Implement "feefilter" P2P message.

The "feefilter" p2p message is used to inform other nodes of your mempool min fee which is the feerate that any new transaction must meet to be accepted to your mempool.  This will allow them to filter invs to you according to this feerate.

1 files changed, 60 insertions, 13 deletions

diff --git a/src/main.cpp b/src/main.cpp
index fc443cfb72..36189f4ffc 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -17,10 +17,12 @@
 #include "init.h"
 #include "merkleblock.h"
 #include "net.h"
+#include "policy/fees.h"
 #include "policy/policy.h"
 #include "pow.h"
 #include "primitives/block.h"
 #include "primitives/transaction.h"
+#include "random.h"
 #include "script/script.h"
 #include "script/sigcache.h"
 #include "script/standard.h"
@@ -81,6 +83,7 @@ CFeeRate minRelayTxFee = CFeeRate(DEFAULT_MIN_RELAY_TX_FEE);
 CAmount maxTxFee = DEFAULT_TRANSACTION_MAXFEE;
 
 CTxMemPool mempool(::minRelayTxFee);
+FeeFilterRounder filterRounder(::minRelayTxFee);
 
 struct COrphanTx {
     CTransaction tx;
@@ -987,7 +990,7 @@ std::string FormatStateMessage(const CValidationState &state)
 }
 
 bool AcceptToMemoryPoolWorker(CTxMemPool& pool, CValidationState& state, const CTransaction& tx, bool fLimitFree,
-                              bool* pfMissingInputs, bool fOverrideMempoolLimit, const CAmount nAbsurdFee,
+                              bool* pfMissingInputs, CFeeRate* txFeeRate, bool fOverrideMempoolLimit, const CAmount& nAbsurdFee,
                               std::vector<uint256>& vHashTxnToUncache)
 {
     const uint256 hash = tx.GetHash();
@@ -1144,6 +1147,9 @@ bool AcceptToMemoryPoolWorker(CTxMemPool& pool, CValidationState& state, const C
 
         CTxMemPoolEntry entry(tx, nFees, GetTime(), dPriority, chainActive.Height(), pool.HasNoInputsOf(tx), inChainInputValue, fSpendsCoinbase, nSigOps, lp);
         unsigned int nSize = entry.GetTxSize();
+        if (txFeeRate) {
+            *txFeeRate = CFeeRate(nFees, nSize);
+        }
 
         // Check that the transaction doesn't have an excessive number of
         // sigops, making it impossible to mine. Since the coinbase transaction
@@ -1392,10 +1398,10 @@ bool AcceptToMemoryPoolWorker(CTxMemPool& pool, CValidationState& state, const C
 }
 
 bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransaction &tx, bool fLimitFree,
-                        bool* pfMissingInputs, bool fOverrideMempoolLimit, const CAmount nAbsurdFee)
+                        bool* pfMissingInputs, CFeeRate* txFeeRate, bool fOverrideMempoolLimit, const CAmount nAbsurdFee)
 {
     std::vector<uint256> vHashTxToUncache;
-    bool res = AcceptToMemoryPoolWorker(pool, state, tx, fLimitFree, pfMissingInputs, fOverrideMempoolLimit, nAbsurdFee, vHashTxToUncache);
+    bool res = AcceptToMemoryPoolWorker(pool, state, tx, fLimitFree, pfMissingInputs, txFeeRate, fOverrideMempoolLimit, nAbsurdFee, vHashTxToUncache);
     if (!res) {
         BOOST_FOREACH(const uint256& hashTx, vHashTxToUncache)
             pcoinsTip->Uncache(hashTx);
@@ -2620,7 +2626,7 @@ bool static DisconnectTip(CValidationState& state, const Consensus::Params& cons
         // ignore validation errors in resurrected transactions
         list<CTransaction> removed;
         CValidationState stateDummy;
-        if (tx.IsCoinBase() || !AcceptToMemoryPool(mempool, stateDummy, tx, false, NULL, true)) {
+        if (tx.IsCoinBase() || !AcceptToMemoryPool(mempool, stateDummy, tx, false, NULL, NULL, true)) {
             mempool.removeRecursive(tx, removed);
         } else if (mempool.exists(tx.GetHash())) {
             vHashUpdate.push_back(tx.GetHash());
@@ -4916,10 +4922,10 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
         pfrom->setAskFor.erase(inv.hash);
         mapAlreadyAskedFor.erase(inv);
 
-        if (!AlreadyHave(inv) && AcceptToMemoryPool(mempool, state, tx, true, &fMissingInputs))
-        {
+        CFeeRate txFeeRate = CFeeRate(0);
+        if (!AlreadyHave(inv) && AcceptToMemoryPool(mempool, state, tx, true, &fMissingInputs, &txFeeRate)) {
             mempool.check(pcoinsTip);
-            RelayTransaction(tx);
+            RelayTransaction(tx, txFeeRate);
             vWorkQueue.push_back(inv.hash);
 
