Merge pull request 'add some Lwt.pause during Disk.check to allow the web server to process requests' (#26) from add-pause-during-check into main

Reviewed-on: #26
Reviewed-by: Reynir Björnsson <reynir@reynir.dk>

mirage/archive_checksum.ml

@@ -0,0 +1,67 @@
+module Hash = struct
+  type t = (* OpamHash.kind = *) [ `MD5 | `SHA256 | `SHA512 ]
+
+  (* Make the compiler check that (t :> Digestif.hash') *)
+  let _ = fun (h :t) -> (h :> Digestif.hash')
+
+  let compare h h' =
+    match h, h' with
+    | `SHA512, `SHA512 -> 0
+    | `SHA512, _ -> 1
+    | _, `SHA512 -> -1
+    | `SHA256, `SHA256 -> 0
+    | `SHA256, _ -> 1
+    | _, `SHA256 -> -1
+    | `MD5, `MD5 -> 0
+
+  let to_string = function
+    | `MD5 -> "md5"
+    | `SHA256 -> "sha256"
+    | `SHA512 -> "sha512"
+
+  let of_string = function
+    | "md5" -> Ok `MD5
+    | "sha256" -> Ok `SHA256
+    | "sha512" -> Ok `SHA512
+    | h -> Error (`Msg ("unknown hash algorithm: " ^ h))
+end
+
+module HM = Map.Make(Hash)
+
+type 'a digests = {
+  md5 : Digestif.MD5.ctx;
+  sha256 : Digestif.SHA256.ctx;
+  sha512 : Digestif.SHA512.ctx;
+}
+
+let empty_digests =
+  {
+    md5 = Digestif.MD5.empty;
+    sha256 = Digestif.SHA256.empty;
+    sha512 = Digestif.SHA512.empty;
+  }
+
+let update_digests { md5; sha256; sha512 } data =
+  {
+    md5 = Digestif.MD5.feed_string md5 data;
+    sha256 = Digestif.SHA256.feed_string sha256 data;
+    sha512 = Digestif.SHA512.feed_string sha512 data;
+  }
+
+let init_write csums =
+  let hash, csum = HM.max_binding csums in
+  (hash, csum), empty_digests
+
+let digests_to_hm digests =
+  HM.empty
+  |> HM.add `MD5
+    Digestif.MD5.(to_raw_string (get digests.md5))
+  |> HM.add `SHA256
+    Digestif.SHA256.(to_raw_string (get digests.sha256))
+  |> HM.add `SHA512
+    Digestif.SHA512.(to_raw_string (get digests.sha512))
+
+let get digests = function
+  | `MD5 -> Digestif.MD5.(to_raw_string (get digests.md5))
+  | `SHA256 -> Digestif.SHA256.(to_raw_string (get digests.sha256))
+  | `SHA512 -> Digestif.SHA512.(to_raw_string (get digests.sha512))

