Commit Graph

292 Commits

Author SHA1 Message Date
Johan T. Halseth
a6e7dce7b7
lnwallet/channel: reject received commitment with too many htlc sigs
This commit adds a check that will make LightningChannel reject a
received commitment if it is accompanied with too many HTLC signatures.
This enforces the requirement in BOLT-2, saying:

if num_htlcs is not equal to the number of HTLC outputs in the local commitment transaction:
    * MUST fail the channel.

A test exercising the behaviour is added.
2018-03-22 14:58:22 +01:00
Johan T. Halseth
70b86e596e
lnwallet/channel: use remote dustlimit when generating HTLC sigs
This commit fixes an issue which would arise in some cases when the
local and remote dust limits would differ, resulting in lnd not
producing the expected number of HTLC signatures. This was a result of
checking dust against the local instead of the remote dust limit.

A test exercising the scenario is added.
2018-03-22 14:58:22 +01:00
Johan T. Halseth
263d6b9c1f
lnwallet/channel: don't accept immediately on empty htlc sigs
This commit fixes an issue where we would blindly accept a commitment
which came without any accompanying HTLC signatures. A test exercising
the scenario is added.
2018-03-22 14:58:22 +01:00
Johan T. Halseth
241c79397f
lnwallet/channel: fix crash on receiving too few HTLC sigs
This commit fixes an out of bounds error that would occur in the case
where we received a new commitment where the accompanying HTLC sigs were
too few. Now we'll just reject such an commitment.

A test exercising the behavior is also added.
2018-03-22 14:58:22 +01:00
Conner Fromknecht
d420266911
lnwallet/channel: expose API changes to channel state transitions 2018-03-09 17:35:53 -08:00
Conner Fromknecht
53e4422a2e
lnwallet/channel: integrate fwdpkgs w/ in-mem buffering 2018-03-09 14:45:30 -08:00
Olaoluwa Osuntokun
b8d0df998a
lnwallet: when validating fee updates, ensure newFee < balance 2018-03-08 12:50:49 -05:00
Olaoluwa Osuntokun
ac90a8288e
lnwallet: precalculate fees in mSAT to avoid multiple conversions 2018-03-08 12:50:49 -05:00
Olaoluwa Osuntokun
217166fb10
lnwallet: within validateCommitmentSanity check for balance underflow
In this commit, we add an additional check within
validateCommitmentSanity due to the recent change to unsigned integers
for peer balances in the channel state machine. If after evaluation
(just applying HTLC updates), the balances are negative, then we’ll
return ErrBelowChanReserve.
2018-03-08 12:50:48 -05:00
Olaoluwa Osuntokun
5f5e4554cb
lnwallet: if the initiator is unable to pay fees, then consume their entire output
In this commit, we add logic to account for an edge case in the
protocol. If they initiator if unable to pay the fees for a commitment,
then their *entire* output is meant to go to fees. The recent change to
properly interpret balances as unsigned integers (within the protocol)
let to the discovery of this missed edge case.
2018-03-08 12:50:48 -05:00
Olaoluwa Osuntokun
22ee0a7576
lnwallet: update state machine due to channeldb and SignDescriptor changes 2018-03-06 16:04:02 -05:00
Johan T. Halseth
1f839d2526
lnwallet/channel: denominate in fee rate types 2018-02-26 22:42:25 +01:00
Johan T. Halseth
7b9f098fe6
lnwallet: fully validate all channel constraints in validateCommitmentSanity
This commit introduces changes to the validateCommitmentSanity
function to fully validate all channel constraints.
validateCommitmentSanity now validates that the
MaxPendingAmount, ChanReserve, MinHTLC, & MaxAcceptedHTLCs
limits are all adhered to during the lifetime of a channel.

When applying a set of updates, the channel constraints are
validated from the point-of-view of either the local or the
remote node, to make sure the updates will be accepted.

Co-authored-by: nsa <elzeigel@gmail.com>
2018-02-08 18:35:25 -05:00
Johan T. Halseth
1873fe1381
lnwallet/channel: move common calculation of balance into computeView
This commit moves common logic used to calculate the state
of a commitment after applying a set of HTLC updates, into
the new method computeView. This method can be used when
calculating the available balance, validating the sanity
of a commitment after applying a set of updates, and also
when creating a new commitment, reducing the duplication
of this logic.
2018-02-08 18:35:25 -05:00
Johan T. Halseth
98d28611e4
lnwallet/channel: let evaluateHTLCView take mutate boolean
This commit adds a new boolean parameter mutateState to
evalueteHTLCView, that let us call it without neccessarily
mutating the addHeight/removeHeight of the HTLCs, which is
useful when evaluating the commitment validity without
mutating the state.
2018-02-08 18:35:25 -05:00
Olaoluwa Osuntokun
9c483c38b1
lnwallet: update state machine to use new lnwire.Sig everywhere 2018-02-06 20:14:31 -08:00
Daniel McNally
8543497dcc multi: fixing it's/its typos in comments 2018-02-06 19:13:07 -08:00
practicalswift
a93736d21e multi: comprehensive typo fixes across all packages 2018-02-06 19:11:11 -08:00
Johan T. Halseth
83b368d20e
lnwallet/channel: use remoteACKedIndex instead of logIndex in
availableBalance
2018-02-02 21:16:37 -05:00
Jim Posen
916b83a6ee lnwallet: Implement test vectors from BOLT 03, Appendix C.
Appendix C of BOLT 03 contains a series of test vectors asserting that
commitment, HTLC success, and HTLC timeout transactions are created
correctly. Here the test cases are transcribed to Go structs and
verified.

We also break out some logic need to tests that bypass the constructor
and remove some redundant fields.
2018-01-31 14:30:56 -08:00
Olaoluwa Osuntokun
f85f1f97ca
lnwallet: add the second level witness script to the HtlcRetribution
In this commit, we add the second level witness script to the
HtlcRetribution struct. We do this as it’s possible that we when
attempt to sweep funds after a channel breach, then the remote party
has already gone to the second layer. In this case, we’ll then need to
update our SignDesc and also the witness, in order to do that we need
this script that’ll get us pass the second layer P2WSH check.
2018-01-22 19:19:58 -08:00
Olaoluwa Osuntokun
1604c75a9c
lnwallet: modify CreateCloseProposal to also return the close txid and local balance 2018-01-22 19:19:53 -08:00
Olaoluwa Osuntokun
5bbe126c34
lnwallet: add new NewUnilateralCloseSummary function
In this commit, we add a new function that allows a caller to create a
UnilateralCloseSummary with the proper materials. This will be used
within a new sub-system to be added in a later commit to properly
dispatch notifications when on-chain events happen for a channel.
2018-01-22 19:19:47 -08:00
Olaoluwa Osuntokun
341c1678fc
lnwallet: publicly export NewBreachRetribution 2018-01-22 19:19:47 -08:00
Olaoluwa Osuntokun
30c4196f91
lnwallet: remove the closeObserver from the channel state machine
In this PR, we entirely remove the closeObserver from the channel state
machine. It was added very early on before most of the other aspects of
the daemon were built out. This goroutine was responsible for
dispatching notifications to outside parties if the commitment
transaction was spent at all. This had several issues, since it was
linked to the *lifetime* of the channel state machine itself. As a
result of this linkage, we had to do weird stuff like hand off in
memory pointers to the state machine in order to ensure notifications
were properly dispatched.
2018-01-22 19:19:47 -08:00
Olaoluwa Osuntokun
b5496c52a2
lnwallet: newHtlcResolution now returns both incoming and outgoing HTLC resolutions
In this commit, we’ve added a new HtlcResolutions struct to house both
the incoming and outgoing HTLC resolutions. This struct will now be
coupled with the object that returns when we detect that a commitment
transaction was closed on chain. For incoming HTLC’s, we’ll check the
preimage cache to see if we can claim the HTLC on-chain. If we can,
then we’ll copy of the preimage, and make a proper incoming HTLC
resolution.
2018-01-22 19:19:32 -08:00
Olaoluwa Osuntokun
d98026f579
lnwallet: modify OutgoingHtlcResolution to also account for remote force closes
In this commit, we modify the OutgoingHtlcResolution struct to detect
if this is the remote party’s commitment transaction or not. With this
change, we’ll now be able to properly time out an HTLC that was
detected on the commitment transaction of the remote peer.
Additionally, we now populate the CsvDelay (if local commitment) and
the ClaimOutpoint (as we may be sweeping directly from the commitment
transaction now.
2018-01-22 19:19:32 -08:00
Olaoluwa Osuntokun
bcfe7192d7
lnwallet: add new IncomingHtlcResolution for resolving incoming HTLC's on-chain
In this commit, we add a new IncomingHtlcResolution struct. This is the
opposite of the existing OutgoingHtlcResolution struct. The items in
this new struct allow callers to sweep an incoming HTLC that we know
the preimage to. These will always be created when a commitment goes
on-chain. However, if we know the preimage, then that will be populated
in place of all zeroes in the Preimage field.
2018-01-22 19:19:31 -08:00
Olaoluwa Osuntokun
ecf6d758a2
lnwallet: add distinct CommitOutputResolution for resolving commit outputs on-chain
In this commit, we modify both the ForceCloseSummary, and the
UnilateralClosureSummary to return the items needed to sweep the
commitment output distinctly. By doing this, it’s now possible to pass
a dedicated struct to a sub-system in order to allow it to sweep a
commitment output. As the maturity delay is a part of this new struct,
this tells the caller if this was on the local commitment (CSV
required) or on the remote commitment (no CSV required).
2018-01-22 19:19:31 -08:00
Olaoluwa Osuntokun
42cd2fa5be
lnwallet: add new ActiveHtlcs to channel state machine
In this commit, we’ve added a new method to the channel state machine:
ActiveHtlcs. This method will allow callers to poll the state of the
channel to retrieve the set of HTLC’s active on *both* commitment
transactions.
2018-01-22 19:19:31 -08:00
Olaoluwa Osuntokun
5f6c15cfa4
lnwallet: RevokeCurrentCommitment now returns the set of active HTLC's
In this commit, we modify the RevokeCurrentCommitment method to now
return the set of active HTLC’s. This will be used by callers in the
future to update other sub-systems when the set of HTLC’s on the
commitment changes, and can also be used on the RPC level to
synchronize systems level integration tests.
2018-01-22 19:19:30 -08:00
Olaoluwa Osuntokun
75d2f09d4c
lnwallet: add a PreimageCache instead of a FeeEstimator as LightningChannel dep 2018-01-22 19:19:29 -08:00
Olaoluwa Osuntokun
9a76b3ee58
lnwallet: only forward freshly locked in HTLC's in ReceiveRevocation
This commit fixes a nasty bug that has been lingering within lnd, and
has been noticed due to the added retransmission logic. Before this
commit, upon a restart, if we had an active HTLC and received a new
commitment update, then we would re-forward ALL active HTLC’s. This
could at times lead to a nasty cycle:
  * We re-forward an HTLC already processed.
  * We then notice that the time-lock is out of date (retransmitted
HTLC), so we go to fail it.
  * This is detected as a replay attack, so we send an
UpdateMalformedHTLC
  * This second failure ends up creating a nil entry in the log,
leading to a panic.
  * Remote party disconnects.
  * Upon reconnect we send again as we need to retransmit the changes,
this goes on forever.

