nim-libp2p/libp2p/protocols/connectivity/relay/client.nim

317 lines
10 KiB
Nim

# Nim-LibP2P
# Copyright (c) 2023 Status Research & Development GmbH
# Licensed under either of
# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
# * MIT license ([LICENSE-MIT](LICENSE-MIT))
# at your option.
# This file may not be copied, modified, or distributed except according to
# those terms.
{.push raises: [].}
import times
import chronos, chronicles
import
./relay,
./messages,
./rconn,
./utils,
../../../peerinfo,
../../../switch,
../../../multiaddress,
../../../stream/connection
logScope:
topics = "libp2p relay relay-client"
const RelayClientMsgSize = 4096
type
RelayClientError* = object of LPError
ReservationError* = object of RelayClientError
RelayV1DialError* = object of RelayClientError
RelayV2DialError* = object of RelayClientError
RelayClientAddConn* = proc(
conn: Connection, duration: uint32, data: uint64
): Future[void] {.gcsafe, raises: [].}
RelayClient* = ref object of Relay
onNewConnection*: RelayClientAddConn
canHop: bool
Rsvp* = object
expire*: uint64 # required, Unix expiration time (UTC)
addrs*: seq[MultiAddress] # relay address for reserving peer
voucher*: Opt[Voucher] # optional, reservation voucher
limitDuration*: uint32 # seconds
limitData*: uint64 # bytes
proc sendStopError(conn: Connection, code: StatusV2) {.async.} =
trace "send stop status", status = $code & " (" & $ord(code) & ")"
let msg = StopMessage(msgType: StopMessageType.Status, status: Opt.some(code))
await conn.writeLp(encode(msg).buffer)
proc handleRelayedConnect(
cl: RelayClient, conn: Connection, msg: StopMessage
) {.async.} =
let
# TODO: check the go version to see in which way this could fail
# it's unclear in the spec
src = msg.peer.valueOr:
await sendStopError(conn, MalformedMessage)
return
limitDuration = msg.limit.duration
limitData = msg.limit.data
msg = StopMessage(msgType: StopMessageType.Status, status: Opt.some(Ok))
pb = encode(msg)
trace "incoming relay connection", src
if cl.onNewConnection == nil:
await sendStopError(conn, StatusV2.ConnectionFailed)
await conn.close()
return
await conn.writeLp(pb.buffer)
# This sound redundant but the callback could, in theory, be set to nil during
# conn.writeLp so it's safer to double check
if cl.onNewConnection != nil:
await cl.onNewConnection(conn, limitDuration, limitData)
else:
await conn.close()
proc reserve*(
cl: RelayClient, peerId: PeerId, addrs: seq[MultiAddress] = @[]
): Future[Rsvp] {.async.} =
let conn = await cl.switch.dial(peerId, addrs, RelayV2HopCodec)
defer:
await conn.close()
let
pb = encode(HopMessage(msgType: HopMessageType.Reserve))
msg =
try:
await conn.writeLp(pb.buffer)
HopMessage.decode(await conn.readLp(RelayClientMsgSize)).tryGet()
except CancelledError as exc:
raise exc
except CatchableError as exc:
trace "error writing or reading reservation message", description = exc.msg
raise newException(ReservationError, exc.msg)
if msg.msgType != HopMessageType.Status:
raise newException(ReservationError, "Unexpected relay response type")
if msg.status.get(UnexpectedMessage) != Ok:
raise newException(ReservationError, "Reservation failed")
let reservation = msg.reservation.valueOr:
raise newException(ReservationError, "Missing reservation information")
if reservation.expire > int64.high().uint64 or
now().utc > reservation.expire.int64.fromUnix.utc:
raise newException(ReservationError, "Bad expiration date")
result.expire = reservation.expire
result.addrs = reservation.addrs
reservation.svoucher.withValue(sv):
let svoucher = SignedVoucher.decode(sv).valueOr:
raise newException(ReservationError, "Invalid voucher")
if svoucher.data.relayPeerId != peerId:
raise newException(ReservationError, "Invalid voucher PeerId")
result.voucher = Opt.some(svoucher.data)
result.limitDuration = msg.limit.duration
result.limitData = msg.limit.data
proc dialPeerV1*(
cl: RelayClient, conn: Connection, dstPeerId: PeerId, dstAddrs: seq[MultiAddress]
): Future[Connection] {.async.} =
var
msg = RelayMessage(
msgType: Opt.some(RelayType.Hop),
srcPeer: Opt.some(
RelayPeer(peerId: cl.switch.peerInfo.peerId, addrs: cl.switch.peerInfo.addrs)
),
dstPeer: Opt.some(RelayPeer(peerId: dstPeerId, addrs: dstAddrs)),
)
pb = encode(msg)
trace "Dial peer", msgSend = msg
try:
await conn.writeLp(pb.buffer)
except CancelledError as exc:
raise exc
except CatchableError as exc:
trace "error writing hop request", description = exc.msg
raise exc
let msgRcvFromRelayOpt =
try:
RelayMessage.decode(await conn.readLp(RelayClientMsgSize))
except CancelledError as exc:
raise exc
except CatchableError as exc:
trace "error reading stop response", description = exc.msg
await sendStatus(conn, StatusV1.HopCantOpenDstStream)
raise exc
try:
let msgRcvFromRelay = msgRcvFromRelayOpt.valueOr:
raise newException(RelayV1DialError, "Hop can't open destination stream")
