-- -- vdi.lua: VirtualBox Disk Image -- -- Copyright (c) 2017, Přemysl Eric Janouch
-- -- Permission to use, copy, modify, and/or distribute this software for any -- purpose with or without fee is hereby granted. -- -- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES -- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF -- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY -- SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES -- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION -- OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN -- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. -- local detect = function (c) c.position = 65 return c:read (4) == "\x7F\x10\xDA\xBE" end -- As described by https://forums.virtualbox.org/viewtopic.php?t=8046 local decode = function (c) if not detect (c ()) then error ("not a VDI file") end c.endianity = "le" -- The header is preceded by an arbitrary string c.position = 65 local signature = c:u32 ("image signature") local p, vmajor, vminor = c.position, c:u16 (), c:u16 () c (p, c.position - 1):mark ("VDI version: %d.%d", vmajor, vminor) local size = c:u32 ("size of header: %d") c (64 + 1, 64 + size):mark ("VDI header") local type = c:u32 ("image type: %s", function (u32) if u32 == 1 then return "dynamic" end if u32 == 2 then return "static" end return "unknown: %d", u32 end) local flags = c:u32 ("image flags: %#x") local p, desc = c.position, c:read (256) c (p, c.position - 1):mark ("image description: %s", desc:match ("%C+")) local offset_blocks = c:u32 ("offset to blocks: %#x") local offset_data = c:u32 ("offset to data: %#x") local n_cylinders = c:u32 ("#cylinders: %d") local n_heads = c:u32 ("#heads: %d") local n_sectors = c:u32 ("#sectors: %d") local sector_size = c:u32 ("sector size: %d") local unused = c:read (4) local disk_size = c:u64 ("disk size: %d bytes") local block_size = c:u32 ("block size: %d") -- TODO: we should probably count that in -> is it in "blocks" or "data"? local block_extra_data = c:u32 ("block extra data: %d") local n_blocks = c:u32 ("#blocks in HDD: %d") local n_blocks_allocated = c:u32 ("#blocks allocated: %d") local function read_uuid4 (c, name) local p, uuid = c.position, c:read (16) local b = table.pack (uuid:byte (1, #uuid)) c (p, c.position - 1):mark ("%s: %02x%02x%02x%02x-" .. "%02x%02x-%02x%02x-%02x%02x-" .. "%02x%02x%02x%02x%02x%02x", name, b[1], b[2], b[3], b[4], b[5], b[6], b[7], b[8], b[9], b[10], b[11], b[12], b[13], b[14], b[15], b[16]) return uuid end local uuid_vdi = read_uuid4 (c, "UUID of VDI") local uuid_last_snap = read_uuid4 (c, "UUID of last snapshot") local uuid_link = read_uuid4 (c, "UUID of link") local uuid_parent = read_uuid4 (c, "UUID of parent") -- TODO: perhaps this should be more granular and identify all blocks c (offset_blocks + 1, offset_blocks + 4 * n_blocks) :mark ("VDI blocks") c (offset_data + 1, offset_data + block_size * n_blocks_allocated) :mark ("VDI data") end hex.register { type="vdi", detect=detect, decode=decode }