docs/interop: Delete qmp-intro.txt
[qemu/ar7.git] / block / crypto.c
blob30093cff9b34e941f89d1257a4b930333d472ee9
1 /*
2 * QEMU block full disk encryption
4 * Copyright (c) 2015-2016 Red Hat, Inc.
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 2.1 of the License, or (at your option) any later version.
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.
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/>.
21 #include "qemu/osdep.h"
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 "qemu/memalign.h"
35 #include "crypto.h"
37 typedef struct BlockCrypto BlockCrypto;
39 struct BlockCrypto {
40 QCryptoBlock *block;
41 bool updating_keys;
45 static int block_crypto_probe_generic(QCryptoBlockFormat format,
46 const uint8_t *buf,
47 int buf_size,
48 const char *filename)
50 if (qcrypto_block_has_format(format, buf, buf_size)) {
51 return 100;
52 } else {
53 return 0;
58 static int block_crypto_read_func(QCryptoBlock *block,
59 size_t offset,
60 uint8_t *buf,
61 size_t buflen,
62 void *opaque,
63 Error **errp)
65 BlockDriverState *bs = opaque;
66 ssize_t ret;
68 ret = bdrv_pread(bs->file, offset, buflen, buf, 0);
69 if (ret < 0) {
70 error_setg_errno(errp, -ret, "Could not read encryption header");
71 return ret;
73 return 0;
76 static int block_crypto_write_func(QCryptoBlock *block,
77 size_t offset,
78 const uint8_t *buf,
79 size_t buflen,
80 void *opaque,
81 Error **errp)
83 BlockDriverState *bs = opaque;
84 ssize_t ret;
86 ret = bdrv_pwrite(bs->file, offset, buflen, buf, 0);
87 if (ret < 0) {
88 error_setg_errno(errp, -ret, "Could not write encryption header");
89 return ret;
91 return 0;
95 struct BlockCryptoCreateData {
96 BlockBackend *blk;
97 uint64_t size;
98 PreallocMode prealloc;
102 static int block_crypto_create_write_func(QCryptoBlock *block,
103 size_t offset,
104 const uint8_t *buf,
105 size_t buflen,
106 void *opaque,
107 Error **errp)
109 struct BlockCryptoCreateData *data = opaque;
110 ssize_t ret;
112 ret = blk_pwrite(data->blk, offset, buflen, buf, 0);
113 if (ret < 0) {
114 error_setg_errno(errp, -ret, "Could not write encryption header");
115 return ret;
117 return 0;
120 static int block_crypto_create_init_func(QCryptoBlock *block,
121 size_t headerlen,
122 void *opaque,
123 Error **errp)
125 struct BlockCryptoCreateData *data = opaque;
126 Error *local_error = NULL;
127 int ret;
129 if (data->size > INT64_MAX || headerlen > INT64_MAX - data->size) {
130 ret = -EFBIG;
131 goto error;
134 /* User provided size should reflect amount of space made
135 * available to the guest, so we must take account of that
136 * which will be used by the crypto header
138 ret = blk_truncate(data->blk, data->size + headerlen, false,
139 data->prealloc, 0, &local_error);
141 if (ret >= 0) {
142 return 0;
145 error:
146 if (ret == -EFBIG) {
147 /* Replace the error message with a better one */
148 error_free(local_error);
149 error_setg(errp, "The requested file size is too large");
150 } else {
151 error_propagate(errp, local_error);
154 return ret;
158 static QemuOptsList block_crypto_runtime_opts_luks = {
159 .name = "crypto",
160 .head = QTAILQ_HEAD_INITIALIZER(block_crypto_runtime_opts_luks.head),
