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.
RFB has several different types of requests and responses. Appropriate calls
to trigger raw stream inspection have been added on completion of each type of
request and response.
Task 7026
Bug 7004
Introduce DetectGetSingleData which does the generic wrapping,
including the transforms, using a new callback prototype
DetectTxGetBufferPtr
The goal is to replace most InspectionBufferGetDataPtr.
For this commit, we do not change every callback to keep the
change relatively small.
Focus here is to remove DetectHelperGetData as its functionality is
provided more directly by the new DetectTxGetBufferPtr.
Ticket: 7667
And prefix SCDetectBufferSetActiveList to be exported
Allows less use of suricata crate in plugin as we get the functions
prototypes from suricata_sys and they are more correct.
Have bindgen generate bindings for app-layer-protos.h, then use the
generated definitions of AppProto/AppProtoEnum instead if defining
them ourselves.
This header was chosen as its used by Rust, and its a simple header
with no circular dependencies.
Ticket: #7341
Both the macros export_tx_data_get and export_state_data_get can
generate non-pub functions as the function they generate is only used
as a pointer during registration.
Remove "pub" and "no_mangle" from the generated functions and update
the names of the generated functions to follow Rust rules as they are
no longer exported into the global C namespace.
Ticket: 7498
To optimize detection, and logging, to avoid going through
all the live transactions when only a few were modified.
Two boolean fields are added to the tx data: updated_tc and ts
The app-layer parsers are now responsible to set these when
needed, and the logging and detection uses them to skip
transactions that were not updated.
There may some more optimization remaining by when we set
both updated_tc and updated_ts in functions returning
a mutable transaction, by checking if all the callers
are called in one direction only (request or response)
Ticket: 7087
truncate fn is only active and used by dcerpc and smb parsers. In case
stream depth is reached for any side, truncate fn is supposed to set the
tx entity (request/response) in the same direction as complete so the
other side is not forever waiting for data.
However, whether the stream depth is reached is already checked by
AppLayerParserGetStateProgress fn which is called by:
- DetectTx
- DetectEngineInspectBufferGeneric
- AppLayerParserSetTransactionInspectId
- OutputTxLog
- AppLayerParserTransactionsCleanup
and, in such a case, StateGetProgressCompletionStatus is returned for
the respective direction. This fn following efc9a7a, always returns 1
as long as the direction is valid meaning that the progress for the
current direction is marked complete. So, there is no need for the additional
callback to mark the entities as done in case of depth or a gap.
Remove all such glue code and callbacks for truncate fns.
Bug 7044
We only try to parse a small subset of what is possible in
RFB. Currently we only understand some standard auth schemes
and stop parsing when the server-client handshake is complete.
Since in IPS mode returning an error from the parser causes
drops that are likely uncalled for, we do not want to return
errors when we simply do not understand what happens in the
traffic. This addresses Redmine #5912.
Bug: #5912.
Update APIs to store files in transactions instead of the per flow state.
Goal is to avoid the overhead of matching up files and transactions in
cases where there are many of both.
Update all protocol implementations to support this.
Update file logging logic to account for having files in transactions. Instead
of it acting separately on file containers, it is now tied into the
transaction logging.
Update the filestore keyword to consider a match if filestore output not
enabled.
Philippe Antoine
Shivani Bhardwaj
Jason Ish
Victor Julien
Alice Akaki
Philippe Antoine
Daniel Olatunji
Sascha Steinbiss
Haleema Khan
Victor Julien