chore: Discovery in libwaku (#2711)

* cwaku_example: add discoveryv5-discovery bool option
* libwaku: implement discovery capabilities
* node_lifecycle_request.nim: better control of possible errors when parsing config

examples/cbindings/waku_example.c

@@ -267,8 +267,8 @@ int main(int argc, char** argv) {
         show_help_and_exit();
     }
 
-    char jsonConfig[2048];
-    snprintf(jsonConfig, 2048, "{ \
+    char jsonConfig[5000];
+    snprintf(jsonConfig, 5000, "{ \
                                     \"listenAddress\": \"%s\",    \
                                     \"tcpPort\": %d,        \
                                     \"nodekey\": \"%s\",     \
@@ -277,7 +277,14 @@ int main(int argc, char** argv) {
                                     \"storeMessageDbUrl\": \"%s\",  \
                                     \"storeMessageRetentionPolicy\": \"%s\",  \
                                     \"storeMaxNumDbConnections\": %d , \
-                                    \"logLevel\": \"DEBUG\" \
+                                    \"logLevel\": \"DEBUG\", \
+                                    \"discv5Discovery\": true, \
+                                    \"discv5BootstrapNodes\": \
+                                        [\"enr:-QESuEB4Dchgjn7gfAvwB00CxTA-nGiyk-aALI-H4dYSZD3rUk7bZHmP8d2U6xDiQ2vZffpo45Jp7zKNdnwDUx6g4o6XAYJpZIJ2NIJpcIRA4VDAim11bHRpYWRkcnO4XAArNiZub2RlLTAxLmRvLWFtczMud2FrdS5zYW5kYm94LnN0YXR1cy5pbQZ2XwAtNiZub2RlLTAxLmRvLWFtczMud2FrdS5zYW5kYm94LnN0YXR1cy5pbQYfQN4DgnJzkwABCAAAAAEAAgADAAQABQAGAAeJc2VjcDI1NmsxoQOvD3S3jUNICsrOILlmhENiWAMmMVlAl6-Q8wRB7hidY4N0Y3CCdl-DdWRwgiMohXdha3UyDw\", \"enr:-QEkuEBIkb8q8_mrorHndoXH9t5N6ZfD-jehQCrYeoJDPHqT0l0wyaONa2-piRQsi3oVKAzDShDVeoQhy0uwN1xbZfPZAYJpZIJ2NIJpcIQiQlleim11bHRpYWRkcnO4bgA0Ni9ub2RlLTAxLmdjLXVzLWNlbnRyYWwxLWEud2FrdS5zYW5kYm94LnN0YXR1cy5pbQZ2XwA2Ni9ub2RlLTAxLmdjLXVzLWNlbnRyYWwxLWEud2FrdS5zYW5kYm94LnN0YXR1cy5pbQYfQN4DgnJzkwABCAAAAAEAAgADAAQABQAGAAeJc2VjcDI1NmsxoQKnGt-GSgqPSf3IAPM7bFgTlpczpMZZLF3geeoNNsxzSoN0Y3CCdl-DdWRwgiMohXdha3UyDw\"], \
+                                    \"discv5UdpPort\": 9999, \
+                                    \"dnsDiscovery\": true, \
+                                    \"dnsDiscoveryUrl\": \"enrtree://AOGYWMBYOUIMOENHXCHILPKY3ZRFEULMFI4DOM442QSZ73TT2A7VI@test.waku.nodes.status.im\", \
+                                    \"dnsDiscoveryNameServers\": [\"8.8.8.8\", \"1.0.0.1\"] \
                                 }", cfgNode.host,
                                     cfgNode.port,
                                     cfgNode.key,
@@ -313,6 +320,11 @@ int main(int argc, char** argv) {
                                     event_handler,
                                     userData) );
 