161 .desc = {
162 BLOCK_CRYPTO_OPT_DEF_LUKS_KEY_SECRET(""),
163 { /* end of list */ }
168 static QemuOptsList block_crypto_create_opts_luks = {
169 .name = "crypto",
170 .head = QTAILQ_HEAD_INITIALIZER(block_crypto_create_opts_luks.head),
171 .desc = {
173 .name = BLOCK_OPT_SIZE,
174 .type = QEMU_OPT_SIZE,
175 .help = "Virtual disk size"
177 BLOCK_CRYPTO_OPT_DEF_LUKS_KEY_SECRET(""),
178 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_ALG(""),
179 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_MODE(""),
180 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_ALG(""),
181 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG(""),
182 BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG(""),
183 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME(""),
184 { /* end of list */ }
189 static QemuOptsList block_crypto_amend_opts_luks = {
190 .name = "crypto",
191 .head = QTAILQ_HEAD_INITIALIZER(block_crypto_create_opts_luks.head),
192 .desc = {
193 BLOCK_CRYPTO_OPT_DEF_LUKS_STATE(""),
194 BLOCK_CRYPTO_OPT_DEF_LUKS_KEYSLOT(""),
195 BLOCK_CRYPTO_OPT_DEF_LUKS_OLD_SECRET(""),
196 BLOCK_CRYPTO_OPT_DEF_LUKS_NEW_SECRET(""),
197 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME(""),
198 { /* end of list */ }
202 QCryptoBlockOpenOptions *
203 block_crypto_open_opts_init(QDict *opts, Error **errp)
205 Visitor *v;
206 QCryptoBlockOpenOptions *ret;
208 v = qobject_input_visitor_new_flat_confused(opts, errp);
209 if (!v) {
210 return NULL;
213 visit_type_QCryptoBlockOpenOptions(v, NULL, &ret, errp);
215 visit_free(v);
216 return ret;
220 QCryptoBlockCreateOptions *
221 block_crypto_create_opts_init(QDict *opts, Error **errp)
223 Visitor *v;
224 QCryptoBlockCreateOptions *ret;
226 v = qobject_input_visitor_new_flat_confused(opts, errp);
227 if (!v) {
228 return NULL;
231 visit_type_QCryptoBlockCreateOptions(v, NULL, &ret, errp);
233 visit_free(v);
234 return ret;
237 QCryptoBlockAmendOptions *
238 block_crypto_amend_opts_init(QDict *opts, Error **errp)
240 Visitor *v;
241 QCryptoBlockAmendOptions *ret;
243 v = qobject_input_visitor_new_flat_confused(opts, errp);
244 if (!v) {
245 return NULL;
248 visit_type_QCryptoBlockAmendOptions(v, NULL, &ret, errp);
250 visit_free(v);
251 return ret;
255 static int block_crypto_open_generic(QCryptoBlockFormat format,
256 QemuOptsList *opts_spec,
257 BlockDriverState *bs,
258 QDict *options,
259 int flags,
260 Error **errp)
262 BlockCrypto *crypto = bs->opaque;
263 QemuOpts *opts = NULL;
264 int ret;
265 QCryptoBlockOpenOptions *open_opts = NULL;
266 unsigned int cflags = 0;
267 QDict *cryptoopts = NULL;
269 ret = bdrv_open_file_child(NULL, options, "file", bs, errp);
270 if (ret < 0) {
271 return ret;
274 bs->supported_write_flags = BDRV_REQ_FUA &
275 bs->file->bs->supported_write_flags;
277 opts = qemu_opts_create(opts_spec, NULL, 0, &error_abort);
278 if (!qemu_opts_absorb_qdict(opts, options, errp)) {
279 ret = -EINVAL;
280 goto cleanup;
283 cryptoopts = qemu_opts_to_qdict(opts, NULL);
284 qdict_put_str(cryptoopts, "format", QCryptoBlockFormat_str(format));
286 open_opts = block_crypto_open_opts_init(cryptoopts, errp);
