block/vmdk.c

   1 /*
   2  * Block driver for the VMDK format
   3  *
   4  * Copyright (c) 2004 Fabrice Bellard
   5  * Copyright (c) 2005 Filip Navara
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  23  * THE SOFTWARE.
  24  */
  25
  26 #include "qemu-common.h"
  27 #include "block_int.h"
  28 #include "module.h"
  29
  30 #define VMDK3_MAGIC (('C' << 24) | ('O' << 16) | ('W' << 8) | 'D')
  31 #define VMDK4_MAGIC (('K' << 24) | ('D' << 16) | ('M' << 8) | 'V')
  32
  33 typedef struct {
  34     uint32_t version;
  35     uint32_t flags;
  36     uint32_t disk_sectors;
  37     uint32_t granularity;
  38     uint32_t l1dir_offset;
  39     uint32_t l1dir_size;
  40     uint32_t file_sectors;
  41     uint32_t cylinders;
  42     uint32_t heads;
  43     uint32_t sectors_per_track;
  44 } VMDK3Header;
  45
  46 typedef struct {
  47     uint32_t version;
  48     uint32_t flags;
  49     int64_t capacity;
  50     int64_t granularity;
  51     int64_t desc_offset;
  52     int64_t desc_size;
  53     int32_t num_gtes_per_gte;
  54     int64_t rgd_offset;
  55     int64_t gd_offset;
  56     int64_t grain_offset;
  57     char filler[1];
  58     char check_bytes[4];
  59 } __attribute__((packed)) VMDK4Header;
  60
  61 #define L2_CACHE_SIZE 16
  62
  63 typedef struct VmdkExtent {
  64     BlockDriverState *file;
  65     bool flat;
  66     int64_t sectors;
  67     int64_t end_sector;
  68     int64_t flat_start_offset;
  69     int64_t l1_table_offset;
  70     int64_t l1_backup_table_offset;
  71     uint32_t *l1_table;
  72     uint32_t *l1_backup_table;
  73     unsigned int l1_size;
  74     uint32_t l1_entry_sectors;
  75
  76     unsigned int l2_size;
  77     uint32_t *l2_cache;
  78     uint32_t l2_cache_offsets[L2_CACHE_SIZE];
  79     uint32_t l2_cache_counts[L2_CACHE_SIZE];
  80
  81     unsigned int cluster_sectors;
  82 } VmdkExtent;
  83
  84 typedef struct BDRVVmdkState {
  85     int desc_offset;
  86     bool cid_updated;
  87     uint32_t parent_cid;
  88     int num_extents;
  89     /* Extent array with num_extents entries, ascend ordered by address */
  90     VmdkExtent *extents;
  91 } BDRVVmdkState;
  92
  93 typedef struct VmdkMetaData {
  94     uint32_t offset;
  95     unsigned int l1_index;
  96     unsigned int l2_index;
  97     unsigned int l2_offset;
  98     int valid;
  99 } VmdkMetaData;
 100
 101 static int vmdk_probe(const uint8_t *buf, int buf_size, const char *filename)
 102 {
 103     uint32_t magic;
 104
 105     if (buf_size < 4) {
 106         return 0;
 107     }
 108     magic = be32_to_cpu(*(uint32_t *)buf);
 109     if (magic == VMDK3_MAGIC ||
 110         magic == VMDK4_MAGIC) {
 111         return 100;
 112     } else {
 113         const char *p = (const char *)buf;
 114         const char *end = p + buf_size;
 115         while (p < end) {
 116             if (*p == '#') {
 117                 /* skip comment line */
 118                 while (p < end && *p != '\n') {
 119                     p++;
 120                 }
 121                 p++;
 122                 continue;
 123             }
 124             if (*p == ' ') {
 125                 while (p < end && *p == ' ') {
 126                     p++;
 127                 }
 128                 /* skip '\r' if windows line endings used. */
 129                 if (p < end && *p == '\r') {
 130                     p++;
 131                 }
 132                 /* only accept blank lines before 'version=' line */
 133                 if (p == end || *p != '\n') {
 134                     return 0;
 135                 }
 136                 p++;
 137                 continue;
 138             }
 139             if (end - p >= strlen("version=X\n")) {
 140                 if (strncmp("version=1\n", p, strlen("version=1\n")) == 0 ||
 141                     strncmp("version=2\n", p, strlen("version=2\n")) == 0) {
 142                     return 100;
 143                 }
 144             }
 145             if (end - p >= strlen("version=X\r\n")) {
 146                 if (strncmp("version=1\r\n", p, strlen("version=1\r\n")) == 0 ||
 147                     strncmp("version=2\r\n", p, strlen("version=2\r\n")) == 0) {
 148                     return 100;
 149                 }
 150             }
 151             return 0;
 152         }
 153         return 0;
 154     }
 155 }
 156
 157 #define CHECK_CID 1
 158
 159 #define SECTOR_SIZE 512
 160 #define DESC_SIZE (20 * SECTOR_SIZE)    /* 20 sectors of 512 bytes each */
 161 #define BUF_SIZE 4096
 162 #define HEADER_SIZE 512                 /* first sector of 512 bytes */
 163
 164 static void vmdk_free_extents(BlockDriverState *bs)
 165 {
 166     int i;
 167     BDRVVmdkState *s = bs->opaque;
 168
 169     for (i = 0; i < s->num_extents; i++) {
 170         g_free(s->extents[i].l1_table);
 171         g_free(s->extents[i].l2_cache);
 172         g_free(s->extents[i].l1_backup_table);
 173     }
 174     g_free(s->extents);
 175 }
 176
 177 static uint32_t vmdk_read_cid(BlockDriverState *bs, int parent)
 178 {
 179     char desc[DESC_SIZE];
 180     uint32_t cid;
 181     const char *p_name, *cid_str;
 182     size_t cid_str_size;
 183     BDRVVmdkState *s = bs->opaque;
 184
 185     if (bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE) != DESC_SIZE) {
 186         return 0;
 187     }
 188
 189     if (parent) {
 190         cid_str = "parentCID";
 191         cid_str_size = sizeof("parentCID");
 192     } else {
 193         cid_str = "CID";
 194         cid_str_size = sizeof("CID");
 195     }
 196
 197     p_name = strstr(desc, cid_str);
 198     if (p_name != NULL) {
 199         p_name += cid_str_size;
 200         sscanf(p_name, "%x", &cid);
 201     }
 202
 203     return cid;
 204 }
 205
 206 static int vmdk_write_cid(BlockDriverState *bs, uint32_t cid)
 207 {
 208     char desc[DESC_SIZE], tmp_desc[DESC_SIZE];
 209     char *p_name, *tmp_str;
 210     BDRVVmdkState *s = bs->opaque;
 211
