Don't penalize flooding peers; Just rate limit them

beacon_chain/eth2_network.nim

@@ -380,7 +380,6 @@ const
   maxRequestQuota = 1000000.0
   fullReplenishTime = 5.seconds
   replenishRate = (maxRequestQuota / fullReplenishTime.nanoseconds.float)
-  requestFloodingThreshold = -500000.0
 
 proc updateRequestQuota*(peer: Peer, reqCost: float) =
   let
@@ -391,9 +390,10 @@ proc updateRequestQuota*(peer: Peer, reqCost: float) =
   peer.lastReqTime = currentTime
   peer.requestQuota = min(replenishedQuota, maxRequestQuota) - reqCost
 
-  if peer.requestQuota < requestFloodingThreshold:
-    peer.updateScore(PeerScoreFlooder)
-    peer.requestQuota = 0.0
+template awaitNonNegativeRequestQuota*(peer: Peer) =
+  let quota = peer.requestQuota
+  if quota < 0:
+    await sleepAsync(nanoseconds(int((-quota) / replenishRate)))
 
 func allowedOpsPerSecondCost*(n: int): float =
   (replenishRate * 1000000000'f / n.float)

beacon_chain/keystore_management.nim

@@ -568,6 +568,7 @@ proc pickPasswordAndSaveWallet(rng: var BrHmacDrbgContext,
     echoP "For your convenience, the wallet can be identified with a name " &
           "of your choice. Please enter a wallet name below or press ENTER " &
           "to continue with a machine-generated name."
+    echo ""
 
     while true:
       var enteredName = ask "Wallet name"

beacon_chain/sync_protocol.nim

@@ -158,6 +158,7 @@ p2pProtocol BeaconSync(version = 1,
       peer.updateRequestQuota(
         blockByRangeLookupCost +
         max(0, endIndex - startIndex + 1).float * blockResponseCost)
+      peer.awaitNonNegativeRequestQuota()
 
       for i in startIndex..endIndex:
         doAssert not blocks[i].isNil, "getBlockRange should return non-nil blocks only"
@@ -168,7 +169,7 @@ p2pProtocol BeaconSync(version = 1,
       debug "Block range request done",
         peer, startSlot, count, reqStep, found = count - startIndex
     else:
-      raise newException(InvalidInputsError, "Potential DoS attack: empty blocksByRange")
+      raise newException(InvalidInputsError, "Empty range requested")
 
   proc beaconBlocksByRoot(
       peer: Peer,
@@ -178,13 +179,14 @@ p2pProtocol BeaconSync(version = 1,
       response: MultipleChunksResponse[SignedBeaconBlock])
       {.async, libp2pProtocol("beacon_blocks_by_root", 1).} =
     if blockRoots.len == 0:
-      raise newException(InvalidInputsError, "Potential DoS attack: empty blocksByRoot")
+      raise newException(InvalidInputsError, "No blocks requested")
 
     let
       chainDag = peer.networkState.chainDag
       count = blockRoots.len
 
     peer.updateRequestQuota(count.float * blockByRootLookupCost)
+    peer.awaitNonNegativeRequestQuota()
 
     var found = 0
     for i in 0..<count: