Merge bitcoin/bitcoin#29619: refactor: consolidate MempoolAcceptResult processing

07cd510ffe791a4dfc1824c67fb440be780a4e2b [refactor] consolidate invalid MempoolAcceptResult processing (glozow)
9353aa4066a85705154800efa61c5601036be921 [refactor] consolidate valid MempoolAcceptResult processing (glozow)

Pull request description:

  Every time we try to `ProcessTransaction` (i.e. submit a tx to mempool), we use the result to update a few net processing data structures. For example, after a failure, the {wtxid, txid, both, neither} (depending on reason) should be cached in `m_recent_rejects` so we don't try to download/validate it again.

  There are 2 current places and at least 1 future place where we need to process `MempoolAcceptResult`:
  - In the `ProcessMessage` logic after receiving and validating a tx
  - In `ProcessOrphanTx` where we retry orphans
  - With #28970, after processing a package of transactions, we should do these updates for each tx in the package.

  Consolidate this code so it isn't repeated in 2 places and so we can reuse it in a future PR.

ACKs for top commit:
  instagibbs:
    ACK 07cd510ffe791a4dfc1824c67fb440be780a4e2b
  achow101:
    ACK 07cd510ffe791a4dfc1824c67fb440be780a4e2b
  dergoegge:
    Code review ACK 07cd510ffe791a4dfc1824c67fb440be780a4e2b
  TheCharlatan:
    ACK 07cd510ffe791a4dfc1824c67fb440be780a4e2b

Tree-SHA512: c4e74cb65e4f52882fca52e6682efa5dcf1562d98418454e09be256ffd026caae642a90aa5b9cccaae214be240d6f4be9d87b516953b2ee69a655f16ea569ed9

1 files changed, 115 insertions, 114 deletions

diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 653daf8ff9..6996af38cb 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -582,6 +582,20 @@ private:
      */
     bool MaybeDiscourageAndDisconnect(CNode& pnode, Peer& peer);
 
+    /** Handle a transaction whose result was not MempoolAcceptResult::ResultType::VALID.
+     * @param[in]   maybe_add_extra_compact_tx    Whether this tx should be added to vExtraTxnForCompact.
+     *                                            Set to false if the tx has already been rejected before,
+     *                                            e.g. is an orphan, to avoid adding duplicate entries.
+     * Updates m_txrequest, m_recent_rejects, m_orphanage, and vExtraTxnForCompact. */
+    void ProcessInvalidTx(NodeId nodeid, const CTransactionRef& tx, const TxValidationState& result,
+                          bool maybe_add_extra_compact_tx)
+        EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex, cs_main);
+
+    /** Handle a transaction whose result was MempoolAcceptResult::ResultType::VALID.
+     * Updates m_txrequest, m_orphanage, and vExtraTxnForCompact. Also queues the tx for relay. */
+    void ProcessValidTx(NodeId nodeid, const CTransactionRef& tx, const std::list<CTransactionRef>& replaced_transactions)
+        EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, g_msgproc_mutex, cs_main);
+
     /**
      * Reconsider orphan transactions after a parent has been accepted to the mempool.
      *
@@ -3054,6 +3068,91 @@ void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, Peer& peer,
     return;
 }
 
