Bitcoin Core 29.99.0
P2P Digital Currency
spend.cpp
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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 <algorithm>
6#include <common/args.h>
7#include <common/messages.h>
8#include <common/system.h>
9#include <consensus/amount.h>
11#include <interfaces/chain.h>
12#include <node/types.h>
13#include <numeric>
14#include <policy/policy.h>
15#include <policy/truc_policy.h>
18#include <script/script.h>
20#include <script/solver.h>
21#include <util/check.h>
22#include <util/moneystr.h>
23#include <util/rbf.h>
24#include <util/trace.h>
25#include <util/translation.h>
26#include <wallet/coincontrol.h>
27#include <wallet/fees.h>
28#include <wallet/receive.h>
29#include <wallet/spend.h>
30#include <wallet/transaction.h>
31#include <wallet/wallet.h>
32
33#include <cmath>
34
39
40TRACEPOINT_SEMAPHORE(coin_selection, selected_coins);
41TRACEPOINT_SEMAPHORE(coin_selection, normal_create_tx_internal);
42TRACEPOINT_SEMAPHORE(coin_selection, attempting_aps_create_tx);
43TRACEPOINT_SEMAPHORE(coin_selection, aps_create_tx_internal);
44
45namespace wallet {
46static constexpr size_t OUTPUT_GROUP_MAX_ENTRIES{100};
47
49static bool IsSegwit(const Descriptor& desc) {
50 if (const auto typ = desc.GetOutputType()) return *typ != OutputType::LEGACY;
51 return false;
52}
53
55static bool UseMaxSig(const std::optional<CTxIn>& txin, const CCoinControl* coin_control) {
56 // Use max sig if watch only inputs were used or if this particular input is an external input
57 // to ensure a sufficient fee is attained for the requested feerate.
58 return coin_control && txin && coin_control->IsExternalSelected(txin->prevout);
59}
60
69static std::optional<int64_t> MaxInputWeight(const Descriptor& desc, const std::optional<CTxIn>& txin,
70 const CCoinControl* coin_control, const bool tx_is_segwit,
71 const bool can_grind_r) {
72 if (const auto sat_weight = desc.MaxSatisfactionWeight(!can_grind_r || UseMaxSig(txin, coin_control))) {
73 if (const auto elems_count = desc.MaxSatisfactionElems()) {
74 const bool is_segwit = IsSegwit(desc);
75 // Account for the size of the scriptsig and the number of elements on the witness stack. Note
76 // that if any input in the transaction is spending a witness program, we need to specify the
77 // witness stack size for every input regardless of whether it is segwit itself.
78 // NOTE: this also works in case of mixed scriptsig-and-witness such as in p2sh-wrapped segwit v0
79 // outputs. In this case the size of the scriptsig length will always be one (since the redeemScript
80 // is always a push of the witness program in this case, which is smaller than 253 bytes).
81 const int64_t scriptsig_len = is_segwit ? 1 : GetSizeOfCompactSize(*sat_weight / WITNESS_SCALE_FACTOR);
82 const int64_t witstack_len = is_segwit ? GetSizeOfCompactSize(*elems_count) : (tx_is_segwit ? 1 : 0);
83 // previous txid + previous vout + sequence + scriptsig len + witstack size + scriptsig or witness
84 // NOTE: sat_weight already accounts for the witness discount accordingly.
85 return (32 + 4 + 4 + scriptsig_len) * WITNESS_SCALE_FACTOR + witstack_len + *sat_weight;
86 }
87 }
88
89 return {};
90}
91
92int CalculateMaximumSignedInputSize(const CTxOut& txout, const COutPoint outpoint, const SigningProvider* provider, bool can_grind_r, const CCoinControl* coin_control)
93{
94 if (!provider) return -1;
95
96 if (const auto desc = InferDescriptor(txout.scriptPubKey, *provider)) {
97 if (const auto weight = MaxInputWeight(*desc, {}, coin_control, true, can_grind_r)) {
98 return static_cast<int>(GetVirtualTransactionSize(*weight, 0, 0));
99 }
100 }
101
102 return -1;
103}
104
105int CalculateMaximumSignedInputSize(const CTxOut& txout, const CWallet* wallet, const CCoinControl* coin_control)
106{
107 const std::unique_ptr<SigningProvider> provider = wallet->GetSolvingProvider(txout.scriptPubKey);
108 return CalculateMaximumSignedInputSize(txout, COutPoint(), provider.get(), wallet->CanGrindR(), coin_control);
109}
110
112static std::unique_ptr<Descriptor> GetDescriptor(const CWallet* wallet, const CCoinControl* coin_control,
113 const CScript script_pubkey)
114{
115 MultiSigningProvider providers;
116 for (const auto spkman: wallet->GetScriptPubKeyMans(script_pubkey)) {
117 providers.AddProvider(spkman->GetSolvingProvider(script_pubkey));
118 }
119 if (coin_control) {
120 providers.AddProvider(std::make_unique<FlatSigningProvider>(coin_control->m_external_provider));
121 }
122 return InferDescriptor(script_pubkey, providers);
123}
124
126static std::optional<int64_t> GetSignedTxinWeight(const CWallet* wallet, const CCoinControl* coin_control,
127 const CTxIn& txin, const CTxOut& txo, const bool tx_is_segwit,
128 const bool can_grind_r)
129{
130 // If weight was provided, use that.
131 std::optional<int64_t> weight;
132 if (coin_control && (weight = coin_control->GetInputWeight(txin.prevout))) {
133 return weight.value();
134 }
135
136 // Otherwise, use the maximum satisfaction size provided by the descriptor.
137 std::unique_ptr<Descriptor> desc{GetDescriptor(wallet, coin_control, txo.scriptPubKey)};
138 if (desc) return MaxInputWeight(*desc, {txin}, coin_control, tx_is_segwit, can_grind_r);
139
140 return {};
141}
142
143// txouts needs to be in the order of tx.vin
144TxSize CalculateMaximumSignedTxSize(const CTransaction &tx, const CWallet *wallet, const std::vector<CTxOut>& txouts, const CCoinControl* coin_control)
145{
146 // version + nLockTime + input count + output count
147 int64_t weight = (4 + 4 + GetSizeOfCompactSize(tx.vin.size()) + GetSizeOfCompactSize(tx.vout.size())) * WITNESS_SCALE_FACTOR;
148 // Whether any input spends a witness program. Necessary to run before the next loop over the
149 // inputs in order to accurately compute the compactSize length for the witness data per input.
150 bool is_segwit = std::any_of(txouts.begin(), txouts.end(), [&](const CTxOut& txo) {
151 std::unique_ptr<Descriptor> desc{GetDescriptor(wallet, coin_control, txo.scriptPubKey)};
152 if (desc) return IsSegwit(*desc);
153 return false;
154 });
155 // Segwit marker and flag
156 if (is_segwit) weight += 2;
157
158 // Add the size of the transaction outputs.
159 for (const auto& txo : tx.vout) weight += GetSerializeSize(txo) * WITNESS_SCALE_FACTOR;
160
161 // Add the size of the transaction inputs as if they were signed.
162 for (uint32_t i = 0; i < txouts.size(); i++) {
163 const auto txin_weight = GetSignedTxinWeight(wallet, coin_control, tx.vin[i], txouts[i], is_segwit, wallet->CanGrindR());
164 if (!txin_weight) return TxSize{-1, -1};
165 assert(*txin_weight > -1);
166 weight += *txin_weight;
167 }
168
169 // It's ok to use 0 as the number of sigops since we never create any pathological transaction.
170 return TxSize{GetVirtualTransactionSize(weight, 0, 0), weight};
171}
172
174{
175 std::vector<CTxOut> txouts;
176 // Look up the inputs. The inputs are either in the wallet, or in coin_control.
177 for (const CTxIn& input : tx.vin) {
178 const auto mi = wallet->mapWallet.find(input.prevout.hash);
179 // Can not estimate size without knowing the input details
180 if (mi != wallet->mapWallet.end()) {
181 assert(input.prevout.n < mi->second.tx->vout.size());
182 txouts.emplace_back(mi->second.tx->vout.at(input.prevout.n));
183 } else if (coin_control) {
184 const auto& txout{coin_control->GetExternalOutput(input.prevout)};
185 if (!txout) return TxSize{-1, -1};
186 txouts.emplace_back(*txout);
187 } else {
188 return TxSize{-1, -1};
189 }
190 }
191 return CalculateMaximumSignedTxSize(tx, wallet, txouts, coin_control);
192}
193
194size_t CoinsResult::Size() const
195{
196 size_t size{0};
197 for (const auto& it : coins) {
198 size += it.second.size();
199 }
200 return size;
201}
202
203std::vector<COutput> CoinsResult::All() const
204{
205 std::vector<COutput> all;
206 all.reserve(coins.size());
207 for (const auto& it : coins) {
208 all.insert(all.end(), it.second.begin(), it.second.end());
209 }
210 return all;
211}
212
213void CoinsResult::Clear() {
214 coins.clear();
215}
216
217void CoinsResult::Erase(const std::unordered_set<COutPoint, SaltedOutpointHasher>& coins_to_remove)
218{
219 for (auto& [type, vec] : coins) {
220 auto remove_it = std::remove_if(vec.begin(), vec.end(), [&](const COutput& coin) {
221 // remove it if it's on the set
222 if (coins_to_remove.count(coin.outpoint) == 0) return false;
223
224 // update cached amounts
225 total_amount -= coin.txout.nValue;
226 if (coin.HasEffectiveValue()) total_effective_amount = *total_effective_amount - coin.GetEffectiveValue();
227 return true;
228 });
229 vec.erase(remove_it, vec.end());
230 }
231}
232
233void CoinsResult::Shuffle(FastRandomContext& rng_fast)
234{
235 for (auto& it : coins) {
236 std::shuffle(it.second.begin(), it.second.end(), rng_fast);
237 }
238}
239
240void CoinsResult::Add(OutputType type, const COutput& out)
241{
242 coins[type].emplace_back(out);
243 total_amount += out.txout.nValue;
244 if (out.HasEffectiveValue()) {
245 total_effective_amount = total_effective_amount.has_value() ?
246 *total_effective_amount + out.GetEffectiveValue() : out.GetEffectiveValue();
247 }
248}
249
250static OutputType GetOutputType(TxoutType type, bool is_from_p2sh)
251{
252 switch (type) {
254 return OutputType::BECH32M;
257 if (is_from_p2sh) return OutputType::P2SH_SEGWIT;
258 else return OutputType::BECH32;
261 return OutputType::LEGACY;
262 default:
263 return OutputType::UNKNOWN;
264 }
265}
266
267// Fetch and validate the coin control selected inputs.
268// Coins could be internal (from the wallet) or external.
270 const CoinSelectionParams& coin_selection_params)
271{
272 PreSelectedInputs result;
273 const bool can_grind_r = wallet.CanGrindR();
274 std::map<COutPoint, CAmount> map_of_bump_fees = wallet.chain().calculateIndividualBumpFees(coin_control.ListSelected(), coin_selection_params.m_effective_feerate);
275 for (const COutPoint& outpoint : coin_control.ListSelected()) {
276 int64_t input_bytes = coin_control.GetInputWeight(outpoint).value_or(-1);
277 if (input_bytes != -1) {
278 input_bytes = GetVirtualTransactionSize(input_bytes, 0, 0);
279 }
280 CTxOut txout;
281 if (auto txo = wallet.GetTXO(outpoint)) {
282 txout = txo->GetTxOut();
283 if (input_bytes == -1) {
284 input_bytes = CalculateMaximumSignedInputSize(txout, &wallet, &coin_control);
285 }
286 const CWalletTx& parent_tx = txo->GetWalletTx();
287 if (wallet.GetTxDepthInMainChain(parent_tx) == 0) {
288 if (parent_tx.tx->version == TRUC_VERSION && coin_control.m_version != TRUC_VERSION) {
289 return util::Error{strprintf(_("Can't spend unconfirmed version 3 pre-selected input with a version %d tx"), coin_control.m_version)};
290 } else if (coin_control.m_version == TRUC_VERSION && parent_tx.tx->version != TRUC_VERSION) {
291 return util::Error{strprintf(_("Can't spend unconfirmed version %d pre-selected input with a version 3 tx"), parent_tx.tx->version)};
292 }
293 }
294 } else {
295 // The input is external. We did not find the tx in mapWallet.
