lnd.xprv/lntest/itest/lnd_forward_interceptor_test.go
Olaoluwa Osuntokun 719e32830d
lntest: fix most linter warnings, silence rest
We fix all linter issues except for the 'lostcontext' and 'unparam' ones
as those are too numerous and would increase the diff even more.
Therefore we silence them in the itest directory for now.
Because the linter is still not build tag aware, we also have to silence
the unused and deadcode sub linters to not get false positives.
2020-09-21 21:16:31 +02:00

416 lines
12 KiB
Go

package itest
import (
"context"
"encoding/hex"
"fmt"
"sync"
"time"
"github.com/btcsuite/btcd/wire"
"github.com/btcsuite/btcutil"
"github.com/lightningnetwork/lnd"
"github.com/lightningnetwork/lnd/lnrpc"
"github.com/lightningnetwork/lnd/lnrpc/routerrpc"
"github.com/lightningnetwork/lnd/lntest"
"github.com/lightningnetwork/lnd/routing/route"
"github.com/stretchr/testify/require"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/status"
)
var (
customTestKey uint64 = 394829
customTestValue = []byte{1, 3, 5}
)
type interceptorTestCase struct {
amountMsat int64
invoice *lnrpc.Invoice
shouldHold bool
interceptorAction routerrpc.ResolveHoldForwardAction
}
// testForwardInterceptor tests the forward interceptor RPC layer.
// The test creates a cluster of 3 connected nodes: Alice -> Bob -> Carol
// Alice sends 4 different payments to Carol while the interceptor handles
// differently the htlcs.
// The test ensures that:
// 1. Intercepted failed htlcs result in no payment (invoice is not settled).
// 2. Intercepted resumed htlcs result in a payment (invoice is settled).
// 3. Intercepted held htlcs result in no payment (invoice is not settled).
// 4. When Interceptor disconnects it resumes all held htlcs, which result in
// valid payment (invoice is settled).
func testForwardInterceptor(net *lntest.NetworkHarness, t *harnessTest) {
// initialize the test context with 3 connected nodes.
testContext := newInterceptorTestContext(t, net)
defer testContext.shutdownNodes()
const (
chanAmt = btcutil.Amount(300000)
)
// Open and wait for channels.
testContext.openChannel(testContext.alice, testContext.bob, chanAmt)
testContext.openChannel(testContext.bob, testContext.carol, chanAmt)
defer testContext.closeChannels()
testContext.waitForChannels()
// Connect the interceptor.
ctx := context.Background()
ctxt, cancelInterceptor := context.WithTimeout(ctx, defaultTimeout)
interceptor, err := testContext.bob.RouterClient.HtlcInterceptor(ctxt)
if err != nil {
t.Fatalf("failed to create HtlcInterceptor %v", err)
}
// Prepare the test cases.
testCases, err := testContext.prepareTestCases()
if err != nil {
t.Fatalf("failed to prepare test cases")
}
// A channel for the interceptor go routine to send the requested packets.
interceptedChan := make(chan *routerrpc.ForwardHtlcInterceptRequest,
len(testCases))
// Run the interceptor loop in its own go routine.
var wg sync.WaitGroup
wg.Add(1)
go func() {
defer wg.Done()
for {
request, err := interceptor.Recv()
if err != nil {
// If it is just the error result of the context cancellation
// the we exit silently.
status, ok := status.FromError(err)
if ok && status.Code() == codes.Canceled {
return
}
// Otherwise it an unexpected error, we fail the test.
t.t.Errorf("unexpected error in interceptor.Recv() %v", err)
return
}
interceptedChan <- request
}
}()
// For each test case make sure we initiate a payment from Alice to Carol
// routed through Bob. For each payment we also test its final status
// according to the interceptorAction specified in the test case.
wg.Add(1)
go func() {
defer wg.Done()
for _, tc := range testCases {
attempt, err := testContext.sendAliceToCarolPayment(
context.Background(), tc.invoice.ValueMsat, tc.invoice.RHash)
if t.t.Failed() {
return
}
if err != nil {
t.t.Errorf("failed to send payment %v", err)
}
switch tc.interceptorAction {
// For 'fail' interceptor action we make sure the payment failed.
case routerrpc.ResolveHoldForwardAction_FAIL:
if attempt.Status != lnrpc.HTLCAttempt_FAILED {
t.t.Errorf("expected payment to fail, instead got %v", attempt.Status)
}
// For settle and resume we make sure the payment is successful.
