v29.4-roots.1 · Commit 3: [PATCH 03/13] policy: restore conservative relay and network controls

src/net.cpp

Before: src/net.cpp · After: src/net.cpp

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index 7684877ec352cfbee891ee61501367d1169e88d5..05ee7224226c339bbe7ad04c8fdf1a4dedc199bd 100644

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src/net.cpp CHANGED Viewed

@@ -115,7 +115,7 @@ const std::string NET_MESSAGE_TYPE_OTHER = "*other*";
 static const uint64_t RANDOMIZER_ID_NETGROUP = 0x6c0edd8036ef4036ULL; // SHA256("netgroup")[0:8]
 static const uint64_t RANDOMIZER_ID_LOCALHOSTNONCE = 0xd93e69e2bbfa5735ULL; // SHA256("localhostnonce")[0:8]
-static const uint64_t RANDOMIZER_ID_ADDRCACHE = 0x1cf2e4ddd306dda9ULL; // SHA256("addrcache")[0:8]
 //
 // Global state variables
 //
@@ -228,7 +228,7 @@ CService GetLocalAddress(const CNode& peer)
     return GetLocal(peer).value_or(CService{CNetAddr(), GetListenPort()});
 }
-static int GetnScore(const CService& addr)
 {
     LOCK(g_maplocalhost_mutex);
     const auto it = mapLocalHost.find(addr);
@@ -284,7 +284,8 @@ bool AddLocal(const CService& addr_, int nScore)
     if (!fDiscover && nScore < LOCAL_MANUAL)
         return false;
-    if (!g_reachable_nets.Contains(addr))
         return false;
     LogPrintf("AddLocal(%s,%i)\n", addr.ToStringAddrPort(), nScore);
@@ -309,9 +310,11 @@ bool AddLocal(const CNetAddr &addr, int nScore)
 void RemoveLocal(const CService& addr)
 {
-    LOCK(g_maplocalhost_mutex);
-    LogPrintf("RemoveLocal(%s)\n", addr.ToStringAddrPort());
-    mapLocalHost.erase(addr);
 }
 /** vote for a local address */
@@ -320,7 +323,9 @@ bool SeenLocal(const CService& addr)
     LOCK(g_maplocalhost_mutex);
     const auto it = mapLocalHost.find(addr);
     if (it == mapLocalHost.end()) return false;
-    ++it->second.nScore;
     return true;
 }
@@ -463,6 +468,9 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
     std::unique_ptr<i2p::sam::Session> i2p_transient_session;
     for (auto& target_addr: connect_to) {
         if (target_addr.IsValid()) {
             const bool use_proxy{GetProxy(target_addr.GetNetwork(), proxy)};
             bool proxyConnectionFailed = false;
@@ -522,8 +530,7 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
         }
         NetPermissionFlags permission_flags = NetPermissionFlags::None;
-        std::vector<NetWhitelistPermissions> whitelist_permissions = conn_type == ConnectionType::MANUAL ? vWhitelistedRangeOutgoing : std::vector<NetWhitelistPermissions>{};
-        AddWhitelistPermissionFlags(permission_flags, target_addr, whitelist_permissions);
         // Add node
         NodeId id = GetNewNodeId();
@@ -531,6 +538,13 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
         if (!addr_bind.IsValid()) {
             addr_bind = GetBindAddress(*sock);
         }
         CNode* pnode = new CNode(id,
                                 std::move(sock),
                                 target_addr,
@@ -540,6 +554,7 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
                                 pszDest ? pszDest : "",
                                 conn_type,
                                 /*inbound_onion=*/false,
                                 CNodeOptions{
                                     .permission_flags = permission_flags,
                                     .i2p_sam_session = std::move(i2p_transient_session),
@@ -587,6 +602,7 @@ void CConnman::AddWhitelistPermissionFlags(NetPermissionFlags& flags, std::optio
         if (whitelist_relay) NetPermissions::AddFlag(flags, NetPermissionFlags::Relay);
         NetPermissions::AddFlag(flags, NetPermissionFlags::Mempool);
         NetPermissions::AddFlag(flags, NetPermissionFlags::NoBan);
     }
 }
@@ -651,6 +667,7 @@ void CNode::CopyStats(CNodeStats& stats)
         if (info.session_id) stats.m_session_id = HexStr(*info.session_id);
     }
     X(m_permission_flags);
     X(m_last_ping_time);
     X(m_min_ping_time);
@@ -660,6 +677,8 @@ void CNode::CopyStats(CNodeStats& stats)
     stats.addrLocal = addrLocalUnlocked.IsValid() ? addrLocalUnlocked.ToStringAddrPort() : "";
     X(m_conn_type);
 }
 #undef X
@@ -1683,7 +1702,7 @@ std::pair<size_t, bool> CConnman::SocketSendData(CNode& node) const
  *   to forge.  In order to partition a node the attacker must be
  *   simultaneously better at all of them than honest peers.
