# beacon_chain # Copyright (c) 2018-2021 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 lib std/[typetraits, os, sequtils, strutils, algorithm, math, tables], # Status libs stew/[leb128, endians2, results, byteutils, io2, bitops2], bearssl, stew/shims/net as stewNet, stew/shims/[macros], faststreams/[inputs, outputs, buffers], snappy, snappy/framing, json_serialization, json_serialization/std/[net, sets, options], chronos, chronicles, metrics, libp2p/[switch, peerinfo, multiaddress, multicodec, crypto/crypto, crypto/secp, builders], libp2p/protocols/pubsub/[ pubsub, gossipsub, rpc/message, rpc/messages, peertable, pubsubpeer], libp2p/stream/connection, libp2p/utils/semaphore, eth/[keys, async_utils], eth/p2p/p2p_protocol_dsl, eth/net/nat, eth/p2p/discoveryv5/[enr, node, random2], ".."/[version, conf, beacon_clock], ../spec/datatypes/[phase0, altair, merge], ../spec/[eth2_ssz_serialization, network, helpers, forks], ../validators/keystore_management, ./eth2_discovery, ./peer_pool, ./libp2p_json_serialization when chronicles.enabledLogLevel == LogLevel.TRACE: import std/sequtils export tables, version, multiaddress, peer_pool, peerinfo, p2pProtocol, connection, libp2p_json_serialization, eth2_ssz_serialization, results, eth2_discovery logScope: topics = "networking" type NetKeyPair* = crypto.KeyPair PublicKey* = crypto.PublicKey PrivateKey* = crypto.PrivateKey Bytes = seq[byte] ErrorMsg = List[byte, 256] # TODO: This is here only to eradicate a compiler # warning about unused import (rpc/messages). GossipMsg = messages.Message SeenItem* = object peerId*: PeerID stamp*: chronos.Moment Eth2Node* = ref object of RootObj switch*: Switch pubsub*: GossipSub discovery*: Eth2DiscoveryProtocol discoveryEnabled*: bool wantedPeers*: int peerPool*: PeerPool[Peer, PeerID] protocolStates*: seq[RootRef] libp2pTransportLoops*: seq[Future[void]] metadata*: altair.MetaData connectTimeout*: chronos.Duration seenThreshold*: chronos.Duration connQueue: AsyncQueue[PeerAddr] seenTable: Table[PeerID, SeenItem] connWorkers: seq[Future[void]] connTable: HashSet[PeerID] forkId*: ENRForkID discoveryForkId*: ENRForkID forkDigests*: ref ForkDigests rng*: ref BrHmacDrbgContext peers*: Table[PeerID, Peer] validTopics: HashSet[string] peerPingerHeartbeatFut: Future[void] cfg: RuntimeConfig getBeaconTime: GetBeaconTimeFn EthereumNode = Eth2Node # needed for the definitions in p2p_backends_helpers AverageThroughput* = object count*: uint64 average*: float Peer* = ref object network*: Eth2Node peerId*: PeerId discoveryId*: Eth2DiscoveryId connectionState*: ConnectionState protocolStates*: seq[RootRef] netThroughput: AverageThroughput score*: int requestQuota*: float lastReqTime*: Moment connections*: int enr*: Option[enr.Record] metadata*: Option[phase0.MetaData] lastMetadataTime*: Moment direction*: PeerType disconnectedFut: Future[void] PeerAddr* = object peerId*: PeerID addrs*: seq[MultiAddress] ConnectionState* = enum None, Connecting, Connected, Disconnecting, Disconnected UntypedResponse* = ref object peer*: Peer stream*: Connection writtenChunks*: int SingleChunkResponse*[MsgType] = distinct UntypedResponse ## Protocol requests using this type will produce request-making ## client-side procs that return `NetRes[MsgType]` MultipleChunksResponse*[MsgType] = distinct UntypedResponse ## Protocol requests using this type will produce request-making ## client-side procs that return `NetRes[seq[MsgType]]`. ## In the future, such procs will return an `InputStream[NetRes[MsgType]]`. MessageInfo* = object name*: string # Private fields: libp2pCodecName: string protocolMounter*: MounterProc ProtocolInfoObj* = object name*: string messages*: seq[MessageInfo] index*: int # the position of the protocol in the # ordered list of supported protocols # Private fields: peerStateInitializer*: PeerStateInitializer networkStateInitializer*: NetworkStateInitializer onPeerConnected*: OnPeerConnectedHandler onPeerDisconnected*: OnPeerDisconnectedHandler ProtocolInfo* = ptr ProtocolInfoObj ResponseCode* = enum Success InvalidRequest ServerError PeerStateInitializer* = proc(peer: Peer): RootRef {.gcsafe, raises: [Defect].} NetworkStateInitializer* = proc(network: EthereumNode): RootRef {.gcsafe, raises: [Defect].} OnPeerConnectedHandler* = proc(peer: Peer, incoming: bool): Future[void] {.gcsafe.} OnPeerDisconnectedHandler* = proc(peer: Peer): Future[void] {.gcsafe, raises: [Defect].} ThunkProc* = LPProtoHandler MounterProc* = proc(network: Eth2Node) {.gcsafe, raises: [Defect, CatchableError].} MessageContentPrinter* = proc(msg: pointer): string {.gcsafe, raises: [Defect].} # https://github.com/ethereum/consensus-specs/blob/v1.1.4/specs/phase0/p2p-interface.md#goodbye DisconnectionReason* = enum # might see other values on the wire! ClientShutDown = 1 IrrelevantNetwork = 2 FaultOrError = 3 # Clients MAY use reason codes above 128 to indicate alternative, # erroneous request-specific responses. PeerScoreLow = 237 # 79 * 3 PeerDisconnected* = object of CatchableError reason*: DisconnectionReason TransmissionError* = object of CatchableError Eth2NetworkingErrorKind* = enum BrokenConnection ReceivedErrorResponse UnexpectedEOF PotentiallyExpectedEOF InvalidResponseCode InvalidSnappyBytes InvalidSszBytes StreamOpenTimeout ReadResponseTimeout ZeroSizePrefix SizePrefixOverflow InvalidContextBytes Eth2NetworkingError = object case kind*: Eth2NetworkingErrorKind of ReceivedErrorResponse: responseCode: ResponseCode errorMsg: string else: discard InvalidInputsError* = object of CatchableError NetRes*[T] = Result[T, Eth2NetworkingError] ## This is type returned from all network requests func phase0metadata*(node: Eth2Node): phase0.MetaData = phase0.MetaData( seq_number: node.metadata.seq_number, attnets: node.metadata.attnets) const clientId* = "Nimbus beacon node " & fullVersionStr nodeMetadataFilename = "node-metadata.json" NewPeerScore = 200 ## Score which will be assigned to new connected Peer PeerScoreLowLimit = 0 ## Score after which peer will be kicked PeerScoreHighLimit = 1000 ## Max value of peer's score PeerScoreInvalidRequest = -500 ## This peer is sending malformed or nonsensical data ConcurrentConnections = 20 ## Maximum number of active concurrent connection requests. SeenTableTimeTimeout = when not defined(local_testnet): 5.minutes else: 10.seconds ## Seen period of time for timeout connections SeenTableTimeDeadPeer = when not defined(local_testnet): 5.minutes else: 10.seconds ## Period of time for dead peers. SeenTableTimeIrrelevantNetwork = 24.hours ## Period of time for `IrrelevantNetwork` error reason. SeenTableTimeClientShutDown = 10.minutes ## Period of time for `ClientShutDown` error reason. SeenTableTimeFaultOrError = 10.minutes ## Period of time for `FaultOnError` error reason. SeenTablePenaltyError = 60.minutes ## Period of time for peers which score below or equal to zero. SeenTableTimeReconnect = 1.minutes ## Minimal time between disconnection and reconnection attempt template neterr*(kindParam: Eth2NetworkingErrorKind): auto = err(type(result), Eth2NetworkingError(kind: kindParam)) # Metrics for tracking attestation and beacon block loss declareCounter nbc_gossip_messages_sent, "Number of gossip messages sent by this peer" declareCounter nbc_gossip_messages_received, "Number of gossip messages received by this peer" declareCounter nbc_gossip_failed_snappy, "Number of gossip messages that failed snappy decompression" declareCounter nbc_gossip_failed_ssz, "Number of gossip messages that failed SSZ parsing" declareCounter nbc_successful_dials, "Number of successfully dialed peers" declareCounter nbc_failed_dials, "Number of dialing attempts that failed" declareCounter nbc_timeout_dials, "Number of dialing attempts that exceeded timeout" declareGauge nbc_peers, "Number of active libp2p peers" declareCounter nbc_successful_discoveries, "Number of successful discoveries" declareCounter nbc_failed_discoveries, "Number of failed discoveries" declareCounter nbc_cycling_kicked_peers, "Number of peers kicked for peer cycling" const delayBuckets = [1.0, 5.0, 10.0, 20.0, 40.0, 60.0] declareHistogram nbc_resolve_time, "Time(s) used while resolving peer information", buckets = delayBuckets const snappy_implementation {.strdefine.} = "libp2p" const useNativeSnappy = when snappy_implementation == "native": true elif snappy_implementation == "libp2p": false else: {.fatal: "Please set snappy_implementation to either 'libp2p' or 'native'".} const libp2p_pki_schemes {.strdefine.} = "" when libp2p_pki_schemes != "secp256k1": {.fatal: "Incorrect building process, please use -d:\"libp2p_pki_schemes=secp256k1\"".