From 976748b777fbbbba41491401c73c83e05e0a7c8a Mon Sep 17 00:00:00 2001
From: Victor Julien <vjulien@oisf.net>
Date: Tue, 19 Apr 2022 12:17:31 +0200
Subject: [PATCH] doc/smb: add resource limits section

---
 doc/userguide/configuration/suricata-yaml.rst | 60 +++++++++++++++++--
 1 file changed, 56 insertions(+), 4 deletions(-)

diff --git a/doc/userguide/configuration/suricata-yaml.rst b/doc/userguide/configuration/suricata-yaml.rst
index f88f9103b3..9938cb5298 100644
--- a/doc/userguide/configuration/suricata-yaml.rst
+++ b/doc/userguide/configuration/suricata-yaml.rst
@@ -1362,10 +1362,8 @@ the app-layer event ``http.compression_bomb`` is set
 (this event can also set from other conditions).
 This can happen on slow configurations (hardware, ASAN, etc...)
 
-Configure SMB (Rust)
-~~~~~~~~~~~~~~~~~~~~
-
-.. note:: for full SMB support compile Suricata with Rust support
+Configure SMB
+~~~~~~~~~~~~~
 
 The SMB parser will parse version 1, 2 and 3 of the SMB protocol over TCP.
 
@@ -1385,6 +1383,60 @@ independent. The ``probing parsers`` will only run on the ``detection-ports``.
 SMB is commonly used to transfer the DCERPC protocol. This traffic is also handled by
 this parser.
 
+Resource limits
+---------------
+
+Several options are available for limiting record sizes and data chunk tracking.
+
+::
+
+    smb:
+      enabled: yes
+      max-read-size: 8mb
+      max-write-size: 1mb
+
+      max-read-queue-size: 16mb
+      max-read-queue-cnt: 16
+
+      max-write-queue-size: 16mb
+      max-write-queue-cnt: 16
+
+The `max-read-size` option can be set to control the max size of accepted
+READ records. Events will be raised if a READ request asks for too much data
+and/or if READ responses are too big. A value of 0 disables the checks.
+
+The `max-write-size` option can be set to control the max size of accepted
+WRITE request records. Events will be raised if a WRITE request sends too much
+data. A value of 0 disables the checks.
+
+Additionally if the `max-read-size` or `max-write-size` values in the
+"negotiate protocol response" exceeds this limit an event will also be raised.
+
+
+For file tracking, extraction and file data inspection the parser queues up
+out of order data chunks for both READs and WRITEs. To avoid using too much
+memory the parser allows for limiting both the size in bytes and the number
+of queued chunks.
+
+::
+
+    smb:
+      enabled: yes
+
+      max-read-queue-size: 16mb
+      max-read-queue-cnt: 16
+
+      max-write-queue-size: 16mb
+      max-write-queue-cnt: 16
+
+`max-read-queue-size` controls how many bytes can be used per SMB flow for
+out of order READs. `max-read-queue-cnt` controls how many READ chunks can be
+queued per SMB flow. Processing of these chunks will be blocked when any of
+the limits are exceeded, and an event will be raised.
+
+`max-write-queue-size` and `max-write-queue-cnt` are as the READ variants,
+but then for WRITEs.
+
 Configure HTTP2
 ~~~~~~~~~~~~~~~