net_processing: drop MaybePunishNodeForTx

Do not discourage nodes even when they send us consensus invalid
transactions.

Because we do not discourage nodes for transactions we consider
non-standard, we don't get any DoS protection from this check in
adversarial scenarios, so remove the check entirely both to simplify the
code and reduce the risk of splitting the network due to changes in tx
relay policy.

NOTE: Backport required additional adjustment in test/functional/p2p_invalid_tx

Github-Pull: #33050
Rebased-From: 266dd0e10d08c0bfde63205db15d6c210a021b90

src/net_processing.cpp

@@ -553,12 +553,6 @@ private:
                                  bool via_compact_block, const std::string& message = "")
         EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
 
-    /**
-     * Potentially disconnect and discourage a node based on the contents of a TxValidationState object
-     */
-    void MaybePunishNodeForTx(NodeId nodeid, const TxValidationState& state)
-        EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
-
     /** Maybe disconnect a peer and discourage future connections from its address.
      *
      * @param[in]   pnode     The node to check.
@@ -1805,32 +1799,6 @@ void PeerManagerImpl::MaybePunishNodeForBlock(NodeId nodeid, const BlockValidati
     }
 }
 
-void PeerManagerImpl::MaybePunishNodeForTx(NodeId nodeid, const TxValidationState& state)
-{
-    PeerRef peer{GetPeerRef(nodeid)};
-    switch (state.GetResult()) {
-    case TxValidationResult::TX_RESULT_UNSET:
-        break;
-    // The node is providing invalid data:
-    case TxValidationResult::TX_CONSENSUS:
-        if (peer) Misbehaving(*peer, "");
-        return;
-    // Conflicting (but not necessarily invalid) data or different policy:
-    case TxValidationResult::TX_INPUTS_NOT_STANDARD:
-    case TxValidationResult::TX_NOT_STANDARD:
-    case TxValidationResult::TX_MISSING_INPUTS:
-    case TxValidationResult::TX_PREMATURE_SPEND:
-    case TxValidationResult::TX_WITNESS_MUTATED:
-    case TxValidationResult::TX_WITNESS_STRIPPED:
-    case TxValidationResult::TX_CONFLICT:
-    case TxValidationResult::TX_MEMPOOL_POLICY:
-    case TxValidationResult::TX_NO_MEMPOOL:
-    case TxValidationResult::TX_RECONSIDERABLE:
-    case TxValidationResult::TX_UNKNOWN:
-        break;
-    }
-}
-
 bool PeerManagerImpl::BlockRequestAllowed(const CBlockIndex* pindex)
 {
     AssertLockHeld(cs_main);
@@ -2987,8 +2955,6 @@ std::optional<node::PackageToValidate> PeerManagerImpl::ProcessInvalidTx(NodeId
         if (peer) AddKnownTx(*peer, parent_txid);
     }
 
-    MaybePunishNodeForTx(nodeid, state);
-
     return package_to_validate;
 }
 

test/functional/data/invalid_txs.py

@@ -89,7 +89,7 @@ class BadTxTemplate:
 
 class OutputMissing(BadTxTemplate):
     reject_reason = "bad-txns-vout-empty"
-    expect_disconnect = True
+    expect_disconnect = False
 
     def get_tx(self):
         tx = CTransaction()
@@ -100,7 +100,7 @@ class OutputMissing(BadTxTemplate):
 
 class InputMissing(BadTxTemplate):
     reject_reason = "bad-txns-vin-empty"
-    expect_disconnect = True
+    expect_disconnect = False
 
     # We use a blank transaction here to make sure
     # it is interpreted as a non-witness transaction.
@@ -149,7 +149,7 @@ class BadInputOutpointIndex(BadTxTemplate):
 
 class DuplicateInput(BadTxTemplate):
     reject_reason = 'bad-txns-inputs-duplicate'
-    expect_disconnect = True
+    expect_disconnect = False
 
     def get_tx(self):
         tx = CTransaction()
@@ -162,7 +162,7 @@ class DuplicateInput(BadTxTemplate):
 
 class PrevoutNullInput(BadTxTemplate):
     reject_reason = 'bad-txns-prevout-null'
-    expect_disconnect = True
+    expect_disconnect = False
 
     def get_tx(self):
         tx = CTransaction()
@@ -188,7 +188,7 @@ class NonexistentInput(BadTxTemplate):
 
 class SpendTooMuch(BadTxTemplate):
     reject_reason = 'bad-txns-in-belowout'
-    expect_disconnect = True
+    expect_disconnect = False
 
