From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Neira Subject: Re: problem with conntrack utility and kernel 2.6.14 Date: Fri, 28 Oct 2005 12:01:03 +0200 Message-ID: <4361F6DF.3050106@eurodev.net> References: <4361EAAB.1090206@fliegl.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: netfilter-devel@lists.netfilter.org Return-path: To: Deti Fliegl In-Reply-To: <4361EAAB.1090206@fliegl.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: netfilter-devel-bounces@lists.netfilter.org Errors-To: netfilter-devel-bounces@lists.netfilter.org List-Id: netfilter-devel.vger.kernel.org Deti Fliegl wrote: > Reading /proc/net/ip_conntrack seems to lock the table as long as being > read which causes delays and loss in network traffic. Now I'm trying to > use the conntrack utility from the subversion repository to list the > conntrack table. This in turn prints out some "Unknown Attribute 5" > lines and what's even worse it runs very often into a segmentation fault at > > recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000008}, > msg_iov(1)=[{"\260\0\0\0\0\1\0\6\0\0\0\0\0\0\0\0\2\0\0\0004\0\2\200\24"..., > 8192}], msg_controllen=0, msg_flags=0}, 0) = 176 > write(2, "nfnl_parse_attr: deficit (4) len"..., 39nfnl_parse_attr: > deficit (4) len (0). > > ) = 39 This problem was already fixed days ago in libnetfilter_conntrack on Oct 17, see SVN. I'm not able to reproduce what you're reporting. Please send me a gdb backtrace, together with other extra info. Are you running conntrack on a x86? > Maybe I'm wrong but it seems to happen due to a race condition when > conntracking entries are being updated by the kernel... (if you like to > reproduce this: just keep a high bandwidth connection open where byte > counters in the conntrack tavle have to be updated very often...) No, that doesn't make too much sense to me. -- Pablo