X-Git-Url: https://git.novaco.in/?a=blobdiff_plain;f=src%2Fcheckpoints.cpp;h=d004c84ef99f069203989938a40043c5111deb67;hb=09f2a990950512cbe418526d91838887a0dded2a;hp=9c4ef34c6797b952687e01a7c8ff9e5c734e1192;hpb=ec9cc61131b8da4f4a192cba704aa11a0fd10dd1;p=novacoin.git

diff --git a/src/checkpoints.cpp b/src/checkpoints.cpp
index 9c4ef34..d004c84 100644
--- a/src/checkpoints.cpp
+++ b/src/checkpoints.cpp
@@ -22,7 +22,7 @@ namespace Checkpoints
     //
     static MapCheckpoints mapCheckpoints =
         boost::assign::map_list_of
-        ( 0, hashGenesisBlock )
+        ( 0, hashGenesisBlockOfficial )
         ; // ppcoin: no checkpoint yet; to be created in future releases
 
     bool CheckHardened(int nHeight, const uint256& hash)
@@ -43,7 +43,12 @@ namespace Checkpoints
 
     CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex)
     {
-        if (fTestNet) return NULL;
+        if (fTestNet) {
+            std::map<uint256, CBlockIndex*>::const_iterator t = mapBlockIndex.find(hashGenesisBlock);
+            if (t != mapBlockIndex.end())
+                return t->second;
+            return NULL;
+        }
 
         int64 nResult;
         BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints)
@@ -57,136 +62,302 @@ namespace Checkpoints
     }
 
     // ppcoin: synchronized checkpoint (centrally broadcasted)
-    uint256 hashSyncCheckpoint;
+    uint256 hashSyncCheckpoint = 0;
+    uint256 hashPendingCheckpoint = 0;
+    CSyncCheckpoint checkpointMessage;
+    CSyncCheckpoint checkpointMessagePending;
+    uint256 hashInvalidCheckpoint = 0;
     CCriticalSection cs_hashSyncCheckpoint;
 
-    bool AcceptNewSyncCheckpoint(uint256 hashCheckpoint)
+    // ppcoin: get last synchronized checkpoint
+    CBlockIndex* GetLastSyncCheckpoint()
     {
+        CRITICAL_BLOCK(cs_hashSyncCheckpoint)
+        {
+            if (!mapBlockIndex.count(hashSyncCheckpoint))
+                error("GetSyncCheckpoint: block index missing for current sync-checkpoint %s", hashSyncCheckpoint.ToString().c_str());
+            else
+                return mapBlockIndex[hashSyncCheckpoint];
+        }
+        return NULL;
     }
 
-    bool CSyncCheckpoint::ProcessSyncCheckpoint()
+    // ppcoin: only descendant of current sync-checkpoint is allowed
+    bool ValidateSyncCheckpoint(uint256 hashCheckpoint)
     {
-        if (!CheckSignature())
-            return false;
+        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());
 
-        CRITICAL_BLOCK(cs_hashSyncCheckpoint)
-            hashSyncCheckpoint = this->hashCheckpoint;
+        CBlockIndex* pindexSyncCheckpoint = mapBlockIndex[hashSyncCheckpoint];
+        CBlockIndex* pindexCheckpointRecv = mapBlockIndex[hashCheckpoint];
+
+        if (pindexCheckpointRecv->nHeight <= pindexSyncCheckpoint->nHeight)
+        {
+            // Received an older checkpoint, trace back from current checkpoint
+            // to the same height of the received checkpoint to verify
+            // that current checkpoint should be a descendant block
+            CBlockIndex* pindex = pindexSyncCheckpoint;
+            while (pindex->nHeight > pindexCheckpointRecv->nHeight)
+                if (!(pindex = pindex->pprev))
+                    return error("ValidateSyncCheckpoint: pprev1 null - block index structure failure");
+            if (pindex->GetBlockHash() != hashCheckpoint)
+            {
+                hashInvalidCheckpoint = hashCheckpoint;
+                return error("ValidateSyncCheckpoint: new sync-checkpoint %s is conflicting with current sync-checkpoint %s", hashCheckpoint.ToString().c_str(), hashSyncCheckpoint.ToString().c_str());
+            }
+            return false; // ignore older checkpoint
+        }
+
+        // Received checkpoint should be a descendant block of the current
+        // checkpoint. Trace back to the same height of current checkpoint
+        // to verify.
+        CBlockIndex* pindex = pindexCheckpointRecv;
+        while (pindex->nHeight > pindexSyncCheckpoint->nHeight)
+            if (!(pindex = pindex->pprev))
+                return error("ValidateSyncCheckpoint: pprev2 null - block index structure failure");
+        if (pindex->GetBlockHash() != hashSyncCheckpoint)
+        {
+            hashInvalidCheckpoint = hashCheckpoint;
+            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;
     }
 
-    // ppcoin: automatic checkpoint (represented by height of checkpoint)
-    int nAutoCheckpoint = 0;
-    int nBranchPoint = 0;    // branch point to alternative branch
+    bool WriteSyncCheckpoint(const uint256& hashCheckpoint)
+    {
+        CTxDB txdb;
+        txdb.TxnBegin();
+        if (!txdb.WriteSyncCheckpoint(hashCheckpoint))
+        {
+            txdb.TxnAbort();
+            return error("WriteSyncCheckpoint(): failed to write to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
+        }
+        if (!txdb.TxnCommit())
+            return error("WriteSyncCheckpoint(): failed to commit to db sync checkpoint %s", hashCheckpoint.ToString().c_str());
+        txdb.Close();
+
+        Checkpoints::hashSyncCheckpoint = hashCheckpoint;
+        return true;
+    }
 
-    // ppcoin: check automatic checkpoint
-    // To pass the check:
-    //   - All ancestors (including the block itself) have block index already
-    //   - The immediate ancestor in main chain must not have height less than
-    //     checkpoint height
-    bool CheckAuto(const CBlockIndex *pindex)
+    bool AcceptPendingSyncCheckpoint()
     {
-        while (pindex)
+        CRITICAL_BLOCK(cs_hashSyncCheckpoint)
         {
-            if (pindex->IsInMainChain())
+            if (hashPendingCheckpoint != 0 && mapBlockIndex.count(hashPendingCheckpoint))
             {
-                if (pindex->nHeight >= nAutoCheckpoint)
-                    return true;
-                else
+                if (!ValidateSyncCheckpoint(hashPendingCheckpoint))
                 {
-                    nBranchPoint = pindex->nHeight;
-                    return error("Checkpoints: new block on alternative branch at height=%d before auto checkpoint at height=%d", pindex->nHeight, nAutoCheckpoint);
+                    hashPendingCheckpoint = 0;
+                    checkpointMessagePending.SetNull();
+                    return false;
                 }
+
+                CTxDB txdb;
+                CBlockIndex* pindexCheckpoint = mapBlockIndex[hashPendingCheckpoint];
+                if (!pindexCheckpoint->IsInMainChain())
+                {
+                    txdb.TxnBegin();
+                    if (!Reorganize(txdb, pindexCheckpoint))
+                    {
+                        txdb.TxnAbort();
+                        hashInvalidCheckpoint = hashPendingCheckpoint;
+                        return error("ProcessSyncCheckpoint: Reorganize failed for sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
+                    }
+                }
+                txdb.Close();
+
+                if (!WriteSyncCheckpoint(hashPendingCheckpoint))
+                    return error("AcceptPendingSyncCheckpoint(): failed to write sync checkpoint %s", hashPendingCheckpoint.ToString().c_str());
+                hashPendingCheckpoint = 0;
+                checkpointMessage = checkpointMessagePending;
+                checkpointMessagePending.SetNull();
+                printf("AcceptPendingSyncCheckpoint : sync-checkpoint at %s\n", hashSyncCheckpoint.ToString().c_str());
+                // relay the checkpoint
+                if (!checkpointMessage.IsNull())
+                    BOOST_FOREACH(CNode* pnode, vNodes)
+                        checkpointMessage.RelayTo(pnode);
+                return true;
             }
-            else
-                pindex = pindex->pprev;
         }
-        return error("Checkpoints: failed to find any ancestor on main chain for the new block - internal error");
+
+        return false;
     }
 