  */
-bool CConnman::AttemptToEvictConnection()
 {
     std::vector<NodeEvictionCandidate> vEvictionCandidates;
     {
@@ -1711,7 +1730,7 @@ bool CConnman::AttemptToEvictConnection()
             vEvictionCandidates.push_back(candidate);
         }
     }
-    const std::optional<NodeId> node_id_to_evict = SelectNodeToEvict(std::move(vEvictionCandidates));
     if (!node_id_to_evict) {
         return false;
     }
@@ -1767,7 +1786,26 @@ void CConnman::CreateNodeFromAcceptedSocket(std::unique_ptr<Sock>&& sock,
 {
     int nInbound = 0;
-    const bool inbound_onion = std::find(m_onion_binds.begin(), m_onion_binds.end(), addr_bind) != m_onion_binds.end();
     // Tor inbound connections do not reveal the peer's actual network address.
     // Therefore do not apply address-based whitelist permissions to them.
@@ -1814,13 +1852,19 @@ void CConnman::CreateNodeFromAcceptedSocket(std::unique_ptr<Sock>&& sock,
         return;
     }
     if (nInbound >= m_max_inbound)
     {
-        if (!AttemptToEvictConnection()) {
             // No connection to evict, disconnect the new connection
             LogDebug(BCLog::NET, "failed to find an eviction candidate - connection dropped (full)\n");
             return;
         }
     }
     NodeId id = GetNewNodeId();
@@ -1831,6 +1875,11 @@ void CConnman::CreateNodeFromAcceptedSocket(std::unique_ptr<Sock>&& sock,
     ServiceFlags local_services = GetLocalServices();
     const bool use_v2transport(local_services & NODE_P2P_V2);
     CNode* pnode = new CNode(id,
                              std::move(sock),
                              CAddress{addr, NODE_NONE},
@@ -1840,9 +1889,11 @@ void CConnman::CreateNodeFromAcceptedSocket(std::unique_ptr<Sock>&& sock,
                              /*addrNameIn=*/"",
                              ConnectionType::INBOUND,
                              inbound_onion,
                              CNodeOptions{
                                  .permission_flags = permission_flags,
                                  .prefer_evict = discouraged,
                                  .recv_flood_size = nReceiveFloodSize,
                                  .use_v2transport = use_v2transport,
                              });
@@ -1913,7 +1964,8 @@ void CConnman::DisconnectNodes()
     {
         LOCK(m_nodes_mutex);
-        if (!fNetworkActive) {
             // Disconnect any connected nodes
             for (CNode* pnode : m_nodes) {
                 if (!pnode->fDisconnect) {
@@ -1935,7 +1987,7 @@ void CConnman::DisconnectNodes()
                 // Add to reconnection list if appropriate. We don't reconnect right here, because
                 // the creation of a connection is a blocking operation (up to several seconds),
                 // and we don't want to hold up the socket handler thread for that long.
-                if (pnode->m_transport->ShouldReconnectV1()) {
                     reconnections_to_add.push_back({
                         .addr_connect = pnode->addr,
                         .grant = std::move(pnode->grantOutbound),
@@ -1994,16 +2046,15 @@ void CConnman::NotifyNumConnectionsChanged()
     }
 }
-bool CConnman::ShouldRunInactivityChecks(const CNode& node, std::chrono::seconds now) const
 {
     return node.m_connected + m_peer_connect_timeout < now;
 }
-bool CConnman::InactivityCheck(const CNode& node) const
 {
     // Tests that see disconnects after using mocktime can start nodes with a
     // large timeout. For example, -peertimeout=999999999.
-    const auto now{GetTime<std::chrono::seconds>()};
     const auto last_send{node.m_last_send.load()};
     const auto last_recv{node.m_last_recv.load()};
@@ -2027,7 +2078,7 @@ bool CConnman::InactivityCheck(const CNode& node) const
     if (now > last_send + TIMEOUT_INTERVAL) {
         LogDebug(BCLog::NET,
-            "socket sending timeout: %is, %s\n", count_seconds(now - last_send),
             node.DisconnectMsg(fLogIPs)
         );
         return true;
@@ -2035,7 +2086,7 @@ bool CConnman::InactivityCheck(const CNode& node) const
     if (now > last_recv + TIMEOUT_INTERVAL) {
         LogDebug(BCLog::NET,
-            "socket receive timeout: %is, %s\n", count_seconds(now - last_recv),
             node.DisconnectMsg(fLogIPs)
         );
         return true;
@@ -2117,6 +2168,8 @@ void CConnman::SocketHandlerConnected(const std::vector<CNode*>& nodes,
 {
     AssertLockNotHeld(m_total_bytes_sent_mutex);
     for (CNode* pnode : nodes) {
         if (interruptNet)
             return;
@@ -2207,7 +2260,7 @@ void CConnman::SocketHandlerConnected(const std::vector<CNode*>& nodes,
             }
         }
-        if (InactivityCheck(*pnode)) pnode->fDisconnect = true;
     }
 }
@@ -2498,6 +2551,11 @@ bool CConnman::MultipleManualOrFullOutboundConns(Network net) const
     return m_network_conn_counts[net] > 1;
 }
 bool CConnman::MaybePickPreferredNetwork(std::optional<Network>& network)
 {
     std::array<Network, 5> nets{NET_IPV4, NET_IPV6, NET_ONION, NET_I2P, NET_CJDNS};
@@ -3050,6 +3108,8 @@ void CConnman::ThreadMessageHandler()
                 if (pnode->fDisconnect)
                     continue;
                 // Receive messages
                 bool fMoreNodeWork = m_msgproc->ProcessMessages(pnode, flagInterruptMsgProc);
                 fMoreWork |= (fMoreNodeWork && !pnode->fPauseSend);
@@ -3287,7 +3347,29 @@ bool CConnman::InitBinds(const Options& options)
         inaddr_any.s_addr = htonl(INADDR_ANY);
         const CService ipv4_any{inaddr_any, GetListenPort()}; // 0.0.0.0
         if (!Bind(ipv4_any, BF_REPORT_ERROR, NetPermissionFlags::None)) {
-            return false;
         }
     }
     return true;
@@ -3458,6 +3540,8 @@ void CConnman::StopThreads()
 void CConnman::StopNodes()
 {
     if (fAddressesInitialized) {
         DumpAddresses();
         fAddressesInitialized = false;
@@ -3485,6 +3569,7 @@ void CConnman::StopNodes()
         DeleteNode(pnode);
     }
     m_nodes_disconnected.clear();
     vhListenSocket.clear();
     semOutbound.reset();
     semAddnode.reset();
@@ -3517,15 +3602,9 @@ std::vector<CAddress> CConnman::GetAddresses(size_t max_addresses, size_t max_pc
 std::vector<CAddress> CConnman::GetAddresses(CNode& requestor, size_t max_addresses, size_t max_pct)
 {
     auto local_socket_bytes = requestor.addrBind.GetAddrBytes();
-    uint64_t cache_id = GetDeterministicRandomizer(RANDOMIZER_ID_ADDRCACHE)
-        .Write(requestor.ConnectedThroughNetwork())
-        .Write(local_socket_bytes)
-        // For outbound connections, the port of the bound address is randomly
-        // assigned by the OS and would therefore not be useful for seeding.
-        .Write(requestor.IsInboundConn() ? requestor.addrBind.GetPort() : 0)
-        .Finalize();
     const auto current_time = GetTime<std::chrono::microseconds>();
-    auto r = m_addr_response_caches.emplace(cache_id, CachedAddrResponse{});
     CachedAddrResponse& cache_entry = r.first->second;
     if (cache_entry.m_cache_entry_expiration < current_time) { // If emplace() added new one it has expiration 0.
         cache_entry.m_addrs_response_cache = GetAddresses(max_addresses, max_pct, /*network=*/std::nullopt);
@@ -3561,12 +3640,17 @@ std::vector<CAddress> CConnman::GetAddresses(CNode& requestor, size_t max_addres
 bool CConnman::AddNode(const AddedNodeParams& add)
 {
-    const CService resolved(LookupNumeric(add.m_added_node, GetDefaultPort(add.m_added_node)));
-    const bool resolved_is_valid{resolved.IsValid()};
     LOCK(m_added_nodes_mutex);
     for (const auto& it : m_added_node_params) {
-        if (add.m_added_node == it.m_added_node || (resolved_is_valid && resolved == LookupNumeric(it.m_added_node, GetDefaultPort(it.m_added_node)))) return false;
     }
     m_added_node_params.push_back(add);
@@ -3802,6 +3886,7 @@ CNode::CNode(NodeId idIn,
              const std::string& addrNameIn,
              ConnectionType conn_type_in,
              bool inbound_onion,
              CNodeOptions&& node_opts)
     : m_transport{MakeTransport(idIn, node_opts.use_v2transport, conn_type_in == ConnectionType::INBOUND)},
       m_permission_flags{node_opts.permission_flags},
@@ -3813,7 +3898,9 @@ CNode::CNode(NodeId idIn,
       m_dest(addrNameIn),
       m_inbound_onion{inbound_onion},
       m_prefer_evict{node_opts.prefer_evict},
       nKeyedNetGroup{nKeyedNetGroupIn},
       m_conn_type{conn_type_in},
       id{idIn},
       nLocalHostNonce{nLocalHostNonceIn},
@@ -3875,7 +3962,7 @@ void CConnman::PushMessage(CNode* pnode, CSerializedNetMsg&& msg)
     AssertLockNotHeld(m_total_bytes_sent_mutex);
     size_t nMessageSize = msg.data.size();
     LogDebug(BCLog::NET, "sending %s (%d bytes) peer=%d\n", msg.m_type, nMessageSize, pnode->GetId());
-    if (gArgs.GetBoolArg("-capturemessages", false)) {
         CaptureMessage(pnode->addr, msg.m_type, msg.data, /*is_incoming=*/false);
     }
@@ -4012,6 +4099,11 @@ static void CaptureMessageToFile(const CAddress& addr,
     uint32_t size = data.size();
     ser_writedata32(f, size);
     f << data;
 }
 std::function<void(const CAddress& addr,

 static const uint64_t RANDOMIZER_ID_NETGROUP = 0x6c0edd8036ef4036ULL; // SHA256("netgroup")[0:8]
 static const uint64_t RANDOMIZER_ID_LOCALHOSTNONCE = 0xd93e69e2bbfa5735ULL; // SHA256("localhostnonce")[0:8]
+static const uint64_t RANDOMIZER_ID_NETWORKKEY = 0x0e8a2b136c592a7dULL; // SHA256("networkkey")[0:8]
 //
 // Global state variables
 //
     return GetLocal(peer).value_or(CService{CNetAddr(), GetListenPort()});
 }
+int GetnScore(const CService& addr)
 {
     LOCK(g_maplocalhost_mutex);
     const auto it = mapLocalHost.find(addr);
     if (!fDiscover && nScore < LOCAL_MANUAL)
         return false;
+    // IPv4 and IPv6 cannot be connected to unless their networks are reachable, but Tor is not necessarily bidirectional
+    if (!(g_reachable_nets.Contains(addr) || addr.IsTor()))
         return false;
     LogPrintf("AddLocal(%s,%i)\n", addr.ToStringAddrPort(), nScore);
 void RemoveLocal(const CService& addr)
 {
+    {
+        LOCK(g_maplocalhost_mutex);
+        LogPrintf("RemoveLocal(%s)\n", addr.ToStringAddrPort());
+        mapLocalHost.erase(addr);
+    }
 }
 /** vote for a local address */
     LOCK(g_maplocalhost_mutex);
     const auto it = mapLocalHost.find(addr);
     if (it == mapLocalHost.end()) return false;
+    if (it->second.nScore < std::numeric_limits<int>::max()) {
+        ++it->second.nScore;
+    }
     return true;
 }
     std::unique_ptr<i2p::sam::Session> i2p_transient_session;
     for (auto& target_addr: connect_to) {
+        if (DisableV1OnClearnet(target_addr.GetNetClass()) && !use_v2transport) {
+            continue;
+        }
         if (target_addr.IsValid()) {
             const bool use_proxy{GetProxy(target_addr.GetNetwork(), proxy)};
             bool proxyConnectionFailed = false;
         }
         NetPermissionFlags permission_flags = NetPermissionFlags::None;
+        AddWhitelistPermissionFlags(permission_flags, target_addr, vWhitelistedRangeOutgoing);
         // Add node
         NodeId id = GetNewNodeId();
         if (!addr_bind.IsValid()) {
             addr_bind = GetBindAddress(*sock);
         }
+        uint64_t network_id = GetDeterministicRandomizer(RANDOMIZER_ID_NETWORKKEY)
+                            .Write(target_addr.GetNetClass())
+                            .Write(addr_bind.GetAddrBytes())
+                            // For outbound connections, the port of the bound address is randomly
+                            // assigned by the OS and would therefore not be useful for seeding.
