-(* 'df' command for virtual domains.
-
- (C) Copyright 2007 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.
-
- Support for Master Boot Record partition scheme.
-*)
-
-open Printf
-open Unix
-open ExtList
-
-open Virt_df_gettext.Gettext
-open Virt_df
-
-let sector_size = 512
-let sector_size64 = 512L
-
-(* Maximum number of extended partitions possible. *)
-let max_extended_partitions = 100
-
-(* Device representing a single partition. It just acts as an offset
- * into the underlying device.
- *
- * Notes:
- * (1) 'start'/'size' are measured in sectors.
- * (2) 'partno' is the partition number, starting at 1
- * (cf. /dev/hda1 is the first partition).
- * (3) 'dev' is the underlying block device.
- *)
-class partition_device partno start size dev =
- let devname = dev#name in
- let name = sprintf "%s%d" devname partno in
- let start = start *^ sector_size64 in
- let size = size *^ sector_size64 in
-object (self)
- inherit offset_device name start size dev
-end
-
-(** Probe the
- {{:http://en.wikipedia.org/wiki/Master_boot_record}master boot record}
- (if it is one) and read the partitions.
-
- @raise Not_found if it is not an MBR.
- *)
-let rec probe_mbr dev =
- (* Adjust size to sectors. *)
- let size = dev#size /^ sector_size64 in
-
- (* Read the first sector. *)
- let bits =
- try dev#read_bitstring 0L sector_size
- with exn -> raise Not_found in
-
- (* Does this match a likely-looking MBR? *)
- bitmatch bits with
- | padding : 3568 : bitstring; (* padding to byte offset 446 *)
- part0 : 128 : bitstring; (* partitions *)
- part1 : 128 : bitstring;
- part2 : 128 : bitstring;
- part3 : 128 : bitstring;
- 0x55 : 8; 0xAA : 8 -> (* MBR signature *)
-
- (* Parse the partition table entries. *)
- let primaries =
- List.mapi (parse_mbr_entry dev) [part0;part1;part2;part3] in
-
-(*
- (* Read extended partition data. *)
- let extendeds = List.map (
- function
- | { part_type = 0x05 } as part ->
- probe_extended_partition
- max_extended_partitions fd part part.part_lba_start
- | part -> []
- ) primaries in
- let extendeds = List.concat extendeds in
- primaries @ extendeds
-*)
- { parts_name = "MBR"; parts = primaries }
-
- | _ ->
- raise Not_found (* not an MBR *)
-
-(* Parse a single partition table entry. See the table here:
- * http://en.wikipedia.org/wiki/Master_boot_record
- *)
-and parse_mbr_entry dev i bits =
- bitmatch bits with
- | 0l : 32; 0l : 32; 0l : 32; 0l : 32 ->
- { part_status = NullEntry; part_type = 0;
- part_dev = null_device; part_content = `Unknown }
-
- | 0 : 8; first_chs : 24;
- part_type : 8; last_chs : 24;
- first_lba : 32 : unsigned, littleendian;
- part_size : 32 : unsigned, littleendian ->
- make_mbr_entry Nonbootable dev (i+1) part_type first_lba part_size
-
- | 0x80 : 8; first_chs : 24;
- part_type : 8; last_chs : 24;
- first_lba : 32 : unsigned, littleendian;
- part_size : 32 : unsigned, littleendian ->
- make_mbr_entry Bootable dev (i+1) part_type first_lba part_size
-
- | _ ->
- { part_status = Malformed; part_type = 0;
- part_dev = null_device; part_content = `Unknown }
-
-and make_mbr_entry part_status dev partno part_type first_lba part_size =
- let first_lba = uint64_of_int32 first_lba in
- let part_size = uint64_of_int32 part_size in
- if !debug then
- eprintf "make_mbr_entry: first_lba = %Lx part_size = %Lx\n%!"
- first_lba part_size;
- { part_status = part_status;
- part_type = part_type;
- part_dev = new partition_device partno first_lba part_size dev;
- part_content = `Unknown }
-
-(*
-This code worked previously, but now needs some love ...
-XXX
-
-(* Probe an extended partition. *)
-and probe_extended_partition max fd epart sect =
- if max > 0 then (
- (* Offset of the first EBR. *)
- let ebr_offs = sect *^ sector_size in
- (* EBR Signature? *)
- LargeFile.lseek fd (ebr_offs +^ 510L) SEEK_SET;
- let str = String.create 2 in
- if read fd str 0 2 <> 2 || str.[0] != '\x55' || str.[1] != '\xAA' then
- [] (* Not EBR *)
- else (
- (* Read the extended partition table entries (just 2 of them). *)
- LargeFile.lseek fd (ebr_offs +^ 446L) SEEK_SET;
- let str = String.create 32 in
- if read fd str 0 32 <> 32 then
- failwith (s_ "error reading extended partition")
- else (
- (* Extract partitions from the data. *)
- let part1, part2 =
- match List.map (get_partition str) [ 0; 16 ] with
- | [p1;p2] -> p1,p2
- | _ -> failwith (s_ "probe_extended_partition: internal error") in
- (* First partition entry has offset to the start of this partition. *)
- let part1 = { part1 with
- part_lba_start = sect +^ part1.part_lba_start } in
- (* Second partition entry is zeroes if end of list, otherwise points
- * to the next partition.
- *)
- if part2.part_status = NullEntry then
- [part1]
- else
- part1 :: probe_extended_partition
- (max-1) fd epart (sect +^ part2.part_lba_start)
- )
- )
- )
- else []
-*)
-
-(* Ugh, fake a UInt32 -> UInt64 conversion without sign extension, until
- * we get working UInt32/UInt64 modules in extlib.
- *)
-and uint64_of_int32 u32 =
- let i64 = Int64.of_int32 u32 in
- if u32 >= 0l then i64
- else Int64.add i64 0x1_0000_0000_L
-
-(* Register with main code. *)
-let () = partition_type_register "MBR" probe_mbr
git.annexia.org / virt-top.git / blobdiff