Ignore gossip blob already imported

[dapplion]

process_gossip_blob returns an error if the blob is already imported

lighthouse/beacon_node/beacon_chain/src/beacon_chain.rs

Lines 2884 to 2889 in 3058b96

	if self
	.canonical_head
	.fork_choice_read_lock()
	.contains_block(&block_root)
	{
	return Err(BlockError::BlockIsAlreadyKnown(blob.block_root()));

The gossip blob handler treats that error as a penalizable offense.

Instead, we should ignore the blob and do nothing

Closes #5602

TODO / Note

This problem stems from re-using BlockError for gossip import, where there are many variants of the enum that do not apply. Maybe we should use a dedicated BlobImportError and explicitly handle each case. This patch addresses #5602 but there are some extra errors that can happen within the availability_cache that are internal errors and should not result in downscoring.

[realbigsean]

This problem stems from re-using BlockError for gossip import, where there are many variants of the enum that do not apply. Maybe we should use a dedicated BlobImportError and explicitly handle each case.

I think @pawanjay176 mentioned he started some work on this?

[realbigsean]

@mergify queue

[mergify]

queue

✅ The pull request has been merged automatically

The pull request has been merged automatically at 40d4126

[pawanjay176]

Yeah I had started some work on it. It would involve changing the result type of BeaconChain::import_block into a Result<Hash256, BlockComponentError<T::EthSpec>> and then defining a

enum BlockComponentError<E: EthSpec> {
    Block(BlockError<E>),
    Blob(BlobError<E>),
}

and then propagate the error types upwards.