+                            .Write(0)
+                            .Finalize();
         CNode* pnode = new CNode(id,
                                 std::move(sock),
                                 target_addr,
                                 pszDest ? pszDest : "",
                                 conn_type,
                                 /*inbound_onion=*/false,
+                                network_id,
                                 CNodeOptions{
                                     .permission_flags = permission_flags,
                                     .i2p_sam_session = std::move(i2p_transient_session),
         if (whitelist_relay) NetPermissions::AddFlag(flags, NetPermissionFlags::Relay);
         NetPermissions::AddFlag(flags, NetPermissionFlags::Mempool);
         NetPermissions::AddFlag(flags, NetPermissionFlags::NoBan);
+        NetPermissions::AddFlag(flags, NetPermissionFlags::Addr);
     }
 }
         if (info.session_id) stats.m_session_id = HexStr(*info.session_id);
     }
     X(m_permission_flags);
+    X(m_forced_inbound);
     X(m_last_ping_time);
     X(m_min_ping_time);
     stats.addrLocal = addrLocalUnlocked.IsValid() ? addrLocalUnlocked.ToStringAddrPort() : "";
     X(m_conn_type);
+    X(m_cpu_time);
 }
 #undef X
  *   to forge.  In order to partition a node the attacker must be
  *   simultaneously better at all of them than honest peers.
  */
+bool CConnman::AttemptToEvictConnection(bool force)
 {
     std::vector<NodeEvictionCandidate> vEvictionCandidates;
     {
             vEvictionCandidates.push_back(candidate);
         }
     }
+    const std::optional<NodeId> node_id_to_evict = SelectNodeToEvict(std::move(vEvictionCandidates), force);
     if (!node_id_to_evict) {
         return false;
     }
 {
     int nInbound = 0;
+    const bool inbound_onion = [this, &addr, &addr_bind]{
+        if (m_onion_binds.empty()) {
+            if (!m_listenonion) {
+                // If -listenonion=0, assume we do not have inbound Tor connections on non-onion listeners
+                return false;
+            }
+            // Tor connections are coming in on the first -bind
+            if ((!m_normal_binds.empty()) && addr_bind == m_normal_binds.front()) {
+                if (addr_bind.IsBindAny()) {
+                    // Tor connections should have a source IP that is local
+                    return addr.IsLocal();
+                }
+                // Otherwise, the source IP is unpredictable, so assume anything could be onion
+                return true;
+            }
+            return false;
+        } else {
+            return std::find(m_onion_binds.begin(), m_onion_binds.end(), addr_bind) != m_onion_binds.end();
+        }
+    }();
     // Tor inbound connections do not reveal the peer's actual network address.
     // Therefore do not apply address-based whitelist permissions to them.
         return;
     }
+    bool forced{false};
     if (nInbound >= m_max_inbound)
     {
+        // If the inbound connection attempt is granted ForceInbound permission, try a little harder
+        // to make room by evicting a peer we may not have otherwise evicted.
+        if (!AttemptToEvictConnection(NetPermissions::HasFlag(permission_flags, NetPermissionFlags::ForceInbound))) {
             // No connection to evict, disconnect the new connection
             LogDebug(BCLog::NET, "failed to find an eviction candidate - connection dropped (full)\n");
             return;
         }
+        // We kicked someone out
+        forced = true;
     }
     NodeId id = GetNewNodeId();
     ServiceFlags local_services = GetLocalServices();
     const bool use_v2transport(local_services & NODE_P2P_V2);
+    uint64_t network_id = GetDeterministicRandomizer(RANDOMIZER_ID_NETWORKKEY)
+                        .Write(inbound_onion ? NET_ONION : addr.GetNetClass())
+                        .Write(addr_bind.GetAddrBytes())
+                        .Write(addr_bind.GetPort()) // inbound connections use bind port
+                        .Finalize();
     CNode* pnode = new CNode(id,
                              std::move(sock),
                              CAddress{addr, NODE_NONE},
                              /*addrNameIn=*/"",
                              ConnectionType::INBOUND,
                              inbound_onion,
+                             network_id,
                              CNodeOptions{
                                  .permission_flags = permission_flags,
                                  .prefer_evict = discouraged,
+                                 .forced_inbound = forced,
                                  .recv_flood_size = nReceiveFloodSize,
                                  .use_v2transport = use_v2transport,
                              });
     {
         LOCK(m_nodes_mutex);
+        const bool network_active{fNetworkActive};
+        if (!network_active) {
             // Disconnect any connected nodes
             for (CNode* pnode : m_nodes) {
                 if (!pnode->fDisconnect) {
                 // Add to reconnection list if appropriate. We don't reconnect right here, because
                 // the creation of a connection is a blocking operation (up to several seconds),
                 // and we don't want to hold up the socket handler thread for that long.
