maintain mix node pool based on discovered nodes

waku/node/waku_node.nim

@@ -14,6 +14,7 @@ import
   eth/p2p/discoveryv5/enr,
   libp2p/crypto/crypto,
   libp2p/crypto/curve25519,
+  libp2p/[multiaddress, multicodec],
   libp2p/protocols/ping,
   libp2p/protocols/pubsub/gossipsub,
   libp2p/protocols/pubsub/rpc/messages,
@@ -59,7 +60,9 @@ import
   ./config,
   ./peer_manager,
   ../common/rate_limit/setting,
-  ../discovery/autonat_service
+  ../discovery/autonat_service,
+  ../common/nimchronos,
+  ../waku_enr/mix
 
 declarePublicCounter waku_node_messages, "number of messages received", ["type"]
 declarePublicHistogram waku_histogram_message_size,
@@ -216,7 +219,7 @@ proc mountSharding*(
   node.wakuSharding = Sharding(clusterId: clusterId, shardCountGenZero: shardCount)
   return ok()
 
-proc getBootStrapMixNodes(node: WakuNode, exceptPeerID: PeerId): Table[PeerId, MixPubInfo] =
+#[ proc getBootStrapMixNodes(node: WakuNode, exceptPeerID: PeerId): Table[PeerId, MixPubInfo] =
   var mixNodes = initTable[PeerId, MixPubInfo]()
   # MixNode Multiaddrs and PublicKeys:
   let bootNodesMultiaddrs = ["/ip4/127.0.0.1/tcp/60001/p2p/16Uiu2HAmPiEs2ozjjJF2iN2Pe2FYeMC9w4caRHKYdLdAfjgbWM6o",
@@ -243,7 +246,79 @@ proc getBootStrapMixNodes(node: WakuNode, exceptPeerID: PeerId): Table[PeerId, M
     mixNodes[peerId] = mixNodePubInfo
   info "using mix bootstrap nodes ", bootNodes = mixNodes
   return mixNodes
+ ]#
 
+#TODO: Ideally these procs should be moved out into mix specific file, but keeping it here for now.
+proc mixPoolFilter*(cluster: Option[uint16], peer: RemotePeerInfo): bool =
+
+  if peer.enr.isNone():
+    debug "peer has no ENR", peer = $peer
+    return false
+
+  if cluster.isSome() and peer.enr.get().isClusterMismatched(cluster.get()):
+    debug "peer has mismatching cluster", peer = $peer
+    return false
+
+  #TODO: Filter if mix is enabled
+
+  return true
+
+proc addPeerId*(multiaddr: MultiAddress, peerId:PeerId): MultiAddress =
+  if multiaddr.contains(multiCodec("p2p")).get():
+    return multiaddr
+
+  var maddrStr = multiaddr.toString().valueOr:
+    error "Failed to convert multiaddress to string.", err = error
+    return multiaddr
+  maddrStr.add("/p2p/" & $peerId)
+  var cleanAddr = MultiAddress.init(maddrStr).valueOr:
+    error "Failed to convert string to multiaddress.", err = error
+    return multiaddr
+  return cleanAddr
+
+proc populateMixNodePool*(node: WakuNode){.async} =
+  var cluster: uint16
+  let enrRes = node.enr.toTyped()
+  if enrRes.isOk():
+    let shardingRes = enrRes.get().relaySharding()
+    if shardingRes.isSome():
+      let relayShard = shardingRes.get()
+      cluster = relayShard.clusterID
+  else:
+    error "could not get cluster from ENR", error = enrRes.error
+
+  # populate only peers that i) are reachable ii) share cluster iii) support mix
+  let remotePeers = node.peerManager.wakuPeerStore.getReachablePeers().filterIt(
+    mixPoolFilter(some(cluster), it)
+    )
+  var mixNodes = initTable[PeerId, MixPubInfo]()
+
+  for i in 0 ..< min(remotePeers.len, 100):
+    let remotePeerENR = remotePeers[i].enr.get()
+    # TODO: use the most exposed/external multiaddr of the peer, right now using the first
+    let maddrWithPeerId = toString(addPeerId(remotePeers[i].addrs[0],remotePeers[i].peerId))
+    debug "remote peer ENR", peerId = remotePeers[i].peerId, enr = remotePeerENR, maddr = maddrWithPeerId
+
+    let peerMixPubKey = mixKey(remotePeerENR).get()
+    let mixNodePubInfo = createMixPubInfo(maddrWithPeerId.value, intoCurve25519Key(peerMixPubKey))
+    mixNodes[remotePeers[i].peerId] = mixNodePubInfo
+
+  # set the mix node pool
+  node.mix.setNodePool(mixNodes)
+  debug "mix node pool updated", poolSize = node.mix.getNodePoolSize()
+  return
+
+
+proc startMixNodePoolMgr*(node: WakuNode ){.async} =
+  # try more aggressively to populate the pool at startup
+  var attempts = 50
+  while node.mix.getNodePoolSize() < 100 and attempts > 0:
+    attempts -= 1
+    discard node.populateMixNodePool()
+    await sleepAsync(1.seconds)
+
+  heartbeat "Updating mix node pool", 10.minutes:
+    discard node.populateMixNodePool()
 
