Wireshark · Wireshark-dev: Re: [Wireshark-dev] Defect in reassembling TCP stream. Bug and Patch are available on Bugzilla.

[Pascal Quantin <pascal.quantin@xxxxxxxxx>]

2014-03-28 16:06 GMT+01:00 Pavel Karneliuk <Pavel_Karneliuk@xxxxxxxx>:

Hello,

At first, thank you all for Wireshark. It is amazing tool!

I found a defect and register Bug 9936 – “epan/follow.c - Incorrect comparing a sequence number of TCP fragment when its value wraps over uint32_t limit”
A capture file and my patch are attached to bug in Bugzilla.

Patch is a one-line fix:

--- a/epan/follow.c

+++ b/epan/follow.c

@@ -441,7 +441,7 @@ check_fragments( int idx, tcp_stream_chunk *sc, guint32 acknowledged ) {

         lowest_seq = current->seq;

       }

-      if( current->seq < seq[idx] ) {

+      if( LT_SEQ(current->seq, seq[idx]) ) {

         guint32 newseq;

         /* this sequence number seems dated, but

            check the end to make sure it has no more

 

It is just a replacement a compare operator to wraps-friendly macro. Similar to code around (with GT_SEQ usage).
What do you think?

Hi Pavel,

while we are at it, shouldn't the comparison done at lines 450 and 459 be wrapped in a GT_SEQ macro also?

Regards,
Pascal.