tipc: involve namespace infrastructure

Involve namespace infrastructure, make the "tipc_net_id" global
variable aware of per namespace, and rename it to "net_id". In
order that the conversion can be successfully done, an instance
of networking namespace must be passed to relevant functions,
allowing them to access the "net_id" variable of per namespace.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Tested-by: Tero Aho <Tero.Aho@coriant.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/core.h

@@ -57,6 +57,7 @@
 #include <linux/vmalloc.h>
 #include <linux/rtnetlink.h>
 #include <linux/etherdevice.h>
+#include <net/netns/generic.h>
 
 #define TIPC_MOD_VER "2.0.0"
 
@@ -75,6 +76,10 @@ extern int sysctl_tipc_named_timeout __read_mostly;
  */
 extern int tipc_random __read_mostly;
 
+struct tipc_net {
+	int net_id;
+};
+
 #ifdef CONFIG_SYSCTL
 int tipc_register_sysctl(void);
 void tipc_unregister_sysctl(void);