Pass Peer& to Misbehaving()

`Misbehaving` has several coding related issues (ignoring the conceptual
issues here for now):
* It is public, but it is not supposed to be called from outside of
  net_processing. Fix that by making it private and creating a public
  `UnitTestMisbehaving` method for unit testing only.
* It doesn't do anything if a `nullptr` is passed. It would be less
  confusing to just skip the call instead. Fix that by passing `Peer&`
  to `Misbehaving()`.
* It calls `GetPeerRef`, causing `!m_peer_mutex` lock annotations to be
  propagated. This is harmless, but verbose. Fix it by removing the no
  longer needed call to `GetPeerRef` and the no longer needed lock
  annotations.

3 files changed, 45 insertions, 45 deletions

diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 502bbb5d99..6f35f2d04a 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -492,7 +492,7 @@ public:
     void SendPings() override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
     void RelayTransaction(const uint256& txid, const uint256& wtxid) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
     void SetBestHeight(int height) override { m_best_height = height; };
-    void Misbehaving(const NodeId pnode, const int howmuch, const std::string& message) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
+    void UnitTestMisbehaving(NodeId peer_id, int howmuch) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex) { Misbehaving(*Assert(GetPeerRef(peer_id)), howmuch, ""); };
     void ProcessMessage(CNode& pfrom, const std::string& msg_type, CDataStream& vRecv,
                         const std::chrono::microseconds time_received, const std::atomic<bool>& interruptMsgProc) override
         EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_recent_confirmed_transactions_mutex, !m_most_recent_block_mutex);
@@ -517,6 +517,12 @@ private:
     PeerRef RemovePeer(NodeId id) EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
 
     /**
+     * Increment peer's misbehavior score. If the new value >= DISCOURAGEMENT_THRESHOLD, mark the node
+     * to be discouraged, meaning the peer might be disconnected and added to the discouragement filter.
+     */
+    void Misbehaving(Peer& peer, int howmuch, const std::string& message);
+
+    /**
      * Potentially mark a node discouraged based on the contents of a BlockValidationState object
      *
      * @param[in] via_compact_block this bool is passed in because net_processing should
@@ -549,13 +555,12 @@ private:
     void ProcessOrphanTx(std::set<uint256>& orphan_work_set) EXCLUSIVE_LOCKS_REQUIRED(cs_main, g_cs_orphans)
         EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
     /** Process a single headers message from a peer. */
-    void ProcessHeadersMessage(CNode& pfrom, const Peer& peer,
+    void ProcessHeadersMessage(CNode& pfrom, Peer& peer,
                                const std::vector<CBlockHeader>& headers,
                                bool via_compact_block)
         EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
 
-    void SendBlockTransactions(CNode& pfrom, const CBlock& block, const BlockTransactionsRequest& req)
-        EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
+    void SendBlockTransactions(CNode& pfrom, Peer& peer, const CBlock& block, const BlockTransactionsRequest& req);
 
     /** Register with TxRequestTracker that an INV has been received from a
      *  peer. The announcement parameters are decided in PeerManager and then
@@ -1441,33 +1446,31 @@ void PeerManagerImpl::AddToCompactExtraTransactions(const CTransactionRef& tx)
     vExtraTxnForCompactIt = (vExtraTxnForCompactIt + 1) % max_extra_txn;
 }
 
-void PeerManagerImpl::Misbehaving(const NodeId pnode, const int howmuch, const std::string& message)
+void PeerManagerImpl::Misbehaving(Peer& peer, int howmuch, const std::string& message)
 {
     assert(howmuch > 0);
 
-    PeerRef peer = GetPeerRef(pnode);
-    if (peer == nullptr) return;
-
-    LOCK(peer->m_misbehavior_mutex);
-    const int score_before{peer->m_misbehavior_score};
-    peer->m_misbehavior_score += howmuch;
-    const int score_now{peer->m_misbehavior_score};
+    LOCK(peer.m_misbehavior_mutex);
+    const int score_before{peer.m_misbehavior_score};
+    peer.m_misbehavior_score += howmuch;
+    const int score_now{peer.m_misbehavior_score};
 
     const std::string message_prefixed = message.empty() ? "" : (": " + message);
     std::string warning;
 
     if (score_now >= DISCOURAGEMENT_THRESHOLD && score_before < DISCOURAGEMENT_THRESHOLD) {
         warning = " DISCOURAGE THRESHOLD EXCEEDED";
-        peer->m_should_discourage = true;
+        peer.m_should_discourage = true;
     }
 
