[Oisf-devel] libhtp 0.5.x integration - bug 775
Anoop Saldanha
anoopsaldanha at gmail.com
Fri Jun 7 14:51:52 UTC 2013
Ivan,
When a request such as "HELLO\r\n", libhtp would have the
"request_protocol_number" set as HTP_PROTOCOL_0_9. Is that right or
should it be HTP_PROTOCOL_UNKNOWN?
On Tue, Jun 4, 2013 at 12:02 AM, Anoop Saldanha <anoopsaldanha at gmail.com> wrote:
> On Mon, Jun 3, 2013 at 10:48 PM, Victor Julien <victor at inliniac.net> wrote:
>> On 06/03/2013 06:07 PM, Anoop Saldanha wrote:
>>> @Victor
>>>
>>> Since we need to store the normalized request uri in our htp_state, we
>>> can probably figure out a solution that we can also reuse in dcerpc
>>> for storing transactions.
>>>
>>> Probably a linked_list that stores the tx_id(tx id for the related
>>> data) of it's head?
>>
>> Would it be an option to use the per tx HtpUserData that we use in the
>> 0.2.x implementation for body tracking?
>
> Yes, we can use it store all generated buffers.
>
>>
>>> On Wed, May 15, 2013 at 12:38 PM, Anoop Saldanha
>>> <anoopsaldanha at gmail.com> wrote:
>>>> Right. Thanks.
>>>>
>>>> On Wed, May 15, 2013 at 12:18 PM, Ivan Ristic <ivan.ristic at gmail.com> wrote:
>>>>> On Wed, May 15, 2013 at 7:37 AM, Anoop Saldanha <anoopsaldanha at gmail.com> wrote:
>>>>>> Ivan,
>>>>>>
>>>>>> I see the introduction of
>>>>>>
>>>>>> htp_tx_t *htp_connp_get_in_tx(const htp_connp_t *connp);
>>>>>> htp_tx_t *htp_connp_get_out_tx(const htp_connp_t *connp);
>>>>>>
>>>>>> Which means I won't be able to retrieve individual txs?
>>>>>
>>>>> Those 2 functions will give you only the currently active request and
>>>>> response, respectively. There can be one of each at any given time.
>>>>>
>>>>> With recent changes, callbacks are sent the correct tx, so the above
>>>>> functions will rarely be needed when you're processing one transaction
>>>>> at a time.
>>>>>
>>>>>
>>>>>> I receive 5
>>>>>> pipelined requests, so that would be 5 txs created. How do I retrieve
>>>>>> the individual txs?
>>>>>
>>>>> The transactions are in htp_conn_t::transactions, which is a list. How
>>>>> to access the htp_conn_t pointer depends on your setup. You probably
>>>>> keep a pointer to connp somewhere in your context, and from there you
>>>>> can get a connection using htp_connp_get_connection().
>>>>>
>>>>>
>>>>>> On Thu, Apr 11, 2013 at 10:16 PM, Anoop Saldanha
>>>>>> <anoopsaldanha at gmail.com> wrote:
>>>>>>> On Thu, Apr 11, 2013 at 9:10 PM, Ivan Ristic <ivan.ristic at gmail.com> wrote:
>>>>>>>> I wouldn't advise you to do any buffering anyhow.
>>>>>>>> But I am curious if you're
>>>>>>>> deleting transactions once you're done with them. Because, if you're not,
>>>>>>>> you may be allocating a lot of memory (all tx instances) on long-lived HTTP
>>>>>>>> connections.
>>>>>>>>
>>>>>>>
>>>>>>> We do delete them, once we're done.
