1 // Copyright (c) 2021-present The Bitcoin Core developers
2 // Distributed under the MIT software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4 5 #include <algorithm>
6 #include <common/args.h>
7 #include <common/messages.h>
8 #include <common/system.h>
9 #include <consensus/amount.h>
10 #include <consensus/validation.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>
16 #include <primitives/transaction.h>
17 #include <primitives/transaction_identifier.h>
18 #include <script/script.h>
19 #include <script/signingprovider.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 35 using common::StringForFeeReason;
36 using common::TransactionErrorString;
37 using interfaces::FoundBlock;
38 using node::TransactionError;
39 40 TRACEPOINT_SEMAPHORE(coin_selection, selected_coins);
41 TRACEPOINT_SEMAPHORE(coin_selection, normal_create_tx_internal);
42 TRACEPOINT_SEMAPHORE(coin_selection, attempting_aps_create_tx);
43 TRACEPOINT_SEMAPHORE(coin_selection, aps_create_tx_internal);
44 45 namespace wallet {
46 static constexpr size_t OUTPUT_GROUP_MAX_ENTRIES{100};
47 48 /** Whether the descriptor represents, directly or not, a witness program. */
49 static bool IsSegwit(const Descriptor& desc) {
50 if (const auto typ = desc.GetOutputType()) return *typ != OutputType::LEGACY;
51 return false;
52 }
53 54 /** Whether to assume ECDSA signatures' will be high-r. */
55 static 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 61 /** Get the size of an input (in witness units) once it's signed.
62 *
63 * @param desc The output script descriptor of the coin spent by this input.
64 * @param txin Optionally the txin to estimate the size of. Used to determine the size of ECDSA signatures.
65 * @param coin_control Information about the context to determine the size of ECDSA signatures.
66 * @param tx_is_segwit Whether the transaction has at least a single input spending a segwit coin.
67 * @param can_grind_r Whether the signer will be able to grind the R of the signature.
68 */
69 static 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 92 int 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, CTxIn{outpoint}, coin_control, true, can_grind_r)) {
98 return static_cast<int>(GetVirtualTransactionSize(*weight, 0, 0));
99 }
100 }
101 102 return -1;
103 }
104 105 int 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 }
110 111 /** Infer a descriptor for the given output script. */
112 static 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 }
124 125 /** Infer the maximum size of this input after it will be signed. */
126 static 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
144 TxSize 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 }
172 173 TxSize CalculateMaximumSignedTxSize(const CTransaction &tx, const CWallet *wallet, const CCoinControl* coin_control)
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 }
193 194 size_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 }
202 203 std::vector<COutput> CoinsResult::All() const
204 {
205 std::vector<COutput> all;
206 all.reserve(Size());
207 for (const auto& it : coins) {
208 all.insert(all.end(), it.second.begin(), it.second.end());
209 }
210 return all;
211 }
212 213 void CoinsResult::Erase(const std::unordered_set<COutPoint, SaltedOutpointHasher>& coins_to_remove)
214 {
215 for (auto& [type, vec] : coins) {
216 auto remove_it = std::remove_if(vec.begin(), vec.end(), [&](const COutput& coin) {
217 // remove it if it's on the set
218 if (!coins_to_remove.contains(coin.outpoint)) return false;
219 220 // update cached amounts
221 total_amount -= coin.txout.nValue;
222 if (coin.HasEffectiveValue() && total_effective_amount.has_value()) total_effective_amount = *total_effective_amount - coin.GetEffectiveValue();
223 return true;
224 });
225 vec.erase(remove_it, vec.end());
226 }
227 }
228 229 void CoinsResult::Shuffle(FastRandomContext& rng_fast)
230 {
231 for (auto& it : coins) {
232 std::shuffle(it.second.begin(), it.second.end(), rng_fast);
233 }
234 }
235 236 void CoinsResult::Add(OutputType type, const COutput& out)
237 {
238 coins[type].emplace_back(out);
239 total_amount += out.txout.nValue;
240 if (out.HasEffectiveValue()) {
241 total_effective_amount = total_effective_amount.has_value() ?
242 *total_effective_amount + out.GetEffectiveValue() : out.GetEffectiveValue();
243 }
244 }
245 246 static OutputType GetOutputType(TxoutType type, bool is_from_p2sh)
247 {
248 switch (type) {
249 case TxoutType::WITNESS_V1_TAPROOT:
250 return OutputType::BECH32M;
251 case TxoutType::WITNESS_V0_KEYHASH:
252 case TxoutType::WITNESS_V0_SCRIPTHASH:
253 if (is_from_p2sh) return OutputType::P2SH_SEGWIT;
254 else return OutputType::BECH32;
255 case TxoutType::SCRIPTHASH:
256 case TxoutType::PUBKEYHASH:
257 return OutputType::LEGACY;
258 default:
259 return OutputType::UNKNOWN;
260 }
261 }
262 263 // Fetch and validate the coin control selected inputs.
264 // Coins could be internal (from the wallet) or external.
265 util::Result<CoinsResult> FetchSelectedInputs(const CWallet& wallet, const CCoinControl& coin_control,
266 const CoinSelectionParams& coin_selection_params)
267 {
268 CoinsResult result;
269 const bool can_grind_r = wallet.CanGrindR();
270 std::map<COutPoint, CAmount> map_of_bump_fees = wallet.chain().calculateIndividualBumpFees(coin_control.ListSelected(), coin_selection_params.m_effective_feerate);
271 for (const COutPoint& outpoint : coin_control.ListSelected()) {
272 int64_t input_bytes = coin_control.GetInputWeight(outpoint).value_or(-1);
273 if (input_bytes != -1) {
274 input_bytes = GetVirtualTransactionSize(input_bytes, 0, 0);
275 }
276 CTxOut txout;
277 if (auto txo = wallet.GetTXO(outpoint)) {
278 txout = txo->GetTxOut();
279 if (input_bytes == -1) {
280 input_bytes = CalculateMaximumSignedInputSize(txout, &wallet, &coin_control);
281 }
282 const CWalletTx& parent_tx = txo->GetWalletTx();
283 if (wallet.GetTxDepthInMainChain(parent_tx) == 0) {
284 if (parent_tx.tx->version == TRUC_VERSION && coin_control.m_version != TRUC_VERSION) {
285 return util::Error{strprintf(_("Can't spend unconfirmed version 3 pre-selected input with a version %d tx"), coin_control.m_version)};
286 } else if (coin_control.m_version == TRUC_VERSION && parent_tx.tx->version != TRUC_VERSION) {
287 return util::Error{strprintf(_("Can't spend unconfirmed version %d pre-selected input with a version 3 tx"), parent_tx.tx->version)};
288 }
289 }
290 } else {
291 // The input is external. We did not find the tx in mapWallet.
