RPC: Add "togglenetwork" method to toggle network activity temporarily

RPC command "togglenetwork" toggles network and returns new state after command.
RPC command "getinfo" returns "networkactive" field in output.

src/net.h

@@ -131,6 +131,7 @@ public:
     bool Start(boost::thread_group& threadGroup, CScheduler& scheduler, std::string& strNodeError, Options options);
     void Stop();
     bool BindListenPort(const CService &bindAddr, std::string& strError, bool fWhitelisted = false);
+    bool GetNetworkActive() const { return fNetworkActive; };
     void SetNetworkActive(bool active);
     bool OpenNetworkConnection(const CAddress& addrConnect, bool fCountFailure, CSemaphoreGrant *grantOutbound = NULL, const char *strDest = NULL, bool fOneShot = false, bool fFeeler = false);
     bool CheckIncomingNonce(uint64_t nonce);

src/rpc/misc.cpp

@@ -89,8 +89,10 @@ UniValue getinfo(const UniValue& params, bool fHelp)
 #endif
     obj.push_back(Pair("blocks",        (int)chainActive.Height()));
     obj.push_back(Pair("timeoffset",    GetTimeOffset()));
-    if(g_connman)
+    if (g_connman) {
+        obj.push_back(Pair("networkactive", g_connman->GetNetworkActive()));
         obj.push_back(Pair("connections",   (int)g_connman->GetNodeCount(CConnman::CONNECTIONS_ALL)));
+    }
     obj.push_back(Pair("proxy",         (proxy.IsValid() ? proxy.proxy.ToStringIPPort() : string())));
     obj.push_back(Pair("difficulty",    (double)GetDifficulty()));
     obj.push_back(Pair("testnet",       Params().TestnetToBeDeprecatedFieldRPC()));

src/rpc/net.cpp

@@ -571,6 +571,24 @@ UniValue clearbanned(const UniValue& params, bool fHelp)
     return NullUniValue;
 }
 
+UniValue togglenetwork(const JSONRPCRequest& request)
+{
+    if (request.fHelp || request.params.size() != 0) {
+        throw runtime_error(
+            "togglenetwork\n"
+            "Toggle all network activity temporarily."
+        );
+    }
+
+    if (!g_connman) {
+        throw JSONRPCError(RPC_CLIENT_P2P_DISABLED, "Error: Peer-to-peer functionality missing or disabled");
+    }
+
+    g_connman->SetNetworkActive(!g_connman->GetNetworkActive());
+
+    return g_connman->GetNetworkActive();
+}
+
 static const CRPCCommand commands[] =
 { //  category              name                      actor (function)         okSafeMode
   //  --------------------- ------------------------  -----------------------  ----------
@@ -585,6 +603,7 @@ static const CRPCCommand commands[] =
     { "network",            "setban",                 &setban,                 true  },
     { "network",            "listbanned",             &listbanned,             true  },
     { "network",            "clearbanned",            &clearbanned,            true  },
+    { "network",            "togglenetwork",          &togglenetwork,          true, },
 };
 
 void RegisterNetRPCCommands(CRPCTable &t)