Licklider Transmission Protocol (CCSDS 734.1-B) for reliable DTN links
Add Eio wrappers for transport, SDLS, CFDP, and LTP
- transport-eio: CLTU/ASM over Eio flows, COP-1 service layer
- sdls-eio: file-backed keystore, SA store, OTAR, security log,
KEK management, encrypted KV store, SDLS server
- cfdp: Eio filesystem-backed filestore for segmented transfers
- ltp-eio: length-prefixed segment send/recv over TCP
Ported from borealis eio/ wrappers with dependency updates
(crypto instead of mirage-crypto, bare int for Spi/Vcid/Scid).
+172
+13
dune-project
+13
dune-project
···
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(fmt (>= 0.9))
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(alcotest :with-test)
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(crowbar :with-test)))
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+
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(package
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(name ltp-eio)
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(synopsis "Eio-based LTP segment transport")
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(description
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"Drives LTP segment encoding/decoding with Eio TCP connections.
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Provides length-prefixed framing for LTP segments over the wire.")
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(depends
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(ocaml (>= 5.1))
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(ltp (= :version))
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(eio (>= 1.0))
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(fmt (>= 0.9))
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(logs (>= 0.7))))
+4
eio/dune
+4
eio/dune
+52
eio/ltp_eio.ml
+52
eio/ltp_eio.ml
···
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(** LTP Eio - Effectful LTP segment transport using Eio.
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Provides Eio-based segment send/receive over flows with length-prefixed
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framing. Wraps the pure LTP segment encoding/decoding. *)
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let src = Logs.Src.create "ltp.eio" ~doc:"LTP Eio transport"
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module Log = (val Logs.src_log src : Logs.LOG)
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(* {1 Wire Framing}
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Segments are length-prefixed on the wire: 4-byte big-endian length followed
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by the segment data. *)
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let send_segment (flow : _ Eio.Flow.sink) seg =
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let data = Ltp.encode_segment seg in
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let len = String.length data in
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let hdr = Bytes.create 4 in
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Bytes.set_int32_be hdr 0 (Int32.of_int len);
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Eio.Flow.copy_string (Bytes.to_string hdr ^ data) flow
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let recv_segment (buf_r : Eio.Buf_read.t) =
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let hdr = Eio.Buf_read.take 4 buf_r in
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let len = Int32.to_int (String.get_int32_be hdr 0) in
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if len <= 0 || len > 1_048_576 then
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Error (Fmt.str "invalid segment length: %d" len)
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else
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let data = Eio.Buf_read.take len buf_r in
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match Ltp.decode_segment data with
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| Ok seg -> Ok seg
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| Error e -> Error (Fmt.str "%a" Ltp.pp_error e)
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(* {1 Connection} *)
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type t = {
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flow : [ `Generic ] Eio.Net.stream_socket_ty Eio.Resource.t;
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buf_r : Eio.Buf_read.t;
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}
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let connect ~sw ~net ~host ~port =
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Log.info (fun m -> m "Connecting to %s:%d" host port);
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let addr = `Tcp (Eio.Net.Ipaddr.of_raw host, port) in
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let flow = Eio.Net.connect ~sw net addr in
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let buf_r = Eio.Buf_read.of_flow ~max_size:(1024 * 1024) flow in
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{ flow; buf_r }
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let close t =
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Log.info (fun m -> m "Closing LTP connection");
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Eio.Flow.close t.flow
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let send t seg = send_segment t.flow seg
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let recv t = recv_segment t.buf_r
+67
eio/ltp_eio.mli
+67
eio/ltp_eio.mli
···
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(** LTP Eio - Effectful LTP segment transport using Eio.
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Provides Eio-based segment send/receive over TCP with length-prefixed
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framing. Wraps the pure {!Ltp} segment encoding/decoding.
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{2 Wire Format}
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{v
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+----------+------------------+
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| Length | LTP Segment |
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| (4B BE) | (variable) |
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+----------+------------------+
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v}
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{2 Quick Start}
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{[
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Eio_main.run @@ fun env ->
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Eio.Switch.run @@ fun sw ->
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let conn =
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Ltp_eio.connect ~sw ~net:env#net ~host:"127.0.0.1" ~port:1113
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in
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let seg =
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Ltp.data_segment ~session_id ~client_service_id:1L ~block_offset:0L
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"hello"
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in
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Ltp_eio.send conn seg;
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match Ltp_eio.recv conn with
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| Ok seg -> process seg
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| Error msg -> Fmt.epr "Error: %s@." msg
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]} *)
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(** {1 Connection} *)
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type t
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(** An LTP transport connection. *)
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val connect :
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sw:Eio.Switch.t ->
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net:[> [ `Generic ] Eio.Net.ty ] Eio.Resource.t ->
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host:string ->
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port:int ->
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t
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(** [connect ~sw ~net ~host ~port] connects to a remote LTP peer over TCP.
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@raise Eio.Io on connection failure. *)
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val close : t -> unit
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(** [close t] closes the connection. *)
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(** {1 Segment I/O} *)
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val send : t -> Ltp.segment -> unit
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(** [send t seg] encodes and sends a segment with length prefix. *)
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val recv : t -> (Ltp.segment, string) result
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(** [recv t] receives and decodes a segment.
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Returns [Error msg] on framing or decoding errors. *)
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(** {1 Low-level} *)
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val send_segment : _ Eio.Flow.sink -> Ltp.segment -> unit
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(** [send_segment flow seg] sends a length-prefixed segment to any Eio sink. *)
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val recv_segment : Eio.Buf_read.t -> (Ltp.segment, string) result
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(** [recv_segment buf_r] reads a length-prefixed segment from a buffered reader.
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*)
+36
ltp-eio.opam
+36
ltp-eio.opam
···
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# This file is generated by dune, edit dune-project instead
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opam-version: "2.0"
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synopsis: "Eio-based LTP segment transport"
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description: """
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Drives LTP segment encoding/decoding with Eio TCP connections.
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Provides length-prefixed framing for LTP segments over the wire."""
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maintainer: ["Thomas Gazagnaire <thomas@gazagnaire.org>"]
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authors: ["Thomas Gazagnaire <thomas@gazagnaire.org>"]
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license: "ISC"
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homepage: "https://tangled.org/gazagnaire.org/ocaml-ltp"
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bug-reports: "https://tangled.org/gazagnaire.org/ocaml-ltp/issues"
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depends: [
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"dune" {>= "3.21"}
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"ocaml" {>= "5.1"}
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"ltp" {= version}
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"eio" {>= "1.0"}
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"fmt" {>= "0.9"}
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"logs" {>= "0.7"}
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"odoc" {with-doc}
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]
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build: [
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["dune" "subst"] {dev}
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[
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"dune"
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"build"
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"-p"
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name
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"-j"
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jobs
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"@install"
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"@runtest" {with-test}
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"@doc" {with-doc}
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]
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]
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dev-repo: "git+https://tangled.org/gazagnaire.org/ocaml-ltp"
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x-maintenance-intent: ["(latest)"]