ligo/src/node/net/RPC_server.ml
2017-11-15 13:13:16 +01:00

262 lines
11 KiB
OCaml

(**************************************************************************)
(* *)
(* Copyright (c) 2014 - 2017. *)
(* Dynamic Ledger Solutions, Inc. <contact@tezos.com> *)
(* *)
(* All rights reserved. No warranty, explicit or implicit, provided. *)
(* *)
(**************************************************************************)
open RPC
open Logging.RPC
(* public types *)
type server = (* hidden *)
{ shutdown : unit -> unit Lwt.t ;
mutable root : unit directory }
module ConnectionMap = Map.Make(Cohttp.Connection)
exception Invalid_method of { allowed : RPC.meth list }
exception Cannot_parse_body of string
let check_origin_matches origin allowed_origin =
String.equal "*" allowed_origin ||
String.equal allowed_origin origin ||
begin
let allowed_w_slash = allowed_origin ^ "/" in
let len_a_w_s = String.length allowed_w_slash in
let len_o = String.length origin in
(len_o >= len_a_w_s) &&
String.equal allowed_w_slash @@ String.sub origin 0 len_a_w_s
end
let find_matching_origin allowed_origins origin =
let matching_origins = List.filter (check_origin_matches origin) allowed_origins in
let compare_by_length_neg a b = ~- (compare (String.length a) (String.length b)) in
let matching_origins_sorted = List.sort compare_by_length_neg matching_origins in
match matching_origins_sorted with
| [] -> None
| x :: _ -> Some x
let make_cors_headers ?(headers=Cohttp.Header.init ())
cors_allowed_headers cors_allowed_origins origin_header =
let cors_headers = Cohttp.Header.add_multi headers
"Access-Control-Allow-Headers" cors_allowed_headers in
match origin_header with
| None -> cors_headers
| Some origin ->
match find_matching_origin cors_allowed_origins origin with
| None -> cors_headers
| Some allowed_origin ->
Cohttp.Header.add_multi cors_headers
"Access-Control-Allow-Origin" [allowed_origin]
(* Promise a running RPC server. *)
let launch ?pre_hook ?post_hook ?(host="::") mode root cors_allowed_origins cors_allowed_headers =
(* launch the worker *)
let cancelation, canceler, _ = Lwt_utils.canceler () in
let open Cohttp_lwt_unix in
let streams = ref ConnectionMap.empty in
let create_stream _io con to_string (s: _ Answer.stream) =
let running = ref true in
let stream =
Lwt_stream.from
(fun () ->
if not !running then Lwt.return None else
s.next () >|= function
| None -> None
| Some x -> Some (to_string x)) in
let shutdown () = running := false ; s.shutdown () in
streams := ConnectionMap.add con shutdown !streams ;
stream
in
let shutdown_stream con =
try ConnectionMap.find con !streams ()
with Not_found -> () in
let call_hook (io, con) req ?(answer_404 = false) hook =
match hook with
| None -> Lwt.return None
| Some hook ->
Lwt.catch
(fun () ->
hook (Uri.path (Cohttp.Request.uri req))
>>= fun (content_type, { Answer.code ; body }) ->
let headers =
match content_type with
| None -> Cohttp.Header.init ()
| Some ct -> Cohttp.Header.init_with "Content-Type" ct
in
if code = 404 && not answer_404 then
Lwt.return None
else
let body = match body with
| Answer.Empty ->
Cohttp_lwt_body.empty
| Single body ->
Cohttp_lwt_body.of_string body
| Stream s ->
let stream =
create_stream io con (fun s -> s) s in
Cohttp_lwt_body.of_stream stream in
Lwt.return_some
(Response.make ~flush:true ~status:(`Code code) ~headers (),
body))
(function
| Not_found -> Lwt.return None
| exn -> Lwt.fail exn) in
let callback (io, con) req body =
(* FIXME: check inbound adress *)
let path = Utils.split_path (Uri.path (Cohttp.Request.uri req)) in
let req_headers = Cohttp.Request.headers req in
let origin_header = Cohttp.Header.get req_headers "origin" in
let answer_with_cors_headers ?headers ?body status =
let headers = match headers with
| None -> Cohttp.Header.init ()
| Some headers -> headers in
let body = match body with
| None -> Cohttp_lwt_body.empty
| Some body -> body in
let headers =
make_cors_headers ~headers
cors_allowed_headers cors_allowed_origins origin_header in
Lwt.return (Response.make ~flush:true ~status ~headers (), body) in
lwt_log_info "(%s) receive request to %s"
(Cohttp.Connection.to_string con) (Uri.path (Cohttp.Request.uri req)) >>= fun () ->