+                if (network_active && pnode->m_transport->ShouldReconnectV1() && !DisableV1OnClearnet(pnode->addr.GetNetClass())) {
                     reconnections_to_add.push_back({
                         .addr_connect = pnode->addr,
                         .grant = std::move(pnode->grantOutbound),
     }
 }
+bool CConnman::ShouldRunInactivityChecks(const CNode& node, std::chrono::microseconds now) const
 {
     return node.m_connected + m_peer_connect_timeout < now;
 }
+bool CConnman::InactivityCheck(const CNode& node, std::chrono::microseconds now) const
 {
     // Tests that see disconnects after using mocktime can start nodes with a
     // large timeout. For example, -peertimeout=999999999.
     const auto last_send{node.m_last_send.load()};
     const auto last_recv{node.m_last_recv.load()};
     if (now > last_send + TIMEOUT_INTERVAL) {
         LogDebug(BCLog::NET,
+            "socket sending timeout: %is, %s\n", Ticks<std::chrono::seconds>(now - last_send),
             node.DisconnectMsg(fLogIPs)
         );
         return true;
     if (now > last_recv + TIMEOUT_INTERVAL) {
         LogDebug(BCLog::NET,
+            "socket receive timeout: %is, %s\n", Ticks<std::chrono::seconds>(now - last_recv),
             node.DisconnectMsg(fLogIPs)
         );
         return true;
 {
     AssertLockNotHeld(m_total_bytes_sent_mutex);
+    auto now = GetTime<std::chrono::microseconds>();
     for (CNode* pnode : nodes) {
         if (interruptNet)
             return;
             }
         }
+        if (InactivityCheck(*pnode, now)) pnode->fDisconnect = true;
     }
 }
     return m_network_conn_counts[net] > 1;
 }
+bool CConnman::DisableV1OnClearnet(Network net) const
+{
+    return disable_v1conn_clearnet && (net == NET_IPV4 || net == NET_IPV6);
+}
 bool CConnman::MaybePickPreferredNetwork(std::optional<Network>& network)
 {
     std::array<Network, 5> nets{NET_IPV4, NET_IPV6, NET_ONION, NET_I2P, NET_CJDNS};
                 if (pnode->fDisconnect)
                     continue;
+                CpuTimer timer{[&pnode](std::chrono::nanoseconds elapsed) { pnode->m_cpu_time += elapsed; }};
                 // Receive messages
                 bool fMoreNodeWork = m_msgproc->ProcessMessages(pnode, flagInterruptMsgProc);
                 fMoreWork |= (fMoreNodeWork && !pnode->fPauseSend);
         inaddr_any.s_addr = htonl(INADDR_ANY);
         const CService ipv4_any{inaddr_any, GetListenPort()}; // 0.0.0.0
         if (!Bind(ipv4_any, BF_REPORT_ERROR, NetPermissionFlags::None)) {
+            int defaultPort = Params().GetDefaultPort();
+            // If listening failed and another port than the standard port was specified,
+            // ask if the user wants to connect via the standard port for the network instead
+            if (GetListenPort() != defaultPort) {
+                bool fRet = uiInterface.ThreadSafeQuestion(
+                    strprintf(_("Do you want to use the standard network port for %s (port %s) instead?"), CLIENT_NAME, defaultPort),
+                    strprintf(_("Listen on port %s failed."), GetListenPort()).translated,
+                    "", CClientUIInterface::MSG_INFORMATION | CClientUIInterface::MODAL | CClientUIInterface::BTN_OK | CClientUIInterface::BTN_ABORT);
+                if (fRet) {
+                    // FIXME: Unbind IPv6 on the other port
+                    gArgs.ForceSetArg("-port", defaultPort);
+                    // Attempt to use standard port
+                    struct in6_addr inaddr6_any = IN6ADDR_ANY_INIT;
+                    Bind(CService(inaddr6_any, defaultPort), BF_NONE, NetPermissionFlags::None);
