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moveonly: factor out headers processing into separate function

ProcessMessages will now return earlier when processing headers
messages, rather than continuing on (and do nothing).

Github-Pull: #11568
Rebased-From: 4637f18522
tags/v0.15.1
Suhas Daftuar 3 years ago
parent
commit
fc966bbd2b
1 changed files with 173 additions and 163 deletions
  1. 173
    163
      src/net_processing.cpp

+ 173
- 163
src/net_processing.cpp View File

@@ -1193,6 +1193,178 @@ inline void static SendBlockTransactions(const CBlock& block, const BlockTransac
connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::BLOCKTXN, resp));
}

bool static ProcessHeadersMessage(CNode *pfrom, CConnman *connman, const std::vector<CBlockHeader>& headers, const CChainParams& chainparams)
{
const CNetMsgMaker msgMaker(pfrom->GetSendVersion());
size_t nCount = headers.size();

if (nCount == 0) {
// Nothing interesting. Stop asking this peers for more headers.
return true;
}

const CBlockIndex *pindexLast = nullptr;
{
LOCK(cs_main);
CNodeState *nodestate = State(pfrom->GetId());

// If this looks like it could be a block announcement (nCount <
// MAX_BLOCKS_TO_ANNOUNCE), use special logic for handling headers that
// don't connect:
// - Send a getheaders message in response to try to connect the chain.
// - The peer can send up to MAX_UNCONNECTING_HEADERS in a row that
// don't connect before giving DoS points
// - Once a headers message is received that is valid and does connect,
// nUnconnectingHeaders gets reset back to 0.
if (mapBlockIndex.find(headers[0].hashPrevBlock) == mapBlockIndex.end() && nCount < MAX_BLOCKS_TO_ANNOUNCE) {
nodestate->nUnconnectingHeaders++;
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexBestHeader), uint256()));
LogPrint(BCLog::NET, "received header %s: missing prev block %s, sending getheaders (%d) to end (peer=%d, nUnconnectingHeaders=%d)\n",
headers[0].GetHash().ToString(),
headers[0].hashPrevBlock.ToString(),
pindexBestHeader->nHeight,
pfrom->GetId(), nodestate->nUnconnectingHeaders);
// Set hashLastUnknownBlock for this peer, so that if we
// eventually get the headers - even from a different peer -
// we can use this peer to download.
UpdateBlockAvailability(pfrom->GetId(), headers.back().GetHash());

if (nodestate->nUnconnectingHeaders % MAX_UNCONNECTING_HEADERS == 0) {
Misbehaving(pfrom->GetId(), 20);
}
return true;
}

uint256 hashLastBlock;
for (const CBlockHeader& header : headers) {
if (!hashLastBlock.IsNull() && header.hashPrevBlock != hashLastBlock) {
Misbehaving(pfrom->GetId(), 20);
return error("non-continuous headers sequence");
}
hashLastBlock = header.GetHash();
}
}

CValidationState state;
if (!ProcessNewBlockHeaders(headers, state, chainparams, &pindexLast)) {
int nDoS;
if (state.IsInvalid(nDoS)) {
if (nDoS > 0) {
LOCK(cs_main);
Misbehaving(pfrom->GetId(), nDoS);
}
return error("invalid header received");
}
}

{
LOCK(cs_main);
CNodeState *nodestate = State(pfrom->GetId());
if (nodestate->nUnconnectingHeaders > 0) {
LogPrint(BCLog::NET, "peer=%d: resetting nUnconnectingHeaders (%d -> 0)\n", pfrom->GetId(), nodestate->nUnconnectingHeaders);
}
nodestate->nUnconnectingHeaders = 0;

assert(pindexLast);
UpdateBlockAvailability(pfrom->GetId(), pindexLast->GetBlockHash());

// From here, pindexBestKnownBlock should be guaranteed to be non-null,
// because it is set in UpdateBlockAvailability. Some nullptr checks
// are still present, however, as belt-and-suspenders.

