1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Creating audit records for mapped devices.
4 *
5 * Copyright (C) 2021 Fraunhofer AISEC. All rights reserved.
6 *
7 * Authors: Michael Wei�� <michael.weiss@aisec.fraunhofer.de>
8 */
9
10#include <linux/audit.h>
11#include <linux/module.h>
12#include <linux/device-mapper.h>
13#include <linux/bio.h>
14#include <linux/blkdev.h>
15
16#include "dm-audit.h"
17#include "dm-core.h"
18
19static struct audit_buffer *dm_audit_log_start(int audit_type,
20					       const char *dm_msg_prefix,
21					       const char *op)
22{
23	struct audit_buffer *ab;
24
25	if (audit_enabled == AUDIT_OFF)
26		return NULL;
27
28	ab = audit_log_start(audit_context(), GFP_KERNEL, audit_type);
29	if (unlikely(!ab))
30		return NULL;
31
32	audit_log_format(ab, "module=%s op=%s", dm_msg_prefix, op);
33	return ab;
34}
35
36void dm_audit_log_ti(int audit_type, const char *dm_msg_prefix, const char *op,
37		     struct dm_target *ti, int result)
38{
39	struct audit_buffer *ab = NULL;
40	struct mapped_device *md = dm_table_get_md(ti->table);
41	int dev_major = dm_disk(md)->major;
42	int dev_minor = dm_disk(md)->first_minor;
43
44	switch (audit_type) {
45	case AUDIT_DM_CTRL:
46		ab = dm_audit_log_start(audit_type, dm_msg_prefix, op);
47		if (unlikely(!ab))
48			return;
49		audit_log_task_info(ab);
50		audit_log_format(ab, " dev=%d:%d error_msg='%s'", dev_major,
51				 dev_minor, !result ? ti->error : "success");
52		break;
53	case AUDIT_DM_EVENT:
54		ab = dm_audit_log_start(audit_type, dm_msg_prefix, op);
55		if (unlikely(!ab))
56			return;
57		audit_log_format(ab, " dev=%d:%d sector=?", dev_major,
58				 dev_minor);
59		break;
60	default: /* unintended use */
61		return;
62	}
63
64	audit_log_format(ab, " res=%d", result);
65	audit_log_end(ab);
66}
67EXPORT_SYMBOL_GPL(dm_audit_log_ti);
68
69void dm_audit_log_bio(const char *dm_msg_prefix, const char *op,
70		      struct bio *bio, sector_t sector, int result)
71{
72	struct audit_buffer *ab;
73	int dev_major = MAJOR(bio->bi_bdev->bd_dev);
74	int dev_minor = MINOR(bio->bi_bdev->bd_dev);
75
76	ab = dm_audit_log_start(AUDIT_DM_EVENT, dm_msg_prefix, op);
77	if (unlikely(!ab))
78		return;
79
80	audit_log_format(ab, " dev=%d:%d sector=%llu res=%d",
81			 dev_major, dev_minor, sector, result);
82	audit_log_end(ab);
83}
84EXPORT_SYMBOL_GPL(dm_audit_log_bio);
85