[dm-devel] [PATCH] cryptsetup: add support for the "fix_padding" option
Mikulas Patocka
mpatocka at redhat.com
Wed Nov 13 11:57:12 UTC 2019
This patch adds support for fixed padding to cryptsetup.
* Cryptsetup will accept superblocks version 4.
* If the dm-integrity target version is greater than 1.4, cryptsetup will
add a flag "fix_padding" to the dm-integrity target arguments.
There is still one quirk: if we have an old libdm without
DM_DEVICE_GET_TARGET_VERSION and if dm-integrity module is not loaded,
cryptsetup will not detect that it can use the "fix_padding" option.
Signed-off-by: Mikulas Patocka <mpatocka at redhat.com>
---
lib/integrity/integrity.c | 7 +++----
lib/integrity/integrity.h | 2 ++
lib/libdevmapper.c | 20 +++++++++++++++++++-
lib/utils_dm.h | 6 +++++-
4 files changed, 29 insertions(+), 6 deletions(-)
Index: cryptsetup/lib/integrity/integrity.c
===================================================================
--- cryptsetup.orig/lib/integrity/integrity.c 2019-11-12 20:09:30.000000000 +0100
+++ cryptsetup/lib/integrity/integrity.c 2019-11-12 21:09:05.000000000 +0100
@@ -41,8 +41,7 @@ static int INTEGRITY_read_superblock(str
if (read_lseek_blockwise(devfd, device_block_size(cd, device),
device_alignment(device), sb, sizeof(*sb), offset) != sizeof(*sb) ||
memcmp(sb->magic, SB_MAGIC, sizeof(sb->magic)) ||
- (sb->version != SB_VERSION_1 && sb->version != SB_VERSION_2 &&
- sb->version != SB_VERSION_3)) {
+ sb->version < SB_VERSION_1 || sb->version > SB_VERSION_4) {
log_std(cd, "No integrity superblock detected on %s.\n",
device_path(device));
r = -EINVAL;
@@ -203,7 +202,7 @@ int INTEGRITY_create_dmd_device(struct c
if (r < 0)
return r;
- return dm_integrity_target_set(&dmd->segment, 0, dmd->size,
+ return dm_integrity_target_set(cd, &dmd->segment, 0, dmd->size,
crypt_metadata_device(cd), crypt_data_device(cd),
crypt_get_integrity_tag_size(cd), crypt_get_data_offset(cd),
crypt_get_sector_size(cd), vk, journal_crypt_key,
@@ -289,7 +288,7 @@ int INTEGRITY_format(struct crypt_device
if (params && params->integrity_key_size)
vk = crypt_alloc_volume_key(params->integrity_key_size, NULL);
- r = dm_integrity_target_set(tgt, 0, dmdi.size, crypt_metadata_device(cd),
+ r = dm_integrity_target_set(cd, tgt, 0, dmdi.size, crypt_metadata_device(cd),
crypt_data_device(cd), crypt_get_integrity_tag_size(cd),
crypt_get_data_offset(cd), crypt_get_sector_size(cd), vk,
journal_crypt_key, journal_mac_key, params);
Index: cryptsetup/lib/integrity/integrity.h
===================================================================
--- cryptsetup.orig/lib/integrity/integrity.h 2019-11-12 20:09:30.000000000 +0100
+++ cryptsetup/lib/integrity/integrity.h 2019-11-12 20:12:54.000000000 +0100
@@ -34,10 +34,12 @@ struct crypt_dm_active_device;
#define SB_VERSION_1 1
#define SB_VERSION_2 2
#define SB_VERSION_3 3
+#define SB_VERSION_4 4
#define SB_FLAG_HAVE_JOURNAL_MAC (1 << 0)
#define SB_FLAG_RECALCULATING (1 << 1) /* V2 only */
#define SB_FLAG_DIRTY_BITMAP (1 << 2) /* V3 only */
+#define SB_FLAG_FIXED_PADDING (1 << 3) /* V4 only */
struct superblock {
uint8_t magic[8];
Index: cryptsetup/lib/libdevmapper.c
===================================================================
--- cryptsetup.orig/lib/libdevmapper.c 2019-11-12 20:09:30.000000000 +0100
+++ cryptsetup/lib/libdevmapper.c 2019-11-13 12:42:39.000000000 +0100
@@ -218,6 +218,9 @@ static void _dm_set_integrity_compat(str
if (_dm_satisfies_version(1, 3, 0, integrity_maj, integrity_min, integrity_patch))
_dm_flags |= DM_INTEGRITY_BITMAP_SUPPORTED;
+ if (_dm_satisfies_version(1, 4, 0, integrity_maj, integrity_min, integrity_patch))