+    WAKU_CALL( waku_discv5_update_bootnodes(ctx,
+                                  "[\"enr:-QEkuEBIkb8q8_mrorHndoXH9t5N6ZfD-jehQCrYeoJDPHqT0l0wyaONa2-piRQsi3oVKAzDShDVeoQhy0uwN1xbZfPZAYJpZIJ2NIJpcIQiQlleim11bHRpYWRkcnO4bgA0Ni9ub2RlLTAxLmdjLXVzLWNlbnRyYWwxLWEud2FrdS5zYW5kYm94LnN0YXR1cy5pbQZ2XwA2Ni9ub2RlLTAxLmdjLXVzLWNlbnRyYWwxLWEud2FrdS5zYW5kYm94LnN0YXR1cy5pbQYfQN4DgnJzkwABCAAAAAEAAgADAAQABQAGAAeJc2VjcDI1NmsxoQKnGt-GSgqPSf3IAPM7bFgTlpczpMZZLF3geeoNNsxzSoN0Y3CCdl-DdWRwgiMohXdha3UyDw\",\"enr:-QEkuEB3WHNS-xA3RDpfu9A2Qycr3bN3u7VoArMEiDIFZJ66F1EB3d4wxZN1hcdcOX-RfuXB-MQauhJGQbpz3qUofOtLAYJpZIJ2NIJpcIQI2SVcim11bHRpYWRkcnO4bgA0Ni9ub2RlLTAxLmFjLWNuLWhvbmdrb25nLWMud2FrdS5zYW5kYm94LnN0YXR1cy5pbQZ2XwA2Ni9ub2RlLTAxLmFjLWNuLWhvbmdrb25nLWMud2FrdS5zYW5kYm94LnN0YXR1cy5pbQYfQN4DgnJzkwABCAAAAAEAAgADAAQABQAGAAeJc2VjcDI1NmsxoQPK35Nnz0cWUtSAhBp7zvHEhyU_AqeQUlqzLiLxfP2L4oN0Y3CCdl-DdWRwgiMohXdha3UyDw\"]",
+                                  event_handler,
+                                  userData) );
+
     show_main_menu();
     while(1) {
         handle_user_input();

library/libwaku.h

@@ -92,6 +92,25 @@ int waku_listen_addresses(void* ctx,
                           WakuCallBack callback,
                           void* userData);
 
+// Returns a list of multiaddress given a url to a DNS discoverable ENR tree
+// Parameters
+//     char* entTreeUrl: URL containing a discoverable ENR tree
+//     char* nameDnsServer: The nameserver to resolve the ENR tree url.
+//     int timeoutMs: Timeout value in milliseconds to execute the call.
+int waku_dns_discovery(void* ctx,
+                       const char* entTreeUrl,
+                       const char* nameDnsServer,
+                       int timeoutMs,
+                       WakuCallBack callback,
+                       void* userData);
+
+// Updates the bootnode list used for discovering new peers via DiscoveryV5
+// bootnodes - JSON array containing the bootnode ENRs i.e. `["enr:...", "enr:..."]`
+int waku_discv5_update_bootnodes(void* ctx,
+                                 char* bootnodes,
+                                 WakuCallBack callback,
+                                 void* userData);
+
 #ifdef __cplusplus
 }
 #endif

library/libwaku.nim

@@ -17,6 +17,7 @@ import
   ./waku_thread/inter_thread_communication/requests/protocols/relay_request,
   ./waku_thread/inter_thread_communication/requests/protocols/store_request,
   ./waku_thread/inter_thread_communication/requests/debug_node_request,
+  ./waku_thread/inter_thread_communication/requests/discovery_request,
   ./waku_thread/inter_thread_communication/waku_thread_request,
   ./alloc,
   ./callback
@@ -397,5 +398,52 @@ proc waku_listen_addresses(
     callback(RET_OK, unsafeAddr msg[0], cast[csize_t](len(msg)), userData)
     return RET_OK
 
+proc waku_dns_discovery(
+    ctx: ptr Context,
+    entTreeUrl: cstring,
+    nameDnsServer: cstring,
+    timeoutMs: cint,
+    callback: WakuCallBack,
+    userData: pointer,
+): cint {.dynlib, exportc.} =
+  ctx[].userData = userData
+
+  let bootstrapPeers = waku_thread.sendRequestToWakuThread(
+    ctx,
+    RequestType.DISCOVERY,
+    DiscoveryRequest.createRetrieveBootstrapNodesRequest(
+      DiscoveryMsgType.GET_BOOTSTRAP_NODES, entTreeUrl, nameDnsServer, timeoutMs
+    ),
+  ).valueOr:
+    let msg = $error
+    callback(RET_ERR, unsafeAddr msg[0], cast[csize_t](len(msg)), userData)
+    return RET_ERR
+
+  let msg = $bootstrapPeers
+  callback(RET_OK, unsafeAddr msg[0], cast[csize_t](len(msg)), userData)
+  return RET_OK
+
+proc waku_discv5_update_bootnodes(
+    ctx: ptr Context, bootnodes: cstring, callback: WakuCallBack, userData: pointer
+): cint {.dynlib, exportc.} =
+  ## Updates the bootnode list used for discovering new peers via DiscoveryV5
+  ## bootnodes - JSON array containing the bootnode ENRs i.e. `["enr:...", "enr:..."]`
+  ctx[].userData = userData
+
+  let resp = waku_thread.sendRequestToWakuThread(
+    ctx,
+    RequestType.DISCOVERY,
+    DiscoveryRequest.createUpdateBootstrapNodesRequest(
+      DiscoveryMsgType.UPDATE_DISCV5_BOOTSTRAP_NODES, bootnodes
+    ),
+  ).valueOr:
+    let msg = $error
+    callback(RET_ERR, unsafeAddr msg[0], cast[csize_t](len(msg)), userData)
+    return RET_ERR
+
+  let msg = $resp
+  callback(RET_OK, unsafeAddr msg[0], cast[csize_t](len(msg)), userData)
+  return RET_OK
+
 ### End of exported procs
 ################################################################################