287 if (!open_opts) {
288 ret = -EINVAL;
289 goto cleanup;
292 if (flags & BDRV_O_NO_IO) {
293 cflags |= QCRYPTO_BLOCK_OPEN_NO_IO;
295 crypto->block = qcrypto_block_open(open_opts, NULL,
296 block_crypto_read_func,
298 cflags,
300 errp);
302 if (!crypto->block) {
303 ret = -EIO;
304 goto cleanup;
307 bs->encrypted = true;
309 ret = 0;
310 cleanup:
311 qobject_unref(cryptoopts);
312 qapi_free_QCryptoBlockOpenOptions(open_opts);
313 return ret;
317 static int coroutine_fn
318 block_crypto_co_create_generic(BlockDriverState *bs, int64_t size,
319 QCryptoBlockCreateOptions *opts,
320 PreallocMode prealloc, Error **errp)
322 int ret;
323 BlockBackend *blk;
324 QCryptoBlock *crypto = NULL;
325 struct BlockCryptoCreateData data;
327 blk = blk_co_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL,
328 errp);
329 if (!blk) {
330 ret = -EPERM;
331 goto cleanup;
334 if (prealloc == PREALLOC_MODE_METADATA) {
335 prealloc = PREALLOC_MODE_OFF;
338 data = (struct BlockCryptoCreateData) {
339 .blk = blk,
340 .size = size,
341 .prealloc = prealloc,
344 crypto = qcrypto_block_create(opts, NULL,
345 block_crypto_create_init_func,
346 block_crypto_create_write_func,
347 &data,
348 errp);
350 if (!crypto) {
351 ret = -EIO;
352 goto cleanup;
355 ret = 0;
356 cleanup:
357 qcrypto_block_free(crypto);
358 blk_co_unref(blk);
359 return ret;
362 static int coroutine_fn GRAPH_RDLOCK
363 block_crypto_co_truncate(BlockDriverState *bs, int64_t offset, bool exact,
364 PreallocMode prealloc, BdrvRequestFlags flags,
365 Error **errp)
367 BlockCrypto *crypto = bs->opaque;
368 uint64_t payload_offset =
369 qcrypto_block_get_payload_offset(crypto->block);
371 if (payload_offset > INT64_MAX - offset) {
372 error_setg(errp, "The requested file size is too large");
373 return -EFBIG;
376 offset += payload_offset;
378 return bdrv_co_truncate(bs->file, offset, exact, prealloc, 0, errp);
381 static void block_crypto_close(BlockDriverState *bs)
383 BlockCrypto *crypto = bs->opaque;
384 qcrypto_block_free(crypto->block);
387 static int block_crypto_reopen_prepare(BDRVReopenState *state,
388 BlockReopenQueue *queue, Error **errp)
390 /* nothing needs checking */
391 return 0;
395 * 1 MB bounce buffer gives good performance / memory tradeoff
396 * when using cache=none|directsync.
398 #define BLOCK_CRYPTO_MAX_IO_SIZE (1024 * 1024)
400 static int coroutine_fn GRAPH_RDLOCK
401 block_crypto_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
402 QEMUIOVector *qiov, BdrvRequestFlags flags)
404 BlockCrypto *crypto = bs->opaque;
405 uint64_t cur_bytes; /* number of bytes in current iteration */
406 uint64_t bytes_done = 0;
407 uint8_t *cipher_data = NULL;
408 QEMUIOVector hd_qiov;
409 int ret = 0;
410 uint64_t sector_size = qcrypto_block_get_sector_size(crypto->block);
411 uint64_t payload_offset = qcrypto_block_get_payload_offset(crypto->block);
413 assert(payload_offset < INT64_MAX);
414 assert(QEMU_IS_ALIGNED(offset, sector_size));
415 assert(QEMU_IS_ALIGNED(bytes, sector_size));
417 qemu_iovec_init(&hd_qiov, qiov->niov);
419 /* Bounce buffer because we don't wish to expose cipher text
420 * in qiov which points to guest memory.