296 const auto out{coin_control.GetExternalOutput(outpoint)};
297 if (!out) {
298 return util::Error{strprintf(_("Not found pre-selected input %s"), outpoint.ToString())};
299 }
300
301 txout = *out;
302 }
303
304 if (input_bytes == -1) {
305 input_bytes = CalculateMaximumSignedInputSize(txout, outpoint, &coin_control.m_external_provider, can_grind_r, &coin_control);
306 }
307
308 if (input_bytes == -1) {
309 return util::Error{strprintf(_("Not solvable pre-selected input %s"), outpoint.ToString())}; // Not solvable, can't estimate size for fee
310 }
311
312 /* Set some defaults for depth, solvable, safe, time, and from_me as these don't matter for preset inputs since no selection is being done. */
313 COutput output(outpoint, txout, /*depth=*/0, input_bytes, /*solvable=*/true, /*safe=*/true, /*time=*/0, /*from_me=*/false, coin_selection_params.m_effective_feerate);
314 output.ApplyBumpFee(map_of_bump_fees.at(output.outpoint));
315 result.Insert(output, coin_selection_params.m_subtract_fee_outputs);
316 }
317 return result;
318}
319
321 const CCoinControl* coinControl,
322 std::optional<CFeeRate> feerate,
323 const CoinFilterParams& params)
324{
325 AssertLockHeld(wallet.cs_wallet);
326
327 CoinsResult result;
328 // track unconfirmed truc outputs separately if we are tracking trucness
329 std::vector<std::pair<OutputType, COutput>> unconfirmed_truc_coins;
330 std::unordered_map<Txid, CAmount, SaltedTxidHasher> truc_txid_by_value;
331 // Either the WALLET_FLAG_AVOID_REUSE flag is not set (in which case we always allow), or we default to avoiding, and only in the case where
332 // a coin control object is provided, and has the avoid address reuse flag set to false, do we allow already used addresses
333 bool allow_used_addresses = !wallet.IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE) || (coinControl && !coinControl->m_avoid_address_reuse);
334 const int min_depth = {coinControl ? coinControl->m_min_depth : DEFAULT_MIN_DEPTH};
335 const int max_depth = {coinControl ? coinControl->m_max_depth : DEFAULT_MAX_DEPTH};
336 const bool only_safe = {coinControl ? !coinControl->m_include_unsafe_inputs : true};
337 const bool can_grind_r = wallet.CanGrindR();
338 std::vector<COutPoint> outpoints;
339
340 std::set<Txid> trusted_parents;
341 // Cache for whether each tx passes the tx level checks (first bool), and whether the transaction is "safe" (second bool)
342 std::unordered_map<Txid, std::pair<bool, bool>, SaltedTxidHasher> tx_safe_cache;
343 for (const auto& [outpoint, txo] : wallet.GetTXOs()) {
344 const CWalletTx& wtx = txo.GetWalletTx();
345 const CTxOut& output = txo.GetTxOut();
346
347 if (tx_safe_cache.contains(outpoint.hash) && !tx_safe_cache.at(outpoint.hash).first) {
348 continue;
349 }
350
351 int nDepth = wallet.GetTxDepthInMainChain(wtx);
352
353 // Perform tx level checks if we haven't already come across outputs from this tx before.
354 if (!tx_safe_cache.contains(outpoint.hash)) {
355 tx_safe_cache[outpoint.hash] = {false, false};
356
357 if (wallet.IsTxImmatureCoinBase(wtx) && !params.include_immature_coinbase)
358 continue;
359
360 if (nDepth < 0)
361 continue;
362
363 // We should not consider coins which aren't at least in our mempool
364 // It's possible for these to be conflicted via ancestors which we may never be able to detect
365 if (nDepth == 0 && !wtx.InMempool())
366 continue;
367
368 bool safeTx = CachedTxIsTrusted(wallet, wtx, trusted_parents);
369
370 // We should not consider coins from transactions that are replacing
371 // other transactions.
372 //
373 // Example: There is a transaction A which is replaced by bumpfee
374 // transaction B. In this case, we want to prevent creation of
375 // a transaction B' which spends an output of B.
376 //
377 // Reason: If transaction A were initially confirmed, transactions B
378 // and B' would no longer be valid, so the user would have to create
379 // a new transaction C to replace B'. However, in the case of a
380 // one-block reorg, transactions B' and C might BOTH be accepted,
381 // when the user only wanted one of them. Specifically, there could
382 // be a 1-block reorg away from the chain where transactions A and C
383 // were accepted to another chain where B, B', and C were all
384 // accepted.
385 if (nDepth == 0 && wtx.mapValue.count("replaces_txid")) {
386 safeTx = false;
387 }
388
389 // Similarly, we should not consider coins from transactions that
390 // have been replaced. In the example above, we would want to prevent
391 // creation of a transaction A' spending an output of A, because if
392 // transaction B were initially confirmed, conflicting with A and
393 // A', we wouldn't want to the user to create a transaction D
394 // intending to replace A', but potentially resulting in a scenario
395 // where A, A', and D could all be accepted (instead of just B and
396 // D, or just A and A' like the user would want).
397 if (nDepth == 0 && wtx.mapValue.count("replaced_by_txid")) {
398 safeTx = false;
399 }
400
401 if (nDepth == 0 && params.check_version_trucness) {
402 if (coinControl->m_version == TRUC_VERSION) {
403 if (wtx.tx->version != TRUC_VERSION) continue;
404 // this unconfirmed v3 transaction already has a child
405 if (wtx.truc_child_in_mempool.has_value()) continue;
406 } else {
407 if (wtx.tx->version == TRUC_VERSION) continue;
408 Assume(!wtx.truc_child_in_mempool.has_value());
409 }
410 }
411
412 if (only_safe && !safeTx) {
413 continue;
414 }
415
416 if (nDepth < min_depth || nDepth > max_depth) {
417 continue;
418 }
419
420 tx_safe_cache[outpoint.hash] = {true, safeTx};
421 }
422 const auto& [tx_ok, tx_safe] = tx_safe_cache.at(outpoint.hash);
423 if (!Assume(tx_ok)) {
424 continue;
425 }
426
427 if (output.nValue < params.min_amount || output.nValue > params.max_amount)
428 continue;
429
430 // Skip manually selected coins (the caller can fetch them directly)
431 if (coinControl && coinControl->HasSelected() && coinControl->IsSelected(outpoint))
432 continue;
433
434 if (wallet.IsLockedCoin(outpoint) && params.skip_locked)
435 continue;
436
437 if (wallet.IsSpent(outpoint))
438 continue;
439
440 if (!allow_used_addresses && wallet.IsSpentKey(output.scriptPubKey)) {
441 continue;
442 }
443
444 bool tx_from_me = CachedTxIsFromMe(wallet, wtx);
445
446 std::unique_ptr<SigningProvider> provider = wallet.GetSolvingProvider(output.scriptPubKey);
447
448 int input_bytes = CalculateMaximumSignedInputSize(output, COutPoint(), provider.get(), can_grind_r, coinControl);
449 // Because CalculateMaximumSignedInputSize infers a solvable descriptor to get the satisfaction size,
450 // it is safe to assume that this input is solvable if input_bytes is greater than -1.
451 bool solvable = input_bytes > -1;
452
453 // Obtain script type
454 std::vector<std::vector<uint8_t>> script_solutions;
455 TxoutType type = Solver(output.scriptPubKey, script_solutions);
456
457 // If the output is P2SH and solvable, we want to know if it is
458 // a P2SH (legacy) or one of P2SH-P2WPKH, P2SH-P2WSH (P2SH-Segwit). We can determine
459 // this from the redeemScript. If the output is not solvable, it will be classified
460 // as a P2SH (legacy), since we have no way of knowing otherwise without the redeemScript
461 bool is_from_p2sh{false};
462 if (type == TxoutType::SCRIPTHASH && solvable) {
464 if (!provider->GetCScript(CScriptID(uint160(script_solutions[0])), script)) continue;
465 type = Solver(script, script_solutions);
466 is_from_p2sh = true;
467 }
468
469 auto available_output_type = GetOutputType(type, is_from_p2sh);
470 auto available_output = COutput(outpoint, output, nDepth, input_bytes, solvable, tx_safe, wtx.GetTxTime(), tx_from_me, feerate);
471 if (wtx.tx->version == TRUC_VERSION && nDepth == 0 && params.check_version_trucness) {
472 unconfirmed_truc_coins.emplace_back(available_output_type, available_output);
473 auto [it, _] = truc_txid_by_value.try_emplace(wtx.tx->GetHash(), 0);
474 it->second += output.nValue;
475 } else {
476 result.Add(available_output_type, available_output);
477 }
478
479 outpoints.push_back(outpoint);
480
481 // Checks the sum amount of all UTXO's.
482 if (params.min_sum_amount != MAX_MONEY) {
483 if (result.GetTotalAmount() >= params.min_sum_amount) {
484 return result;
485 }
486 }
487
488 // Checks the maximum number of UTXO's.
489 if (params.max_count > 0 && result.Size() >= params.max_count) {
490 return result;
491 }
492 }
493
494 // Return all the coins from one TRUC transaction, that have the highest value.
495 // This could be improved in the future by encoding these restrictions in
496 // the coin selection itself so that we don't have to filter out
497 // other unconfirmed TRUC coins beforehand.
498 if (params.check_version_trucness && unconfirmed_truc_coins.size() > 0) {
499 auto highest_value_truc_tx = std::max_element(truc_txid_by_value.begin(), truc_txid_by_value.end(), [](const auto& tx1, const auto& tx2){
500 return tx1.second < tx2.second;
501 });
502
503 const Txid& truc_txid = highest_value_truc_tx->first;
504 for (const auto& [type, output] : unconfirmed_truc_coins) {
505 if (output.outpoint.hash == truc_txid) {
506 result.Add(type, output);
507 }
508 }
509 }
510
511 if (feerate.has_value()) {
512 std::map<COutPoint, CAmount> map_of_bump_fees = wallet.chain().calculateIndividualBumpFees(outpoints, feerate.value());
513
514 for (auto& [_, outputs] : result.coins) {
515 for (auto& output : outputs) {
516 output.ApplyBumpFee(map_of_bump_fees.at(output.outpoint));
517 }
518 }
519 }
520
521 return result;
522}
523
525{
526 AssertLockHeld(wallet.cs_wallet);
527 const CWalletTx* wtx{Assert(wallet.GetWalletTx(outpoint.hash))};
528
529 const CTransaction* ptx = wtx->tx.get();
530 int n = outpoint.n;
531 while (OutputIsChange(wallet, ptx->vout[n]) && ptx->vin.size() > 0) {
532 const COutPoint& prevout = ptx->vin[0].prevout;
533 const CWalletTx* it = wallet.GetWalletTx(prevout.hash);
534 if (!it || it->tx->vout.size() <= prevout.n ||
535 !wallet.IsMine(it->tx->vout[prevout.n])) {
536 break;
537 }
538 ptx = it->tx.get();
539 n = prevout.n;
540 }
541 return ptx->vout[n];
542}
543
544std::map<CTxDestination, std::vector<COutput>> ListCoins(const CWallet& wallet)
545{
546 AssertLockHeld(wallet.cs_wallet);
547
548 std::map<CTxDestination, std::vector<COutput>> result;
549
550 CCoinControl coin_control;
551 CoinFilterParams coins_params;
552 coins_params.skip_locked = false;
553 for (const COutput& coin : AvailableCoins(wallet, &coin_control, /*feerate=*/std::nullopt, coins_params).All()) {
554 CTxDestination address;
555 if (!ExtractDestination(FindNonChangeParentOutput(wallet, coin.outpoint).scriptPubKey, address)) {
556 // For backwards compatibility, we convert P2PK output scripts into PKHash destinations
557 if (auto pk_dest = std::get_if<PubKeyDestination>(&address)) {
558 address = PKHash(pk_dest->GetPubKey());
559 } else {
560 continue;
561 }
562 }
563 result[address].emplace_back(coin);
564 }
565 return result;
566}
567
569 const CoinsResult& coins,
570 const CoinSelectionParams& coin_sel_params,
571 const std::vector<SelectionFilter>& filters,
572 std::vector<OutputGroup>& ret_discarded_groups)
573{
574 FilteredOutputGroups filtered_groups;
575
576 if (!coin_sel_params.m_avoid_partial_spends) {
577 // Allowing partial spends means no grouping. Each COutput gets its own OutputGroup
578 for (const auto& [type, outputs] : coins.coins) {
579 for (const COutput& output : outputs) {
580 // Get mempool info
581 size_t ancestors, descendants;
582 wallet.chain().getTransactionAncestry(output.outpoint.hash, ancestors, descendants);
583
584 // Create a new group per output and add it to the all groups vector
585 OutputGroup group(coin_sel_params);
586 group.Insert(std::make_shared<COutput>(output), ancestors, descendants);
587
588 // Each filter maps to a different set of groups
589 bool accepted = false;
590 for (const auto& sel_filter : filters) {
591 const auto& filter = sel_filter.filter;
592 if (!group.EligibleForSpending(filter)) continue;
593 filtered_groups[filter].Push(group, type, /*insert_positive=*/true, /*insert_mixed=*/true);
594 accepted = true;
595 }
596 if (!accepted) ret_discarded_groups.emplace_back(group);
597 }
598 }
599 return filtered_groups;
600 }
601
602 // We want to combine COutputs that have the same scriptPubKey into single OutputGroups
603 // except when there are more than OUTPUT_GROUP_MAX_ENTRIES COutputs grouped in an OutputGroup.
