From: xu xin xu.xin16@zte.com.cn
[ Upstream commit 8c8b7aa7fb0cf9e1cc9204e6bc6e1353b8393502 ]
Inside netns owned by non-init userns, sysctls about ARP/neighbor is currently not visible and configurable.
For the attributes these sysctls correspond to, any modifications make effects on the performance of networking(ARP, especilly) only in the scope of netns, which does not affect other netns.
Actually, some tools via netlink can modify these attribute. iproute2 is an example. see as follows:
$ unshare -ur -n $ cat /proc/sys/net/ipv4/neigh/lo/retrans_time cat: can't open '/proc/sys/net/ipv4/neigh/lo/retrans_time': No such file or directory $ ip ntable show dev lo inet arp_cache dev lo refcnt 1 reachable 19494 base_reachable 30000 retrans 1000 gc_stale 60000 delay_probe 5000 queue 101 app_probes 0 ucast_probes 3 mcast_probes 3 anycast_delay 1000 proxy_delay 800 proxy_queue 64 locktime 1000
inet6 ndisc_cache dev lo refcnt 1 reachable 42394 base_reachable 30000 retrans 1000 gc_stale 60000 delay_probe 5000 queue 101 app_probes 0 ucast_probes 3 mcast_probes 3 anycast_delay 1000 proxy_delay 800 proxy_queue 64 locktime 0 $ ip ntable change name arp_cache dev <if> retrans 2000 inet arp_cache dev lo refcnt 1 reachable 22917 base_reachable 30000 retrans 2000 gc_stale 60000 delay_probe 5000 queue 101 app_probes 0 ucast_probes 3 mcast_probes 3 anycast_delay 1000 proxy_delay 800 proxy_queue 64 locktime 1000
inet6 ndisc_cache dev lo refcnt 1 reachable 35524 base_reachable 30000 retrans 1000 gc_stale 60000 delay_probe 5000 queue 101 app_probes 0 ucast_probes 3 mcast_probes 3 anycast_delay 1000 proxy_delay 800 proxy_queue 64 locktime 0
Reported-by: Zeal Robot zealci@zte.com.cn Signed-off-by: xu xin xu.xin16@zte.com.cn Acked-by: Joanne Koong joannekoong@fb.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/neighbour.c | 4 ---- 1 file changed, 4 deletions(-)
diff --git a/net/core/neighbour.c b/net/core/neighbour.c index ff049733cceeb..71d5615b0e0b0 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -3687,10 +3687,6 @@ int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p, neigh_proc_base_reachable_time; }
- /* Don't export sysctls to unprivileged users */ - if (neigh_parms_net(p)->user_ns != &init_user_ns) - t->neigh_vars[0].procname = NULL; - switch (neigh_parms_family(p)) { case AF_INET: p_name = "ipv4";