+void PeerManagerImpl::ProcessInvalidTx(NodeId nodeid, const CTransactionRef& ptx, const TxValidationState& state,
+                                       bool maybe_add_extra_compact_tx)
+{
+    AssertLockNotHeld(m_peer_mutex);
+    AssertLockHeld(g_msgproc_mutex);
+    AssertLockHeld(cs_main);
+
+    LogDebug(BCLog::MEMPOOLREJ, "%s (wtxid=%s) from peer=%d was not accepted: %s\n",
+        ptx->GetHash().ToString(),
+        ptx->GetWitnessHash().ToString(),
+        nodeid,
+        state.ToString());
+
+    if (state.GetResult() == TxValidationResult::TX_MISSING_INPUTS) {
+        return;
+    } else if (state.GetResult() != TxValidationResult::TX_WITNESS_STRIPPED) {
+        // We can add the wtxid of this transaction to our reject filter.
+        // Do not add txids of witness transactions or witness-stripped
+        // transactions to the filter, as they can have been malleated;
+        // adding such txids to the reject filter would potentially
+        // interfere with relay of valid transactions from peers that
+        // do not support wtxid-based relay. See
+        // https://github.com/bitcoin/bitcoin/issues/8279 for details.
+        // We can remove this restriction (and always add wtxids to
+        // the filter even for witness stripped transactions) once
+        // wtxid-based relay is broadly deployed.
+        // See also comments in https://github.com/bitcoin/bitcoin/pull/18044#discussion_r443419034
+        // for concerns around weakening security of unupgraded nodes
+        // if we start doing this too early.
+        m_recent_rejects.insert(ptx->GetWitnessHash().ToUint256());
+        m_txrequest.ForgetTxHash(ptx->GetWitnessHash());
+        // If the transaction failed for TX_INPUTS_NOT_STANDARD,
+        // then we know that the witness was irrelevant to the policy
+        // failure, since this check depends only on the txid
+        // (the scriptPubKey being spent is covered by the txid).
+        // Add the txid to the reject filter to prevent repeated
+        // processing of this transaction in the event that child
+        // transactions are later received (resulting in
+        // parent-fetching by txid via the orphan-handling logic).
+        if (state.GetResult() == TxValidationResult::TX_INPUTS_NOT_STANDARD && ptx->HasWitness()) {
+            m_recent_rejects.insert(ptx->GetHash().ToUint256());
+            m_txrequest.ForgetTxHash(ptx->GetHash());
+        }
+        if (maybe_add_extra_compact_tx && RecursiveDynamicUsage(*ptx) < 100000) {
+            AddToCompactExtraTransactions(ptx);
+        }
+    }
+
+    MaybePunishNodeForTx(nodeid, state);
+
+    // If the tx failed in ProcessOrphanTx, it should be removed from the orphanage unless the
+    // tx was still missing inputs. If the tx was not in the orphanage, EraseTx does nothing and returns 0.
+    if (Assume(state.GetResult() != TxValidationResult::TX_MISSING_INPUTS) && m_orphanage.EraseTx(ptx->GetHash()) > 0) {
+        LogDebug(BCLog::TXPACKAGES, "   removed orphan tx %s (wtxid=%s)\n", ptx->GetHash().ToString(), ptx->GetWitnessHash().ToString());
+    }
+}
+
+void PeerManagerImpl::ProcessValidTx(NodeId nodeid, const CTransactionRef& tx, const std::list<CTransactionRef>& replaced_transactions)
+{
+    AssertLockNotHeld(m_peer_mutex);
+    AssertLockHeld(g_msgproc_mutex);
+    AssertLockHeld(cs_main);
+
+    // As this version of the transaction was acceptable, we can forget about any requests for it.
+    // No-op if the tx is not in txrequest.
+    m_txrequest.ForgetTxHash(tx->GetHash());
+    m_txrequest.ForgetTxHash(tx->GetWitnessHash());
+
+    m_orphanage.AddChildrenToWorkSet(*tx);
+    // If it came from the orphanage, remove it. No-op if the tx is not in txorphanage.
+    m_orphanage.EraseTx(tx->GetHash());
+
+    LogDebug(BCLog::MEMPOOL, "AcceptToMemoryPool: peer=%d: accepted %s (wtxid=%s) (poolsz %u txn, %u kB)\n",
+             nodeid,
+             tx->GetHash().ToString(),
+             tx->GetWitnessHash().ToString(),
+             m_mempool.size(), m_mempool.DynamicMemoryUsage() / 1000);
+
+    RelayTransaction(tx->GetHash(), tx->GetWitnessHash());
+
+    for (const CTransactionRef& removedTx : replaced_transactions) {
+        AddToCompactExtraTransactions(removedTx);
+    }
+}
+
 bool PeerManagerImpl::ProcessOrphanTx(Peer& peer)
 {
     AssertLockHeld(g_msgproc_mutex);
@@ -3069,66 +3168,23 @@ bool PeerManagerImpl::ProcessOrphanTx(Peer& peer)
 