In order to fix this, we now ensure that we only forward HTLC’s that
have been newly locked in at this next state. With this, we now avoid
the loop described above, and also ensure that we don’t accidentally
attempt an HTLC replay attack on our selves.

Fixes #528.

Fixes #545.
2018-01-08 19:50:25 -08:00
Olaoluwa Osuntokun
b4bdd55081
lnwallet: if we fail to validate a remote commit sig, return detailed error
In this commit, we add a new detailed error that’s to be returned
when/if the remote peer sends us an invalid commit signature. The new
error contains the transaction that we attempted to validate the
signature over, the sighs, and the state number. Returning this
additional information will serve to aide in debugging any
cross-implementation issues.
2018-01-08 19:50:22 -08:00
Olaoluwa Osuntokun
95de109844
lnwallet: return our final local balance from CompleteCooperativeClose
In this commit, add an additional return value to
CompleteCooperativeClose. We’ll now report to the caller our final
balance in the cooperative closure transaction. We report this as
depending on if we’re the initiator or not, our final balance may not
exactly match the balance we had in the last state.
2018-01-08 19:50:20 -08:00
Conner Fromknecht
9703ab9161
lnwallet/channel: exposes channelState via State for testing 2018-01-05 13:47:17 -08:00
Conner Fromknecht
bb8c5f82da
lnwallet/channel: delete state after ack from breach arb 2018-01-05 13:47:16 -08:00
Olaoluwa Osuntokun
9777176d7d
lnwallet: don't use persistent pointer to funding tx within channel state machine
This commit fixes a lingering bug that could at times cause
incompatibilities with other implementations when attempting a
cooperative channel close. Before this commit, we would use a pointer
to the funding txin everywhere. As a result, each time we made a new
state, or verified one, we would modify the sequence field of the main
txin of the commitment transaction. Due to this if we updated the
channel, then went to do a cooperative channel closure, the sequence of
the txin would still be set to the value we used as the state hint.