 212     memset(desc, 0, sizeof(desc));
 213     if (bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE) != DESC_SIZE) {
 214         return -EIO;
 215     }
 216
 217     tmp_str = strstr(desc, "parentCID");
 218     pstrcpy(tmp_desc, sizeof(tmp_desc), tmp_str);
 219     p_name = strstr(desc, "CID");
 220     if (p_name != NULL) {
 221         p_name += sizeof("CID");
 222         snprintf(p_name, sizeof(desc) - (p_name - desc), "%x\n", cid);
 223         pstrcat(desc, sizeof(desc), tmp_desc);
 224     }
 225
 226     if (bdrv_pwrite_sync(bs->file, s->desc_offset, desc, DESC_SIZE) < 0) {
 227         return -EIO;
 228     }
 229     return 0;
 230 }
 231
 232 static int vmdk_is_cid_valid(BlockDriverState *bs)
 233 {
 234 #ifdef CHECK_CID
 235     BDRVVmdkState *s = bs->opaque;
 236     BlockDriverState *p_bs = bs->backing_hd;
 237     uint32_t cur_pcid;
 238
 239     if (p_bs) {
 240         cur_pcid = vmdk_read_cid(p_bs, 0);
 241         if (s->parent_cid != cur_pcid) {
 242             /* CID not valid */
 243             return 0;
 244         }
 245     }
 246 #endif
 247     /* CID valid */
 248     return 1;
 249 }
 250
 251 static int vmdk_parent_open(BlockDriverState *bs)
 252 {
 253     char *p_name;
 254     char desc[DESC_SIZE + 1];
 255     BDRVVmdkState *s = bs->opaque;
 256
 257     desc[DESC_SIZE] = '\0';
 258     if (bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE) != DESC_SIZE) {
 259         return -1;
 260     }
 261
 262     p_name = strstr(desc, "parentFileNameHint");
 263     if (p_name != NULL) {
 264         char *end_name;
 265
 266         p_name += sizeof("parentFileNameHint") + 1;
 267         end_name = strchr(p_name, '\"');
 268         if (end_name == NULL) {
 269             return -1;
 270         }
 271         if ((end_name - p_name) > sizeof(bs->backing_file) - 1) {
 272             return -1;
 273         }
 274
 275         pstrcpy(bs->backing_file, end_name - p_name + 1, p_name);
 276     }
 277
 278     return 0;
 279 }
 280
 281 /* Create and append extent to the extent array. Return the added VmdkExtent
 282  * address. return NULL if allocation failed. */
 283 static VmdkExtent *vmdk_add_extent(BlockDriverState *bs,
 284                            BlockDriverState *file, bool flat, int64_t sectors,
 285                            int64_t l1_offset, int64_t l1_backup_offset,
 286                            uint32_t l1_size,
 287                            int l2_size, unsigned int cluster_sectors)
 288 {
 289     VmdkExtent *extent;
 290     BDRVVmdkState *s = bs->opaque;
 291
 292     s->extents = g_realloc(s->extents,
 293                               (s->num_extents + 1) * sizeof(VmdkExtent));
 294     extent = &s->extents[s->num_extents];
 295     s->num_extents++;
 296
 297     memset(extent, 0, sizeof(VmdkExtent));
 298     extent->file = file;
 299     extent->flat = flat;
 300     extent->sectors = sectors;
 301     extent->l1_table_offset = l1_offset;
 302     extent->l1_backup_table_offset = l1_backup_offset;
 303     extent->l1_size = l1_size;
 304     extent->l1_entry_sectors = l2_size * cluster_sectors;
 305     extent->l2_size = l2_size;
 306     extent->cluster_sectors = cluster_sectors;
 307
 308     if (s->num_extents > 1) {
 309         extent->end_sector = (*(extent - 1)).end_sector + extent->sectors;
 310     } else {
 311         extent->end_sector = extent->sectors;
 312     }
 313     bs->total_sectors = extent->end_sector;
 314     return extent;
 315 }
 316
 317 static int vmdk_init_tables(BlockDriverState *bs, VmdkExtent *extent)
 318 {
 319     int ret;
 320     int l1_size, i;
 321
 322     /* read the L1 table */
 323     l1_size = extent->l1_size * sizeof(uint32_t);
 324     extent->l1_table = g_malloc(l1_size);
 325     ret = bdrv_pread(extent->file,
 326                     extent->l1_table_offset,
 327                     extent->l1_table,
 328                     l1_size);
 329     if (ret < 0) {
 330         goto fail_l1;
 331     }
 332     for (i = 0; i < extent->l1_size; i++) {
 333         le32_to_cpus(&extent->l1_table[i]);
 334     }
 335
 336     if (extent->l1_backup_table_offset) {
 337         extent->l1_backup_table = g_malloc(l1_size);
 338         ret = bdrv_pread(extent->file,
 339                         extent->l1_backup_table_offset,
 340                         extent->l1_backup_table,
 341                         l1_size);
 342         if (ret < 0) {
 343             goto fail_l1b;
 344         }
 345         for (i = 0; i < extent->l1_size; i++) {
 346             le32_to_cpus(&extent->l1_backup_table[i]);
 347         }
 348     }
 349
 350     extent->l2_cache =
 351         g_malloc(extent->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));
 352     return 0;
 353  fail_l1b:
 354     g_free(extent->l1_backup_table);
 355  fail_l1:
 356     g_free(extent->l1_table);
 357     return ret;
 358 }
 359
 360 static int vmdk_open_vmdk3(BlockDriverState *bs, int flags)
 361 {
 362     int ret;
 363     uint32_t magic;
 364     VMDK3Header header;
 365     BDRVVmdkState *s = bs->opaque;
 366     VmdkExtent *extent;
 367
 368     s->desc_offset = 0x200;
 369     ret = bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header));
 370     if (ret < 0) {
 371         goto fail;
 372     }
 373     extent = vmdk_add_extent(bs,
 374                              bs->file, false,
 375                              le32_to_cpu(header.disk_sectors),
 376                              le32_to_cpu(header.l1dir_offset) << 9,
 377                              0, 1 << 6, 1 << 9,
 378                              le32_to_cpu(header.granularity));
 379     ret = vmdk_init_tables(bs, extent);
 380     if (ret) {
 381         /* vmdk_init_tables cleans up on fail, so only free allocation of
 382          * vmdk_add_extent here. */
 383         goto fail;
 384     }
 385     return 0;
 386  fail:
 387     vmdk_free_extents(bs);
 388     return ret;
 389 }
 390
