block/crypto.c

   1 /*
   2  * QEMU block full disk encryption
   3  *
   4  * Copyright (c) 2015-2016 Red Hat, Inc.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20
  21 #include "qemu/osdep.h"
  22
  23 #include "block/block_int.h"
  24 #include "block/qdict.h"
  25 #include "sysemu/block-backend.h"
  26 #include "crypto/block.h"
  27 #include "qapi/opts-visitor.h"
  28 #include "qapi/qapi-visit-crypto.h"
  29 #include "qapi/qobject-input-visitor.h"
  30 #include "qapi/error.h"
  31 #include "qemu/module.h"
  32 #include "qemu/option.h"
  33 #include "qemu/cutils.h"
  34 #include "crypto.h"
  35
  36 typedef struct BlockCrypto BlockCrypto;
  37
  38 struct BlockCrypto {
  39     QCryptoBlock *block;
  40 };
  41
  42
  43 static int block_crypto_probe_generic(QCryptoBlockFormat format,
  44                                       const uint8_t *buf,
  45                                       int buf_size,
  46                                       const char *filename)
  47 {
  48     if (qcrypto_block_has_format(format, buf, buf_size)) {
  49         return 100;
  50     } else {
  51         return 0;
  52     }
  53 }
  54
  55
  56 static ssize_t block_crypto_read_func(QCryptoBlock *block,
  57                                       size_t offset,
  58                                       uint8_t *buf,
  59                                       size_t buflen,
  60                                       void *opaque,
  61                                       Error **errp)
  62 {
  63     BlockDriverState *bs = opaque;
  64     ssize_t ret;
  65
  66     ret = bdrv_pread(bs->file, offset, buf, buflen);
  67     if (ret < 0) {
  68         error_setg_errno(errp, -ret, "Could not read encryption header");
  69         return ret;
  70     }
  71     return ret;
  72 }
  73
  74
  75 struct BlockCryptoCreateData {
  76     BlockBackend *blk;
  77     uint64_t size;
  78     PreallocMode prealloc;
  79 };
  80
  81
  82 static ssize_t block_crypto_write_func(QCryptoBlock *block,
  83                                        size_t offset,
  84                                        const uint8_t *buf,
  85                                        size_t buflen,
  86                                        void *opaque,
  87                                        Error **errp)
  88 {
  89     struct BlockCryptoCreateData *data = opaque;
  90     ssize_t ret;
  91
  92     ret = blk_pwrite(data->blk, offset, buf, buflen, 0);
  93     if (ret < 0) {
  94         error_setg_errno(errp, -ret, "Could not write encryption header");
  95         return ret;
  96     }
  97     return ret;
  98 }
  99
 100
 101 static ssize_t block_crypto_init_func(QCryptoBlock *block,
 102                                       size_t headerlen,
 103                                       void *opaque,
 104                                       Error **errp)
 105 {
 106     struct BlockCryptoCreateData *data = opaque;
 107     Error *local_error = NULL;
 108     int ret;
 109
 110     if (data->size > INT64_MAX || headerlen > INT64_MAX - data->size) {
 111         ret = -EFBIG;
 112         goto error;
 113     }
 114
 115     /* User provided size should reflect amount of space made
 116      * available to the guest, so we must take account of that
 117      * which will be used by the crypto header
 118      */
 119     ret = blk_truncate(data->blk, data->size + headerlen, false,
 120                        data->prealloc, 0, &local_error);
 121
 122     if (ret >= 0) {
 123         return ret;
 124     }
 125
 126 error:
 127     if (ret == -EFBIG) {
 128         /* Replace the error message with a better one */
 129         error_free(local_error);
 130         error_setg(errp, "The requested file size is too large");
 131     } else {
 132         error_propagate(errp, local_error);
 133     }
 134
 135     return ret;
 136 }
 137
 138
 139 static QemuOptsList block_crypto_runtime_opts_luks = {
