bug(devp2p): unsolicited type 3 transactions broadcast

[merklefruit]

Context

At @chainbound, we run a fleet of custom nodes that participate in the Ethereum p2p networks.
The software we use is not part of Besu. Our devp2p network implementation is based off Reth's.

Issue

Since after the Dencun fork, we have noticed an unexpected behaviour from Besu peers on all of our nodes.
It looks like we are getting some type 3 transaction messages unsolicited from devp2p. The specific ETH wire message type is Transactions (0x02) which according to EIP-4844 specs should not contain type 3 transactions:

Nodes MUST NOT automatically broadcast blob transactions to their peers. Instead, those transactions are only announced using NewPooledTransactionHashes messages, and can then be manually requested via GetPooledTransactions.

From a first analysis, it looks like Besu has a check to enforce the correct behaviour in the transaction broadcaster here:

besu/ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/transactions/TransactionBroadcaster.java

Line 41 in 42b32d2

private static final EnumSet<TransactionType> ANNOUNCE_HASH_ONLY_TX_TYPES = EnumSet.of(BLOB);

I'm not overly familiar with the Besu codebase, but happy to help debug this however I can!

[macfarla]

hey @merklefruit thanks a bunch for reporting this issue, it was a subtle one to track down actually and the fix will be in the next release! Let us know if you find anything else :)

[merklefruit]

Awesome, really happy to hear this has been useful. Have a great weekend :)