if msgRcvFromRelay.msgType.tryGet() != RelayType.Status:
raise newException(
RelayV1DialError, "Hop can't open destination stream: wrong message type"
)
if msgRcvFromRelay.status.tryGet() != StatusV1.Success:
raise newException(
RelayV1DialError, "Hop can't open destination stream: status failed"
)
except RelayV1DialError as exc:
await sendStatus(conn, StatusV1.HopCantOpenDstStream)
raise exc
except ValueError as exc:
await sendStatus(conn, StatusV1.HopCantOpenDstStream)
raise newException(RelayV1DialError, exc.msg)
result = conn
proc dialPeerV2*(
cl: RelayClient,
conn: RelayConnection,
dstPeerId: PeerId,
dstAddrs: seq[MultiAddress],
): Future[Connection] {.async.} =
let
p = Peer(peerId: dstPeerId, addrs: dstAddrs)
pb = encode(HopMessage(msgType: HopMessageType.Connect, peer: Opt.some(p)))
trace "Dial peer", p
let msgRcvFromRelay =
try:
await conn.writeLp(pb.buffer)
HopMessage.decode(await conn.readLp(RelayClientMsgSize)).tryGet()
except CancelledError as exc:
raise exc
except CatchableError as exc:
trace "error reading stop response", description = exc.msg
raise newException(RelayV2DialError, exc.msg)
if msgRcvFromRelay.msgType != HopMessageType.Status:
raise newException(RelayV2DialError, "Unexpected stop response")
if msgRcvFromRelay.status.get(UnexpectedMessage) != Ok:
trace "Relay stop failed", description = msgRcvFromRelay.status
raise newException(RelayV2DialError, "Relay stop failure")
conn.limitDuration = msgRcvFromRelay.limit.duration
conn.limitData = msgRcvFromRelay.limit.data
return conn
proc handleStopStreamV2(cl: RelayClient, conn: Connection) {.async.} =
let msg = StopMessage.decode(await conn.readLp(RelayClientMsgSize)).valueOr:
await sendHopStatus(conn, MalformedMessage)
return
trace "client circuit relay v2 handle stream", msg
if msg.msgType == StopMessageType.Connect:
await cl.handleRelayedConnect(conn, msg)
else:
trace "Unexpected client / relayv2 handshake", msgType = msg.msgType
await sendStopError(conn, MalformedMessage)
proc handleStop(cl: RelayClient, conn: Connection, msg: RelayMessage) {.async.} =
let src = msg.srcPeer.valueOr:
await sendStatus(conn, StatusV1.StopSrcMultiaddrInvalid)
return
let dst = msg.dstPeer.valueOr:
await sendStatus(conn, StatusV1.StopDstMultiaddrInvalid)
return
if dst.peerId != cl.switch.peerInfo.peerId:
await sendStatus(conn, StatusV1.StopDstMultiaddrInvalid)
return
trace "get a relay connection", src, conn
if cl.onNewConnection == nil:
await sendStatus(conn, StatusV1.StopRelayRefused)
await conn.close()
return
await sendStatus(conn, StatusV1.Success)
# This sound redundant but the callback could, in theory, be set to nil during
# sendStatus(Success) so it's safer to double check
if cl.onNewConnection != nil:
await cl.onNewConnection(conn, 0, 0)
else:
await conn.close()
proc handleStreamV1(cl: RelayClient, conn: Connection) {.async.} =
let msg = RelayMessage.decode(await conn.readLp(RelayClientMsgSize)).valueOr:
await sendStatus(conn, StatusV1.MalformedMessage)
return
trace "client circuit relay v1 handle stream", msg
let typ = msg.msgType.valueOr:
trace "Message type not set"
await sendStatus(conn, StatusV1.MalformedMessage)
return
case typ
of RelayType.Hop:
if cl.canHop:
await cl.handleHop(conn, msg)
else:
await sendStatus(conn, StatusV1.HopCantSpeakRelay)
of RelayType.Stop:
await cl.handleStop(conn, msg)
of RelayType.CanHop:
if cl.canHop:
await sendStatus(conn, StatusV1.Success)
else:
await sendStatus(conn, StatusV1.HopCantSpeakRelay)
else:
trace "Unexpected relay handshake", msgType = msg.msgType
await sendStatus(conn, StatusV1.MalformedMessage)
proc new*(
T: typedesc[RelayClient],
canHop: bool = false,
reservationTTL: times.Duration = DefaultReservationTTL,
limitDuration: uint32 = DefaultLimitDuration,
limitData: uint64 = DefaultLimitData,
heartbeatSleepTime: uint32 = DefaultHeartbeatSleepTime,
maxCircuit: int = MaxCircuit,
maxCircuitPerPeer: int = MaxCircuitPerPeer,
msgSize: int = RelayClientMsgSize,
circuitRelayV1: bool = false,
): T =
let cl = T(
canHop: canHop,
reservationTTL: reservationTTL,
limit: Limit(duration: limitDuration, data: limitData),
heartbeatSleepTime: heartbeatSleepTime,
maxCircuit: maxCircuit,
maxCircuitPerPeer: maxCircuitPerPeer,
msgSize: msgSize,
isCircuitRelayV1: circuitRelayV1,
)
proc handleStream(conn: Connection, proto: string) {.async.} =
try:
case proto
of RelayV1Codec:
await cl.handleStreamV1(conn)
of RelayV2StopCodec:
await cl.handleStopStreamV2(conn)
of RelayV2HopCodec:
await cl.handleHopStreamV2(conn)
except CancelledError as exc:
raise exc
except CatchableError as exc:
trace "exception in client handler", description = exc.msg, conn
finally:
trace "exiting client handler", conn
await conn.close()
cl.handler = handleStream
cl.codecs =
if cl.canHop:
@[RelayV1Codec, RelayV2HopCodec, RelayV2StopCodec]
else:
@[RelayV1Codec, RelayV2StopCodec]
cl