 140     .name = "crypto",
 141     .head = QTAILQ_HEAD_INITIALIZER(block_crypto_runtime_opts_luks.head),
 142     .desc = {
 143         BLOCK_CRYPTO_OPT_DEF_LUKS_KEY_SECRET(""),
 144         { /* end of list */ }
 145     },
 146 };
 147
 148
 149 static QemuOptsList block_crypto_create_opts_luks = {
 150     .name = "crypto",
 151     .head = QTAILQ_HEAD_INITIALIZER(block_crypto_create_opts_luks.head),
 152     .desc = {
 153         {
 154             .name = BLOCK_OPT_SIZE,
 155             .type = QEMU_OPT_SIZE,
 156             .help = "Virtual disk size"
 157         },
 158         BLOCK_CRYPTO_OPT_DEF_LUKS_KEY_SECRET(""),
 159         BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_ALG(""),
 160         BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_MODE(""),
 161         BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_ALG(""),
 162         BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG(""),
 163         BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG(""),
 164         BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME(""),
 165         { /* end of list */ }
 166     },
 167 };
 168
 169
 170 QCryptoBlockOpenOptions *
 171 block_crypto_open_opts_init(QDict *opts, Error **errp)
 172 {
 173     Visitor *v;
 174     QCryptoBlockOpenOptions *ret;
 175
 176     v = qobject_input_visitor_new_flat_confused(opts, errp);
 177     if (!v) {
 178         return NULL;
 179     }
 180
 181     visit_type_QCryptoBlockOpenOptions(v, NULL, &ret, errp);
 182
 183     visit_free(v);
 184     return ret;
 185 }
 186
 187
 188 QCryptoBlockCreateOptions *
 189 block_crypto_create_opts_init(QDict *opts, Error **errp)
 190 {
 191     Visitor *v;
 192     QCryptoBlockCreateOptions *ret;
 193
 194     v = qobject_input_visitor_new_flat_confused(opts, errp);
 195     if (!v) {
 196         return NULL;
 197     }
 198
 199     visit_type_QCryptoBlockCreateOptions(v, NULL, &ret, errp);
 200
 201     visit_free(v);
 202     return ret;
 203 }
 204
 205
 206 static int block_crypto_open_generic(QCryptoBlockFormat format,
 207                                      QemuOptsList *opts_spec,
 208                                      BlockDriverState *bs,
 209                                      QDict *options,
 210                                      int flags,
 211                                      Error **errp)
 212 {
 213     BlockCrypto *crypto = bs->opaque;
 214     QemuOpts *opts = NULL;
 215     Error *local_err = NULL;
 216     int ret = -EINVAL;
 217     QCryptoBlockOpenOptions *open_opts = NULL;
 218     unsigned int cflags = 0;
 219     QDict *cryptoopts = NULL;
 220
 221     bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
 222                                BDRV_CHILD_IMAGE, false, errp);
 223     if (!bs->file) {
 224         return -EINVAL;
 225     }
 226
 227     bs->supported_write_flags = BDRV_REQ_FUA &
 228         bs->file->bs->supported_write_flags;
 229
 230     opts = qemu_opts_create(opts_spec, NULL, 0, &error_abort);
 231     qemu_opts_absorb_qdict(opts, options, &local_err);
 232     if (local_err) {
 233         error_propagate(errp, local_err);
 234         goto cleanup;
 235     }
 236
 237     cryptoopts = qemu_opts_to_qdict(opts, NULL);
 238     qdict_put_str(cryptoopts, "format", QCryptoBlockFormat_str(format));
 239
 240     open_opts = block_crypto_open_opts_init(cryptoopts, errp);
 241     if (!open_opts) {
 242         goto cleanup;
 243     }
 244
 245     if (flags & BDRV_O_NO_IO) {
 246         cflags |= QCRYPTO_BLOCK_OPEN_NO_IO;
 247     }
 248     crypto->block = qcrypto_block_open(open_opts, NULL,
 249                                        block_crypto_read_func,
 250                                        bs,
 251                                        cflags,
 252                                        1,
 253                                        errp);
