Fix Eio signatures

Forgot to commit the interface before, also send_packet should take a Cstruct.t
like the other backends.

Author: haesbaert

bin/test_arp.ml

@@ -27,8 +27,7 @@ let pp hdr buf =
   print_newline ()
 
 let send link hdr pkt =
-  Eio_rawlink.send_packet link
-    (Eio.Flow.cstruct_source [ pkt ]);
+  Eio_rawlink.send_packet link pkt;
   pp hdr pkt
 
 let recv link hdr =

lib/eio_rawlink.ml

@@ -23,14 +23,17 @@ type t = {
   buffer : Cstruct.t;
 }
 
+let dhcp_server_filter = Lowlevel.dhcp_server_filter
+let dhcp_client_filter = Lowlevel.dhcp_client_filter
+
 let open_link ?filter ?(promisc=false) ifname ~sw =
   let fd = Lowlevel.opensock ?filter:filter ~promisc ifname in
   let flow = Eio_unix.FD.as_socket ~sw ~close_unix:true fd in
   { flow; fd; packets = ref []; buffer = (Cstruct.create 65536) }
 
 let close_link t = t.flow#close
 
-let send_packet t buf = t.flow#copy buf
+let send_packet t buf = t.flow#copy @@ Eio.Flow.cstruct_source [ buf ]
 
 let rec read_packet t =
   match !(t.packets) with

lib/eio_rawlink.mli

@@ -0,0 +1,52 @@
+(*
+ * Copyright (c) 2015-2022 Christiano F. Haesbaert <haesbaert@haesbaert.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *)
+
+(** A portable API to send and receive raw packets.
+
+    There are times when one needs to construct the full ethernet frame to
+    send/receive. Most unixes support BPF (BSD Packet Filter) to achieve it, but
+    linux provides the same functionality via AF_SOCKET. This API works with
+    either a BPF or AF_SOCKET backend, so it should work on every usable UNIX,
+    as well as linux out there.
+*)
+
+type t
+(** Type of a rawlink. *)
+
+val open_link : ?filter:string -> ?promisc:bool -> string -> sw:Eio.Switch.t -> t
+(** [open_link ~filter ~promisc interface sw]. Creates a rawlink on the
+   specified [interface], a BPF program [filter] can be passed to
+   filter out incoming packets. If [promisc] is true, sets [interface]
+   to promiscuous mode, defaults to false.*)
+
+val close_link : t -> unit
+(** [close_link]. Closes a rawlink. *)
+
+val read_packet : t -> Cstruct.t
+(** [read_packet t]. Reads a full packet, may raise Unix.Unix_error. *)
+
+val send_packet : t -> Cstruct.t -> unit
+(** [send_packet t]. Sends a full packet, may raise Unix.Unix_error. *)
+
+val dhcp_server_filter : unit -> string
+(** [dhcp_server_filter]. Returns a BPF program suitable to be passed in
+    [open_link ~filter], it accepts UDP packets destined to
+    port 67 (DHCP server). *)
+
+val dhcp_client_filter : unit -> string
+(** [dhcp_client_filter]. Returns a BPF program suitable to be passed in
+    [open_link ~filter], it accepts UDP packets destined to
+    port 68 (DHCP client). *)

lib/lwt_rawlink.ml

@@ -26,6 +26,9 @@ type t = {
   buffer : Cstruct.t;
 }
 
+let dhcp_server_filter = Lowlevel.dhcp_server_filter
+let dhcp_client_filter = Lowlevel.dhcp_client_filter
+
 let open_link ?filter ?(promisc=false) ifname =
   let fd = Lwt_unix.of_unix_file_descr (Lowlevel.opensock ?filter:filter ~promisc ifname) in
   let () = Lwt_unix.set_blocking fd false in
@@ -54,6 +57,3 @@ let send_packet t buf =
         Lwt.fail (Unix.Unix_error(Unix.ENOBUFS, "send_packet: short write", ""))
       else
         Lwt.return_unit)
-
-let dhcp_server_filter = Lowlevel.dhcp_server_filter
-let dhcp_client_filter = Lowlevel.dhcp_client_filter