diff --git a/src/wallet/feebumper.cpp b/src/wallet/feebumper.cpp index ce76f4e512..b87231293f 100644 --- a/src/wallet/feebumper.cpp +++ b/src/wallet/feebumper.cpp @@ -57,6 +57,58 @@ static feebumper::Result PreconditionChecks(interfaces::Chain::Lock& locked_chai return feebumper::Result::OK; } +//! Check if the user provided a valid feeRate +static feebumper::Result CheckFeeRate(const CWallet* wallet, const CWalletTx& wtx, const CFeeRate& newFeerate, const int64_t maxTxSize, std::vector& errors) { + // check that fee rate is higher than mempool's minimum fee + // (no point in bumping fee if we know that the new tx won't be accepted to the mempool) + // This may occur if the user set FeeRate, TotalFee or paytxfee too low, if fallbackfee is too low, or, perhaps, + // in a rare situation where the mempool minimum fee increased significantly since the fee estimation just a + // moment earlier. In this case, we report an error to the user, who may adjust the fee. + CFeeRate minMempoolFeeRate = wallet->chain().mempoolMinFee(); + + if (newFeerate.GetFeePerK() < minMempoolFeeRate.GetFeePerK()) { + errors.push_back(strprintf( + "New fee rate (%s) is lower than the minimum fee rate (%s) to get into the mempool -- ", + FormatMoney(newFeerate.GetFeePerK()), + FormatMoney(minMempoolFeeRate.GetFeePerK()))); + return feebumper::Result::WALLET_ERROR; + } + + CAmount new_total_fee = newFeerate.GetFee(maxTxSize); + + CFeeRate incrementalRelayFee = std::max(wallet->chain().relayIncrementalFee(), CFeeRate(WALLET_INCREMENTAL_RELAY_FEE)); + + // Given old total fee and transaction size, calculate the old feeRate + CAmount old_fee = wtx.GetDebit(ISMINE_SPENDABLE) - wtx.tx->GetValueOut(); + const int64_t txSize = GetVirtualTransactionSize(*(wtx.tx)); + CFeeRate nOldFeeRate(old_fee, txSize); + // Min total fee is old fee + relay fee + CAmount minTotalFee = nOldFeeRate.GetFee(maxTxSize) + incrementalRelayFee.GetFee(maxTxSize); + + if (new_total_fee < minTotalFee) { + errors.push_back(strprintf("Insufficient total fee %s, must be at least %s (oldFee %s + incrementalFee %s)", + FormatMoney(new_total_fee), FormatMoney(minTotalFee), FormatMoney(nOldFeeRate.GetFee(maxTxSize)), FormatMoney(incrementalRelayFee.GetFee(maxTxSize)))); + return feebumper::Result::INVALID_PARAMETER; + } + + CAmount requiredFee = GetRequiredFee(*wallet, maxTxSize); + if (new_total_fee < requiredFee) { + errors.push_back(strprintf("Insufficient total fee (cannot be less than required fee %s)", + FormatMoney(requiredFee))); + return feebumper::Result::INVALID_PARAMETER; + } + + // Check that in all cases the new fee doesn't violate maxTxFee + const CAmount max_tx_fee = wallet->m_default_max_tx_fee; + if (new_total_fee > max_tx_fee) { + errors.push_back(strprintf("Specified or calculated fee %s is too high (cannot be higher than -maxtxfee %s)", + FormatMoney(new_total_fee), FormatMoney(max_tx_fee))); + return feebumper::Result::WALLET_ERROR; + } + + return feebumper::Result::OK; +} + static CFeeRate EstimateFeeRate(CWallet* wallet, const CWalletTx& wtx, CCoinControl& coin_control, CAmount& old_fee) { // Get the fee rate of the original transaction. This is calculated from @@ -260,6 +312,12 @@ Result CreateRateBumpTransaction(CWallet* wallet, const uint256& txid, const CCo if (coin_control.m_feerate) { // The user provided a feeRate argument. + // We calculate this here to avoid compiler warning on the cs_wallet lock + const int64_t maxTxSize = CalculateMaximumSignedTxSize(*wtx.tx, wallet); + Result res = CheckFeeRate(wallet, wtx, *(new_coin_control.m_feerate), maxTxSize, errors); + if (res != Result::OK) { + return res; + } } else { // The user did not provide a feeRate argument new_coin_control.m_feerate = EstimateFeeRate(wallet, wtx, new_coin_control, old_fee);