include/net/dst_cache.h

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