dm-ima

對於給定系統，各種外部服務/基礎設施工具（包括認證服務）在設定和系統執行時都會與它互動。它們共享敏感資料和/或在該系統上執行關鍵工作負載。外部服務可能希望在完全信任該系統承載業務關鍵資料/工作負載之前，驗證相關核心子系統的當前執行時狀態。

裝置對映器透過使用各種目標型別（如 crypt、verity、integrity 等）為塊裝置提供各種重要功能，在給定系統上發揮著關鍵作用。這些目標型別中的每一種功能都可以透過各種屬性進行配置。選擇用於配置這些目標型別的屬性可以顯著影響塊裝置乃至系統本身的安全配置檔案。例如，加密演算法的型別和金鑰大小決定了給定塊裝置的加密強度。

因此，在外部服務完全信任系統承載業務關鍵資料/工作負載之前，驗證各種塊裝置的當前狀態及其各種目標屬性至關重要。

IMA 核心子系統提供了裝置對映器測量各種塊裝置狀態和配置所需的功能——

• 由裝置對映器本身在核心內部進行測量，

• 以防篡改的方式進行測量，

• 並在狀態/配置更改時重新測量。

設定 IMA 策略：

為了讓 IMA 測量給定系統上的資料，系統上的 IMA 策略需要更新為包含以下行，並且系統需要重新啟動才能使測量生效。

/etc/ima/ima-policy
   measure func=CRITICAL_DATA label=device-mapper template=ima-buf

測量結果將反映在 IMA 日誌中，日誌位於

/sys/kernel/security/integrity/ima/ascii_runtime_measurements
/sys/kernel/security/integrity/ima/binary_runtime_measurements

IMA ASCII 測量日誌的格式如下

<PCR> <TEMPLATE_DATA_DIGEST> <TEMPLATE_NAME> <TEMPLATE_DATA>

PCR := Platform Configuration Register, in which the values are registered.
      This is applicable if TPM chip is in use.

TEMPLATE_DATA_DIGEST := Template data digest of the IMA record.
TEMPLATE_NAME := Template name that registered the integrity value (e.g. ima-buf).

TEMPLATE_DATA := <ALG> ":" <EVENT_DIGEST> <EVENT_NAME> <EVENT_DATA>
                 It contains data for the specific event to be measured,
                 in a given template data format.

ALG := Algorithm to compute event digest
EVENT_DIGEST := Digest of the event data
EVENT_NAME := Description of the event (e.g. 'dm_table_load').
EVENT_DATA := The event data to be measured.

注 1

DM 子系統測量的資料可以透過設定 DM_IMA_MEASUREMENT_FLAG 和 DM_TABLE_STATUS_CMD 從使用者空間查詢。

注 2

核心配置 CONFIG_IMA_DISABLE_HTABLE 允許測量重複記錄。

為了支援在 IMA 日誌中記錄重複的 IMA 事件，核心需要配置 CONFIG_IMA_DISABLE_HTABLE=y。

支援的裝置狀態：

以下裝置狀態更改將觸發 IMA 測量

1. 表載入 (Table load)

2. 裝置恢復 (Device resume)

3. 裝置移除 (Device remove)

4. 表清除 (Table clear)

5. 裝置重新命名 (Device rename)

1. 表載入：

當新表載入到裝置的非活動表槽中時，將測量裝置資訊和表中目標的特定細節。

IMA 測量日誌中“dm_table_load”的格式如下

EVENT_NAME := "dm_table_load"
EVENT_DATA := <dm_version_str> ";" <device_metadata> ";" <table_load_data>

dm_version_str := "dm_version=" <N> "." <N> "." <N>
                 Same as Device Mapper driver version.
device_metadata := <device_name> "," <device_uuid> "," <device_major> "," <device_minor> ","
                  <minor_count> "," <num_device_targets> ";"

device_name := "name=" <dm-device-name>
device_uuid := "uuid=" <dm-device-uuid>
device_major := "major=" <N>
device_minor := "minor=" <N>
minor_count := "minor_count=" <N>
num_device_targets := "num_targets=" <N>
dm-device-name := Name of the device. If it contains special characters like '\', ',', ';',
                  they are prefixed with '\'.
dm-device-uuid := UUID of the device. If it contains special characters like '\', ',', ';',
                  they are prefixed with '\'.

