policy: Enforce TRUC restrictions by default

doc/release-notes-447.md

@@ -0,0 +1,9 @@
+Mempool policy
+--------------
+
+- The default for `mempooltruc` changes from `accept` to `enforce`,
+  applying the existing version-3 topology, inheritance, and size checks
+  by default. Explicit policy settings remain available.
+  This also selects the existing version-3 exemption from the individual
+  minimum relay fee check; package fee requirements still apply.
+  Ephemeral-dust rules, dust-penalty defaults, and mining policy are unchanged.

src/init.cpp

@@ -738,7 +738,7 @@ void SetupServerArgs(ArgsManager& argsman, bool can_listen_ipc)
                    ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
     argsman.AddArg("-mempoolfullrbf", strprintf("Accept transaction replace-by-fee without requiring replaceability signaling (default: %u)", (DEFAULT_MEMPOOL_RBF_POLICY == RBFPolicy::Always)), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
     argsman.AddArg("-mempoolreplacement", strprintf("Set to 0 to disable RBF entirely, \"fee,optin\" to honour RBF opt-out signal, or \"fee,-optin\" to always RBF aka full RBF (default: %s)", "fee,-optin"), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
-    argsman.AddArg("-mempooltruc", strprintf("Behaviour for transactions requesting TRUC limits: \"reject\" the transactions entirely, \"accept\" them just like any other, or \"enforce\" to impose their requested restrictions (default: %s)", "accept"), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
+    argsman.AddArg("-mempooltruc", strprintf("Behaviour for transactions requesting TRUC limits: \"reject\" the transactions entirely, \"accept\" them just like any other, or \"enforce\" to impose their requested restrictions (default: %s)", "enforce"), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
     argsman.AddArg("-permitbareanchor",
                    strprintf("Relay transactions that only have ephemeral anchor outputs (default: %u)", DEFAULT_PERMITBAREANCHOR),
                    ArgsManager::ALLOW_ANY,
@@ -880,7 +880,6 @@ void InitParameterInteraction(ArgsManager& args)
         args.SoftSetArg("-datacarrierfullcount", "0");
         args.SoftSetArg("-maxtxlegacysigops", strprintf("%s", std::numeric_limits<unsigned int>::max()));
         args.SoftSetArg("-maxscriptsize", strprintf("%s", std::numeric_limits<unsigned int>::max()));
-        args.SoftSetArg("-mempooltruc", "enforce");
         args.SoftSetArg("-permitephemeral", "anchor,send,dust");
         args.SoftSetArg("-spkreuse", "allow");
         args.SoftSetArg("-blockprioritysize", "0");

src/kernel/mempool_options.h

@@ -33,7 +33,7 @@ static constexpr int DEFAULT_MINRELAYMATURITY{0};
 /** Default for -mempoolreplacement; must update docs in init.cpp manually */
 static constexpr RBFPolicy DEFAULT_MEMPOOL_RBF_POLICY{RBFPolicy::Always};
 /** Default for -mempooltruc; must update docs in init.cpp manually */
-static constexpr TRUCPolicy DEFAULT_MEMPOOL_TRUC_POLICY{TRUCPolicy::Accept};
+static constexpr TRUCPolicy DEFAULT_MEMPOOL_TRUC_POLICY{TRUCPolicy::Enforce};
 /** Whether to fall back to legacy V1 serialization when writing mempool.dat */
 static constexpr bool DEFAULT_PERSIST_V1_DAT{false};
 /** Default for -acceptnonstddatacarrier */

test/functional/mempool_truc.py

@@ -682,6 +682,35 @@ def test_minrelay_in_package_combos(self):
                 self.check_mempool([tx_v2_0fee_parent["txid"], tx_v2_child["txid"], tx_v3_0fee_parent["txid"], tx_v3_child["txid"]])
 
 
+    def test_default_and_overrides(self):
+        self.log.info("Test native TRUC default and explicit overrides with both corepolicy settings")
+        node = self.nodes[0]
+        for corepolicy in (0, 1):
+            for mode in (None, "accept", "reject", "enforce"):
+                args = [f"-corepolicy={corepolicy}", "-acceptnonstdtxn=0", "-persistmempool=0"]
+                if mode is not None:
+                    args.append(f"-mempooltruc={mode}")
+                self.restart_node(0, extra_args=args)
+                assert_equal(node.getmempoolinfo()["truc_policy"], mode or "enforce")
+                self.wallet.rescan_utxos()
+                parent = self.wallet.create_self_transfer(version=3, confirmed_only=True)
+                child = self.wallet.create_self_transfer(utxo_to_spend=parent["new_utxo"], version=2)
+                if mode == "reject":
+                    result = node.testmempoolaccept([parent["hex"]])[0]
+                    assert_equal(result["allowed"], False)
+                    assert_equal(result["reject-reason"], "version")
+                    continue
+                node.sendrawtransaction(parent["hex"])
+                result = node.testmempoolaccept([child["hex"]])[0]
+                assert_equal(result["allowed"], mode == "accept")
+                if mode != "accept":
+                    assert_equal(result["reject-reason"], "truc-spent-by-nontruc")
+                if mode in (None, "enforce"):
+                    parent = self.wallet.create_self_transfer(version=3, confirmed_only=True, fee=0, fee_rate=0)
+                    child = self.wallet.create_self_transfer(utxo_to_spend=parent["new_utxo"], version=3, fee_rate=DEFAULT_FEE*50)
+                    assert_equal(node.submitpackage([parent["hex"], child["hex"]])["package_msg"], "success")
+        self.restart_node(0)
+
     def run_test(self):
         self.log.info("Generate blocks to create UTXOs")
         node = self.nodes[0]
@@ -702,6 +731,7 @@ def run_test(self):
         self.test_truc_sibling_eviction()
         self.test_reorg_sibling_eviction_1p2c()
         self.test_minrelay_in_package_combos()
+        self.test_default_and_overrides()
 
 
 if __name__ == "__main__":