mirage/bad.ml

@@ -1,193 +0,0 @@
-let archives =
-  let too_big =
-    [ "https://github.com/Opsian/opsian-ocaml/releases/download/0.1/0.1.tar.gz" ]
-
-  and hash_mismatch = [
-    "http://cdn.skylable.com/source/libres3-1.3.tar.gz" ;
-    "http://cdn.skylable.com/source/libres3-0.3.tar.gz" ;
-    "http://cdn.skylable.com/source/libres3-1.2.tar.gz" ;
-    "http://cdn.skylable.com/source/libres3-0.9.tar.gz" ;
-    "http://cdn.skylable.com/source/libres3-0.2.tar.gz" ;
-    "http://cdn.skylable.com/source/libres3-1.0.tar.gz" ;
-    "http://cdn.skylable.com/source/libres3-1.1.tar.gz" ;
-    "http://cdn.skylable.com/source/libres3-0.1.tar.gz" ;
-    "https://github.com/lemaetech/http-cookie/releases/download/v3.0.0/http-cookie-v3.0.0.tbz" ;
-    "http://oqamldebug.forge.ocamlcore.org/oqamldebug-0.9.4.tar.gz" ;
-    "http://oqamldebug.forge.ocamlcore.org/oqamldebug-0.9.2.tar.gz" ;
-    "http://oqamldebug.forge.ocamlcore.org/oqamldebug-0.9.3.tar.gz" ;
-    "http://oqamldebug.forge.ocamlcore.org/oqamldebug-0.9.5.tar.gz" ;
-    "http://oqamldebug.forge.ocamlcore.org/oqamldebug-0.9.1.tar.gz" ;
-    "https://github.com/OCamlPro/ezjs_fetch/archive/0.1.tar.gz" ;
-    "http://github.com/OCamlPro/typerex-build/archive/1.99.13-beta.tar.gz" ;
-    "https://github.com/mirage/dyntype/tarball/dyntype-0.8.5" ;
-    "https://github.com/mirage/dyntype/tarball/dyntype-0.8.3" ;
-    "https://github.com/mirage/dyntype/tarball/dyntype-0.8.2" ;
-    "https://github.com/mirage/dyntype/tarball/dyntype-0.8.4" ;
-    "https://github.com/mirage/mirage-http-unix/archive/v1.0.0.tar.gz" ;
-    "http://github.com/OCamlPro/typerex-build/archive/1.99.15-beta.tar.gz" ;
-    "http://github.com/OCamlPro/typerex-build/archive/1.99.14-beta.tar.gz" ;
-    "https://github.com/paulpatault/ocamlog/archive/v0.1.tar.gz" ;
-    "https://github.com/pveber/OCaml-R/archive/pre-nyc-refactoring.tar.gz" ;
-    "https://github.com/paulpatault/ocamlog/archive/v0.2.tar.gz" ;
-    "http://github.com/OCamlPro/typerex-build/archive/1.99.16-beta.tar.gz" ;
-    "https://github.com/FStarLang/kremlin/archive/v0.9.6.0.zip" ;
-    "https://gitlab.com/dailambda/plebeia/-/archive/2.0.2/plebeia-2.0.2.tar.gz" ;
-    "https://github.com/mirleft/ocaml-tls/archive/0.5.0.tar.gz" ;
-    "https://github.com/eth-sri/ELINA/archive/1.3.tar.gz" ;
-    "https://gitlab.com/trustworthy-refactoring/refactorer/-/archive/0.1/refactorer-0.1.zip" ;
-    "https://github.com/completium/archetype-lang/archive/1.3.3.tar.gz" ;
-    "https://github.com/chetmurthy/pa_ppx/archive/0.01.tar.gz" ;
-    "https://github.com/chambart/ocaml-1/archive/lto.tar.gz" ;
-    "https://github.com/Kappa-Dev/KaSim/archive/v3.5-250915.tar.gz" ;
-    "https://github.com/bsansouci/bsb-native/archive/1.9.4.tar.gz"
-  ]
-
-  and bad_request = [
-    "http://cgit.freedesktop.org/cairo-ocaml/snapshot/cairo-ocaml-1.2.0.tar.gz"
-  ]
-
-  and not_found = [
-    "http://pw374.github.io/distrib/frag/frag-0.1.0.tar.gz" ;
-    "http://pw374.github.io/distrib/glical/glical-0.0.3.tar.gz" ;
-    "http://pw374.github.io/distrib/glical/glical-0.0.4.tar.gz" ;
-    "http://pw374.github.io/distrib/glical/glical-0.0.1.tar.gz" ;
-    "http://pw374.github.io/distrib/glical/glical-0.0.2.tar.gz" ;
-    "http://pw374.github.io/distrib/glical/glical-0.0.5.tar.gz" ;
-    "http://pw374.github.io/distrib/glical/glical-0.0.7.tar.gz" ;
-    "http://pw374.github.io/distrib/mpp/mpp-0.1.1.tar.gz" ;
-    "http://pw374.github.io/distrib/mpp/mpp-0.1.0.tar.gz" ;
-    "http://pw374.github.io/distrib/mpp/mpp-0.1.2.tar.gz" ;
-    "http://pw374.github.io/distrib/mpp/mpp-0.1.7.tar.gz" ;
-    "http://pw374.github.io/distrib/mpp/mpp-0.1.3.tar.gz" ;
-    "http://pw374.github.io/distrib/mpp/mpp-0.1.8.tar.gz" ;
-    "http://pw374.github.io/distrib/mpp/mpp-0.1.4.tar.gz" ;
-    "http://pw374.github.io/distrib/mpp/mpp-0.1.5.tar.gz" ;
-    "http://pw374.github.io/distrib/mpp/mpp-0.2.0.tar.gz" ;
-    "http://pw374.github.io/distrib/mpp/mpp-0.2.1.tar.gz" ;
-    "http://pw374.github.io/distrib/mpp/mpp-0.3.0.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.3.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.4.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.5.4.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.5.5.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.5.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.6.0.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.6.2.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.6.3.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.6.4.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.6.5.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.7.0.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.7.1.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.7.2.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.7.4.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.7.3.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.7.5.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.8.2.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.8.0.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.8.1.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.9.0.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.9.1.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.9.7.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-1.0.0.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-1.0.1.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-1.1.0.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-1.1.1.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-1.1.2.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-1.2.0.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-1.2.1.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-1.2.2.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-1.2.4.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-1.2.5.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-1.2.6.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-1.2.3.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-1.3.0.tar.gz" ;
-    "http://zoggy.github.com/ocamldot/ocamldot-1.0.tar.gz" ;
-    "http://zoggy.github.io/stog/stog-0.4.tar.gz" ;
-    "http://zoggy.github.io/genet/genet-0.6.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.6.1.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.9.4.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.9.6.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.9.5.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-0.9.3.tar.gz" ;
-    "http://pw374.github.io/distrib/omd/omd-1.1.3.tar.gz" ;
-    "http://coccinelle.lip6.fr/distrib/coccinelle-1.0.0-rc22.tgz" ;
-    "http://coccinelle.lip6.fr/distrib/coccinelle-1.0.0-rc21.tgz" ;
-    "http://coccinelle.lip6.fr/distrib/coccinelle-1.0.0.tgz" ;
-    "http://proverif.inria.fr/proverif1.96pl1.tar.gz" ;
-    "http://proverif.inria.fr/proverif1.97.tar.gz" ;
-    "http://proverif.inria.fr/proverif1.98.tar.gz" ;
-    "http://proverif.inria.fr/proverif1.97pl3.tar.gz" ;
-    "http://proverif.inria.fr/proverif1.98pl1.tar.gz" ;
-    "http://proverif.inria.fr/proverif1.97pl1.tar.gz" ;
-    "https://github.com/jrochel/eliom/archive/6.4.0.tar.gz" ;
-    "https://github.com/drjdn/ocaml_lua_parser/archive/1.0.1.tar.gz" ;
-    "https://github.com/sagotch/To.ml/archive/v1.0.0.tar.gz" ;
-    "https://zoggy.github.io/ocaml-rdf/ocaml-rdf-0.9.0.tar.gz" ;
-    "https://github.com/sagotch/To.ml/archive/v2.1.0.tar.gz" ;
-    "https://github.com/sagotch/To.ml/archive/v2.0.0.tar.gz" ;
-    "https://zoggy.github.io/ocaml-taglog/taglog-0.1.0.tar.gz" ;
-    "https://zoggy.github.io/ocaml-taglog/taglog-0.2.0.tar.gz" ;
-    "https://zoggy.github.io/ocf/ocf-0.3.0.tar.gz" ;
-    "https://zoggy.github.io/ojs-base/ojs-base-0.1.0.tar.gz" ;
-    "https://zoggy.github.io/stog/plugins/stog-writing-0.8.0.tar.gz" ;
-    "https://zoggy.github.io/stog/stog-0.13.0.tar.gz" ;
-    "https://zoggy.github.io/ocaml-taglog/taglog-0.3.0.tar.gz" ;
-    "https://zoggy.github.io/ocf/ocf-0.1.0.tar.gz" ;
-    "https://opam.ocaml.org/cache/md5/24/24b163eb77e6832747dccd6cc8a5d57c" ;
-  ]
-
-  and forbidden = [
-    "https://gforge.inria.fr/frs/download.php/33440/heptagon-1.00.06.tar.gz" ;
-    "https://gforge.inria.fr/frs/download.php/file/33677/dose3-3.2.2.tar.gz" ;
-    "https://gforge.inria.fr/frs/download.php/file/34920/javalib-2.3.1.tar.bz2" ;
-    "https://gforge.inria.fr/frs/download.php/file/36092/javalib-2.3.2.tar.bz2" ;
-    "https://gforge.inria.fr/frs/download.php/file/36093/sawja-1.5.2.tar.bz2" ;
-    "https://gforge.inria.fr/frs/download.php/file/37154/javalib-2.3.4.tar.bz2" ;
-    "https://gforge.inria.fr/frs/download.php/file/37403/sawja-1.5.3.tar.bz2" ;
-    "https://gforge.inria.fr/frs/download.php/file/36307/javalib-2.3.3.tar.bz2" ;
-    "https://gforge.inria.fr/frs/download.php/file/37655/javalib-2.3.5.tar.bz2" ;
-    "https://gforge.inria.fr/frs/download.php/file/37656/sawja-1.5.4.tar.bz2" ;
-    "https://gforge.inria.fr/frs/download.php/file/34921/sawja-1.5.1.tar.bz2" ;
-  ]
-
-  and three_o_o = [
-    "https://github.com/Gbury/dolmen/archive/v0.4.tar.gz" ;
-    "https://github.com/Stevendeo/Pilat/archive/1.3.tar.gz" ;
-    "https://github.com/OCamlPro/ocp-indent/archive/1.5.tar.gz" ;
-    "https://github.com/backtracking/combine/archive/release-0.6.zip" ;
-    "https://github.com/cakeplus/pa_comprehension/archive/0.4.tar.gz" ;
-    "https://github.com/cakeplus/mparser/archive/1.0.tar.gz" ;
-    "https://github.com/chenyukang/rubytt/archive/v0.1.tar.gz" ;
-    "https://github.com/cakeplus/pa_where/archive/0.4.tar.gz" ;
-    "https://github.com/metaocaml/ber-metaocaml/archive/ber-n102.tar.gz" ;
-    "https://github.com/cakeplus/pa_solution/archive/0.5.tar.gz" ;
-    "https://github.com/cakeplus/mparser/archive/1.2.1.tar.gz" ;
-    "https://github.com/cakeplus/pa_solution/archive/0.7.tar.gz" ;
-    "https://github.com/cakeplus/pa_solution/archive/0.6.tar.gz" ;
-    "https://github.com/mirage/mirage-tcpip/archive/v2.8.1.tar.gz" ;
-    "https://github.com/modlfo/pla/archive/v1.4.tar.gz" ;
-    "https://github.com/murmour/pa_qualified/archive/0.5.tar.gz" ;
-    "https://github.com/ocaml-ppx/ocamlformat/archive/v0.2.tar.gz" ;
-    "https://github.com/murmour/pa_qualified/archive/0.6.tar.gz" ;
-    "https://github.com/ocaml-ppx/ocamlformat/archive/support.0.2.tar.gz" ;
-    "https://github.com/ocaml/oloop/archive/0.1.2.tar.gz" ;
-    "https://github.com/cakeplus/mparser/archive/1.0.1.tar.gz" ;
-    "https://github.com/cakeplus/mparser/archive/1.1.tar.gz" ;
-    "https://github.com/savonet/ocaml-ffmpeg/archive/v1.0.0-rc1.tar.gz" ;
-    "https://github.com/ocaml/opam2web/archive/2.0.tar.gz" ;
-    "https://github.com/savonet/ocaml-ffmpeg/archive/v1.0.0.tar.gz" ;
-  ]
-
-  and five_o_three = [ "https://gitlab.com/gasche/build_path_prefix_map/repository/0.2/archive.tar.gz" ]
-
-  and is_ftp = [ "ftp://ftp.netbsd.org/pub/pkgsrc/distfiles/wyrd-1.4.6.tar.gz" ]
-
-  and connect_fails = [
-    "http://godi.0ok.org/godi-backup/shcaml-0.1.3.tar.gz" ;
-    "http://www.first.in-berlin.de/software/tools/apalogretrieve/apalogretrieve-0-9-6_4.tgz" ;
-    "https://cavale.enseeiht.fr/osdp/osdp-0.5.4.tgz" ;
-    "https://cavale.enseeiht.fr/osdp/osdp-0.6.0.tgz" ;
-    "https://cavale.enseeiht.fr/osdp/osdp-1.0.0.tgz" ;
-  ]
-  in
-
-  too_big @ hash_mismatch @ bad_request @ not_found @ forbidden @ three_o_o @ five_o_three @ is_ftp @ connect_fails