292 const auto out{coin_control.GetExternalOutput(outpoint)};
293 if (!out) {
294 return util::Error{strprintf(_("Not found pre-selected input %s"), outpoint.ToString())};
295 }
296 297 txout = *out;
298 }
299 300 if (input_bytes == -1) {
301 input_bytes = CalculateMaximumSignedInputSize(txout, outpoint, &coin_control.m_external_provider, can_grind_r, &coin_control);
302 }
303 304 if (input_bytes == -1) {
305 return util::Error{strprintf(_("Not solvable pre-selected input %s"), outpoint.ToString())}; // Not solvable, can't estimate size for fee
306 }
307 308 /* 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. */
309 COutput output(outpoint, txout, /*depth=*/0, input_bytes, /*solvable=*/true, /*safe=*/true, /*time=*/0, /*from_me=*/false, coin_selection_params.m_effective_feerate);
310 output.ApplyBumpFee(map_of_bump_fees.at(output.outpoint));
311 result.Add(OutputType::UNKNOWN, output);
312 }
313 return result;
314 }
315 316 CoinsResult AvailableCoins(const CWallet& wallet,
317 const CCoinControl* coinControl,
318 std::optional<CFeeRate> feerate,
319 const CoinFilterParams& params)
320 {
321 AssertLockHeld(wallet.cs_wallet);
322 323 CoinsResult result;
324 // track unconfirmed truc outputs separately if we are tracking trucness
325 std::vector<std::pair<OutputType, COutput>> unconfirmed_truc_coins;
326 std::unordered_map<Txid, CAmount, SaltedTxidHasher> truc_txid_by_value;
327 // 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
328 // a coin control object is provided, and has the avoid address reuse flag set to false, do we allow already used addresses
329 bool allow_used_addresses = !wallet.IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE) || (coinControl && !coinControl->m_avoid_address_reuse);
330 const int min_depth = {coinControl ? coinControl->m_min_depth : DEFAULT_MIN_DEPTH};
331 const int max_depth = {coinControl ? coinControl->m_max_depth : DEFAULT_MAX_DEPTH};
332 const bool only_safe = {coinControl ? !coinControl->m_include_unsafe_inputs : true};
333 const bool can_grind_r = wallet.CanGrindR();
334 std::vector<COutPoint> outpoints;
335 336 std::set<Txid> trusted_parents;
337 // Cache for whether each tx passes the tx level checks (first bool), and whether the transaction is "safe" (second bool)
338 std::unordered_map<Txid, std::pair<bool, bool>, SaltedTxidHasher> tx_safe_cache;
339 for (const auto& [outpoint, txo] : wallet.GetTXOs()) {
340 const CWalletTx& wtx = txo.GetWalletTx();
341 const CTxOut& output = txo.GetTxOut();
342 343 if (tx_safe_cache.contains(outpoint.hash) && !tx_safe_cache.at(outpoint.hash).first) {
344 continue;
345 }
346 347 int nDepth = wallet.GetTxDepthInMainChain(wtx);
348 349 // Perform tx level checks if we haven't already come across outputs from this tx before.
350 if (!tx_safe_cache.contains(outpoint.hash)) {
351 tx_safe_cache[outpoint.hash] = {false, false};
352 353 if (wallet.IsTxImmatureCoinBase(wtx) && !params.include_immature_coinbase)
354 continue;
355 356 if (nDepth < 0)
357 continue;
358 359 // We should not consider coins which aren't at least in our mempool
360 // It's possible for these to be conflicted via ancestors which we may never be able to detect
361 if (nDepth == 0 && !wtx.InMempool())
362 continue;
363 364 bool safeTx = CachedTxIsTrusted(wallet, wtx, trusted_parents);
365 366 // We should not consider coins from transactions that are replacing
367 // other transactions.
368 //
369 // Example: There is a transaction A which is replaced by bumpfee
370 // transaction B. In this case, we want to prevent creation of
371 // a transaction B' which spends an output of B.
372 //
373 // Reason: If transaction A were initially confirmed, transactions B
374 // and B' would no longer be valid, so the user would have to create
375 // a new transaction C to replace B'. However, in the case of a
376 // one-block reorg, transactions B' and C might BOTH be accepted,
377 // when the user only wanted one of them. Specifically, there could
378 // be a 1-block reorg away from the chain where transactions A and C
379 // were accepted to another chain where B, B', and C were all
380 // accepted.
381 if (nDepth == 0 && wtx.m_replaces_txid) {
382 safeTx = false;
383 }
384 385 // Similarly, we should not consider coins from transactions that
386 // have been replaced. In the example above, we would want to prevent
387 // creation of a transaction A' spending an output of A, because if
388 // transaction B were initially confirmed, conflicting with A and
389 // A', we wouldn't want to the user to create a transaction D
390 // intending to replace A', but potentially resulting in a scenario
391 // where A, A', and D could all be accepted (instead of just B and
392 // D, or just A and A' like the user would want).
393 if (nDepth == 0 && wtx.m_replaced_by_txid) {
394 safeTx = false;
395 }
396 397 if (nDepth == 0 && params.check_version_trucness) {
398 if (coinControl->m_version == TRUC_VERSION) {
399 if (wtx.tx->version != TRUC_VERSION) continue;
400 // this unconfirmed v3 transaction already has a child
401 if (wtx.truc_child_in_mempool.has_value()) continue;
402 403 // this unconfirmed v3 transaction has a parent: spending would create a third generation
404 size_t ancestors, unused_cluster_count;
405 wallet.chain().getTransactionAncestry(wtx.tx->GetHash(), ancestors, unused_cluster_count);
406 if (ancestors > 1) continue;
407 } else {
408 if (wtx.tx->version == TRUC_VERSION) continue;
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) {
463 CScript script;
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 }
523 524 const CTxOut& FindNonChangeParentOutput(const CWallet& wallet, const COutPoint& outpoint)
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 }
543 544 std::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 }
567 568 FilteredOutputGroups GroupOutputs(const CWallet& wallet,
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, cluster_count;
582 wallet.chain().getTransactionAncestry(output.outpoint.hash, ancestors, cluster_count);
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, cluster_count);
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 cluster_count,
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, cluster_count);
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, cluster_count;
639 wallet.chain().getTransactionAncestry(output.outpoint.hash, ancestors, cluster_count);
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, cluster_count, spk_to_positive_groups_map);
645 }
646 647 // 'All' groups
648 insert_output(shared_output, type, ancestors, cluster_count, 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 }
685 686 FilteredOutputGroups GroupOutputs(const CWallet& wallet,
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
696 static bool HasErrorMsg(const util::Result<SelectionResult>& res) { return !util::ErrorString(res).empty(); }
697 698 util::Result<SelectionResult> AttemptSelection(interfaces::Chain& chain, const CAmount& nTargetValue, OutputGroupTypeMap& groups,
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 };
724 725 util::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 OutputSet 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 }
809 810 util::Result<SelectionResult> SelectCoins(const CWallet& wallet, CoinsResult& available_coins, const CoinsResult& pre_set_inputs,
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.GetAppropriateTotal(coin_selection_params.m_subtract_fee_outputs).value_or(0);
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 OutputSet preset_coin_set;
824 for (const auto& output: pre_set_inputs.All()) {
825 preset_coin_set.insert(std::make_shared<COutput>(output));
826 }
827 828 // Return if we can cover the target only with the preset inputs
829 if (selection_target <= 0) {
830 SelectionResult result(nTargetValue, SelectionAlgorithm::MANUAL);
831 result.AddInputs(preset_coin_set, coin_selection_params.m_subtract_fee_outputs);
832 result.RecalculateWaste(coin_selection_params.min_viable_change, coin_selection_params.m_cost_of_change, coin_selection_params.m_change_fee);
833 return result;
834 }
835 836 // Return early if we cannot cover the target with the wallet's UTXO.
837 // We use the total effective value if we are not subtracting fee from outputs and 'available_coins' contains the data.
838 CAmount available_coins_total_amount = available_coins.GetAppropriateTotal(coin_selection_params.m_subtract_fee_outputs).value_or(0);
839 if (selection_target > available_coins_total_amount) {
840 return util::Error(); // Insufficient funds
841 }
842 843 // Start wallet Coin Selection procedure
844 auto op_selection_result = AutomaticCoinSelection(wallet, available_coins, selection_target, coin_selection_params);
845 if (!op_selection_result) return op_selection_result;
846 847 // If needed, add preset inputs to the automatic coin selection result
848 if (!pre_set_inputs.coins.empty()) {
849 auto preset_total = pre_set_inputs.GetAppropriateTotal(coin_selection_params.m_subtract_fee_outputs);
850 assert(preset_total.has_value());
851 SelectionResult preselected(preset_total.value(), SelectionAlgorithm::MANUAL);
852 preselected.AddInputs(preset_coin_set, coin_selection_params.m_subtract_fee_outputs);
853 op_selection_result->Merge(preselected);
854 op_selection_result->RecalculateWaste(coin_selection_params.min_viable_change,
855 coin_selection_params.m_cost_of_change,
856 coin_selection_params.m_change_fee);
857 858 // Verify we haven't exceeded the maximum allowed weight
859 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);
860 if (op_selection_result->GetWeight() > max_inputs_weight) {
861 return util::Error{_("The combination of the pre-selected inputs and the wallet automatic inputs selection exceeds the transaction maximum weight. "
862 "Please try sending a smaller amount or manually consolidating your wallet's UTXOs")};
863 }
864 }
865 return op_selection_result;
866 }
867 868 util::Result<SelectionResult> AutomaticCoinSelection(const CWallet& wallet, CoinsResult& available_coins, const CAmount& value_to_select, const CoinSelectionParams& coin_selection_params)
869 {
870 // Try to enforce a mixture of cluster limits and ancestor/descendant limits on transactions we create by limiting
871 // the ancestors and the maximum cluster count of any UTXO we use. We use the ancestor/descendant limits, which are
872 // lower than the cluster limits, to avoid exceeding any ancestor/descendant limits of legacy nodes. This filter is safe
873 // because a transaction's ancestor or descendant count cannot be larger than its cluster count.
874 // TODO: these limits can be relaxed in the future, and we can replace the ancestor filter with a cluster equivalent.
875 unsigned int limit_ancestor_count = 0;
876 unsigned int limit_descendant_count = 0;
877 wallet.chain().getPackageLimits(limit_ancestor_count, limit_descendant_count);
878 const size_t max_ancestors = (size_t)std::max<int64_t>(1, limit_ancestor_count);
879 const size_t max_cluster_count = (size_t)std::max<int64_t>(1, limit_descendant_count);
880 const bool fRejectLongChains = gArgs.GetBoolArg("-walletrejectlongchains", DEFAULT_WALLET_REJECT_LONG_CHAINS);
881 882 // Cases where we have 101+ outputs all pointing to the same destination may result in
883 // privacy leaks as they will potentially be deterministically sorted. We solve that by
884 // explicitly shuffling the outputs before processing
885 if (coin_selection_params.m_avoid_partial_spends && available_coins.Size() > OUTPUT_GROUP_MAX_ENTRIES) {
886 available_coins.Shuffle(coin_selection_params.rng_fast);
887 }
888 889 // Coin Selection attempts to select inputs from a pool of eligible UTXOs to fund the
890 // transaction at a target feerate. If an attempt fails, more attempts may be made using a more
891 // permissive CoinEligibilityFilter.
892 {
893 // Place coins eligibility filters on a scope increasing order.
894 std::vector<SelectionFilter> ordered_filters{
895 // If possible, fund the transaction with confirmed UTXOs only. Prefer at least six
896 // confirmations on outputs received from other wallets and only spend confirmed change.
897 {CoinEligibilityFilter(1, 6, 0), /*allow_mixed_output_types=*/false},
898 {CoinEligibilityFilter(1, 1, 0)},
899 };
900 // Fall back to using zero confirmation change (but with as few ancestors in the mempool as
901 // possible) if we cannot fund the transaction otherwise.
902 if (wallet.m_spend_zero_conf_change) {
903 ordered_filters.push_back({CoinEligibilityFilter(0, 1, 2)});
904 ordered_filters.push_back({CoinEligibilityFilter(0, 1, std::min(size_t{4}, max_ancestors/3), std::min(size_t{4}, max_cluster_count/3))});
905 ordered_filters.push_back({CoinEligibilityFilter(0, 1, max_ancestors/2, max_cluster_count/2)});
906 // If partial groups are allowed, relax the requirement of spending OutputGroups (groups
907 // of UTXOs sent to the same address, which are obviously controlled by a single wallet)
908 // in their entirety.
909 ordered_filters.push_back({CoinEligibilityFilter(0, 1, max_ancestors-1, max_cluster_count-1, /*include_partial=*/true)});
910 // Try with unsafe inputs if they are allowed. This may spend unconfirmed outputs
911 // received from other wallets.
912 if (coin_selection_params.m_include_unsafe_inputs) {
913 ordered_filters.push_back({CoinEligibilityFilter(/*conf_mine=*/0, /*conf_theirs=*/0, max_ancestors-1, max_cluster_count-1, /*include_partial=*/true)});
914 }
915 // Try with unlimited ancestors/clusters. The transaction will still need to meet
916 // local mempool policy (i.e. cluster limits) to be accepted to mempool and broadcasted, and
917 // limits of other nodes (e.g. ancestor/descendant limits) to propagate, but OutputGroups
918 // use heuristics that may overestimate.
