nimbus-eth2/beacon_chain/gossip_processing
Etan Kissling efbd4e395a
avoid sending redundant LC finality updates (#4546)
When the epoch boundary block is missed, we incorrectly assume that the
next couple blocks improve finality, leading to repeated pushes of the
same light client finality update and incorrectly ignoring some gossip.
2023-01-24 17:44:55 +00:00
..
README.md automated update from v1.3.0-rc.0 to v1.3.0-rc.1 consensus spec URLs (#4517) 2023-01-17 16:10:52 +00:00
batch_validation.nim remove Nim 1.2-compatible `push raise`s and update copyright notice years (#4528) 2023-01-20 14:14:37 +00:00
block_processor.nim use shortLog for execution payload logging (#4544) 2023-01-24 13:19:38 +00:00
eth2_processor.nim Add metrics and debug logging for dropped BLS to execution change messages 2023-01-23 14:58:40 +01:00
gossip_validation.nim remove Nim 1.2-compatible `push raise`s and update copyright notice years (#4528) 2023-01-20 14:14:37 +00:00
light_client_processor.nim avoid sending redundant LC finality updates (#4546) 2023-01-24 17:44:55 +00:00
optimistic_processor.nim remove Nim 1.2-compatible `push raise`s and update copyright notice years (#4528) 2023-01-20 14:14:37 +00:00

README.md

Gossip Processing

This folder holds a collection of modules to:

  • validate raw gossip data before
    • rebroadcasting it (potentially aggregated)
    • sending it to one of the consensus object pools

Validation

Gossip validation is different from consensus verification in particular for blocks.

There are multiple consumers of validated consensus objects:

  • a ValidationResult.Accept output triggers rebroadcasting in libp2p
    • We jump into method validate(PubSub, Message) in libp2p/protocols/pubsub/pubsub.nim
    • which was called by rpcHandler(GossipSub, PubSubPeer, RPCMsg)
  • a blockValidator message enqueues the validated object to the processing queue in block_processor
    • blockQueue: AsyncQueue[BlockEntry] (shared with request_manager and sync_manager)
    • This queue is then regularly processed to be made available to the consensus object pools.
  • a xyzValidator message adds the validated object to a pool in eth2_processor
    • Attestations (unaggregated and aggregated) get collected into batches.
    • Once a threshold is exceeded or after a timeout, they get validated together using BatchCrypto.

Security concerns

As the first line of defense in Nimbus, modules must be able to handle bursts of data that may come:

  • from malicious nodes trying to DOS us
  • from long periods of non-finality, creating lots of forks, attestations