>>>>>>>
>>>>>>>>
>>>>>>>> On Tue, Apr 9, 2013 at 1:06 PM, Anoop Saldanha <anoopsaldanha at gmail.com>
>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>> On Tue, Apr 9, 2013 at 2:36 PM, Victor Julien <victor at inliniac.net> wrote:
>>>>>>>>>> (bad juju to brian and ivan for top posting and/or html emails! :)
>>>>>>>>>>
>>>>>>>>>> On 04/09/2013 10:21 AM, Ivan Ristic wrote:
>>>>>>>>>>> On Mon, Apr 8, 2013 at 3:54 PM, Anoop Saldanha <anoopsaldanha at gmail.com
>>>>>>>>>>> <mailto:anoopsaldanha at gmail.com>> wrote:
>>>>>>>>>>>
>>>>>>>>>>> On Mon, Apr 8, 2013 at 7:50 PM, Brian Rectanus <brectanu at gmail.com
>>>>>>>>>>> <mailto:brectanu at gmail.com>> wrote:
>>>>>>>>>>> >
>>>>>>>>>>> > On Mon, Apr 8, 2013 at 9:16 AM, Brian Rectanus
>>>>>>>>>>> <brectanu at gmail.com
>>>>>>>>>>> <mailto:brectanu at gmail.com>> wrote:
>>>>>>>>>>> >>
>>>>>>>>>>> >>
>>>>>>>>>>> >> On Mon, Apr 8, 2013 at 8:47 AM, Anoop Saldanha
>>>>>>>>>>> <anoopsaldanha at gmail.com <mailto:anoopsaldanha at gmail.com>>
>>>>>>>>>>> >> wrote:
>>>>>>>>>>> >>>
>>>>>>>>>>> >>> On Mon, Apr 8, 2013 at 3:42 PM, Victor Julien
>>>>>>>>>>> <victor at inliniac.net <mailto:victor at inliniac.net>>
>>>>>>>>>>> >>> wrote:
>>>>>>>>>>> >>> > (moving to oisf-devel)
>>>>>>>>>>> >>> >
>>>>>>>>>>> >>> > On 04/08/2013 06:17 AM, Anoop Saldanha wrote:
>>>>>>>>>>> >>> >>>> I recollect we introduced path and query double decoding
>>>>>>>>>>> through
>>>>>>>>>>> >>> >>>> configurable params, and also we had this thing with query
>>>>>>>>>>> >>> >>>> decoding(single level). Can you explain a bit what the
>>>>>>>>>>> status was
>>>>>>>>>>> >>> >>>> previously. Seeing related failed uts.
>>>>>>>>>>> >>> >>>>
>>>>>>>>>>> >>> >>>
>>>>>>>>>>> >>> >>> We run the path normalization on the query through our
>>>>>>>>>>> >>> >>> HTPCallbackRequestUriNormalizeQuery callback. Previously we
>>>>>>>>>>> used
>>>>>>>>>>> >>> >>> htp_decode_path_inplace to normalize the query (e.g. for
>>>>>>>>>>> >>> >>> uridecoding).
>>>>>>>>>>> >>> >>> However, this was causing issues (remember that pcre "bug"
>>>>>>>>>>> we
>>>>>>>>>>> >>> >>> discussed
>>>>>>>>>>> >>> >>> a while back, where http:// turned into http:/).
>>>>>>>>>>> >>> >>>
>>>>>>>>>>> >>> >>> In libhtp I copied htp_decode_path_inplace to
>>>>>>>>>>> >>> >>> htp_decode_query_inplace
>>>>>>>>>>> >>> >>> and also copied the config params and cfg funcs:
>>>>>>>>>>> >>> >>>
>>>>>>>>>>> >>> >>>
>>>>>>>>>>>
>>>>>>>>>>> https://github.com/inliniac/suricata/commit/d41c762689a08e6814dc93e8bfebeceab97175c3
>>>>>>>>>>> >>> >>>
>>>>>>>>>>> >>> >>> Hack of the 1st order, which is wrong in many ways. But it
>>>>>>>>>>> basically
>>>>>>>>>>> >>> >>> allowed me to make sure we don't normalize the query as if
>>>>>>>>>>> it's path,
>>>>>>>>>>> >>> >>> esp with turning ftp:// into ftp:/ and such.
>>>>>>>>>>> >>> >>>
>>>>>>>>>>> >>> >>> For 0.5 integration I think we need a proper solution. The
>>>>>>>>>>> only
>>>>>>>>>>> >>> >>> reason I
>>>>>>>>>>> >>> >>> pushed my hack like this was that I knew in 0.5 we would
>>>>>>>>>>> make things
>>>>>>>>>>> >>> >>> right.
>>>>>>>>>>> >>> >>>
>>>>>>>>>>> >>> >>
>>>>>>>>>>> >>> >> I think if we still want to double decode, we still require
>>>>>>>>>>> all of
>>>>>>>>>>> >>> >> these above things from our bundled htp.
>>>>>>>>>>> >>> >>
>>>>>>>>>>> >>> >> -----
>>>>>>>>>>> >>> >>
>>>>>>>>>>> >>> >> In 0.5.x, tx->request_uri_normalized has been removed, and
>>>>>>>>>>> we'd now
>>>>>>>>>>> >>> >> have to use the REQUEST_URI hook. We'll have to carry out
>>>>>>>>>>> the
>>>>>>>>>>> >>> >> reconstruction ourselves, and store it ourselves in our
>>>>>>>>>>> HTPState.
>>>>>>>>>>> >>> >>
>>>>>>>>>>> >>>
>>>>>>>>>>> >>> What are your thoughts on this?
