Configuring local mempool limits and relay policy

1// Copyright (c) 2022-present 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 <node/mempool_args.h>
6
7#include <kernel/mempool_limits.h>
8#include <kernel/mempool_options.h>
9
10#include <common/args.h>
11#include <common/messages.h>
12#include <consensus/amount.h>
13#include <kernel/chainparams.h>
14#include <policy/feerate.h>
15#include <policy/policy.h>
16#include <tinyformat.h>
17#include <txgraph.h>
18#include <util/log.h>
19#include <util/moneystr.h>
20#include <util/translation.h>
21
22#include <chrono>
23#include <memory>
24
25using common::AmountErrMsg;
26using kernel::MemPoolLimits;
27using kernel::MemPoolOptions;
28
29//! Maximum mempool size on 32-bit systems.
30static constexpr int MAX_32BIT_MEMPOOL_MB{500};
31
32namespace {
33void ApplyArgsManOptions(const ArgsManager& argsman, MemPoolLimits& mempool_limits)
34{
35    mempool_limits.cluster_count = argsman.GetIntArg("-limitclustercount", mempool_limits.cluster_count);
36
37    if (auto vkb = argsman.GetIntArg("-limitclustersize")) mempool_limits.cluster_size_vbytes = *vkb * 1'000;
38
39    mempool_limits.ancestor_count = argsman.GetIntArg("-limitancestorcount", mempool_limits.ancestor_count);
40
41    mempool_limits.descendant_count = argsman.GetIntArg("-limitdescendantcount", mempool_limits.descendant_count);
42}
43}
44
45util::Result<void> ApplyArgsManOptions(const ArgsManager& argsman, const CChainParams& chainparams, MemPoolOptions& mempool_opts)
46{
47    mempool_opts.check_ratio = argsman.GetIntArg("-checkmempool", mempool_opts.check_ratio);
48
49    if (auto mb = argsman.GetIntArg("-maxmempool")) {
50        constexpr bool is_32bit{sizeof(void*) == 4};
51        if (is_32bit && *mb > MAX_32BIT_MEMPOOL_MB) {
52            return util::Error{Untranslated(strprintf("-maxmempool is set to %i but can't be over %i MB on 32-bit systems", *mb, MAX_32BIT_MEMPOOL_MB))};
53        }
54        mempool_opts.max_size_bytes = *mb * 1'000'000;
55    }
56
57    if (auto hours = argsman.GetIntArg("-mempoolexpiry")) mempool_opts.expiry = std::chrono::hours{*hours};
58
59    // incremental relay fee sets the minimum feerate increase necessary for replacement in the mempool
60    // and the amount the mempool min fee increases above the feerate of txs evicted due to mempool limiting.
61    if (const auto arg{argsman.GetArg("-incrementalrelayfee")}) {
62        if (std::optional<CAmount> inc_relay_fee = ParseMoney(*arg)) {
63            mempool_opts.incremental_relay_feerate = CFeeRate{inc_relay_fee.value()};
64        } else {
65            return util::Error{AmountErrMsg("incrementalrelayfee", *arg)};
66        }
67    }
68
69    static_assert(DEFAULT_MIN_RELAY_TX_FEE == DEFAULT_INCREMENTAL_RELAY_FEE);
70    if (const auto arg{argsman.GetArg("-minrelaytxfee")}) {
71        if (std::optional<CAmount> min_relay_feerate = ParseMoney(*arg)) {
72            // High fee check is done afterward in CWallet::Create()
73            mempool_opts.min_relay_feerate = CFeeRate{min_relay_feerate.value()};
74        } else {
75            return util::Error{AmountErrMsg("minrelaytxfee", *arg)};
76        }
77    } else if (mempool_opts.incremental_relay_feerate > mempool_opts.min_relay_feerate) {
78        // Allow only setting incremental fee to control both
79        mempool_opts.min_relay_feerate = mempool_opts.incremental_relay_feerate;
80        LogInfo("Increasing minrelaytxfee to %s to match incrementalrelayfee", mempool_opts.min_relay_feerate.ToString());
81    }
82
83    // Feerate used to define dust.  Shouldn't be changed lightly as old
84    // implementations may inadvertently create non-standard transactions
85    if (const auto arg{argsman.GetArg("-dustrelayfee")}) {
86        if (std::optional<CAmount> parsed = ParseMoney(*arg)) {
87            mempool_opts.dust_relay_feerate = CFeeRate{parsed.value()};
88        } else {
89            return util::Error{AmountErrMsg("dustrelayfee", *arg)};
90        }
91    }
92
93    mempool_opts.permit_bare_multisig = argsman.GetBoolArg("-permitbaremultisig", DEFAULT_PERMIT_BAREMULTISIG);
94
95    if (argsman.GetBoolArg("-datacarrier", DEFAULT_ACCEPT_DATACARRIER)) {
96        mempool_opts.max_datacarrier_bytes = argsman.GetIntArg("-datacarriersize", MAX_OP_RETURN_RELAY);
97    } else {
98        mempool_opts.max_datacarrier_bytes = std::nullopt;
99    }
100
101    mempool_opts.require_standard = !argsman.GetBoolArg("-acceptnonstdtxn", DEFAULT_ACCEPT_NON_STD_TXN);
102    if (!chainparams.IsTestChain() && !mempool_opts.require_standard) {
103        return util::Error{Untranslated(strprintf("acceptnonstdtxn is not currently supported for %s chain", chainparams.GetChainTypeString()))};
104    }
105
106    mempool_opts.persist_v1_dat = argsman.GetBoolArg("-persistmempoolv1", mempool_opts.persist_v1_dat);
107
108    ApplyArgsManOptions(argsman, mempool_opts.limits);
109
110    if (mempool_opts.limits.cluster_count > MAX_CLUSTER_COUNT_LIMIT) {
111        return util::Error{Untranslated(strprintf("limitclustercount must be less than or equal to %d", MAX_CLUSTER_COUNT_LIMIT))};
112    }
113
114    return {};
115}
116