Waku v2 Node Discovery via DNS: Integration (#690)

.gitmodules

@@ -130,3 +130,8 @@
 	url = https://github.com/status-im/nim-zlib.git
 	ignore = untracked
 	branch = master
+[submodule "vendor/nim-dnsdisc"]
+	path = vendor/nim-dnsdisc
+	url = https://github.com/status-im/nim-dnsdisc.git
+	ignore = untracked
+	branch = main

CHANGELOG.md

@@ -6,6 +6,8 @@ This release contains the following:
 
 ### Features
 
+- Start of Waku node discovery via DNS following [EIP-1459](https://eips.ethereum.org/EIPS/eip-1459)
+
 ### Changes
 
 - GossipSub [prune backoff period](https://github.com/libp2p/specs/blob/master/pubsub/gossipsub/gossipsub-v1.1.md#prune-backoff-and-peer-exchange) is now the recommended 1 minute

tests/all_tests_v2.nim

@@ -16,7 +16,8 @@ import
   ./v2/test_peer_storage,
   ./v2/test_waku_keepalive,
   ./v2/test_migration_utils,
-  ./v2/test_namespacing_utils
+  ./v2/test_namespacing_utils,
+  ./v2/test_waku_dnsdisc
 
 when defined(rln):
   import ./v2/test_waku_rln_relay

tests/v2/test_waku_dnsdisc.nim

@@ -0,0 +1,97 @@
+{.used.}
+
+import
+  std/[sequtils, tables],
+  chronicles,
+  chronos,
+  testutils/unittests,
+  stew/shims/net,
+  stew/[base32, results],
+  libp2p/crypto/crypto,
+  eth/keys,
+  discovery/dnsdisc/builder,
+  ../../waku/v2/node/dnsdisc/waku_dnsdisc,
+  ../../waku/v2/node/wakunode2,
+  ../test_helpers
+
+procSuite "Waku DNS Discovery":
+  asyncTest "Waku DNS Discovery end-to-end":
+    ## Tests integrated DNS discovery, from building
+    ## the tree to connecting to discovered nodes
+    
+    # Create nodes and ENR. These will be added to the discoverable list
+    let
+      bindIp = ValidIpAddress.init("0.0.0.0")
+      nodeKey1 = crypto.PrivateKey.random(Secp256k1, rng[])[]
+      node1 = WakuNode.new(nodeKey1, bindIp, Port(60000))
+      enr1 = node1.enr
+      nodeKey2 = crypto.PrivateKey.random(Secp256k1, rng[])[]
+      node2 = WakuNode.new(nodeKey2, bindIp, Port(60002))
+      enr2 = node2.enr
+      nodeKey3 = crypto.PrivateKey.random(Secp256k1, rng[])[]
+      node3 = WakuNode.new(nodeKey3, bindIp, Port(60003))
+      enr3 = node3.enr
+    
+    node1.mountRelay()
+    node2.mountRelay()
+    node3.mountRelay()
+    await allFutures([node1.start(), node2.start(), node3.start()])
+    
+    # Build and sign tree
+    var tree = buildTree(1,                   # Seq no
+                         @[enr1, enr2, enr3], # ENR entries
+                         @[]).get()           # No link entries
+
+    let treeKeys = keys.KeyPair.random(rng[])
+
+    # Sign tree
+    check:
+      tree.signTree(treeKeys.seckey()).isOk()
+
+    # Create TXT records at domain
+    let
+      domain = "testnodes.aq"
+      zoneTxts = tree.buildTXT(domain).get()
+      username = Base32.encode(treeKeys.pubkey().toRawCompressed())
+      location = LinkPrefix & username & "@" & domain # See EIP-1459: https://eips.ethereum.org/EIPS/eip-1459
+    
+    # Create a resolver for the domain
+
+    proc resolver(domain: string): Future[string] {.async, gcsafe.} =
+      return zoneTxts[domain]
+    
+    # Create Waku DNS discovery client on a new Waku v2 node using the resolver
+
+    let
+      nodeKey4 = crypto.PrivateKey.random(Secp256k1, rng[])[]
+      node4 = WakuNode.new(nodeKey4, bindIp, Port(60004))
+      enr4 = node4.enr
+    
+    node4.mountRelay()
+    await node4.start()
+    
+    var wakuDnsDisc = WakuDnsDiscovery.init(enr4, location, resolver).get()
+
+    let res = wakuDnsDisc.findPeers()
+
+    check:
+      # We have discovered all three nodes
+      res.isOk()
+      res[].len == 3
+      res[].mapIt(it.peerId).contains(node1.peerInfo.peerId)
+      res[].mapIt(it.peerId).contains(node2.peerInfo.peerId)
+      res[].mapIt(it.peerId).contains(node3.peerInfo.peerId)
+    
+    # Connect to discovered nodes
+    await node4.connectToNodes(res[])
+
+    check:
+      # We have successfully connected to all discovered nodes
+      node4.peerManager.peers().anyIt(it.peerId == node1.peerInfo.peerId)
+      node4.peerManager.connectedness(node1.peerInfo.peerId) == Connected
+      node4.peerManager.peers().anyIt(it.peerId == node2.peerInfo.peerId)
+      node4.peerManager.connectedness(node2.peerInfo.peerId) == Connected
+      node4.peerManager.peers().anyIt(it.peerId == node3.peerInfo.peerId)
+      node4.peerManager.connectedness(node3.peerInfo.peerId) == Connected
+
+    await allFutures([node1.stop(), node2.stop(), node3.stop(), node4.stop()])