table_load_data := <target_data>
                   Represents the data (as name=value pairs) from various targets in the table,
                   which is being loaded into the DM device's inactive table slot.
target_data := <target_data_row> | <target_data><target_data_row>

target_data_row := <target_index> "," <target_begin> "," <target_len> "," <target_name> ","
                   <target_version> "," <target_attributes> ";"
target_index := "target_index=" <N>
                Represents nth target in the table (from 0 to N-1 targets specified in <num_device_targets>)
                If all the data for N targets doesn't fit in the given buffer - then the data that fits
                in the buffer (say from target 0 to x) is measured in a given IMA event.
                The remaining data from targets x+1 to N-1 is measured in the subsequent IMA events,
                with the same format as that of 'dm_table_load'
                i.e. <dm_version_str> ";" <device_metadata> ";" <table_load_data>.

target_begin := "target_begin=" <N>
target_len := "target_len=" <N>
target_name := Name of the target. 'linear', 'crypt', 'integrity' etc.
               The targets that are supported for IMA measurements are documented below in the
               'Supported targets' section.
target_version := "target_version=" <N> "." <N> "." <N>
target_attributes := Data containing comma separated list of name=value pairs of target specific attributes.

For instance, if a linear device is created with the following table entries,
 # dmsetup create linear1
 0 2 linear /dev/loop0 512
 2 2 linear /dev/loop0 512
 4 2 linear /dev/loop0 512
 6 2 linear /dev/loop0 512

Then IMA ASCII measurement log will have the following entry:
(converted from ASCII to text for readability)

10 a8c5ff755561c7a28146389d1514c318592af49a ima-buf sha256:4d73481ecce5eadba8ab084640d85bb9ca899af4d0a122989252a76efadc5b72
dm_table_load
dm_version=4.45.0;
name=linear1,uuid=,major=253,minor=0,minor_count=1,num_targets=4;
target_index=0,target_begin=0,target_len=2,target_name=linear,target_version=1.4.0,device_name=7:0,start=512;
target_index=1,target_begin=2,target_len=2,target_name=linear,target_version=1.4.0,device_name=7:0,start=512;
target_index=2,target_begin=4,target_len=2,target_name=linear,target_version=1.4.0,device_name=7:0,start=512;
target_index=3,target_begin=6,target_len=2,target_name=linear,target_version=1.4.0,device_name=7:0,start=512;

2. 裝置恢復：

當掛起的裝置恢復時，將測量裝置資訊和上次載入活動表時的資料雜湊。

IMA 測量日誌中“dm_device_resume”的格式如下

EVENT_NAME := "dm_device_resume"
EVENT_DATA := <dm_version_str> ";" <device_metadata> ";" <active_table_hash> ";" <current_device_capacity> ";"

dm_version_str := As described in the 'Table load' section above.
device_metadata := As described in the 'Table load' section above.
active_table_hash := "active_table_hash=" <table_hash_alg> ":" <table_hash>
                     Rerpresents the hash of the IMA data being measured for the
                     active table for the device.
table_hash_alg := Algorithm used to compute the hash.
table_hash := Hash of the (<dm_version_str> ";" <device_metadata> ";" <table_load_data> ";")
              as described in the 'dm_table_load' above.
              Note: If the table_load data spans across multiple IMA 'dm_table_load'
              events for a given device, the hash is computed combining all the event data
              i.e. (<dm_version_str> ";" <device_metadata> ";" <table_load_data> ";")
              across all those events.
current_device_capacity := "current_device_capacity=" <N>

For instance, if a linear device is resumed with the following command,
#dmsetup resume linear1

then IMA ASCII measurement log will have an entry with:
(converted from ASCII to text for readability)

10 56c00cc062ffc24ccd9ac2d67d194af3282b934e ima-buf sha256:e7d12c03b958b4e0e53e7363a06376be88d98a1ac191fdbd3baf5e4b77f329b6
dm_device_resume
dm_version=4.45.0;
name=linear1,uuid=,major=253,minor=0,minor_count=1,num_targets=4;
active_table_hash=sha256:4d73481ecce5eadba8ab084640d85bb9ca899af4d0a122989252a76efadc5b72;current_device_capacity=8;

