linux-stable/net/core/dst_cache.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

164 lines
3.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* net/core/dst_cache.c - dst entry cache
*
* Copyright (c) 2016 Paolo Abeni <pabeni@redhat.com>
*/
#include <linux/kernel.h>
#include <linux/percpu.h>
#include <net/dst_cache.h>
#include <net/route.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ip6_fib.h>
#endif
#include <uapi/linux/in.h>
struct dst_cache_pcpu {
unsigned long refresh_ts;
struct dst_entry *dst;
u32 cookie;
union {
struct in_addr in_saddr;
struct in6_addr in6_saddr;
};
};
static void dst_cache_per_cpu_dst_set(struct dst_cache_pcpu *dst_cache,
struct dst_entry *dst, u32 cookie)
{
dst_release(dst_cache->dst);
if (dst)
dst_hold(dst);
dst_cache->cookie = cookie;
dst_cache->dst = dst;
}
static struct dst_entry *dst_cache_per_cpu_get(struct dst_cache *dst_cache,
struct dst_cache_pcpu *idst)
{
struct dst_entry *dst;
dst = idst->dst;
if (!dst)
goto fail;
/* the cache already hold a dst reference; it can't go away */
dst_hold(dst);
if (unlikely(!time_after(idst->refresh_ts, dst_cache->reset_ts) ||
(dst->obsolete && !dst->ops->check(dst, idst->cookie)))) {
dst_cache_per_cpu_dst_set(idst, NULL, 0);
dst_release(dst);
goto fail;
}
return dst;
fail:
idst->refresh_ts = jiffies;
return NULL;
}
struct dst_entry *dst_cache_get(struct dst_cache *dst_cache)
{
if (!dst_cache->cache)
return NULL;
return dst_cache_per_cpu_get(dst_cache, this_cpu_ptr(dst_cache->cache));
}
EXPORT_SYMBOL_GPL(dst_cache_get);
struct rtable *dst_cache_get_ip4(struct dst_cache *dst_cache, __be32 *saddr)
{
struct dst_cache_pcpu *idst;
struct dst_entry *dst;
if (!dst_cache->cache)
return NULL;
idst = this_cpu_ptr(dst_cache->cache);
dst = dst_cache_per_cpu_get(dst_cache, idst);
if (!dst)
return NULL;
*saddr = idst->in_saddr.s_addr;
return container_of(dst, struct rtable, dst);
}
EXPORT_SYMBOL_GPL(dst_cache_get_ip4);
void dst_cache_set_ip4(struct dst_cache *dst_cache, struct dst_entry *dst,
__be32 saddr)
{
struct dst_cache_pcpu *idst;
if (!dst_cache->cache)
return;
idst = this_cpu_ptr(dst_cache->cache);
dst_cache_per_cpu_dst_set(idst, dst, 0);
idst->in_saddr.s_addr = saddr;
}
EXPORT_SYMBOL_GPL(dst_cache_set_ip4);
#if IS_ENABLED(CONFIG_IPV6)
void dst_cache_set_ip6(struct dst_cache *dst_cache, struct dst_entry *dst,
const struct in6_addr *saddr)
{
struct dst_cache_pcpu *idst;
if (!dst_cache->cache)
return;
idst = this_cpu_ptr(dst_cache->cache);
dst_cache_per_cpu_dst_set(this_cpu_ptr(dst_cache->cache), dst,
rt6_get_cookie((struct rt6_info *)dst));
idst->in6_saddr = *saddr;
}
EXPORT_SYMBOL_GPL(dst_cache_set_ip6);
struct dst_entry *dst_cache_get_ip6(struct dst_cache *dst_cache,
struct in6_addr *saddr)
{
struct dst_cache_pcpu *idst;
struct dst_entry *dst;
if (!dst_cache->cache)
return NULL;
idst = this_cpu_ptr(dst_cache->cache);
dst = dst_cache_per_cpu_get(dst_cache, idst);
if (!dst)
return NULL;
*saddr = idst->in6_saddr;
return dst;
}
EXPORT_SYMBOL_GPL(dst_cache_get_ip6);
#endif
int dst_cache_init(struct dst_cache *dst_cache, gfp_t gfp)
{
dst_cache->cache = alloc_percpu_gfp(struct dst_cache_pcpu,
gfp | __GFP_ZERO);
if (!dst_cache->cache)
return -ENOMEM;
dst_cache_reset(dst_cache);
return 0;
}
EXPORT_SYMBOL_GPL(dst_cache_init);
void dst_cache_destroy(struct dst_cache *dst_cache)
{
int i;
if (!dst_cache->cache)
return;
for_each_possible_cpu(i)
dst_release(per_cpu_ptr(dst_cache->cache, i)->dst);
free_percpu(dst_cache->cache);
}
EXPORT_SYMBOL_GPL(dst_cache_destroy);