From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH v5] ipv6: Fix problem with expired dst cache Date: Fri, 16 Mar 2012 22:33:53 -0700 (PDT) Message-ID: <20120316.223353.988595838790067214.davem@davemloft.net> References: <1330064404-24763-1-git-send-email-gaofeng@cn.fujitsu.com> <1330931762-1466-1-git-send-email-gaofeng@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com To: gaofeng@cn.fujitsu.com Return-path: Received: from shards.monkeyblade.net ([198.137.202.13]:39648 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751448Ab2CQFd6 (ORCPT ); Sat, 17 Mar 2012 01:33:58 -0400 In-Reply-To: <1330931762-1466-1-git-send-email-gaofeng@cn.fujitsu.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Gao feng Date: Mon, 5 Mar 2012 15:16:02 +0800 > If the ipv6 dst cache which copy from the dst generated by ICMPV6 RA packet. > this dst cache will not check expire because it has no RTF_EXPIRES flag. > So this dst cache will always be used until the dst gc run. > > Change the struct dst_entry,add a union contains new pointer from and expires. > When rt6_info.rt6i_flags has no RTF_EXPIRES flag,the dst.expires has no use. > we can use this field to point to where the dst cache copy from. > The dst.from is only used in IPV6. > > In func rt6_check_expired check if rt6_info.dst.from is expired. > > In func ip6_rt_copy only set dst.from when the ort has flag RTF_ADDRCONF > and RTF_DEFAULT.then hold the ort. > > In func ip6_dst_destroy release the ort. > > Add some functions to operate the RTF_EXPIRES flag and expires(from) together. > and change the code to use these new adding functions. > > Signed-off-by: Gao feng I see some unprotected access to dst.expires in the router discovery code in net/ipv6/ndisc.c, doesn't that need to be updated? There are probably some more similar cases elsewhere in the ipv6 code too.