3. 裝置移除：

當裝置移除時，將測量裝置資訊和活動表與非活動表資料的 sha256 雜湊。

IMA 測量日誌中“dm_device_remove”的格式如下

EVENT_NAME := "dm_device_remove"
EVENT_DATA := <dm_version_str> ";" <device_active_metadata> ";" <device_inactive_metadata> ";"
              <active_table_hash> "," <inactive_table_hash> "," <remove_all> ";" <current_device_capacity> ";"

dm_version_str := As described in the 'Table load' section above.
device_active_metadata := Device metadata that reflects the currently loaded active table.
                          The format is same as 'device_metadata' described in the 'Table load' section above.
device_inactive_metadata := Device metadata that reflects the inactive table.
                            The format is same as 'device_metadata' described in the 'Table load' section above.
active_table_hash := Hash of the currently loaded active table.
                     The format is same as 'active_table_hash' described in the 'Device resume' section above.
inactive_table_hash :=  Hash of the inactive table.
                        The format is same as 'active_table_hash' described in the 'Device resume' section above.
remove_all := "remove_all=" <yes_no>
yes_no := "y" | "n"
current_device_capacity := "current_device_capacity=" <N>

For instance, if a linear device is removed with the following command,
 #dmsetup remove l1

then IMA ASCII measurement log will have the following entry:
(converted from ASCII to text for readability)

10 790e830a3a7a31590824ac0642b3b31c2d0e8b38 ima-buf sha256:ab9f3c959367a8f5d4403d6ce9c3627dadfa8f9f0e7ec7899299782388de3840
dm_device_remove
dm_version=4.45.0;
device_active_metadata=name=l1,uuid=,major=253,minor=2,minor_count=1,num_targets=2;
device_inactive_metadata=name=l1,uuid=,major=253,minor=2,minor_count=1,num_targets=1;
active_table_hash=sha256:4a7e62efaebfc86af755831998b7db6f59b60d23c9534fb16a4455907957953a,
inactive_table_hash=sha256:9d79c175bc2302d55a183e8f50ad4bafd60f7692fd6249e5fd213e2464384b86,remove_all=n;
current_device_capacity=2048;

4. 表清除：

當非活動表從裝置中清除時，將測量裝置資訊和非活動表資料的 sha256 雜湊。

IMA 測量日誌中“dm_table_clear”的格式如下

EVENT_NAME := "dm_table_clear"
EVENT_DATA := <dm_version_str> ";" <device_inactive_metadata> ";" <inactive_table_hash> ";" <current_device_capacity> ";"

dm_version_str := As described in the 'Table load' section above.
device_inactive_metadata := Device metadata that was captured during the load time inactive table being cleared.
                            The format is same as 'device_metadata' described in the 'Table load' section above.
inactive_table_hash := Hash of the inactive table being cleared from the device.
                       The format is same as 'active_table_hash' described in the 'Device resume' section above.
current_device_capacity := "current_device_capacity=" <N>

For instance, if a linear device's inactive table is cleared,
 #dmsetup clear l1

then IMA ASCII measurement log will have an entry with:
(converted from ASCII to text for readability)

10 77d347408f557f68f0041acb0072946bb2367fe5 ima-buf sha256:42f9ca22163fdfa548e6229dece2959bc5ce295c681644240035827ada0e1db5
dm_table_clear
dm_version=4.45.0;
name=l1,uuid=,major=253,minor=2,minor_count=1,num_targets=1;
inactive_table_hash=sha256:75c0dc347063bf474d28a9907037eba060bfe39d8847fc0646d75e149045d545;current_device_capacity=1024;

5. 裝置重新命名：

當裝置的 NAME 或 UUID 更改時，將測量裝置資訊、新的 NAME 和 UUID。

IMA 測量日誌中“dm_device_rename”的格式如下

EVENT_NAME := "dm_device_rename"
EVENT_DATA := <dm_version_str> ";" <device_active_metadata> ";" <new_device_name> "," <new_device_uuid> ";" <current_device_capacity> ";"

dm_version_str := As described in the 'Table load' section above.
device_active_metadata := Device metadata that reflects the currently loaded active table.
                          The format is same as 'device_metadata' described in the 'Table load' section above.
new_device_name := "new_name=" <dm-device-name>
dm-device-name := Same as <dm-device-name> described in 'Table load' section above
new_device_uuid := "new_uuid=" <dm-device-uuid>
dm-device-uuid := Same as <dm-device-uuid> described in 'Table load' section above
current_device_capacity := "current_device_capacity=" <N>

