drivers/md/dm-audit.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Creating audit records for mapped devices.
   4  *
   5  * Copyright (C) 2021 Fraunhofer AISEC. All rights reserved.
   6  *
   7  * Authors: Michael Weiß <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
  19 static 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
  36 void 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 }
  67 EXPORT_SYMBOL_GPL(dm_audit_log_ti);
  68
  69 void 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 }
  84 EXPORT_SYMBOL_GPL(dm_audit_log_bio);