 391 static int vmdk_open_vmdk4(BlockDriverState *bs, int flags)
 392 {
 393     int ret;
 394     uint32_t magic;
 395     uint32_t l1_size, l1_entry_sectors;
 396     VMDK4Header header;
 397     BDRVVmdkState *s = bs->opaque;
 398     VmdkExtent *extent;
 399
 400     s->desc_offset = 0x200;
 401     ret = bdrv_pread(bs->file, sizeof(magic), &header, sizeof(header));
 402     if (ret < 0) {
 403         goto fail;
 404     }
 405     l1_entry_sectors = le32_to_cpu(header.num_gtes_per_gte)
 406                         * le64_to_cpu(header.granularity);
 407     l1_size = (le64_to_cpu(header.capacity) + l1_entry_sectors - 1)
 408                 / l1_entry_sectors;
 409     extent = vmdk_add_extent(bs, bs->file, false,
 410                           le64_to_cpu(header.capacity),
 411                           le64_to_cpu(header.gd_offset) << 9,
 412                           le64_to_cpu(header.rgd_offset) << 9,
 413                           l1_size,
 414                           le32_to_cpu(header.num_gtes_per_gte),
 415                           le64_to_cpu(header.granularity));
 416     if (extent->l1_entry_sectors <= 0) {
 417         ret = -EINVAL;
 418         goto fail;
 419     }
 420     /* try to open parent images, if exist */
 421     ret = vmdk_parent_open(bs);
 422     if (ret) {
 423         goto fail;
 424     }
 425     s->parent_cid = vmdk_read_cid(bs, 1);
 426     ret = vmdk_init_tables(bs, extent);
 427     if (ret) {
 428         goto fail;
 429     }
 430     return 0;
 431  fail:
 432     vmdk_free_extents(bs);
 433     return ret;
 434 }
 435
 436 /* find an option value out of descriptor file */
 437 static int vmdk_parse_description(const char *desc, const char *opt_name,
 438         char *buf, int buf_size)
 439 {
 440     char *opt_pos, *opt_end;
 441     const char *end = desc + strlen(desc);
 442
 443     opt_pos = strstr(desc, opt_name);
 444     if (!opt_pos) {
 445         return -1;
 446     }
 447     /* Skip "=\"" following opt_name */
 448     opt_pos += strlen(opt_name) + 2;
 449     if (opt_pos >= end) {
 450         return -1;
 451     }
 452     opt_end = opt_pos;
 453     while (opt_end < end && *opt_end != '"') {
 454         opt_end++;
 455     }
 456     if (opt_end == end || buf_size < opt_end - opt_pos + 1) {
 457         return -1;
 458     }
 459     pstrcpy(buf, opt_end - opt_pos + 1, opt_pos);
 460     return 0;
 461 }
 462
 463 static int vmdk_parse_extents(const char *desc, BlockDriverState *bs,
 464         const char *desc_file_path)
 465 {
 466     int ret;
 467     char access[11];
 468     char type[11];
 469     char fname[512];
 470     const char *p = desc;
 471     int64_t sectors = 0;
 472     int64_t flat_offset;
 473
 474     while (*p) {
 475         /* parse extent line:
 476          * RW [size in sectors] FLAT "file-name.vmdk" OFFSET
 477          * or
 478          * RW [size in sectors] SPARSE "file-name.vmdk"
 479          */
 480         flat_offset = -1;
 481         ret = sscanf(p, "%10s %" SCNd64 " %10s %511s %" SCNd64,
 482                 access, &sectors, type, fname, &flat_offset);
 483         if (ret < 4 || strcmp(access, "RW")) {
 484             goto next_line;
 485         } else if (!strcmp(type, "FLAT")) {
 486             if (ret != 5 || flat_offset < 0) {
 487                 return -EINVAL;
 488             }
 489         } else if (ret != 4) {
 490             return -EINVAL;
 491         }
 492
 493         /* trim the quotation marks around */
 494         if (fname[0] == '"') {
 495             memmove(fname, fname + 1, strlen(fname));
 496             if (strlen(fname) <= 1 || fname[strlen(fname) - 1] != '"') {
 497                 return -EINVAL;
 498             }
 499             fname[strlen(fname) - 1] = '\0';
 500         }
 501         if (sectors <= 0 ||
 502             (strcmp(type, "FLAT") && strcmp(type, "SPARSE")) ||
 503             (strcmp(access, "RW"))) {
 504             goto next_line;
 505         }
 506
 507         /* save to extents array */
 508         if (!strcmp(type, "FLAT")) {
 509             /* FLAT extent */
 510             char extent_path[PATH_MAX];
 511             BlockDriverState *extent_file;
 512             VmdkExtent *extent;
 513
 514             path_combine(extent_path, sizeof(extent_path),
 515                     desc_file_path, fname);
 516             ret = bdrv_file_open(&extent_file, extent_path, bs->open_flags);
 517             if (ret) {
 518                 return ret;
 519             }
 520             extent = vmdk_add_extent(bs, extent_file, true, sectors,
 521                             0, 0, 0, 0, sectors);
 522             extent->flat_start_offset = flat_offset;
 523         } else {
 524             /* SPARSE extent, not supported for now */
 525             fprintf(stderr,
 526                 "VMDK: Not supported extent type \"%s\""".\n", type);
 527             return -ENOTSUP;
 528         }
 529 next_line:
 530         /* move to next line */
 531         while (*p && *p != '\n') {
 532             p++;
 533         }
 534         p++;
 535     }
 536     return 0;
 537 }
 538
 539 static int vmdk_open_desc_file(BlockDriverState *bs, int flags)
 540 {
 541     int ret;
 542     char buf[2048];
 543     char ct[128];
 544     BDRVVmdkState *s = bs->opaque;
 545
 546     ret = bdrv_pread(bs->file, 0, buf, sizeof(buf));
 547     if (ret < 0) {
 548         return ret;
 549     }
 550     buf[2047] = '\0';
 551     if (vmdk_parse_description(buf, "createType", ct, sizeof(ct))) {
 552         return -EINVAL;
 553     }
 554     if (strcmp(ct, "monolithicFlat")) {
 555         fprintf(stderr,
 556                 "VMDK: Not supported image type \"%s\""".\n", ct);
 557         return -ENOTSUP;
 558     }
 559     s->desc_offset = 0;
 560     ret = vmdk_parse_extents(buf, bs, bs->file->filename);
 561     if (ret) {
 562         return ret;
 563     }
 564
 565     /* try to open parent images, if exist */
 566     if (vmdk_parent_open(bs)) {
