mirror of https://github.com/BTCPrivate/lnd.git
lnwallet: finish initial draft of LightningChannel state machine
This commit finishes the initial draft of the commitment state machine. A full re-write of the prior protocol which combines aspects of the former ‘lnstate’ package has replaced the prior un-finished stop-and-wait protocol. This new protocol is designed to operate in an asynchronous environment and to facilitate non-blocking batched and pipelined updates to the committed channel states. The protocol is also de-synchronized meaning that either side can propose new commitment states independent of the actions of the other party. The state machine implemented is very similar to that of c-lightning, however we allow multiple unrevoked commentates in order to minimize blocking, and also to reduce latency across several hops in a bi-directional setting. The current implementation consists of 3 main data structures: a commitment chain which consist of unrevoked commitment transactions (one for each side), and a (mostly) append-only log of HTLC updates shared between both sides. New commitments proposed index into the log denoting which updates they include, this allows both parties to progress chains independent of one another. Revoked commitments, reduce the length of the chain by one, and free up space within the revocation window. At this point only basic tests are in place for the state machine, however more extensive testing infrastructure along with formal proofs using PlusCall are planned.
This commit is contained in:
Olaoluwa Osuntokun
parent
8775107454
commit
94c242073a
1343
lnwallet/channel.go
1343
lnwallet/channel.go
File diff suppressed because it is too large
Load Diff
|
|
@ -0,0 +1,425 @@
|
|||
package lnwallet
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"fmt"
|
||||
"io/ioutil"
|
||||
"os"
|
||||
"testing"
|
||||
|
||||
"github.com/btcsuite/fastsha256"
|
||||
"github.com/davecgh/go-spew/spew"
|
||||
"github.com/lightningnetwork/lnd/channeldb"
|
||||
"github.com/lightningnetwork/lnd/elkrem"
|
||||
"github.com/lightningnetwork/lnd/lnwire"
|
||||
"github.com/roasbeef/btcd/btcec"
|
||||
"github.com/roasbeef/btcd/chaincfg"
|
||||
"github.com/roasbeef/btcd/wire"
|
||||
"github.com/roasbeef/btcutil"
|
||||
)
|
||||
|
||||
// MockEncryptorDecryptor is a mock implementation of EncryptorDecryptor that
|
||||
// simply returns the passed bytes without encrypting or decrypting. This is
|
||||
// used for testing purposes to be able to create a channldb instance which
|
||||
// doesn't use encryption.
|
||||
type MockEncryptorDecryptor struct {
|
||||
}
|
||||
|
||||
func (m *MockEncryptorDecryptor) Encrypt(n []byte) ([]byte, error) {
|
||||
return n, nil
|
||||
}
|
||||
|
||||
func (m *MockEncryptorDecryptor) Decrypt(n []byte) ([]byte, error) {
|
||||
return n, nil
|
||||
}
|
||||
|
||||
func (m *MockEncryptorDecryptor) OverheadSize() uint32 {
|
||||
return 0
|
||||
}
|
||||
|
||||
// createTestChannels creates two test channels funded with 10 BTC, with 5 BTC
|
||||
// allocated to each side.
|
||||
func createTestChannels() (*LightningChannel, *LightningChannel, func(), error) {
|
||||
aliceKeyPriv, aliceKeyPub := btcec.PrivKeyFromBytes(btcec.S256(),
|
||||
testWalletPrivKey)
|
||||
bobKeyPriv, bobKeyPub := btcec.PrivKeyFromBytes(btcec.S256(),
|
||||
bobsPrivKey)
|
||||
|
||||
channelCapacity := btcutil.Amount(10 * 1e8)
|
||||
channelBal := channelCapacity / 2
|
||||
csvTimeoutAlice := uint32(5)
|
||||
csvTimeoutBob := uint32(4)
|
||||
|
||||
redeemScript, _, err := genFundingPkScript(aliceKeyPub.SerializeCompressed(),
|
||||
bobKeyPub.SerializeCompressed(), int64(channelCapacity))
|
||||
if err != nil {
