dnp3: trigger raw stream inspection

Internals
---------
Suricata's stream engine returns data for inspection to the detection
engine from the stream when the chunk size is reached.

Bug
---
Inspection triggered only in the specified chunk sizes may be too late
when it comes to inspection of smaller protocol specific data which
could result in delayed inspection, incorrect data logged with a transaction
and logs misindicating the pkt that triggered an alert.

Fix
---
Fix this by making an explicit call from all respective applayer parsers to
trigger raw stream inspection which shall make the data available for inspection
in the following call of the stream engine. This needs to happen per direction
on the completion of an entity like a request or a response.

Important notes
---------------
1. The above mentioned behavior with and without this patch is
affected internally by the following conditions.
- inspection depth
- stream depth
In these special cases, the inspection window will be affected and
Suricata may not consider all the data that could be expected to be
inspected.
2. This only applies to applayer protocols running over TCP.
3. The inspection window is only considered up to the ACK'd data.
4. This entire issue is about IDS mode only.

DNP3 parser creates a transaction per direction. Appropriate calls to trigger
raw stream inspection have been added on succesful parsing of each request and
response.

Task 7026
Bug 7004

diff --git a/src/app-layer-dnp3.c b/src/app-layer-dnp3.c
index df7d5e13beafcd93882953a0482e2e30659d35ba..63e5972319afb97a0825347518db8a846a65a10d 100644 (file)
--- a/src/app-layer-dnp3.c
+++ b/src/app-layer-dnp3.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2015-2024 Open Information Security Foundation
+/* Copyright (C) 2015-2025 Open Information Security Foundation
  *
  * You can copy, redistribute or modify this Program under the terms of
  * the GNU General Public License version 2 as published by the Free
@@ -848,8 +848,8 @@ done:
  * \param input pointer to the DNP3 frame (starting with link header)
  * \param input_len length of the input frame
  */
-static void DNP3HandleUserDataRequest(DNP3State *dnp3, const uint8_t *input,
-    uint32_t input_len)
+static void DNP3HandleUserDataRequest(
+        Flow *f, DNP3State *dnp3, const uint8_t *input, uint32_t input_len)
 {
     DNP3LinkHeader *lh;
     DNP3TransportHeader th;
@@ -923,10 +923,13 @@ static void DNP3HandleUserDataRequest(DNP3State *dnp3, const uint8_t *input,
                 tx->buffer_len - sizeof(DNP3ApplicationHeader), &tx->objects)) {
         tx->complete = 1;
     }
+    if (f != NULL) {
+        AppLayerParserTriggerRawStreamInspection(f, STREAM_TOSERVER);
+    }
 }
 
-static void DNP3HandleUserDataResponse(DNP3State *dnp3, const uint8_t *input,
-    uint32_t input_len)
+static void DNP3HandleUserDataResponse(
+        Flow *f, DNP3State *dnp3, const uint8_t *input, uint32_t input_len)
 {
     DNP3LinkHeader *lh;
     DNP3TransportHeader th;
@@ -997,6 +1000,9 @@ static void DNP3HandleUserDataResponse(DNP3State *dnp3, const uint8_t *input,
                 tx, tx->buffer + offset, tx->buffer_len - offset, &tx->objects)) {
         tx->complete = 1;
     }
+    if (f != NULL) {
+        AppLayerParserTriggerRawStreamInspection(f, STREAM_TOCLIENT);
+    }
 }
 
 /**
@@ -1005,8 +1011,8 @@ static void DNP3HandleUserDataResponse(DNP3State *dnp3, const uint8_t *input,
  * \retval number of bytes processed or -1 if the data stream does not look
  *     like DNP3.
  */
-static int DNP3HandleRequestLinkLayer(DNP3State *dnp3, const uint8_t *input,
-    uint32_t input_len)
+static int DNP3HandleRequestLinkLayer(
+        Flow *f, DNP3State *dnp3, const uint8_t *input, uint32_t input_len)
 {
     SCEnter();
     uint32_t processed = 0;
@@ -1057,7 +1063,7 @@ static int DNP3HandleRequestLinkLayer(DNP3State *dnp3, const uint8_t *input,
             goto next;
         }
 
