Wireshark-dev: Re: [Wireshark-dev] pcap_next_ex() crashes

From: Jaap Keuter <jaap.keuter@xxxxxxxxx>
Date: Fri, 05 Mar 2010 14:57:53 +0100
Hi,

Although Wireshark uses libpcap, these are libpcap questions, not
Wireshark questions. 
You should post them to the right forum, which in this case is
tcpdump-workers@xxxxxxxxxxxxxxxxx.

Thanks,
Jaap

On Fri, 5 Mar 2010 10:15:29 +0200, Selçuk Cevher <cevhers@xxxxxxxxx>
wrote:
> Hi All,
> 
> I wrote a small program which calls pcap_next_ex() function to read
> packets while processing a bunch of PCAP files (offline mode)
> "sequentially" - one after another.
> 
> However, pcap_next_ex() generates a segmentation fault (I observed this
> using GNU gdb).
> 
> By the way, my program also produces some user logs so that I have the
> opportunity to observe which PCAP file is being processed at a certain
> time.
> 
> On the other hand, when I re-run the same program with the individual
> PCAP file as the only program input, which I observed in the user logs
> that pcap_next_ex() generated segfault in the previous run while the
file
> was being processed, I observe no crash.
> 
> Hence, I began to think that there is problem with pcap_next_ex() in
> terms of memory leak, etc which becomes apparent when it is called
> successively for a bunch of PCAP files, not for a single file.
> 
> Questions:
> 
> 1. Is there such a pcap_next_ex() behaviour reported before ?
> 
> 2. If you think, this is impossible, what might I be doing wrong ?
> 
> 3. Should I use some other function other than pcap_next_ex() ?
> 
> etc.
> 
> I use Ubuntu 9.10 (64-bit).
> 
> libpcap version is 1.0.0-2ubuntu1
> 
> Thanks.