if (nCount == MAX_HEADERS_RESULTS) {
// Headers message had its maximum size; the peer may have more headers.
// TODO: optimize: if pindexLast is an ancestor of chainActive.Tip or pindexBestHeader, continue
// from there instead.
LogPrint(BCLog::NET, "more getheaders (%d) to end to peer=%d (startheight:%d)\n", pindexLast->nHeight, pfrom->GetId(), pfrom->nStartingHeight);
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexLast), uint256()));
}

bool fCanDirectFetch = CanDirectFetch(chainparams.GetConsensus());
// If this set of headers is valid and ends in a block with at least as
// much work as our tip, download as much as possible.
if (fCanDirectFetch && pindexLast->IsValid(BLOCK_VALID_TREE) && chainActive.Tip()->nChainWork <= pindexLast->nChainWork) {
std::vector<const CBlockIndex*> vToFetch;
const CBlockIndex *pindexWalk = pindexLast;
// Calculate all the blocks we'd need to switch to pindexLast, up to a limit.
while (pindexWalk && !chainActive.Contains(pindexWalk) && vToFetch.size() <= MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
if (!(pindexWalk->nStatus & BLOCK_HAVE_DATA) &&
!mapBlocksInFlight.count(pindexWalk->GetBlockHash()) &&
(!IsWitnessEnabled(pindexWalk->pprev, chainparams.GetConsensus()) || State(pfrom->GetId())->fHaveWitness)) {
// We don't have this block, and it's not yet in flight.
vToFetch.push_back(pindexWalk);
}
pindexWalk = pindexWalk->pprev;
}
// If pindexWalk still isn't on our main chain, we're looking at a
// very large reorg at a time we think we're close to caught up to
// the main chain -- this shouldn't really happen. Bail out on the
// direct fetch and rely on parallel download instead.
if (!chainActive.Contains(pindexWalk)) {
LogPrint(BCLog::NET, "Large reorg, won't direct fetch to %s (%d)\n",
pindexLast->GetBlockHash().ToString(),
pindexLast->nHeight);
} else {
std::vector<CInv> vGetData;
// Download as much as possible, from earliest to latest.
for (const CBlockIndex *pindex : reverse_iterate(vToFetch)) {
if (nodestate->nBlocksInFlight >= MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
// Can't download any more from this peer
break;
}
uint32_t nFetchFlags = GetFetchFlags(pfrom);
vGetData.push_back(CInv(MSG_BLOCK | nFetchFlags, pindex->GetBlockHash()));
MarkBlockAsInFlight(pfrom->GetId(), pindex->GetBlockHash(), pindex);
LogPrint(BCLog::NET, "Requesting block %s from peer=%d\n",
pindex->GetBlockHash().ToString(), pfrom->GetId());
}
if (vGetData.size() > 1) {
LogPrint(BCLog::NET, "Downloading blocks toward %s (%d) via headers direct fetch\n",
pindexLast->GetBlockHash().ToString(), pindexLast->nHeight);
}
if (vGetData.size() > 0) {
if (nodestate->fSupportsDesiredCmpctVersion && vGetData.size() == 1 && mapBlocksInFlight.size() == 1 && pindexLast->pprev->IsValid(BLOCK_VALID_CHAIN)) {
// In any case, we want to download using a compact block, not a regular one
vGetData[0] = CInv(MSG_CMPCT_BLOCK, vGetData[0].hash);
}
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, vGetData));
}
}
}
// If we're in IBD, we want outbound peers that will serve us a useful
// chain. Disconnect peers that are on chains with insufficient work.
if (IsInitialBlockDownload() && nCount != MAX_HEADERS_RESULTS) {
// When nCount < MAX_HEADERS_RESULTS, we know we have no more
// headers to fetch from this peer.
if (nodestate->pindexBestKnownBlock && nodestate->pindexBestKnownBlock->nChainWork < nMinimumChainWork) {
// This peer has too little work on their headers chain to help
// us sync -- disconnect if using an outbound slot (unless
// whitelisted or addnode).
// Note: We compare their tip to nMinimumChainWork (rather than
// chainActive.Tip()) because we won't start block download
// until we have a headers chain that has at least
// nMinimumChainWork, even if a peer has a chain past our tip,
// as an anti-DoS measure.
if (IsOutboundDisconnectionCandidate(pfrom)) {
LogPrintf("Disconnecting outbound peer %d -- headers chain has insufficient work\n", pfrom->GetId());
pfrom->fDisconnect = true;
}
}
}

if (!pfrom->fDisconnect && IsOutboundDisconnectionCandidate(pfrom) && nodestate->pindexBestKnownBlock != nullptr) {
// If this is an outbound peer, check to see if we should protect
// it from the bad/lagging chain logic.
if (g_outbound_peers_with_protect_from_disconnect < MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT && nodestate->pindexBestKnownBlock->nChainWork >= chainActive.Tip()->nChainWork && !nodestate->m_chain_sync.m_protect) {
nodestate->m_chain_sync.m_protect = true;
++g_outbound_peers_with_protect_from_disconnect;
}
}
}

