[SR-Users] TEXTOPS parser problem with binary data in MIME body
Federico San Martín
fsanmartin at telecentro.net.ar
Fri Feb 27 15:12:59 CET 2015
Thank you for the quick reply Klaus! I'm currently trying a new patch for the SIPT module created by Torrey Searle that allows me to modify the binary data on the BCI byte, the only caveat is that you have to receive the BCI to modify it, you can't create it on the fly.
BR,
Federico
----- Original Message -----
From: "Klaus Feichtinger" <klaus.lists at inode.at>
To: sr-users at lists.sip-router.org, fsanmartin at telecentro.net.ar
Sent: Thursday, February 26, 2015 5:10:22 PM
Subject: Re: [SR-Users] TEXTOPS parser problem with binary data in MIME body
Hi Frederico,
the only (quick) solution I had found was doing message parsing (MIME
body) in an external PERL script, returning the information that I was
searching for (from that body) to the config script and reducing the
multipart body to a single body. This is (until now) working fine...
However, I was using Kamailio version 3.2.x in this situation, but I
think that there will be no change to the newest version, as it is a
basic C language problem.
Please note that PERL was the language that I was finding the fastest
solution with. Maybe you can use an alternative language, too.
regards,
Klaus
Am 21.02.2015 um 01:19 schrieb Federico San Martín:
> Hi Klaus, did you find a solution to this problem? I'm working with SIP-I and having the same issue with Binary encoding. I need to encode a 0x00 value and when the config script gets to that point, it breaks. If I encode any other hex value it's fine. This is the config part I'm using:
>
> route[INSERT_ACM]{
> if(has_body()){
> # Save the SDP body for future reference
> $var(sdp_body) = $rb;
> replace_body_atonce("^.+$", "");
> remove_hf("Content-Type");
> append_hf("MIME-Version: 1.0\r\n", "Content-Length");
> append_hf("Content-Type: multipart/mixed; boundary=unique-boundary-1\r\n", "Allow");
> replace_body_atonce("^.+$", "--unique-boundary-1\r\nContent-Disposition: signal; handling=optional\r\nContent-Type: application/isup; version=itu-t92+\r\n\r\n'\x06''\x02''\x04''\x01''\x29''\x01''\x01''\x00'\r\n-unique-boundary-1\r\n");
> msg_apply_changes();
> replace_body_all("\047", "");
> append_body_part("$var(sdp_body)","application/sdp");
> }
> return;
> }
>
> I tried with the escape character \0 which should be translated to ASCII hex value '00' but it's parsed as ASCII literal values \0...
>
> Thanks!
>
> Federico
>
> Federico San Martín
> e-mail : fsanmartin at telecentro.net.ar
>
> On 9/17/13 4:34 PM, Daniel wrote:
>> Hello,
>>
>> most of the functions for pseudo-variables work with string types, that
>> because a script variable can have only integer or string values. Even
>> the length can be higher, these functions truncate at first 0. But
>> internally all should be kept, just not passed to config variables.
>>
>> Have you tried exec_msg(), that should pass entire msg?
>>
>> Otherwise, I presume there is need for some C coding to make binary
>> values work with variables in config.
>>
>> Cheers,
>> Daniel
> On 9/17/13 4:03 PM, Klaus Feichtinger wrote:
>> Hello,
>>
>> I have an update to the side effects of receiving an INVITE message that
>> contains a MIME body with binary data:
>> - pseudo variables are affected, too
>> - the message buffer ($mb) does not include the whole message; it is
>> ending with the nul character
>> - as the message buffer does not include all data, the modification
>> cannot be done with an external script / program (e.g. perl, bash script)
>>
>> The behaviour was tested with kamailio 4.0.3, too - no difference!
>>
>> In general, the whole message is stored in a buffer, but parts of it are
>> inaccessible for parsing / text functions.
>>
>> Any idea, what could cause this problem?
>>
>> regards,
>> Klaus
>>
>>> Hello,
>>>
>>> I have a problem with Kamailio version 3.2.4 (tested also with 3.3.5)
>>> regarding "binary data" in message bodies. According RFC3261 it is
>>> explicitly allowed using binary data within MIME bodies:
>>>
>>> RFC 3261 section 7.4.1: SIP messages MAY contain binary bodies or body
>>> parts. When no explicit charset parameter is provided by the sender,
>>> media subtypes of the "text" type are defined to have a default charset
>>> value of "UTF-8".
>>>
>>> However, the Kamailio function "Regular Expression Transformation"
>>> (re.subst), which is based on the transformation class (exported by the
>>> textops module) is causing problems in our customer system. In regular
>>> scenarios, Kamailio is receiving SIP INVITE messages with a MIME body,
>>> which is containing following parts:
>>> - application/sdp (standard conform)
>>> - application/x-q931 (Cisco proprietary with BINARY data!)
>>> - application/gtd (Cisco proprietary with ASCII strings)
>>>
>>> The content of the "x-q931" and "gtd" body parts is depending on (UUS1)
>>> data that were received on the ISDN line. Kamailio has to forward
>>> User-User specific information from the ISDN line to SIP user agents (in
>>> form of the "User-to-User" header field). The content of these UUS1 data
>>> may contain also byte values "00", which is legitimate. In general,
>>> Kamailio is in every INVITE message searching specific content in the
>>> last body (application/gtd) and copying this content to a config
>>> variable. As soon as the x-q931 body contains nul values (0x00 in binary
>>> format), the parser stops at this position and cannot parse the rest of
>>> the message. Therefore, I am missing the information that should be
>>> copied to the SIP header field, as the parser stops before the end of
>>> the message body!
