aboutsummaryrefslogtreecommitdiff
path: root/src/txorphanage.cpp
blob: 94f64abca73192794b5e0727f41f8c87e0ebc047 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
// Copyright (c) 2021-2022 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <txorphanage.h>

#include <consensus/validation.h>
#include <logging.h>
#include <policy/policy.h>

#include <cassert>

/** 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;


bool TxOrphanage::AddTx(const CTransactionRef& tx, NodeId peer)
{
    LOCK(m_mutex);

    const uint256& hash = tx->GetHash();
    if (m_orphans.count(hash))
        return false;

    // 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;
    }

    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);
    }

    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;
}

int TxOrphanage::EraseTx(const uint256& txid)
{
    LOCK(m_mutex);
    return _EraseTx(txid);
}

int TxOrphanage::_EraseTx(const uint256& txid)
{
    AssertLockHeld(m_mutex);
    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);
    }

    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());

    m_orphans.erase(it);
    return 1;
}

void TxOrphanage::EraseForPeer(NodeId peer)
{
    LOCK(m_mutex);

    m_peer_work_set.erase(peer);

    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);
}

void TxOrphanage::LimitOrphans(unsigned int max_orphans)
{
    LOCK(m_mutex);

    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;
    }
    if (nEvicted > 0) LogPrint(BCLog::MEMPOOL, "orphanage overflow, removed %u tx\n", nEvicted);
}

void TxOrphanage::AddChildrenToWorkSet(const CTransaction& tx, NodeId peer)
{
    LOCK(m_mutex);

    // Get this peer's work set, emplacing an empty set it didn't exist
    std::set<uint256>& orphan_work_set = m_peer_work_set.try_emplace(peer).first->second;

    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);
            }
        }
    }
}

bool TxOrphanage::HaveTx(const GenTxid& gtxid) const
{
    LOCK(m_mutex);
    if (gtxid.IsWtxid()) {
        return m_wtxid_to_orphan_it.count(gtxid.GetHash());
    } else {
        return m_orphans.count(gtxid.GetHash());
    }
}

CTransactionRef TxOrphanage::GetTxToReconsider(NodeId peer, NodeId& originator, bool& more)
{
    LOCK(m_mutex);

    auto work_set_it = m_peer_work_set.find(peer);
    if (work_set_it != m_peer_work_set.end()) {
        auto& work_set = work_set_it->second;
        while (!work_set.empty()) {
            uint256 txid = *work_set.begin();
            work_set.erase(work_set.begin());

            const auto orphan_it = m_orphans.find(txid);
            if (orphan_it != m_orphans.end()) {
                more = !work_set.empty();
                originator = orphan_it->second.fromPeer;
                return orphan_it->second.tx;
            }
        }
    }
    more = false;
    return nullptr;
}

void TxOrphanage::EraseForBlock(const CBlock& block)
{
    LOCK(m_mutex);

    std::vector<uint256> vOrphanErase;

    for (const CTransactionRef& ptx : block.vtx) {
        const CTransaction& tx = *ptx;

        // 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);
            }
        }
    }

    // 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);
    }
}