TCP reassembly is now deactivated more frequently and triggering a
bypass on it is resulting in missing some alerts due forgetting
about packet based signature.
So this patch is introducing a dedicated flag that can be set in
the app layer and transmitted in the streaming to trigger bypass.
It is currently used by the SSL app layer to trigger bypass when
the stream becomes encrypted.
A parser can now set a flag that will tell the application
layer that it is capable of handling gaps. If enabled, and a
gap occurs, the app-layer needs to be prepared to accept
input that is NULL with a length, where the length is the
number of bytes lost. It is up to the app-layer to
determine if it can sync up with the input data again.
In various scenarios buffers would be checked my MPM more than
once. This was because the buffers would be inspected for a
certain progress value or higher.
For example, for each packet in a file upload, the engine would
not just rerun the 'http client body' MPM on the new data, it
would also rerun the method, uri, headers, cookie, etc MPMs.
This was obviously inefficent, so this patch changes the logic.
The patch only runs the MPM engines when the progress is exactly
the intended progress. If the progress is beyond the desired
value, it is run once. A tracker is added to the app layer API,
where the completed MPMs are tracked.
Implemented for HTTP, TLS and SSH.
Prevents the case where the logged id is incremented if a newer
transaction is complete and an older one is still outstanding.
For example, dns request0, unsolicited dns response, dns response0
would result in the valid response0 never being logged.
Similarily this could happen for:
request0, request1, response1, response0
which would end up having request0, request1 and response1 logged,
but response0 would not be logged.
This permits to set a stream depth value for each
app-layer.
By default, the stream depth specified for tcp is set,
then it's possible to specify a own value into the app-layer
module with a proper API.
Add support for the ENIP/CIP Industrial protocol
This is an app layer implementation which uses the "enip" protocol
and "cip_service" and "enip_command" keywords
Implements AFL entry points
This patch adds a transaction counter for application layers
supporting it. Analysis is done after the parsing by the
different application layers.
This result in new data in the stats output, that looks like:
```
"app-layer": {
"tx": {
"dns_udp": 21433,
"http": 12766,
"smtp": 0,
"dns_tcp": 0
}
},
```
To be able to add a transaction counter we will need a ThreadVars
in the AppLayerParserParse function.
This function is massively used in unittests
and this result in an long commit.
This function globally checks if the protocol is registered and
enabled by testing for the per alproto callback:
StateGetProgressCompletionStatus
This check is to be used before enabling Tx-aware code, like loggers.
Add function AppLayerParserRegisterLoggerFuncs for registering
a callback function for checking if a specific logger has logged
a transaction, and a callback function for specifying that it has.
Also add functions AppLayerParserGetTxLogged and
AppLayerParserSetTxLogged to invoke these callback functions.
Change AppLayerParserRegisterGetStateProgressCompletionStatus to
only store one ProgressCompletionStatus callback function for each
alproto, instead of storing one for each ipproto.
This enables us to use AppLayerParserGetStateProgressCompletionStatus
in functions where we do not know the ipproto used.
Add support for AFL PERSISTANT_MODE when Suricata is compiled with
a supported compiler (only afl-clang-fast for now).
This gives a ~10x performance boost when fuzzing.
This patch introduces a new set of commandline options meant for
assisting in fuzz testing the app layer implementations.
Per protocol, 2 commandline options are added:
--afl-http-request=<filename>
--afl-http=<filename>
In the former case, the contents of the file are passed directly to
the HTTP parser as request data.
In the latter case, the data is devided between request and responses.
First 64 bytes are request, then next 64 are response, next 64 are
request, etc, etc.
Stream GAPs and stream reassembly depth are tracked per direction. In
many cases they will happen in one direction, but not in the other.
Example:
HTTP requests a generally smaller than responses. So on the response
side we may hit the depth limit, but not on the request side.
The asynchronious 'disruption' has a side effect in the transaction
engine. The 'progress' tracking would never mark such transactions
as complete, and thus some inspection and logging wouldn't happen
until the very last moment: when EOF's are passed around.
Especially in proxy environments with _very_ many transactions in a
single TCP connection, this could lead to serious resource issues. The
EOF handling would suddenly have to handle thousands or more
transactions. These transactions would have been stored for a long time.
This patch introduces the concept of disruption flags. Flags passed to
the tx progress logic that are and indication of disruptions in the
traffic or the traffic handling. The idea is that the progress is
marked as complete on disruption, even if a tx is not complete. This
allows the detection and logging engines to process the tx after which
it can be cleaned up.