919 if (!fRejectLongChains) {
920 ordered_filters.push_back({CoinEligibilityFilter(0, 1, std::numeric_limits<uint64_t>::max(),
921 std::numeric_limits<uint64_t>::max(),
922 /*include_partial=*/true)});
923 }
924 }
925 926 // Group outputs and map them by coin eligibility filter
927 std::vector<OutputGroup> discarded_groups;
928 FilteredOutputGroups filtered_groups = GroupOutputs(wallet, available_coins, coin_selection_params, ordered_filters, discarded_groups);
929 930 // Check if we still have enough balance after applying filters (some coins might be discarded)
931 CAmount total_discarded = 0;
932 CAmount total_unconf_long_chain = 0;
933 for (const auto& group : discarded_groups) {
934 total_discarded += group.GetSelectionAmount();
935 if (group.m_ancestors >= max_ancestors || group.m_max_cluster_count >= max_cluster_count) total_unconf_long_chain += group.GetSelectionAmount();
936 }
937 938 if (CAmount total_amount = available_coins.GetTotalAmount() - total_discarded; total_amount < value_to_select) {
939 // Special case, too-long-mempool cluster.
940 if (total_amount + total_unconf_long_chain > value_to_select) {
941 return util::Error{_("Unconfirmed UTXOs are available, but spending them creates a chain of transactions that will be rejected by the mempool")};
942 }
943 return util::Error{}; // General "Insufficient Funds"
944 }
945 946 // Walk-through the filters until the solution gets found.
947 // If no solution is found, return the first detailed error (if any).
948 // future: add "error level" so the worst one can be picked instead.
949 std::vector<util::Result<SelectionResult>> res_detailed_errors;
950 CoinSelectionParams updated_selection_params = coin_selection_params;
951 for (const auto& select_filter : ordered_filters) {
952 auto it = filtered_groups.find(select_filter.filter);
953 if (it == filtered_groups.end()) continue;
954 if (updated_selection_params.m_version == TRUC_VERSION && (select_filter.filter.conf_mine == 0 || select_filter.filter.conf_theirs == 0)) {
955 if (updated_selection_params.m_max_tx_weight > (TRUC_CHILD_MAX_WEIGHT)) {
956 updated_selection_params.m_max_tx_weight = TRUC_CHILD_MAX_WEIGHT;
957 }
958 }
959 if (auto res{AttemptSelection(wallet.chain(), value_to_select, it->second,
960 updated_selection_params, select_filter.allow_mixed_output_types)}) {
961 return res; // result found
962 } else {
963 // If any specific error message appears here, then something particularly wrong might have happened.
964 // Save the error and continue the selection process. So if no solutions gets found, we can return
965 // the detailed error to the upper layers.
966 if (HasErrorMsg(res)) res_detailed_errors.emplace_back(std::move(res));
967 }
968 }
969 970 // Return right away if we have a detailed error
971 if (!res_detailed_errors.empty()) return std::move(res_detailed_errors.front());
972 973 974 // General "Insufficient Funds"
975 return util::Error{};
976 }
977 }
978 979 static bool IsCurrentForAntiFeeSniping(interfaces::Chain& chain, const uint256& block_hash)
980 {
981 if (chain.isInitialBlockDownload()) {
982 return false;
983 }
984 constexpr int64_t MAX_ANTI_FEE_SNIPING_TIP_AGE = 8 * 60 * 60; // in seconds
985 int64_t block_time;
986 CHECK_NONFATAL(chain.findBlock(block_hash, FoundBlock().time(block_time)));
987 if (block_time < (GetTime() - MAX_ANTI_FEE_SNIPING_TIP_AGE)) {
988 return false;
989 }
990 return true;
991 }
992 993 void DiscourageFeeSniping(CMutableTransaction& tx, FastRandomContext& rng_fast,
994 interfaces::Chain& chain, const uint256& block_hash, int block_height)
995 {
996 // All inputs must be added by now
997 assert(!tx.vin.empty());
998 // Discourage fee sniping.
999 //
1000 // For a large miner the value of the transactions in the best block and
1001 // the mempool can exceed the cost of deliberately attempting to mine two
1002 // blocks to orphan the current best block. By setting nLockTime such that
1003 // only the next block can include the transaction, we discourage this
1004 // practice as the height restricted and limited blocksize gives miners
1005 // considering fee sniping fewer options for pulling off this attack.
1006 //
1007 // A simple way to think about this is from the wallet's point of view we
1008 // always want the blockchain to move forward. By setting nLockTime this
1009 // way we're basically making the statement that we only want this
1010 // transaction to appear in the next block; we don't want to potentially
1011 // encourage reorgs by allowing transactions to appear at lower heights
1012 // than the next block in forks of the best chain.
1013 //
1014 // Of course, the subsidy is high enough, and transaction volume low
1015 // enough, that fee sniping isn't a problem yet, but by implementing a fix
1016 // now we ensure code won't be written that makes assumptions about
1017 // nLockTime that preclude a fix later.
1018 if (IsCurrentForAntiFeeSniping(chain, block_hash)) {
1019 tx.nLockTime = block_height;
1020 1021 // Secondly occasionally randomly pick a nLockTime even further back, so
1022 // that transactions that are delayed after signing for whatever reason,
1023 // e.g. high-latency mix networks and some CoinJoin implementations, have
1024 // better privacy.
1025 if (rng_fast.randrange(10) == 0) {
1026 tx.nLockTime = std::max(0, int(tx.nLockTime) - int(rng_fast.randrange(100)));
1027 }
1028 } else {
1029 // If our chain is lagging behind, we can't discourage fee sniping nor help
1030 // the privacy of high-latency transactions. To avoid leaking a potentially
1031 // unique "nLockTime fingerprint", set nLockTime to a constant.
1032 tx.nLockTime = 0;
1033 }
1034 // Sanity check all values
1035 assert(tx.nLockTime < LOCKTIME_THRESHOLD); // Type must be block height
1036 assert(tx.nLockTime <= uint64_t(block_height));
1037 for (const auto& in : tx.vin) {
1038 // Can not be FINAL for locktime to work
1039 assert(in.nSequence != CTxIn::SEQUENCE_FINAL);
1040 // May be MAX NONFINAL to disable both BIP68 and BIP125
1041 if (in.nSequence == CTxIn::MAX_SEQUENCE_NONFINAL) continue;
1042 // May be MAX BIP125 to disable BIP68 and enable BIP125
1043 if (in.nSequence == MAX_BIP125_RBF_SEQUENCE) continue;
1044 // The wallet does not support any other sequence-use right now.
