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Merge pull request #2658 from TheBlueMatt/forkalert 

Detect any sufficiently long fork and alert the user just like any other alert
This commit is contained in:
Gavin Andresen 2013-08-12 23:33:40 -07:00
parent 6fc537f490 f65e7092a2
commit 8fa9b5cc45
2 changed files with 89 additions and 7 deletions
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2
src/init.cpp
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@ -228,7 +228,7 @@ std::string HelpMessage()
strUsage += " -rpcthreads=<n> " + _("Set the number of threads to service RPC calls (default: 4)") + "\n";
strUsage += " -blocknotify=<cmd> " + _("Execute command when the best block changes (%s in cmd is replaced by block hash)") + "\n";
strUsage += " -walletnotify=<cmd> " + _("Execute command when a wallet transaction changes (%s in cmd is replaced by TxID)") + "\n";
strUsage += " -alertnotify=<cmd> " + _("Execute command when a relevant alert is received (%s in cmd is replaced by message)") + "\n";
strUsage += " -alertnotify=<cmd> " + _("Execute command when a relevant alert is received or we see a really long fork (%s in cmd is replaced by message)") + "\n";
strUsage += " -upgradewallet " + _("Upgrade wallet to latest format") + "\n";
strUsage += " -keypool=<n> " + _("Set key pool size to <n> (default: 100)") + "\n";
strUsage += " -rescan " + _("Rescan the block chain for missing wallet transactions") + "\n";

94
src/main.cpp
View File

@ -1376,6 +1376,82 @@ bool IsInitialBlockDownload()
pindexBest->GetBlockTime() < GetTime() - 24 * 60 * 60);
}
bool fLargeWorkForkFound = false;
bool fLargeWorkInvalidChainFound = false;
CBlockIndex *pindexBestForkTip = NULL, *pindexBestForkBase = NULL;
void CheckForkWarningConditions()
{
// If our best fork is no longer within 72 blocks (+/- 12 hours if no one mines it)
// of our head, drop it
if (pindexBestForkTip && nBestHeight - pindexBestForkTip->nHeight >= 72)
pindexBestForkTip = NULL;
if (pindexBestForkTip || nBestInvalidWork > nBestChainWork + (pindexBest->GetBlockWork() * 6).getuint256())
{
if (!fLargeWorkForkFound)
{
std::string strCmd = GetArg("-alertnotify", "");
if (!strCmd.empty())
{
std::string warning = std::string("'Warning: Large-work fork detected, forking after block ") +
pindexBestForkBase->phashBlock->ToString() + std::string("'");
boost::replace_all(strCmd, "%s", warning);
boost::thread t(runCommand, strCmd); // thread runs free
}
}
if (pindexBestForkTip)
{
printf("CheckForkWarningConditions: Warning: Large valid fork found\n forking the chain at height %d (%s)\n lasting to height %d (%s).\nChain state database corruption likely.\n",
pindexBestForkBase->nHeight, pindexBestForkBase->phashBlock->ToString().c_str(),
pindexBestForkTip->nHeight, pindexBestForkTip->phashBlock->ToString().c_str());
fLargeWorkForkFound = true;
}
else
{
printf("CheckForkWarningConditions: Warning: Found invalid chain at least ~6 blocks longer than our best chain.\nChain state database corruption likely.\n");
fLargeWorkInvalidChainFound = true;
}
}
else
{
fLargeWorkForkFound = false;
fLargeWorkInvalidChainFound = false;
}
}
void CheckForkWarningConditionsOnNewFork(CBlockIndex* pindexNewForkTip)
{
// If we are on a fork that is sufficiently large, set a warning flag
CBlockIndex* pfork = pindexNewForkTip;
CBlockIndex* plonger = pindexBest;
while (pfork && pfork != plonger)
{
while (plonger && plonger->nHeight > pfork->nHeight)
plonger = plonger->pprev;
if (pfork == plonger)
break;
pfork = pfork->pprev;
}
// We define a condition which we should warn the user about as a fork of at least 7 blocks
// who's tip is within 72 blocks (+/- 12 hours if no one mines it) of ours
// We use 7 blocks rather arbitrarily as it represents just under 10% of sustained network
// hash rate operating on the fork.
// or a chain that is entirely longer than ours and invalid (note that this should be detected by both)
// We define it this way because it allows us to only store the highest fork tip (+ base) which meets
// the 7-block condition and from this always have the most-likely-to-cause-warning fork
if (pfork && (!pindexBestForkTip || (pindexBestForkTip && pindexNewForkTip->nHeight > pindexBestForkTip->nHeight)) &&
pindexNewForkTip->nChainWork - pfork->nChainWork > (pfork->GetBlockWork() * 7).getuint256() &&
nBestHeight - pindexNewForkTip->nHeight < 72)
{
pindexBestForkTip = pindexNewForkTip;
pindexBestForkBase = pfork;
}
CheckForkWarningConditions();
}
void static InvalidChainFound(CBlockIndex* pindexNew)
{
if (pindexNew->nChainWork > nBestInvalidWork)
@ -1391,8 +1467,7 @@ void static InvalidChainFound(CBlockIndex* pindexNew)
printf("InvalidChainFound: current best=%s height=%d log2_work=%.8g date=%s\n",
hashBestChain.ToString().c_str(), nBestHeight, log(nBestChainWork.getdouble())/log(2.0),
DateTimeStrFormat("%Y-%m-%d %H:%M:%S", pindexBest->GetBlockTime()).c_str());
if (pindexBest && nBestInvalidWork > nBestChainWork + (pindexBest->GetBlockWork() * 6).getuint256())
printf("InvalidChainFound: Warning: Displayed transactions may not be correct! You may need to upgrade, or other nodes may need to upgrade.\n");
CheckForkWarningConditions();
}
void static InvalidBlockFound(CBlockIndex *pindex) {
@ -2103,11 +2178,14 @@ bool AddToBlockIndex(CBlock& block, CValidationState& state, const CDiskBlockPos
if (pindexNew == pindexBest)
{
// Clear fork warning if its no longer applicable
CheckForkWarningConditions();
// Notify UI to display prev block's coinbase if it was ours
static uint256 hashPrevBestCoinBase;
UpdatedTransaction(hashPrevBestCoinBase);
hashPrevBestCoinBase = block.GetTxHash(0);
}
} else
CheckForkWarningConditionsOnNewFork(pindexNew);
if (!pblocktree->Flush())
return state.Abort(_("Failed to sync block index"));
@ -3066,11 +3144,15 @@ string GetWarnings(string strFor)
strStatusBar = strMiscWarning;
}
// Longer invalid proof-of-work chain
if (pindexBest && nBestInvalidWork > nBestChainWork + (pindexBest->GetBlockWork() * 6).getuint256())
if (fLargeWorkForkFound)
{
nPriority = 2000;
strStatusBar = strRPC = _("Warning: Displayed transactions may not be correct! You may need to upgrade, or other nodes may need to upgrade.");
strStatusBar = strRPC = _("Warning: The network does not appear to fully agree! Some miners appear to be experiencing issues.");
}
else if (fLargeWorkInvalidChainFound)
{
nPriority = 2000;
strStatusBar = strRPC = _("Warning: We do not appear to fully agree with our peers! You may need to upgrade, or other nodes may need to upgrade.");
}
// Alerts