} const NetworkInsecureKeyPassword = "INSECUREPASSWORD" template libp2pProtocol*(name: string, version: int) {.pragma.} func shortLog*(peer: Peer): string = shortLog(peer.peerId) chronicles.formatIt(Peer): shortLog(it) chronicles.formatIt(PublicKey): byteutils.toHex(it.getBytes().tryGet()) template remote*(peer: Peer): untyped = peer.peerId proc openStream(node: Eth2Node, peer: Peer, protocolId: string): Future[Connection] {.async.} = # When dialling here, we do not provide addresses - all new connection # attempts are handled via `connect` which also takes into account # reconnection timeouts let protocolId = protocolId & "ssz_snappy" conn = await dial( node.switch, peer.peerId, protocolId) return conn proc init*(T: type Peer, network: Eth2Node, peerId: PeerId): Peer {.gcsafe.} func peerId*(node: Eth2Node): PeerID = node.switch.peerInfo.peerId func enrRecord*(node: Eth2Node): Record = node.discovery.localNode.record proc getPeer*(node: Eth2Node, peerId: PeerID): Peer = node.peers.withValue(peerId, peer) do: return peer[] do: let peer = Peer.init(node, peerId) return node.peers.mgetOrPut(peerId, peer) proc peerFromStream(network: Eth2Node, conn: Connection): Peer = result = network.getPeer(conn.peerId) result.peerId = conn.peerId proc getKey*(peer: Peer): PeerID {.inline.} = peer.peerId proc getFuture*(peer: Peer): Future[void] {.inline.} = if isNil(peer.disconnectedFut): peer.disconnectedFut = newFuture[void]("Peer.disconnectedFut") peer.disconnectedFut proc getScore*(a: Peer): int = ## Returns current score value for peer ``peer``. a.score proc updateScore*(peer: Peer, score: int) {.inline.} = ## Update peer's ``peer`` score with value ``score``. peer.score = peer.score + score if peer.score > PeerScoreHighLimit: peer.score = PeerScoreHighLimit proc calcThroughput(dur: Duration, value: uint64): float = let secs = float(chronos.seconds(1).nanoseconds) if isZero(dur): 0.0 else: float(value) * (secs / float(dur.nanoseconds)) proc updateNetThroughput*(peer: Peer, dur: Duration, bytesCount: uint64) {.inline.} = ## Update peer's ``peer`` network throughput. let bytesPerSecond = calcThroughput(dur, bytesCount) let a = peer.netThroughput.average let n = peer.netThroughput.count peer.netThroughput.average = a + (bytesPerSecond - a) / float(n + 1) inc(peer.netThroughput.count) proc netBps*(peer: Peer): float {.inline.} = ## Returns current network throughput average value in Bps for peer ``peer``. round((peer.netThroughput.average * 10_000) / 10_000) proc netKbps*(peer: Peer): float {.inline.} = ## Returns current network throughput average value in Kbps for peer ``peer``. round(((peer.netThroughput.average / 1024) * 10_000) / 10_000) proc netMbps*(peer: Peer): float {.inline.} = ## Returns current network throughput average value in Mbps for peer ``peer``. round(((peer.netThroughput.average / (1024 * 1024)) * 10_000) / 10_000) proc `<`*(a, b: Peer): bool = ## Comparison function, which first checks peer's scores, and if the peers' ## score is equal it compares peers' network throughput. if a.score < b.score: true elif a.score == b.score: (a.netThroughput.average < b.netThroughput.average) else: false const maxRequestQuota = 1000000.0 fullReplenishTime = 5.seconds replenishRate = (maxRequestQuota / fullReplenishTime.nanoseconds.float) proc updateRequestQuota*(peer: Peer, reqCost: float) = let currentTime = now(chronos.Moment) nanosSinceLastReq = nanoseconds(currentTime - peer.lastReqTime) replenishedQuota = peer.requestQuota + nanosSinceLastReq.float * replenishRate peer.lastReqTime = currentTime peer.requestQuota = min(replenishedQuota, maxRequestQuota) - reqCost template awaitNonNegativeRequestQuota*(peer: Peer) = let quota = peer.requestQuota if quota < 0: await sleepAsync(nanoseconds(int((-quota) / replenishRate))) func allowedOpsPerSecondCost*(n: int): float = (replenishRate * 1000000000'f / n.float) proc isSeen*(network: ETh2Node, peerId: PeerID): bool = ## Returns ``true`` if ``peerId`` present in SeenTable and time period is not ## yet expired. let currentTime = now(chronos.Moment) if peerId notin network.seenTable: false else: let item = try: network.seenTable[peerId] except KeyError: raiseAssert "checked with notin" if currentTime >= item.stamp: # Peer is in SeenTable, but the time period has expired. network.seenTable.del(peerId) false else: true proc addSeen*(network: ETh2Node, peerId: PeerID, period: chronos.Duration) = ## Adds peer with PeerID ``peerId`` to SeenTable and timeout ``period``. let item = SeenItem(peerId: peerId, stamp: now(chronos.Moment) + period) withValue(network.seenTable, peerId, entry) do: if entry.stamp < item.stamp: entry.stamp = item.stamp do: network.seenTable[peerId] = item proc disconnect*(peer: Peer, reason: DisconnectionReason, notifyOtherPeer = false) {.async.} = # TODO(zah): How should we notify the other peer? try: if peer.connectionState notin {Disconnecting, Disconnected}: peer.connectionState = Disconnecting # We adding peer in SeenTable before actual disconnect to avoid races. let seenTime = case reason of ClientShutDown: SeenTableTimeClientShutDown of IrrelevantNetwork: SeenTableTimeIrrelevantNetwork of FaultOrError: SeenTableTimeFaultOrError of PeerScoreLow: SeenTablePenaltyError peer.network.addSeen(peer.peerId, seenTime) await peer.network.switch.disconnect(peer.peerId) except CatchableError: # We do not care about exceptions in disconnection procedure. trace "Exception while disconnecting peer", peer = peer.peerId, reason = reason include eth/p2p/p2p_backends_helpers include eth/p2p/p2p_tracing proc getRequestProtoName(fn: NimNode): NimNode = # `getCustomPragmaVal` doesn't work yet on regular nnkProcDef nodes # (TODO: file as an issue) let pragmas = fn.pragma if pragmas.kind == nnkPragma and pragmas.len > 0: for pragma in pragmas: try: if pragma.len > 0 and $pragma[0] == "libp2pProtocol": let protoName = $(pragma[1]) let protoVer = $(pragma[2].intVal) return newLit("/eth2/beacon_chain/req/" & protoName & "/" & protoVer & "/") except Exception as exc: raiseAssert exc.msg # TODO https://github.com/nim-lang/Nim/issues/17454 return newLit("") proc writeChunk*(conn: Connection, responseCode: Option[ResponseCode], payload: Bytes, contextBytes: openarray[byte] = []): Future[void] = var output = memoryOutput() try: if responseCode.isSome: output.write byte(responseCode.get) if contextBytes.len > 0: output.write contextBytes output.write toBytes(payload.lenu64, Leb128).toOpenArray() framingFormatCompress(output, payload) except IOError as exc: raiseAssert exc.msg # memoryOutput shouldn't raise conn.write(output.getOutput) template errorMsgLit(x: static string): ErrorMsg = const val = ErrorMsg toBytes(x) val func formatErrorMsg(msg: ErrorMsg): string = # ErrorMsg "usually" contains a human-readable string - we'll try to parse it # as ASCII and return hex if that fails for c in msg: if c < 32 or c > 127: return byteutils.toHex(asSeq(msg)) string.fromBytes(asSeq(msg)) proc sendErrorResponse(peer: Peer, conn: Connection, responseCode: ResponseCode, errMsg: ErrorMsg): Future[void] = debug "Error processing request", peer, responseCode, errMsg = formatErrorMsg(errMsg) conn.writeChunk(some responseCode, SSZ.encode(errMsg)) proc sendNotificationMsg(peer: Peer, protocolId: string, requestBytes: Bytes) {.async.} = var deadline = sleepAsync RESP_TIMEOUT streamFut = peer.network.openStream(peer, protocolId) await streamFut or deadline if not streamFut.finished: await streamFut.cancelAndWait() raise newException(TransmissionError, "Failed to open LibP2P stream") let stream = streamFut.read try: await stream.writeChunk(none ResponseCode, requestBytes) finally: await stream.close() proc sendResponseChunkBytes(response: UntypedResponse, payload: Bytes): Future[void] = inc response.writtenChunks response.stream.writeChunk(some Success, payload) proc sendResponseChunk*(response: UntypedResponse, val: auto): Future[void] = inc response.writtenChunks response.stream.writeChunk(some Success, SSZ.encode(val)) template sendUserHandlerResultAsChunkImpl*(stream: Connection, handlerResultFut: Future): untyped = let handlerRes = await handlerResultFut writeChunk(stream, some Success, SSZ.encode(handlerRes)) template sendUserHandlerResultAsChunkImpl*(stream: Connection, handlerResult: auto): untyped = writeChunk(stream, some Success, SSZ.encode(handlerResult)) when useNativeSnappy: include faststreams_backend else: include libp2p_streams_backend proc makeEth2Request(peer: Peer, protocolId: string, requestBytes: Bytes, ResponseMsg: type, timeout: Duration): Future[NetRes[ResponseMsg]] {.async.} = var deadline = sleepAsync timeout let stream = awaitWithTimeout(peer.network.openStream(peer, protocolId), deadline): return neterr StreamOpenTimeout try: # Send the request # Some clients don't want a length sent for empty requests # So don't send anything on empty requests if requestBytes.len > 0: await stream.writeChunk(none ResponseCode, requestBytes) # Half-close the stream to mark the end of the request - if this is not # done, the other peer might never send us the response. await stream.close() # Read the response return await readResponse(when useNativeSnappy: libp2pInput(stream) else: stream, peer, ResponseMsg, timeout) finally: await stream.closeWithEOF() proc init*[MsgType](T: type MultipleChunksResponse[MsgType], peer: Peer, conn: Connection): T = T(UntypedResponse(peer: peer, stream: conn)) proc init*[MsgType](T: type SingleChunkResponse[MsgType], peer: Peer, conn: Connection): T = T(UntypedResponse(peer: peer, stream: conn)) template write*[M](r: MultipleChunksResponse[M], val: M): untyped = mixin sendResponseChunk sendResponseChunk(UntypedResponse(r), val) template send*[M](r: SingleChunkResponse[M], val: M): untyped = mixin sendResponseChunk doAssert UntypedResponse(r).writtenChunks == 0 sendResponseChunk(UntypedResponse(r), val) proc performProtocolHandshakes*(peer: Peer, incoming: bool) {.async.} = # Loop down serially because it's easier to reason about the connection state # when there are fewer async races, specially during setup for protocol in allProtocols: if protocol.onPeerConnected != nil: await protocol.onPeerConnected(peer, incoming) proc initProtocol(name: string, peerInit: PeerStateInitializer, networkInit: NetworkStateInitializer): ProtocolInfoObj = ProtocolInfoObj( name: name, messages: @[], peerStateInitializer: peerInit, networkStateInitializer: networkInit) proc registerProtocol(protocol: ProtocolInfo) = # TODO: This can be done at compile-time in the future let pos = lowerBound(gProtocols, protocol) gProtocols.insert(protocol, pos) for i in 0 ..< gProtocols.len: gProtocols[i].index = i proc setEventHandlers(p: ProtocolInfo, onPeerConnected: OnPeerConnectedHandler, onPeerDisconnected: OnPeerDisconnectedHandler) = p.onPeerConnected = onPeerConnected p.onPeerDisconnected = onPeerDisconnected proc implementSendProcBody(sendProc: SendProc) = let msg = sendProc.msg UntypedResponse = bindSym "UntypedResponse" proc sendCallGenerator(peer, bytes: NimNode): NimNode = if msg.kind != msgResponse: let msgProto = getRequestProtoName(msg.procDef) case msg.kind of msgRequest: let ResponseRecord = msg.response.recName quote: makeEth2Request(`peer`, `msgProto`, `bytes`, `ResponseRecord`, `timeoutVar`) else: quote: sendNotificationMsg(`peer`, `msgProto`, `bytes`) else: quote: sendResponseChunkBytes(`UntypedResponse`(`peer`), `bytes`) sendProc.useStandardBody(nil, nil, sendCallGenerator) proc handleIncomingStream(network: Eth2Node, conn: Connection, MsgType: type) {.async.} = mixin callUserHandler, RecType type MsgRec = RecType(MsgType) const msgName {.used.} = typetraits.name(MsgType) ## Uncomment this to enable tracing on all incoming requests ## You can include `msgNameLit` in the condition to select ## more specific requests: # when chronicles.runtimeFilteringEnabled: # setLogLevel(LogLevel.TRACE) # defer: setLogLevel(LogLevel.DEBUG) # trace "incoming " & `msgNameLit` & " conn" let peer = peerFromStream(network, conn) try: case peer.connectionState of Disconnecting, Disconnected, None: # We got incoming stream request while disconnected or disconnecting. debug "Got incoming request from disconnected peer", peer = peer, message = msgName await conn.closeWithEOF() return of Connecting: # We got incoming stream request while handshake is not yet finished, # TODO: We could check it here. debug "Got incoming request from peer while in handshake", peer = peer, msgName of Connected: # We got incoming stream from peer with proper connection state. debug "Got incoming request from peer", peer = peer, msgName template returnInvalidRequest(msg: ErrorMsg) = peer.updateScore(PeerScoreInvalidRequest) await sendErrorResponse(peer, conn, InvalidRequest, msg) return template returnInvalidRequest(msg: string) = returnInvalidRequest(ErrorMsg msg.toBytes) let s = when useNativeSnappy: let fs = libp2pInput(conn) if fs.timeoutToNextByte(TTFB_TIMEOUT): returnInvalidRequest(errorMsgLit "Request first byte not sent in time") fs else: # TODO(zah) The TTFB timeout is not implemented in LibP2P streams back-end conn let deadline = sleepAsync RESP_TIMEOUT let msg = if sizeof(MsgRec) > 0: try: awaitWithTimeout(readChunkPayload(s, peer, MsgRec), deadline): returnInvalidRequest(errorMsgLit "Request full data not sent in time") except SerializationError as err: returnInvalidRequest err.formatMsg("msg") except SnappyError as err: returnInvalidRequest err.msg else: NetRes[MsgRec].ok default(MsgRec) if msg.isErr: let (responseCode, errMsg) = case msg.error.kind of UnexpectedEOF, PotentiallyExpectedEOF: (InvalidRequest, errorMsgLit "Incomplete request") of InvalidContextBytes: (ServerError, errorMsgLit "Unrecognized context bytes") of InvalidSnappyBytes: (InvalidRequest, errorMsgLit "Failed to decompress snappy payload") of InvalidSszBytes: (InvalidRequest, errorMsgLit "Failed to decode SSZ payload") of ZeroSizePrefix: (InvalidRequest, errorMsgLit "The request chunk cannot have a size of zero") of SizePrefixOverflow: (InvalidRequest, errorMsgLit "The chunk size exceed the maximum allowed") of InvalidResponseCode, ReceivedErrorResponse, StreamOpenTimeout, ReadResponseTimeout: # These shouldn't be possible in a request, because # there are no response codes being read, no stream # openings and no reading of responses: (ServerError, errorMsgLit "Internal server error") of BrokenConnection: return await sendErrorResponse(peer, conn, responseCode, errMsg) return try: logReceivedMsg(peer, MsgType(msg.get)) await callUserHandler(MsgType, peer, conn, msg.get) except InvalidInputsError as err: returnInvalidRequest err.msg await sendErrorResponse(peer, conn, ServerError, ErrorMsg err.msg.toBytes) except CatchableError as err: await sendErrorResponse(peer, conn, ServerError, ErrorMsg err.msg.toBytes) except CatchableError as err: debug "Error processing an incoming request", err = err.msg, msgName finally: await conn.closeWithEOF() discard network.peerPool.checkPeerScore(peer) proc toPeerAddr*(r: enr.TypedRecord, proto: IpTransportProtocol): Result[PeerAddr, cstring] = if not r.secp256k1.isSome: return err("enr: no secp256k1 key in record") let pubKey = ? keys.PublicKey.fromRaw(r.secp256k1.get) peerId = ? PeerID.init(crypto.PublicKey( scheme: Secp256k1, skkey: secp.SkPublicKey(pubKey))) var addrs = newSeq[MultiAddress]() case proto of tcpProtocol: if r.ip.isSome and r.tcp.isSome: let ip = ipv4(r.ip.get) addrs.add MultiAddress.init(ip, tcpProtocol, Port r.tcp.get) if r.ip6.isSome: let ip = ipv6(r.ip6.get) if r.tcp6.isSome: addrs.add MultiAddress.init(ip, tcpProtocol, Port r.tcp6.get) elif r.tcp.isSome: addrs.add MultiAddress.init(ip, tcpProtocol, Port r.tcp.get) else: discard of udpProtocol: if r.ip.isSome and r.udp.isSome: let ip = ipv4(r.ip.get) addrs.add MultiAddress.init(ip, udpProtocol, Port r.udp.get) if r.ip6.isSome: let ip = ipv6(r.ip6.get) if r.udp6.isSome: addrs.add MultiAddress.init(ip, udpProtocol, Port r.udp6.get) elif r.udp.isSome: addrs.add MultiAddress.init(ip, udpProtocol, Port r.udp.get) else: discard if addrs.len == 0: return err("enr: no addresses in record") ok(PeerAddr(peerId: peerId, addrs: addrs)) proc checkPeer(node: Eth2Node, peerAddr: PeerAddr): bool = logScope: peer = peerAddr.peerId let peerId = peerAddr.peerId if node.peerPool.hasPeer(peerId): trace "Already connected" false else: if node.isSeen(peerId): trace "Recently connected" false else: true proc dialPeer*(node: Eth2Node, peerAddr: PeerAddr, index = 0) {.async.} = ## Establish connection with remote peer identified by address ``peerAddr``. logScope: peer = peerAddr.peerId index = index if not(node.checkPeer(peerAddr)): return debug "Connecting to discovered peer" var deadline = sleepAsync(node.connectTimeout) var workfut = node.switch.connect(peerAddr.peerId, peerAddr.addrs) try: # `or` operation will only raise exception of `workfut`, because `deadline` # could not raise exception. await workfut or deadline if workfut.finished(): if not deadline.finished(): deadline.cancel() inc nbc_successful_dials else: debug "Connection to remote peer timed out" inc nbc_timeout_dials node.addSeen(peerAddr.peerId, SeenTableTimeTimeout) await cancelAndWait(workfut) except CatchableError as exc: debug "Connection to remote peer failed", msg = exc.msg inc nbc_failed_dials node.addSeen(peerAddr.peerId, SeenTableTimeDeadPeer) proc connectWorker(node: Eth2Node, index: int) {.async.