Merge 349632e022 into merged_master (Bitcoin PR bitcoin/bitcoin#30807)

src/init.cpp

@@ -1734,7 +1734,12 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
         // This is defined and set here instead of inline in validation.h to avoid a hard
         // dependency between validation and index/base, since the latter is not in
         // libbitcoinkernel.
-        chainman.restart_indexes = [&node]() {
+        chainman.snapshot_download_completed = [&node]() {
+            if (!node.chainman->m_blockman.IsPruneMode()) {
+                LogPrintf("[snapshot] re-enabling NODE_NETWORK services\n");
+                node.connman->AddLocalServices(NODE_NETWORK);
+            }
+
             LogPrintf("[snapshot] restarting indexes\n");
 
             // Drain the validation interface queue to ensure that the old indexes
@@ -1871,8 +1876,13 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
             }
         }
     } else {
-        LogPrintf("Setting NODE_NETWORK on non-prune mode\n");
-        nLocalServices = ServiceFlags(nLocalServices | NODE_NETWORK);
+        // Prior to setting NODE_NETWORK, check if we can provide historical blocks.
+        if (!WITH_LOCK(chainman.GetMutex(), return chainman.BackgroundSyncInProgress())) {
+            LogPrintf("Setting NODE_NETWORK on non-prune mode\n");
+            nLocalServices = ServiceFlags(nLocalServices | NODE_NETWORK);
+        } else {
+            LogPrintf("Running node in NODE_NETWORK_LIMITED mode until snapshot background sync completes\n");
+        }
     }
 
     // ********************************************************* Step 11: import blocks

src/net.cpp

@@ -1791,7 +1791,8 @@ void CConnman::CreateNodeFromAcceptedSocket(std::unique_ptr<Sock>&& sock,
     const bool inbound_onion = std::find(m_onion_binds.begin(), m_onion_binds.end(), addr_bind) != m_onion_binds.end();
     // The V2Transport transparently falls back to V1 behavior when an incoming V1 connection is
     // detected, so use it whenever we signal NODE_P2P_V2.
-    const bool use_v2transport(nLocalServices & NODE_P2P_V2);
+    ServiceFlags local_services = GetLocalServices();
+    const bool use_v2transport(local_services & NODE_P2P_V2);
 
     CNode* pnode = new CNode(id,
                              std::move(sock),
@@ -1809,7 +1810,7 @@ void CConnman::CreateNodeFromAcceptedSocket(std::unique_ptr<Sock>&& sock,
                                  .use_v2transport = use_v2transport,
                              });
     pnode->AddRef();
-    m_msgproc->InitializeNode(*pnode, nLocalServices);
+    m_msgproc->InitializeNode(*pnode, local_services);
     {
         LOCK(m_nodes_mutex);
         m_nodes.push_back(pnode);

src/net.h

@@ -1221,6 +1221,11 @@ public:
     //! that peer during `net_processing.cpp:PushNodeVersion()`.
     ServiceFlags GetLocalServices() const;
 
+    //! Updates the local services that this node advertises to other peers
+    //! during connection handshake.
+    void AddLocalServices(ServiceFlags services) { nLocalServices = ServiceFlags(nLocalServices | services); };
+    void RemoveLocalServices(ServiceFlags services) { nLocalServices = ServiceFlags(nLocalServices & ~services); }
+
     uint64_t GetMaxOutboundTarget() const EXCLUSIVE_LOCKS_REQUIRED(!m_total_bytes_sent_mutex);
     std::chrono::seconds GetMaxOutboundTimeframe() const;
 
@@ -1460,11 +1465,12 @@ private:
      * This data is replicated in each Peer instance we create.
      *
      * This data is not marked const, but after being set it should not
-     * change.
+     * change. Unless AssumeUTXO is started, in which case, the peer
+     * will be limited until the background chain sync finishes.
      *
      * \sa Peer::our_services
      */
-    ServiceFlags nLocalServices;
+    std::atomic<ServiceFlags> nLocalServices;
 
     std::unique_ptr<CSemaphore> semOutbound;
     std::unique_ptr<CSemaphore> semAddnode;

src/rpc/blockchain.cpp

@@ -3318,6 +3318,13 @@ static RPCHelpMan loadtxoutset()
         throw JSONRPCError(RPC_INTERNAL_ERROR, strprintf("Unable to load UTXO snapshot: %s. (%s)", util::ErrorString(activation_result).original, path.utf8string()));
     }
 
+    // Because we can't provide historical blocks during tip or background sync.
+    // Update local services to reflect we are a limited peer until we are fully sync.
+    node.connman->RemoveLocalServices(NODE_NETWORK);
+    // Setting the limited state is usually redundant because the node can always
+    // provide the last 288 blocks, but it doesn't hurt to set it.
+    node.connman->AddLocalServices(NODE_NETWORK_LIMITED);
+
     CBlockIndex& snapshot_index{*CHECK_NONFATAL(*activation_result)};
 
     UniValue result(UniValue::VOBJ);

src/validation.cpp

@@ -4049,8 +4049,8 @@ bool Chainstate::ActivateBestChain(BlockValidationState& state, std::shared_ptr<
             //
             // This cannot be done while holding cs_main (within
             // MaybeCompleteSnapshotValidation) or a cs_main deadlock will occur.
-            if (m_chainman.restart_indexes) {
-                m_chainman.restart_indexes();
+            if (m_chainman.snapshot_download_completed) {
+                m_chainman.snapshot_download_completed();
             }
             break;
         }

src/validation.h

@@ -988,7 +988,7 @@ public:
 
     //! Function to restart active indexes; set dynamically to avoid a circular
     //! dependency on `base/index.cpp`.
-    std::function<void()> restart_indexes = std::function<void()>();
+    std::function<void()> snapshot_download_completed = std::function<void()>();
 
     const CChainParams& GetParams() const { return m_options.chainparams; }
     const Consensus::Params& GetConsensus() const { return m_options.chainparams.GetConsensus(); }