dnsdist: Fix a data race reported by TSAN in SNMP metrics

Unless I'm mistaken, the report (below) is a false positive since
`std::atomic<T>::operator T` is equivalent to `load()` and
`std::atomic<T>::operator=` to `store()`, but perhaps I'm missing
something.
Note that I could not reproduce the issue using clang++ 11.1.0's
TSAN, only with the one from g++ 11.1.0.

```
==================
WARNING: ThreadSanitizer: data race (pid=11157)
  Atomic read of size 8 at 0x7b7400002580 by thread T2:
    #0 __tsan_atomic64_load <null> (dnsdist+0x7a6eb0)
    #1 std::atomic<double>::load(std::memory_order) const /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/atomic:250:2 (dnsdist+0x83c4da)
    #2 pdns::stat_t_trait<double>::operator double() const /opt/project/pdns/dnsdistdist/./stat_t.hh:67:60 (dnsdist+0xd05b2e)
    #3 backendStatTable_handler(netsnmp_mib_handler_s*, netsnmp_handler_registration_s*, netsnmp_agent_request_info_s*, netsnmp_request_info_s*) /opt/project/pdns/dnsdistdist/dnsdist-snmp.cc:356:54 (dnsdist+0xeceab8)
    #4 netsnmp_call_next_handler <null> (libnetsnmpagent.so.30+0x2a0cc)
    #5 SNMPAgent::handleSNMPQueryCB(int, boost::any&) /opt/project/pdns/dnsdistdist/snmp-agent.cc:96:13 (dnsdist+0xfb2417)
    #6 boost::detail::function::void_function_invoker2<void (*)(int, boost::any&), void, int, boost::any&>::invoke(boost::detail::function::function_buffer&, int, boost::any&) /usr/include/boost/function/function_template.hpp:118:11 (dnsdist+0x8956e8)
    #7 boost::function2<void, int, boost::any&>::operator()(int, boost::any&) const /usr/include/boost/function/function_template.hpp:768:14 (dnsdist+0xf9f13c)
    #8 EpollFDMultiplexer::run(timeval*, int) /opt/project/pdns/dnsdistdist/epollmplexer.cc:176:7 (dnsdist+0xfd1feb)
    #9 SNMPAgent::worker() /opt/project/pdns/dnsdistdist/snmp-agent.cc:141:24 (dnsdist+0xfb273f)
    #10 void std::__invoke_impl<void, void (SNMPAgent::*)(), SNMPAgent*>(std::__invoke_memfun_deref, void (SNMPAgent::*&&)(), SNMPAgent*&&) /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/invoke.h:73:14 (dnsdist+0xf36079)
    #11 std::__invoke_result<void (SNMPAgent::*)(), SNMPAgent*>::type std::__invoke<void (SNMPAgent::*)(), SNMPAgent*>(void (SNMPAgent::*&&)(), SNMPAgent*&&) /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/invoke.h:95:14 (dnsdist+0xf35f71)
    #12 decltype(std::__invoke(_S_declval<0ul>(), _S_declval<1ul>())) std::thread::_Invoker<std::tuple<void (SNMPAgent::*)(), SNMPAgent*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/thread:244:13 (dnsdist+0xf35f1e)
    #13 std::thread::_Invoker<std::tuple<void (SNMPAgent::*)(), SNMPAgent*> >::operator()() /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/thread:253:11 (dnsdist+0xf35ec5)
    #14 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (SNMPAgent::*)(), SNMPAgent*> > >::_M_run() /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/thread:196:13 (dnsdist+0xf35c29)
    #15 <null> <null> (libstdc++.so.6+0xbbb2e)

  Previous write of size 8 at 0x7b7400002580 by thread T18:
    [failed to restore the stack]

  Location is heap block of size 2304 at 0x7b7400001e00 allocated by main thread:
    #0 operator new(unsigned long, std::align_val_t) <null> (dnsdist+0x7e8c57)
    #1 __gnu_cxx::new_allocator<std::_Sp_counted_ptr_inplace<DownstreamState, std::allocator<DownstreamState>, (__gnu_cxx::_Lock_policy)2> >::allocate(unsigned long, void const*) /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/ext/new_allocator.h:108:31 (dnsdist+0xe6b4e2)
    #2 std::allocator_traits<std::allocator<std::_Sp_counted_ptr_inplace<DownstreamState, std::allocator<DownstreamState>, (__gnu_cxx::_Lock_policy)2> > >::allocate(std::allocator<std::_Sp_counted_ptr_inplace<DownstreamState, std::allocator<DownstreamState>, (__gnu_cxx::_Lock_policy)2> >&, unsigned long) /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/alloc_traits.h:436:20 (dnsdist+0xe6b430)
    #3 std::__allocated_ptr<std::allocator<std::_Sp_counted_ptr_inplace<DownstreamState, std::allocator<DownstreamState>, (__gnu_cxx::_Lock_policy)2> > > std::__allocate_guarded<std::allocator<std::_Sp_counted_ptr_inplace<DownstreamState, std::allocator<DownstreamState>, (__gnu_cxx::_Lock_policy)2> > >(std::allocator<std::_Sp_counted_ptr_inplace<DownstreamState, std::allocator<DownstreamState>, (__gnu_cxx::_Lock_policy)2> >&) /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/allocated_ptr.h:97:21 (dnsdist+0xe6b1d0)
    #4 std::__shared_count<(__gnu_cxx::_Lock_policy)2>::__shared_count<DownstreamState, std::allocator<DownstreamState>, ComboAddress&, ComboAddress&, unsigned int&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, unsigned long&, bool>(DownstreamState*&, std::_Sp_alloc_shared_tag<std::allocator<DownstreamState> >, ComboAddress&, ComboAddress&, unsigned int&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, unsigned long&, bool&&) /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/shared_ptr_base.h:675:19 (dnsdist+0xe6fb0a)
    #5 std::__shared_ptr<DownstreamState, (__gnu_cxx::_Lock_policy)2>::__shared_ptr<std::allocator<DownstreamState>, ComboAddress&, ComboAddress&, unsigned int&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, unsigned long&, bool>(std::_Sp_alloc_shared_tag<std::allocator<DownstreamState> >, ComboAddress&, ComboAddress&, unsigned int&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, unsigned long&, bool&&) /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/shared_ptr_base.h:1342:14 (dnsdist+0xe6fa7a)
    #6 std::shared_ptr<DownstreamState>::shared_ptr<std::allocator<DownstreamState>, ComboAddress&, ComboAddress&, unsigned int&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, unsigned long&, bool>(std::_Sp_alloc_shared_tag<std::allocator<DownstreamState> >, ComboAddress&, ComboAddress&, unsigned int&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, unsigned long&, bool&&) /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/shared_ptr.h:359:4 (dnsdist+0xe6f99d)
    #7 std::shared_ptr<DownstreamState> std::allocate_shared<DownstreamState, std::allocator<DownstreamState>, ComboAddress&, ComboAddress&, unsigned int&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, unsigned long&, bool>(std::allocator<DownstreamState> const&, ComboAddress&, ComboAddress&, unsigned int&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, unsigned long&, bool&&) /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/shared_ptr.h:705:14 (dnsdist+0xe6f8e0)
    #8 std::shared_ptr<DownstreamState> std::make_shared<DownstreamState, ComboAddress&, ComboAddress&, unsigned int&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, unsigned long&, bool>(ComboAddress&, ComboAddress&, unsigned int&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, unsigned long&, bool&&) /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/shared_ptr.h:721:14 (dnsdist+0xe6a726)
    #9 setupLuaConfig(LuaContext&, bool, bool)::$_2::operator()(boost::variant<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> > > > > >, boost::optional<int>) const /opt/project/pdns/dnsdistdist/dnsdist-lua.cc:356:11 (dnsdist+0xdf9166)