         if (result.m_result_type == MempoolAcceptResult::ResultType::VALID) {
             LogPrint(BCLog::TXPACKAGES, "   accepted orphan tx %s (wtxid=%s)\n", orphanHash.ToString(), orphan_wtxid.ToString());
-            LogPrint(BCLog::MEMPOOL, "AcceptToMemoryPool: peer=%d: accepted %s (wtxid=%s) (poolsz %u txn, %u kB)\n",
-                peer.m_id,
-                orphanHash.ToString(),
-                orphan_wtxid.ToString(),
-                m_mempool.size(), m_mempool.DynamicMemoryUsage() / 1000);
-            RelayTransaction(orphanHash, porphanTx->GetWitnessHash());
-            m_orphanage.AddChildrenToWorkSet(*porphanTx);
-            m_orphanage.EraseTx(orphanHash);
-            for (const CTransactionRef& removedTx : result.m_replaced_transactions.value()) {
-                AddToCompactExtraTransactions(removedTx);
-            }
+            Assume(result.m_replaced_transactions.has_value());
+            std::list<CTransactionRef> empty_replacement_list;
+            ProcessValidTx(peer.m_id, porphanTx, result.m_replaced_transactions.value_or(empty_replacement_list));
             return true;
         } else if (state.GetResult() != TxValidationResult::TX_MISSING_INPUTS) {
-            if (state.IsInvalid()) {
-                LogPrint(BCLog::TXPACKAGES, "   invalid orphan tx %s (wtxid=%s) from peer=%d. %s\n",
-                    orphanHash.ToString(),
-                    orphan_wtxid.ToString(),
-                    peer.m_id,
-                    state.ToString());
-                LogPrint(BCLog::MEMPOOLREJ, "%s (wtxid=%s) from peer=%d was not accepted: %s\n",
-                    orphanHash.ToString(),
-                    orphan_wtxid.ToString(),
-                    peer.m_id,
-                    state.ToString());
-                // Maybe punish peer that gave us an invalid orphan tx
-                MaybePunishNodeForTx(peer.m_id, state);
-            }
-            // Has inputs but not accepted to mempool
-            // Probably non-standard or insufficient fee
-            LogPrint(BCLog::TXPACKAGES, "   removed orphan tx %s (wtxid=%s)\n", orphanHash.ToString(), orphan_wtxid.ToString());
-            if (state.GetResult() != TxValidationResult::TX_WITNESS_STRIPPED) {
-                // We can add the wtxid of this transaction to our reject filter.
-                // Do not add txids of witness transactions or witness-stripped
-                // transactions to the filter, as they can have been malleated;
-                // adding such txids to the reject filter would potentially
-                // interfere with relay of valid transactions from peers that
-                // do not support wtxid-based relay. See
-                // https://github.com/bitcoin/bitcoin/issues/8279 for details.
-                // We can remove this restriction (and always add wtxids to
-                // the filter even for witness stripped transactions) once
-                // wtxid-based relay is broadly deployed.
-                // See also comments in https://github.com/bitcoin/bitcoin/pull/18044#discussion_r443419034
-                // for concerns around weakening security of unupgraded nodes
-                // if we start doing this too early.
-                m_recent_rejects.insert(porphanTx->GetWitnessHash().ToUint256());
-                // If the transaction failed for TX_INPUTS_NOT_STANDARD,
-                // then we know that the witness was irrelevant to the policy
-                // failure, since this check depends only on the txid
-                // (the scriptPubKey being spent is covered by the txid).
-                // Add the txid to the reject filter to prevent repeated
-                // processing of this transaction in the event that child
-                // transactions are later received (resulting in
-                // parent-fetching by txid via the orphan-handling logic).
-                if (state.GetResult() == TxValidationResult::TX_INPUTS_NOT_STANDARD && porphanTx->HasWitness()) {
-                    // We only add the txid if it differs from the wtxid, to
-                    // avoid wasting entries in the rolling bloom filter.
-                    m_recent_rejects.insert(porphanTx->GetHash().ToUint256());
-                }
+            LogPrint(BCLog::TXPACKAGES, "   invalid orphan tx %s (wtxid=%s) from peer=%d. %s\n",
+                orphanHash.ToString(),
+                orphan_wtxid.ToString(),
+                peer.m_id,
+                state.ToString());
+
+            if (Assume(state.IsInvalid() &&
+                       state.GetResult() != TxValidationResult::TX_UNKNOWN &&
+                       state.GetResult() != TxValidationResult::TX_NO_MEMPOOL &&
+                       state.GetResult() != TxValidationResult::TX_RESULT_UNSET)) {
+                ProcessInvalidTx(peer.m_id, porphanTx, state, /*maybe_add_extra_compact_tx=*/false);
             }
-            m_orphanage.EraseTx(orphanHash);
             return true;
         }
     }
@@ -4298,24 +4354,8 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
         const TxValidationState& state = result.m_state;
 
