freebsd-src/usr.bin/mkimg/vhd.c
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413 lines
10 KiB
C

/*-
* Copyright (c) 2014, 2015 Marcel Moolenaar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#include <sys/errno.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "endian.h"
#include "image.h"
#include "format.h"
#include "mkimg.h"
#ifndef __has_extension
#define __has_extension(x) 0
#endif
/*
* General notes:
* o File is in network byte order.
* o The timestamp is seconds since 1/1/2000 12:00:00 AM UTC
*
* This file is divided in 3 parts:
* 1. Common definitions
* 2. Dynamic VHD support
* 3. Fixed VHD support
*/
/*
* PART 1: Common definitions
*/
#define VHD_SECTOR_SIZE 512
#define VHD_BLOCK_SIZE (4096 * VHD_SECTOR_SIZE) /* 2MB blocks */
struct vhd_geom {
uint16_t cylinders;
uint8_t heads;
uint8_t sectors;
};
struct vhd_footer {
uint64_t cookie;
#define VHD_FOOTER_COOKIE 0x636f6e6563746978ULL
uint32_t features;
#define VHD_FEATURES_TEMPORARY 0x01
#define VHD_FEATURES_RESERVED 0x02
uint32_t version;
#define VHD_VERSION 0x00010000
uint64_t data_offset;
uint32_t timestamp;
uint32_t creator_tool;
#define VHD_CREATOR_TOOL 0x2a696d67 /* FreeBSD mkimg */
uint32_t creator_version;
#define VHD_CREATOR_VERSION 0x00020000
uint32_t creator_os;
#define VHD_CREATOR_OS 0x5769326b /* Wi2k */
uint64_t original_size;
uint64_t current_size;
struct vhd_geom geometry;
uint32_t disk_type;
#define VHD_DISK_TYPE_FIXED 2
#define VHD_DISK_TYPE_DYNAMIC 3
#define VHD_DISK_TYPE_DIFF 4
uint32_t checksum;
mkimg_uuid_t id;
uint8_t saved_state;
uint8_t _reserved[427];
};
#if __has_extension(c_static_assert)
_Static_assert(sizeof(struct vhd_footer) == VHD_SECTOR_SIZE,
"Wrong size for footer");
#endif
static uint32_t
vhd_checksum(void *buf, size_t sz)
{
uint8_t *p = buf;
uint32_t sum;
size_t ofs;
sum = 0;
for (ofs = 0; ofs < sz; ofs++)
sum += p[ofs];
return (~sum);
}
static void
vhd_geometry(uint64_t image_size, struct vhd_geom *geom)
{
lba_t imgsz;
long cth;
imgsz = image_size / VHD_SECTOR_SIZE;
/* Respect command line options if possible. */
if (nheads > 1 && nheads < 256 &&
nsecs > 1 && nsecs < 256 &&
ncyls < 65536) {
geom->cylinders = (ncyls != 0) ? ncyls :
imgsz / (nheads * nsecs);
geom->heads = nheads;
geom->sectors = nsecs;
return;
}
if (imgsz > 65536 * 16 * 255)
imgsz = 65536 * 16 * 255;
if (imgsz >= 65535 * 16 * 63) {
geom->cylinders = imgsz / (16 * 255);
geom->heads = 16;
geom->sectors = 255;
return;
}
geom->sectors = 17;
cth = imgsz / 17;
geom->heads = (cth + 1023) / 1024;
if (geom->heads < 4)
geom->heads = 4;
if (cth >= (geom->heads * 1024) || geom->heads > 16) {
geom->heads = 16;
geom->sectors = 31;
cth = imgsz / 31;
}
if (cth >= (geom->heads * 1024)) {
geom->heads = 16;
geom->sectors = 63;
cth = imgsz / 63;
}
geom->cylinders = cth / geom->heads;
}
static uint64_t
vhd_resize(uint64_t origsz)
{
struct vhd_geom geom;
uint64_t newsz;
/*
* Round the image size to the pre-determined geometry that
* matches the image size. This circular dependency implies
* that we need to loop to handle boundary conditions.