mirage/config.ml

@@ -1,106 +1,40 @@
+(* mirage >= 4.8.0 & < 4.9.0 *)
 open Mirage
 
-type http_client = HTTP_client
-let http_client = typ HTTP_client
-
-let check =
-  let doc =
-    Key.Arg.info ~doc:"Only check the cache" ["check"]
-  in
-  Key.(create "check" Arg.(flag doc))
-
-let verify =
-  let doc =
-    Key.Arg.info ~doc:"Verify the cache contents" ["verify"]
-  in
-  Key.(create "verify" Arg.(flag doc))
-
-let remote =
-  let doc =
-    Key.Arg.info
-      ~doc:"Remote repository url"
-      ["remote"]
-  in
-  Key.(create "remote" Arg.(opt string "https://opam.ocaml.org" doc))
-
-let parallel_downloads =
-  let doc =
-    Key.Arg.info
-      ~doc:"Amount of parallel HTTP downloads"
-      ["parallel-downloads"]
-  in
-  Key.(create "parallel-downloads" Arg.(opt int 20 doc))
-
-let hook_url =
-  let doc =
-    Key.Arg.info
-      ~doc:"URL to conduct an update of the opam repository" ["hook-url"]
-  in
-  Key.(create "hook-url" Arg.(opt string "update" doc))
-
-let port =
-  let doc = Key.Arg.info ~doc:"HTTP listen port." ["port"] in
-  Key.(create "port" Arg.(opt int 80 doc))
-
-let tls_authenticator =
-  (* this will not look the same in the help printout *)
-  let doc = "TLS host authenticator. See git_http in lib/mirage/mirage.mli for a description of the format."
-  in
-  let doc = Key.Arg.info ~doc ["tls-authenticator"] in
-  Key.(create "tls-authenticator" Arg.(opt (some string) None doc))
-
-let sectors_cache =
-  let doc = "Number of sectors reserved for each checksum cache (md5, sha512)." in
-  let doc = Key.Arg.info ~doc ["sectors-cache"] in
-  Key.(create "sectors-cache" Arg.(opt int64 Int64.(mul 4L 2048L) doc))
-
 let mirror =
-  foreign "Unikernel.Make"
-    ~keys:[ Key.v check ; Key.v verify ; Key.v remote ;
-            Key.v parallel_downloads ; Key.v hook_url ; Key.v tls_authenticator ;
-            Key.v port ; Key.v sectors_cache ; ]
+  main "Unikernel.Make"
     ~packages:[
-      package ~min:"0.2.0" ~sublibs:[ "mirage" ] "paf" ;
+      package ~min:"0.3.0" ~sublibs:[ "mirage" ] "paf" ;
       package "h2" ;
+      package "ohex" ;
       package "httpaf" ;
+      package ~min:"0.0.5" "git-kv" ;
+      package ~min:"3.10.0" "git-paf" ;
       package "opam-file-format" ;
-      package ~min:"2.1.0" ~sublibs:[ "gz" ] "tar" ~pin:"git+https://github.com/hannesm/ocaml-tar.git#kv-rw-kv-5" ;
-      package ~pin:"git+https://github.com/hannesm/ocaml-tar.git#kv-rw-kv-5" "tar-mirage" ;
-      package "mirage-block-partition" ;
+      package ~min:"3.0.0" ~sublibs:[ "gz" ] "tar" ;
+      package ~min:"3.0.0" "tar-mirage" ;
+      package ~max:"0.2.0" "mirage-block-partition" ;
+      package ~min:"0.0.8" "http-mirage-client" ;
+      package "gpt" ;
+      package "gptar" ;
       package "oneffs" ;
-      package "hex" ;
+      package "digestif" ;
+      package "swapfs" ;
     ]
-    (block @-> time @-> pclock @-> stackv4v6 @-> http_client @-> job)
+    (block @-> time @-> pclock @-> stackv4v6 @-> git_client @-> alpn_client @-> job)
 
 let stack = generic_stackv4v6 default_network
-
-let dns = generic_dns_client stack
-
+let he = generic_happy_eyeballs stack
+let dns = generic_dns_client stack he
 let tcp = tcpv4v6_of_stackv4v6 stack
-
-let http_client =
-  let connect _ modname = function
-    | [ _time; _pclock; _tcpv4v6; ctx ] ->
-      Fmt.str {ocaml|%s.connect %s|ocaml} modname ctx
-    | _ -> assert false in
-  impl ~connect "Http_mirage_client.Make"
-    (time @-> pclock @-> tcpv4v6 @-> git_client @-> http_client)
-(* XXX(dinosaure): [git_client] seems bad but it becames from a long discussion
-   when a "mimic" device seems not accepted by everyone. We can copy [git_happy_eyeballs]
-   and provide an [http_client] instead of a [git_client] but that mostly means that
-   2 instances of happy-eyeballs will exists together which is not really good
-   (it puts a pressure on the scheduler). *)
-
-let http_client =
-  let happy_eyeballs = generic_happy_eyeballs stack dns in
-  let happy_eyeballs = git_happy_eyeballs stack dns happy_eyeballs in
-  http_client $ default_time $ default_posix_clock $ tcp $ happy_eyeballs
-
-let program_block_size =
-  let doc = Key.Arg.info [ "program-block-size" ] in
-  Key.(create "program_block_size" Arg.(opt int 16 doc))
-
 let block = block_of_file "tar"
 