604 // To do this, we maintain a map where the key is the scriptPubKey and the value is a vector of OutputGroups.
605 // For each COutput, we check if the scriptPubKey is in the map, and if it is, the COutput is added
606 // to the last OutputGroup in the vector for the scriptPubKey. When the last OutputGroup has
607 // OUTPUT_GROUP_MAX_ENTRIES COutputs, a new OutputGroup is added to the end of the vector.
608 typedef std::map<std::pair<CScript, OutputType>, std::vector<OutputGroup>> ScriptPubKeyToOutgroup;
609 const auto& insert_output = [&](
610 const std::shared_ptr<COutput>& output, OutputType type, size_t ancestors, size_t descendants,
611 ScriptPubKeyToOutgroup& groups_map) {
612 std::vector<OutputGroup>& groups = groups_map[std::make_pair(output->txout.scriptPubKey,type)];
613
614 if (groups.size() == 0) {
615 // No OutputGroups for this scriptPubKey yet, add one
616 groups.emplace_back(coin_sel_params);
617 }
618
619 // Get the last OutputGroup in the vector so that we can add the COutput to it
620 // A pointer is used here so that group can be reassigned later if it is full.
621 OutputGroup* group = &groups.back();
622
623 // Check if this OutputGroup is full. We limit to OUTPUT_GROUP_MAX_ENTRIES when using -avoidpartialspends
624 // to avoid surprising users with very high fees.
625 if (group->m_outputs.size() >= OUTPUT_GROUP_MAX_ENTRIES) {
626 // The last output group is full, add a new group to the vector and use that group for the insertion
627 groups.emplace_back(coin_sel_params);
628 group = &groups.back();
629 }
630
631 group->Insert(output, ancestors, descendants);
632 };
633
634 ScriptPubKeyToOutgroup spk_to_groups_map;
635 ScriptPubKeyToOutgroup spk_to_positive_groups_map;
636 for (const auto& [type, outs] : coins.coins) {
637 for (const COutput& output : outs) {
638 size_t ancestors, descendants;
639 wallet.chain().getTransactionAncestry(output.outpoint.hash, ancestors, descendants);
640
641 const auto& shared_output = std::make_shared<COutput>(output);
642 // Filter for positive only before adding the output
643 if (output.GetEffectiveValue() > 0) {
644 insert_output(shared_output, type, ancestors, descendants, spk_to_positive_groups_map);
645 }
646
647 // 'All' groups
648 insert_output(shared_output, type, ancestors, descendants, spk_to_groups_map);
649 }
650 }
651
652 // Now we go through the entire maps and pull out the OutputGroups
653 const auto& push_output_groups = [&](const ScriptPubKeyToOutgroup& groups_map, bool positive_only) {
654 for (const auto& [script, groups] : groups_map) {
655 // Go through the vector backwards. This allows for the first item we deal with being the partial group.
656 for (auto group_it = groups.rbegin(); group_it != groups.rend(); group_it++) {
657 const OutputGroup& group = *group_it;
658
659 // Each filter maps to a different set of groups
660 bool accepted = false;
661 for (const auto& sel_filter : filters) {
662 const auto& filter = sel_filter.filter;
663 if (!group.EligibleForSpending(filter)) continue;
664
665 // Don't include partial groups if there are full groups too and we don't want partial groups
666 if (group_it == groups.rbegin() && groups.size() > 1 && !filter.m_include_partial_groups) {
667 continue;
668 }
669
670 OutputType type = script.second;
671 // Either insert the group into the positive-only groups or the mixed ones.
672 filtered_groups[filter].Push(group, type, positive_only, /*insert_mixed=*/!positive_only);
673 accepted = true;
674 }
675 if (!accepted) ret_discarded_groups.emplace_back(group);
676 }
677 }
678 };
679
680 push_output_groups(spk_to_groups_map, /*positive_only=*/ false);
681 push_output_groups(spk_to_positive_groups_map, /*positive_only=*/ true);
682
683 return filtered_groups;
684}
685
687 const CoinsResult& coins,
688 const CoinSelectionParams& params,
689 const std::vector<SelectionFilter>& filters)
690{
691 std::vector<OutputGroup> unused;
692 return GroupOutputs(wallet, coins, params, filters, unused);
693}
694
695// Returns true if the result contains an error and the message is not empty
696static bool HasErrorMsg(const util::Result<SelectionResult>& res) { return !util::ErrorString(res).empty(); }
697
699 const CoinSelectionParams& coin_selection_params, bool allow_mixed_output_types)
700{
701 // Run coin selection on each OutputType and compute the Waste Metric
702 std::vector<SelectionResult> results;
703 for (auto& [type, group] : groups.groups_by_type) {
704 auto result{ChooseSelectionResult(chain, nTargetValue, group, coin_selection_params)};
705 // If any specific error message appears here, then something particularly wrong happened.
706 if (HasErrorMsg(result)) return result; // So let's return the specific error.
707 // Append the favorable result.
708 if (result) results.push_back(*result);
709 }
710 // If we have at least one solution for funding the transaction without mixing, choose the minimum one according to waste metric
711 // and return the result
712 if (results.size() > 0) return *std::min_element(results.begin(), results.end());
713
714 // If we can't fund the transaction from any individual OutputType, run coin selection one last time
715 // over all available coins, which would allow mixing.
716 // If TypesCount() <= 1, there is nothing to mix.
717 if (allow_mixed_output_types && groups.TypesCount() > 1) {
718 return ChooseSelectionResult(chain, nTargetValue, groups.all_groups, coin_selection_params);
719 }
720 // Either mixing is not allowed and we couldn't find a solution from any single OutputType, or mixing was allowed and we still couldn't
721 // find a solution using all available coins
722 return util::Error();
723};
724
725util::Result<SelectionResult> ChooseSelectionResult(interfaces::Chain& chain, const CAmount& nTargetValue, Groups& groups, const CoinSelectionParams& coin_selection_params)
726{
727 // Vector of results. We will choose the best one based on waste.
728 std::vector<SelectionResult> results;
729 std::vector<util::Result<SelectionResult>> errors;
730 auto append_error = [&] (util::Result<SelectionResult>&& result) {
731 // If any specific error message appears here, then something different from a simple "no selection found" happened.
732 // Let's save it, so it can be retrieved to the user if no other selection algorithm succeeded.
733 if (HasErrorMsg(result)) {
734 errors.emplace_back(std::move(result));
735 }
736 };
737
738 // Maximum allowed weight for selected coins.
739 int max_transaction_weight = coin_selection_params.m_max_tx_weight.value_or(MAX_STANDARD_TX_WEIGHT);
740 int tx_weight_no_input = coin_selection_params.tx_noinputs_size * WITNESS_SCALE_FACTOR;
741 int max_selection_weight = max_transaction_weight - tx_weight_no_input;
742 if (max_selection_weight <= 0) {
743 return util::Error{_("Maximum transaction weight is less than transaction weight without inputs")};
744 }
745
746 // SFFO frequently causes issues in the context of changeless input sets: skip BnB when SFFO is active
747 if (!coin_selection_params.m_subtract_fee_outputs) {
748 if (auto bnb_result{SelectCoinsBnB(groups.positive_group, nTargetValue, coin_selection_params.m_cost_of_change, max_selection_weight)}) {
749 results.push_back(*bnb_result);
750 } else append_error(std::move(bnb_result));
751 }
752
753 // Deduct change weight because remaining Coin Selection algorithms can create change output
754 int change_outputs_weight = coin_selection_params.change_output_size * WITNESS_SCALE_FACTOR;
755 max_selection_weight -= change_outputs_weight;
756 if (max_selection_weight < 0 && results.empty()) {
757 return util::Error{_("Maximum transaction weight is too low, can not accommodate change output")};
758 }
759
760 // The knapsack solver has some legacy behavior where it will spend dust outputs. We retain this behavior, so don't filter for positive only here.
761 if (auto knapsack_result{KnapsackSolver(groups.mixed_group, nTargetValue, coin_selection_params.m_min_change_target, coin_selection_params.rng_fast, max_selection_weight)}) {
762 results.push_back(*knapsack_result);
763 } else append_error(std::move(knapsack_result));
764
765 if (coin_selection_params.m_effective_feerate > CFeeRate{3 * coin_selection_params.m_long_term_feerate}) { // Minimize input set for feerates of at least 3×LTFRE (default: 30 ṩ/vB+)
766 if (auto cg_result{CoinGrinder(groups.positive_group, nTargetValue, coin_selection_params.m_min_change_target, max_selection_weight)}) {
767 cg_result->RecalculateWaste(coin_selection_params.min_viable_change, coin_selection_params.m_cost_of_change, coin_selection_params.m_change_fee);
768 results.push_back(*cg_result);
769 } else {
770 append_error(std::move(cg_result));
771 }
772 }
773
774 if (auto srd_result{SelectCoinsSRD(groups.positive_group, nTargetValue, coin_selection_params.m_change_fee, coin_selection_params.rng_fast, max_selection_weight)}) {
775 results.push_back(*srd_result);
776 } else append_error(std::move(srd_result));
777
778 if (results.empty()) {
779 // No solution found, retrieve the first explicit error (if any).
780 // future: add 'severity level' to errors so the worst one can be retrieved instead of the first one.
781 return errors.empty() ? util::Error() : std::move(errors.front());
782 }
783
784 // If the chosen input set has unconfirmed inputs, check for synergies from overlapping ancestry
785 for (auto& result : results) {
786 std::vector<COutPoint> outpoints;
787 std::set<std::shared_ptr<COutput>> coins = result.GetInputSet();
788 CAmount summed_bump_fees = 0;
789 for (auto& coin : coins) {
790 if (coin->depth > 0) continue; // Bump fees only exist for unconfirmed inputs
791 outpoints.push_back(coin->outpoint);
792 summed_bump_fees += coin->ancestor_bump_fees;
793 }
794 std::optional<CAmount> combined_bump_fee = chain.calculateCombinedBumpFee(outpoints, coin_selection_params.m_effective_feerate);
795 if (!combined_bump_fee.has_value()) {
796 return util::Error{_("Failed to calculate bump fees, because unconfirmed UTXOs depend on an enormous cluster of unconfirmed transactions.")};
797 }
798 CAmount bump_fee_overestimate = summed_bump_fees - combined_bump_fee.value();
799 if (bump_fee_overestimate) {
800 result.SetBumpFeeDiscount(bump_fee_overestimate);
801 }
802 result.RecalculateWaste(coin_selection_params.min_viable_change, coin_selection_params.m_cost_of_change, coin_selection_params.m_change_fee);
803 }
804
805 // Choose the result with the least waste
806 // If the waste is the same, choose the one which spends more inputs.
807 return *std::min_element(results.begin(), results.end());
808}
809
811 const CAmount& nTargetValue, const CCoinControl& coin_control,
812 const CoinSelectionParams& coin_selection_params)
813{
814 // Deduct preset inputs amount from the search target
815 CAmount selection_target = nTargetValue - pre_set_inputs.total_amount;
816
817 // Return if automatic coin selection is disabled, and we don't cover the selection target
818 if (!coin_control.m_allow_other_inputs && selection_target > 0) {
819 return util::Error{_("The preselected coins total amount does not cover the transaction target. "
820 "Please allow other inputs to be automatically selected or include more coins manually")};
821 }
822
823 // Return if we can cover the target only with the preset inputs
824 if (selection_target <= 0) {
825 SelectionResult result(nTargetValue, SelectionAlgorithm::MANUAL);
826 result.AddInputs(pre_set_inputs.coins, coin_selection_params.m_subtract_fee_outputs);
827 result.RecalculateWaste(coin_selection_params.min_viable_change, coin_selection_params.m_cost_of_change, coin_selection_params.m_change_fee);
828 return result;
829 }
830
831 // Return early if we cannot cover the target with the wallet's UTXO.