    #10 _ZN10LuaContext6BinderIRZL14setupLuaConfigRS_bbE3$_2RKN5boost7variantINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEJSt13unordered_mapISB_NS5_IbJSB_St6vectorISt4pairIiSB_ESaISF_EESt8functionIFSt5tupleIJ7DNSNamettEERKSK_ttP9dnsheaderEEEEESt4hashISB_ESt8equal_toISB_ESaISE_IKSB_SS_EEEEEEEclIJRKNS4_8optionalIiEEEEEDTcldtdefpT8functiondtdefpT5paramspclsr3stdE7forwardIT_Efp_EEEDpOS1A_ /opt/project/pdns/dnsdistdist/./ext/luawrapper/include/LuaContext.hpp:1846:20 (dnsdist+0xdf89af)
    #11 _ZN10LuaContext6BinderIRNS0_IRZL14setupLuaConfigRS_bbE3$_2RKN5boost7variantINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEJSt13unordered_mapISB_NS5_IbJSB_St6vectorISt4pairIiSB_ESaISF_EESt8functionIFSt5tupleIJ7DNSNamettEERKSK_ttP9dnsheaderEEEEESt4hashISB_ESt8equal_toISB_ESaISE_IKSB_SS_EEEEEEEERKNS4_8optionalIiEEEclIJEEEDTcldtdefpT8functiondtdefpT5paramspclsr3stdE7forwardIT_Efp_EEEDpOS1C_ /opt/project/pdns/dnsdistdist/./ext/luawrapper/include/LuaContext.hpp:1846:20 (dnsdist+0xdf8917)
    #12 std::shared_ptr<DownstreamState> LuaContext::readIntoFunction<std::shared_ptr<DownstreamState>, LuaContext::Binder<LuaContext::Binder<setupLuaConfig(LuaContext&, bool, bool)::$_2&, boost::variant<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> > > > > > const&>&, boost::optional<int> const&>&>(lua_State*, LuaContext::tag<std::shared_ptr<DownstreamState> >, LuaContext::Binder<LuaContext::Binder<setupLuaConfig(LuaContext&, bool, bool)::$_2&, boost::variant<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> > > > > > const&>&, boost::optional<int> const&>&, int) /opt/project/pdns/dnsdistdist/./ext/luawrapper/include/LuaContext.hpp:1766:16 (dnsdist+0xdf88be)
    #13 std::enable_if<IsOptional<boost::optional<int> >::value, std::shared_ptr<DownstreamState> >::type LuaContext::readIntoFunction<std::shared_ptr<DownstreamState>, LuaContext::Binder<setupLuaConfig(LuaContext&, bool, bool)::$_2&, boost::variant<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> > > > > > const&>&, boost::optional<int> >(lua_State*, LuaContext::tag<std::shared_ptr<DownstreamState> >, LuaContext::Binder<setupLuaConfig(LuaContext&, bool, bool)::$_2&, boost::variant<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> > > > > > const&>&, int, LuaContext::tag<boost::optional<int> >) /opt/project/pdns/dnsdistdist/./ext/luawrapper/include/LuaContext.hpp:1774:20 (dnsdist+0xdf8624)
    #14 std::enable_if<!(IsOptional<boost::variant<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> > > > > > >::value), std::shared_ptr<DownstreamState> >::type LuaContext::readIntoFunction<std::shared_ptr<DownstreamState>, setupLuaConfig(LuaContext&, bool, bool)::$_2&, boost::variant<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> > > > > >, boost::optional<int> >(lua_State*, LuaContext::tag<std::shared_ptr<DownstreamState> >, setupLuaConfig(LuaContext&, bool, bool)::$_2&, int, LuaContext::tag<boost::variant<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> > > > > > >, LuaContext::tag<boost::optional<int> >) /opt/project/pdns/dnsdistdist/./ext/luawrapper/include/LuaContext.hpp:1796:16 (dnsdist+0xdf848d)
    #15 std::enable_if<(!(std::integral_constant<bool, false>::value)) && (!(std::is_void<bool>::value)), LuaContext::PushedObject>::type LuaContext::Pusher<std::shared_ptr<DownstreamState> (boost::variant<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> > > > > >, boost::optional<int>), void>::callback2<setupLuaConfig(LuaContext&, bool, bool)::$_2&>(lua_State*, bool&&, int) /opt/project/pdns/dnsdistdist/./ext/luawrapper/include/LuaContext.hpp:2429:31 (dnsdist+0xdf83c2)
