Apply -limitdummyscriptdatasize

src/init.cpp

@@ -641,6 +641,7 @@ void SetupServerArgs(ArgsManager& argsman, bool can_listen_ipc)
                              "is of this size or less (default: %u)",
                              MAX_OP_RETURN_RELAY),
                    ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
+    argsman.AddArg("-limitdummyscriptdatasize", strprintf("Maximum size of dummy script data we relay and mine (default: %u)", MAX_DUMMY_SCRIPT_RELAY), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
     argsman.AddArg("-permitbaremultisig", strprintf("Relay transactions creating non-P2SH multisig outputs (default: %u)", DEFAULT_PERMIT_BAREMULTISIG), ArgsManager::ALLOW_ANY,
                    OptionsCategory::NODE_RELAY);
     argsman.AddArg("-minrelaytxfee=<amt>", strprintf("Fees (in %s/kvB) smaller than this are considered zero fee for relaying, mining and transaction creation (default: %s)",

src/kernel/mempool_options.h

@@ -51,6 +51,7 @@ struct MemPoolOptions {
      * If nullopt, any size is nonstandard.
      */
     std::optional<unsigned> max_datacarrier_bytes{DEFAULT_ACCEPT_DATACARRIER ? std::optional{MAX_OP_RETURN_RELAY} : std::nullopt};
+    unsigned int max_dummy_script_bytes{MAX_DUMMY_SCRIPT_RELAY};
     bool permit_bare_multisig{DEFAULT_PERMIT_BAREMULTISIG};
     bool require_standard{true};
     bool persist_v1_dat{DEFAULT_PERSIST_V1_DAT};

src/node/mempool_args.cpp

@@ -87,6 +87,8 @@ util::Result<void> ApplyArgsManOptions(const ArgsManager& argsman, const CChainP
         mempool_opts.max_datacarrier_bytes = std::nullopt;
     }
 
+    mempool_opts.max_dummy_script_bytes = argsman.GetIntArg("-limitdummyscriptdatasize", MAX_DUMMY_SCRIPT_RELAY);
+
     mempool_opts.require_standard = !argsman.GetBoolArg("-acceptnonstdtxn", DEFAULT_ACCEPT_NON_STD_TXN);
     if (!chainparams.IsTestChain() && !mempool_opts.require_standard) {
         return util::Error{Untranslated(strprintf("acceptnonstdtxn is not currently supported for %s chain", chainparams.GetChainTypeString()))};

src/policy/policy.cpp

@@ -368,3 +368,19 @@ std::pair<CScript, unsigned int> GetScriptForTransactionInput(CScript prev_scrip
 
     return std::make_pair(CScript(), 0);
 }
+
+size_t DummyScriptBytes(const CTransaction& tx, const CCoinsViewCache& view)
+{
+    size_t ret{0};
+
+    for (const CTxIn& txin : tx.vin) {
+        const CTxOut &utxo = view.AccessCoin(txin.prevout).out;
+        auto[script, consensus_weight_per_byte] = GetScriptForTransactionInput(utxo.scriptPubKey, txin);
+        ret += script.DummyScriptBytes();
+    }
+    for (const CTxOut& txout : tx.vout) {
+        ret += txout.scriptPubKey.DummyScriptBytes();
+    }
+
+    return ret;
+}

src/policy/policy.h

@@ -73,6 +73,8 @@ static constexpr unsigned int DEFAULT_DESCENDANT_LIMIT{25};
 static constexpr unsigned int DEFAULT_DESCENDANT_SIZE_LIMIT_KVB{101};
 /** Default for -datacarrier */
 static const bool DEFAULT_ACCEPT_DATACARRIER = true;
+/** Default setting for -limitdummyscriptdatasize */
+static const unsigned int MAX_DUMMY_SCRIPT_RELAY{0};
 /**
  * Default setting for -datacarriersize. 80 bytes of data, +1 for OP_RETURN,
  * +2 for the pushdata opcodes.
@@ -184,4 +186,6 @@ static inline int64_t GetVirtualTransactionInputSize(const CTxIn& tx)
 
 std::pair<CScript, unsigned int> GetScriptForTransactionInput(CScript prev_script, const CTxIn&);
 
+size_t DummyScriptBytes(const CTransaction& tx, const CCoinsViewCache& view);
+
 #endif // BITCOIN_POLICY_POLICY_H

src/validation.cpp

@@ -882,6 +882,12 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
         return state.Invalid(TxValidationResult::TX_INPUTS_NOT_STANDARD, "bad-txns-nonstandard-inputs");
     }
 
+    if (tx.GetTotalSize() > m_pool.m_opts.max_dummy_script_bytes) {
+        if (DummyScriptBytes(tx, m_view) > m_pool.m_opts.max_dummy_script_bytes) {
+            return state.Invalid(TxValidationResult::TX_INPUTS_NOT_STANDARD, "txn-dummyscript-exceeded");
+        }
+    }
+
     // Check for non-standard witnesses.
     if (tx.HasWitness() && m_pool.m_opts.require_standard && !IsWitnessStandard(tx, m_view)) {
         return state.Invalid(TxValidationResult::TX_WITNESS_MUTATED, "bad-witness-nonstandard");