>>>
>>> As long as the message body does not contain 0x00, it is working fine!
>>>
>>> My question is:
>>> - is this a bug in Kamailio parsing functions?
>>> - is this a design issue of Kamailio text parsers (as binary data are
>>> allowed acc. RFC3261) - does anybody know a solution for this problem?
>>> This "bug" is causing big troubles....
>>>
>>> Thanks in advance,
>>> Klaus Feichtinger
>>>
>>>
>>> P.S. trace data (1)...(3) of my problem
>>>
>>> (1) exemplary content of the x-q931 body
>>> ======================Sending: Binary Message Body
>>> Sep 13 10:50:19: Content-Type: application/x-q931
>>> 08 01 B4 05 04 03 80 90 A2 18 01 89 1E 02 82 88 6C 05 B1 35 30 30 34 70
>>> 05 B1 35 30 30 31 7D 02 91 81 7E 18 04 1D 42 75 25 92 43 31 62 94 00 00
>>> 2C 68 20 64 00 62 F2 10 41 B9 D7 BD 0D 0A
>>>
>>> (2) SIP INVITE message (debugger view)
>>> =============================INVITE sip:115101@<ipv4>:5060 SIP/2.0 Via:
>>> SIP/2.0/UDP <ipv4>:5060;branch=z9hG4bK171164E
>>> From: <sip:1101015004@<ipv4>>;tag=29E16410-2541
>>> To: <sip:115101@<ipv4>>
>>> Call-ID: 1DBCDACB-1B9911E3-8992FF70-D2BED293@<ipv4>
>>> Supported: timer,resource-priority,replaces,sdp-anat
>>> Min-SE: 90
>>> CSeq: 101 INVITE
>>> Max-Forwards: 70
>>> Contact: <sip:1101015004@<ipv4>:5060>
>>> Expires: 1800
>>> P-Asserted-Identity: <sip:1101015004@<ipv4>>
>>> Content-Type: multipart/mixed;boundary=uniqueBoundary
>>> Mime-Version: 1.0
>>> Content-Length: 820
>>>
>>> --uniqueBoundary
>>> Content-Type: application/sdp
>>> Content-Disposition: session;handling=required
>>>
>>> v=0
>>> o=CiscoSystemsSIP-GW-UserAgent 1770 5294 IN IP4 <ipv4>
>>> s=SIP Call
>>> c=IN IP4 <ipv4>
>>> t=0 0
>>> m=audio 16384 RTP/AVP 8 0
>>> c=IN IP4 <ipv4>
>>> a=rtpmap:8 PCMA/8000
>>> a=rtpmap:0 PCMU/8000
>>>
>>> --uniqueBoundary
>>> Content-Type: application/x-q931
>>> Content-Disposition: signal;handling=optional
>>> Content-Length: 62
>>> 4" l15004p15001}~Bu%C1b..,h d.brA9W
>>> --uniqueBoundary
>>> Content-Type: application/gtd
>>> Content-Disposition: signal;handling=optional
>>>
>>> IAM,
>>> PRN,isdn*,,,
>>> USI,rate,c,s,c,1
>>> USI,lay1,ulaw
>>> TMR,00
>>> CPN,08,,1,5001
>>> CGN,08,,1,,,5004
>>> UUS,3,1d427525924331629400002c6820640062f21041b9d7bd
>>> CPC,09
>>> FCI,,,,,,,y,
>>> GCI,185ef1291b9911e381d500270dff3fa0
>>>
>>> --uniqueBoundary--
>>>
>>> (3) config excerpt
>>> ============if (has_body("multipart/mixed")) {
>>> if (filter_body("application/sdp")) {
>>> remove_hf("Mime-Version");
>>> remove_hf("Content-Type");
>>> append_hf("Content-Type: application/sdp\r\n");
>>> } else {
>>> xlog("L_WARN", " <route> message body part 'application/sdp' not
>>> found\n");
>>> }
>>> $var(UUS)=$(rb{re.subst,/^(.*)UUS,.,([a-z0-9,]*)..[A-Z][A-Z][A-Z],(.*)/\2/s});
>>> append_hf("User-to-User: $var(UUS)\r\n", "CSeq");
>>>
>>> if
>>> !(subst_body('/Content-Disposition..session.handling=required....//s'))
>>> {
>>> xlog("L_WARN", " <route> substituting Content-Disposition
>>> FAILED!!! \n");
>>> }
>>> msg_apply_changes();
>>> if (search_body("a=[a-z]+:.+[\r\n]{4}$")) {
>>> #!ifdef WITH_XLOGDEBUG
>>> xlog("L_INFO", " <route> double CRLF at the end of the message
>>> body detected - is reduced to one now. \n"); #!endif
>>> $var(sdp) = $(rb{s.striptail,2});
>>> set_body("$var(sdp)", "application/sdp");
>>> }
>>> }
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
>>> sr-users at lists.sip-router.org
>>> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
>>
>>
>> _______________________________________________
>> SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
>> sr-users at lists.sip-router.org
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>>
>> --
>> Daniel-Constantin Mierla - http://www.asipto.com
>> http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
>> Kamailio Advanced Trainings - Berlin, Oct 21-24; Miami, Nov 11-13, 2013
>> - more details about Kamailio trainings at http://www.asipto.com -
>
>
>
>
>
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