Rebase & make chunked RLPx messages optional by a compiler flag

why:
  This is a legacy feature and its usage should peter out over time.

details:
  Use -d:chunked_rlpx_enabled for enabling chunked RLPx message handling.
This commit is contained in:
Jordan Hrycaj 2022-03-22 17:42:25 +00:00
parent 2ff455f26d
commit 4bc020384f
1 changed files with 88 additions and 60 deletions

View File

@ -13,6 +13,17 @@ import
".."/[rlp, common, keys, async_utils],
./private/p2p_types, "."/[kademlia, auth, rlpxcrypt, enode, p2p_protocol_dsl]
const
# Insane kludge for suppporting chunked messages when syncing against clients
# like Nethermind.
#
# The original specs which are now obsoleted can be found here:
# github.com/ethereum/devp2p/commit/6504d410bc4b8dda2b43941e1cb48c804b90cf22.
#
# The current requirement is stated at
# github.com/ethereum/devp2p/blob/master/rlpx.md#framing
allowObsoletedChunkedMessages = defined(chunked_rlpx_enabled)
when useSnappy:
import snappy
const devp2pSnappyVersion* = 5
@ -455,8 +466,8 @@ proc resolveResponseFuture(peer: Peer, msgId: int, msg: pointer, reqId: int) =
proc getRlpxHeaderData(header: RlpxHeader): (int,int,int) =
## Helper for `recvMsg()`
# This is insane. Some clients like Nethermid use the now obsoleted
# chunked frame protocol, see
# This is insane. Some clients like Nethermind use the now obsoleted
# chunked message frame protocol, see
# github.com/ethereum/devp2p/commit/6504d410bc4b8dda2b43941e1cb48c804b90cf22.
result = (-1, -1, 0)
proc datagramSize: int =
@ -535,6 +546,22 @@ proc recvMsg*(peer: Peer): Future[tuple[msgId: int, msgData: Rlp]] {.async.} =
if decryptedBytes.len == 0:
await peer.disconnectAndRaise(BreachOfProtocol,
"Snappy uncompress encountered malformed data")
# Check embedded header-data for start of an obsoleted chunked message.
#
# The current RLPx requirements need all triple entries <= 0, see
# github.com/ethereum/devp2p/blob/master/rlpx.md#framing
let (capaId, ctxId, totalMsgSize) = msgHeader.getRlpxHeaderData
when not allowObsoletedChunkedMessages:
# Note that the check should come *before* the `msgId` is read. For
# instance, if this is a malformed packet, then the `msgId` might be
# random which in turn might try to access a `peer.dispatcher.messages[]`
# slot with a `nil` entry.
if 0 < capaId or 0 < ctxId or 0 < totalMsgSize:
await peer.disconnectAndRaise(
BreachOfProtocol, "Rejected obsoleted chunked message header")
var rlp = rlpFromBytes(decryptedBytes)
var msgId: int32
@ -546,74 +573,75 @@ proc recvMsg*(peer: Peer): Future[tuple[msgId: int, msgData: Rlp]] {.async.} =
await peer.disconnectAndRaise(BreachOfProtocol,
"Cannot read RLPx message id")
# Snappy with obsolete chunked RLPx message datagrams is unsupported here
when useSnappy:
if peer.snappyEnabled:
# Handle chunked messages
when allowObsoletedChunkedMessages:
# Snappy with obsolete chunked RLPx message datagrams is unsupported here
when useSnappy:
if peer.snappyEnabled:
return
# This also covers totalMessageSize <= 0
if totalMsgSize <= msgSize:
return
# Check embedded header-data for start of a chunked message
let (capaId, ctxId, totalMsgSize) = msgHeader.getRlpxHeaderData
# Loop over chunked RLPx datagram fragments
var moreData = totalMsgSize - msgSize
while 0 < moreData:
# This also covers totalMessageSize <= 0
if totalMsgSize <= msgSize:
return
# Load and parse next header
block:
await peer.transport.readExactly(addr headerBytes[0], 32)
if decryptHeaderAndGetMsgSize(peer.secretsState,
headerBytes, msgSize, msgHeader).isErr():
trace "RLPx next chunked header-data failed",
peer, msgId, ctxId, maxSize = moreData
