contract: Standardize contract validation and add block context

src/alert.cpp

@@ -200,13 +200,42 @@ bool CAlert::ProcessAlert(bool fThread)
                 nMaxVer == maxInt &&
                 setSubVer.empty() &&
                 nPriority == maxInt &&
-                strStatusBar == "URGENT: Alert key compromised, upgrade required"
+                strStatusBar == "URGENT: Alert key compromised, upgrade required" &&
+                strComment == "" &&
+                strReserved == "" &&
+                nVersion == 1
                 ))
             return false;
     }
 
     {
         LOCK(cs_mapAlerts);
+
+        // Check if this alert has been cancelled
+        for (const auto& alert_pair : mapAlerts)
+        {
+            const CAlert& alert = alert_pair.second;
+            if (alert.Cancels(*this))
+            {
+                LogPrint("alert", "alert already cancelled by %d\n", alert.nID);
+                return false;
+            }
+            if (
+                alert.nExpiration == maxInt &&
+                alert.nCancel == (maxInt-1) &&
+                alert.nMinVer == 0 &&
+                alert.nMaxVer == maxInt &&
+                alert.setSubVer.empty() &&
+                alert.nPriority == maxInt &&
+                alert.strStatusBar == "URGENT: Alert key compromised, upgrade required" &&
+                alert.strComment == "" &&
+                alert.strReserved == "" &&
+                alert.nVersion == 1
+                ) { // If we have a final alert, do not continue
+                return false;
+            }
+        }
+
         // Cancel previous alerts
         for (map<uint256, CAlert>::iterator mi = mapAlerts.begin(); mi != mapAlerts.end();)
         {
@@ -227,15 +256,9 @@ bool CAlert::ProcessAlert(bool fThread)
                 mi++;
         }
 
-        // Check if this alert has been cancelled
-        for (auto const& item : mapAlerts)
-        {
-            const CAlert& alert = item.second;
-            if (alert.Cancels(*this))
-            {
-                LogPrint(BCLog::LogFlags::ALERT, "alert already cancelled by %d", alert.nID);
-                return false;
-            }
+        // Do not allow more than 5 concurrent alerts
+        if (mapAlerts.size() >= 5) {
+            return false;
         }
 
         // Add to mapAlerts

src/main.cpp

@@ -1328,13 +1328,11 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CTransaction &tx, bool* pfMissingInput
     if (!fTestNet && !IsStandardTx(tx))
         return error("AcceptToMemoryPool : nonstandard transaction type");
 
-    // Verify beacon contract in tx if found
-    for (const auto& contract : tx.GetContracts()) {
-        if (contract.m_type == NN::ContractType::BEACON
-            && !NN::GetBeaconRegistry().Validate(contract, tx))
-        {
-            return tx.DoS(25, error("%s: bad beacon contract in tx %s", __func__, tx.GetHash().ToString()));
-        }
+    // Perform contextual validation for any contracts:
+    if (!tx.GetContracts().empty() && !NN::ValidateContracts(tx)) {
+        return tx.DoS(25, error("%s: invalid contract in tx %s",
+            __func__,
+            tx.GetHash().ToString()));
     }
 
     // is it already in the memory pool?
@@ -2231,7 +2229,7 @@ bool CBlock::DisconnectBlock(CTxDB& txdb, CBlockIndex* pindex)
 
         if (pindex->nIsContract == 1)
         {
-            NN::RevertContracts(vtx[i]);
+            NN::RevertContracts(vtx[i], pindex);
         }
     }
 
@@ -2732,7 +2730,7 @@ bool GridcoinConnectBlock(
     }
 
     bool found_contract;
-    NN::ApplyContracts(block, found_contract);
+    NN::ApplyContracts(block, pindex, found_contract);
 
     pindex->SetMiningId(claim.m_mining_id);
     pindex->nResearchSubsidy = claim.m_research_subsidy;
@@ -3612,15 +3610,12 @@ bool CBlock::AcceptBlock(bool generated_by_me)
         if (!IsFinalTx(tx, nHeight, GetBlockTime()))
             return DoS(10, error("AcceptBlock() : contains a non-final transaction"));
 
