From: Hyman Huang <yong.hu...@smartx.com>
Firstly, enable the ability to choose the block device containing
a detachable LUKS header by adding the 'header' parameter to
BlockdevCreateOptionsLUKS.
Secondly, when formatting the LUKS volume with a detachable header,
truncate the payload volume to length without a header size.
Using the qmp blockdev command, create the LUKS volume with a
detachable header as follows:
1. add the secret to lock/unlock the cipher stored in the
detached LUKS header
$ virsh qemu-monitor-command vm '{"execute":"object-add",
> "arguments":{"qom-type": "secret", "id": "sec0", "data": "foo"}}'
2. create a header img with 0 size
$ virsh qemu-monitor-command vm '{"execute":"blockdev-create",
> "arguments":{"job-id":"job0", "options":{"driver":"file",
> "filename":"/path/to/detached_luks_header.img", "size":0 }}}'
3. add protocol blockdev node for header
$ virsh qemu-monitor-command vm '{"execute":"blockdev-add",
> "arguments": {"driver":"file", "filename":
> "/path/to/detached_luks_header.img", "node-name":
> "detached-luks-header-storage"}}'
4. create a payload img with 0 size
$ virsh qemu-monitor-command vm '{"execute":"blockdev-create",
> "arguments":{"job-id":"job1", "options":{"driver":"file",
> "filename":"/path/to/detached_luks_payload_raw.img", "size":0}}}'
5. add protocol blockdev node for payload
$ virsh qemu-monitor-command vm '{"execute":"blockdev-add",
> "arguments": {"driver":"file", "filename":
> "/path/to/detached_luks_payload_raw.img", "node-name":
> "luks-payload-raw-storage"}}'
6. do the formatting with 128M size
$ virsh qemu-monitor-command c81_node1 '{"execute":"blockdev-create",
> "arguments":{"job-id":"job2", "options":{"driver":"luks", "header":
> "detached-luks-header-storage", "file":"luks-payload-raw-storage",
> "size":134217728, "preallocation":"full", "key-secret":"sec0" }}}'
Signed-off-by: Hyman Huang <yong.hu...@smartx.com>
Reviewed-by: Daniel P. Berrangé <berra...@redhat.com>
Signed-off-by: Daniel P. Berrangé <berra...@redhat.com>
---
block/crypto.c | 101 +++++++++++++++++++++++++++++++++++++++----
qapi/block-core.json | 3 ++
2 files changed, 96 insertions(+), 8 deletions(-)
diff --git a/block/crypto.c b/block/crypto.c
index 1b3f87922a..8e7ee5e9ac 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -162,6 +162,48 @@ error:
return ret;
}
+static int coroutine_fn GRAPH_UNLOCKED
+block_crypto_co_format_luks_payload(BlockdevCreateOptionsLUKS *luks_opts,
+ Error **errp)
+{
+ BlockDriverState *bs = NULL;
+ BlockBackend *blk = NULL;
+ Error *local_error = NULL;
+ int ret;
+
+ if (luks_opts->size > INT64_MAX) {
+ return -EFBIG;
+ }
+
+ bs = bdrv_co_open_blockdev_ref(luks_opts->file, errp);
+ if (bs == NULL) {
+ return -EIO;
+ }
+
+ blk = blk_co_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE,
+ BLK_PERM_ALL, errp);
+ if (!blk) {
+ ret = -EPERM;
+ goto fail;
+ }
+
+ ret = blk_truncate(blk, luks_opts->size, true,
+ luks_opts->preallocation, 0, &local_error);
+ if (ret < 0) {
+ if (ret == -EFBIG) {
+ /* Replace the error message with a better one */
+ error_free(local_error);
+ error_setg(errp, "The requested file size is too large");
+ }
+ goto fail;
+ }
+
+ ret = 0;
+
+fail:
+ bdrv_co_unref(bs);
+ return ret;
+}
static QemuOptsList block_crypto_runtime_opts_luks = {
.name = "crypto",
@@ -341,7 +383,9 @@ static int block_crypto_open_generic(QCryptoBlockFormat
format,
static int coroutine_fn GRAPH_UNLOCKED
block_crypto_co_create_generic(BlockDriverState *bs, int64_t size,
QCryptoBlockCreateOptions *opts,
- PreallocMode prealloc, Error **errp)