1045 assert(false);
1046 }
1047 }
1048 1049 uint64_t GetSerializeSizeForRecipient(const CRecipient& recipient)
1050 {
1051 return ::GetSerializeSize(CTxOut(recipient.nAmount, GetScriptForDestination(recipient.dest)));
1052 }
1053 1054 bool IsDust(const CRecipient& recipient, const CFeeRate& dustRelayFee)
1055 {
1056 return ::IsDust(CTxOut(recipient.nAmount, GetScriptForDestination(recipient.dest)), dustRelayFee);
1057 }
1058 1059 static util::Result<CreatedTransactionResult> CreateTransactionInternal(
1060 CWallet& wallet,
1061 const std::vector<CRecipient>& vecSend,
1062 std::optional<unsigned int> change_pos,
1063 const CCoinControl& coin_control,
1064 bool sign) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet)
1065 {
1066 AssertLockHeld(wallet.cs_wallet);
1067 1068 FastRandomContext rng_fast;
1069 CMutableTransaction txNew; // The resulting transaction that we make
1070 1071 txNew.version = coin_control.m_version;
1072 1073 CoinSelectionParams coin_selection_params{rng_fast}; // Parameters for coin selection, init with dummy
1074 coin_selection_params.m_avoid_partial_spends = coin_control.m_avoid_partial_spends;
1075 coin_selection_params.m_include_unsafe_inputs = coin_control.m_include_unsafe_inputs;
1076 coin_selection_params.m_max_tx_weight = coin_control.m_max_tx_weight.value_or(MAX_STANDARD_TX_WEIGHT);
1077 coin_selection_params.m_version = coin_control.m_version;
1078 int minimum_tx_weight = MIN_STANDARD_TX_NONWITNESS_SIZE * WITNESS_SCALE_FACTOR;
1079 if (coin_selection_params.m_max_tx_weight.value() < minimum_tx_weight || coin_selection_params.m_max_tx_weight.value() > MAX_STANDARD_TX_WEIGHT) {
1080 return util::Error{strprintf(_("Maximum transaction weight must be between %d and %d"), minimum_tx_weight, MAX_STANDARD_TX_WEIGHT)};
1081 }
1082 // Set the long term feerate estimate to the wallet's consolidate feerate
1083 coin_selection_params.m_long_term_feerate = wallet.m_consolidate_feerate;
1084 // Static vsize overhead + outputs vsize. 4 nVersion, 4 nLocktime, 1 input count, 1 witness overhead (dummy, flag, stack size)
1085 coin_selection_params.tx_noinputs_size = 10 + GetSizeOfCompactSize(vecSend.size()); // bytes for output count
1086 1087 CAmount recipients_sum = 0;
1088 const OutputType change_type = wallet.TransactionChangeType(coin_control.m_change_type ? *coin_control.m_change_type : wallet.m_default_change_type, vecSend);
1089 ReserveDestination reservedest(&wallet, change_type);
1090 unsigned int outputs_to_subtract_fee_from = 0; // The number of outputs which we are subtracting the fee from
1091 for (const auto& recipient : vecSend) {
1092 if (IsDust(recipient, wallet.chain().relayDustFee())) {
1093 return util::Error{_("Transaction amount too small")};
1094 }
1095 1096 // Include the fee cost for outputs.
1097 coin_selection_params.tx_noinputs_size += GetSerializeSizeForRecipient(recipient);
1098 recipients_sum += recipient.nAmount;
1099 1100 if (recipient.fSubtractFeeFromAmount) {
1101 outputs_to_subtract_fee_from++;
1102 coin_selection_params.m_subtract_fee_outputs = true;
1103 }
1104 }
1105 1106 // Create change script that will be used if we need change
1107 CScript scriptChange;
1108 bilingual_str error; // possible error str
1109 1110 // coin control: send change to custom address
1111 if (!std::get_if<CNoDestination>(&coin_control.destChange)) {
1112 scriptChange = GetScriptForDestination(coin_control.destChange);
1113 } else { // no coin control: send change to newly generated address
1114 // Note: We use a new key here to keep it from being obvious which side is the change.
1115 // The drawback is that by not reusing a previous key, the change may be lost if a
1116 // backup is restored, if the backup doesn't have the new private key for the change.
1117 // If we reused the old key, it would be possible to add code to look for and
1118 // rediscover unknown transactions that were written with keys of ours to recover
1119 // post-backup change.
1120 1121 // Reserve a new key pair from key pool. If it fails, provide a dummy
1122 // destination in case we don't need change.
1123 CTxDestination dest;
1124 auto op_dest = reservedest.GetReservedDestination(true);
1125 if (!op_dest) {
1126 error = _("Transaction needs a change address, but we can't generate it.") + Untranslated(" ") + util::ErrorString(op_dest);
1127 } else {
1128 dest = *op_dest;
1129 scriptChange = GetScriptForDestination(dest);
1130 }
1131 // A valid destination implies a change script (and
1132 // vice-versa). An empty change script will abort later, if the
1133 // change keypool ran out, but change is required.
1134 CHECK_NONFATAL(IsValidDestination(dest) != scriptChange.empty());
1135 }
1136 CTxOut change_prototype_txout(0, scriptChange);
1137 coin_selection_params.change_output_size = GetSerializeSize(change_prototype_txout);
1138 1139 // Get size of spending the change output
1140 int change_spend_size = CalculateMaximumSignedInputSize(change_prototype_txout, &wallet, /*coin_control=*/nullptr);
1141 // If the wallet doesn't know how to sign change output, assume p2sh-p2wpkh
1142 // as lower-bound to allow BnB to do its thing
1143 if (change_spend_size == -1) {
1144 coin_selection_params.change_spend_size = DUMMY_NESTED_P2WPKH_INPUT_SIZE;
1145 } else {
1146 coin_selection_params.change_spend_size = change_spend_size;
1147 }
1148 1149 // Set discard feerate
1150 coin_selection_params.m_discard_feerate = GetDiscardRate(wallet);
1151 1152 // Get the fee rate to use effective values in coin selection
1153 FeeCalculation feeCalc;
1154 coin_selection_params.m_effective_feerate = GetMinimumFeeRate(wallet, coin_control, &feeCalc);
1155 // Do not, ever, assume that it's fine to change the fee rate if the user has explicitly
1156 // provided one
1157 if (coin_control.m_feerate && coin_selection_params.m_effective_feerate > *coin_control.m_feerate) {
1158 const auto feerate_format = FeeRateFormat::SAT_VB;
1159 auto msg{strprintf(_("Fee rate (%s) is lower than the minimum fee rate setting (%s)."),
1160 coin_control.m_feerate->ToString(feerate_format),
1161 coin_selection_params.m_effective_feerate.ToString(feerate_format))};
1162 if (feeCalc.reason == FeeReason::REQUIRED) {
1163 msg += strprintf(_("\nConsider modifying %s (%s) or %s (%s)."),
1164 "-mintxfee",
1165 wallet.m_min_fee.ToString(feerate_format),
1166 "-minrelaytxfee",
1167 wallet.chain().relayMinFee().ToString(feerate_format));
1168 }
1169 return util::Error{msg};
1170 }
1171 if (feeCalc.reason == FeeReason::FALLBACK && !wallet.m_allow_fallback_fee) {
1172 // eventually allow a fallback fee
1173 return util::Error{strprintf(_("Fee estimation failed. Fallbackfee is disabled. Wait a few blocks or enable %s."), "-fallbackfee")};
1174 }
1175 1176 // Calculate the cost of change
1177 // Cost of change is the cost of creating the change output + cost of spending the change output in the future.