+let git_client, alpn_client =
+  let git = mimic_happy_eyeballs stack he dns in
+  merge_git_clients (git_ssh tcp git)
+    (merge_git_clients (git_tcp tcp git)
+      (git_http tcp git)),
+  paf_client tcp (mimic_happy_eyeballs stack he dns)
+
 let () = register "mirror"
-    [ mirror $ block $ default_time $ default_posix_clock $ stack $ http_client ]
+  [ mirror $ block $ default_time $ default_posix_clock $ stack $ git_client $ alpn_client ]

mirage/http_mirage_client.ml

@@ -1,340 +0,0 @@
-let http_scheme = Mimic.make ~name:"http-scheme"
-let http_port = Mimic.make ~name:"http-port"
-let http_hostname = Mimic.make ~name:"http-hostname"
-let tls_config = Mimic.make ~name:"tls-config"
-
-open Lwt.Infix
-
-module type S = sig
-  val connect : Mimic.ctx -> Mimic.ctx Lwt.t
-  val alpn_protocol : Mimic.flow -> string option
-  val authenticator : (X509.Authenticator.t, [> `Msg of string ]) result
-end
-
-module Make
-  (Time : Mirage_time.S)
-  (Pclock : Mirage_clock.PCLOCK)
-  (TCP : Tcpip.Tcp.S)
-  (Happy_eyeballs : Mimic_happy_eyeballs.S with type flow = TCP.flow) : S = struct
-  module TCP = struct
-    include TCP
-    type endpoint = Happy_eyeballs.t * string * int
-    type nonrec write_error =
-      [ `Write of write_error | `Connect of string | `Closed ]
-    let pp_write_error ppf = function
-      | `Connect err -> Fmt.string ppf err
-      | `Write err -> pp_write_error ppf err
-      | `Closed as err -> pp_write_error ppf err
-
-    let write flow cs =
-      let open Lwt.Infix in
-      write flow cs >>= function
-      | Ok _ as v -> Lwt.return v
-      | Error err -> Lwt.return_error (`Write err)
-
-    let writev flow css =
-      writev flow css >>= function
-      | Ok _ as v -> Lwt.return v
-      | Error err -> Lwt.return_error (`Write err)
-
-    let connect (happy_eyeballs, hostname, port) =
-      Happy_eyeballs.resolve happy_eyeballs hostname [ port ] >>= function
-      | Error (`Msg err) -> Lwt.return_error (`Connect err)
-      | Ok ((_ipaddr, _port), flow) -> Lwt.return_ok flow
-  end
-
-  let tcp_edn, _tcp_protocol = Mimic.register ~name:"tcp" (module TCP)
-
-  module TLS = struct
-    type endpoint = Happy_eyeballs.t * Tls.Config.client * string * int
-
-    include Tls_mirage.Make (TCP)
-
-    let connect (happy_eyeballs, cfg, hostname, port) =
-      let peer_name =
-        Result.(to_option (bind (Domain_name.of_string hostname) Domain_name.host)) in
-      Happy_eyeballs.resolve happy_eyeballs hostname [ port ] >>= function
-      | Ok ((_ipaddr, _port), flow) -> client_of_flow cfg ?host:peer_name flow
-      | Error (`Msg err) -> Lwt.return_error (`Write (`Connect err))
-  end
-
-  let tls_edn, tls_protocol =
-    Mimic.register ~name:"tls" (module TLS)
-
-  let connect ctx =
-    let k0 happy_eyeballs http_scheme http_hostname http_port = match http_scheme with
-      | "http" -> Lwt.return_some (happy_eyeballs, http_hostname, http_port)
-      | _      -> Lwt.return_none in
-    let k1 happy_eyeballs http_scheme http_hostname http_port tls_config = match http_scheme with
-      | "https" -> Lwt.return_some (happy_eyeballs, tls_config, http_hostname, http_port)
-      | _       -> Lwt.return_none in
-    let ctx = Mimic.fold tcp_edn
-      Mimic.Fun.[ req Happy_eyeballs.happy_eyeballs
-                ; req http_scheme; req http_hostname; dft http_port 80 ]
-      ~k:k0 ctx in
-    Lwt.return (Mimic.fold tls_edn
-                  Mimic.Fun.[ req Happy_eyeballs.happy_eyeballs
-                            ; req http_scheme; req http_hostname; dft http_port 443
-                            ; req tls_config ]
-                  ~k:k1 ctx)
-
-  let alpn_protocol flow =
-    let module M = (val (Mimic.repr tls_protocol)) in
-    match flow with
-    | M.T flow ->
-      ( match TLS.epoch flow with
-      | Ok { Tls.Core.alpn_protocol; _ } -> alpn_protocol
-      | Error _ -> None )
-    | _ -> None
-
-  let authenticator =
-    let module V = Ca_certs_nss.Make (Pclock) in
-    V.authenticator ()
-end
-
-module Version = Httpaf.Version
-module Status = H2.Status
-module Headers = H2.Headers
-
-type response =
-  { version : Version.t
-  ; status  : Status.t
-  ; reason  : string
-  ; headers : Headers.t }
-
-module HTTP_1_1 = struct
-  include Httpaf.Client_connection
-  let yield_reader _ = assert false
-  let next_read_operation t =
-    (next_read_operation t :> [ `Close | `Read | `Yield ])
-end
-
-let add_authentication ~add headers = function
-  | None -> headers
-  | Some (user, pass) ->
-    let data = Base64.encode_string (user ^ ":" ^ pass) in
-    add headers "authorization" ("Basic " ^ data)
-
-let prepare_http_1_1_headers headers host user_pass body_length =
-  let headers = Httpaf.Headers.of_list headers in
-  let add = Httpaf.Headers.add_unless_exists in
-  let headers = add headers "user-agent" ("http-mirage-client/%%VERSION%%") in
-  let headers = add headers "host" host in
-  let headers = add headers "connection" "close" in
-  let headers = match body_length with
-    | None -> headers
-    | Some v -> add headers "content-length" (string_of_int v) in
-  add_authentication ~add headers user_pass
-
-let single_http_1_1_request ?config flow user_pass host meth path headers body =
-  let body_length = Option.map String.length body in
-  let headers = prepare_http_1_1_headers headers host user_pass body_length in
-  let req = Httpaf.Request.create ~headers meth path in
-  let finished, notify_finished = Lwt.wait () in
-  let wakeup = let w = ref false in
-    fun v -> if not !w then Lwt.wakeup_later notify_finished v ; w := true in
-  let response_handler response body =
-    let buf = Buffer.create 0x100 in
-    let rec on_eof () =
-      let response =
-        { version= response.Httpaf.Response.version
-        ; status = (response.Httpaf.Response.status :> H2.Status.t)
-        ; reason = response.Httpaf.Response.reason
-        ; headers= H2.Headers.of_list (Httpaf.Headers.to_list response.Httpaf.Response.headers) } in
-      wakeup (Ok (response, Some (Buffer.contents buf)))
-    and on_read ba ~off ~len =
-      Buffer.add_string buf (Bigstringaf.substring ~off ~len ba) ;
-      Httpaf.Body.schedule_read body ~on_read ~on_eof in
-    let on_eof () =
-      let response =
-        { version= response.Httpaf.Response.version
-        ; status = (response.Httpaf.Response.status :> H2.Status.t)
-        ; reason = response.Httpaf.Response.reason
-        ; headers= H2.Headers.of_list (Httpaf.Headers.to_list response.Httpaf.Response.headers) } in
-      wakeup (Ok (response, None)) in
-    Httpaf.Body.schedule_read body ~on_read ~on_eof in
-  let error_handler e =
-    let err = match e with
-      | `Malformed_response x -> Error (`Msg ("Malformed response: " ^ x))
-      | `Invalid_response_body_length _ -> Error (`Msg ("Invalid response body length"))
-      | `Exn e -> Error (`Msg ("Exception here: " ^ Printexc.to_string e)) in
-    wakeup err in
-  let request_body, conn = Httpaf.Client_connection.request ?config req ~error_handler
-    ~response_handler in
-  Lwt.async (fun () -> Paf.run (module HTTP_1_1) conn flow) ;
-  Option.iter (Httpaf.Body.write_string request_body) body ;
-  Httpaf.Body.close_writer request_body ;
-  finished
-
-let prepare_h2_headers headers host user_pass body_length =
-  let headers = H2.Headers.of_list headers in
-  let add hdr = H2.Headers.add_unless_exists hdr ?sensitive:None in
-  let headers = add headers ":authority" host in
-  let headers = add headers "content-length" (string_of_int (Option.value ~default:0 body_length)) in