|
||||
return nil, nil, nil, err
|
||||
}
|
||||
|
||||
prevOut := &wire.OutPoint{
|
||||
Hash: wire.ShaHash(testHdSeed),
|
||||
Index: 0,
|
||||
}
|
||||
fundingTxIn := wire.NewTxIn(prevOut, nil, nil)
|
||||
|
||||
bobElkrem := elkrem.NewElkremSender(deriveElkremRoot(bobKeyPriv, aliceKeyPub))
|
||||
bobFirstRevoke, err := bobElkrem.AtIndex(0)
|
||||
if err != nil {
|
||||
return nil, nil, nil, err
|
||||
}
|
||||
bobRevokeKey := deriveRevocationPubkey(aliceKeyPub, bobFirstRevoke[:])
|
||||
|
||||
aliceElkrem := elkrem.NewElkremSender(deriveElkremRoot(aliceKeyPriv, bobKeyPub))
|
||||
aliceFirstRevoke, err := aliceElkrem.AtIndex(0)
|
||||
if err != nil {
|
||||
return nil, nil, nil, err
|
||||
}
|
||||
aliceRevokeKey := deriveRevocationPubkey(bobKeyPub, aliceFirstRevoke[:])
|
||||
|
||||
aliceCommitTx, err := createCommitTx(fundingTxIn, aliceKeyPub,
|
||||
bobKeyPub, aliceRevokeKey, csvTimeoutAlice, channelBal, channelBal)
|
||||
if err != nil {
|
||||
return nil, nil, nil, err
|
||||
}
|
||||
bobCommitTx, err := createCommitTx(fundingTxIn, bobKeyPub,
|
||||
aliceKeyPub, bobRevokeKey, csvTimeoutBob, channelBal, channelBal)
|
||||
if err != nil {
|
||||
return nil, nil, nil, err
|
||||
}
|
||||
|
||||
alicePath, err := ioutil.TempDir("", "alicedb")
|
||||
dbAlice, err := channeldb.Open(alicePath, &chaincfg.TestNet3Params)
|
||||
if err != nil {
|
||||
return nil, nil, nil, err
|
||||
}
|
||||
dbAlice.RegisterCryptoSystem(&MockEncryptorDecryptor{})
|
||||
bobPath, err := ioutil.TempDir("", "bobdb")
|
||||
dbBob, err := channeldb.Open(bobPath, &chaincfg.TestNet3Params)
|
||||
if err != nil {
|
||||
return nil, nil, nil, err
|
||||
}
|
||||
dbBob.RegisterCryptoSystem(&MockEncryptorDecryptor{})
|
||||
|
||||
aliceChannelState := &channeldb.OpenChannel{
|
||||
TheirLNID: testHdSeed,
|
||||
ChanID: prevOut,
|
||||
OurCommitKey: aliceKeyPriv,
|
||||
TheirCommitKey: bobKeyPub,
|
||||
Capacity: channelCapacity,
|
||||
OurBalance: channelBal,
|
||||
TheirBalance: channelBal,
|
||||
OurCommitTx: aliceCommitTx,
|
||||
FundingOutpoint: prevOut,
|
||||
OurMultiSigKey: aliceKeyPriv,
|
||||
TheirMultiSigKey: bobKeyPub,
|
||||
FundingRedeemScript: redeemScript,
|
||||
LocalCsvDelay: csvTimeoutAlice,
|
||||
RemoteCsvDelay: csvTimeoutBob,
|
||||
TheirCurrentRevocation: bobRevokeKey,
|
||||
LocalElkrem: aliceElkrem,
|
||||
RemoteElkrem: &elkrem.ElkremReceiver{},
|
||||
Db: dbAlice,
|
||||
}
|
||||
bobChannelState := &channeldb.OpenChannel{
|
||||
TheirLNID: testHdSeed,
|
||||
ChanID: prevOut,
|
||||
OurCommitKey: bobKeyPriv,
|
||||
TheirCommitKey: aliceKeyPub,
|
||||
Capacity: channelCapacity,
|
||||
OurBalance: channelBal,
|
||||
TheirBalance: channelBal,
|
||||
OurCommitTx: bobCommitTx,
|
||||
FundingOutpoint: prevOut,
|
||||
OurMultiSigKey: bobKeyPriv,
|
||||
TheirMultiSigKey: aliceKeyPub,
|
||||
FundingRedeemScript: redeemScript,
|
||||
LocalCsvDelay: csvTimeoutBob,
|
||||
RemoteCsvDelay: csvTimeoutAlice,
|
||||
TheirCurrentRevocation: aliceRevokeKey,
|
||||
LocalElkrem: bobElkrem,
|
||||
RemoteElkrem: &elkrem.ElkremReceiver{},
|
||||
Db: dbBob,
|
||||
}
|
||||
|
||||
cleanUpFunc := func() {
|
||||
os.RemoveAll(bobPath)
|
||||
os.RemoveAll(alicePath)
|
||||
}
|
||||
|
||||
channelAlice, err := NewLightningChannel(nil, nil, dbAlice, aliceChannelState)
|
||||
if err != nil {
|
||||
return nil, nil, nil, err
|
||||
}
|
||||
channelBob, err := NewLightningChannel(nil, nil, dbBob, bobChannelState)
|
||||
if err != nil {
|
||||
return nil, nil, nil, err
|
||||
}
|
||||
|
||||
return channelAlice, channelBob, cleanUpFunc, nil
|
||||
}
|
||||
|
||||
// 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 commited in both commit chains.
