In this commit, we create a new chainfee package, that houses all fee
related functionality used within the codebase. The creation of this new
package furthers our long-term goal of extracting functionality from the
bloated `lnwallet` package into new distinct packages. Additionally,
this new packages resolves a class of import cycle that could arise if a
new package that was imported by something in `lnwallet` wanted to use
the existing fee related functions in the prior `lnwallet` package.
In the scenario where the requested channel does not have enough balance
and another channel towards the same node generates a different failure,
we erroneously returned UnknownNextPeer instead of the expected
TemporaryChannelFailure.
This commit rewrites the non-strict forwarding logic in the switch to
return the proper failure message. Part of this is moving the link
balance check inside the link.
In this commit, we update the router and link to support users
updating the max HTLC policy for their channels. By updating these internal
systems before updating the RPC server and lncli, we protect users from
being shown an option that doesn't actually work.
Since we will now wait to deliver the event after channel reestablish,
notifying when the link is added to the switch will no longer be
sufficient. Later, we will add receiving reestablish as an additional
requirement for EligibleToForward returning true.
The inactive ntfn is also moved, to ensure that we don't fire inactive
notifications if no corresponding active notification was sent.
In this commit, we fix a bug where if a user updates a forwarding policy to be
zero, the update will be applied to the policy correctly on-disk, but not
in-memory.
We solve this issue by having the gossiper return the list of on-disk updated
policies and passing these policies to the switch, so the switch can assume
that zero-valued fields are intentional and not just uninitialized.
In this commit, we begin to enforce a maximum channel commitment fee for
channel initiators when attempting to update their commitment fee. Now,
if the new commitment fee happens to exceed their maximum, then a fee
update of the maximum fee allocation will be proposed instead if needed.
A default of up to 50% of the channel initiator's balance is enforced
for the maximum channel commitment fee. It can be modified through the
`--max-channel-fee-allocation` CLI flag.
Debug invoices are rarely used nowadays, but keep asking for maintenance
every time refactoring in primarily the invoice registry occurs. We have
passed the cost/benefit tipping point, so therefore the debug invoice
concept is removed in this commit.
Previously the debughtlc flag also controlled whether hodl masks were
active. It is safe to remove that additional condition because the hodl
masks are still guarded by the dev build tag.
In order to prevent information leaks by nodes probing with a payment
hash, this commit changes exit hop processing so that it always returns
incorrect_or_unknown_payment_details and leaves the prober in the dark
about whether an invoice actually exists.
Align naming better with the lightning spec. Not the full name of the
failure (FailIncorrectOrUnknownPaymentDetails) is used, because this
would cause too many long lines in the code.
This commit makes the outgoing link pipeline the settle to the
switch as soon as it receives it. Previously, it would wait for a
revocation before sending it, which caused increased latency on
payments as well as possibly never settling on the incoming link.
A duplicate settle is still sent to the switch, but it is handled
gracefully. A new AckEventTicker was added to the switch which
acknowledges any pending settle / fail entries in an outgoing
link's fwd pkgs in batch. This was needed in order to reduce the
number of db txn's which would have been incurred by acking whenever
we receive a duplicate settle without batching.
In this commit, we fix a lingering TOOD statement in the channel arb.
Before this commitment, we would simply wipe our our local HTLC set of
the HTLC set that was on the remote commitment transaction on force
close. This was incorrect as if our commitment transaction had an HTLC
that the remote commitment didn't, then we would fail to cancel that
back, and cause both channels to time out on chain.
In order to remedy this, we introduce a new `HtlcSetKey` struct to track
all 3 possible in-flight set of HTLCs: ours, theirs, and their pending.
We also we start to tack on additional data to all the unilateral close
messages we send to subscribers. This new data is the CommitSet, or the
set of valid commitments at channel closure time. This new information
will be used by the channel arb in an upcoming commit to ensure it will
cancel back HTLCs in the case of split commitment state.
Finally, we start to thread through an optional *CommitSet to the
advanceState method. This additional information will give the channel
arb addition information it needs to ensure it properly cancels back
HTLCs that are about to time out or may time out depending on which
commitment is played.
Within the htlcswitch pakage, we modify the `SignNextCommitment` method
to return the new set of pending HTLCs for the remote party's commitment
transaction and `ReceiveRevocation` to return the latest set of
commitment transactions on the remote party's commitment as well. This
is a preparatory change which is part of a larger change to address a
lingering TODO in the cnct.
Additionally, rather than just send of the set of HTLCs after the we
revoke, we'll also send of the set of HTLCs after the remote party
revokes, and we create a pending commitment state for it.
In this commit we move handing the deobfuscator from the router to the
switch from when the payment is initiated, to when the result is
queried.
We do this because only the router can recreate the deobfuscator after a
restart, and we are preparing for being able to handle results across
restarts.
Since the deobfuscator cannot be nil anymore, we can also get rid of
that special case.
This lets us distinguish an critical error from a actual payment result
(success or failure). This is important since we know that we can only
attempt another payment when a final result from the previous payment
attempt is received.
This commit moves the responsibility of generating a unique payment ID
from the switch to the router. This will make it easier for the router
to keep track of which HTLCs were successfully forwarded onto the
network, as it can query the switch for existing HTLCs as long as the
paymentIDs are kept.
The router is expected to maintain a map from paymentHash->paymentID,
such that they can be replayed on restart. This also lets the router
check the status of a sent payment after a restart, by querying the
switch for the paymentID in question.
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>
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.
