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Abstract context-dependent block checking from acceptance

tags/v0.15.1
Luke Dashjr 6 years ago
parent
commit
a48f2d6ddd
2 changed files with 75 additions and 53 deletions
  1. 71
    53
      src/main.cpp
  2. 4
    0
      src/main.h

+ 71
- 53
src/main.cpp View File

@@ -2334,6 +2334,73 @@ bool CheckBlock(const CBlock& block, CValidationState& state, bool fCheckPOW, bo
return true;
}

bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationState& state, CBlockIndex * const pindexPrev)
{
uint256 hash = block.GetHash();
if (hash == Params().HashGenesisBlock())
return true;

assert(pindexPrev);

int nHeight = pindexPrev->nHeight+1;

// Check proof of work
if ((!Params().SkipProofOfWorkCheck()) &&
(block.nBits != GetNextWorkRequired(pindexPrev, &block)))
return state.DoS(100, error("%s : incorrect proof of work", __func__),
REJECT_INVALID, "bad-diffbits");

// Check timestamp against prev
if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast())
return state.Invalid(error("%s : block's timestamp is too early", __func__),
REJECT_INVALID, "time-too-old");

// Check that the block chain matches the known block chain up to a checkpoint
if (!Checkpoints::CheckBlock(nHeight, hash))
return state.DoS(100, error("%s : rejected by checkpoint lock-in at %d", __func__, nHeight),
REJECT_CHECKPOINT, "checkpoint mismatch");

// Don't accept any forks from the main chain prior to last checkpoint
CBlockIndex* pcheckpoint = Checkpoints::GetLastCheckpoint();
if (pcheckpoint && nHeight < pcheckpoint->nHeight)
return state.DoS(100, error("%s : forked chain older than last checkpoint (height %d)", __func__, nHeight));

// Reject block.nVersion=1 blocks when 95% (75% on testnet) of the network has upgraded:
if (block.nVersion < 2 &&
CBlockIndex::IsSuperMajority(2, pindexPrev, Params().RejectBlockOutdatedMajority()))
{
return state.Invalid(error("%s : rejected nVersion=1 block", __func__),
REJECT_OBSOLETE, "bad-version");
}

return true;
}

bool ContextualCheckBlock(const CBlock& block, CValidationState& state, CBlockIndex * const pindexPrev)
{
const int nHeight = pindexPrev == NULL ? 0 : pindexPrev->nHeight + 1;

// Check that all transactions are finalized
BOOST_FOREACH(const CTransaction& tx, block.vtx)
if (!IsFinalTx(tx, nHeight, block.GetBlockTime())) {
return state.DoS(10, error("%s : contains a non-final transaction", __func__), REJECT_INVALID, "bad-txns-nonfinal");
}

// Enforce block.nVersion=2 rule that the coinbase starts with serialized block height
// if 750 of the last 1,000 blocks are version 2 or greater (51/100 if testnet):
if (block.nVersion >= 2 &&
CBlockIndex::IsSuperMajority(2, pindexPrev, Params().EnforceBlockUpgradeMajority()))
{
CScript expect = CScript() << nHeight;
if (block.vtx[0].vin[0].scriptSig.size() < expect.size() ||
!std::equal(expect.begin(), expect.end(), block.vtx[0].vin[0].scriptSig.begin())) {
return state.DoS(100, error("%s : block height mismatch in coinbase", __func__), REJECT_INVALID, "bad-cb-height");
}
}

return true;
}

bool AcceptBlockHeader(const CBlockHeader& block, CValidationState& state, CBlockIndex** ppindex)
{
AssertLockHeld(cs_main);
@@ -2353,44 +2420,16 @@ bool AcceptBlockHeader(const CBlockHeader& block, CValidationState& state, CBloc

// Get prev block index
CBlockIndex* pindexPrev = NULL;
int nHeight = 0;
if (hash != Params().HashGenesisBlock()) {
BlockMap::iterator mi = mapBlockIndex.find(block.hashPrevBlock);
if (mi == mapBlockIndex.end())
return state.DoS(10, error("%s : prev block not found", __func__), 0, "bad-prevblk");
pindexPrev = (*mi).second;
nHeight = pindexPrev->nHeight+1;