|
||||
// TODO(roasbeef): write higher level framework to excercise various states of
|
||||
// the state machine
|
||||
// * DSL language perhaps?
|
||||
// * constructed via input/output files
|
||||
func TestSimpleAddSettleWorkflow(t *testing.T) {
|
||||
// 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()
|
||||
if err != nil {
|
||||
t.Fatalf("unable to create test channels: %v", err)
|
||||
}
|
||||
defer cleanUp()
|
||||
|
||||
// Now that the channel are open, simulate the start of a session by
|
||||
// having Alice and Bob extend their revocation windows to each other.
|
||||
// For testing purposes we'll use a revocation window of size 3.
|
||||
for i := 1; i < 4; i++ {
|
||||
aliceNextRevoke, err := aliceChannel.ExtendRevocationWindow()
|
||||
if err != nil {
|
||||
t.Fatalf("unable to create new alice revoke")
|
||||
}
|
||||
if htlcs, err := bobChannel.ReceiveRevocation(aliceNextRevoke); err != nil {
|
||||
t.Fatalf("bob unable to process alice revocation increment: %v", err)
|
||||
} else if htlcs != nil {
|
||||
t.Fatalf("revocation window extend should not trigger htlc "+
|
||||
"forward, instead %v marked for forwarding", spew.Sdump(htlcs))
|
||||
}
|
||||
|
||||
bobNextRevoke, err := bobChannel.ExtendRevocationWindow()
|
||||
if err != nil {
|
||||
t.Fatalf("unable to create new bob revoke")
|
||||
}
|
||||
if htlcs, err := aliceChannel.ReceiveRevocation(bobNextRevoke); err != nil {
|
||||
t.Fatalf("bob unable to process alice revocation increment: %v", err)
|
||||
} else if htlcs != nil {
|
||||
t.Fatalf("revocation window extend should not trigger htlc "+
|
||||
"forward, instead %v marked for forwarding", spew.Sdump(htlcs))
|
||||
}
|
||||
}
|
||||
|
||||
// The edge of the revocation window for both sides should be 3 at this
|
||||
// point.
|
||||
if aliceChannel.revocationWindowEdge != 3 {
|
||||
t.Fatalf("alice revocation window not incremented, is %v should be %v",
|
||||
aliceChannel.revocationWindowEdge, 3)
|
||||
}
|
||||
if bobChannel.revocationWindowEdge != 3 {
|
||||
t.Fatalf("alice revocation window not incremented, is %v should be %v",
|
||||
bobChannel.revocationWindowEdge, 3)
|
||||
}
|
||||
|
||||
paymentPreimage := bytes.Repeat([]byte{1}, 32)
|
||||
paymentHash := fastsha256.Sum256(paymentPreimage)
|
||||
htlc := &lnwire.HTLCAddRequest{
|
||||
RedemptionHashes: [][32]byte{paymentHash},
|
||||
// TODO(roasbeef): properly switch to credits: (1 msat)
|
||||
Amount: lnwire.CreditsAmount(1e8),
|
||||
Expiry: uint32(5),
|
||||
}
|
||||
|
||||
// First Alice adds the outgoing HTLC to her local channel's state
|
||||
// update log.
|
||||
if err := aliceChannel.AddHTLC(htlc, false); err != nil {
|
||||
t.Fatalf("unable to add htlc to alice's channel: %v", err)
|
||||
}
|
||||
|
||||
// Then Alice sends this wire message over to Bob who also adds this
|
||||
// htlc to his local state update log.
|
||||
if err := bobChannel.AddHTLC(htlc, true); err != nil {
|
||||
t.Fatalf("unable to add htlc bob's channel: %v", err)
|
||||
}
|
||||
|
||||
// Next alice commits this change by sending a signature message.
|
||||
aliceSig, bobLogIndex, err := aliceChannel.SignNextCommitment()
|
||||
if err != nil {
|
||||
t.Fatalf("alice unable to sign commitment: %v", err)
|
||||
}
|
||||
|
||||
// Bob recieves this signature message, then generates a signature for
|
||||
// Alice's commitment transaction, and the revocation to his prior
|
||||
// commitment transaction.