422 cipher_data =
423 qemu_try_blockalign(bs->file->bs, MIN(BLOCK_CRYPTO_MAX_IO_SIZE,
424 qiov->size));
425 if (cipher_data == NULL) {
426 ret = -ENOMEM;
427 goto cleanup;
430 while (bytes) {
431 cur_bytes = MIN(bytes, BLOCK_CRYPTO_MAX_IO_SIZE);
433 qemu_iovec_reset(&hd_qiov);
434 qemu_iovec_add(&hd_qiov, cipher_data, cur_bytes);
436 ret = bdrv_co_preadv(bs->file, payload_offset + offset + bytes_done,
437 cur_bytes, &hd_qiov, 0);
438 if (ret < 0) {
439 goto cleanup;
442 if (qcrypto_block_decrypt(crypto->block, offset + bytes_done,
443 cipher_data, cur_bytes, NULL) < 0) {
444 ret = -EIO;
445 goto cleanup;
448 qemu_iovec_from_buf(qiov, bytes_done, cipher_data, cur_bytes);
450 bytes -= cur_bytes;
451 bytes_done += cur_bytes;
454 cleanup:
455 qemu_iovec_destroy(&hd_qiov);
456 qemu_vfree(cipher_data);
458 return ret;
462 static int coroutine_fn GRAPH_RDLOCK
463 block_crypto_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
464 QEMUIOVector *qiov, BdrvRequestFlags flags)
466 BlockCrypto *crypto = bs->opaque;
467 uint64_t cur_bytes; /* number of bytes in current iteration */
468 uint64_t bytes_done = 0;
469 uint8_t *cipher_data = NULL;
470 QEMUIOVector hd_qiov;
471 int ret = 0;
472 uint64_t sector_size = qcrypto_block_get_sector_size(crypto->block);
473 uint64_t payload_offset = qcrypto_block_get_payload_offset(crypto->block);
475 flags &= ~BDRV_REQ_REGISTERED_BUF;
477 assert(payload_offset < INT64_MAX);
478 assert(QEMU_IS_ALIGNED(offset, sector_size));
479 assert(QEMU_IS_ALIGNED(bytes, sector_size));
481 qemu_iovec_init(&hd_qiov, qiov->niov);
483 /* Bounce buffer because we're not permitted to touch
484 * contents of qiov - it points to guest memory.
486 cipher_data =
487 qemu_try_blockalign(bs->file->bs, MIN(BLOCK_CRYPTO_MAX_IO_SIZE,
488 qiov->size));
489 if (cipher_data == NULL) {
490 ret = -ENOMEM;
491 goto cleanup;
494 while (bytes) {
495 cur_bytes = MIN(bytes, BLOCK_CRYPTO_MAX_IO_SIZE);
497 qemu_iovec_to_buf(qiov, bytes_done, cipher_data, cur_bytes);
499 if (qcrypto_block_encrypt(crypto->block, offset + bytes_done,
500 cipher_data, cur_bytes, NULL) < 0) {
501 ret = -EIO;
502 goto cleanup;
505 qemu_iovec_reset(&hd_qiov);
506 qemu_iovec_add(&hd_qiov, cipher_data, cur_bytes);
508 ret = bdrv_co_pwritev(bs->file, payload_offset + offset + bytes_done,
509 cur_bytes, &hd_qiov, flags);
510 if (ret < 0) {
511 goto cleanup;
514 bytes -= cur_bytes;
515 bytes_done += cur_bytes;
518 cleanup:
519 qemu_iovec_destroy(&hd_qiov);
520 qemu_vfree(cipher_data);
522 return ret;
525 static void block_crypto_refresh_limits(BlockDriverState *bs, Error **errp)
527 BlockCrypto *crypto = bs->opaque;
528 uint64_t sector_size = qcrypto_block_get_sector_size(crypto->block);
529 bs->bl.request_alignment = sector_size; /* No sub-sector I/O */
533 static int64_t coroutine_fn GRAPH_RDLOCK
534 block_crypto_co_getlength(BlockDriverState *bs)
536 BlockCrypto *crypto = bs->opaque;
537 int64_t len = bdrv_co_getlength(bs->file->bs);
539 uint64_t offset = qcrypto_block_get_payload_offset(crypto->block);
540 assert(offset < INT64_MAX);
542 if (offset > len) {
543 return -EIO;
546 len -= offset;
548 return len;
552 static BlockMeasureInfo *block_crypto_measure(QemuOpts *opts,
553 BlockDriverState *in_bs,
554 Error **errp)
556 g_autoptr(QCryptoBlockCreateOptions) create_opts = NULL;
557 Error *local_err = NULL;
558 BlockMeasureInfo *info;
559 uint64_t size;
560 size_t luks_payload_size;
561 QDict *cryptoopts;
564 * Preallocation mode doesn't affect size requirements but we must consume
565 * the option.