+ _dm_flags |= DM_INTEGRITY_FIX_PADDING_SUPPORTED;
+
_dm_integrity_checked = true;
}
@@ -866,6 +869,11 @@ static char *get_dm_integrity_params(con
strncat(features, feature, sizeof(features) - strlen(features) - 1);
crypt_safe_free(hexkey);
}
+ if (tgt->u.integrity.fix_padding) {
+ num_options++;
+ snprintf(feature, sizeof(feature), "fix_padding ");
+ strncat(features, feature, sizeof(features) - strlen(features) - 1);
+ }
if (flags & CRYPT_ACTIVATE_RECALCULATE) {
num_options++;
@@ -2334,6 +2342,8 @@ static int _dm_target_query_integrity(st
}
} else if (!strcmp(arg, "recalculate")) {
*act_flags |= CRYPT_ACTIVATE_RECALCULATE;
+ } else if (!strcmp(arg, "fix_padding")) {
+ tgt->u.integrity.fix_padding = true;
} else /* unknown option */
goto err;
}
@@ -2865,16 +2875,21 @@ int dm_verity_target_set(struct dm_targe
return 0;
}
-int dm_integrity_target_set(struct dm_target *tgt, uint64_t seg_offset, uint64_t seg_size,
+int dm_integrity_target_set(struct crypt_device *cd,
+ struct dm_target *tgt, uint64_t seg_offset, uint64_t seg_size,
struct device *meta_device,
struct device *data_device, uint64_t tag_size, uint64_t offset,
uint32_t sector_size, struct volume_key *vk,
struct volume_key *journal_crypt_key, struct volume_key *journal_mac_key,
const struct crypt_params_integrity *ip)
{
+ uint32_t dmi_flags;
+
if (!data_device)
return -EINVAL;
+ _dm_check_versions(cd, DM_INTEGRITY);
+
tgt->type = DM_INTEGRITY;
tgt->direction = TARGET_SET;
tgt->offset = seg_offset;
@@ -2890,6 +2905,9 @@ int dm_integrity_target_set(struct dm_ta
tgt->u.integrity.journal_crypt_key = journal_crypt_key;
tgt->u.integrity.journal_integrity_key = journal_mac_key;
+ if (!dm_flags(cd, DM_INTEGRITY, &dmi_flags) && dmi_flags & DM_INTEGRITY_FIX_PADDING_SUPPORTED)
+ tgt->u.integrity.fix_padding = true;
+
if (ip) {
tgt->u.integrity.journal_size = ip->journal_size;
tgt->u.integrity.journal_watermark = ip->journal_watermark;
Index: cryptsetup/lib/utils_dm.h
===================================================================
--- cryptsetup.orig/lib/utils_dm.h 2019-11-12 20:09:30.000000000 +0100
+++ cryptsetup/lib/utils_dm.h 2019-11-12 21:09:25.000000000 +0100
@@ -64,6 +64,7 @@ static inline uint32_t act2dmflags(uint3
#define DM_INTEGRITY_RECALC_SUPPORTED (1 << 16) /* dm-integrity automatic recalculation supported */
#define DM_INTEGRITY_BITMAP_SUPPORTED (1 << 17) /* dm-integrity bitmap mode supported */
#define DM_GET_TARGET_VERSION_SUPPORTED (1 << 18) /* dm DM_GET_TARGET version ioctl supported */
+#define DM_INTEGRITY_FIX_PADDING_SUPPORTED (1 << 19) /* supports the parameter fix_padding that fixes a bug that caused excessive padding */
typedef enum { DM_CRYPT = 0, DM_VERITY, DM_INTEGRITY, DM_LINEAR, DM_ERROR, DM_UNKNOWN } dm_target_type;
enum tdirection { TARGET_SET = 1, TARGET_QUERY };
@@ -138,6 +139,8 @@ struct dm_target {
struct volume_key *journal_crypt_key;
struct device *meta_device;
+
+ bool fix_padding;
} integrity;
struct {
uint64_t offset;
@@ -177,7 +180,8 @@ int dm_verity_target_set(struct dm_targe
struct device *data_device, struct device *hash_device, struct device *fec_device,
const char *root_hash, uint32_t root_hash_size, uint64_t hash_offset_block,
uint64_t hash_blocks, struct crypt_params_verity *vp);
-int dm_integrity_target_set(struct dm_target *tgt, uint64_t seg_offset, uint64_t seg_size,
+int dm_integrity_target_set(struct crypt_device *cd,
+ struct dm_target *tgt, uint64_t seg_offset, uint64_t seg_size,
struct device *meta_device,
struct device *data_device, uint64_t tag_size, uint64_t offset, uint32_t sector_size,
struct volume_key *vk,
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