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fixup! serve blocks and headers when using unvalidated snapshot
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when previously we refused to serve these until we had validated
the snapshot. This was suggested by Greg Maxwell
(bitcoin#15606 (comment)).
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@jamesob
jamesob committed Mar 27, 2019
1 parent 3925a31 commit 6cc2c6f
Showing 1 changed file with 15 additions and 27 deletions.
42 changes: 15 additions & 27 deletions src/net_processing.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1357,7 +1357,7 @@ void static ProcessGetBlockData(CNode* pfrom, const CChainParams& chainparams, c
}
// Avoid leaking prune-height by never sending blocks below the NODE_NETWORK_LIMITED threshold
if (send && !pfrom->fWhitelisted && (
(((pfrom->GetLocalServices() & NODE_NETWORK_LIMITED) == NODE_NETWORK_LIMITED) && ((pfrom->GetLocalServices() & NODE_NETWORK) != NODE_NETWORK) && (g_chainman.ValidatedTip()->nHeight - pindex->nHeight > (int)NODE_NETWORK_LIMITED_MIN_BLOCKS + 2 /* add two blocks buffer extension for possible races */) )
(((pfrom->GetLocalServices() & NODE_NETWORK_LIMITED) == NODE_NETWORK_LIMITED) && ((pfrom->GetLocalServices() & NODE_NETWORK) != NODE_NETWORK) && (::ChainActive().Tip()->nHeight - pindex->nHeight > (int)NODE_NETWORK_LIMITED_MIN_BLOCKS + 2 /* add two blocks buffer extension for possible races */) )
)) {
LogPrint(BCLog::NET, "Ignore block request below NODE_NETWORK_LIMITED threshold from peer=%d\n", pfrom->GetId());

Expand Down Expand Up @@ -1427,9 +1427,7 @@ void static ProcessGetBlockData(CNode* pfrom, const CChainParams& chainparams, c
// instead we respond with the full, non-compact block.
bool fPeerWantsWitness = State(pfrom->GetId())->fWantsCmpctWitness;
int nSendFlags = fPeerWantsWitness ? 0 : SERIALIZE_TRANSACTION_NO_WITNESS;
// Consult the ValidatedChain since we likely can't serve blocks
// from the snapshot chain, if in use.
if (CanDirectFetch(consensusParams) && pindex->nHeight >= g_chainman.ValidatedChain().Height() - MAX_CMPCTBLOCK_DEPTH) {
if (CanDirectFetch(consensusParams) && pindex->nHeight >= ::ChainActive().Height() - MAX_CMPCTBLOCK_DEPTH) {
if ((fPeerWantsWitness || !fWitnessesPresentInARecentCompactBlock) && a_recent_compact_block && a_recent_compact_block->header.GetHash() == pindex->GetBlockHash()) {
connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK, *a_recent_compact_block));
} else {
Expand All @@ -1449,9 +1447,7 @@ void static ProcessGetBlockData(CNode* pfrom, const CChainParams& chainparams, c
// and we want it right after the last block so they don't
// wait for other stuff first.
std::vector<CInv> vInv;
// Use the ValidatedTip - we only share blocks from a chain that
// has been fully validated.
vInv.push_back(CInv(MSG_BLOCK, g_chainman.ValidatedTip()->GetBlockHash()));
vInv.push_back(CInv(MSG_BLOCK, ::ChainActive().Tip()->GetBlockHash()));
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::INV, vInv));
pfrom->hashContinue.SetNull();
}
Expand Down Expand Up @@ -2245,9 +2241,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
}

LOCK(cs_main);
// Use the validated chain here because otherwise we both don't want to serve data
// from an unvalidated tip and likely don't have any block data to serve.
const CChain& chain = g_chainman.ValidatedChain();
const CChain& chain = ::ChainActive();

// Find the last block the caller has in the main chain
const CBlockIndex* pindex = FindForkInGlobalIndex(chain, locator);
Expand Down Expand Up @@ -2302,17 +2296,14 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
}