     LogPrint(BCLog::NET, "Misbehaving: peer=%d (%d -> %d)%s%s\n",
-             pnode, score_before, score_now, warning, message_prefixed);
+             peer.m_id, score_before, score_now, warning, message_prefixed);
 }
 
 bool PeerManagerImpl::MaybePunishNodeForBlock(NodeId nodeid, const BlockValidationState& state,
                                               bool via_compact_block, const std::string& message)
 {
+    PeerRef peer{GetPeerRef(nodeid)};
     switch (state.GetResult()) {
     case BlockValidationResult::BLOCK_RESULT_UNSET:
         break;
@@ -1475,7 +1478,7 @@ bool PeerManagerImpl::MaybePunishNodeForBlock(NodeId nodeid, const BlockValidati
     case BlockValidationResult::BLOCK_CONSENSUS:
     case BlockValidationResult::BLOCK_MUTATED:
         if (!via_compact_block) {
-            Misbehaving(nodeid, 100, message);
+            if (peer) Misbehaving(*peer, 100, message);
             return true;
         }
         break;
@@ -1490,7 +1493,7 @@ bool PeerManagerImpl::MaybePunishNodeForBlock(NodeId nodeid, const BlockValidati
             // Discourage outbound (but not inbound) peers if on an invalid chain.
             // Exempt HB compact block peers. Manual connections are always protected from discouragement.
             if (!via_compact_block && !node_state->m_is_inbound) {
-                Misbehaving(nodeid, 100, message);
+                if (peer) Misbehaving(*peer, 100, message);
                 return true;
             }
             break;
@@ -1498,12 +1501,12 @@ bool PeerManagerImpl::MaybePunishNodeForBlock(NodeId nodeid, const BlockValidati
     case BlockValidationResult::BLOCK_INVALID_HEADER:
     case BlockValidationResult::BLOCK_CHECKPOINT:
     case BlockValidationResult::BLOCK_INVALID_PREV:
-        Misbehaving(nodeid, 100, message);
+        if (peer) Misbehaving(*peer, 100, message);
         return true;
     // Conflicting (but not necessarily invalid) data or different policy:
     case BlockValidationResult::BLOCK_MISSING_PREV:
         // TODO: Handle this much more gracefully (10 DoS points is super arbitrary)
-        Misbehaving(nodeid, 10, message);
+        if (peer) Misbehaving(*peer, 10, message);
         return true;
     case BlockValidationResult::BLOCK_RECENT_CONSENSUS_CHANGE:
     case BlockValidationResult::BLOCK_TIME_FUTURE:
@@ -1517,12 +1520,13 @@ bool PeerManagerImpl::MaybePunishNodeForBlock(NodeId nodeid, const BlockValidati
 
 bool PeerManagerImpl::MaybePunishNodeForTx(NodeId nodeid, const TxValidationState& state, const std::string& message)
 {
+    PeerRef peer{GetPeerRef(nodeid)};
     switch (state.GetResult()) {
     case TxValidationResult::TX_RESULT_UNSET:
         break;
     // The node is providing invalid data:
     case TxValidationResult::TX_CONSENSUS:
-        Misbehaving(nodeid, 100, message);
+        if (peer) Misbehaving(*peer, 100, message);
         return true;
     // Conflicting (but not necessarily invalid) data or different policy:
     case TxValidationResult::TX_RECENT_CONSENSUS_CHANGE:
@@ -2172,12 +2176,12 @@ uint32_t PeerManagerImpl::GetFetchFlags(const CNode& pfrom) const EXCLUSIVE_LOCK
     return nFetchFlags;
 }
 
-void PeerManagerImpl::SendBlockTransactions(CNode& pfrom, const CBlock& block, const BlockTransactionsRequest& req)
+void PeerManagerImpl::SendBlockTransactions(CNode& pfrom, Peer& peer, const CBlock& block, const BlockTransactionsRequest& req)
 {
     BlockTransactions resp(req);
     for (size_t i = 0; i < req.indexes.size(); i++) {
         if (req.indexes[i] >= block.vtx.size()) {
-            Misbehaving(pfrom.GetId(), 100, "getblocktxn with out-of-bounds tx indices");
+            Misbehaving(peer, 100, "getblocktxn with out-of-bounds tx indices");
             return;
         }
         resp.txn[i] = block.vtx[req.indexes[i]];
@@ -2187,7 +2191,7 @@ void PeerManagerImpl::SendBlockTransactions(CNode& pfrom, const CBlock& block, c
     m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::BLOCKTXN, resp));
 }
 
