Smtp inspection fix/v3 #13550
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Smtp inspection fix/v3 #13550
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to build the correct behavior. As a part of ab01a1b, in order to match the behavior in master, the calls for triggering raw stream inspection were made when communication in one direction for a transaction was completed. However, it was incorrect to do so. Reliable inspection requires any request line/response line to be completed. Bug 7783
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. SMTP parser can handle multiple command lines per direction. Appropriate calls to trigger raw stream inspection have been added on succesful parsing of each request line and response line. For the requests, the call to trigger inspection has been added in the beginning rather than the completion of transactions. This does not affect the inspection as it is actually triggered in the following call. This covers the case for anomaly as well. There are two benefits for this: - immediate inspection for anomalous data - flushing of the anomalous data making next data's inspection cleaner Bug 7783
Codecov ReportAll modified and coverable lines are covered by tests ✅
Additional details and impacted files@@ Coverage Diff @@
## master #13550 +/- ##
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Coverage 83.51% 83.51%
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Files 1011 1011
Lines 275053 275052 -1
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+ Hits 229707 229715 +8
+ Misses 45346 45337 -9
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Information: QA ran without warnings. Pipeline = 26665 |
victorjulien
approved these changes
Jun 30, 2025
catenacyber
approved these changes
Jun 30, 2025
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Thanks for the work,
CI : ✅ (not sure about the internal test you are mentioning)
Code : good
Commits segmentation : ok
Commit messages : good (I do not know if we are doing reverts)
Git ID set : looks fine for me
CLA : you already contributed
Doc update : nice
Redmine ticket : ok
Rustfmt : no rust
Tests : Should we have a SV test ?
Dependencies added: none
Merged
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Merged in #13557, thanks! |
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Link to ticket: https://redmine.openinfosecfoundation.org/issues/7783
Restores behavior from the past rejected PR b4c51d3 as that was correct.
Previous PR: #13507
Changes since v2:
NOTE: Requires upgrading of at least one internal test.