diff options
| -rw-r--r-- | plugins/vdi.lua | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/plugins/vdi.lua b/plugins/vdi.lua new file mode 100644 index 0000000..75bfd78 --- /dev/null +++ b/plugins/vdi.lua @@ -0,0 +1,88 @@ +-- +-- vdi.lua: VirtualBox Disk Image +-- +-- Copyright (c) 2017, Přemysl Janouch <p.janouch@gmail.com> +-- +-- Permission to use, copy, modify, and/or distribute this software for any +-- purpose with or without fee is hereby granted, provided that the above +-- copyright notice and this permission notice appear in all copies. +-- +-- 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 } + |