The qemu-img info command has the ability to expose format
specific metadata about volumes. Wire up this facility for
the LUKS driver to report on cipher configuration and key
slot usage.
$ qemu-img info ~/VirtualMachines/demo.luks
image: /home/berrange/VirtualMachines/demo.luks
file format: luks
virtual size: 98M (102760448 bytes)
disk size: 100M
encrypted: yes
Format specific information:
ivgen alg: plain64
hash alg: sha1
cipher alg: aes-128
uuid: 6ddee74b-3a22-408c-8909-6789d4fa2594
cipher mode: xts
slots:
[0]:
active: true
iters: 572706
key offset: 4096
stripes: 4000
[1]:
active: false
key offset: 135168
[2]:
active: false
key offset: 266240
[3]:
active: false
key offset: 397312
[4]:
active: false
key offset: 528384
[5]:
active: false
key offset: 659456
[6]:
active: false
key offset: 790528
[7]:
active: false
key offset: 921600
payload offset: 2097152
master key iters: 142375
One somewhat undesirable artifact is that the data fields are
printed out in (apparently) random order. This will be addressed
later by changing the way the block layer pretty-prints the
image specific data.
Signed-off-by: Daniel P. Berrange <berra...@redhat.com>
---
block/crypto.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++
qapi/block-core.json | 7 ++++++-
2 files changed, 65 insertions(+), 1 deletion(-)
diff --git a/block/crypto.c b/block/crypto.c
index 758e14e..823572f 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -565,6 +565,63 @@ static int block_crypto_create_luks(const char *filename,
filename, opts, errp);
}
+static int block_crypto_get_info_luks(BlockDriverState *bs,
+ BlockDriverInfo *bdi)
+{
+ BlockDriverInfo subbdi;
+ int ret;
+
+ ret = bdrv_get_info(bs->file->bs, &subbdi);
+ if (ret != 0) {
+ return ret;
+ }
+
+ bdi->unallocated_blocks_are_zero = false;
+ bdi->can_write_zeroes_with_unmap = false;
+ bdi->cluster_size = subbdi.cluster_size;
+
+ return 0;
+}
+
+static ImageInfoSpecific *
+block_crypto_get_specific_info_luks(BlockDriverState *bs)
+{
+ BlockCrypto *crypto = bs->opaque;
+ ImageInfoSpecific *spec_info;
+ QCryptoBlockInfo *info;
+
+ info = qcrypto_block_get_info(crypto->block, NULL);
+ if (!info) {
+ return NULL;
+ }
+ if (info->format != Q_CRYPTO_BLOCK_FORMAT_LUKS) {
+ qapi_free_QCryptoBlockInfo(info);
+ return NULL;
+ }
+
+ spec_info = g_new(ImageInfoSpecific, 1);
+ spec_info->type = IMAGE_INFO_SPECIFIC_KIND_LUKS;
+ spec_info->u.luks.data = g_new(QCryptoBlockInfoLUKS, 1);
+ spec_info->u.luks.data->cipher_alg = info->u.luks.cipher_alg;
+ spec_info->u.luks.data->cipher_mode = info->u.luks.cipher_mode;
+ spec_info->u.luks.data->ivgen_alg = info->u.luks.ivgen_alg;
+ spec_info->u.luks.data->has_ivgen_hash_alg =
+ info->u.luks.has_ivgen_hash_alg;
+ spec_info->u.luks.data->ivgen_hash_alg = info->u.luks.ivgen_hash_alg;
+ spec_info->u.luks.data->hash_alg = info->u.luks.hash_alg;
+ spec_info->u.luks.data->payload_offset = info->u.luks.payload_offset;
+ spec_info->u.luks.data->master_key_iters = info->u.luks.master_key_iters;
+ spec_info->u.luks.data->uuid = g_strdup(info->u.luks.uuid);
+
+ /* Steal the pointer instead of bothering to copy */
+ spec_info->u.luks.data->slots = info->u.luks.slots;
+ info->u.luks.slots = NULL;
+
+ qapi_free_QCryptoBlockInfo(info);
+
+ return spec_info;
+}
+
BlockDriver bdrv_crypto_luks = {
.format_name = "luks",
.instance_size = sizeof(BlockCrypto),
@@ -578,6 +635,8 @@ BlockDriver bdrv_crypto_luks = {
.bdrv_co_readv = block_crypto_co_readv,
.bdrv_co_writev = block_crypto_co_writev,
.bdrv_getlength = block_crypto_getlength,
+ .bdrv_get_info = block_crypto_get_info_luks,
+ .bdrv_get_specific_info = block_crypto_get_specific_info_luks,
};
static void block_crypto_init(void)
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 98a20d2..959dd8b 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -74,6 +74,7 @@
'extents': ['ImageInfo']
} }
+
##
# @ImageInfoSpecific:
#
@@ -85,7 +86,11 @@
{ 'union': 'ImageInfoSpecific',
'data': {
'qcow2': 'ImageInfoSpecificQCow2',
- 'vmdk': 'ImageInfoSpecificVmdk'
+ 'vmdk': 'ImageInfoSpecificVmdk',
+ # If we need to add block driver specific parameters for
+ # LUKS in future, then we'll subclass QCryptoBlockInfoLUKS
+ # to define a ImageInfoSpecificLUKS
+ 'luks': 'QCryptoBlockInfoLUKS'
} }
##
--
2.5.5
