net: Avoid redundant and confusing FAILED log

Every `return false` is preceeded by a detailed debug log message to
explain that a disconnect or misbehavior happened. Logging another
generic "FAILED" message seems redundant.

Also, the size of the message and the message type has already been
logged and is thus redundant as well.

Finally, claiming that message processing FAILED seems odd, because the
message was fully processed to the point where it was concluded that the
peer should be either disconnected or marked as misbehaving.

Author: MarcoFalke

src/net_processing.cpp

@@ -1793,7 +1793,7 @@ bool static ProcessHeadersMessage(CNode& pfrom, CConnman* connman, ChainstateMan
         for (const CBlockHeader& header : headers) {
             if (!hashLastBlock.IsNull() && header.hashPrevBlock != hashLastBlock) {
                 Misbehaving(pfrom.GetId(), 20, "non-continuous headers sequence");
-                return false;
+                return true;
             }
             hashLastBlock = header.GetHash();
         }
@@ -1809,7 +1809,7 @@ bool static ProcessHeadersMessage(CNode& pfrom, CConnman* connman, ChainstateMan
     if (!chainman.ProcessNewBlockHeaders(headers, state, chainparams, &pindexLast)) {
         if (state.IsInvalid()) {
             MaybePunishNodeForBlock(pfrom.GetId(), state, via_compact_block, "invalid header received");
-            return false;
+            return true;
         }
     }
 
@@ -2221,7 +2221,7 @@ bool ProcessMessage(CNode& pfrom, const std::string& msg_type, CDataStream& vRec
         {
             LOCK(cs_main);
             Misbehaving(pfrom.GetId(), 1);
-            return false;
+            return true;
         }
 
         int64_t nTime;
@@ -2247,14 +2247,14 @@ bool ProcessMessage(CNode& pfrom, const std::string& msg_type, CDataStream& vRec
         {
             LogPrint(BCLog::NET, "peer=%d does not offer the expected services (%08x offered, %08x expected); disconnecting\n", pfrom.GetId(), nServices, GetDesirableServiceFlags(nServices));
             pfrom.fDisconnect = true;
-            return false;
+            return true;
         }
 
         if (nVersion < MIN_PEER_PROTO_VERSION) {
             // disconnect from peers older than this proto version
             LogPrint(BCLog::NET, "peer=%d using obsolete version %i; disconnecting\n", pfrom.GetId(), nVersion);
             pfrom.fDisconnect = true;
-            return false;
+            return true;
         }
 
         if (!vRecv.empty())
@@ -2381,7 +2381,7 @@ bool ProcessMessage(CNode& pfrom, const std::string& msg_type, CDataStream& vRec
         // Must have a version message before anything else
         LOCK(cs_main);
         Misbehaving(pfrom.GetId(), 1);
-        return false;
+        return true;
     }
 
     // At this point, the outgoing message serialization version can't change.
@@ -2429,7 +2429,7 @@ bool ProcessMessage(CNode& pfrom, const std::string& msg_type, CDataStream& vRec
         // Must have a verack message before anything else
         LOCK(cs_main);
         Misbehaving(pfrom.GetId(), 1);
-        return false;
+        return true;
     }
 
     if (msg_type == NetMsgType::ADDR) {
@@ -2446,7 +2446,7 @@ bool ProcessMessage(CNode& pfrom, const std::string& msg_type, CDataStream& vRec
         {
             LOCK(cs_main);
             Misbehaving(pfrom.GetId(), 20, strprintf("message addr size() = %u", vAddr.size()));
-            return false;
+            return true;
         }
 
         // Store the new addresses
@@ -2522,7 +2522,7 @@ bool ProcessMessage(CNode& pfrom, const std::string& msg_type, CDataStream& vRec
         {
             LOCK(cs_main);
             Misbehaving(pfrom.GetId(), 20, strprintf("message inv size() = %u", vInv.size()));
-            return false;
+            return true;
         }
 
         // We won't accept tx inv's if we're in blocks-only mode, or this is a
@@ -2588,7 +2588,7 @@ bool ProcessMessage(CNode& pfrom, const std::string& msg_type, CDataStream& vRec
         {
             LOCK(cs_main);
             Misbehaving(pfrom.GetId(), 20, strprintf("message getdata size() = %u", vInv.size()));
-            return false;
+            return true;
         }
 
         LogPrint(BCLog::NET, "received getdata (%u invsz) peer=%d\n", vInv.size(), pfrom.GetId());
@@ -3246,7 +3246,7 @@ bool ProcessMessage(CNode& pfrom, const std::string& msg_type, CDataStream& vRec
         if (nCount > MAX_HEADERS_RESULTS) {
             LOCK(cs_main);
             Misbehaving(pfrom.GetId(), 20, strprintf("headers message size = %u", nCount));
-            return false;
+            return true;
         }
         headers.resize(nCount);
         for (unsigned int n = 0; n < nCount; n++) {