[auditbeat] fim: implement kprobes backend

CHANGELOG.next.asciidoc

@@ -18,6 +18,7 @@ you can achieve this by overwriting the value using an `add_fields` processor. {
 
 *Auditbeat*
 
+- Add opt-in `KProbes` backend for file_integrity module. {pull}37796[37796]
 
 *Filebeat*
 

NOTICE.txt

@@ -15825,6 +15825,218 @@ Contents of probable licence file $GOMODCACHE/github.com/elastic/[email protected]/LIC
    limitations under the License.
 
 
+--------------------------------------------------------------------------------
+Dependency : github.com/elastic/tk-btf
+Version: v0.1.0
+Licence type (autodetected): Apache-2.0
+--------------------------------------------------------------------------------
+
+Contents of probable licence file $GOMODCACHE/github.com/elastic/[email protected]/LICENSE.txt:
+
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+
+
 --------------------------------------------------------------------------------
 Dependency : github.com/elastic/toutoumomoma
 Version: v0.0.0-20221026030040-594ef30cb640

auditbeat/auditbeat.reference.yml

@@ -92,6 +92,10 @@ auditbeat.modules:
   # Auditbeat will ignore files unless they match a pattern.
   #include_files:
   #- '/\.ssh($|/)'
+  # Select the backend which will be used to source events.
+  # Valid values: ebpf, kprobes, fsnotify.
+  # Default: fsnotify.
+  force_backend: fsnotify
 
   # Scan over the configured file paths at startup and send events for new or
   # modified files since the last time Auditbeat was running.

auditbeat/docker-compose.yml

@@ -14,6 +14,7 @@ services:
       - KIBANA_PORT=5601
     volumes:
       - ${PWD}/..:/go/src/github.com/elastic/beats/
+      - /sys:/sys
     command: make
     privileged: true
     pid: host

auditbeat/docs/modules/file_integrity.asciidoc

@@ -28,8 +28,12 @@ to only send events for new or modified files.
 
 The operating system features that power this feature are as follows.
 
-* Linux - `inotify` is used, and therefore the kernel must have inotify support.
-Inotify was initially merged into the 2.6.13 Linux kernel.
+* Linux - As of now, three kernel backends are supported: `ebpf`, `kprobes` and `fsnotify`.
+By default, `fsnotify` is used, and therefore the kernel must have inotify support.
+`Inotify` was initially merged into the 2.6.13 Linux kernel.
+The `Kprobes` backend uses tracefs and supports 3.10+ kernels.
+The `eBPF` backend uses modern eBPF features and supports 5.10.16+ kernels.
+The preferred backend can be selected by specifying the `force_backend` config option.
 * macOS (Darwin) - Uses the `FSEvents` API, present since macOS 10.5. This API
 coalesces multiple changes to a file into a single event. {beatname_uc} translates
 this coalesced changes into a meaningful sequence of actions. However,

auditbeat/module/file_integrity/_meta/config.yml.tmpl

@@ -55,6 +55,13 @@
   #- '/\.ssh($|/)'
   {{- end }}
 
+  {{- if eq .GOOS "linux" }}
+  # Select the backend which will be used to source events.
+  # Valid values: ebpf, kprobes, fsnotify.
+  # Default: fsnotify.
+  force_backend: fsnotify
+  {{- end }}
+
   # Scan over the configured file paths at startup and send events for new or
   # modified files since the last time Auditbeat was running.
   scan_at_start: true

auditbeat/module/file_integrity/_meta/docs.asciidoc

@@ -21,8 +21,12 @@ to only send events for new or modified files.
 
 The operating system features that power this feature are as follows.
 
-* Linux - `inotify` is used, and therefore the kernel must have inotify support.
-Inotify was initially merged into the 2.6.13 Linux kernel.
+* Linux - As of now, three kernel backends are supported: `ebpf`, `kprobes` and `fsnotify`.
+By default, `fsnotify` is used, and therefore the kernel must have inotify support.
+`Inotify` was initially merged into the 2.6.13 Linux kernel.
+The `Kprobes` backend uses tracefs and supports 3.10+ kernels.
+The `eBPF` backend uses modern eBPF features and supports 5.10.16+ kernels.
+The preferred backend can be selected by specifying the `force_backend` config option.
 * macOS (Darwin) - Uses the `FSEvents` API, present since macOS 10.5. This API
 coalesces multiple changes to a file into a single event. {beatname_uc} translates
 this coalesced changes into a meaningful sequence of actions. However,

auditbeat/module/file_integrity/config.go

@@ -18,10 +18,12 @@
 package file_integrity
 
 import (
+	"errors"
 	"fmt"
 	"math"
 	"path/filepath"
 	"regexp"
+	"runtime"
 	"sort"
 	"strings"
 
@@ -72,6 +74,19 @@ const (
 	XXH64       HashType = "xxh64"
 )
 
+type Backend string
+
+const (
+	BackendFSNotify Backend = "fsnotify"
+	BackendEBPF     Backend = "ebpf"
+	BackendKProbes  Backend = "kprobes"
+)
+
+func (b *Backend) Unpack(v string) error {
+	*b = Backend(v)
+	return nil
+}
+
 // Config contains the configuration parameters for the file integrity
 // metricset.
 type Config struct {
@@ -86,6 +101,7 @@ type Config struct {
 	Recursive           bool            `config:"recursive"` // Recursive enables recursive monitoring of directories.
 	ExcludeFiles        []match.Matcher `config:"exclude_files"`
 	IncludeFiles        []match.Matcher `config:"include_files"`
+	ForceBackend        Backend         `config:"force_backend"`
 }
 
 // Validate validates the config data and return an error explaining all the
@@ -160,6 +176,19 @@ nextHash:
 	if err != nil {
 		errs = append(errs, fmt.Errorf("invalid scan_rate_per_sec value: %w", err))
 	}
+
+	if len(c.ForceBackend) > 0 {
+		if runtime.GOOS != "linux" {
+			errs = append(errs, errors.New("force_backend can only be specified on linux"))
+		}
+
+		switch c.ForceBackend {
+		case BackendEBPF, BackendKProbes, BackendFSNotify:
+		default:
+			errs = append(errs, errors.New("force_backend can only be 'ebpf', 'kprobes' or 'fsnotify'"))
+		}
+	}
+
 	return errs.Err()
 }
 

auditbeat/module/file_integrity/event.go

@@ -62,14 +62,19 @@ func (s Source) MarshalText() ([]byte, error) { return []byte(s.String()), nil }
 const (
 	// SourceScan identifies events triggered by a file system scan.
 	SourceScan Source = iota
-	// SourceFSNotify identifies events triggered by a notification from the
-	// file system.
+	// SourceFSNotify identifies file integrity events triggered by fsnotify backend.
 	SourceFSNotify
+	// SourceEBPF identifies file integrity events triggered by eBPF backend.
+	SourceEBPF
+	// SourceKProbes identifies file integrity events triggered by KProbes backend.
+	SourceKProbes
 )
 
 var sourceNames = map[Source]string{
 	SourceScan:     "scan",
 	SourceFSNotify: "fsnotify",
+	SourceEBPF:     "ebpf",
+	SourceKProbes:  "kprobes",
 }
 
 // Type identifies the file type (e.g. dir, file, symlink).