 254
 255     if (!crypto->block) {
 256         ret = -EIO;
 257         goto cleanup;
 258     }
 259
 260     bs->encrypted = true;
 261
 262     ret = 0;
 263  cleanup:
 264     qobject_unref(cryptoopts);
 265     qapi_free_QCryptoBlockOpenOptions(open_opts);
 266     return ret;
 267 }
 268
 269
 270 static int block_crypto_co_create_generic(BlockDriverState *bs,
 271                                           int64_t size,
 272                                           QCryptoBlockCreateOptions *opts,
 273                                           PreallocMode prealloc,
 274                                           Error **errp)
 275 {
 276     int ret;
 277     BlockBackend *blk;
 278     QCryptoBlock *crypto = NULL;
 279     struct BlockCryptoCreateData data;
 280
 281     blk = blk_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL,
 282                           errp);
 283     if (!blk) {
 284         ret = -EPERM;
 285         goto cleanup;
 286     }
 287
 288     if (prealloc == PREALLOC_MODE_METADATA) {
 289         prealloc = PREALLOC_MODE_OFF;
 290     }
 291
 292     data = (struct BlockCryptoCreateData) {
 293         .blk = blk,
 294         .size = size,
 295         .prealloc = prealloc,
 296     };
 297
 298     crypto = qcrypto_block_create(opts, NULL,
 299                                   block_crypto_init_func,
 300                                   block_crypto_write_func,
 301                                   &data,
 302                                   errp);
 303
 304     if (!crypto) {
 305         ret = -EIO;
 306         goto cleanup;
 307     }
 308
 309     ret = 0;
 310  cleanup:
 311     qcrypto_block_free(crypto);
 312     blk_unref(blk);
 313     return ret;
 314 }
 315
 316 static int coroutine_fn
 317 block_crypto_co_truncate(BlockDriverState *bs, int64_t offset, bool exact,
 318                          PreallocMode prealloc, BdrvRequestFlags flags,
 319                          Error **errp)
 320 {
 321     BlockCrypto *crypto = bs->opaque;
 322     uint64_t payload_offset =
 323         qcrypto_block_get_payload_offset(crypto->block);
 324
 325     if (payload_offset > INT64_MAX - offset) {
 326         error_setg(errp, "The requested file size is too large");
 327         return -EFBIG;
 328     }
 329
 330     offset += payload_offset;
 331
 332     return bdrv_co_truncate(bs->file, offset, exact, prealloc, 0, errp);
 333 }
 334
 335 static void block_crypto_close(BlockDriverState *bs)
 336 {
 337     BlockCrypto *crypto = bs->opaque;
 338     qcrypto_block_free(crypto->block);
 339 }
 340
 341 static int block_crypto_reopen_prepare(BDRVReopenState *state,
 342                                        BlockReopenQueue *queue, Error **errp)
 343 {
 344     /* nothing needs checking */
 345     return 0;
 346 }
 347
 348 /*
 349  * 1 MB bounce buffer gives good performance / memory tradeoff
 350  * when using cache=none|directsync.
 351  */
 352 #define BLOCK_CRYPTO_MAX_IO_SIZE (1024 * 1024)
 353
 354 static coroutine_fn int
 355 block_crypto_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 356                        QEMUIOVector *qiov, int flags)
 357 {
 358     BlockCrypto *crypto = bs->opaque;
 359     uint64_t cur_bytes; /* number of bytes in current iteration */
 360     uint64_t bytes_done = 0;
 361     uint8_t *cipher_data = NULL;
 362     QEMUIOVector hd_qiov;
 363     int ret = 0;
 364     uint64_t sector_size = qcrypto_block_get_sector_size(crypto->block);
 365     uint64_t payload_offset = qcrypto_block_get_payload_offset(crypto->block);
 366
 367     assert(!flags);
 368     assert(payload_offset < INT64_MAX);
 369     assert(QEMU_IS_ALIGNED(offset, sector_size));
 370     assert(QEMU_IS_ALIGNED(bytes, sector_size));
 371
 372     qemu_iovec_init(&hd_qiov, qiov->niov);
 373
 374     /* Bounce buffer because we don't wish to expose cipher text
 375      * in qiov which points to guest memory.