-  add_authentication ~add headers user_pass
-
-let single_h2_request ?config ~scheme flow user_pass host meth path headers body =
-  let body_length = Option.map String.length body in
-  let headers = prepare_h2_headers headers host user_pass body_length in
-  let req = H2.Request.create ~scheme ~headers meth path in
-  let finished, notify_finished = Lwt.wait () in
-  let wakeup = let w = ref false in
-    fun v -> if not !w then Lwt.wakeup_later notify_finished v ; w := true in
-  let response_handler response response_body =
-    let buf = Buffer.create 0x100 in
-    let rec on_eof () =
-      let response =
-        { version= { major= 2; minor= 0; }
-        ; status = response.H2.Response.status
-        ; reason = ""
-        ; headers= response.H2.Response.headers } in
-      wakeup (Ok (response, Some (Buffer.contents buf)))
-    and on_read ba ~off ~len =
-      Buffer.add_string buf (Bigstringaf.substring ~off ~len ba) ;
-      H2.Body.Reader.schedule_read response_body
-        ~on_read ~on_eof in
-    let on_eof () =
-      let response =
-        { version= { major= 2; minor= 0; }
-        ; status = response.H2.Response.status
-        ; reason = ""
-        ; headers= response.H2.Response.headers } in
-      wakeup (Ok (response, None)) in
-    H2.Body.Reader.schedule_read response_body
-      ~on_read ~on_eof in
-  let error_handler e =
-    let err = match e with
-      | `Malformed_response x -> Error (`Msg ("Malformed response: " ^ x))
-      | `Invalid_response_body_length _ -> Error (`Msg "Invalid response body length")
-      | `Protocol_error (err, msg) ->
-        let kerr _ = Error (`Msg (Format.flush_str_formatter ())) in
-        Format.kfprintf kerr Format.str_formatter "%a: %s" H2.Error_code.pp_hum err msg
-      | `Exn e -> Error (`Msg ("Exception here: " ^ Printexc.to_string e)) in
-    wakeup err in
-  let conn = H2.Client_connection.create ?config ?push_handler:None
-    ~error_handler in
-  let request_body = H2.Client_connection.request conn req ~error_handler ~response_handler in
-  Lwt.async (fun () -> Paf.run (module H2.Client_connection) conn flow) ;
-  Option.iter (H2.Body.Writer.write_string request_body) body ;
-  H2.Body.Writer.close request_body ;
-  finished >|= fun v ->
-  H2.Client_connection.shutdown conn ;
-  v
-
-let decode_uri ~ctx uri =
-  let ( >>= ) = Result.bind in
-  match String.split_on_char '/' uri with
-  | proto :: "" :: user_pass_host_port :: path ->
-    ( if String.equal proto "http:"
-      then Ok ("http", Mimic.add http_scheme "http" ctx)
-      else if String.equal proto "https:"
-      then Ok ("https", Mimic.add http_scheme "https" ctx)
-      else Error (`Msg "Couldn't decode user and password") ) >>= fun (scheme, ctx) ->
-    let decode_user_pass up = match String.split_on_char ':' up with
-      | [ user; pass; ] -> Ok (user, pass)
-      | _ -> Error (`Msg "Couldn't decode user and password") in
-    ( match String.split_on_char '@' user_pass_host_port with
-    | [ host_port ] -> Ok (None, host_port)
-    | [ user_pass; host_port ] ->
-      decode_user_pass user_pass >>= fun up ->
-      Ok (Some up, host_port)
-    | _ -> Error (`Msg "Couldn't decode URI") ) >>= fun (user_pass, host_port) ->
-    ( match String.split_on_char ':' host_port with
-    | [] -> Error (`Msg "Empty host & port")
-    | [ hostname ] -> Ok (hostname, Mimic.add http_hostname hostname ctx)
-    | hd :: tl ->
-      let port, hostname = match List.rev (hd :: tl) with
-        | hd :: tl -> hd, String.concat ":" (List.rev tl)
-        | _ -> assert false in
-      ( try Ok (hostname, Mimic.add http_hostname hostname (Mimic.add http_port (int_of_string port) ctx))
-        with Failure _ -> Error (`Msg "Couldn't decode port") ) ) >>= fun (hostname, ctx) ->
-    Ok (ctx, scheme, hostname, user_pass, "/" ^ String.concat "/" path)
-  | _ -> Error (`Msg "Couldn't decode URI on top")
-
-let ( >>? ) = Lwt_result.bind
-
-let alpn_protocol_of_string = function
-  | "http/1.1" -> Some `HTTP_1_1
-  | "h2" -> Some `H2
-  | _ -> None
-
-let single_request ~ctx ~alpn_protocol ?config cfg ~meth ~headers ?body uri =
-  Lwt.return (decode_uri ~ctx uri) >>? fun (ctx, scheme, host, user_pass, path) ->
-  let ctx = match Lazy.force cfg with
-    | Ok (`Custom cfg) -> Mimic.add tls_config cfg ctx
-    | Ok (`Default cfg) ->
-      ( match Result.bind (Domain_name.of_string host) Domain_name.host with
-      | Ok peer -> Mimic.add tls_config (Tls.Config.peer cfg peer) ctx
-      | Error _ -> Mimic.add tls_config cfg ctx )
-    | Error _ -> ctx in
-  Mimic.resolve ctx >>? fun flow ->
-  (match Option.bind (alpn_protocol flow) alpn_protocol_of_string, config with
-   | (Some `HTTP_1_1 | None), Some (`HTTP_1_1 config) ->
-     single_http_1_1_request ~config flow user_pass host meth path headers body
-   | (Some `HTTP_1_1 | None), None ->
-     single_http_1_1_request flow user_pass host meth path headers body
-   | (Some `H2 | None), Some (`H2 config) ->
-     single_h2_request ~config ~scheme flow user_pass host meth path headers body
-   | Some `H2, None ->
-     single_h2_request ~scheme flow user_pass host meth path headers body
-   | Some `H2, (Some (`HTTP_1_1 _)) ->
-     single_h2_request ~scheme flow user_pass host meth path headers body
-   | Some `HTTP_1_1, Some (`H2 _) ->
-     single_http_1_1_request flow user_pass host meth path headers body) >>= fun r ->
-  Mimic.close flow >|= fun () ->
-  r
-
-let tls_config ?tls_config ?config authenticator =
-  lazy ( match tls_config with
-  | Some cfg -> Ok (`Custom cfg)
-  | None ->
-    let alpn_protocols = match config with
-      | None -> [ "h2"; "http/1.1" ]
-      | Some (`H2 _) -> [ "h2" ]
-      | Some (`HTTP_1_1 _) -> [ "http/1.1" ] in
-    Result.map (fun authenticator -> `Default (Tls.Config.client ~alpn_protocols ~authenticator ())) authenticator )
-
-let resolve_location ~uri ~location =
-  match String.split_on_char '/' location with
-  | "http:" :: "" :: _ -> Ok location
-  | "https:" :: "" :: _ -> Ok location
-  | "" :: "" :: _ ->
-    let schema = String.sub uri 0 (String.index uri '/') in
-    Ok (schema ^ location)
-  | "" :: _ ->
-    (match String.split_on_char '/' uri with
-     | schema :: "" :: user_pass_host_port :: _ ->
-       Ok (String.concat "/" [schema ; "" ; user_pass_host_port ^ location])
-     | _ -> Error (`Msg ("expected an absolute uri, got: " ^ uri)))
-  | _ -> Error (`Msg ("unknown location (relative path): " ^ location))
-
-let one_request
-  ?config
-  ?tls_config:cfg
-  ~ctx
-  ~alpn_protocol
-  ~authenticator
-  ?(meth= `GET)
-  ?(headers= [])
-  ?body
-  ?(max_redirect= 5)
-  ?(follow_redirect= true) uri =
-  let tls_config = tls_config ?tls_config:cfg ?config authenticator in
-  if not follow_redirect
-  then single_request ~ctx ~alpn_protocol ?config tls_config ~meth ~headers ?body uri
-  else
-    let rec follow_redirect count uri =
-      if count = 0 then Lwt.return_error (`Msg "Redirect limit exceeded")
-      else
-        single_request ~ctx ~alpn_protocol ?config tls_config ~meth ~headers ?body uri
-        >>? fun (resp, body) ->
-        if Status.is_redirection resp.status then
-          ( match Headers.get resp.headers "location" with
-          | Some location ->
-            Lwt.return (resolve_location ~uri ~location) >>? fun uri ->
-            follow_redirect (pred count) uri
-          | None ->
-            Lwt.return_ok (resp, body) )
-        else
-          Lwt.return_ok (resp, body) in
-    follow_redirect max_redirect uri

