1 /* SPDX-License-Identifier: GPL-2.0
2  *
3  * Copyright (C) 2021 Microsoft Corporation
4  *
5  * Author: Tushar Sugandhi <tusharsu@linux.microsoft.com>
6  *
7  * File: dm-ima.h
8  *       Header file for device mapper IMA measurements.
9  */
10 
11 #ifndef DM_IMA_H
12 #define DM_IMA_H
13 
14 #define DM_IMA_MEASUREMENT_BUF_LEN	4096
15 #define DM_IMA_DEVICE_BUF_LEN		1024
16 #define DM_IMA_TARGET_METADATA_BUF_LEN	128
17 #define DM_IMA_TARGET_DATA_BUF_LEN	2048
18 #define DM_IMA_DEVICE_CAPACITY_BUF_LEN	128
19 #define DM_IMA_TABLE_HASH_ALG		"sha256"
20 
21 #define __dm_ima_stringify(s) #s
22 #define __dm_ima_str(s) __dm_ima_stringify(s)
23 
24 #define DM_IMA_VERSION_STR "dm_version="	\
25 	__dm_ima_str(DM_VERSION_MAJOR) "."	\
26 	__dm_ima_str(DM_VERSION_MINOR) "."	\
27 	__dm_ima_str(DM_VERSION_PATCHLEVEL) ";"
28 
29 #ifdef CONFIG_IMA
30 
31 struct dm_ima_device_table_metadata {
32 	/*
33 	 * Contains data specific to the device which is common across
34 	 * all the targets in the table (e.g. name, uuid, major, minor, etc).
35 	 * The values are stored in comma separated list of key1=val1,key2=val2;
36 	 * pairs delimited by a semicolon at the end of the list.
37 	 */
38 	char *device_metadata;
39 	unsigned int device_metadata_len;
40 	unsigned int num_targets;
41 
42 	/*
43 	 * Contains the sha256 hashes of the IMA measurements of the target
44 	 * attributes' key-value pairs from the active/inactive tables.
45 	 */
46 	char *hash;
47 	unsigned int hash_len;
48 };
49 
50 /*
51  * This structure contains device metadata, and table hash for
52  * active and inactive tables for ima measurements.
53  */
54 struct dm_ima_measurements {
55 	struct dm_ima_device_table_metadata active_table;
56 	struct dm_ima_device_table_metadata inactive_table;
57 	unsigned int dm_version_str_len;
58 };
59 
60 void dm_ima_reset_data(struct mapped_device *md);
61 void dm_ima_measure_on_table_load(struct dm_table *table, unsigned int status_flags);
62 void dm_ima_measure_on_device_resume(struct mapped_device *md, bool swap);
63 void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all);
64 void dm_ima_measure_on_table_clear(struct mapped_device *md, bool new_map);
65 void dm_ima_measure_on_device_rename(struct mapped_device *md);
66 
67 #else
68 
dm_ima_reset_data(struct mapped_device * md)69 static inline void dm_ima_reset_data(struct mapped_device *md) {}
dm_ima_measure_on_table_load(struct dm_table * table,unsigned int status_flags)70 static inline void dm_ima_measure_on_table_load(struct dm_table *table, unsigned int status_flags) {}
dm_ima_measure_on_device_resume(struct mapped_device * md,bool swap)71 static inline void dm_ima_measure_on_device_resume(struct mapped_device *md, bool swap) {}
dm_ima_measure_on_device_remove(struct mapped_device * md,bool remove_all)72 static inline void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all) {}
dm_ima_measure_on_table_clear(struct mapped_device * md,bool new_map)73 static inline void dm_ima_measure_on_table_clear(struct mapped_device *md, bool new_map) {}
dm_ima_measure_on_device_rename(struct mapped_device * md)74 static inline void dm_ima_measure_on_device_rename(struct mapped_device *md) {}
75 
76 #endif /* CONFIG_IMA */
77 
78 #endif /* DM_IMA_H */
79