[NETNS][IPV6]: Make multiple instance of sysctl tables.

Each network namespace wants its own set of sysctl value, eg. we
should not be able from a namespace to set a sysctl value for another
namespace , especially for the initial network namespace.

This patch duplicates the sysctl table when we register a new network
namespace for ipv6. The duplicated table are postfixed with the
"template" word to notify the developper the table is cloned.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 11 insertions, 2 deletions

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 3e086f8bb449..5519035491e7 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -619,8 +619,8 @@ static inline int snmp6_unregister_dev(struct inet6_dev *idev)
 #endif
 
 #ifdef CONFIG_SYSCTL
-extern ctl_table ipv6_route_table[];
-extern ctl_table ipv6_icmp_table[];
+extern ctl_table ipv6_route_table_template[];
+extern ctl_table ipv6_icmp_table_template[];
 
 extern int ipv6_sysctl_register(void);
 extern void ipv6_sysctl_unregister(void);
diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h
index 6f82046e3013..58fbf30d9fdb 100644
--- a/include/net/netns/ipv6.h
+++ b/include/net/netns/ipv6.h
@@ -5,6 +5,15 @@
 #ifndef __NETNS_IPV6_H__
 #define __NETNS_IPV6_H__
 
+struct ctl_table_header;
+
+struct netns_sysctl_ipv6 {
+#ifdef CONFIG_SYSCTL
+        struct ctl_table_header *table;
+#endif
+};
+
 struct netns_ipv6 {
+        struct netns_sysctl_ipv6 sysctl;
 };
 #endif