mirror of
https://github.com/libguestfs/libguestfs.git
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500acb15f8
The current detection code for Linux kernels assumes that a kernel
package contains everything in it, i.e. the kernel itself, its modules,
and its configuration. However, since recent Ubuntu versions (e.g.
starting from 18.04) modules & config (with few more files) are split in
an own package, thus not detecting the modpath from installed vmlinuz
files.
To overcome this situation, rework this detection a bit:
1) find the vmlinuz file as before, but then immediately make sure it
exists by stat'ing it
2) find the modules path from the package as before:
2a) if found, extract the version in the same step
2b) if not found, get the kernel version from the vmlinuz filename,
and use it to detect the modules path
3) check that the modules path exists
The detection done in (2b) is based on the current packaging scheme
found in the most important Linux distributions (Fedora, RHEL, CentOS,
Debian, Ubuntu, openSUSE, AltLinux, and possibly more). The notable
exception is Arch Linux.
As additional change, do not assume the config file is in the same
package as vmlinuz, but directly look into the filesystem using the
version we already have.
308 lines
12 KiB
OCaml
308 lines
12 KiB
OCaml
(* virt-v2v
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* Copyright (C) 2009-2018 Red Hat Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*)
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(* Detect which kernels are installed and offered by the bootloader. *)
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open Printf
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open Std_utils
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open Tools_utils
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open Common_gettext.Gettext
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open Types
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module G = Guestfs
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(* Kernel information. *)
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type kernel_info = {
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ki_app : G.application2;
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ki_name : string;
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ki_version : string;
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ki_arch : string;
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ki_vmlinuz : string;
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ki_vmlinuz_stat : G.statns;
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ki_initrd : string option;
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ki_modpath : string;
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ki_modules : string list;
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ki_supports_virtio_blk : bool;
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ki_supports_virtio_net : bool;
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ki_supports_virtio_rng : bool;
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ki_supports_virtio_balloon : bool;
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ki_supports_isa_pvpanic : bool;
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ki_is_xen_pv_only_kernel : bool;
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ki_is_debug : bool;
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ki_config_file : string option;
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}
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let print_kernel_info chan prefix ki =
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let fpf fs = output_string chan prefix; fprintf chan fs in
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fprintf chan "* %s %s (%s)\n" ki.ki_name ki.ki_version ki.ki_arch;
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fpf "%s\n" ki.ki_vmlinuz;
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fpf "%s\n" (match ki.ki_initrd with None -> "no initrd" | Some s -> s);
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fpf "%s\n" (match ki.ki_config_file with None -> "no config" | Some s -> s);
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fpf "%s\n" ki.ki_modpath;
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fpf "%d modules found\n" (List.length ki.ki_modules);
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fpf "virtio: blk=%b net=%b rng=%b balloon=%b\n"
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ki.ki_supports_virtio_blk ki.ki_supports_virtio_net
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ki.ki_supports_virtio_rng ki.ki_supports_virtio_balloon;
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fpf "pvpanic=%b xen=%b debug=%b\n"
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ki.ki_supports_isa_pvpanic ki.ki_is_xen_pv_only_kernel ki.ki_is_debug
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let rex_ko = PCRE.compile "\\.k?o(?:\\.xz)?$"
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let rex_ko_extract = PCRE.compile "/([^/]+)\\.k?o(?:\\.xz)?$"
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let detect_kernels (g : G.guestfs) inspect family bootloader =
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(* What kernel/kernel-like packages are installed on the current guest? *)
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let installed_kernels : kernel_info list =
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let check_config feature = function
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| None -> false
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| Some config ->
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let prefix = "^CONFIG_" ^ String.uppercase_ascii feature ^ "=" in
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let lines = g#grep ~extended:true prefix config in
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let lines = Array.to_list lines in
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match lines with
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| [] -> false
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| line :: _ ->
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let kind = snd (String.split "=" line) in
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(match kind with
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| "m" | "y" -> true
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| _ -> false
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)
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in
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let rex_initrd =
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if family = `Debian_family then
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PCRE.compile "^initrd.img-.*$"
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else
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PCRE.compile "^initr(?:d|amfs)-.*(?:\\.img)?$" in
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List.filter_map (
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function
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| { G.app2_name = name } as app
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when name = "kernel" || String.is_prefix name "kernel-"
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|| String.is_prefix name "linux-image-" ->
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(try
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(* For each kernel, list the files directly owned by the kernel. *)
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let files = Linux.file_list_of_package g inspect app in
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if files = [] then (
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warning (f_"package ‘%s’ contains no files") name;
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None
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)
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else (
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(* Which of these is the kernel itself? Also, make sure to check
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* it exists by stat'ing it.
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*)
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let vmlinuz = List.find (
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fun filename -> String.is_prefix filename "/boot/vmlinuz-"
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) files in
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let vmlinuz_stat =
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try g#statns vmlinuz with G.Error _ -> raise Not_found in
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(* Determine the modpath from the package, falling back to the
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* version in the vmlinuz file name.
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*)
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let modpath, version =
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let prefix = "/lib/modules/" in
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try
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let prefix_len = String.length prefix in
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List.find_map (
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fun filename ->
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let filename_len = String.length filename in
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if filename_len > prefix_len &&
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String.is_prefix filename prefix then (
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let version = String.sub filename prefix_len
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(filename_len - prefix_len) in
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Some (filename, version)
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) else
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None
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) files
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with Not_found ->
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let version =
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String.sub vmlinuz 14 (String.length vmlinuz - 14) in
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let modpath = prefix ^ version in
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modpath, version in
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(* Check that the modpath exists. *)
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if not (g#is_dir ~followsymlinks:true modpath) then
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raise Not_found;
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(* Find the initramfs which corresponds to the kernel.
