/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _NET_DST_CACHE_H
#define _NET_DST_CACHE_H
#include <linux/jiffies.h>
#include <net/dst.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ip6_fib.h>
#endif
struct dst_cache {
struct dst_cache_pcpu __percpu *cache;
unsigned long reset_ts;
};
/**
* dst_cache_get - perform cache lookup
* @dst_cache: the cache
*
* The caller should use dst_cache_get_ip4() if it need to retrieve the
* source address to be used when xmitting to the cached dst.
* local BH must be disabled.
*/
struct dst_entry *dst_cache_get(struct dst_cache *dst_cache);
/**
* dst_cache_get_ip4 - perform cache lookup and fetch ipv4 source address
* @dst_cache: the cache
* @saddr: return value for the retrieved source address
*
* local BH must be disabled.
*/
struct rtable *dst_cache_get_ip4(struct dst_cache *dst_cache, __be32 *saddr);
/**
* dst_cache_set_ip4 - store the ipv4 dst into the cache
* @dst_cache: the cache
* @dst: the entry to be cached
* @saddr: the source address to be stored inside the cache
*
* local BH must be disabled.
*/
void dst_cache_set_ip4(struct dst_cache *dst_cache, struct dst_entry *dst,
__be32 saddr);
#if IS_ENABLED(CONFIG_IPV6)
/**
* dst_cache_set_ip6 - store the ipv6 dst into the cache
* @dst_cache: the cache
* @dst: the entry to be cached
* @saddr: the source address to be stored inside the cache
*
* local BH must be disabled.
*/
void dst_cache_set_ip6(struct dst_cache *dst_cache, struct dst_entry *dst,
const struct in6_addr *saddr);
/**
* dst_cache_get_ip6 - perform cache lookup and fetch ipv6 source address
* @dst_cache: the cache
* @saddr: return value for the retrieved source address
*
* local BH must be disabled.
*/
struct dst_entry *dst_cache_get_ip6(struct dst_cache *dst_cache,
struct in6_addr *saddr);
#endif
/**
* dst_cache_reset - invalidate the cache contents
* @dst_cache: the cache
*
* This does not free the cached dst to avoid races and contentions.
* the dst will be freed on later cache lookup.
*/
static inline void dst_cache_reset(struct dst_cache *dst_cache)
{
WRITE_ONCE(dst_cache->reset_ts, jiffies);
}
/**
* dst_cache_reset_now - invalidate the cache contents immediately
* @dst_cache: the cache
*
* The caller must be sure there are no concurrent users, as this frees
* all dst_cache users immediately, rather than waiting for the next
* per-cpu usage like dst_cache_reset does. Most callers should use the
* higher speed lazily-freed dst_cache_reset function instead.
*/
void dst_cache_reset_now(struct dst_cache *dst_cache);
/**
* dst_cache_init - initialize the cache, allocating the required storage
* @dst_cache: the cache
* @gfp: allocation flags
*/
int dst_cache_init(struct dst_cache *dst_cache, gfp_t gfp);
/**
* dst_cache_destroy - empty the cache and free the allocated storage
* @dst_cache: the cache
*
* No synchronization is enforced: it must be called only when the cache
* is unused.
*/
void dst_cache_destroy(struct dst_cache *dst_cache);
#endif