832 // We use the total effective value if we are not subtracting fee from outputs and 'available_coins' contains the data.
833 CAmount available_coins_total_amount = coin_selection_params.m_subtract_fee_outputs ? available_coins.GetTotalAmount() :
834 (available_coins.GetEffectiveTotalAmount().has_value() ? *available_coins.GetEffectiveTotalAmount() : 0);
835 if (selection_target > available_coins_total_amount) {
836 return util::Error(); // Insufficient funds
837 }
838
839 // Start wallet Coin Selection procedure
840 auto op_selection_result = AutomaticCoinSelection(wallet, available_coins, selection_target, coin_selection_params);
841 if (!op_selection_result) return op_selection_result;
842
843 // If needed, add preset inputs to the automatic coin selection result
844 if (!pre_set_inputs.coins.empty()) {
845 SelectionResult preselected(pre_set_inputs.total_amount, SelectionAlgorithm::MANUAL);
846 preselected.AddInputs(pre_set_inputs.coins, coin_selection_params.m_subtract_fee_outputs);
847 op_selection_result->Merge(preselected);
848 op_selection_result->RecalculateWaste(coin_selection_params.min_viable_change,
849 coin_selection_params.m_cost_of_change,
850 coin_selection_params.m_change_fee);
851
852 // Verify we haven't exceeded the maximum allowed weight
853 int max_inputs_weight = coin_selection_params.m_max_tx_weight.value_or(MAX_STANDARD_TX_WEIGHT) - (coin_selection_params.tx_noinputs_size * WITNESS_SCALE_FACTOR);
854 if (op_selection_result->GetWeight() > max_inputs_weight) {
855 return util::Error{_("The combination of the pre-selected inputs and the wallet automatic inputs selection exceeds the transaction maximum weight. "
856 "Please try sending a smaller amount or manually consolidating your wallet's UTXOs")};
857 }
858 }
859 return op_selection_result;
860}
861
862util::Result<SelectionResult> AutomaticCoinSelection(const CWallet& wallet, CoinsResult& available_coins, const CAmount& value_to_select, const CoinSelectionParams& coin_selection_params)
863{
864 unsigned int limit_ancestor_count = 0;
865 unsigned int limit_descendant_count = 0;
866 wallet.chain().getPackageLimits(limit_ancestor_count, limit_descendant_count);
867 const size_t max_ancestors = (size_t)std::max<int64_t>(1, limit_ancestor_count);
868 const size_t max_descendants = (size_t)std::max<int64_t>(1, limit_descendant_count);
869 const bool fRejectLongChains = gArgs.GetBoolArg("-walletrejectlongchains", DEFAULT_WALLET_REJECT_LONG_CHAINS);
870
871 // Cases where we have 101+ outputs all pointing to the same destination may result in
872 // privacy leaks as they will potentially be deterministically sorted. We solve that by
873 // explicitly shuffling the outputs before processing
874 if (coin_selection_params.m_avoid_partial_spends && available_coins.Size() > OUTPUT_GROUP_MAX_ENTRIES) {
875 available_coins.Shuffle(coin_selection_params.rng_fast);
876 }
877
878 // Coin Selection attempts to select inputs from a pool of eligible UTXOs to fund the
879 // transaction at a target feerate. If an attempt fails, more attempts may be made using a more
880 // permissive CoinEligibilityFilter.
881 {
882 // Place coins eligibility filters on a scope increasing order.
883 std::vector<SelectionFilter> ordered_filters{
884 // If possible, fund the transaction with confirmed UTXOs only. Prefer at least six
885 // confirmations on outputs received from other wallets and only spend confirmed change.
886 {CoinEligibilityFilter(1, 6, 0), /*allow_mixed_output_types=*/false},
887 {CoinEligibilityFilter(1, 1, 0)},
888 };
889 // Fall back to using zero confirmation change (but with as few ancestors in the mempool as
890 // possible) if we cannot fund the transaction otherwise.
891 if (wallet.m_spend_zero_conf_change) {
892 ordered_filters.push_back({CoinEligibilityFilter(0, 1, 2)});
893 ordered_filters.push_back({CoinEligibilityFilter(0, 1, std::min(size_t{4}, max_ancestors/3), std::min(size_t{4}, max_descendants/3))});
894 ordered_filters.push_back({CoinEligibilityFilter(0, 1, max_ancestors/2, max_descendants/2)});
895 // If partial groups are allowed, relax the requirement of spending OutputGroups (groups
896 // of UTXOs sent to the same address, which are obviously controlled by a single wallet)
897 // in their entirety.
898 ordered_filters.push_back({CoinEligibilityFilter(0, 1, max_ancestors-1, max_descendants-1, /*include_partial=*/true)});
899 // Try with unsafe inputs if they are allowed. This may spend unconfirmed outputs
900 // received from other wallets.
901 if (coin_selection_params.m_include_unsafe_inputs) {
902 ordered_filters.push_back({CoinEligibilityFilter(/*conf_mine=*/0, /*conf_theirs*/0, max_ancestors-1, max_descendants-1, /*include_partial=*/true)});
903 }
904 // Try with unlimited ancestors/descendants. The transaction will still need to meet
905 // mempool ancestor/descendant policy to be accepted to mempool and broadcasted, but
906 // OutputGroups use heuristics that may overestimate ancestor/descendant counts.
907 if (!fRejectLongChains) {
908 ordered_filters.push_back({CoinEligibilityFilter(0, 1, std::numeric_limits<uint64_t>::max(),
909 std::numeric_limits<uint64_t>::max(),
910 /*include_partial=*/true)});
911 }
912 }
913
914 // Group outputs and map them by coin eligibility filter
915 std::vector<OutputGroup> discarded_groups;
916 FilteredOutputGroups filtered_groups = GroupOutputs(wallet, available_coins, coin_selection_params, ordered_filters, discarded_groups);
917
918 // Check if we still have enough balance after applying filters (some coins might be discarded)
919 CAmount total_discarded = 0;
920 CAmount total_unconf_long_chain = 0;
921 for (const auto& group : discarded_groups) {
922 total_discarded += group.GetSelectionAmount();
923 if (group.m_ancestors >= max_ancestors || group.m_descendants >= max_descendants) total_unconf_long_chain += group.GetSelectionAmount();
924 }
925
926 if (CAmount total_amount = available_coins.GetTotalAmount() - total_discarded < value_to_select) {
927 // Special case, too-long-mempool cluster.
928 if (total_amount + total_unconf_long_chain > value_to_select) {
929 return util::Error{_("Unconfirmed UTXOs are available, but spending them creates a chain of transactions that will be rejected by the mempool")};
930 }
931 return util::Error{}; // General "Insufficient Funds"
932 }
933
934 // Walk-through the filters until the solution gets found.
935 // If no solution is found, return the first detailed error (if any).
936 // future: add "error level" so the worst one can be picked instead.
937 std::vector<util::Result<SelectionResult>> res_detailed_errors;
938 CoinSelectionParams updated_selection_params = coin_selection_params;
939 for (const auto& select_filter : ordered_filters) {
940 auto it = filtered_groups.find(select_filter.filter);
941 if (it == filtered_groups.end()) continue;
942 if (updated_selection_params.m_version == TRUC_VERSION && (select_filter.filter.conf_mine == 0 || select_filter.filter.conf_theirs == 0)) {
943 if (updated_selection_params.m_max_tx_weight > (TRUC_CHILD_MAX_WEIGHT)) {
944 updated_selection_params.m_max_tx_weight = TRUC_CHILD_MAX_WEIGHT;
945 }
946 }
947 if (auto res{AttemptSelection(wallet.chain(), value_to_select, it->second,
948 updated_selection_params, select_filter.allow_mixed_output_types)}) {
949 return res; // result found
950 } else {
951 // If any specific error message appears here, then something particularly wrong might have happened.
952 // Save the error and continue the selection process. So if no solutions gets found, we can return
953 // the detailed error to the upper layers.
954 if (HasErrorMsg(res)) res_detailed_errors.emplace_back(std::move(res));
955 }
956 }
957
958 // Return right away if we have a detailed error
959 if (!res_detailed_errors.empty()) return std::move(res_detailed_errors.front());
960
961
962 // General "Insufficient Funds"
963 return util::Error{};
964 }
965}
966
967static bool IsCurrentForAntiFeeSniping(interfaces::Chain& chain, const uint256& block_hash)
968{
969 if (chain.isInitialBlockDownload()) {
970 return false;
971 }
972 constexpr int64_t MAX_ANTI_FEE_SNIPING_TIP_AGE = 8 * 60 * 60; // in seconds
973 int64_t block_time;
974 CHECK_NONFATAL(chain.findBlock(block_hash, FoundBlock().time(block_time)));
975 if (block_time < (GetTime() - MAX_ANTI_FEE_SNIPING_TIP_AGE)) {
976 return false;
977 }
978 return true;
979}
980
982 interfaces::Chain& chain, const uint256& block_hash, int block_height)
983{
984 // All inputs must be added by now
985 assert(!tx.vin.empty());
986 // Discourage fee sniping.
987 //
988 // For a large miner the value of the transactions in the best block and
989 // the mempool can exceed the cost of deliberately attempting to mine two
990 // blocks to orphan the current best block. By setting nLockTime such that
991 // only the next block can include the transaction, we discourage this
992 // practice as the height restricted and limited blocksize gives miners
993 // considering fee sniping fewer options for pulling off this attack.
994 //
995 // A simple way to think about this is from the wallet's point of view we
996 // always want the blockchain to move forward. By setting nLockTime this
997 // way we're basically making the statement that we only want this
998 // transaction to appear in the next block; we don't want to potentially
999 // encourage reorgs by allowing transactions to appear at lower heights
1000 // than the next block in forks of the best chain.
1001 //
1002 // Of course, the subsidy is high enough, and transaction volume low
1003 // enough, that fee sniping isn't a problem yet, but by implementing a fix
1004 // now we ensure code won't be written that makes assumptions about
1005 // nLockTime that preclude a fix later.
1006 if (IsCurrentForAntiFeeSniping(chain, block_hash)) {
1007 tx.nLockTime = block_height;
1008
1009 // Secondly occasionally randomly pick a nLockTime even further back, so
1010 // that transactions that are delayed after signing for whatever reason,
1011 // e.g. high-latency mix networks and some CoinJoin implementations, have
1012 // better privacy.
1013 if (rng_fast.randrange(10) == 0) {
1014 tx.nLockTime = std::max(0, int(tx.nLockTime) - int(rng_fast.randrange(100)));
1015 }
1016 } else {
1017 // If our chain is lagging behind, we can't discourage fee sniping nor help
1018 // the privacy of high-latency transactions. To avoid leaking a potentially
1019 // unique "nLockTime fingerprint", set nLockTime to a constant.
1020 tx.nLockTime = 0;
1021 }
1022 // Sanity check all values
1023 assert(tx.nLockTime < LOCKTIME_THRESHOLD); // Type must be block height
1024 assert(tx.nLockTime <= uint64_t(block_height));
1025 for (const auto& in : tx.vin) {
1026 // Can not be FINAL for locktime to work
1027 assert(in.nSequence != CTxIn::SEQUENCE_FINAL);
1028 // May be MAX NONFINAL to disable both BIP68 and BIP125
1029 if (in.nSequence == CTxIn::MAX_SEQUENCE_NONFINAL) continue;
1030 // May be MAX BIP125 to disable BIP68 and enable BIP125
1031 if (in.nSequence == MAX_BIP125_RBF_SEQUENCE) continue;
1032 // The wallet does not support any other sequence-use right now.
1033 assert(false);
1034 }
1035}
1036
1038{
1040}
1041
1042bool IsDust(const CRecipient& recipient, const CFeeRate& dustRelayFee)
1043{
1044 return ::IsDust(CTxOut(recipient.nAmount, GetScriptForDestination(recipient.dest)), dustRelayFee);
1045}
1046
1048 CWallet& wallet,
1049 const std::vector<CRecipient>& vecSend,
1050 std::optional<unsigned int> change_pos,
1051 const CCoinControl& coin_control,
1052 bool sign) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet)
1053{
1054 AssertLockHeld(wallet.cs_wallet);
1055
1056 FastRandomContext rng_fast;
1057 CMutableTransaction txNew; // The resulting transaction that we make
1058
1059 txNew.version = coin_control.m_version;
1060
1061 CoinSelectionParams coin_selection_params{rng_fast}; // Parameters for coin selection, init with dummy
1062 coin_selection_params.m_avoid_partial_spends = coin_control.m_avoid_partial_spends;
1063 coin_selection_params.m_include_unsafe_inputs = coin_control.m_include_unsafe_inputs;
1064 coin_selection_params.m_max_tx_weight = coin_control.m_max_tx_weight.value_or(MAX_STANDARD_TX_WEIGHT);
1065 coin_selection_params.m_version = coin_control.m_version;
1066 int minimum_tx_weight = MIN_STANDARD_TX_NONWITNESS_SIZE * WITNESS_SCALE_FACTOR;
1067 if (coin_selection_params.m_max_tx_weight.value() < minimum_tx_weight || coin_selection_params.m_max_tx_weight.value() > MAX_STANDARD_TX_WEIGHT) {
1068 return util::Error{strprintf(_("Maximum transaction weight must be between %d and %d"), minimum_tx_weight, MAX_STANDARD_TX_WEIGHT)};
1069 }
1070 // Set the long term feerate estimate to the wallet's consolidate feerate
1071 coin_selection_params.m_long_term_feerate = wallet.m_consolidate_feerate;
1072 // Static vsize overhead + outputs vsize. 4 nVersion, 4 nLocktime, 1 input count, 1 witness overhead (dummy, flag, stack size)
1073 coin_selection_params.tx_noinputs_size = 10 + GetSizeOfCompactSize(vecSend.size()); // bytes for output count
1074
1075 CAmount recipients_sum = 0;
1076 const OutputType change_type = wallet.TransactionChangeType(coin_control.m_change_type ? *coin_control.m_change_type : wallet.m_default_change_type, vecSend);
1077 ReserveDestination reservedest(&wallet, change_type);
1078 unsigned int outputs_to_subtract_fee_from = 0; // The number of outputs which we are subtracting the fee from
1079 for (const auto& recipient : vecSend) {
1080 if (IsDust(recipient, wallet.chain().relayDustFee())) {
1081 return util::Error{_("Transaction amount too small")};
1082 }
1083
1084 // Include the fee cost for outputs.
1085 coin_selection_params.tx_noinputs_size += GetSerializeSizeForRecipient(recipient);
1086 recipients_sum += recipient.nAmount;
1087
1088 if (recipient.fSubtractFeeFromAmount) {
1089 outputs_to_subtract_fee_from++;
1090 coin_selection_params.m_subtract_fee_outputs = true;
1091 }
1092 }
1093
1094 // Create change script that will be used if we need change
1095 CScript scriptChange;
1096 bilingual_str error; // possible error str
1097
1098 // coin control: send change to custom address
1099 if (!std::get_if<CNoDestination>(&coin_control.destChange)) {
1100 scriptChange = GetScriptForDestination(coin_control.destChange);
1101 } else { // no coin control: send change to newly generated address
1102 // Note: We use a new key here to keep it from being obvious which side is the change.
1103 // The drawback is that by not reusing a previous key, the change may be lost if a
1104 // backup is restored, if the backup doesn't have the new private key for the change.
1105 // If we reused the old key, it would be possible to add code to look for and
1106 // rediscover unknown transactions that were written with keys of ours to recover
1107 // post-backup change.
1108
1109 // Reserve a new key pair from key pool. If it fails, provide a dummy
1110 // destination in case we don't need change.
1111 CTxDestination dest;
1112 auto op_dest = reservedest.GetReservedDestination(true);
1113 if (!op_dest) {
1114 error = _("Transaction needs a change address, but we can't generate it.") + Untranslated(" ") + util::ErrorString(op_dest);
1115 } else {
1116 dest = *op_dest;
1117 scriptChange = GetScriptForDestination(dest);
1118 }
1119 // A valid destination implies a change script (and
1120 // vice-versa). An empty change script will abort later, if the
1121 // change keypool ran out, but change is required.
1122 CHECK_NONFATAL(IsValidDestination(dest) != scriptChange.empty());
1123 }
1124 CTxOut change_prototype_txout(0, scriptChange);
1125 coin_selection_params.change_output_size = GetSerializeSize(change_prototype_txout);
1126
1127 // Get size of spending the change output
1128 int change_spend_size = CalculateMaximumSignedInputSize(change_prototype_txout, &wallet, /*coin_control=*/nullptr);
1129 // If the wallet doesn't know how to sign change output, assume p2sh-p2wpkh
1130 // as lower-bound to allow BnB to do its thing
1131 if (change_spend_size == -1) {
1132 coin_selection_params.change_spend_size = DUMMY_NESTED_P2WPKH_INPUT_SIZE;
1133 } else {
1134 coin_selection_params.change_spend_size = change_spend_size;
1135 }
1136
1137 // Set discard feerate
1138 coin_selection_params.m_discard_feerate = GetDiscardRate(wallet);
1139
1140 // Get the fee rate to use effective values in coin selection
1141 FeeCalculation feeCalc;
1142 coin_selection_params.m_effective_feerate = GetMinimumFeeRate(wallet, coin_control, &feeCalc);
1143 // Do not, ever, assume that it's fine to change the fee rate if the user has explicitly
1144 // provided one
1145 if (coin_control.m_feerate && coin_selection_params.m_effective_feerate > *coin_control.m_feerate) {
1146 return util::Error{strprintf(_("Fee rate (%s) is lower than the minimum fee rate setting (%s)"), coin_control.m_feerate->ToString(FeeEstimateMode::SAT_VB), coin_selection_params.m_effective_feerate.ToString(FeeEstimateMode::SAT_VB))};
1147 }
1148 if (feeCalc.reason == FeeReason::FALLBACK && !wallet.m_allow_fallback_fee) {
1149 // eventually allow a fallback fee
1150 return util::Error{strprintf(_("Fee estimation failed. Fallbackfee is disabled. Wait a few blocks or enable %s."), "-fallbackfee")};
1151 }
1152
1153 // Calculate the cost of change
1154 // Cost of change is the cost of creating the change output + cost of spending the change output in the future.
1155 // For creating the change output now, we use the effective feerate.
1156 // For spending the change output in the future, we use the discard feerate for now.
1157 // So cost of change = (change output size * effective feerate) + (size of spending change output * discard feerate)
1158 coin_selection_params.m_change_fee = coin_selection_params.m_effective_feerate.GetFee(coin_selection_params.change_output_size);
1159 coin_selection_params.m_cost_of_change = coin_selection_params.m_discard_feerate.GetFee(coin_selection_params.change_spend_size) + coin_selection_params.m_change_fee;
1160
1161 coin_selection_params.m_min_change_target = GenerateChangeTarget(std::floor(recipients_sum / vecSend.size()), coin_selection_params.m_change_fee, rng_fast);
1162
1163 // The smallest change amount should be:
1164 // 1. at least equal to dust threshold
1165 // 2. at least 1 sat greater than fees to spend it at m_discard_feerate
1166 const auto dust = GetDustThreshold(change_prototype_txout, coin_selection_params.m_discard_feerate);
1167 const auto change_spend_fee = coin_selection_params.m_discard_feerate.GetFee(coin_selection_params.change_spend_size);
1168 coin_selection_params.min_viable_change = std::max(change_spend_fee + 1, dust);
1169
1170 // Include the fees for things that aren't inputs, excluding the change output
1171 const CAmount not_input_fees = coin_selection_params.m_effective_feerate.GetFee(coin_selection_params.m_subtract_fee_outputs ? 0 : coin_selection_params.tx_noinputs_size);
1172 CAmount selection_target = recipients_sum + not_input_fees;
1173
1174 // This can only happen if feerate is 0, and requested destinations are value of 0 (e.g. OP_RETURN)
1175 // and no pre-selected inputs. This will result in 0-input transaction, which is consensus-invalid anyways
1176 if (selection_target == 0 && !coin_control.HasSelected()) {
1177 return util::Error{_("Transaction requires one destination of non-zero value, a non-zero feerate, or a pre-selected input")};
1178 }
1179
1180 // Fetch manually selected coins
1181 PreSelectedInputs preset_inputs;
1182 if (coin_control.HasSelected()) {
1183 auto res_fetch_inputs = FetchSelectedInputs(wallet, coin_control, coin_selection_params);
1184 if (!res_fetch_inputs) return util::Error{util::ErrorString(res_fetch_inputs)};
1185 preset_inputs = *res_fetch_inputs;
1186 }
1187
1188 // Fetch wallet available coins if "other inputs" are
1189 // allowed (coins automatically selected by the wallet)
1190 CoinsResult available_coins;
1191 if (coin_control.m_allow_other_inputs) {
1192 available_coins = AvailableCoins(wallet, &coin_control, coin_selection_params.m_effective_feerate);
1193 }
1194
1195 // Choose coins to use
1196 auto select_coins_res = SelectCoins(wallet, available_coins, preset_inputs, /*nTargetValue=*/selection_target, coin_control, coin_selection_params);
1197 if (!select_coins_res) {
1198 // 'SelectCoins' either returns a specific error message or, if empty, means a general "Insufficient funds".
1199 const bilingual_str& err = util::ErrorString(select_coins_res);
1200 return util::Error{err.empty() ?_("Insufficient funds") : err};
1201 }
1202 const SelectionResult& result = *select_coins_res;
1203 TRACEPOINT(coin_selection, selected_coins,
1204 wallet.GetName().c_str(),
1205 GetAlgorithmName(result.GetAlgo()).c_str(),
1206 result.GetTarget(),
1207 result.GetWaste(),
1208 result.GetSelectedValue());
1209
1210 // vouts to the payees
1211 txNew.vout.reserve(vecSend.size() + 1); // + 1 because of possible later insert
1212 for (const auto& recipient : vecSend)
1213 {
1214 txNew.vout.emplace_back(recipient.nAmount, GetScriptForDestination(recipient.dest));
1215 }
1216 const CAmount change_amount = result.GetChange(coin_selection_params.min_viable_change, coin_selection_params.m_change_fee);
1217 if (change_amount > 0) {
1218 CTxOut newTxOut(change_amount, scriptChange);
1219 if (!change_pos) {
1220 // Insert change txn at random position:
1221 change_pos = rng_fast.randrange(txNew.vout.size() + 1);
1222 } else if ((unsigned int)*change_pos > txNew.vout.size()) {
1223 return util::Error{_("Transaction change output index out of range")};
1224 }
1225 txNew.vout.insert(txNew.vout.begin() + *change_pos, newTxOut);
1226 } else {
1227 change_pos = std::nullopt;
1228 }
1229
1230 // Shuffle selected coins and fill in final vin
1231 std::vector<std::shared_ptr<COutput>> selected_coins = result.GetShuffledInputVector();
1232
1233 if (coin_control.HasSelected() && coin_control.HasSelectedOrder()) {
1234 // When there are preselected inputs, we need to move them to be the first UTXOs
1235 // and have them be in the order selected. We can use stable_sort for this, where we
1236 // compare with the positions stored in coin_control. The COutputs that have positions
1237 // will be placed before those that don't, and those positions will be in order.
1238 std::stable_sort(selected_coins.begin(), selected_coins.end(),
1239 [&coin_control](const std::shared_ptr<COutput>& a, const std::shared_ptr<COutput>& b) {
1240 auto a_pos = coin_control.GetSelectionPos(a->outpoint);
1241 auto b_pos = coin_control.GetSelectionPos(b->outpoint);
1242 if (a_pos.has_value() && b_pos.has_value()) {
1243 return a_pos.value() < b_pos.value();
1244 } else if (a_pos.has_value() && !b_pos.has_value()) {
1245 return true;
1246 } else {
1247 return false;
1248 }
1249 });
1250 }
1251
1252 // The sequence number is set to non-maxint so that DiscourageFeeSniping
1253 // works.
1254 //
1255 // BIP125 defines opt-in RBF as any nSequence < maxint-1, so
1256 // we use the highest possible value in that range (maxint-2)
1257 // to avoid conflicting with other possible uses of nSequence,
1258 // and in the spirit of "smallest possible change from prior
1259 // behavior."