} = debug "Connection worker started", index = index while true: # This loop will never produce HIGH CPU usage because it will wait # and block until it not obtains new peer from the queue ``connQueue``. let remotePeerAddr = await node.connQueue.popFirst() # Previous worker dial might have hit the maximum peers. # TODO: could clear the whole connTable and connQueue here also, best # would be to have this event based coming from peer pool or libp2p. if node.switch.connManager.outSema.count > 0: await node.dialPeer(remotePeerAddr, index) # Peer was added to `connTable` before adding it to `connQueue`, so we # excluding peer here after processing. node.connTable.excl(remotePeerAddr.peerId) proc toPeerAddr(node: Node): Result[PeerAddr, cstring] = let nodeRecord = ? node.record.toTypedRecord() let peerAddr = ? nodeRecord.toPeerAddr(tcpProtocol) ok(peerAddr) proc isCompatibleForkId*(discoveryForkId: ENRForkID, peerForkId: ENRForkID): bool = if discoveryForkId.fork_digest == peerForkId.fork_digest: if discoveryForkId.next_fork_version < peerForkId.next_fork_version: # Peer knows about a fork and we don't true elif discoveryForkId.next_fork_version == peerForkId.next_fork_version: # We should have the same next_fork_epoch discoveryForkId.next_fork_epoch == peerForkId.next_fork_epoch else: # Our next fork version is bigger than the peer's one false else: # Wrong fork digest false proc queryRandom*( d: Eth2DiscoveryProtocol, forkId: ENRForkID, wantedAttnets: AttnetBits, wantedSyncnets: SyncnetBits): Future[seq[Node]] {.async.} = ## Perform a discovery query for a random target ## (forkId) and matching at least one of the attestation subnets. let nodes = await d.queryRandom() var filtered: seq[(int, Node)] for n in nodes: var score: int = 0 let eth2FieldBytes = n.record.tryGet(enrForkIdField, seq[byte]) if eth2FieldBytes.isNone(): continue let peerForkId = try: SSZ.decode(eth2FieldBytes.get(), ENRForkID) except SszError as e: debug "Could not decode the eth2 field of peer", peer = n.record.toURI(), exception = e.name, msg = e.msg continue if not forkId.isCompatibleForkId(peerForkId): continue let attnetsBytes = n.record.tryGet(enrAttestationSubnetsField, seq[byte]) if attnetsBytes.isSome(): let attnetsNode = try: SSZ.decode(attnetsBytes.get(), AttnetBits) except SszError as e: debug "Could not decode the attnets ERN bitfield of peer", peer = n.record.toURI(), exception = e.name, msg = e.msg continue for i in 0.. 0: filtered.add((score, n)) d.rng[].shuffle(filtered) return filtered.sortedByIt(-it[0]).mapIt(it[1]) proc trimConnections(node: Eth2Node, count: int) {.async.} = # Kill `count` peers, scoring them to remove the least useful ones var scores = initOrderedTable[PeerID, int]() # Take into account the stabilitySubnets # During sync, only this will be used to score peers # # A peer subscribed to all stabilitySubnets will # have 640 points for peer in node.peers.values: if peer.connectionState != Connected: continue if peer.metadata.isNone: continue let stabilitySubnets = peer.metadata.get().attnets stabilitySubnetsCount = stabilitySubnets.countOnes() thisPeersScore = 10 * stabilitySubnetsCount scores[peer.peerId] = thisPeersScore # Split a 1000 points for each topic's peers # This gives priority to peers in topics with few peers # For instance, a topic with `dHigh` peers will give 80 points to each peer # Whereas a topic with `dLow` peers will give 250 points to each peer for topic, _ in node.pubsub.topics: let peerCount = node.pubsub.mesh.peers(topic) scorePerPeer = 1_000 div max(peerCount, 1) if peerCount == 0: continue for peer in node.pubsub.mesh[topic]: if peer.peerId notin scores: continue # Divide by the number of connections # A peer using multiple connections is wasteful let connCount = node.switch.connmanager.connCount(peer.peerId) thisPeersScore = scorePerPeer div max(1, connCount) scores[peer.peerId] = scores[peer.peerId] + thisPeersScore proc sortPerScore(a, b: (PeerID, int)): int = system.cmp(a[1], b[1]) scores.sort(sortPerScore) var toKick = count for peerId in scores.keys: #TODO kill a single connection instead of the whole peer # Not possible with the current libp2p's conn management debug "kicking peer", peerId, score=scores[peerId] await node.switch.disconnect(peerId) dec toKick inc(nbc_cycling_kicked_peers) if toKick <= 0: return proc getLowSubnets(node: Eth2Node, epoch: Epoch): (AttnetBits, SyncnetBits) = # Returns the subnets required to have a healthy mesh # The subnets are computed, to, in order: # - Have 0 subscribed subnet below `dLow` # - Have 0 subnet with < `d` peers from topic subscription # - Have 0 subscribed subnet below `dOut` outgoing peers template findLowSubnets(topicNameGenerator: untyped, SubnetIdType: type, totalSubnets: static int): auto = var lowOutgoingSubnets: BitArray[totalSubnets] belowDLowSubnets: BitArray[totalSubnets] belowDOutSubnets: BitArray[totalSubnets] for subNetId in 0 ..< totalSubnets: let topic = topicNameGenerator(node.forkId.forkDigest, SubnetIdType(subNetId)) if node.pubsub.gossipsub.peers(topic) < node.pubsub.parameters.d: lowOutgoingSubnets.setBit(subNetId) # Not subscribed if topic notin node.pubsub.mesh: continue if node.pubsub.mesh.peers(topic) < node.pubsub.parameters.dLow: belowDlowSubnets.setBit(subNetId) let outPeers = node.pubsub.mesh.getOrDefault(topic).countIt(it.outbound) if outPeers < node.pubsub.parameters.dOut: belowDOutSubnets.setBit(subNetId) if belowDLowSubnets.countOnes() > 0: belowDLowSubnets elif lowOutgoingSubnets.countOnes() > 0: lowOutgoingSubnets else: belowDOutSubnets return ( findLowSubnets(getAttestationTopic, SubnetId, ATTESTATION_SUBNET_COUNT), # We start looking one epoch before the transition in order to allow # some time for the gossip meshes to get healthy: if epoch + 1 >= node.cfg.ALTAIR_FORK_EPOCH: findLowSubnets(getSyncCommitteeTopic, SyncSubcommitteeIndex, SYNC_COMMITTEE_SUBNET_COUNT) else: default(SyncnetBits) ) proc runDiscoveryLoop*(node: Eth2Node) {.async.} = debug "Starting discovery loop" while true: let currentEpoch = node.getBeaconTime().slotOrZero.epoch (wantedAttnets, wantedSyncnets) = node.getLowSubnets(currentEpoch) wantedAttnetsCount = wantedAttnets.countOnes() wantedSyncnetsCount = wantedSyncnets.countOnes() if wantedAttnetsCount > 0 or wantedSyncnetsCount > 0: let discoveredNodes = await node.discovery.queryRandom( node.discoveryForkId, wantedAttnets, wantedSyncnets) let newPeers = block: var np = newSeq[PeerAddr]() for discNode in discoveredNodes: let res = discNode.toPeerAddr() if res.isErr(): debug "Failed to decode discovery's node address", node = discnode, errMsg = res.error continue let peerAddr = res.get() if node.checkPeer(peerAddr) and peerAddr.peerId notin node.connTable: np.add(peerAddr) np # We have to be careful to kick enough peers to make room for new ones # (If we are here, we have an unhealthy mesh, so if we're full, we have bad peers) # But no kick too many peers because with low max-peers, that can cause disruption # Also keep in mind that a lot of dial fails, and that we can have incoming peers waiting let roomRequired = 1 + newPeers.len() roomCurrent = node.peerPool.lenSpace({PeerType.Outgoing}) roomDelta = roomRequired - roomCurrent maxPeersToKick = len(node.peerPool) div 5 peersToKick = min(roomDelta, maxPeersToKick) if peersToKick > 0 and newPeers.len() > 0: await node.trimConnections(peersToKick) for peerAddr in newPeers: # We adding to pending connections table here, but going # to remove it only in `connectWorker`. node.connTable.incl(peerAddr.peerId) await node.connQueue.addLast(peerAddr) debug "Discovery tick", wanted_peers = node.wantedPeers, space = node.peerPool.shortLogSpace(), acquired = node.peerPool.shortLogAcquired(), available = node.peerPool.shortLogAvailable(), current = node.peerPool.shortLogCurrent(), length = len(node.peerPool), discovered_nodes = len(discoveredNodes), kicked_peers = max(0, peersToKick), new_peers = len(newPeers) if len(newPeers) == 0: let currentPeers = node.peerPool.lenCurrent() if currentPeers <= node.wantedPeers shr 2: # 25% warn "Peer count low, no new peers discovered", discovered_nodes = len(discoveredNodes), new_peers = newPeers, current_peers = currentPeers, wanted_peers = node.wantedPeers # Discovery `queryRandom` can have a synchronous fast path for example # when no peers are in the routing table. Don't run it in continuous loop. # # Also, give some time to dial the discovered nodes and update stats etc await sleepAsync(5.seconds) proc getPersistentNetMetadata*(config: BeaconNodeConf): altair.MetaData {.raises: [Defect, IOError, SerializationError].