4 files changed, 90 insertions, 2 deletions

diff --git a/src/zmq/zmqnotificationinterface.cpp b/src/zmq/zmqnotificationinterface.cpp
index 68b425fa08..8cbc969972 100644
--- a/src/zmq/zmqnotificationinterface.cpp
+++ b/src/zmq/zmqnotificationinterface.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2015-2017 The Bitcoin Core developers
+// Copyright (c) 2015-2018 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -29,6 +29,15 @@ CZMQNotificationInterface::~CZMQNotificationInterface()
     }
 }
 
+std::list<const CZMQAbstractNotifier*> CZMQNotificationInterface::GetActiveNotifiers() const
+{
+    std::list<const CZMQAbstractNotifier*> result;
+    for (const auto* n : notifiers) {
+        result.push_back(n);
+    }
+    return result;
+}
+
 CZMQNotificationInterface* CZMQNotificationInterface::Create()
 {
     CZMQNotificationInterface* notificationInterface = nullptr;
@@ -180,3 +189,5 @@ void CZMQNotificationInterface::BlockDisconnected(const std::shared_ptr<const CB
         TransactionAddedToMempool(ptx);
     }
 }
+
+CZMQNotificationInterface* g_zmq_notification_interface = nullptr;
diff --git a/src/zmq/zmqnotificationinterface.h b/src/zmq/zmqnotificationinterface.h
index dee926ea5e..a0cc26a162 100644
--- a/src/zmq/zmqnotificationinterface.h
+++ b/src/zmq/zmqnotificationinterface.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2015-2017 The Bitcoin Core developers
+// Copyright (c) 2015-2018 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -18,6 +18,8 @@ class CZMQNotificationInterface final : public CValidationInterface
 public:
     virtual ~CZMQNotificationInterface();
 
+    std::list<const CZMQAbstractNotifier*> GetActiveNotifiers() const;
+
     static CZMQNotificationInterface* Create();
 
 protected:
@@ -37,4 +39,6 @@ private:
     std::list<CZMQAbstractNotifier*> notifiers;
 };
 
+extern CZMQNotificationInterface* g_zmq_notification_interface;
+
 #endif // BITCOIN_ZMQ_ZMQNOTIFICATIONINTERFACE_H
diff --git a/src/zmq/zmqrpc.cpp b/src/zmq/zmqrpc.cpp
new file mode 100644
index 0000000000..4f88bf4eb9
--- /dev/null
+++ b/src/zmq/zmqrpc.cpp
@@ -0,0 +1,61 @@
+// Copyright (c) 2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <zmq/zmqrpc.h>
+
+#include <rpc/server.h>
+#include <zmq/zmqabstractnotifier.h>
+#include <zmq/zmqnotificationinterface.h>
+
+#include <univalue.h>
+
+namespace {
+
+UniValue getzmqnotifications(const JSONRPCRequest& request)
+{
+    if (request.fHelp || request.params.size() != 0) {
+        throw std::runtime_error(
+            "getzmqnotifications\n"
+            "\nReturns information about the active ZeroMQ notifications.\n"
+            "\nResult:\n"
+            "[\n"
+            "  {                        (json object)\n"
+            "    \"type\": \"pubhashtx\",   (string) Type of notification\n"
+            "    \"address\": \"...\"       (string) Address of the publisher\n"
+            "  },\n"
+            "  ...\n"
+            "]\n"
+            "\nExamples:\n"
+            + HelpExampleCli("getzmqnotifications", "")
+            + HelpExampleRpc("getzmqnotifications", "")
+        );
+    }
+
+    UniValue result(UniValue::VARR);
+    if (g_zmq_notification_interface != nullptr) {
+        for (const auto* n : g_zmq_notification_interface->GetActiveNotifiers()) {
+            UniValue obj(UniValue::VOBJ);
+            obj.pushKV("type", n->GetType());
+            obj.pushKV("address", n->GetAddress());
+            result.push_back(obj);
+        }
+    }
+
+    return result;
+}
+
+const CRPCCommand commands[] =
+{ //  category              name                                actor (function)                argNames
+  //  -----------------     ------------------------            -----------------------         ----------
+    { "zmq",                "getzmqnotifications",              &getzmqnotifications,           {} },
+};
+
+} // anonymous namespace
+
+void RegisterZMQRPCCommands(CRPCTable& t)
+{
+    for (const auto& c : commands) {
+        t.appendCommand(c.name, &c);
+    }
+}
diff --git a/src/zmq/zmqrpc.h b/src/zmq/zmqrpc.h
new file mode 100644
index 0000000000..5a810a16fb
--- /dev/null
+++ b/src/zmq/zmqrpc.h
@@ -0,0 +1,12 @@
+// Copyright (c) 2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_ZMQ_ZMQRPC_H
+#define BITCOIN_ZMQ_ZMQRPC_H
+
+class CRPCTable;
+
+void RegisterZMQRPCCommands(CRPCTable& t);
+
+#endif // BITCOIN_ZMQ_ZMRRPC_H