Add new Ipaddr_cstruct and Macaddr_cstruct libraries

for conversion to/from cstructs

based on mirage#36

Co-authored-by: Nicolás Ojeda Bär <[email protected]>

.travis.yml

@@ -7,7 +7,7 @@ script: bash ./.travis-docker.sh
 env:
  global:
    - PACKAGE="ipaddr"
-   - PINS="ipaddr:. macaddr:."
+   - PINS="ipaddr:. macaddr:. ipaddr-sexp:. macaddr-sexp:. ipaddr-cstruct:. macaddr-cstruct:."
  matrix:
    - DISTRO=debian-stable OCAML_VERSION=4.04
    - DISTRO=ubuntu OCAML_VERSION=4.05

CHANGES.md

@@ -21,6 +21,9 @@
   subpackages and instead have `ipaddr-sexp` and `macaddr-sexp`
   to match the opam package names.
 
+* Add new `Ipaddr_cstruct` and `Macaddr_cstruct` libraries
+  for conversion to/from cstructs (#36 @nojb @avsm)
+
 ## v3.1.0 (2019-03-02)
 
 * Do not leak a `Not_found` exception when parsing `[:`

dune-project

@@ -1,2 +1,3 @@
-(lang dune 1.0)
+(lang dune 1.9)
 (name ipaddr)
+(allow_approximate_merlin)

ipaddr-cstruct.opam

@@ -0,0 +1,24 @@
+opam-version: "2.0"
+maintainer: "[email protected]"
+authors: ["David Sheets" "Anil Madhavapeddy" "Hugo Heuzard"]
+synopsis: "A library for manipulation of IP address representations using Cstructs"
+license: "ISC"
+tags: ["org:mirage" "org:xapi-project"]
+homepage: "https://github.com/mirage/ocaml-ipaddr"
+doc: "https://mirage.github.io/ocaml-ipaddr/"
+bug-reports: "https://github.com/mirage/ocaml-ipaddr/issues"
+depends: [
+  "ocaml" {>= "4.04.0"}
+  "dune" {build}
+  "ipaddr"
+  "cstruct"
+]
+build: [
+  ["dune" "subst"] {pinned}
+  ["dune" "build" "-p" name "-j" jobs]
+  ["dune" "runtest" "-p" name "-j" jobs] {with-test}
+]
+dev-repo: "git+https://github.com/mirage/ocaml-ipaddr.git"
+description: """
+Cstruct convertions for macaddr
+"""

ipaddr-sexp.opam

@@ -1,7 +1,7 @@
 opam-version: "2.0"
 maintainer: "[email protected]"
 authors: ["David Sheets" "Anil Madhavapeddy" "Hugo Heuzard"]
-synopsis: "A library for manipulation of IP (and MAC) address representations"
+synopsis: "A library for manipulation of IP address representations usnig sexp"
 description: """
 Sexp convertions for ipaddr
 """
@@ -15,6 +15,7 @@ depends: [
   "ocaml" {>= "4.04.0"}
   "dune" {build}
   "ipaddr"
+  "ipaddr-cstruct" {with-test}
   "ounit" {with-test}
   "ppx_sexp_conv" {>= "v0.9.0"}
 ]

lib/dune

@@ -29,6 +29,18 @@
  (modules ipaddr_unix)
  (libraries unix ipaddr))
 
+(library
+ (name        ipaddr_cstruct)
+ (public_name ipaddr-cstruct)
+ (modules ipaddr_cstruct)
+ (libraries ipaddr cstruct))
+
+(library
+ (name        macaddr_cstruct)
+ (public_name macaddr-cstruct)
+ (modules macaddr_cstruct)
+ (libraries macaddr cstruct))
+
 (library
  (name        ipaddr_top)
  (public_name ipaddr.top)