} = let metadataPath = config.dataDir / nodeMetadataFilename if not fileExists(metadataPath): var res: altair.MetaData for i in 0 ..< ATTESTATION_SUBNET_COUNT: # TODO: # Persistent (stability) subnets should be stored with their expiration # epochs. For now, indicate that we participate in no persistent subnets. res.attnets[i] = false Json.saveFile(metadataPath, res) res else: Json.loadFile(metadataPath, altair.MetaData) proc resolvePeer(peer: Peer) = # Resolve task which performs searching of peer's public key and recovery of # ENR using discovery5. We only resolve ENR for peers we know about to avoid # querying the network - as of now, the ENR is not needed, except for # debuggging logScope: peer = peer.peerId let startTime = now(chronos.Moment) let nodeId = block: var key: PublicKey # `secp256k1` keys are always stored inside PeerID. discard peer.peerId.extractPublicKey(key) keys.PublicKey.fromRaw(key.skkey.getBytes()).get().toNodeId() debug "Peer's ENR recovery task started", node_id = $nodeId # This is "fast-path" for peers which was dialed. In this case discovery # already has most recent ENR information about this peer. let gnode = peer.network.discovery.getNode(nodeId) if gnode.isSome(): peer.enr = some(gnode.get().record) inc(nbc_successful_discoveries) let delay = now(chronos.Moment) - startTime nbc_resolve_time.observe(delay.toFloatSeconds()) debug "Peer's ENR recovered", delay proc handlePeer*(peer: Peer) {.async.} = let res = peer.network.peerPool.addPeerNoWait(peer, peer.direction) case res: of PeerStatus.LowScoreError, PeerStatus.NoSpaceError: # Peer has low score or we do not have enough space in PeerPool, # we are going to disconnect it gracefully. # Peer' state will be updated in connection event. debug "Peer has low score or there no space in PeerPool", peer = peer, reason = res await peer.disconnect(FaultOrError) of PeerStatus.DeadPeerError: # Peer's lifetime future is finished, so its already dead, # we do not need to perform gracefull disconect. # Peer's state will be updated in connection event. discard of PeerStatus.DuplicateError: # Peer is already present in PeerPool, we can't perform disconnect, # because in such case we could kill both connections (connection # which is present in PeerPool and new one). # This is possible bug, because we could enter here only if number # of `peer.connections == 1`, it means that Peer's lifetime is not # tracked properly and we still not received `Disconnected` event. debug "Peer is already present in PeerPool", peer = peer of PeerStatus.Success: # Peer was added to PeerPool. peer.score = NewPeerScore peer.connectionState = Connected # We spawn task which will obtain ENR for this peer. resolvePeer(peer) debug "Peer successfully connected", peer = peer, connections = peer.connections proc onConnEvent(node: Eth2Node, peerId: PeerID, event: ConnEvent) {.async.} = let peer = node.getPeer(peerId) case event.kind of ConnEventKind.Connected: inc peer.connections debug "Peer connection upgraded", peer = $peerId, connections = peer.connections if peer.connections == 1: # Libp2p may connect multiple times to the same peer - using different # transports for both incoming and outgoing. For now, we'll count our # "fist" encounter with the peer as the true connection, leaving the # other connections be - libp2p limits the number of concurrent # connections to the same peer, and only one of these connections will be # active. Nonetheless, this quirk will cause a number of odd behaviours: # * For peer limits, we might miscount the incoming vs outgoing quota # * Protocol handshakes are wonky: we'll not necessarily use the newly # connected transport - instead we'll just pick a random one! case peer.connectionState of Disconnecting: # We got connection with peer which we currently disconnecting. # Normally this does not happen, but if a peer is being disconnected # while a concurrent (incoming for example) connection attempt happens, # we might end up here debug "Got connection attempt from peer that we are disconnecting", peer = peerId await node.switch.disconnect(peerId) return of None: # We have established a connection with the new peer. peer.connectionState = Connecting of Disconnected: # We have established a connection with the peer that we have seen # before - reusing the existing peer object is fine peer.connectionState = Connecting peer.score = 0 # Will be set to NewPeerScore after handshake of Connecting, Connected: # This means that we got notification event from peer which we already # connected or connecting right now. If this situation will happened, # it means bug on `nim-libp2p` side. warn "Got connection attempt from peer which we already connected", peer = peerId await peer.disconnect(FaultOrError) return # Store connection direction inside Peer object. if event.incoming: peer.direction = PeerType.Incoming else: peer.direction = PeerType.Outgoing await performProtocolHandshakes(peer, event.incoming) of ConnEventKind.Disconnected: dec peer.connections debug "Lost connection to peer", peer = peerId, connections = peer.connections if peer.connections == 0: debug "Peer disconnected", peer = $peerId, connections = peer.connections # Whatever caused disconnection, avoid connection spamming node.addSeen(peerId, SeenTableTimeReconnect) let fut = peer.disconnectedFut if not(isNil(fut)): fut.complete() peer.disconnectedFut = nil else: # TODO (cheatfate): This could be removed when bug will be fixed inside # `nim-libp2p`. debug "Got new event while peer is already disconnected", peer = peerId, peer_state = peer.connectionState peer.connectionState = Disconnected proc new*(T: type Eth2Node, config: BeaconNodeConf, runtimeCfg: RuntimeConfig, enrForkId: ENRForkID, discoveryForkId: ENRForkId, forkDigests: ref ForkDigests, getBeaconTime: GetBeaconTimeFn, switch: Switch, pubsub: GossipSub, ip: Option[ValidIpAddress], tcpPort, udpPort: Option[Port], privKey: keys.PrivateKey, discovery: bool, rng: ref BrHmacDrbgContext): T {.raises: [Defect, CatchableError].} = let metadata = getPersistentNetMetadata(config) when not defined(local_testnet): let connectTimeout = 1.minutes seenThreshold = 5.minutes else: let connectTimeout = 10.seconds seenThreshold = 10.seconds let node = T( switch: switch, pubsub: pubsub, wantedPeers: config.maxPeers, cfg: runtimeCfg, peerPool: newPeerPool[Peer, PeerID](maxPeers = config.maxPeers), # Its important here to create AsyncQueue with limited size, otherwise # it could produce HIGH cpu usage. connQueue: newAsyncQueue[PeerAddr](ConcurrentConnections), # TODO: The persistent net metadata should only be used in the case of reusing # the previous netkey. metadata: metadata, forkId: enrForkId, discoveryForkId: discoveryForkId, forkDigests: forkDigests, getBeaconTime: getBeaconTime, discovery: Eth2DiscoveryProtocol.new( config, ip, tcpPort, udpPort, privKey, { enrForkIdField: SSZ.encode(enrForkId), enrAttestationSubnetsField: SSZ.encode(metadata.attnets) }, rng), discoveryEnabled: discovery, rng: rng, connectTimeout: connectTimeout, seenThreshold: seenThreshold ) newSeq node.protocolStates, allProtocols.len for proto in allProtocols: if proto.networkStateInitializer != nil: node.protocolStates[proto.index] = proto.networkStateInitializer(node) for msg in proto.messages: if msg.protocolMounter != nil: msg.protocolMounter node proc peerHook(peerId: PeerId, event: ConnEvent): Future[void] {.gcsafe.} = onConnEvent(node, peerId, event) switch.addConnEventHandler(peerHook, ConnEventKind.Connected) switch.addConnEventHandler(peerHook, ConnEventKind.Disconnected) proc scoreCheck(peer: Peer): bool = peer.score >= PeerScoreLowLimit proc onDeletePeer(peer: Peer) = if peer.connectionState notin {ConnectionState.Disconnecting, ConnectionState.Disconnected}: if peer.score < PeerScoreLowLimit: debug "Peer was removed from PeerPool due to low score", peer = peer, peer_score = peer.score, score_low_limit = PeerScoreLowLimit, score_high_limit = PeerScoreHighLimit asyncSpawn(peer.disconnect(PeerScoreLow)) else: debug "Peer was removed from PeerPool", peer = peer, peer_score = peer.score, score_low_limit = PeerScoreLowLimit, score_high_limit = PeerScoreHighLimit asyncSpawn(peer.disconnect(FaultOrError)) # Shouldn't actually happen! node.peerPool.setScoreCheck(scoreCheck) node.peerPool.setOnDeletePeer(onDeletePeer) node template publicKey*(node: Eth2Node): keys.PublicKey = node.discovery.privKey.toPublicKey proc startListening*(node: Eth2Node) {.async.