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>
diff --git a/net/tipc/msg.c b/net/tipc/msg.c
index 35523fb..a38f6a6 100644
--- a/net/tipc/msg.c
+++ b/net/tipc/msg.c
@@ -34,6 +34,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <net/sock.h>
 #include "core.h"
 #include "msg.h"
 #include "addr.h"
@@ -214,6 +215,7 @@
 		skb = tipc_buf_acquire(msz);
 		if (unlikely(!skb))
 			return -ENOMEM;
+		skb_orphan(skb);
 		__skb_queue_tail(list, skb);
 		skb_copy_to_linear_data(skb, mhdr, mhsz);
 		pktpos = skb->data + mhsz;
@@ -234,6 +236,7 @@
 	skb = tipc_buf_acquire(pktmax);
 	if (!skb)
 		return -ENOMEM;
+	skb_orphan(skb);
 	__skb_queue_tail(list, skb);
 	pktpos = skb->data;
 	skb_copy_to_linear_data(skb, &pkthdr, INT_H_SIZE);
@@ -267,6 +270,7 @@
 			rc = -ENOMEM;
 			goto error;
 		}
+		skb_orphan(skb);
 		__skb_queue_tail(list, skb);
 		msg_set_type(&pkthdr, FRAGMENT);
 		msg_set_size(&pkthdr, pktsz);