 376      */
 377     cipher_data =
 378         qemu_try_blockalign(bs->file->bs, MIN(BLOCK_CRYPTO_MAX_IO_SIZE,
 379                                               qiov->size));
 380     if (cipher_data == NULL) {
 381         ret = -ENOMEM;
 382         goto cleanup;
 383     }
 384
 385     while (bytes) {
 386         cur_bytes = MIN(bytes, BLOCK_CRYPTO_MAX_IO_SIZE);
 387
 388         qemu_iovec_reset(&hd_qiov);
 389         qemu_iovec_add(&hd_qiov, cipher_data, cur_bytes);
 390
 391         ret = bdrv_co_preadv(bs->file, payload_offset + offset + bytes_done,
 392                              cur_bytes, &hd_qiov, 0);
 393         if (ret < 0) {
 394             goto cleanup;
 395         }
 396
 397         if (qcrypto_block_decrypt(crypto->block, offset + bytes_done,
 398                                   cipher_data, cur_bytes, NULL) < 0) {
 399             ret = -EIO;
 400             goto cleanup;
 401         }
 402
 403         qemu_iovec_from_buf(qiov, bytes_done, cipher_data, cur_bytes);
 404
 405         bytes -= cur_bytes;
 406         bytes_done += cur_bytes;
 407     }
 408
 409  cleanup:
 410     qemu_iovec_destroy(&hd_qiov);
 411     qemu_vfree(cipher_data);
 412
 413     return ret;
 414 }
 415
 416
 417 static coroutine_fn int
 418 block_crypto_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 419                         QEMUIOVector *qiov, int flags)
 420 {
 421     BlockCrypto *crypto = bs->opaque;
 422     uint64_t cur_bytes; /* number of bytes in current iteration */
 423     uint64_t bytes_done = 0;
 424     uint8_t *cipher_data = NULL;
 425     QEMUIOVector hd_qiov;
 426     int ret = 0;
 427     uint64_t sector_size = qcrypto_block_get_sector_size(crypto->block);
 428     uint64_t payload_offset = qcrypto_block_get_payload_offset(crypto->block);
 429
 430     assert(!(flags & ~BDRV_REQ_FUA));
 431     assert(payload_offset < INT64_MAX);
 432     assert(QEMU_IS_ALIGNED(offset, sector_size));
 433     assert(QEMU_IS_ALIGNED(bytes, sector_size));
 434
 435     qemu_iovec_init(&hd_qiov, qiov->niov);
 436
 437     /* Bounce buffer because we're not permitted to touch
 438      * contents of qiov - it points to guest memory.
 439      */
 440     cipher_data =
 441         qemu_try_blockalign(bs->file->bs, MIN(BLOCK_CRYPTO_MAX_IO_SIZE,
 442                                               qiov->size));
 443     if (cipher_data == NULL) {
 444         ret = -ENOMEM;
 445         goto cleanup;
 446     }
 447
 448     while (bytes) {
 449         cur_bytes = MIN(bytes, BLOCK_CRYPTO_MAX_IO_SIZE);
 450
 451         qemu_iovec_to_buf(qiov, bytes_done, cipher_data, cur_bytes);
 452
 453         if (qcrypto_block_encrypt(crypto->block, offset + bytes_done,
 454                                   cipher_data, cur_bytes, NULL) < 0) {
 455             ret = -EIO;
 456             goto cleanup;
 457         }
 458
 459         qemu_iovec_reset(&hd_qiov);
 460         qemu_iovec_add(&hd_qiov, cipher_data, cur_bytes);
 461
 462         ret = bdrv_co_pwritev(bs->file, payload_offset + offset + bytes_done,
 463                               cur_bytes, &hd_qiov, flags);
 464         if (ret < 0) {
 465             goto cleanup;
 466         }
 467
 468         bytes -= cur_bytes;
 469         bytes_done += cur_bytes;
 470     }
 471
 472  cleanup:
 473     qemu_iovec_destroy(&hd_qiov);
 474     qemu_vfree(cipher_data);
 475
 476     return ret;
 477 }
 478
 479 static void block_crypto_refresh_limits(BlockDriverState *bs, Error **errp)
 480 {
 481     BlockCrypto *crypto = bs->opaque;
 482     uint64_t sector_size = qcrypto_block_get_sector_size(crypto->block);
 483     bs->bl.request_alignment = sector_size; /* No sub-sector I/O */
 484 }
 485
 486
 487 static int64_t block_crypto_getlength(BlockDriverState *bs)
 488 {
 489     BlockCrypto *crypto = bs->opaque;
 490     int64_t len = bdrv_getlength(bs->file->bs);
 491
 492     uint64_t offset = qcrypto_block_get_payload_offset(crypto->block);
 493     assert(offset < INT64_MAX);
 494
 495     if (offset > len) {
 496         return -EIO;
 497     }
 498
 499     len -= offset;
 500
 501     return len;
 502 }
 503
 504
 505 static BlockMeasureInfo *block_crypto_measure(QemuOpts *opts,
 506                                               BlockDriverState *in_bs,
 507                                               Error **errp)
 508 {
 509     g_autoptr(QCryptoBlockCreateOptions) create_opts = NULL;
 510     Error *local_err = NULL;
 511     BlockMeasureInfo *info;
 512     uint64_t size;
 513     size_t luks_payload_size;
 514     QDict *cryptoopts;
 515
 516     /*
 517      * Preallocation mode doesn't affect size requirements but we must consume
 518      * the option.
 519      */
 520     g_free(qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC));
 521
 522     size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0);
 523
 524     if (in_bs) {
 525         int64_t ssize = bdrv_getlength(in_bs);
 526
 527         if (ssize < 0) {
 528             error_setg_errno(&local_err, -ssize,
 529                              "Unable to get image virtual_size");
 530             goto err;
 531         }
 532
 533         size = ssize;
 534     }
 535
 536     cryptoopts = qemu_opts_to_qdict_filtered(opts, NULL,
 537             &block_crypto_create_opts_luks, true);
 538     qdict_put_str(cryptoopts, "format", "luks");
 539     create_opts = block_crypto_create_opts_init(cryptoopts, &local_err);
 540     qobject_unref(cryptoopts);
 541     if (!create_opts) {
 542         goto err;
 543     }
 544
 545     if (!qcrypto_block_calculate_payload_offset(create_opts, NULL,
 546                                                 &luks_payload_size,
 547                                                 &local_err)) {
 548         goto err;
 549     }
 550
 551     /*
 552      * Unallocated blocks are still encrypted so allocation status makes no
 553      * difference to the file size.
