History

Etan Kissling d028baea2a introduce `ForkedBlobSidecar` for EIP-7688 Electra period before PeerDAS On `ELECTRA_FORK_EPOCH`, PeerDAS is not yet activated, hence the current mechanism based on `BlobSidecar` is still in use. With EIP-7688, the generalized indices of `BeaconBlockBody` get reindexed, changing the length of the inclusion proof within the `BlobSidecar`. Because network Req/Resp operations allow responses across fork boundaries, this creates the need for a `ForkedBlobSidecar` in that layer, same as already done for `ForkedSignedBeaconBock` for similar reasons. Note: This PR is only needed if PeerDAS is adopted _after_ EIP-7688. If PeerDAS is adopted _before_ EIP-7688, a similar PR may be needed for forked columns. Coincidental `Forked` jank can only be fully avoided if both features activate at the same epoch, actual changes to blobs aside. Delaying EIP-7688 for sole purpose of epoch alignemnt is not worth it.		2024-07-25 18:54:38 +02:00
..
README.md	some consensus spec v1.4.0 spec URL updates (#6208 )	2024-04-17 05:51:16 +02:00
batch_validation.nim	add some support for electra aggregated attestations (#6283 )	2024-05-14 06:12:35 +02:00
block_processor.nim	introduce `ForkedBlobSidecar` for EIP-7688 Electra period before PeerDAS	2024-07-25 18:54:38 +02:00
eth2_processor.nim	introduce `ForkedBlobSidecar` for EIP-7688 Electra period before PeerDAS	2024-07-25 18:54:38 +02:00
gossip_validation.nim	construct info object for `BlobSidecar` earlier (#6445 )	2024-07-23 20:22:29 +00:00
light_client_processor.nim	extend light client protocol for Electra (#6375 )	2024-06-26 19:02:03 +00:00
optimistic_processor.nim	remove Bellatrix EL syncing support from light client (#6352 )	2024-06-14 01:23:17 +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.

Blocks: https://github.com/ethereum/consensus-specs/blob/v1.4.0-beta.5/specs/phase0/p2p-interface.md#beacon_block
Attestations (aggregated): https://github.com/ethereum/consensus-specs/blob/v1.4.0/specs/phase0/p2p-interface.md#beacon_aggregate_and_proof
Attestations (unaggregated): https://github.com/ethereum/consensus-specs/blob/v1.4.0/specs/phase0/p2p-interface.md#attestation-subnets
Voluntary exits: https://github.com/ethereum/consensus-specs/blob/v1.4.0-beta.4/specs/phase0/p2p-interface.md#voluntary_exit
Proposer slashings: https://github.com/ethereum/consensus-specs/blob/v1.4.0-beta.5/specs/phase0/p2p-interface.md#proposer_slashing
Attester slashing: https://github.com/ethereum/consensus-specs/blob/v1.4.0-beta.5/specs/phase0/p2p-interface.md#attester_slashing

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