validation: avoid masking of difficulty adjustment errors

Currently difficulty adjustment violations are not reported for
chains that branch off before the last checkpoint. Change this
by moving the checkpoint check after the difficulty check.

Original Author: Pieter Wuille <pieter.wuille@gmail.com>

Cherry-picked from: 215fc33d
Github Pull Request: #3576
This commit is contained in:
Patrick Lodder 2024-07-03 16:51:15 -04:00
parent b961bab134
commit c4e76a3697
No known key found for this signature in database
GPG Key ID: 7C523F5FBABE80E7

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@ -2999,20 +2999,6 @@ bool CheckBlock(const CBlock& block, CValidationState& state, bool fCheckPOW, bo
return true;
}
static bool CheckIndexAgainstCheckpoint(const CBlockIndex* pindexPrev, CValidationState& state, const CChainParams& chainparams, const uint256& hash)
{
if (*pindexPrev->phashBlock == chainparams.GetConsensus(0).hashGenesisBlock)
return true;
int nHeight = pindexPrev->nHeight+1;
// Don't accept any forks from the main chain prior to last checkpoint
CBlockIndex* pcheckpoint = Checkpoints::GetLastCheckpoint(chainparams.Checkpoints());
if (pcheckpoint && nHeight < pcheckpoint->nHeight)
return state.DoS(100, error("%s: forked chain older than last checkpoint (height %d)", __func__, nHeight));
return true;
}
bool IsWitnessEnabled(const CBlockIndex* pindexPrev, const Consensus::Params& params)
{
// Dogecoin: Disable SegWit
@ -3080,7 +3066,8 @@ std::vector<unsigned char> GenerateCoinbaseCommitment(CBlock& block, const CBloc
bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationState& state, const CBlockIndex* pindexPrev, int64_t nAdjustedTime)
{
const int nHeight = pindexPrev == NULL ? 0 : pindexPrev->nHeight + 1;
const Consensus::Params& consensusParams = Params().GetConsensus(nHeight);
const CChainParams& params = Params();
const Consensus::Params& consensusParams = params.GetConsensus(nHeight);
// Disallow legacy blocks after merge-mining start.
if (!consensusParams.fAllowLegacyBlocks
@ -3102,6 +3089,16 @@ bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationState& sta
if (block.nBits != GetNextWorkRequired(pindexPrev, &block, consensusParams))
return state.DoS(100, false, REJECT_INVALID, "bad-diffbits", false, "incorrect proof of work");
// Check against checkpoints
if (fCheckpointsEnabled) {
// Don't accept any forks from the main chain prior to last checkpoint.
// GetLastCheckpoint finds the last checkpoint in MapCheckpoints that's in our
// MapBlockIndex.
CBlockIndex* pcheckpoint = Checkpoints::GetLastCheckpoint(params.Checkpoints());
if (pcheckpoint && nHeight < pcheckpoint->nHeight)
return state.DoS(100, error("%s: forked chain older than last checkpoint (height %d)", __func__, nHeight), REJECT_CHECKPOINT, "bad-fork-prior-to-checkpoint");
}
// Check timestamp against prev
if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast())
return state.Invalid(false, REJECT_INVALID, "time-too-old", "block's timestamp is too early");
@ -3237,8 +3234,6 @@ static bool AcceptBlockHeader(const CBlockHeader& block, CValidationState& state
return state.DoS(100, error("%s: prev block invalid", __func__), REJECT_INVALID, "bad-prevblk");
assert(pindexPrev);
if (fCheckpointsEnabled && !CheckIndexAgainstCheckpoint(pindexPrev, state, chainparams, hash))
return error("%s: CheckIndexAgainstCheckpoint(): %s", __func__, state.GetRejectReason().c_str());
if (!ContextualCheckBlockHeader(block, state, pindexPrev, GetAdjustedTime()))
return error("%s: Consensus::ContextualCheckBlockHeader: %s, %s", __func__, hash.ToString(), FormatStateMessage(state));
@ -3418,9 +3413,6 @@ bool TestBlockValidity(CValidationState& state, const CChainParams& chainparams,
{
AssertLockHeld(cs_main);
assert(pindexPrev && pindexPrev == chainActive.Tip());
if (fCheckpointsEnabled && !CheckIndexAgainstCheckpoint(pindexPrev, state, chainparams, block.GetHash()))
return error("%s: CheckIndexAgainstCheckpoint(): %s", __func__, state.GetRejectReason().c_str());
CCoinsViewCache viewNew(pcoinsTip);
CBlockIndex indexDummy(block);
indexDummy.pprev = pindexPrev;