E.g 1: if a linear device's name is changed with the following command,
 #dmsetup rename linear1 --setuuid 1234-5678

then IMA ASCII measurement log will have an entry with:
(converted from ASCII to text for readability)

10 8b0423209b4c66ac1523f4c9848c9b51ee332f48 ima-buf sha256:6847b7258134189531db593e9230b257c84f04038b5a18fd2e1473860e0569ac
dm_device_rename
dm_version=4.45.0;
name=linear1,uuid=,major=253,minor=2,minor_count=1,num_targets=1;new_name=linear1,new_uuid=1234-5678;
current_device_capacity=1024;

E.g 2:  if a linear device's name is changed with the following command,
 # dmsetup rename linear1 linear=2

then IMA ASCII measurement log will have an entry with:
(converted from ASCII to text for readability)

10 bef70476b99c2bdf7136fae033aa8627da1bf76f ima-buf sha256:8c6f9f53b9ef9dc8f92a2f2cca8910e622543d0f0d37d484870cb16b95111402
dm_device_rename
dm_version=4.45.0;
name=linear1,uuid=1234-5678,major=253,minor=2,minor_count=1,num_targets=1;
new_name=linear\=2,new_uuid=1234-5678;
current_device_capacity=1024;

支援的目標：

以下目標支援使用 IMA 測量其資料

1. cache (快取)

2. crypt (加密)

3. integrity (完整性)

4. linear (線性)

5. mirror (映象)

6. multipath (多路徑)

7. raid (RAID)

8. snapshot (快照)

9. striped (條帶)

10. verity (真實性)

1. 快取 (cache)

“cache”目標的“target_attributes”（如上文“Table load”部分 EVENT_DATA 中所述）具有以下資料格式。

target_attributes := <target_name> "," <target_version> "," <metadata_mode> "," <cache_metadata_device> ","
                     <cache_device> "," <cache_origin_device> "," <writethrough> "," <writeback> ","
                     <passthrough> "," <no_discard_passdown> ";"

target_name := "target_name=cache"
target_version := "target_version=" <N> "." <N> "." <N>
metadata_mode := "metadata_mode=" <cache_metadata_mode>
cache_metadata_mode := "fail" | "ro" | "rw"
cache_device := "cache_device=" <cache_device_name_string>
cache_origin_device := "cache_origin_device=" <cache_origin_device_string>
writethrough := "writethrough=" <yes_no>
writeback := "writeback=" <yes_no>
passthrough := "passthrough=" <yes_no>
no_discard_passdown := "no_discard_passdown=" <yes_no>
yes_no := "y" | "n"

E.g.
When a 'cache' target is loaded, then IMA ASCII measurement log will have an entry
similar to the following, depicting what 'cache' attributes are measured in EVENT_DATA
for 'dm_table_load' event.
(converted from ASCII to text for readability)

dm_version=4.45.0;name=cache1,uuid=cache_uuid,major=253,minor=2,minor_count=1,num_targets=1;
target_index=0,target_begin=0,target_len=28672,target_name=cache,target_version=2.2.0,metadata_mode=rw,
cache_metadata_device=253:4,cache_device=253:3,cache_origin_device=253:5,writethrough=y,writeback=n,
passthrough=n,metadata2=y,no_discard_passdown=n;

2. 加密 (crypt)

“crypt”目標的“target_attributes”（如上文“Table load”部分 EVENT_DATA 中所述）具有以下資料格式。

target_attributes := <target_name> "," <target_version> "," <allow_discards> "," <same_cpu_crypt> ","
                     <submit_from_crypt_cpus> "," <no_read_workqueue> "," <no_write_workqueue> ","
                     <iv_large_sectors> "," <iv_large_sectors> "," [<integrity_tag_size> ","] [<cipher_auth> ","]
                     [<sector_size> ","] [<cipher_string> ","] <key_size> "," <key_parts> ","
                     <key_extra_size> "," <key_mac_size> ";"