case routerrpc.ResolveHoldForwardAction_SETTLE:
fallthrough
case routerrpc.ResolveHoldForwardAction_RESUME:
if attempt.Status != lnrpc.HTLCAttempt_SUCCEEDED {
t.t.Errorf("expected payment to succeed, instead got %v", attempt.Status)
}
}
}
}()
// We make sure here the interceptor has processed all packets before we
// check the payment statuses.
for i := 0; i < len(testCases); i++ {
select {
case request := <-interceptedChan:
// Assert sanity of informational packet data.
require.NotZero(t.t, request.OutgoingRequestedChanId)
require.NotZero(t.t, request.IncomingExpiry)
require.NotZero(t.t, request.IncomingAmountMsat)
require.Less(
t.t,
request.OutgoingExpiry, request.IncomingExpiry,
)
require.Less(
t.t,
request.OutgoingAmountMsat,
request.IncomingAmountMsat,
)
value, ok := request.CustomRecords[customTestKey]
require.True(t.t, ok, "expected custom record")
require.Equal(t.t, customTestValue, value)
testCase := testCases[i]
// For held packets we ignore, keeping them in hold status.
if testCase.shouldHold {
continue
}
// For all other packets we resolve according to the test case.
_ = interceptor.Send(&routerrpc.ForwardHtlcInterceptResponse{
IncomingCircuitKey: request.IncomingCircuitKey,
Action: testCase.interceptorAction,
Preimage: testCase.invoice.RPreimage,
})
case <-time.After(defaultTimeout):
t.Fatalf("response from interceptor was not received %v", i)
}
}
// At this point we are left with the held packets, we want to make sure
// each one of them has a corresponding 'in-flight' payment at
// Alice's node.
payments, err := testContext.alice.ListPayments(context.Background(),
&lnrpc.ListPaymentsRequest{IncludeIncomplete: true})
if err != nil {
t.Fatalf("failed to fetch payments")
}
for _, testCase := range testCases {
if testCase.shouldHold {
hashStr := hex.EncodeToString(testCase.invoice.RHash)
var foundPayment *lnrpc.Payment
expectedAmt := testCase.invoice.ValueMsat
for _, p := range payments.Payments {
if p.PaymentHash == hashStr {
foundPayment = p
break
}
}
if foundPayment == nil {
t.Fatalf("expected to find pending payment for held"+
"htlc %v", hashStr)
}
if foundPayment.ValueMsat != expectedAmt ||
foundPayment.Status != lnrpc.Payment_IN_FLIGHT {
t.Fatalf("expected to find in flight payment for"+
"amount %v, %v", testCase.invoice.ValueMsat, foundPayment.Status)
}
}
}
// Disconnect interceptor should cause resume held packets.
// After that we wait for all go routines to finish, including the one
// that tests the payment final status for the held payment.
cancelInterceptor()
wg.Wait()
}
// interceptorTestContext is a helper struct to hold the test context and
// provide the needed functionality.
type interceptorTestContext struct {
t *harnessTest
net *lntest.NetworkHarness
// Keep a list of all our active channels.
networkChans []*lnrpc.ChannelPoint
closeChannelFuncs []func()
alice, bob, carol *lntest.HarnessNode
nodes []*lntest.HarnessNode
}
func newInterceptorTestContext(t *harnessTest,
net *lntest.NetworkHarness) *interceptorTestContext {
ctxb := context.Background()
// Create a three-node context consisting of Alice, Bob and Carol
carol, err := net.NewNode("carol", nil)
if err != nil {
t.Fatalf("unable to create carol: %v", err)
}
// Connect nodes
nodes := []*lntest.HarnessNode{net.Alice, net.Bob, carol}
for i := 0; i < len(nodes); i++ {
for j := i + 1; j < len(nodes); j++ {
ctxt, _ := context.WithTimeout(ctxb, defaultTimeout)
if err := net.EnsureConnected(ctxt, nodes[i], nodes[j]); err != nil {
t.Fatalf("unable to connect nodes: %v", err)
}
}
}
ctx := interceptorTestContext{
t: t,
net: net,
alice: net.Alice,
bob: net.Bob,
carol: carol,
nodes: nodes,
}
return &ctx
}
// prepareTestCases prepares 4 tests:
// 1. failed htlc.
// 2. resumed htlc.
// 3. settling htlc externally.
