cert-service/lib/wire_lwt.ml
2020-12-09 20:28:07 +01:00

62 lines
1.7 KiB
OCaml

open Lwt.Infix
let safe_close s =
Lwt.catch (fun () -> Lwt_unix.close s)
(fun _ -> Lwt.return_unit)
let read_wire fd =
let buf = Bytes.create 4 in
let rec r b i l =
Lwt.catch (fun () ->
Lwt_unix.read fd b i l >>= function
| 0 ->
Lwt.return (Error `Eof)
| n when n == l -> Lwt.return (Ok ())
| n when n < l -> r b (i + n) (l - n)
| _ ->
Lwt.return (Error `Toomuch))
(fun _ ->
safe_close fd >|= fun () ->
Error `Exception)
in
r buf 0 4 >>= function
| Error e -> Lwt.return (Error e)
| Ok () ->
let len = Cstruct.BE.get_uint32 (Cstruct.of_bytes buf) 0 in
if len > 0l then begin
let b = Bytes.create (Int32.to_int len) in
r b 0 (Int32.to_int len) >|= function
| Error e -> Error e
| Ok () ->
match Wire_asn.wire_of_cstruct (Cstruct.of_bytes b) with
| Error (`Msg _msg) ->
Error `Exception
| (Ok (hdr, _)) as w ->
if not (hdr.version = `V1) then
assert false; (* FIXME *)
w
end else begin
Lwt.return (Error `Eof)
end
let write_raw fd buf =
let rec w off l =
Lwt.catch (fun () ->
Lwt_unix.send fd buf off l [] >>= fun n ->
if n = l then
Lwt.return (Ok ())
else
w (off + n) (l - n))
(fun _ ->
safe_close fd >|= fun () ->
Error `Exception)
in
w 0 (Bytes.length buf)
let write_wire fd wire =
let data = Wire_asn.wire_to_cstruct wire in
let dlen = Cstruct.create 4 in
Cstruct.BE.set_uint32 dlen 0 (Int32.of_int (Cstruct.len data)) ;
let buf = Cstruct.(to_bytes (append dlen data)) in
write_raw fd buf