mirror of https://github.com/status-im/nim-eth.git
Simplify UseDiscv51 compile flag (#305)
This commit is contained in:
Kim De Mey
GitHub
parent
345dac702b
commit
6bdf1b4b0f
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@ -2,16 +2,7 @@ import
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std/[options, strutils],
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chronos, chronicles, chronicles/topics_registry, confutils, metrics,
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stew/byteutils, confutils/std/net,
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eth/keys, eth/net/nat, enr, node
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### This is all just temporary to be compatible with both versions
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const UseDiscv51* {.booldefine.} = false
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when UseDiscv51:
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import protocolv1
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else:
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import protocol
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###
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eth/keys, eth/net/nat, enr, node, protocol
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type
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DiscoveryCmd* = enum
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@ -175,6 +166,7 @@ proc run(config: DiscoveryConf) =
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else:
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echo "No Pong message returned"
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of findnode:
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# Discv5.1 and Discv5.0 have a different findnode API
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when UseDiscv51:
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let nodes = waitFor d.findNode(config.findNodeTarget, @[config.distance])
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else:
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@ -1,835 +1,9 @@
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# nim-eth - Node Discovery Protocol v5
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# Copyright (c) 2020 Status Research & Development GmbH
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# Licensed under either of
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# * Apache License, version 2.0, (LICENSE-APACHEv2)
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# * MIT license (LICENSE-MIT)
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# at your option. This file may not be copied, modified, or distributed except
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# according to those terms.
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## Node Discovery Protocol v5
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##
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## Node discovery protocol implementation as per specification:
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## https://github.com/ethereum/devp2p/blob/master/discv5/discv5.md
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##
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## This node discovery protocol implementation uses the same underlying
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## implementation of routing table as is also used for the discovery v4
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## implementation, which is the same or similar as the one described in the
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## original Kademlia paper:
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## https://pdos.csail.mit.edu/~petar/papers/maymounkov-kademlia-lncs.pdf
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##
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## This might not be the most optimal implementation for the node discovery
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## protocol v5. Why?
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##
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## The Kademlia paper describes an implementation that starts off from one
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## k-bucket, and keeps splitting the bucket as more nodes are discovered and
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## added. The bucket splits only on the part of the binary tree where our own
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## node its id belongs too (same prefix). Resulting eventually in a k-bucket per
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## logarithmic distance (log base2 distance). Well, not really, as nodes with
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## ids in the closer distance ranges will never be found. And because of this an
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## optimisation is done where buckets will also split sometimes even if the
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## nodes own id does not have the same prefix (this is to avoid creating highly
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## unbalanced branches which would require longer lookups).
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##
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## Now, some implementations take a more simplified approach. They just create
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## directly a bucket for each possible logarithmic distance (e.g. here 1->256).
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## Some implementations also don't create buckets with logarithmic distance
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## lower than a certain value (e.g. only 1/15th of the highest buckets),
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## because the closer to the node (the lower the distance), the less chance
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## there is to still find nodes.
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##
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## The discovery protocol v4 its `FindNode` call will request the k closest
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## nodes. As does original Kademlia. This effectively puts the work at the node
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## that gets the request. This node will have to check its buckets and gather
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## the closest. Some implementations go over all the nodes in all the buckets
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## for this (e.g. go-ethereum discovery v4). However, in our bucket splitting
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## approach, this search is improved.
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##
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## In the discovery protocol v5 the `FindNode` call is changed and now the
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## logarithmic distance is passed as parameter instead of the NodeId. And only
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## nodes that match that logarithmic distance are allowed to be returned.
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## This change was made to not put the trust at the requested node for selecting
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## the closest nodes. To counter a possible (mistaken) difference in
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## implementation, but more importantly for security reasons. See also:
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## https://github.com/ethereum/devp2p/blob/master/discv5/discv5-rationale.md#115-guard-against-kademlia-implementation-flaws
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##
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## The result is that in an implementation which just stores buckets per
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## logarithmic distance, it simply needs to return the right bucket. In our
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## split-bucket implementation, this cannot be done as such and thus the closest
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## neighbours search is still done. And to do this, a reverse calculation of an
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## id at given logarithmic distance is needed (which is why there is the
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## `idAtDistance` proc). Next, nodes with invalid distances need to be filtered
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## out to be compliant to the specification. This can most likely get further
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## optimised, but it sounds likely better to switch away from the split-bucket
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## approach. I believe that the main benefit it has is improved lookups
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## (due to no unbalanced branches), and it looks like this will be negated by
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## limiting the returned nodes to only the ones of the requested logarithmic
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## distance for the `FindNode` call.
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## This `FindNode` change in discovery v5 will also have an effect on the
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## efficiency of the network. Work will be moved from the receiver of
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## `FindNodes` to the requester. But this also means more network traffic,
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## as less nodes will potentially be passed around per `FindNode` call, and thus
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## more requests will be needed for a lookup (adding bandwidth and latency).
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## This might be a concern for mobile devices.
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import
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std/[tables, sets, options, math, sequtils],
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stew/shims/net as stewNet, json_serialization/std/net,
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stew/[byteutils, endians2], chronicles, chronos, stint, bearssl,
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eth/[rlp, keys, async_utils],
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types, encoding, node, routing_table, enr, random2, sessions
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import nimcrypto except toHex
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export options
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{.push raises: [Defect].}
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logScope:
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topics = "discv5"
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const
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alpha = 3 ## Kademlia concurrency factor
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lookupRequestLimit = 3
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findNodeResultLimit = 15 # applies in FINDNODE handler
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maxNodesPerMessage = 3
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lookupInterval = 60.seconds ## Interval of launching a random lookup to
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## populate the routing table. go-ethereum seems to do 3 runs every 30
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## minutes. Trinity starts one every minute.
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revalidateMax = 1000 ## Revalidation of a peer is done between 0 and this
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## value in milliseconds
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handshakeTimeout* = 2.seconds ## timeout for the reply on the
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## whoareyou message
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responseTimeout* = 4.seconds ## timeout for the response of a request-response
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## call
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magicSize = 32 ## size of the magic which is the start of the whoareyou
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## message
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type
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Protocol* = ref object
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transp: DatagramTransport
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localNode*: Node
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privateKey: PrivateKey
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bindAddress: Address ## UDP binding address
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whoareyouMagic: array[magicSize, byte]
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idHash: array[32, byte]
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pendingRequests: Table[AuthTag, PendingRequest]
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routingTable: RoutingTable
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codec*: Codec
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awaitedMessages: Table[(NodeId, RequestId), Future[Option[Message]]]
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lookupLoop: Future[void]
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revalidateLoop: Future[void]
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bootstrapRecords*: seq[Record]
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rng*: ref BrHmacDrbgContext
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PendingRequest = object
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node: Node
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message: seq[byte]
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DiscResult*[T] = Result[T, cstring]
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proc addNode*(d: Protocol, node: Node): bool =
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## Add `Node` to discovery routing table.
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##
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## Returns false only if `Node` is not eligable for adding (no Address).
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if node.address.isSome():
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# Only add nodes with an address to the routing table
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discard d.routingTable.addNode(node)
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return true
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proc addNode*(d: Protocol, r: Record): bool =
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## Add `Node` from a `Record` to discovery routing table.
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##
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## Returns false only if no valid `Node` can be created from the `Record` or
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## on the conditions of `addNode` from a `Node`.
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let node = newNode(r)
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if node.isOk():
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return d.addNode(node[])
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proc addNode*(d: Protocol, enr: EnrUri): bool =
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## Add `Node` from a ENR URI to discovery routing table.
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##
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## Returns false if no valid ENR URI, or on the conditions of `addNode` from
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## an `Record`.
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var r: Record
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let res = r.fromUri(enr)
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if res:
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return d.addNode(r)
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proc getNode*(d: Protocol, id: NodeId): Option[Node] =
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## Get the node with id from the routing table.
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d.routingTable.getNode(id)
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proc randomNodes*(d: Protocol, maxAmount: int): seq[Node] =
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## Get a `maxAmount` of random nodes from the local routing table.
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d.routingTable.randomNodes(maxAmount)
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proc randomNodes*(d: Protocol, maxAmount: int,
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pred: proc(x: Node): bool {.gcsafe, noSideEffect.}): seq[Node] =
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## Get a `maxAmount` of random nodes from the local routing table with the
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## `pred` predicate function applied as filter on the nodes selected.
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d.routingTable.randomNodes(maxAmount, pred)
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proc randomNodes*(d: Protocol, maxAmount: int,
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enrField: (string, seq[byte])): seq[Node] =
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## Get a `maxAmount` of random nodes from the local routing table. The
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## the nodes selected are filtered by provided `enrField`.
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d.randomNodes(maxAmount, proc(x: Node): bool = x.record.contains(enrField))
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proc neighbours*(d: Protocol, id: NodeId, k: int = BUCKET_SIZE): seq[Node] =
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## Return up to k neighbours (closest node ids) of the given node id.
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d.routingTable.neighbours(id, k)
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proc nodesDiscovered*(d: Protocol): int {.inline.} = d.routingTable.len
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func privKey*(d: Protocol): lent PrivateKey =
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d.privateKey
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func getRecord*(d: Protocol): Record =
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## Get the ENR of the local node.
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d.localNode.record
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proc updateRecord*(
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d: Protocol, enrFields: openarray[(string, seq[byte])]): DiscResult[void] =
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## Update the ENR of the local node with provided `enrFields` k:v pairs.
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let fields = mapIt(enrFields, toFieldPair(it[0], it[1]))
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d.localNode.record.update(d.privateKey, fields)
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# TODO: Would it make sense to actively ping ("broadcast") to all the peers
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# we stored a handshake with in order to get that ENR updated?
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proc send(d: Protocol, a: Address, data: seq[byte]) =
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let ta = initTAddress(a.ip, a.port)
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try:
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let f = d.transp.sendTo(ta, data)
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f.callback = proc(data: pointer) {.gcsafe.} =
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if f.failed:
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# Could be `TransportUseClosedError` in case the transport is already
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# closed, or could be `TransportOsError` in case of a socket error.
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# In the latter case this would probably mostly occur if the network
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# interface underneath gets disconnected or similar.
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# TODO: Should this kind of error be propagated upwards? Probably, but
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# it should not stop the process as that would reset the discovery
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# progress in case there is even a small window of no connection.
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# One case that needs this error available upwards is when revalidating
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# nodes. Else the revalidation might end up clearing the routing tabl
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# because of ping failures due to own network connection failure.
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debug "Discovery send failed", msg = f.readError.msg
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except Exception as e:
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# TODO: General exception still being raised from Chronos, but in practice
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# all CatchableErrors should be grabbed by the above `f.failed`.