         if (result.m_result_type == MempoolAcceptResult::ResultType::VALID) {
-            // As this version of the transaction was acceptable, we can forget about any
-            // requests for it.
-            m_txrequest.ForgetTxHash(tx.GetHash());
-            m_txrequest.ForgetTxHash(tx.GetWitnessHash());
-            RelayTransaction(tx.GetHash(), tx.GetWitnessHash());
-            m_orphanage.AddChildrenToWorkSet(tx);
-
+            ProcessValidTx(pfrom.GetId(), ptx, result.m_replaced_transactions.value());
             pfrom.m_last_tx_time = GetTime<std::chrono::seconds>();
-
-            LogPrint(BCLog::MEMPOOL, "AcceptToMemoryPool: peer=%d: accepted %s (wtxid=%s) (poolsz %u txn, %u kB)\n",
-                pfrom.GetId(),
-                tx.GetHash().ToString(),
-                tx.GetWitnessHash().ToString(),
-                m_mempool.size(), m_mempool.DynamicMemoryUsage() / 1000);
-
-            for (const CTransactionRef& removedTx : result.m_replaced_transactions.value()) {
-                AddToCompactExtraTransactions(removedTx);
-            }
         }
         else if (state.GetResult() == TxValidationResult::TX_MISSING_INPUTS)
         {
@@ -4376,48 +4416,9 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
                 m_txrequest.ForgetTxHash(tx.GetHash());
                 m_txrequest.ForgetTxHash(tx.GetWitnessHash());
             }
-        } else {
-            if (state.GetResult() != TxValidationResult::TX_WITNESS_STRIPPED) {
-                // We can add the wtxid of this transaction to our reject filter.
-                // Do not add txids of witness transactions or witness-stripped
-                // transactions to the filter, as they can have been malleated;
-                // adding such txids to the reject filter would potentially
-                // interfere with relay of valid transactions from peers that
-                // do not support wtxid-based relay. See
-                // https://github.com/bitcoin/bitcoin/issues/8279 for details.
-                // We can remove this restriction (and always add wtxids to
-                // the filter even for witness stripped transactions) once
-                // wtxid-based relay is broadly deployed.
-                // See also comments in https://github.com/bitcoin/bitcoin/pull/18044#discussion_r443419034
-                // for concerns around weakening security of unupgraded nodes
-                // if we start doing this too early.
-                m_recent_rejects.insert(tx.GetWitnessHash().ToUint256());
-                m_txrequest.ForgetTxHash(tx.GetWitnessHash());
-                // If the transaction failed for TX_INPUTS_NOT_STANDARD,
-                // then we know that the witness was irrelevant to the policy
-                // failure, since this check depends only on the txid
-                // (the scriptPubKey being spent is covered by the txid).
-                // Add the txid to the reject filter to prevent repeated
-                // processing of this transaction in the event that child
-                // transactions are later received (resulting in
-                // parent-fetching by txid via the orphan-handling logic).
-                if (state.GetResult() == TxValidationResult::TX_INPUTS_NOT_STANDARD && tx.HasWitness()) {
-                    m_recent_rejects.insert(tx.GetHash().ToUint256());
-                    m_txrequest.ForgetTxHash(tx.GetHash());
-                }
-                if (RecursiveDynamicUsage(*ptx) < 100000) {
-                    AddToCompactExtraTransactions(ptx);
-                }
-            }
         }
-
         if (state.IsInvalid()) {
-            LogPrint(BCLog::MEMPOOLREJ, "%s (wtxid=%s) from peer=%d was not accepted: %s\n",
-                tx.GetHash().ToString(),
-                tx.GetWitnessHash().ToString(),
-                pfrom.GetId(),
-                state.ToString());
-            MaybePunishNodeForTx(pfrom.GetId(), state);
+            ProcessInvalidTx(pfrom.GetId(), ptx, state, /*maybe_add_extra_compact_tx=*/true);
         }
         return;
     }