// Check proof of work
if ((!Params().SkipProofOfWorkCheck()) &&
(block.nBits != GetNextWorkRequired(pindexPrev, &block)))
return state.DoS(100, error("%s : incorrect proof of work", __func__),
REJECT_INVALID, "bad-diffbits");

// Check timestamp against prev
if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast())
return state.Invalid(error("%s : block's timestamp is too early", __func__),
REJECT_INVALID, "time-too-old");

// Check that the block chain matches the known block chain up to a checkpoint
if (!Checkpoints::CheckBlock(nHeight, hash))
return state.DoS(100, error("%s : rejected by checkpoint lock-in at %d", __func__, nHeight),
REJECT_CHECKPOINT, "checkpoint mismatch");

// Don't accept any forks from the main chain prior to last checkpoint
CBlockIndex* pcheckpoint = Checkpoints::GetLastCheckpoint();
if (pcheckpoint && nHeight < pcheckpoint->nHeight)
return state.DoS(100, error("%s : forked chain older than last checkpoint (height %d)", __func__, nHeight));

// Reject block.nVersion=1 blocks when 95% (75% on testnet) of the network has upgraded:
if (block.nVersion < 2 &&
CBlockIndex::IsSuperMajority(2, pindexPrev, Params().RejectBlockOutdatedMajority()))
{
return state.Invalid(error("%s : rejected nVersion=1 block", __func__),
REJECT_OBSOLETE, "bad-version");
}
}

if (!ContextualCheckBlockHeader(block, state, pindexPrev))
return false;

if (pindex == NULL)
pindex = AddToBlockIndex(block);

@@ -2415,7 +2454,7 @@ bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex** ppindex,
return true;
}

if (!CheckBlock(block, state)) {
if ((!CheckBlock(block, state)) || !ContextualCheckBlock(block, state, pindex->pprev)) {
if (state.IsInvalid() && !state.CorruptionPossible()) {
pindex->nStatus |= BLOCK_FAILED_VALID;
}
@@ -2424,27 +2463,6 @@ bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex** ppindex,

int nHeight = pindex->nHeight;

// Check that all transactions are finalized
BOOST_FOREACH(const CTransaction& tx, block.vtx)
if (!IsFinalTx(tx, nHeight, block.GetBlockTime())) {
pindex->nStatus |= BLOCK_FAILED_VALID;
return state.DoS(10, error("AcceptBlock() : contains a non-final transaction"),
REJECT_INVALID, "bad-txns-nonfinal");
}

// Enforce block.nVersion=2 rule that the coinbase starts with serialized block height
// if 750 of the last 1,000 blocks are version 2 or greater (51/100 if testnet):
if (block.nVersion >= 2 &&
CBlockIndex::IsSuperMajority(2, pindex->pprev, Params().EnforceBlockUpgradeMajority()))
{
CScript expect = CScript() << nHeight;
if (block.vtx[0].vin[0].scriptSig.size() < expect.size() ||
!std::equal(expect.begin(), expect.end(), block.vtx[0].vin[0].scriptSig.begin())) {
pindex->nStatus |= BLOCK_FAILED_VALID;
return state.DoS(100, error("AcceptBlock() : block height mismatch in coinbase"), REJECT_INVALID, "bad-cb-height");
}
}

// Write block to history file
try {
unsigned int nBlockSize = ::GetSerializeSize(block, SER_DISK, CLIENT_VERSION);

+ 4
- 0
src/main.h View File

@@ -463,6 +463,10 @@ bool ConnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex, C
bool CheckBlockHeader(const CBlockHeader& block, CValidationState& state, bool fCheckPOW = true);
bool CheckBlock(const CBlock& block, CValidationState& state, bool fCheckPOW = true, bool fCheckMerkleRoot = true);

// Context-dependent validity checks
bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationState& state, CBlockIndex *pindexPrev);
bool ContextualCheckBlock(const CBlock& block, CValidationState& state, CBlockIndex *pindexPrev);

// Store block on disk
// if dbp is provided, the file is known to already reside on disk
bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex **pindex, CDiskBlockPos* dbp = NULL);

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