xref: /linux/include/net/dst_ops.h (revision f884ab15afdc5514e88105c92a4e2e1e6539869a)
1 #ifndef _NET_DST_OPS_H
2 #define _NET_DST_OPS_H
3 #include <linux/types.h>
4 #include <linux/percpu_counter.h>
5 #include <linux/cache.h>
6 
7 struct dst_entry;
8 struct kmem_cachep;
9 struct net_device;
10 struct sk_buff;
11 struct sock;
12 
13 struct dst_ops {
14 	unsigned short		family;
15 	__be16			protocol;
16 	unsigned int		gc_thresh;
17 
18 	int			(*gc)(struct dst_ops *ops);
19 	struct dst_entry *	(*check)(struct dst_entry *, __u32 cookie);
20 	unsigned int		(*default_advmss)(const struct dst_entry *);
21 	unsigned int		(*mtu)(const struct dst_entry *);
22 	u32 *			(*cow_metrics)(struct dst_entry *, unsigned long);
23 	void			(*destroy)(struct dst_entry *);
24 	void			(*ifdown)(struct dst_entry *,
25 					  struct net_device *dev, int how);
26 	struct dst_entry *	(*negative_advice)(struct dst_entry *);
27 	void			(*link_failure)(struct sk_buff *);
28 	void			(*update_pmtu)(struct dst_entry *dst, struct sock *sk,
29 					       struct sk_buff *skb, u32 mtu);
30 	void			(*redirect)(struct dst_entry *dst, struct sock *sk,
31 					    struct sk_buff *skb);
32 	int			(*local_out)(struct sk_buff *skb);
33 	struct neighbour *	(*neigh_lookup)(const struct dst_entry *dst,
34 						struct sk_buff *skb,
35 						const void *daddr);
36 
37 	struct kmem_cache	*kmem_cachep;
38 
39 	struct percpu_counter	pcpuc_entries ____cacheline_aligned_in_smp;
40 };
41 
42 static inline int dst_entries_get_fast(struct dst_ops *dst)
43 {
44 	return percpu_counter_read_positive(&dst->pcpuc_entries);
45 }
46 
47 static inline int dst_entries_get_slow(struct dst_ops *dst)
48 {
49 	int res;
50 
51 	local_bh_disable();
52 	res = percpu_counter_sum_positive(&dst->pcpuc_entries);
53 	local_bh_enable();
54 	return res;
55 }
56 
57 static inline void dst_entries_add(struct dst_ops *dst, int val)
58 {
59 	local_bh_disable();
60 	percpu_counter_add(&dst->pcpuc_entries, val);
61 	local_bh_enable();
62 }
63 
64 static inline int dst_entries_init(struct dst_ops *dst)
65 {
66 	return percpu_counter_init(&dst->pcpuc_entries, 0);
67 }
68 
69 static inline void dst_entries_destroy(struct dst_ops *dst)
70 {
71 	percpu_counter_destroy(&dst->pcpuc_entries);
72 }
73 
74 #endif
75