Files
libguestfs/builder/index_parser.ml
Cédric Bosdonnat efaf570aaa builder: add a template parameter to get_index
get_index now gets a new template parameter. Setting it to true will
make the index parsing less picky about missing important data. This
can be used to parse a partial index file.
2017-11-21 16:16:19 +00:00

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(* virt-builder
* Copyright (C) 2013 Red Hat Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*)
open Std_utils
open Tools_utils
open Common_gettext.Gettext
open Utils
open Printf
open Unix
let get_index ~downloader ~sigchecker ?(template = false) { Sources.uri; proxy } =
let corrupt_file () =
error (f_"The index file downloaded from %s is corrupt.\nYou need to ask the supplier of this file to fix it and upload a fixed version.") uri
in
let rec get_index () =
(* Get the index page. *)
let tmpfile, _ = Downloader.download downloader ~proxy uri in
(* Check index file signature (also verifies it was fully
* downloaded and not corrupted in transit).
*)
Sigchecker.verify sigchecker tmpfile;
(* Try parsing the file. *)
let sections = Ini_reader.read_ini tmpfile in
(* Check for repeated os-version+arch combination. *)
let name_arch_map = List.map (
fun (n, fields) ->
let rec find_arch = function
| ("arch", None, value) :: y -> value
| _ :: y -> find_arch y
| [] -> ""
in
n, (find_arch fields)
) sections in
let nseen = Hashtbl.create 13 in
List.iter (
fun (n, arch) ->
let id = n, arch in
if Hashtbl.mem nseen id then (
eprintf (f_"%s: index is corrupt: os-version %s with architecture %s appears two or more times\n") prog n arch;
corrupt_file ()
);
Hashtbl.add nseen id true
) name_arch_map;
(* Check for repeated fields. *)
List.iter (
fun (n, fields) ->
let fseen = Hashtbl.create 13 in
List.iter (
fun (field, subkey, _) ->
let hashkey = (field, subkey) in
if Hashtbl.mem fseen hashkey then (
(match subkey with
| Some value ->
eprintf (f_"%s: index is corrupt: %s: field %s[%s] appears two or more times\n") prog n field value
| None ->
eprintf (f_"%s: index is corrupt: %s: field %s appears two or more times\n") prog n field);
corrupt_file ()
);
Hashtbl.add fseen hashkey true
) fields
) sections;
(* Turn the sections into the final index. *)
let entries =
List.map (
fun (n, fields) ->
let fields = List.map (fun (k, sk, v) -> (k, sk), v) fields in
let printable_name =
try Some (List.assoc ("name", None) fields) with Not_found -> None in
let osinfo =
try Some (List.assoc ("osinfo", None) fields) with Not_found -> None in
let file_uri =
try make_absolute_uri (List.assoc ("file", None) fields)
with Not_found ->
eprintf (f_"%s: no file (URI) entry for %s\n") prog n;
corrupt_file () in
let arch =
try Index.Arch (List.assoc ("arch", None) fields)
with Not_found ->
if template then
let g = open_guestfs ~identifier:"template" () in
g#add_drive_ro file_uri;
g#launch ();
let roots = g#inspect_os () in
let nroots = Array.length roots in
if nroots <> 1 then (
eprintf (f_"%s: no arch entry for %s and failed to guess it\n") prog n;
corrupt_file ()
);
let inspected_arch = g#inspect_get_arch (Array.get roots 0) in
g#close();
Index.GuessedArch inspected_arch
else (
eprintf (f_"%s: no arch entry for %s\n") prog n;
corrupt_file ()
) in
let signature_uri =
try Some (make_absolute_uri (List.assoc ("sig", None) fields))
with Not_found -> None in
let checksum_sha512 =
try Some (List.assoc ("checksum", Some "sha512") fields)
with Not_found ->
try Some (List.assoc ("checksum", None) fields)
with Not_found -> None in
let revision =
try Rev_int (int_of_string (List.assoc ("revision", None) fields))
with
| Not_found -> if template then Rev_int 0 else Rev_int 1
| Failure _ ->
eprintf (f_"%s: cannot parse revision field for %s\n") prog n;
corrupt_file () in
let format =
try Some (List.assoc ("format", None) fields) with Not_found -> None in
let size =
let get_image_size filepath =
(* If a compressed image manages to reach this code, qemu-img just
returns a virtual-size equal to actual-size *)
match detect_file_type filepath with
| `Unknown ->
