limit pos by temperature

emercoin · Oct 22, 2018 · ec32762b99cc68fb9abb2909dda96bc7a13bd819 · ec32762
1 parent af491ca
commit ec32762b99cc68fb9abb2909dda96bc7a13bd819
Unified Split

Showing with 21 additions and 1 deletion.

+1 −0 src/net.cpp

+5 −0 src/net.h

+15 −1 src/net_processing.cpp
diff --git a/src/net.cpp b/src/net.cpp
@@ -2743,6 +2743,7 @@ CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn
    fPauseSend = false;
    nProcessQueueSize = 0;
    temperature = 0;
+  
+    nPoSTemperature = MAX_CONSECUTIVE_POS_HEADERS / 4;  // by default we don't trust new peer complemetely
    BOOST_FOREACH(const std::string &msg, getAllNetMessageTypes())
        mapRecvBytesPerMsgCmd[msg] = 0;

diff --git a/src/net.h b/src/net.h
@@ -92,6 +92,9 @@ static const ServiceFlags REQUIRED_SERVICES = NODE_NETWORK;
 // NOTE: When adjusting this, update rpcnet:setban's help ("24h")
 static const unsigned int DEFAULT_MISBEHAVING_BANTIME = 60 * 60 * 24;  // Default 24-hour ban
+  
+/** emercoin: Number of consecutive PoS headers are allowed from a single peer. Used to prevent out of memory attack. */
+  
+static const unsigned int MAX_CONSECUTIVE_POS_HEADERS = 1000;
+  
+
 typedef int64_t NodeId;
 struct AddedNodeInfo
@@ -684,6 +687,8 @@ class CNode
    // emercoin: temperature to measure how many tx has been sent by this client.
    uint32_t temperature;
+  
+    // emercoin: temperature to measure how many PoS headers have been sent by this client
+  
+    uint32_t nPoSTemperature;
    CNode(NodeId id, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn, SOCKET hSocketIn, const CAddress &addrIn, uint64_t nKeyedNetGroupIn, uint64_t nLocalHostNonceIn, const std::string &addrNameIn = "", bool fInboundIn = false);
    ~CNode();

diff --git a/src/net_processing.cpp b/src/net_processing.cpp
@@ -2269,6 +2269,16 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
            vRecv >> headers[n];
            ReadCompactSize(vRecv); // ignore tx count; assume it is 0.
            ReadCompactSize(vRecv); // ignore vchBlockSig.
+  
+
+  
+            // emercoin: ban peers that spam PoS headers without any PoW headers
+  
+            pfrom->nPoSTemperature = headers[n].nFlags & BLOCK_PROOF_OF_STAKE ? pfrom->nPoSTemperature + 1 : 0;
+  
+            if (pfrom->nPoSTemperature >= MAX_CONSECUTIVE_POS_HEADERS)
+  
+            {
+  
+                pfrom->nPoSTemperature = (MAX_CONSECUTIVE_POS_HEADERS / 4) * 3;
+  
+                LOCK(cs_main);
+  
+                Misbehaving(pfrom->GetId(), 100);
+  
+                return error("too many consecutive pos headers");
+  
+            }
        }
        if (nCount == 0) {
@@ -2324,7 +2334,11 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
            if (state.IsInvalid(nDoS)) {
                if (nDoS > 0) {
                    LOCK(cs_main);
-  
-                    Misbehaving(pfrom->GetId(), nDoS);
+  
+                    if (pfrom->nPoSTemperature >= 100) { // recieved 100+ pos headers in a row, probably out of memory attack
+  
+                        pfrom->nPoSTemperature = (MAX_CONSECUTIVE_POS_HEADERS / 4) * 3;
+  
+                        Misbehaving(pfrom->GetId(), 100);
+  
+                    } else
+  
+                        Misbehaving(pfrom->GetId(), nDoS);
                }
                return error("invalid header received");
            }