vendor/nim-dnsdisc

@@ -0,0 +1 @@
+Subproject commit dcb9290d004476fb0a5389baa88121b072abf135

waku/v2/node/config.nim

@@ -180,6 +180,18 @@ type
       desc: "Enable metrics logging: true|false"
       defaultValue: false
       name: "metrics-logging" }: bool
+    
+    ## DNS discovery config
+    
+    dnsDiscovery* {.
+      desc: "Enable discovering nodes via DNS"
+      defaultValue: false
+      name: "dns-discovery" }: bool
+    
+    dnsDiscoveryUrl* {.
+      desc: "URL for DNS node list in format 'enrtree://<key>@<fqdn>'",
+      defaultValue: ""
+      name: "dns-discovery-url" }: string
 
 # NOTE: Keys are different in nim-libp2p
 proc parseCmdArg*(T: type crypto.PrivateKey, p: TaintedString): T =

waku/v2/node/dnsdisc/waku_dnsdisc.nim

@@ -0,0 +1,174 @@
+{.push raises: [Defect].}
+
+## A set of utilities to integrate EIP-1459 DNS-based discovery
+## for Waku v2 nodes.
+## 
+## EIP-1459 is defined in https://eips.ethereum.org/EIPS/eip-1459
+
+import
+  std/options,
+  stew/shims/net,
+  chronicles,
+  chronos,
+  metrics,
+  eth/keys,
+  eth/p2p/discoveryv5/enr,
+  libp2p/crypto/crypto,
+  libp2p/crypto/secp,
+  libp2p/peerinfo,
+  libp2p/multiaddress,
+  discovery/dnsdisc/client
+
+export client
+
+declarePublicGauge waku_dnsdisc_discovered, "number of nodes discovered"
+declarePublicGauge waku_dnsdisc_errors, "number of waku dnsdisc errors", ["type"]
+
+logScope:
+  topics = "wakudnsdisc"
+
+type
+  WakuDnsDiscovery* = object
+    enr*: enr.Record
+    client*: Client
+    resolver*: Resolver
+
+##################
+# Util functions #
+##################
+
+func getTransportProtocol(typedR: TypedRecord): Option[IpTransportProtocol] =
+  if typedR.tcp6.isSome or typedR.tcp.isSome:
+    return some(IpTransportProtocol.tcpProtocol)
+
+  if typedR.udp6.isSome or typedR.udp.isSome:
+    return some(IpTransportProtocol.udpProtocol)
+
+  return none(IpTransportProtocol)
+
+func toPeerInfo*(enr: enr.Record): Result[PeerInfo, cstring] =
+  let typedR = ? enr.toTypedRecord
+
+  if not typedR.secp256k1.isSome:
+    return err("enr: no secp256k1 key in record")
+  
+  let
+    pubKey = ? keys.PublicKey.fromRaw(typedR.secp256k1.get)
+    peerId = ? PeerID.init(crypto.PublicKey(scheme: Secp256k1,
+                                            skkey: secp.SkPublicKey(pubKey)))
+  
+  var addrs = newSeq[MultiAddress]()
+
+  let transportProto = getTransportProtocol(typedR)
+  if transportProto.isNone:
+    return err("enr: could not determine transport protocol")
+
+  case transportProto.get()
+  of tcpProtocol:
+    if typedR.ip.isSome and typedR.tcp.isSome:
+      let ip = ipv4(typedR.ip.get)
+      addrs.add MultiAddress.init(ip, tcpProtocol, Port typedR.tcp.get)
+
+    if typedR.ip6.isSome:
+      let ip = ipv6(typedR.ip6.get)
+      if typedR.tcp6.isSome:
+        addrs.add MultiAddress.init(ip, tcpProtocol, Port typedR.tcp6.get)
+      elif typedR.tcp.isSome:
+        addrs.add MultiAddress.init(ip, tcpProtocol, Port typedR.tcp.get)
+      else:
+        discard
+
+  of udpProtocol:
+    if typedR.ip.isSome and typedR.udp.isSome:
+      let ip = ipv4(typedR.ip.get)
+      addrs.add MultiAddress.init(ip, udpProtocol, Port typedR.udp.get)
+
+    if typedR.ip6.isSome:
+      let ip = ipv6(typedR.ip6.get)
+      if typedR.udp6.isSome:
+        addrs.add MultiAddress.init(ip, udpProtocol, Port typedR.udp6.get)
+      elif typedR.udp.isSome:
+        addrs.add MultiAddress.init(ip, udpProtocol, Port typedR.udp.get)
+      else:
+        discard
+
+  if addrs.len == 0:
+    return err("enr: no addresses in record")
+
+  return ok(PeerInfo.init(peerId, addrs))
+
+func createEnr*(privateKey: crypto.PrivateKey,
+                enrIp: Option[ValidIpAddress],
+                enrTcpPort, enrUdpPort: Option[Port]): enr.Record =
+  
+  assert privateKey.scheme == PKScheme.Secp256k1
+
+  let
+    rawPk = privateKey.getRawBytes().expect("Private key is valid")
+    pk = keys.PrivateKey.fromRaw(rawPk).expect("Raw private key is of valid length")
+    enr = enr.Record.init(1, pk, enrIp, enrTcpPort, enrUdpPort).expect("Record within size limits")
+  
+  return enr
+
+#####################
+# DNS Discovery API #
+#####################
+
+proc emptyResolver*(domain: string): Future[string] {.async, gcsafe.} =
+  debug "Empty resolver called", domain=domain
+  return ""
+
+proc findPeers*(wdd: var WakuDnsDiscovery): Result[seq[PeerInfo], cstring] =
+  ## Find peers to connect to using DNS based discovery
+  
+  info "Finding peers using Waku DNS discovery"
+  
+  # Synchronise client tree using configured resolver
+  var tree: Tree
+  try:
+    tree = wdd.client.getTree(wdd.resolver)  # @TODO: this is currently a blocking operation to not violate memory safety
+  except Exception:
+    error "Failed to synchronise client tree"
+    waku_dnsdisc_errors.inc(labelValues = ["tree_sync_failure"])
+    return err("Node discovery failed")
+
+  let discoveredEnr = wdd.client.getNodeRecords()
+
+  if discoveredEnr.len > 0:
+    info "Successfully discovered ENR", count=discoveredEnr.len
+  else:
+    trace "No ENR retrieved from client tree"
+
+  var discoveredNodes: seq[PeerInfo]
+
+  for enr in discoveredEnr:
+    # Convert discovered ENR to PeerInfo and add to discovered nodes
+    let res = enr.toPeerInfo()
+
+    if res.isOk():
+      discoveredNodes.add(res.get())
+    else:
+      error "Failed to convert ENR to peer info", enr=enr, err=res.error()
+      waku_dnsdisc_errors.inc(labelValues = ["peer_info_failure"])
+
+  if discoveredNodes.len > 0:
+    info "Successfully discovered nodes", count=discoveredNodes.len
+    waku_dnsdisc_discovered.inc(discoveredNodes.len.int64)
+
+  return ok(discoveredNodes)
+
+proc init*(T: type WakuDnsDiscovery,
+           enr: enr.Record,
+           locationUrl: string,
+           resolver: Resolver): Result[T, cstring] =
+  ## Initialise Waku peer discovery via DNS
+  
+  debug "init WakuDnsDiscovery", enr=enr, locationUrl=locationUrl
+  
+  let
+    client = ? Client.init(locationUrl)
+    wakuDnsDisc = WakuDnsDiscovery(enr: enr, client: client, resolver: resolver)
+
+  debug "init success"
+
+  return ok(wakuDnsDisc)

