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)
}
// ppcoin: synchronized checkpoint (centrally broadcasted)
- uint256 hashSyncCheckpoint;
+ uint256 hashSyncCheckpoint = 0;
+ uint256 hashPendingCheckpoint = 0;
CSyncCheckpoint checkpointMessage;
CSyncCheckpoint checkpointMessagePending;
+ uint256 hashInvalidCheckpoint = 0;
CCriticalSection cs_hashSyncCheckpoint;
+ // 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;
+ }
+
// ppcoin: only descendant of current sync-checkpoint is allowed
bool ValidateSyncCheckpoint(uint256 hashCheckpoint)
{
CBlockIndex* pindexSyncCheckpoint = mapBlockIndex[hashSyncCheckpoint];
CBlockIndex* pindexCheckpointRecv = mapBlockIndex[hashCheckpoint];
+
if (pindexCheckpointRecv->nHeight <= pindexSyncCheckpoint->nHeight)
- return false; // this is an older checkpoint, ignore
+ {
+ // 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)
- pindex = pindex->pprev;
+ 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;
}
- bool AcceptPendingSyncCheckpoint(uint256 hashAcceptedBlock)
+ bool WriteSyncCheckpoint(const uint256& hashCheckpoint)
{
- if (!mapBlockIndex.count(hashAcceptedBlock))
- return false;
+ 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;
+ }
+
+ bool AcceptPendingSyncCheckpoint()
+ {
CRITICAL_BLOCK(cs_hashSyncCheckpoint)
- if ((!checkpointMessagePending.IsNull()) && checkpointMessagePending.hashCheckpoint == hashAcceptedBlock)
+ {
+ if (hashPendingCheckpoint != 0 && mapBlockIndex.count(hashPendingCheckpoint))
{
- if (!ValidateSyncCheckpoint(checkpointMessagePending.hashCheckpoint))
+ if (!ValidateSyncCheckpoint(hashPendingCheckpoint))
{
+ hashPendingCheckpoint = 0;
checkpointMessagePending.SetNull();
return false;
}
- hashSyncCheckpoint = checkpointMessagePending.hashCheckpoint;
+
+ 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;
}
+ }
return false;
}
- // ppcoin: automatic checkpoint (represented by height of checkpoint)
- int nAutoCheckpoint = 0;
- int nBranchPoint = 0; // branch point to alternative branch
+ uint256 AutoSelectSyncCheckpoint()
+ {
+ // select block roughly 8 hours ago
+ CBlockIndex *pindex = mapBlockIndex[hashSyncCheckpoint];
+ while (pindex->pnext && pindex->pnext->GetBlockTime() + AUTO_CHECKPOINT_MIN_SPAN <= GetAdjustedTime())
+ pindex = pindex->pnext;
+ return pindex->GetBlockHash();
+ }
- // 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)
+ // Check against synchronized checkpoint
+ bool CheckSync(const uint256& hashBlock, const CBlockIndex* pindexPrev)
{
- while (pindex)
+ if (fTestNet) return true; // Testnet has no checkpoints
+ int nHeight = pindexPrev->nHeight + 1;
+
+ CRITICAL_BLOCK(cs_hashSyncCheckpoint)
{
- if (pindex->IsInMainChain())
+ // sync-checkpoint should always be accepted block
+ assert(mapBlockIndex.count(hashSyncCheckpoint));
+ const CBlockIndex* pindexSync = mapBlockIndex[hashSyncCheckpoint];
+
+ if (nHeight > pindexSync->nHeight)
{
- if (pindex->nHeight >= nAutoCheckpoint)
- return true;
- else
- {
- nBranchPoint = pindex->nHeight;
- return error("Checkpoints: new block on alternative branch at height=%d before auto checkpoint at height=%d", pindex->nHeight, nAutoCheckpoint);
- }
+ // 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
}
- else
- pindex = pindex->pprev;
+ 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;
+ }
+
+ 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 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)
+ // ppcoin: reset synchronized checkpoint to last hardened checkpoint
+ bool ResetSyncCheckpoint()
{
- 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)
+ CRITICAL_BLOCK(cs_hashSyncCheckpoint)
{
- bnTarget.SetCompact(pindex->nBits);
- if (bnTarget > bnTargetMax)
- bnTargetMax = bnTarget;
- if (nCheckpointMax > 0 && bnTarget < bnTargetMin)
+ const uint256& hash = mapCheckpoints.rbegin()->second;
+ if (mapBlockIndex.count(hash) && !mapBlockIndex[hash]->IsInMainChain())
{
- bnTargetMin = bnTarget;
- nMinTargetHeight = pindex->nHeight;
+ // 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();
}
- if (nCheckpointMax == 0 && pindexLast->GetBlockTime() - pindex->GetBlockTime() > AUTO_CHECKPOINT_MIN_SPAN)
+ else if(!mapBlockIndex.count(hash))
{
- nCheckpointMax = pindex->nHeight;
- bnTargetMin.SetCompact(pindex->nBits);
- nMinTargetHeight = pindex->nHeight;
+ // checkpoint block not yet accepted
+ hashPendingCheckpoint = hash;
+ checkpointMessagePending.SetNull();
+ printf("ResetSyncCheckpoint: pending for sync-checkpoint %s\n", hashPendingCheckpoint.ToString().c_str());
+ // TODO: when to ask for the checkpoint chain?
}
- if (pindexLast->GetBlockTime() - pindex->GetBlockTime() < AUTO_CHECKPOINT_MAX_SPAN)
- nCheckpointMin = pindex->nHeight;
- pindex = pindex->pprev;
- nDepth--;
- }
- 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;
- }
-
- // ppcoin: get next auto checkpoint from the new chain checkpoint
- int GetNextAutoCheckpoint(int nCheckpoint)
- {
- return (std::max(nAutoCheckpoint, nCheckpoint));
- }
+ 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;
+ }
+ }
- // ppcoin: advance to next automatic checkpoint
- void AdvanceAutoCheckpoint(int nCheckpoint)
- {
- nAutoCheckpoint = GetNextAutoCheckpoint(nCheckpoint);
- printf("Checkpoints: auto checkpoint now at height=%d\n", nAutoCheckpoint);
+ return false;
+ }
}
+}
- // ppcoin: reset auto checkpoint
- bool ResetAutoCheckpoint(int nCheckpoint)
- {
- 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
+// ppcoin: sync-checkpoint master key
+const std::string CSyncCheckpoint::strMasterPubKey = "0424f20205e5da98ba632bbd278a11a6499585f62bfb2c782377ef59f0251daab8085fc31471bcb8180bc75ed0fa41bb50c7c084511d54015a3a5241d645c7268a";
- // clear ban list to accept alternative branches
- CRITICAL_BLOCK(cs_vNodes)
- {
- BOOST_FOREACH(CNode* pnode, vNodes)
- pnode->ClearBanned();
- }
+// 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");
- return true;
- }
+ // Now unserialize the data
+ CDataStream sMsg(vchMsg);
+ sMsg >> *(CUnsignedSyncCheckpoint*)this;
+ return true;
}
// ppcoin: process synchronized checkpoint
{
if (!mapBlockIndex.count(hashCheckpoint))
{
- // We haven't accepted this block, keep the checkpoint as pending
+ // 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;
}
+
if (!Checkpoints::ValidateSyncCheckpoint(hashCheckpoint))
return false;
- Checkpoints::hashSyncCheckpoint = this->hashCheckpoint;
+
+ CTxDB txdb;
+ CBlockIndex* pindexCheckpoint = mapBlockIndex[hashCheckpoint];
+ if (!pindexCheckpoint->IsInMainChain())
+ {
+ // 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();
+
+ 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;
}