    #16 LuaContext::PushedObject LuaContext::Pusher<std::shared_ptr<DownstreamState> (boost::variant<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> > > > > >, boost::optional<int>), void>::callback<setupLuaConfig(LuaContext&, bool, bool)::$_2>(lua_State*, setupLuaConfig(LuaContext&, bool, bool)::$_2*, int) /opt/project/pdns/dnsdistdist/./ext/luawrapper/include/LuaContext.hpp:2398:20 (dnsdist+0xdf8169)
    #17 std::enable_if<boost::has_trivial_destructor<setupLuaConfig(LuaContext&, bool, bool)::$_2>::value, LuaContext::PushedObject>::type LuaContext::Pusher<std::shared_ptr<DownstreamState> (boost::variant<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> > > > > >, boost::optional<int>), void>::push<setupLuaConfig(LuaContext&, bool, bool)::$_2>(lua_State*, setupLuaConfig(LuaContext&, bool, bool)::$_2)::'lambda'(lua_State*)::operator()(lua_State*) const /opt/project/pdns/dnsdistdist/./ext/luawrapper/include/LuaContext.hpp:2327:20 (dnsdist+0xdf80c9)
    #18 std::enable_if<boost::has_trivial_destructor<setupLuaConfig(LuaContext&, bool, bool)::$_2>::value, LuaContext::PushedObject>::type LuaContext::Pusher<std::shared_ptr<DownstreamState> (boost::variant<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, boost::variant<bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::vector<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::function<std::tuple<DNSName, unsigned short, unsigned short> (DNSName const&, unsigned short, unsigned short, dnsheader*)> > > > > >, boost::optional<int>), void>::push<setupLuaConfig(LuaContext&, bool, bool)::$_2>(lua_State*, setupLuaConfig(LuaContext&, bool, bool)::$_2)::'lambda'(lua_State*)::__invoke(lua_State*) /opt/project/pdns/dnsdistdist/./ext/luawrapper/include/LuaContext.hpp:2323:31 (dnsdist+0xdf8055)
    #19 _init <null> (libluajit-5.1.so.2+0x9dd6)
    #20 std::tuple<> LuaContext::call<std::tuple<> >(lua_State*, LuaContext::PushedObject) /opt/project/pdns/dnsdistdist/./ext/luawrapper/include/LuaContext.hpp:1413:29 (dnsdist+0xc9ae67)
    #21 LuaContext::executeCode(std::istream&) /opt/project/pdns/dnsdistdist/./ext/luawrapper/include/LuaContext.hpp:267:9 (dnsdist+0xe6077a)
    #22 setupLua(LuaContext&, bool, bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) /opt/project/pdns/dnsdistdist/dnsdist-lua.cc:2599:10 (dnsdist+0xdf4ff3)
    #23 main /opt/project/pdns/dnsdistdist/dnsdist.cc:2235:17 (dnsdist+0xf282ea)

  Thread T2 'dnsdist/SNMP' (tid=11160, running) created by main thread at:
    #0 pthread_create <null> (dnsdist+0x75f2d5)
    #1 std::thread::_M_start_thread(std::unique_ptr<std::thread::_State, std::default_delete<std::thread::_State> >, void (*)()) <null> (libstdc++.so.6+0xbbdb4)
    #2 SNMPAgent::run() /opt/project/pdns/dnsdistdist/./snmp-agent.hh:36:14 (dnsdist+0xf3087c)
    #3 main /opt/project/pdns/dnsdistdist/dnsdist.cc:2373:20 (dnsdist+0xf28f32)

  Thread T18 'dnsdist/healthC' (tid=11176, running) created by main thread at:
    #0 pthread_create <null> (dnsdist+0x75f2d5)
    #1 std::thread::_M_start_thread(std::unique_ptr<std::thread::_State, std::default_delete<std::thread::_State> >, void (*)()) <null> (libstdc++.so.6+0xbbdb4)
    #2 main /opt/project/pdns/dnsdistdist/dnsdist.cc:2463:12 (dnsdist+0xf29769)

SUMMARY: ThreadSanitizer: data race (/opt/dnsdist-with-tsan/bin/dnsdist+0x7a6eb0) in __tsan_atomic64_load
```

Merge pull request #10430 from mind04/pdns-wording

auth: use primary and secondary for pdnsutil and pdns_control commands

auth: update pdnsutil help message

auth: use primary/seconday in pddns_control and s/zone/domain

auth: use primary/seconday in pdnsutil

Merge pull request #10399 from mind04/pdns-recheck

auth: make sure we recheck failed SOA lookups for notifies

Merge pull request #10429 from rgacogne/loop-warnings

Fix 'temporary used in loop' warnings reported by g++ 11.1.0

auth: Fix a 'temporary used in loop' warning reported by g++ 11.1.0

```
common_startup.cc: In function ‘void mainthread()’:
common_startup.cc:617:24: warning: loop variable ‘algotype’ of type ‘const string&’ {aka ‘const std::__cxx11::basic_string<char>&’} binds to a temporary constructed from type ‘const char* const’ [-Wrange-loop-construct]
  617 |     for (const string& algotype : {"ksk", "zsk"}) {
      |                        ^~~~~~~~
common_startup.cc:617:24: note: use non-reference type ‘const string’ {aka ‘const std::__cxx11::basic_string<char>’} to make the copy explicit or ‘const char* const&’ to prevent copying
```

test-dnsname_cc.cc: Fix a 'temporary used in loop' warning reported by g++ 11.1.0

```
test-dnsname_cc.cc: In member function ‘void test_dnsname_cc::test_compare_canonical::test_method()’:
test-dnsname_cc.cc:684:26: warning: loop variable ‘b’ of type ‘const string&’ {aka ‘const std::__cxx11::basic_string<char>&’} binds to a temporary constructed from type ‘const char* const’ [-Wrange-loop-construct]
  684 |   for(const std::string& b : {"bert.com.", "alpha.nl.", "articles.xxx.",
      |                          ^
test-dnsname_cc.cc:684:26: note: use non-reference type ‘const string’ {aka ‘const std::__cxx11::basic_string<char>’} to make the copy explicit or ‘const char* const&’ to prevent copying
```

Merge pull request #10421 from mind04/pdns-list-zones

auth: add an option to in/exclude disabled zones in the pdnsutil list-all-zone and list-keys output.

Merge pull request #10260 from mind04/pdns-nsec3param

auth: lower max-nsec3-iterations to 100

auth: pdnsutil, use cmds.at()

auth: optionally include disabled or empty zones in the pdnsutil list-all-zone and list-keys output

auth: lower max-nsec3-iterations to 100

Merge pull request #10424 from mind04/pdns-domain2zone

auth: replace domain-metadata-cache-ttl by zone-metadata-cache-ttl

auth: change domain to zone round 1

auth: replace domain-metadata-cache-ttl by zone-metadata-cache-ttl

Merge pull request #9464 from zeha/zonecache

auth: cache list of all domains

test zone-cache in gsqlite3 master and slave, with low TTL for more intensive testing

Merge pull request #10349 from omoerbeek/rec-tcpiohandler

rec: move to tcpiohandler for outgoing TCP

Merge pull request #10420 from omoerbeek/rec-nod-no-qm

rec: For the NOD lookup case, we don't want QName Minimization.