  # Mix Protocol
 proc mountMix*(node: WakuNode, mixPrivKey: string): Future[Result[void, string]] {.async.}  =
@@ -261,8 +336,9 @@ proc mountMix*(node: WakuNode, mixPrivKey: string): Future[Result[void, string]]
     localaddrStr & "/p2p/" & $node.peerId, mixPubKey, mixKey, node.switch.peerInfo.publicKey.skkey,
     node.switch.peerInfo.privateKey.skkey,
   )
-
-  let protoRes = MixProtocol.initMix(localMixNodeInfo, node.switch, node.getBootStrapMixNodes(node.peerId))
+  # TODO: Pass bootnodes from config, 
+  # TODO : ideally mix should not be marked ready until certain min pool of mixNodes are discovered
+  let protoRes = MixProtocol.initMix(localMixNodeInfo, node.switch, initTable[PeerId, MixPubInfo]())
   if protoRes.isErr:
     error "Mix protocol initialization failed", err = protoRes.error
     return
@@ -273,6 +349,8 @@ proc mountMix*(node: WakuNode, mixPrivKey: string): Future[Result[void, string]]
   if catchRes.isErr():
     return err(catchRes.error.msg)
 
+  discard startMixNodePoolMgr(node)
+
   return ok()
 
 ## Waku Sync

waku/waku_enr/capabilities.nim

@@ -3,6 +3,7 @@
 import
   std/[options, bitops, sequtils, net, tables], results, eth/keys, libp2p/crypto/crypto
 import ../common/enr, ../waku_core/codecs
+import ../../vendor/mix/src/mix_protocol
 
 const CapabilitiesEnrField* = "waku2"
 
@@ -28,6 +29,7 @@ const capabilityToCodec = {
   Capabilities.Filter: WakuFilterSubscribeCodec,
   Capabilities.Lightpush: WakuLightPushCodec,
   Capabilities.Sync: WakuSyncCodec,
+  Capabilities.Mix: MixProtocolID
 }.toTable
 
 func init*(

waku/waku_enr/mix.nim

@@ -20,3 +20,13 @@ func mixKey*(record: TypedRecord): Option[seq[byte]] =
   if field.isNone():
     return none(seq[byte])
   return field
+
+func mixKey*(record: Record): Option[seq[byte]] =
+  let recordRes = record.toTyped()
+  if recordRes.isErr():
+    return none(seq[byte])
+
+  let field = recordRes.value.tryGet(MixKeyEnrField, seq[byte])
+  if field.isNone():
+    return none(seq[byte])
+  return field