 554      */
 555     info = g_new0(BlockMeasureInfo, 1);
 556     info->fully_allocated = luks_payload_size + size;
 557     info->required = luks_payload_size + size;
 558     return info;
 559
 560 err:
 561     error_propagate(errp, local_err);
 562     return NULL;
 563 }
 564
 565
 566 static int block_crypto_probe_luks(const uint8_t *buf,
 567                                    int buf_size,
 568                                    const char *filename) {
 569     return block_crypto_probe_generic(Q_CRYPTO_BLOCK_FORMAT_LUKS,
 570                                       buf, buf_size, filename);
 571 }
 572
 573 static int block_crypto_open_luks(BlockDriverState *bs,
 574                                   QDict *options,
 575                                   int flags,
 576                                   Error **errp)
 577 {
 578     return block_crypto_open_generic(Q_CRYPTO_BLOCK_FORMAT_LUKS,
 579                                      &block_crypto_runtime_opts_luks,
 580                                      bs, options, flags, errp);
 581 }
 582
 583 static int coroutine_fn
 584 block_crypto_co_create_luks(BlockdevCreateOptions *create_options, Error **errp)
 585 {
 586     BlockdevCreateOptionsLUKS *luks_opts;
 587     BlockDriverState *bs = NULL;
 588     QCryptoBlockCreateOptions create_opts;
 589     PreallocMode preallocation = PREALLOC_MODE_OFF;
 590     int ret;
 591
 592     assert(create_options->driver == BLOCKDEV_DRIVER_LUKS);
 593     luks_opts = &create_options->u.luks;
 594
 595     bs = bdrv_open_blockdev_ref(luks_opts->file, errp);
 596     if (bs == NULL) {
 597         return -EIO;
 598     }
 599
 600     create_opts = (QCryptoBlockCreateOptions) {
 601         .format = Q_CRYPTO_BLOCK_FORMAT_LUKS,
 602         .u.luks = *qapi_BlockdevCreateOptionsLUKS_base(luks_opts),
 603     };
 604
 605     if (luks_opts->has_preallocation) {
 606         preallocation = luks_opts->preallocation;
 607     }
 608
 609     ret = block_crypto_co_create_generic(bs, luks_opts->size, &create_opts,
 610                                          preallocation, errp);
 611     if (ret < 0) {
 612         goto fail;
 613     }
 614
 615     ret = 0;
 616 fail:
 617     bdrv_unref(bs);
 618     return ret;
 619 }
 620
 621 static int coroutine_fn block_crypto_co_create_opts_luks(BlockDriver *drv,
 622                                                          const char *filename,
 623                                                          QemuOpts *opts,
 624                                                          Error **errp)
 625 {
 626     QCryptoBlockCreateOptions *create_opts = NULL;
 627     BlockDriverState *bs = NULL;
 628     QDict *cryptoopts;
 629     PreallocMode prealloc;
 630     char *buf = NULL;
 631     int64_t size;
 632     int ret;
 633     Error *local_err = NULL;
 634
 635     /* Parse options */
 636     size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0);
 637
 638     buf = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
 639     prealloc = qapi_enum_parse(&PreallocMode_lookup, buf,
 640                                PREALLOC_MODE_OFF, &local_err);
 641     g_free(buf);
 642     if (local_err) {
 643         error_propagate(errp, local_err);
 644         return -EINVAL;
 645     }
 646
 647     cryptoopts = qemu_opts_to_qdict_filtered(opts, NULL,
 648                                              &block_crypto_create_opts_luks,
 649                                              true);
 650
 651     qdict_put_str(cryptoopts, "format", "luks");
 652     create_opts = block_crypto_create_opts_init(cryptoopts, errp);
 653     if (!create_opts) {
 654         ret = -EINVAL;
 655         goto fail;
 656     }
 657
 658     /* Create protocol layer */
 659     ret = bdrv_create_file(filename, opts, errp);
 660     if (ret < 0) {
 661         goto fail;
 662     }
 663
 664     bs = bdrv_open(filename, NULL, NULL,
 665                    BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
 666     if (!bs) {
 667         ret = -EINVAL;
 668         goto fail;
 669     }
 670
 671     /* Create format layer */
 672     ret = block_crypto_co_create_generic(bs, size, create_opts, prealloc, errp);
 673     if (ret < 0) {
 674         goto fail;
 675     }
 676
 677     ret = 0;
 678 fail:
 679     /*
 680      * If an error occurred, delete 'filename'. Even if the file existed
 681      * beforehand, it has been truncated and corrupted in the process.
 682      */
 683     if (ret && bs) {
 684         Error *local_delete_err = NULL;
 685         int r_del = bdrv_co_delete_file(bs, &local_delete_err);
 686         /*
 687          * ENOTSUP will happen if the block driver doesn't support
 688          * the 'bdrv_co_delete_file' interface. This is a predictable
 689          * scenario and shouldn't be reported back to the user.