Lwt.catch
(fun () ->
call_hook (io, con) req pre_hook >>= function
| Some res ->
Lwt.return res
| None ->
let existing_methods () =
let supported_meths =
[ `OPTIONS ; `POST ; `PUT ; `PATCH ; `DELETE ; `GET ; `HEAD ] in
Lwt_list.filter_map_p
(fun meth ->
Lwt.catch
(fun () ->
lookup root ~meth () path >>= fun _handler ->
Lwt.return_some meth)
(function Not_found | Cannot_parse _ -> Lwt.return_none
| exn -> Lwt.fail exn))
supported_meths >>= function
| [] -> Lwt.fail Not_found (* No handler at all -> 404 *)
| meths -> Lwt.return meths in
Lwt.catch
(fun () ->
lookup root ~meth:req.meth () path >>= fun handler ->
Lwt.return_some handler)
(function Not_found | Cannot_parse _ -> Lwt.return_none
| exn -> Lwt.fail exn) >>= function
| None ->
begin
(* Default OPTIONS handler for CORS preflight *)
if req.meth = `OPTIONS && origin_header <> None then
match Cohttp.Header.get req_headers
"Access-Control-Request-Method" with
| Some meth ->
let meth = Cohttp.Code.method_of_string meth in
lookup root ~meth () path >>= fun _handler ->
(* unless [lookup] failed with [Not_found] -> 404 *)
Lwt.return [ meth ]
| None -> existing_methods ()
else
existing_methods () >>= fun allowed ->
Lwt.fail (Invalid_method { allowed })
end >>= fun cors_allowed_meths ->
lwt_log_info "(%s) RPC preflight"
(Cohttp.Connection.to_string con) >>= fun () ->
let headers =
Cohttp.Header.add_multi
(Cohttp.Header.init ())
"Access-Control-Allow-Methods"
(List.map Cohttp.Code.string_of_method cors_allowed_meths) in
answer_with_cors_headers ~headers `OK
| Some handler ->
begin match req.meth with
| `POST
| `PUT
| `PATCH
| `DELETE -> begin
Cohttp_lwt_body.to_string body >>= fun body ->
match Data_encoding_ezjsonm.from_string body with
| Error msg -> Lwt.fail (Cannot_parse_body msg)
| Ok body -> Lwt.return (Some body)
end
| `GET
| `HEAD
| `OPTIONS -> Lwt.return None
| _ ->
existing_methods () >>= fun allowed ->
Lwt.fail (Invalid_method { allowed })
end >>= fun body ->
handler body >>= fun { Answer.code ; body } ->
let body = match body with
| Empty ->
Cohttp_lwt_body.empty
| Single json ->
Cohttp_lwt_body.of_string (Data_encoding_ezjsonm.to_string json)
| Stream s ->
let stream =
create_stream io con Data_encoding_ezjsonm.to_string s in
Cohttp_lwt_body.of_stream stream in
lwt_log_info "(%s) RPC %s"
(Cohttp.Connection.to_string con)
(if Cohttp.Code.is_error code
then "failed"
else "success") >>= fun () ->
let headers =
Cohttp.Header.init_with "Content-Type" "application/json" in
answer_with_cors_headers ~headers ~body (`Code code))
(function
| Not_found | Cannot_parse _ ->
lwt_log_info "(%s) not found"
(Cohttp.Connection.to_string con) >>= fun () ->
(call_hook (io, con) req ~answer_404: true post_hook >>= function
| Some res -> Lwt.return res
| None -> answer_with_cors_headers `Not_found)
| Invalid_method { allowed } ->
lwt_log_info "(%s) bad method"
(Cohttp.Connection.to_string con) >>= fun () ->
let headers =
Cohttp.Header.add_multi (Cohttp.Header.init ())
"Allow"
(List.map Cohttp.Code.string_of_method allowed) in
answer_with_cors_headers ~headers `Method_not_allowed
| Cannot_parse_body msg ->
lwt_log_info "(%s) can't parse RPC body"
(Cohttp.Connection.to_string con) >>= fun () ->
let body = Cohttp_lwt_body.of_string msg in
answer_with_cors_headers ~body `Bad_request
| e -> Lwt.fail e)
and conn_closed (_, con) =
log_info "connection closed %s" (Cohttp.Connection.to_string con) ;
shutdown_stream con in
Conduit_lwt_unix.init ~src:host () >>= fun ctx ->
let ctx = Cohttp_lwt_unix_net.init ~ctx () in
let stop = cancelation () in
let on_exn = function
| Unix.Unix_error (Unix.EADDRINUSE, "bind", _) ->
log_error "RPC server port already taken, \
the node will be shutdown" ;
Lwt_exit.exit 1
| Unix.Unix_error (ECONNRESET, _, _)
| Unix.Unix_error (EPIPE, _, _) -> ()
| exn -> !Lwt.async_exception_hook exn
in
let server =
Server.create ~stop ~ctx ~mode ~on_exn
(Server.make ~callback ~conn_closed ()) in
let shutdown () =
canceler () >>= fun () ->
server in
Lwt.return { shutdown ; root }
let root_service { root } = root
let set_root_service server root = server.root <- root
let shutdown server =
server.shutdown ()