} = if node.discoveryEnabled: try: node.discovery.open() except CatchableError: fatal "Failed to start discovery service. UDP port may be already in use" quit 1 try: node.libp2pTransportLoops = await node.switch.start() except CatchableError: fatal "Failed to start LibP2P transport. TCP port may be already in use" quit 1 await node.pubsub.start() proc peerPingerHeartbeat(node: Eth2Node): Future[void] {.gcsafe.} proc start*(node: Eth2Node) {.async.} = proc onPeerCountChanged() = trace "Number of peers has been changed", space = node.peerPool.shortLogSpace(), acquired = node.peerPool.shortLogAcquired(), available = node.peerPool.shortLogAvailable(), current = node.peerPool.shortLogCurrent(), length = len(node.peerPool) nbc_peers.set int64(len(node.peerPool)) node.peerPool.setPeerCounter(onPeerCountChanged) for i in 0 ..< ConcurrentConnections: node.connWorkers.add connectWorker(node, i) if node.discoveryEnabled: node.discovery.start() traceAsyncErrors node.runDiscoveryLoop() else: notice "Discovery disabled; trying bootstrap nodes", nodes = node.discovery.bootstrapRecords.len for enr in node.discovery.bootstrapRecords: let tr = enr.toTypedRecord() if tr.isOk(): let pa = tr.get().toPeerAddr(tcpProtocol) if pa.isOk(): await node.connQueue.addLast(pa.get()) node.peerPingerHeartbeatFut = node.peerPingerHeartbeat() proc stop*(node: Eth2Node) {.async.} = # Ignore errors in futures, since we're shutting down (but log them on the # TRACE level, if a timeout is reached). let waitedFutures = if node.discoveryEnabled: @[node.discovery.closeWait(), node.switch.stop()] else: @[node.switch.stop()] timeout = 5.seconds completed = await withTimeout(allFutures(waitedFutures), timeout) if not completed: trace "Eth2Node.stop(): timeout reached", timeout, futureErrors = waitedFutures.filterIt(it.error != nil).mapIt(it.error.msg) proc init*(T: type Peer, network: Eth2Node, peerId: PeerId): Peer = let res = Peer( peerId: peerId, network: network, connectionState: ConnectionState.None, lastReqTime: now(chronos.Moment), lastMetadataTime: now(chronos.Moment), protocolStates: newSeq[RootRef](len(allProtocols)) ) for i in 0 ..< len(allProtocols): let proto = allProtocols[i] if not(isNil(proto.peerStateInitializer)): res.protocolStates[i] = proto.peerStateInitializer(res) res proc registerMsg(protocol: ProtocolInfo, name: string, mounter: MounterProc, libp2pCodecName: string) = protocol.messages.add MessageInfo(name: name, protocolMounter: mounter, libp2pCodecName: libp2pCodecName) proc p2pProtocolBackendImpl*(p: P2PProtocol): Backend = var Format = ident "SSZ" Bool = bindSym "bool" Connection = bindSym "Connection" Peer = bindSym "Peer" Eth2Node = bindSym "Eth2Node" registerMsg = bindSym "registerMsg" initProtocol = bindSym "initProtocol" msgVar = ident "msg" networkVar = ident "network" callUserHandler = ident "callUserHandler" MSG = ident "MSG" p.useRequestIds = false p.useSingleRecordInlining = true new result result.PeerType = Peer result.NetworkType = Eth2Node result.registerProtocol = bindSym "registerProtocol" result.setEventHandlers = bindSym "setEventHandlers" result.SerializationFormat = Format result.RequestResultsWrapper = ident "NetRes" result.implementMsg = proc (msg: p2p_protocol_dsl.Message) = if msg.kind == msgResponse: return let protocol = msg.protocol msgName = $msg.ident msgNameLit = newLit msgName MsgRecName = msg.recName MsgStrongRecName = msg.strongRecName codecNameLit = getRequestProtoName(msg.procDef) protocolMounterName = ident(msgName & "Mounter") ## ## Implement the Thunk: ## ## The protocol handlers in nim-libp2p receive only a `Connection` ## parameter and there is no way to access the wider context (such ## as the current `Switch`). In our handlers, we may need to list all ## peers in the current network, so we must keep a reference to the ## network object in the closure environment of the installed handlers. ## ## For this reason, we define a `protocol mounter` proc that will ## initialize the network object by creating handlers bound to the ## specific network. ## var userHandlerCall = newTree(nnkDiscardStmt) if msg.userHandler != nil: var OutputParamType = if msg.kind == msgRequest: msg.outputParamType else: nil if OutputParamType == nil: userHandlerCall = msg.genUserHandlerCall(msgVar, [peerVar]) if msg.kind == msgRequest: userHandlerCall = newCall(ident"sendUserHandlerResultAsChunkImpl", streamVar, userHandlerCall) else: if OutputParamType.kind == nnkVarTy: OutputParamType = OutputParamType[0] let isChunkStream = eqIdent(OutputParamType[0], "MultipleChunksResponse") msg.response.recName = if isChunkStream: newTree(nnkBracketExpr, ident"seq", OutputParamType[1]) else: OutputParamType[1] let responseVar = ident("response") userHandlerCall = newStmtList( newVarStmt(responseVar, newCall(ident"init", OutputParamType, peerVar, streamVar)), msg.genUserHandlerCall(msgVar, [peerVar], outputParam = responseVar)) protocol.outRecvProcs.add quote do: template `callUserHandler`(`MSG`: type `MsgStrongRecName`, `peerVar`: `Peer`, `streamVar`: `Connection`, `msgVar`: `MsgRecName`): untyped = `userHandlerCall` proc `protocolMounterName`(`networkVar`: `Eth2Node`) = proc snappyThunk(`streamVar`: `Connection`, `protocolVar`: string): Future[void] {.gcsafe.} = return handleIncomingStream(`networkVar`, `streamVar`, `MsgStrongRecName`) mount `networkVar`.switch, LPProtocol(codecs: @[`codecNameLit` & "ssz_snappy"], handler: snappyThunk) ## ## Implement Senders and Handshake ## if msg.kind == msgHandshake: macros.error "Handshake messages are not supported in LibP2P protocols" else: var sendProc = msg.createSendProc() implementSendProcBody sendProc protocol.outProcRegistrations.add( newCall(registerMsg, protocol.protocolInfoVar, msgNameLit, protocolMounterName, codecNameLit)) result.implementProtocolInit = proc (p: P2PProtocol): NimNode = return newCall(initProtocol, newLit(p.name), p.peerInit, p.netInit) #Must import here because of cyclicity import ../sync/sync_protocol proc updatePeerMetadata(node: Eth2Node, peerId: PeerID) {.async.} = trace "updating peer metadata", peerId var peer = node.getPeer(peerId) #getMetaData can fail with an exception let newMetadata = try: tryGet(await peer.getMetaData()) except CatchableError: let metadataV2 = try: tryGet(await peer.getMetadata_v2()) except CatchableError as exc: debug "Failed to retrieve metadata from peer!", peerId, msg=exc.msg return phase0.MetaData(seq_number: metadataV2.seq_number, attnets: metadataV2.attnets) peer.metadata = some(newMetadata) peer.lastMetadataTime = Moment.now() const # For Phase0, metadata change every +27 hours MetadataRequestFrequency = 30.minutes # Metadata request has 10 seconds timeout, and the loop sleeps for 5 seconds # 50 seconds = 3 attempts MetadataRequestMaxFailureTime = 50.seconds proc peerPingerHeartbeat(node: Eth2Node) {.async.} = while true: let heartbeatStart_m = Moment.now() var updateFutures: seq[Future[void]] for peer in node.peers.values: if peer.connectionState != Connected: continue if peer.metadata.isNone or heartbeatStart_m - peer.lastMetadataTime > MetadataRequestFrequency: updateFutures.add(node.updatePeerMetadata(peer.peerId)) discard await allFinished(updateFutures) for peer in node.peers.values: if peer.connectionState != Connected: continue let lastMetadata = if peer.metadata.isNone: peer.lastMetadataTime else: peer.lastMetadataTime + MetadataRequestFrequency if heartbeatStart_m - lastMetadata > MetadataRequestMaxFailureTime: debug "no metadata from peer, kicking it", peer asyncSpawn peer.disconnect(PeerScoreLow) await sleepAsync(5.seconds) func asLibp2pKey*(key: keys.PublicKey): PublicKey = PublicKey(scheme: Secp256k1, skkey: secp.SkPublicKey(key)) func asEthKey*(key: PrivateKey): keys.PrivateKey = keys.PrivateKey(key.skkey) proc initAddress*(T: type MultiAddress, str: string): T = let address = MultiAddress.init(str) if IPFS.match(address) and matchPartial(multiaddress.TCP, address): result = address else: raise newException(MultiAddressError, "Invalid bootstrap node multi-address") template tcpEndPoint(address, port): auto = MultiAddress.init(address, tcpProtocol, port) proc getPersistentNetKeys*(rng: var BrHmacDrbgContext, config: BeaconNodeConf): NetKeyPair = case config.cmd of noCommand, record: if config.netKeyFile == "random": let res = PrivateKey.random(Secp256k1, rng) if res.isErr(): fatal "Could not generate random network key file" quit QuitFailure let privKey = res.get() pubKey = privKey.getPublicKey().expect("working public key from random") pres = PeerID.init(pubKey) if pres.isErr(): fatal "Could not obtain PeerID from network key" quit QuitFailure info "Generating new networking key", network_public_key = pubKey, network_peer_id = $pres.get() NetKeyPair(seckey: privKey, pubkey: pubKey) else: let keyPath = if isAbsolute(config.netKeyFile): config.netKeyFile else: config.dataDir / config.netKeyFile if fileAccessible(keyPath, {AccessFlags.Find}): info "Network key storage is present, unlocking", key_path = keyPath # Insecure password used only for automated testing. let insecurePassword = if config.netKeyInsecurePassword: some(NetworkInsecureKeyPassword) else: none[string]() let res = loadNetKeystore(keyPath, insecurePassword) if res.isNone(): fatal "Could not load network key file" quit QuitFailure let privKey = res.get() pubKey = privKey.getPublicKey().expect("working public key from file") info "Network key storage was successfully unlocked", key_path = keyPath, network_public_key = pubKey NetKeyPair(seckey: privKey, pubkey: pubKey) else: info "Network key storage is missing, creating a new one", key_path = keyPath let rres = PrivateKey.random(Secp256k1, rng) if rres.isErr(): fatal "Could not generate random network key file" quit QuitFailure let privKey = rres.get() pubKey = privKey.getPublicKey().expect("working public key from random") # Insecure password used only for automated testing. let insecurePassword = if config.netKeyInsecurePassword: some(NetworkInsecureKeyPassword) else: none[string]() let sres = saveNetKeystore(rng, keyPath, privKey, insecurePassword) if sres.isErr(): fatal "Could not create network key file", key_path = keyPath quit QuitFailure info "New network key storage was created", key_path = keyPath, network_public_key = pubKey NetKeyPair(seckey: privKey, pubkey: pubKey) of createTestnet: if config.netKeyFile == "random": fatal "Could not create testnet using `random` network key" quit QuitFailure let keyPath = if isAbsolute(config.netKeyFile): config.netKeyFile else: config.dataDir / config.netKeyFile let rres = PrivateKey.random(Secp256k1, rng) if rres.isErr(): fatal "Could not generate random network key file" quit QuitFailure let privKey = rres.get() pubKey = privKey.getPublicKey().expect("working public key from random") # Insecure password used only for automated testing. let insecurePassword = if config.netKeyInsecurePassword: some(NetworkInsecureKeyPassword) else: none[string]() let sres = saveNetKeystore(rng, keyPath, privKey, insecurePassword) if sres.isErr(): fatal "Could not create network key file", key_path = keyPath quit QuitFailure info "New network key storage was created", key_path = keyPath, network_public_key = pubKey NetKeyPair(seckey: privKey, pubkey: pubKey) else: let res = PrivateKey.random(Secp256k1, rng) if res.isErr(): fatal "Could not generate random network key file" quit QuitFailure let privKey = res.get() pubKey = privKey.getPublicKey().expect("working public key from random") NetKeyPair(seckey: privKey, pubkey: pubKey) func gossipId( data: openArray[byte], altairPrefix, topic: string, valid: bool): seq[byte] = # https://github.com/ethereum/consensus-specs/blob/v1.0.1/specs/phase0/p2p-interface.md#topics-and-messages # https://github.com/ethereum/consensus-specs/blob/v1.1.4/specs/altair/p2p-interface.md#topics-and-messages const MESSAGE_DOMAIN_INVALID_SNAPPY = [0x00'u8, 0x00, 0x00, 0x00] MESSAGE_DOMAIN_VALID_SNAPPY = [0x01'u8, 0x00, 0x00, 0x00] let messageDigest = withEth2Hash: h.update( if valid: MESSAGE_DOMAIN_VALID_SNAPPY else: MESSAGE_DOMAIN_INVALID_SNAPPY) if topic.startsWith(altairPrefix): h.update topic.len.uint64.toBytesLE h.update topic h.update data messageDigest.data[0..19] proc newBeaconSwitch*(config: BeaconNodeConf, seckey: PrivateKey, address: MultiAddress, rng: ref BrHmacDrbgContext): Switch {.raises: [Defect, CatchableError].} = SwitchBuilder .new() .withPrivateKey(seckey) .withAddress(address) .withRng(rng) .withNoise() .withMplex(5.minutes, 5.minutes) .withMaxConnections(config.maxPeers) .withAgentVersion(config.agentString) .withTcpTransport({ServerFlags.ReuseAddr}) .build() proc createEth2Node*(rng: ref BrHmacDrbgContext, config: BeaconNodeConf, netKeys: NetKeyPair, cfg: RuntimeConfig, forkDigests: ref ForkDigests, getBeaconTime: GetBeaconTimeFn, genesisValidatorsRoot: Eth2Digest): Eth2Node {.raises: [Defect, CatchableError].} = let enrForkId = getENRForkID( cfg, getBeaconTime().slotOrZero.epoch, genesisValidatorsRoot) discoveryForkId = getDiscoveryForkID( cfg, getBeaconTime().slotOrZero.epoch, genesisValidatorsRoot) (extIp, extTcpPort, extUdpPort) = try: setupAddress( config.nat, config.listenAddress, config.tcpPort, config.udpPort, clientId) except CatchableError as exc: raise exc except Exception as exc: raiseAssert exc.msg hostAddress = tcpEndPoint(config.listenAddress, config.tcpPort) announcedAddresses = if extIp.isNone() or extTcpPort.isNone(): @[] else: @[tcpEndPoint(extIp.get(), extTcpPort.get())] debug "Initializing networking", hostAddress, network_public_key = netKeys.pubkey, announcedAddresses # TODO nim-libp2p still doesn't have support for announcing addresses # that are different from the host address (this is relevant when we # are running behind a NAT). var switch = newBeaconSwitch(config, netKeys.seckey, hostAddress, rng) let altairPrefix = "/eth2/" & $forkDigests.altair func msgIdProvider(m: messages.Message): seq[byte] = template topic: untyped = if m.topicIDs.len > 0: m.topicIDs[0] else: "" try: let decoded = snappy.decode(m.data, GOSSIP_MAX_SIZE) gossipId(decoded, altairPrefix, topic, true) except CatchableError: gossipId(m.data, altairPrefix, topic, false) let params = GossipSubParams( explicit: true, pruneBackoff: 1.minutes, floodPublish: true, gossipFactor: 0.05, d: 8, dLow: 6, dHigh: 12, dScore: 6, dOut: 6 div 2, # less than dlow and no more than dlow/2 dLazy: 6, heartbeatInterval: 700.milliseconds, historyLength: 6, historyGossip: 3, fanoutTTL: 60.seconds, seenTTL: 385.seconds, gossipThreshold: -4000, publishThreshold: -8000, graylistThreshold: -16000, # also disconnect threshold opportunisticGraftThreshold: 0, decayInterval: 12.seconds, decayToZero: 0.01, retainScore: 385.seconds, appSpecificWeight: 0.0, ipColocationFactorWeight: -53.75, ipColocationFactorThreshold: 3.0, behaviourPenaltyWeight: -15.9, behaviourPenaltyDecay: 0.986, disconnectBadPeers: true, directPeers: block: var res = initTable[PeerId, seq[MultiAddress]]() if config.directPeers.len > 0: for s in config.directPeers: let maddress = MultiAddress.init(s).tryGet() mpeerId = maddress[multiCodec("p2p")].tryGet() peerId = PeerID.init(mpeerId.protoAddress().tryGet()).tryGet() res.mgetOrPut(peerId, @[]).add(maddress) info "Adding priviledged direct peer", peerId, address = maddress res ) pubsub = GossipSub.init( switch = switch, msgIdProvider = msgIdProvider, triggerSelf = true, sign = false, verifySignature = false, anonymize = true, parameters = params) switch.mount(pubsub) let node = Eth2Node.new( config, cfg, enrForkId, discoveryForkId, forkDigests, getBeaconTime, switch, pubsub, extIp, extTcpPort, extUdpPort, netKeys.seckey.asEthKey, discovery = config.discv5Enabled, rng = rng) node.pubsub.subscriptionValidator = proc(topic: string): bool {.gcsafe, raises: [Defect].} = topic in node.validTopics node proc announcedENR*(node: Eth2Node): enr.Record = doAssert node.discovery != nil, "The Eth2Node must be initialized" node.discovery.localNode.record proc shortForm*(id: NetKeyPair): string = $PeerID.init(id.pubkey) proc subscribe*( node: Eth2Node, topic: string, topicParams: TopicParams, enableTopicMetrics: bool = false) = if enableTopicMetrics: node.pubsub.knownTopics.incl(topic) node.pubsub.topicParams[topic] = topicParams # Passing in `nil` because we do all message processing in the validator node.pubsub.subscribe(topic, nil) proc newValidationResultFuture(v: ValidationResult): Future[ValidationResult] = let res = newFuture[ValidationResult]("eth2_network.execValidator") res.complete(v) res proc addValidator*[MsgType](node: Eth2Node, topic: string, msgValidator: proc(msg: MsgType): ValidationResult {.gcsafe, raises: [Defect].} ) = # Message validators run when subscriptions are enabled - they validate the # data and return an indication of whether the message should be broadcast # or not - validation is `async` but implemented without the macro because # this is a performance hotspot. proc execValidator(topic: string, message: GossipMsg): Future[ValidationResult] {.raises: [Defect].