let infos = Utils.get_image_infos filepath in
Yajl.object_get_number "virtual-size" infos
| `XZ | `GZip | `Tar | ` Zip ->
eprintf (f_"%s: cannot determine the virtual size of %s due to compression")
prog filepath;
corrupt_file () in
try Int64.of_string (List.assoc ("size", None) fields)
with
| Not_found ->
if template then
get_image_size file_uri
else (
eprintf (f_"%s: no size field for %s\n") prog n;
corrupt_file ()
)
| Failure _ ->
if template then
get_image_size file_uri
else (
eprintf (f_"%s: cannot parse size field for %s\n") prog n;
corrupt_file ()
) in
let compressed_size =
try Some (Int64.of_string (List.assoc ("compressed_size", None) fields))
with
| Not_found ->
None
| Failure _ ->
eprintf (f_"%s: cannot parse compressed_size field for %s\n")
prog n;
corrupt_file () in
let expand =
try Some (List.assoc ("expand", None) fields) with Not_found -> None in
let lvexpand =
try Some (List.assoc ("lvexpand", None) fields) with Not_found -> None in
let notes =
let rec loop = function
| [] -> []
| (("notes", subkey), value) :: xs ->
let subkey = match subkey with
| None -> ""
| Some v -> v in
(subkey, value) :: loop xs
| _ :: xs -> loop xs in
List.sort (
fun (k1, _) (k2, _) ->
String.compare k1 k2
) (loop fields) in
let hidden =
try bool_of_string (List.assoc ("hidden", None) fields)
with
| Not_found -> false
| Failure _ ->
eprintf (f_"%s: cannot parse hidden field for %s\n")
prog n;
corrupt_file () in
let aliases =
let l =
try String.nsplit " " (List.assoc ("aliases", None) fields)
with Not_found -> [] in
match l with
| [] -> None
| l -> Some l in
let checksums =
match checksum_sha512 with
| Some c -> Some [Checksums.SHA512 c]
| None -> None in
let entry = { Index.printable_name = printable_name;
osinfo = osinfo;
file_uri = file_uri;
arch = arch;
signature_uri = signature_uri;
checksums = checksums;
revision = revision;
format = format;
size = size;
compressed_size = compressed_size;
expand = expand;
lvexpand = lvexpand;
notes = notes;
hidden = hidden;
aliases = aliases;
proxy = proxy;
sigchecker = sigchecker } in
n, entry
) sections in
if verbose () then (
printf "index file (%s) after parsing (C parser):\n" uri;
List.iter (Index.print_entry Pervasives.stdout) entries
);
entries
(* Verify same-origin policy for the file= and sig= fields. *)
and make_absolute_uri path =
if String.length path = 0 then (
eprintf (f_"%s: zero length path in the index file\n") prog;
corrupt_file ()
)
else if String.find path "://" >= 0 then (
eprintf (f_"%s: cannot use a URI (%s) in the index file\n") prog path;
corrupt_file ()
)
else if path.[0] = '/' then (
eprintf (f_"%s: you must use relative paths (not %s) in the index file\n") prog path;
corrupt_file ()
)
else (
(* Construct the URI. *)
try
let i = String.rindex uri '/' in
String.sub uri 0 (i+1) ^ path
with
Not_found -> uri // path
)
in
get_index ()
let write_entry chan (name, { Index.printable_name; file_uri; arch; osinfo;
signature_uri; checksums; revision; format; size;
compressed_size; expand; lvexpand; notes;
aliases; hidden}) =
let fp fs = fprintf chan fs in
fp "[%s]\n" name;
Option.may (fp "name=%s\n") printable_name;
Option.may (fp "osinfo=%s\n") osinfo;
fp "file=%s\n" file_uri;
fp "arch=%s\n" (Index.string_of_arch arch);
Option.may (fp "sig=%s\n") signature_uri;
(match checksums with
| None -> ()
| Some checksums ->
List.iter (
fun c ->
fp "checksum[%s]=%s\n"
(Checksums.string_of_csum_t c) (Checksums.string_of_csum c)
) checksums
);
fp "revision=%s\n" (string_of_revision revision);
Option.may (fp "format=%s\n") format;
fp "size=%Ld\n" size;
Option.may (fp "compressed_size=%Ld\n") compressed_size;
Option.may (fp "expand=%s\n") expand;
Option.may (fp "lvexpand=%s\n") lvexpand;
let format_notes notes =
String.concat "\n " (String.nsplit "\n" notes) in
List.iter (
fun (lang, notes) ->
match lang with
| "" -> fp "notes=%s\n" (format_notes notes)
| lang -> fp "notes[%s]=%s\n" lang (format_notes notes)
) notes;
(match aliases with
| None -> ()
| Some l -> fp "aliases=%s\n" (String.concat " " l)
);
if hidden then fp "hidden=true\n";
fp "\n"