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if e of Defect:
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raise (ref Defect)(e)
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else: doAssert(false)
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proc send(d: Protocol, n: Node, data: seq[byte]) =
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doAssert(n.address.isSome())
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d.send(n.address.get(), data)
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proc `xor`[N: static[int], T](a, b: array[N, T]): array[N, T] =
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for i in 0 .. a.high:
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result[i] = a[i] xor b[i]
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proc whoareyouMagic*(toNode: NodeId): array[magicSize, byte] =
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const prefix = "WHOAREYOU"
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var data: array[prefix.len + sizeof(toNode), byte]
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data[0 .. sizeof(toNode) - 1] = toNode.toByteArrayBE()
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for i, c in prefix: data[sizeof(toNode) + i] = byte(c)
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sha256.digest(data).data
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proc isWhoAreYou(d: Protocol, packet: openArray[byte]): bool =
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if packet.len > d.whoareyouMagic.len:
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result = d.whoareyouMagic == packet.toOpenArray(0, magicSize - 1)
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proc decodeWhoAreYou(d: Protocol, packet: openArray[byte]):
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Whoareyou {.raises: [RlpError].} =
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result = Whoareyou()
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result[] = rlp.decode(packet.toOpenArray(magicSize, packet.high), WhoareyouObj)
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proc sendWhoareyou(d: Protocol, address: Address, toNode: NodeId,
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authTag: AuthTag): DiscResult[void] {.raises: [Exception, Defect].} =
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trace "sending who are you", to = $toNode, toAddress = $address
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let n = d.getNode(toNode)
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let challenge = if n.isSome():
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Whoareyou(authTag: authTag, recordSeq: n.get().record.seqNum,
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pubKey: some(n.get().pubkey))
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else:
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Whoareyou(authTag: authTag, recordSeq: 0)
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brHmacDrbgGenerate(d.rng[], challenge.idNonce)
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# If there is already a handshake going on for this nodeid then we drop this
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# new one. Handshake will get cleaned up after `handshakeTimeout`.
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# If instead overwriting the handshake would be allowed, the handshake timeout
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# will need to be canceled each time.
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# TODO: could also clean up handshakes in a seperate call, e.g. triggered in
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# a loop.
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# Use toNode + address to make it more difficult for an attacker to occupy
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# the handshake of another node.
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let key = HandShakeKey(nodeId: toNode, address: $address)
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if not d.codec.handshakes.hasKeyOrPut(key, challenge):
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# TODO: raises: [Exception], but it shouldn't.
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sleepAsync(handshakeTimeout).addCallback() do(data: pointer):
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# TODO: should we still provide cancellation in case handshake completes
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# correctly?
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d.codec.handshakes.del(key)
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var data = @(whoareyouMagic(toNode))
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data.add(rlp.encode(challenge[]))
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d.send(address, data)
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ok()
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else:
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err("NodeId already has ongoing handshake")
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proc sendNodes(d: Protocol, toId: NodeId, toAddr: Address, reqId: RequestId,
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nodes: openarray[Node]) =
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proc sendNodes(d: Protocol, toId: NodeId, toAddr: Address,
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message: NodesMessage, reqId: RequestId) {.nimcall.} =
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let (data, _) = encodePacket(
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d.rng[], d.codec, toId, toAddr,
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encodeMessage(message, reqId), challenge = nil)
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d.send(toAddr, data)
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if nodes.len == 0:
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# In case of 0 nodes, a reply is still needed
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d.sendNodes(toId, toAddr, NodesMessage(total: 1, enrs: @[]), reqId)
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return
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var message: NodesMessage
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# TODO: Do the total calculation based on the max UDP packet size we want to
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# send and the ENR size of all (max 16) nodes.
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# Which UDP packet size to take? 1280? 576?
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message.total = ceil(nodes.len / maxNodesPerMessage).uint32
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for i in 0 ..< nodes.len:
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message.enrs.add(nodes[i].record)
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if message.enrs.len == maxNodesPerMessage:
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d.sendNodes(toId, toAddr, message, reqId)
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message.enrs.setLen(0)
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if message.enrs.len != 0:
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d.sendNodes(toId, toAddr, message, reqId)
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proc handlePing(d: Protocol, fromId: NodeId, fromAddr: Address,
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ping: PingMessage, reqId: RequestId) =
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let a = fromAddr
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var pong: PongMessage
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pong.enrSeq = d.localNode.record.seqNum
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pong.ip = case a.ip.family
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of IpAddressFamily.IPv4: @(a.ip.address_v4)
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of IpAddressFamily.IPv6: @(a.ip.address_v6)
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pong.port = a.port.uint16
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let (data, _) = encodePacket(d.rng[], d.codec, fromId, fromAddr,
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encodeMessage(pong, reqId), challenge = nil)
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d.send(fromAddr, data)
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proc handleFindNode(d: Protocol, fromId: NodeId, fromAddr: Address,
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fn: FindNodeMessage, reqId: RequestId) =
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if fn.distance == 0:
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d.sendNodes(fromId, fromAddr, reqId, [d.localNode])
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else:
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if fn.distance <= 256:
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d.sendNodes(fromId, fromAddr, reqId,
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d.routingTable.neighboursAtDistance(fn.distance, seenOnly = true))
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else:
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# The polite node we are, still respond with empty nodes.
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d.sendNodes(fromId, fromAddr, reqId, [])
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proc receive*(d: Protocol, a: Address, packet: openArray[byte]) {.gcsafe,
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raises: [
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Defect,
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# This just comes now from a future.complete() and `sendWhoareyou` which
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# has it because of `sleepAsync` with `addCallback`, but practically, no
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# CatchableError should be raised here, we just can't enforce it for now.
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Exception
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].} =
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if packet.len < tagSize: # or magicSize, can be either
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return # Invalid packet
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# debug "Packet received: ", length = packet.len
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if d.isWhoAreYou(packet):
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trace "Received whoareyou", localNode = $d.localNode, address = a
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var whoareyou: WhoAreYou
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try:
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whoareyou = d.decodeWhoAreYou(packet)
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except RlpError:
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debug "Invalid WhoAreYou packet, decoding failed"
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return
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var pr: PendingRequest
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if d.pendingRequests.take(whoareyou.authTag, pr):
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let toNode = pr.node
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whoareyou.pubKey = some(toNode.pubkey) # TODO: Yeah, rather ugly this.
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doAssert(toNode.address.isSome())
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let (data, _) = encodePacket(d.rng[], d.codec, toNode.id, toNode.address.get(),
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pr.message, challenge = whoareyou)
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d.send(toNode, data)
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else:
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debug "Timed out or unrequested WhoAreYou packet"
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else:
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var tag: array[tagSize, byte]
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tag[0 .. ^1] = packet.toOpenArray(0, tagSize - 1)
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let senderData = tag xor d.idHash
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let sender = readUintBE[256](senderData)
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|
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var authTag: AuthTag
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var node: Node
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let decoded = d.codec.decodePacket(sender, a, packet, authTag, node)
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if decoded.isOk:
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let message = decoded[]
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if not node.isNil:
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# Not filling table with nodes without correct IP in the ENR
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# TODO: Should we care about this???
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if node.address.isSome() and a == node.address.get():
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debug "Adding new node to routing table", node = $node,
|
||||
localNode = $d.localNode
|
||||
discard d.addNode(node)
|
||||
|
||||
case message.kind
|
||||
of ping:
|
||||
d.handlePing(sender, a, message.ping, message.reqId)
|
||||
of findNode:
|
||||
d.handleFindNode(sender, a, message.findNode, message.reqId)
|
||||
else:
|
||||
var waiter: Future[Option[Message]]
|
||||
if d.awaitedMessages.take((sender, message.reqId), waiter):
|
||||
waiter.complete(some(message)) # TODO: raises: [Exception]
|
||||
else:
|
||||
trace "Timed out or unrequested message", message = message.kind,
|
||||
origin = a
|
||||
elif decoded.error == DecodeError.DecryptError:
|
||||
trace "Could not decrypt packet, respond with whoareyou",
|
||||
localNode = $d.localNode, address = a
|
||||
# only sendingWhoareyou in case it is a decryption failure
|
||||
let res = d.sendWhoareyou(a, sender, authTag)
|
||||
if res.isErr():
|
||||
trace "Sending WhoAreYou packet failed", err = res.error
|
||||
elif decoded.error == DecodeError.UnsupportedMessage:
|
||||
# Still adding the node in case failure is because of unsupported message.
|
||||
if not node.isNil:
|
||||
# Not filling table with nodes without correct IP in the ENR
|
||||
# TODO: Should we care about this???s
|
||||
if node.address.isSome() and a == node.address.get():
|
||||
debug "Adding new node to routing table", node = $node,
|
||||
localNode = $d.localNode
|
||||
discard d.addNode(node)
|
||||
# elif decoded.error == DecodeError.PacketError:
|
||||
# Not adding this node as from our perspective it is sending rubbish.
|
||||
|
||||
# TODO: Not sure why but need to pop the raises here as it is apparently not
|
||||
# enough to put it in the raises pragma of `processClient` and other async procs.
|
||||
{.pop.}
|
||||
# Next, below there is no more effort done in catching the general `Exception`
|
||||
# as async procs always require `Exception` in the raises pragma, see also:
|
||||
# https://github.com/status-im/nim-chronos/issues/98
|
||||
# So I don't bother for now and just add them in the raises pragma until this
|
||||
# gets fixed. It does not mean that we expect these calls to be raising
|
||||
# CatchableErrors, in fact, we really don't, but hey, they might, considering we
|
||||
# can't enforce it.
|
||||
proc processClient(transp: DatagramTransport, raddr: TransportAddress):
|
||||
Future[void] {.async, gcsafe, raises: [Exception, Defect].} =
|
||||
let proto = getUserData[Protocol](transp)
|
||||
|
||||
# TODO: should we use `peekMessage()` to avoid allocation?
|
||||
# TODO: This can still raise general `Exception` while it probably should
|
||||
# only give TransportOsError.
|
||||
let buf = try: transp.getMessage()
|
||||
except TransportOsError as e:
|
||||
# This is likely to be local network connection issues.
|
||||
error "Transport getMessage", exception = e.name, msg = e.msg
|
||||
return
|
||||
except Exception as e:
|
||||
if e of Defect:
|
||||
raise (ref Defect)(e)
|
||||
else: doAssert(false)
|
||||
return # Make compiler happy
|
||||
|
||||
let ip = try: raddr.address()
|
||||
except ValueError as e:
|
||||
error "Not a valid IpAddress", exception = e.name, msg = e.msg
|
||||
return
|
||||
let a = Address(ip: ValidIpAddress.init(ip), port: raddr.port)
|
||||
|
||||
try:
|
||||
proto.receive(a, buf)
|
||||
except Exception as e:
|
||||
if e of Defect:
|
||||
raise (ref Defect)(e)
|
||||
else: doAssert(false)
|
||||
|
||||
proc validIp(sender, address: IpAddress): bool {.raises: [Defect].} =
|
||||
let
|
||||
s = initTAddress(sender, Port(0))
|
||||
a = initTAddress(address, Port(0))
|
||||
if a.isAnyLocal():
|
||||
return false
|
||||
if a.isMulticast():
|
||||
return false
|
||||
if a.isLoopback() and not s.isLoopback():
|
||||
return false
|
||||
if a.isSiteLocal() and not s.isSiteLocal():
|
||||
return false
|
||||
# TODO: Also check for special reserved ip addresses:
|
||||
# https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml
|
||||
# https://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml
|
||||
return true
|
||||
|
||||
proc replaceNode(d: Protocol, n: Node) =
|
||||
if n.record notin d.bootstrapRecords:
|
||||
d.routingTable.replaceNode(n)
|
||||
else:
|
||||
# For now we never remove bootstrap nodes. It might make sense to actually
|
||||
# do so and to retry them only in case we drop to a really low amount of
|
||||
# peers in the routing table.
|
||||
debug "Message request to bootstrap node failed", enr = toURI(n.record)
|
||||
|
||||
# TODO: This could be improved to do the clean-up immediatily in case a non
|
||||
# whoareyou response does arrive, but we would need to store the AuthTag
|
||||
# somewhere
|
||||
proc registerRequest(d: Protocol, n: Node, message: seq[byte], nonce: AuthTag)
|
||||
{.raises: [Exception, Defect].} =
|
||||
let request = PendingRequest(node: n, message: message)
|
||||
if not d.pendingRequests.hasKeyOrPut(nonce, request):
|
||||
# TODO: raises: [Exception]
|
||||
sleepAsync(responseTimeout).addCallback() do(data: pointer):
|
||||
d.pendingRequests.del(nonce)
|
||||
|
||||
proc waitMessage(d: Protocol, fromNode: Node, reqId: RequestId):
|
||||
Future[Option[Message]] {.raises: [Exception, Defect].} =
|
||||
result = newFuture[Option[Message]]("waitMessage")
|
||||
let res = result
|
||||
let key = (fromNode.id, reqId)
|
||||
# TODO: raises: [Exception]
|
||||
sleepAsync(responseTimeout).addCallback() do(data: pointer):
|
||||
d.awaitedMessages.del(key)
|
||||
if not res.finished:
|
||||
res.complete(none(Message)) # TODO: raises: [Exception]
|
||||
d.awaitedMessages[key] = result
|
||||
|
||||
proc verifyNodesRecords*(enrs: openarray[Record], fromNode: Node,
|
||||
distance: uint32): seq[Node] {.raises: [Defect].} =
|
||||
## Verify and convert ENRs to a sequence of nodes. Only ENRs that pass
|
||||
## verification will be added. ENRs are verified for duplicates, invalid
|
||||
## addresses and invalid distances.
|
||||
# TODO:
|
||||
# - Should we fail and ignore values on first invalid Node?
|
||||
# - Should we limit the amount of nodes? The discovery v5 specification holds
|
||||
# no limit on the amount that can be returned.
|
||||
var seen: HashSet[Node]
|
||||
for r in enrs:
|
||||
let node = newNode(r)
|
||||
if node.isOk():
|
||||
let n = node.get()
|
||||
# Check for duplicates in the nodes reply. Duplicates are checked based
|
||||
# on node id.
|
||||
if n in seen:
|
||||
trace "Nodes reply contained records with duplicate node ids",
|
||||
record = n.record.toURI, sender = fromNode.record.toURI, id = n.id
|
||||
continue
|
||||
# Check if the node has an address and if the address is public or from
|
||||
# the same local network or lo network as the sender. The latter allows
|
||||
# for local testing.
|
||||
if not n.address.isSome() or not
|
||||
validIp(fromNode.address.get().ip, n.address.get().ip):
|
||||
trace "Nodes reply contained record with invalid ip-address",
|
||||
record = n.record.toURI, sender = fromNode.record.toURI, node = $n
|
||||
continue
|
||||
# Check if returned node has exactly the requested distance.
|
||||
if logDist(n.id, fromNode.id) != distance:
|
||||
warn "Nodes reply contained record with incorrect distance",
|
||||
record = n.record.toURI, sender = fromNode.record.toURI
|
||||
continue
|
||||
# No check on UDP port and thus any port is allowed, also the so called
|
||||
# "well-known" ports.
|
||||
|
||||
seen.incl(n)
|
||||
result.add(n)
|
||||
|
||||
proc waitNodes(d: Protocol, fromNode: Node, reqId: RequestId):
|
||||
Future[DiscResult[seq[Record]]] {.async, raises: [Exception, Defect].} =
|
||||
## Wait for one or more nodes replies.
|
||||
##
|
||||
## The first reply will hold the total number of replies expected, and based
|
||||
## on that, more replies will be awaited.
|
||||
## If one reply is lost here (timed out), others are ignored too.
|
||||
## Same counts for out of order receival.
|
||||
var op = await d.waitMessage(fromNode, reqId)
|
||||
if op.isSome and op.get.kind == nodes:
|
||||
var res = op.get.nodes.enrs
|
||||
let total = op.get.nodes.total
|
||||
for i in 1 ..< total:
|
||||
op = await d.waitMessage(fromNode, reqId)
|
||||
if op.isSome and op.get.kind == nodes:
|
||||
res.add(op.get.nodes.enrs)
|
||||
else:
|
||||
# No error on this as we received some nodes.
|
||||
break
|
||||
return ok(res)
|
||||
else:
|
||||
return err("Nodes message not received in time")
|
||||
|
||||
proc sendMessage*[T: SomeMessage](d: Protocol, toNode: Node, m: T):
|
||||
RequestId {.raises: [Exception, Defect].} =
|
||||
doAssert(toNode.address.isSome())
|
||||
let
|
||||
reqId = RequestId.init(d.rng[])
|
||||
message = encodeMessage(m, reqId)
|
||||
(data, nonce) = encodePacket(d.rng[], d.codec, toNode.id, toNode.address.get(),
|
||||
message, challenge = nil)
|
||||
d.registerRequest(toNode, message, nonce)
|
||||
d.send(toNode, data)
|
||||
return reqId
|
||||
|
||||
proc ping*(d: Protocol, toNode: Node):
|
||||
Future[DiscResult[PongMessage]] {.async, raises: [Exception, Defect].} =
|
||||
## Send a discovery ping message.
|
||||
##
|
||||
## Returns the received pong message or an error.
|
||||
let reqId = d.sendMessage(toNode,
|
||||
PingMessage(enrSeq: d.localNode.record.seqNum))
|
||||
let resp = await d.waitMessage(toNode, reqId)
|
||||
|
||||
if resp.isSome() and resp.get().kind == pong:
|
||||
d.routingTable.setJustSeen(toNode)
|
||||
return ok(resp.get().pong)
|
||||
else:
|
||||
d.replaceNode(toNode)
|
||||
return err("Pong message not received in time")
|
||||
|
||||
proc findNode*(d: Protocol, toNode: Node, distance: uint32):
|
||||
Future[DiscResult[seq[Node]]] {.async, raises: [Exception, Defect].} =
|
||||
## Send a discovery findNode message.
|
||||
##
|
||||
## Returns the received nodes or an error.
|
||||
## Received ENRs are already validated and converted to `Node`.
|
||||
let reqId = d.sendMessage(toNode, FindNodeMessage(distance: distance))
|
||||
let nodes = await d.waitNodes(toNode, reqId)
|
||||
|
||||
if nodes.isOk:
|
||||
let res = verifyNodesRecords(nodes.get(), toNode, distance)
|
||||
d.routingTable.setJustSeen(toNode)
|
||||
return ok(res)
|
||||
else:
|
||||
d.replaceNode(toNode)
|
||||
return err(nodes.error)
|
||||
|
||||
proc lookupDistances(target, dest: NodeId): seq[uint32] {.raises: [Defect].} =
|
||||
let td = logDist(target, dest)
|
||||
result.add(td)
|
||||
var i = 1'u32
|
||||
while result.len < lookupRequestLimit:
|
||||
if td + i < 256:
|
||||
result.add(td + i)
|
||||
if td - i > 0'u32:
|
||||
result.add(td - i)
|
||||
inc i
|
||||
|
||||
proc lookupWorker(d: Protocol, destNode: Node, target: NodeId):
|
||||
Future[seq[Node]] {.async, raises: [Exception, Defect].} =
|
||||
let dists = lookupDistances(target, destNode.id)
|
||||
var i = 0
|
||||
while i < lookupRequestLimit and result.len < findNodeResultLimit:
|
||||
let r = await d.findNode(destNode, dists[i])
|
||||
# TODO: Handle failures better. E.g. stop on different failures than timeout
|
||||
if r.isOk:
|
||||
# TODO: I guess it makes sense to limit here also to `findNodeResultLimit`?
|
||||
result.add(r[])
|
||||
inc i
|
||||
|
||||
for n in result:
|
||||
discard d.routingTable.addNode(n)
|
||||
|
||||
proc lookup*(d: Protocol, target: NodeId): Future[seq[Node]]
|
||||
{.async, raises: [Exception, Defect].} =
|
||||
## Perform a lookup for the given target, return the closest n nodes to the
|
||||
## target. Maximum value for n is `BUCKET_SIZE`.
|
||||
# TODO: Sort the returned nodes on distance
|
||||
# Also use unseen nodes as a form of validation.
|
||||
result = d.routingTable.neighbours(target, BUCKET_SIZE, seenOnly = false)
|
||||
var asked = initHashSet[NodeId]()
|
||||
asked.incl(d.localNode.id)
|
||||
var seen = asked
|
||||
for node in result:
|
||||
seen.incl(node.id)
|
||||
|
||||
var pendingQueries = newSeqOfCap[Future[seq[Node]]](alpha)
|
||||
|
||||
while true:
|
||||
var i = 0
|
||||
while i < result.len and pendingQueries.len < alpha:
|
||||
let n = result[i]
|
||||
if not asked.containsOrIncl(n.id):
|
||||
pendingQueries.add(d.lookupWorker(n, target))
|
||||
inc i
|
||||
|
||||
trace "discv5 pending queries", total = pendingQueries.len
|
||||
|
||||
if pendingQueries.len == 0:
|
||||
break
|
||||
|
||||
let idx = await oneIndex(pendingQueries)
|
||||
trace "Got discv5 lookup response", idx
|
||||
|
||||
let nodes = pendingQueries[idx].read
|
||||
pendingQueries.del(idx)
|
||||
for n in nodes:
|
||||
if not seen.containsOrIncl(n.id):
|
||||
if result.len < BUCKET_SIZE:
|
||||
result.add(n)
|
||||
|
||||
proc lookupRandom*(d: Protocol): Future[seq[Node]]