-    // ppcoin: get next chain checkpoint
-    int GetNextChainCheckpoint(const CBlockIndex *pindexLast)
+    uint256 AutoSelectSyncCheckpoint()
     {
-        CBigNum bnTarget;
-        CBigNum bnTargetMax = 0;  // max target of all blocks since checkpoint
-        CBigNum bnTargetMin = 0;  // min target of all candidate checkpoints
-        int nMinTargetHeight = 0; // min target height of candidate checkpoints
-        int nCheckpointMin = 0;   // minimum candidate checkpoint
-        int nCheckpointMax = 0;   // maximum candidate checkpoint
-        int nDepth = pindexLast->nHeight - pindexLast->nCheckpoint;
-        const CBlockIndex *pindex = pindexLast;
-        while (nDepth >= 0 && pindex)
+        // select a block some time ago
+        CBlockIndex *pindex = mapBlockIndex[hashSyncCheckpoint];
+        while (pindex->pnext && pindex->pnext->GetBlockTime() + CHECKPOINT_MIN_SPAN <= GetAdjustedTime())
+            pindex = pindex->pnext;
+        return pindex->GetBlockHash();
+    }
+
+    // Check against synchronized checkpoint
+    bool CheckSync(const uint256& hashBlock, const CBlockIndex* pindexPrev)
+    {
+        if (fTestNet) return true; // Testnet has no checkpoints
+        int nHeight = pindexPrev->nHeight + 1;
+
+        CRITICAL_BLOCK(cs_hashSyncCheckpoint)
         {
-            bnTarget.SetCompact(pindex->nBits);
-            if (bnTarget > bnTargetMax)
-                bnTargetMax = bnTarget;
-            if (nCheckpointMax > 0 && bnTarget < bnTargetMin)
-            {
-                bnTargetMin = bnTarget;
-                nMinTargetHeight = pindex->nHeight;
-            }
-            if (nCheckpointMax == 0 && pindexLast->GetBlockTime() - pindex->GetBlockTime() > AUTO_CHECKPOINT_MIN_SPAN)
+            // sync-checkpoint should always be accepted block
+            assert(mapBlockIndex.count(hashSyncCheckpoint));
+            const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
+
+            if (nHeight > pindexSync->nHeight)
             {
-                nCheckpointMax = pindex->nHeight;
-                bnTargetMin.SetCompact(pindex->nBits);
-                nMinTargetHeight = pindex->nHeight;
+                // trace back to same height as sync-checkpoint
+                const CBlockIndex* pindex = pindexPrev;
+                while (pindex->nHeight > pindexSync->nHeight)
+                    if (!(pindex = pindex->pprev))
+                        return error("CheckSync: pprev null - block index structure failure");
+                if (pindex->nHeight < pindexSync->nHeight || pindex->GetBlockHash() != hashSyncCheckpoint)
+                    return false; // only descendant of sync-checkpoint can pass check
             }
-            if (pindexLast->GetBlockTime() - pindex->GetBlockTime() < AUTO_CHECKPOINT_MAX_SPAN)
-                nCheckpointMin = pindex->nHeight;
-            pindex = pindex->pprev;
-            nDepth--;
+            if (nHeight == pindexSync->nHeight && hashBlock != hashSyncCheckpoint)
+                return false; // same height with sync-checkpoint
+            if (nHeight < pindexSync->nHeight && !mapBlockIndex.count(hashBlock))
+                return false; // lower height than sync-checkpoint
         }
+        return true;
+    }
 
