(* Memory info for virtual domains.
   (C) Copyright 2008 Richard W.M. Jones, Red Hat Inc.
   http://libvirt.org/

   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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *)

open Printf

open Virt_mem_gettext.Gettext
open Virt_mem_utils
open Virt_mem_mmap

let run debug images =
  (* Print new_utsname structure from bitstring. *)
  let print_new_utsname name bs =
    (* Truncate an OCaml string at the first ASCII NUL character, ie. as
     * if it were a C string.
     *)
    let truncate str =
      try
	let i = String.index str '\000' in
	String.sub str 0 i
      with
	Not_found -> str
    in
    (* Expect the first (sysname) field to always be "Linux", which is
     * also a good way to tell if we're synchronized to the right bit of
     * memory.
     *)
    bitmatch bs with
    | { "Linux\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000" : 65*8 : string;
	nodename : 65*8 : string;
	release : 65*8 : string;
	version : 65*8 : string;
	machine : 65*8 : string;
	domainname : 65*8 : string } ->
	printf "%s: Linux %s %s %s %s %s\n"
	  name
	  (truncate nodename) (truncate release)
	  (truncate version) (truncate machine) (truncate domainname)
    | { _ } ->
	eprintf (f_"%s: unexpected system_utsname in kernel image\n")
	  name
  in

  List.iter (
    fun (name, arch, mem, lookup_ksym) ->
      (* In Linux 2.6.25, the symbol is init_uts_ns.
       * http://lxr.linux.no/linux/init/version.c
       *)
      try
	let addr = lookup_ksym "init_uts_ns" in

	let bs = Bitmatch.bitstring_of_string (get_bytes mem addr (65*6+4)) in
	(bitmatch bs with
	 | { _ : 32 : int;		(* the kref, atomic_t, always 32 bits *)
	     new_utsname : -1 : bitstring } ->
	     print_new_utsname name new_utsname
	 | { _ } ->
	     eprintf (f_"%s: unexpected init_uts_ns in kernel image\n")
	       name)
      with
	Not_found ->
	  (* In Linux 2.6.9, the symbol is system_utsname.
	   * http://lxr.linux.no/linux-bk+v2.6.9/include/linux/utsname.h#L24
	   *)
	  try
	    let addr = lookup_ksym "system_utsname" in

	    let bs =
	      Bitmatch.bitstring_of_string (get_bytes mem addr (65*6)) in
	    print_new_utsname name bs
	  with
	    Not_found ->
	      eprintf (f_"%s: could not find utsname in kernel image\n") name
  ) images

let summary = s_"uname command for virtual machines"
let description = s_"\
virt-uname prints the uname information such as OS version,
architecture and node name for virtual machines running under
libvirt."

let () = Virt_mem.register "uname" summary description true run