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authorThomas Graf <tgraf@suug.ch>2015-07-21 11:43:56 +0300
committerDavid S. Miller <davem@davemloft.net>2015-07-21 20:39:05 +0300
commitf38a9eb1f77b296ff07e000823884a0f64d67b2a (patch)
treef1404a06ffc6ce0f2bfc8a24e12a1faa7bc0db57 /include/net/dst.h
parent773a69d64bf65eb6c212c97e9737963a2cf668fd (diff)
downloadlinux-f38a9eb1f77b296ff07e000823884a0f64d67b2a.tar.xz
dst: Metadata destinations
Introduces a new dst_metadata which enables to carry per packet metadata between forwarding and processing elements via the skb->dst pointer. The structure is set up to be a union. Thus, each separate type of metadata requires its own dst instance. If demand arises to carry multiple types of metadata concurrently, metadata dst entries can be made stackable. The metadata dst entry is refcnt'ed as expected for now but a non reference counted use is possible if the reference is forced before queueing the skb. In order to allow allocating dsts with variable length, the existing dst_alloc() is split into a dst_alloc() and dst_init() function. The existing dst_init() function to initialize the subsystem is being renamed to dst_subsys_init() to make it clear what is what. The check before ip_route_input() is changed to ignore metadata dsts and drop the dst inside the routing function thus allowing to interpret metadata in a later commit. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/dst.h')
-rw-r--r--include/net/dst.h6
1 files changed, 5 insertions, 1 deletions
diff --git a/include/net/dst.h b/include/net/dst.h
index 2bc73f8a00a9..2578811cef51 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -57,6 +57,7 @@ struct dst_entry {
#define DST_FAKE_RTABLE 0x0040
#define DST_XFRM_TUNNEL 0x0080
#define DST_XFRM_QUEUE 0x0100
+#define DST_METADATA 0x0200
unsigned short pending_confirm;
@@ -356,6 +357,9 @@ static inline int dst_discard(struct sk_buff *skb)
}
void *dst_alloc(struct dst_ops *ops, struct net_device *dev, int initial_ref,
int initial_obsolete, unsigned short flags);
+void dst_init(struct dst_entry *dst, struct dst_ops *ops,
+ struct net_device *dev, int initial_ref, int initial_obsolete,
+ unsigned short flags);
void __dst_free(struct dst_entry *dst);
struct dst_entry *dst_destroy(struct dst_entry *dst);
@@ -457,7 +461,7 @@ static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
return dst;
}
-void dst_init(void);
+void dst_subsys_init(void);
/* Flags for xfrm_lookup flags argument. */
enum {