[linux.git] / net / core / dst_cache.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * net/core/dst_cache.c - dst entry cache
 *
 * Copyright (c) 2016 Paolo Abeni <[email protected]>
 */

#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);
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
911362c7 PA	2	/*
	3	* net/core/dst_cache.c - dst entry cache
	4	*
	5	* Copyright (c) 2016 Paolo Abeni <[email protected]>
911362c7 PA	6	*/
	7
	8	#include <linux/kernel.h>
	9	#include <linux/percpu.h>
	10	#include <net/dst_cache.h>
	11	#include <net/route.h>
	12	#if IS_ENABLED(CONFIG_IPV6)
	13	#include <net/ip6_fib.h>
	14	#endif
	15	#include <uapi/linux/in.h>
	16
	17	struct dst_cache_pcpu {
	18	unsigned long refresh_ts;
	19	struct dst_entry *dst;
	20	u32 cookie;
	21	union {
	22	struct in_addr in_saddr;
	23	struct in6_addr in6_saddr;
	24	};
	25	};
	26
b73f96fc WF	27	static void dst_cache_per_cpu_dst_set(struct dst_cache_pcpu *dst_cache,
b73f96fc WF	28	struct dst_entry *dst, u32 cookie)
911362c7 PA	29	{
	30	dst_release(dst_cache->dst);
	31	if (dst)
	32	dst_hold(dst);
	33
	34	dst_cache->cookie = cookie;
	35	dst_cache->dst = dst;
	36	}
	37
b73f96fc WF	38	static struct dst_entry dst_cache_per_cpu_get(struct dst_cache dst_cache,
b73f96fc WF	39	struct dst_cache_pcpu *idst)
911362c7 PA	40	{
	41	struct dst_entry *dst;
	42
	43	dst = idst->dst;
	44	if (!dst)
	45	goto fail;
	46
	47	/* the cache already hold a dst reference; it can't go away */
	48	dst_hold(dst);
	49
	50	if (unlikely(!time_after(idst->refresh_ts, dst_cache->reset_ts) \|\|
	51	(dst->obsolete && !dst->ops->check(dst, idst->cookie)))) {
	52	dst_cache_per_cpu_dst_set(idst, NULL, 0);
	53	dst_release(dst);
	54	goto fail;
	55	}
	56	return dst;
	57
	58	fail:
	59	idst->refresh_ts = jiffies;
	60	return NULL;
	61	}
	62
	63	struct dst_entry dst_cache_get(struct dst_cache dst_cache)
	64	{
	65	if (!dst_cache->cache)
	66	return NULL;
	67
	68	return dst_cache_per_cpu_get(dst_cache, this_cpu_ptr(dst_cache->cache));
	69	}
	70	EXPORT_SYMBOL_GPL(dst_cache_get);
	71
	72	struct rtable dst_cache_get_ip4(struct dst_cache dst_cache, __be32 *saddr)
	73	{
	74	struct dst_cache_pcpu *idst;
	75	struct dst_entry *dst;
	76
	77	if (!dst_cache->cache)
	78	return NULL;
	79
	80	idst = this_cpu_ptr(dst_cache->cache);
	81	dst = dst_cache_per_cpu_get(dst_cache, idst);
	82	if (!dst)
	83	return NULL;
	84
	85	*saddr = idst->in_saddr.s_addr;
	86	return container_of(dst, struct rtable, dst);
	87	}
	88	EXPORT_SYMBOL_GPL(dst_cache_get_ip4);
	89
	90	void dst_cache_set_ip4(struct dst_cache dst_cache, struct dst_entry dst,
	91	__be32 saddr)
	92	{
	93	struct dst_cache_pcpu *idst;
	94
	95	if (!dst_cache->cache)
	96	return;
	97
	98	idst = this_cpu_ptr(dst_cache->cache);
	99	dst_cache_per_cpu_dst_set(idst, dst, 0);
	100	idst->in_saddr.s_addr = saddr;
	101	}
	102	EXPORT_SYMBOL_GPL(dst_cache_set_ip4);
	103
104	#if IS_ENABLED(CONFIG_IPV6)
105	void dst_cache_set_ip6(struct dst_cache dst_cache, struct dst_entry dst,
4c1342d9	106	const struct in6_addr *saddr)
911362c7 PA	107	{
	108	struct dst_cache_pcpu *idst;
	109
	110	if (!dst_cache->cache)
	111	return;
	112
	113	idst = this_cpu_ptr(dst_cache->cache);
	114	dst_cache_per_cpu_dst_set(this_cpu_ptr(dst_cache->cache), dst,
	115	rt6_get_cookie((struct rt6_info *)dst));
4c1342d9	116	idst->in6_saddr = *saddr;
911362c7 PA	117	}
	118	EXPORT_SYMBOL_GPL(dst_cache_set_ip6);
	119
	120	struct dst_entry dst_cache_get_ip6(struct dst_cache dst_cache,
	121	struct in6_addr *saddr)
	122	{
	123	struct dst_cache_pcpu *idst;
	124	struct dst_entry *dst;
	125
	126	if (!dst_cache->cache)
	127	return NULL;
	128
	129	idst = this_cpu_ptr(dst_cache->cache);
	130	dst = dst_cache_per_cpu_get(dst_cache, idst);
	131	if (!dst)
	132	return NULL;
	133
	134	*saddr = idst->in6_saddr;
	135	return dst;
	136	}
	137	EXPORT_SYMBOL_GPL(dst_cache_get_ip6);
	138	#endif
	139
	140	int dst_cache_init(struct dst_cache *dst_cache, gfp_t gfp)
	141	{
	142	dst_cache->cache = alloc_percpu_gfp(struct dst_cache_pcpu,
	143	gfp \| __GFP_ZERO);
	144	if (!dst_cache->cache)
	145	return -ENOMEM;
	146
	147	dst_cache_reset(dst_cache);
	148	return 0;
	149	}
	150	EXPORT_SYMBOL_GPL(dst_cache_init);
	151
	152	void dst_cache_destroy(struct dst_cache *dst_cache)
	153	{
	154	int i;
	155
	156	if (!dst_cache->cache)
	157	return;
	158
	159	for_each_possible_cpu(i)
	160	dst_release(per_cpu_ptr(dst_cache->cache, i)->dst);
	161
	162	free_percpu(dst_cache->cache);
	163	}
	164	EXPORT_SYMBOL_GPL(dst_cache_destroy);