} = inc nbc_gossip_messages_received trace "Validating incoming gossip message", len = message.data.len, topic var decompressed = snappy.decode(message.data, GOSSIP_MAX_SIZE) let res = if decompressed.len > 0: try: let decoded = SSZ.decode(decompressed, MsgType) decompressed = newSeq[byte](0) # release memory before validating msgValidator(decoded) # doesn't raise! except SszError as e: inc nbc_gossip_failed_ssz debug "Error decoding gossip", topic, len = message.data.len, decompressed = decompressed.len, error = e.msg ValidationResult.Reject else: # snappy returns empty seq on failed decompression inc nbc_gossip_failed_snappy debug "Error decompressing gossip", topic, len = message.data.len ValidationResult.Reject newValidationResultFuture(res) node.validTopics.incl topic # Only allow subscription to validated topics node.pubsub.addValidator(topic, execValidator) proc addAsyncValidator*[MsgType](node: Eth2Node, topic: string, msgValidator: proc(msg: MsgType): Future[ValidationResult] {.gcsafe, raises: [Defect].} ) = proc execValidator(topic: string, message: GossipMsg): Future[ValidationResult] {.raises: [Defect].} = inc nbc_gossip_messages_received trace "Validating incoming gossip message", len = message.data.len, topic var decompressed = snappy.decode(message.data, GOSSIP_MAX_SIZE) if decompressed.len > 0: try: let decoded = SSZ.decode(decompressed, MsgType) decompressed = newSeq[byte](0) # release memory before validating msgValidator(decoded) # doesn't raise! except SszError as e: inc nbc_gossip_failed_ssz debug "Error decoding gossip", topic, len = message.data.len, decompressed = decompressed.len, error = e.msg newValidationResultFuture(ValidationResult.Reject) else: # snappy returns empty seq on failed decompression inc nbc_gossip_failed_snappy debug "Error decompressing gossip", topic, len = message.data.len newValidationResultFuture(ValidationResult.Reject) node.validTopics.incl topic # Only allow subscription to validated topics node.pubsub.addValidator(topic, execValidator) proc unsubscribe*(node: Eth2Node, topic: string) = node.pubsub.unsubscribeAll(topic) proc traceMessage(fut: FutureBase, topic: string) = fut.addCallback do (arg: pointer): if not(fut.failed): trace "Outgoing pubsub message sent" elif fut.error != nil: debug "Gossip message not sent", topic, err = fut.error.msg else: debug "Unexpected future state for gossip", topic, state = fut.state proc broadcast*(node: Eth2Node, topic: string, msg: auto) = try: let uncompressed = SSZ.encode(msg) compressed = try: snappy.encode(uncompressed) except InputTooLarge: raiseAssert "More than 4gb? not likely.." # This is only for messages we create. A message this large amounts to an # internal logic error. doAssert uncompressed.len <= GOSSIP_MAX_SIZE inc nbc_gossip_messages_sent var futSnappy = node.pubsub.publish(topic, compressed) traceMessage(futSnappy, topic) except IOError as exc: raiseAssert exc.msg # TODO in-memory compression shouldn't fail proc subscribeAttestationSubnets*( node: Eth2Node, subnets: AttnetBits, forkDigest: ForkDigest) = # https://github.com/ethereum/consensus-specs/blob/v1.0.1/specs/phase0/p2p-interface.md#attestations-and-aggregation # Nimbus won't score attestation subnets for now, we just rely on block and # aggregate which are more stable and reliable for subnet_id, enabled in subnets: if enabled: node.subscribe(getAttestationTopic( forkDigest, SubnetId(subnet_id)), TopicParams.init()) # don't score attestation subnets for now proc unsubscribeAttestationSubnets*( node: Eth2Node, subnets: AttnetBits, forkDigest: ForkDigest) = # https://github.com/ethereum/consensus-specs/blob/v1.1.4/specs/phase0/p2p-interface.md#attestations-and-aggregation # Nimbus won't score attestation subnets for now; we just rely on block and # aggregate which are more stable and reliable for subnet_id, enabled in subnets: if enabled: node.unsubscribe(getAttestationTopic(forkDigest, SubnetId(subnet_id))) proc updateStabilitySubnetMetadata*(node: Eth2Node, attnets: AttnetBits) = # https://github.com/ethereum/consensus-specs/blob/v1.1.4/specs/phase0/p2p-interface.md#metadata if node.metadata.attnets == attnets: return node.metadata.seq_number += 1 node.metadata.attnets = attnets # https://github.com/ethereum/consensus-specs/blob/v1.0.1/specs/phase0/validator.md#phase-0-attestation-subnet-stability # https://github.com/ethereum/consensus-specs/blob/v1.1.4/specs/phase0/p2p-interface.md#attestation-subnet-bitfield let res = node.discovery.updateRecord({ enrAttestationSubnetsField: SSZ.encode(node.metadata.attnets) }) if res.isErr(): # This should not occur in this scenario as the private key would always # be the correct one and the ENR will not increase in size. warn "Failed to update the ENR attnets field", error = res.error else: debug "Stability subnets changed; updated ENR attnets", attnets proc updateSyncnetsMetadata*(node: Eth2Node, syncnets: SyncnetBits) = # https://github.com/ethereum/consensus-specs/blob/v1.1.0-beta.4/specs/altair/validator.md#sync-committee-subnet-stability if node.metadata.syncnets == syncnets: return node.metadata.seq_number += 1 node.metadata.syncnets = syncnets let res = node.discovery.updateRecord({ enrSyncSubnetsField: SSZ.encode(node.metadata.syncnets) }) if res.isErr(): # This should not occur in this scenario as the private key would always # be the correct one and the ENR will not increase in size. warn "Failed to update the ENR syncnets field", error = res.error else: debug "Sync committees changed; updated ENR syncnets", syncnets proc updateForkId(node: Eth2Node, value: ENRForkID) = node.forkId = value let res = node.discovery.updateRecord({enrForkIdField: SSZ.encode value}) if res.isErr(): # This should not occur in this scenario as the private key would always # be the correct one and the ENR will not increase in size. warn "Failed to update the ENR fork id", value, error = res.error else: debug "ENR fork id changed", value proc updateForkId*(node: Eth2Node, epoch: Epoch, genesisValidatorsRoot: Eth2Digest) = node.updateForkId(getENRForkId(node.cfg, epoch, genesisValidatorsRoot)) node.discoveryForkId = getDiscoveryForkID(node.cfg, epoch, genesisValidatorsRoot) func forkDigestAtEpoch(node: Eth2Node, epoch: Epoch): ForkDigest = case node.cfg.stateForkAtEpoch(epoch) of BeaconStateFork.Merge: node.forkDigests.merge of BeaconStateFork.Altair: node.forkDigests.altair of BeaconStateFork.Phase0: node.forkDigests.phase0 proc getWallEpoch(node: Eth2Node): Epoch = node.getBeaconTime().slotOrZero.epoch proc broadcastAttestation*(node: Eth2Node, subnet_id: SubnetId, attestation: Attestation) = # Regardless of the contents of the attestation, # https://github.com/ethereum/consensus-specs/blob/v1.1.0-beta.4/specs/altair/p2p-interface.md#transitioning-the-gossip # implies that pre-fork, messages using post-fork digests might be # ignored, whilst post-fork, there is effectively a seen_ttl-based # timer unsubscription point that means no new pre-fork-forkdigest # should be sent. let forkPrefix = node.forkDigestAtEpoch(node.getWallEpoch) let topic = getAttestationTopic(forkPrefix, subnet_id) node.broadcast(topic, attestation) proc broadcastVoluntaryExit*(node: Eth2Node, exit: SignedVoluntaryExit) = let topic = getVoluntaryExitsTopic( node.forkDigestAtEpoch(node.getWallEpoch)) node.broadcast(topic, exit) proc broadcastAttesterSlashing*(node: Eth2Node, slashing: AttesterSlashing) = let topic = getAttesterSlashingsTopic( node.forkDigestAtEpoch(node.getWallEpoch)) node.broadcast(topic, slashing) proc broadcastProposerSlashing*(node: Eth2Node, slashing: ProposerSlashing) = let topic = getProposerSlashingsTopic( node.forkDigestAtEpoch(node.getWallEpoch)) node.broadcast(topic, slashing) proc broadcastAggregateAndProof*(node: Eth2Node, proof: SignedAggregateAndProof) = let topic = getAggregateAndProofsTopic( node.forkDigestAtEpoch(node.getWallEpoch)) node.broadcast(topic, proof) proc broadcastBeaconBlock*(node: Eth2Node, blck: phase0.SignedBeaconBlock) = let topic = getBeaconBlocksTopic(node.forkDigests.phase0) node.broadcast(topic, blck) proc broadcastBeaconBlock*(node: Eth2Node, blck: altair.SignedBeaconBlock) = let topic = getBeaconBlocksTopic(node.forkDigests.altair) node.broadcast(topic, blck) proc broadcastBeaconBlock*(node: Eth2Node, blck: merge.SignedBeaconBlock) = let topic = getBeaconBlocksTopic(node.forkDigests.merge) node.broadcast(topic, blck) proc broadcastBeaconBlock*(node: Eth2Node, forked: ForkedSignedBeaconBlock) = withBlck(forked): node.broadcastBeaconBlock(blck) proc broadcastSyncCommitteeMessage*( node: Eth2Node, msg: SyncCommitteeMessage, committeeIdx: SyncSubcommitteeIndex) = let topic = getSyncCommitteeTopic(node.forkDigests.altair, committeeIdx) node.broadcast(topic, msg) proc broadcastSignedContributionAndProof*( node: Eth2Node, msg: SignedContributionAndProof) = let topic = getSyncCommitteeContributionAndProofTopic(node.forkDigests.altair) node.broadcast(topic, msg)