target_name := "target_name=crypt"
target_version := "target_version=" <N> "." <N> "." <N>
allow_discards := "allow_discards=" <yes_no>
same_cpu_crypt := "same_cpu_crypt=" <yes_no>
submit_from_crypt_cpus := "submit_from_crypt_cpus=" <yes_no>
no_read_workqueue := "no_read_workqueue=" <yes_no>
no_write_workqueue := "no_write_workqueue=" <yes_no>
iv_large_sectors := "iv_large_sectors=" <yes_no>
integrity_tag_size := "integrity_tag_size=" <N>
cipher_auth := "cipher_auth=" <string>
sector_size := "sector_size="  <N>
cipher_string := "cipher_string="
key_size := "key_size="  <N>
key_parts := "key_parts="  <N>
key_extra_size := "key_extra_size="  <N>
key_mac_size := "key_mac_size="  <N>
yes_no := "y" | "n"

E.g.
When a 'crypt' target is loaded, then IMA ASCII measurement log will have an entry
similar to the following, depicting what 'crypt' attributes are measured in EVENT_DATA
for 'dm_table_load' event.
(converted from ASCII to text for readability)

dm_version=4.45.0;
name=crypt1,uuid=crypt_uuid1,major=253,minor=0,minor_count=1,num_targets=1;
target_index=0,target_begin=0,target_len=1953125,target_name=crypt,target_version=1.23.0,
allow_discards=y,same_cpu=n,submit_from_crypt_cpus=n,no_read_workqueue=n,no_write_workqueue=n,
iv_large_sectors=n,cipher_string=aes-xts-plain64,key_size=32,key_parts=1,key_extra_size=0,key_mac_size=0;

3. 完整性 (integrity)

“integrity”目標的“target_attributes”（如上文“Table load”部分 EVENT_DATA 中所述）具有以下資料格式。

target_attributes := <target_name> "," <target_version> "," <dev_name> "," <start>
                     <tag_size> "," <mode> "," [<meta_device> ","] [<block_size> ","] <recalculate> ","
                     <allow_discards> "," <fix_padding> "," <fix_hmac> "," <legacy_recalculate> ","
                     <journal_sectors> "," <interleave_sectors> "," <buffer_sectors> ";"

target_name := "target_name=integrity"
target_version := "target_version=" <N> "." <N> "." <N>
dev_name := "dev_name=" <device_name_str>
start := "start=" <N>
tag_size := "tag_size=" <N>
mode := "mode=" <integrity_mode_str>
integrity_mode_str := "J" | "B" | "D" | "R"
meta_device := "meta_device=" <meta_device_str>
block_size := "block_size=" <N>
recalculate := "recalculate=" <yes_no>
allow_discards := "allow_discards=" <yes_no>
fix_padding := "fix_padding=" <yes_no>
fix_hmac := "fix_hmac=" <yes_no>
legacy_recalculate := "legacy_recalculate=" <yes_no>
journal_sectors := "journal_sectors=" <N>
interleave_sectors := "interleave_sectors=" <N>
buffer_sectors := "buffer_sectors=" <N>
yes_no := "y" | "n"

E.g.
When a 'integrity' target is loaded, then IMA ASCII measurement log will have an entry
similar to the following, depicting what 'integrity' attributes are measured in EVENT_DATA
for 'dm_table_load' event.
(converted from ASCII to text for readability)

dm_version=4.45.0;
name=integrity1,uuid=,major=253,minor=1,minor_count=1,num_targets=1;
target_index=0,target_begin=0,target_len=7856,target_name=integrity,target_version=1.10.0,
dev_name=253:0,start=0,tag_size=32,mode=J,recalculate=n,allow_discards=n,fix_padding=n,
fix_hmac=n,legacy_recalculate=n,journal_sectors=88,interleave_sectors=32768,buffer_sectors=128;

4. 線性 (linear)

“linear”目標的“target_attributes”（如上文“Table load”部分 EVENT_DATA 中所述）具有以下資料格式。

target_attributes := <target_name> "," <target_version> "," <device_name> <,> <start> ";"

target_name := "target_name=linear"
target_version := "target_version=" <N> "." <N> "." <N>
device_name := "device_name=" <linear_device_name_str>
start := "start=" <N>

