2 * Copyright (c) 2014, 2015 Marcel Moolenaar
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/errno.h>
40 #ifndef __has_extension
41 #define __has_extension(x) 0
46 * o File is in network byte order.
47 * o The timestamp is seconds since 1/1/2000 12:00:00 AM UTC
49 * This file is divided in 3 parts:
50 * 1. Common definitions
51 * 2. Dynamic VHD support
52 * 3. Fixed VHD support
56 * PART 1: Common definitions
59 #define VHD_SECTOR_SIZE 512
60 #define VHD_BLOCK_SIZE (4096 * VHD_SECTOR_SIZE) /* 2MB blocks */
70 #define VHD_FOOTER_COOKIE 0x636f6e6563746978ULL
72 #define VHD_FEATURES_TEMPORARY 0x01
73 #define VHD_FEATURES_RESERVED 0x02
75 #define VHD_VERSION 0x00010000
78 uint32_t creator_tool;
79 #define VHD_CREATOR_TOOL 0x2a696d67 /* FreeBSD mkimg */
80 uint32_t creator_version;
81 #define VHD_CREATOR_VERSION 0x00020000
83 #define VHD_CREATOR_OS 0x5769326b /* Wi2k */
84 uint64_t original_size;
85 uint64_t current_size;
86 struct vhd_geom geometry;
88 #define VHD_DISK_TYPE_FIXED 2
89 #define VHD_DISK_TYPE_DYNAMIC 3
90 #define VHD_DISK_TYPE_DIFF 4
94 uint8_t _reserved[427];
96 #if __has_extension(c_static_assert)
97 _Static_assert(sizeof(struct vhd_footer) == VHD_SECTOR_SIZE,
98 "Wrong size for footer");
102 vhd_checksum(void *buf, size_t sz)
109 for (ofs = 0; ofs < sz; ofs++)
115 vhd_geometry(uint64_t image_size, struct vhd_geom *geom)
120 imgsz = image_size / VHD_SECTOR_SIZE;
122 /* Respect command line options if possible. */
123 if (nheads > 1 && nheads < 256 &&
124 nsecs > 1 && nsecs < 256 &&
126 geom->cylinders = (ncyls != 0) ? ncyls :
127 imgsz / (nheads * nsecs);
128 geom->heads = nheads;
129 geom->sectors = nsecs;
133 if (imgsz > 65536 * 16 * 255)
134 imgsz = 65536 * 16 * 255;
135 if (imgsz >= 65535 * 16 * 63) {
136 geom->cylinders = imgsz / (16 * 255);
143 geom->heads = (cth + 1023) / 1024;
146 if (cth >= (geom->heads * 1024) || geom->heads > 16) {
151 if (cth >= (geom->heads * 1024)) {
156 geom->cylinders = cth / geom->heads;
160 vhd_resize(uint64_t origsz)
162 struct vhd_geom geom;
166 * Round the image size to the pre-determined geometry that
167 * matches the image size. This circular dependency implies
168 * that we need to loop to handle boundary conditions.
169 * The first time, newsz equals origsz and the geometry will
170 * typically yield a new size that's smaller. We keep adding
171 * cylinder's worth of sectors to the new size until its
172 * larger or equal or origsz. But during those iterations,
173 * the geometry can change, so we need to account for that.
177 vhd_geometry(newsz, &geom);
178 newsz = (int64_t)geom.cylinders * geom.heads *
179 geom.sectors * VHD_SECTOR_SIZE;
182 newsz += geom.heads * geom.sectors * VHD_SECTOR_SIZE;
194 return (t - 0x386d4380);
201 vhd_make_footer(struct vhd_footer *footer, uint64_t image_size,
202 uint32_t disk_type, uint64_t data_offset)
206 memset(footer, 0, sizeof(*footer));
207 be64enc(&footer->cookie, VHD_FOOTER_COOKIE);
208 be32enc(&footer->features, VHD_FEATURES_RESERVED);
209 be32enc(&footer->version, VHD_VERSION);
210 be64enc(&footer->data_offset, data_offset);
211 be32enc(&footer->timestamp, vhd_timestamp());
212 be32enc(&footer->creator_tool, VHD_CREATOR_TOOL);
213 be32enc(&footer->creator_version, VHD_CREATOR_VERSION);
214 be32enc(&footer->creator_os, VHD_CREATOR_OS);
215 be64enc(&footer->original_size, image_size);
216 be64enc(&footer->current_size, image_size);
217 vhd_geometry(image_size, &footer->geometry);
218 be16enc(&footer->geometry.cylinders, footer->geometry.cylinders);
219 be32enc(&footer->disk_type, disk_type);
221 mkimg_uuid_enc(&footer->id, &id);
