Some version of the findContent JSON-RPC proc (#918)

Also includes fixing instantiation of the history network json-rpc
API handles.

fluffy/docs/protocol_interop.md

@@ -48,6 +48,10 @@ curl -s -X POST -H 'Content-Type: application/json' -d '{"jsonrpc":"2.0","id":"1
 # Extra parameter is an array of requested logarithmic distances
 curl -s -X POST -H 'Content-Type: application/json' -d '{"jsonrpc":"2.0","id":"1","method":"portal_state_findNodes","params":["enr:<base64 encoding of ENR>", [254, 255, 256]]}' http://localhost:8545 | jq
 
+# FindContent / Content
+# A request with an invalid content key will not receive a response
+curl -s -X POST -H 'Content-Type: application/json' -d '{"jsonrpc":"2.0","id":"1","method":"portal_state_findContent","params":["enr:<base64 encoding of ENR>", "02829bd824b016326a401d083b33d092293333a830d1c390624d3bd4e409a61a858e5dcc5517729a9170d014a6c96530d64dd8621d"]}' http://localhost:8545 | jq
+
 # Read out the Portal state network routing table contents
 curl -s -X POST -H 'Content-Type: application/json' -d '{"jsonrpc":"2.0","id":"1","method":"portal_state_routingTableInfo","params":[]}' http://localhost:8545 | jq
 ```

fluffy/fluffy.nim

@@ -99,7 +99,7 @@ proc run(config: PortalConf) {.raises: [CatchableError, Defect].} =
     rpcHttpServerWithProxy.installEthApiHandlers()
     rpcHttpServerWithProxy.installDiscoveryApiHandlers(d)
     rpcHttpServerWithProxy.installPortalApiHandlers(stateNetwork.portalProtocol, "state")
-    rpcHttpServerWithProxy.installPortalApiHandlers(stateNetwork.portalProtocol, "history")
+    rpcHttpServerWithProxy.installPortalApiHandlers(historyNetwork.portalProtocol, "history")
     # TODO for now we can only proxy to local node (or remote one without ssl) to make it possible
     # to call infura https://github.com/status-im/nim-json-rpc/pull/101 needs to get merged for http client to support https/
     waitFor rpcHttpServerWithProxy.start()

fluffy/network/wire/portal_protocol.nim

@@ -24,7 +24,7 @@ logScope:
 
 const
   alpha = 3 ## Kademlia concurrency factor
-  enrsResultLimit = 32 ## Maximum amount of ENRs in the total Nodes messages
+  enrsResultLimit* = 32 ## Maximum amount of ENRs in the total Nodes messages
   ## that will be processed
   refreshInterval = 5.minutes ## Interval of launching a random query to
   ## refresh the routing table.
@@ -308,7 +308,7 @@ proc offer*(p: PortalProtocol, dst: Node, contentKeys: ContentKeysList):
   # id, and initiate an uTP stream with given uTP connection id to get the data
   # out.
 
-proc recordsFromBytes(rawRecords: List[ByteList, 32]): PortalResult[seq[Record]] =
+proc recordsFromBytes*(rawRecords: List[ByteList, 32]): PortalResult[seq[Record]] =
   var records: seq[Record]
   for r in rawRecords.asSeq():
     var record: Record

fluffy/rpc/rpc_portal_api.nim

@@ -10,6 +10,7 @@
 import
   std/sequtils,
   json_rpc/[rpcproxy, rpcserver], stew/byteutils,
+  eth/p2p/discoveryv5/nodes_verification,
   ../network/wire/portal_protocol,
   ./rpc_types
 
@@ -63,6 +64,49 @@ proc installPortalApiHandlers*(
     else:
       return nodes.get().map(proc(n: Node): Record = n.record)
 
+  # TODO: This returns null values for the `none`s. Not sure what it should be
+  # according to spec, no k:v pair at all?
+  # Note: Would it not be nice to have a call that resturns either content or
+  # ENRs, and that the connection id is used in the background instead of this
+  # "raw" `findContent` call.
+  rpcServer.rpc("portal_" & network & "_findContent") do(
+      enr: Record, contentKey: string) -> tuple[
+        connectionId: Option[string],
+        content: Option[string],
+        enrs: Option[seq[Record]]]:
+    let
+      node = toNodeWithAddress(enr)
+      content = await p.findContent(
+        node, ByteList.init(hexToSeqByte(contentKey)))
+
+    if content.isErr():
+      raise newException(ValueError, $content.error)
+    else:
+      let contentMessage = content.get()
+      case contentMessage.contentMessageType:
+      of connectionIdType:
+        return (
+          some("0x" & contentMessage.connectionId.toHex()),
+          none(string),
+          none(seq[Record]))
+      of contentType:
+        return (
+          none(string),
+          some("0x" & contentMessage.content.asSeq().toHex()),
+          none(seq[Record]))
+      of enrsType:
+        let records = recordsFromBytes(contentMessage.enrs)
+        if records.isErr():
+          raise newException(ValueError, $records.error)
+        else:
+          return (
+            none(string),
+            none(string),
+            # Note: Could also pass not verified nodes
+            some(verifyNodesRecords(
+              records.get(), node, enrsResultLimit).map(
+                proc(n: Node): Record = n.record)))
+
   rpcServer.rpc("portal_" & network & "_recursiveFindNodes") do() -> seq[Record]:
     let discovered = await p.queryRandom()
     return discovered.map(proc(n: Node): Record = n.record)