|
||||
{.async, raises:[Exception, Defect].} =
|
||||
## Perform a lookup for a random target, return the closest n nodes to the
|
||||
## target. Maximum value for n is `BUCKET_SIZE`.
|
||||
var id: NodeId
|
||||
var buf: array[sizeof(id), byte]
|
||||
brHmacDrbgGenerate(d.rng[], buf)
|
||||
copyMem(addr id, addr buf[0], sizeof(id))
|
||||
|
||||
return await d.lookup(id)
|
||||
|
||||
proc resolve*(d: Protocol, id: NodeId): Future[Option[Node]]
|
||||
{.async, raises: [Exception, Defect].} =
|
||||
## Resolve a `Node` based on provided `NodeId`.
|
||||
##
|
||||
## This will first look in the own routing table. If the node is known, it
|
||||
## will try to contact if for newer information. If node is not known or it
|
||||
## does not reply, a lookup is done to see if it can find a (newer) record of
|
||||
## the node on the network.
|
||||
|
||||
let node = d.getNode(id)
|
||||
if node.isSome():
|
||||
let request = await d.findNode(node.get(), 0)
|
||||
|
||||
# TODO: Handle failures better. E.g. stop on different failures than timeout
|
||||
if request.isOk() and request[].len > 0:
|
||||
return some(request[][0])
|
||||
|
||||
let discovered = await d.lookup(id)
|
||||
for n in discovered:
|
||||
if n.id == id:
|
||||
if node.isSome() and node.get().record.seqNum >= n.record.seqNum:
|
||||
return node
|
||||
else:
|
||||
return some(n)
|
||||
|
||||
return node
|
||||
|
||||
proc revalidateNode*(d: Protocol, n: Node)
|
||||
{.async, raises: [Exception, Defect].} = # TODO: Exception
|
||||
let pong = await d.ping(n)
|
||||
|
||||
if pong.isOK():
|
||||
if pong.get().enrSeq > n.record.seqNum:
|
||||
# Request new ENR
|
||||
let nodes = await d.findNode(n, 0)
|
||||
if nodes.isOk() and nodes[].len > 0:
|
||||
discard d.addNode(nodes[][0])
|
||||
|
||||
proc revalidateLoop(d: Protocol) {.async, raises: [Exception, Defect].} =
|
||||
# TODO: General Exception raised.
|
||||
try:
|
||||
while true:
|
||||
await sleepAsync(d.rng[].rand(revalidateMax).milliseconds)
|
||||
let n = d.routingTable.nodeToRevalidate()
|
||||
if not n.isNil:
|
||||
traceAsyncErrors d.revalidateNode(n)
|
||||
except CancelledError:
|
||||
trace "revalidateLoop canceled"
|
||||
|
||||
proc lookupLoop(d: Protocol) {.async, raises: [Exception, Defect].} =
|
||||
# TODO: General Exception raised.
|
||||
try:
|
||||
# lookup self (neighbour nodes)
|
||||
let selfLookup = await d.lookup(d.localNode.id)
|
||||
trace "Discovered nodes in self lookup", nodes = $selfLookup
|
||||
while true:
|
||||
let randomLookup = await d.lookupRandom()
|
||||
trace "Discovered nodes in random lookup", nodes = $randomLookup
|
||||
trace "Total nodes in routing table", total = d.routingTable.len()
|
||||
await sleepAsync(lookupInterval)
|
||||
except CancelledError:
|
||||
trace "lookupLoop canceled"
|
||||
|
||||
proc newProtocol*(privKey: PrivateKey,
|
||||
externalIp: Option[ValidIpAddress], tcpPort, udpPort: Port,
|
||||
localEnrFields: openarray[(string, seq[byte])] = [],
|
||||
bootstrapRecords: openarray[Record] = [],
|
||||
previousRecord = none[enr.Record](),
|
||||
bindIp = IPv4_any(), rng = newRng()):
|
||||
Protocol {.raises: [Defect].} =
|
||||
# TODO: Tried adding bindPort = udpPort as parameter but that gave
|
||||
# "Error: internal error: environment misses: udpPort" in nim-beacon-chain.
|
||||
# Anyhow, nim-beacon-chain would also require some changes to support port
|
||||
# remapping through NAT and this API is also subject to change once we
|
||||
# introduce support for ipv4 + ipv6 binding/listening.
|
||||
let extraFields = mapIt(localEnrFields, toFieldPair(it[0], it[1]))
|
||||
# TODO:
|
||||
# - Defect as is now or return a result for enr errors?
|
||||
# - In case incorrect key, allow for new enr based on new key (new node id)?
|
||||
var record: Record
|
||||
if previousRecord.isSome():
|
||||
record = previousRecord.get()
|
||||
record.update(privKey, externalIp, tcpPort, udpPort,
|
||||
extraFields).expect("Record within size limits and correct key")
|
||||
else:
|
||||
record = enr.Record.init(1, privKey, externalIp, tcpPort, udpPort,
|
||||
extraFields).expect("Record within size limits")
|
||||
let node = newNode(record).expect("Properly initialized record")
|
||||
|
||||
# TODO Consider whether this should be a Defect
|
||||
doAssert rng != nil, "RNG initialization failed"
|
||||
|
||||
result = Protocol(
|
||||
privateKey: privKey,
|
||||
localNode: node,
|
||||
bindAddress: Address(ip: ValidIpAddress.init(bindIp), port: udpPort),
|
||||
whoareyouMagic: whoareyouMagic(node.id),
|
||||
idHash: sha256.digest(node.id.toByteArrayBE).data,
|
||||
codec: Codec(localNode: node, privKey: privKey,
|
||||
sessions: Sessions.init(256)),
|
||||
bootstrapRecords: @bootstrapRecords,
|
||||
rng: rng)
|
||||
|
||||
result.routingTable.init(node, 5, rng)
|
||||
|
||||
proc open*(d: Protocol) {.raises: [Exception, Defect].} =
|
||||
info "Starting discovery node", node = $d.localNode,
|
||||
uri = toURI(d.localNode.record), bindAddress = d.bindAddress
|
||||
# TODO allow binding to specific IP / IPv6 / etc
|
||||
let ta = initTAddress(d.bindAddress.ip, d.bindAddress.port)
|
||||
# TODO: raises `OSError` and `IOSelectorsException`, the latter which is
|
||||
# object of Exception. In Nim devel this got changed to CatchableError.
|
||||
d.transp = newDatagramTransport(processClient, udata = d, local = ta)
|
||||
|
||||
for record in d.bootstrapRecords:
|
||||
debug "Adding bootstrap node", uri = toURI(record)
|
||||
discard d.addNode(record)
|
||||
|
||||
proc start*(d: Protocol) {.raises: [Exception, Defect].} =
|
||||
d.lookupLoop = lookupLoop(d)
|
||||
d.revalidateLoop = revalidateLoop(d)
|
||||
|
||||
proc close*(d: Protocol) {.raises: [Exception, Defect].} =
|
||||
doAssert(not d.transp.closed)
|
||||
|
||||
debug "Closing discovery node", node = $d.localNode
|
||||
if not d.revalidateLoop.isNil:
|
||||
d.revalidateLoop.cancel()
|
||||
if not d.lookupLoop.isNil:
|
||||
d.lookupLoop.cancel()
|
||||
|
||||
d.transp.close()
|
||||
|
||||
proc closeWait*(d: Protocol) {.async, raises: [Exception, Defect].} =
|
||||
doAssert(not d.transp.closed)
|
||||
|
||||
debug "Closing discovery node", node = $d.localNode
|
||||
if not d.revalidateLoop.isNil:
|
||||
await d.revalidateLoop.cancelAndWait()
|
||||
if not d.lookupLoop.isNil:
|
||||
await d.lookupLoop.cancelAndWait()
|
||||
|
||||
await d.transp.closeWait()
|
||||
### This is all just temporary to support both versions
|
||||
const UseDiscv51* {.booldefine.} = false
|
||||
|
||||
when UseDiscv51:
|
||||
import protocolv1
|
||||
export protocolv1
|
||||
else:
|
||||
import protocolv0
|
||||
export protocolv0
|
||||
|
|
|
|||
|
|
@ -0,0 +1,835 @@
|
|||
# nim-eth - Node Discovery Protocol v5
|
||||
# Copyright (c) 2020 Status Research & Development GmbH
|
||||
# Licensed under either of
|
||||
# * Apache License, version 2.0, (LICENSE-APACHEv2)
|
||||
# * MIT license (LICENSE-MIT)
|
||||
# at your option. This file may not be copied, modified, or distributed except
|
||||
# according to those terms.
|
||||
|
||||
## Node Discovery Protocol v5
|
||||
##
|
||||
## Node discovery protocol implementation as per specification:
|
||||
## https://github.com/ethereum/devp2p/blob/master/discv5/discv5.md
|
||||
##
|
||||
## This node discovery protocol implementation uses the same underlying
|
||||
## implementation of routing table as is also used for the discovery v4
|
||||
## implementation, which is the same or similar as the one described in the
|
||||
## original Kademlia paper:
|
||||
## https://pdos.csail.mit.edu/~petar/papers/maymounkov-kademlia-lncs.pdf
|
||||
##
|
||||
## This might not be the most optimal implementation for the node discovery
|
||||
## protocol v5. Why?
|
||||
##
|
||||
## The Kademlia paper describes an implementation that starts off from one
|
||||
## k-bucket, and keeps splitting the bucket as more nodes are discovered and
|
||||
## added. The bucket splits only on the part of the binary tree where our own
|
||||
## node its id belongs too (same prefix). Resulting eventually in a k-bucket per
|
||||
## logarithmic distance (log base2 distance). Well, not really, as nodes with
|
||||
## ids in the closer distance ranges will never be found. And because of this an
|
||||
## optimisation is done where buckets will also split sometimes even if the
|
||||
## nodes own id does not have the same prefix (this is to avoid creating highly
|
||||
## unbalanced branches which would require longer lookups).
|
||||
##
|
||||
## Now, some implementations take a more simplified approach. They just create
|
||||
## directly a bucket for each possible logarithmic distance (e.g. here 1->256).
|
||||
## Some implementations also don't create buckets with logarithmic distance
|
||||
## lower than a certain value (e.g. only 1/15th of the highest buckets),
|
||||
## because the closer to the node (the lower the distance), the less chance
|
||||
## there is to still find nodes.
|
||||
##
|
||||
## The discovery protocol v4 its `FindNode` call will request the k closest
|
||||
## nodes. As does original Kademlia. This effectively puts the work at the node
|
||||
## that gets the request. This node will have to check its buckets and gather
|
||||
## the closest. Some implementations go over all the nodes in all the buckets
|
||||
## for this (e.g. go-ethereum discovery v4). However, in our bucket splitting
|
||||
## approach, this search is improved.
|
||||
##
|
||||
## In the discovery protocol v5 the `FindNode` call is changed and now the
|
||||
## logarithmic distance is passed as parameter instead of the NodeId. And only
|
||||
## nodes that match that logarithmic distance are allowed to be returned.
|
||||
## This change was made to not put the trust at the requested node for selecting
|
||||
## the closest nodes. To counter a possible (mistaken) difference in
|
||||
## implementation, but more importantly for security reasons. See also:
|
||||
## https://github.com/ethereum/devp2p/blob/master/discv5/discv5-rationale.md#115-guard-against-kademlia-implementation-flaws
|
||||
##
|
||||
## The result is that in an implementation which just stores buckets per
|
||||
## logarithmic distance, it simply needs to return the right bucket. In our
|
||||
## split-bucket implementation, this cannot be done as such and thus the closest
|
||||
## neighbours search is still done. And to do this, a reverse calculation of an
|
||||
## id at given logarithmic distance is needed (which is why there is the
|
||||
## `idAtDistance` proc). Next, nodes with invalid distances need to be filtered
|
||||
## out to be compliant to the specification. This can most likely get further
|
||||
## optimised, but it sounds likely better to switch away from the split-bucket
|
||||
## approach. I believe that the main benefit it has is improved lookups
|
||||
## (due to no unbalanced branches), and it looks like this will be negated by
|
||||
## limiting the returned nodes to only the ones of the requested logarithmic
|
||||
## distance for the `FindNode` call.
|
||||
|
||||
## This `FindNode` change in discovery v5 will also have an effect on the
|
||||
## efficiency of the network. Work will be moved from the receiver of
|
||||
## `FindNodes` to the requester. But this also means more network traffic,
|
||||
## as less nodes will potentially be passed around per `FindNode` call, and thus
|
||||
## more requests will be needed for a lookup (adding bandwidth and latency).
|
||||
## This might be a concern for mobile devices.
|
||||
|
||||
import
|
||||
std/[tables, sets, options, math, sequtils],
|
||||
stew/shims/net as stewNet, json_serialization/std/net,
|
||||
stew/[byteutils, endians2], chronicles, chronos, stint, bearssl,
|
||||
eth/[rlp, keys, async_utils],
|
||||
types, encoding, node, routing_table, enr, random2, sessions
|
||||
|
||||
import nimcrypto except toHex
|
||||
|
||||
export options
|
||||
|
||||
{.push raises: [Defect].}
|
||||
|
||||
logScope:
|
||||
topics = "discv5"
|
||||
|
||||
const
|
||||
alpha = 3 ## Kademlia concurrency factor
|
||||
lookupRequestLimit = 3
|
||||
findNodeResultLimit = 15 # applies in FINDNODE handler
|
||||
maxNodesPerMessage = 3
|
||||
lookupInterval = 60.seconds ## Interval of launching a random lookup to
|
||||
## populate the routing table. go-ethereum seems to do 3 runs every 30
|
||||
## minutes. Trinity starts one every minute.
|
||||
revalidateMax = 1000 ## Revalidation of a peer is done between 0 and this
|
||||
## value in milliseconds
|
||||
handshakeTimeout* = 2.seconds ## timeout for the reply on the
|
||||
## whoareyou message
|
||||
responseTimeout* = 4.seconds ## timeout for the response of a request-response
|
||||
## call
|
||||
magicSize = 32 ## size of the magic which is the start of the whoareyou
|
||||
## message
|
||||
|
||||
type
|
||||
Protocol* = ref object
|
||||
transp: DatagramTransport
|
||||
localNode*: Node
|
||||
privateKey: PrivateKey
|
||||
bindAddress: Address ## UDP binding address
|
||||
whoareyouMagic: array[magicSize, byte]
|
||||
idHash: array[32, byte]
|
||||
pendingRequests: Table[AuthTag, PendingRequest]
|
||||
routingTable: RoutingTable
|
||||
codec*: Codec
|
||||
awaitedMessages: Table[(NodeId, RequestId), Future[Option[Message]]]
|
||||
lookupLoop: Future[void]
|
||||
revalidateLoop: Future[void]
|
||||
bootstrapRecords*: seq[Record]
|
||||
rng*: ref BrHmacDrbgContext
|
||||
|
||||
PendingRequest = object
|
||||
node: Node
|
||||
message: seq[byte]
|
||||
|
||||
DiscResult*[T] = Result[T, cstring]
|
||||
|
||||
proc addNode*(d: Protocol, node: Node): bool =
|
||||
## Add `Node` to discovery routing table.
|
||||
##
|
||||
## Returns false only if `Node` is not eligable for adding (no Address).
|
||||
if node.address.isSome():
|
||||
# Only add nodes with an address to the routing table
|
||||
discard d.routingTable.addNode(node)
|
||||
return true
|
||||
|
||||
proc addNode*(d: Protocol, r: Record): bool =
|
||||
## Add `Node` from a `Record` to discovery routing table.
|
||||
##
|
||||
## Returns false only if no valid `Node` can be created from the `Record` or
|
||||
## on the conditions of `addNode` from a `Node`.
|
||||
let node = newNode(r)
|
||||
if node.isOk():
|
||||
return d.addNode(node[])
|
||||
|
||||
proc addNode*(d: Protocol, enr: EnrUri): bool =
|
||||
## Add `Node` from a ENR URI to discovery routing table.
|
||||
##
|
||||
## Returns false if no valid ENR URI, or on the conditions of `addNode` from
|
||||
## an `Record`.
|
||||
var r: Record
|
||||
let res = r.fromUri(enr)
|
||||
if res:
|
||||
return d.addNode(r)
|
||||
|
||||
proc getNode*(d: Protocol, id: NodeId): Option[Node] =
|
||||
## Get the node with id from the routing table.
|
||||
d.routingTable.getNode(id)
|
||||
|
||||
proc randomNodes*(d: Protocol, maxAmount: int): seq[Node] =
|
||||
## Get a `maxAmount` of random nodes from the local routing table.
|
||||
d.routingTable.randomNodes(maxAmount)
|
||||
|
||||
proc randomNodes*(d: Protocol, maxAmount: int,
|
||||
pred: proc(x: Node): bool {.gcsafe, noSideEffect.}): seq[Node] =
|
||||
## Get a `maxAmount` of random nodes from the local routing table with the
|
||||
## `pred` predicate function applied as filter on the nodes selected.
|
||||
d.routingTable.randomNodes(maxAmount, pred)
|
||||
|
||||
proc randomNodes*(d: Protocol, maxAmount: int,
|
||||
enrField: (string, seq[byte])): seq[Node] =
|
||||
## Get a `maxAmount` of random nodes from the local routing table. The
|
||||
## the nodes selected are filtered by provided `enrField`.
|
||||
d.randomNodes(maxAmount, proc(x: Node): bool = x.record.contains(enrField))
|
||||
|
||||
proc neighbours*(d: Protocol, id: NodeId, k: int = BUCKET_SIZE): seq[Node] =
|
||||
## Return up to k neighbours (closest node ids) of the given node id.
|
||||
d.routingTable.neighbours(id, k)
|
||||
|
||||
proc nodesDiscovered*(d: Protocol): int {.inline.} = d.routingTable.len
|
||||
|
||||
func privKey*(d: Protocol): lent PrivateKey =
|
||||
d.privateKey
|
||||
|
||||
func getRecord*(d: Protocol): Record =
|
||||
## Get the ENR of the local node.
|
||||
d.localNode.record
|
||||
|
||||
proc updateRecord*(
|
||||
d: Protocol, enrFields: openarray[(string, seq[byte])]): DiscResult[void] =
|
||||
## Update the ENR of the local node with provided `enrFields` k:v pairs.
|
||||
let fields = mapIt(enrFields, toFieldPair(it[0], it[1]))
|
||||
d.localNode.record.update(d.privateKey, fields)
|
||||
# TODO: Would it make sense to actively ping ("broadcast") to all the peers
|
||||
# we stored a handshake with in order to get that ENR updated?
|
||||
|
||||
proc send(d: Protocol, a: Address, data: seq[byte]) =
|
||||
let ta = initTAddress(a.ip, a.port)
|
||||
try:
|
||||
let f = d.transp.sendTo(ta, data)
|
||||
f.callback = proc(data: pointer) {.gcsafe.} =
|
||||
if f.failed:
|
||||
# Could be `TransportUseClosedError` in case the transport is already
|
||||
# closed, or could be `TransportOsError` in case of a socket error.
|
||||
# In the latter case this would probably mostly occur if the network
|
||||
# interface underneath gets disconnected or similar.
|
||||
# TODO: Should this kind of error be propagated upwards? Probably, but
|
||||
# it should not stop the process as that would reset the discovery
|
||||
# progress in case there is even a small window of no connection.
|
||||
# One case that needs this error available upwards is when revalidating
|
||||
# nodes. Else the revalidation might end up clearing the routing tabl
|
||||
# because of ping failures due to own network connection failure.
|
||||
debug "Discovery send failed", msg = f.readError.msg
|
||||
except Exception as e:
|
||||
# TODO: General exception still being raised from Chronos, but in practice
|
||||
# all CatchableErrors should be grabbed by the above `f.failed`.
|
||||
if e of Defect:
|
||||
raise (ref Defect)(e)
|
||||
else: doAssert(false)
|
||||
|
||||
proc send(d: Protocol, n: Node, data: seq[byte]) =
|
||||
doAssert(n.address.isSome())
|
||||
d.send(n.address.get(), data)
|
||||
|
||||
proc `xor`[N: static[int], T](a, b: array[N, T]): array[N, T] =
|
||||
for i in 0 .. a.high:
|
||||
result[i] = a[i] xor b[i]
|
||||
|
||||
proc whoareyouMagic*(toNode: NodeId): array[magicSize, byte] =
|
||||
const prefix = "WHOAREYOU"
|
||||
var data: array[prefix.len + sizeof(toNode), byte]
|
||||
data[0 .. sizeof(toNode) - 1] = toNode.toByteArrayBE()
|
||||
for i, c in prefix: data[sizeof(toNode) + i] = byte(c)
|
||||
sha256.digest(data).data
|
||||
|
||||
proc isWhoAreYou(d: Protocol, packet: openArray[byte]): bool =
|
||||
if packet.len > d.whoareyouMagic.len:
|
||||
result = d.whoareyouMagic == packet.toOpenArray(0, magicSize - 1)
|
||||
|
||||
proc decodeWhoAreYou(d: Protocol, packet: openArray[byte]):
|
||||
Whoareyou {.raises: [RlpError].} =
|
||||
result = Whoareyou()
|
||||
result[] = rlp.decode(packet.toOpenArray(magicSize, packet.high), WhoareyouObj)
|
||||
|
||||
proc sendWhoareyou(d: Protocol, address: Address, toNode: NodeId,
|
||||
authTag: AuthTag): DiscResult[void] {.raises: [Exception, Defect].} =
|
||||
trace "sending who are you", to = $toNode, toAddress = $address
|
||||
let n = d.getNode(toNode)
|
||||
let challenge = if n.isSome():
|
||||
Whoareyou(authTag: authTag, recordSeq: n.get().record.seqNum,
|
||||
pubKey: some(n.get().pubkey))
|
||||
else:
|
||||
Whoareyou(authTag: authTag, recordSeq: 0)
|
||||
brHmacDrbgGenerate(d.rng[], challenge.idNonce)