222 be32enc(&footer->checksum, vhd_checksum(footer, sizeof(*footer)));
226 * PART 2: Dynamic VHD support
230 * copy of disk footer
231 * dynamic disk header
232 * block allocation table (BAT)
237 struct vhd_dyn_header {
239 #define VHD_HEADER_COOKIE 0x6378737061727365ULL
240 uint64_t data_offset;
241 uint64_t table_offset;
243 uint32_t max_entries;
246 mkimg_uuid_t parent_id;
247 uint32_t parent_timestamp;
249 uint16_t parent_name[256]; /* UTF-16 */
253 uint32_t data_length;
255 uint64_t data_offset;
257 char _reserved2[256];
259 #if __has_extension(c_static_assert)
260 _Static_assert(sizeof(struct vhd_dyn_header) == VHD_SECTOR_SIZE * 2,
261 "Wrong size for header");
265 vhd_dyn_resize(lba_t imgsz)
269 imagesz = vhd_resize(imgsz * secsz);
270 return (image_set_size(imagesz / secsz));
274 vhd_dyn_write(int fd)
276 struct vhd_footer footer;
277 struct vhd_dyn_header header;
278 uint64_t imgsz, rawsz;
279 lba_t blk, blkcnt, nblks;
284 int bat_entries, error, entry;
286 rawsz = image_get_size() * secsz;
287 imgsz = (rawsz + VHD_BLOCK_SIZE - 1) & ~(VHD_BLOCK_SIZE - 1);
289 vhd_make_footer(&footer, rawsz, VHD_DISK_TYPE_DYNAMIC, sizeof(footer));
290 if (sparse_write(fd, &footer, sizeof(footer)) < 0)
293 bat_entries = imgsz / VHD_BLOCK_SIZE;
294 memset(&header, 0, sizeof(header));
295 be64enc(&header.cookie, VHD_HEADER_COOKIE);
296 be64enc(&header.data_offset, ~0ULL);
297 be64enc(&header.table_offset, sizeof(footer) + sizeof(header));
298 be32enc(&header.version, VHD_VERSION);
299 be32enc(&header.max_entries, bat_entries);
300 be32enc(&header.block_size, VHD_BLOCK_SIZE);
301 be32enc(&header.checksum, vhd_checksum(&header, sizeof(header)));
302 if (sparse_write(fd, &header, sizeof(header)) < 0)
305 batsz = bat_entries * sizeof(uint32_t);
306 batsz = (batsz + VHD_SECTOR_SIZE - 1) & ~(VHD_SECTOR_SIZE - 1);
310 memset(bat, 0xff, batsz);
311 blkcnt = VHD_BLOCK_SIZE / secsz;
312 sector = (sizeof(footer) + sizeof(header) + batsz) / VHD_SECTOR_SIZE;
313 for (entry = 0; entry < bat_entries; entry++) {
314 blk = entry * blkcnt;
315 if (image_data(blk, blkcnt)) {
316 be32enc(&bat[entry], sector);
317 sector += (VHD_BLOCK_SIZE / VHD_SECTOR_SIZE) + 1;
320 if (sparse_write(fd, bat, batsz) < 0) {
326 bitmap = malloc(VHD_SECTOR_SIZE);
329 memset(bitmap, 0xff, VHD_SECTOR_SIZE);
332 blkcnt = VHD_BLOCK_SIZE / secsz;
334 nblks = rawsz / secsz;
335 while (blk < nblks) {
336 if (!image_data(blk, blkcnt)) {
340 if (sparse_write(fd, bitmap, VHD_SECTOR_SIZE) < 0) {
344 /* Handle partial last block */
345 if (blk + blkcnt > nblks)
346 blkcnt = nblks - blk;
347 error = image_copyout_region(fd, blk, blkcnt);
355 error = image_copyout_zeroes(fd, imgsz - rawsz);
358 if (sparse_write(fd, &footer, sizeof(footer)) < 0)
364 static struct mkimg_format vhd_dyn_format = {
366 .description = "Virtual Hard Disk",
367 .resize = vhd_dyn_resize,
368 .write = vhd_dyn_write,
371 FORMAT_DEFINE(vhd_dyn_format);
378 vhd_fix_resize(lba_t imgsz)
382 imagesz = vhd_resize(imgsz * secsz);
384 * Azure demands that images are a whole number of megabytes.
386 imagesz = (imagesz + 0xfffffULL) & ~0xfffffULL;
387 return (image_set_size(imagesz / secsz));
391 vhd_fix_write(int fd)
393 struct vhd_footer footer;
397 error = image_copyout(fd);
401 imagesz = image_get_size() * secsz;
402 vhd_make_footer(&footer, imagesz, VHD_DISK_TYPE_FIXED, ~0ULL);
403 error = (sparse_write(fd, &footer, sizeof(footer)) < 0) ? errno : 0;
407 static struct mkimg_format vhd_fix_format = {
409 .description = "Fixed Virtual Hard Disk",
410 .resize = vhd_fix_resize,
411 .write = vhd_fix_write,
414 FORMAT_DEFINE(vhd_fix_format);