waku/v2/node/wakunode2.nim

@@ -5,6 +5,7 @@ import
   chronos, chronicles, metrics,
   stew/shims/net as stewNet,
   eth/keys,
+  eth/p2p/discoveryv5/enr,
   libp2p/crypto/crypto,
   libp2p/protocols/ping,
   libp2p/protocols/pubsub/gossipsub,
@@ -18,7 +19,8 @@ import
   ../utils/peers,
   ../utils/requests,
   ./storage/migration/migration_types,
-  ./peer_manager/peer_manager
+  ./peer_manager/peer_manager,
+  ./dnsdisc/waku_dnsdisc
 
 export
   builders,
@@ -74,6 +76,7 @@ type
     wakuRlnRelay*: WakuRLNRelay
     wakuLightPush*: WakuLightPush
     peerInfo*: PeerInfo
+    enr*: enr.Record
     libp2pPing*: Ping
     libp2pTransportLoops*: seq[Future[void]]
     filters*: Filters
@@ -135,6 +138,12 @@ proc new*(T: type WakuNode, nodeKey: crypto.PrivateKey,
     announcedAddresses = if extIp.isNone() or extPort.isNone(): @[]
                          else: @[tcpEndPoint(extIp.get(), extPort.get())]
     peerInfo = PeerInfo.init(nodekey)
+    enrIp = if extIp.isSome(): extIp
+            else: some(bindIp)
+    enrTcpPort = if extPort.isSome(): extPort
+                 else: some(bindPort)
+    enr = createEnr(nodeKey, enrIp, enrTcpPort, none(Port))
+  
   info "Initializing networking", hostAddress,
                                   announcedAddresses
   # XXX: Add this when we create node or start it?
@@ -156,6 +165,7 @@ proc new*(T: type WakuNode, nodeKey: crypto.PrivateKey,
     switch: switch,
     rng: rng,
     peerInfo: peerInfo,
+    enr: enr,
     filters: initTable[string, Filter]()
   )
 
@@ -659,6 +669,7 @@ proc start*(node: WakuNode) {.async.} =
   let listenStr = $peerInfo.addrs[^1] & "/p2p/" & $peerInfo.peerId
   ## XXX: this should be /ip4..., / stripped?
   info "Listening on", full = listenStr
+  info "Discoverable ENR ", enr = node.enr.toURI()
 
   if not node.wakuRelay.isNil:
     await node.startRelay()
@@ -838,6 +849,22 @@ when isMainModule:
     # Connect to configured static nodes
     if conf.staticnodes.len > 0:
       waitFor connectToNodes(node, conf.staticnodes)
+    
+    # Connect to discovered nodes
+    if conf.dnsDiscovery and conf.dnsDiscoveryUrl != "":
+      # @ TODO: this is merely POC integration with an empty resolver
+      debug "Waku DNS Discovery enabled. Using empty resolver."
+      
+      var wakuDnsDiscovery = WakuDnsDiscovery.init(node.enr,
+                                                   conf.dnsDiscoveryUrl,
+                                                   emptyResolver)  # TODO: Add DNS resolver
+      if wakuDnsDiscovery.isOk:
+        let discoveredPeers = wakuDnsDiscovery.get().findPeers()
+        if discoveredPeers.isOk:
+          info "Connecting to discovered peers"
+          waitFor connectToNodes(node, discoveredPeers.get())
+      else:
+        warn "Failed to init Waku DNS discovery"
 
     # Start keepalive, if enabled
     if conf.keepAlive: