nimbus-eth1/fluffy/network/wire/portal_stream.nim

198 lines
7.4 KiB
Nim

# Nimbus
# Copyright (c) 2022 Status Research & Development GmbH
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
{.push raises: [Defect].}
import
std/sequtils,
chronos, stew/byteutils, chronicles,
eth/utp/utp_discv5_protocol,
# even though utp_discv5_protocol exports this, import is still needed,
# perhaps protocol.Protocol type of usage?
eth/p2p/discoveryv5/protocol,
./messages
export utp_discv5_protocol
const
utpProtocolId = "utp".toBytes()
defaultConnectionTimeout = 5.seconds
defaultReadTimeout = 2.seconds
type
ContentRequest = object
connectionId: uint16
nodeId: NodeId
content: seq[byte]
timeout: Moment
ContentOffer = object
connectionId: uint16
nodeId: NodeId
contentKeys: ContentKeysList
timeout: Moment
PortalStream* = ref object
transport*: UtpDiscv5Protocol
# TODO:
# Decide on what's the better collection to use and set some limits in them
# on how many uTP transfers allowed to happen concurrently.
# Either set some limit, and drop whatever comes next. Unsure how to
# communicate that with the peer however. Or have some more async waiting
# until a spot becomes free, like with an AsyncQueue. Although the latter
# probably can not be used here directly. This system however does needs
# some agreement on timeout values of how long a uTP socket may be
# "listening" before it times out because of inactivity.
# Or, depending on the direction, it might also depend on the time out
# values of the discovery v5 talkresp message.
# TODO: Should the content key also be stored to be able to validate the
# received data?
contentRequests: seq[ContentRequest]
contentOffers: seq[ContentOffer]
connectionTimeout: Duration
readTimeout*: Duration
rng: ref BrHmacDrbgContext
proc addContentOffer*(
stream: PortalStream, nodeId: NodeId, contentKeys: ContentKeysList): Bytes2 =
var connectionId: Bytes2
brHmacDrbgGenerate(stream.rng[], connectionId)
# uTP protocol uses BE for all values in the header, incl. connection id.
let id = uint16.fromBytesBE(connectionId)
let contentOffer = ContentOffer(
connectionId: id,
nodeId: nodeId,
contentKeys: contentKeys,
timeout: Moment.now() + stream.connectionTimeout)
stream.contentOffers.add(contentOffer)
return connectionId
proc addContentRequest*(
stream: PortalStream, nodeId: NodeId, content: seq[byte]): Bytes2 =
var connectionId: Bytes2
brHmacDrbgGenerate(stream.rng[], connectionId)
# uTP protocol uses BE for all values in the header, incl. connection id.
let id = uint16.fromBytesBE(connectionId)
let contentRequest = ContentRequest(
connectionId: id,
nodeId: nodeId,
content: content,
timeout: Moment.now() + stream.connectionTimeout)
stream.contentRequests.add(contentRequest)
return connectionId
proc writeAndClose(socket: UtpSocket[Node], data: seq[byte]) {.async.} =
let dataWritten = await socket.write(data)
if dataWritten.isErr():
debug "Error writing requested data", error = dataWritten.error
await socket.closeWait()
proc readAndClose(socket: UtpSocket[Node], stream: PortalStream) {.async.} =
# Read all bytes from the socket
# This will either end with a FIN, or because the read action times out.
# A FIN does not necessarily mean that the data read is complete. Further
# validation is required, using a length prefix here might be beneficial for
# this.
# TODO: Should also limit the amount of data to read and/or total time.
var readData = socket.read()
if await readData.withTimeout(stream.readTimeout):
# TODO: Content needs to be validated, stored and also offered again as part
# of the neighborhood gossip. This will require access to the specific
# Portal wire protocol for the network it was received on. Some async event
# will probably be required for this.
let content = readData.read
echo content.toHex()
# Destroy socket and not closing as we already received. Closing would send
# also a FIN from our side, see also:
# https://github.com/status-im/nim-eth/blob/b2dab4be0839c95ca2564df9eacf81995bf57802/eth/utp/utp_socket.nim#L1223
await socket.destroyWait()
else:
debug "Reading data from socket timed out, content request failed"
# Even though reading timed out, lets be nice and still send a FIN.
# Not waiting here for its ACK however, so no `closeWait`
socket.close()
proc pruneAllowedConnections(stream: PortalStream) =
# Prune requests and offers that didn't receive a connection request
# before `connectionTimeout`.
let now = Moment.now()
stream.contentRequests.keepIf(proc(x: ContentRequest): bool =
x.timeout > now)
stream.contentOffers.keepIf(proc(x: ContentOffer): bool =
x.timeout > now)
# TODO: I think I'd like it more if we weren't to capture the stream.
proc registerIncomingSocketCallback(
stream: PortalStream): AcceptConnectionCallback[Node] =
return (
proc(server: UtpRouter[Node], client: UtpSocket[Node]): Future[void] =
# Note: Connection id of uTP SYN is different from other packets, it is
# actually the peers `send_conn_id`, opposed to `receive_conn_id` for all
# other packets.
for i, request in stream.contentRequests:
if request.connectionId == client.connectionId and
request.nodeId == client.remoteAddress.id:
let fut = client.writeAndClose(request.content)
stream.contentRequests.del(i)
return fut
for i, offer in stream.contentOffers:
if offer.connectionId == client.connectionId and
offer.nodeId == client.remoteAddress.id:
let fut = client.readAndClose(stream)
stream.contentOffers.del(i)
return fut
# TODO: Is there a scenario where this can happen,
# considering `allowRegisteredIdCallback`? If not, doAssert?
var fut = newFuture[void]("fluffy.AcceptConnectionCallback")
fut.complete()
return fut
)
proc allowRegisteredIdCallback(
stream: PortalStream): AllowConnectionCallback[Node] =
return (
proc(r: UtpRouter[Node], remoteAddress: Node, connectionId: uint16): bool =
# stream.pruneAllowedConnections()
# `connectionId` is the connection id ofthe uTP SYN packet header, thus
# the peers `send_conn_id`.
return
stream.contentRequests.any(
proc (x: ContentRequest): bool =
x.connectionId == connectionId and x.nodeId == remoteAddress.id) or
stream.contentOffers.any(
proc (x: ContentOffer): bool =
x.connectionId == connectionId and x.nodeId == remoteAddress.id)
)
proc new*(
T: type PortalStream, baseProtocol: protocol.Protocol,
connectionTimeout = defaultConnectionTimeout,
readTimeout = defaultReadTimeout): T =
let
stream = PortalStream(
connectionTimeout: connectionTimeout,
readTimeout: readTimeout,
rng: baseProtocol.rng)
socketConfig = SocketConfig.init(
incomingSocketReceiveTimeout = none(Duration))
stream.transport = UtpDiscv5Protocol.new(
baseProtocol,
utpProtocolId,
registerIncomingSocketCallback(stream),
allowRegisteredIdCallback(stream),
socketConfig)
stream