LXR linux/include/net/dst

   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
  11struct 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 */
  24struct 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 */
  33struct 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 */
  43void 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 */
  56void 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 */
  66struct 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 */
  77static inline void dst_cache_reset(struct dst_cache *dst_cache)
  78{
  79        dst_cache->reset_ts = jiffies;
  80}
  81
  82/**
  83 *      dst_cache_init - initialize the cache, allocating the required storage
  84 *      @dst_cache: the cache
  85 *      @gfp: allocation flags
  86 */
  87int dst_cache_init(struct dst_cache *dst_cache, gfp_t gfp);
  88
  89/**
  90 *      dst_cache_destroy - empty the cache and free the allocated storage
  91 *      @dst_cache: the cache
  92 *
  93 *      No synchronization is enforced: it must be called only when the cache
  94 *      is unsed.
  95 */
  96void dst_cache_destroy(struct dst_cache *dst_cache);
  97
  98#endif
  99