeRate ensures we correctly compute a channel initiator's max // fee rate based on an allocation and its available balance. It should never // dip below the established fee floor. func TestChannelMaxFeeRate(t *testing.T) { t.Parallel() aliceChannel, _, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() assertMaxFeeRate := func(maxAlloc float64, expFeeRate chainfee.SatPerKWeight) { maxFeeRate := aliceChannel.MaxFeeRate(maxAlloc) if maxFeeRate != expFeeRate { t.Fatalf("expected max fee rate of %v with max "+ "allocation of %v, got %v", expFeeRate, maxAlloc, maxFeeRate) } } assertMaxFeeRate(1.0, 690607734) assertMaxFeeRate(0.001, 690607) assertMaxFeeRate(0.000001, 690) assertMaxFeeRate(0.0000001, chainfee.FeePerKwFloor) } // TestChannelFeeRateFloor asserts that valid commitments can be proposed and // received using chainfee.FeePerKwFloor as the initiator's fee rate. func TestChannelFeeRateFloor(t *testing.T) { t.Parallel() alice, bob, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) if err != nil { t.Fatalf("unable to create test channels: %v", err) } defer cleanUp() // Set the fee rate to the proposing fee rate floor. minFee := chainfee.FeePerKwFloor // Alice is the initiator, so only she can propose fee updates. if err := alice.UpdateFee(minFee); err != nil { t.Fatalf("unable to send fee update") } if err := bob.ReceiveUpdateFee(minFee); err != nil { t.Fatalf("unable to receive fee update") } // Check that alice can still sign commitments. sig, htlcSigs, _, err := alice.SignNextCommitment() if err != nil { t.Fatalf("alice unable to sign commitment: %v", err) } // Check that bob can still receive commitments. err = bob.ReceiveNewCommitment(sig, htlcSigs) if err != nil { t.Fatalf("bob unable to process alice's new commitment: %v", err) } } // TestFetchParent tests lookup of an entry's parent in the appropriate log. func TestFetchParent(t *testing.T) { tests := []struct { name string remoteChain bool remoteLog bool localEntries []*PaymentDescriptor remoteEntries []*PaymentDescriptor // parentIndex is the parent index of the entry that we will // lookup with fetch parent. parentIndex uint64 // expectErr indicates that we expect fetch parent to fail. expectErr bool // expectedIndex is the htlc index that we expect the parent // to have. expectedIndex uint64 }{ { name: "not found in remote log", localEntries: nil, remoteEntries: nil, remoteChain: true, remoteLog: true, parentIndex: 0, expectErr: true, }, { name: "not found in local log", localEntries: nil, remoteEntries: nil, remoteChain: false, remoteLog: false, parentIndex: 0, expectErr: true, }, { name: "remote log + chain, remote add height 0", localEntries: nil, remoteEntries: []*PaymentDescriptor{ // This entry will be added at log index =0. { HtlcIndex: 1, addCommitHeightLocal: 100, addCommitHeightRemote: 100, }, // This entry will be added at log index =1, it // is the parent entry we are looking for. { HtlcIndex: 2, addCommitHeightLocal: 100, addCommitHeightRemote: 0, }, }, remoteChain: true, remoteLog: true, parentIndex: 1, expectErr: true, }, { name: "remote log, local chain, local add height 0", remoteEntries: []*PaymentDescriptor{ // This entry will be added at log index =0. { HtlcIndex: 1, addCommitHeightLocal: 100, addCommitHeightRemote: 100, }, // This entry will be added at log index =1, it // is the parent entry we are looking for. { HtlcIndex: 2, addCommitHeightLocal: 0, addCommitHeightRemote: 100, }, }, localEntries: nil, remoteChain: false, remoteLog: true, parentIndex: 1, expectErr: true, }, { name: "local log + chain, local add height 0", localEntries: []*PaymentDescriptor{ // This entry will be added at log index =0. { HtlcIndex: 1, addCommitHeightLocal: 100, addCommitHeightRemote: 100, }, // This entry will be added at log index =1, it // is the parent entry we are looking for. { HtlcIndex: 2, addCommitHeightLocal: 0, addCommitHeightRemote: 100, }, }, remoteEntries: nil, remoteChain: false, remoteLog: false, parentIndex: 1, expectErr: true, }, { name: "local log + remote chain, remote add height 0", localEntries: []*PaymentDescriptor{ // This entry will be added at log index =0. { HtlcIndex: 1, addCommitHeightLocal: 100, addCommitHeightRemote: 100, }, // This entry will be added at log index =1, it // is the parent entry we are looking for. { HtlcIndex: 2, addCommitHeightLocal: 100, addCommitHeightRemote: 0, }, }, remoteEntries: nil, remoteChain: true, remoteLog: false, parentIndex: 1, expectErr: true, }, { name: "remote log found", localEntries: nil, remoteEntries: []*PaymentDescriptor{ // This entry will be added at log index =0. { HtlcIndex: 1, addCommitHeightLocal: 100, addCommitHeightRemote: 0, }, // This entry will be added at log index =1, it // is the parent entry we are looking for. { HtlcIndex: 2, addCommitHeightLocal: 100, addCommitHeightRemote: 100, }, }, remoteChain: true, remoteLog: true, parentIndex: 1, expectErr: false, expectedIndex: 2, }, { name: "local log found", localEntries: []*PaymentDescriptor{ // This entry will be added at log index =0. { HtlcIndex: 1, addCommitHeightLocal: 0, addCommitHeightRemote: 100, }, // This entry will be added at log index =1, it // is the parent entry we are looking for. { HtlcIndex: 2, addCommitHeightLocal: 100, addCommitHeightRemote: 100, }, }, remoteEntries: nil, remoteChain: false, remoteLog: false, parentIndex: 1, expectErr: false, expectedIndex: 2, }, } for _, test := range tests { test := test t.Run(test.name, func(t *testing.T) { // Create a lightning channel with newly initialized // local and remote logs. lc := LightningChannel{ localUpdateLog: newUpdateLog(0, 0), remoteUpdateLog: newUpdateLog(0, 0), } // Add the local and remote entries to update logs. for _, entry := range test.localEntries { lc.localUpdateLog.appendHtlc(entry) } for _, entry := range test.remoteEntries { lc.remoteUpdateLog.appendHtlc(entry) } parent, err := lc.fetchParent( &PaymentDescriptor{ ParentIndex: test.parentIndex, }, test.remoteChain, test.remoteLog, ) gotErr := err != nil if test.expectErr != gotErr { t.Fatalf("expected error: %v, got: %v, "+ "error:%v", test.expectErr, gotErr, err) } // If our lookup failed, we do not need to check parent // index. if err != nil { return } if parent.HtlcIndex != test.expectedIndex { t.Fatalf("expected parent index: %v, got: %v", test.parentIndex, parent.HtlcIndex) } }) } } // TestEvaluateView tests the creation of a htlc view and the opt in mutation of // send and receive balances. This test does not check htlc mutation on a htlc // level. func TestEvaluateView(t *testing.T) { const ( // addHeight is a non-zero height that is used for htlc adds. addHeight = 200 // nextHeight is a constant that we use for the next height in // all unit tests. nextHeight = 400 // feePerKw is the fee we start all of our unit tests with. feePerKw = 1 // htlcAddAmount is the amount for htlc adds in tests. htlcAddAmount = 15 // ourFeeUpdateAmt is an amount that we update fees to // expressed in msat. ourFeeUpdateAmt = 20000 // ourFeeUpdatePerSat is the fee rate *in satoshis* that we // expect if we update to ourFeeUpdateAmt. ourFeeUpdatePerSat = chainfee.SatPerKWeight(20) // theirFeeUpdateAmt iis an amount that they update fees to // expressed in msat. theirFeeUpdateAmt = 10000 // theirFeeUpdatePerSat is the fee rate *in satoshis* that we // expect if we update to ourFeeUpdateAmt. theirFeeUpdatePerSat = chainfee.SatPerKWeight(10) ) tests := []struct { name string ourHtlcs []*PaymentDescriptor theirHtlcs []*PaymentDescriptor remoteChain bool mutateState bool // ourExpectedHtlcs is the set of our htlcs that we expect in // the htlc view once it has been evaluated. We just store // htlc index -> bool for brevity, because we only check the // presence of the htlc in the returned set. ourExpectedHtlcs map[uint64]bool // theirExpectedHtlcs is the set of their htlcs that we expect // in the htlc view once it has been evaluated. We just store // htlc index -> bool for brevity, because we only check the // presence of the htlc in the returned set. theirExpectedHtlcs map[uint64]bool // expectedFee is the fee we expect to be set after evaluating // the htlc view. expectedFee chainfee.SatPerKWeight // expectReceived is the amount we expect the channel to have // tracked as our receive total. expectReceived lnwire.MilliSatoshi // expectSent is the amount we expect the channel to have // tracked as our send total. expectSent lnwire.MilliSatoshi }{ { name: "our fee update is applied", remoteChain: false, mutateState: false, ourHtlcs: []*PaymentDescriptor{ { Amount: ourFeeUpdateAmt, EntryType: FeeUpdate, }, }, theirHtlcs: nil, expectedFee: ourFeeUpdatePerSat, ourExpectedHtlcs: nil, theirExpectedHtlcs: nil, expectReceived: 0, expectSent: 0, }, { name: "their fee update is applied", remoteChain: false, mutateState: false, ourHtlcs: []*PaymentDescriptor{}, theirHtlcs: []*PaymentDescriptor{ { Amount: theirFeeUpdateAmt, EntryType: FeeUpdate, }, }, expectedFee: theirFeeUpdatePerSat, ourExpectedHtlcs: nil, theirExpectedHtlcs: nil, expectReceived: 0, expectSent: 0, }, { // We expect unresolved htlcs to to remain in the view. name: "htlcs adds without settles", remoteChain: false, mutateState: false, ourHtlcs: []*PaymentDescriptor{ { HtlcIndex: 0, Amount: htlcAddAmount, EntryType: Add, }, }, theirHtlcs: []*PaymentDescriptor{ { HtlcIndex: 0, Amount: htlcAddAmount, EntryType: Add, }, { HtlcIndex: 1, Amount: htlcAddAmount, EntryType: Add, }, }, expectedFee: feePerKw, ourExpectedHtlcs: map[uint64]bool{ 0: true, }, theirExpectedHtlcs: map[uint64]bool{ 0: true, 1: true, }, expectReceived: 0, expectSent: 0, }, { name: "our htlc settled, state mutated", remoteChain: false, mutateState: true, ourHtlcs: []*PaymentDescriptor{ { HtlcIndex: 0, Amount: htlcAddAmount, EntryType: Add, addCommitHeightLocal: addHeight, }, }, theirHtlcs: []*PaymentDescriptor{ { HtlcIndex: 0, Amount: htlcAddAmount, EntryType: Add, }, { HtlcIndex: 1, Amount: htlcAddAmount, EntryType: Settle, // Map their htlc settle update to our // htlc add (0). ParentIndex: 0, }, }, expectedFee: feePerKw, ourExpectedHtlcs: nil, theirExpectedHtlcs: map[uint64]bool{ 0: true, }, expectReceived: 0, expectSent: htlcAddAmount, }, { name: "our htlc settled, state not mutated", remoteChain: false, mutateState: false, ourHtlcs: []*PaymentDescriptor{ { HtlcIndex: 0, Amount: htlcAddAmount, EntryType: Add, addCommitHeightLocal: addHeight, }, }, theirHtlcs: []*PaymentDescriptor{ { HtlcIndex: 0, Amount: htlcAddAmount, EntryType: Add, }, { HtlcIndex: 1, Amount: htlcAddAmount, EntryType: Settle, // Map their htlc settle update to our // htlc add (0). ParentIndex: 0, }, }, expectedFee: feePerKw, ourExpectedHtlcs: nil, theirExpectedHtlcs: map[uint64]bool{ 0: true, }, expectReceived: 0, expectSent: 0, }, { name: "their htlc settled, state mutated", remoteChain: false, mutateState: true, ourHtlcs: []*PaymentDescriptor{ { HtlcIndex: 0, Amount: htlcAddAmount, EntryType: Add, }, { HtlcIndex: 1, Amount: htlcAddAmount, EntryType: Settle, // Map our htlc settle update to their // htlc add (1). ParentIndex: 1, }, }, theirHtlcs: []*PaymentDescriptor{ { HtlcIndex: 0, Amount: htlcAddAmount, EntryType: Add, addCommitHeightLocal: addHeight, }, { HtlcIndex: 1, Amount: htlcAddAmount, EntryType: Add, addCommitHeightLocal: addHeight, }, }, expectedFee: feePerKw, ourExpectedHtlcs: map[uint64]bool{ 0: true, }, theirExpectedHtlcs: map[uint64]bool{ 0: true, }, expectReceived: htlcAddAmount, expectSent: 0, }, { name: "their htlc settled, state not mutated", remoteChain: false, mutateState: false, ourHtlcs: []*PaymentDescriptor{ { HtlcIndex: 0, Amount: htlcAddAmount, EntryType: Add, }, { HtlcIndex: 1, Amount: htlcAddAmount, EntryType: Settle, // Map our htlc settle update to their // htlc add (0). ParentIndex: 0, }, }, theirHtlcs: []*PaymentDescriptor{ { HtlcIndex: 0, Amount: htlcAddAmount, EntryType: Add, addCommitHeightLocal: addHeight, }, }, expectedFee: feePerKw, ourExpectedHtlcs: map[uint64]bool{ 0: true, }, theirExpectedHtlcs: nil, expectReceived: 0, expectSent: 0, }, } for _, test := range tests { test := test t.Run(test.name, func(t *testing.T) { lc := LightningChannel{ channelState: &channeldb.OpenChannel{ TotalMSatSent: 0, TotalMSatReceived: 0, }, // Create update logs for local and remote. localUpdateLog: newUpdateLog(0, 0), remoteUpdateLog: newUpdateLog(0, 0), } for _, htlc := range test.ourHtlcs { if htlc.EntryType == Add { lc.localUpdateLog.appendHtlc(htlc) } else { lc.localUpdateLog.appendUpdate(htlc) } } for _, htlc := range test.theirHtlcs { if htlc.EntryType == Add { lc.remoteUpdateLog.appendHtlc(htlc) } else { lc.remoteUpdateLog.appendUpdate(htlc) } } view := &htlcView{ ourUpdates: test.ourHtlcs, theirUpdates: test.theirHtlcs, feePerKw: feePerKw, } var ( // Create vars to store balance changes. We do // not check these values in this test because // balance modification happens on the htlc // processing level. ourBalance lnwire.MilliSatoshi theirBalance lnwire.MilliSatoshi ) // Evaluate the htlc view, mutate as test expects. result, err := lc.evaluateHTLCView( view, &ourBalance, &theirBalance, nextHeight, test.remoteChain, test.mutateState, ) if err != nil { t.Fatalf("unexpected error: %v", err) } if result.feePerKw != test.expectedFee { t.Fatalf("expected fee: %v, got: %v", test.expectedFee, result.feePerKw) } checkExpectedHtlcs( t, result.ourUpdates, test.ourExpectedHtlcs, ) checkExpectedHtlcs( t, result.theirUpdates, test.theirExpectedHtlcs, ) if lc.channelState.TotalMSatSent != test.expectSent { t.Fatalf("expected sent: %v, got: %v", test.expectSent, lc.channelState.TotalMSatSent) } if lc.channelState.TotalMSatReceived != test.expectReceived { t.Fatalf("expected received: %v, got: %v", test.expectReceived, lc.channelState.TotalMSatReceived) } }) } } // checkExpectedHtlcs checks that a set of htlcs that we have contains all the // htlcs we expect. func checkExpectedHtlcs(t *testing.T, actual []*PaymentDescriptor, expected map[uint64]bool) { if len(expected) != len(actual) { t.Fatalf("expected: %v htlcs, got: %v", len(expected), len(actual)) } for _, htlc := range actual { _, ok := expected[htlc.HtlcIndex] if !ok { t.Fatalf("htlc with index: %v not "+ "expected in set", htlc.HtlcIndex) } } } // heights represents the heights on a payment descriptor. type heights struct { localAdd uint64 localRemove uint64 remoteAdd uint64 remoteRemove uint64 } // TestProcessFeeUpdate tests the applying of fee updates and mutation of // local and remote add and remove heights on update messages. func TestProcessFeeUpdate(t *testing.T) { const ( // height is a non-zero height that can be used for htlcs // heights. height = 200 // nextHeight is a constant that we use for the next height in // all unit tests. nextHeight = 400 // feePerKw is the fee we start all of our unit tests with. feePerKw = 1 // ourFeeUpdateAmt is an amount that we update fees to expressed // in msat. ourFeeUpdateAmt = 20000 // ourFeeUpdatePerSat is the fee rate *in satoshis* that we // expect if we update to ourFeeUpdateAmt. ourFeeUpdatePerSat = chainfee.SatPerKWeight(20) ) tests := []struct { name string startHeights heights expectedHeights heights remoteChain bool mutate bool expectedFee chainfee.SatPerKWeight }{ { // Looking at local chain, local add is non-zero so // the update has been applied already; no fee change. name: "non-zero local height, fee unchanged", startHeights: heights{ localAdd: height, localRemove: 0, remoteAdd: 0, remoteRemove: height, }, expectedHeights: heights{ localAdd: height, localRemove: 0, remoteAdd: 0, remoteRemove: height, }, remoteChain: false, mutate: false, expectedFee: feePerKw, }, { // Looking at local chain, local add is zero so the // update has not been applied yet; we expect a fee // update. name: "zero local height, fee changed", startHeights: heights{ localAdd: 0, localRemove: 0, remoteAdd: height, remoteRemove: 0, }, expectedHeights: heights{ localAdd: 0, localRemove: 0, remoteAdd: height, remoteRemove: 0, }, remoteChain: false, mutate: false, expectedFee: ourFeeUpdatePerSat, }, { // Looking at remote chain, the remote add height is // zero, so the update has not been applied so we expect // a fee change. name: "zero remote height, fee changed", startHeights: heights{ localAdd: height, localRemove: 0, remoteAdd: 0, remoteRemove: 0, }, expectedHeights: heights{ localAdd: height, localRemove: 0, remoteAdd: 0, remoteRemove: 0, }, remoteChain: true, mutate: false, expectedFee: ourFeeUpdatePerSat, }, { // Looking at remote chain, the remote add height is // non-zero, so the update has been applied so we expect // no fee change. name: "non-zero remote height, no fee change", startHeights: heights{ localAdd: height, localRemove: 0, remoteAdd: height, remoteRemove: 0, }, expectedHeights: heights{ localAdd: height, localRemove: 0, remoteAdd: height, remoteRemove: 0, }, remoteChain: true, mutate: false, expectedFee: feePerKw, }, { // Local add height is non-zero, so the update has // already been applied; we do not expect fee to // change or any mutations to be applied. name: "non-zero local height, mutation not applied", startHeights: heights{ localAdd: height, localRemove: 0, remoteAdd: 0, remoteRemove: height, }, expectedHeights: heights{ localAdd: height, localRemove: 0, remoteAdd: 0, remoteRemove: height, }, remoteChain: false, mutate: true, expectedFee: feePerKw, }, { // Local add is zero and we are looking at our local // chain, so the update has not been applied yet. We // expect the local add and remote heights to be // mutated. name: "zero height, fee changed, mutation applied", startHeights: heights{ localAdd: 0, localRemove: 0, remoteAdd: 0, remoteRemove: 0, }, expectedHeights: heights{ localAdd: nextHeight, localRemove: nextHeight, remoteAdd: 0, remoteRemove: 0, }, remoteChain: false, mutate: true, expectedFee: ourFeeUpdatePerSat, }, } for _, test := range tests { test := test t.Run(test.name, func(t *testing.T) { // Create a fee update with add and remove heights as // set in the test. heights := test.startHeights update := &PaymentDescriptor{ Amount: ourFeeUpdateAmt, addCommitHeightRemote: heights.remoteAdd, addCommitHeightLocal: heights.localAdd, removeCommitHeightRemote: heights.remoteRemove, removeCommitHeightLocal: heights.localRemove, EntryType: FeeUpdate, } view := &htlcView{ feePerKw: chainfee.SatPerKWeight(feePerKw), } processFeeUpdate( update, nextHeight, test.remoteChain, test.mutate, view, ) if view.feePerKw != test.expectedFee { t.Fatalf("expected fee: %v, got: %v", test.expectedFee, feePerKw) } checkHeights(t, update, test.expectedHeights) }) } } func checkHeights(t *testing.T, update *PaymentDescriptor, expected heights) { updateHeights := heights{ localAdd: update.addCommitHeightLocal, localRemove: update.removeCommitHeightLocal, remoteAdd: update.addCommitHeightRemote, remoteRemove: update.removeCommitHeightRemote, } if !reflect.DeepEqual(updateHeights, expected) { t.Fatalf("expected: %v, got: %v", expected, updateHeights) } } // TestProcessAddRemoveEntry tests the updating of our and their balances when // we process adds, settles and fails. It also tests the mutating of add and // remove heights. func TestProcessAddRemoveEntry(t *testing.T) { const ( // addHeight is a non-zero addHeight that is used for htlc // add heights. addHeight = 100 // removeHeight is a non-zero removeHeight that is used for // htlc remove heights. removeHeight = 200 // nextHeight is a constant that we use for the nextHeight in // all unit tests. nextHeight = 400 // updateAmount is the amount that the update is set to. updateAmount = lnwire.MilliSatoshi(10) // startBalance is a balance we start both sides out with // so that balances can be incremented. startBalance = lnwire.MilliSatoshi(100) ) tests := []struct { name string startHeights heights remoteChain bool isIncoming bool mutateState bool ourExpectedBalance lnwire.MilliSatoshi theirExpectedBalance lnwire.MilliSatoshi expectedHeights heights updateType updateType }{ { name: "add, remote chain, already processed", startHeights: heights{ localAdd: 0, remoteAdd: addHeight, localRemove: 0, remoteRemove: 0, }, remoteChain: true, isIncoming: false, mutateState: false, ourExpectedBalance: startBalance, theirExpectedBalance: startBalance, expectedHeights: heights{ localAdd: 0, remoteAdd: addHeight, localRemove: 0, remoteRemove: 0, }, updateType: Add, }, { name: "add, local chain, already processed", startHeights: heights{ localAdd: addHeight, remoteAdd: 0, localRemove: 0, remoteRemove: 0, }, remoteChain: false, isIncoming: false, mutateState: false, ourExpectedBalance: startBalance, theirExpectedBalance: startBalance, expectedHeights: heights{ localAdd: addHeight, remoteAdd: 0, localRemove: 0, remoteRemove: 0, }, updateType: Add, }, { name: "incoming add, local chain, not mutated", startHeights: heights{ localAdd: 0, remoteAdd: 0, localRemove: 0, remoteRemove: 0, }, remoteChain: false, isIncoming: true, mutateState: false, ourExpectedBalance: startBalance, theirExpectedBalance: startBalance - updateAmount, expectedHeights: heights{ localAdd: 