1260 bool use_anti_fee_sniping = true;
1261 const uint32_t default_sequence{coin_control.m_signal_bip125_rbf.value_or(wallet.m_signal_rbf) ? MAX_BIP125_RBF_SEQUENCE : CTxIn::MAX_SEQUENCE_NONFINAL};
1262 txNew.vin.reserve(selected_coins.size());
1263 for (const auto& coin : selected_coins) {
1264 std::optional<uint32_t> sequence = coin_control.GetSequence(coin->outpoint);
1265 if (sequence) {
1266 // If an input has a preset sequence, we can't do anti-fee-sniping
1267 use_anti_fee_sniping = false;
1268 }
1269 txNew.vin.emplace_back(coin->outpoint, CScript{}, sequence.value_or(default_sequence));
1270
1271 auto scripts = coin_control.GetScripts(coin->outpoint);
1272 if (scripts.first) {
1273 txNew.vin.back().scriptSig = *scripts.first;
1274 }
1275 if (scripts.second) {
1276 txNew.vin.back().scriptWitness = *scripts.second;
1277 }
1278 }
1279 if (coin_control.m_locktime) {
1280 txNew.nLockTime = coin_control.m_locktime.value();
1281 // If we have a locktime set, we can't use anti-fee-sniping
1282 use_anti_fee_sniping = false;
1283 }
1284 if (use_anti_fee_sniping) {
1285 DiscourageFeeSniping(txNew, rng_fast, wallet.chain(), wallet.GetLastBlockHash(), wallet.GetLastBlockHeight());
1286 }
1287
1288 // Calculate the transaction fee
1289 TxSize tx_sizes = CalculateMaximumSignedTxSize(CTransaction(txNew), &wallet, &coin_control);
1290 int nBytes = tx_sizes.vsize;
1291 if (nBytes == -1) {
1292 return util::Error{_("Missing solving data for estimating transaction size")};
1293 }
1294 CAmount fee_needed = coin_selection_params.m_effective_feerate.GetFee(nBytes) + result.GetTotalBumpFees();
1295 const CAmount output_value = CalculateOutputValue(txNew);
1296 Assume(recipients_sum + change_amount == output_value);
1297 CAmount current_fee = result.GetSelectedValue() - output_value;
1298
1299 // Sanity check that the fee cannot be negative as that means we have more output value than input value
1300 if (current_fee < 0) {
1301 return util::Error{Untranslated(STR_INTERNAL_BUG("Fee paid < 0"))};
1302 }
1303
1304 // If there is a change output and we overpay the fees then increase the change to match the fee needed
1305 if (change_pos && fee_needed < current_fee) {
1306 auto& change = txNew.vout.at(*change_pos);
1307 change.nValue += current_fee - fee_needed;
1308 current_fee = result.GetSelectedValue() - CalculateOutputValue(txNew);
1309 if (fee_needed != current_fee) {
1310 return util::Error{Untranslated(STR_INTERNAL_BUG("Change adjustment: Fee needed != fee paid"))};
1311 }
1312 }
1313
1314 // Reduce output values for subtractFeeFromAmount
1315 if (coin_selection_params.m_subtract_fee_outputs) {
1316 CAmount to_reduce = fee_needed - current_fee;
1317 unsigned int i = 0;
1318 bool fFirst = true;
1319 for (const auto& recipient : vecSend)
1320 {
1321 if (change_pos && i == *change_pos) {
1322 ++i;
1323 }
1324 CTxOut& txout = txNew.vout[i];
1325
1326 if (recipient.fSubtractFeeFromAmount)
1327 {
1328 txout.nValue -= to_reduce / outputs_to_subtract_fee_from; // Subtract fee equally from each selected recipient
1329
1330 if (fFirst) // first receiver pays the remainder not divisible by output count
1331 {
1332 fFirst = false;
1333 txout.nValue -= to_reduce % outputs_to_subtract_fee_from;
1334 }
1335
1336 // Error if this output is reduced to be below dust
1337 if (IsDust(txout, wallet.chain().relayDustFee())) {
1338 if (txout.nValue < 0) {
1339 return util::Error{_("The transaction amount is too small to pay the fee")};
1340 } else {
1341 return util::Error{_("The transaction amount is too small to send after the fee has been deducted")};
1342 }
1343 }
1344 }
1345 ++i;
1346 }
1347 current_fee = result.GetSelectedValue() - CalculateOutputValue(txNew);
1348 if (fee_needed != current_fee) {
1349 return util::Error{Untranslated(STR_INTERNAL_BUG("SFFO: Fee needed != fee paid"))};
1350 }
1351 }
1352
1353 // fee_needed should now always be less than or equal to the current fees that we pay.
1354 // If it is not, it is a bug.
1355 if (fee_needed > current_fee) {
1356 return util::Error{Untranslated(STR_INTERNAL_BUG("Fee needed > fee paid"))};
1357 }
1358
1359 // Give up if change keypool ran out and change is required
1360 if (scriptChange.empty() && change_pos) {
1361 return util::Error{error};
1362 }
1363
1364 if (sign && !wallet.SignTransaction(txNew)) {
1365 return util::Error{_("Signing transaction failed")};
1366 }
1367
1368 // Return the constructed transaction data.
1369 CTransactionRef tx = MakeTransactionRef(std::move(txNew));
1370
1371 // Limit size
1373 (!sign && tx_sizes.weight > MAX_STANDARD_TX_WEIGHT))
1374 {
1375 return util::Error{_("Transaction too large")};
1376 }
1377
1378 if (current_fee > wallet.m_default_max_tx_fee) {
1379 return util::Error{TransactionErrorString(TransactionError::MAX_FEE_EXCEEDED)};
1380 }
1381
1382 if (gArgs.GetBoolArg("-walletrejectlongchains", DEFAULT_WALLET_REJECT_LONG_CHAINS)) {
1383 // Lastly, ensure this tx will pass the mempool's chain limits
1384 auto result = wallet.chain().checkChainLimits(tx);
1385 if (!result) {
1386 return util::Error{util::ErrorString(result)};
1387 }
1388 }
1389
1390 // Before we return success, we assume any change key will be used to prevent
1391 // accidental reuse.
1392 reservedest.KeepDestination();
1393
1394 wallet.WalletLogPrintf("Coin Selection: Algorithm:%s, Waste Metric Score:%d\n", GetAlgorithmName(result.GetAlgo()), result.GetWaste());
1395 wallet.WalletLogPrintf("Fee Calculation: Fee:%d Bytes:%u Tgt:%d (requested %d) Reason:\"%s\" Decay %.5f: Estimation: (%g - %g) %.2f%% %.1f/(%.1f %d mem %.1f out) Fail: (%g - %g) %.2f%% %.1f/(%.1f %d mem %.1f out)\n",
1396 current_fee, nBytes, feeCalc.returnedTarget, feeCalc.desiredTarget, StringForFeeReason(feeCalc.reason), feeCalc.est.decay,
1397 feeCalc.est.pass.start, feeCalc.est.pass.end,
1398 (feeCalc.est.pass.totalConfirmed + feeCalc.est.pass.inMempool + feeCalc.est.pass.leftMempool) > 0.0 ? 100 * feeCalc.est.pass.withinTarget / (feeCalc.est.pass.totalConfirmed + feeCalc.est.pass.inMempool + feeCalc.est.pass.leftMempool) : 0.0,
1399 feeCalc.est.pass.withinTarget, feeCalc.est.pass.totalConfirmed, feeCalc.est.pass.inMempool, feeCalc.est.pass.leftMempool,
1400 feeCalc.est.fail.start, feeCalc.est.fail.end,
1401 (feeCalc.est.fail.totalConfirmed + feeCalc.est.fail.inMempool + feeCalc.est.fail.leftMempool) > 0.0 ? 100 * feeCalc.est.fail.withinTarget / (feeCalc.est.fail.totalConfirmed + feeCalc.est.fail.inMempool + feeCalc.est.fail.leftMempool) : 0.0,
1402 feeCalc.est.fail.withinTarget, feeCalc.est.fail.totalConfirmed, feeCalc.est.fail.inMempool, feeCalc.est.fail.leftMempool);
1403 return CreatedTransactionResult(tx, current_fee, change_pos, feeCalc);
1404}
1405
1407 CWallet& wallet,
1408 const std::vector<CRecipient>& vecSend,
1409 std::optional<unsigned int> change_pos,
1410 const CCoinControl& coin_control,
1411 bool sign)
1412{
1413 if (vecSend.empty()) {
1414 return util::Error{_("Transaction must have at least one recipient")};
1415 }
1416
1417 if (std::any_of(vecSend.cbegin(), vecSend.cend(), [](const auto& recipient){ return recipient.nAmount < 0; })) {
1418 return util::Error{_("Transaction amounts must not be negative")};
1419 }
1420
1421 LOCK(wallet.cs_wallet);
1422
1423 auto res = CreateTransactionInternal(wallet, vecSend, change_pos, coin_control, sign);
1424 TRACEPOINT(coin_selection, normal_create_tx_internal,
1425 wallet.GetName().c_str(),
1426 bool(res),
1427 res ? res->fee : 0,
1428 res && res->change_pos.has_value() ? int32_t(*res->change_pos) : -1);
1429 if (!res) return res;
1430 const auto& txr_ungrouped = *res;
1431 // try with avoidpartialspends unless it's enabled already
1432 if (txr_ungrouped.fee > 0 /* 0 means non-functional fee rate estimation */ && wallet.m_max_aps_fee > -1 && !coin_control.m_avoid_partial_spends) {
1433 TRACEPOINT(coin_selection, attempting_aps_create_tx, wallet.GetName().c_str());
1434 CCoinControl tmp_cc = coin_control;
1435 tmp_cc.m_avoid_partial_spends = true;
1436
1437 // Reuse the change destination from the first creation attempt to avoid skipping BIP44 indexes
1438 if (txr_ungrouped.change_pos) {
1439 ExtractDestination(txr_ungrouped.tx->vout[*txr_ungrouped.change_pos].scriptPubKey, tmp_cc.destChange);
1440 }
1441
1442 auto txr_grouped = CreateTransactionInternal(wallet, vecSend, change_pos, tmp_cc, sign);
1443 // if fee of this alternative one is within the range of the max fee, we use this one
1444 const bool use_aps{txr_grouped.has_value() ? (txr_grouped->fee <= txr_ungrouped.fee + wallet.m_max_aps_fee) : false};
1445 TRACEPOINT(coin_selection, aps_create_tx_internal,
1446 wallet.GetName().c_str(),
1447 use_aps,
1448 txr_grouped.has_value(),
1449 txr_grouped.has_value() ? txr_grouped->fee : 0,
1450 txr_grouped.has_value() && txr_grouped->change_pos.has_value() ? int32_t(*txr_grouped->change_pos) : -1);
1451 if (txr_grouped) {
1452 wallet.WalletLogPrintf("Fee non-grouped = %lld, grouped = %lld, using %s\n",
1453 txr_ungrouped.fee, txr_grouped->fee, use_aps ? "grouped" : "non-grouped");
1454 if (use_aps) return txr_grouped;
1455 }
1456 }
1457 return res;
1458}
1459
1460util::Result<CreatedTransactionResult> FundTransaction(CWallet& wallet, const CMutableTransaction& tx, const std::vector<CRecipient>& vecSend, std::optional<unsigned int> change_pos, bool lockUnspents, CCoinControl coinControl)
1461{
1462 // We want to make sure tx.vout is not used now that we are passing outputs as a vector of recipients.
1463 // This sets us up to remove tx completely in a future PR in favor of passing the inputs directly.
1464 assert(tx.vout.empty());
1465
1466 // Set the user desired locktime
1467 coinControl.m_locktime = tx.nLockTime;
1468
1469 // Set the user desired version
1470 coinControl.m_version = tx.version;
1471
1472 // Acquire the locks to prevent races to the new locked unspents between the
1473 // CreateTransaction call and LockCoin calls (when lockUnspents is true).
1474 LOCK(wallet.cs_wallet);
1475
1476 // Fetch specified UTXOs from the UTXO set to get the scriptPubKeys and values of the outputs being selected
1477 // and to match with the given solving_data. Only used for non-wallet outputs.
1478 std::map<COutPoint, Coin> coins;
1479 for (const CTxIn& txin : tx.vin) {
1480 coins[txin.prevout]; // Create empty map entry keyed by prevout.