return true;
}

bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStream& vRecv, int64_t nTimeReceived, const CChainParams& chainparams, CConnman* connman, const std::atomic<bool>& interruptMsgProc)
{
LogPrint(BCLog::NET, "received: %s (%u bytes) peer=%d\n", SanitizeString(strCommand), vRecv.size(), pfrom->GetId());
@@ -2286,169 +2458,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
ReadCompactSize(vRecv); // ignore tx count; assume it is 0.
}

if (nCount == 0) {
// Nothing interesting. Stop asking this peers for more headers.
return true;
}

const CBlockIndex *pindexLast = nullptr;
{
LOCK(cs_main);
CNodeState *nodestate = State(pfrom->GetId());

// If this looks like it could be a block announcement (nCount <
// MAX_BLOCKS_TO_ANNOUNCE), use special logic for handling headers that
// don't connect:
// - Send a getheaders message in response to try to connect the chain.
// - The peer can send up to MAX_UNCONNECTING_HEADERS in a row that
// don't connect before giving DoS points
// - Once a headers message is received that is valid and does connect,
// nUnconnectingHeaders gets reset back to 0.
if (mapBlockIndex.find(headers[0].hashPrevBlock) == mapBlockIndex.end() && nCount < MAX_BLOCKS_TO_ANNOUNCE) {
nodestate->nUnconnectingHeaders++;
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexBestHeader), uint256()));
LogPrint(BCLog::NET, "received header %s: missing prev block %s, sending getheaders (%d) to end (peer=%d, nUnconnectingHeaders=%d)\n",
headers[0].GetHash().ToString(),
headers[0].hashPrevBlock.ToString(),
pindexBestHeader->nHeight,
pfrom->GetId(), nodestate->nUnconnectingHeaders);
// Set hashLastUnknownBlock for this peer, so that if we
// eventually get the headers - even from a different peer -
// we can use this peer to download.
UpdateBlockAvailability(pfrom->GetId(), headers.back().GetHash());

if (nodestate->nUnconnectingHeaders % MAX_UNCONNECTING_HEADERS == 0) {
Misbehaving(pfrom->GetId(), 20);
}
return true;
}

uint256 hashLastBlock;
for (const CBlockHeader& header : headers) {
if (!hashLastBlock.IsNull() && header.hashPrevBlock != hashLastBlock) {
Misbehaving(pfrom->GetId(), 20);
return error("non-continuous headers sequence");
}
hashLastBlock = header.GetHash();
}
}

CValidationState state;
if (!ProcessNewBlockHeaders(headers, state, chainparams, &pindexLast)) {
int nDoS;
if (state.IsInvalid(nDoS)) {
if (nDoS > 0) {
LOCK(cs_main);
Misbehaving(pfrom->GetId(), nDoS);
}
return error("invalid header received");
}
}

{
LOCK(cs_main);
CNodeState *nodestate = State(pfrom->GetId());
if (nodestate->nUnconnectingHeaders > 0) {
LogPrint(BCLog::NET, "peer=%d: resetting nUnconnectingHeaders (%d -> 0)\n", pfrom->GetId(), nodestate->nUnconnectingHeaders);
}
nodestate->nUnconnectingHeaders = 0;

assert(pindexLast);
UpdateBlockAvailability(pfrom->GetId(), pindexLast->GetBlockHash());

// From here, pindexBestKnownBlock should be guaranteed to be non-null,
// because it is set in UpdateBlockAvailability. Some nullptr checks
// are still present, however, as belt-and-suspenders.

if (nCount == MAX_HEADERS_RESULTS) {
// Headers message had its maximum size; the peer may have more headers.
// TODO: optimize: if pindexLast is an ancestor of chainActive.Tip or pindexBestHeader, continue
// from there instead.
LogPrint(BCLog::NET, "more getheaders (%d) to end to peer=%d (startheight:%d)\n", pindexLast->nHeight, pfrom->GetId(), pfrom->nStartingHeight);
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexLast), uint256()));
}