1178 // For creating the change output now, we use the effective feerate.
1179 // For spending the change output in the future, we use the discard feerate for now.
1180 // So cost of change = (change output size * effective feerate) + (size of spending change output * discard feerate)
1181 coin_selection_params.m_change_fee = coin_selection_params.m_effective_feerate.GetFee(coin_selection_params.change_output_size);
1182 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;
1183 1184 coin_selection_params.m_min_change_target = GenerateChangeTarget(std::floor(recipients_sum / vecSend.size()), coin_selection_params.m_change_fee, rng_fast);
1185 1186 // The smallest change amount should be:
1187 // 1. at least equal to dust threshold
1188 // 2. at least 1 sat greater than fees to spend it at m_discard_feerate
1189 const auto dust = GetDustThreshold(change_prototype_txout, coin_selection_params.m_discard_feerate);
1190 const auto change_spend_fee = coin_selection_params.m_discard_feerate.GetFee(coin_selection_params.change_spend_size);
1191 coin_selection_params.min_viable_change = std::max(change_spend_fee + 1, dust);
1192 1193 // Include the fees for things that aren't inputs, excluding the change output
1194 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);
1195 CAmount selection_target = recipients_sum + not_input_fees;
1196 1197 // This can only happen if feerate is 0, and requested destinations are value of 0 (e.g. OP_RETURN)
1198 // and no pre-selected inputs. This will result in 0-input transaction, which is consensus-invalid anyways
1199 if (selection_target == 0 && !coin_control.HasSelected()) {
1200 return util::Error{_("Transaction requires one destination of non-zero value, a non-zero feerate, or a pre-selected input")};
1201 }
1202 1203 // Fetch manually selected coins
1204 CoinsResult preset_inputs;
1205 if (coin_control.HasSelected()) {
1206 auto res_fetch_inputs = FetchSelectedInputs(wallet, coin_control, coin_selection_params);
1207 if (!res_fetch_inputs) return util::Error{util::ErrorString(res_fetch_inputs)};
1208 preset_inputs = *res_fetch_inputs;
1209 }
1210 1211 // Fetch wallet available coins if "other inputs" are
1212 // allowed (coins automatically selected by the wallet)
1213 CoinsResult available_coins;
1214 if (coin_control.m_allow_other_inputs) {
1215 available_coins = AvailableCoins(wallet, &coin_control, coin_selection_params.m_effective_feerate);
1216 }
1217 1218 // Choose coins to use
1219 auto select_coins_res = SelectCoins(wallet, available_coins, preset_inputs, /*nTargetValue=*/selection_target, coin_control, coin_selection_params);
1220 if (!select_coins_res) {
1221 // 'SelectCoins' either returns a specific error message or, if empty, means a general "Insufficient funds".
1222 const bilingual_str& err = util::ErrorString(select_coins_res);
1223 if (!err.empty()) return util::Error{err};
1224 1225 // Check if we have enough balance but cannot cover the fees
1226 CAmount available_balance = preset_inputs.GetTotalAmount() + available_coins.GetTotalAmount();
1227 // Note: if SelectCoins() fails when SFFO is enabled (recipients_sum = selection_target with SFFO),
1228 // then recipients_sum > available_balance and we wouldn't enter into the if condition below.
1229 if (available_balance >= recipients_sum) {
1230 // If we have coins with balance, they should have effective values since we constructed them with valid feerate.
1231 assert(!preset_inputs.Size() || preset_inputs.GetEffectiveTotalAmount().has_value());
1232 assert(!available_coins.Size() || available_coins.GetEffectiveTotalAmount().has_value());
1233 CAmount available_effective_balance = preset_inputs.GetEffectiveTotalAmount().value_or(0) + available_coins.GetEffectiveTotalAmount().value_or(0);
1234 if (available_effective_balance < selection_target) {
1235 Assume(!coin_selection_params.m_subtract_fee_outputs);
1236 return util::Error{strprintf(_("The total exceeds your balance when the %s transaction fee is included."), FormatMoney(selection_target - recipients_sum))};
1237 }
1238 }
1239 1240 // General failure description
1241 return util::Error{_("Insufficient funds")};
1242 }
1243 const SelectionResult& result = *select_coins_res;
1244 TRACEPOINT(coin_selection, selected_coins,
1245 wallet.GetName().c_str(),
1246 GetAlgorithmName(result.GetAlgo()).c_str(),
1247 result.GetTarget(),
1248 result.GetWaste(),
1249 result.GetSelectedValue());
1250 1251 // vouts to the payees
1252 txNew.vout.reserve(vecSend.size() + 1); // + 1 because of possible later insert
1253 for (const auto& recipient : vecSend)
1254 {
1255 txNew.vout.emplace_back(recipient.nAmount, GetScriptForDestination(recipient.dest));
1256 }
1257 const CAmount change_amount = result.GetChange(coin_selection_params.min_viable_change, coin_selection_params.m_change_fee);
1258 if (change_amount > 0) {
1259 CTxOut newTxOut(change_amount, scriptChange);
1260 if (!change_pos) {
1261 // Insert change txn at random position:
1262 change_pos = rng_fast.randrange(txNew.vout.size() + 1);
1263 } else if ((unsigned int)*change_pos > txNew.vout.size()) {
1264 return util::Error{_("Transaction change output index out of range")};
1265 }
1266 txNew.vout.insert(txNew.vout.begin() + *change_pos, newTxOut);
1267 } else {
1268 change_pos = std::nullopt;
1269 }
1270 1271 // Shuffle selected coins and fill in final vin
1272 std::vector<std::shared_ptr<COutput>> selected_coins = result.GetShuffledInputVector();
1273 1274 if (coin_control.HasSelected() && coin_control.HasSelectedOrder()) {
1275 // When there are preselected inputs, we need to move them to be the first UTXOs
1276 // and have them be in the order selected. We can use stable_sort for this, where we
1277 // compare with the positions stored in coin_control. The COutputs that have positions
1278 // will be placed before those that don't, and those positions will be in order.