-        // Verify beacon contract if a transaction contains a beacon contract
-        // Current bad contracts in chain would cause a fork on sync, skip them
         if (nVersion >= 9) {
-            for (const auto& contract : tx.GetContracts()) {
-                if (contract.m_type == NN::ContractType::BEACON
-                    && !NN::GetBeaconRegistry().Validate(contract, tx))
-                {
-                    return tx.DoS(25, error("%s: bad beacon contract in tx %s", __func__, tx.GetHash().ToString()));
-                }
+            // Perform contextual validation for any contracts:
+            if (!tx.GetContracts().empty() && !NN::ValidateContracts(tx)) {
+                return tx.DoS(25, error("%s: invalid contract in tx %s",
+                    __func__,
+                    tx.GetHash().ToString()));
             }
         }
     }

src/miner.cpp

@@ -273,6 +273,17 @@ bool CreateRestOfTheBlock(CBlock &block, CBlockIndex* pindexPrev)
             if (tx.IsCoinBase() || tx.IsCoinStake() || !IsFinalTx(tx, nHeight))
                 continue;
 
+            // Double-check that contracts pass contextual validation again so
+            // that we don't include a transaction that disrupts validation of
+            // the block:
+            //
+            if (!tx.GetContracts().empty() && !NN::ValidateContracts(tx)) {
+                LogPrint(BCLog::LogFlags::MINER,
+                    "%s: contract failed contextual validation. Skipped tx %s",
+                    __func__,
+                    tx.GetHash().ToString());
+            }
+
             COrphan* porphan = NULL;
             double dPriority = 0;
             int64_t nTotalIn = 0;

src/neuralnet/beacon.cpp

@@ -319,15 +319,14 @@ bool BeaconRegistry::ContainsActive(const Cpid& cpid) const
     return ContainsActive(cpid, GetAdjustedTime());
 }
 
-void BeaconRegistry::Add(Contract contract, const CTransaction& tx)
+void BeaconRegistry::Add(const ContractContext& ctx)
 {
-    BeaconPayload payload = contract.CopyPayloadAs<BeaconPayload>();
-
-    payload.m_beacon.m_timestamp = tx.nTime;
+    BeaconPayload payload = ctx->CopyPayloadAs<BeaconPayload>();
+    payload.m_beacon.m_timestamp = ctx.m_tx.nTime;
 
     // Legacy beacon contracts before block version 11--just load the beacon:
     //
-    if (contract.m_version == 1) {
+    if (ctx->m_version == 1) {
         m_beacons[payload.m_cpid] = std::move(payload.m_beacon);
         return;
     }
@@ -347,11 +346,11 @@ void BeaconRegistry::Add(Contract contract, const CTransaction& tx)
     m_pending.emplace(pending.GetId(), std::move(pending));
 }
 
-void BeaconRegistry::Delete(const Contract& contract, const CTransaction& tx)
+void BeaconRegistry::Delete(const ContractContext& ctx)
 {
-    const auto payload = contract.SharePayloadAs<BeaconPayload>();
+    const auto payload = ctx->SharePayloadAs<BeaconPayload>();
 
-    if (contract.m_version >= 2) {
+    if (ctx->m_version >= 2) {
         m_pending.erase(payload->m_beacon.GetId());
     }
 

src/neuralnet/beacon.h

@@ -473,23 +473,21 @@ class BeaconRegistry : public IContractHandler
     //!
     //! \return \c true if the contract contains a valid beacon.
     //!
-    bool Validate(const Contract& contract, const CTransaction& tx) const;
+    bool Validate(const Contract& contract, const CTransaction& tx) const override;
 
     //!
     //! \brief Register a beacon from contract data.
     //!
-    //! \param contract Contains information about the beacon to add.
-    //! \param tx       Transaction that contains the contract.
+    //! \param ctx References the beacon contract and associated context.
     //!
-    void Add(Contract contract, const CTransaction& tx) override;
+    void Add(const ContractContext& ctx) override;
 
     //!
     //! \brief Deregister the beacon specified by contract data.
     //!
-    //! \param contract Contains information about the beacon to remove.
-    //! \param tx       Transaction that contains the contract.
+    //! \param ctx References the beacon contract and associated context.
     //!
-    void Delete(const Contract& contract, const CTransaction& tx) override;
+    void Delete(const ContractContext& ctx) override;
 
     //!
     //! \brief Activate the set of pending beacons verified in a superblock.

src/neuralnet/claim.h

@@ -220,7 +220,7 @@ class Claim : public IContractPayload
     //!
     //! \brief Get the type of contract that this payload contains data for.
     //!
-    NN::ContractType ContractType() const
+    NN::ContractType ContractType() const override
     {
         return NN::ContractType::CLAIM;
     }
@@ -270,7 +270,7 @@ class Claim : public IContractPayload
     //!
     //! \return Burn fee in units of 1/100000000 GRC.
     //!
-    int64_t RequiredBurnAmount() const
+    int64_t RequiredBurnAmount() const override
     {
         // TODO: remove redefinition of this constant when porting amount.h
         // from Bitcoin: