netns: ip6mr: store netns in struct mfc6_cache

This patch stores into struct mfc6_cache the network namespace each
mfc6_cache belongs to. The new member is mfc6_net.

mfc6_net is assigned at cache allocation and doesn't change during
the rest of the cache entry life.

This will help to retrieve the current netns around the IPv6 multicast
forwarding code.

At the moment, all mfc6_cache are allocated in init_net.

Changelog:
==========
* Use write_pnet()/read_pnet() to set and get mfc6_net.

Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 0 deletions

diff --git a/include/linux/mroute6.h b/include/linux/mroute6.h
index 2cd9901ee5c7..15d85fe12bbd 100644
--- a/include/linux/mroute6.h
+++ b/include/linux/mroute6.h
@@ -188,6 +188,9 @@ struct mif_device
 struct mfc6_cache
 {
         struct mfc6_cache *next;                /* Next entry on cache line     */
+#ifdef CONFIG_NET_NS
+        struct net *mfc6_net;
+#endif
         struct in6_addr mf6c_mcastgrp;                  /* Group the entry belongs to   */
         struct in6_addr mf6c_origin;                    /* Source of packet             */
         mifi_t mf6c_parent;                     /* Source interface             */
@@ -210,6 +213,18 @@ struct mfc6_cache
         } mfc_un;
 };
 
+static inline
+struct net *mfc6_net(const struct mfc6_cache *mfc)
+{
+        return read_pnet(&mfc->mfc6_net);
+}
+
+static inline
+void mfc6_net_set(struct mfc6_cache *mfc, struct net *net)
+{
+        write_pnet(&mfc->mfc6_net, hold_net(net));
+}
+
 #define MFC_STATIC              1
 #define MFC_NOTIFY              2