1279 std::stable_sort(selected_coins.begin(), selected_coins.end(),
1280 [&coin_control](const std::shared_ptr<COutput>& a, const std::shared_ptr<COutput>& b) {
1281 auto a_pos = coin_control.GetSelectionPos(a->outpoint);
1282 auto b_pos = coin_control.GetSelectionPos(b->outpoint);
1283 if (a_pos.has_value() && b_pos.has_value()) {
1284 return a_pos.value() < b_pos.value();
1285 } else if (a_pos.has_value() && !b_pos.has_value()) {
1286 return true;
1287 } else {
1288 return false;
1289 }
1290 });
1291 }
1292 1293 // The sequence number is set to non-maxint so that DiscourageFeeSniping
1294 // works.
1295 //
1296 // BIP125 defines opt-in RBF as any nSequence < maxint-1, so
1297 // we use the highest possible value in that range (maxint-2)
1298 // to avoid conflicting with other possible uses of nSequence,
1299 // and in the spirit of "smallest possible change from prior
1300 // behavior."
1301 bool use_anti_fee_sniping = true;
1302 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};
1303 txNew.vin.reserve(selected_coins.size());
1304 for (const auto& coin : selected_coins) {
1305 std::optional<uint32_t> sequence = coin_control.GetSequence(coin->outpoint);
1306 if (sequence) {
1307 // If an input has a preset sequence, we can't do anti-fee-sniping
1308 use_anti_fee_sniping = false;
1309 }
1310 txNew.vin.emplace_back(coin->outpoint, CScript{}, sequence.value_or(default_sequence));
1311 1312 auto scripts = coin_control.GetScripts(coin->outpoint);
1313 if (scripts.first) {
1314 txNew.vin.back().scriptSig = *scripts.first;
1315 }
1316 if (scripts.second) {
1317 txNew.vin.back().scriptWitness = *scripts.second;
1318 }
1319 }
1320 if (coin_control.m_locktime) {
1321 txNew.nLockTime = coin_control.m_locktime.value();
1322 // If we have a locktime set, we can't use anti-fee-sniping
1323 use_anti_fee_sniping = false;
1324 }
1325 if (use_anti_fee_sniping) {
1326 DiscourageFeeSniping(txNew, rng_fast, wallet.chain(), wallet.GetLastBlockHash(), wallet.GetLastBlockHeight());
1327 }
1328 1329 // Calculate the transaction fee
1330 TxSize tx_sizes = CalculateMaximumSignedTxSize(CTransaction(txNew), &wallet, &coin_control);
1331 int nBytes = tx_sizes.vsize;
1332 if (nBytes == -1) {
1333 return util::Error{_("Missing solving data for estimating transaction size")};
1334 }
1335 CAmount fee_needed = coin_selection_params.m_effective_feerate.GetFee(nBytes) + result.GetTotalBumpFees();
1336 const CAmount output_value = CalculateOutputValue(txNew);
1337 Assume(recipients_sum + change_amount == output_value);
1338 CAmount current_fee = result.GetSelectedValue() - output_value;
1339 1340 // Sanity check that the fee cannot be negative as that means we have more output value than input value
1341 if (current_fee < 0) {
1342 return util::Error{Untranslated(STR_INTERNAL_BUG("Fee paid < 0"))};
1343 }
1344 1345 // If there is a change output and we overpay the fees then increase the change to match the fee needed
1346 if (change_pos && fee_needed < current_fee) {
1347 auto& change = txNew.vout.at(*change_pos);
1348 change.nValue += current_fee - fee_needed;
1349 current_fee = result.GetSelectedValue() - CalculateOutputValue(txNew);
1350 if (fee_needed != current_fee) {
1351 return util::Error{Untranslated(STR_INTERNAL_BUG("Change adjustment: Fee needed != fee paid"))};
1352 }
1353 }
1354 1355 // Reduce output values for subtractFeeFromAmount
1356 if (coin_selection_params.m_subtract_fee_outputs) {
1357 CAmount to_reduce = fee_needed - current_fee;
1358 unsigned int i = 0;
1359 bool fFirst = true;
1360 for (const auto& recipient : vecSend)
1361 {
1362 if (change_pos && i == *change_pos) {
1363 ++i;
1364 }
1365 CTxOut& txout = txNew.vout[i];
1366 1367 if (recipient.fSubtractFeeFromAmount)
1368 {
1369 txout.nValue -= to_reduce / outputs_to_subtract_fee_from; // Subtract fee equally from each selected recipient
1370 1371 if (fFirst) // first receiver pays the remainder not divisible by output count
1372 {
1373 fFirst = false;
1374 txout.nValue -= to_reduce % outputs_to_subtract_fee_from;
1375 }
1376 1377 // Error if this output is reduced to be below dust
1378 if (IsDust(txout, wallet.chain().relayDustFee())) {
1379 if (txout.nValue < 0) {
1380 return util::Error{_("The transaction amount is too small to pay the fee")};
1381 } else {
1382 return util::Error{_("The transaction amount is too small to send after the fee has been deducted")};
1383 }
1384 }
1385 }
1386 ++i;
1387 }
1388 current_fee = result.GetSelectedValue() - CalculateOutputValue(txNew);
1389 if (fee_needed != current_fee) {
1390 return util::Error{Untranslated(STR_INTERNAL_BUG("SFFO: Fee needed != fee paid"))};
1391 }
1392 }
1393 1394 // fee_needed should now always be less than or equal to the current fees that we pay.
1395 // If it is not, it is a bug.
1396 if (fee_needed > current_fee) {
1397 return util::Error{Untranslated(STR_INTERNAL_BUG("Fee needed > fee paid"))};
1398 }
1399 1400 // Give up if change keypool ran out and change is required
1401 if (scriptChange.empty() && change_pos) {
1402 return util::Error{error};
1403 }
1404 1405 if (sign && !wallet.SignTransaction(txNew)) {
1406 return util::Error{_("Signing transaction failed")};
1407 }
1408 1409 // Return the constructed transaction data.
1410 CTransactionRef tx = MakeTransactionRef(std::move(txNew));
1411 1412 // Limit size
1413 if ((sign && GetTransactionWeight(*tx) > MAX_STANDARD_TX_WEIGHT) ||
1414 (!sign && tx_sizes.weight > MAX_STANDARD_TX_WEIGHT))
1415 {
1416 return util::Error{_("Transaction too large")};
1417 }
1418 1419 if (current_fee > wallet.m_default_max_tx_fee) {
1420 return util::Error{TransactionErrorString(TransactionError::MAX_FEE_EXCEEDED)};
1421 }
1422 1423 if (gArgs.GetBoolArg("-walletrejectlongchains", DEFAULT_WALLET_REJECT_LONG_CHAINS)) {
1424 // Lastly, ensure this tx will pass the mempool's chain limits
1425 auto result = wallet.chain().checkChainLimits(tx);
1426 if (!result) {
1427 return util::Error{util::ErrorString(result)};
1428 }
1429 }
1430 1431 // Before we return success, we assume any change key will be used to prevent
1432 // accidental reuse.