library/waku_thread/inter_thread_communication/requests/discovery_request.nim

@@ -0,0 +1,99 @@
+import std/[json, sequtils]
+import chronos, stew/results, libp2p/multiaddress
+import
+  ../../../../waku/factory/waku,
+  ../../../../waku/discovery/waku_dnsdisc,
+  ../../../../waku/discovery/waku_discv5,
+  ../../../../waku/waku_core/peers,
+  ../../../alloc
+
+type DiscoveryMsgType* = enum
+  GET_BOOTSTRAP_NODES
+  UPDATE_DISCV5_BOOTSTRAP_NODES
+
+type DiscoveryRequest* = object
+  operation: DiscoveryMsgType
+
+  ## used in GET_BOOTSTRAP_NODES
+  enrTreeUrl: cstring
+  nameDnsServer: cstring
+  timeoutMs: cint
+
+  ## used in UPDATE_DISCV5_BOOTSTRAP_NODES
+  nodes: cstring
+
+proc createShared(
+    T: type DiscoveryRequest,
+    op: DiscoveryMsgType,
+    enrTreeUrl: cstring,
+    nameDnsServer: cstring,
+    timeoutMs: cint,
+    nodes: cstring,
+): ptr type T =
+  var ret = createShared(T)
+  ret[].operation = op
+  ret[].enrTreeUrl = enrTreeUrl.alloc()
+  ret[].nameDnsServer = nameDnsServer.alloc()
+  ret[].timeoutMs = timeoutMs
+  ret[].nodes = nodes.alloc()
+  return ret
+
+proc createRetrieveBootstrapNodesRequest*(
+    T: type DiscoveryRequest,
+    op: DiscoveryMsgType,
+    enrTreeUrl: cstring,
+    nameDnsServer: cstring,
+    timeoutMs: cint,
+): ptr type T =
+  return T.createShared(op, enrTreeUrl, nameDnsServer, timeoutMs, "")
+
+proc createUpdateBootstrapNodesRequest*(
+    T: type DiscoveryRequest, op: DiscoveryMsgType, nodes: cstring
+): ptr type T =
+  return T.createShared(op, "", "", 0, nodes)
+
+proc destroyShared(self: ptr DiscoveryRequest) =
+  deallocShared(self[].enrTreeUrl)
+  deallocShared(self[].nameDnsServer)
+  deallocShared(self)
+
+proc retrieveBootstrapNodes(
+    enrTreeUrl: string, ipDnsServer: string
+): Result[seq[string], string] =
+  let dnsNameServers = @[parseIpAddress(ipDnsServer)]
+  let discoveredPeers: seq[RemotePeerInfo] = retrieveDynamicBootstrapNodes(
+    true, enrTreeUrl, dnsNameServers
+  ).valueOr:
+    return err("failed discovering peers from DNS: " & $error)
+
+  var multiAddresses = newSeq[string]()
+
+  for discPeer in discoveredPeers:
+    for address in discPeer.addrs:
+      multiAddresses.add($address & "/" & $discPeer)
+
+  return ok(multiAddresses)
+
+proc updateDiscv5BootstrapNodes(nodes: string, waku: ptr Waku): Result[void, string] =
+  waku.wakuDiscv5.updateBootstrapRecords(nodes).isOkOr:
+    return err("error in updateDiscv5BootstrapNodes: " & $error)
+  return ok()
+
+proc process*(
+    self: ptr DiscoveryRequest, waku: ptr Waku
+): Future[Result[string, string]] {.async.} =
+  defer:
+    destroyShared(self)
+
+  case self.operation
+  of GET_BOOTSTRAP_NODES:
+    let nodes = retrieveBootstrapNodes($self[].enrTreeUrl, $self[].nameDnsServer).valueOr:
+      return err($error)
+
+    return ok($(%*nodes))
+  of UPDATE_DISCV5_BOOTSTRAP_NODES:
+    updateDiscv5BootstrapNodes($self[].nodes, waku).isOkOr:
+      return err($error)
+    return ok("discovery request processed correctly")
+
+  return err("discovery request not handled")

library/waku_thread/inter_thread_communication/requests/node_lifecycle_request.nim