1481 }
1482 wallet.chain().findCoins(coins);
1483
1484 for (const CTxIn& txin : tx.vin) {
1485 const auto& outPoint = txin.prevout;
1486 PreselectedInput& preset_txin = coinControl.Select(outPoint);
1487 if (!wallet.IsMine(outPoint)) {
1488 if (coins[outPoint].out.IsNull()) {
1489 return util::Error{_("Unable to find UTXO for external input")};
1490 }
1491
1492 // The input was not in the wallet, but is in the UTXO set, so select as external
1493 preset_txin.SetTxOut(coins[outPoint].out);
1494 }
1495 preset_txin.SetSequence(txin.nSequence);
1496 preset_txin.SetScriptSig(txin.scriptSig);
1497 preset_txin.SetScriptWitness(txin.scriptWitness);
1498 }
1499
1500 auto res = CreateTransaction(wallet, vecSend, change_pos, coinControl, false);
1501 if (!res) {
1502 return res;
1503 }
1504
1505 if (lockUnspents) {
1506 for (const CTxIn& txin : res->tx->vin) {
1507 wallet.LockCoin(txin.prevout, /*persist=*/false);
1508 }
1509 }
1510
1511 return res;
1512}
1513} // namespace wallet
bool ExtractDestination(const CScript &scriptPubKey, CTxDestination &addressRet)
Parse a scriptPubKey for the destination.
Definition: addresstype.cpp:49
bool IsValidDestination(const CTxDestination &dest)
Check whether a CTxDestination corresponds to one with an address.
CScript GetScriptForDestination(const CTxDestination &dest)
Generate a Bitcoin scriptPubKey for the given CTxDestination.
std::variant< CNoDestination, PubKeyDestination, PKHash, ScriptHash, WitnessV0ScriptHash, WitnessV0KeyHash, WitnessV1Taproot, PayToAnchor, WitnessUnknown > CTxDestination
A txout script categorized into standard templates.
Definition: addresstype.h:143
static constexpr CAmount MAX_MONEY
No amount larger than this (in satoshi) is valid.
Definition: amount.h:26
int64_t CAmount
Amount in satoshis (Can be negative)
Definition: amount.h:12
ArgsManager gArgs
Definition: args.cpp:42
if(!SetupNetworking())
#define CHECK_NONFATAL(condition)
Identity function.
Definition: check.h:102
#define Assert(val)
Identity function.
Definition: check.h:106
#define STR_INTERNAL_BUG(msg)
Definition: check.h:89
#define Assume(val)
Assume is the identity function.
Definition: check.h:118
bool GetBoolArg(const std::string &strArg, bool fDefault) const
Return boolean argument or default value.
Definition: args.cpp:507
Fee rate in satoshis per virtualbyte: CAmount / vB the feerate is represented internally as FeeFrac.
Definition: feerate.h:35
An outpoint - a combination of a transaction hash and an index n into its vout.
Definition: transaction.h:29
uint32_t n
Definition: transaction.h:32
Txid hash
Definition: transaction.h:31
Serialized script, used inside transaction inputs and outputs.
Definition: script.h:413
A reference to a CScript: the Hash160 of its serialization.
Definition: script.h:602
The basic transaction that is broadcasted on the network and contained in blocks.
Definition: transaction.h:296
const std::vector< CTxOut > vout
Definition: transaction.h:307
const std::vector< CTxIn > vin
Definition: transaction.h:306
An input of a transaction.
Definition: transaction.h:67
static const uint32_t MAX_SEQUENCE_NONFINAL
This is the maximum sequence number that enables both nLockTime and OP_CHECKLOCKTIMEVERIFY (BIP 65).
Definition: transaction.h:87
uint32_t nSequence
Definition: transaction.h:71
static const uint32_t SEQUENCE_FINAL
Setting nSequence to this value for every input in a transaction disables nLockTime/IsFinalTx().
Definition: transaction.h:81
CScript scriptSig
Definition: transaction.h:70
CScriptWitness scriptWitness
Only serialized through CTransaction.
Definition: transaction.h:72
COutPoint prevout
Definition: transaction.h:69
An output of a transaction.
Definition: transaction.h:150
CScript scriptPubKey
Definition: transaction.h:153
CAmount nValue
Definition: transaction.h:152
Fast randomness source.
Definition: random.h:386
A signing provider to be used to interface with multiple signing providers at once.
void AddProvider(std::unique_ptr< SigningProvider > provider)
I randrange(I range) noexcept
Generate a random integer in the range [0..range), with range > 0.
Definition: random.h:254
An interface to be implemented by keystores that support signing.
Interface giving clients (wallet processes, maybe other analysis tools in the future) ability to acce...
Definition: chain.h:130
virtual bool isInitialBlockDownload()=0
Check if in IBD.
virtual std::optional< CAmount > calculateCombinedBumpFee(const std::vector< COutPoint > &outpoints, const CFeeRate &target_feerate)=0
Calculate the combined bump fee for an input set per the same strategy.
virtual bool findBlock(const uint256 &hash, const FoundBlock &block={})=0
Return whether node has the block and optionally return block metadata or contents.
Helper for findBlock to selectively return pieces of block data.
Definition: chain.h:49
bool empty() const
Definition: prevector.h:259
160-bit opaque blob.
Definition: uint256.h:184
256-bit opaque blob.
Definition: uint256.h:196
Coin Control Features.
Definition: coincontrol.h:83
bool IsSelected(const COutPoint &outpoint) const
Returns true if the given output is pre-selected.
Definition: coincontrol.cpp:20
std::optional< CTxOut > GetExternalOutput(const COutPoint &outpoint) const
Returns the external output for the given outpoint if it exists.
Definition: coincontrol.cpp:31
bool m_avoid_address_reuse
Forbids inclusion of dirty (previously used) addresses.
Definition: coincontrol.h:105
std::optional< int64_t > GetInputWeight(const COutPoint &outpoint) const
Returns the input weight.
Definition: coincontrol.cpp:72
PreselectedInput & Select(const COutPoint &outpoint)
Lock-in the given output for spending.
Definition: coincontrol.cpp:40
bool HasSelected() const
Returns true if there are pre-selected inputs.
Definition: coincontrol.cpp:15
bool IsExternalSelected(const COutPoint &outpoint) const
Returns true if the given output is selected as an external input.
Definition: coincontrol.cpp:25
int m_min_depth
Minimum chain depth value for coin availability.
Definition: coincontrol.h:109
bool m_allow_other_inputs
If true, the selection process can add extra unselected inputs from the wallet while requires all sel...
Definition: coincontrol.h:93
int m_max_depth
Maximum chain depth value for coin availability.
Definition: coincontrol.h:111
bool m_include_unsafe_inputs
If false, only safe inputs will be used.
Definition: coincontrol.h:90
bool m_avoid_partial_spends
Avoid partial use of funds sent to a given address.
Definition: coincontrol.h:103
uint32_t m_version
Version.
Definition: coincontrol.h:115
FlatSigningProvider m_external_provider
SigningProvider that has pubkeys and scripts to do spend size estimation for external inputs.
Definition: coincontrol.h:113
CTxDestination destChange
Custom change destination, if not set an address is generated.
Definition: coincontrol.h:86
std::vector< COutPoint > ListSelected() const
List the selected inputs.
Definition: coincontrol.cpp:57
std::optional< uint32_t > m_locktime
Locktime.
Definition: coincontrol.h:117
A CWallet maintains a set of transactions and balances, and provides the ability to create new transa...
Definition: wallet.h:311
A transaction with a bunch of additional info that only the owner cares about.
Definition: transaction.h:195
mapValue_t mapValue
Key/value map with information about the transaction.
Definition: transaction.h:222
CTransactionRef tx
Definition: transaction.h:267
bool InMempool() const
Definition: transaction.cpp:27
std::optional< Txid > truc_child_in_mempool
Definition: transaction.h:280
int64_t GetTxTime() const
Definition: transaction.cpp:32
void SetScriptSig(const CScript &script)
Set the scriptSig for this input.
void SetSequence(uint32_t sequence)
Set the sequence for this input.
void SetScriptWitness(const CScriptWitness &script_wit)
Set the scriptWitness for this input.
void SetTxOut(const CTxOut &txout)
Set the previous output for this input.
Definition: coincontrol.cpp:90
A wrapper to reserve an address from a wallet.
Definition: wallet.h:199
util::Result< CTxDestination > GetReservedDestination(bool internal)
Reserve an address.
Definition: wallet.cpp:2569
static int32_t GetTransactionWeight(const CTransaction &tx)
Definition: validation.h:132
static const int WITNESS_SCALE_FACTOR
Definition: consensus.h:21
@ SAT_VB
Use sat/vB fee rate unit.
uint64_t sequence
is a home for simple string functions returning descriptive messages that are used in RPC and GUI int...
static int sign(const secp256k1_context *ctx, struct signer_secrets *signer_secrets, struct signer *signer, const secp256k1_musig_keyagg_cache *cache, const unsigned char *msg32, unsigned char *sig64)
Definition: musig.c:106
bilingual_str TransactionErrorString(const TransactionError err)
Definition: messages.cpp:128
std::string StringForFeeReason(FeeReason reason)
Definition: messages.cpp:26
TransactionError
Definition: types.h:24
bilingual_str ErrorString(const Result< T > &result)
Definition: result.h:93
static constexpr size_t DUMMY_NESTED_P2WPKH_INPUT_SIZE
Pre-calculated constants for input size estimation in virtual size
Definition: wallet.h:144
const CTxOut & FindNonChangeParentOutput(const CWallet &wallet, const COutPoint &outpoint)
Find non-change parent output.
Definition: spend.cpp:524
bool OutputIsChange(const CWallet &wallet, const CTxOut &txout)
Definition: receive.cpp:74
util::Result< SelectionResult > AutomaticCoinSelection(const CWallet &wallet, CoinsResult &available_coins, const CAmount &value_to_select, const CoinSelectionParams &coin_selection_params)
Select a set of coins such that nTargetValue is met; never select unconfirmed coins if they are not o...
Definition: spend.cpp:862
util::Result< CreatedTransactionResult > FundTransaction(CWallet &wallet, const CMutableTransaction &tx, const std::vector< CRecipient > &vecSend, std::optional< unsigned int > change_pos, bool lockUnspents, CCoinControl coinControl)
Insert additional inputs into the transaction by calling CreateTransaction();.
Definition: spend.cpp:1460
util::Result< CreatedTransactionResult > CreateTransaction(CWallet &wallet, const std::vector< CRecipient > &vecSend, std::optional< unsigned int > change_pos, const CCoinControl &coin_control, bool sign)
Create a new transaction paying the recipients with a set of coins selected by SelectCoins(); Also cr...
Definition: spend.cpp:1406
bool CachedTxIsFromMe(const CWallet &wallet, const CWalletTx &wtx)
Definition: receive.cpp:196
const int DEFAULT_MIN_DEPTH
Definition: coincontrol.h:21
bool CachedTxIsTrusted(const CWallet &wallet, const CWalletTx &wtx, std::set< Txid > &trusted_parents)
Definition: receive.cpp:202
util::Result< SelectionResult > SelectCoinsBnB(std::vector< OutputGroup > &utxo_pool, const CAmount &selection_target, const CAmount &cost_of_change, int max_selection_weight)
CAmount GenerateChangeTarget(const CAmount payment_value, const CAmount change_fee, FastRandomContext &rng)
Choose a random change target for each transaction to make it harder to fingerprint the Core wallet b...
static std::unique_ptr< Descriptor > GetDescriptor(const CWallet *wallet, const CCoinControl *coin_control, const CScript script_pubkey)
Infer a descriptor for the given output script.
Definition: spend.cpp:112
static bool UseMaxSig(const std::optional< CTxIn > &txin, const CCoinControl *coin_control)
Whether to assume ECDSA signatures' will be high-r.
Definition: spend.cpp:55
static std::optional< int64_t > GetSignedTxinWeight(const CWallet *wallet, const CCoinControl *coin_control, const CTxIn &txin, const CTxOut &txo, const bool tx_is_segwit, const bool can_grind_r)
Infer the maximum size of this input after it will be signed.
Definition: spend.cpp:126
util::Result< SelectionResult > CoinGrinder(std::vector< OutputGroup > &utxo_pool, const CAmount &selection_target, CAmount change_target, int max_selection_weight)
util::Result< PreSelectedInputs > FetchSelectedInputs(const CWallet &wallet, const CCoinControl &coin_control, const CoinSelectionParams &coin_selection_params)
Fetch and validate coin control selected inputs.
Definition: spend.cpp:269
bool IsDust(const CRecipient &recipient, const CFeeRate &dustRelayFee)
Definition: spend.cpp:1042
static OutputType GetOutputType(TxoutType type, bool is_from_p2sh)
Definition: spend.cpp:250
static bool IsSegwit(const Descriptor &desc)
Whether the descriptor represents, directly or not, a witness program.
