netns: ipmr: store netns in struct mfc_cache

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

mfc_net is assigned at cache allocation and doesn't change during
the rest of the cache entry life.
A new net parameter is added to ipmr_cache_alloc/ipmr_cache_alloc_unres.

This will help to retrieve the current netns around the IPv4 multicast
routing code.

At the moment, all mfc_cache are allocated in init_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/mroute.h b/include/linux/mroute.h
index 8a455694d682..beaf3aae8aaf 100644
--- a/include/linux/mroute.h
+++ b/include/linux/mroute.h
@@ -193,6 +193,9 @@ struct vif_device
 struct mfc_cache 
 {
         struct mfc_cache *next;                 /* Next entry on cache line     */
+#ifdef CONFIG_NET_NS
+        struct net *mfc_net;
+#endif
         __be32 mfc_mcastgrp;                    /* Group the entry belongs to   */
         __be32 mfc_origin;                      /* Source of packet             */
         vifi_t mfc_parent;                      /* Source interface             */
@@ -215,6 +218,18 @@ struct mfc_cache
         } mfc_un;
 };
 
+static inline
+struct net *mfc_net(const struct mfc_cache *mfc)
+{
+        return read_pnet(&mfc->mfc_net);
+}
+
+static inline
+void mfc_net_set(struct mfc_cache *mfc, struct net *net)
+{
+        write_pnet(&mfc->mfc_net, hold_net(net));
+}
+
 #define MFC_STATIC              1
 #define MFC_NOTIFY              2