websocket-lwt 2.12 · OCaml Package

Module Websocket: websocket library for Lwt

This module implements a websocket client and server library in the spirit of the otherwise similar TCP functions of the Lwt_io module. The websocket protocol add message framing in addition of simple TCP communication, and this library implement framing and unframing of messages.

val section : Lwt_log_core.section

module Connected_client : sig ... end

val check_origin : 
  ?origin_mandatory:bool ->
  hosts:string list ->
  Cohttp.Request.t ->
  bool

check_origin ~hosts req will return true if the origin header exists and matches one of the provided hostnames. If origin header is not present, return not origin_mandatory. Default value of origin_mandatory is false. If origin header is present but does not contain a hostname, return false. Hostnames in hosts are (ascii-)lowercased when compared.

val check_origin_with_host : Cohttp.Request.t -> bool

check_origin_with_host returns false if the origin header exists and its host doesn't match the host header

val with_connection : 
  ?extra_headers:Cohttp.Header.t ->
  ?random_string:(int -> string) ->
  ?ctx:Conduit_lwt_unix.ctx ->
  Conduit_lwt_unix.client ->
  Uri.t ->
  ((unit -> Websocket.Frame.t Lwt.t) * (Websocket.Frame.t -> unit Lwt.t)) Lwt.t

val establish_server : 
  ?read_buf:Stdlib.Buffer.t ->
  ?write_buf:Stdlib.Buffer.t ->
  ?timeout:int ->
  ?stop:unit Lwt.t ->
  ?on_exn:(exn -> unit) ->
  ?check_request:(Cohttp.Request.t -> bool) ->
  ?ctx:Conduit_lwt_unix.ctx ->
  mode:Conduit_lwt_unix.server ->
  (Connected_client.t -> unit Lwt.t) ->
  unit Lwt.t

exception_handler defaults to Lwt.async_exception_hook check_request is called before the http upgrade. If it returns false, the websocket connection is aborted with a "403 Forbidden" response. It defaults to check_origin_with_host

Convenience functions

val mk_frame_stream : 
  (unit -> Websocket.Frame.t Lwt.t) ->
  Websocket.Frame.t Lwt_stream.t

mk_frame_stream f is a stream build from f, which role is to receive the frames that will form the stream. When a Close frame is received, the stream will be closed.

val establish_standard_server : 
  ?read_buf:Stdlib.Buffer.t ->
  ?write_buf:Stdlib.Buffer.t ->
  ?timeout:int ->
  ?stop:unit Lwt.t ->
  ?on_exn:(exn -> unit) ->
  ?check_request:(Cohttp.Request.t -> bool) ->
  ?ctx:Conduit_lwt_unix.ctx ->
  mode:Conduit_lwt_unix.server ->
  (Connected_client.t -> unit Lwt.t) ->
  unit Lwt.t

establish_standard_server is like establish_server but with automatic handling of some frames:

A Pong frame is sent in response to a Ping frame,
a Close frame is sent in response to a Close frame.

All frames are then passed to the frame handling function.

package websocket-lwt

Convenience functions