To remedy this, we now copy the txin each time when making the
commitment transaction, and also the cooperative closure transaction.
This avoids accidentally mutating the txin itself.

Fixes #502.
2017-12-22 19:26:35 +01:00
Matt Drollette
adf0d98194 multi: fix several typos in godoc comments 2017-12-17 18:40:05 -08:00
Jim Posen
e66f3a37a3 lnwallet: Remove rHashMap.
rHashMap in LightningChannel is no longer needed since HTLCs are now
identified by ID/index instead of payment hash.
2017-12-14 17:53:58 -08:00
Jim Posen
317b44e220 lnwallet: Change channel update methods to accept HTLC ID.
Previously, some methods on a LightningChannel like SettleHTLC and
FailHTLC would identify HTLCs by payment hash. This would not always
work correctly if there are multiple HTLCs with the same payment hash,
so instead we change these methods to identify HTLCs by their unique
identifiers instead.
2017-12-14 17:53:58 -08:00
Olaoluwa Osuntokun
ef520f49c3
lnwallet: during channel resynchronization detect lack of commitment window
In this commit, we extend the ProcessChanSyncMsg to detect a case where
we don’t have the necessary revocation window to send out a new commit.
This can arise if the remote party sends us a new state, but we haven’t
yet fully processed their FundingLocked message yet, so we would be
unable to create a new commitment state.

We fix this by enumerating each of our actions in the case of an error.
If we get ErrNoWindow, then this indicates that we can’t give the
remote party the commitment we would like to optimistically send over.
This isn’t an issue though, as in the next round, we’ll resynchronize
our state.
2017-12-11 15:42:15 -08:00
Olaoluwa Osuntokun
62da377f78
lnwallet: properly reject new commitment if next revocation point isn't known 2017-12-11 15:32:31 -08:00
Olaoluwa Osuntokun
ff6993bb5d
lnwallet: ensure the onion blob is copied over properly when restore log updates
In this commit, we fix an existing bug that would cause issues within
the switch due to a value not being properly set. Before this commit we
would copy a byte array into a slice without first creating the
necessary capacity for that slice. To fix this, we’ll now ensure that
the blob has the proper capacity before copying over. Several tests
have been updated to always set a fake onion blob.
2017-12-10 16:14:41 -08:00
Olaoluwa Osuntokun
5b4aa82667
lnwallet: don't sign new commitment if next revocation point is unknown
In this commit, we extend the initial check within SignNextCommitment
to bail out early if we don’t yet know the commitment point of the
remote party. This prevents a class of nil pointer panics if we attempt
to create a new state without yet having received the FundingLocked
message.
2017-12-10 16:10:57 -08:00
Olaoluwa Osuntokun
d6dcc4276c
lnwallet: add new IsPending method to the channel state machine
The IsPending method will allow callers to determine if a channel has
been fully confirmed or not.
2017-12-06 16:43:01 -08:00
Conner Fromknecht
e8590b12ba
lnwallet/channel: handle error from sigpool start 2017-12-02 17:16:43 -08:00
Olaoluwa Osuntokun
c27e87f168
lnwallet: update UpdateFee msg usage to latest API changes 2017-11-30 22:10:42 -08:00
Olaoluwa Osuntokun
4bec706b11
lnwallet: fix bug in htlcIsDust, outgoing HTLC on remote commit is htlcSuccess 2017-11-30 22:09:49 -08:00
Olaoluwa Osuntokun
94ba7f964d
channel: properly roll over fee from commit tx during co-op chan close
In this commit, we fix an existing bug within our cooperative channel
closing transaction generation. Before this commit, we wouldn’t account
for the fee already allocated within the commitment transaction. As a
result, we would calculate the evaluated balance considering the fee
incorrectly. In this commit, we fix this by adding the commitment fee
to the balance of the initiator when crafting the closing transaction
2017-11-29 16:14:22 -08:00