Allow using Lwt_ssl and / or Tls_lwt, or neither of them

examples/lwt/lwt_https_get.ml

@@ -61,7 +61,7 @@ let () =
     let response_handler = response_handler notify_response_received in
 
     let request_body =
-      Httpaf_lwt.Client.request_tls
+      Httpaf_lwt.Client.TLS.request
         socket
         request_headers
         ~error_handler

examples/lwt/lwt_https_server.ml

@@ -70,7 +70,7 @@ let connection_handler : Unix.sockaddr -> Lwt_unix.file_descr -> unit Lwt.t =
 
   let certfile = "./certificates/server.pem" in
   let keyfile = "./certificates/server.key" in
-  Httpaf_lwt.Server.create_tls_connection_handler
+  Httpaf_lwt.Server.TLS.create_connection_handler
     ?server:None
     ~certfile
     ~keyfile

lwt/dune

@@ -1,9 +1,36 @@
+(* -*- tuareg -*- *)
+(* This was inspired by `conduit-lwt-unix`'s dune file *)
+
+let v ~ssl ~tls () =
+  let ssl, ssl_d =
+    if ssl then "ssl_io_real", "lwt_ssl "
+    else "ssl_io_dummy", ""
+  in
+  let tls, tls_d =
+    if tls then "tls_io_real", "tls.lwt "
+    else "tls_io_dummy", ""
+  in
+  Printf.sprintf {|
+(rule (copy %s.ml ssl_io.ml))
+(rule (copy %s.ml tls_io.ml))
+
 (library
  (name httpaf_lwt)
  (public_name httpaf-lwt)
- (libraries faraday-lwt-unix httpaf lwt.unix
-  (select tls_impl.ml from
-   (tls.lwt -> tls_io.ml)
-   (lwt_ssl -> ssl_io.ml)))
- (modules buffer httpaf_lwt tls_impl)
+ (libraries faraday-lwt-unix httpaf lwt.unix %s%s)
+ (modules buffer httpaf_lwt tls_io ssl_io)
  (flags (:standard -safe-string)))
+|} ssl tls ssl_d tls_d
+
+let main () =
+  let is_installed s = Printf.kprintf Sys.command "ocamlfind query %s" s = 0 in
+  let ssl = is_installed "lwt_ssl" in
+  let tls = Sys.unix && is_installed "tls.lwt" in
+  Printf.printf
+    "Configuration\n\
+    \  ssl    : %b\n\
+    \  tls    : %b\n%!"
+    ssl tls;
+  v ~ssl ~tls ()
+
+let () = Jbuild_plugin.V1.send @@ main ()

lwt/httpaf_lwt.ml

@@ -130,25 +130,49 @@ module Server = struct
       in
       start_read_write_loops ~config ~socket connection
 
-  let create_tls_connection_handler
-    ?server
-    ?certfile
-    ?keyfile
-    ?(config=Config.default)
-    ~request_handler
-    ~error_handler =
-    fun client_addr socket ->
-      let connection =
-        Server_connection.create
-          ~config
-          ~error_handler:(error_handler client_addr)
-          (request_handler client_addr)
-      in
-      Tls_impl.make_server ?server ?certfile ?keyfile socket >>= fun tls_server ->
-      let readf = Tls_impl.readf tls_server in
-      let writev = Tls_impl.writev tls_server in
-      start_read_write_loops ~config ~readf ~writev ~socket connection
-      >>= Lwt.return
+  module TLS = struct
+    let create_connection_handler
+      ?server
+      ?certfile
+      ?keyfile
+      ?(config=Config.default)
+      ~request_handler
+      ~error_handler =
+      fun client_addr socket ->
+        let connection =
+          Server_connection.create
+            ~config
+            ~error_handler:(error_handler client_addr)
+            (request_handler client_addr)
+        in
+        Tls_io.make_server ?server ?certfile ?keyfile socket >>= fun tls_server ->
+        let readf = Tls_io.readf tls_server in
+        let writev = Tls_io.writev tls_server in
+        start_read_write_loops ~config ~readf ~writev ~socket connection
+        >>= Lwt.return
+  end
+
+  module SSL = struct
+    let create_connection_handler
+      ?server
+      ?certfile
+      ?keyfile
+      ?(config=Config.default)
+      ~request_handler
+      ~error_handler =
+      fun client_addr socket ->
+        let connection =
+          Server_connection.create
+            ~config
+            ~error_handler:(error_handler client_addr)
+            (request_handler client_addr)
+        in
+        Ssl_io.make_server ?server ?certfile ?keyfile socket >>= fun tls_server ->
+        let readf = Ssl_io.readf tls_server in
+        let writev = Ssl_io.writev tls_server in
+        start_read_write_loops ~config ~readf ~writev ~socket connection
+        >>= Lwt.return
+  end
 end
 
 
@@ -249,18 +273,33 @@ module Client = struct
     start_read_write_loops ~config ~socket connection;
     request_body
 
-  let request_tls ?client ?(config=Config.default) socket request ~error_handler ~response_handler =
-    let request_body, connection =
-      Client_connection.request ~config request ~error_handler ~response_handler
-    in
+  module TLS = struct
+    let request ?client ?(config=Config.default) socket request ~error_handler ~response_handler =
+      let request_body, connection =
+        Client_connection.request ~config request ~error_handler ~response_handler
+      in
 