* The first time, newsz equals origsz and the geometry will
* typically yield a new size that's smaller. We keep adding
* cylinder's worth of sectors to the new size until its
* larger or equal or origsz. But during those iterations,
* the geometry can change, so we need to account for that.
*/
newsz = origsz;
while (1) {
vhd_geometry(newsz, &geom);
newsz = (int64_t)geom.cylinders * geom.heads *
geom.sectors * VHD_SECTOR_SIZE;
if (newsz >= origsz)
break;
newsz += geom.heads * geom.sectors * VHD_SECTOR_SIZE;
}
return (newsz);
}
static uint32_t
vhd_timestamp(void)
{
time_t t;
if (!unit_testing) {
t = time(NULL);
return (t - 0x386d4380);
}
return (0x01234567);
}
static void
vhd_make_footer(struct vhd_footer *footer, uint64_t image_size,
uint32_t disk_type, uint64_t data_offset)
{
mkimg_uuid_t id;
memset(footer, 0, sizeof(*footer));
be64enc(&footer->cookie, VHD_FOOTER_COOKIE);
be32enc(&footer->features, VHD_FEATURES_RESERVED);
be32enc(&footer->version, VHD_VERSION);
be64enc(&footer->data_offset, data_offset);
be32enc(&footer->timestamp, vhd_timestamp());
be32enc(&footer->creator_tool, VHD_CREATOR_TOOL);
be32enc(&footer->creator_version, VHD_CREATOR_VERSION);
be32enc(&footer->creator_os, VHD_CREATOR_OS);
be64enc(&footer->original_size, image_size);
be64enc(&footer->current_size, image_size);
vhd_geometry(image_size, &footer->geometry);
be16enc(&footer->geometry.cylinders, footer->geometry.cylinders);
be32enc(&footer->disk_type, disk_type);
mkimg_uuid(&id);
mkimg_uuid_enc(&footer->id, &id);
be32enc(&footer->checksum, vhd_checksum(footer, sizeof(*footer)));
}
/*
* PART 2: Dynamic VHD support
*
* Notes:
* o File layout:
* copy of disk footer
* dynamic disk header
* block allocation table (BAT)
* data blocks
* disk footer
*/
struct vhd_dyn_header {
uint64_t cookie;
#define VHD_HEADER_COOKIE 0x6378737061727365ULL
uint64_t data_offset;
uint64_t table_offset;
uint32_t version;
uint32_t max_entries;
uint32_t block_size;
uint32_t checksum;
mkimg_uuid_t parent_id;
uint32_t parent_timestamp;
char _reserved1[4];
uint16_t parent_name[256]; /* UTF-16 */
struct {
uint32_t code;
uint32_t data_space;
uint32_t data_length;
uint32_t _reserved;
uint64_t data_offset;
} parent_locator[8];
char _reserved2[256];
};
#if __has_extension(c_static_assert)
_Static_assert(sizeof(struct vhd_dyn_header) == VHD_SECTOR_SIZE * 2,
"Wrong size for header");
#endif
static int
vhd_dyn_resize(lba_t imgsz)
{
uint64_t imagesz;
imagesz = vhd_resize(imgsz * secsz);
return (image_set_size(imagesz / secsz));
}
static int
vhd_dyn_write(int fd)
{
struct vhd_footer footer;
struct vhd_dyn_header header;
uint64_t imgsz, rawsz;
lba_t blk, blkcnt, nblks;
uint32_t *bat;
void *bitmap;
size_t batsz;
uint32_t sector;
int bat_entries, error, entry;
rawsz = image_get_size() * secsz;
imgsz = (rawsz + VHD_BLOCK_SIZE - 1) & ~(VHD_BLOCK_SIZE - 1);