1433 reservedest.KeepDestination();
1434 1435 wallet.WalletLogPrintf("Coin Selection: Algorithm:%s, Waste Metric Score:%d\n", GetAlgorithmName(result.GetAlgo()), result.GetWaste());
1436 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",
1437 current_fee, nBytes, feeCalc.returnedTarget, feeCalc.desiredTarget, StringForFeeReason(feeCalc.reason), feeCalc.est.decay,
1438 feeCalc.est.pass.start, feeCalc.est.pass.end,
1439 (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,
1440 feeCalc.est.pass.withinTarget, feeCalc.est.pass.totalConfirmed, feeCalc.est.pass.inMempool, feeCalc.est.pass.leftMempool,
1441 feeCalc.est.fail.start, feeCalc.est.fail.end,
1442 (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,
1443 feeCalc.est.fail.withinTarget, feeCalc.est.fail.totalConfirmed, feeCalc.est.fail.inMempool, feeCalc.est.fail.leftMempool);
1444 return CreatedTransactionResult(tx, current_fee, change_pos, feeCalc);
1445 }
1446 1447 util::Result<CreatedTransactionResult> CreateTransaction(
1448 CWallet& wallet,
1449 const std::vector<CRecipient>& vecSend,
1450 std::optional<unsigned int> change_pos,
1451 const CCoinControl& coin_control,
1452 bool sign)
1453 {
1454 if (vecSend.empty()) {
1455 return util::Error{_("Transaction must have at least one recipient")};
1456 }
1457 1458 if (std::any_of(vecSend.cbegin(), vecSend.cend(), [](const auto& recipient){ return recipient.nAmount < 0; })) {
1459 return util::Error{_("Transaction amounts must not be negative")};
1460 }
1461 1462 LOCK(wallet.cs_wallet);
1463 1464 auto res = CreateTransactionInternal(wallet, vecSend, change_pos, coin_control, sign);
1465 TRACEPOINT(coin_selection, normal_create_tx_internal,
1466 wallet.GetName().c_str(),
1467 bool(res),
1468 res ? res->fee : 0,
1469 res && res->change_pos.has_value() ? int32_t(*res->change_pos) : -1);
1470 if (!res) return res;
1471 const auto& txr_ungrouped = *res;
1472 // try with avoidpartialspends unless it's enabled already
1473 if (txr_ungrouped.fee > 0 /* 0 means non-functional fee rate estimation */ && wallet.m_max_aps_fee > -1 && !coin_control.m_avoid_partial_spends) {
1474 TRACEPOINT(coin_selection, attempting_aps_create_tx, wallet.GetName().c_str());
1475 CCoinControl tmp_cc = coin_control;
1476 tmp_cc.m_avoid_partial_spends = true;
1477 1478 // Reuse the change destination from the first creation attempt to avoid skipping BIP44 indexes
1479 if (txr_ungrouped.change_pos) {
1480 ExtractDestination(txr_ungrouped.tx->vout[*txr_ungrouped.change_pos].scriptPubKey, tmp_cc.destChange);
1481 }
1482 1483 auto txr_grouped = CreateTransactionInternal(wallet, vecSend, change_pos, tmp_cc, sign);
1484 // if fee of this alternative one is within the range of the max fee, we use this one
1485 const bool use_aps{txr_grouped.has_value() ? (txr_grouped->fee <= txr_ungrouped.fee + wallet.m_max_aps_fee) : false};
1486 TRACEPOINT(coin_selection, aps_create_tx_internal,
1487 wallet.GetName().c_str(),
1488 use_aps,
1489 txr_grouped.has_value(),
1490 txr_grouped.has_value() ? txr_grouped->fee : 0,
1491 txr_grouped.has_value() && txr_grouped->change_pos.has_value() ? int32_t(*txr_grouped->change_pos) : -1);
1492 if (txr_grouped) {
1493 wallet.WalletLogPrintf("Fee non-grouped = %lld, grouped = %lld, using %s\n",
1494 txr_ungrouped.fee, txr_grouped->fee, use_aps ? "grouped" : "non-grouped");
1495 if (use_aps) return txr_grouped;
1496 }
1497 }
1498 return res;
1499 }
1500 1501 util::Result<CreatedTransactionResult> FundTransaction(CWallet& wallet, const CMutableTransaction& tx, const std::vector<CRecipient>& vecSend, std::optional<unsigned int> change_pos, bool lockUnspents, CCoinControl coinControl)
1502 {
1503 // We want to make sure tx.vout is not used now that we are passing outputs as a vector of recipients.
1504 // This sets us up to remove tx completely in a future PR in favor of passing the inputs directly.
1505 assert(tx.vout.empty());
1506 1507 // Set the user desired locktime
1508 coinControl.m_locktime = tx.nLockTime;
1509 1510 // Set the user desired version
1511 coinControl.m_version = tx.version;
1512 1513 // Acquire the locks to prevent races to the new locked unspents between the
1514 // CreateTransaction call and LockCoin calls (when lockUnspents is true).
1515 LOCK(wallet.cs_wallet);
1516 1517 // Fetch specified UTXOs from the UTXO set to get the scriptPubKeys and values of the outputs being selected
1518 // and to match with the given solving_data. Only used for non-wallet outputs.
1519 std::map<COutPoint, Coin> coins;
1520 for (const CTxIn& txin : tx.vin) {
1521 coins[txin.prevout]; // Create empty map entry keyed by prevout.
1522 }
1523 wallet.chain().findCoins(coins);
1524 1525 for (const CTxIn& txin : tx.vin) {
1526 const auto& outPoint = txin.prevout;
1527 PreselectedInput& preset_txin = coinControl.Select(outPoint);
1528 if (!wallet.IsMine(outPoint)) {
1529 if (coins[outPoint].out.IsNull()) {
1530 return util::Error{_("Unable to find UTXO for external input")};
1531 }
1532 1533 // The input was not in the wallet, but is in the UTXO set, so select as external
1534 preset_txin.SetTxOut(coins[outPoint].out);
1535 }
1536 preset_txin.SetSequence(txin.nSequence);
1537 preset_txin.SetScriptSig(txin.scriptSig);
1538 preset_txin.SetScriptWitness(txin.scriptWitness);
1539 }
1540 1541 auto res = CreateTransaction(wallet, vecSend, change_pos, coinControl, false);
1542 if (!res) {
1543 return res;
1544 }
1545 1546 if (lockUnspents) {
1547 for (const CTxIn& txin : res->tx->vin) {
1548 wallet.LockCoin(txin.prevout, /*persist=*/false);
1549 }
1550 }
1551 1552 return res;
1553 }
1554 } // namespace wallet
1555