-    Lwt.async(fun () ->
-      Tls_impl.make_client ?client socket >|= fun tls_client ->
-      let readf = Tls_impl.readf tls_client in
-      let writev = Tls_impl.writev tls_client in
+      Lwt.async(fun () ->
+        Tls_io.make_client ?client socket >|= fun tls_client ->
+        let readf = Tls_io.readf tls_client in
+        let writev = Tls_io.writev tls_client in
 
-      start_read_write_loops ~config ~readf ~writev ~socket connection);
-    request_body
-end
+        start_read_write_loops ~config ~readf ~writev ~socket connection);
+      request_body
+  end
 
-module Tls_impl = Tls_impl
+  module SSL = struct
+    let request ?client ?(config=Config.default) socket request ~error_handler ~response_handler =
+      let request_body, connection =
+        Client_connection.request ~config request ~error_handler ~response_handler
+      in
+
+      Lwt.async(fun () ->
+        Ssl_io.make_client ?client socket >|= fun tls_client ->
+        let readf = Ssl_io.readf tls_client in
+        let writev = Ssl_io.writev tls_client in
+
+        start_read_write_loops ~config ~readf ~writev ~socket connection);
+      request_body
+  end
+end

lwt/httpaf_lwt.mli

@@ -13,16 +13,31 @@ module Server : sig
     -> Lwt_unix.file_descr
     -> unit Lwt.t
 
-  val create_tls_connection_handler
-    :  ?server         : Tls_impl.server
-    -> ?certfile       : string
-    -> ?keyfile        : string
-    -> ?config         : Config.t
-    -> request_handler : (Unix.sockaddr -> Server_connection.request_handler)
-    -> error_handler   : (Unix.sockaddr -> Server_connection.error_handler)
-    -> Unix.sockaddr
-    -> Lwt_unix.file_descr
-    -> unit Lwt.t
+  module TLS : sig
+    val create_connection_handler
+      :  ?server         : Tls_io.server
+      -> ?certfile       : string
+      -> ?keyfile        : string
+      -> ?config         : Config.t
+      -> request_handler : (Unix.sockaddr -> Server_connection.request_handler)
+      -> error_handler   : (Unix.sockaddr -> Server_connection.error_handler)
+      -> Unix.sockaddr
+      -> Lwt_unix.file_descr
+      -> unit Lwt.t
+  end
+
+  module SSL : sig
+    val create_connection_handler
+      :  ?server         : Ssl_io.server
+      -> ?certfile       : string
+      -> ?keyfile        : string
+      -> ?config         : Config.t
+      -> request_handler : (Unix.sockaddr -> Server_connection.request_handler)
+      -> error_handler   : (Unix.sockaddr -> Server_connection.error_handler)
+      -> Unix.sockaddr
+      -> Lwt_unix.file_descr
+      -> unit Lwt.t
+  end
 end
 
 (* For an example, see [examples/lwt_get.ml]. *)
@@ -35,17 +50,25 @@ module Client : sig
     -> response_handler : Client_connection.response_handler
     -> [`write] Body.t
 
-  val request_tls
-    :  ?client          : Tls_impl.client
-    -> ?config          : Config.t
-    -> Lwt_unix.file_descr
-    -> Request.t
-    -> error_handler    : Client_connection.error_handler
-    -> response_handler : Client_connection.response_handler
-    -> [`write] Body.t
-end
+  module TLS : sig
+    val request
+      :  ?client          : Tls_io.client
+      -> ?config          : Config.t
+      -> Lwt_unix.file_descr
+      -> Request.t
+      -> error_handler    : Client_connection.error_handler
+      -> response_handler : Client_connection.response_handler
+      -> [`write] Body.t
+  end
 
-module Tls_impl : sig
-  type client = Tls_impl.client
-  type server = Tls_impl.server
+  module SSL : sig
+    val request
+      :  ?client          : Ssl_io.client
+      -> ?config          : Config.t
+      -> Lwt_unix.file_descr
+      -> Request.t
+      -> error_handler    : Client_connection.error_handler
+      -> response_handler : Client_connection.response_handler
+      -> [`write] Body.t
+  end
 end

lwt/ssl_io_dummy.ml

@@ -0,0 +1,16 @@
+let readf _socket =
+  fun _fd _buffer ->
+  Lwt.fail_with "Ssl not available"
+
+let writev _socket _fd =
+  fun _iovecs ->
+  Lwt.fail_with "Ssl not available"
+
+type client = [ `Ssl_not_available  ]
+type server = [ `Ssl_not_available  ]
+
+let make_client ?client:_ _socket =
+  Lwt.fail_with "Ssl not available"
+
+let make_server ?server:_ ?certfile:_ ?keyfile:_ _socket =
+  Lwt.fail_with "Ssl not available"

lwt/tls_io_dummy.ml

@@ -0,0 +1,16 @@
+let readf _tls =
+  fun _fd _buffer ->
+  Lwt.fail_with "Tls not available"
+
+let writev _tls _fd =
+  fun _iovecs ->
+  Lwt.fail_with "Tls not available"
+
+type client = [ `Tls_not_available ]
+type server = [ `Tls_not_available ]
+
+let make_client ?client:_ _socket =
+  Lwt.fail_with "Tls not available"
+
+let make_server ?server:_ ?certfile:_ ?keyfile:_ _socket =
+  Lwt.fail_with "Tls not available"