0, remoteAdd: 0, localRemove: 0, remoteRemove: 0, }, updateType: Add, }, { name: "incoming add, local chain, mutated", startHeights: heights{ localAdd: 0, remoteAdd: 0, localRemove: 0, remoteRemove: 0, }, remoteChain: false, isIncoming: true, mutateState: true, ourExpectedBalance: startBalance, theirExpectedBalance: startBalance - updateAmount, expectedHeights: heights{ localAdd: nextHeight, remoteAdd: 0, localRemove: 0, remoteRemove: 0, }, updateType: Add, }, { name: "outgoing add, remote chain, not mutated", startHeights: heights{ localAdd: 0, remoteAdd: 0, localRemove: 0, remoteRemove: 0, }, remoteChain: true, isIncoming: false, mutateState: false, ourExpectedBalance: startBalance - updateAmount, theirExpectedBalance: startBalance, expectedHeights: heights{ localAdd: 0, remoteAdd: 0, localRemove: 0, remoteRemove: 0, }, updateType: Add, }, { name: "outgoing add, remote chain, mutated", startHeights: heights{ localAdd: 0, remoteAdd: 0, localRemove: 0, remoteRemove: 0, }, remoteChain: true, isIncoming: false, mutateState: true, ourExpectedBalance: startBalance - updateAmount, theirExpectedBalance: startBalance, expectedHeights: heights{ localAdd: 0, remoteAdd: nextHeight, localRemove: 0, remoteRemove: 0, }, updateType: Add, }, { name: "settle, remote chain, already processed", startHeights: heights{ localAdd: addHeight, remoteAdd: addHeight, localRemove: 0, remoteRemove: removeHeight, }, remoteChain: true, isIncoming: false, mutateState: false, ourExpectedBalance: startBalance, theirExpectedBalance: startBalance, expectedHeights: heights{ localAdd: addHeight, remoteAdd: addHeight, localRemove: 0, remoteRemove: removeHeight, }, updateType: Settle, }, { name: "settle, local chain, already processed", startHeights: heights{ localAdd: addHeight, remoteAdd: addHeight, localRemove: removeHeight, remoteRemove: 0, }, remoteChain: false, isIncoming: false, mutateState: false, ourExpectedBalance: startBalance, theirExpectedBalance: startBalance, expectedHeights: heights{ localAdd: addHeight, remoteAdd: addHeight, localRemove: removeHeight, remoteRemove: 0, }, updateType: Settle, }, { // Remote chain, and not processed yet. Incoming settle, // so we expect our balance to increase. name: "incoming settle", startHeights: heights{ localAdd: addHeight, remoteAdd: addHeight, localRemove: 0, remoteRemove: 0, }, remoteChain: true, isIncoming: true, mutateState: false, ourExpectedBalance: startBalance + updateAmount, theirExpectedBalance: startBalance, expectedHeights: heights{ localAdd: addHeight, remoteAdd: addHeight, localRemove: 0, remoteRemove: 0, }, updateType: Settle, }, { // Remote chain, and not processed yet. Incoming settle, // so we expect our balance to increase. name: "outgoing settle", startHeights: heights{ localAdd: addHeight, remoteAdd: addHeight, localRemove: 0, remoteRemove: 0, }, remoteChain: true, isIncoming: false, mutateState: false, ourExpectedBalance: startBalance, theirExpectedBalance: startBalance + updateAmount, expectedHeights: heights{ localAdd: addHeight, remoteAdd: addHeight, localRemove: 0, remoteRemove: 0, }, updateType: Settle, }, { // Remote chain, and not processed yet. Incoming fail, // so we expect their balance to increase. name: "incoming fail", startHeights: heights{ localAdd: addHeight, remoteAdd: addHeight, localRemove: 0, remoteRemove: 0, }, remoteChain: true, isIncoming: true, mutateState: false, ourExpectedBalance: startBalance, theirExpectedBalance: startBalance + updateAmount, expectedHeights: heights{ localAdd: addHeight, remoteAdd: addHeight, localRemove: 0, remoteRemove: 0, }, updateType: Fail, }, { // Remote chain, and not processed yet. Outgoing fail, // so we expect our balance to increase. name: "outgoing fail", startHeights: heights{ localAdd: addHeight, remoteAdd: addHeight, localRemove: 0, remoteRemove: 0, }, remoteChain: true, isIncoming: false, mutateState: false, ourExpectedBalance: startBalance + updateAmount, theirExpectedBalance: startBalance, expectedHeights: heights{ localAdd: addHeight, remoteAdd: addHeight, localRemove: 0, remoteRemove: 0, }, updateType: Fail, }, { // Local chain, and not processed yet. Incoming settle, // so we expect our balance to increase. Mutate is // true, so