From mboxrd@z Thu Jan 1 00:00:00 1970 From: zhuyj Subject: ipv4: net namespace does not inherit network configurations Date: Tue, 29 Jul 2014 17:29:32 +0800 Message-ID: <53D7697C.6020103@gmail.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------050905080402070203080408" Cc: LKML , netdev , zhuyj , "Tao, Yue" , Alexandre Dietsch To: "David S. Miller" , Hong Zhiguo Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org This is a multi-part message in MIME format. --------------050905080402070203080408 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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. Based on this patch [ipv6: fix bad free of addrconf_init_net], I made a new patch to fix this problem on ipv4. Any reply is appreciated. Zhu Yanjun --------------050905080402070203080408 Content-Type: text/x-patch; name="0001-ipv4-net-namespace-does-not-inherit-network-configur.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename*0="0001-ipv4-net-namespace-does-not-inherit-network-configur.pa"; filename*1="tch" >>From f3a68831d7c58b185d57f30130217b22a8e2c71f Mon Sep 17 00:00:00 2001 From: Zhu Yanjun Date: Tue, 29 Jul 2014 17:23:10 +0800 Subject: [PATCH 1/1] ipv4: net namespace does not inherit network configurations Ipv4 net namespace requires a similar logic change as commit c900a800 [ipv6: fix bad free of addrconf_init_net] introduces for newer kernels. Since a net namespace is independent to another. That is, there is no any relationship between the net namespaces. So a new net namespace should not inherit network configurations from another net namespace including the host. CC: Hong Zhiguo CC: David S. Miller Signed-off-by: Zhu Yanjun --- net/ipv4/devinet.c | 29 ++++++++++++----------------- 1 file changed, 12 insertions(+), 17 deletions(-) diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index e944937..a16aa39 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -2220,28 +2220,23 @@ static __net_init int devinet_init_net(struct net *net) #endif err = -ENOMEM; - all = &ipv4_devconf; - dflt = &ipv4_devconf_dflt; - if (!net_eq(net, &init_net)) { - all = kmemdup(all, sizeof(ipv4_devconf), GFP_KERNEL); - if (all == NULL) - goto err_alloc_all; - - dflt = kmemdup(dflt, sizeof(ipv4_devconf_dflt), GFP_KERNEL); - if (dflt == NULL) - goto err_alloc_dflt; + all = kmemdup(&ipv4_devconf, sizeof(ipv4_devconf), GFP_KERNEL); + if (all == NULL) + goto err_alloc_all; + dflt = kmemdup(&ipv4_devconf_dflt, sizeof(ipv4_devconf_dflt), GFP_KERNEL); + if (dflt == NULL) + goto err_alloc_dflt; #ifdef CONFIG_SYSCTL - tbl = kmemdup(tbl, sizeof(ctl_forward_entry), GFP_KERNEL); - if (tbl == NULL) - goto err_alloc_ctl; + tbl = kmemdup(tbl, sizeof(ctl_forward_entry), GFP_KERNEL); + if (tbl == NULL) + goto err_alloc_ctl; - tbl[0].data = &all->data[IPV4_DEVCONF_FORWARDING - 1]; - tbl[0].extra1 = all; - tbl[0].extra2 = net; + tbl[0].data = &all->data[IPV4_DEVCONF_FORWARDING - 1]; + tbl[0].extra1 = all; + tbl[0].extra2 = net; #endif - } #ifdef CONFIG_SYSCTL err = __devinet_sysctl_register(net, "all", all); -- 1.9.1 --------------050905080402070203080408--