Wireshark · Wireshark-bugs: [Wireshark-bugs] [Bug 8502] New: Allow reassemble for sequences, where sequence does not start with

[bugzilla-daemon@xxxxxxxxxxxxx]

Bug ID	8502
Summary	Allow reassemble for sequences, where sequence does not start with no 0
Classification	Unclassified
Product	Wireshark
Version	unspecified
Hardware	All
OS	All
Status	UNCONFIRMED
Severity	Enhancement
Priority	Low
Component	Dissection engine (libwireshark)
Assignee	bugzilla-admin@wireshark.org
Reporter	rknall@gmail.com

Created attachment 10398 [details]
Patch for adding a numbering offset to sequence number for reassembly

Build Information:
TShark 1.9.1 (SVN Rev 48440 from /trunk)

Copyright 1998-2013 Gerald Combs <gerald@wireshark.org> and contributors.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Compiled (64-bit) with GLib 2.32.3, with libpcap, with libz 1.2.3.4, with POSIX
capabilities (Linux), without libnl, with SMI 0.4.8, with c-ares 1.7.5, with
Lua
5.1, without Python, with GnuTLS 2.12.14, with Gcrypt 1.5.0, with MIT Kerberos,
with GeoIP.

Running on Linux 3.2.0-38-generic, with locale de_AT.UTF-8, with libpcap
version
1.1.1, with libz 1.2.3.4.
Intel(R) Core(TM)2 Quad CPU    Q8400  @ 2.66GHz

Built using gcc 4.6.3.

--
In some protocols, sequence numbering of fragmented packages may not start with
the sequence number 0, or the frame id of the first package is not 0.

In such cases reassemble fails based on using the sequence numbers. The usual
approach would be to add the first sequence entry with the number 0 and add
every other frame with seq_next, or use the non-sequence version of reassemble
functions. In both such cases retransmission and duplicate transmission has to
be handled by the dissector itself.

The proposed patch introduces the possibility, to set a sequence numbering
offset, AFTER the first package has been added to the frame sequence. Every
other package can than be added using the seq_check functions, and with their
real sequence numbers.

The reassemble functions calculate the frame numbering considering the
numbering offset, and handle the reassemble accordingly.

The patch has been tested with various capture files. At it only comes into
affect, if the number offset has explicitly been set, side-effects to other
dissectors should not exist.

---

      You are receiving this mail because:

• You are watching all bug changes.