From mboxrd@z Thu Jan 1 00:00:00 1970 From: zhuyj Subject: Re: ipv4: net namespace does not inherit network configurations Date: Thu, 31 Jul 2014 09:59:12 +0800 Message-ID: <53D9A2F0.4040808@gmail.com> References: <53D7697C.6020103@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: "David S. Miller" , Hong Zhiguo , LKML , netdev , "Tao, Yue" , Alexandre Dietsch , zhuyj To: Cong Wang Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 07/30/2014 01:48 AM, Cong Wang wrote: > On Tue, Jul 29, 2014 at 2:29 AM, zhuyj wrote: >> Hi,all >> >> I did a test on kernel3.16 rc6: >> >> root@qemu1:~# echo 1 > /proc/sys/net/ipv6/conf/all/forwarding >> root@qemu1:~# echo 1 > /proc/sys/net/ipv4/conf/all/forwarding >> root@qemu1:~# ip netns list >> root@qemu1:~# ip netns add fib1 >> root@qemu1:~# ip netns exec fib1 bash >> root@qemu1:~# cat /proc/sys/net/ipv6/conf/all/forwarding >> 0 >> root@qemu1:~# cat /proc/sys/net/ipv4/conf/all/forwarding >> 1 >> >> The behavior of ipv4 and ipv6 is very inconsistent. I checked >> the kernel source code. I found that from this patch >> [ipv6: fix bad free of addrconf_init_net], the above difference >> appeared. >> >> Since a net namespace is independent to another. That is, there >> is no any relationship between the net namespaces. So the behavior >> of ipv4 is not correct. >> > Well, they are already independent, not shared, just that the initial > value is duplicated from init_net for IPv4. > > This change might break existing applications which rely on this > behavior, but given IPv6 change is almost the same, I think it's ok. > > BTW, you need to submit a patch as normal, instead of as an attachment. > OK. Thanks a lot. Zhu Yanjun