5f0fad85be
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.
Lightning Network Daemon
The Lightning Network Daemon (lnd) - is a complete implementation of a
Lightning Network node. lnd has several pluggable back-end
chain services including btcd (a
full-node), bitcoind, and
neutrino (a new experimental light client). The project's codebase uses the
btcsuite set of Bitcoin libraries, and also
exports a large set of isolated re-usable Lightning Network related libraries
within it. In the current state lnd is capable of:
- Creating channels.
- Closing channels.
- Completely managing all channel states (including the exceptional ones!).
- Maintaining a fully authenticated+validated channel graph.
- Performing path finding within the network, passively forwarding incoming payments.
- Sending outgoing onion-encrypted payments through the network.
- Updating advertised fee schedules.
- Automatic channel management (
autopilot).
Lightning Network Specification Compliance
lnd fully conforms to the Lightning Network specification
(BOLTs). BOLT stands for:
Basis of Lightning Technology. The specifications are currently being drafted
by several groups of implementers based around the world including the
developers of lnd. The set of specification documents as well as our
implementation of the specification are still a work-in-progress. With that
said, the current status of lnd's BOLT compliance is:
- BOLT 1: Base Protocol
- BOLT 2: Peer Protocol for Channel Management
- BOLT 3: Bitcoin Transaction and Script Formats
- BOLT 4: Onion Routing Protocol
- BOLT 5: Recommendations for On-chain Transaction Handling
- BOLT 7: P2P Node and Channel Discovery
- BOLT 8: Encrypted and Authenticated Transport
- BOLT 9: Assigned Feature Flags
- BOLT 10: DNS Bootstrap and Assisted Node Location
- BOLT 11: Invoice Protocol for Lightning Payments
Developer Resources
The daemon has been designed to be as developer friendly as possible in order
to facilitate application development on top of lnd. Two primary RPC
interfaces are exported: an HTTP REST API, and a gRPC
service. The exported API's are not yet stable, so be warned: they may change
drastically in the near future.
An automatically generated set of documentation for the RPC APIs can be found at api.lightning.community. A set of developer resources including talks, articles, and example applications can be found at: dev.lightning.community.
Finally, we also have an active
Slack where protocol developers, application developers, testers and users gather to
discuss various aspects of lnd and also Lightning in general.
Installation
In order to build from source, please see the installation instructions.
Docker
To run lnd from Docker, please see the main Docker instructions
IRC
- irc.freenode.net
- channel #lnd
- webchat
Security
The developers of lnd take security very seriously. The disclosure of
security vulnerabilities helps us secure the health of lnd, privacy of our
users, and also the health of the Lightning Network as a whole. If you find
any issues regarding security or privacy, please disclose the information
responsibly by sending an email to security at lightning dot engineering,
preferably encrypted using our designated PGP key
(91FE464CD75101DA6B6BAB60555C6465E5BCB3AF) which can be found
here.