@@ -36,17 +36,28 @@ proc createWaku(configJson: cstring): Future[Result[Waku, string]] {.async.} =
 
   var errorResp: string
 
+  var jsonNode: JsonNode
   try:
-    let jsonNode = parseJson($configJson)
+    jsonNode = parseJson($configJson)
+  except Exception:
+    return err(
+      "exception in createWaku when calling parseJson: " & getCurrentExceptionMsg() &
+        " configJson string: " & $configJson
+    )
 
-    for confField, confValue in fieldPairs(conf):
-      if jsonNode.contains(confField):
-        # Make sure string doesn't contain the leading or trailing " character
-        let formattedString = ($jsonNode[confField]).strip(chars = {'\"'})
-        # Override conf field with the value set in the json-string
+  for confField, confValue in fieldPairs(conf):
+    if jsonNode.contains(confField):
+      # Make sure string doesn't contain the leading or trailing " character
+      let formattedString = ($jsonNode[confField]).strip(chars = {'\"'})
+      # Override conf field with the value set in the json-string
+      try:
         confValue = parseCmdArg(typeof(confValue), formattedString)
-  except Exception:
-    return err("exception parsing configuration: " & getCurrentExceptionMsg())
+      except Exception:
+        return err(
+          "exception in createWaku when parsing configuration. exc: " &
+            getCurrentExceptionMsg() & ". string that could not be parsed: " &
+            formattedString & ". expected type: " & $typeof(confValue)
+        )
 
   let wakuRes = Waku.init(conf).valueOr:
     error "waku initialization failed", error = error

library/waku_thread/inter_thread_communication/waku_thread_request.nim

@@ -10,14 +10,16 @@ import
   ./requests/peer_manager_request,
   ./requests/protocols/relay_request,
   ./requests/protocols/store_request,
-  ./requests/debug_node_request
+  ./requests/debug_node_request,
+  ./requests/discovery_request
 
 type RequestType* {.pure.} = enum
   LIFECYCLE
   PEER_MANAGER
   RELAY
   STORE
   DEBUG
+  DISCOVERY
 
 type InterThreadRequest* = object
   reqType: RequestType
@@ -52,6 +54,8 @@ proc process*(
       cast[ptr StoreRequest](request[].reqContent).process(waku)
     of DEBUG:
       cast[ptr DebugNodeRequest](request[].reqContent).process(waku[])
+    of DISCOVERY:
+      cast[ptr DiscoveryRequest](request[].reqContent).process(waku)
 
   return await retFut
 

waku/discovery/waku_discv5.nim

@@ -4,7 +4,7 @@ else:
   {.push raises: [].}
 
 import
-  std/[sequtils, strutils, options, sets, net],
+  std/[sequtils, strutils, options, sets, net, json],
   stew/results,
   chronos,
   chronicles,
@@ -373,3 +373,28 @@ proc setupDiscoveryV5*(
   WakuDiscoveryV5.new(
     rng, discv5Conf, some(myENR), some(nodePeerManager), nodeTopicSubscriptionQueue
   )
+
+proc updateBootstrapRecords*(
+    self: var WakuDiscoveryV5, newRecordsString: string
+): Result[void, string] =
+  ## newRecordsString - JSON array containing the bootnode ENRs i.e. `["enr:...", "enr:..."]`
+  var newRecords = newSeq[waku_enr.Record]()
+
+  var jsonNode: JsonNode
+  try:
+    jsonNode = parseJson(newRecordsString)
+  except Exception:
+    return err("exception parsing json enr records: " & getCurrentExceptionMsg())
+
+  if jsonNode.kind != JArray:
+    return err("updateBootstrapRecords should receive a json array containing ENRs")
+
+  for enr in jsonNode:
+    let enrWithoutQuotes = ($enr).replace("\"", "")
+    var bootstrapNodeEnr: waku_enr.Record
+    if not bootstrapNodeEnr.fromURI(enrWithoutQuotes):
+      return err("wrong enr given: " & enrWithoutQuotes)
+
+  self.protocol.bootstrapRecords = newRecords
+
+  return ok()