>>>>>>>>>>> >>>
>>>>>>>>>>> >>> >
>>>>>>>>>>> >>> > IIRC there is some function in libhtp that does just the
>>>>>>>>>>> decoding of
>>>>>>>>>>> >>> > uriencoding and unicode. We should probably just use that on
>>>>>>>>>>> the query
>>>>>>>>>>> >>> > and do the full normalization on the path.
>>>>>>>>>>> >>> >
>>>>>>>>>>> >>> > As a side thought: I think it would be nice to store path and
>>>>>>>>>>> query
>>>>>>>>>>> >>> > separately so that we can add http_path and http_query
>>>>>>>>>>> keywords later
>>>>>>>>>>> >>> > on.
>>>>>>>>>>> >>> >
>>>>>>>>>>> >>>
>>>>>>>>>>> >>> We'd pretty much extract it directly from parsed_uri. Will
>>>>>>>>>>> have to
>>>>>>>>>>> >>> check if we need the extract double decode phase we have
>>>>>>>>>>> currently in
>>>>>>>>>>> >>> our bundled htp, in which case we'd need to store them
>>>>>>>>>>> separately.
>>>>>>>>>>> >>>
>>>>>>>>>>> >>
>>>>>>>>>>> >> Yes, all the normalized components are in tx->parsed_uri. This
>>>>>>>>>>> is what is
>>>>>>>>>>> >> used in ironbee to expose all the various parts like
>>>>>>>>>>> tx->parsed_uri->path
>>>>>>>>>>> >> and tx->parsed_uri->query.
>>>>>>>>>>> >>
>>>>>>>>>>> >> Also note that the hostname should now be obtained from
>>>>>>>>>>> >> tx->request_hostname in 0.5.
>>>>>>>>>>> >>
>>>>>>>>>>> >> -B
>>>>>>>>>>> >
>>>>>>>>>>> >
>>>>>>>>>>> > FYI, for an example using libhtp 0.5 see ironbee code. This was
>>>>>>>>>>> all
>>>>>>>>>>> > recently updated for 0.5.
>>>>>>>>>>> >
>>>>>>>>>>> > https://github.com/ironbee/ironbee/blob/0.7.x/modules/modhtp.c
>>>>>>>>>>> >
>>>>>>>>>>>
>>>>>>>>>>> Will have a look. Thanks.
>>>>>>>>>>>
>>>>>>>>>>> Previously we would use tx->connp->conn->transactions to access txs
>>>>>>>>>>> in the state. Now that htp_connp_t is an opaque pointer how do I
>>>>>>>>>>> access the txs? Tried locating helper functions to retrieve it, but
>>>>>>>>>>> I
>>>>>>>>>>> didn't find any.
>>>>>>>>>>>
>>>>>>>>>>> It's an oversight that there isn't a helper function to retrieve
>>>>>>>>>>> transactions on a connections. I will add one tomorrow.
>>>>>>>>>>>
>>>>>>>>>>> Having said that, what is your use case that you require to retrieve
>>>>>>>>>>> transactions? I thought your code was driven by the callbacks, which >
>>>>>>>>>>> all
>>>>>>>>>>> come with a tx instance (via connp)? For my education, can you explain
>>>>>>>>>>> how you process connection data?
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> One of the things that we don't do out of the callbacks is logging the
>>>>>>>>>> requests. This is one of the things we need access to the TX store for.
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> And to add to it, since we already have the txs stored in a list
>>>>>>>>> inside libhtp, re-buffering the txs would come as a redundant task,
>>>>>>>>> from where I see it.
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> Anoop Saldanha
>>>>>>>>> _______________________________________________
>>>>>>>>> Suricata IDS Devel mailing list: oisf-devel at openinfosecfoundation.org
>>>>>>>>> Site: http://suricata-ids.org | Participate:
>>>>>>>>> http://suricata-ids.org/participate/
>>>>>>>>> List: https://lists.openinfosecfoundation.org/mailman/listinfo/oisf-devel
>>>>>>>>> Redmine: https://redmine.openinfosecfoundation.org/
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>> Ivan Ristić
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Anoop Saldanha
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Anoop Saldanha
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Ivan Ristić
>>>>
>>>>
>>>>
>>>> --
>>>> Anoop Saldanha
>>>
>>>
>>>
>>
>>
>> --
>> ---------------------------------------------
>> Victor Julien
>> http://www.inliniac.net/
>> PGP: http://www.inliniac.net/victorjulien.asc
>> ---------------------------------------------
>>
>
>
>
> --
> -------------------------------
> Anoop Saldanha
> http://www.poona.me
> -------------------------------
--
-------------------------------
Anoop Saldanha
http://www.poona.me
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