Messages in this thread Patch in this message | | | Date | Tue, 29 Jul 2014 17:29:32 +0800 | From | zhuyj <> | Subject | ipv4: net namespace does not inherit network configurations |
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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 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
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