Split orphan handling from net_processing into txorphanage #21148
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| // Copyright (c) 2021 The Bitcoin Core developers | ||
| // Distributed under the MIT software license, see the accompanying | ||
| // file COPYING or http://www.opensource.org/licenses/mit-license.php. | ||
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| #include <txorphanage.h> | ||
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| #include <consensus/validation.h> | ||
| #include <logging.h> | ||
| #include <policy/policy.h> | ||
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| #include <cassert> | ||
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| /** Expiration time for orphan transactions in seconds */ | ||
| static constexpr int64_t ORPHAN_TX_EXPIRE_TIME = 20 * 60; | ||
| /** Minimum time between orphan transactions expire time checks in seconds */ | ||
| static constexpr int64_t ORPHAN_TX_EXPIRE_INTERVAL = 5 * 60; | ||
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| RecursiveMutex g_cs_orphans; | ||
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| bool TxOrphanage::AddTx(const CTransactionRef& tx, NodeId peer) | ||
| { | ||
| AssertLockHeld(g_cs_orphans); | ||
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| const uint256& hash = tx->GetHash(); | ||
| if (m_orphans.count(hash)) | ||
| return false; | ||
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| // Ignore big transactions, to avoid a | ||
| // send-big-orphans memory exhaustion attack. If a peer has a legitimate | ||
| // large transaction with a missing parent then we assume | ||
| // it will rebroadcast it later, after the parent transaction(s) | ||
| // have been mined or received. | ||
| // 100 orphans, each of which is at most 100,000 bytes big is | ||
| // at most 10 megabytes of orphans and somewhat more byprev index (in the worst case): | ||
| unsigned int sz = GetTransactionWeight(*tx); | ||
| if (sz > MAX_STANDARD_TX_WEIGHT) | ||
| { | ||
| LogPrint(BCLog::MEMPOOL, "ignoring large orphan tx (size: %u, hash: %s)\n", sz, hash.ToString()); | ||
| return false; | ||
| } | ||
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| auto ret = m_orphans.emplace(hash, OrphanTx{tx, peer, GetTime() + ORPHAN_TX_EXPIRE_TIME, m_orphan_list.size()}); | ||
| assert(ret.second); | ||
| m_orphan_list.push_back(ret.first); | ||
| // Allow for lookups in the orphan pool by wtxid, as well as txid | ||
| m_wtxid_to_orphan_it.emplace(tx->GetWitnessHash(), ret.first); | ||
| for (const CTxIn& txin : tx->vin) { | ||
| m_outpoint_to_orphan_it[txin.prevout].insert(ret.first); | ||
| } | ||
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| LogPrint(BCLog::MEMPOOL, "stored orphan tx %s (mapsz %u outsz %u)\n", hash.ToString(), | ||
| m_orphans.size(), m_outpoint_to_orphan_it.size()); | ||
| return true; | ||
| } | ||
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| int TxOrphanage::EraseTx(const uint256& txid) | ||
| { | ||
| AssertLockHeld(g_cs_orphans); | ||
| std::map<uint256, OrphanTx>::iterator it = m_orphans.find(txid); | ||
| if (it == m_orphans.end()) | ||
| return 0; | ||
| for (const CTxIn& txin : it->second.tx->vin) | ||
| { | ||
| auto itPrev = m_outpoint_to_orphan_it.find(txin.prevout); | ||
| if (itPrev == m_outpoint_to_orphan_it.end()) | ||
| continue; | ||
| itPrev->second.erase(it); | ||
| if (itPrev->second.empty()) | ||
| m_outpoint_to_orphan_it.erase(itPrev); | ||
| } | ||
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| size_t old_pos = it->second.list_pos; | ||
| assert(m_orphan_list[old_pos] == it); | ||
| if (old_pos + 1 != m_orphan_list.size()) { | ||
| // Unless we're deleting the last entry in m_orphan_list, move the last | ||
| // entry to the position we're deleting. | ||
| auto it_last = m_orphan_list.back(); | ||
| m_orphan_list[old_pos] = it_last; | ||
| it_last->second.list_pos = old_pos; | ||
| } | ||
| m_orphan_list.pop_back(); | ||
| m_wtxid_to_orphan_it.erase(it->second.tx->GetWitnessHash()); | ||
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| m_orphans.erase(it); | ||
| return 1; | ||
| } | ||
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| void TxOrphanage::EraseForPeer(NodeId peer) | ||
| { | ||
| AssertLockHeld(g_cs_orphans); | ||
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| int nErased = 0; | ||
| std::map<uint256, OrphanTx>::iterator iter = m_orphans.begin(); | ||
| while (iter != m_orphans.end()) | ||
| { | ||
| std::map<uint256, OrphanTx>::iterator maybeErase = iter++; // increment to avoid iterator becoming invalid | ||
| if (maybeErase->second.fromPeer == peer) | ||
| { | ||
| nErased += EraseTx(maybeErase->second.tx->GetHash()); | ||
| } | ||
| } | ||
| if (nErased > 0) LogPrint(BCLog::MEMPOOL, "Erased %d orphan tx from peer=%d\n", nErased, peer); | ||
| } | ||
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| unsigned int TxOrphanage::LimitOrphans(unsigned int max_orphans) | ||
| { | ||
| AssertLockHeld(g_cs_orphans); | ||
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| unsigned int nEvicted = 0; | ||
| static int64_t nNextSweep; | ||
| int64_t nNow = GetTime(); | ||
| if (nNextSweep <= nNow) { | ||
| // Sweep out expired orphan pool entries: | ||
| int nErased = 0; | ||
| int64_t nMinExpTime = nNow + ORPHAN_TX_EXPIRE_TIME - ORPHAN_TX_EXPIRE_INTERVAL; | ||
| std::map<uint256, OrphanTx>::iterator iter = m_orphans.begin(); | ||
| while (iter != m_orphans.end()) | ||
| { | ||
| std::map<uint256, OrphanTx>::iterator maybeErase = iter++; | ||
| if (maybeErase->second.nTimeExpire <= nNow) { | ||
| nErased += EraseTx(maybeErase->second.tx->GetHash()); | ||
| } else { | ||
| nMinExpTime = std::min(maybeErase->second.nTimeExpire, nMinExpTime); | ||
| } | ||
| } | ||
| // Sweep again 5 minutes after the next entry that expires in order to batch the linear scan. | ||
| nNextSweep = nMinExpTime + ORPHAN_TX_EXPIRE_INTERVAL; | ||
| if (nErased > 0) LogPrint(BCLog::MEMPOOL, "Erased %d orphan tx due to expiration\n", nErased); | ||
| } | ||
| FastRandomContext rng; | ||
| while (m_orphans.size() > max_orphans) | ||
| { | ||
| // Evict a random orphan: | ||
| size_t randompos = rng.randrange(m_orphan_list.size()); | ||
| EraseTx(m_orphan_list[randompos]->first); | ||
| ++nEvicted; | ||
| } | ||
| return nEvicted; | ||
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There was a problem hiding this comment. Couldn't the "orphanage overflow" log L3131 in net_processing be moved here instead of returning |
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| } | ||
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| void TxOrphanage::AddChildrenToWorkSet(const CTransaction& tx, std::set<uint256>& orphan_work_set) const | ||
| { | ||
| AssertLockHeld(g_cs_orphans); | ||
| for (unsigned int i = 0; i < tx.vout.size(); i++) { | ||
| const auto it_by_prev = m_outpoint_to_orphan_it.find(COutPoint(tx.GetHash(), i)); | ||
| if (it_by_prev != m_outpoint_to_orphan_it.end()) { | ||
| for (const auto& elem : it_by_prev->second) { | ||
| orphan_work_set.insert(elem->first); | ||
| } | ||
| } | ||
| } | ||
| } | ||
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| bool TxOrphanage::HaveTx(const GenTxid& gtxid) const | ||
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There was a problem hiding this comment. Let's say an attacker sends an invalid orphan Z to Alice. Such orphan will be stored If Bob sends a valid Z's parent, it should be accepted but Alice's version of Z will be Is the following description correct ? If yes, I don't think that's concerning, assuming Bob Though not introduced by this PR. There was a problem hiding this comment. I think what you're saying is: Bob has tx I think the expected behaviour is then: Carol announces both There was a problem hiding this comment.
Once the transaction is rejected from orphanage in reason of an already present orphan, we forget its txid/wtxid from tx-requester. So effectively, we shouldn't re-request it from other onest peers at that stage. Ultimately, parent Yes I agree #21061 should make things better. |
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| { | ||
| LOCK(g_cs_orphans); | ||
| if (gtxid.IsWtxid()) { | ||
| return m_wtxid_to_orphan_it.count(gtxid.GetHash()); | ||
| } else { | ||
| return m_orphans.count(gtxid.GetHash()); | ||
| } | ||
| } | ||
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| std::pair<CTransactionRef, NodeId> TxOrphanage::GetTx(const uint256& txid) const | ||
| { | ||
| AssertLockHeld(g_cs_orphans); | ||
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| const auto it = m_orphans.find(txid); | ||
| if (it == m_orphans.end()) return {nullptr, -1}; | ||
| return {it->second.tx, it->second.fromPeer}; | ||
| } | ||
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| void TxOrphanage::EraseForBlock(const CBlock& block) | ||
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There was a problem hiding this comment. If we had a Otherwise, I think you might have stalling valid orphans never re-processed. Any ulterior parent announcement should be bounce off by |
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| { | ||
| LOCK(g_cs_orphans); | ||
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| std::vector<uint256> vOrphanErase; | ||
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| for (const CTransactionRef& ptx : block.vtx) { | ||
| const CTransaction& tx = *ptx; | ||
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| // Which orphan pool entries must we evict? | ||
| for (const auto& txin : tx.vin) { | ||
| auto itByPrev = m_outpoint_to_orphan_it.find(txin.prevout); | ||
| if (itByPrev == m_outpoint_to_orphan_it.end()) continue; | ||
| for (auto mi = itByPrev->second.begin(); mi != itByPrev->second.end(); ++mi) { | ||
| const CTransaction& orphanTx = *(*mi)->second.tx; | ||
| const uint256& orphanHash = orphanTx.GetHash(); | ||
| vOrphanErase.push_back(orphanHash); | ||
| } | ||
| } | ||
| } | ||
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| // Erase orphan transactions included or precluded by this block | ||
| if (vOrphanErase.size()) { | ||
| int nErased = 0; | ||
| for (const uint256& orphanHash : vOrphanErase) { | ||
| nErased += EraseTx(orphanHash); | ||
| } | ||
| LogPrint(BCLog::MEMPOOL, "Erased %d orphan tx included or conflicted by block\n", nErased); | ||
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