await peer.disconnectAndRaise(
BreachOfProtocol, "Cannot decrypt next chunked RLPx header")
# Loop over chunked RLPx datagram fragments
var moreData = totalMsgSize - msgSize
while 0 < moreData:
# Verify that this is really the next chunk
block:
let (_, ctyId, totalSize) = msgHeader.getRlpxHeaderData
if ctyId != ctxId or 0 < totalSize:
trace "Malformed RLPx next chunked header-data",
peer, msgId, msgSize, ctxtId = ctyId, expCtxId = ctxId, totalSize
await peer.disconnectAndRaise(
BreachOfProtocol, "Malformed next chunked RLPx header")
# Load and parse next header
block:
await peer.transport.readExactly(addr headerBytes[0], 32)
if decryptHeaderAndGetMsgSize(peer.secretsState,
headerBytes, msgSize, msgHeader).isErr():
trace "RLPx next chunked header-data failed",
peer, msgId, ctxId, maxSize = moreData
await peer.disconnectAndRaise(BreachOfProtocol,
"Cannot decrypt next chunked RLPx header")
# Append payload to `decryptedBytes` collector
block:
var encBytes = newSeq[byte](msgSize.encryptedLength - 32)
await peer.transport.readExactly(addr encBytes[0], encBytes.len)
var
dcrBytes = newSeq[byte](msgSize.decryptedLength)
dcrBytesCount = 0
# TODO: This should be improved by passing a reference into
# `decryptedBytes` where to append the data.
if decryptBody(peer.secretsState, encBytes, msgSize,
dcrBytes, dcrBytesCount).isErr():
await peer.disconnectAndRaise(
BreachOfProtocol, "Cannot decrypt next chunked RLPx frame body")
decryptedBytes.add dcrBytes[0 ..< dcrBytesCount]
moreData -= msgSize
#[
trace "RLPx next chunked datagram fragment",
peer, msgId = result[0], ctxId, msgSize, moreData, totalMsgSize,
dcrBytesCount, payloadSoFar = decryptedBytes.len
#]#
# Verify that this is really the next chunk
block:
let (_, ctyId, totalSize) = msgHeader.getRlpxHeaderData
if ctyId != ctxId or 0 < totalSize:
trace "Malformed RLPx next chunked header-data",
peer, msgId, msgSize, ctxtId = ctyId, expCtxId = ctxId, totalSize
await peer.disconnectAndRaise(BreachOfProtocol,
"Malformed next chunked RLPx header")
# End While
# Append payload to `decryptedBytes` collector
block:
var encBytes = newSeq[byte](msgSize.encryptedLength - 32)
await peer.transport.readExactly(addr encBytes[0], encBytes.len)
var
dcrBytes = newSeq[byte](msgSize.decryptedLength)
dcrBytesCount = 0
# TODO: This should be improved by passing a reference into
# `decryptedBytes` where to append the data.
if decryptBody(peer.secretsState, encBytes, msgSize,
dcrBytes, dcrBytesCount).isErr():
await peer.disconnectAndRaise(BreachOfProtocol,
"Cannot decrypt next chunked RLPx frame body")
decryptedBytes.add dcrBytes[0 ..< dcrBytesCount]
moreData -= msgSize
#[
trace "RLPx next chunked datagram fragment",
peer, msgId = result[0], ctxId, msgSize, moreData, totalMsgSize,
dcrBytesCount, payloadSoFar = decryptedBytes.len
#]#
if moreData != 0:
await peer.disconnectAndRaise(
BreachOfProtocol, "Malformed assembly of chunked RLPx message")
# End While
# Pass back extended message (first entry remains `msgId`)
result[1] = decryptedBytes.rlpFromBytes
result[1].position = rlp.position
if moreData != 0:
await peer.disconnectAndRaise(BreachOfProtocol,
"Malformed assembly of chunked RLPx message")
trace "RLPx chunked datagram payload",
peer, msgId, ctxId, totalMsgSize, moreData, payload = decryptedBytes.len
# Pass back extended message (first entry remains `msgId`)
result[1] = decryptedBytes.rlpFromBytes
result[1].position = rlp.position
trace "RLPx chunked datagram payload",
peer, msgId, ctxId, totalMsgSize, moreData, payload = decryptedBytes.len
# End `allowObsoletedChunkedMessages`
proc checkedRlpRead(peer: Peer, r: var Rlp, MsgType: type):