mirage/http_mirage_client.mli

@@ -1,35 +0,0 @@
-module type S = sig
-  val connect : Mimic.ctx -> Mimic.ctx Lwt.t
-  val alpn_protocol : Mimic.flow -> string option
-  val authenticator : (X509.Authenticator.t, [> `Msg of string ]) result
-end
-
-module Make
-  (Time : Mirage_time.S)
-  (Pclock : Mirage_clock.PCLOCK)
-  (TCP : Tcpip.Tcp.S)
-  (Happy_eyeballs : Mimic_happy_eyeballs.S with type flow = TCP.flow) : S
-
-module Version = Httpaf.Version
-module Status = H2.Status
-module Headers = H2.Headers
-
-type response =
-  { version : Version.t
-  ; status  : Status.t
-  ; reason  : string
-  ; headers : Headers.t }
-
-val one_request :
-  ?config:[ `H2 of H2.Config.t | `HTTP_1_1 of Httpaf.Config.t ] ->
-  ?tls_config:Tls.Config.client ->
-  ctx:Mimic.ctx ->
-  alpn_protocol:(Mimic.flow -> string option) ->
-  authenticator:(X509.Authenticator.t, [> `Msg of string ]) result ->
-  ?meth:Httpaf.Method.t ->
-  ?headers:(string * string) list ->
-  ?body:string ->
-  ?max_redirect:int ->
-  ?follow_redirect:bool ->
-  string ->
-  (response * string option, [> Mimic.error ]) result Lwt.t

