[Consensus] Stricter checks for coinbase for v10+

PIVX-Project · May 3, 2021 · c14870b · c14870b
1 parent e8c35ee
commit c14870b
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Showing 3 changed files with 47 additions and 9 deletions.
diff --git a/src/masternode-payments.cpp b/src/masternode-payments.cpp
@@ -211,7 +211,7 @@ void DumpMasternodePayments()
     LogPrint(BCLog::MASTERNODE,"Budget dump finished  %dms\n", GetTimeMillis() - nStart);
 }
 
-bool IsBlockValueValid(int nHeight, CAmount& nExpectedValue, CAmount nMinted)
+bool IsBlockValueValid(int nHeight, CAmount& nExpectedValue, CAmount nMinted, CAmount& nBudgetAmt)
 {
     if (!masternodeSync.IsSynced()) {
         //there is no budget data to use to check anything
@@ -227,9 +227,8 @@ bool IsBlockValueValid(int nHeight, CAmount& nExpectedValue, CAmount nMinted)
         // if the superblock spork is enabled
         if (sporkManager.IsSporkActive(SPORK_13_ENABLE_SUPERBLOCKS)) {
             // add current payee amount to the expected block value
-            CAmount expectedPayAmount;
-            if (g_budgetman.GetExpectedPayeeAmount(nHeight, expectedPayAmount)) {
-                nExpectedValue += expectedPayAmount;
+            if (g_budgetman.GetExpectedPayeeAmount(nHeight, nBudgetAmt)) {
+                nExpectedValue += nBudgetAmt;
             }
         }
     }
@@ -726,3 +725,30 @@ std::string CMasternodePayments::ToString() const
 
     return info.str();
 }
+
+bool IsCoinbaseValueValid(const CTransactionRef& tx, CAmount nBudgetAmt)
+{
+    assert(tx->IsCoinBase());
+    if (masternodeSync.IsSynced()) {
+        const CAmount nCBaseOutAmt = tx->GetValueOut();
+        if (nBudgetAmt > 0) {
+            // Superblock
+            if (nCBaseOutAmt != nBudgetAmt) {
+                return error("%s: invalid coinbase payment for budget (%s vs expected=%s)",
+                             __func__, FormatMoney(nCBaseOutAmt), FormatMoney(nBudgetAmt));
+            }
+            return true;
+        } else {
+            // regular block
+            CAmount nMnAmt = GetMasternodePayment();
+            // if enforcement is disabled, there could be no masternode payment
+            bool sporkEnforced = sporkManager.IsSporkActive(SPORK_8_MASTERNODE_PAYMENT_ENFORCEMENT);
+            if ((sporkEnforced && nCBaseOutAmt != nMnAmt) || (!sporkEnforced && nCBaseOutAmt > nMnAmt)) {
+                return error("%s: invalid coinbase payment for masternode (%s vs expected=%s)",
+                             __func__, FormatMoney(nCBaseOutAmt), FormatMoney(nMnAmt));
+            }
+            return true;
+        }
+    }
+    return true;
+}
diff --git a/src/masternode-payments.h b/src/masternode-payments.h
@@ -26,9 +26,15 @@ extern CMasternodePayments masternodePayments;
 void ProcessMessageMasternodePayments(CNode* pfrom, std::string& strCommand, CDataStream& vRecv);
 bool IsBlockPayeeValid(const CBlock& block, int nBlockHeight);
 std::string GetRequiredPaymentsString(int nBlockHeight);
-bool IsBlockValueValid(int nHeight, CAmount& nExpectedValue, CAmount nMinted);
+bool IsBlockValueValid(int nHeight, CAmount& nExpectedValue, CAmount nMinted, CAmount& nBudgetAmt);
 void FillBlockPayee(CMutableTransaction& txCoinbase, CMutableTransaction& txCoinstake, const int nHeight, bool fProofOfStake);
 
+/**
+ * Check coinbase output value for blocks v10+.
+ * It must pay the masternode for regular blocks and a proposal during superblocks.
+ */
+bool IsCoinbaseValueValid(const CTransactionRef& tx, CAmount nBudgetAmt);
+
 void DumpMasternodePayments();
 
 /** Save Masternode Payment Data (mnpayments.dat)

diff --git a/src/validation.cpp b/src/validation.cpp
@@ -1740,10 +1740,16 @@ static bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockInd
         nExpectedMint += nFees;
 
     //Check that the block does not overmint
-    if (!IsBlockValueValid(pindex->nHeight, nExpectedMint, nMint)) {
-        return state.DoS(100, error("ConnectBlock() : reward pays too much (actual=%s vs limit=%s)",
-                                    FormatMoney(nMint), FormatMoney(nExpectedMint)),
-                         REJECT_INVALID, "bad-cb-amount");
+    CAmount nBudgetAmt = 0;     // If this is a superblock, amount to be paid to the winning proposal, otherwise 0
+    if (!IsBlockValueValid(pindex->nHeight, nExpectedMint, nMint, nBudgetAmt)) {
+        return state.DoS(100, error("%s: reward pays too much (actual=%s vs limit=%s)",
+                                    __func__, FormatMoney(nMint), FormatMoney(nExpectedMint)),
+                         REJECT_INVALID, "bad-blk-amount");
+    }
+
+    // For blocks v10+: Check that the coinbase pays the exact amount
+    if (isPoSActive && pindex->nVersion >= 10 && !IsCoinbaseValueValid(block.vtx[0], nBudgetAmt)) {
+        return state.DoS(100, false, REJECT_INVALID, "bad-cb-amount");
     }
 
     if (!control.Wait())