|
||||
|
||||
# If there is already a handshake going on for this nodeid then we drop this
|
||||
# new one. Handshake will get cleaned up after `handshakeTimeout`.
|
||||
# If instead overwriting the handshake would be allowed, the handshake timeout
|
||||
# will need to be canceled each time.
|
||||
# TODO: could also clean up handshakes in a seperate call, e.g. triggered in
|
||||
# a loop.
|
||||
# Use toNode + address to make it more difficult for an attacker to occupy
|
||||
# the handshake of another node.
|
||||
let key = HandShakeKey(nodeId: toNode, address: $address)
|
||||
if not d.codec.handshakes.hasKeyOrPut(key, challenge):
|
||||
# TODO: raises: [Exception], but it shouldn't.
|
||||
sleepAsync(handshakeTimeout).addCallback() do(data: pointer):
|
||||
# TODO: should we still provide cancellation in case handshake completes
|
||||
# correctly?
|
||||
d.codec.handshakes.del(key)
|
||||
|
||||
var data = @(whoareyouMagic(toNode))
|
||||
data.add(rlp.encode(challenge[]))
|
||||
d.send(address, data)
|
||||
ok()
|
||||
else:
|
||||
err("NodeId already has ongoing handshake")
|
||||
|
||||
proc sendNodes(d: Protocol, toId: NodeId, toAddr: Address, reqId: RequestId,
|
||||
nodes: openarray[Node]) =
|
||||
proc sendNodes(d: Protocol, toId: NodeId, toAddr: Address,
|
||||
message: NodesMessage, reqId: RequestId) {.nimcall.} =
|
||||
let (data, _) = encodePacket(
|
||||
d.rng[], d.codec, toId, toAddr,
|
||||
encodeMessage(message, reqId), challenge = nil)
|
||||
d.send(toAddr, data)
|
||||
|
||||
if nodes.len == 0:
|
||||
# In case of 0 nodes, a reply is still needed
|
||||
d.sendNodes(toId, toAddr, NodesMessage(total: 1, enrs: @[]), reqId)
|
||||
return
|
||||
|
||||
var message: NodesMessage
|
||||
# TODO: Do the total calculation based on the max UDP packet size we want to
|
||||
# send and the ENR size of all (max 16) nodes.
|
||||
# Which UDP packet size to take? 1280? 576?
|
||||
message.total = ceil(nodes.len / maxNodesPerMessage).uint32
|
||||
|
||||
for i in 0 ..< nodes.len:
|
||||
message.enrs.add(nodes[i].record)
|
||||
if message.enrs.len == maxNodesPerMessage:
|
||||
d.sendNodes(toId, toAddr, message, reqId)
|
||||
message.enrs.setLen(0)
|
||||
|
||||
if message.enrs.len != 0:
|
||||
d.sendNodes(toId, toAddr, message, reqId)
|
||||
|
||||
proc handlePing(d: Protocol, fromId: NodeId, fromAddr: Address,
|
||||
ping: PingMessage, reqId: RequestId) =
|
||||
let a = fromAddr
|
||||
var pong: PongMessage
|
||||
pong.enrSeq = d.localNode.record.seqNum
|
||||
pong.ip = case a.ip.family
|
||||
of IpAddressFamily.IPv4: @(a.ip.address_v4)
|
||||
of IpAddressFamily.IPv6: @(a.ip.address_v6)
|
||||
pong.port = a.port.uint16
|
||||
|
||||
let (data, _) = encodePacket(d.rng[], d.codec, fromId, fromAddr,
|
||||
encodeMessage(pong, reqId), challenge = nil)
|
||||
|
||||
d.send(fromAddr, data)
|
||||
|
||||
proc handleFindNode(d: Protocol, fromId: NodeId, fromAddr: Address,
|
||||
fn: FindNodeMessage, reqId: RequestId) =
|
||||
if fn.distance == 0:
|
||||
d.sendNodes(fromId, fromAddr, reqId, [d.localNode])
|
||||
else:
|
||||
if fn.distance <= 256:
|
||||
d.sendNodes(fromId, fromAddr, reqId,
|
||||
d.routingTable.neighboursAtDistance(fn.distance, seenOnly = true))
|
||||
else:
|
||||
# The polite node we are, still respond with empty nodes.
|
||||
d.sendNodes(fromId, fromAddr, reqId, [])
|
||||
|
||||
proc receive*(d: Protocol, a: Address, packet: openArray[byte]) {.gcsafe,
|
||||
raises: [
|
||||
Defect,
|
||||
# This just comes now from a future.complete() and `sendWhoareyou` which
|
||||
# has it because of `sleepAsync` with `addCallback`, but practically, no
|
||||
# CatchableError should be raised here, we just can't enforce it for now.
|
||||
Exception
|
||||
].} =
|
||||
if packet.len < tagSize: # or magicSize, can be either
|
||||
return # Invalid packet
|
||||
|
||||
# debug "Packet received: ", length = packet.len
|
||||
|
||||
if d.isWhoAreYou(packet):
|
||||
trace "Received whoareyou", localNode = $d.localNode, address = a
|
||||
var whoareyou: WhoAreYou
|
||||
try:
|
||||
whoareyou = d.decodeWhoAreYou(packet)
|
||||
except RlpError:
|
||||
debug "Invalid WhoAreYou packet, decoding failed"
|
||||
return
|
||||
|
||||
var pr: PendingRequest
|
||||
if d.pendingRequests.take(whoareyou.authTag, pr):
|
||||
let toNode = pr.node
|
||||
whoareyou.pubKey = some(toNode.pubkey) # TODO: Yeah, rather ugly this.
|
||||
doAssert(toNode.address.isSome())
|
||||
let (data, _) = encodePacket(d.rng[], d.codec, toNode.id, toNode.address.get(),
|
||||
pr.message, challenge = whoareyou)
|
||||
d.send(toNode, data)
|
||||
else:
|
||||
debug "Timed out or unrequested WhoAreYou packet"
|
||||
|
||||
else:
|
||||
var tag: array[tagSize, byte]
|
||||
tag[0 .. ^1] = packet.toOpenArray(0, tagSize - 1)
|
||||
let senderData = tag xor d.idHash
|
||||
let sender = readUintBE[256](senderData)
|
||||
|
||||
var authTag: AuthTag
|
||||
var node: Node
|
||||
let decoded = d.codec.decodePacket(sender, a, packet, authTag, node)
|
||||
if decoded.isOk:
|
||||
let message = decoded[]
|
||||
if not node.isNil:
|
||||
# Not filling table with nodes without correct IP in the ENR
|
||||
# TODO: Should we care about this???
|
||||
if node.address.isSome() and a == node.address.get():
|
||||
debug "Adding new node to routing table", node = $node,
|
||||
localNode = $d.localNode
|
||||
discard d.addNode(node)
|
||||
|
||||
case message.kind
|
||||
of ping:
|
||||
d.handlePing(sender, a, message.ping, message.reqId)
|
||||
of findNode:
|
||||
d.handleFindNode(sender, a, message.findNode, message.reqId)
|
||||
else:
|
||||
var waiter: Future[Option[Message]]
|
||||
if d.awaitedMessages.take((sender, message.reqId), waiter):
|
||||
waiter.complete(some(message)) # TODO: raises: [Exception]
|
||||
else:
|
||||
trace "Timed out or unrequested message", message = message.kind,
|
||||
origin = a
|
||||
elif decoded.error == DecodeError.DecryptError:
|
||||
trace "Could not decrypt packet, respond with whoareyou",
|
||||
localNode = $d.localNode, address = a
|
||||
# only sendingWhoareyou in case it is a decryption failure
|
||||
let res = d.sendWhoareyou(a, sender, authTag)
|
||||
if res.isErr():
|
||||
trace "Sending WhoAreYou packet failed", err = res.error
|
||||
elif decoded.error == DecodeError.UnsupportedMessage:
|
||||
# Still adding the node in case failure is because of unsupported message.
|
||||
if not node.isNil:
|
||||
# Not filling table with nodes without correct IP in the ENR
|
||||
# TODO: Should we care about this???s
|
||||
if node.address.isSome() and a == node.address.get():
|
||||
debug "Adding new node to routing table", node = $node,
|
||||
localNode = $d.localNode
|
||||
discard d.addNode(node)
|
||||
# elif decoded.error == DecodeError.PacketError:
|
||||
# Not adding this node as from our perspective it is sending rubbish.
|
||||
|
||||
# TODO: Not sure why but need to pop the raises here as it is apparently not
|
||||
# enough to put it in the raises pragma of `processClient` and other async procs.
|
||||
{.pop.}
|
||||
# Next, below there is no more effort done in catching the general `Exception`
|
||||
# as async procs always require `Exception` in the raises pragma, see also:
|
||||
# https://github.com/status-im/nim-chronos/issues/98
|
||||
# So I don't bother for now and just add them in the raises pragma until this
|
||||
# gets fixed. It does not mean that we expect these calls to be raising
|
||||
# CatchableErrors, in fact, we really don't, but hey, they might, considering we
|
||||
# can't enforce it.
|
||||
proc processClient(transp: DatagramTransport, raddr: TransportAddress):
|
||||
Future[void] {.async, gcsafe, raises: [Exception, Defect].} =
|
||||
let proto = getUserData[Protocol](transp)
|
||||
|
||||
# TODO: should we use `peekMessage()` to avoid allocation?
|
||||
# TODO: This can still raise general `Exception` while it probably should
|
||||
# only give TransportOsError.
|
||||
let buf = try: transp.getMessage()
|
||||
except TransportOsError as e:
