Merge #16507: feefilter: Compute the absolute fee rather than stored rate

eb7b78165966f2c79da71b993c4c4d793e37297f modify p2p_feefilter test to catch rounding error (Gregory Sanders)
6a51f7951716d6d6fc0f9b56028f3a0dd02b61c8 Disallow implicit conversion for CFeeRate constructor (Gregory Sanders)
8e59af55aaf1b196575084bce2448af02d97d745 feefilter: Compute the absolute fee rather than stored rate to match mempool acceptance logic (Gregory Sanders)

Pull request description:

  This means we will use the rounding-down behavior in `GetFee` to match both mempool acceptance and wallet logic, with minimal changes.

  Fixes https://github.com/bitcoin/bitcoin/issues/16499

  Replacement PR for https://github.com/bitcoin/bitcoin/pull/16500

ACKs for top commit:
  ajtowns:
    ACK eb7b78165966f2c79da71b993c4c4d793e37297f code review only
  naumenkogs:
    utACK eb7b78165966f2c79da71b993c4c4d793e37297f
  achow101:
    re ACK eb7b78165966f2c79da71b993c4c4d793e37297f
  promag:
    ACK eb7b78165966f2c79da71b993c4c4d793e37297f.

Tree-SHA512: 484a11c8f0e825f0c983b1f7e71cf6252b1bba6858194abfe4c088da3bae8a418ec539ef6c4181bf30940e277a95c08d493595d59dfcc6ddf77c65b05563dd7e

1 files changed, 9 insertions, 8 deletions

diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index e345af604..9aa0294c2 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -3847,10 +3847,10 @@ bool PeerLogicValidation::SendMessages(CNode* pto)
                 if (fSendTrickle && pto->m_tx_relay->fSendMempool) {
                     auto vtxinfo = mempool.infoAll();
                     pto->m_tx_relay->fSendMempool = false;
-                    CAmount filterrate = 0;
+                    CFeeRate filterrate;
                     {
                         LOCK(pto->m_tx_relay->cs_feeFilter);
-                        filterrate = pto->m_tx_relay->minFeeFilter;
+                        filterrate = CFeeRate(pto->m_tx_relay->minFeeFilter);
                     }
 
                     LOCK(pto->m_tx_relay->cs_filter);
@@ -3859,9 +3859,9 @@ bool PeerLogicValidation::SendMessages(CNode* pto)
                         const uint256& hash = txinfo.tx->GetHash();
                         CInv inv(MSG_TX, hash);
                         pto->m_tx_relay->setInventoryTxToSend.erase(hash);
-                        if (filterrate) {
-                            if (txinfo.feeRate.GetFeePerK() < filterrate)
-                                continue;
+                        // Don't send transactions that peers will not put into their mempool
+                        if (txinfo.fee < filterrate.GetFee(txinfo.vsize)) {
+                            continue;
                         }
                         if (pto->m_tx_relay->pfilter) {
                             if (!pto->m_tx_relay->pfilter->IsRelevantAndUpdate(*txinfo.tx)) continue;
@@ -3884,10 +3884,10 @@ bool PeerLogicValidation::SendMessages(CNode* pto)
                     for (std::set<uint256>::iterator it = pto->m_tx_relay->setInventoryTxToSend.begin(); it != pto->m_tx_relay->setInventoryTxToSend.end(); it++) {
                         vInvTx.push_back(it);
                     }
-                    CAmount filterrate = 0;
+                    CFeeRate filterrate;
                     {
                         LOCK(pto->m_tx_relay->cs_feeFilter);
-                        filterrate = pto->m_tx_relay->minFeeFilter;
+                        filterrate = CFeeRate(pto->m_tx_relay->minFeeFilter);
                     }
                     // Topologically and fee-rate sort the inventory we send for privacy and priority reasons.
                     // A heap is used so that not all items need sorting if only a few are being sent.
@@ -3914,7 +3914,8 @@ bool PeerLogicValidation::SendMessages(CNode* pto)
                         if (!txinfo.tx) {
                             continue;
                         }
-                        if (filterrate && txinfo.feeRate.GetFeePerK() < filterrate) {
+                        // Peer told you to not send transactions at that feerate? Don't bother sending it.
+                        if (txinfo.fee < filterrate.GetFee(txinfo.vsize)) {
                             continue;
                         }
                         if (pto->m_tx_relay->pfilter && !pto->m_tx_relay->pfilter->IsRelevantAndUpdate(*txinfo.tx)) continue;