Bugfix: Don't ban peers just because they have header chains we consi…

…der invalid
luke-jr · Jun 14, 2017 · 6fda801 · 6fda801
1 parent 228c319
commit 6fda801
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Showing 2 changed files with 13 additions and 17 deletions.
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
@@ -2260,12 +2260,23 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
         LOCK(cs_main);
         CNodeState *nodestate = State(pfrom->GetId());
 
+        uint256 hashLastBlock;
+        for (const CBlockHeader& header : headers) {
+            if (!hashLastBlock.IsNull() && header.hashPrevBlock != hashLastBlock) {
+                Misbehaving(pfrom->GetId(), 20);
+                return error("non-continuous headers sequence");
+            }
+            hashLastBlock = header.GetHash();
+            if (!CheckProofOfWork(header.GetHash(), header.nBits, chainparams.GetConsensus())) {
+                Misbehaving(pfrom->GetId(), 50);
+                return error("proof of work failed");
+            }
+        }
+
         // If this looks like it could be a block announcement (nCount <
         // MAX_BLOCKS_TO_ANNOUNCE), use special logic for handling headers that
         // don't connect:
         // - Send a getheaders message in response to try to connect the chain.
-        // - The peer can send up to MAX_UNCONNECTING_HEADERS in a row that
-        //   don't connect before giving DoS points
         // - Once a headers message is received that is valid and does connect,
         //   nUnconnectingHeaders gets reset back to 0.
         if (mapBlockIndex.find(headers[0].hashPrevBlock) == mapBlockIndex.end() && nCount < MAX_BLOCKS_TO_ANNOUNCE) {
@@ -2281,20 +2292,8 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
             // we can use this peer to download.
             UpdateBlockAvailability(pfrom->GetId(), headers.back().GetHash());
 
-            if (nodestate->nUnconnectingHeaders % MAX_UNCONNECTING_HEADERS == 0) {
-                Misbehaving(pfrom->GetId(), 20);
-            }
             return true;
         }
-
-        uint256 hashLastBlock;
-        for (const CBlockHeader& header : headers) {
-            if (!hashLastBlock.IsNull() && header.hashPrevBlock != hashLastBlock) {
-                Misbehaving(pfrom->GetId(), 20);
-                return error("non-continuous headers sequence");
-            }
-            hashLastBlock = header.GetHash();
-        }
         }
 
         CValidationState state;

diff --git a/src/validation.h b/src/validation.h
@@ -141,9 +141,6 @@ static const bool DEFAULT_FEEFILTER = true;
 /** Maximum number of headers to announce when relaying blocks with headers message.*/
 static const unsigned int MAX_BLOCKS_TO_ANNOUNCE = 8;
 
-/** Maximum number of unconnecting headers announcements before DoS score */
-static const int MAX_UNCONNECTING_HEADERS = 10;
-
 static const bool DEFAULT_PEERBLOOMFILTERS = true;
 
 /** Default for -stopatheight */