mirage/opam_file.ml

@@ -0,0 +1,144 @@
+module HM = Archive_checksum.HM
+
+let hash_to_string = Archive_checksum.Hash.to_string
+
+let hex_of_string s =
+  match Ohex.decode s with
+  | d -> Ok d
+  | exception Invalid_argument err -> Error (`Msg err)
+
+let decode_digest filename str =
+  let hex h s =
+    match hex_of_string s with
+    | Ok d -> Ok (h, d)
+    | Error _ as e -> e
+  in
+  match String.split_on_char '=' str with
+  | [ data ] -> hex `MD5 data
+  | [ "md5" ; data ] -> hex `MD5 data
+  | [ "sha256" ; data ] -> hex `SHA256 data
+  | [ "sha512" ; data ] -> hex `SHA512 data
+  | [ hash ; _ ] -> Error (`Msg ("unknown hash " ^ hash))
+  | _ -> Error (`Msg ("unexpected hash format " ^ str))
+
+let extract_url_checksum filename items =
+  let open OpamParserTypes.FullPos in
+  let url =
+    List.find_opt
+      (function { pelem = Variable ({ pelem = "src" ; _ }, _); _ } -> true | _ -> false)
+      items
+  and archive =
+    List.find_opt
+      (function { pelem = Variable ({ pelem = "archive" ; _ }, _); _ } -> true | _ -> false)
+      items
+  and checksum =
+    List.find_opt
+      (function { pelem = Variable ({ pelem = "checksum" ; _ }, _); _ } -> true | _ -> false)
+      items
+  and mirrors =
+    List.find_opt
+      (function { pelem = Variable ({ pelem = "mirrors" ; _ }, _); _ } -> true | _ -> false)
+      items
+  in
+  let url =
+    match url, archive with
+    | Some { pelem = Variable (_, { pelem = String url ; _ }) ; _ }, None -> Ok url
+    | None, Some { pelem = Variable (_, { pelem = String url ; _ }); _ } -> Ok url
+    | _ -> Error (`Msg "neither 'src' nor 'archive' present")
+  and mirrors = match mirrors with
+    | None -> []
+    | Some { pelem = Variable (_, { pelem = String url ; _ }) ; _ } -> [ url ]
+    | Some { pelem = Variable (_, { pelem = List { pelem = urls ; _ } ; _ }) } ->
+      List.fold_left (fun acc -> function
+          | { pelem = String url ; _ } -> url :: acc
+          | v ->
+            Logs.err (fun m -> m "bad mirror data (expected a string in the list): %s"
+                         (OpamPrinter.FullPos.value v));
+            acc)
+        [] urls
+    | Some v ->
+      Logs.err (fun m -> m "bad mirror data (expected string or string list): %s"
+                   (OpamPrinter.FullPos.items [ v ]));
+      []
+  in
+  let csum, csum_errs =
+    match checksum with
+    | Some { pelem = Variable (_, { pelem = List { pelem = csums ; _ } ; _ }); _ } ->
+      let csums, errs =
+        List.fold_left (fun (csums, errs) ->
+            function
+            | { pelem = String csum ; _ } ->
+              begin match decode_digest filename csum with
+                | Error e -> csums, e :: errs
+                | Ok (h, v) ->
+                  HM.update h (function
+                      | None -> Some v
+                      | Some v' when String.equal v v' -> None
+                      | Some v' ->
+                        Logs.warn (fun m -> m "for %s, hash %s, multiple keys are present: %s %s"
+                                      (Result.value ~default:"NONE" url) (hash_to_string h) (Ohex.encode v) (Ohex.encode v'));
+                        None)
+                    csums, errs
+              end
+            | v ->
+              csums, `Msg (Fmt.str "bad checksum data: %s" (OpamPrinter.FullPos.value v)) :: errs)
+          (HM.empty, []) csums
+      in
+      if HM.is_empty csums then
+        match errs with
+        | hd :: tl -> Error hd, tl
+        | [] -> Error (`Msg "empty checksums"), []
+      else
+        Ok csums, errs
+    | Some { pelem = Variable (_, { pelem = String csum ; _ }) ; _ } ->
+      begin match decode_digest filename csum with
+        | Error _ as e -> e, []
+        | Ok (h, v) -> Ok (HM.singleton h v), []
+      end
+    | _ -> Error (`Msg "couldn't find or decode 'checksum'"), []
+  in
+  (match url, csum with
+   | Ok url, Ok csum -> Ok (url, csum, mirrors)
+   | Error _ as e, _
+   | _, (Error _ as e) -> e), csum_errs
+
+let extract_checksums_and_urls filename opam =
+  let open OpamParserTypes.FullPos in
+  List.fold_left (fun (csum_urls, errs) ->
+      function
+      | { pelem = Section ({ section_kind = { pelem = "url" ; _ } ; section_items = { pelem = items ; _ } ; _ }) ; _} ->
+        begin match extract_url_checksum filename items with
+          | Error `Msg msg, errs' -> csum_urls, `Msg ("url: " ^ msg) :: errs' @ errs
+          | Ok url, errs' -> url :: csum_urls, errs' @ errs
+        end
+      | { pelem = Section ({ section_kind = { pelem = "extra-source" ; _ } ; section_name = Some { pelem ; _ } ;  section_items = { pelem = items ; _ };  _ }) ; _} ->
+        begin
+          match extract_url_checksum filename items with
+          | Error `Msg msg, errs' -> csum_urls, `Msg ("extra-source " ^ pelem ^ " " ^ msg) :: errs' @ errs
+          | Ok url, errs' -> url :: csum_urls, errs' @ errs
+        end
+      | _ -> csum_urls, errs)
+    ([], []) opam.file_contents
+
+let extract_urls filename str =
+  (* in an opam file, there may be:
+     url { src: <string> checksum: [ STRING ] } <- list of hash
+     url { src: <string> checksum: STRING } <- single hash
+     url { archive: <string> checksum: STRING } <- MD5
+     extra-source NAME { src: URL checksum: [ STRING ] } (OR checksum: STRING) <- multiple occurences possible
+  *)
+  let open OpamParserTypes.FullPos in
+  let opamfile = OpamParser.FullPos.string str filename in
+  let unavailable =
+    List.exists
+      (function
+        | { pelem = Variable ({ pelem = "available" ; _ },
+                              { pelem = (Bool false | List { pelem = [{ pelem = Bool false; _ }] ; _ }); _ })
+          ; _ } -> true
+        | _ -> false)
+      opamfile.file_contents
+  in
+  if unavailable then
+     [], []
+  else
+    extract_checksums_and_urls filename opamfile