Definition: spend.cpp:49
const int DEFAULT_MAX_DEPTH
Definition: coincontrol.h:22
util::Result< SelectionResult > AttemptSelection(interfaces::Chain &chain, const CAmount &nTargetValue, OutputGroupTypeMap &groups, const CoinSelectionParams &coin_selection_params, bool allow_mixed_output_types)
Attempt to find a valid input set that preserves privacy by not mixing OutputTypes.
Definition: spend.cpp:698
util::Result< SelectionResult > ChooseSelectionResult(interfaces::Chain &chain, const CAmount &nTargetValue, Groups &groups, const CoinSelectionParams &coin_selection_params)
Attempt to find a valid input set that meets the provided eligibility filter and target.
Definition: spend.cpp:725
util::Result< SelectionResult > KnapsackSolver(std::vector< OutputGroup > &groups, const CAmount &nTargetValue, CAmount change_target, FastRandomContext &rng, int max_selection_weight)
util::Result< SelectionResult > SelectCoins(const CWallet &wallet, CoinsResult &available_coins, const PreSelectedInputs &pre_set_inputs, const CAmount &nTargetValue, const CCoinControl &coin_control, const CoinSelectionParams &coin_selection_params)
Select all coins from coin_control, and if coin_control 'm_allow_other_inputs=true',...
Definition: spend.cpp:810
CFeeRate GetMinimumFeeRate(const CWallet &wallet, const CCoinControl &coin_control, FeeCalculation *feeCalc)
Estimate the minimum fee rate considering user set parameters and the required fee.
Definition: fees.cpp:29
std::map< CTxDestination, std::vector< COutput > > ListCoins(const CWallet &wallet)
Return list of available coins and locked coins grouped by non-change output address.
Definition: spend.cpp:544
int CalculateMaximumSignedInputSize(const CTxOut &txout, const CWallet *wallet, const CCoinControl *coin_control)
Get the marginal bytes if spending the specified output from this transaction.
Definition: spend.cpp:105
std::string GetAlgorithmName(const SelectionAlgorithm algo)
void DiscourageFeeSniping(CMutableTransaction &tx, FastRandomContext &rng_fast, interfaces::Chain &chain, const uint256 &block_hash, int block_height)
Set a height-based locktime for new transactions (uses the height of the current chain tip unless we ...
Definition: spend.cpp:981
TxSize CalculateMaximumSignedTxSize(const CTransaction &tx, const CWallet *wallet, const CCoinControl *coin_control)
Definition: spend.cpp:173
static bool HasErrorMsg(const util::Result< SelectionResult > &res)
Definition: spend.cpp:696
size_t GetSerializeSizeForRecipient(const CRecipient &recipient)
Definition: spend.cpp:1037
CFeeRate GetDiscardRate(const CWallet &wallet)
Return the maximum feerate for discarding change.
Definition: fees.cpp:84
std::map< CoinEligibilityFilter, OutputGroupTypeMap > FilteredOutputGroups
TxSize CalculateMaximumSignedTxSize(const CTransaction &tx, const CWallet *wallet, const std::vector< CTxOut > &txouts, const CCoinControl *coin_control)
Calculate the size of the transaction using CoinControl to determine whether to expect signature grin...
Definition: spend.cpp:144
static util::Result< CreatedTransactionResult > CreateTransactionInternal(CWallet &wallet, const std::vector< CRecipient > &vecSend, std::optional< unsigned int > change_pos, const CCoinControl &coin_control, bool sign) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet)
Definition: spend.cpp:1047
@ WALLET_FLAG_AVOID_REUSE
Definition: walletutil.h:21
static bool IsCurrentForAntiFeeSniping(interfaces::Chain &chain, const uint256 &block_hash)
Definition: spend.cpp:967
FilteredOutputGroups GroupOutputs(const CWallet &wallet, const CoinsResult &coins, const CoinSelectionParams &params, const std::vector< SelectionFilter > &filters)
Group coins by the provided filters.
Definition: spend.cpp:686
static constexpr size_t OUTPUT_GROUP_MAX_ENTRIES
Definition: spend.cpp:46
int CalculateMaximumSignedInputSize(const CTxOut &txout, const COutPoint outpoint, const SigningProvider *provider, bool can_grind_r, const CCoinControl *coin_control)
Definition: spend.cpp:92
static std::optional< int64_t > MaxInputWeight(const Descriptor &desc, const std::optional< CTxIn > &txin, const CCoinControl *coin_control, const bool tx_is_segwit, const bool can_grind_r)
Get the size of an input (in witness units) once it's signed.
Definition: spend.cpp:69
static const bool DEFAULT_WALLET_REJECT_LONG_CHAINS
Default for -walletrejectlongchains.
Definition: wallet.h:129
util::Result< SelectionResult > SelectCoinsSRD(const std::vector< OutputGroup > &utxo_pool, CAmount target_value, CAmount change_fee, FastRandomContext &rng, int max_selection_weight)
Select coins by Single Random Draw.
is a home for public enum and struct type definitions that are used internally by node code,...
OutputType
Definition: outputtype.h:17
CAmount GetDustThreshold(const CTxOut &txout, const CFeeRate &dustRelayFeeIn)
Definition: policy.cpp:26
int64_t GetVirtualTransactionSize(int64_t nWeight, int64_t nSigOpCost, unsigned int bytes_per_sigop)
Compute the virtual transaction size (weight reinterpreted as bytes).
Definition: policy.cpp:376
static constexpr unsigned int MIN_STANDARD_TX_NONWITNESS_SIZE
The minimum non-witness size for transactions we're willing to relay/mine: one larger than 64
Definition: policy.h:36
static constexpr int32_t MAX_STANDARD_TX_WEIGHT
The maximum weight for transactions we're willing to relay/mine.
Definition: policy.h:34
CAmount CalculateOutputValue(const TxType &tx)
Definition: transaction.h:286
static CTransactionRef MakeTransactionRef(Tx &&txIn)
Definition: transaction.h:424
std::shared_ptr< const CTransaction > CTransactionRef
Definition: transaction.h:423
std::unique_ptr< Descriptor > InferDescriptor(const CScript &script, const SigningProvider &provider)
Find a descriptor for the specified script, using information from provider where possible.
static const unsigned int LOCKTIME_THRESHOLD
Definition: script.h:47
size_t GetSerializeSize(const T &t)
Definition: serialize.h:1094
constexpr unsigned int GetSizeOfCompactSize(uint64_t nSize)
Compact Size size < 253 – 1 byte size <= USHRT_MAX – 3 bytes (253 + 2 bytes) size <= UINT_MAX – 5 byt...
Definition: serialize.h:288
TxoutType Solver(const CScript &scriptPubKey, std::vector< std::vector< unsigned char > > &vSolutionsRet)
Parse a scriptPubKey and identify script type for standard scripts.
Definition: solver.cpp:141
TxoutType
Definition: solver.h:22
@ WITNESS_V1_TAPROOT
@ WITNESS_V0_SCRIPTHASH
@ WITNESS_V0_KEYHASH
TRACEPOINT_SEMAPHORE(coin_selection, selected_coins)
A mutable version of CTransaction.
Definition: transaction.h:378
std::vector< CTxOut > vout
Definition: transaction.h:380
std::vector< CTxIn > vin
Definition: transaction.h:379
Interface for parsed descriptor objects.
Definition: descriptor.h:98
virtual std::optional< int64_t > MaxSatisfactionElems() const =0
Get the maximum size number of stack elements for satisfying this descriptor.
virtual std::optional< int64_t > MaxSatisfactionWeight(bool use_max_sig) const =0
Get the maximum size of a satisfaction for this descriptor, in weight units.
virtual std::optional< OutputType > GetOutputType() const =0
FeeReason reason
Definition: fees.h:95
Bilingual messages:
Definition: translation.h:24
bool empty() const
Definition: translation.h:35
A UTXO under consideration for use in funding a new transaction.
Definition: coinselection.h:28
COutPoint outpoint
The outpoint identifying this UTXO.
Definition: coinselection.h:38
void ApplyBumpFee(CAmount bump_fee)
CAmount nAmount
Definition: wallet.h:302
CTxDestination dest
Definition: wallet.h:301
Parameters for filtering which OutputGroups we may use in coin selection.
uint64_t max_count
Definition: spend.h:79
bool check_version_trucness
Definition: spend.h:86
bool include_immature_coinbase
Definition: spend.h:81
CAmount min_sum_amount
Definition: spend.h:77
Parameters for one iteration of Coin Selection.
uint32_t m_version
The version of the transaction we are trying to create.
FastRandomContext & rng_fast
Randomness to use in the context of coin selection.
CAmount m_min_change_target
Mininmum change to target in Knapsack solver and CoinGrinder: select coins to cover the payment and a...
bool m_subtract_fee_outputs
Indicate that we are subtracting the fee from outputs.
bool m_include_unsafe_inputs
When true, allow unsafe coins to be selected during Coin Selection.
CFeeRate m_effective_feerate
The targeted feerate of the transaction being built.
CAmount min_viable_change
Minimum amount for creating a change output.
CAmount m_cost_of_change
Cost of creating the change output + cost of spending the change output in the future.
CAmount m_change_fee
Cost of creating the change output.
int change_output_size
Size of a change output in bytes, determined by the output type.
int tx_noinputs_size
Size of the transaction before coin selection, consisting of the header and recipient output(s),...
std::optional< int > m_max_tx_weight
The maximum weight for this transaction.
bool m_avoid_partial_spends
When true, always spend all (up to OUTPUT_GROUP_MAX_ENTRIES) or none of the outputs associated with t...
COutputs available for spending, stored by OutputType.
Definition: spend.h:45
std::optional< CAmount > GetEffectiveTotalAmount()
Definition: spend.h:62
void Add(OutputType type, const COutput &out)
Definition: spend.cpp:240
size_t Size() const
The following methods are provided so that CoinsResult can mimic a vector, i.e., methods can work wit...
Definition: spend.cpp:194
std::map< OutputType, std::vector< COutput > > coins
Definition: spend.h:46
void Shuffle(FastRandomContext &rng_fast)
Definition: spend.cpp:233
CAmount GetTotalAmount()
Definition: spend.h:61
std::vector< OutputGroup > positive_group
std::vector< OutputGroup > mixed_group
A group of UTXOs paid to the same output script.
Stores several 'Groups' whose were mapped by output type.
std::map< OutputType, Groups > groups_by_type
std::set< std::shared_ptr< COutput > > coins
Definition: spend.h:158
void Insert(const COutput &output, bool subtract_fee_outputs)
Definition: spend.h:164
CAmount GetChange(const CAmount min_viable_change, const CAmount change_fee) const
Get the amount for the change output after paying needed fees.
CAmount GetSelectedValue() const
Get the sum of the input values.
CAmount GetTarget() const
void RecalculateWaste(const CAmount min_viable_change, const CAmount change_cost, const CAmount change_fee)
Calculates and stores the waste for this result given the cost of change and the opportunity cost of ...
SelectionAlgorithm GetAlgo() const
void AddInputs(const std::set< std::shared_ptr< COutput > > &inputs, bool subtract_fee_outputs)
std::vector< std::shared_ptr< COutput > > GetShuffledInputVector() const
Get the vector of COutputs that will be used to fill in a CTransaction's vin.
CAmount GetWaste() const
#define LOCK(cs)
Definition: sync.h:259
#define EXCLUSIVE_LOCKS_REQUIRED(...)
Definition: threadsafety.h:51
#define strprintf
Format arguments and return the string or write to given std::ostream (see tinyformat::format doc for...
Definition: tinyformat.h:1172
#define TRACEPOINT(context,...)
Definition: trace.h:49
consteval auto _(util::TranslatedLiteral str)
Definition: translation.h:79
bilingual_str Untranslated(std::string original)
Mark a bilingual_str as untranslated.
Definition: translation.h:82
static constexpr decltype(CTransaction::version) TRUC_VERSION
Definition: truc_policy.h:20
static constexpr int64_t TRUC_CHILD_MAX_WEIGHT
Definition: truc_policy.h:34
static constexpr uint32_t MAX_BIP125_RBF_SEQUENCE
Definition: rbf.h:12
int64_t GetTime()
DEPRECATED Use either ClockType::now() or Now<TimePointType>() if a cast is needed.
Definition: time.cpp:77
AssertLockHeld(pool.cs)
assert(!tx.IsCoinBase())
static void AvailableCoins(benchmark::Bench &bench, const std::vector< OutputType > &output_type)