fix: address dns review feedback

easytier/src/instance/dns_server/server.rs

@@ -5,7 +5,7 @@ use hickory_proto::rr::LowerName;
 use hickory_resolver::config::ResolverOpts;
 use hickory_resolver::net::runtime::TokioRuntimeProvider;
 use hickory_resolver::system_conf::read_system_conf;
-use hickory_server::net::runtime::{Time, TokioTime};
+use hickory_server::net::runtime::TokioTime;
 use hickory_server::server::Server as HickoryServer;
 use hickory_server::server::{Request, RequestHandler, ResponseHandler, ResponseInfo};
 use hickory_server::store::forwarder::ForwardConfig;
@@ -221,7 +221,7 @@ impl Server {
             .update(
                 update,
                 response_edns.as_ref(),
-                TokioTime::current_time(),
+                <TokioTime as hickory_server::net::runtime::Time>::current_time(),
                 response_handle,
             )
             .await
@@ -243,7 +243,7 @@ impl Server {
             .lookup(
                 request,
                 response_edns.as_ref(),
-                TokioTime::current_time(),
+                <TokioTime as hickory_server::net::runtime::Time>::current_time(),
                 response_handle,
             )
             .await

easytier/src/instance/dns_server/server_instance.rs

@@ -272,6 +272,7 @@ impl ResponseHandler for ResponseWrapper {
             .response
             .lock()
             .map_err(|_| NetError::Msg("lock poisoned".to_string()))?;
+        buffer.clear();
 
         let mut encoder = BinEncoder::new(&mut buffer);
 

easytier/src/instance/dns_server/tests.rs

@@ -10,6 +10,7 @@ use hickory_resolver::config::{
     ConnectionConfig, NameServerConfig, ResolverConfig, ResolverOpts,
 };
 use hickory_resolver::net::runtime::TokioRuntimeProvider;
+use hickory_resolver::net::{DnsError, NetError};
 use tokio::sync::Notify;
 use tokio_util::sync::CancellationToken;
 
@@ -92,8 +93,12 @@ pub async fn check_dns_record_missing(fake_ip: &Ipv4Addr, domain: &str) {
     let response = resolver
         .lookup(rr::Name::from_str(domain).unwrap(), rr::RecordType::A)
         .await;
-    if let Ok(response) = response {
-        assert!(response.answers().is_empty(), "{:?}", response);
+    match response {
+        Ok(response) => assert!(response.answers().is_empty(), "{:?}", response),
+        Err(NetError::Dns(DnsError::NoRecordsFound(_))) => {}
+        Err(e) => {
+            panic!("DNS query for missing record failed unexpectedly for domain '{domain}': {e}")
+        }
     }
 }