-        assert (nDepth == -1);  // arrive at chain checkpoint now
-
-        printf("Checkpoints: min=%d max=%d tminheight=%d tmin=0x%08x tmax=0x%08x\n",
-            nCheckpointMin, nCheckpointMax, nMinTargetHeight,
-            bnTargetMin.GetCompact(), bnTargetMax.GetCompact());
-        if (nCheckpointMax == 0) // checkpoint stays if max candidate not found
-            return pindexLast->nCheckpoint;
-
-        if (bnTargetMin * 100 > bnTargetMax * 90)
-            return nCheckpointMax;
-        if (bnTarget * 100 > bnTargetMax * 90)
-            return nMinTargetHeight;
-        else
-            return nCheckpointMin;
+    bool WantedByPendingSyncCheckpoint(uint256 hashBlock)
+    {
+        CRITICAL_BLOCK(cs_hashSyncCheckpoint)
+        {
+            if (hashPendingCheckpoint == 0)
+                return false;
+            if (hashBlock == hashPendingCheckpoint)
+                return true;
+            if (mapOrphanBlocks.count(hashPendingCheckpoint) 
+                && hashBlock == WantedByOrphan(mapOrphanBlocks[hashPendingCheckpoint]))
+                return true;
+        }
+        return false;
     }
 
-    // ppcoin: get next auto checkpoint from the new chain checkpoint
-    int GetNextAutoCheckpoint(int nCheckpoint)
+    // ppcoin: reset synchronized checkpoint to last hardened checkpoint
+    bool ResetSyncCheckpoint()
     {
-        return (std::max(nAutoCheckpoint, nCheckpoint));
+        CRITICAL_BLOCK(cs_hashSyncCheckpoint)
+        {
+            const uint256& hash = mapCheckpoints.rbegin()->second;
+            if (mapBlockIndex.count(hash) && !mapBlockIndex[hash]->IsInMainChain())
+            {
+                // checkpoint block accepted but not yet in main chain
+                printf("ResetSyncCheckpoint: Reorganize to hardened checkpoint %s\n", hash.ToString().c_str());
+                CTxDB txdb;
+                txdb.TxnBegin();
+                if (!Reorganize(txdb, mapBlockIndex[hash]))
+                {
+                    txdb.TxnAbort();
+                    return error("ResetSyncCheckpoint: Reorganize failed for hardened checkpoint %s", hash.ToString().c_str());
+                }
+                txdb.Close();
+            }
+            else if(!mapBlockIndex.count(hash))
+            {
+                // checkpoint block not yet accepted
+                hashPendingCheckpoint = hash;
+                checkpointMessagePending.SetNull();
+                printf("ResetSyncCheckpoint: pending for sync-checkpoint %s\n", hashPendingCheckpoint.ToString().c_str());
+            }
+
+            BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, mapCheckpoints)
+            {
+                const uint256& hash = i.second;
+                if (mapBlockIndex.count(hash) && mapBlockIndex[hash]->IsInMainChain())
+                {
+                    if (!WriteSyncCheckpoint(hash))
+                        return error("ResetSyncCheckpoint: failed to write sync checkpoint %s", hash.ToString().c_str());
+                    printf("ResetSyncCheckpoint: sync-checkpoint reset to %s\n", hashSyncCheckpoint.ToString().c_str());
+                    return true;
+                }
+            }
+
+            return false;
+        }
     }
 
-    // ppcoin: advance to next automatic checkpoint
-    void AdvanceAutoCheckpoint(int nCheckpoint)
+    void AskForPendingSyncCheckpoint(CNode* pfrom)
     {
-        nAutoCheckpoint = GetNextAutoCheckpoint(nCheckpoint);
-        printf("Checkpoints: auto checkpoint now at height=%d\n", nAutoCheckpoint);
+        CRITICAL_BLOCK(cs_hashSyncCheckpoint)
+            if (pfrom && hashPendingCheckpoint != 0 && (!mapBlockIndex.count(hashPendingCheckpoint)) && (!mapOrphanBlocks.count(hashPendingCheckpoint)))
+                pfrom->AskFor(CInv(MSG_BLOCK, hashPendingCheckpoint));
     }
+}
+
+// ppcoin: sync-checkpoint master key
+const std::string CSyncCheckpoint::strMasterPubKey = "0424f20205e5da98ba632bbd278a11a6499585f62bfb2c782377ef59f0251daab8085fc31471bcb8180bc75ed0fa41bb50c7c084511d54015a3a5241d645c7268a";
+
+// ppcoin: verify signature of sync-checkpoint message
+bool CSyncCheckpoint::CheckSignature()
+{
+    CKey key;
+    if (!key.SetPubKey(ParseHex(CSyncCheckpoint::strMasterPubKey)))
+        return error("CSyncCheckpoint::CheckSignature() : SetPubKey failed");
+    if (!key.Verify(Hash(vchMsg.begin(), vchMsg.end()), vchSig))
+        return error("CSyncCheckpoint::CheckSignature() : verify signature failed");
+
+    // Now unserialize the data
+    CDataStream sMsg(vchMsg);
+    sMsg >> *(CUnsignedSyncCheckpoint*)this;
+    return true;
+}
+
+// ppcoin: process synchronized checkpoint
+bool CSyncCheckpoint::ProcessSyncCheckpoint(CNode* pfrom)
+{
+    if (!CheckSignature())
+        return false;
 
