rewire up dns reconfiguration for macos

llarp/dns/server.cpp

@@ -400,9 +400,11 @@ namespace llarp::dns
       }
 
       void
-      ResetInternalState() override
+      ResetInternalState(std::optional<std::vector<SockAddr>> replace_upstream) override
       {
         Down();
+        if (replace_upstream)
+          m_conf.m_upstreamDNS = *replace_upstream;
         Up(m_conf);
       }
 

llarp/dns/server.hpp

@@ -174,9 +174,12 @@ namespace llarp::dns
     virtual std::string_view
     ResolverName() const = 0;
 
-    /// reset state
+    /// reset state, replace upstream info with new info if desired
     virtual void
-    ResetInternalState(){};
+    ResetInternalState(std::optional<std::vector<SockAddr>> replace_upstream = std::nullopt)
+    {
+      (void)replace_upstream;
+    };
 
     /// cancel all pending requests and ceace further operation
     virtual void

llarp/handlers/exit.hpp

@@ -24,9 +24,6 @@ namespace llarp
         return "snode";
       }
 
-      void
-      ResetInternalState() override{};
-
       void
       CancelPendingQueries() override{};
 

llarp/handlers/tun.cpp

@@ -67,7 +67,7 @@ namespace llarp
           : m_Reply{std::move(reply)}, m_OurIP{std::move(our_ip)}, m_Config{std::move(conf)}
       {}
 
-       ~DnsInterceptor() override = default;
+      ~DnsInterceptor() override = default;
 
       void
       SendTo(const SockAddr& to, const SockAddr& from, OwnedBuffer buf) const override
@@ -91,14 +91,16 @@ namespace llarp
       bool
       WouldLoop(const SockAddr& to, const SockAddr& from) const override
       {
-          if constexpr (platform::is_apple) {
-        // DNS on Apple is a bit weird because in order for the NetworkExtension itself to send data
-        // through the tunnel we have to proxy DNS requests through Apple APIs (and so our actual
-        // upstream DNS won't be set in our resolvers, which is why the vanilla WouldLoop won't work
-        // for us).  However when active the mac also only queries the main tunnel IP for DNS, so we
-        // consider anything else to be upstream-bound DNS to let it through the tunnel.
-        return to.getIP() != m_OurIP;
-          }
+        if constexpr (platform::is_apple)
+        {
+          // DNS on Apple is a bit weird because in order for the NetworkExtension itself to send
+          // data through the tunnel we have to proxy DNS requests through Apple APIs (and so our
+          // actual upstream DNS won't be set in our resolvers, which is why the vanilla WouldLoop
+          // won't work for us).  However when active the mac also only queries the main tunnel IP
+          // for DNS, so we consider anything else to be upstream-bound DNS to let it through the
+          // tunnel.
+          return to.getIP() != m_OurIP;
+        }
         else if (auto maybe_addr = m_Config.m_QueryBind)
         {
           const auto& addr = *maybe_addr;
@@ -261,7 +263,14 @@ namespace llarp
     std::vector<SockAddr>
     TunEndpoint::ReconfigureDNS(std::vector<SockAddr> servers)
     {
-      // TODO: implement me
+      if (m_DNS)
+      {
+        for (auto weak : m_DNS->GetAllResolvers())
+        {
+          if (auto ptr = weak.lock())
+            ptr->ResetInternalState(servers);
+        }
+      }
       return servers;
     }
 

llarp/net/posix.cpp

@@ -22,7 +22,6 @@
 
 namespace llarp::net
 {
-
   class Platform_Impl : public Platform
   {
     template <typename Visit_t>