path: root/net/ipv6/addrconf.c
diff options
authorCong Wang <xiyou.wangcong@gmail.com>2019-01-17 23:27:11 -0800
committerDavid S. Miller <davem@davemloft.net>2019-01-22 11:07:21 -0800
commit856c395cfa63b94a1d8215182f0243c222f6f927 (patch)
treee2bf59f5b64962b46a254f6c8d75334e38828520 /net/ipv6/addrconf.c
parentMerge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net (diff)
net: introduce a knob to control whether to inherit devconf config
There have been many people complaining about the inconsistent behaviors of IPv4 and IPv6 devconf when creating new network namespaces. Currently, for IPv4, we inherit all current settings from init_net, but for IPv6 we reset all setting to default. This patch introduces a new /proc file /proc/sys/net/core/devconf_inherit_init_net to control the behavior of whether to inhert sysctl current settings from init_net. This file itself is only available in init_net. As demonstrated below: Initial setup in init_net: # cat /proc/sys/net/ipv4/conf/all/rp_filter 2 # cat /proc/sys/net/ipv6/conf/all/accept_dad 1 Default value 0 (current behavior): # ip netns del test # ip netns add test # ip netns exec test cat /proc/sys/net/ipv4/conf/all/rp_filter 2 # ip netns exec test cat /proc/sys/net/ipv6/conf/all/accept_dad 0 Set to 1 (inherit from init_net): # echo 1 > /proc/sys/net/core/devconf_inherit_init_net # ip netns del test # ip netns add test # ip netns exec test cat /proc/sys/net/ipv4/conf/all/rp_filter 2 # ip netns exec test cat /proc/sys/net/ipv6/conf/all/accept_dad 1 Set to 2 (reset to default): # echo 2 > /proc/sys/net/core/devconf_inherit_init_net # ip netns del test # ip netns add test # ip netns exec test cat /proc/sys/net/ipv4/conf/all/rp_filter 0 # ip netns exec test cat /proc/sys/net/ipv6/conf/all/accept_dad 0 Set to a value out of range (invalid): # echo 3 > /proc/sys/net/core/devconf_inherit_init_net -bash: echo: write error: Invalid argument # echo -1 > /proc/sys/net/core/devconf_inherit_init_net -bash: echo: write error: Invalid argument Reported-by: Zhu Yanjun <Yanjun.Zhu@windriver.com> Reported-by: Tonghao Zhang <xiangxia.m.yue@gmail.com> Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Tonghao Zhang <xiangxia.m.yue@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
1 files changed, 5 insertions, 0 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 57198b3c86da..48cd36311901 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -6902,6 +6902,11 @@ static int __net_init addrconf_init_net(struct net *net)
if (!dflt)
goto err_alloc_dflt;
+ if (sysctl_devconf_inherit_init_net == 1 && !net_eq(net, &init_net)) {
+ memcpy(all, init_net.ipv6.devconf_all, sizeof(ipv6_devconf));
+ memcpy(dflt, init_net.ipv6.devconf_dflt, sizeof(ipv6_devconf_dflt));
+ }
/* these will be inherited by all namespaces */
dflt->autoconf = ipv6_defaults.autoconf;
dflt->disable_ipv6 = ipv6_defaults.disable_ipv6;