From 7f29529f0bb83bd216f396447f45e4ecf6d454dc Mon Sep 17 00:00:00 2001
From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Tue, 17 Sep 2019 10:52:50 +0200
Subject: [PATCH] dnsdist: Don't connect to remote logger in client/command
 mode

---
 pdns/dnsdist-lua-actions.cc                   | 24 +++++++++++--------
 .../dnsdist-lua-bindings-protobuf.cc          | 16 ++++++++++++-
 2 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/pdns/dnsdist-lua-actions.cc b/pdns/dnsdist-lua-actions.cc
index 3f7c3a638..4b9499340 100644
--- a/pdns/dnsdist-lua-actions.cc
+++ b/pdns/dnsdist-lua-actions.cc
@@ -1330,11 +1330,13 @@ void setupLuaActions()
     });
 
   g_lua.writeFunction("RemoteLogAction", [](std::shared_ptr<RemoteLoggerInterface> logger, boost::optional<std::function<void(DNSQuestion*, DNSDistProtoBufMessage*)> > alterFunc, boost::optional<std::unordered_map<std::string, std::string>> vars) {
-      // avoids potentially-evaluated-expression warning with clang.
-      RemoteLoggerInterface& rl = *logger.get();
-      if (typeid(rl) != typeid(RemoteLogger)) {
-        // We could let the user do what he wants, but wrapping PowerDNS Protobuf inside a FrameStream tagged as dnstap is logically wrong.
-        throw std::runtime_error(std::string("RemoteLogAction only takes RemoteLogger. For other types, please look at DnstapLogAction."));
+      if (logger) {
+        // avoids potentially-evaluated-expression warning with clang.
+        RemoteLoggerInterface& rl = *logger.get();
+        if (typeid(rl) != typeid(RemoteLogger)) {
+          // We could let the user do what he wants, but wrapping PowerDNS Protobuf inside a FrameStream tagged as dnstap is logically wrong.
+          throw std::runtime_error(std::string("RemoteLogAction only takes RemoteLogger. For other types, please look at DnstapLogAction."));
+        }
       }
 
       std::string serverID;
@@ -1356,11 +1358,13 @@ void setupLuaActions()
     });
 
   g_lua.writeFunction("RemoteLogResponseAction", [](std::shared_ptr<RemoteLoggerInterface> logger, boost::optional<std::function<void(DNSResponse*, DNSDistProtoBufMessage*)> > alterFunc, boost::optional<bool> includeCNAME, boost::optional<std::unordered_map<std::string, std::string>> vars) {
-      // avoids potentially-evaluated-expression warning with clang.
-      RemoteLoggerInterface& rl = *logger.get();
-      if (typeid(rl) != typeid(RemoteLogger)) {
-        // We could let the user do what he wants, but wrapping PowerDNS Protobuf inside a FrameStream tagged as dnstap is logically wrong.
-        throw std::runtime_error("RemoteLogResponseAction only takes RemoteLogger. For other types, please look at DnstapLogResponseAction.");
+      if (logger) {
+        // avoids potentially-evaluated-expression warning with clang.
+        RemoteLoggerInterface& rl = *logger.get();
+        if (typeid(rl) != typeid(RemoteLogger)) {
+          // We could let the user do what he wants, but wrapping PowerDNS Protobuf inside a FrameStream tagged as dnstap is logically wrong.
+          throw std::runtime_error("RemoteLogResponseAction only takes RemoteLogger. For other types, please look at DnstapLogResponseAction.");
+        }
       }
 
       std::string serverID;
diff --git a/pdns/dnsdistdist/dnsdist-lua-bindings-protobuf.cc b/pdns/dnsdistdist/dnsdist-lua-bindings-protobuf.cc
index ebc165fef..876c8124d 100644
--- a/pdns/dnsdistdist/dnsdist-lua-bindings-protobuf.cc
+++ b/pdns/dnsdistdist/dnsdist-lua-bindings-protobuf.cc
@@ -95,11 +95,17 @@ void setupLuaBindingsProtoBuf(bool client)
 
   /* RemoteLogger */
   g_lua.writeFunction("newRemoteLogger", [client](const std::string& remote, boost::optional<uint16_t> timeout, boost::optional<uint64_t> maxQueuedEntries, boost::optional<uint8_t> reconnectWaitTime) {
+      if (client) {
+        return std::shared_ptr<RemoteLoggerInterface>(nullptr);
+      }
       return std::shared_ptr<RemoteLoggerInterface>(new RemoteLogger(ComboAddress(remote), timeout ? *timeout : 2, maxQueuedEntries ? (*maxQueuedEntries*100) : 10000, reconnectWaitTime ? *reconnectWaitTime : 1, client));
     });
 
   g_lua.writeFunction("newFrameStreamUnixLogger", [client](const std::string& address) {
 #ifdef HAVE_FSTRM
+      if (client) {
+        return std::shared_ptr<RemoteLoggerInterface>(nullptr);
+      }
       return std::shared_ptr<RemoteLoggerInterface>(new FrameStreamLogger(AF_UNIX, address, !client));
 #else
       throw std::runtime_error("fstrm support is required to build an AF_UNIX FrameStreamLogger");
@@ -108,11 +114,19 @@ void setupLuaBindingsProtoBuf(bool client)
 
   g_lua.writeFunction("newFrameStreamTcpLogger", [client](const std::string& address) {
 #if defined(HAVE_FSTRM) && defined(HAVE_FSTRM_TCP_WRITER_INIT)
+      if (client) {
+        return std::shared_ptr<RemoteLoggerInterface>(nullptr);
+      }
       return std::shared_ptr<RemoteLoggerInterface>(new FrameStreamLogger(AF_INET, address, !client));
 #else
       throw std::runtime_error("fstrm with TCP support is required to build an AF_INET FrameStreamLogger");
 #endif /* HAVE_FSTRM */
     });
 
-  g_lua.registerFunction("toString", &RemoteLoggerInterface::toString);
+  g_lua.registerFunction<std::string(std::shared_ptr<RemoteLoggerInterface>::*)()>("toString", [](const std::shared_ptr<RemoteLoggerInterface>& logger) {
+      if (logger) {
+        return logger->toString();
+      }
+      return std::string();
+  });
 }
-- 
2.40.0