we expect our remove removeHeight to have // changed. name: "fail, our remove height mutated", startHeights: heights{ localAdd: addHeight, remoteAdd: addHeight, localRemove: 0, remoteRemove: 0, }, remoteChain: false, isIncoming: true, mutateState: true, ourExpectedBalance: startBalance + updateAmount, theirExpectedBalance: startBalance, expectedHeights: heights{ localAdd: addHeight, remoteAdd: addHeight, localRemove: nextHeight, remoteRemove: 0, }, updateType: Settle, }, { // Remote chain, and not processed yet. Incoming settle, // so we expect our balance to increase. Mutate is // true, so we expect their remove removeHeight to have // changed. name: "fail, their remove height mutated", startHeights: heights{ localAdd: addHeight, remoteAdd: addHeight, localRemove: 0, remoteRemove: 0, }, remoteChain: true, isIncoming: true, mutateState: true, ourExpectedBalance: startBalance + updateAmount, theirExpectedBalance: startBalance, expectedHeights: heights{ localAdd: addHeight, remoteAdd: addHeight, localRemove: 0, remoteRemove: nextHeight, }, updateType: Settle, }, } for _, test := range tests { test := test t.Run(test.name, func(t *testing.T) { t.Parallel() heights := test.startHeights update := &PaymentDescriptor{ Amount: updateAmount, addCommitHeightLocal: heights.localAdd, addCommitHeightRemote: heights.remoteAdd, removeCommitHeightLocal: heights.localRemove, removeCommitHeightRemote: heights.remoteRemove, EntryType: test.updateType, } var ( // Start both parties off with an initial // balance. Copy by value here so that we do // not mutate the startBalance constant. ourBalance, theirBalance = startBalance, startBalance ) // Choose the processing function we need based on the // update type. Process remove is used for settles, // fails and malformed htlcs. process := processRemoveEntry if test.updateType == Add { process = processAddEntry } process( update, &ourBalance, &theirBalance, nextHeight, test.remoteChain, test.isIncoming, test.mutateState, ) // Check that balances were updated as expected. if ourBalance != test.ourExpectedBalance { t.Fatalf("expected our balance: %v, got: %v", test.ourExpectedBalance, ourBalance) } if theirBalance != test.theirExpectedBalance { t.Fatalf("expected their balance: %v, got: %v", test.theirExpectedBalance, theirBalance) } // Check that heights on the update are as expected. checkHeights(t, update, test.expectedHeights) }) } } // TestChannelUnsignedAckedFailure tests that unsigned acked updates are // properly restored after signing for them and disconnecting. // // The full state transition of this test is: // // Alice Bob // -----add-----> // -----sig-----> // <----rev------ // <----sig------ // -----rev-----> // <----fail----- // <----sig------ // -----rev-----> // -----sig-----X (does not reach Bob! Alice dies!) // // -----sig-----> // <----rev------ // <----add------ // <----sig------ // // The last sig was rejected with the old behavior of deleting unsigned // acked updates from the database after signing for them. The current // behavior of filtering them for deletion upon receiving a revocation // causes Alice to accept the signature as valid. func TestChannelUnsignedAckedFailure(t *testing.T) { t.Parallel() // Create a test channel so that we can test the buggy behavior. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) require.NoError(t, err) defer cleanUp() // First we create an HTLC that Alice sends to Bob. htlc, _ := createHTLC(0, lnwire.MilliSatoshi(500000)) // -----add-----> _, err = aliceChannel.AddHTLC(htlc, nil) require.NoError(t, err) _, err = bobChannel.ReceiveHTLC(htlc) require.NoError(t, err) // Force a state transition to lock in this add on both commitments. // -----sig-----> // <----rev------ // <----sig------ // -----rev-----> err = ForceStateTransition(aliceChannel, bobChannel) require.NoError(t, err) // Now Bob should fail the htlc back to Alice. // <----fail----- err = bobChannel.FailHTLC(0, []byte("failreason"), nil, nil, nil) require.NoError(t, err) err = aliceChannel.ReceiveFailHTLC(0, []byte("bad")) require.NoError(t, err) // Bob should send a commitment signature to Alice. // <----sig------ bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() require.NoError(t, err) err = aliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) require.NoError(t, err) // Alice should reply with a revocation. // -----rev-----> aliceRevocation, _, err := aliceChannel.RevokeCurrentCommitment() require.NoError(t, err) _, _, _, _, err = bobChannel.ReceiveRevocation(aliceRevocation) require.NoError(t, err) // Alice should sign the next commitment and go down before // sending it. // -----sig-----X aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() require.NoError(t, err) newAliceChannel, err := NewLightningChannel( aliceChannel.Signer, aliceChannel.channelState, aliceChannel.sigPool, ) require.NoError(t, err) // Bob receives Alice's signature. // -----sig-----> err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) require.NoError(t, err) // Bob revokes his current commitment and sends a revocation // to Alice. // <----rev------ bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() require.NoError(t, err) _, _, _, _, err = newAliceChannel.ReceiveRevocation(bobRevocation) require.NoError(t, err) // Now Bob sends an HTLC to Alice. htlc2, _ := createHTLC(0, lnwire.MilliSatoshi(500000)) // <----add------ _, err = bobChannel.AddHTLC(htlc2, nil) require.NoError(t, err) _, err = newAliceChannel.ReceiveHTLC(htlc2) require.NoError(t, err) // Bob sends the final signature to Alice and Alice should not // reject it, given that we properly restore the unsigned acked // updates and therefore our update log is structured correctly. bobSig, bobHtlcSigs, _, err = bobChannel.SignNextCommitment() require.NoError(t, err) err = newAliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) require.NoError(t, err) } // TestChannelLocalUnsignedUpdatesFailure checks that updates from the local // log are restored if the remote hasn't sent us a signature covering them. // // The full state transition is: // // Alice Bob // <----add----- // <----sig----- // -----rev----> // -----sig----> // <----rev----- // ----fail----> // -----sig----> // <----rev----- // *reconnect* // <----sig----- // // Alice should reject the last signature since the settle is not restored // into the local update log and thus calculates Bob's signature as invalid. func TestChannelLocalUnsignedUpdatesFailure(t *testing.T) { t.Parallel() // Create a test channel so that we can test the buggy behavior. aliceChannel, bobChannel, cleanUp, err := CreateTestChannels( channeldb.SingleFunderTweaklessBit, ) require.NoError(t, err) defer cleanUp() // First we create an htlc that Bob sends to Alice. htlc, _ := createHTLC(0, lnwire.MilliSatoshi(500000)) // <----add----- _, err = bobChannel.AddHTLC(htlc, nil) require.NoError(t, err) _, err = aliceChannel.ReceiveHTLC(htlc) require.NoError(t, err) // Force a state transition to lock in this add on both commitments. // <----sig----- // -----rev----> // -----sig----> // <----rev----- err = ForceStateTransition(bobChannel, aliceChannel) require.NoError(t, err) // Now Alice should fail the htlc back to Bob. // -----fail---> err = aliceChannel.FailHTLC(0, []byte("failreason"), nil, nil, nil) require.NoError(t, err) err = bobChannel.ReceiveFailHTLC(0, []byte("bad")) require.NoError(t, err) // Alice should send a commitment signature to Bob. // -----sig----> aliceSig, aliceHtlcSigs, _, err := aliceChannel.SignNextCommitment() require.NoError(t, err) err = bobChannel.ReceiveNewCommitment(aliceSig, aliceHtlcSigs) require.NoError(t, err) // Bob should reply with a revocation and Alice should save the fail as // an unsigned local update. // <----rev----- bobRevocation, _, err := bobChannel.RevokeCurrentCommitment() require.NoError(t, err) _, _, _, _, err = aliceChannel.ReceiveRevocation(bobRevocation) require.NoError(t, err) // Restart Alice and assert that she can receive Bob's next commitment // signature. // *reconnect* newAliceChannel, err := NewLightningChannel( aliceChannel.Signer, aliceChannel.channelState, aliceChannel.sigPool, ) require.NoError(t, err) // Bob sends the final signature and Alice should not reject it. // <----sig----- bobSig, bobHtlcSigs, _, err := bobChannel.SignNextCommitment() require.NoError(t, err) err = newAliceChannel.ReceiveNewCommitment(bobSig, bobHtlcSigs) require.NoError(t, err) }