-    // ppcoin: reset auto checkpoint
-    bool ResetAutoCheckpoint(int nCheckpoint)
+    CRITICAL_BLOCK(Checkpoints::cs_hashSyncCheckpoint)
     {
-        if (nCheckpoint <= 0 || nCheckpoint > nBestHeight)
-            return error("ResetAutoCheckpoint() : new checkpoint invalid");
-        if (nCheckpoint >= nAutoCheckpoint)
-            return error("ResetAutoCheckpoint() : new checkpoint not earlier than current auto checkpoint");
-        CTxDB txdb;
-        txdb.TxnBegin();
-        if (!txdb.WriteAutoCheckpoint(nCheckpoint, true))
-            return error("ResetAutoCheckpoint() : database write failed");
-        if (!txdb.TxnCommit())
-            return error("ResetAutoCheckpoint() : database commit failed");
-        nAutoCheckpoint = nCheckpoint;
-        nBranchPoint = 0;  // clear branch point
+        if (!mapBlockIndex.count(hashCheckpoint))
+        {
+            // We haven't received the checkpoint chain, keep the checkpoint as pending
+            Checkpoints::hashPendingCheckpoint = hashCheckpoint;
+            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);
+                // ask directly as well in case rejected earlier by duplicate
+                // proof-of-stake because getblocks may not get it this time
+                pfrom->AskFor(CInv(MSG_BLOCK, mapOrphanBlocks.count(hashCheckpoint)? WantedByOrphan(mapOrphanBlocks[hashCheckpoint]) : hashCheckpoint));
+            }
+            return false;
+        }
 
-        // clear ban list to accept alternative branches
-        CRITICAL_BLOCK(cs_vNodes)
+        if (!Checkpoints::ValidateSyncCheckpoint(hashCheckpoint))
+            return false;
+
+        CTxDB txdb;
+        CBlockIndex* pindexCheckpoint = mapBlockIndex[hashCheckpoint];
+        if (!pindexCheckpoint->IsInMainChain())
         {
-            BOOST_FOREACH(CNode* pnode, vNodes)
-                pnode->ClearBanned();
+            // checkpoint chain received but not yet main chain
+            txdb.TxnBegin();
+            if (!Reorganize(txdb, pindexCheckpoint))
+            {
+                txdb.TxnAbort();
+                Checkpoints::hashInvalidCheckpoint = hashCheckpoint;
+                return error("ProcessSyncCheckpoint: Reorganize failed for sync checkpoint %s", hashCheckpoint.ToString().c_str());
+            }
         }
+        txdb.Close();
 
-        return true;
+        if (!Checkpoints::WriteSyncCheckpoint(hashCheckpoint))
+            return error("ProcessSyncCheckpoint(): failed to write sync checkpoint %s", hashCheckpoint.ToString().c_str());
+        Checkpoints::checkpointMessage = *this;
+        Checkpoints::hashPendingCheckpoint = 0;
+        Checkpoints::checkpointMessagePending.SetNull();
+        printf("ProcessSyncCheckpoint: sync-checkpoint at %s\n", hashCheckpoint.ToString().c_str());
     }
+    return true;
 }