linux/drivers/md/dm-ima.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2021 Microsoft Corporation
 *
 * Author: Tushar Sugandhi <[email protected]>
 *
 * Enables IMA measurements for DM targets
 */

#include "dm-core.h"
#include "dm-ima.h"

#include <linux/ima.h>
#include <linux/sched/mm.h>
#include <crypto/hash.h>
#include <linux/crypto.h>
#include <crypto/hash_info.h>

#define DM_MSG_PREFIX …

/*
 * Internal function to prefix separator characters in input buffer with escape
 * character, so that they don't interfere with the construction of key-value pairs,
 * and clients can split the key1=val1,key2=val2,key3=val3; pairs properly.
 */
static void fix_separator_chars(char **buf)
{ … }

/*
 * Internal function to allocate memory for IMA measurements.
 */
static void *dm_ima_alloc(size_t len, gfp_t flags, bool noio)
{ … }

/*
 * Internal function to allocate and copy name and uuid for IMA measurements.
 */
static int dm_ima_alloc_and_copy_name_uuid(struct mapped_device *md, char **dev_name,
					   char **dev_uuid, bool noio)
{ … }

/*
 * Internal function to allocate and copy device data for IMA measurements.
 */
static int dm_ima_alloc_and_copy_device_data(struct mapped_device *md, char **device_data,
					     unsigned int num_targets, bool noio)
{ … }

/*
 * Internal wrapper function to call IMA to measure DM data.
 */
static void dm_ima_measure_data(const char *event_name, const void *buf, size_t buf_len,
				bool noio)
{ … }

/*
 * Internal function to allocate and copy current device capacity for IMA measurements.
 */
static int dm_ima_alloc_and_copy_capacity_str(struct mapped_device *md, char **capacity_str,
					      bool noio)
{ … }

/*
 * Initialize/reset the dm ima related data structure variables.
 */
void dm_ima_reset_data(struct mapped_device *md)
{ … }

/*
 * Build up the IMA data for each target, and finally measure.
 */
void dm_ima_measure_on_table_load(struct dm_table *table, unsigned int status_flags)
{ … }

/*
 * Measure IMA data on device resume.
 */
void dm_ima_measure_on_device_resume(struct mapped_device *md, bool swap)
{ … }

/*
 * Measure IMA data on remove.
 */
void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all)
{ … }

/*
 * Measure ima data on table clear.
 */
void dm_ima_measure_on_table_clear(struct mapped_device *md, bool new_map)
{ … }

/*
 * Measure IMA data on device rename.
 */
void dm_ima_measure_on_device_rename(struct mapped_device *md)
{ … }