| Message ID | 53D7697C.6020103@gmail.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On Tue, Jul 29, 2014 at 2:29 AM, zhuyj <zyjzyj2000@gmail.com> 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. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 07/30/2014 01:48 AM, Cong Wang wrote: > On Tue, Jul 29, 2014 at 2:29 AM, zhuyj <zyjzyj2000@gmail.com> 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 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi, Miller && Cong Can we merge this patch into kernel mainline? since the independence between ipv4 and ipv6 is inconsistent even in the latest linux kernel(3.17-rc7), that is, the net namespace is independent in ipv6 while it is not in ipv4. Thanks a lot. Zhu Yanjun On 07/30/2014 01:48 AM, Cong Wang wrote: > On Tue, Jul 29, 2014 at 2:29 AM, zhuyj <zyjzyj2000@gmail.com> 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. > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From f3a68831d7c58b185d57f30130217b22a8e2c71f Mon Sep 17 00:00:00 2001 From: Zhu Yanjun <zyjzyj2000@gmail.com> 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 <honkiko@gmail.com> CC: David S. Miller <davem@davemloft.net> Signed-off-by: Zhu Yanjun <zyjzyj2000@gmail.com> --- 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