E.g.
When a 'linear' target is loaded, then IMA ASCII measurement log will have an entry
similar to the following, depicting what 'linear' attributes are measured in EVENT_DATA
for 'dm_table_load' event.
(converted from ASCII to text for readability)

dm_version=4.45.0;
name=linear1,uuid=linear_uuid1,major=253,minor=2,minor_count=1,num_targets=1;
target_index=0,target_begin=0,target_len=28672,target_name=linear,target_version=1.4.0,
device_name=253:1,start=2048;

5. 映象 (mirror)

“mirror”目標的“target_attributes”（如上文“Table load”部分 EVENT_DATA 中所述）具有以下資料格式。

target_attributes := <target_name> "," <target_version> "," <nr_mirrors> ","
                     <mirror_device_data> "," <handle_errors> "," <keep_log> "," <log_type_status> ";"

target_name := "target_name=mirror"
target_version := "target_version=" <N> "." <N> "." <N>
nr_mirrors := "nr_mirrors=" <NR>
mirror_device_data := <mirror_device_row> | <mirror_device_data><mirror_device_row>
                      mirror_device_row is repeated <NR> times - for <NR> described in <nr_mirrors>.
mirror_device_row := <mirror_device_name> "," <mirror_device_status>
mirror_device_name := "mirror_device_" <X> "=" <mirror_device_name_str>
                      where <X> ranges from 0 to (<NR> -1) - for <NR> described in <nr_mirrors>.
mirror_device_status := "mirror_device_" <X> "_status=" <mirror_device_status_char>
                        where <X> ranges from 0 to (<NR> -1) - for <NR> described in <nr_mirrors>.
mirror_device_status_char := "A" | "F" | "D" | "S" | "R" | "U"
handle_errors := "handle_errors=" <yes_no>
keep_log := "keep_log=" <yes_no>
log_type_status := "log_type_status=" <log_type_status_str>
yes_no := "y" | "n"

E.g.
When a 'mirror' target is loaded, then IMA ASCII measurement log will have an entry
similar to the following, depicting what 'mirror' attributes are measured in EVENT_DATA
for 'dm_table_load' event.
(converted from ASCII to text for readability)

dm_version=4.45.0;
name=mirror1,uuid=mirror_uuid1,major=253,minor=6,minor_count=1,num_targets=1;
target_index=0,target_begin=0,target_len=2048,target_name=mirror,target_version=1.14.0,nr_mirrors=2,
   mirror_device_0=253:4,mirror_device_0_status=A,
   mirror_device_1=253:5,mirror_device_1_status=A,
handle_errors=y,keep_log=n,log_type_status=;

6. 多路徑 (multipath)

“multipath”目標的“target_attributes”（如上文“Table load”部分 EVENT_DATA 中所述）具有以下資料格式。

target_attributes := <target_name> "," <target_version> "," <nr_priority_groups>
                     ["," <pg_state> "," <priority_groups> "," <priority_group_paths>] ";"

target_name := "target_name=multipath"
target_version := "target_version=" <N> "." <N> "." <N>
nr_priority_groups := "nr_priority_groups=" <NPG>
priority_groups := <priority_groups_row>|<priority_groups_row><priority_groups>
priority_groups_row := "pg_state_" <X> "=" <pg_state_str> "," "nr_pgpaths_" <X>  "=" <NPGP> ","
                       "path_selector_name_" <X> "=" <string> "," <priority_group_paths>
                       where <X> ranges from 0 to (<NPG> -1) - for <NPG> described in <nr_priority_groups>.
pg_state_str := "E" | "A" | "D"
<priority_group_paths> := <priority_group_paths_row> | <priority_group_paths_row><priority_group_paths>
priority_group_paths_row := "path_name_" <X> "_" <Y> "=" <string> "," "is_active_" <X> "_" <Y> "=" <is_active_str>
                            "fail_count_" <X> "_" <Y> "=" <N> "," "path_selector_status_" <X> "_" <Y> "=" <path_selector_status_str>
                            where <X> ranges from 0 to (<NPG> -1) - for <NPG> described in <nr_priority_groups>,
                            and <Y> ranges from 0 to (<NPGP> -1) - for <NPGP> described in <priority_groups_row>.
is_active_str := "A" | "F"

