dnsdist: avoid LuaWrapper assert on errors in newServer()

diff --git a/pdns/dnsdist-lua.cc b/pdns/dnsdist-lua.cc
index 1c9f18c604c19079c44dd655c7f5e076e35388eb..6f46af20a50c5acd10cdf8c896346a0f14a60301 100644 (file)
--- a/pdns/dnsdist-lua.cc
+++ b/pdns/dnsdist-lua.cc
@@ -110,66 +110,48 @@ void setupLuaConfig(bool client)
   });
 
   g_lua.writeFunction("newServer",
-                     [client](boost::variant<string,newserver_t> pvars, boost::optional<int> qps) {
-                        setLuaSideEffect();
-                       if(client) {
-                         return std::make_shared<DownstreamState>(ComboAddress());
-                       }
-                       ComboAddress sourceAddr;
-                       unsigned int sourceItf = 0;
-                        size_t numberOfSockets = 1;
-                        std::set<int> cpus;
-                       if(auto addressStr = boost::get<string>(&pvars)) {
-                         std::shared_ptr<DownstreamState> ret;
-                         try {
-                           ComboAddress address(*addressStr, 53);
-                           if(IsAnyAddress(address)) {
-                             g_outputBuffer="Error creating new server: invalid address for a downstream server.";
-                             errlog("Error creating new server: %s is not a valid address for a downstream server", *addressStr);
-                             return ret;
-                           }
-                           ret=std::make_shared<DownstreamState>(address);
-                         }
-                         catch(const PDNSException& e) {
-                           g_outputBuffer="Error creating new server: "+string(e.reason);
-                           errlog("Error creating new server with address %s: %s", addressStr, e.reason);
-                           return ret;
-                         }
-                         catch(std::exception& e) {
-                           g_outputBuffer="Error creating new server: "+string(e.what());
-                           errlog("Error creating new server with address %s: %s", addressStr, e.what());
-                           return ret;
-                         }
+      [client](boost::variant<string,newserver_t> pvars, boost::optional<int> qps) {
+      setLuaSideEffect();
 
-                         if(qps) {
-                           ret->qps=QPSLimiter(*qps, *qps);
-                         }
-                         g_dstates.modify([ret](servers_t& servers) {
-                             servers.push_back(ret);
-                             std::stable_sort(servers.begin(), servers.end(), [](const decltype(ret)& a, const decltype(ret)& b) {
-                                 return a->order < b->order;
-                               });
+      std::shared_ptr<DownstreamState> ret = std::make_shared<DownstreamState>(ComboAddress());
+      newserver_t vars;
 
-                           });
+      ComboAddress serverAddr;
+      std::string serverAddressStr;
+      if(auto addrStr = boost::get<string>(&pvars)) {
+        serverAddressStr = *addrStr;
+        if(qps) {
+          vars["qps"] = std::to_string(*qps);
+        }
+      } else {
+        vars = boost::get<newserver_t>(pvars);
+        serverAddressStr = boost::get<string>(vars["address"]);
+      }
 
-                         auto localPools = g_pools.getCopy();
-                         addServerToPool(localPools, "", ret);
-                         g_pools.setState(localPools);
+      try {
+        serverAddr = ComboAddress(serverAddressStr, 53);
+      }
+      catch(const PDNSException& e) {
+        g_outputBuffer="Error creating new server: "+string(e.reason);
+        errlog("Error creating new server with address %s: %s", serverAddressStr, e.reason);
+        return ret;
+      }
+      catch(std::exception& e) {
+        g_outputBuffer="Error creating new server: "+string(e.what());
+        errlog("Error creating new server with address %s: %s", serverAddressStr, e.what());
+        return ret;
+      }
 
-                         if (ret->connected) {
-                           if(g_launchWork) {
-                             g_launchWork->push_back([ret]() {
-                               ret->tid = thread(responderThread, ret);
-                             });
-                           }
-                           else {
-                             ret->tid = thread(responderThread, ret);
-                           }
-                         }
+      if(IsAnyAddress(serverAddr)) {
+        g_outputBuffer="Error creating new server: invalid address for a downstream server.";
+        errlog("Error creating new server: %s is not a valid address for a downstream server", serverAddressStr);
+        return ret;
+      }
 
-                         return ret;
-                       }
-                       auto vars=boost::get<newserver_t>(pvars);
+      ComboAddress sourceAddr;
+      unsigned int sourceItf = 0;
+      size_t numberOfSockets = 1;
+      std::set<int> cpus;
 
                        if(vars.count("source")) {
                          /* handle source in the following forms:
@@ -225,26 +207,11 @@ void setupLuaConfig(bool client)
                           }
                         }
 
-                       std::shared_ptr<DownstreamState> ret;
-                       try {
-                         ComboAddress address(boost::get<string>(vars["address"]), 53);
-                         if(IsAnyAddress(address)) {
-                           g_outputBuffer="Error creating new server: invalid address for a downstream server.";
-                           errlog("Error creating new server: %s is not a valid address for a downstream server", boost::get<string>(vars["address"]));
-                           return ret;
-                         }
-                         ret=std::make_shared<DownstreamState>(address, sourceAddr, sourceItf, numberOfSockets);
-                       }
-                       catch(const PDNSException& e) {
-                         g_outputBuffer="Error creating new server: "+string(e.reason);
-                         errlog("Error creating new server with address %s: %s", boost::get<string>(vars["address"]), e.reason);
-                         return ret;
-                       }
-                       catch(std::exception& e) {
-                         g_outputBuffer="Error creating new server: "+string(e.what());
-                         errlog("Error creating new server with address %s: %s", boost::get<string>(vars["address"]), e.what());
-                         return ret;
-                       }
+      if(client) {
+        // do not construct DownstreamState now, it would try binding sockets.
+        return ret;
+      }
+      ret=std::make_shared<DownstreamState>(serverAddr, sourceAddr, sourceItf, numberOfSockets);
 
                        if(vars.count("qps")) {
                          int qpsVal=std::stoi(boost::get<string>(vars["qps"]));