In this commit, we fix a bug that caused us to be unable to properly
handle malformed HTLC failures from our direct link. Before this commit,
we would attempt to decrypt it and fail since it wasn't well formed. In
this commit, if its an error for a local payment, and it needed to be
converted, then we'll decode it w/o decrypting since it's already
plaintext.
In this commit, we add a new method to the ErrorEncrypter interface:
`EncryptMalformedError`. This takes a raw error (no encryption or MAC),
and encrypts it as if we were the originator of this error. This will be
used by the switch to convert malformed fail errors to regular fully
encrypted errors.
In this commit, we start the first phase of fixing an existing bug
within the switch. As is, we don't properly convert
`UpdateFailMalformedHTLC` to regular `UpdateFailHTLC` messages that are
fully encrypted. When we receive a `UpdateFailMalformedHTLC` today,
we'll convert it into a regular fail message by simply encoding the
failure message raw. This failure message doesn't have a MAC yet, so if
we sent it backwards, then the destination wouldn't be able to decrypt
it. We can recognize this type of failure as it'll be the same size as
the raw failure message max size, but it has 4 extra bytes for the
encoding. When we come across this message, we'll mark is as needing
conversion so the switch can take care of it.
In this commit, we fix a bug that would cause a node with a hodl HTLC to
cancel back the HTLC upon restart if the invoice has been settled, but
the HTLC is still present on the commitment transaction. A fix for the
HTLC still being present (not triggering a new commitment) has been
fixed recently. However, for older nodes with a lingering HTLC, on
restart it would be failed back.
In this commit, we make the check stricter by only performing these
checks for HTLCs that are in the open state. This ensures that we'll
only check this constraints the first time around, before the HTLC has
been transitioned to the accepted state.
This commit adds a brief delay when sending our channel reestablish
message if the link contains a restored channel to ensure we first have
a stable connection. Sending the message will cause the remote peer to
force close the channel, which currently may not be resumed reliably if
the connection is being torn town simultaneously. This delay can be
removed after the force close is reliable, but in the meantime it
improves the reliability of successfully closing out the channel and
allows the `channel_backup_restore/restore_during_creation` to pass
reliably.
In this commit, we modify the starting link logic to always send the
chan sync message to the remote peer in a synchronous manner. Otherwise,
it's possible that we fail very quickly below this block, and don't ever
send the message to the remote peer.
The idea of the batch counter is to increase it for commit tx updates,
so that if the commit tx cannot be updated immediately (revocation
window exhausted), the batch ticker makes sure it happens later.
The batch counter was increased for forwarded htlcs, but not for exit hop
resolutions.
This lead to the situation where the commitment tx would not be updated,
even though the htlc was settled locally. When no other changes happen
on the channel, the htlc eventually reaches its expiry and the channel
is force closed.
This commits exposes the various parameters around going to chain and
accepting htlcs in a clear way.
In addition to this, it reverts those parameters to what they were
before the merge of commit d1076271456bdab1625ea6b52b93ca3e1bd9aed9.
This commit increase the expiry grace delta to a value above the
broadcast delta. This prevents htlcs from being accepted that would
immediately trigger a channel force close.
A correct delta is generated in server.go where there is access to
the broadcast delta and passed via the peer to the links.
Co-authored-by: Jim Posen <jim.posen@gmail.com>
Previously there was no minimum remaining blocks requirement on
forwarded htlcs, which may cause channel arbitrator to force
close the channel directly after forwarding the htlc.
Co-authored-by: Jim Posen <jim.posen@gmail.com>
This commit modifies the invoice registry to handle invoices for which
the preimage is not known yet (hodl invoices). In that case, the
resolution channel passed in from links and resolvers is stored until we
either learn the preimage or want to cancel the htlc.
This commit detaches signaling the invoice registry that an htlc was
locked in from the actually settling of the htlc.
It is a preparation for hodl invoices.
In further commits the behaviour of invoice registry becomes more
intrinsically connected to the link. This commit prepares for that by
allowing link and registry to be tested as a single unit.
In the TestChannelLinkMultiHopUnknownPaymentHash test, a preimage was
modified to trigger an unknown payment hash failure. The way the mock is
implemented, it would take the hash of that modified preimage and store
it. It basically stores a completely different invoice. For this test,
it is just as good to store no invoice at all.
Previously it could happen that an invoice was open at the time of the
LookupInvoice call, the htlc was settled because of that, but when the
SettleInvoice call was made eventually, it would fail because the
invoice was canceled in the mean time. The htlc would then be settled,
but the invoice not marked as such.
In this commit, we set a default max HTLC in the forwarding
policies of newly open channels.
