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-rw-r--r--src/net_processing.cpp153
1 files changed, 143 insertions, 10 deletions
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index b26caf377f..52387b32f4 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -23,6 +23,7 @@
#include "primitives/transaction.h"
#include "random.h"
#include "reverse_iterator.h"
+#include "scheduler.h"
#include "tinyformat.h"
#include "txmempool.h"
#include "ui_interface.h"
@@ -127,6 +128,9 @@ namespace {
/** Number of outbound peers with m_chain_sync.m_protect. */
int g_outbound_peers_with_protect_from_disconnect = 0;
+ /** When our tip was last updated. */
+ int64_t g_last_tip_update = 0;
+
/** Relay map, protected by cs_main. */
typedef std::map<uint256, CTransactionRef> MapRelay;
MapRelay mapRelay;
@@ -231,6 +235,9 @@ struct CNodeState {
ChainSyncTimeoutState m_chain_sync;
+ //! Time of last new block announcement
+ int64_t m_last_block_announcement;
+
CNodeState(CAddress addrIn, std::string addrNameIn) : address(addrIn), name(addrNameIn) {
fCurrentlyConnected = false;
nMisbehavior = 0;
@@ -254,6 +261,7 @@ struct CNodeState {
fWantsCmpctWitness = false;
fSupportsDesiredCmpctVersion = false;
m_chain_sync = { 0, nullptr, false, false };
+ m_last_block_announcement = 0;
}
};
@@ -427,6 +435,15 @@ void MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid, CConnman* connman) {
}
}
+bool TipMayBeStale(const Consensus::Params &consensusParams)
+{
+ AssertLockHeld(cs_main);
+ if (g_last_tip_update == 0) {
+ g_last_tip_update = GetTime();
+ }
+ return g_last_tip_update < GetTime() - consensusParams.nPowTargetSpacing * 3 && mapBlocksInFlight.empty();
+}
+
// Requires cs_main
bool CanDirectFetch(const Consensus::Params &consensusParams)
{
@@ -533,6 +550,15 @@ void FindNextBlocksToDownload(NodeId nodeid, unsigned int count, std::vector<con
} // namespace
+// This function is used for testing the stale tip eviction logic, see
+// DoS_tests.cpp
+void UpdateLastBlockAnnounceTime(NodeId node, int64_t time_in_seconds)
+{
+ LOCK(cs_main);
+ CNodeState *state = State(node);
+ if (state) state->m_last_block_announcement = time_in_seconds;
+}
+
// Returns true for outbound peers, excluding manual connections, feelers, and
// one-shots
bool IsOutboundDisconnectionCandidate(const CNode *node)
@@ -607,7 +633,7 @@ bool GetNodeStateStats(NodeId nodeid, CNodeStateStats &stats) {
// mapOrphanTransactions
//
-void AddToCompactExtraTransactions(const CTransactionRef& tx)
+void AddToCompactExtraTransactions(const CTransactionRef& tx) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
size_t max_extra_txn = gArgs.GetArg("-blockreconstructionextratxn", DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN);
if (max_extra_txn <= 0)
@@ -766,9 +792,17 @@ static bool BlockRequestAllowed(const CBlockIndex* pindex, const Consensus::Para
(GetBlockProofEquivalentTime(*pindexBestHeader, *pindex, *pindexBestHeader, consensusParams) < STALE_RELAY_AGE_LIMIT);
}
-PeerLogicValidation::PeerLogicValidation(CConnman* connmanIn) : connman(connmanIn) {
+PeerLogicValidation::PeerLogicValidation(CConnman* connmanIn, CScheduler &scheduler) : connman(connmanIn), m_stale_tip_check_time(0) {
// Initialize global variables that cannot be constructed at startup.
recentRejects.reset(new CRollingBloomFilter(120000, 0.000001));
+
+ const Consensus::Params& consensusParams = Params().GetConsensus();
+ // Stale tip checking and peer eviction are on two different timers, but we
+ // don't want them to get out of sync due to drift in the scheduler, so we
+ // combine them in one function and schedule at the quicker (peer-eviction)
+ // timer.
