Line data Source code
1 : // Copyright (c) 2021-2022 The Bitcoin Core developers
2 : // Distributed under the MIT software license, see the accompanying
3 : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4 :
5 : #include <txorphanage.h>
6 :
7 : #include <consensus/validation.h>
8 : #include <logging.h>
9 : #include <policy/policy.h>
10 :
11 : #include <cassert>
12 :
13 : /** Expiration time for orphan transactions in seconds */
14 : static constexpr int64_t ORPHAN_TX_EXPIRE_TIME = 20 * 60;
15 : /** Minimum time between orphan transactions expire time checks in seconds */
16 : static constexpr int64_t ORPHAN_TX_EXPIRE_INTERVAL = 5 * 60;
17 2 :
18 2 :
19 0 : bool TxOrphanage::AddTx(const CTransactionRef& tx, NodeId peer)
20 : {
21 0 : LOCK(m_mutex);
22 :
23 0 : const uint256& hash = tx->GetHash();
24 0 : const uint256& wtxid = tx->GetWitnessHash();
25 0 : if (m_orphans.count(hash))
26 0 : return false;
27 :
28 : // Ignore big transactions, to avoid a
29 : // send-big-orphans memory exhaustion attack. If a peer has a legitimate
30 : // large transaction with a missing parent then we assume
31 : // it will rebroadcast it later, after the parent transaction(s)
32 : // have been mined or received.
33 : // 100 orphans, each of which is at most 100,000 bytes big is
34 : // at most 10 megabytes of orphans and somewhat more byprev index (in the worst case):
35 0 : unsigned int sz = GetTransactionWeight(*tx);
36 0 : if (sz > MAX_STANDARD_TX_WEIGHT)
37 : {
38 0 : LogPrint(BCLog::TXPACKAGES, "ignoring large orphan tx (size: %u, txid: %s, wtxid: %s)\n", sz, hash.ToString(), wtxid.ToString());
39 0 : return false;
40 : }
41 :
42 0 : auto ret = m_orphans.emplace(hash, OrphanTx{tx, peer, GetTime() + ORPHAN_TX_EXPIRE_TIME, m_orphan_list.size()});
43 0 : assert(ret.second);
44 0 : m_orphan_list.push_back(ret.first);
45 : // Allow for lookups in the orphan pool by wtxid, as well as txid
46 0 : m_wtxid_to_orphan_it.emplace(tx->GetWitnessHash(), ret.first);
47 0 : for (const CTxIn& txin : tx->vin) {
48 0 : m_outpoint_to_orphan_it[txin.prevout].insert(ret.first);
49 : }
50 :
51 0 : LogPrint(BCLog::TXPACKAGES, "stored orphan tx %s (wtxid=%s) (mapsz %u outsz %u)\n", hash.ToString(), wtxid.ToString(),
52 : m_orphans.size(), m_outpoint_to_orphan_it.size());
53 0 : return true;
54 0 : }
55 :
56 0 : int TxOrphanage::EraseTx(const uint256& txid)
57 : {
58 0 : LOCK(m_mutex);
59 0 : return EraseTxNoLock(txid);
60 0 : }
61 :
62 0 : int TxOrphanage::EraseTxNoLock(const uint256& txid)
63 : {
64 0 : AssertLockHeld(m_mutex);
65 0 : std::map<uint256, OrphanTx>::iterator it = m_orphans.find(txid);
66 0 : if (it == m_orphans.end())
67 0 : return 0;
68 0 : for (const CTxIn& txin : it->second.tx->vin)
69 : {
70 0 : auto itPrev = m_outpoint_to_orphan_it.find(txin.prevout);
71 0 : if (itPrev == m_outpoint_to_orphan_it.end())
72 0 : continue;
73 0 : itPrev->second.erase(it);
74 2 : if (itPrev->second.empty())
75 0 : m_outpoint_to_orphan_it.erase(itPrev);
76 : }
77 :
78 0 : size_t old_pos = it->second.list_pos;
79 0 : assert(m_orphan_list[old_pos] == it);
80 0 : if (old_pos + 1 != m_orphan_list.size()) {
81 : // Unless we're deleting the last entry in m_orphan_list, move the last
82 : // entry to the position we're deleting.
83 2 : auto it_last = m_orphan_list.back();
84 0 : m_orphan_list[old_pos] = it_last;
85 0 : it_last->second.list_pos = old_pos;
86 0 : }
87 0 : const auto& wtxid = it->second.tx->GetWitnessHash();
88 0 : LogPrint(BCLog::TXPACKAGES, " removed orphan tx %s (wtxid=%s)\n", txid.ToString(), wtxid.ToString());
89 0 : m_orphan_list.pop_back();
90 0 : m_wtxid_to_orphan_it.erase(it->second.tx->GetWitnessHash());
91 :
92 0 : m_orphans.erase(it);
93 0 : return 1;
94 0 : }
95 :
96 0 : void TxOrphanage::EraseForPeer(NodeId peer)
97 : {
98 0 : LOCK(m_mutex);
99 :
100 0 : m_peer_work_set.erase(peer);
101 :
102 0 : int nErased = 0;
103 0 : std::map<uint256, OrphanTx>::iterator iter = m_orphans.begin();
104 0 : while (iter != m_orphans.end())
105 : {
106 0 : std::map<uint256, OrphanTx>::iterator maybeErase = iter++; // increment to avoid iterator becoming invalid
107 0 : if (maybeErase->second.fromPeer == peer)
108 : {
109 0 : nErased += EraseTxNoLock(maybeErase->second.tx->GetHash());
110 0 : }
111 : }
112 0 : if (nErased > 0) LogPrint(BCLog::TXPACKAGES, "Erased %d orphan tx from peer=%d\n", nErased, peer);
113 0 : }
114 :
115 0 : void TxOrphanage::LimitOrphans(unsigned int max_orphans)
116 : {
117 0 : LOCK(m_mutex);
118 :
119 0 : unsigned int nEvicted = 0;
120 : static int64_t nNextSweep;
121 0 : int64_t nNow = GetTime();
122 0 : if (nNextSweep <= nNow) {
123 : // Sweep out expired orphan pool entries:
124 0 : int nErased = 0;
125 0 : int64_t nMinExpTime = nNow + ORPHAN_TX_EXPIRE_TIME - ORPHAN_TX_EXPIRE_INTERVAL;
126 0 : std::map<uint256, OrphanTx>::iterator iter = m_orphans.begin();
127 0 : while (iter != m_orphans.end())
128 : {
129 0 : std::map<uint256, OrphanTx>::iterator maybeErase = iter++;
130 0 : if (maybeErase->second.nTimeExpire <= nNow) {
131 0 : nErased += EraseTxNoLock(maybeErase->second.tx->GetHash());
132 0 : } else {
133 0 : nMinExpTime = std::min(maybeErase->second.nTimeExpire, nMinExpTime);
134 : }
135 : }
136 : // Sweep again 5 minutes after the next entry that expires in order to batch the linear scan.
137 0 : nNextSweep = nMinExpTime + ORPHAN_TX_EXPIRE_INTERVAL;
138 0 : if (nErased > 0) LogPrint(BCLog::TXPACKAGES, "Erased %d orphan tx due to expiration\n", nErased);
139 0 : }
140 0 : FastRandomContext rng;
141 0 : while (m_orphans.size() > max_orphans)
142 : {
143 : // Evict a random orphan:
144 0 : size_t randompos = rng.randrange(m_orphan_list.size());
145 0 : EraseTxNoLock(m_orphan_list[randompos]->first);
146 0 : ++nEvicted;
147 : }
148 0 : if (nEvicted > 0) LogPrint(BCLog::TXPACKAGES, "orphanage overflow, removed %u tx\n", nEvicted);
149 0 : }
150 :
151 0 : void TxOrphanage::AddChildrenToWorkSet(const CTransaction& tx)
152 : {
153 0 : LOCK(m_mutex);
154 :
155 :
156 0 : for (unsigned int i = 0; i < tx.vout.size(); i++) {
157 0 : const auto it_by_prev = m_outpoint_to_orphan_it.find(COutPoint(tx.GetHash(), i));
158 0 : if (it_by_prev != m_outpoint_to_orphan_it.end()) {
159 0 : for (const auto& elem : it_by_prev->second) {
160 : // Get this source peer's work set, emplacing an empty set if it didn't exist
161 : // (note: if this peer wasn't still connected, we would have removed the orphan tx already)
162 0 : std::set<uint256>& orphan_work_set = m_peer_work_set.try_emplace(elem->second.fromPeer).first->second;
163 : // Add this tx to the work set
164 0 : orphan_work_set.insert(elem->first);
165 0 : LogPrint(BCLog::TXPACKAGES, "added %s (wtxid=%s) to peer %d workset\n",
166 : tx.GetHash().ToString(), tx.GetWitnessHash().ToString(), elem->second.fromPeer);
167 : }
168 0 : }
169 0 : }
170 0 : }
171 :
172 0 : bool TxOrphanage::HaveTx(const GenTxid& gtxid) const
173 : {
174 0 : LOCK(m_mutex);
175 0 : if (gtxid.IsWtxid()) {
176 0 : return m_wtxid_to_orphan_it.count(gtxid.GetHash());
177 : } else {
178 0 : return m_orphans.count(gtxid.GetHash());
179 : }
180 0 : }
181 :
182 0 : CTransactionRef TxOrphanage::GetTxToReconsider(NodeId peer)
183 : {
184 0 : LOCK(m_mutex);
185 :
186 0 : auto work_set_it = m_peer_work_set.find(peer);
187 0 : if (work_set_it != m_peer_work_set.end()) {
188 0 : auto& work_set = work_set_it->second;
189 0 : while (!work_set.empty()) {
190 0 : uint256 txid = *work_set.begin();
191 0 : work_set.erase(work_set.begin());
192 :
193 0 : const auto orphan_it = m_orphans.find(txid);
194 0 : if (orphan_it != m_orphans.end()) {
195 0 : return orphan_it->second.tx;
196 : }
197 : }
198 0 : }
199 0 : return nullptr;
200 0 : }
201 :
202 0 : bool TxOrphanage::HaveTxToReconsider(NodeId peer)
203 : {
204 0 : LOCK(m_mutex);
205 :
206 0 : auto work_set_it = m_peer_work_set.find(peer);
207 0 : if (work_set_it != m_peer_work_set.end()) {
208 0 : auto& work_set = work_set_it->second;
209 0 : return !work_set.empty();
210 : }
211 0 : return false;
212 0 : }
213 :
214 0 : void TxOrphanage::EraseForBlock(const CBlock& block)
215 : {
216 0 : LOCK(m_mutex);
217 :
218 0 : std::vector<uint256> vOrphanErase;
219 :
220 0 : for (const CTransactionRef& ptx : block.vtx) {
221 0 : const CTransaction& tx = *ptx;
222 :
223 : // Which orphan pool entries must we evict?
224 0 : for (const auto& txin : tx.vin) {
225 0 : auto itByPrev = m_outpoint_to_orphan_it.find(txin.prevout);
226 0 : if (itByPrev == m_outpoint_to_orphan_it.end()) continue;
227 0 : for (auto mi = itByPrev->second.begin(); mi != itByPrev->second.end(); ++mi) {
228 0 : const CTransaction& orphanTx = *(*mi)->second.tx;
229 0 : const uint256& orphanHash = orphanTx.GetHash();
230 0 : vOrphanErase.push_back(orphanHash);
231 0 : }
232 : }
233 : }
234 :
235 : // Erase orphan transactions included or precluded by this block
236 0 : if (vOrphanErase.size()) {
237 0 : int nErased = 0;
238 0 : for (const uint256& orphanHash : vOrphanErase) {
239 0 : nErased += EraseTxNoLock(orphanHash);
240 : }
241 0 : LogPrint(BCLog::TXPACKAGES, "Erased %d orphan tx included or conflicted by block\n", nErased);
242 0 : }
243 0 : }
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