RLP Enum deserialization would currently not check if "hole values"
were attempted to be converted to the enum type. Now use
checkedEnumAssign and fail with RlpTypeMismatch on invalid values.
There is at least one occurance of an enum with holes in rlpx p2p:
DisconnectionReason. For this enum the issue could occur.
Also:
- Added enum RLP tests and rlpx p2p disconnect message tests to
test the DisconnectionReason with enum hole value.
- Fixed worse custom DisconnectionReason decoding occurance
in rlpx in waitSingleMsg proc where this issue could occur.
* Provide dedicated `DisconnectionReason` enum type RLP reader
why:
Without this reader, the program communicating via RLPX will crash when
receiving out of bound reason codes disconnect message.
Out of bound value assignments to an enum causes a `RangeError`defect
and consequently the program to terminate. This `RangeError` is avoided
here and a `MalformedRlpError` catchable error raised.
* Using default exception type in bespoke `read(DisconnectionReason)`
why:
This should not differ from the default enum parser. The particular
message is different and more targeted, here.
Note: The default RLP parser was not used because `
`array[1,DisconnectionReason]` is currently not properly handled and
should give a siliar error message as a `DisconnectionReason` error.
* De-clutter, custom read() was not needed
Co-authored-by: jordan <jordan@curd.mjh-it.com>
why:
Rlp errors throw exceptions which cause the dispatcher loop to
terminate the current session immediately.
details:
The DisconnectionReasonList message requires a single entry list.
Observed and now accepted deviations are:
Geth: single byte number
bor(a Geth fork): blobbed single entry list containing a number