567 g_free(qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC));
569 size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0);
571 if (in_bs) {
572 int64_t ssize = bdrv_getlength(in_bs);
574 if (ssize < 0) {
575 error_setg_errno(&local_err, -ssize,
576 "Unable to get image virtual_size");
577 goto err;
580 size = ssize;
583 cryptoopts = qemu_opts_to_qdict_filtered(opts, NULL,
584 &block_crypto_create_opts_luks, true);
585 qdict_put_str(cryptoopts, "format", "luks");
586 create_opts = block_crypto_create_opts_init(cryptoopts, &local_err);
587 qobject_unref(cryptoopts);
588 if (!create_opts) {
589 goto err;
592 if (!qcrypto_block_calculate_payload_offset(create_opts, NULL,
593 &luks_payload_size,
594 &local_err)) {
595 goto err;
599 * Unallocated blocks are still encrypted so allocation status makes no
600 * difference to the file size.
602 info = g_new0(BlockMeasureInfo, 1);
603 info->fully_allocated = luks_payload_size + size;
604 info->required = luks_payload_size + size;
605 return info;
607 err:
608 error_propagate(errp, local_err);
609 return NULL;
613 static int block_crypto_probe_luks(const uint8_t *buf,
614 int buf_size,
615 const char *filename) {
616 return block_crypto_probe_generic(Q_CRYPTO_BLOCK_FORMAT_LUKS,
617 buf, buf_size, filename);
620 static int block_crypto_open_luks(BlockDriverState *bs,
621 QDict *options,
622 int flags,
623 Error **errp)
625 return block_crypto_open_generic(Q_CRYPTO_BLOCK_FORMAT_LUKS,
626 &block_crypto_runtime_opts_luks,
627 bs, options, flags, errp);
630 static int coroutine_fn
631 block_crypto_co_create_luks(BlockdevCreateOptions *create_options, Error **errp)
633 BlockdevCreateOptionsLUKS *luks_opts;
634 BlockDriverState *bs = NULL;
635 QCryptoBlockCreateOptions create_opts;
636 PreallocMode preallocation = PREALLOC_MODE_OFF;
637 int ret;
639 assert(create_options->driver == BLOCKDEV_DRIVER_LUKS);
640 luks_opts = &create_options->u.luks;
642 bs = bdrv_co_open_blockdev_ref(luks_opts->file, errp);
643 if (bs == NULL) {
644 return -EIO;
647 create_opts = (QCryptoBlockCreateOptions) {
648 .format = Q_CRYPTO_BLOCK_FORMAT_LUKS,
649 .u.luks = *qapi_BlockdevCreateOptionsLUKS_base(luks_opts),
652 if (luks_opts->has_preallocation) {
653 preallocation = luks_opts->preallocation;
656 ret = block_crypto_co_create_generic(bs, luks_opts->size, &create_opts,
657 preallocation, errp);
658 if (ret < 0) {
659 goto fail;
662 ret = 0;
663 fail:
664 bdrv_co_unref(bs);
665 return ret;
668 static int coroutine_fn GRAPH_RDLOCK
669 block_crypto_co_create_opts_luks(BlockDriver *drv, const char *filename,
670 QemuOpts *opts, Error **errp)
672 QCryptoBlockCreateOptions *create_opts = NULL;
673 BlockDriverState *bs = NULL;
674 QDict *cryptoopts;
675 PreallocMode prealloc;
676 char *buf = NULL;
677 int64_t size;
678 int ret;
679 Error *local_err = NULL;
681 /* Parse options */
682 size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0);
684 buf = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
685 prealloc = qapi_enum_parse(&PreallocMode_lookup, buf,
686 PREALLOC_MODE_OFF, &local_err);
687 g_free(buf);
688 if (local_err) {
689 error_propagate(errp, local_err);
690 return -EINVAL;
693 cryptoopts = qemu_opts_to_qdict_filtered(opts, NULL,
694 &block_crypto_create_opts_luks,
695 true);
697 qdict_put_str(cryptoopts, "format", "luks");
698 create_opts = block_crypto_create_opts_init(cryptoopts, errp);
699 if (!create_opts) {
700 ret = -EINVAL;
701 goto fail;
704 /* Create protocol layer */
705 ret = bdrv_co_create_file(filename, opts, errp);
706 if (ret < 0) {
707 goto fail;
710 bs = bdrv_co_open(filename, NULL, NULL,
711 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
712 if (!bs) {
713 ret = -EINVAL;
714 goto fail;
717 /* Create format layer */
718 ret = block_crypto_co_create_generic(bs, size, create_opts, prealloc, errp);
719 if (ret < 0) {
720 goto fail;
723 ret = 0;
724 fail:
726 * If an error occurred, delete 'filename'. Even if the file existed
727 * beforehand, it has been truncated and corrupted in the process.
