nimbus-eth2/beacon_chain/gossip_processing
Etan Kissling ba3884f449
ignore instead of reject duplicate sync msgs (#2903)
The P2P spec defines how certain error classes should be handled through
either IGNORE or REJECT verdicts. For sync committee message, the spec
defines that only the first message from each validator per subcommittee
and slot shall be accepted, the rest is ignored. However, current code
rejects those messages instead of ignoring them. Fixed to match spec.
2021-09-27 14:36:28 +00:00
..
README.md update gossip_processing and attestation docs (#2860) 2021-09-27 15:11:10 +02:00
batch_validation.nim Parallel attestation verification (#2718) 2021-09-17 03:13:52 +03:00
block_processor.nim implement forked merge state/block support (#2890) 2021-09-27 14:22:58 +00:00
consensus_manager.nim disentangle eth2 types from the ssz library (#2785) 2021-08-18 20:57:58 +02:00
eth2_processor.nim Parallel attestation verification (#2718) 2021-09-17 03:13:52 +03:00
gossip_validation.nim ignore instead of reject duplicate sync msgs (#2903) 2021-09-27 14:36:28 +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
    • blocksQueue: 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