             LogPrint("mempool", "AcceptToMemoryPool: peer=%d: accepted %s (poolsz %u txn, %u kB)\n",
@@ -4950,10 +4956,10 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
 
                     if (setMisbehaving.count(fromPeer))
                         continue;
-                    if (AcceptToMemoryPool(mempool, stateDummy, orphanTx, true, &fMissingInputs2))
-                    {
+                    CFeeRate orphanFeeRate = CFeeRate(0);
+                    if (AcceptToMemoryPool(mempool, stateDummy, orphanTx, true, &fMissingInputs2, &orphanFeeRate)) {
                         LogPrint("mempool", "   accepted orphan tx %s\n", orphanHash.ToString());
-                        RelayTransaction(orphanTx);
+                        RelayTransaction(orphanTx, orphanFeeRate);
                         vWorkQueue.push_back(orphanHash);
                         vEraseQueue.push_back(orphanHash);
                     }
@@ -5006,7 +5012,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
                 int nDoS = 0;
                 if (!state.IsInvalid(nDoS) || nDoS == 0) {
                     LogPrintf("Force relaying tx %s from whitelisted peer=%d\n", tx.GetHash().ToString(), pfrom->id);
-                    RelayTransaction(tx);
+                    RelayTransaction(tx, txFeeRate);
                 } else {
                     LogPrintf("Not relaying invalid transaction %s from whitelisted peer=%d (%s)\n", tx.GetHash().ToString(), pfrom->id, FormatStateMessage(state));
                 }
@@ -5200,6 +5206,13 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
                 if (!fInMemPool) continue; // another thread removed since queryHashes, maybe...
                 if (!pfrom->pfilter->IsRelevantAndUpdate(tx)) continue;
             }
+            if (pfrom->minFeeFilter) {
+                CFeeRate feeRate;
+                mempool.lookupFeeRate(hash, feeRate);
+                LOCK(pfrom->cs_feeFilter);
+                if (feeRate.GetFeePerK() < pfrom->minFeeFilter)
+                    continue;
+            }
             vInv.push_back(inv);
             if (vInv.size() == MAX_INV_SZ) {
                 pfrom->PushMessage(NetMsgType::INV, vInv);
@@ -5362,8 +5375,19 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
         }
     }
 
-    else
-    {
+    else if (strCommand == NetMsgType::FEEFILTER) {
+        CAmount newFeeFilter = 0;
+        vRecv >> newFeeFilter;
+        if (MoneyRange(newFeeFilter)) {
+            {
+                LOCK(pfrom->cs_feeFilter);
+                pfrom->minFeeFilter = newFeeFilter;
+            }
+            LogPrint("net", "received: feefilter of %s from peer=%d\n", CFeeRate(newFeeFilter).ToString(), pfrom->id);
+        }
+    }
+
+    else {
         // Ignore unknown commands for extensibility
         LogPrint("net", "Unknown command \"%s\" from peer=%d\n", SanitizeString(strCommand), pfrom->id);
     }
@@ -5845,6 +5869,29 @@ bool SendMessages(CNode* pto)
         if (!vGetData.empty())
             pto->PushMessage(NetMsgType::GETDATA, vGetData);
 
+        //
+        // Message: feefilter
+        //
+        // We don't want white listed peers to filter txs to us if we have -whitelistforcerelay
+        if (pto->nVersion >= FEEFILTER_VERSION && GetBoolArg("-feefilter", DEFAULT_FEEFILTER) &&
+            !(pto->fWhitelisted && GetBoolArg("-whitelistforcerelay", DEFAULT_WHITELISTFORCERELAY))) {
+            CAmount currentFilter = mempool.GetMinFee(GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000).GetFeePerK();
+            int64_t timeNow = GetTimeMicros();
+            if (timeNow > pto->nextSendTimeFeeFilter) {
+                CAmount filterToSend = filterRounder.round(currentFilter);
+                if (filterToSend != pto->lastSentFeeFilter) {
+                    pto->PushMessage(NetMsgType::FEEFILTER, filterToSend);
+                    pto->lastSentFeeFilter = filterToSend;
+                }
+                pto->nextSendTimeFeeFilter = PoissonNextSend(timeNow, AVG_FEEFILTER_BROADCAST_INTERVAL);
+            }
+            // If the fee filter has changed substantially and it's still more than MAX_FEEFILTER_CHANGE_DELAY
+            // until scheduled broadcast, then move the broadcast to within MAX_FEEFILTER_CHANGE_DELAY.
+            else if (timeNow + MAX_FEEFILTER_CHANGE_DELAY * 1000000 < pto->nextSendTimeFeeFilter &&
+                     (currentFilter < 3 * pto->lastSentFeeFilter / 4 || currentFilter > 4 * pto->lastSentFeeFilter / 3)) {
+                pto->nextSendTimeFeeFilter = timeNow + (insecure_rand() % MAX_FEEFILTER_CHANGE_DELAY) * 1000000;
+            }
+        }
     }
     return true;
 }