PPCoin: RPC command 'sendcheckpoint'

[novacoin.git] / src / checkpoints.cpp

diff --git a/src/checkpoints.cpp b/src/checkpoints.cpp
index f3bfe5d..4afdab9 100644 (file)
--- a/src/checkpoints.cpp
+++ b/src/checkpoints.cpp
@@ -25,10 +25,6 @@ namespace Checkpoints
         ( 0, hashGenesisBlock )
         ; // ppcoin: no checkpoint yet; to be created in future releases
 
-    // ppcoin: automatic checkpoint (represented by height of checkpoint)
-    int nAutoCheckpoint = 0;
-    int nBranchPoint = 0;    // branch point to alternative branch
-
     bool CheckHardened(int nHeight, const uint256& hash)
     {
         if (fTestNet) return true; // Testnet has no checkpoints
@@ -38,6 +34,85 @@ namespace Checkpoints
         return hash == i->second;
     }
 
+    int GetTotalBlocksEstimate()
+    {
+        if (fTestNet) return 0;
+
+        return mapCheckpoints.rbegin()->first;
+    }
+
+    CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex)
+    {
+        if (fTestNet) return NULL;
+
+        int64 nResult;
+        BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints)
+        {
+            const uint256& hash = i.second;
+            std::map<uint256, CBlockIndex*>::const_iterator t = mapBlockIndex.find(hash);
+            if (t != mapBlockIndex.end())
+                return t->second;
+        }
+        return NULL;
+    }
+
+    // ppcoin: synchronized checkpoint (centrally broadcasted)
+    uint256 hashSyncCheckpoint;
+    CSyncCheckpoint checkpointMessage;
+    CSyncCheckpoint checkpointMessagePending;
+    CCriticalSection cs_hashSyncCheckpoint;
+
+    // ppcoin: only descendant of current sync-checkpoint is allowed
+    bool ValidateSyncCheckpoint(uint256 hashCheckpoint)
+    {
+        if (!mapBlockIndex.count(hashSyncCheckpoint))
+            return error("ValidateSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
+        if (!mapBlockIndex.count(hashCheckpoint))
+            return error("ValidateSyncCheckpoint: block index missing for received sync-checkpoint %s", hashCheckpoint.ToString().c_str());
+
+        CBlockIndex* pindexSyncCheckpoint = mapBlockIndex[hashSyncCheckpoint];
+        CBlockIndex* pindexCheckpointRecv = mapBlockIndex[hashCheckpoint];
+        if (pindexCheckpointRecv->nHeight <= pindexSyncCheckpoint->nHeight)
+            return false;  // this is an older checkpoint, ignore
+
+        CBlockIndex* pindex = pindexCheckpointRecv;
+        while (pindex->nHeight > pindexSyncCheckpoint->nHeight)
+            pindex = pindex->pprev;
+        if (pindex->GetBlockHash() != hashSyncCheckpoint)
+            return error("ValidateSyncCheckpoint: new sync-checkpoint %s is not a descendant of current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
+        return true;
+    }
+
+    bool AcceptPendingSyncCheckpoint(uint256 hashAcceptedBlock)
+    {
+        if (!mapBlockIndex.count(hashAcceptedBlock))
+            return false;
+
+        CRITICAL_BLOCK(cs_hashSyncCheckpoint)
+            if ((!checkpointMessagePending.IsNull()) && checkpointMessagePending.hashCheckpoint == hashAcceptedBlock)
+            {
+                if (!ValidateSyncCheckpoint(checkpointMessagePending.hashCheckpoint))
+                {
+                    checkpointMessagePending.SetNull();
+                    return false;
+                }
+                hashSyncCheckpoint = checkpointMessagePending.hashCheckpoint;
+                checkpointMessage = checkpointMessagePending;
+                checkpointMessagePending.SetNull();
+                printf("AcceptPendingSyncCheckpoint : sync-checkpoint at %s\n", hashSyncCheckpoint.ToString().c_str());
+                // relay the checkpoint
+                BOOST_FOREACH(CNode* pnode, vNodes)
+                    checkpointMessage.RelayTo(pnode);
+                return true;
+            }
+
+        return false;
+    }
+
+    // ppcoin: automatic checkpoint (represented by height of checkpoint)
+    int nAutoCheckpoint = 0;
+    int nBranchPoint = 0;    // branch point to alternative branch
+
     // ppcoin: check automatic checkpoint
     // To pass the check:
     //   - All ancestors (including the block itself) have block index already
@@ -125,13 +200,6 @@ namespace Checkpoints
         printf("Checkpoints: auto checkpoint now at height=%d\n", nAutoCheckpoint);
     }
 
-    int GetTotalBlocksEstimate()
-    {
-        if (fTestNet) return 0;
-
-        return mapCheckpoints.rbegin()->first;
-    }
-
     // ppcoin: reset auto checkpoint
     bool ResetAutoCheckpoint(int nCheckpoint)
     {
@@ -157,19 +225,32 @@ namespace Checkpoints
 
         return true;
     }
+}
 
-    CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex)
-    {
-        if (fTestNet) return NULL;
+// ppcoin: process synchronized checkpoint
+bool CSyncCheckpoint::ProcessSyncCheckpoint(CNode* pfrom)
+{
+    if (!CheckSignature())
+        return false;
 
-        int64 nResult;
-        BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints)
+    CRITICAL_BLOCK(Checkpoints::cs_hashSyncCheckpoint)
+    {
+        if (!mapBlockIndex.count(hashCheckpoint))
         {
-            const uint256& hash = i.second;
-            std::map<uint256, CBlockIndex*>::const_iterator t = mapBlockIndex.find(hash);
-            if (t != mapBlockIndex.end())
-                return t->second;
+            // We haven't accepted this block, keep the checkpoint as pending
+            Checkpoints::checkpointMessagePending = *this;
+            printf("ProcessSyncCheckpoint : pending for sync-checkpoint %s\n", hashCheckpoint.ToString().c_str());
+            // Ask this guy to fill in what we're missing
+            if (pfrom)
+                pfrom->PushGetBlocks(pindexBest, hashCheckpoint);
+            return false;
         }
-        return NULL;
+        if (!Checkpoints::ValidateSyncCheckpoint(hashCheckpoint))
+            return false;
+        Checkpoints::hashSyncCheckpoint = this->hashCheckpoint;
+        Checkpoints::checkpointMessage = *this;
+        Checkpoints::checkpointMessagePending.SetNull();
+        printf("ProcessSyncCheckpoint : sync-checkpoint at %s\n", Checkpoints::hashSyncCheckpoint.ToString().c_str());
     }
+    return true;
 }