dns-client-mirage udp

client/dns_client.ml

@@ -186,7 +186,7 @@ module type S = sig
   val rng : int -> Cstruct.t
   val clock : unit -> int64
 
-  val connect : t -> (context, [> `Msg of string ]) result io
+  val connect : t -> (Dns.proto * context, [> `Msg of string ]) result io
   val send_recv : context -> Cstruct.t -> (Cstruct.t, [> `Msg of string ]) result io
   val close : context -> unit io
 
@@ -222,8 +222,8 @@ struct
   }
 
   (* TODO eventually use Auto, and retry without on FormErr *)
-  let create ?(size = 32) ?(edns = `None) ?nameservers ?(timeout = Duration.of_sec 5) stack =
-    { cache = Dns_cache.empty size ;
+  let create ?(cache_size = 32) ?(edns = `None) ?nameservers ?(timeout = Duration.of_sec 5) stack =
+    { cache = Dns_cache.empty cache_size ;
       transport = Transport.create ?nameservers ~timeout stack ;
       edns ;
     }
@@ -254,12 +254,11 @@ struct
       | Error _ -> Error (`Msg "")
 
   let get_raw_reply t query_type name =
-    let proto, _ = Transport.nameservers t.transport in
+    Transport.connect t.transport >>| fun (proto, socket) ->
+    Log.debug (fun m -> m "Connected to NS.");
     let tx, state =
       Pure.make_query Transport.rng proto ~dnssec:true t.edns name query_type
     in
-    Transport.connect t.transport >>| fun socket ->
-    Log.debug (fun m -> m "Connected to NS.");
     (Transport.send_recv socket tx >>| fun recv_buffer ->
      Log.debug (fun m -> m "Read @[<v>%d bytes@]"
                     (Cstruct.length recv_buffer)) ;
@@ -285,12 +284,11 @@ struct
       | Ok _ as ok -> Transport.lift ok
       | Error ((`No_data _ | `No_domain _) as nod) -> Error nod |> Transport.lift
       | Error `Msg _ ->
-        let proto, _ = Transport.nameservers t.transport in
+        Transport.connect t.transport >>| fun (proto, socket) ->
+        Log.debug (fun m -> m "Connected to NS.");
         let tx, state =
           Pure.make_query Transport.rng proto t.edns name query_type
         in
-        Transport.connect t.transport >>| fun socket ->
-        Log.debug (fun m -> m "Connected to NS.");
         (Transport.send_recv socket tx >>| fun recv_buffer ->
          Log.debug (fun m -> m "Read @[<v>%d bytes@]"
                         (Cstruct.length recv_buffer)) ;

client/dns_client.mli

@@ -46,8 +46,8 @@ module type S = sig
   val clock : unit -> int64
   (** [clock t] is the monotonic clock. *)
 
-  val connect : t -> (context, [> `Msg of string ]) result io
-  (** [connect addr] is a new connection ([context]) to [addr], or an error. *)
+  val connect : t -> (Dns.proto * context, [> `Msg of string ]) result io
+  (** [connect t] is a new connection ([context]) to [t], or an error. *)
 
   val send_recv : context -> Cstruct.t -> (Cstruct.t, [> `Msg of string ]) result io
   (** [send_recv context buffer] sends [buffer] to the [context] upstream, and
@@ -67,12 +67,13 @@ sig
 
   type t
 
-  val create : ?size:int -> ?edns:[ `None | `Auto | `Manual of Dns.Edns.t ] ->
+  val create : ?cache_size:int ->
+    ?edns:[ `None | `Auto | `Manual of Dns.Edns.t ] ->
     ?nameservers:(Dns.proto * T.io_addr list) -> ?timeout:int64 ->
     T.stack -> t
-  (** [create ~size ~edns ~nameservers ~timeout stack] creates the state of the
-      DNS client. We use [timeout] (ns, default 5s) as a time budget for connect
-      and request timeouts. To specify a timeout, use
+  (** [create ~cache_size ~edns ~nameservers ~timeout stack] creates the state
+      of the DNS client. We use [timeout] (ns, default 5s) as a time budget for
+      connect and request timeouts. To specify a timeout, use
       [create ~timeout:(Duration.of_sec 3)]. Whether or not to use
       {{:https://tools.ietf.org/html/rfc6891}EDNS} in queries is controlled
       by [~edns] (defaults to [`None]): if [None], no EDNS will be present,

lwt/client/dns_client_lwt.ml

@@ -395,7 +395,7 @@ module Transport : Dns_client.S
 
   let connect t =
     connect_via_tcp_to_ns t >|= function
-    | Ok () -> Ok t
+    | Ok () -> Ok (`Tcp, t)
     | Error `Msg msg -> Error (`Msg msg)
 end