vhd_make_footer(&footer, rawsz, VHD_DISK_TYPE_DYNAMIC, sizeof(footer));
if (sparse_write(fd, &footer, sizeof(footer)) < 0)
return (errno);
bat_entries = imgsz / VHD_BLOCK_SIZE;
memset(&header, 0, sizeof(header));
be64enc(&header.cookie, VHD_HEADER_COOKIE);
be64enc(&header.data_offset, ~0ULL);
be64enc(&header.table_offset, sizeof(footer) + sizeof(header));
be32enc(&header.version, VHD_VERSION);
be32enc(&header.max_entries, bat_entries);
be32enc(&header.block_size, VHD_BLOCK_SIZE);
be32enc(&header.checksum, vhd_checksum(&header, sizeof(header)));
if (sparse_write(fd, &header, sizeof(header)) < 0)
return (errno);
batsz = bat_entries * sizeof(uint32_t);
batsz = (batsz + VHD_SECTOR_SIZE - 1) & ~(VHD_SECTOR_SIZE - 1);
bat = malloc(batsz);
if (bat == NULL)
return (errno);
memset(bat, 0xff, batsz);
blkcnt = VHD_BLOCK_SIZE / secsz;
sector = (sizeof(footer) + sizeof(header) + batsz) / VHD_SECTOR_SIZE;
for (entry = 0; entry < bat_entries; entry++) {
blk = entry * blkcnt;
if (image_data(blk, blkcnt)) {
be32enc(&bat[entry], sector);
sector += (VHD_BLOCK_SIZE / VHD_SECTOR_SIZE) + 1;
}
}
if (sparse_write(fd, bat, batsz) < 0) {
free(bat);
return (errno);
}
free(bat);
bitmap = malloc(VHD_SECTOR_SIZE);
if (bitmap == NULL)
return (errno);
memset(bitmap, 0xff, VHD_SECTOR_SIZE);
blk = 0;
blkcnt = VHD_BLOCK_SIZE / secsz;
error = 0;
nblks = rawsz / secsz;
while (blk < nblks) {
if (!image_data(blk, blkcnt)) {
blk += blkcnt;
continue;
}
if (sparse_write(fd, bitmap, VHD_SECTOR_SIZE) < 0) {
error = errno;
break;
}
/* Handle partial last block */
if (blk + blkcnt > nblks)
blkcnt = nblks - blk;
error = image_copyout_region(fd, blk, blkcnt);
if (error)
break;
blk += blkcnt;
}
free(bitmap);
if (error)
return (error);
error = image_copyout_zeroes(fd, imgsz - rawsz);
if (error)
return (error);
if (sparse_write(fd, &footer, sizeof(footer)) < 0)
return (errno);
return (0);
}
static struct mkimg_format vhd_dyn_format = {
.name = "vhd",
.description = "Virtual Hard Disk",
.resize = vhd_dyn_resize,
.write = vhd_dyn_write,
};
FORMAT_DEFINE(vhd_dyn_format);
/*
* PART 3: Fixed VHD
*/
static int
vhd_fix_resize(lba_t imgsz)
{
uint64_t imagesz;
imagesz = vhd_resize(imgsz * secsz);
/*
* Azure demands that images are a whole number of megabytes.
*/
imagesz = (imagesz + 0xfffffULL) & ~0xfffffULL;
return (image_set_size(imagesz / secsz));
}
static int
vhd_fix_write(int fd)
{
struct vhd_footer footer;
uint64_t imagesz;
int error;
error = image_copyout(fd);
if (error)
return (error);
imagesz = image_get_size() * secsz;
vhd_make_footer(&footer, imagesz, VHD_DISK_TYPE_FIXED, ~0ULL);
error = (sparse_write(fd, &footer, sizeof(footer)) < 0) ? errno : 0;
return (error);
}
static struct mkimg_format vhd_fix_format = {
.name = "vhdf",
.description = "Fixed Virtual Hard Disk",
.resize = vhd_fix_resize,
.write = vhd_fix_write,
};
FORMAT_DEFINE(vhd_fix_format);