We now close the send payment stream after receiving a response.
Otherwise if the RPC server is asynchronously handling requests then,
closing the stream would result in the server returning an EOF error,
terminating the request.
This commit changes the current behavior around channeldb.Wipe().
Previously if a channel had never been closed, and a wipe was
attempted, then wipe operation would fail and the transaction would be
rolled back.
This commit fixes this behavior by checking for bolt.ErrBucketNotFound
error, and handling the specific error as a noop.
With this commit, calls to htlcSwitch.SendHTLC() are now synchronous,
only returning after the payment has been fully settled. This will
allow one to accurately measure the commitment update speed with the
current state machine implementation which is missing a number of
low-hanging optimizations.
The htlcManager for each channel now keeps a map of cleared HTLC’s
keyed by the index number of the add entry within the state machine’s
HTLC log. This map of HTLC’s will later be used to properly implement
time outs
Additionally, a slight refactoring has been executed w.r.t handling
upstream/downstream messages. This cleans up the main htlcManager loop,
freeing it up for the addition of future logic to properly observe
timeouts as well as, proper batching+trickling of HTLC updates, and a
commitment signature ticker.
This commit fixes a slight bug in the channel state machine’s code
executed when processing a revocation messages. With this commit after
processing a revocation, log entries which we should forward to the
downstream or upstream peer for settling/adding HTLC’s are now properly
returned.
The testa have also been updated to ensure to correct htlc’s are
returned “for forwarding”.
This commit adds two Dockerfiles, along with a docker-compose file
which links the two docker files together allowing for single-command
deployment.
Using the docker-compose file, two containers are deployed. One running
btcd, and the other running lnd. Both containers share the same shared
volume mounted to the file system in order to allow land to read btcd’s
certificates for the TLS RPC connections.
Additionally, the btcd instance comes will an automatic RPC
configuration generated allowing one to use btcctl out of the box via
calls to “docker-compose exec btcctl …”.
With this commit, support for changing the target network (testnet,
simnet, etc) has been finalized. Previously a command line option was
present to swap networks, but the RPC port wouldn’t automatically be
updated to reflect the network.
With this commitment, the daemon is now able to properly send+redeem
single-hop HTLC’s with another daemon running on the same network.
The htlcManager gains an additional channel which is reads from
receiving updates from either downstream peers, or the rpc server. An
htlcManager is spawned for each active channel with the remote peer. As
a result, the readHandler must now de-multiplex any messages which
update a known channel to the proper htlcManager.
Batching HTLC add updates with a trickle timer has not yet been
implemented, but will be in the near future along with several other
optimizations.
We no longer track HTLC’s by their r-hash within the log into the
index, as we may have multiple HTLC’s that can be redeemed by the same
pre-image. Instead we now use a separate index which is keyed by a
log-index.
Additionally, the SettleHTLC method now also returns the index of the
HTLC being settled which allows the remote party to quickly locate the
HTLC within their log.
This commit also introduces a few trace/debug log messages which will
likely be pruned in the near future
This commit introduces the invoice registry which is a central
repository of all outstanding invoices related to the daemon.
This registry will be used by the goroutines which manage the htlc’s
for a particular channel, and later by the point-to-point workflow
which negotiates the conditions for payment along with signed recipes.
This commit adds a new nested main function “lndMain”, within the
packages’s normal main function. This nesting is required in order to
properly execute all queued defer statements in the case of a forced
exit.
This commit fixes a bug caused by overriding the prefix key for storing
commitment keys with the first few bytes of a channel’s channel point.
Once a channel was deleted, then all future channels would result in a
panic due to a nil pointer deference since the prefix key was mutated,
causing all future stores/gets to fail.
Each active channel now gains its a dedicated htlcManager goroutine
which currently accepts to two golang channels, and a lightning
channel. The “downstream” channel will be used for dispatched multi-hop
payments sent from the htlcSwitch, while the “upstream” channel will be
used once the readHandler de-multiplexes hltc add/timeout/settle
messages.
Each time a new channel is fully created after N confirmations, the
peer’s channelManager registers the new link with the htlcSwitch. Once
the channel is closed either cooperatively or non-cooperatively, then
the link is unregistered.
This commit introduces the HtlcSwitch service into the daemon. The
purpose of the switch is to manage the message passing between the
goutiness within he peer managing each active channel. The switch
treats connected peers as interfaces, and their active channels as
links. All multi-hop, single-hop, and channel closure orchestration
will be managed by various goroutines within the HtlcSwitch.
The HtlcSwitch will also serve as the L2 contact point between the
yet-to-be-written LightningRouter and the switch, forwarding the new
htlc packet on the proper interface. Additionally, the switch will
handle dispatching htlc’s created locally via RPC, and multi-hop
forwarding initiated by peers.
This commit implements the “pendingchannels” RPC within the rpcserver.
This RPC allows callers to receive details concerning the current
pending channels associated with the daemon. Pending channels are those
waiting for additional confirmations before they can be considered
opened/closed.
At the time of this commit, only open channels are shown. A future
commit will also add the confirmation updates, along with information
for close channels.
This commit switches the implementation of the open/close channel RPC’s
from a fully blocking synchronous model to one that’s async by default,
allowing callers to add a sync wrapper.
The new proto specs also allow for “updates” for the pending channels
in the form of new confirmations which progress the pending status of
the channel. At this point, only the final open/close updates have been
implemented. Obtaining confirmation notifications requires a bit of
re-working within the current ChainNotifier interface, thus this has
been deferred to a later time.
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 changes prior behavior which stored a “hot” commitment
transaction, meaning one which all the sigScript fully assembled and
able to be broadcast.
Instead, we now store the current signature for our commitment
transaction as a separate field within the database and within memory.
As a result, this eliminates a class of bugs which would erroneously
broadcast a fully loaded commitment transaction, either leading to a
loss of funds, or suspending availability to funds for a period of
time.