+ static_assert(EXTRA_PEER_CHECK_INTERVAL < STALE_CHECK_INTERVAL, "peer eviction timer should be less than stale tip check timer");
+ scheduler.scheduleEvery(std::bind(&PeerLogicValidation::CheckForStaleTipAndEvictPeers, this, consensusParams), EXTRA_PEER_CHECK_INTERVAL * 1000);
}
void PeerLogicValidation::BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex* pindex, const std::vector<CTransactionRef>& vtxConflicted) {
@@ -799,6 +833,8 @@ void PeerLogicValidation::BlockConnected(const std::shared_ptr<const CBlock>& pb
}
LogPrint(BCLog::MEMPOOL, "Erased %d orphan tx included or conflicted by block\n", nErased);
}
+
+ g_last_tip_update = GetTime();
}
// All of the following cache a recent block, and are protected by cs_most_recent_block
@@ -1212,6 +1248,7 @@ bool static ProcessHeadersMessage(CNode *pfrom, CConnman *connman, const std::ve
return true;
}
+ bool received_new_header = false;
const CBlockIndex *pindexLast = nullptr;
{
LOCK(cs_main);
@@ -1252,6 +1289,12 @@ bool static ProcessHeadersMessage(CNode *pfrom, CConnman *connman, const std::ve
}
hashLastBlock = header.GetHash();
}
+
+ // If we don't have the last header, then they'll have given us
+ // something new (if these headers are valid).
+ if (mapBlockIndex.find(hashLastBlock) == mapBlockIndex.end()) {
+ received_new_header = true;
+ }
}
CValidationState state;
@@ -1259,8 +1302,8 @@ bool static ProcessHeadersMessage(CNode *pfrom, CConnman *connman, const std::ve
if (!ProcessNewBlockHeaders(headers, state, chainparams, &pindexLast, &first_invalid_header)) {
int nDoS;
if (state.IsInvalid(nDoS)) {
+ LOCK(cs_main);
if (nDoS > 0) {
- LOCK(cs_main);
Misbehaving(pfrom->GetId(), nDoS);
}
if (punish_duplicate_invalid && mapBlockIndex.find(first_invalid_header.GetHash()) != mapBlockIndex.end()) {
@@ -1316,6 +1359,10 @@ bool static ProcessHeadersMessage(CNode *pfrom, CConnman *connman, const std::ve
// because it is set in UpdateBlockAvailability. Some nullptr checks
// are still present, however, as belt-and-suspenders.
+ if (received_new_header && pindexLast->nChainWork > chainActive.Tip()->nChainWork) {
+ nodestate->m_last_block_announcement = GetTime();
+ }
+
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
@@ -1400,6 +1447,7 @@ bool static ProcessHeadersMessage(CNode *pfrom, CConnman *connman, const std::ve
// 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) {
+ LogPrint(BCLog::NET, "Protecting outbound peer=%d from eviction\n", pfrom->GetId());
nodestate->m_chain_sync.m_protect = true;
++g_outbound_peers_with_protect_from_disconnect;
}
@@ -2215,6 +2263,8 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
CBlockHeaderAndShortTxIDs cmpctblock;
vRecv >> cmpctblock;
+ bool received_new_header = false;
+
{
LOCK(cs_main);
@@ -2224,6 +2274,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexBestHeader), uint256()));
return true;
}
+
+ if (mapBlockIndex.find(cmpctblock.header.GetHash()) == mapBlockIndex.end()) {
+ received_new_header = true;
+ }
}
const CBlockIndex *pindex = nullptr;
@@ -2262,6 +2316,14 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
assert(pindex);
UpdateBlockAvailability(pfrom->GetId(), pindex->GetBlockHash());
+ CNodeState *nodestate = State(pfrom->GetId());
+
+ // If this was a new header with more work than our tip, update the
+ // peer's last block announcement time
+ if (received_new_header && pindex->nChainWork > chainActive.Tip()->nChainWork) {
+ nodestate->m_last_block_announcement = GetTime();
+ }
+
std::map<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator> >::iterator blockInFlightIt = mapBlocksInFlight.find(pindex->GetBlockHash());
bool fAlreadyInFlight = blockInFlightIt != mapBlocksInFlight.end();
@@ -2284,8 +2346,6 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
if (!fAlreadyInFlight && !CanDirectFetch(chainparams.GetConsensus()))
return true;
- CNodeState *nodestate = State(pfrom->GetId());
-
if (IsWitnessEnabled(pindex->pprev, chainparams.GetConsensus()) && !nodestate->fSupportsDesiredCmpctVersion) {
// Don't bother trying to process compact blocks from v1 peers
// after segwit activates.
