Topics validation and direct peers (#2237)

* pick the right libp2p branch

* add topics validation

beacon_chain/eth2_network.nim

@@ -1,6 +1,6 @@
 import
   # Std lib
-  std/[typetraits, strutils, os, algorithm, math, sets],
+  std/[typetraits, strutils, sequtils, os, algorithm, math, sets],
   std/options as stdOptions,
 
   # Status libs
@@ -74,6 +74,7 @@ type
     forkId: ENRForkID
     rng*: ref BrHmacDrbgContext
     peers*: Table[PeerID, Peer]
+    validTopics: HashSet[string]
 
   EthereumNode = Eth2Node # needed for the definitions in p2p_backends_helpers
 
@@ -1596,6 +1597,14 @@ proc subscribe*(node: Eth2Node, topic: string, enableTopicMetrics: bool = false)
 
   node.pubsub.subscribe(topicName, dummyMsgHandler)
 
+proc setValidTopics*(node: Eth2Node, topics: openArray[string]) =
+  let topicsSnappy = topics.mapIt(it & "_snappy")
+  node.validTopics = topicsSnappy.toHashSet()
+  # there is a window of time where we got the switch open, we need this lazy update for now
+  node.pubsub.subscriptionValidator =
+    proc(topic: string): bool {.gcsafe, raises: [Defect].} =
+      topic in node.validTopics
+
 proc addValidator*[MsgType](node: Eth2Node,
                             topic: string,
                             msgValidator: proc(msg: MsgType):

beacon_chain/nimbus_beacon_node.nim

@@ -296,6 +296,21 @@ proc init*(T: type BeaconNode,
     topicAggregateAndProofs: topicAggregateAndProofs,
   )
 
+  # set topic validation routine
+  network.setValidTopics(
+    block:
+      var
+        topics = @[
+            topicBeaconBlocks,
+            getAttesterSlashingsTopic(enrForkId.forkDigest),
+            getProposerSlashingsTopic(enrForkId.forkDigest),
+            getVoluntaryExitsTopic(enrForkId.forkDigest),
+            getAggregateAndProofsTopic(enrForkId.forkDigest)
+          ]
+      for subnet in 0'u64 ..< ATTESTATION_SUBNET_COUNT:
+        topics &= getAttestationTopic(enrForkId.forkDigest, subnet)
+      topics)
+
   info "Loading slashing protection database", path = conf.validatorsDir()
   res.attachedValidators = ValidatorPool.init(
     SlashingProtectionDB.init(

vendor/nim-libp2p

@@ -1 +1 @@
-Subproject commit 3878a95b23306494b5ad1138383b78df7c7e42d0
+Subproject commit 983003a52b22926603f25bdf54c26e8a23c97254