 567         g_free(s->extents);
 568         return -EINVAL;
 569     }
 570     s->parent_cid = vmdk_read_cid(bs, 1);
 571     return 0;
 572 }
 573
 574 static int vmdk_open(BlockDriverState *bs, int flags)
 575 {
 576     uint32_t magic;
 577
 578     if (bdrv_pread(bs->file, 0, &magic, sizeof(magic)) != sizeof(magic)) {
 579         return -EIO;
 580     }
 581
 582     magic = be32_to_cpu(magic);
 583     if (magic == VMDK3_MAGIC) {
 584         return vmdk_open_vmdk3(bs, flags);
 585     } else if (magic == VMDK4_MAGIC) {
 586         return vmdk_open_vmdk4(bs, flags);
 587     } else {
 588         return vmdk_open_desc_file(bs, flags);
 589     }
 590 }
 591
 592 static int get_whole_cluster(BlockDriverState *bs,
 593                 VmdkExtent *extent,
 594                 uint64_t cluster_offset,
 595                 uint64_t offset,
 596                 bool allocate)
 597 {
 598     /* 128 sectors * 512 bytes each = grain size 64KB */
 599     uint8_t  whole_grain[extent->cluster_sectors * 512];
 600
 601     /* we will be here if it's first write on non-exist grain(cluster).
 602      * try to read from parent image, if exist */
 603     if (bs->backing_hd) {
 604         int ret;
 605
 606         if (!vmdk_is_cid_valid(bs)) {
 607             return -1;
 608         }
 609
 610         /* floor offset to cluster */
 611         offset -= offset % (extent->cluster_sectors * 512);
 612         ret = bdrv_read(bs->backing_hd, offset >> 9, whole_grain,
 613                 extent->cluster_sectors);
 614         if (ret < 0) {
 615             return -1;
 616         }
 617
 618         /* Write grain only into the active image */
 619         ret = bdrv_write(extent->file, cluster_offset, whole_grain,
 620                 extent->cluster_sectors);
 621         if (ret < 0) {
 622             return -1;
 623         }
 624     }
 625     return 0;
 626 }
 627
 628 static int vmdk_L2update(VmdkExtent *extent, VmdkMetaData *m_data)
 629 {
 630     /* update L2 table */
 631     if (bdrv_pwrite_sync(
 632                 extent->file,
 633                 ((int64_t)m_data->l2_offset * 512)
 634                     + (m_data->l2_index * sizeof(m_data->offset)),
 635                 &(m_data->offset),
 636                 sizeof(m_data->offset)
 637             ) < 0) {
 638         return -1;
 639     }
 640     /* update backup L2 table */
 641     if (extent->l1_backup_table_offset != 0) {
 642         m_data->l2_offset = extent->l1_backup_table[m_data->l1_index];
 643         if (bdrv_pwrite_sync(
 644                     extent->file,
 645                     ((int64_t)m_data->l2_offset * 512)
 646                         + (m_data->l2_index * sizeof(m_data->offset)),
 647                     &(m_data->offset), sizeof(m_data->offset)
 648                 ) < 0) {
 649             return -1;
 650         }
 651     }
 652
 653     return 0;
 654 }
 655
 656 static int get_cluster_offset(BlockDriverState *bs,
 657                                     VmdkExtent *extent,
 658                                     VmdkMetaData *m_data,
 659                                     uint64_t offset,
 660                                     int allocate,
 661                                     uint64_t *cluster_offset)
 662 {
 663     unsigned int l1_index, l2_offset, l2_index;
 664     int min_index, i, j;
 665     uint32_t min_count, *l2_table, tmp = 0;
 666
 667     if (m_data) {
 668         m_data->valid = 0;
 669     }
 670     if (extent->flat) {
 671         *cluster_offset = extent->flat_start_offset;
 672         return 0;
 673     }
 674
 675     l1_index = (offset >> 9) / extent->l1_entry_sectors;
 676     if (l1_index >= extent->l1_size) {
 677         return -1;
 678     }
 679     l2_offset = extent->l1_table[l1_index];
 680     if (!l2_offset) {
 681         return -1;
 682     }
 683     for (i = 0; i < L2_CACHE_SIZE; i++) {
 684         if (l2_offset == extent->l2_cache_offsets[i]) {
 685             /* increment the hit count */
 686             if (++extent->l2_cache_counts[i] == 0xffffffff) {
 687                 for (j = 0; j < L2_CACHE_SIZE; j++) {
 688                     extent->l2_cache_counts[j] >>= 1;
 689                 }
 690             }
 691             l2_table = extent->l2_cache + (i * extent->l2_size);
 692             goto found;
 693         }
 694     }
 695     /* not found: load a new entry in the least used one */
 696     min_index = 0;
 697     min_count = 0xffffffff;
 698     for (i = 0; i < L2_CACHE_SIZE; i++) {
 699         if (extent->l2_cache_counts[i] < min_count) {
 700             min_count = extent->l2_cache_counts[i];
 701             min_index = i;
 702         }
 703     }
 704     l2_table = extent->l2_cache + (min_index * extent->l2_size);
 705     if (bdrv_pread(
 706                 extent->file,
 707                 (int64_t)l2_offset * 512,
 708                 l2_table,
 709                 extent->l2_size * sizeof(uint32_t)
 710             ) != extent->l2_size * sizeof(uint32_t)) {
 711         return -1;
 712     }
 713
 714     extent->l2_cache_offsets[min_index] = l2_offset;
 715     extent->l2_cache_counts[min_index] = 1;
 716  found:
 717     l2_index = ((offset >> 9) / extent->cluster_sectors) % extent->l2_size;
 718     *cluster_offset = le32_to_cpu(l2_table[l2_index]);
 719
 720     if (!*cluster_offset) {
 721         if (!allocate) {
 722             return -1;
 723         }
 724
 725         /* Avoid the L2 tables update for the images that have snapshots. */
 726         *cluster_offset = bdrv_getlength(extent->file);
 727         bdrv_truncate(
 728             extent->file,
 729             *cluster_offset + (extent->cluster_sectors << 9)
 730         );
 731
 732         *cluster_offset >>= 9;
 733         tmp = cpu_to_le32(*cluster_offset);
 734         l2_table[l2_index] = tmp;
 735
 736         /* First of all we write grain itself, to avoid race condition
 737          * that may to corrupt the image.
