On 14.06.2016 12:56, Daniel P. Berrange wrote:
> 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;
One space too many.
> + 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;
Why not just steal everything by *spec_info->u.luks.data = info->u.luks
and then making sure the qapi_free() call below won't free anything in
there with a memset(&info->u.luks, 0, sizeof(info->u.luks))?
> +
> + 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:
> #
This hunk looks unnecessary.
Max
> @@ -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'
> } }
>
> ##
>
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