729 if (ret) {
730 bdrv_co_delete_file_noerr(bs);
733 bdrv_co_unref(bs);
734 qapi_free_QCryptoBlockCreateOptions(create_opts);
735 qobject_unref(cryptoopts);
736 return ret;
739 static int coroutine_fn GRAPH_RDLOCK
740 block_crypto_co_get_info_luks(BlockDriverState *bs, BlockDriverInfo *bdi)
742 BlockDriverInfo subbdi;
743 int ret;
745 ret = bdrv_co_get_info(bs->file->bs, &subbdi);
746 if (ret != 0) {
747 return ret;
750 bdi->cluster_size = subbdi.cluster_size;
752 return 0;
755 static ImageInfoSpecific *
756 block_crypto_get_specific_info_luks(BlockDriverState *bs, Error **errp)
758 BlockCrypto *crypto = bs->opaque;
759 ImageInfoSpecific *spec_info;
760 QCryptoBlockInfo *info;
762 info = qcrypto_block_get_info(crypto->block, errp);
763 if (!info) {
764 return NULL;
766 assert(info->format == Q_CRYPTO_BLOCK_FORMAT_LUKS);
768 spec_info = g_new(ImageInfoSpecific, 1);
769 spec_info->type = IMAGE_INFO_SPECIFIC_KIND_LUKS;
770 spec_info->u.luks.data = g_new(QCryptoBlockInfoLUKS, 1);
771 *spec_info->u.luks.data = info->u.luks;
773 /* Blank out pointers we've just stolen to avoid double free */
774 memset(&info->u.luks, 0, sizeof(info->u.luks));
776 qapi_free_QCryptoBlockInfo(info);
778 return spec_info;
781 static int
782 block_crypto_amend_prepare(BlockDriverState *bs, Error **errp)
784 BlockCrypto *crypto = bs->opaque;
785 int ret;
787 /* apply for exclusive read/write permissions to the underlying file */
788 crypto->updating_keys = true;
789 ret = bdrv_child_refresh_perms(bs, bs->file, errp);
790 if (ret < 0) {
791 /* Well, in this case we will not be updating any keys */
792 crypto->updating_keys = false;
794 return ret;
797 static void
798 block_crypto_amend_cleanup(BlockDriverState *bs)
800 BlockCrypto *crypto = bs->opaque;
801 Error *errp = NULL;
803 /* release exclusive read/write permissions to the underlying file */
804 crypto->updating_keys = false;
805 bdrv_child_refresh_perms(bs, bs->file, &errp);
807 if (errp) {
808 error_report_err(errp);
812 static int
813 block_crypto_amend_options_generic_luks(BlockDriverState *bs,
814 QCryptoBlockAmendOptions *amend_options,
815 bool force,
816 Error **errp)
818 BlockCrypto *crypto = bs->opaque;
820 assert(crypto);
821 assert(crypto->block);
823 return qcrypto_block_amend_options(crypto->block,
824 block_crypto_read_func,
825 block_crypto_write_func,
827 amend_options,
828 force,
829 errp);
832 static int
833 block_crypto_amend_options_luks(BlockDriverState *bs,
834 QemuOpts *opts,
835 BlockDriverAmendStatusCB *status_cb,
836 void *cb_opaque,
837 bool force,
838 Error **errp)
840 BlockCrypto *crypto = bs->opaque;
841 QDict *cryptoopts = NULL;
842 QCryptoBlockAmendOptions *amend_options = NULL;
843 int ret = -EINVAL;
845 assert(crypto);
846 assert(crypto->block);
848 cryptoopts = qemu_opts_to_qdict(opts, NULL);
849 qdict_put_str(cryptoopts, "format", "luks");
850 amend_options = block_crypto_amend_opts_init(cryptoopts, errp);
851 qobject_unref(cryptoopts);
852 if (!amend_options) {
853 goto cleanup;
856 ret = block_crypto_amend_prepare(bs, errp);
857 if (ret) {
858 goto perm_cleanup;
860 ret = block_crypto_amend_options_generic_luks(bs, amend_options,
861 force, errp);
863 perm_cleanup:
864 block_crypto_amend_cleanup(bs);
865 cleanup:
866 qapi_free_QCryptoBlockAmendOptions(amend_options);
867 return ret;
870 static int