E.g.
When a 'multipath' target is loaded, then IMA ASCII measurement log will have an entry
similar to the following, depicting what 'multipath' attributes are measured in EVENT_DATA
for 'dm_table_load' event.
(converted from ASCII to text for readability)

dm_version=4.45.0;
name=mp,uuid=,major=253,minor=0,minor_count=1,num_targets=1;
target_index=0,target_begin=0,target_len=2097152,target_name=multipath,target_version=1.14.0,nr_priority_groups=2,
   pg_state_0=E,nr_pgpaths_0=2,path_selector_name_0=queue-length,
       path_name_0_0=8:16,is_active_0_0=A,fail_count_0_0=0,path_selector_status_0_0=,
       path_name_0_1=8:32,is_active_0_1=A,fail_count_0_1=0,path_selector_status_0_1=,
   pg_state_1=E,nr_pgpaths_1=2,path_selector_name_1=queue-length,
       path_name_1_0=8:48,is_active_1_0=A,fail_count_1_0=0,path_selector_status_1_0=,
       path_name_1_1=8:64,is_active_1_1=A,fail_count_1_1=0,path_selector_status_1_1=;

7. RAID

“raid”目標的“target_attributes”（如上文“Table load”部分 EVENT_DATA 中所述）具有以下資料格式。

target_attributes := <target_name> "," <target_version> "," <raid_type> "," <raid_disks> "," <raid_state>
                     <raid_device_status> ["," journal_dev_mode] ";"

target_name := "target_name=raid"
target_version := "target_version=" <N> "." <N> "." <N>
raid_type := "raid_type=" <raid_type_str>
raid_disks := "raid_disks=" <NRD>
raid_state := "raid_state=" <raid_state_str>
raid_state_str := "frozen" | "reshape" |"resync" | "check" | "repair" | "recover" | "idle" |"undef"
raid_device_status := <raid_device_status_row> | <raid_device_status_row><raid_device_status>
                      <raid_device_status_row> is repeated <NRD> times - for <NRD> described in <raid_disks>.
raid_device_status_row := "raid_device_" <X> "_status=" <raid_device_status_str>
                          where <X> ranges from 0 to (<NRD> -1) - for <NRD> described in <raid_disks>.
raid_device_status_str := "A" | "D" | "a" | "-"
journal_dev_mode := "journal_dev_mode=" <journal_dev_mode_str>
journal_dev_mode_str := "writethrough" | "writeback" | "invalid"

E.g.
When a 'raid' target is loaded, then IMA ASCII measurement log will have an entry
similar to the following, depicting what 'raid' attributes are measured in EVENT_DATA
for 'dm_table_load' event.
(converted from ASCII to text for readability)

dm_version=4.45.0;
name=raid_LV1,uuid=uuid_raid_LV1,major=253,minor=12,minor_count=1,num_targets=1;
target_index=0,target_begin=0,target_len=2048,target_name=raid,target_version=1.15.1,
raid_type=raid10,raid_disks=4,raid_state=idle,
   raid_device_0_status=A,
   raid_device_1_status=A,
   raid_device_2_status=A,
   raid_device_3_status=A;

8. 快照 (snapshot)

“snapshot”目標的“target_attributes”（如上文“Table load”部分 EVENT_DATA 中所述）具有以下資料格式。

target_attributes := <target_name> "," <target_version> "," <snap_origin_name> ","
                     <snap_cow_name> "," <snap_valid> "," <snap_merge_failed> "," <snapshot_overflowed> ";"

target_name := "target_name=snapshot"
target_version := "target_version=" <N> "." <N> "." <N>
snap_origin_name := "snap_origin_name=" <string>
snap_cow_name := "snap_cow_name=" <string>
snap_valid := "snap_valid=" <yes_no>
snap_merge_failed := "snap_merge_failed=" <yes_no>
snapshot_overflowed := "snapshot_overflowed=" <yes_no>
yes_no := "y" | "n"

E.g.
When a 'snapshot' target is loaded, then IMA ASCII measurement log will have an entry
similar to the following, depicting what 'snapshot' attributes are measured in EVENT_DATA
for 'dm_table_load' event.
(converted from ASCII to text for readability)

dm_version=4.45.0;
name=snap1,uuid=snap_uuid1,major=253,minor=13,minor_count=1,num_targets=1;
target_index=0,target_begin=0,target_len=4096,target_name=snapshot,target_version=1.16.0,
snap_origin_name=253:11,snap_cow_name=253:12,snap_valid=y,snap_merge_failed=n,snapshot_overflowed=n;

9. 條帶 (striped)