The app layer state 'version' field is incremented with each update
to the state. It is used by the detection engine to see if the current
version of the state has already been inspected. Since app layer and
detect always run closely together there is no need for a big number
here. The detect code really only checks for equal/not-equal, so wrap
arounds are not an issue.
On receiving TCP end of stream packets (e.g. RST, but also sometimes FIN
packets), in some cases the AppLayer parser would not be notified. This
could happen in IDS mode, but would especially be an issue in IPS mode.
This patch changes the logic of the AppLayer API to handle this. When no
new data is available, and the stream ends, the AppLayer API now gets
called with a NULL/0 input, but with the EOF flag set.
This allows the AppLayer parser to call it's final routines still in the
context of a real packet.
Instead, intruduce StreamTcpDisableAppLayer to disable app layer
tracking and reassembly. StreamTcpAppLayerIsDisabled can be used
to check it.
Replace all uses of FlowSetSessionNoApplayerInspectionFlag and
the FLOW_NO_APPLAYER_INSPECTION.
Decode Modbus request and response messages, and extracts
MODBUS Application Protocol header and the code function.
In case of read/write function, extracts message contents
(read/write address, quantity, count, data to write).
Links request and response messages in a transaction according to
Transaction Identifier (transaction management based on DNS source code).
MODBUS Messaging on TCP/IP Implementation Guide V1.0b
(http://www.modbus.org/docs/Modbus_Messaging_Implementation_Guide_V1_0b.pdf)
MODBUS Application Protocol Specification V1.1b3
(http://www.modbus.org/docs/Modbus_Application_Protocol_V1_1b3.pdf)
Based on DNS source code.
Signed-off-by: David DIALLO <diallo@et.esia.fr>
StreamTcpSetDisableRawReassemblyFlag() has the same effect as
AppLayerParserTriggerRawStreamReassembly in that it will force the
raw reassembly to flush out asap. So it is redundant to call both.
Implement StreamTcpSetDisableRawReassemblyFlag() which stops raw
reassembly for _NEW_ segments in a stream direction.
It is used only by TLS/SSL now, to flag the streams as encrypted.
Existing segments will still be reassembled and inspected, while
new segments won't be. This allows for pattern based inspection
of the TLS handshake.
Like is the case with completely disabled 'raw' reassembly, the
logic is that the segments are flagged as completed for 'raw' right
away. So they are not considered in raw reassembly anymore.
As no new segments will be considered, the chunk limit check will
return true on the next call.
AppLayerParserProtocolIsTxEventAware would check if a proto is tx
event aware by checking if it had registered a StateHasEvents function.
However, this is an optimization function. This patch changes it to
use the StateGetEvents function instead, which is a better indicator.
The new API call:
int AppLayerParserProtocolHasLogger(uint8_t ipproto,
AppProto alproto)
Returns TRUE if a logger is registered on the ip/alproto pair, and
FALSE otherwise.
If a protocol parser is active without a logger when detection is
disabled, the transaction handling logic would fail. Now it will
return the proper tx id so we can clean up the complete transactions.
When running w/o detect, TX cleanup handling needs to ignore the
inspect_id as it's only updated by detect.
This patch introduces a new ActiveTx handler for logging only:
AppLayerTransactionGetActiveLogOnly
If --disable-detection is passed on the commandline, this function
is registered.
Move app layer event handling into app-layer-event.[ch].
Convert 'Set' macro's to functions.
Get rid of duplication in Set and SetRaw. Set now calls SetRaw.
Fix potentential int overflow condition in the event storage.
Update callers.
In preparation of a patchset that will allow for disabling the detect
module, this patch introduces a way to register a function for getting
the lowest active tx id. This is used by the app layer for cleaning up
transactions that already fully inspected, and by the flow timeout code
to determine if a flow is fully inspected and logged at timeout.
The registration function RegisterAppLayerGetActiveTxIdFunc allows for
registration of a custom function of type:
uint64_t (*GetActiveTxIdFunc)(Flow *f, uint8_t flags);
If no function is called, AppLayerTransactionGetActiveDetectLog is used,
which implements the existing behaviour of considering both the
inspect_id's and the log_id.
In AppLayerTransactionsCleanup instead of figuring out 'done' tx id's
itself, now call AppLayerTransactionGetActive for both directions to
figure out the completed TX id's.
For AppLayerThreadCtx, AppLayerParserState, AppLayerParserThreadCtx
and AppLayerProtoDetectThreadCtx, use opaque pointers instead of
void pointers.