+ PreallocMode prealloc,
+ unsigned int flags,
+ Error **errp)
{
int ret;
BlockBackend *blk;
@@ -369,7 +413,7 @@ block_crypto_co_create_generic(BlockDriverState *bs,
int64_t size,
block_crypto_create_init_func,
block_crypto_create_write_func,
&data,
- 0,
+ flags,
errp);
if (!crypto) {
@@ -656,16 +700,26 @@ static int coroutine_fn GRAPH_UNLOCKED
block_crypto_co_create_luks(BlockdevCreateOptions *create_options, Error
**errp)
{
BlockdevCreateOptionsLUKS *luks_opts;
+ BlockDriverState *hdr_bs = NULL;
BlockDriverState *bs = NULL;
QCryptoBlockCreateOptions create_opts;
PreallocMode preallocation = PREALLOC_MODE_OFF;
+ unsigned int cflags = 0;
int ret;
assert(create_options->driver == BLOCKDEV_DRIVER_LUKS);
luks_opts = &create_options->u.luks;
- if (luks_opts->file == NULL) {
- error_setg(errp, "Formatting LUKS disk requires parameter 'file'");
+ if (luks_opts->header == NULL && luks_opts->file == NULL) {
+ error_setg(errp, "Either the parameter 'header' or 'file' must "
+ "be specified");
+ return -EINVAL;
+ }
+
+ if ((luks_opts->preallocation != PREALLOC_MODE_OFF) &&
+ (luks_opts->file == NULL)) {
+ error_setg(errp, "Parameter 'preallocation' requires 'file' to be "
+ "specified for formatting LUKS disk");
return -EINVAL;
}
@@ -678,14 +732,38 @@ block_crypto_co_create_luks(BlockdevCreateOptions
*create_options, Error **errp)
preallocation = luks_opts->preallocation;
}
- if (luks_opts->file) {
+ if (luks_opts->header) {
+ /* LUKS volume with detached header */
+ hdr_bs = bdrv_co_open_blockdev_ref(luks_opts->header, errp);
+ if (hdr_bs == NULL) {
+ return -EIO;
+ }
+
+ cflags |= QCRYPTO_BLOCK_CREATE_DETACHED;
+
+ /* Format the LUKS header node */
+ ret = block_crypto_co_create_generic(hdr_bs, 0, &create_opts,
+ PREALLOC_MODE_OFF, cflags, errp);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ /* Format the LUKS payload node */
+ if (luks_opts->file) {
+ ret = block_crypto_co_format_luks_payload(luks_opts, errp);
+ if (ret < 0) {
+ goto fail;
+ }
+ }
+ } else if (luks_opts->file) {
+ /* LUKS volume with none-detached header */
bs = bdrv_co_open_blockdev_ref(luks_opts->file, errp);
if (bs == NULL) {
return -EIO;
}
ret = block_crypto_co_create_generic(bs, luks_opts->size, &create_opts,
- preallocation, errp);
+ preallocation, cflags, errp);
if (ret < 0) {
goto fail;
}
@@ -693,7 +771,13 @@ block_crypto_co_create_luks(BlockdevCreateOptions
*create_options, Error **errp)
ret = 0;
fail:
- bdrv_co_unref(bs);
+ if (hdr_bs != NULL) {
+ bdrv_co_unref(hdr_bs);
+ }
+
+ if (bs != NULL) {
+ bdrv_co_unref(bs);
+ }
return ret;
}
@@ -747,7 +831,8 @@ block_crypto_co_create_opts_luks(BlockDriver *drv, const
char *filename,
}
/* Create format layer */
- ret = block_crypto_co_create_generic(bs, size, create_opts, prealloc,
errp);
+ ret = block_crypto_co_create_generic(bs, size, create_opts,
+ prealloc, 0, errp);
if (ret < 0) {
goto fail;
}
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 77d1f50d55..e4ef36d2aa 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -4958,6 +4958,8 @@
# @file: Node to create the image format on, mandatory except when
# 'preallocation' is not requested
#
+# @header: Block device holding a detached LUKS header. (since 9.0)
+#
# @size: Size of the virtual disk in bytes
#
# @preallocation: Preallocation mode for the new image (since: 4.2)
@@ -4968,6 +4970,7 @@
{ 'struct': 'BlockdevCreateOptionsLUKS',
'base': 'QCryptoBlockCreateOptionsLUKS',
'data': { '*file': 'BlockdevRef',
+ '*header': 'BlockdevRef',
'size': 'size',
'*preallocation': 'PreallocMode' } }
--
2.43.0