Merge pull request #10381 from rgacogne/ddist-better-padding

dnsdist: Reorganize the IDState and Rings fields

Rename domaincache to zonecache, also ttl to refreshinterval

Merge pull request #10282 from omoerbeek/qtype-tostring

Rename QType.getName() to QType.toString()

Rename QType.getName() to QType.toString()

Merge pull request #10401 from mind04/consistent

auth: change the consistent-backends default to 'yes'

For the NOD lookup case, we don't want QName Minimization.

ueberbackend: include disabled domains in cache

Add (domain-)cache-ttl to gsqlite3-master CI

auth: change the consistent-backends default to 'yes'

Treat vanished domains like they were never in the cache

Merge pull request #10400 from mind04/headers

add missing includes (Fedora 34, gcc 11.1 / clang 12)

getAuth: abort if backend returned wrong SOA for cached domain

getAuth: avoid throwing when no SOA is returned for cached domain

auth-domaincache: use info-zone-query for inserted zone id

Also apply "RETURNING id" optimization for postgresql.

lmdbbackend/createDomain: reuse RW transaction

auth-domaincache: apply suggested comment improvement

Apply clang-format

auth-domaincache: add "new" headers

setReplacePending: avoid lock

test-auth-domaincache_cc: check zoneId value explicitly

Tidy up style nits

domaincache: preserve domains added while replace data collection was running

Reformat

Remove unused d_ops

Add separate auth domain cache test

AuthDomainCache: init d_ttl

AuthDomainCache: use std::move

Move extern AuthDomainCache into auth-domaincache.hh

Enable domain cache on gsql tests

Avoid abort if database server goes away

auth: add a cache of existing domains

add missing includes (Fedora 34, gcc 11.1 / clang 12)

Merge pull request #10397 from aj-gh/fixdoc-refreshonttlperc

Fix docs: refresh-on-ttl-perc was added in 4.5.0

Fix docs: refresh-on-ttl-perc was added in 4.5.0

Merge pull request #10392 from Habbie/gpgsql-select-returning

auth gpgsql: use SELECT .. RETURNING to get inserted row ID

Merge pull request #10394 from mnordhoff/rec-upgrade

Combine duplicate sections in Recursor upgrade guide

pdnsutil add-zone-key: better error formatting

auth gpgsql: use SELECT .. RETURNING to get inserted row ID, fixes #7175

Combine duplicate sections in Recursor upgrade guide.

Also use more consistent capitalization and wording.

Merge pull request #10389 from Habbie/dockerignore-git

.dockerignore: do not ignore .git

Merge pull request #10391 from omoerbeek/rec-fastopen-docs

rec: Better wording for fastopen docs.

Merge pull request #10350 from rgacogne/rec-duplicate-nsec-wc-proof

rec: Only add the NSEC and RRSIG records once in wildcard NODATA answers

Better wording for fastopen docs.

Merge pull request #10388 from rgacogne/ddist-document-default-cache-cleaning-delay

dnsdist: Document the default value of setCacheCleaningDelay()

.dockerignore: do not ignore .git

because we ignore **/*.1 to not drag built manpages into the docker
context - but this also prevents any tags ending in .1 (like rec-4.5.1)
from being built

dnsdist: Document the default value of setCacheCleaningDelay()

Merge pull request #10368 from omoerbeek/rec-prep-4.5.0

rec: Prep rec-4.5.1

Rebase after secpoll update

It's going to be 4.5.1

Update pdns/recursordist/docs/appendices/EOL.rst

Co-authored-by: Pieter Lexis <pieter@plexis.eu>

Prep rec-4.5.0

Merge pull request #10374 from rgacogne/ddist160-changelog

dnsdist: Changelog and secpoll update for 1.6.0

dnsdist: Changelog and secpoll update for 1.6.0

dnsdist: Add a few words about memory consumption in the documentation

dnsdist: Reorganize the IDState and Rings fields

Reducing the space lost to padding and thus the memory usage. This
change saves 1 MB of memory per downstream server in the default
configuration, and around 8 bytes per entry in the ring buffer.