|
||||
if err := bobChannel.ReceiveNewCommitment(aliceSig, bobLogIndex); err != nil {
|
||||
t.Fatalf("bob unable to process alice's new commitment: %v", err)
|
||||
}
|
||||
bobSig, aliceLogIndex, err := bobChannel.SignNextCommitment()
|
||||
if err != nil {
|
||||
t.Fatalf("bob unable to sign alice's commitment: %v", err)
|
||||
}
|
||||
bobRevocation, err := bobChannel.RevokeCurrentCommitment()
|
||||
if err != nil {
|
||||
t.Fatalf("unable to generate bob revocation: %v", err)
|
||||
}
|
||||
|
||||
// Alice then proceses bob's signature, and generates a revocation for
|
||||
// bob.
|
||||
if err := aliceChannel.ReceiveNewCommitment(bobSig, aliceLogIndex); err != nil {
|
||||
t.Fatalf("alice unable to process bob's new commitment: %v", err)
|
||||
}
|
||||
// Alice then processes this revocation, sending her own revovation for
|
||||
// her prior commitment transaction. Alice shouldn't have any HTLC's to
|
||||
// forward since she's sending anoutgoing HTLC.
|
||||
if htlcs, err := aliceChannel.ReceiveRevocation(bobRevocation); err != nil {
|
||||
t.Fatalf("alice unable to rocess bob's revocation: %v", err)
|
||||
} else if len(htlcs) != 0 {
|
||||
t.Fatalf("alice forwards %v htlcs, should forward none: ", len(htlcs))
|
||||
}
|
||||
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.
|
||||
if htlcs, err := bobChannel.ReceiveRevocation(aliceRevocation); err != nil {
|
||||
t.Fatalf("bob unable to process alive's revocation: %v", err)
|
||||
} else if len(htlcs) != 1 {
|
||||
t.Fatalf("bob should be able to forward an HTLC, instead can "+
|
||||
"forward %v", len(htlcs))
|
||||
}
|
||||
|
||||
// At this point, both sides should have the proper balance, and
|
||||
// commitment height updated within their local channel state.
|
||||
aliceBalance := btcutil.Amount(4 * 1e8)
|
||||
bobBalance := btcutil.Amount(5 * 1e8)
|
||||
if aliceChannel.channelState.OurBalance != aliceBalance {
|
||||
t.Fatalf("alice has incorrect local balance %v vs %v",
|
||||
aliceChannel.channelState.OurBalance, aliceBalance)
|
||||
}
|
||||
if aliceChannel.channelState.TheirBalance != bobBalance {
|
||||
t.Fatalf("alice has incorrect remote balance %v vs %v",
|
||||
aliceChannel.channelState.TheirBalance, bobBalance)
|
||||
}
|
||||
if bobChannel.channelState.OurBalance != bobBalance {
|
||||
t.Fatalf("bob has incorrect local balance %v vs %v",
|
||||
bobChannel.channelState.OurBalance, bobBalance)
|
||||
}
|
||||
if bobChannel.channelState.TheirBalance != aliceBalance {
|
||||
t.Fatalf("bob has incorrect remote balance %v vs %v",
|
||||
bobChannel.channelState.TheirBalance, aliceBalance)
|
||||
}
|
||||
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)
|
||||
}
|
||||
|
||||
// Alice's revocation window should now be one beyond the size of the
|
||||
// intial window. Same goes for Bob.