871 coroutine_fn block_crypto_co_amend_luks(BlockDriverState *bs,
872 BlockdevAmendOptions *opts,
873 bool force,
874 Error **errp)
876 QCryptoBlockAmendOptions amend_opts;
878 amend_opts = (QCryptoBlockAmendOptions) {
879 .format = Q_CRYPTO_BLOCK_FORMAT_LUKS,
880 .u.luks = *qapi_BlockdevAmendOptionsLUKS_base(&opts->u.luks),
882 return block_crypto_amend_options_generic_luks(bs, &amend_opts,
883 force, errp);
886 static void
887 block_crypto_child_perms(BlockDriverState *bs, BdrvChild *c,
888 const BdrvChildRole role,
889 BlockReopenQueue *reopen_queue,
890 uint64_t perm, uint64_t shared,
891 uint64_t *nperm, uint64_t *nshared)
894 BlockCrypto *crypto = bs->opaque;
896 bdrv_default_perms(bs, c, role, reopen_queue, perm, shared, nperm, nshared);
899 * For backward compatibility, manually share the write
900 * and resize permission
902 *nshared |= shared & (BLK_PERM_WRITE | BLK_PERM_RESIZE);
904 * Since we are not fully a format driver, don't always request
905 * the read/resize permission but only when explicitly
906 * requested
908 *nperm &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE);
909 *nperm |= perm & (BLK_PERM_WRITE | BLK_PERM_RESIZE);
912 * This driver doesn't modify LUKS metadata except
913 * when updating the encryption slots.
914 * Thus unlike a proper format driver we don't ask for
915 * shared write/read permission. However we need it
916 * when we are updating the keys, to ensure that only we
917 * have access to the device.
919 * Encryption update will set the crypto->updating_keys
920 * during that period and refresh permissions
923 if (crypto->updating_keys) {
924 /* need exclusive write access for header update */
925 *nperm |= BLK_PERM_WRITE;
926 /* unshare read and write permission */
927 *nshared &= ~(BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE);
932 static const char *const block_crypto_strong_runtime_opts[] = {
933 BLOCK_CRYPTO_OPT_LUKS_KEY_SECRET,
935 NULL
938 static BlockDriver bdrv_crypto_luks = {
939 .format_name = "luks",
940 .instance_size = sizeof(BlockCrypto),
941 .bdrv_probe = block_crypto_probe_luks,
942 .bdrv_open = block_crypto_open_luks,
943 .bdrv_close = block_crypto_close,
944 .bdrv_child_perm = block_crypto_child_perms,
945 .bdrv_co_create = block_crypto_co_create_luks,
946 .bdrv_co_create_opts = block_crypto_co_create_opts_luks,
947 .bdrv_co_truncate = block_crypto_co_truncate,
948 .create_opts = &block_crypto_create_opts_luks,
949 .amend_opts = &block_crypto_amend_opts_luks,
951 .bdrv_reopen_prepare = block_crypto_reopen_prepare,
952 .bdrv_refresh_limits = block_crypto_refresh_limits,
953 .bdrv_co_preadv = block_crypto_co_preadv,
954 .bdrv_co_pwritev = block_crypto_co_pwritev,
955 .bdrv_co_getlength = block_crypto_co_getlength,
956 .bdrv_measure = block_crypto_measure,
957 .bdrv_co_get_info = block_crypto_co_get_info_luks,
958 .bdrv_get_specific_info = block_crypto_get_specific_info_luks,
959 .bdrv_amend_options = block_crypto_amend_options_luks,
960 .bdrv_co_amend = block_crypto_co_amend_luks,
961 .bdrv_amend_pre_run = block_crypto_amend_prepare,
962 .bdrv_amend_clean = block_crypto_amend_cleanup,
964 .is_format = true,
966 .strong_runtime_opts = block_crypto_strong_runtime_opts,
969 static void block_crypto_init(void)
971 bdrv_register(&bdrv_crypto_luks);
974 block_init(block_crypto_init);