Merge pull request #10379 from rgacogne/ddist-fix-changelog

dnsdist: Fix a typo in the ChangeLog header for 1.5.2

dnsdist: Fix a typo in the ChangeLog header for 1.5.2

Merge pull request #10163 from rgacogne/ddist152-changelog

dnsdist: Update ChangeLog and secpoll zone for 1.5.2

Merge pull request #10375 from rgacogne/rec-aggressive-nsec-salt-race

rec: Prevent a race in the aggressive NSEC cache

Merge pull request #10364 from rgacogne/auth-fromiscmap-b64

auth: Don't choke on non-base64 values when importing zone keys

rec: Prevent a race in the aggressive NSEC cache

When a new NSEC3 record has a different salt than the one we know, we
update the zone entry with the new salt. Unfortunately, that salt was
read without holding the lock in `AggressiveNSECCache::getNSEC3Denial`,
leading to a possible data race.

Merge pull request #10370 from yantarou/ixfrdist_typo

docs: fix typo in ixfrdist docs

Merge pull request #10371 from mnordhoff/dnsdist-docs-tcaction

dnsdist docs: switch RA and RD

dnsdist docs: switch RA and RD

docs: fix typo in ixfrdist docs

dnsdist: May the 10th seems more realistic for the 1.5.2 release

Merge pull request #10353 from rgacogne/rec-dns64-on-rpz-hit-after-gettag-ffi-hit

rec: Apply dns64 on RPZ hits generated after a gettag_ffi hit

Merge pull request #10292 from omoerbeek/rec-more-tsan

rec: Fix TSAN complaints: max stacksize and response stats size counters

Merge pull request #10361 from dmachard/auth-timeout-luarecords

auth: change default timeout to 2s for lua records

Fix typo in DNSCryptoKeyEngine::makeFromISCString

Co-authored-by: Peter van Dijk <peter.van.dijk@powerdns.com>

auth: Don't choke on non-base64 values when importing zone keys

DNSCryptoKeyEngine::makeFromISCFile(), called by `pdnsutil import-zone-key`
or the API, for example, would try to parse almost all values as a
base64 string. Depending on the version of OpenSSL, it could have lead
to a weird `Error: BIO_read failed to read all data from memory buffer`
error when the file contains a non-base64 value, like for example:
```
Flags: 257
```
Recent versions of OpenSSL seems to simply return that the value could
not be parsed, but older ones (OpenSSL 1.0.2k from CentOS 7 for example)
would report an incomplete read (BIO_should_retry() returning 1),
triggering an exception that prevents the key from being loaded.
This commits keeps a longer list of known non-base64 values, but
more importantly catch the base64 decoding exception and then store the
initial value instead of aborting. Only failure to decode known base64
values prevents the key from being loaded.

Merge pull request #10362 from Habbie/dnsdist-docs-tcaction

dnsdist docs: correct bits for TCAction

dnsdist docs: correct bits for TCAction

change default timeout to 2s for lua records

rec: Test the most simple condition first

Co-authored-by: Otto Moerbeek <otto.moerbeek@open-xchange.com>

dnsdist: Update ChangeLog and secpoll zone for 1.5.2

Start using tcpiohandler for real

rec: Add a regression test for gettag_ffi, RPZ and DNS64 interaction

rec: Apply dns64 on RPZ hits generated after a gettag_ffi hit

We do special case the qname RPZ processing after a gettag_ffi hit,
leading to dns64 to not be applied in that case. This commit adds
dns64 handling to the special case.