From 5e8cfb0ccde77a6c9a77b356961cc3e3b6f1e562 Mon Sep 17 00:00:00 2001
From: Trolli Schmittlauch <t.schmittlauch@orlives.de>
Date: Wed, 24 Jun 2020 22:27:35 +0200
Subject: [PATCH] mark successfully Pinged nodes as verified

for #29
---
 src/Hash2Pub/DHTProtocol.hs | 66 ++++++++++++++++++++++++++++---------
 1 file changed, 50 insertions(+), 16 deletions(-)

diff --git a/src/Hash2Pub/DHTProtocol.hs b/src/Hash2Pub/DHTProtocol.hs
index bfcdf9e..f02bd59 100644
--- a/src/Hash2Pub/DHTProtocol.hs
+++ b/src/Hash2Pub/DHTProtocol.hs
@@ -3,9 +3,10 @@ module Hash2Pub.DHTProtocol
     , queryLocalCache
     , addCacheEntry
     , addCacheEntryPure
+    , addNodeAsVerified
+    , addNodeAsVerifiedPure
     , deleteCacheEntry
     , deserialiseMessage
-    , markCacheEntryAsVerified
     , RemoteCacheEntry(..)
     , toRemoteCacheEntry
     , remoteNode
@@ -64,9 +65,10 @@ import           Hash2Pub.FediChordTypes        (CacheEntry (..),
                                                  addRMapEntry, addRMapEntryWith,
                                                  cacheGetNodeStateUnvalidated,
                                                  cacheLookup, cacheLookupPred,
-                                                 cacheLookupSucc, getKeyID,
-                                                 localCompare, rMapFromList,
-                                                 rMapLookupPred, rMapLookupSucc,
+                                                 cacheLookupSucc, genNodeID,
+                                                 getKeyID, localCompare,
+                                                 rMapFromList, rMapLookupPred,
+                                                 rMapLookupSucc,
                                                  setPredecessors, setSuccessors)
 import           Hash2Pub.ProtocolTypes
 
@@ -154,6 +156,26 @@ deleteCacheEntry nid = RingMap . Map.update modifier nid . getRingMap
     modifier (ProxyEntry idPointer _) = Just (ProxyEntry idPointer Nothing)
     modifier KeyEntry {}              = Nothing
 
+
+-- | Add a 'RemoteNodeState' to the node cache marked as verified.
+-- If an entry already exists, it is replaced by the new verified one.
+addNodeAsVerified :: RemoteNodeState
+                  -> NodeCache
+                  -> IO NodeCache
+addNodeAsVerified node cache = do
+    now <- getPOSIXTime
+    pure $ addNodeAsVerifiedPure now node cache
+
+
+-- | Pure variant of 'addNodeAsVerified' with current time explicitly specified as an argument
+addNodeAsVerifiedPure :: POSIXTime
+                      -> RemoteNodeState
+                      -> NodeCache
+                      -> NodeCache
+addNodeAsVerifiedPure now node = addRMapEntry (CacheEntry True node now)
+
+
+
 -- | Mark a cache entry as verified after pinging it, possibly bumping its timestamp.
 markCacheEntryAsVerified :: Maybe POSIXTime     -- ^ the (current) timestamp to be
                                                 -- given to the entry, or Nothing
@@ -540,26 +562,38 @@ requestPing :: LocalNodeState      -- ^ sending node
                  -> RemoteNodeState     -- ^ node to be PINGed
                  -> IO (Either String [RemoteNodeState])   -- ^ all active vServers of the pinged node
 requestPing ns target = do
-    responses <- bracket (mkSendSocket (getDomain target) (getDhtPort target)) close (fmap Right . sendRequestTo 5000 3 (\rid ->
-        Request {
-            requestID = rid
-          , sender = toRemoteNodeState ns
-          , part = 1
-          , isFinalPart = False
-          , action = Ping
-          , payload = Just PingRequestPayload
-                }
-                         )
-                                                                                           ) `catch`  (\e -> pure . Left $ displayException (e :: IOException))
+    responses <- bracket (mkSendSocket (getDomain target) (getDhtPort target)) close
+        (\sock -> do
+            resp <- sendRequestTo 5000 3 (\rid ->
+                Request {
+                    requestID = rid
+                  , sender = toRemoteNodeState ns
+                  , part = 1
+                  , isFinalPart = False
+                  , action = Ping
+                  , payload = Just PingRequestPayload
+                        }
+                             ) sock
+            (SockAddrInet6 _ _ peerAddr _) <- getPeerName sock
+            pure $ Right (peerAddr, resp)
+                                                                                               ) `catch`  (\e -> pure . Left $ displayException (e :: IOException))
     either
         -- forward IO error messages
         (pure . Left)
-        (\respSet -> do
+        (\(peerAddr, respSet) -> do
             -- fold all reply parts together
             let responseVss = foldr' (\msg acc ->
                     maybe acc (foldr' (:) acc) (pingNodeStates <$> payload msg)
                                                       )
                                                       [] respSet
+            -- recompute ID for each received node and mark as verified in cache
+            now <- getPOSIXTime
+            forM_ responseVss (\vs ->
+                let recomputedID = genNodeID peerAddr (getDomain vs) (fromInteger $ getVServerID vs)
+                 in if recomputedID == getNid vs
+                       then atomically $ writeTQueue (cacheWriteQueue ns) $ addNodeAsVerifiedPure now vs
+                       else pure ()
+                              )
             pure $ if null responseVss
                       then Left "no active vServer IDs returned, ignoring node"
                       else Right responseVss