linux-kernel - Re: ipv4: net namespace does not inherit network configurations

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 31 Jul 2014 09:59:12 +0800
From:	zhuyj <zyjzyj2000@...il.com>
To:	Cong Wang <cwang@...pensource.com>
CC:	"David S. Miller" <davem@...emloft.net>,
	Hong Zhiguo <honkiko@...il.com>,
	LKML <linux-kernel@...r.kernel.org>,
	netdev <netdev@...r.kernel.org>,
	"Tao, Yue" <Yue.Tao@...driver.com>,
	Alexandre Dietsch <alexandre.dietsch@...driver.com>,
	zhuyj <zyjzyj2000@...il.com>
Subject: Re: ipv4: net namespace does not inherit network configurations

On 07/30/2014 01:48 AM, Cong Wang wrote:
> On Tue, Jul 29, 2014 at 2:29 AM, zhuyj <zyjzyj2000@...il.com> wrote:
>> Hi,all
>>
>> I did a test on kernel3.16 rc6:
>>
>> root@...u1:~# echo 1 > /proc/sys/net/ipv6/conf/all/forwarding
>> root@...u1:~# echo 1 > /proc/sys/net/ipv4/conf/all/forwarding
>> root@...u1:~# ip netns list
>> root@...u1:~# ip netns add fib1
>> root@...u1:~# ip netns exec fib1 bash
>> root@...u1:~# cat /proc/sys/net/ipv6/conf/all/forwarding
>> 0
>> root@...u1:~# 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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/