The ForwardingPolicy's MaxHTLC field (added in this commit)
will later be used to decide whether an HTLC satisfies our policy before
forwarding it.
To ensure the ForwardingPolicy's MaxHTLC default matches the max HTLC
advertised in the ChannelUpdate sent out for this channel, we also add
a MaxPendingAmount() function to the lnwallet.Channel.
This commit makes use of the batched AddWitness
method of the WitnessCache, in order to avoid
performing one write for each accepted preimage.
Additionally, this fixes an existing hole in the
consistency guarantees since the batched writes
are now guaranteed to take place before accepting
the next CommitSig. Previously, these writes were
processed in an unsynchronized go routine that
could be delayed arbitrarily long before being
executed.
With this change, the async_payments_benchmarks
actually shows a slight improvement in
performance, presumably because we no longer do
an individual write per preimage, even though
the execution is now explicitly in the critical
path. There is likely also a marginal performance
improvement from the reduction in goroutine
overhead.
In this commit, we modify the WitnessCache's
AddPreimage method to accept a variadic number
of preimages. This enables callers to batch
preimage writes in performance critical areas
of the codebase, e.g. the htlcswitch.
Additionally, we lift the computation of the
witnesses' keys outside of the db transaction.
This saves us from having to do hashing inside
and blocking other callers, and limits extraneous
blocking at the call site.
This function will be used in the switch to retrieve the channel point for a link,
allowing the switch to retrieve individual channels from the database.
This commit is a step to split the lnwallet package. It puts the Input
interface and implementations in a separate package along with all their
dependencies from lnwallet.
In this commit, we deprecate the `IncorrectHtlcAmount` onion error.
We'll still decode this error to use when retrying paths, but we'll no
longer send this ourselves. The `UnknownPaymentHash` error has been
amended to also include the value of the payment as well. This allows us
to worry about one less error.
This commit modifies the behavior of the
HasActiveLink method within the switch to
only return true if the link is in the
link index and is eligible to forward
HTLCs.
The prior version returns true whenever
the link is found in the link index,
which may return true for pending
channels that are not actually active.
This commit adds conversion between the lnwire.UpdateFee message and the
new FeeUpdate PaymentDescriptor. We re-purpose the existing Amount field
in the PaymentDescriptor stuct to hold the feerate.
This commit is a preparation for the addition of new invoice
states. A database migration is not needed because we keep
the same field length and values.
In this commit, we fix a minor discrepancy with the spec. We should
return a FinalFailExpiryTooSoon error, rather than a
FinalFailIncorrectCltvExpiry error, when the last HTLC of a route (exit
hop) has an expiration height that is deemed too soon by the final
destination of the HTLC.
In this commit, we remove the per channel `sigPool` within the
`lnwallet.LightningChannel` struct. With this change, we ensure that as
the number of channels grows, the number of gouroutines idling in the
sigPool stays constant. It's the case that currently on the daemon, most
channels are likely inactive, with only a hand full actually
consistently carrying out channel updates. As a result, this change
should reduce the amount of idle CPU usage, as we have less active
goroutines in select loops.
In order to make this change, the `SigPool` itself has been publicly
exported such that outside callers can make a `SigPool` and pass it into
newly created channels. Since the sig pool now lives outside the
channel, we were also able to do away with the Stop() method on the
channel all together.
Finally, the server is the sub-system that is currently responsible for
managing the `SigPool` within lnd.
Per team decision all tests should run with "debug" flag.
Makefile updated accordingly.
A developer may still run the test from command line by "go test ...."
The commit protects against this and issue an error if needed.
In this commit we add a check to HtlcSatifiesPolicy to verify that the
time lock for the outgoing htlc that is requested in the onion packet
isn't too far in the future.
Without this check, anyone could force an unreasonably long time lock on
the forwarding node.
In this commit, we increase the fwdpkg gc interval
to avoid having it conflict with switch tests that
inspect forwarding packages. The current timeout is
a little too short on travis, and sporadically fails
TestChannelLinkCleanupSpuriousResponses, which was
added recently.
This commit moves the logic handling responses to
locally-initiated payments to be asynchronous. The
reordering of operations into handleLocalDispatch
brings a serious performance burden to the switch's
main event loop. However, the at-most once semantics
of circuit map and idempotency of cleanup methods
allows concurrent operations to run in parallel.
Prior to this commit, the async_payments_benchmark
would timeout due to the forcibly serial nature of
the prior design. With this change, there is no
perceptible difference in the benchmark OMM, even
though we've added two extra db calls.
Composes the new payment status helper methods such that
we only require one db txn per state transition. This
also allows us to remove the exclusive lock from the
control tower, and enable more concurrent requests.
