libpcap/DAG build issues

[Stephen Donnelly]

Hi Carter,

The tcpdump 4.1.1 version from tcpdump.org should be fine. It appears to be backwards compatible for building against older libpcap versions, pcap-config is optional.

The Argus specific modifications in AC_QOSIENT_LIBPCAP seem to be mostly around preferring libpcap variants such as lpcap or wpcap if available? If so it may be cleaner to make those separate tests, and call AC_LBL_LIBPCAP if they fail.

Regards,
Stephen.

-----Original Message-----
From: Carter Bullard [mailto:carter at qosient.com] 
Sent: Thursday, 17 February 2011 12:28 a.m.
To: Stephen Donnelly
Cc: argus-info at lists.andrew.cmu.edu
Subject: Re: [ARGUS] libpcap/DAG build issues

Hey Stephen,
I suspect AC_LBL_LIBPCAP will be fine.  Which version should I grab?  From the latest tcpdump?  Is it backward compatible?

Carter


On Feb 15, 2011, at 9:48 PM, Stephen Donnelly <Stephen.Donnelly at endace.com> wrote:

> I have received some reports of issues compiling the current Argus release against recent versions of libpcap built against the current Endace DAG software release.
> 
> There seem to be two issues. Firstly static builds of libpcap do not currently work correctly when using the latest DAG software releases. I will submit patches upstream to resolve these issues for static libpcap builds. This will resolve issues building applications that link against static libpcap libraries, provided they use the 'pcap-config' mechanism to pick up additional library dependencies. It will take time any changes to be incorporated into a stable libpcap release version.
> 
> Dynamic (shared object) builds of libpcap are currently working correctly with the latest DAG software releases and applications dynamically linking against libpcap are not seeing any issues.
> 
> Secondly the Argus aclocal.m4/acsite.m4 defines AC_QOSIENT_LIBPCAP rather than using the upstream AC_LBL_LIBPCAP. This appears to be based on an older version of AC_LBL_LIBPCAP and does not support the 'pcap-config' method. This will not work with the libpcap DAG updates and may not be working for other static libpcap builds with external dependencies.
> 
> AC_QOSIENT_LIBPCAP also may not find local installs of libpcap built from git as the egrep regex has not been updated for the git version name scheme (-PRE-GIT).
> 
> The simplest solution for these issues may be to pull AC_LBL_LIBPCAP from tcpdump upstream. Argus could call this from inside AC_QOSIENT_LIBPCAP either before or after looking for libpcap variants such as lpcap, wpcap etc? Alternatively at minimum AC_QOSIENT_LIBPCAP needs to be updated to support 'pcap-config'.
> 
> Let me know if you want me to submit a patch.
> 
> Regards,
> Stephen.
> -- 
> Dr Stephen Donnelly
> Core Software Manager 
> +64 7 959 2640
> stephen.donnelly at endace.com
> Level 9, 85 Alexandra St, 
> Hamilton 3204, New Zealand. 
> www.endace.com, follow us on Twitter 
> 
> 
>