eae9dd07f0
This PR is a follow up, to a [follow up](https://github.com/lightningnetwork/lnd/pull/7938) of an [initial concurrency issue](https://github.com/lightningnetwork/lnd/pull/7856) fixed in the peer goroutine. In #7938, we noticed that the introduction of `p.startReady` can cause `Disconnect` to block. This happens as `Disconnect` cannot be called until `p.startReady` has been closed. `Disconnect` is also called from `InboundPeerConnected` (the case of concurrent peers, so we need to remove one of the connections) while the main server mutex is held. If `p.Start` blocks for any reason, then this leads to the deadlock as: we can't disconnect until we've finished starting, and we can't finish starting as we need the disconnect caller to exit as it has the mutex. In this commit, we now make the call to `prunePersistentPeerConnection` async. The call to `prunePersistentPeerConnection` eventually wants to grab the server mutex, which triggers the circular waiting scenario above. The main learning here is that no calls to the main server mutex path can block from `p.Start`. This is more or less a stop gap to resolve the issue initially introduced in v0.16.4. Assuming we want to move forward with this fix, we should reexamine `p.startReady` all together, and also revisit attempt to refactor this section of the code to eliminate the mega mutex in the server in favor of a dedicated event loop. |
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| .github | ||
| .vscode | ||
| aezeed | ||
| aliasmgr | ||
| amp | ||
| autopilot | ||
| batch | ||
| blockcache | ||
| brontide | ||
| buffer | ||
| build | ||
| cert | ||
| chainntnfs | ||
| chainreg | ||
| chanacceptor | ||
| chanbackup | ||
| chanfitness | ||
| channeldb | ||
| channelnotifier | ||
| clock | ||
| cluster | ||
| cmd | ||
| contractcourt | ||
| contrib | ||
| discovery | ||
| docker | ||
| docs | ||
| feature | ||
| funding | ||
| healthcheck | ||
| htlcswitch | ||
| input | ||
| internal/musig2v040 | ||
| invoices | ||
| itest | ||
| keychain | ||
| kvdb | ||
| labels | ||
| lncfg | ||
| lnencrypt | ||
| lnmock | ||
| lnpeer | ||
| lnrpc | ||
| lntest | ||
| lntypes | ||
| lnutils | ||
| lnwallet | ||
| lnwire | ||
| macaroons | ||
| make | ||
| mobile | ||
| monitoring | ||
| multimutex | ||
| nat | ||
| netann | ||
| peer | ||
| peernotifier | ||
| pool | ||
| queue | ||
| record | ||
| routing | ||
| rpcperms | ||
| scripts | ||
| shachain | ||
| signal | ||
| sqldb | ||
| subscribe | ||
| sweep | ||
| ticker | ||
| tlv | ||
| tools | ||
| tor | ||
| walletunlocker | ||
| watchtower | ||
| zpay32 | ||
| .editorconfig | ||
| .gitignore | ||
| .golangci.yml | ||
| .travis.yml | ||
| channel_notifier.go | ||
| chanrestore.go | ||
| config.go | ||
| config_builder.go | ||
| dev.Dockerfile | ||
| doc.go | ||
| Dockerfile | ||
| go.mod | ||
| go.sum | ||
| intercepted_forward.go | ||
| LICENSE | ||
| lnd.go | ||
| log.go | ||
| logo.png | ||
| Makefile | ||
| pilot.go | ||
| README.md | ||
| rpcserver.go | ||
| rpcserver_test.go | ||
| sample-lnd.conf | ||
| SECURITY.md | ||
| server.go | ||
| server_test.go | ||
| sqlc.yaml | ||
| subrpcserver_config.go | ||
| sweeper_wallet.go | ||
| tls_manager.go | ||
| tls_manager_test.go | ||
| witness_beacon.go | ||
| witness_beacon_test.go | ||
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 guides, articles, example applications and community resources can be found at: docs.lightning.engineering.
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.libera.chat
- channel #lnd
- webchat
Safety
When operating a mainnet lnd node, please refer to our operational safety
guidelines. It is important to note that lnd is still
beta software and that ignoring these operational guidelines can lead to
loss of funds.
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.