lib/ipaddr_cstruct.ml

@@ -0,0 +1,76 @@
+(*
+ * 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 need_more x = Ipaddr.Parse_error ("not enough data", x)
+
+let try_with_result fn a =
+  try Ok (fn a)
+  with Ipaddr.Parse_error (msg, _) -> Error (`Msg ("Ipaddr: " ^ msg))
+
+module V4 = struct
+
+  let of_cstruct_exn cs =
+    let len = Cstruct.len cs in
+    if len < 4 then raise (need_more (Cstruct.to_string cs));
+    Ipaddr.V4.of_int32 (Cstruct.BE.get_uint32 cs 0)
+
+  let of_cstruct cs =
+    try_with_result of_cstruct_exn cs
+
+  let write_cstruct_exn i cs =
+    let len = Cstruct.len cs in
+    if len < 4 then raise (need_more (Cstruct.to_string cs));
+    Cstruct.BE.set_uint32 cs 0 (Ipaddr.V4.to_int32 i)
+
+  let to_cstruct ?(allocator = Cstruct.create) i =
+    let cs = allocator 4 in
+    write_cstruct_exn i cs;
+    cs
+
+end
+
+module V6 = struct
+
+  open Ipaddr.V6
+
+  let of_cstruct_exn cs =
+    let len = Cstruct.len cs in
+    if len < 16 then raise (need_more (Cstruct.to_string cs));
+    let hihi = Cstruct.BE.get_uint32 cs 0 in
+    let hilo = Cstruct.BE.get_uint32 cs 4 in
+    let lohi = Cstruct.BE.get_uint32 cs 8 in
+    let lolo = Cstruct.BE.get_uint32 cs 12 in
+    of_int32 (hihi, hilo, lohi, lolo)
+
+  let of_cstruct cs =
+    try_with_result of_cstruct_exn cs
+
+  let write_cstruct_exn i cs =
+    let len = Cstruct.len cs in
+    if len < 16 then raise (need_more (Cstruct.to_string cs));
+    let a, b, c, d = to_int32 i in
+    Cstruct.BE.set_uint32 cs 0 a;
+    Cstruct.BE.set_uint32 cs 4 b;
+    Cstruct.BE.set_uint32 cs 8 c;
+    Cstruct.BE.set_uint32 cs 12 d
+
+  let to_cstruct ?(allocator = Cstruct.create) i =
+    let cs = allocator 16 in
+    write_cstruct_exn i cs;
+    cs
+end

lib/ipaddr_cstruct.mli

@@ -0,0 +1,61 @@
+(*
+ * 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.
+ *
+ *)
+
+(** Convert to and from Cstructs and IP addresses *)
+
+(** Ipv4 address conversions *)
+module V4 : sig
+
+  (** [of_cstruct c] parses the first 4 octets of [c] into an IPv4 address. *)
+  val of_cstruct : Cstruct.t -> (Ipaddr.V4.t, [> `Msg of string ]) result
+
+  (** [of_cstruct_exn] parses the first 4 octets of [c] into an IPv4 address.
+      Raises {!Ipaddr.Parse_failure} on error. *)
+  val of_cstruct_exn : Cstruct.t -> Ipaddr.V4.t
+
+  (** [to_cstruct ipv4] is a cstruct of length 4 encoding [ipv4].
+      The cstruct is allocated using [allocator]. If [allocator] is
+      not provided, [Cstruct.create] is used. *)
+  val to_cstruct: ?allocator:(int -> Cstruct.t) -> Ipaddr.V4.t -> Cstruct.t
+
+  (** [write_cstruct_exn ipv4 cs] writes 4 bytes into [cs] representing
+      the [ipv4] address octets. Raises {!Ipaddr.Parse_error} if [cs]
+      is not at least 4 bytes long. *)
+  val write_cstruct_exn : Ipaddr.V4.t -> Cstruct.t -> unit
+end
+
+(** Ipv6 address conversions *)
+module V6 : sig
+
+  (** [of_cstruct c] parses the first 16 octets of [c] into an IPv6 address. *)
+  val of_cstruct : Cstruct.t -> (Ipaddr.V6.t, [> `Msg of string ]) result
+
+  (** [of_cstruct_exn] parses the first 16 octets of [c] into an IPv6 address.
+      Raises {!Ipaddr.Parse_failure} on error. *)
+  val of_cstruct_exn : Cstruct.t -> Ipaddr.V6.t
+
+  (** [to_cstruct ipv6] is a cstruct of length 16 encoding [ipv6].
+      The cstruct is allocated using [allocator]. If [allocator] is
+      not provided, [Cstruct.create] is used. *)
+  val to_cstruct: ?allocator:(int -> Cstruct.t) -> Ipaddr.V6.t -> Cstruct.t
+
+  (** [write_cstruct_exn ipv6 cs] writes 16 bytes into [cs] representing
+      the [ipv6] address octets. Raises {!Ipaddr.Parse_error} if [cs]
+      is not at least 16 bytes long. *)
+  val write_cstruct_exn : Ipaddr.V6.t -> Cstruct.t -> unit
+end

lib/macaddr_cstruct.ml

@@ -0,0 +1,40 @@
+(*
+ * 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.len 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.len 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

lib/macaddr_cstruct.mli

@@ -0,0 +1,36 @@
+(*
+ * 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.
+ *
+ *)
+
+(** Convert to and from Cstructs and MAC address. *)
+
+(** [of_cstruct c] parses the 6 octets of [c] into a MAC address. *)
+val of_cstruct : Cstruct.t -> (Macaddr.t, [> `Msg of string ]) result
+
+(** [of_cstruct_exn] parses the 6 octets of [c] into a MAC address.
+    Raises {!Macaddr.Parse_failure} on error. *)
+val of_cstruct_exn : Cstruct.t -> Macaddr.t
+
+(** [to_cstruct mac] is a cstruct of length 4 encoding [ipv4].
+    The cstruct is allocated using [allocator]. If [allocator] is
+    not provided, [Cstruct.create] is used. *)
+val to_cstruct: ?allocator:(int -> Cstruct.t) -> Macaddr.t -> Cstruct.t
+
+(** [write_cstruct_exn mac cs] writes 6 bytes into [cs] representing
+    the [mac] address octets. Raises {!Macaddr.Parse_error} if [cs]
+    is not 6 bytes long. *)
+val write_cstruct_exn : Macaddr.t -> Cstruct.t -> unit

