cmd/evm: make t8ntool handle transaction decoding errors better

[holiman]

This PR closes #27730 . By using an iterator instead of a slice of transactions, we can better handle the case when an individual transaction (within an otherwise well-formed RLP-list) cannot be decoded.

For reviewers:

• First commit just moves existing code into separate file (no change)
• Second commit just moves existing functionality from slice-form into iterator-form (no functional change)
• Third commit introduces rlp-iterator with individual handling of rlp-errors (functional change) + adds tests

cc @winsvega

[winsvega]

https://github.com/ethereum/tests/blob/develop/GeneralStateTests/Cancun/stEIP4844-[blobtransactions/blobhashListBounds7.json]

Error: Client didn't reject transaction: (0xdb696fdd98aad26d3444d688df1ca50dd5947ebd11d5d8f3ef6c70fac0f8334f) 
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
Test Expected: TR_BLOBLIST_OVERSIZE

good, now I confirm t8n rejecting invalid blob transactions but this one still got through.
maximum allowed blobs.

  transaction:
    data:
        - data: :raw 0x00
          accessList:
          - address: 0x095e7baea6a6c7c4c2dfeb977efac326af552d87
            storageKeys:
            - 0x00
            - 0x01

    maxFeePerGas: '0x12A05F200'
    maxPriorityFeePerGas: '2'
    gasLimit:
    - '4000000'
    nonce: '0'
    to: 0x095e7baea6a6c7c4c2dfeb977efac326af552d87
    value:
    - '100000'
    secretKey: "45a915e4d060149eb4365960e6a7a45f334393093061116b197e3240065ff2d8"
    maxFeePerBlobGas: '10'
    blobVersionedHashes:
        - "0x01a915e4d060149eb4365960e6a7a45f334393093061116b197e3240065f0001"
        - "0x01a915e4d060149eb4365960e6a7a45f334393093061116b197e3240065f0002"
        - "0x01a915e4d060149eb4365960e6a7a45f334393093061116b197e3240065f0003"
        - "0x01a915e4d060149eb4365960e6a7a45f334393093061116b197e3240065f0004"
        - "0x01a915e4d060149eb4365960e6a7a45f334393093061116b197e3240065f0005"
        - "0x01a915e4d060149eb4365960e6a7a45f334393093061116b197e3240065f0006"
        - "0x01a915e4d060149eb4365960e6a7a45f334393093061116b197e3240065f0007"

[holiman]

@winsvega if that is indeed a bug, then it deserves it's own issue in the tracker. But where is the max blobs per transaction defined? I don't see it in https://eips.ethereum.org/EIPS/eip-4844

[winsvega]

it is not defined expicitly but by calculating the blob price. max blobs defined per block. so one tx can have 2, another 3.
but the whole block no more than 6 because of header value calculations

MAX_BLOB_GAS_PER_BLOCK / GAS_PER_BLOB

this might not be a bug, need hive confirmation, as block logic might not be checked in t8n

[holiman]

Ok, pushed a fix, PTAL

[winsvega]

Error: Client reject transaction expected to be valid: (0x6f26856255f46b27b31d06e00750d8d75067fd8a28e15e8f5557a33fba288cb5) 
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
Reason: blob gas (262144) would exceed maximum allowance 786432

false rejections allover the correct blob transactions. (correct by nimbus)
262144 <> 786432 ?

[winsvega]

now works!

[MariusVanDerWijden]

lgtm