1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _NET_DST_CACHE_H |
3 | #define _NET_DST_CACHE_H |
4 | |
5 | #include <linux/jiffies.h> |
6 | #include <net/dst.h> |
7 | #if IS_ENABLED(CONFIG_IPV6) |
8 | #include <net/ip6_fib.h> |
9 | #endif |
10 | |
11 | struct dst_cache { |
12 | struct dst_cache_pcpu __percpu *cache; |
13 | unsigned long reset_ts; |
14 | }; |
15 | |
16 | /** |
17 | * dst_cache_get - perform cache lookup |
18 | * @dst_cache: the cache |
19 | * |
20 | * The caller should use dst_cache_get_ip4() if it need to retrieve the |
21 | * source address to be used when xmitting to the cached dst. |
22 | * local BH must be disabled. |
23 | */ |
24 | struct dst_entry *dst_cache_get(struct dst_cache *dst_cache); |
25 | |
26 | /** |
27 | * dst_cache_get_ip4 - perform cache lookup and fetch ipv4 source address |
28 | * @dst_cache: the cache |
29 | * @saddr: return value for the retrieved source address |
30 | * |
31 | * local BH must be disabled. |
32 | */ |
33 | struct rtable *dst_cache_get_ip4(struct dst_cache *dst_cache, __be32 *saddr); |
34 | |
35 | /** |
36 | * dst_cache_set_ip4 - store the ipv4 dst into the cache |
37 | * @dst_cache: the cache |
38 | * @dst: the entry to be cached |
39 | * @saddr: the source address to be stored inside the cache |
40 | * |
41 | * local BH must be disabled. |
42 | */ |
43 | void dst_cache_set_ip4(struct dst_cache *dst_cache, struct dst_entry *dst, |
44 | __be32 saddr); |
45 | |
46 | #if IS_ENABLED(CONFIG_IPV6) |
47 | |
48 | /** |
49 | * dst_cache_set_ip6 - store the ipv6 dst into the cache |
50 | * @dst_cache: the cache |
51 | * @dst: the entry to be cached |
52 | * @saddr: the source address to be stored inside the cache |
53 | * |
54 | * local BH must be disabled. |
55 | */ |
56 | void dst_cache_set_ip6(struct dst_cache *dst_cache, struct dst_entry *dst, |
57 | const struct in6_addr *saddr); |
58 | |
59 | /** |
60 | * dst_cache_get_ip6 - perform cache lookup and fetch ipv6 source address |
61 | * @dst_cache: the cache |
62 | * @saddr: return value for the retrieved source address |
63 | * |
64 | * local BH must be disabled. |
65 | */ |
66 | struct dst_entry *dst_cache_get_ip6(struct dst_cache *dst_cache, |
67 | struct in6_addr *saddr); |
68 | #endif |
69 | |
70 | /** |
71 | * dst_cache_reset - invalidate the cache contents |
72 | * @dst_cache: the cache |
73 | * |
74 | * This does not free the cached dst to avoid races and contentions. |
75 | * the dst will be freed on later cache lookup. |
76 | */ |
77 | static inline void dst_cache_reset(struct dst_cache *dst_cache) |
78 | { |
79 | dst_cache->reset_ts = jiffies; |
80 | } |
81 | |
82 | /** |
83 | * dst_cache_reset_now - invalidate the cache contents immediately |
84 | * @dst_cache: the cache |
85 | * |
86 | * The caller must be sure there are no concurrent users, as this frees |
87 | * all dst_cache users immediately, rather than waiting for the next |
88 | * per-cpu usage like dst_cache_reset does. Most callers should use the |
89 | * higher speed lazily-freed dst_cache_reset function instead. |
90 | */ |
91 | void dst_cache_reset_now(struct dst_cache *dst_cache); |
92 | |
93 | /** |
94 | * dst_cache_init - initialize the cache, allocating the required storage |
95 | * @dst_cache: the cache |
96 | * @gfp: allocation flags |
97 | */ |
98 | int dst_cache_init(struct dst_cache *dst_cache, gfp_t gfp); |
99 | |
100 | /** |
101 | * dst_cache_destroy - empty the cache and free the allocated storage |
102 | * @dst_cache: the cache |
103 | * |
104 | * No synchronization is enforced: it must be called only when the cache |
105 | * is unsed. |
106 | */ |
107 | void dst_cache_destroy(struct dst_cache *dst_cache); |
108 | |
109 | #endif |
110 | |