Re: Debugging an issue with pcap_compile/pcap_setfilter

[Adayadil Thomas <adayadil.thomas () gmail com>]

The filter I was using is "tcp[13]&7!=0"

Thanks

On Fri, Oct 30, 2009 at 1:50 AM, Gianluca Varenni
<gianluca.varenni () cacetech com> wrote:
> What is the value of filter?
>
> GV
>
> ----- Original Message ----- From: "Adayadil Thomas"
> <adayadil.thomas () gmail com>
> To: <tcpdump-workers () lists tcpdump org>
> Sent: Thursday, October 29, 2009 8:23 AM
> Subject: [tcpdump-workers] Debugging an issue with
> pcap_compile/pcap_setfilter
>
>
> > Hi All,
> >
> > I have a program that uses libpcap to read and analyze packets.
> > Libpcap version: 0.9.4
> >
> > The pseudo code of my program looks like this
> >
> > PacketFunc()
> > {
> >
> >   pd = pcap_open_live( ifname, snaplen, 1, 10, errorbuf);
> >   if ( !pd ) {
> >       //error out
> >   }
> >
> >   if(pcap_compile(pd, &fcode, filter, 1, netmask) < 0)
> >   {
> >       //error out
> >   }
> >
> >   if(pcap_setfilter(pd, &fcode) < 0)
> >   {
> >       //error out
> >   }
> >
> >   if(pcap_loop(pd, -1, (pcap_handler) analyze, (u_char *)&args) < 0) {
> >     //error out
> >   }
> >
> > }
> >
> >
> >
> > I get a seg fault with the following dump -
> >
> >
> > Program terminated with signal 11, Segmentation fault.
> > [New process 9556]
> > [New process 9555]
> > [New process 9551]
> > #0 0xb761807c in ?? ()
> > (gdb) bt
> > #0 0xb761807c in ?? ()
> > #1 0xb7fb308a in _dl_signal_error () from /lib/ld-linux.so.2
> > #2 0xb7fb313a in _dl_signal_cerror () from /lib/ld-linux.so.2
> > #3 0xb7faf3ee in _dl_lookup_symbol_x () from /lib/ld-linux.so.2
> > #4 0xb7fb2cc8 in _dl_fixup () from /lib/ld-linux.so.2
> > #5 0xb7fb84d0 in _dl_runtime_resolve () from /lib/ld-linux.so.2
> > #6 0xb7f7da78 in pcap_compile () from /usr/lib/libpcap.so.0.9.4
> > #7 0x0804bbe5 in PacketFunc (t_id=0x1) at program.c:959
> > #8 0xb7f6449b in start_thread () from /lib/libpthread.so.0
> > #9 0xb7eec42e in clone () from /lib/libc.so.6
> >
> > The following message was found in log file :
> >
> > symbol lookup error: /usr/lib/libpcap.so.0.9.4: undefined symbol:
> > lex_cleanup
> >
> >
> >
> > Any ideas or pointers to what the issue may be?
> >
> > Thanks
> > -
> > This is the tcpdump-workers list.
> > Visit https://cod.sandelman.ca/ to unsubscribe.
>
> -
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