unikernel/duniverse/ocaml-ipaddr/lib/macaddr_cstruct.ml

@@ -0,0 +1,39 @@
+(*
+ * Copyright (c) 2019 Anil Madhavapeddy
+ * Copyright (c) 2014 Nicolás Ojeda Bär
+ *
+ * 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.
+ *
+ *)
+
+let try_with_result fn a =
+  try Ok (fn a)
+  with Macaddr.Parse_error (msg, _) -> Error (`Msg ("Macaddr: " ^ msg))
+
+let of_cstruct_exn cs =
+  if Cstruct.length cs <> 6 then
+    raise (Macaddr.Parse_error ("MAC is exactly 6 bytes", Cstruct.to_string cs))
+  else Cstruct.to_string cs |> Macaddr.of_octets_exn
+
+let of_cstruct cs = try_with_result of_cstruct_exn cs
+
+let write_cstruct_exn (mac : Macaddr.t) cs =
+  let len = Cstruct.length cs in
+  let mac = Macaddr.to_octets mac in
+  if len <> 6 then raise (Macaddr.Parse_error ("MAC is exactly 6 bytes", mac));
+  Cstruct.blit_from_string mac 0 cs 0 6
+
+let to_cstruct ?(allocator = Cstruct.create) mac =
+  let cs = allocator 6 in
+  write_cstruct_exn mac cs;
+  cs