 738          * This problem may occur because of insufficient space on host disk
 739          * or inappropriate VM shutdown.
 740          */
 741         if (get_whole_cluster(
 742                 bs, extent, *cluster_offset, offset, allocate) == -1) {
 743             return -1;
 744         }
 745
 746         if (m_data) {
 747             m_data->offset = tmp;
 748             m_data->l1_index = l1_index;
 749             m_data->l2_index = l2_index;
 750             m_data->l2_offset = l2_offset;
 751             m_data->valid = 1;
 752         }
 753     }
 754     *cluster_offset <<= 9;
 755     return 0;
 756 }
 757
 758 static VmdkExtent *find_extent(BDRVVmdkState *s,
 759                                 int64_t sector_num, VmdkExtent *start_hint)
 760 {
 761     VmdkExtent *extent = start_hint;
 762
 763     if (!extent) {
 764         extent = &s->extents[0];
 765     }
 766     while (extent < &s->extents[s->num_extents]) {
 767         if (sector_num < extent->end_sector) {
 768             return extent;
 769         }
 770         extent++;
 771     }
 772     return NULL;
 773 }
 774
 775 static int vmdk_is_allocated(BlockDriverState *bs, int64_t sector_num,
 776                              int nb_sectors, int *pnum)
 777 {
 778     BDRVVmdkState *s = bs->opaque;
 779     int64_t index_in_cluster, n, ret;
 780     uint64_t offset;
 781     VmdkExtent *extent;
 782
 783     extent = find_extent(s, sector_num, NULL);
 784     if (!extent) {
 785         return 0;
 786     }
 787     ret = get_cluster_offset(bs, extent, NULL,
 788                             sector_num * 512, 0, &offset);
 789     /* get_cluster_offset returning 0 means success */
 790     ret = !ret;
 791
 792     index_in_cluster = sector_num % extent->cluster_sectors;
 793     n = extent->cluster_sectors - index_in_cluster;
 794     if (n > nb_sectors) {
 795         n = nb_sectors;
 796     }
 797     *pnum = n;
 798     return ret;
 799 }
 800
 801 static int vmdk_read(BlockDriverState *bs, int64_t sector_num,
 802                     uint8_t *buf, int nb_sectors)
 803 {
 804     BDRVVmdkState *s = bs->opaque;
 805     int ret;
 806     uint64_t n, index_in_cluster;
 807     VmdkExtent *extent = NULL;
 808     uint64_t cluster_offset;
 809
 810     while (nb_sectors > 0) {
 811         extent = find_extent(s, sector_num, extent);
 812         if (!extent) {
 813             return -EIO;
 814         }
 815         ret = get_cluster_offset(
 816                             bs, extent, NULL,
 817                             sector_num << 9, 0, &cluster_offset);
 818         index_in_cluster = sector_num % extent->cluster_sectors;
 819         n = extent->cluster_sectors - index_in_cluster;
 820         if (n > nb_sectors) {
 821             n = nb_sectors;
 822         }
 823         if (ret) {
 824             /* if not allocated, try to read from parent image, if exist */
 825             if (bs->backing_hd) {
 826                 if (!vmdk_is_cid_valid(bs)) {
 827                     return -EINVAL;
 828                 }
 829                 ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
 830                 if (ret < 0) {
 831                     return ret;
 832                 }
 833             } else {
 834                 memset(buf, 0, 512 * n);
 835             }
 836         } else {
 837             ret = bdrv_pread(extent->file,
 838                             cluster_offset + index_in_cluster * 512,
 839                             buf, n * 512);
 840             if (ret < 0) {
 841                 return ret;
 842             }
 843         }
 844         nb_sectors -= n;
 845         sector_num += n;
 846         buf += n * 512;
 847     }
 848     return 0;
 849 }
 850
 851 static int vmdk_write(BlockDriverState *bs, int64_t sector_num,
 852                      const uint8_t *buf, int nb_sectors)
 853 {
 854     BDRVVmdkState *s = bs->opaque;
 855     VmdkExtent *extent = NULL;
 856     int n, ret;
 857     int64_t index_in_cluster;
 858     uint64_t cluster_offset;
 859     VmdkMetaData m_data;
 860
 861     if (sector_num > bs->total_sectors) {
 862         fprintf(stderr,
 863                 "(VMDK) Wrong offset: sector_num=0x%" PRIx64
 864                 " total_sectors=0x%" PRIx64 "\n",
 865                 sector_num, bs->total_sectors);
 866         return -EIO;
 867     }
 868
 869     while (nb_sectors > 0) {
 870         extent = find_extent(s, sector_num, extent);
 871         if (!extent) {
 872             return -EIO;
 873         }
 874         ret = get_cluster_offset(
 875                                 bs,
 876                                 extent,
 877                                 &m_data,
 878                                 sector_num << 9, 1,
 879                                 &cluster_offset);
 880         if (ret) {
 881             return -EINVAL;
 882         }
 883         index_in_cluster = sector_num % extent->cluster_sectors;
 884         n = extent->cluster_sectors - index_in_cluster;
 885         if (n > nb_sectors) {
 886             n = nb_sectors;
 887         }
 888
 889         ret = bdrv_pwrite(extent->file,
 890                         cluster_offset + index_in_cluster * 512,