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* Since the initramfs is built at runtime, and doesn't have
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* to be covered by the RPM file list, this is basically
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* guesswork.
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*)
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let initrd =
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let files = g#ls "/boot" in
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let files = Array.to_list files in
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let files =
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List.filter (fun n -> PCRE.matches rex_initrd n) files in
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let files =
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List.filter (
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fun n ->
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String.find n version >= 0
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) files in
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(* Don't consider kdump initramfs images (RHBZ#1138184). *)
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let files =
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List.filter (fun n -> String.find n "kdump" == -1) files in
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(* If several files match, take the shortest match. This
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* handles the case where we have a mix of same-version non-Xen
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* and Xen kernels:
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* initrd-2.6.18-308.el5.img
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* initrd-2.6.18-308.el5xen.img
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* and kernel 2.6.18-308.el5 (non-Xen) will match both
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* (RHBZ#1141145).
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*)
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let cmp a b = compare (String.length a) (String.length b) in
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let files = List.sort cmp files in
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match files with
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| [] ->
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warning (f_"no initrd was found in /boot matching %s %s.")
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name version;
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None
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| x :: _ -> Some ("/boot/" ^ x) in
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(* Get all modules, which might include custom-installed
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* modules that don't appear in 'files' list above.
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*)
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let modules = g#find modpath in
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let modules = Array.to_list modules in
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let modules =
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List.filter (fun m -> PCRE.matches rex_ko m) modules in
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assert (List.length modules > 0);
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(* Determine the kernel architecture by looking at the
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* architecture of an arbitrary kernel module.
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*)
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let arch =
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let any_module = modpath ^ List.hd modules in
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g#file_architecture any_module in
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(* Just return the module names, without path or extension. *)
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let modules = List.filter_map (
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fun m ->
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if PCRE.matches rex_ko_extract m then
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Some (PCRE.sub 1)
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else
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None
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) modules in
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assert (List.length modules > 0);
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let config_file =
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let cfg = "/boot/config-" ^ version in
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if g#is_file ~followsymlinks:true cfg then Some cfg
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else None in
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let kernel_supports what kconf =
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List.mem what modules || check_config kconf config_file in
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let supports_virtio_blk =
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kernel_supports "virtio_blk" "VIRTIO_BLK" in
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let supports_virtio_net =
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kernel_supports "virtio_net" "VIRTIO_NET" in
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let supports_virtio_rng =
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kernel_supports "virtio-rng" "HW_RANDOM_VIRTIO" in
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let supports_virtio_balloon =
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kernel_supports "virtio_balloon" "VIRTIO_BALLOON" in
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let supports_isa_pvpanic =
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kernel_supports "pvpanic" "PVPANIC" in
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let is_xen_pv_only_kernel =
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check_config "X86_XEN" config_file ||
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check_config "X86_64_XEN" config_file in
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(* If the package name is like "kernel-debug", then it's
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* a debug kernel.
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*)
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let is_debug =
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String.is_suffix app.G.app2_name "-debug" ||
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String.is_suffix app.G.app2_name "-dbg" in
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Some {
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ki_app = app;
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ki_name = name;
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ki_version = version;
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ki_arch = arch;
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ki_vmlinuz = vmlinuz;
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ki_vmlinuz_stat = vmlinuz_stat;
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ki_initrd = initrd;
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ki_modpath = modpath;
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ki_modules = modules;
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ki_supports_virtio_blk = supports_virtio_blk;
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ki_supports_virtio_net = supports_virtio_net;
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ki_supports_virtio_rng = supports_virtio_rng;
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ki_supports_virtio_balloon = supports_virtio_balloon;
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ki_supports_isa_pvpanic = supports_isa_pvpanic;
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ki_is_xen_pv_only_kernel = is_xen_pv_only_kernel;
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ki_is_debug = is_debug;
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ki_config_file = config_file;
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}
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)
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with Not_found -> None
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)
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| _ -> None
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) inspect.i_apps in
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if verbose () then (
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eprintf "installed kernel packages in this guest:\n";
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List.iter (print_kernel_info stderr "\t") installed_kernels;
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flush stderr
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);
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if installed_kernels = [] then
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error (f_"no installed kernel packages were found.\n\nThis probably indicates that %s was unable to inspect this guest properly.")
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prog;
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(* Now the difficult bit. Get the bootloader kernels. The first in this
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* list is the default booting kernel.
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*)
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let bootloader_kernels : kernel_info list =
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let vmlinuzes = bootloader#list_kernels in
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(* Map these to installed kernels. *)
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List.filter_map (
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fun vmlinuz ->
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try
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let statbuf = g#statns vmlinuz in
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let kernel =
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List.find (
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fun { ki_vmlinuz_stat = s } ->
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statbuf.G.st_dev = s.G.st_dev && statbuf.G.st_ino = s.G.st_ino
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) installed_kernels in
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Some kernel
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with
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| Not_found -> None
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| G.Error msg as exn ->
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(* If it isn't "no such file or directory", then re-raise it. *)
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if g#last_errno () <> G.Errno.errno_ENOENT then raise exn;
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warning (f_"ignoring kernel %s in bootloader, as it does not exist.")
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vmlinuz;
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None
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) vmlinuzes in
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if verbose () then (
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eprintf "kernels offered by the bootloader in this guest (first in list is default):\n";
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List.iter (print_kernel_info stderr "\t") bootloader_kernels;
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flush stderr
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);
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if bootloader_kernels = [] then
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error (f_"no kernels were found in the bootloader configuration.\n\nThis probably indicates that %s was unable to parse the bootloader configuration of this guest.")
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prog;
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bootloader_kernels
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