|
||||
if aliceChannel.revocationWindowEdge != 4 {
|
||||
t.Fatalf("alice revocation window not incremented, is %v should be %v",
|
||||
aliceChannel.revocationWindowEdge, 4)
|
||||
}
|
||||
if bobChannel.revocationWindowEdge != 4 {
|
||||
t.Fatalf("alice revocation window not incremented, is %v should be %v",
|
||||
bobChannel.revocationWindowEdge, 4)
|
||||
}
|
||||
|
||||
// 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)
|
||||
wireSettleMsg := &lnwire.HTLCSettleRequest{
|
||||
RedemptionProofs: [][32]byte{preimage},
|
||||
}
|
||||
if err := bobChannel.SettleHTLC(wireSettleMsg, false); err != nil {
|
||||
t.Fatalf("bob unable to settle inbound htlc: %v", err)
|
||||
}
|
||||
if err := aliceChannel.SettleHTLC(wireSettleMsg, true); err != nil {
|
||||
t.Fatalf("alice unable to accept settle of outbound htlc: %v", err)
|
||||
}
|
||||
bobSig2, aliceIndex2, err := bobChannel.SignNextCommitment()
|
||||
if err != nil {
|
||||
t.Fatalf("bob unable to sign settle commitment: %v", err)
|
||||
}
|
||||
if err := aliceChannel.ReceiveNewCommitment(bobSig2, aliceIndex2); err != nil {
|
||||
t.Fatalf("alice unable to process bob's new commitment: %v", err)
|
||||
}
|
||||
aliceSig2, bobLogIndex2, err := aliceChannel.SignNextCommitment()
|
||||
if err != nil {
|
||||
t.Fatalf("alice unable to sign new commitment: %v", err)
|
||||
}
|
||||
aliceRevocation2, err := aliceChannel.RevokeCurrentCommitment()
|
||||
if err != nil {
|
||||
t.Fatalf("alice unable to generate revoation: %v", err)
|
||||
}
|
||||
if err := bobChannel.ReceiveNewCommitment(aliceSig2, bobLogIndex2); 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)
|
||||
}
|
||||
if htlcs, err := bobChannel.ReceiveRevocation(aliceRevocation2); err != nil {
|
||||
t.Fatalf("bob unable to process alice's revocation: %v", err)
|
||||
} else {
|
||||
fmt.Println("bob forward htlcs: %v", htlcs)
|
||||
}
|
||||
if htlcs, err := aliceChannel.ReceiveRevocation(bobRevocation2); err != nil {
|
||||
t.Fatalf("alice unable to process bob's revocation: %v", err)
|
||||
} else {
|
||||
fmt.Println("alice forward htlcs: %v", spew.Sdump(htlcs))
|
||||
}
|
||||
|
||||
// At this point, bob should have 6BTC settled, with Alice still having
|
||||
// 4 BTC. They should also be at a commitment height at two, with the
|
||||
// revocation window extended by by 1 (5).
|
||||
aliceSettleBalance := btcutil.Amount(4 * 1e8)
|
||||
bobSettleBalance := btcutil.Amount(6 * 1e8)
|
||||
if aliceChannel.channelState.OurBalance != aliceSettleBalance {
|
||||
t.Fatalf("alice has incorrect local balance %v vs %v",
|
||||
aliceChannel.channelState.OurBalance, aliceSettleBalance)
|
||||
}
|
||||
if aliceChannel.channelState.TheirBalance != bobSettleBalance {
|
||||
t.Fatalf("alice has incorrect remote balance %v vs %v",
|
||||
aliceChannel.channelState.TheirBalance, bobSettleBalance)
|
||||
}
|
||||
if bobChannel.channelState.OurBalance != bobSettleBalance {
|
||||
t.Fatalf("bob has incorrect local balance %v vs %v",
|
||||
bobChannel.channelState.OurBalance, bobSettleBalance)
|
||||
}
|
||||
if bobChannel.channelState.TheirBalance != aliceSettleBalance {
|
||||
t.Fatalf("bob has incorrect remote balance %v vs %v",
|
||||
bobChannel.channelState.TheirBalance, aliceSettleBalance)
|
||||
}
|
||||
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)
|
||||
}
|
||||
if aliceChannel.revocationWindowEdge != 5 {
|
||||
t.Fatalf("alice revocation window not incremented, is %v should be %v",
|
||||
aliceChannel.revocationWindowEdge, 5)
|
||||
}
|
||||
if bobChannel.revocationWindowEdge != 5 {
|
||||
t.Fatalf("alice revocation window not incremented, is %v should be %v",
|
||||
bobChannel.revocationWindowEdge, 5)
|
||||
}
|
||||
|
||||
// The logs of both sides should now be cleared since the entry adding
|
||||
// the HTLC should have been removed once both sides recieve the
|
||||
// revocation.
|
||||
aliceLogLen := aliceChannel.stateUpdateLog.Len()
|
||||
if aliceLogLen != 0 {
|
||||
t.Fatalf("alice's log not updated, should be empty, has %v entries "+
|
||||
"instead", aliceLogLen)
|
||||
}
|
||||
bobLogLen := bobChannel.stateUpdateLog.Len()
|
||||
if bobLogLen != 0 {
|
||||
t.Fatalf("bob's log not updated, should be empty, has %v entries "+
|
||||
"instead", bobLogLen)
|
||||
}
|
||||
}
|
||||
|
|
@ -50,7 +50,6 @@ var (
|
|||
0x4f, 0x2f, 0x6f, 0x25, 0x88, 0xa3, 0xef, 0xb9,
|
||||
0x6a, 0x49, 0x18, 0x83, 0x31, 0x98, 0x47, 0x53,
|
||||
}
|
||||
zeroHash = bytes.Repeat([]byte{0}, 32)
|
||||
|
||||
// The number of confirmations required to consider any created channel
|
||||
// open.
|
||||
|
|
|
|||
Loading…
Reference in New Issue