 891                         buf,
 892                         n * 512);
 893         if (ret < 0) {
 894             return ret;
 895         }
 896         if (m_data.valid) {
 897             /* update L2 tables */
 898             if (vmdk_L2update(extent, &m_data) == -1) {
 899                 return -EIO;
 900             }
 901         }
 902         nb_sectors -= n;
 903         sector_num += n;
 904         buf += n * 512;
 905
 906         /* update CID on the first write every time the virtual disk is
 907          * opened */
 908         if (!s->cid_updated) {
 909             vmdk_write_cid(bs, time(NULL));
 910             s->cid_updated = true;
 911         }
 912     }
 913     return 0;
 914 }
 915
 916
 917 static int vmdk_create_extent(const char *filename, int64_t filesize, bool flat)
 918 {
 919     int ret, i;
 920     int fd = 0;
 921     VMDK4Header header;
 922     uint32_t tmp, magic, grains, gd_size, gt_size, gt_count;
 923
 924     fd = open(
 925         filename,
 926         O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
 927         0644);
 928     if (fd < 0) {
 929         return -errno;
 930     }
 931     if (flat) {
 932         ret = ftruncate(fd, filesize);
 933         if (ret < 0) {
 934             ret = -errno;
 935         }
 936         goto exit;
 937     }
 938     magic = cpu_to_be32(VMDK4_MAGIC);
 939     memset(&header, 0, sizeof(header));
 940     header.version = 1;
 941     header.flags = 3; /* ?? */
 942     header.capacity = filesize / 512;
 943     header.granularity = 128;
 944     header.num_gtes_per_gte = 512;
 945
 946     grains = (filesize / 512 + header.granularity - 1) / header.granularity;
 947     gt_size = ((header.num_gtes_per_gte * sizeof(uint32_t)) + 511) >> 9;
 948     gt_count =
 949         (grains + header.num_gtes_per_gte - 1) / header.num_gtes_per_gte;
 950     gd_size = (gt_count * sizeof(uint32_t) + 511) >> 9;
 951
 952     header.desc_offset = 1;
 953     header.desc_size = 20;
 954     header.rgd_offset = header.desc_offset + header.desc_size;
 955     header.gd_offset = header.rgd_offset + gd_size + (gt_size * gt_count);
 956     header.grain_offset =
 957        ((header.gd_offset + gd_size + (gt_size * gt_count) +
 958          header.granularity - 1) / header.granularity) *
 959         header.granularity;
 960     /* swap endianness for all header fields */
 961     header.version = cpu_to_le32(header.version);
 962     header.flags = cpu_to_le32(header.flags);
 963     header.capacity = cpu_to_le64(header.capacity);
 964     header.granularity = cpu_to_le64(header.granularity);
 965     header.num_gtes_per_gte = cpu_to_le32(header.num_gtes_per_gte);
 966     header.desc_offset = cpu_to_le64(header.desc_offset);
 967     header.desc_size = cpu_to_le64(header.desc_size);
 968     header.rgd_offset = cpu_to_le64(header.rgd_offset);
 969     header.gd_offset = cpu_to_le64(header.gd_offset);
 970     header.grain_offset = cpu_to_le64(header.grain_offset);
 971
 972     header.check_bytes[0] = 0xa;
 973     header.check_bytes[1] = 0x20;
 974     header.check_bytes[2] = 0xd;
 975     header.check_bytes[3] = 0xa;
 976
 977     /* write all the data */
 978     ret = qemu_write_full(fd, &magic, sizeof(magic));
 979     if (ret != sizeof(magic)) {
 980         ret = -errno;
 981         goto exit;
 982     }
 983     ret = qemu_write_full(fd, &header, sizeof(header));
 984     if (ret != sizeof(header)) {
 985         ret = -errno;
 986         goto exit;
 987     }
 988
 989     ret = ftruncate(fd, le64_to_cpu(header.grain_offset) << 9);
 990     if (ret < 0) {
 991         ret = -errno;
 992         goto exit;
 993     }
 994
 995     /* write grain directory */
 996     lseek(fd, le64_to_cpu(header.rgd_offset) << 9, SEEK_SET);
 997     for (i = 0, tmp = le64_to_cpu(header.rgd_offset) + gd_size;
 998          i < gt_count; i++, tmp += gt_size) {
 999         ret = qemu_write_full(fd, &tmp, sizeof(tmp));
1000         if (ret != sizeof(tmp)) {
1001             ret = -errno;
1002             goto exit;
1003         }
1004     }
1005
1006     /* write backup grain directory */
1007     lseek(fd, le64_to_cpu(header.gd_offset) << 9, SEEK_SET);
1008     for (i = 0, tmp = le64_to_cpu(header.gd_offset) + gd_size;
1009          i < gt_count; i++, tmp += gt_size) {
1010         ret = qemu_write_full(fd, &tmp, sizeof(tmp));
1011         if (ret != sizeof(tmp)) {
1012             ret = -errno;
1013             goto exit;
1014         }
1015     }
1016
1017     ret = 0;
1018  exit:
1019     close(fd);
1020     return ret;
1021 }
1022
1023 static int filename_decompose(const char *filename, char *path, char *prefix,
1024         char *postfix, size_t buf_len)
1025 {
1026     const char *p, *q;
1027
1028     if (filename == NULL || !strlen(filename)) {
1029         fprintf(stderr, "Vmdk: no filename provided.\n");
1030         return -1;
1031     }
1032     p = strrchr(filename, '/');
1033     if (p == NULL) {
1034         p = strrchr(filename, '\\');
1035     }
1036     if (p == NULL) {
1037         p = strrchr(filename, ':');
1038     }
1039     if (p != NULL) {
1040         p++;
1041         if (p - filename >= buf_len) {
1042             return -1;
1043         }