lib_test/dune

@@ -17,18 +17,18 @@
 
 (test
  (name test_ipaddr)
- (package ipaddr)
+ (package ipaddr-sexp)
  (modules test_ipaddr)
- (libraries ipaddr test_ipaddr_sexp oUnit))
+ (libraries ipaddr ipaddr-cstruct test_ipaddr_sexp oUnit))
 
 (test
  (name test_macaddr)
- (package macaddr)
+ (package macaddr-sexp)
  (modules test_macaddr)
- (libraries macaddr test_macaddr_sexp oUnit))
+ (libraries macaddr macaddr-cstruct test_macaddr_sexp oUnit))
 
 (test
  (name test_ppx)
  (modules test_ppx)
- (package ipaddr)
+ (package ipaddr-sexp)
  (libraries ipaddr macaddr test_ipaddr_sexp test_macaddr_sexp oUnit))

lib_test/test_ipaddr.ml

@@ -290,13 +290,29 @@ module Test_v4 = struct
       (V4.to_domain_name ip) name ;
     assert_equal ~msg:"of_domain_name" (V4.of_domain_name name) (Some ip)
 
+  let test_cstruct_rt () =
+    let addr = "\254\099\003\128" in
+    assert_equal ~msg:(String.escaped addr)
+      (Cstruct.to_string Ipaddr_cstruct.V4.(to_cstruct (of_cstruct_exn (Cstruct.of_string addr)))) addr
+
+  let test_cstruct_rt_bad () =
+    let addrs = [
+      need_more "\254\099\003";
+    ] in
+    List.iter (fun (addr,exn) ->
+      assert_raises ~msg:(String.escaped addr) exn
+        (fun () -> Ipaddr_cstruct.V4.of_cstruct_exn (Cstruct.of_string addr))
+    ) addrs
+
   let suite = "Test V4" >::: [
     "string_rt"            >:: test_string_rt;
     "string_rt_bad"        >:: test_string_rt_bad;
     "string_raw_rt"        >:: test_string_raw_rt;
     "string_raw_rt_bad"    >:: test_string_raw_rt_bad;
     "bytes_rt"             >:: test_bytes_rt;
     "bytes_rt_bad"         >:: test_bytes_rt_bad;
+    "cstruct_rt"           >:: test_cstruct_rt;
+    "cstruct_rt_bad"       >:: test_cstruct_rt_bad;
     "int32_rt"             >:: test_int32_rt;
     "prefix_string_rt"     >:: test_prefix_string_rt;
     "prefix_string_rt_bad" >:: test_prefix_string_rt_bad;
@@ -415,6 +431,22 @@ module Test_v6 = struct
         (fun () -> V6.of_octets_exn addr)
     ) addrs
 
+  let test_cstruct_rt () =
+    let addr =
+      "\000\000\000\000\000\000\000\000\000\000\255\255\192\168\000\001"
+    in
+    let v6 = Ipaddr_cstruct.V6.of_cstruct_exn (Cstruct.of_string addr) in
+    assert_equal ~msg:(String.escaped addr) (Cstruct.to_string Ipaddr_cstruct.V6.(to_cstruct v6)) addr
+
+  let test_cstruct_rt_bad () =
+    let addrs = [
+      need_more "\000\000\000\000\000\000\000\000\000\000\255\255\192\168\001";
+    ] in
+    List.iter (fun (addr,exn) ->
+      assert_raises ~msg:(String.escaped addr) exn
+        (fun () -> Ipaddr_cstruct.V6.of_cstruct_exn (Cstruct.of_string addr))
+    ) addrs
+
   let test_int32_rt () =
     let (a,b,c,d) as addr =
       0x2001_0665_l, 0x0000_0000_l, 0xff00_00ff_l, 0xfe00_0001_l
@@ -622,6 +654,8 @@ module Test_v6 = struct
     "string_raw_rt_bad"    >:: test_string_raw_rt_bad;
     "bytes_rt"             >:: test_bytes_rt;
     "bytes_rt_bad"         >:: test_bytes_rt_bad;
+    "cstruct_rt"           >:: test_cstruct_rt;
+    "cstruct_rt_bad"       >:: test_cstruct_rt_bad;
     "int32_rt"             >:: test_int32_rt;
     "prefix_string_rt"     >:: test_prefix_string_rt;
     "prefix_string_rt_bad" >:: test_prefix_string_rt_bad;