1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _NET_DST_OPS_H
3 #define _NET_DST_OPS_H
4 #include <linux/types.h>
5 #include <linux/percpu_counter.h>
6 #include <linux/cache.h>
7 
8 struct dst_entry;
9 struct kmem_cachep;
10 struct net_device;
11 struct sk_buff;
12 struct sock;
13 struct net;
14 
15 struct dst_ops {
16 	unsigned short		family;
17 	unsigned int		gc_thresh;
18 
19 	void			(*gc)(struct dst_ops *ops);
20 	struct dst_entry *	(*check)(struct dst_entry *, __u32 cookie);
21 	unsigned int		(*default_advmss)(const struct dst_entry *);
22 	unsigned int		(*mtu)(const struct dst_entry *);
23 	u32 *			(*cow_metrics)(struct dst_entry *, unsigned long);
24 	void			(*destroy)(struct dst_entry *);
25 	void			(*ifdown)(struct dst_entry *,
26 					  struct net_device *dev);
27 	struct dst_entry *	(*negative_advice)(struct dst_entry *);
28 	void			(*link_failure)(struct sk_buff *);
29 	void			(*update_pmtu)(struct dst_entry *dst, struct sock *sk,
30 					       struct sk_buff *skb, u32 mtu,
31 					       bool confirm_neigh);
32 	void			(*redirect)(struct dst_entry *dst, struct sock *sk,
33 					    struct sk_buff *skb);
34 	int			(*local_out)(struct net *net, struct sock *sk, struct sk_buff *skb);
35 	struct neighbour *	(*neigh_lookup)(const struct dst_entry *dst,
36 						struct sk_buff *skb,
37 						const void *daddr);
38 	void			(*confirm_neigh)(const struct dst_entry *dst,
39 						 const void *daddr);
40 
41 	struct kmem_cache	*kmem_cachep;
42 
43 	struct percpu_counter	pcpuc_entries ____cacheline_aligned_in_smp;
44 };
45 
dst_entries_get_fast(struct dst_ops * dst)46 static inline int dst_entries_get_fast(struct dst_ops *dst)
47 {
48 	return percpu_counter_read_positive(&dst->pcpuc_entries);
49 }
50 
dst_entries_get_slow(struct dst_ops * dst)51 static inline int dst_entries_get_slow(struct dst_ops *dst)
52 {
53 	return percpu_counter_sum_positive(&dst->pcpuc_entries);
54 }
55 
56 #define DST_PERCPU_COUNTER_BATCH 32
dst_entries_add(struct dst_ops * dst,int val)57 static inline void dst_entries_add(struct dst_ops *dst, int val)
58 {
59 	percpu_counter_add_batch(&dst->pcpuc_entries, val,
60 				 DST_PERCPU_COUNTER_BATCH);
61 }
62 
dst_entries_init(struct dst_ops * dst)63 static inline int dst_entries_init(struct dst_ops *dst)
64 {
65 	return percpu_counter_init(&dst->pcpuc_entries, 0, GFP_KERNEL);
66 }
67 
dst_entries_destroy(struct dst_ops * dst)68 static inline void dst_entries_destroy(struct dst_ops *dst)
69 {
70 	percpu_counter_destroy(&dst->pcpuc_entries);
71 }
72 
73 #endif
74