 690          */
 691         if ((r_del < 0) && (r_del != -ENOTSUP)) {
 692             error_report_err(local_delete_err);
 693         }
 694     }
 695
 696     bdrv_unref(bs);
 697     qapi_free_QCryptoBlockCreateOptions(create_opts);
 698     qobject_unref(cryptoopts);
 699     return ret;
 700 }
 701
 702 static int block_crypto_get_info_luks(BlockDriverState *bs,
 703                                       BlockDriverInfo *bdi)
 704 {
 705     BlockDriverInfo subbdi;
 706     int ret;
 707
 708     ret = bdrv_get_info(bs->file->bs, &subbdi);
 709     if (ret != 0) {
 710         return ret;
 711     }
 712
 713     bdi->unallocated_blocks_are_zero = false;
 714     bdi->cluster_size = subbdi.cluster_size;
 715
 716     return 0;
 717 }
 718
 719 static ImageInfoSpecific *
 720 block_crypto_get_specific_info_luks(BlockDriverState *bs, Error **errp)
 721 {
 722     BlockCrypto *crypto = bs->opaque;
 723     ImageInfoSpecific *spec_info;
 724     QCryptoBlockInfo *info;
 725
 726     info = qcrypto_block_get_info(crypto->block, errp);
 727     if (!info) {
 728         return NULL;
 729     }
 730     assert(info->format == Q_CRYPTO_BLOCK_FORMAT_LUKS);
 731
 732     spec_info = g_new(ImageInfoSpecific, 1);
 733     spec_info->type = IMAGE_INFO_SPECIFIC_KIND_LUKS;
 734     spec_info->u.luks.data = g_new(QCryptoBlockInfoLUKS, 1);
 735     *spec_info->u.luks.data = info->u.luks;
 736
 737     /* Blank out pointers we've just stolen to avoid double free */
 738     memset(&info->u.luks, 0, sizeof(info->u.luks));
 739
 740     qapi_free_QCryptoBlockInfo(info);
 741
 742     return spec_info;
 743 }
 744
 745 static const char *const block_crypto_strong_runtime_opts[] = {
 746     BLOCK_CRYPTO_OPT_LUKS_KEY_SECRET,
 747
 748     NULL
 749 };
 750
 751 static BlockDriver bdrv_crypto_luks = {
 752     .format_name        = "luks",
 753     .instance_size      = sizeof(BlockCrypto),
 754     .bdrv_probe         = block_crypto_probe_luks,
 755     .bdrv_open          = block_crypto_open_luks,
 756     .bdrv_close         = block_crypto_close,
 757     /* This driver doesn't modify LUKS metadata except when creating image.
 758      * Allow share-rw=on as a special case. */
 759     .bdrv_child_perm    = bdrv_default_perms,
 760     .bdrv_co_create     = block_crypto_co_create_luks,
 761     .bdrv_co_create_opts = block_crypto_co_create_opts_luks,
 762     .bdrv_co_truncate   = block_crypto_co_truncate,
 763     .create_opts        = &block_crypto_create_opts_luks,
 764
 765     .bdrv_reopen_prepare = block_crypto_reopen_prepare,
 766     .bdrv_refresh_limits = block_crypto_refresh_limits,
 767     .bdrv_co_preadv     = block_crypto_co_preadv,
 768     .bdrv_co_pwritev    = block_crypto_co_pwritev,
 769     .bdrv_getlength     = block_crypto_getlength,
 770     .bdrv_measure       = block_crypto_measure,
 771     .bdrv_get_info      = block_crypto_get_info_luks,
 772     .bdrv_get_specific_info = block_crypto_get_specific_info_luks,
 773
 774     .is_format          = true,
 775
 776     .strong_runtime_opts = block_crypto_strong_runtime_opts,
 777 };
 778
 779 static void block_crypto_init(void)
 780 {
 781     bdrv_register(&bdrv_crypto_luks);
 782 }
 783
 784 block_init(block_crypto_init);