mirage/partitions.ml

@@ -0,0 +1,222 @@
+open Lwt.Syntax
+
+module Make(BLOCK : Mirage_block.S) = struct
+  module Part = Mirage_block_partition.Make(BLOCK)
+
+  include Part
+
+  type partitions = {
+    tar : Part.t ;
+    swap : Part.t ;
+    git_dump : Part.t ;
+    md5s : Part.t ;
+    sha512s : Part.t ;
+  }
+
+  (* I just made these ones up... *)
+  let swap_guid = Uuidm.of_string "76515dc1-953f-4c59-8b41-90011bdddfcd" |> Option.get
+  let tar_guid = Uuidm.of_string "53cd6812-46cc-474e-a141-30b3aed85f53" |> Option.get
+  let cache_guid = Uuidm.of_string "22ab9cf5-6e51-45c2-998a-862e23aab264" |> Option.get
+  let git_guid = Uuidm.of_string "30faa50a-4c9d-47ff-a1a5-ecfb3401c027" |> Option.get
+
+  (* GPT uses a 72 byte utf16be encoded string for partition names *)
+  let utf16be_of_ascii s =
+    String.init 72
+      (fun i ->
+         if i mod 2 = 0 && i / 2 < String.length s then
+           s.[i/2]
+         else
+           '\000')
+
+  let read_partition_table info block =
+    let b = Cstruct.create info.Mirage_block.sector_size in
+    (* We will ignore the protective MBR at lba [0L] *)
+    let* r = BLOCK.read block 1L [b] in
+    match r with
+    | Error e ->
+      Format.kasprintf failwith "Reading partition table: %a"
+        BLOCK.pp_error e
+    | Ok () ->
+      match Gpt.unmarshal b ~sector_size:info.Mirage_block.sector_size with
+      | Error e ->
+        Format.kasprintf failwith "Reading partition table: %s" e
+      | Ok (`Read_partition_table (lba, sectors), k) ->
+        let b = Cstruct.create (sectors * info.Mirage_block.sector_size) in
+        let* r = BLOCK.read block lba [b] in
+        match r with
+        | Error e ->
+          Format.kasprintf failwith "Reading partition table: %a"
+            BLOCK.pp_error e
+        | Ok () ->
+          match k b with
+          | Error e ->
+            Format.kasprintf failwith "Reading partition table: %s" e
+          | Ok gpt -> Lwt.return gpt
+
+  let connect block =
+    let* info = BLOCK.get_info block in
+    let* gpt = read_partition_table info block in
+    let tar, swap, git_dump, md5s, sha512s =
+      match
+        List.fold_left
+          (fun (tar, swap, git_dump, md5s, sha512s) p ->
+             if String.equal p.Gpt.Partition.name
+                 (utf16be_of_ascii "tar")
+             then
+               (Some p, swap, git_dump, md5s, sha512s)
+             else if String.equal p.name
+                 (utf16be_of_ascii "git_dump")
+             then
+               (tar, swap, Some p, md5s, sha512s)
+             else if String.equal p.name
+                 (utf16be_of_ascii "md5s")
+             then
+               (tar, swap, git_dump, Some p, sha512s)
+             else if String.equal p.name
+                 (utf16be_of_ascii "sha512s")
+             then
+               (tar, swap, git_dump, md5s, Some p)
+             else if String.equal p.name
+                 (utf16be_of_ascii "swap")
+             then
+               (tar, Some p, git_dump, md5s, sha512s)
+             else
+               Format.kasprintf failwith "Unknown partition %S" p.name)
+          (None, None, None, None, None)
+          gpt.partitions
+      with
+      | (Some tar, Some swap, Some git_dump, Some md5s, Some sha512s) ->
+        (tar, swap, git_dump, md5s, sha512s)
+      | _ ->
+        failwith "not all partitions found :("
+    in
+    let+ (_empty, p) = Part.connect 0L block in
+    let get_part part =
+      let len = Int64.(succ (sub part.Gpt.Partition.ending_lba part.starting_lba)) in
+      let (_before, after) = Part.subpartition part.starting_lba p in
+      let (part, _after) = Part.subpartition len after in
+      part
+    in
+    let tar = get_part tar and swap = get_part swap and git_dump = get_part git_dump
+    and md5s = get_part md5s and sha512s = get_part sha512s in
+    { tar ; swap; git_dump ; md5s ; sha512s }
+
+  let format block ~cache_size ~git_size ~swap_size =
+    let* { size_sectors; sector_size; _ } = BLOCK.get_info block in
+    let ( let*? ) = Lwt_result.bind in
+    (* ocaml-gpt uses a fixed size partition entries table. Create an empty GPT
+       to figure out the first usable LBA *)
+    let empty =
+      Gpt.make ~sector_size ~disk_sectors:size_sectors []
+      |> Result.get_ok
+    in
+    let mb_in_sectors mb =
+      (* 1 megabyte is 2^20 bytes (1024 * 1024) *)
+      let mb_in_bytes = Int64.(shift_left (of_int mb) 20) in
+      let ss = Int64.of_int sector_size in
+      Int64.(div (add mb_in_bytes (sub ss 1L)) ss)
+    in
+    let sectors_cache = mb_in_sectors cache_size
+    and sectors_git = mb_in_sectors git_size
+    and sectors_swap = mb_in_sectors swap_size
+    in
+    let*? () =
+      if size_sectors <
+         (* protective MBR + GPT header + GPT table *)
+         let ( + ) = Int64.add in
+         empty.first_usable_lba +
+         min 1L (Int64.of_int (2 * Tar.Header.length / sector_size)) + sectors_cache + sectors_cache + sectors_git
+         + 1L (* backup GPT header *) then
+        Lwt.return_error (`Msg "too small disk")
+      else Lwt_result.return ()
+    in
+    (* Current implementation of [Gpt.Partition.make] only returns [Ok _] or
+       raises [Invalid_argument _] :/ *)
+    let attributes = 1L in
+    let sha512s =
+      Gpt.Partition.make
+        ~name:(utf16be_of_ascii "sha512s")
+        ~type_guid:cache_guid
+        ~attributes
+        Int64.(succ (sub empty.last_usable_lba sectors_cache))
+        empty.last_usable_lba
+      |> Result.get_ok
+    in
+    let md5s =
+      Gpt.Partition.make
+        ~name:(utf16be_of_ascii "md5s")
+        ~type_guid:cache_guid
+        ~attributes
+        (Int64.sub sha512s.starting_lba sectors_cache)
+        (Int64.pred sha512s.starting_lba)
+      |> Result.get_ok
+    in
+    let git_dump =
+      Gpt.Partition.make
+        ~name:(utf16be_of_ascii "git_dump")
+        ~type_guid:git_guid
+        ~attributes
+        (Int64.sub md5s.starting_lba sectors_git)
+        (Int64.pred md5s.starting_lba)
+      |> Result.get_ok
+    in
+    let swap =
+      Gpt.Partition.make
+        ~name:(utf16be_of_ascii "swap")
+        ~type_guid:swap_guid
+        ~attributes
+        (Int64.sub git_dump.starting_lba sectors_swap)
+        (Int64.pred git_dump.starting_lba)
+      |> Result.get_ok
+    in
+    let tar =
+      Gpt.Partition.make
+        ~name:(utf16be_of_ascii "tar")
+        ~type_guid:tar_guid
+        ~attributes
+        empty.first_usable_lba
+        (Int64.pred swap.starting_lba)
+      |> Result.get_ok
+    in
+    let gpt =
+      let partitions =
+        [ tar; swap; git_dump; md5s; sha512s ]
+      in
+      Gpt.make ~sector_size ~disk_sectors:size_sectors partitions
+      |> Result.get_ok
+    in
+    let buf =
+      Cstruct.create (sector_size * (Int64.to_int gpt.first_usable_lba + 2 * Tar.Header.length))
+    in
+    Gptar.marshal_header ~sector_size buf gpt;
+    Gpt.marshal_partition_table ~sector_size
+      (Cstruct.shift buf (sector_size * Int64.to_int gpt.partition_entry_lba))
+    gpt;
+    let write block sector_start buffers =
+      BLOCK.write block sector_start buffers
+      |> Lwt_result.map_error (fun e -> `Block e)
+    in
+    let*? () =
+      write block 0L [ buf ]
+    in
+    (* Format the file systems by writing zeroes *)
+    (* For tar we need to zero (at least) the first 2*512 bytes so we round up
+       to the nearest sector alignment *)
+    let zeroes =
+      let sectors =
+        (2 * Tar.Header.length + sector_size - 1) / sector_size * sector_size
+      in
+      Cstruct.create sectors in
+    let*? () =
+      write block tar.starting_lba [ zeroes ]
+    in
+    (* For the OneFFS filesystems we just need to zero out the first sector *)
+    let zero_sector = Cstruct.create sector_size in
+    let*? () =
+      write block git_dump.starting_lba [ zero_sector ]
+    in
+    let*? () =
+      write block md5s.starting_lba [ zero_sector ]
+    in
+    write block sha512s.starting_lba [ zero_sector ]
+end