// 4. held htlc that is resumed later.
func (c *interceptorTestContext) prepareTestCases() (
[]*interceptorTestCase, error) {
cases := []*interceptorTestCase{
{amountMsat: 1000, shouldHold: false,
interceptorAction: routerrpc.ResolveHoldForwardAction_FAIL},
{amountMsat: 1000, shouldHold: false,
interceptorAction: routerrpc.ResolveHoldForwardAction_RESUME},
{amountMsat: 1000, shouldHold: false,
interceptorAction: routerrpc.ResolveHoldForwardAction_SETTLE},
{amountMsat: 1000, shouldHold: true,
interceptorAction: routerrpc.ResolveHoldForwardAction_RESUME},
}
for _, t := range cases {
addResponse, err := c.carol.AddInvoice(context.Background(), &lnrpc.Invoice{
ValueMsat: t.amountMsat,
})
if err != nil {
return nil, fmt.Errorf("unable to add invoice: %v", err)
}
invoice, err := c.carol.LookupInvoice(context.Background(), &lnrpc.PaymentHash{
RHashStr: hex.EncodeToString(addResponse.RHash),
})
if err != nil {
return nil, fmt.Errorf("unable to add invoice: %v", err)
}
t.invoice = invoice
}
return cases, nil
}
func (c *interceptorTestContext) openChannel(from, to *lntest.HarnessNode, chanSize btcutil.Amount) {
ctxb := context.Background()
ctxt, _ := context.WithTimeout(ctxb, defaultTimeout)
err := c.net.SendCoins(ctxt, btcutil.SatoshiPerBitcoin, from)
if err != nil {
c.t.Fatalf("unable to send coins : %v", err)
}
ctxt, _ = context.WithTimeout(ctxb, channelOpenTimeout)
chanPoint := openChannelAndAssert(
ctxt, c.t, c.net, from, to,
lntest.OpenChannelParams{
Amt: chanSize,
},
)
c.closeChannelFuncs = append(c.closeChannelFuncs, func() {
ctxt, _ := context.WithTimeout(ctxb, channelCloseTimeout)
closeChannelAndAssert(
ctxt, c.t, c.net, from, chanPoint, false,
)
})
c.networkChans = append(c.networkChans, chanPoint)
}
func (c *interceptorTestContext) closeChannels() {
for _, f := range c.closeChannelFuncs {
f()
}
}
func (c *interceptorTestContext) shutdownNodes() {
shutdownAndAssert(c.net, c.t, c.carol)
}
func (c *interceptorTestContext) waitForChannels() {
ctxb := context.Background()
// Wait for all nodes to have seen all channels.
for _, chanPoint := range c.networkChans {
for _, node := range c.nodes {
txid, err := lnd.GetChanPointFundingTxid(chanPoint)
if err != nil {
c.t.Fatalf("unable to get txid: %v", err)
}
point := wire.OutPoint{
Hash: *txid,
Index: chanPoint.OutputIndex,
}
ctxt, _ := context.WithTimeout(ctxb, defaultTimeout)
err = node.WaitForNetworkChannelOpen(ctxt, chanPoint)
if err != nil {
c.t.Fatalf("(%d): timeout waiting for "+
"channel(%s) open: %v",
node.NodeID, point, err)
}
}
}
}
// sendAliceToCarolPayment sends a payment from alice to carol and make an
// attempt to pay. The lnrpc.HTLCAttempt is returned.
func (c *interceptorTestContext) sendAliceToCarolPayment(ctx context.Context,
amtMsat int64, paymentHash []byte) (*lnrpc.HTLCAttempt, error) {
// Build a route from alice to carol.
route, err := c.buildRoute(ctx, amtMsat, []*lntest.HarnessNode{c.bob, c.carol})
if err != nil {
return nil, err
}
sendReq := &routerrpc.SendToRouteRequest{
PaymentHash: paymentHash,
Route: route,
}
// Send a custom record to the forwarding node.
route.Hops[0].CustomRecords = map[uint64][]byte{
customTestKey: customTestValue,
}
// Send the payment.
return c.alice.RouterClient.SendToRouteV2(ctx, sendReq)
}
// buildRoute is a helper function to build a route with given hops.
func (c *interceptorTestContext) buildRoute(ctx context.Context, amtMsat int64, hops []*lntest.HarnessNode) (
*lnrpc.Route, error) {
rpcHops := make([][]byte, 0, len(hops))
for _, hop := range hops {
k := hop.PubKeyStr
pubkey, err := route.NewVertexFromStr(k)
if err != nil {
return nil, fmt.Errorf("error parsing %v: %v",
k, err)
}
rpcHops = append(rpcHops, pubkey[:])
}
req := &routerrpc.BuildRouteRequest{
AmtMsat: amtMsat,
FinalCltvDelta: lnd.DefaultBitcoinTimeLockDelta,
HopPubkeys: rpcHops,
}
routeResp, err := c.alice.RouterClient.BuildRoute(ctx, req)
if err != nil {
return nil, err
}
return routeResp.Route, nil
}