1044         pstrcpy(path, p - filename + 1, filename);
1045     } else {
1046         p = filename;
1047         path[0] = '\0';
1048     }
1049     q = strrchr(p, '.');
1050     if (q == NULL) {
1051         pstrcpy(prefix, buf_len, p);
1052         postfix[0] = '\0';
1053     } else {
1054         if (q - p >= buf_len) {
1055             return -1;
1056         }
1057         pstrcpy(prefix, q - p + 1, p);
1058         pstrcpy(postfix, buf_len, q);
1059     }
1060     return 0;
1061 }
1062
1063 static int relative_path(char *dest, int dest_size,
1064         const char *base, const char *target)
1065 {
1066     int i = 0;
1067     int n = 0;
1068     const char *p, *q;
1069 #ifdef _WIN32
1070     const char *sep = "\\";
1071 #else
1072     const char *sep = "/";
1073 #endif
1074
1075     if (!(dest && base && target)) {
1076         return -1;
1077     }
1078     if (path_is_absolute(target)) {
1079         dest[dest_size - 1] = '\0';
1080         strncpy(dest, target, dest_size - 1);
1081         return 0;
1082     }
1083     while (base[i] == target[i]) {
1084         i++;
1085     }
1086     p = &base[i];
1087     q = &target[i];
1088     while (*p) {
1089         if (*p == *sep) {
1090             n++;
1091         }
1092         p++;
1093     }
1094     dest[0] = '\0';
1095     for (; n; n--) {
1096         pstrcat(dest, dest_size, "..");
1097         pstrcat(dest, dest_size, sep);
1098     }
1099     pstrcat(dest, dest_size, q);
1100     return 0;
1101 }
1102
1103 static int vmdk_create(const char *filename, QEMUOptionParameter *options)
1104 {
1105     int fd, idx = 0;
1106     char desc[BUF_SIZE];
1107     int64_t total_size = 0, filesize;
1108     const char *backing_file = NULL;
1109     const char *fmt = NULL;
1110     int flags = 0;
1111     int ret = 0;
1112     bool flat, split;
1113     char ext_desc_lines[BUF_SIZE] = "";
1114     char path[PATH_MAX], prefix[PATH_MAX], postfix[PATH_MAX];
1115     const int64_t split_size = 0x80000000;  /* VMDK has constant split size */
1116     const char *desc_extent_line;
1117     char parent_desc_line[BUF_SIZE] = "";
1118     uint32_t parent_cid = 0xffffffff;
1119     const char desc_template[] =
1120         "# Disk DescriptorFile\n"
1121         "version=1\n"
1122         "CID=%x\n"
1123         "parentCID=%x\n"
1124         "createType=\"%s\"\n"
1125         "%s"
1126         "\n"
1127         "# Extent description\n"
1128         "%s"
1129         "\n"
1130         "# The Disk Data Base\n"
1131         "#DDB\n"
1132         "\n"
1133         "ddb.virtualHWVersion = \"%d\"\n"
1134         "ddb.geometry.cylinders = \"%" PRId64 "\"\n"
1135         "ddb.geometry.heads = \"16\"\n"
1136         "ddb.geometry.sectors = \"63\"\n"
1137         "ddb.adapterType = \"ide\"\n";
1138
1139     if (filename_decompose(filename, path, prefix, postfix, PATH_MAX)) {
1140         return -EINVAL;
1141     }
1142     /* Read out options */
1143     while (options && options->name) {
1144         if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
1145             total_size = options->value.n;
1146         } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
1147             backing_file = options->value.s;
1148         } else if (!strcmp(options->name, BLOCK_OPT_COMPAT6)) {
1149             flags |= options->value.n ? BLOCK_FLAG_COMPAT6 : 0;
1150         } else if (!strcmp(options->name, BLOCK_OPT_SUBFMT)) {
1151             fmt = options->value.s;
1152         }
1153         options++;
1154     }
1155     if (!fmt) {
1156         /* Default format to monolithicSparse */
1157         fmt = "monolithicSparse";
1158     } else if (strcmp(fmt, "monolithicFlat") &&
1159                strcmp(fmt, "monolithicSparse") &&
1160                strcmp(fmt, "twoGbMaxExtentSparse") &&
1161                strcmp(fmt, "twoGbMaxExtentFlat")) {
1162         fprintf(stderr, "VMDK: Unknown subformat: %s\n", fmt);
1163         return -EINVAL;
1164     }
1165     split = !(strcmp(fmt, "twoGbMaxExtentFlat") &&
1166               strcmp(fmt, "twoGbMaxExtentSparse"));
1167     flat = !(strcmp(fmt, "monolithicFlat") &&
1168              strcmp(fmt, "twoGbMaxExtentFlat"));
1169     if (flat) {
1170         desc_extent_line = "RW %lld FLAT \"%s\" 0\n";
1171     } else {
1172         desc_extent_line = "RW %lld SPARSE \"%s\"\n";
1173     }
1174     if (flat && backing_file) {
1175         /* not supporting backing file for flat image */
1176         return -ENOTSUP;
1177     }
1178     if (backing_file) {
1179         char parent_filename[PATH_MAX];
1180         BlockDriverState *bs = bdrv_new("");
1181         ret = bdrv_open(bs, backing_file, 0, NULL);
1182         if (ret != 0) {
1183             bdrv_delete(bs);
1184             return ret;
1185         }
1186         if (strcmp(bs->drv->format_name, "vmdk")) {
1187             bdrv_delete(bs);
1188             return -EINVAL;
1189         }
1190         filesize = bdrv_getlength(bs);
1191         parent_cid = vmdk_read_cid(bs, 0);
1192         bdrv_delete(bs);
1193         relative_path(parent_filename, sizeof(parent_filename),
1194                       filename, backing_file);
1195         snprintf(parent_desc_line, sizeof(parent_desc_line),