@@ -2527,11 +2587,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
LogPrint(BCLog::NET, "received block %s peer=%d\n", pblock->GetHash().ToString(), pfrom->GetId());
- // Process all blocks from whitelisted peers, even if not requested,
- // unless we're still syncing with the network.
- // Such an unrequested block may still be processed, subject to the
- // conditions in AcceptBlock().
- bool forceProcessing = pfrom->fWhitelisted && !IsInitialBlockDownload();
+ bool forceProcessing = false;
const uint256 hash(pblock->GetHash());
{
LOCK(cs_main);
@@ -2967,6 +3023,83 @@ void PeerLogicValidation::ConsiderEviction(CNode *pto, int64_t time_in_seconds)
}
}
+void PeerLogicValidation::EvictExtraOutboundPeers(int64_t time_in_seconds)
+{
+ // Check whether we have too many outbound peers
+ int extra_peers = connman->GetExtraOutboundCount();
+ if (extra_peers > 0) {
+ // If we have more outbound peers than we target, disconnect one.
+ // Pick the outbound peer that least recently announced
+ // us a new block, with ties broken by choosing the more recent
+ // connection (higher node id)
+ NodeId worst_peer = -1;
+ int64_t oldest_block_announcement = std::numeric_limits<int64_t>::max();
+
+ LOCK(cs_main);
+
+ connman->ForEachNode([&](CNode* pnode) {
+ // Ignore non-outbound peers, or nodes marked for disconnect already
+ if (!IsOutboundDisconnectionCandidate(pnode) || pnode->fDisconnect) return;
+ CNodeState *state = State(pnode->GetId());
+ if (state == nullptr) return; // shouldn't be possible, but just in case
+ // Don't evict our protected peers
+ if (state->m_chain_sync.m_protect) return;
+ if (state->m_last_block_announcement < oldest_block_announcement || (state->m_last_block_announcement == oldest_block_announcement && pnode->GetId() > worst_peer)) {
+ worst_peer = pnode->GetId();
+ oldest_block_announcement = state->m_last_block_announcement;
+ }
+ });
+ if (worst_peer != -1) {
+ bool disconnected = connman->ForNode(worst_peer, [&](CNode *pnode) {
+ // Only disconnect a peer that has been connected to us for
+ // some reasonable fraction of our check-frequency, to give
+ // it time for new information to have arrived.
+ // Also don't disconnect any peer we're trying to download a
+ // block from.
+ CNodeState &state = *State(pnode->GetId());
+ if (time_in_seconds - pnode->nTimeConnected > MINIMUM_CONNECT_TIME && state.nBlocksInFlight == 0) {
+ LogPrint(BCLog::NET, "disconnecting extra outbound peer=%d (last block announcement received at time %d)\n", pnode->GetId(), oldest_block_announcement);
+ pnode->fDisconnect = true;
+ return true;
+ } else {
+ LogPrint(BCLog::NET, "keeping outbound peer=%d chosen for eviction (connect time: %d, blocks_in_flight: %d)\n", pnode->GetId(), pnode->nTimeConnected, state.nBlocksInFlight);
+ return false;
+ }
+ });
+ if (disconnected) {
+ // If we disconnected an extra peer, that means we successfully
+ // connected to at least one peer after the last time we
+ // detected a stale tip. Don't try any more extra peers until
+ // we next detect a stale tip, to limit the load we put on the
+ // network from these extra connections.
+ connman->SetTryNewOutboundPeer(false);
+ }
+ }
+ }
+}
+
+void PeerLogicValidation::CheckForStaleTipAndEvictPeers(const Consensus::Params &consensusParams)
+{
+ if (connman == nullptr) return;
+
+ int64_t time_in_seconds = GetTime();
+
+ EvictExtraOutboundPeers(time_in_seconds);
+
+ if (time_in_seconds > m_stale_tip_check_time) {
+ LOCK(cs_main);
+ // Check whether our tip is stale, and if so, allow using an extra
+ // outbound peer
+ if (TipMayBeStale(consensusParams)) {
+ LogPrintf("Potential stale tip detected, will try using extra outbound peer (last tip update: %d seconds ago)\n", time_in_seconds - g_last_tip_update);
+ connman->SetTryNewOutboundPeer(true);
+ } else if (connman->GetTryNewOutboundPeer()) {
+ connman->SetTryNewOutboundPeer(false);
+ }
+ m_stale_tip_check_time = time_in_seconds + STALE_CHECK_INTERVAL;
+ }
+}
+
class CompareInvMempoolOrder
{
CTxMemPool *mp;