AppLayerParserState is declared in flow.h as it's part of the Flow
structure.
AppLayerThreadCtx is declared in decode.h, as it's part of the
DecodeThreadVars structure.
app-layer.[ch], app-layer-detect-proto.[ch] and app-layer-parser.[ch].
Things addressed in this commit:
- Brings out a proper separation between protocol detection phase and the
parser phase.
- The dns app layer now is registered such that we don't use "dnstcp" and
"dnsudp" in the rules. A user who previously wrote a rule like this -
"alert dnstcp....." or
"alert dnsudp....."
would now have to use,
alert dns (ipproto:tcp;) or
alert udp (app-layer-protocol:dns;) or
alert ip (ipproto:udp; app-layer-protocol:dns;)
The same rules extend to other another such protocol, dcerpc.
- The app layer parser api now takes in the ipproto while registering
callbacks.
- The app inspection/detection engine also takes an ipproto.
- All app layer parser functions now take direction as STREAM_TOSERVER or
STREAM_TOCLIENT, as opposed to 0 or 1, which was taken by some of the
functions.
- FlowInitialize() and FlowRecycle() now resets proto to 0. This is
needed by unittests, which would try to clean the flow, and that would
call the api, AppLayerParserCleanupParserState(), which would try to
clean the app state, but the app layer now needs an ipproto to figure
out which api to internally call to clean the state, and if the ipproto
is 0, it would return without trying to clean the state.
- A lot of unittests are now updated where if they are using a flow and
they need to use the app layer, we would set a flow ipproto.
- The "app-layer" section in the yaml conf has also been updated as well.
of the archaic features we use in the app layer. We will reintroduce this
parser shortly. Also do note that keywords that rely on the ssh parser
would now be disabled.
Flow timeout code worked by luck when checking if a flow still needed
reassembly for app layer inspection or logging. It would check for a
part of raw reassembly (smsg list) to determine if detection was
needed. In this case it would also process app layer cleanup,
including logging.
Introduced AppLayerTransactionGetActive which returns the lowest tx_id
in a direction that still needs some work.
FlowForceReassemblyNeedReassmbly now uses it to determine if the
applayer still needs work.
Converted FlowForceReassemblyForHash to use the checking function
FlowForceReassemblyNeedReassmbly as well, so that checking if a flow
needs work is now unified.
When logging is disabled, the app layer would still be flagged
as logging. This caused transactions not to be freed until the
end of the flow as the logged tx id would never increment.
This fix postpones the setting of the app layer parser "logger"
flag to the point where we know the logger is enabled.
This patch is a result of applying the following coccinelle
transformation to suricata sources:
@istested@
identifier x;
statement S1;
identifier func =~ "(SCMalloc|SCStrdup|SCCalloc|SCMallocAligned|SCRealloc)";
@@
x = func(...)
... when != x
- if (x == NULL) S1
+ if (unlikely(x == NULL)) S1
We don't support jabber protocol detection atm. Disable the code check
inside suricata to check if jabber protocol detection is enabled in the
yaml file.
Also updated an error log message for app layer.
app-layer-parser.c: In function ‘AppLayerPPTestData’:
app-layer-parser.c:2525:9: error: variable ‘dir’ set but not used [-Werror=unused-but-set-variable]
int dir = 0;
^
Removed a flag parameter introuced earlier to indicate the data
that is first acceptable by the parser. We now use a differently
named parameter to carry out the same activity.
1. Proto detection
2. Parsers
For app layer protocols.
libhtp has now been moved to the section under app-layer.protocols.http,
but we still provide backward compatibility with older conf files.
In debug validation mode, it is required to call application layer
parsing and other functions with a lock on flow. This patch updates
the code to do so.
Also, update StateTransactionFree to take an u64 tx id, so it's
consistant with the rest of the engine.
To reflect these changes, AppLayerRegisterTransactionIdFuncs has
been renamed to AppLayerRegisterTxFreeFunc.
HTP, DNS, SMB, DCERPC parsers updated.
Per TX decoder events resulted in significant overhead to the
detection engine, as it walked all TX' all the time to check
if decoder events were available.
This commit introduces a new API call StateHasEvents, which speeds
up this process, at the expense of keeping a counter in the state.
Implement this for DNS as well.
Victor Julien
Eric Leblond
Jason Ish
Giuseppe Longo
kwong
Justin Viiret
Mats Klepsland
maxtors
DIALLO David
Ken Steele
jeka
Will Metcalf
Anoop Saldanha