1196                 "parentFileNameHint=\"%s\"", parent_filename);
1197     }
1198
1199     /* Create extents */
1200     filesize = total_size;
1201     while (filesize > 0) {
1202         char desc_line[BUF_SIZE];
1203         char ext_filename[PATH_MAX];
1204         char desc_filename[PATH_MAX];
1205         int64_t size = filesize;
1206
1207         if (split && size > split_size) {
1208             size = split_size;
1209         }
1210         if (split) {
1211             snprintf(desc_filename, sizeof(desc_filename), "%s-%c%03d%s",
1212                     prefix, flat ? 'f' : 's', ++idx, postfix);
1213         } else if (flat) {
1214             snprintf(desc_filename, sizeof(desc_filename), "%s-flat%s",
1215                     prefix, postfix);
1216         } else {
1217             snprintf(desc_filename, sizeof(desc_filename), "%s%s",
1218                     prefix, postfix);
1219         }
1220         snprintf(ext_filename, sizeof(ext_filename), "%s%s",
1221                 path, desc_filename);
1222
1223         if (vmdk_create_extent(ext_filename, size, flat)) {
1224             return -EINVAL;
1225         }
1226         filesize -= size;
1227
1228         /* Format description line */
1229         snprintf(desc_line, sizeof(desc_line),
1230                     desc_extent_line, size / 512, desc_filename);
1231         pstrcat(ext_desc_lines, sizeof(ext_desc_lines), desc_line);
1232     }
1233     /* generate descriptor file */
1234     snprintf(desc, sizeof(desc), desc_template,
1235             (unsigned int)time(NULL),
1236             parent_cid,
1237             fmt,
1238             parent_desc_line,
1239             ext_desc_lines,
1240             (flags & BLOCK_FLAG_COMPAT6 ? 6 : 4),
1241             total_size / (int64_t)(63 * 16 * 512));
1242     if (split || flat) {
1243         fd = open(
1244                 filename,
1245                 O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
1246                 0644);
1247     } else {
1248         fd = open(
1249                 filename,
1250                 O_WRONLY | O_BINARY | O_LARGEFILE,
1251                 0644);
1252     }
1253     if (fd < 0) {
1254         return -errno;
1255     }
1256     /* the descriptor offset = 0x200 */
1257     if (!split && !flat && 0x200 != lseek(fd, 0x200, SEEK_SET)) {
1258         ret = -errno;
1259         goto exit;
1260     }
1261     ret = qemu_write_full(fd, desc, strlen(desc));
1262     if (ret != strlen(desc)) {
1263         ret = -errno;
1264         goto exit;
1265     }
1266     ret = 0;
1267 exit:
1268     close(fd);
1269     return ret;
1270 }
1271
1272 static void vmdk_close(BlockDriverState *bs)
1273 {
1274     vmdk_free_extents(bs);
1275 }
1276
1277 static int vmdk_flush(BlockDriverState *bs)
1278 {
1279     int i, ret, err;
1280     BDRVVmdkState *s = bs->opaque;
1281
1282     ret = bdrv_flush(bs->file);
1283     for (i = 0; i < s->num_extents; i++) {
1284         err = bdrv_flush(s->extents[i].file);
1285         if (err < 0) {
1286             ret = err;
1287         }
1288     }
1289     return ret;
1290 }
1291
1292 static int64_t vmdk_get_allocated_file_size(BlockDriverState *bs)
1293 {
1294     int i;
1295     int64_t ret = 0;
1296     int64_t r;
1297     BDRVVmdkState *s = bs->opaque;
1298
1299     ret = bdrv_get_allocated_file_size(bs->file);
1300     if (ret < 0) {
1301         return ret;
1302     }
1303     for (i = 0; i < s->num_extents; i++) {
1304         if (s->extents[i].file == bs->file) {
1305             continue;
1306         }
1307         r = bdrv_get_allocated_file_size(s->extents[i].file);
1308         if (r < 0) {
1309             return r;
1310         }
1311         ret += r;
1312     }
1313     return ret;
1314 }
1315
1316 static QEMUOptionParameter vmdk_create_options[] = {
1317     {
1318         .name = BLOCK_OPT_SIZE,
1319         .type = OPT_SIZE,
1320         .help = "Virtual disk size"
1321     },
1322     {
1323         .name = BLOCK_OPT_BACKING_FILE,
1324         .type = OPT_STRING,
1325         .help = "File name of a base image"
1326     },
1327     {
1328         .name = BLOCK_OPT_COMPAT6,
1329         .type = OPT_FLAG,
1330         .help = "VMDK version 6 image"
1331     },
1332     {
1333         .name = BLOCK_OPT_SUBFMT,
1334         .type = OPT_STRING,
1335         .help =
1336             "VMDK flat extent format, can be one of "
1337             "{monolithicSparse (default) | monolithicFlat | twoGbMaxExtentSparse | twoGbMaxExtentFlat} "
1338     },
1339     { NULL }
1340 };
1341
1342 static BlockDriver bdrv_vmdk = {
1343     .format_name    = "vmdk",
1344     .instance_size  = sizeof(BDRVVmdkState),
1345     .bdrv_probe     = vmdk_probe,
1346     .bdrv_open      = vmdk_open,
1347     .bdrv_read      = vmdk_read,
1348     .bdrv_write     = vmdk_write,
1349     .bdrv_close     = vmdk_close,
1350     .bdrv_create    = vmdk_create,
1351     .bdrv_flush     = vmdk_flush,
1352     .bdrv_is_allocated  = vmdk_is_allocated,
1353     .bdrv_get_allocated_file_size  = vmdk_get_allocated_file_size,
1354
1355     .create_options = vmdk_create_options,
1356 };
1357
1358 static void bdrv_vmdk_init(void)
1359 {
1360     bdrv_register(&bdrv_vmdk);
1361 }
1362
1363 block_init(bdrv_vmdk_init);