respect the lsp timelockdelta

cln_interceptor.go

@@ -168,7 +168,7 @@ func (i *ClnHtlcInterceptor) intercept() error {
 					interceptorClient.Send(i.defaultResolution(request))
 					i.doneWg.Done()
 				}
-				interceptResult := intercept(i.client, i.config, nextHop, paymentHash, request.Onion.ForwardMsat, request.Htlc.CltvExpiry)
+				interceptResult := intercept(i.client, i.config, nextHop, paymentHash, request.Onion.ForwardMsat, request.Onion.OutgoingCltvValue, request.Htlc.CltvExpiry)
 				switch interceptResult.action {
 				case INTERCEPT_RESUME_WITH_ONION:
 					interceptorClient.Send(i.resumeWithOnion(request, interceptResult))

intercept.go

@@ -45,7 +45,7 @@ type interceptResult struct {
 	onionBlob    []byte
 }
 
-func intercept(client LightningClient, config *NodeConfig, nextHop string, reqPaymentHash []byte, reqOutgoingAmountMsat uint64, reqOutgoingExpiry uint32) interceptResult {
+func intercept(client LightningClient, config *NodeConfig, nextHop string, reqPaymentHash []byte, reqOutgoingAmountMsat uint64, reqOutgoingExpiry uint32, reqIncomingExpiry uint32) interceptResult {
 	reqPaymentHashStr := hex.EncodeToString(reqPaymentHash)
 	resp, _, _ := payHashGroup.Do(reqPaymentHashStr, func() (interface{}, error) {
 		paymentHash, paymentSecret, destination, incomingAmountMsat, outgoingAmountMsat, channelPoint, err := paymentInfo(reqPaymentHash)
@@ -66,6 +66,13 @@ func intercept(client LightningClient, config *NodeConfig, nextHop string, reqPa
 
 		if channelPoint == nil {
 			if bytes.Equal(paymentHash, reqPaymentHash) {
+				if int64(reqIncomingExpiry)-int64(reqOutgoingExpiry) < int64(config.TimeLockDelta) {
+					return interceptResult{
+						action:      INTERCEPT_FAIL_HTLC_WITH_CODE,
+						failureCode: FAILURE_TEMPORARY_CHANNEL_FAILURE,
+					}, nil
+				}
+
 				channelPoint, err = openChannel(client, config, reqPaymentHash, destination, incomingAmountMsat)
 				if err != nil {
 					log.Printf("openChannel(%x, %v) err: %v", destination, incomingAmountMsat, err)

itest/cltv_test.go

@@ -0,0 +1,58 @@
+package itest
+
+import (
+	"log"
+	"time"
+
+	"github.com/breez/lntest"
+	lspd "github.com/breez/lspd/rpc"
+	"github.com/stretchr/testify/assert"
+)
+
+func testInvalidCltv(p *testParams) {
+	alice := lntest.NewClnNode(p.h, p.m, "Alice")
+	alice.Start()
+	alice.Fund(10000000)
+	p.lsp.LightningNode().Fund(10000000)
+
+	log.Print("Opening channel between Alice and the lsp")
+	channel := alice.OpenChannel(p.lsp.LightningNode(), &lntest.OpenChannelOptions{
+		AmountSat: publicChanAmount,
+	})
+	channelId := alice.WaitForChannelReady(channel)
+
+	log.Printf("Adding bob's invoices")
+	outerAmountMsat := uint64(2100000)
+	innerAmountMsat, lspAmountMsat := calculateInnerAmountMsat(p.lsp, outerAmountMsat)
+	description := "Please pay me"
+	innerInvoice, outerInvoice := GenerateInvoices(p.BreezClient(),
+		generateInvoicesRequest{
+			innerAmountMsat: innerAmountMsat,
+			outerAmountMsat: outerAmountMsat,
+			description:     description,
+			lsp:             p.lsp,
+		})
+
+	log.Print("Connecting bob to lspd")
+	p.BreezClient().Node().ConnectPeer(p.lsp.LightningNode())
+
+	log.Printf("Registering payment with lsp")
+	RegisterPayment(p.lsp, &lspd.PaymentInformation{
+		PaymentHash:        innerInvoice.paymentHash,
+		PaymentSecret:      innerInvoice.paymentSecret,
+		Destination:        p.BreezClient().Node().NodeId(),
+		IncomingAmountMsat: int64(outerAmountMsat),
+		OutgoingAmountMsat: int64(lspAmountMsat),
+	})
+
+	// TODO: Fix race waiting for htlc interceptor.
+	log.Printf("Waiting %v to allow htlc interceptor to activate.", htlcInterceptorDelay)
+	<-time.After(htlcInterceptorDelay)
+	log.Printf("Alice paying")
+	route := constructRoute(p.lsp.LightningNode(), p.BreezClient().Node(), channelId, lntest.NewShortChanIDFromString("1x0x0"), outerAmountMsat)
+
+	// Decrement the delay in the first hop, so the cltv delta will become 143 (too little)
+	route.Hops[0].Delay--
+	_, err := alice.PayViaRoute(outerAmountMsat, outerInvoice.paymentHash, outerInvoice.paymentSecret, route)
+	assert.Contains(p.t, err.Error(), "WIRE_TEMPORARY_CHANNEL_FAILURE")
+}

itest/lspd_node.go

@@ -30,7 +30,7 @@ var (
 var (
 	lspBaseFeeMsat uint32 = 1000
 	lspFeeRatePpm  uint32 = 1
-	lspCltvDelta   uint16 = 40
+	lspCltvDelta   uint16 = 144
 )
 
 type LspNode interface {

itest/lspd_test.go

@@ -97,4 +97,8 @@ var allTestCases = []*testCase{
 		name: "testProbing",
 		test: testProbing,
 	},
+	{
+		name: "testInvalidCltv",
+		test: testInvalidCltv,
+	},
 }

lnd_interceptor.go

@@ -148,7 +148,7 @@ func (i *LndHtlcInterceptor) intercept() error {
 
 			i.doneWg.Add(1)
 			go func() {
-				interceptResult := intercept(i.client, i.config, nextHop, request.PaymentHash, request.OutgoingAmountMsat, request.OutgoingExpiry)
+				interceptResult := intercept(i.client, i.config, nextHop, request.PaymentHash, request.OutgoingAmountMsat, request.OutgoingExpiry, request.IncomingExpiry)
 				switch interceptResult.action {
 				case INTERCEPT_RESUME_WITH_ONION:
 					interceptorClient.Send(&routerrpc.ForwardHtlcInterceptResponse{