-        DNP3HandleUserDataRequest(dnp3, input, frame_len);
+        DNP3HandleUserDataRequest(f, dnp3, input, frame_len);
 
     next:
         /* Advance the input buffer. */
@@ -1100,9 +1106,8 @@ static AppLayerResult DNP3ParseRequest(Flow *f, void *state, AppLayerParserState
         if (!DNP3BufferAdd(buffer, input, input_len)) {
             goto error;
         }
-        processed = DNP3HandleRequestLinkLayer(dnp3,
-            buffer->buffer + buffer->offset,
-            buffer->len - buffer->offset);
+        processed = DNP3HandleRequestLinkLayer(
+                f, dnp3, buffer->buffer + buffer->offset, buffer->len - buffer->offset);
         if (processed < 0) {
             goto error;
         }
@@ -1110,7 +1115,7 @@ static AppLayerResult DNP3ParseRequest(Flow *f, void *state, AppLayerParserState
         DNP3BufferTrim(buffer);
     }
     else {
-        processed = DNP3HandleRequestLinkLayer(dnp3, input, input_len);
+        processed = DNP3HandleRequestLinkLayer(f, dnp3, input, input_len);
         if (processed < 0) {
             SCLogDebug("Failed to process request link layer.");
             goto error;
@@ -1141,8 +1146,8 @@ error:
  * \retval number of bytes processed or -1 if the data stream does not
  *     like look DNP3.
  */
-static int DNP3HandleResponseLinkLayer(DNP3State *dnp3, const uint8_t *input,
-    uint32_t input_len)
+static int DNP3HandleResponseLinkLayer(
+        Flow *f, DNP3State *dnp3, const uint8_t *input, uint32_t input_len)
 {
     SCEnter();
     uint32_t processed = 0;
@@ -1194,7 +1199,7 @@ static int DNP3HandleResponseLinkLayer(DNP3State *dnp3, const uint8_t *input,
             goto next;
         }
 
-        DNP3HandleUserDataResponse(dnp3, input, frame_len);
+        DNP3HandleUserDataResponse(f, dnp3, input, frame_len);
 
     next:
         /* Advance the input buffer. */
@@ -1235,9 +1240,8 @@ static AppLayerResult DNP3ParseResponse(Flow *f, void *state, AppLayerParserStat
         if (!DNP3BufferAdd(buffer, input, input_len)) {
             goto error;
         }
-        processed = DNP3HandleResponseLinkLayer(dnp3,
-            buffer->buffer + buffer->offset,
-            buffer->len - buffer->offset);
+        processed = DNP3HandleResponseLinkLayer(
+                f, dnp3, buffer->buffer + buffer->offset, buffer->len - buffer->offset);
         if (processed < 0) {
             goto error;
         }
@@ -1251,7 +1255,7 @@ static AppLayerResult DNP3ParseResponse(Flow *f, void *state, AppLayerParserStat
             goto done;
         }
 
-        processed = DNP3HandleResponseLinkLayer(dnp3, input, input_len);
+        processed = DNP3HandleResponseLinkLayer(f, dnp3, input, input_len);
         if (processed < 0) {
             goto error;
         }
@@ -2464,7 +2468,7 @@ static int DNP3ParserTestParsePDU01(void)
     };
 
     DNP3State *dnp3state = DNP3StateAlloc(NULL, ALPROTO_UNKNOWN);
-    int pdus = DNP3HandleRequestLinkLayer(dnp3state, pkt, sizeof(pkt));
+    int pdus = DNP3HandleRequestLinkLayer(NULL, dnp3state, pkt, sizeof(pkt));
     FAIL_IF(pdus < 1);
     DNP3Transaction *dnp3tx = DNP3GetTx(dnp3state, 0);
     FAIL_IF_NULL(dnp3tx);
@@ -2504,7 +2508,7 @@ static int DNP3ParserDecodeG70V3Test(void)
 
     DNP3State *dnp3state = DNP3StateAlloc(NULL, ALPROTO_UNKNOWN);
     FAIL_IF_NULL(dnp3state);
-    int bytes = DNP3HandleRequestLinkLayer(dnp3state, pkt, sizeof(pkt));
+    int bytes = DNP3HandleRequestLinkLayer(NULL, dnp3state, pkt, sizeof(pkt));
     FAIL_IF(bytes != sizeof(pkt));
     DNP3Transaction *tx = DNP3GetTx(dnp3state, 0);
     FAIL_IF_NULL(tx);
@@ -2565,7 +2569,7 @@ static int DNP3ParserUnknownEventAlertTest(void)
 
     DNP3State *dnp3state = DNP3StateAlloc(NULL, ALPROTO_UNKNOWN);
     FAIL_IF_NULL(dnp3state);
-    int bytes = DNP3HandleRequestLinkLayer(dnp3state, pkt, sizeof(pkt));
+    int bytes = DNP3HandleRequestLinkLayer(NULL, dnp3state, pkt, sizeof(pkt));
     FAIL_IF(bytes != sizeof(pkt));
 
     DNP3StateFree(dnp3state);