|
||||
# This is likely to be local network connection issues.
|
||||
error "Transport getMessage", exception = e.name, msg = e.msg
|
||||
return
|
||||
except Exception as e:
|
||||
if e of Defect:
|
||||
raise (ref Defect)(e)
|
||||
else: doAssert(false)
|
||||
return # Make compiler happy
|
||||
|
||||
let ip = try: raddr.address()
|
||||
except ValueError as e:
|
||||
error "Not a valid IpAddress", exception = e.name, msg = e.msg
|
||||
return
|
||||
let a = Address(ip: ValidIpAddress.init(ip), port: raddr.port)
|
||||
|
||||
try:
|
||||
proto.receive(a, buf)
|
||||
except Exception as e:
|
||||
if e of Defect:
|
||||
raise (ref Defect)(e)
|
||||
else: doAssert(false)
|
||||
|
||||
proc validIp(sender, address: IpAddress): bool {.raises: [Defect].} =
|
||||
let
|
||||
s = initTAddress(sender, Port(0))
|
||||
a = initTAddress(address, Port(0))
|
||||
if a.isAnyLocal():
|
||||
return false
|
||||
if a.isMulticast():
|
||||
return false
|
||||
if a.isLoopback() and not s.isLoopback():
|
||||
return false
|
||||
if a.isSiteLocal() and not s.isSiteLocal():
|
||||
return false
|
||||
# TODO: Also check for special reserved ip addresses:
|
||||
# https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml
|
||||
# https://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml
|
||||
return true
|
||||
|
||||
proc replaceNode(d: Protocol, n: Node) =
|
||||
if n.record notin d.bootstrapRecords:
|
||||
d.routingTable.replaceNode(n)
|
||||
else:
|
||||
# For now we never remove bootstrap nodes. It might make sense to actually
|
||||
# do so and to retry them only in case we drop to a really low amount of
|
||||
# peers in the routing table.
|
||||
debug "Message request to bootstrap node failed", enr = toURI(n.record)
|
||||
|
||||
# TODO: This could be improved to do the clean-up immediatily in case a non
|
||||
# whoareyou response does arrive, but we would need to store the AuthTag
|
||||
# somewhere
|
||||
proc registerRequest(d: Protocol, n: Node, message: seq[byte], nonce: AuthTag)
|
||||
{.raises: [Exception, Defect].} =
|
||||
let request = PendingRequest(node: n, message: message)
|
||||
if not d.pendingRequests.hasKeyOrPut(nonce, request):
|
||||
# TODO: raises: [Exception]
|
||||
sleepAsync(responseTimeout).addCallback() do(data: pointer):
|
||||
d.pendingRequests.del(nonce)
|
||||
|
||||
proc waitMessage(d: Protocol, fromNode: Node, reqId: RequestId):
|
||||
Future[Option[Message]] {.raises: [Exception, Defect].} =
|
||||
result = newFuture[Option[Message]]("waitMessage")
|
||||
let res = result
|
||||
let key = (fromNode.id, reqId)
|
||||
# TODO: raises: [Exception]
|
||||
sleepAsync(responseTimeout).addCallback() do(data: pointer):
|
||||
d.awaitedMessages.del(key)
|
||||
if not res.finished:
|
||||
res.complete(none(Message)) # TODO: raises: [Exception]
|
||||
d.awaitedMessages[key] = result
|
||||
|
||||
proc verifyNodesRecords*(enrs: openarray[Record], fromNode: Node,
|
||||
distance: uint32): seq[Node] {.raises: [Defect].} =
|
||||
## Verify and convert ENRs to a sequence of nodes. Only ENRs that pass
|
||||
## verification will be added. ENRs are verified for duplicates, invalid
|
||||
## addresses and invalid distances.
|
||||
# TODO:
|
||||
# - Should we fail and ignore values on first invalid Node?
|
||||
# - Should we limit the amount of nodes? The discovery v5 specification holds
|
||||
# no limit on the amount that can be returned.
|
||||
var seen: HashSet[Node]
|
||||
for r in enrs:
|
||||
let node = newNode(r)
|
||||
if node.isOk():
|
||||
let n = node.get()
|
||||
# Check for duplicates in the nodes reply. Duplicates are checked based
|
||||
# on node id.
|
||||
if n in seen:
|
||||
trace "Nodes reply contained records with duplicate node ids",
|
||||
record = n.record.toURI, sender = fromNode.record.toURI, id = n.id
|
||||
continue
|
||||
# Check if the node has an address and if the address is public or from
|
||||
# the same local network or lo network as the sender. The latter allows
|
||||
# for local testing.
|
||||
if not n.address.isSome() or not
|
||||
validIp(fromNode.address.get().ip, n.address.get().ip):
|
||||
trace "Nodes reply contained record with invalid ip-address",
|
||||
record = n.record.toURI, sender = fromNode.record.toURI, node = $n
|
||||
continue
|
||||
# Check if returned node has exactly the requested distance.
|
||||
if logDist(n.id, fromNode.id) != distance:
|
||||
warn "Nodes reply contained record with incorrect distance",
|
||||
record = n.record.toURI, sender = fromNode.record.toURI
|
||||
continue
|
||||
# No check on UDP port and thus any port is allowed, also the so called
|
||||
# "well-known" ports.
|
||||
|
||||
seen.incl(n)
|
||||
result.add(n)
|
||||
|
||||
proc waitNodes(d: Protocol, fromNode: Node, reqId: RequestId):
|
||||
Future[DiscResult[seq[Record]]] {.async, raises: [Exception, Defect].} =
|
||||
## Wait for one or more nodes replies.
|
||||
##
|
||||
## The first reply will hold the total number of replies expected, and based
|
||||
## on that, more replies will be awaited.
|
||||
## If one reply is lost here (timed out), others are ignored too.
|
||||
## Same counts for out of order receival.
|
||||
var op = await d.waitMessage(fromNode, reqId)
|
||||
if op.isSome and op.get.kind == nodes:
|
||||
var res = op.get.nodes.enrs
|
||||
let total = op.get.nodes.total
|
||||
for i in 1 ..< total:
|
||||
op = await d.waitMessage(fromNode, reqId)
|
||||
if op.isSome and op.get.kind == nodes:
|
||||
res.add(op.get.nodes.enrs)
|
||||
else:
|
||||
# No error on this as we received some nodes.
|
||||
break
|
||||
return ok(res)
|
||||
else:
|
||||
return err("Nodes message not received in time")
|
||||
|
||||
proc sendMessage*[T: SomeMessage](d: Protocol, toNode: Node, m: T):
|
||||
RequestId {.raises: [Exception, Defect].} =
|
||||
doAssert(toNode.address.isSome())
|
||||
let
|
||||
reqId = RequestId.init(d.rng[])
|
||||
message = encodeMessage(m, reqId)
|
||||
(data, nonce) = encodePacket(d.rng[], d.codec, toNode.id, toNode.address.get(),
|
||||
message, challenge = nil)
|
||||
d.registerRequest(toNode, message, nonce)
|
||||
d.send(toNode, data)
|
||||
return reqId
|
||||
|
||||
proc ping*(d: Protocol, toNode: Node):
|
||||
Future[DiscResult[PongMessage]] {.async, raises: [Exception, Defect].} =
|
||||
## Send a discovery ping message.
|
||||
##
|
||||
## Returns the received pong message or an error.
|
||||
let reqId = d.sendMessage(toNode,
|
||||
PingMessage(enrSeq: d.localNode.record.seqNum))
|
||||
let resp = await d.waitMessage(toNode, reqId)
|
||||
|
||||
if resp.isSome() and resp.get().kind == pong:
|
||||
d.routingTable.setJustSeen(toNode)
|
||||
return ok(resp.get().pong)
|
||||
else:
|
||||
d.replaceNode(toNode)
|
||||
return err("Pong message not received in time")
|
||||
|
||||
proc findNode*(d: Protocol, toNode: Node, distance: uint32):
|
||||
Future[DiscResult[seq[Node]]] {.async, raises: [Exception, Defect].} =
|
||||
## Send a discovery findNode message.
|
||||
##
|
||||
## Returns the received nodes or an error.
|
||||
## Received ENRs are already validated and converted to `Node`.
|
||||
let reqId = d.sendMessage(toNode, FindNodeMessage(distance: distance))
|
||||
let nodes = await d.waitNodes(toNode, reqId)
|
||||
|
||||
if nodes.isOk:
|
||||
let res = verifyNodesRecords(nodes.get(), toNode, distance)
|
||||
d.routingTable.setJustSeen(toNode)
|
||||
return ok(res)
|
||||
else:
|
||||
d.replaceNode(toNode)
|
||||
return err(nodes.error)
|
||||
|
||||
proc lookupDistances(target, dest: NodeId): seq[uint32] {.raises: [Defect].} =
|
||||
let td = logDist(target, dest)
|
||||
result.add(td)
|
||||
var i = 1'u32
|
||||
while result.len < lookupRequestLimit:
|
||||
if td + i < 256:
|
||||
result.add(td + i)
|
||||
if td - i > 0'u32:
|
||||
result.add(td - i)
|
||||
inc i
|
||||
|
||||
proc lookupWorker(d: Protocol, destNode: Node, target: NodeId):
|
||||
Future[seq[Node]] {.async, raises: [Exception, Defect].} =
|
||||
let dists = lookupDistances(target, destNode.id)
|
||||
var i = 0
|
||||
while i < lookupRequestLimit and result.len < findNodeResultLimit:
|
||||
let r = await d.findNode(destNode, dists[i])
|
||||
# TODO: Handle failures better. E.g. stop on different failures than timeout
|
||||
if r.isOk:
|
||||
# TODO: I guess it makes sense to limit here also to `findNodeResultLimit`?
|
||||
result.add(r[])
|
||||
inc i
|
||||
|
||||
for n in result:
|
||||
discard d.routingTable.addNode(n)
|
||||
|
||||
proc lookup*(d: Protocol, target: NodeId): Future[seq[Node]]
|
||||
{.async, raises: [Exception, Defect].} =
|
||||
## Perform a lookup for the given target, return the closest n nodes to the
|
||||
## target. Maximum value for n is `BUCKET_SIZE`.
|
||||
# TODO: Sort the returned nodes on distance
|
||||
# Also use unseen nodes as a form of validation.
|
||||
result = d.routingTable.neighbours(target, BUCKET_SIZE, seenOnly = false)
|
||||
var asked = initHashSet[NodeId]()
|
||||
asked.incl(d.localNode.id)
|
||||
var seen = asked
|
||||
for node in result:
|
||||
seen.incl(node.id)
|
||||
|
||||
var pendingQueries = newSeqOfCap[Future[seq[Node]]](alpha)
|
||||
|
||||
while true:
|
||||
var i = 0
|
||||
while i < result.len and pendingQueries.len < alpha:
|
||||
let n = result[i]
|
||||
if not asked.containsOrIncl(n.id):
|
||||
pendingQueries.add(d.lookupWorker(n, target))
|
||||
inc i
|
||||
|
||||
trace "discv5 pending queries", total = pendingQueries.len
|
||||
|
||||
if pendingQueries.len == 0:
|
||||
break
|
||||
|
||||
let idx = await oneIndex(pendingQueries)
|
||||
trace "Got discv5 lookup response", idx
|
||||
|
||||
let nodes = pendingQueries[idx].read
|
||||
pendingQueries.del(idx)
|
||||
for n in nodes:
|
||||
if not seen.containsOrIncl(n.id):
|
||||
if result.len < BUCKET_SIZE:
|
||||
result.add(n)
|
||||
|
||||
proc lookupRandom*(d: Protocol): Future[seq[Node]]
