Add resolve proc + test

eth/p2p/discoveryv5/protocol.nim

@@ -61,7 +61,7 @@ proc addNode*(d: Protocol, enr: EnrUri) =
   doAssert(res)
   d.addNode newNode(r)
 
-proc getNode*(d: Protocol, id: NodeId): Node =
+proc getNode*(d: Protocol, id: NodeId): Option[Node] =
   d.routingTable.getNode(id)
 
 proc randomNodes*(d: Protocol, count: int): seq[Node] =
@@ -213,9 +213,7 @@ proc receive*(d: Protocol, a: Address, msg: openArray[byte]) {.gcsafe,
     var packet: Packet
     let decoded = d.codec.decodeEncrypted(sender, a, msg, authTag, node, packet)
     if decoded == DecodeStatus.Success:
-      if node.isNil:
-        node = d.routingTable.getNode(sender)
-      else:
+      if not node.isNil:
         # Not filling table with nodes without correct IP in the ENR
         if a.ip == node.address.ip:
           debug "Adding new node to routing table", node = $node,
@@ -232,7 +230,7 @@ proc receive*(d: Protocol, a: Address, msg: openArray[byte]) {.gcsafe,
         if d.awaitedPackets.take((sender, packet.reqId), waiter):
           waiter.complete(packet.some)
         else:
-          debug "TODO: handle packet: ", packet = packet.kind, origin = $node
+          debug "TODO: handle packet: ", packet = packet.kind, origin = a
     elif decoded == DecodeStatus.DecryptError:
       debug "Could not decrypt packet, respond with whoareyou",
         localNode = $d.localNode, address = a
@@ -418,6 +416,31 @@ proc lookupRandom*(d: Protocol): Future[seq[Node]]
     raise newException(RandomSourceDepleted, "Could not randomize bytes")
   d.lookup(id)
 
+proc resolve*(d: Protocol, id: NodeId): Future[Option[Node]] {.async.} =
+  ## Resolve a `Node` based on provided `NodeId`.
+  ##
+  ## This will first look in the own DHT. 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)
+
+    if request.len > 0:
+      return some(request[0])
+
+  let discovered = await d.lookup(id)
+  for n in discovered:
+    if n.id == id:
+      # TODO: Not getting any new seqNum here as in a lookup nodes in table with
+      # new seqNum don't get replaced.
+      if node.isSome() and node.get().record.seqNum >= n.record.seqNum:
+        return node
+      else:
+        return some(n)
+
 proc revalidateNode*(d: Protocol, n: Node)
     {.async, raises:[Defect, Exception].} = # TODO: Exception
   trace "Ping to revalidate node", node = $n

eth/p2p/discoveryv5/routing_table.nim

@@ -1,5 +1,6 @@
 import
-  std/[algorithm, times, sequtils, bitops, random, sets], stint, chronicles,
+  std/[algorithm, times, sequtils, bitops, random, sets, options],
+  stint, chronicles,
   types, node
 
 type
@@ -174,11 +175,11 @@ proc addNode*(r: var RoutingTable, n: Node): Node =
     # Nothing added, ping evictionCandidate
     return evictionCandidate
 
-proc getNode*(r: RoutingTable, id: NodeId): Node =
+proc getNode*(r: RoutingTable, id: NodeId): Option[Node] =
   let b = r.bucketForNode(id)
   for n in b.nodes:
     if n.id == id:
-      return n
+      return some(n)
 
 proc contains*(r: RoutingTable, n: Node): bool = n in r.bucketForNode(n.id)
 

tests/p2p/test_discoveryv5.nim

@@ -60,7 +60,9 @@ suite "Discovery v5 Tests":
     for i in 0..<1000:
       node.addNode(generateNode())
 
-    check node.getNode(targetNode.id) == targetNode
+    let n = node.getNode(targetNode.id)
+    require n.isSome()
+    check n.get() == targetNode
 
     await node.closeWait()
 
@@ -82,8 +84,10 @@ suite "Discovery v5 Tests":
     await node1.revalidateNode(bootnode.localNode)
     await node1.revalidateNode(node2.localNode)
 
-    check node1.getNode(bootnode.localNode.id) == bootnode.localNode
-    check node1.getNode(node2.localNode.id) == nil
+    let n = node1.getNode(bootnode.localNode.id)
+    require n.isSome()
+    check n.get() == bootnode.localNode
+    check node1.getNode(node2.localNode.id).isNone()
 
     await node1.closeWait()
 
@@ -310,3 +314,66 @@ suite "Discovery v5 Tests":
 
     for node in nodes:
       await node.closeWait()
+
+  asyncTest "Resolve target":
+    let
+      mainNode = initDiscoveryNode(PrivateKey.random()[], localAddress(20301))
+      lookupNode = initDiscoveryNode(PrivateKey.random()[], localAddress(20302))
+      targetKey = PrivateKey.random()[]
+      targetAddress = localAddress(20303)
+      targetNode = initDiscoveryNode(targetKey, targetAddress)
+      targetId = targetNode.localNode.id
+
+    var targetSeqNum = targetNode.localNode.record.seqNum
+
+    # Populate DHT with target through a ping. Next, close target and see
+    # if resolve works (only local lookup)
+    block:
+      let pong = await targetNode.ping(mainNode.localNode)
+      require pong.isSome()
+      await targetNode.closeWait()
+      let n = await mainNode.resolve(targetId)
+      require n.isSome()
+      check:
+        n.get().id == targetId
+        n.get().record.seqNum == targetSeqNum
+
+    # Bring target back online, update seqNum in ENR, check if we get the
+    # updated ENR.
+    block:
+      # TODO: need to add some logic to update ENRs properly
+      targetSeqNum.inc()
+      let r = enr.Record.init(targetSeqNum, targetKey,
+        some(targetAddress.ip), targetAddress.tcpPort, targetAddress.udpPort)
+      targetNode.localNode.record = r
+      targetNode.open()
+      let n = await mainNode.resolve(targetId)
+      require n.isSome()
+      check:
+        n.get().id == targetId
+        n.get().record.seqNum == targetSeqNum
+
+    # Update seqNum in ENR again, ping lookupNode to be added in DHT,
+    # close targetNode, resolve should lookup, check if we get updated ENR.
+    block:
+      targetSeqNum.inc()
+      let r = enr.Record.init(3, targetKey, some(targetAddress.ip),
+        targetAddress.tcpPort, targetAddress.udpPort)
+      targetNode.localNode.record = r
+      let pong = await targetNode.ping(lookupNode.localNode)
+      require pong.isSome()
+
+      await targetNode.closeWait()
+      # TODO: This step should eventually not be needed and ENRs with new seqNum
+      # should just get updated in the lookup.
+      await mainNode.revalidateNode(targetNode.localNode)
+
+      mainNode.addNode(lookupNode.localNode.record)
+      let n = await mainNode.resolve(targetId)
+      require n.isSome()
+      check:
+        n.get().id == targetId
+        n.get().record.seqNum == targetSeqNum
+
+    await mainNode.closeWait()
+    await lookupNode.closeWait()