netns: embed ip6_dst_ops directly

struct net::ipv6.ip6_dst_ops is separatedly dynamically allocated,
but there is no fundamental reason for it. Embed it directly into
struct netns_ipv6.

For that:
* move struct dst_ops into separate header to fix circular dependencies
	I honestly tried not to, it's pretty impossible to do other way
* drop dynamical allocation, allocate together with netns

For a change, remove struct dst_ops::dst_net, it's deducible
by using container_of() given dst_ops pointer.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 28 insertions, 0 deletions

diff --git a/include/net/dst_ops.h b/include/net/dst_ops.h
new file mode 100644
index 000000000000..d1ff9b7e99b8
--- /dev/null
+++ b/include/net/dst_ops.h
@@ -0,0 +1,28 @@
+#ifndef _NET_DST_OPS_H
+#define _NET_DST_OPS_H
+#include <linux/types.h>
+
+struct dst_entry;
+struct kmem_cachep;
+struct net_device;
+struct sk_buff;
+
+struct dst_ops {
+        unsigned short          family;
+        __be16                  protocol;
+        unsigned                gc_thresh;
+
+        int                     (*gc)(struct dst_ops *ops);
+        struct dst_entry *      (*check)(struct dst_entry *, __u32 cookie);
+        void                    (*destroy)(struct dst_entry *);
+        void                    (*ifdown)(struct dst_entry *,
+                                          struct net_device *dev, int how);
+        struct dst_entry *      (*negative_advice)(struct dst_entry *);
+        void                    (*link_failure)(struct sk_buff *);
+        void                    (*update_pmtu)(struct dst_entry *dst, u32 mtu);
+        int                     (*local_out)(struct sk_buff *skb);
+
+        atomic_t                entries;
+        struct kmem_cache       *kmem_cachep;
+};
+#endif