bool fCanDirectFetch = CanDirectFetch(chainparams.GetConsensus());
// If this set of headers is valid and ends in a block with at least as
// much work as our tip, download as much as possible.
if (fCanDirectFetch && pindexLast->IsValid(BLOCK_VALID_TREE) && chainActive.Tip()->nChainWork <= pindexLast->nChainWork) {
std::vector<const CBlockIndex*> vToFetch;
const CBlockIndex *pindexWalk = pindexLast;
// Calculate all the blocks we'd need to switch to pindexLast, up to a limit.
while (pindexWalk && !chainActive.Contains(pindexWalk) && vToFetch.size() <= MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
if (!(pindexWalk->nStatus & BLOCK_HAVE_DATA) &&
!mapBlocksInFlight.count(pindexWalk->GetBlockHash()) &&
(!IsWitnessEnabled(pindexWalk->pprev, chainparams.GetConsensus()) || State(pfrom->GetId())->fHaveWitness)) {
// We don't have this block, and it's not yet in flight.
vToFetch.push_back(pindexWalk);
}
pindexWalk = pindexWalk->pprev;
}
// If pindexWalk still isn't on our main chain, we're looking at a
// very large reorg at a time we think we're close to caught up to
// the main chain -- this shouldn't really happen. Bail out on the
// direct fetch and rely on parallel download instead.
if (!chainActive.Contains(pindexWalk)) {
LogPrint(BCLog::NET, "Large reorg, won't direct fetch to %s (%d)\n",
pindexLast->GetBlockHash().ToString(),
pindexLast->nHeight);
} else {
std::vector<CInv> vGetData;
// Download as much as possible, from earliest to latest.
for (const CBlockIndex *pindex : reverse_iterate(vToFetch)) {
if (nodestate->nBlocksInFlight >= MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
// Can't download any more from this peer
break;
}
uint32_t nFetchFlags = GetFetchFlags(pfrom);
vGetData.push_back(CInv(MSG_BLOCK | nFetchFlags, pindex->GetBlockHash()));
MarkBlockAsInFlight(pfrom->GetId(), pindex->GetBlockHash(), pindex);
LogPrint(BCLog::NET, "Requesting block %s from peer=%d\n",
pindex->GetBlockHash().ToString(), pfrom->GetId());
}
if (vGetData.size() > 1) {
LogPrint(BCLog::NET, "Downloading blocks toward %s (%d) via headers direct fetch\n",
pindexLast->GetBlockHash().ToString(), pindexLast->nHeight);
}
if (vGetData.size() > 0) {
if (nodestate->fSupportsDesiredCmpctVersion && vGetData.size() == 1 && mapBlocksInFlight.size() == 1 && pindexLast->pprev->IsValid(BLOCK_VALID_CHAIN)) {
// In any case, we want to download using a compact block, not a regular one
vGetData[0] = CInv(MSG_CMPCT_BLOCK, vGetData[0].hash);
}
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETDATA, vGetData));
}
}
}
// If we're in IBD, we want outbound peers that will serve us a useful
// chain. Disconnect peers that are on chains with insufficient work.
if (IsInitialBlockDownload() && nCount != MAX_HEADERS_RESULTS) {
// When nCount < MAX_HEADERS_RESULTS, we know we have no more
// headers to fetch from this peer.
if (nodestate->pindexBestKnownBlock && nodestate->pindexBestKnownBlock->nChainWork < nMinimumChainWork) {
// This peer has too little work on their headers chain to help
// us sync -- disconnect if using an outbound slot (unless
// whitelisted or addnode).
// Note: We compare their tip to nMinimumChainWork (rather than
// chainActive.Tip()) because we won't start block download
// until we have a headers chain that has at least
// nMinimumChainWork, even if a peer has a chain past our tip,
// as an anti-DoS measure.
if (IsOutboundDisconnectionCandidate(pfrom)) {
LogPrintf("Disconnecting outbound peer %d -- headers chain has insufficient work\n", pfrom->GetId());
pfrom->fDisconnect = true;
}
}
}

if (!pfrom->fDisconnect && IsOutboundDisconnectionCandidate(pfrom) && nodestate->pindexBestKnownBlock != nullptr) {
// If this is an outbound peer, check to see if we should protect
// it from the bad/lagging chain logic.
if (g_outbound_peers_with_protect_from_disconnect < MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT && nodestate->pindexBestKnownBlock->nChainWork >= chainActive.Tip()->nChainWork && !nodestate->m_chain_sync.m_protect) {
nodestate->m_chain_sync.m_protect = true;
++g_outbound_peers_with_protect_from_disconnect;
}
}
}
return ProcessHeadersMessage(pfrom, connman, headers, chainparams);
}

else if (strCommand == NetMsgType::BLOCK && !fImporting && !fReindex) // Ignore blocks received while importing

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