ANNOUNCEMENT: Live Wireshark University & Allegro Packets online APAC Wireshark Training Session
July 17th, 2024 | 10:00am-11:55am SGT (UTC+8) | Online

Ethereal-dev: Re: [Ethereal-dev] [DCE RPC] Incorrect dissection with CVS version 2004060315332

Note: This archive is from the project's previous web site, ethereal.com. This list is no longer active.

Date: Mon, 7 Jun 2004 21:01:05 -0700
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Well the problem appears to be the change to add the activity id.

http://www.ethereal.com/cgi-bin/viewcvs.cgi/ethereal/packet-dcerpc.c.diff?r1=1.176&r2=1.177

Once I reveresed this change it decodes the last two packets as EPM Map
as it should.



On Sun, 06 Jun 2004 06:38:27 -0700 Jean-Baptiste Marchand <Jean-Baptiste.Marchand@xxxxxx>
wrote:
>Hello,
>
>* Jean-Baptiste Marchand <Jean-Baptiste.Marchand@xxxxxx> [04/06/04
>- 11:29]:
>
>> it seems that there is a dissection problem with a current version
>of
>> the DCE RPC dissector.
>>
>> The first attached capture (epm1_anon.cap) contains 6 frames,
>2 two TCP segments
>> (SYN-ACK, ACK) and 4 DCE RPC PDUs. The last two DCE RPC PDUs are
>not
>> properly dissected as EPM operations.
>>
>> The second attached capture (epm2_anon.cap) is identical to the
>first one,
>> except that the first TCP segment has been removed. The last two
>DCE RPC
>> PDUs are properly dissected as EPM operations.
>>
>> The only difference is that in the first case, we see a SYN-ACK
>TCP
>> segment and thus, this might be something related to TCP conversations?
>>
>> PS: attached traces have been anonymized with ipsumdump
>> (http://www.icir.org/kohler/ipsumdump/), thus IP addresses are
>different
>> in the traces but they were both generated from the same original
>trace.
>
>I'm a bit confused because I've tried to open these two captures
>on a
>recent build of ethereal on MacOS X (CVS tree updated this morning)
>and
>the two are dissected properly.
>
>On the other hand, I've just updated my CVS tree on my FreeBSD laptop
>and I still have the same problem I described on ethereal-dev@.
>
>It does not seem to be related to a difference in my preferences,
> as
>I've tried with the default ethereal preference settings (I rename
>the
>~/.ethereal directory to ~/.ethereal_old).
>
>Follow tethereal outputs for me (checksum is incorrect because IP
>addresses have been modified because of anonymization with ipsumdump):
>
>jbm@garbarek ~> tethereal -r epm1_anon.cap
>  1   0.000000 194.115.240.203 -> 194.115.240.48 TCP loc-srv > 1053
>[SYN, ACK] Seq=0 Ack=1 Win=17520 [CHECKSUM INCORRECT] Len=0 MSS=1460
>  2   0.001235 194.115.240.48 -> 194.115.240.203 TCP 1053 > loc-
>srv
>[ACK] Seq=1 Ack=1 Win=17520 [CHECKSUM INCORRECT] Len=0
>  3   0.006250 194.115.240.48 -> 194.115.240.203 DCERPC Bind: call_id:
>1
>UUID: EPM
>  4   0.016912 194.115.240.203 -> 194.115.240.48 DCERPC Bind_ack:
>call_id: 1 accept max_xmit: 5840 max_recv: 5840
>  5   0.018674 194.115.240.48 -> 194.115.240.203 DCERPC Request:
>call_id: 1 opnum: 3 ctx_id: 0
>  6   0.021197 194.115.240.203 -> 194.115.240.48 DCERPC Response:
>call_id: 1 ctx_id: 0
>
>jbm@garbarek ~> tethereal -r epm2_anon.cap
>  1   0.000000 205.61.107.240 -> 205.61.107.6 TCP 1053 > loc-srv
>[ACK]
>Seq=0 Ack=0 Win=17520 [CHECKSUM INCORRECT] Len=0
>  2   0.005015 205.61.107.240 -> 205.61.107.6 DCERPC Bind: call_id:
>1
>UUID: EPM
>  3   0.015677 205.61.107.6 -> 205.61.107.240 DCERPC Bind_ack: call_id:
>1 accept max_xmit: 5840 max_recv: 5840
>  4   0.017439 205.61.107.240 -> 205.61.107.6 EPM Map request
>  5   0.019962 205.61.107.6 -> 205.61.107.240 EPM Map response
>
>
>As you can, frames 5 and 6 are not properly dissected in the first
>trace
>whereas in the second one, frames 4 and 5 (the first frame is remove
>in
>the second trace), there are properly recognized as EPM operations...
>
>Any ideas?
>
>Thanks in advance,
>
>Jean-Baptiste Marchand
>--
>Jean-Baptiste.Marchand@xxxxxx
>HSC - http://www.hsc.fr/
>
>_______________________________________________
>Ethereal-dev mailing list
>Ethereal-dev@xxxxxxxxxxxx
>http://www.ethereal.com/mailman/listinfo/ethereal-dev
-----BEGIN PGP SIGNATURE-----
Note: This signature can be verified at https://www.hushtools.com/verify
Version: Hush 2.4

wkYEARECAAYFAkDFOWgACgkQFh/Ot+gyoF5enACgsSGBYttzQowj4epOiLVjpOwc3lAA
n2+PHOcJeJng1Kacfr2kUy8pjl+u
=uSLt
-----END PGP SIGNATURE-----