|
||||
{.async, raises:[Exception, Defect].} =
|
||||
## Perform a lookup for a random target, return the closest n nodes to the
|
||||
## target. Maximum value for n is `BUCKET_SIZE`.
|
||||
var id: NodeId
|
||||
var buf: array[sizeof(id), byte]
|
||||
brHmacDrbgGenerate(d.rng[], buf)
|
||||
copyMem(addr id, addr buf[0], sizeof(id))
|
||||
|
||||
return await d.lookup(id)
|
||||
|
||||
proc resolve*(d: Protocol, id: NodeId): Future[Option[Node]]
|
||||
{.async, raises: [Exception, Defect].} =
|
||||
## Resolve a `Node` based on provided `NodeId`.
|
||||
##
|
||||
## This will first look in the own routing table. If the node is known, it
|
||||
## will try to contact if for newer information. If node is not known or it
|
||||
## does not reply, a lookup is done to see if it can find a (newer) record of
|
||||
## the node on the network.
|
||||
|
||||
let node = d.getNode(id)
|
||||
if node.isSome():
|
||||
let request = await d.findNode(node.get(), 0)
|
||||
|
||||
# TODO: Handle failures better. E.g. stop on different failures than timeout
|
||||
if request.isOk() and request[].len > 0:
|
||||
return some(request[][0])
|
||||
|
||||
let discovered = await d.lookup(id)
|
||||
for n in discovered:
|
||||
if n.id == id:
|
||||
if node.isSome() and node.get().record.seqNum >= n.record.seqNum:
|
||||
return node
|
||||
else:
|
||||
return some(n)
|
||||
|
||||
return node
|
||||
|
||||
proc revalidateNode*(d: Protocol, n: Node)
|
||||
{.async, raises: [Exception, Defect].} = # TODO: Exception
|
||||
let pong = await d.ping(n)
|
||||
|
||||
if pong.isOK():
|
||||
if pong.get().enrSeq > n.record.seqNum:
|
||||
# Request new ENR
|
||||
let nodes = await d.findNode(n, 0)
|
||||
if nodes.isOk() and nodes[].len > 0:
|
||||
discard d.addNode(nodes[][0])
|
||||
|
||||
proc revalidateLoop(d: Protocol) {.async, raises: [Exception, Defect].} =
|
||||
# TODO: General Exception raised.
|
||||
try:
|
||||
while true:
|
||||
await sleepAsync(d.rng[].rand(revalidateMax).milliseconds)
|
||||
let n = d.routingTable.nodeToRevalidate()
|
||||
if not n.isNil:
|
||||
traceAsyncErrors d.revalidateNode(n)
|
||||
except CancelledError:
|
||||
trace "revalidateLoop canceled"
|
||||
|
||||
proc lookupLoop(d: Protocol) {.async, raises: [Exception, Defect].} =
|
||||
# TODO: General Exception raised.
|
||||
try:
|
||||
# lookup self (neighbour nodes)
|
||||
let selfLookup = await d.lookup(d.localNode.id)
|
||||
trace "Discovered nodes in self lookup", nodes = $selfLookup
|
||||
while true:
|
||||
let randomLookup = await d.lookupRandom()
|
||||
trace "Discovered nodes in random lookup", nodes = $randomLookup
|
||||
trace "Total nodes in routing table", total = d.routingTable.len()
|
||||
await sleepAsync(lookupInterval)
|
||||
except CancelledError:
|
||||
trace "lookupLoop canceled"
|
||||
|
||||
proc newProtocol*(privKey: PrivateKey,
|
||||
externalIp: Option[ValidIpAddress], tcpPort, udpPort: Port,
|
||||
localEnrFields: openarray[(string, seq[byte])] = [],
|
||||
bootstrapRecords: openarray[Record] = [],
|
||||
previousRecord = none[enr.Record](),
|
||||
bindIp = IPv4_any(), rng = newRng()):
|
||||
Protocol {.raises: [Defect].} =
|
||||
# TODO: Tried adding bindPort = udpPort as parameter but that gave
|
||||
# "Error: internal error: environment misses: udpPort" in nim-beacon-chain.
|
||||
# Anyhow, nim-beacon-chain would also require some changes to support port
|
||||
# remapping through NAT and this API is also subject to change once we
|
||||
# introduce support for ipv4 + ipv6 binding/listening.
|
||||
let extraFields = mapIt(localEnrFields, toFieldPair(it[0], it[1]))
|
||||
# TODO:
|
||||
# - Defect as is now or return a result for enr errors?
|
||||
# - In case incorrect key, allow for new enr based on new key (new node id)?
|
||||
var record: Record
|
||||
if previousRecord.isSome():
|
||||
record = previousRecord.get()
|
||||
record.update(privKey, externalIp, tcpPort, udpPort,
|
||||
extraFields).expect("Record within size limits and correct key")
|
||||
else:
|
||||
record = enr.Record.init(1, privKey, externalIp, tcpPort, udpPort,
|
||||
extraFields).expect("Record within size limits")
|
||||
let node = newNode(record).expect("Properly initialized record")
|
||||
|
||||
# TODO Consider whether this should be a Defect
|
||||
doAssert rng != nil, "RNG initialization failed"
|
||||
|
||||
result = Protocol(
|
||||
privateKey: privKey,
|
||||
localNode: node,
|
||||
bindAddress: Address(ip: ValidIpAddress.init(bindIp), port: udpPort),
|
||||
whoareyouMagic: whoareyouMagic(node.id),
|
||||
idHash: sha256.digest(node.id.toByteArrayBE).data,
|
||||
codec: Codec(localNode: node, privKey: privKey,
|
||||
sessions: Sessions.init(256)),
|
||||
bootstrapRecords: @bootstrapRecords,
|
||||
rng: rng)
|
||||
|
||||
result.routingTable.init(node, 5, rng)
|
||||
|
||||
proc open*(d: Protocol) {.raises: [Exception, Defect].} =
|
||||
info "Starting discovery node", node = $d.localNode,
|
||||
uri = toURI(d.localNode.record), bindAddress = d.bindAddress
|
||||
# TODO allow binding to specific IP / IPv6 / etc
|
||||
let ta = initTAddress(d.bindAddress.ip, d.bindAddress.port)
|
||||
# TODO: raises `OSError` and `IOSelectorsException`, the latter which is
|
||||
# object of Exception. In Nim devel this got changed to CatchableError.
|
||||
d.transp = newDatagramTransport(processClient, udata = d, local = ta)
|
||||
|
||||
for record in d.bootstrapRecords:
|
||||
debug "Adding bootstrap node", uri = toURI(record)
|
||||
discard d.addNode(record)
|
||||
|
||||
proc start*(d: Protocol) {.raises: [Exception, Defect].} =
|
||||
d.lookupLoop = lookupLoop(d)
|
||||
d.revalidateLoop = revalidateLoop(d)
|
||||
|
||||
proc close*(d: Protocol) {.raises: [Exception, Defect].} =
|
||||
doAssert(not d.transp.closed)
|
||||
|
||||
debug "Closing discovery node", node = $d.localNode
|
||||
if not d.revalidateLoop.isNil:
|
||||
d.revalidateLoop.cancel()
|
||||
if not d.lookupLoop.isNil:
|
||||
d.lookupLoop.cancel()
|
||||
|
||||
d.transp.close()
|
||||
|
||||
proc closeWait*(d: Protocol) {.async, raises: [Exception, Defect].} =
|
||||
doAssert(not d.transp.closed)
|
||||
|
||||
debug "Closing discovery node", node = $d.localNode
|
||||
if not d.revalidateLoop.isNil:
|
||||
await d.revalidateLoop.cancelAndWait()
|
||||
if not d.lookupLoop.isNil:
|
||||
await d.lookupLoop.cancelAndWait()
|
||||
|
||||
await d.transp.closeWait()
|
||||
|
|
@ -1,17 +1,7 @@
|
|||
import
|
||||
stew/shims/net, bearssl,
|
||||
eth/[keys, rlp],
|
||||
eth/p2p/discoveryv5/[enr, node, routing_table]
|
||||
|
||||
const UseDiscv51* {.booldefine.} = false
|
||||
|
||||
when UseDiscv51:
|
||||
import
|
||||
eth/p2p/discoveryv5/[typesv1, encodingv1],
|
||||
eth/p2p/discoveryv5/protocolv1 as discv5_protocol
|
||||
else:
|
||||
import
|
||||
eth/p2p/discoveryv5/[types, encoding],
|
||||
eth/keys,
|
||||
eth/p2p/discoveryv5/[enr, node, routing_table],
|
||||
eth/p2p/discoveryv5/protocol as discv5_protocol
|
||||
|
||||
proc localAddress*(port: int): Address =
|
||||
|
|
|
|||
|
|
@ -3,20 +3,13 @@ import
|
|||
chronos, chronicles, stint, testutils/unittests,
|
||||
stew/shims/net, eth/[keys, rlp], bearssl,
|
||||
eth/p2p/discoveryv5/[enr, node, routing_table],
|
||||
eth/p2p/discoveryv5/protocol as discv5_protocol,
|
||||
./discv5_test_helper
|
||||
|
||||
|
||||
### This is all just temporary to be compatible with both versions
|
||||
const UseDiscv51* {.booldefine.} = false
|
||||
|
||||
when UseDiscv51:
|
||||
### This is all just temporary to support both versions
|
||||
when not UseDiscv51:
|
||||
import
|
||||
eth/p2p/discoveryv5/[typesv1, encodingv1],
|
||||
eth/p2p/discoveryv5/protocolv1 as discv5_protocol
|
||||
else:
|
||||
import
|
||||
eth/p2p/discoveryv5/[types, encoding],
|
||||
eth/p2p/discoveryv5/protocol as discv5_protocol
|
||||
eth/p2p/discoveryv5/[types, encoding]
|
||||
|
||||
proc findNode*(d: discv5_protocol.Protocol, toNode: Node, distances: seq[uint32]):
|
||||
Future[DiscResult[seq[Node]]] =
|
||||
|
|
@ -344,6 +337,7 @@ procSuite "Discovery v5 Tests":
|
|||
block:
|
||||
targetSeqNum.inc()
|
||||
let update = targetNode.updateRecord({"addsomefield": @[byte 2]})
|
||||
check update.isOk()
|
||||
|
||||
# ping node so that its ENR gets added
|
||||
check (await targetNode.ping(lookupNode.localNode)).isOk()
|
||||
|
|
|
|||
Loading…
Reference in New Issue