+                    struct in_addr inaddr_any;
+                    inaddr_any.s_addr = INADDR_ANY;
+                    if (!Bind(CService(inaddr_any, defaultPort), BF_REPORT_ERROR, NetPermissionFlags::None)) {
+                        return false;
+                    }
+                }
+            }
         }
     }
     return true;
 void CConnman::StopNodes()
 {
+    AssertLockNotHeld(m_reconnections_mutex);
     if (fAddressesInitialized) {
         DumpAddresses();
         fAddressesInitialized = false;
         DeleteNode(pnode);
     }
     m_nodes_disconnected.clear();
+    WITH_LOCK(m_reconnections_mutex, m_reconnections.clear());
     vhListenSocket.clear();
     semOutbound.reset();
     semAddnode.reset();
 std::vector<CAddress> CConnman::GetAddresses(CNode& requestor, size_t max_addresses, size_t max_pct)
 {
     auto local_socket_bytes = requestor.addrBind.GetAddrBytes();
+    uint64_t network_id = requestor.m_network_key;
     const auto current_time = GetTime<std::chrono::microseconds>();
+    auto r = m_addr_response_caches.emplace(network_id, CachedAddrResponse{});
     CachedAddrResponse& cache_entry = r.first->second;
     if (cache_entry.m_cache_entry_expiration < current_time) { // If emplace() added new one it has expiration 0.
         cache_entry.m_addrs_response_cache = GetAddresses(max_addresses, max_pct, /*network=*/std::nullopt);
 bool CConnman::AddNode(const AddedNodeParams& add)
 {
+    const CService resolved{MaybeFlipIPv6toCJDNS(LookupNumeric(add.m_added_node, GetDefaultPort(add.m_added_node)))};
+    const bool resolved_invalid{!resolved.IsValid()};
     LOCK(m_added_nodes_mutex);
     for (const auto& it : m_added_node_params) {
+        if (add.m_added_node == it.m_added_node) return false;
+        if (resolved_invalid) continue;
+        const CService service{MaybeFlipIPv6toCJDNS(LookupNumeric(it.m_added_node, GetDefaultPort(it.m_added_node)))};
+        if (resolved == service) return false;
+        // Check if CJDNS address matches regardless of port to detect already-connected inbound peers.
+        if (resolved.IsCJDNS() && static_cast<CNetAddr>(resolved) == static_cast<CNetAddr>(service)) return false;
     }
     m_added_node_params.push_back(add);
              const std::string& addrNameIn,
              ConnectionType conn_type_in,
              bool inbound_onion,
+             uint64_t network_key,
              CNodeOptions&& node_opts)
     : m_transport{MakeTransport(idIn, node_opts.use_v2transport, conn_type_in == ConnectionType::INBOUND)},
       m_permission_flags{node_opts.permission_flags},
       m_dest(addrNameIn),
       m_inbound_onion{inbound_onion},
       m_prefer_evict{node_opts.prefer_evict},
+      m_forced_inbound{node_opts.forced_inbound},
       nKeyedNetGroup{nKeyedNetGroupIn},
+      m_network_key{network_key},
       m_conn_type{conn_type_in},
       id{idIn},
       nLocalHostNonce{nLocalHostNonceIn},
     AssertLockNotHeld(m_total_bytes_sent_mutex);
     size_t nMessageSize = msg.data.size();
     LogDebug(BCLog::NET, "sending %s (%d bytes) peer=%d\n", msg.m_type, nMessageSize, pnode->GetId());
+    if (m_capture_messages) {
         CaptureMessage(pnode->addr, msg.m_type, msg.data, /*is_incoming=*/false);
     }
     uint32_t size = data.size();
     ser_writedata32(f, size);
     f << data;
+    if (f.fclose() != 0) {
+        throw std::ios_base::failure(
+            strprintf("Error closing %s after write, file contents are likely incomplete", fs::PathToString(path)));
+    }
 }
 std::function<void(const CAddress& addr,