Ethereal-dev: Re: [Ethereal-dev] Bug, dissector warnings and protocol hierarchy problem in tet

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 This list is no longer active.

From: Ulf Lamping <ulf.lamping@xxxxxx>
Date: Thu, 27 Jan 2005 00:18:29 +0100
Matev� Pusti�ek wrote:

Hi!

During the analysis of a larger capture set, I encountered several warnings
and an error in tethereal (0.10.9-SVN-13086). There are files attached, that
cause problems:
Yes, it's a very good idea to attach small example captures, this makes debugging *a lot* easier :-)

crash_00026_20050124150108.cap,
when accessed through:
tethereal -r crash_00026_20050124150108.cap  -V
Reports: ** ERROR **: file tvbuff.c: line 583 (tvb_length_remaining): assertion
failed: (tvb->initialized)
aborting... Aborted
(occasionaly i received a segmentation fault, too, but am not sure if it was
for the same reason or not).
Bug: Dissector wrote behind end of a fixed array, checked in a fix.

crash_00001_20050124142515.cap

when accessed through:
tethereal -r crash_00001_20050124142515.cap tcp
Reports a warning:
** (process:20887): WARNING **: Dissector bug, protocol DAAP, in packet
186405: "" - "" invalid length: -642766212 (p
roto.c:2098)

Bug: Dissector used a length value from a field in the data, but didn't checked if it contains a reasonable value, checked in a fix.

crash_00010_20050124143724.cap

when accessed through:
tethereal -r crash_00010_20050124143724.cap tcp
Reports a warning:
** (process:20928): WARNING **: Frame 154776: rtsp: unknown transport
(This is probably protocol related issue and not ethereal problem)
As the message notes, this is an unknown transport protocol "x-real-rdt/" for the rtsp dissector. First of all, I've added the protocol name to the output. However, I tend to uncomment the g_warning() calls causing this output. What do other's think?

crash_00005_20050124143113-no2.cap
when accessed through:
tethereal -r crash_00005_20050124143113-no2.cap -w tmp.cap "tcp"
Reports:
tethereal: XMLStub: Unable to open module libxml2.so
tethereal: Diameter: Using static dictionary! (Unable to use XML)
(this again is most likely problem of my installation/configuration, but do
not know how to handle it).
Well, as I'm using Win32, I don't use .so files at all. You might install the library/package libxml2 on your computer to resolve this. How you have to do this, will depend on your operating system.

And again to other's: should this message be removed?

crash_00005_20050124143113.cap

when accessed through:
tethereal -r crash_00005_20050124143113.cap -w tmp.cap "tcp"
Reports:
ICQ: Unknown version (8420)
(What exactly does it want to say, Unknown version of ICQ? Or some
underlying protocol ).

The field containing the ICQ version number (the first two bytes after the UDP part) contains 8420 (0x20e4). This seems to me like a missinterpreted packet (Ethereal thinks it is an ICQ packet but it isn't), or the packet is an ICQ packet and contains only garbage.

Beside this I often encounter strage outputs (happens for other protocols
than ssl, too) for -q -z io,phs tethereal option, e.g.:


       ssl                              frames:35388 bytes:44488430
         unreassembled                  frames:31933 bytes:43063232
                                        frames:3741 bytes:904355
         short                          frames:55 bytes:5389
         unreassembled                  frames:389 bytes:434790
                                        frames:348 bytes:106872
                                        frames:123 bytes:49475
                                        frames:66 bytes:29387
                                        frames:54 bytes:25156
                                        frames:31 bytes:14710
                                        frames:20 bytes:9096
                                        frames:17 bytes:8001
                                        frames:13 bytes:7438
                                        frames:10 bytes:6067
                                        frames:7 bytes:2905
                                        frames:7 bytes:2905
                                        frames:5 bytes:2515
                                        frames:5 bytes:2515
                                        frames:5 bytes:2515
                                        frames:5 bytes:2515
                                        frames:5 bytes:2515
                                          frames:5 bytes:2515
                                            frames:4 bytes:2180
                                              frames:4 bytes:2180
                                                frames:4 bytes:2180
                                                  frames:4 bytes:2180
                                                    frames:3 bytes:1904
                                                      frames:3 bytes:1904
                                                        frames:3 bytes:1904
                                                          frames:3
bytes:1904
                                                            frames:3
bytes:1904
                                                              frames:3
bytes:1904
                                                                frames:3
bytes:1904
                                                                  frames:3
bytes:1904

frames:3 bytes:1904

frames:3 bytes:1904

frames:3 bytes:1904

frames:3 bytes:1904
I have searched the ethereal list and have been through the
protocol-over-protocol encapsulation, but do not think this output is
related to that matter.

That seems to be output from the "Protocol Hierarchy Statistics" tapprotohierstat.c line 149, however I don't know tethereal well, so I can't give you good advise here.


Hope this was helpful to you,

Regards, ULFL