Merge pull request #187 from TheLindaProjectInc/govPaymentCheck

Ensure the winner cannot also be the staker

Changelog.md

@@ -1,6 +1,7 @@
 This document describes breaking changes between Metrix releases for both RPC APIs and for blockchain consensus.
 ## Consensus Parameters/Rules
 * 4.0.7.0 - Upgrade to protocol verion to 70018, soft fork when MIP1 active will disconnect node versions prior to this.
+* 4.0.8.2 - Upgrade to protocol verion to 70021.
 ## EVM Behavior
 
 ## RPC APIs

configure.ac

@@ -3,7 +3,7 @@ AC_PREREQ([2.60])
 define(_CLIENT_VERSION_MAJOR, 4)
 define(_CLIENT_VERSION_MINOR, 0)
 define(_CLIENT_VERSION_REVISION, 8)
-define(_CLIENT_VERSION_BUILD, 1)
+define(_CLIENT_VERSION_BUILD, 2)
 define(_CLIENT_VERSION_RC, 0)
 define(_CLIENT_VERSION_IS_RELEASE, true)
 define(_COPYRIGHT_YEAR, 2022)

doc/release-notes/release-notes-4.0.8.2.md

@@ -0,0 +1,15 @@
+# Metrix 4.0.8.2
+
+## Bugfix update
+
+Please report bugs using the issue tracker at github: https://github.com/thelindaproject/metrix/issues
+
+## How to Upgrade
+Shut down Metrix, wait until it has completely shut down (which might take a few minutes
+for older versions), then just copy over the appropriate metrixd file.
+
+# Core
+
+- Bugfix - Prevent staker from also receiving the gov reward, in very rare cases this causes consensus issues and unexpected forks.
+- Increment version 4.0.8.2
+- New protocol version 70021

src/miner.cpp

@@ -13,6 +13,7 @@
 #include <consensus/merkle.h>
 #include <consensus/tx_verify.h>
 #include <consensus/validation.h>
+#include <key_io.h>
 #include <policy/feerate.h>
 #include <policy/policy.h>
 #include <pow.h>
@@ -598,6 +599,39 @@ void BlockAssembler::AddToBlock(CTxMemPool::txiter iter)
     }
 }
 
+bool BlockAssembler::IsRewardToSelf(dev::Address addrWinner, CMutableTransaction* coinstakeTx)
+{
+    // Get the senderaddress from the output tx script
+    CTxDestination addressBit;
+    PKHash senderAddress;
+    txnouttype txType;
+    if(!ExtractDestination(coinstakeTx->vout[1].scriptPubKey, addressBit, &txType)) {
+        return error("%s: Could not extract sender pubkey from output", __func__);
+    }
+
+    std::string currentAddress = EncodeDestination(addressBit);
+
+    // Get convert the govWinner hex to a PK address
+    std::string hexAddress = HexStr(addrWinner.asBytes());
+    if (hexAddress.size() != 40)
+        return error("%s: Invalid pubkeyhash hex size (should be 40 hex characters)", __func__);
+    PKHash raw;
+    raw.SetReverseHex(hexAddress);
+    CTxDestination govWinner(raw);
+
+    std::string govWinnerStr = EncodeDestination(govWinner);
+
+    // If these match then the staker is choosing itsself as winning gov.
+    // In rare cases this causes bad consensus, and should just be avoided.
+    if (currentAddress == govWinnerStr) {
+        LogPrintf("IsRewardToSelf: Gov Winner : %s, Staker Address : %s, gov reward abandoned. The winner cannot be the staker.\n", govWinnerStr, currentAddress);
+        return true;
+    }
+
+    return false;
+}
+
+
 void BlockAssembler::AddCoinstakeContracts(CMutableTransaction* coinstakeTx)
 {
     uint64_t nGasLimit = DEFAULT_GAS_LIMIT_OP_SEND;
@@ -610,6 +644,10 @@ void BlockAssembler::AddCoinstakeContracts(CMutableTransaction* coinstakeTx)
     CAmount nGasPrice = qtumDGP.getMinGasPrice(nHeight);
     uint64_t nCollateral = qtumDGP.getGovernanceCollateral(nHeight);
     uint64_t nGovernorSubsidy = GetGovernorSubsidy(nHeight, nCollateral);
+
+    if(hasGovernorToReward) {
+        IsRewardToSelf(addrWinner, coinstakeTx) ? hasGovernorToReward = false : 0;
+    }
     //LogPrintf("Gov Winner : %s | hasGovernorToReward : %t | Subsidy : %d\n", 
     //    HexStr(addrWinner.asBytes()),
     //    hasGovernorToReward,

src/miner.h

@@ -306,6 +306,8 @@ class BlockAssembler
     /** Add coinstake contract transactions to the coinstake transaction 
      * of the block. */
     void AddCoinstakeContracts(CMutableTransaction* coinstakeTx);
+
+    bool IsRewardToSelf(dev::Address addrWinner, CMutableTransaction* coinstakeTx);
 };
 
 #ifdef ENABLE_WALLET

src/version.h

@@ -9,7 +9,7 @@
  * network protocol versioning
  */
 
-static const int PROTOCOL_VERSION = 70020;
+static const int PROTOCOL_VERSION = 70021;
 
 //! initial proto version, to be increased after version/verack negotiation
 static const int INIT_PROTO_VERSION = 209;