This simplifies the pending payment handling code because it allows it
be handled in nearly the same way as forwarded HTLCs by treating an
empty channel ID as local dispatch.
The src/dest terminology for routing packets is kind of confusing
because the source HTLC may not be the source of the packet for
settles/fails traversing the circuit in the opposite direction. This
changes the nomenclature to incoming/outgoing and always references
the HTLCs themselves.
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.
This changes the circuit map internals and API to reference circuits
by a primary key of (channel ID, HTLC ID) instead of paymnet
hash. This is because each circuit has a unique offered HTLC, but
there may be multiple circuits for a payment hash with different
source or destination channels.
The constructor functions have no additional logic other than passing
function parameters into struct fields. Given the large function
signatures, it is more clear to directly construct the htlcPacket in
client code than call a function with lots of positional arguments.
In this commit, we modify the existing logic to handle
UpdateFailMalformedHLTC message from an incoming peer. Rather than fail
the Chanel if they give us an invalid failure code, we’ll instead treat
it as a temporary channel failure so we can continue to forward the
error.
This commit is a follow up to a prior commit which skipped sending the
commitment sig message (and sending out the update fee) message if the
channel wasn’t yet able to forward any HTLC’s. We’ll modify the prior
commit to not add the fee update to the channel at all. Otherwise, we
risk a state desynchronization.
This commit adds a check to `updateChannelFee` which skipssending the
`update_fee` message when the channel is not eligable for forwarding
messages (likely due to the channel's `RemoteNextRevocation` not yet
being set).
This addresses #470.
This commit fixes an existing bug wherein we would incorrectly attempt
to forward and HTLC to a link that wasn’t yet eligible for forwarding.
This would occur when we’ve added a link to the switch, but haven’t yet
received a FundingLocked message for the channel. As a result, the
channel won’t have the next revocation point available. A logic error
prior to this commit would skip tallying the largest bandwidth rather
than skipping examining the link all together.
Fixes#464.
In this commit, when selecting a candidate link to forward a payment,
we’ll ensure that it’s actually able to take on the HTLC. Otherwise,
we’ll skip over the link itself. Currently, a link is only fully
eligible for forwarding, *after* we’ve received and fully processed the
FundingLocked message.
In this commit, we add a new method to the ChanneLink interface:
EligibleToForward. This method allows a link to be added to the switch,
but in an intermediate state which indicates that it isn’t yet ready to
forward any incoming HTLC’s.
In this commit we add a new case to the main select statement within a
channel link. This select statement will serve as a Sipping Bird which
will check the network fee rate (as returned by the fee estimator) and
compare that to the fee on the commitment transaction. Using the
shouldAdjustCommitFee function, we determine if we should update the
commitment fee. If so, then we’ll send an UpdateFee message and also
trigger a new commitment update.
We also add a new unit test: TestChannelLinkUpdateCommitFee to ensure
that we update the fee accordingly if the fee increases or decreases by
a large portion.
In this commit, we add a new helper function to the link which will be
utilized in a later commit. This helper function will help us determine
if we should update the commitment fee, in response to a change in the
network fee return by our fee estimators.
In this commit we modify the primary InvoiceRegistry interface within
the package to instead return a direct value for LookupInvoice rather
than a pointer. This fixes an existing race condition wherein a caller
could modify or read the value of the returned invoice.
In this commit we add a quit case to the select statement that’s
entered once a link is created. Before this commit, upon restart it
would be possible that the deamon would never ben able to shutdown as
the link would be waiting for the messages to be sent by the other
side.
In this commit, we update getChanID to be aware of the FundingLocked
message as it will be retransmitted upon reconnect if both nodes think
that they’re at the very first commitment state.
In this commit, we’ve re-written the process of syncing the state of
channels after we reconnect. This re-write ensure correctness, and also
simplified the existing logic which would attempt to launch another
goroutine to handle requests from the switch to ensure that it doesn’t
block. This is no longer necessary as the AddPacket method that the
switch indirectly calls is non-blocking.
In this commit, we modify the existing implementation of the
Bandwidth() method on the default ChannelLink implementation to use
much tighter accounting. Before this commit, there was a bug wherein if
the link restarted with pending un-settled HTLC’s, and one of them was
settled, then the bandwidth wouldn’t properly be updated to reflect
this fact.
To fix this, we’ve done away with the manual accounting and instead
grab the current balances from two sources: the set of active HTLC’s
within the overflow queue, and the report from the link itself which
includes the pending HTLC’s and factors in the amount we’d need to (or
not need to) pay in fees for each HTLC.
In this commit, we’ve modified the link and the switch to start to use
the new mailBox in place of the existing synchronous message send
directly into the link’s upstream/downstream channels. With his change,
we no longer need to spawn a new goroutine each time an HTLC needs to
be forwarded, or a user payment is initiated.