-void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, const Peer& peer,
+void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, Peer& peer,
                                             const std::vector<CBlockHeader>& headers,
                                             bool via_compact_block)
 {
@@ -2227,7 +2231,7 @@ void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, const Peer& peer,
             UpdateBlockAvailability(pfrom.GetId(), headers.back().GetHash());
 
             if (nodestate->nUnconnectingHeaders % MAX_UNCONNECTING_HEADERS == 0) {
-                Misbehaving(pfrom.GetId(), 20, strprintf("%d non-connecting headers", nodestate->nUnconnectingHeaders));
+                Misbehaving(peer, 20, strprintf("%d non-connecting headers", nodestate->nUnconnectingHeaders));
             }
             return;
         }
@@ -2235,7 +2239,7 @@ void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, const Peer& peer,
         uint256 hashLastBlock;
         for (const CBlockHeader& header : headers) {
             if (!hashLastBlock.IsNull() && header.hashPrevBlock != hashLastBlock) {
-                Misbehaving(pfrom.GetId(), 20, "non-continuous headers sequence");
+                Misbehaving(peer, 20, "non-continuous headers sequence");
                 return;
             }
             hashLastBlock = header.GetHash();
@@ -2998,7 +3002,7 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
 
         if (vAddr.size() > MAX_ADDR_TO_SEND)
         {
-            Misbehaving(pfrom.GetId(), 20, strprintf("%s message size = %u", msg_type, vAddr.size()));
+            Misbehaving(*peer, 20, strprintf("%s message size = %u", msg_type, vAddr.size()));
             return;
         }
 
@@ -3079,7 +3083,7 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
         vRecv >> vInv;
         if (vInv.size() > MAX_INV_SZ)
         {
-            Misbehaving(pfrom.GetId(), 20, strprintf("inv message size = %u", vInv.size()));
+            Misbehaving(*peer, 20, strprintf("inv message size = %u", vInv.size()));
             return;
         }
 
@@ -3154,7 +3158,7 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
         vRecv >> vInv;
         if (vInv.size() > MAX_INV_SZ)
         {
-            Misbehaving(pfrom.GetId(), 20, strprintf("getdata message size = %u", vInv.size()));
+            Misbehaving(*peer, 20, strprintf("getdata message size = %u", vInv.size()));
             return;
         }
 
@@ -3252,7 +3256,7 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
             // Unlock m_most_recent_block_mutex to avoid cs_main lock inversion
         }
         if (recent_block) {
-            SendBlockTransactions(pfrom, *recent_block, req);
+            SendBlockTransactions(pfrom, *peer, *recent_block, req);
             return;
         }
 
@@ -3270,7 +3274,7 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
                 bool ret = ReadBlockFromDisk(block, pindex, m_chainparams.GetConsensus());
                 assert(ret);
 
-                SendBlockTransactions(pfrom, block, req);
+                SendBlockTransactions(pfrom, *peer, block, req);
                 return;
             }
         }
@@ -3678,7 +3682,7 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
                 ReadStatus status = partialBlock.InitData(cmpctblock, vExtraTxnForCompact);
                 if (status == READ_STATUS_INVALID) {
                     RemoveBlockRequest(pindex->GetBlockHash()); // Reset in-flight state in case Misbehaving does not result in a disconnect
-                    Misbehaving(pfrom.GetId(), 100, "invalid compact block");
+                    Misbehaving(*peer, 100, "invalid compact block");
                     return;
                 } else if (status == READ_STATUS_FAILED) {
                     // Duplicate txindexes, the block is now in-flight, so just request it
@@ -3805,7 +3809,7 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
             ReadStatus status = partialBlock.FillBlock(*pblock, resp.txn);
             if (status == READ_STATUS_INVALID) {
                 RemoveBlockRequest(resp.blockhash); // Reset in-flight state in case Misbehaving does not result in a disconnect
-                Misbehaving(pfrom.GetId(), 100, "invalid compact block/non-matching block transactions");
+                Misbehaving(*peer, 100, "invalid compact block/non-matching block transactions");
                 return;
             } else if (status == READ_STATUS_FAILED) {
                 // Might have collided, fall back to getdata now :(
@@ -3866,7 +3870,7 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
         // Bypass the normal CBlock deserialization, as we don't want to risk deserializing 2000 full blocks.
         unsigned int nCount = ReadCompactSize(vRecv);
         if (nCount > MAX_HEADERS_RESULTS) {
-            Misbehaving(pfrom.GetId(), 20, strprintf("headers message size = %u", nCount));
+            Misbehaving(*peer, 20, strprintf("headers message size = %u", nCount));
             return;
         }
         headers.resize(nCount);
@@ -4060,7 +4064,7 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
         if (!filter.IsWithinSizeConstraints())
         {
             // There is no excuse for sending a too-large filter
-            Misbehaving(pfrom.GetId(), 100, "too-large bloom filter");
+            Misbehaving(*peer, 100, "too-large bloom filter");
         } else if (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) {
             {
                 LOCK(tx_relay->m_bloom_filter_mutex);
@@ -4095,7 +4099,7 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
             }
         }
         if (bad) {
-            Misbehaving(pfrom.GetId(), 100, "bad filteradd message");
+            Misbehaving(*peer, 100, "bad filteradd message");
         }
         return;
     }
diff --git a/src/net_processing.h b/src/net_processing.h
index d5c73e6c79..5fbae98c27 100644
--- a/src/net_processing.h
+++ b/src/net_processing.h
@@ -71,12 +71,8 @@ public:
     /** Set the best height */
     virtual void SetBestHeight(int height) = 0;
 
-    /**
-     * Increment peer's misbehavior score. If the new value >= DISCOURAGEMENT_THRESHOLD, mark the node
-     * to be discouraged, meaning the peer might be disconnected and added to the discouragement filter.
-     * Public for unit testing.
-     */
-    virtual void Misbehaving(const NodeId pnode, const int howmuch, const std::string& message) = 0;
+    /* Public for unit testing. */
+    virtual void UnitTestMisbehaving(NodeId peer_id, int howmuch) = 0;
 
     /**
      * Evict extra outbound peers. If we think our tip may be stale, connect to an extra outbound.
diff --git a/src/test/denialofservice_tests.cpp b/src/test/denialofservice_tests.cpp
index 3b4a6f2637..c87ed82c88 100644
--- a/src/test/denialofservice_tests.cpp
+++ b/src/test/denialofservice_tests.cpp
@@ -305,7 +305,7 @@ BOOST_AUTO_TEST_CASE(peer_discouragement)
     peerLogic->InitializeNode(nodes[0]);
     nodes[0]->fSuccessfullyConnected = true;
     connman->AddTestNode(*nodes[0]);
-    peerLogic->Misbehaving(nodes[0]->GetId(), DISCOURAGEMENT_THRESHOLD, /*message=*/""); // Should be discouraged
+    peerLogic->UnitTestMisbehaving(nodes[0]->GetId(), DISCOURAGEMENT_THRESHOLD); // Should be discouraged
     {
         LOCK(nodes[0]->cs_sendProcessing);
         BOOST_CHECK(peerLogic->SendMessages(nodes[0]));
@@ -328,7 +328,7 @@ BOOST_AUTO_TEST_CASE(peer_discouragement)
     peerLogic->InitializeNode(nodes[1]);
     nodes[1]->fSuccessfullyConnected = true;
     connman->AddTestNode(*nodes[1]);
-    peerLogic->Misbehaving(nodes[1]->GetId(), DISCOURAGEMENT_THRESHOLD - 1, /*message=*/"");
+    peerLogic->UnitTestMisbehaving(nodes[1]->GetId(), DISCOURAGEMENT_THRESHOLD - 1);
     {
         LOCK(nodes[1]->cs_sendProcessing);
         BOOST_CHECK(peerLogic->SendMessages(nodes[1]));
@@ -339,7 +339,7 @@ BOOST_AUTO_TEST_CASE(peer_discouragement)
     // [1] is not discouraged/disconnected yet.
     BOOST_CHECK(!banman->IsDiscouraged(addr[1]));
     BOOST_CHECK(!nodes[1]->fDisconnect);
-    peerLogic->Misbehaving(nodes[1]->GetId(), 1, /*message=*/""); // [1] reaches discouragement threshold
+    peerLogic->UnitTestMisbehaving(nodes[1]->GetId(), 1); // [1] reaches discouragement threshold
     {
         LOCK(nodes[1]->cs_sendProcessing);
         BOOST_CHECK(peerLogic->SendMessages(nodes[1]));
@@ -366,7 +366,7 @@ BOOST_AUTO_TEST_CASE(peer_discouragement)
     peerLogic->InitializeNode(nodes[2]);
     nodes[2]->fSuccessfullyConnected = true;
     connman->AddTestNode(*nodes[2]);
-    peerLogic->Misbehaving(nodes[2]->GetId(), DISCOURAGEMENT_THRESHOLD, /*message=*/"");
+    peerLogic->UnitTestMisbehaving(nodes[2]->GetId(), DISCOURAGEMENT_THRESHOLD);
     {
         LOCK(nodes[2]->cs_sendProcessing);
         BOOST_CHECK(peerLogic->SendMessages(nodes[2]));
@@ -411,7 +411,7 @@ BOOST_AUTO_TEST_CASE(DoS_bantime)
     peerLogic->InitializeNode(&dummyNode);
     dummyNode.fSuccessfullyConnected = true;
 
-    peerLogic->Misbehaving(dummyNode.GetId(), DISCOURAGEMENT_THRESHOLD, /*message=*/"");
+    peerLogic->UnitTestMisbehaving(dummyNode.GetId(), DISCOURAGEMENT_THRESHOLD);
     {
         LOCK(dummyNode.cs_sendProcessing);
         BOOST_CHECK(peerLogic->SendMessages(&dummyNode));