     def get_tx(self):
         return create_tx_with_script(
@@ -197,7 +197,7 @@ class SpendTooMuch(BadTxTemplate):
 
 class CreateNegative(BadTxTemplate):
     reject_reason = 'bad-txns-vout-negative'
-    expect_disconnect = True
+    expect_disconnect = False
 
     def get_tx(self):
         return create_tx_with_script(self.spend_tx, 0, amount=-1)
@@ -205,7 +205,7 @@ class CreateNegative(BadTxTemplate):
 
 class CreateTooLarge(BadTxTemplate):
     reject_reason = 'bad-txns-vout-toolarge'
-    expect_disconnect = True
+    expect_disconnect = False
 
     def get_tx(self):
         return create_tx_with_script(self.spend_tx, 0, amount=MAX_MONEY + 1)
@@ -213,7 +213,7 @@ class CreateTooLarge(BadTxTemplate):
 
 class CreateSumTooLarge(BadTxTemplate):
     reject_reason = 'bad-txns-txouttotal-toolarge'
-    expect_disconnect = True
+    expect_disconnect = False
 
     def get_tx(self):
         tx = create_tx_with_script(self.spend_tx, 0, amount=MAX_MONEY)
@@ -224,7 +224,7 @@ class CreateSumTooLarge(BadTxTemplate):
 
 class InvalidOPIFConstruction(BadTxTemplate):
     reject_reason = "mandatory-script-verify-flag-failed (Invalid OP_IF construction)"
-    expect_disconnect = True
+    expect_disconnect = False
     valid_in_block = True
 
     def get_tx(self):
@@ -266,7 +266,7 @@ def getDisabledOpcodeTemplate(opcode):
 class NonStandardAndInvalid(BadTxTemplate):
     """A non-standard transaction which is also consensus-invalid should return the consensus error."""
     reject_reason = "mandatory-script-verify-flag-failed (OP_RETURN was encountered)"
-    expect_disconnect = True
+    expect_disconnect = False
     valid_in_block = False
 
     def get_tx(self):

test/functional/p2p_invalid_tx.py

@@ -73,7 +73,7 @@ class InvalidTxRequestTest(BitcoinTestFramework):
             tx = template.get_tx()
             node.p2ps[0].send_txs_and_test(
                 [tx], node, success=False,
-                expect_disconnect=template.expect_disconnect,
+                expect_disconnect=False,
                 reject_reason=template.reject_reason,
             )
 
@@ -144,7 +144,6 @@ class InvalidTxRequestTest(BitcoinTestFramework):
         # tx_orphan_2_no_fee, because it has too low fee (p2ps[0] is not disconnected for relaying that tx)
         # tx_orphan_2_invalid, because it has negative fee (p2ps[1] is disconnected for relaying that tx)
 
-        self.wait_until(lambda: 1 == len(node.getpeerinfo()), timeout=12)  # p2ps[1] is no longer connected
         assert_equal(expected_mempool, set(node.getrawmempool()))
 
         self.log.info('Test orphan pool overflow')
@@ -165,7 +164,7 @@ class InvalidTxRequestTest(BitcoinTestFramework):
             node.p2ps[0].send_txs_and_test([rejected_parent], node, success=False)
 
         self.log.info('Test that a peer disconnection causes erase its transactions from the orphan pool')
-        with node.assert_debug_log(['Erased 100 orphan transaction(s) from peer=26']):
+        with node.assert_debug_log(['Erased 100 orphan transaction(s) from peer=']):
             self.reconnect_p2p(num_connections=1)
 
         self.log.info('Test that a transaction in the orphan pool is included in a new tip block causes erase this transaction from the orphan pool')

test/functional/p2p_opportunistic_1p1c.py

@@ -251,8 +251,10 @@ class PackageRelayTest(BitcoinTestFramework):
         assert tx_orphan_bad_wit.rehash() not in node_mempool
 
         # 5. Have the other peer send the tx too, so that tx_orphan_bad_wit package is attempted.
-        bad_orphan_sender.send_message(msg_tx(low_fee_parent["tx"]))
-        bad_orphan_sender.wait_for_disconnect()
+        bad_orphan_sender.send_and_ping(msg_tx(low_fee_parent["tx"]))
+
+        # The bad orphan sender should not be disconnected.
+        bad_orphan_sender.sync_with_ping()
 
         # The peer that didn't provide the orphan should not be disconnected.
         parent_sender.sync_with_ping()