LOCK(cs_main);
// Use the validated chain here because otherwise we both don't want to serve data
// from an unvalidated tip and likely don't have any block data to serve.
const CChain& chain = g_chainman.ValidatedChain();

const CBlockIndex* pindex = LookupBlockIndex(req.blockhash);
if (!pindex || !(pindex->nStatus & BLOCK_HAVE_DATA)) {
LogPrint(BCLog::NET, "Peer %d sent us a getblocktxn for a block we don't have\n", pfrom->GetId());
return true;
}

if (pindex->nHeight < chain.Height() - MAX_BLOCKTXN_DEPTH) {
if (pindex->nHeight < ::ChainActive().Height() - MAX_BLOCKTXN_DEPTH) {
// If an older block is requested (should never happen in practice,
// but can happen in tests) send a block response instead of a
// blocktxn response. Sending a full block response instead of a
Expand Down Expand Up @@ -2350,10 +2341,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr

LOCK(cs_main);

// Only service data requests using a chain that we've fully validated.
const CChain& chain = g_chainman.ValidatedChain();

if (::ChainstateActive()->IsInitialBlockDownload() && !pfrom->fWhitelisted) {
if (::ActiveChainstate()->IsInitialBlockDownload() && !pfrom->fWhitelisted) {
LogPrint(BCLog::NET, "Ignoring getheaders from peer=%d because node is in initial block download\n", pfrom->GetId());
return true;
}
Expand All @@ -2376,23 +2364,23 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
else
{
// Find the last block the caller has in the main chain
pindex = FindForkInGlobalIndex(chain, locator);
pindex = FindForkInGlobalIndex(::ChainActive(), locator);
if (pindex)
pindex = chain.Next(pindex);
pindex = ::ChainActive().Next(pindex);
}

// we must use CBlocks, as CBlockHeaders won't include the 0x00 nTx count at the end
std::vector<CBlock> vHeaders;
int nLimit = MAX_HEADERS_RESULTS;
LogPrint(BCLog::NET, "getheaders %d to %s from peer=%d\n", (pindex ? pindex->nHeight : -1), hashStop.IsNull() ? "end" : hashStop.ToString(), pfrom->GetId());
for (; pindex; pindex = chain.Next(pindex))
for (; pindex; pindex = ::ChainActive().Next(pindex))
{
vHeaders.push_back(pindex->GetBlockHeader());
if (--nLimit <= 0 || pindex->GetBlockHash() == hashStop)
break;
}
// pindex can be nullptr either if we sent chain.Tip() OR
// if our peer has chain.Tip() (and thus we are sending an empty
// pindex can be nullptr either if we sent ::ChainActive().Tip() OR
// if our peer has ::ChainActive().Tip() (and thus we are sending an empty
// headers message). In both cases it's safe to update
// pindexBestHeaderSent to be our tip.
//
Expand All @@ -2403,7 +2391,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
// without the new block. By resetting the BestHeaderSent, we ensure we
// will re-announce the new block via headers (or compact blocks again)
// in the SendMessages logic.
nodestate->pindexBestHeaderSent = pindex ? pindex : chain.Tip();
nodestate->pindexBestHeaderSent = pindex ? pindex : ::ChainActive().Tip();
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::HEADERS, vHeaders));
return true;
}
Expand Down Expand Up @@ -3650,7 +3638,7 @@ bool PeerLogicValidation::SendMessages(CNode* pto)
for (const uint256 &hash : pto->vBlockHashesToAnnounce) {
const CBlockIndex* pindex = LookupBlockIndex(hash);
assert(pindex);
if (g_chainman.ValidatedChain()[pindex->nHeight] != pindex) {
if (::ChainActive()[pindex->nHeight] != pindex) {
// Bail out if we reorged away from this block
fRevertToInv = true;
break;
Expand Down Expand Up @@ -3746,10 +3734,10 @@ bool PeerLogicValidation::SendMessages(CNode* pto)
// Warn if we're announcing a block that is not on the main chain.
// This should be very rare and could be optimized out.
// Just log for now.
if (g_chainman.ValidatedChain()[pindex->nHeight] != pindex) {
if (::ChainActive()[pindex->nHeight] != pindex) {
LogPrint(BCLog::NET, "Announcing block %s not on main chain (tip=%s)\n",
hashToAnnounce.ToString(),
g_chainman.ValidatedTip()->GetBlockHash().ToString());
::ChainActive().Tip()->GetBlockHash().ToString());
}

// If the peer's chain has this block, don't inv it back.
Expand Down

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