“striped”目標的“target_attributes”（如上文“Table load”部分 EVENT_DATA 中所述）具有以下資料格式。

target_attributes := <target_name> "," <target_version> "," <stripes> "," <chunk_size> ","
                     <stripe_data> ";"

target_name := "target_name=striped"
target_version := "target_version=" <N> "." <N> "." <N>
stripes := "stripes=" <NS>
chunk_size := "chunk_size=" <N>
stripe_data := <stripe_data_row>|<stripe_data><stripe_data_row>
stripe_data_row := <stripe_device_name> "," <stripe_physical_start> "," <stripe_status>
stripe_device_name := "stripe_" <X> "_device_name=" <stripe_device_name_str>
                      where <X> ranges from 0 to (<NS> -1) - for <NS> described in <stripes>.
stripe_physical_start := "stripe_" <X> "_physical_start=" <N>
                          where <X> ranges from 0 to (<NS> -1) - for <NS> described in <stripes>.
stripe_status := "stripe_" <X> "_status=" <stripe_status_str>
                 where <X> ranges from 0 to (<NS> -1) - for <NS> described in <stripes>.
stripe_status_str := "D" | "A"

E.g.
When a 'striped' target is loaded, then IMA ASCII measurement log will have an entry
similar to the following, depicting what 'striped' attributes are measured in EVENT_DATA
for 'dm_table_load' event.
(converted from ASCII to text for readability)

dm_version=4.45.0;
name=striped1,uuid=striped_uuid1,major=253,minor=5,minor_count=1,num_targets=1;
target_index=0,target_begin=0,target_len=640,target_name=striped,target_version=1.6.0,stripes=2,chunk_size=64,
   stripe_0_device_name=253:0,stripe_0_physical_start=2048,stripe_0_status=A,
   stripe_1_device_name=253:3,stripe_1_physical_start=2048,stripe_1_status=A;

10. 真實性 (verity)

“verity”目標的“target_attributes”（如上文“Table load”部分 EVENT_DATA 中所述）具有以下資料格式。

target_attributes := <target_name> "," <target_version> "," <hash_failed> "," <verity_version> ","
                     <data_device_name> "," <hash_device_name> "," <verity_algorithm> "," <root_digest> ","
                     <salt> "," <ignore_zero_blocks> "," <check_at_most_once> ["," <root_hash_sig_key_desc>]
                     ["," <verity_mode>] ";"

target_name := "target_name=verity"
target_version := "target_version=" <N> "." <N> "." <N>
hash_failed := "hash_failed=" <hash_failed_str>
hash_failed_str := "C" | "V"
verity_version := "verity_version=" <verity_version_str>
data_device_name := "data_device_name=" <data_device_name_str>
hash_device_name := "hash_device_name=" <hash_device_name_str>
verity_algorithm := "verity_algorithm=" <verity_algorithm_str>
root_digest := "root_digest=" <root_digest_str>
salt := "salt=" <salt_str>
salt_str := "-" <verity_salt_str>
ignore_zero_blocks := "ignore_zero_blocks=" <yes_no>
check_at_most_once := "check_at_most_once=" <yes_no>
root_hash_sig_key_desc := "root_hash_sig_key_desc="
verity_mode := "verity_mode=" <verity_mode_str>
verity_mode_str := "ignore_corruption" | "restart_on_corruption" | "panic_on_corruption" | "invalid"
yes_no := "y" | "n"

E.g.
When a 'verity' target is loaded, then IMA ASCII measurement log will have an entry
similar to the following, depicting what 'verity' attributes are measured in EVENT_DATA
for 'dm_table_load' event.
(converted from ASCII to text for readability)

dm_version=4.45.0;
name=test-verity,uuid=,major=253,minor=2,minor_count=1,num_targets=1;
target_index=0,target_begin=0,target_len=1953120,target_name=verity,target_version=1.8.0,hash_failed=V,
verity_version=1,data_device_name=253:1,hash_device_name=253:0,verity_algorithm=sha256,
root_digest=29cb87e60ce7b12b443ba6008266f3e41e93e403d7f298f8e3f316b29ff89c5e,
salt=e48da609055204e89ae53b655ca2216dd983cf3cb829f34f63a297d106d53e2d,
ignore_zero_blocks=n,check_at_most_once=n;